Academic literature on the topic 'Mitochondria'
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Journal articles on the topic "Mitochondria"
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Amchenkova, A. A., L. E. Bakeeva, Y. S. Chentsov, V. P. Skulachev, and D. B. Zorov. "Coupling membranes as energy-transmitting cables. I. Filamentous mitochondria in fibroblasts and mitochondrial clusters in cardiomyocytes." Journal of Cell Biology 107, no. 2 (August 1, 1988): 481–95. http://dx.doi.org/10.1083/jcb.107.2.481.
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An hypothesis considering mitochondria as intracellular power-transmitting protonic cables was tested in human fibroblasts where mitochondria are thin and long and in rat cardiomyocytes where they show cluster organization. Mitochondria in the cell were specifically stained with fluorescent-penetrating cation ethylrhodamine, which electrophoretically accumulates in the mitochondrial matrix. A 40-micron-long mitochondrial filament of fibroblast was illuminated by a very narrow (less than or equal to 0.5 micron) laser beam to induce local damage of the mitochondrial membranes. Such a treatment was found to induce quenching of the ethylrhodamine fluorescence in the entire filament. According to the electron microscope examination, the laser-treated filament retained its continuity after the laser illumination. Other mitochondrial filaments (some of which were localized at a distance less than 10 micron from the laser-treated one) remained fluorescent. In a cell where mitochondrial filaments seemed to be united in a network, laser illumination of one filament resulted in fluorescence quenching in the whole network, whereas fluorescence of small mitochondria not connected with the network was unaffected. The illumination of cardiomyocyte was found to result in the fluorescence quenching not only in a laser-illuminated mitochondrion but also in a large cluster of organelles composed of many mitochondria. Electron microscopy showed that all the mitochondria in the cluster change from the orthodox to the condensed state. It was also found that mitochondria in the cluster are connected to one another with specific junctions. If a mitochondrion did not form junctions with a quenched cluster, its fluorescence was not decreased even when this mitochondrion was localized close to an illuminated one. The size of the mitochondrial cluster may be as long as 50 micron. The cluster is formed by branched chains of contacting mitochondria, which may be defined as Streptio mitochondriale. In the cardiomyocyte there are several mitochondrial clusters or, alternatively, the quenched cluster is a result of decomposition of a supercluster uniting all the mitochondria of the cell. Cluster organization of mitochondria could also be revealed when a single mitochondrion was punctured in situ with a microcapillary. The obtained data are in agreement with the idea that mitochondrial junctions are H+ permeable so that, within the cluster, delta psi may be transmitted from one mitochondrion to another. The above results are consistent with the assumption that mitochondrial filaments or networks represent a united electrical system.(ABSTRACT TRUNCATED AT 400 WORDS)
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Banerjee, Partha S., Junfeng Ma, and Gerald W. Hart. "Diabetes-associated dysregulation ofO-GlcNAcylation in rat cardiac mitochondria." Proceedings of the National Academy of Sciences 112, no. 19 (April 27, 2015): 6050–55. http://dx.doi.org/10.1073/pnas.1424017112.
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Elevated mitochondrialO-GlcNAcylation caused by hyperglycemia, as occurs in diabetes, significantly contributes to mitochondrial dysfunction and to diabetic cardiomyopathy. However, little is known about the enzymology of mitochondrialO-GlcNAcylation. Herein, we investigated the enzymes responsible for cyclingO-GlcNAc on mitochondrial proteins and studied the mitochondrial transport of UDP-GlcNAc. Analyses of purified rat heart mitochondria from normal and streptozocin-treated diabetic rats show increased mitochondrialO-GlcNAc transferase (OGT) and a concomitant decrease in the mito-specific O-GlcNAcase (OGA). Strikingly, OGT is mislocalized in cardiac mitochondria from diabetic rats. Interaction of OGT and complex IV observed in normal rat heart mitochondria is visibly reduced in diabetic samples, where OGT is mislocalized to the matrix. Live cell OGA activity assays establish the presence of O-GlcNAcase within the mitochondria. Furthermore, we establish that the inner mitochondrial membrane transporter, pyrimidine nucleotide carrier, transports UDP-GlcNAc from the cytosol to the inside of the mitochondria. Knockdown of this transporter substantially lowers mitochondrialO-GlcNAcylation. Inhibition of OGT or OGA activity within neonatal rat cardiomyocytes significantly affects energy production, mitochondrial membrane potential, and mitochondrial oxygen consumption. These data suggest that cardiac mitochondria not only have robustO-GlcNAc cycling, but also that dysregulation ofO-GlcNAcylation likely plays a key role in mitochondrial dysfunction associated with diabetes.
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Seo, Young Ah, Veronica Lopez, and Shannon L. Kelleher. "A histidine-rich motif mediates mitochondrial localization of ZnT2 to modulate mitochondrial function." American Journal of Physiology-Cell Physiology 300, no. 6 (June 2011): C1479—C1489. http://dx.doi.org/10.1152/ajpcell.00420.2010.
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Female reproductive tissues such as mammary glands, ovaries, uterus, and placenta are phenotypically dynamic, requiring tight integration of bioenergetic and apoptotic mechanisms. Mitochondrial zinc (Zn) pools have emerged as a central player in regulating bioenergetics and apoptosis. Zn must first be imported into mitochondria to modulate mitochondrion-specific functions; however, mitochondrial Zn import mechanisms have not been identified. Here we documented that the Zn transporter ZnT2 is associated with the inner mitochondrial membrane and acts as an auxiliary Zn importer into mitochondria in mammary cells. We found that attenuation of ZnT2 expression significantly reduced mitochondrial Zn uptake and total mitochondrial Zn pools. Moreover, expression of a ZnT2-hemagglutinin (HA) fusion protein was localized to mitochondria and significantly increased Zn uptake and mitochondrial Zn pools, directly implicating ZnT2 in Zn import into mitochondria. Confocal microscopy of truncated and point mutants of ZnT2-green fluorescent protein (GFP) fusion proteins revealed a histidine-rich motif (51HH XH54) in the NH2 terminus that is important for mitochondrial targeting of ZnT2. More importantly, the expansion of mitochondrial Zn pools by ZnT2 overexpression significantly reduced ATP biogenesis and mitochondrial oxidation concurrent with increased apoptosis, suggesting a functional role for ZnT2-mediated Zn import into mitochondria. These results identify the first Zn transporter directly associated with mitochondria and suggest that unique secretory tissues such as the mammary gland require novel mechanisms to modulate mitochondrion-specific functions.
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Scanlon, David P., and Michael W. Salter. "Strangers in strange lands: mitochondrial proteins found at extra-mitochondrial locations." Biochemical Journal 476, no. 1 (January 7, 2019): 25–37. http://dx.doi.org/10.1042/bcj20180473.
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Abstract The mitochondrial proteome is estimated to contain ∼1100 proteins, the vast majority of which are nuclear-encoded, with only 13 proteins encoded by the mitochondrial genome. The import of these nuclear-encoded proteins into mitochondria was widely believed to be unidirectional, but recent discoveries have revealed that many these ‘mitochondrial’ proteins are exported, and have extra-mitochondrial activities divergent from their mitochondrial function. Surprisingly, three of the exported proteins discovered thus far are mitochondrially encoded and have significantly different extra-mitochondrial roles than those performed within the mitochondrion. In this review, we will detail the wide variety of proteins once thought to only reside within mitochondria, but now known to ‘emigrate’ from mitochondria in order to attain ‘dual citizenship’, present both within mitochondria and elsewhere.
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Deng, Huichao, Xinhua Qiao, Ting Xie, Wenfeng Fu, Hang Li, Yanmei Zhao, Miaomiao Guo, et al. "SLC-30A9 is required for Zn2+ homeostasis, Zn2+ mobilization, and mitochondrial health." Proceedings of the National Academy of Sciences 118, no. 35 (August 25, 2021): e2023909118. http://dx.doi.org/10.1073/pnas.2023909118.
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The trace element zinc is essential for many aspects of physiology. The mitochondrion is a major Zn2+ store, and excessive mitochondrial Zn2+ is linked to neurodegeneration. How mitochondria maintain their Zn2+ homeostasis is unknown. Here, we find that the SLC-30A9 transporter localizes on mitochondria and is required for export of Zn2+ from mitochondria in both Caenorhabditis elegans and human cells. Loss of slc-30a9 leads to elevated Zn2+ levels in mitochondria, a severely swollen mitochondrial matrix in many tissues, compromised mitochondrial metabolic function, reductive stress, and induction of the mitochondrial stress response. SLC-30A9 is also essential for organismal fertility and sperm activation in C. elegans, during which Zn2+ exits from mitochondria and acts as an activation signal. In slc-30a9–deficient neurons, misshapen mitochondria show reduced distribution in axons and dendrites, providing a potential mechanism for the Birk–Landau–Perez cerebrorenal syndrome where an SLC30A9 mutation was found.
