Littérature scientifique sur le sujet « CELLULE STAMINALI UMANE MIDOLLO OSSEO »

In questa seconda parte, l’attenzione viene focalizzata sulle “cellule staminali non embrionali”, cioè le cellule staminali somatiche (di origine fetale o adulta) e le cellule staminali del sangue del cordone ombelicale. Queste cellule, spesso definite “cellule staminali adulte”, sono state identificate prima delle cellule staminali embrionali. Infatti, l’espressione stessa di cellula “staminale” deriva dall’identificazione delle cellule staminali emopoietiche nel midollo osseo (1961). Più tardi le ricerche hanno evidenziato la presenza di tali cellule immature, multipotenti, che si auto-rinnovano e si auto-differenziano pressoché in tutti i tessuti ed organi del feto e dell’adulto. Appena scoperte, queste cellule staminali “adulte” hanno trovato subito un impiego terapeutico con i primi trapianti di midollo osseo per il trattamento di patologie, maligne e non, del sangue e del sistema linfoide. Oggi le cellule staminali emopoietiche sono usate anche nel trattamento di malattie auto-immuni, come la sclerosi multipla o il lupus erythematosus e nella medicina rigenerativa. Una seconda fonte importante di cellule staminali “adulte” è rappresentata dalle cellule staminali mesenchimali, situate principalmente nel midollo osseo, progenitrici di vari ceppi cellulari: osso, cartilagine, muscolo, tessuto adiposo e astrociti. Queste cellule sembrano avere un ruolo-chiave nella rigenerazione dei tessuti. Sono stati isolati diversi tipi di cellule mesenchimali multipotenti, con proprietà paragonabili a quelle delle cellule staminali embrionali. Il più noto è quello delle MAPCs di Catherine Verfaillie. Queste cellule sono usate clinicamente per vari scopi, tra cui la rigenerazione del miocardio infartuato, l’angiogenesi terapeutica in pazienti con ischemia periferica acuta (specialmente la malattia di Buerger) e il bioengineering (rivestimento cellulare di legamenti o di valvole cardiache sostitutive). In questo ambito si sono registrati risultati incoraggianti nell’animale per il trattamento delle malattie neurodegenerative, dell’ictus, del trauma cerebrale e dei danni del midollo spinale. Sono stati isolati molti altri tipi di cellule staminali “adulte” le cui proprietà riparatrici sono state verificate con successo nell’animale: cellule staminali neuronali (per il morbo di Parkinson, la sclerosi multipla, il morbo di Huntington, l’ictus, il trauma cerebrale, le lesioni del midollo spinale), cellule staminali muscolari (per l’incontinenza urinaria, il danno miocardico), cellule staminali endoteliali (per l’ischemia acuta periferica), cellule staminali cardiache, cellule staminali della retina (per la degenerazione maculare), cellule staminali del limbus della cornea (per il danno corneale). Allo stato attuale, i risultati clinici più promettenti si sono ottenuti con le cellule staminali del sangue del cordone ombelicale (UCB), che hanno portato allo sviluppo di un’area di mercato caratterizzata dalla creazione di banche private di UCB. Generalmente le cellule UCB provocano, al massimo, una reazione immune piuttosto blanda quando vengono trapiantate in soggetti con donatori non compatibili. Si usano con successo laddove sia necessaria una riparazione o rigenerazione nell’organismo del ricevente. I migliori risultati con cellule staminali UCB, fino ad ora, sono stati ottenuti nel trattamento di bambini con morbo di Krabbe. Benefici si sono ottenuti anche dal trapianto locale di cellule UCB in pazienti con danni al midollo spinale. ---------- In this second part of the article, the attention is focused on “non embryonic stem cells”, that is somatic stem cells (from fetus or adult organisms), and umbilical cord blood stem cells. These stem cells, sometimes referred to as “adult stem cells”, were known and recognized as such before the embryonic ones. In fact the mere expression “stem” cells to designate this particular type of immature cell, from which derive all the others, more differentiated cells, came from the identification of the hematopoietic stem cells, in bone marrow (1961). Later investigations have shown that there are such cells, immature, multipotent, self-renewing, and self-differentiating ones in almost all tissues and organs of fetus or adult organism. As soon as they were discovered, these “adult”, autologous stem cells were immediately put in the service of patients, with the first transplantations of bone marrow performed either for the treatment of malignancies, or for the treatment of hematologic disorders. Today, autologous hematopoietic stem cells are also used for the treatment of auto-immune diseases, such as multiple sclerosis or lupus erythematosus and for regenerative medicine. A second, important source of “adult” stem cells are the mesenchymal stem cells, found mainly in bone marrow, but also in blood, progenitors of multiple cell lineages, including bone, cartilage, muscle, adipose tissue and astrocytes, and which seem to hold the key to tissue regeneration. Different types of multipotent mesenchymal stem cells, with properties comparable to those of embryonic stem cells, have been isolated, the best known being the multipotent adult progenitor cells (MAPCs). These cells are used clinically mainly for the healing of the heart after myocardial infarction, with positive statistically significant results, for therapeutic angiogenesis in patients suffering of peripheric ischemic disease (especially Buerger’s disease), and for bioengineering (cellular coating of artificial ligaments or of prosthetic heart valves). They have given promising results in animals for the treatment of neurodegenerative diseases, ictus, brain trauma and spinal cord injuries. Many other types of “adult” stem cells have been isolated and their healing properties assessed with success in animals, such as neural stem cells (for Parkinson’s disease, multiple sclerosis, Huntington’s disease, ictus, brain trauma, spinal cord injury), muscle stem cells (for urinary incontinence, myocardial infarction), endothelial stem cells (for critical limb ischemia), cardiac stem cells, retinal stem cells (for macular degeneration), limbal stem cells (for damaged cornea). At the moment, the more promising results in patients have been obtained with umbilical cord blood stem cells (UCB), prompting the birth of a commercial trade based on private banks. Umbilical cord blood stem cells offer indeed the advantage of their immaturity: as such, they rarely trigger more than a mild immune reaction when transplanted in unrelated recipient organisms. They are used with profit wherever a healing or regenerative process is necessary in a given patient. Up to now, best results with the UCB cells have been obtained in the treatment of children with Krabbe’s disease. Some patients with injured spinal cords have also experienced benefits from UCB cells grafts.