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Zorov, Dmitry B., Magdalena Juhaszova, and Steven J. Sollott. "Mitochondrial Reactive Oxygen Species (ROS) and ROS-Induced ROS Release." Physiological Reviews 94, no. 3 (July 2014): 909–50. http://dx.doi.org/10.1152/physrev.00026.2013.
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Byproducts of normal mitochondrial metabolism and homeostasis include the buildup of potentially damaging levels of reactive oxygen species (ROS), Ca2+, etc., which must be normalized. Evidence suggests that brief mitochondrial permeability transition pore (mPTP) openings play an important physiological role maintaining healthy mitochondria homeostasis. Adaptive and maladaptive responses to redox stress may involve mitochondrial channels such as mPTP and inner membrane anion channel (IMAC). Their activation causes intra- and intermitochondrial redox-environment changes leading to ROS release. This regenerative cycle of mitochondrial ROS formation and release was named ROS-induced ROS release (RIRR). Brief, reversible mPTP opening-associated ROS release apparently constitutes an adaptive housekeeping function by the timely release from mitochondria of accumulated potentially toxic levels of ROS (and Ca2+). At higher ROS levels, longer mPTP openings may release a ROS burst leading to destruction of mitochondria, and if propagated from mitochondrion to mitochondrion, of the cell itself. The destructive function of RIRR may serve a physiological role by removal of unwanted cells or damaged mitochondria, or cause the pathological elimination of vital and essential mitochondria and cells. The adaptive release of sufficient ROS into the vicinity of mitochondria may also activate local pools of redox-sensitive enzymes involved in protective signaling pathways that limit ischemic damage to mitochondria and cells in that area. Maladaptive mPTP- or IMAC-related RIRR may also be playing a role in aging. Because the mechanism of mitochondrial RIRR highlights the central role of mitochondria-formed ROS, we discuss all of the known ROS-producing sites (shown in vitro) and their relevance to the mitochondrial ROS production in vivo.
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Henderson, V., and M. J. Song. "Morphology of mitochondria in a teleost, salmo gairdneri." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 194–95. http://dx.doi.org/10.1017/s0424820100142591.
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Mitochondria have been observed at the ultrastructural level as spherical, oval, or sausagelike. Mitochondria average 0.3 to 1.0 um in diameter and 1.0 to 10.0 μm in length. Mitochondria may exceed these dimensions under certian physiological or pathological conditions. The number of mitochondria may reflect the metabolic condition of cells. Cells with high ATP demands display a large number of mitochondria. High energy requirements characterize muscles in both vertebrates and invertebrates. It has been established that yeast cells have but a single mitochondrion. This investigation was designed to ascertain if the numerous mitochondrial profiles represent a single mitochondrion in vertebrate cells.
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Haseeb, Abdul, Hong Chen, Yufei Huang, Ping Yang, Xuejing Sun, Adeela Iqbal, Nisar Ahmed, et al. "Remodelling of mitochondria during spermiogenesis of Chinese soft-shelled turtle (Pelodiscus sinensis)." Reproduction, Fertility and Development 30, no. 11 (2018): 1514. http://dx.doi.org/10.1071/rd18010.
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Mitochondria are vital cellular organelles that have the ability to change their shape under different conditions, such as in response to stress, disease, changes in metabolic rate, energy requirements and apoptosis. In the present study, we observed remodelling of mitochondria during spermiogenesis and its relationship with mitochondria-associated granules (MAG). At the beginning of spermiogenesis, mitochondria are characterised by their round shape. As spermiogenesis progresses, the round-shaped mitochondria change into elongated and then swollen mitochondria, subsequently forming a crescent-like shape and finally developing into onion-like shaped mitochondria. We also noted changes in mitochondrial size, location and patterns of cristae at different stages of spermiogenesis. Significant differences (P < 0.0001) were found in the size of the different-shaped mitochondria. In early spermatids transitioning to the granular nucleus stage, the size of the mitochondria decreased, but increased subsequently during spermiogenesis. Changes in size and morphological variations were achieved through marked mitochondrial fusion. We also observed a non-membranous structure (MAG) closely associated with mitochondria that may stimulate or control fusion during mitochondrial remodelling. The end product of this sophisticated remodelling process in turtle spermatozoa is an onion-like mitochondrion. The acquisition of this kind of mitochondrial configuration is one strategy for long-term sperm storage in turtles.
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Fu, Ailing. "Mitotherapy as a Novel Therapeutic Strategy for Mitochondrial Diseases." Current Molecular Pharmacology 13, no. 1 (January 15, 2020): 41–49. http://dx.doi.org/10.2174/1874467212666190920144115.
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Background: The mitochondrion is a multi-functional organelle that is mainly responsible for energy supply in the mammalian cells. Over 100 human diseases are attributed to mitochondrial dysfunction. Mitochondrial therapy (mitotherapy) aims to transfer functional exogenous mitochondria into mitochondria-defective cells for recovery of the cell viability and consequently, prevention of the disease progress. Conclusion: Mitotherapy makes the of modulation of cell survival possible, and it would be a potential therapeutic strategy for mitochondrial diseases. Objective: The review summarizes the evidence on exogenous mitochondria that can directly enter mammalian cells for disease therapy following local and intravenous administration, and suggests that when healthy cells donate their mitochondria to damaged cells, the mitochondrial transfer between cells serve as a new mode of cell rescue. Then the transferred mitochondria play their roles in recipient cells, including energy production and maintenance of cell function.
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Qin, Lingyu, and Shuhua Xi. "The role of Mitochondrial Fission Proteins in Mitochondrial Dynamics in Kidney Disease." International Journal of Molecular Sciences 23, no. 23 (November 25, 2022): 14725. http://dx.doi.org/10.3390/ijms232314725.
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Mitochondria have many forms and can change their shape through fusion and fission of the outer and inner membranes, called “mitochondrial dynamics”. Mitochondrial outer membrane proteins, such as mitochondrial fission protein 1 (FIS1), mitochondrial fission factor (MFF), mitochondrial 98 dynamics proteins of 49 kDa (MiD49), and mitochondrial dynamics proteins of 51 kDa (MiD51), can aggregate at the outer mitochondrial membrane and thus attract Dynamin-related protein 1 (DRP1) from the cytoplasm to the outer mitochondrial membrane, where DRP1 can perform a scissor-like function to cut a complete mitochondrion into two separate mitochondria. Other organelles can promote mitochondrial fission alongside mitochondria. FIS1 plays an important role in mitochondrial–lysosomal contacts, differentiating itself from other mitochondrial-fission-associated proteins. The contact between the two can also induce asymmetric mitochondrial fission. The kidney is a mitochondria-rich organ, requiring large amounts of mitochondria to produce energy for blood circulation and waste elimination. Pathological increases in mitochondrial fission can lead to kidney damage that can be ameliorated by suppressing their excessive fission. This article reviews the current knowledge on the key role of mitochondrial-fission-associated proteins in the pathogenesis of kidney injury and the role of their various post-translational modifications in activation or degradation of fission-associated proteins and targeted drug therapy.
Dissertations / Theses on the topic "Mitochondria"
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Jugé, Romain. "Étude de la dynamique mitochondriale dans des cellules cutanées humaines : Mise en place de modèles pour des applications en cosmétologie." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEN007.
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La peau est un épithélium spécialisé vital et fragile, qui évolue avec l’âge et est influencé par l’environnement, notamment les radiations solaires. Des données sont disponibles sur la réponse du réseau mitochondrial et le devenir des mitochondries endommagées en réponse à des stress chimiques et environnementaux dans plusieurs systèmes expérimentaux, mais ces processus restent peu étudiés dans les cellules cutanées. Dans ce contexte, le projet de thèse visait à analyser l’effet (i) de l’irradiation UVB sur la dynamique mitochondriale (en particulier la fragmentation des mitochondries) dans des kératinocytes primaires humains normaux, qui constituent la première ligne de défense contre les agressions externes ; (ii) d’un traitement par des poisons mitochondriaux sur les mitochondries contenues dans des kératinocytes ou des fibroblastes primaires humains normaux. Dans un premier axe de la thèse, nous avons mis au point une méthode originale (Mitoshape) basée sur l’imagerie confocale, permettant d’estimer à la fois qualitativement et quantitativement la morphologie du réseau mitochondrial dans des cellules vivantes après irradiation UVB. Grâce à cette technologie, nous avons pu montrer que les UVB induisaient une fragmentation du réseau mitochondrial dans les kératinocytes primaires, dont nous avons étudié les acteurs biochimiques. Dans un deuxième axe, nous avons montré que les poisons mitochondriaux avaient la capacité d’endommager les mitochondries dans des kératinocytes et des fibroblastes humains primaires et induisaient une autophagie générale sans toutefois exclure la présence d’une mitophagie dépendante de la voie PINK1/PARKIN. Outre son intérêt fondamental, ce travail (réalisé en collaboration avec la société de cosmétologie SILAB dans le cadre d’un partenariat industriel CIFRE) ouvre la voie à l’identification d’actifs naturels capables de préserver et/ou restaurer les paramètres fonctionnels mitochondriaux suite à des stressThe skin is a specialized type of epithelium, both vital and fragile, which evolves with age and is continuously exposed to environmental stresses, such as solar radiations. While data is available about the response of the mitochondrial network and the fate of damaged mitochondria after chemical or environmental stresses in numerous experimental systems, little is known about these processes in skin cells. The aim of the present thesis was to study the impact (i) of UVB irradiation on mitochondrial dynamics (especially mitochondrial fragmentation) in normal human epidermal keratinocytes, which represent the first line of defence against environmental insults; (ii) of poisoning mitochondria of keratinocytes and normal human fibroblasts with chemical drugs. In a first axis, we developed an original method (called Mitoshape) based on confocal microscopy, to estimate qualitatively and quantitatively the morphology of the mitochondrial network within live cells following UVB irradiation. Using this technology, we demonstrated that UVB irradiation induces mitochondrial fragmentation in normal human keratinocytes, and studied the biochemical actors involved in this response. In a second axis, we showed that the use of mitochondrial poisons could damage mitochondria of keratinocytes and normal human fibroblasts and induce bulk autophagy, although it is not possible to formally rule out the involvement of a PINK1/PARKIN-dependent pathway of mitophagy. In addition to its fundamental interest, this work (performed in collaboration with the cosmetic company SILAB in the context of a CIFRE PhD fellowship from ANRT) paves the way for the screening of novel bioactive agents able to protect and restore mitochondria following stresses
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Mortz, Mathieu. "Flexibilités bioénergétique et génomique mitochondriales chez l’oiseau." Thesis, Lyon, 2019. https://n2t.net/ark:/47881/m6v40tjz.
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Les oiseaux sont des organismes endothermes faisant preuve d’une flexibilité métabolique remarquable en réponse aux contraintes énergétiques inhérentes à leur mode de vie. Cette flexibilité est notamment stimulée lors de transitions nutritionnelles pour adapter leur intensité métabolique selon les ressources énergétiques disponibles, est déterminante pour la survie chez ces animaux. Les mitochondries constituant le principal carrefour métabolique, en permettant l’essentiel de la production d’ATP cellulaire, sont largement impliquées dans les modulations observées au cours d’un jeûne et lors de la réalimentation. Le but de cette thèse était d’étudier la flexibilité de la fonction mitochondriale face à un jeûne alimentaire et lors de la réalimentation chez le canard de Barbarie. Plusieurs aspects allant de la bioénergétique, à l’organisation anatomique jusqu’à la génomique et l’évolution des espèces ont été analysés pour mieux comprendre les modulations impliquées et leurs interrelations potentielles pour ajuster le fonctionnement mitochondrial aux contraintes énergétiques. Une 1ère étude a décrit la cinétique de l’installation d’un hypométabolisme musculaire associé à l’augmentation de l’efficacité bioénergétique mitochondriale en réponse au jeûne, avec une acclimatation maximale après 3 jours. L’étude en parallèle du remodelage des réseaux grâce à une double approche par anticorps et microscopie confocale a montré une flexibilité bidirectionnelle de l’organisation des réseaux de mitochondries musculaires, avec une fusion accrue au tout début du jeûne précédant une fragmentation accrue après 4 jours. Une 2ème étude a montré l’implication potentielle de l’activité de la monoxyde d’azote synthase (NOS) mitochondriale dans les modulations de la bioénergétique mitochondriale induites par le jeûne alimentaire. L’activité de la NOS mitochondriale est accrue par le jeûne et sa modulation in vitro reproduit de façon rapidement réversible sur des mitochondries musculaires d’oiseaux nourris les effets induits par le jeûne alimentaire. Une 3ème étude a exploré la flexibilité du génome mitochondrial pour détecter la présence de cadres ouverts de lecture (ORF) codant pour des peptides bioactifs, similaires à ceux qui chez les mammifères sont codés par les gènes 12S et 16S et sont métaboliquement actifs. Les analyses génétiques ont mis en évidence chez les oiseaux la présence d’ORFs incorporés dans le gène codant pour l’ARNr 16S et dont l’évolution moléculaire est similaire à celle des gènes mitochondriaux codant pour des sous-unités de la chaîne respiratoire. Parmi les ORFs détectés, certains correspondent à ceux décrits chez les mammifères (humanine, SHLP6). Une 4ème étude a montré que la très forte conservation chez les mammifères, les oiseaux et les ectothermes terrestres, des ORFs situés sur le gène 16S ne peut être un artéfact lié à une contrainte imposée par la structure de l’ARNr codé, n’étant pas retrouvée sur des simulations de séquences générées en tenant compte de la structure secondaire et tertiaire. Chez les 3 groupes de vertébrés étudiés, l’ORF codant pour l’humanine, un peptide identifié chez l’homme, a subi au cours de l’évolution une pression de sélection purifiante maintenant sa composition en acides aminés. Ce travail souligne la remarquable flexibilité bioénergétique et génomique des mitochondries chez les oiseaux qui peut contribuer aux ajustements de l’activité énergétique lors des transitions nutritionnelles. Les résultats obtenus ont ouvert un nouveau champ d’investigations sur les nouveaux peptides codés par le génome mitochondrial et dont les rôles biologiques restent à explorerBirds are endotherms that exhibit a remarkable metabolic flexibility in response to energetic constraints related to their lifestyles. This flexibility is notably involved during nutritional transitions in order to adjust metabolic intensity to the available energy resources, a prerequisite for survival. Mitochondria, that produce most of cellular ATP production, are involved in the modulations observed during a fast and during refeeding. The aim of this thesis was to investigate the flexibility of mitochondrial functions in response to fasting and refeeding in Muscovy ducks (Cairina moschata). Several aspects, ranging from bioenergetics and anatomical organization to genomics and evolution of species, were analysed to better understand the modulations involved to adjust mitochondrial functioning to energy constraints. A first study described the kinetics of the installation of fasting-induced muscle hypometabolism and the associated improved mitochondrial bioenergetics efficiency and showed that maximum acclimation was reached after 3 days. Mitochondrial networks remodelling, investigated by antibodies (Western blot) and confocal microscopy, showed a bidirectional flexibility with an increased fusion at the beginning of the fast preceding an increased fragmentation observable after 4 days of fasting. A second study suggested the potential involvement of a nitric oxide synthase (NOS) activity detected in mitochondrial fractions in the modulations of mitochondrial bioenergetics induced by fasting. The activity of mitochondrial NOS was found to be increased by fasting and its in vitro modulation mimicked the effects induced by fasting in nourished birds, in a rapid and reversible manner. A third study explored the flexibility of the mitochondrial genome in order to detect the presence of open reading frames (ORF) potentially encoding bioactive peptides similar to those described in mammals and that are encoded by small regions included in the 12S and 16S genes. Our genetic analyses demonstrated the presence of ORFs incorporated into the 16S rRNA coding gene of most avian species. The molecular evolution of these ORFs among bird species was found to be similar to that calculated for all mitochondrial genes coding for subunits of the respiratory chain. Among the detected ORFs, some corresponded to those described in mammals (humanin and SHLP6) but others had never been described. A fourth study showed that the very strong nucleotide conservation of ORFs located in the 16S gene, and observed in mammals, birds and terrestrial ectotherms, was not an artifact linked to a constraint imposed by the structure of the encoded rRNA. Indeed, the strong nucleotide conservation was not found on alignments of sequences generated by simulations of evolution that took into account the secondary and tertiary structures of 16S rRNA. In the 3 groups of vertebrates, the ORF coding humanin, a peptide identified in humans, underwent a specific negative selection pressure in order to maintain its amino-acid composition during evolution. In conclusion, this thesis highlighted the remarkable bioenergetics and genomic flexibilities of mitochondrial function in birds, which could contribute to the metabolic adjustments required during nutritional transitions. Our results have also opened up a new field of investigation concerning the putative peptides encoded by the mitochondrial genome and their biological roles remain to be explored
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Al, Amir Dache Zahra. "Étude de la structure de l'ADN circulant d'origine mitochondriale." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTT059.