Otto anni dopo l'inizio della ricerca sulle cellule staminali umane, sembra essere arrivato il momento di considerare oggettivamente quale possa essere il futuro di tale ricerca, e quali siano i problemi etici collegati. In questo articolo sono considerate le cellule staminali embrionali (ES) a livello tecnico e clinico. L'interesse particolare di tali cellule risiede nella loro capacità di continua proliferazione indifferenziata e di stabile sviluppo potenziale in un’ampia tipologia di cellule, anche dopo una coltura prolungata. Numerosi lavori mostrano, in particolare, che le cellule ES possono essere differenziate in neuroni e glia ed integrarsi nel tessuto neurale in animali riceventi. La differenziazione verso neuroni dopaminergici è stata ottenuta per le cellule staminali embrionali umane (hES) con promesse per il trattamento clinico della malattia di Parkinson. Le cellule ES hanno anche dimostrato la capacità di facilitare il recupero del danno del midollo spinale, nel topo. L'innesto di cellule ES in ratti con infarto miocardico provoca un miglioramento a lungo termine della funzione del cuore ed aumenta la percentuale di sopravvivenza. Tuttavia, ci sono molti ostacoli che devono essere superati prima di pensare ad un uso clinico di tali cellule. Il problema forse più complesso è di poter dirigere in modo efficiente e riproducibile la differenziazione delle cellule ES attraverso percorsi specifici. In secondo luogo, il rischio di difetti o instabilità epigenetiche nelle cellule ES è reale, tenendo conto della loro origine da embrioni ottenuti da fecondazione in vitro e del processo di coltura di tali cellule, una volta individuate. Terzo, le cellule ES allo stato indifferenziato sono cancerogeniche, il che, per un uso clinico, rende necessaria la loro differenziazione e l’attenta eliminazione di cellule ES rimaste indifferenziate. Infine, l'uso clinico delle cellule ES richiede la soluzione del problema immunologico della compatibilità HLA con il ricevente. A tale scopo sono state proposte varie soluzioni, per prima il trasferimento nucleare, detto anche “clonazione terapeutica”. Allo stato attuale essa non è applicabile ai primati ed alla specie umana. Inoltre sarebbe necessaria una quantità enorme ed irrealistica di ovociti umani. Ci si orienta oggi, anche per motivi etici, verso soluzioni "alternative" come il trasferimento nucleare modificato, nel quale si producono embrioni deficitari incapaci di svilupparsi correttamente, la partenogenesi, la raccolta di blastomeri in occasione della diagnosi preimpiantatoria, o la riprogrammazione delle cellule staminali somatiche. Ad oggi, lo studio delle cellule staminali embrionali rappresenta una promettente chiave per futuri progressi in ambito biologico (biologia dello sviluppo, biologia cellulare e biologia molecolare), nella misura in cui permette di capire meglio i processi ed i meccanismi della differenziazione e della rigenerazione dei tessuti. ---------- Eight years after the onset of the investigation on embryonic stem cells (ESCs), it seems that time has come to consider objectively what the future of such research can be, and what are the ethical issues that are involved. In this first part ESCs are considered at the technical and clinical level. The particular interest of such cells resides in their ability for endless undifferentiated proliferation and for potential development in a large array of various types of cells, even after prolonged culture. A large amount of studies show in particular that ESCs can differentiate in neurons and glia and integrate in the neural tissue of recipient animals. The promotion of such differentiation toward dopaminergic neurons has been obtained for human embryonic stem cells (hESCS), which is promising for possible future clinical application to the treatment of Parkinson's disease. The ESCs have also demonstrated their ability to facilitate the recovery of damaged spinal cord in mice. The graft of ESCs in the hearts of rats with myocardial infarction leads to an improvement of heart function and increases survival. Nevertheless, there are many obstacles that must be overcome before thinking to a clinical use of such cells. The problem perhaps more complex is to be able to direct in an efficient and reproducible way the differentiation of the ESCs in culture. Second, the risk of epigenetic defects or instability with ESCs is real, keeping in mind their origin from embryos created by in vitro fertilization, and the fact that they are kept proliferating in culture for a long period of time, once individualized. Third, ESCs in the undifferentiated state generate cancers when injected in tissues, and that makes necessary, for a clinical use, to start their differentiation in vitro and then to eliminate carefully from the end product these ESCs that are still undifferentiated. Finally, the clinical use of ESCs supposes resolved the immunological problem of their HLA compatibility with the patient who will receive them. Various solutions have been proposed for resolving this last problem, with, in first line, nuclear transfer, the so called "therapeutic cloning." Up to now this nuclear transfer has not been successful in primates and humans. Moreover, it would require the availability of unrealistically large amounts of human ovocytes. Today, also for ethical reasons, the tendency is to look after "alternative solutions" such as "altered nuclear transfer", in which are created disabled embryos, unable to develop correctly, parthenogenesis, the harvest of human blastomeres in the course of preimplantation diagnosis or the reprogramming of human somatic stem cells to an "embryonic state". At present time, the study of ESCs represents a promising key to progresses in the knowledge of cellular and molecular aspects of development, healing and tissue regeneration. These progresses may in turn lead to clinical applications, especially in the field of degenerative diseases and for the recovery of damaged tissues and organs.