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Le plasma transporte des cellules sanguines avec un mélange de composés, y compris les nutriments, déchets, anticorps, et messagers chimiques... dans tout l'organisme. Des facteurs non solubles tels que l’ADN circulant et les vésicules extracellulaires ont récemment été ajoutés à la liste de ces composants et ont fait l'objet d'études approfondies en raison de leur rôle dans la communication intercellulaire. Or, l’ADN circulant (ADNcir) est composé de fragments d’ADN libres ou associés à d’autres particules, libérés par tous les types cellulaires. Cet ADN est non seulement de l'ADN génomique mais aussi de l'ADN mitochondrial extra-chromosomique. De nombreux travaux réalisés au cours des dernières années indiquent que l’analyse quantitative et qualitative de l’ADNcir représente une avancée dans les applications cliniques en tant que biomarqueur non invasif de diagnostic, de pronostic et de suivi thérapeutique. Cependant, malgré l'avenir prometteur de cet ADNcir dans les applications cliniques, notamment en oncologie, les connaissances sur ses origines, sa composition et ses fonctions qui pourraient pourtant permettre d’optimiser considérablement sa valeur diagnostique, font encore défaut. Le principal objectif de ma thèse a été d’identifier et de caractériser les propriétés structurales de l’ADN extracellulaire d’origine mitochondrial. En examinant l'intégrité de cet ADN, ainsi que la taille et la densité des structures associées, ce travail a révélé la présence de particules denses d’une taille supérieure à 0,2 µm contenant des génomes mitochondriaux complets et non fragmentés. Nous avons caractérisé ces structures notamment par microscopie électronique et cytométrie en flux et nous avons identifié des mitochondries intactes dans le milieu extracellulaire in vitro et ex-vivo (dans des échantillons de plasma d’individus sains). Une consommation d'oxygène par ces mitochondries a été détectée par la technique du Seahorse, suggérant qu'au moins une partie de ces mitochondries extracellulaires intactes pourraient être fonctionnelles. Par ailleurs, j’ai participé à d’autres travaux réalisées dans l’équipe, dont (1) une étude visant à évaluer l’influence des paramètres pré-analytiques et démographiques sur la quantification d’ADNcir d’origine nucléaire et mitochondrial sur une cohorte composée de 104 individus sains et 118 patients atteints de cancer colorectal métastatique, (2) une étude dont l’objectif était d’évaluer l’influence de l’hypoxie sur le relargage de l’ADN circulant in vitro et in vivo, et (3) une étude visant à évaluer le potentiel de l’analyse de l’ADN circulant dans le dépistage et la détection précoce du cancer. Ce manuscrit présente une synthèse récente de la littérature sur l’ADNcir, ses différents mécanismes de relargage, qui vont de pair avec la caractérisation structurelle de cet ADN, ses aspects fonctionnels et ses différentes applications en cliniques. De plus, cette thèse apporte des connaissances nouvelles sur la structure de l’ADN mitochondrial extracellulaire tout en ouvrant de nouvelles pistes de réflexion notamment sur l’impact que pourrait avoir la présence de ces structures circulantes sur la communication cellulaire, l’inflammation et des applications en cliniquePlasma transports blood cells with a mixture of compounds, including nutrients, waste, antibodies, and chemical messengers...throughout the body. Non-soluble factors such as circulating DNA and extracellular vesicles have recently been added to the list of these components and have been the subject of extensive research due to their role in intercellular communication. Circulating DNA (cirDNA) is composed of cell-free and particle-associated DNA fragments, which can be released by all cell types. cirDNA is derived not only from genomic DNA but also from extrachromosomal mitochondrial DNA. Numerous studies carried out lately indicate that the quantitative and qualitative analysis of cirDNA represents a breakthrough in clinical applications as a non-invasive biomarker for diagnosis, prognosis and therapeutic follow-up. However, despite the promising future of cirDNA in clinical applications, particularly in oncology, knowledge regarding its origins, composition and functions, that could considerably optimize its diagnostic value, is still lacking.The main goal of my thesis was to identify and characterize the structural properties of extracellular DNA of mitochondrial origin. By examining the integrity of this DNA, as well as the size and density of associated structures, this work revealed the presence of dense particles larger than 0.2 µm containing whole mitochondrial genomes. We characterized these structures by electron microscopy and flow cytometry and identified intact mitochondria in the extracellular medium in vitro and ex vivo (in plasma samples from healthy individuals). Oxygen consumption by these mitochondria was detected by the Seahorse technology, suggesting that at least some of these intact extracellular mitochondria may be functional.In addition, I contributed to other studies carried out in the team, such as studies aiming at evaluating (1) the influence of pre-analytical and demographic parameters on the quantification of nuclear and mitochondrial cirDNA on a cohort of 104 healthy individuals and 118 patients with metastatic colorectal cancer, (2) the influence of hypoxia on the release of cirDNA in vitro and in vivo, and (3) the potential of cirDNA analysis in the early detection and screening of cancer.This manuscript present a recent review on cirDNA and its different mechanisms of release, which go hand in hand with the structural characterization of this DNA, its functional aspects and its clinical applications. In addition, this thesis provides new knowledge on the structure of extracellular mitochondrial DNA and opens up new avenues for reflection, particularly on the potential impact that could have those circulating mitochondria on cell-cell communication, inflammation and clinical applications
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Beinat, Marine. "Caractérisation génétique des atteintes hépatiques mitochondriales." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05T007/document.
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Les maladies mitochondriales sont les anomalies congénitales du métabolisme les plus fréquentes. Elles sont caractérisées par une très grande hétérogénéité clinique et génétique, et le gène responsable de la maladie n’a pu être identifié que pour seulement 30% d’entre elles. Malgré l’hétérogénéité de ces maladies, il est possible d’identifier des groupes de patients cliniquement homogènes. C’est notamment le cas des atteintes hépatiques mitochondriales, qui peuvent se présenter sous une forme syndromique ou isolée. Les patients ayant une forme isolée ont soit une déplétion de l’ADNmt, soit une quantité d’ADNmt normale. Les patients avec déplétion de l’ADNmt sont très bien caractérisés génétiquement et sont mutés dans les gènes DGUOK, POLG, PEO1 ou MPV17, alors que les atteintes hépatiques sans déplétion de l’ADNmt n’ont commencé à l’être que plus récemment et montrent une très grande hétérogénéité génétique.Nous avons dans ce travail de recherche constitué une cohorte cliniquement homogène de 70 patients provenant des hôpitaux Necker-Enfants Malades et du Kremlin-Bicêtre présentant une atteinte hépatique mitochondriale isolée ou syndromique, sans déplétion de l’ADNmt, dont nous disposions de matériel (fibroblastes, ADN) nécessaire à leur étude. Nous avons tout d’abord identifié des mutations dans le gène TRMU, codant pour une enzyme de modification des ARNt mitochondriaux, responsables d’une anomalie de la traduction mitochondriale. Nous avons par ailleurs établi l’hétérogénéité génétique de ce groupe de patients, puisque nous avons pu exclure la présence de mutations dans les gènes TRMU, TSFM, GFM1 et LARS chez 40 patients, démontrant qu’il n’y a pas de gènes majeurs associé aux atteintes hépatiques sans déplétion de l’ADNmt. Pour deux familles multiplex pour lesquels l’ADN de plusieurs membres de la famille était disponible, nous avons réalisé une cartographie génétique combinée avec un séquençage exome et une étude du transcriptome, qui n’a pas permis de mettre en évidence de gène causal. Pour 38 autres patients, essentiellement des cas sporadiques, nous avons utilisé les stratégies du transcriptome et du séquençage exome, ce qui nous a permis d’identifier des variations robustes dans de nouveaux gènes MRPS5, ALDH1B, NOX5, MTUS1, AARS2, PPA2, MTHFD1, ALDH6A1, NME4 et GLDC pour 17 patients. Enfin, nous avons étudié particulièrement les mutations identifiées dans le gène NOX5, retrouvées chez 3 patients de la cohorte. Ce gène code pour une protéine NADPH de fonction inconnue, que pensons être impliquée dans la traduction mitochondrialeGenetic characterization of mitochondrial liver damage
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Reinhardt, Camille. "Impact de la voie d’import mitochondrial contrôlée par le complexe AIF/CHCHD4 sur la survie des cellules cancéreuses et la réponse aux traitements anticancéreux." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS542.
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Dans la majorité des cas, les mitochondries sont nécessaires à la tumorigenèse et à la réponse des cellules cancéreuses aux signaux générés par les facteurs micro-environnementaux (exemples : privation de nutriments, hypoxie) ou par les traitements anticancéreux (exemples : chimiothérapie, radiothérapie). Presque toutes les protéines mitochondriales sont codées par le génome nucléaire et importées dans l'organelle. Des machineries d'import ont donc évolué afin de répondre aux besoins d'import protéique. Dans ce contexte, la machinerie régulée par CHCHD4/Mia40 fonctionne dans l’espace intermembranaire et contrôle l’import d’un groupe de protéines (substrats) qui joue des rôles importants dans la survie et la réponse au stress. Les substrats de CHCHD4/Mia40 sont impliqués dans un vaste panel d’activités mitochondriales qui inclut la biogenèse des complexes de la chaîne respiratoire, l’homéostasie lipidique, le stockage du calcium, ainsi que l'ultrastructure et la dynamique mitochondriale. Ce programme de thèse a été dédié à l’étude de la voie d’import CHCHD4/Mia40 dans les cellules cancéreuses et a porté un intérêt tout particulier à l'un des substrats CHCHD4/Mia40 qui façonne l'ultrastructure mitochondriale. En utilisant des techniques d’ARN interférence et de sur-expression de protéines recombinantes, dans un modèle de cancer du côlon, nous avons montré que l’expression du substrat étudié a un effet crucial sur la prolifération et la croissance tumorale. Nos données ont également impliqué cette protéine dans la réponse aux traitements anticancéreux. Dans l'ensemble, ces travaux ouvrent un nouveau champ d'investigations qui non seulement permettra de mieux comprendre la plasticité métabolique des cellules cancéreuses, mais aidera également à identifier de nouveaux biomarqueurs métaboliquesIn the vast majority of cases, mitochondria are required for tumorigenesis and also for the tumoral response to signals generated by the microenvironmental factors (e.g. nutrient deprivation, hypoxia) or to the effects of anti-cancer treatments (e.g. chemotherapy, radiotherapy). As almost all mitochondrial proteins are nuclear-encoded and imported into the organelle, specialized import machineries have evolved in order to meet the need for protein import. Among these machineries, the one that operates in the intermembrane space and is controlled by CHCHD4/Mia40, regulates the import of a group of proteins (substrates) that play important roles in survival and stress response. Substrates of CHCHD4/Mia40 are involved in a broad panel of mitochondrial activities that includes the biogenesis of respiratory chain complexes, lipid homeostasis, calcium storage, as well as ultrastructure and mitochondrial dynamics. This thesis program was dedicated to the study of the CHCHD4/Mia40 import pathway in cancer cells, with a particular interest for one of the CHCHD4/Mia40 substrates that shapes mitochondrial ultrastructure. Using RNA interference approach and recombinant protein overexpression technique, in a colon cancer model, we showed that the expression of this substrate had a crucial effect on proliferation and tumor growth. Our data also involved this protein in the response to anti-cancer treatments. All together, this work opens a new field of investigations that will not only shed new lights on the metabolic plasticity of cancer cells but also help to identify new metabolic biomarkers
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Renken, Christian Wolfgang. "The structure of mitochondria /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3141929.
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Craig, Elaine. "Protein import into cardiac mitochondria." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ39261.pdf.
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Esteves, Pauline. "Etude de l’action anti-tumorale de la protéine mitochondriale UCP2." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T024.
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Les cellules tumorales sont caractérisées par un métabolisme hautement glycolytique à l’inverse des cellules normales qui utilisent préférentiellement un métabolisme oxydatif. Cette adaptation métabolique permet aux cellules d’être moins dépendantes de l’oxygène et favorise les processus d’invasion. D’autres mécanismes associés aux espèces réactives de l’oxygène qui induisent des dommages de l’ADN contribuent à la transformation cellulaire et à l’initiation tumorale. Le transporteur mitochondrial UCP2 est le deuxième membre identifié dans la famille des UCP dont la fonction mitochondriale reste encore mal comprise. Cependant, UCP2 a été impliquée dans un grand nombre de fonctions biologiques telles la régulation de la production de radicaux libres, l’inflammation, la prolifération cellulaire ou encore le métabolisme énergétique. UCP2 est donc un bon candidat pour comprendre le dialogue entre ces événements connus pour favoriser l'initiation, la progression et l'invasion du cancer. Au cours de ma thèse, dans une première partie, nous avons montré que la surexpression d’UCP2 dans différentes lignées de cellules cancéreuses entraîne une diminution de leur prolifération. En effet, les cellules cancéreuses surexprimant UCP2 changent leur métabolisme de la glycolyse vers l’oxydation phosphorylante et deviennent peu tumorigènes. La modification de l’expression des enzymes de la glycolyse et de la phosphorylation oxydative contribue à ce changement métabolique. De plus, la surexpression d’UCP2 augmente la signalisation d’AMPK et diminue l’expression de HIF. UCP2 agit donc dans le contrôle du routage des substrats mitochondriaux. Dans une seconde partie, nous avons étudié si UCP2 joue un rôle dans le développement des tumeurs in vivo en modulant le métabolisme énergétique cellulaire et la production des ROS. Ainsi, nous avons montré in vivo l’impact de l’invalidation du gène Ucp2 (souris Ucp2-/-) dans deux modèles murins de cancer colorectal : un modèle transgénique (souris APCmin/+) et un modèle chimique (azoxyméthane + dextran disulfate (AOM-DSS)). Chez des souris APCmin/+ Ucp2+/+ ou des souris Ucp2+/+ sous traitement AOM-DSS, les tumeurs présentent une augmentation d’expression d’UCP2 par rapport au tissu adjacent non tumoral. L’invalidation du gène Ucp2 dans le modèle APCmin/+ diminue la survie des animaux. Une augmentation du nombre total de tumeurs est observée dans les deux modèles. Ces résultats suggèrent que l’initiation tumorale pourrait être augmentée en absence d’UCP2Dysregulation of cellular metabolism has been associated with malignant transformation. Switching from oxidative phosphorylation (OXPHOS) to glycolysis for ATP production allows cancer cells to be less oxygen dependent, thus favoring invasion processes. Effects on metabolism, and more particularly mitochondria metabolism, thus represent a potential therapeutic target for cancer therapy. Uncoupling protein 2 (UCP2) is a member of UCPs, a subfamily of the mitochondrial carriers. The function of UCP2 is still controversial but we recently showed its role in the modulation of cell metabolism. Therefore, UCP2 is a good candidate to address the crosstalk between metabolic alteration and promotion of cancer progression and invasion. We show that cancer cells overexpressing UCP2 shift their metabolism from glycolysis toward oxidative phosphorylation and become poorly tumorigenic. Altered expression of glycolytic and oxidative enzymes underlies the cell metabolic shift. Moreover, UCP2 overexpression is associated with an increased adenosine monophosphate-activated protein kinase (AMPK) signaling together with a downregulation of hypoxia-induced factor (HIF) expression. In line with our previous observations, UCP2 does not function as an uncoupling protein but rather controls mitochondrial substrate routing. To address UCP2 role in cancer in vivo, we investigate the impact of Ucp2 deletion in two colorectal cancer mice models: a transgenic mice model APCmin/+ and a chemical cancer mice model (azoxymethane + dextran disulfate (AOM-DSS)). These two models are complementary because they allow us to determine if the role of UCP2 in cancer differs in only one genetic background (APC) compared with an inflammatory model (AOM + DSS). We found in those two colorectal cancer models that UCP2 is more expressed in tumors instead of the adjacent healthy mucosa. Deletion of Ucp2 in APCmin/+ mice leads to decrease in animal survival and Ucp2 deletion is associated in both mice models with an increased number of tumors. Altogether the results suggest that tumor initiation could be increased with Ucp2 deletion. UCP2 thus appears as a critical regulator of cellular metabolism with a relevant action against tumor maintenance and malignancy
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Ruby, Vincent. "Étude des évènements mitochondriaux impliqués dans le contrôle de l'apoptose par rbf1, l'homologue de drosophile du gène suppresseur de tumeur rb." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV039/document.
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Le gène rb est le premier suppresseur de tumeur découvert chez l’homme. Il prévient l’apparition de tumeurs notamment en régulant négativement le cycle cellulaire. Le rôle de pRb dans le contrôle de l’apoptose est plus complexe et les mécanismes moléculaires contrôlés par ce facteur de transcription ne sont pas complétement élucidés. Il existe un homologue de rb chez la drosophile : rbf1. J’ai contribué à caractériser les évènements mitochondriaux induits au cours de l’activation de l’apoptose par Rbf1 dans le disque imaginal d'aile, un tissu en prolifération de la larve de drosophile. Dans cette voie d’apoptose, la protéine Debcl, seule membre pro-apoptotique de la famille Bcl-2 chez la drosophile, est activée et induit le recrutement et l’oligomérisation de Drp1, protéine effectrice principale de la fission mitochondriale. C’est ainsi qu’est déclenchée la fragmentation mitochondriale et l’accumulation d’espèces activées de l’oxygène (EAOs) mitochondriales. Ces deux évènements participent à la transmission du signal apoptotique. J’ai par ailleurs pu mettre en évidence l’implication de facteurs participant au maintien du contrôle qualité mitochondriale. Celui-ci s’assure de l’intégrité des mitochondries et, le cas échéant, déclenche la digestion des éléments défaillants par mitophagie. Enfin, j’ai contribué à l’étude des liens entre la traduction et l’apoptose induite par Rbf1. Dans cette étude, nous montrons que la poly-A binding protein (PABP) peut supprimer le phénotype d’encoche induit par Rbf1 chez l’adulte alors que la mort cellulaire induite au cours du stade larvaire n’est pas inhibée mais augmentée. Ces résultats nous ont poussé à étudier les mécanismes de compensation induits par l’appareil traductionnel, ce qui nous a permis de montrer qu'une modulation de la traduction pourrait permettre de compenser la perte de tissu consécutive à l'apoptose induite par Rbf1 sans impliquer une inhibition de l'apoptoseThe gene rb is the first tumor suppressor discovered in humans. Its prevents the appearance of tumors by regulating negatively the cell cycle. The role of pRb in apoptosis is more complex and the molecular mechanisms triggered by this transcription factor are not completely elucidated. There is a rb homologue in drosophila: rbf1. I participated in the characterization of mitochondrial events induced during activation of apoptosis by Rbf1 in a proliferating tissue of this model organism, the wing disc. In this apoptosis pathway, the Debcl protein, the only drosophila pro-apoptotic member of the Bcl-2 family, is activated and induces recruitment and oligomerization of Drp1, the main effector of mitochondrial fission. This triggers the mitochondrial fragmentation and the accumulation of mitochondrial reactive oxygen species (ROS). Both events participate to the transmission of the apoptotic signal. I have also been able to highlight the implication of factors involved in maintaining mitochondrial quality control which ensures the integrity of the mitochondria and, if necessary, triggers the degradation of damaged elements by mitophagy. Finally, I have contributed to the study of the links between translation and apoptosis induced by Rbf1. In this study, we show that the Poly-A Binding Protein (PABP) can suppress the Rbf1-induced notch phenotype in adults while cell death induced during larval stage was not inhibited but increased. These results prompted us to study the compensation mechanisms induced by the translational apparatus, which allowed us to show that a mRNA translation-related mechanism could counteract the loss of tissue resulting from Rbf1-induced apoptosis independently of apoptosis inhibition
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Heller, Anne Sabine [Verfasser], and Achim [Akademischer Betreuer] Göpferich. "Targeting mitochondria by mitochondrial fusion, mitochondria-specific peptides and nanotechnology / Anne Sabine Heller. Betreuer: Achim Göpferich." Regensburg : Universitätsbibliothek Regensburg, 2013. http://d-nb.info/103321664X/34.
Full textBooks on the topic "Mitochondria"
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St. John, Justin C., ed. Mitochondrial DNA, Mitochondria, Disease and Stem Cells. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-101-1.
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John, Justin C. St. Mitochondrial DNA, mitochondria, disease, and stem cells. New York: Humana Press, 2013.
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Tomar, Namrata, ed. Mitochondria. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2309-1.
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Mokranjac, Dejana, and Fabiana Perocchi, eds. Mitochondria. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-6824-4.
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Schaffer, Stephen W., and M.-Saadeh Suleiman, eds. Mitochondria. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5.
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Scheffler, Immo E. Mitochondria. New York, USA: John Wiley & Sons, Inc., 1999. http://dx.doi.org/10.1002/0471223891.
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Leister, Dario, and Johannes M. Herrmann, eds. Mitochondria. Totowa, NJ: Humana Press, 2007. http://dx.doi.org/10.1007/978-1-59745-365-3.
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A, Pon Liza, and Schon Eric A, eds. Mitochondria. San Diego, Calif: Academic, 2001.
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W, Schaffer S., and Suleiman M. -Saadeh, eds. Mitochondria: The dynamic organelle. New York: Springer, 2007.
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Van Aken, Olivier, and Allan G. Rasmusson, eds. Plant Mitochondria. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-1653-6.
Full textBook chapters on the topic "Mitochondria"
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Hangay, George, Susan V. Gruner, F. W. Howard, John L. Capinera, Eugene J. Gerberg, Susan E. Halbert, John B. Heppner, et al. "Mitochondrion, (pl., Mitochondria)." In Encyclopedia of Entomology, 2441–42. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6359-6_4638.
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Valk, Jacob, and Marjo S. van der Knaap. "Mitochondria and Mitochondrial Dysfunction." In Magnetic Resonance of Myelin, Myelination, and Myelin Disorders, 128–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-662-02568-0_23.
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Morava, E., and J. A. M. Smeitink. "Mitochondria and Mitochondrial Disorders." In Magnetic Resonance of Myelination and Myelin Disorders, 195–203. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-27660-2_23.
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van der Knaap, Marjo S., and Jacob Valk. "Mitochondria and Mitochondrial Disorders." In Magnetic Resonance of Myelin, Myelination, and Myelin Disorders, 140–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-662-03078-3_20.
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Mattedi, Francesca, George Chennell, and Alessio Vagnoni. "Detailed Imaging of Mitochondrial Transport and Precise Manipulation of Mitochondrial Function with Genetically Encoded Photosensitizers in Adult Drosophila Neurons." In Methods in Molecular Biology, 385–407. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-1990-2_20.
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AbstractPrecise distribution of mitochondria is essential for maintaining neuronal homeostasis. Although detailed mechanisms governing the transport of mitochondria have emerged, it is still poorly understood how the regulation of transport is coordinated in space and time within the physiological context of an organism. How alteration in mitochondrial functionality may trigger changes in organellar dynamics also remains unclear in this context. Therefore, the use of genetically encoded tools to perturb mitochondrial functionality in real time would be desirable. Here we describe methods to interfere with mitochondrial function with high spatiotemporal precision with the use of photosensitizers in vivo in the intact wing nerve of adult Drosophila. We also provide details on how to visualize the transport of mitochondria and to improve the quality of the imaging to attain super-resolution in this tissue.
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Hassinen, Ilmo. "Regulation of Mitochondrial Respiration in Heart Muscle." In Mitochondria, 3–25. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5_1.
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O’Rourke, Brian. "Mitochondrial Ion Channels." In Mitochondria, 221–38. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5_10.
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Halestrap, Andrew P., Samatha J. Clarke, and Igor Khalilin. "The Mitochondrial Permeability Transition Pore – from Molecular Mechanism to Reperfusion Injury and Cardioprotection." In Mitochondria, 241–69. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5_11.
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Suleiman, M.-Saadeh, and Stephen W. Schaffer. "The Apoptotic Mitochondrial Pathway – Modulators, Interventions and Clinical Implications." In Mitochondria, 271–90. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5_12.
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Murphy, Elizabeth, and Charles Steenbergen. "The Role of Mitochondria in Necrosis Following Myocardial Ischemia-Reperfusion." In Mitochondria, 291–301. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-69945-5_13.
Full textConference papers on the topic "Mitochondria"
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Li, Ching-Wen, Pao-Hsin Yen, and Gou-Jen Wang. "A Cascade Microfluidic Device for High Quality Mitochondria Extraction." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-46117.
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Recent researches have demonstrated that cells ingest mitochondrial by endocytosis to repair cell damage. This new mitochondrial therapy approach can be used for curing particular disease of neuropathy related diseases. Hence the obtainment of high quality and healthy mitochondria play an important role in mitochondrial based disease therapy. In this study, we propose a cascade microfluidic device for green extraction of healthy mitochondria. The geometry of the device was designed using the commercially available COMSOL package. Soft lithography process was than conducted to realize the device of PDMS. We used C2-GFP cells to demonstrate the efficiency of the proposed cascade microfluidic device. The total protein assay kit (complex I-V) was conducted to examine the extractive protein and the SDS page (Tom 20) was used for measuring the activity of the extracted mitochondria. Experimental results illustrate that the complex I-V expression of the extracted mitochondria by the proposed device is much higher than that of the extracted mitochondria by conventional kit. Furthermore, the results of the Tom 20 expression also demonstrate that our device is able to extract more amounts of mitochondria than the conventional kit.
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Vitkovac, Aleksandra, Tanja Pajić, Marta Bukumira, Marina Stanić, Mihailo Rabasović, and Nataša Todorović. "Slight cooling during growth induced changes in filamentous fungi hypha mitochondrial morphology." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.334v.
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Adaptive changes in mitochondrial morphology are associated with changes in the mitochondrial function and metabolic fitness of eukaryotic cells. We previously described in young hyphae of the filamentous fungus Phycomyces blakesleeanus a dramatic effect of an increase in ambient temperature during growth: a 3°C warmer environment compared with a control temperature of 22°C resulted in the appearance of long elongated (“tubular”) mitochondria accompanied by an increase in lipid droplet density. Here, we examined how cooler ambient temperature (18°C) during growth affects mitochondrial morphology in P. blakesleeanus compared with the control grown at 22°C. We used two-photon fluorescence imaging (TPEF) of live hyphae stained with the vital mitochondrial dye rhodamine 123. Extraction of relevant parameters (number, size, and shape of mitochondria) from TPEF images was performed using the Ilastik machine learning-based software. The suitability of the Ilastik analysis was compared with the Particle Analysis (ImageJ). Cold treatment resulted in the appearance of tubular mitochondrial morphology that was absent in the control group. Tubular mitochondrial morphology appears to be an adaptive feature that occurs in both warmer and colder conditions and is likely part of the stress response.
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Getmanskaya, Alexandra, Nikolai Sokolov, and Vadim Turlapov. "Multiclass U-Net Segmentation of Brain Electron Microscopy Data." In 31th International Conference on Computer Graphics and Vision. Keldysh Institute of Applied Mathematics, 2021. http://dx.doi.org/10.20948/graphicon-2021-3027-508-518.
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This work focuses on multi-class labeling and segmentation of electron microscopy data. The well-known and state-of-the-art EPFL open dataset has been labeled for 6 classes (instead of 1) and a multi-class version of the U-Net was trained. The new labeled classes are mitochondrion together with its border, mitochondrion’s border (separately), membrane, PSD, axon, vesicle. Our labeling results are available on GitHub. Our study showed that the quality of segmentation is affected by the presence of a sufficient number of specific features that distinguish the selected classes and the representation of these features in the training dataset. With 6-classes segmentation, mitochondria were segmented with the Dice index of 0.94, which is higher than with 5-classes (without mitochondrial boundaries) segmentation (Dice index of 0.892).
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Altaee, Muddather, Samaraa Youns, Abdullah Al-Nuaymia, Sara Dabdob, and Muhammad Alkataan. "The Protective Effects of a Phenolic Clove Extract on Mitochondria: An Animal Study." In 5th International Conference on Biomedical and Health Sciences, 439–43. Cihan University-Erbil, 2024. http://dx.doi.org/10.24086/biohs2024/paper.1201.
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Background: Plants represent a treasure chest with many unrevealed medical applications that have made them traditionally used for thousands of years to treat different diseases. One of these applications is the hypoglycemic and antioxidant roles of some plants. A pathological condition characterized by hyperglycemia, insulin resistance, and dyslipidemia known as metabolic syndrome. Objectives: This work focuses on examining the hypoglycemic effect of Syzygium aromaticum on a metabolic syndrome-induced animal model and studying the role of the extracted phenolic compounds on different mitochondrial function genomic parameters. Methods: Sánchez-Rangel et al. (2013) described the extraction and quantification of phenolic components from Syzygium aromaticum using the Folin-Ciocalteu reagent. In this work, forty albino rats were involved. They were split up into the following four groups, each consisting of five animals: Syzygium aromaticum treatment for metabolic syndrome, non-metabolic syndrome animals treated with Syzygium aromaticum, and negative control (normal), positive control (metabolic syndrome produced with fructose without treatment). Serum glucose, pyruvate, lactate, lipid profile, liver function tests, and molar lactate/pyruvate ratio. Green and red mitotrackers are used to measure the mass and action potential of mitochondria. Results: According to the study's findings, clove extract dramatically lowers blood sugar levels in rats with metabolic syndrome. The plants return serum lactate, pyruvate, and molar lactate: pyruvate ratio to normal control negative values. Mitochondrial mass and action potential significantly improve after treatment. In comparison to metabolic syndrome animals, the mitochondrial copy number of peripheral blood cells significantly increases after treatment with the plant extract. Conclusion: Metabolic syndrome significantly reduces mitochondrial genome copies number. The application of the phenolic extract of Syzygium aromaticum.
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Joseph Mathuram, T. L., Y. Su, M. Hatzoglou, Y. Perry, Y. Wu, and A. Blumental-Perry. "Mitochondria-to-Nucleus Retrograde Signaling Via Mitochondrial DNA Encoded Non-coding RNA Regulates Mitochondrial Bioenergetics." In American Thoracic Society 2023 International Conference, May 19-24, 2023 - Washington, DC. American Thoracic Society, 2023. http://dx.doi.org/10.1164/ajrccm-conference.2023.207.1_meetingabstracts.a4400.
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Belury, Martha. "Targeting inflammation and mitochondria with dietary linoleic acid for cardiometabolic health when research comes full circle." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ivnn3784.
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As a new graduate student, I was eager to study the new theory that fish oil rich in long chain omega 3 fatty acids would be protective against skin cancer due to their anti-inflammatory properties. Lo and behold, the fish oil diet had some effects on prostaglandin species but no effect on cancer. Surprisingly, diet rich in linoleic acid (LA) protected against skin cancer in a dose responsive manner. From this point forward, I was infected with the bug that biology is complex and not always what you calculate on paper. Over the 30 years of my career, my lab has evolved to now study how LA impacts mitochondrial respiration. We conduct our studies based on the solid knowledge that low levels of LA-rich cardiolipin, e.g., 4-LA cardiolipin, reduce mitochondrial respiration and therefore, ATP synthesis. Because LA is a required nutrient that cannot be endogenously synthesized, the diet is the only way to increase LA, and therefore support 4-LA-cardiolipin turnover in mitochondria. In a mouse model of middle age, we have discovered that a diet enriched with LA oil increases hind limb strength and lean mass. Further, we show that LA diet increased 4-LA-cardiolipin and mitochondrial respiration in skeletal muscle, liver and brown adipose tissue. The effects occur without changes of markers of inflammation. We have now shown that fortifying the diets of healthy adults with a modest amount of LA-rich oil also increases 4-LA-cardiolipin and mitochondrial respiration. The implications of our findings for cardiometabolic health will be discussed.
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Chen, Chang-Lin, Jia-Chen Tsai, Wei-Ling Huang, Ying-Hsuan Meng, Ju-Chun Huang, Ying-Chieh Chen, and Chuang-Rung Chang. "Mitochondria dynamics and pathogenesis." In PROCEEDINGS OF THE 3RD INTERNATIONAL SEMINAR ON METALLURGY AND MATERIALS (ISMM2019): Exploring New Innovation in Metallurgy and Materials. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0002464.
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Brandenberger, Christina, and Jahar Bhattacharya. "Alveolar Mitochondria Are Motile." In American Thoracic Society 2011 International Conference, May 13-18, 2011 • Denver Colorado. American Thoracic Society, 2011. http://dx.doi.org/10.1164/ajrccm-conference.2011.183.1_meetingabstracts.a2536.
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Novaković, Ivana, Milena Janković, Ana Marjanović, Marija Branković, Marina Svetel, and Jasna Jančić. "Challenges in rare diseases: The example of mitochondrial diseases." In Proceedings of the International Congress Public Health - Achievements and Challenges, 161. Institute of Public Health of Serbia "Dr Milan Jovanović Batut", 2024. http://dx.doi.org/10.5937/batutphco24114n.
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Background: Mitochondrial diseases are a group of disorders caused by dysfunction of mitochondria - the organelles that generate energy for the cell by converting the energy of food molecules into the ATP that powers most cell functions. Mitochondrial diseases are one of the most common groups of rare diseases with a minimum prevalence of greater than 1 in 5000 in adults. Clinical manifestations of mitochondrial diseases are heterogonous, mostly affecting nervous and muscle systems and sensory organs; symptoms can appear at birth or they may not appear until adulthood These diseases have genetic basis, and could be caused by mutations in nuclear genes, as well as by mutations in mitochondrial DNA (mtDNA) - small, maternally inherited, DNA molecule. An additional aspect of their genetic complexity is given by phenomenon of mtDNA heteroplasmy. Having all this in mind, the detection of the causative gene mutation is of crucial importance for diagnostics and further management of mitochondrial diseases. In addition, development of new therapeutic strategies is based on best knowledge ate genomic level. Methods and objectives: Genetic analyses were performed at patients suspect with mitochondrial diseases in order to detect causative gene mutations. Applied methods were targeted sequencing of mtDNA and clinical exome analysis by next generation sequencing. Results: In this report we will present our experience with genetic testing of mitochondrial diseases, challenges in genetic counselling, and possible new therapeutic options in mitochondrial diseases. Conclusion: Modern management of mitochondrial diseases is based on their genetic diagnostics. Contemporary algorithms and guidelines should be applied in this field of rare diseases.
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Zhao, Tinghan, Sweety Singh, Yuanwei Zhang, and Kevin D. Belfield. "Novel mitochondria penetrating peptide for live-cell long-term tracking of mitochondria." In Optical Molecular Probes, Imaging and Drug Delivery. Washington, D.C.: OSA, 2019. http://dx.doi.org/10.1364/omp.2019.om3d.5.
Full textReports on the topic "Mitochondria"
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Ostersetzer-Biran, Oren, and Alice Barkan. Nuclear Encoded RNA Splicing Factors in Plant Mitochondria. United States Department of Agriculture, February 2009. http://dx.doi.org/10.32747/2009.7592111.bard.
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Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for a small number of genes required in organellar genome expression and respiration. Yet, the vast majority of the organellar proteins are encoded by nuclear genes, thus necessitating complex mechanisms to coordinate the expression and accumulation of proteins encoded by the two remote genomes. Many organellar genes are interrupted by intervening sequences (introns), which are removed from the primary presequences via splicing. According to conserved features of their sequences these introns are all classified as “group-II”. Their splicing is necessary for organellar activity and is dependent upon nuclear-encoded RNA-binding cofactors. However, to-date, only a tiny fraction of the proteins expected to be involved in these activities have been identified. Accordingly, this project aimed to identify nuclear-encoded proteins required for mitochondrial RNA splicing in plants, and to analyze their specific roles in the splicing of group-II intron RNAs. In non-plant systems, group-II intron splicing is mediated by proteins encoded within the introns themselves, known as maturases, which act specifically in the splicing of the introns in which they are encoded. Only one mitochondrial intron in plants has retained its maturaseORF (matR), but its roles in organellar intron splicing are unknown. Clues to other proteins required for organellar intron splicing are scarce, but these are likely encoded in the nucleus as there are no other obvious candidates among the remaining ORFs within the mtDNA. Through genetic screens in maize, the Barkan lab identified numerous nuclear genes that are required for the splicing of many of the introns within the plastid genome. Several of these genes are related to one another (i.e. crs1, caf1, caf2, and cfm2) in that they share a previously uncharacterized domain of archaeal origin, the CRM domain. The Arabidopsis genome contains 16 CRM-related genes, which contain between one and four repeats of the domain. Several of these are predicted to the mitochondria and are thus postulated to act in the splicing of group-II introns in the organelle(s) to which they are localized. In addition, plant genomes also harbor several genes that are closely related to group-II intron-encoded maturases (nMats), which exist in the nucleus as 'self-standing' ORFs, out of the context of their cognate "host" group-II introns and are predicted to reside within the mitochondria. The similarity with known group-II intron splicing factors identified in other systems and their predicted localization to mitochondria in plants suggest that nuclear-encoded CRM and nMat related proteins may function in the splicing of mitochondrial-encoded introns. In this proposal we proposed to (i) establish the intracellular locations of several CRM and nMat proteins; (ii) to test whether mutations in their genes impairs the splicing of mitochondrial introns; and to (iii) determine whether these proteins are bound to the mitochondrial introns in vivo.
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Aachi, Venkat. Preliminary Characterization of Mitochondrial ATP-sensitive Potassium Channel (MitoKATP) Activity in Mouse Heart Mitochondria. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.1666.
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Kumar, Om. do you know about mitochondria ? ResearchHub Technologies, Inc., December 2023. http://dx.doi.org/10.55277/researchhub.11eubx1d.
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Kurtz, Andreas. Mitochondria Polymorphism in Neurofibromatosis Type 1. Fort Belvoir, VA: Defense Technical Information Center, November 2001. http://dx.doi.org/10.21236/ada400622.
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Kurtz, Andreas. Mitochondria Polymorphism in Neurofibromatosis Type 1. Fort Belvoir, VA: Defense Technical Information Center, November 2002. http://dx.doi.org/10.21236/ada411354.
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Kurtz, Andreas C. Mitochondria Polymorphism in Neurofibromatosis Type 1. Fort Belvoir, VA: Defense Technical Information Center, November 2003. http://dx.doi.org/10.21236/ada420949.
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Siedow, J. N. Molecular studies of functional aspects of plant mitochondria. Office of Scientific and Technical Information (OSTI), March 1992. http://dx.doi.org/10.2172/7194216.
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Dr. Carol Lynn George, Dr Carol Lynn George. Can our cell's mitochondria power a cell phone? Experiment, December 2013. http://dx.doi.org/10.18258/1755.
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Ostersetzer-Biran, Oren, and Jeffrey Mower. Novel strategies to induce male sterility and restore fertility in Brassicaceae crops. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604267.bard.
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Abstract Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for rRNAs, tRNAs and some mitochondrial proteins. Although all mitochondria have probably evolved from a common alpha-proteobacterial ancestor, notable genomic reorganizations have occurred in the mtDNAs of different eukaryotic lineages. Plant mtDNAs are notably larger and more variable in size (ranging from 70~11,000 kbp in size) than the mrDNAs in higher animals (16~19 kbp). Another unique feature of plant mitochondria includes the presence of both circular and linear DNA fragments, which undergo intra- and intermolecular recombination. DNA-seq data indicate that such recombination events result with diverged mitochondrial genome configurations, even within a single plant species. One common plant phenotype that emerges as a consequence of altered mtDNA configuration is cytoplasmic male sterility CMS (i.e. reduced production of functional pollen). The maternally-inherited male sterility phenotype is highly valuable agriculturally. CMS forces the production of F1 hybrids, particularly in predominantly self-pollinating crops, resulting in enhanced crop growth and productivity through heterosis (i.e. hybrid vigor or outbreeding enhancement). CMS lines have been implemented in some cereal and vegetables, but most crops still lack a CMS system. This work focuses on the analysis of the molecular basis of CMS. We also aim to induce nuclear or organellar induced male-sterility in plants, and to develop a novel approach for fertility restoration. Our work focuses on Brassicaceae, a large family of flowering plants that includes Arabidopsis thaliana, a key model organism in plant sciences, as well as many crops of major economic importance (e.g., broccoli, cauliflower, cabbage, and various seeds for oil production). In spite of the genomic rearrangements in the mtDNAs of plants, the number of genes and the coding sequences are conserved among different mtDNAs in angiosperms (i.e. ~60 genes encoding different tRNAs, rRNAs, ribosomal proteins and subunits of the respiratory system). Yet, in addition to the known genes, plant mtDNAs also harbor numerous ORFs, most of which are not conserved among species and are currently of unknown function. Remarkably, and relevant to our study, CMS in plants is primarily associated with the expression of novel chimericORFs, which likely derive from recombination events within the mtDNAs. Whereas the CMS loci are localized to the mtDNAs, the factors that restore fertility (Rfs) are identified as nuclear-encoded RNA-binding proteins. Interestingly, nearly all of the Rf’s are identified as pentatricopeptide repeat (PPR) proteins, a large family of modular RNA-binding proteins that mediate several aspects of gene expression primarily in plant organelles. In this project we proposed to develop a system to test the ability of mtORFs in plants, which are closely related to known CMS factors. We will induce male fertility in various species of Brassicaceae, and test whether a down-relation in the expression of the recombinantCMS-genes restores fertility, using synthetically designed PPR proteins.
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Sick, Thomas J. Pro-Apoptotic Changes in Brain Mitochondria After Toxic Exposure. Fort Belvoir, VA: Defense Technical Information Center, July 2001. http://dx.doi.org/10.21236/ada397717.
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