Il trapianto di fegato e' il trattamento di scelta per pazienti con patologia epatica cronica, cirrotica e/o neoplastica. Il limitato numero di donatori, nonche' il rigetto e l'uso prolungato di immunosoppressori, ne limitano l'applicazione clinica. Inoltre, la possibilita' di ottenere epatociti trapiantabili e' ostacolato dal basso potenziale replicativo delle cellule epatiche, dalla loro concomitante perdita di funzionalita' in coltura e dal ridotto numero di cellule vitali e funzionali che si ottengono dopo criopreservazione. Le cellule dello stroma midollare hanno la capacita' di differenziare in epatociti. In particolare, le cellule staminali mesenchimali (BM-MSCs) possiedono self-renewal e, coltivate in vitro e sotto opportuno condizionamento, possono differenziare in osteoblasti, adipociti, condrociti, miociti, rappresentando un potenziale trapiantologico. Scopo del nostro studio e' valutare le differenze in vitro delle hBM-MSCs in epatociti ed il loro stato funzionale.
Liver transplantation is the treatment of choice for patients with chronic liver disease, cirrhosis and / or cancer. The limited number of donors and rejection prolonged use of immunosuppressants, thus limiting their clinical application. In addition, the possibility of obtaining transplantable hepatocytes is hampered by the low replicative potential of liver cells, their concomitant loss of function in culture and the reduced number of viable cells and functional are obtained after cryopreservation. The bone marrow stromal cells have the ability to differentiate into hepatocytes. In particular, mesenchymal stem cells (BM-MSCs) possess self-renewal, and cultured in vitro and under appropriate conditions, can differentiate into osteoblasts, adipocytes, chondrocytes, myocytes, representing a potential transplant. The aim of our study was to evaluate the differences of the HBM-MSCs in vitro in hepatocytes and their functional status.

"Human Bone Marrow and Adipose Tissue Mesenchimal Stem cells: isolation, differentiation and growth on polimeric scaffold" Tissue engineering has demonstrated his positive role in the repair of damaged tissues. This study investigated the properties of adult mesenchimal stem cells (MSCs) obteined from adipose tissue and bone marrow. The plastic-adherent (PA) and immunomagnetic by anti-nerve growth factor receptor antibodies (anti-NFGR) isolation tecniques were compared. In vitro MSCs diffusion and differentiation was studied for multiple lineage (chondrogenic, adipogenic, fibroblastic and osteoblastic). Adesive and proliferation cells properties were studied on commercial homologous idrossilapatite and on biomaterials polyurethane polimeric scaffold constructed and developed just for this research. Results suggested that adipose tissue may be a source of pluripotent stem cells and that NGFR+ cells are a population highly primitive and homogeneous. The polyurethane scaffolds aren' t citotossic and permit the diffusion and proliferation of MSCs

2017 - 2018
Introduction; Mesenchymal stem cells (Mesenchymal Stem Cells, MSC) are one of the most studied and well-characterized adult stem cell populations. They are excellent candidates in regenerative medicine, mainly because of their immunomodulatory properties and their emerging role in intercellular communication. MSCs as cellular components of bone marrow hematopoietic niche play a fundamental role in maintaining the physiological balance of the niche and in promoting and regulating hematopoietic stem cell (HSCs) functions, such as proliferation and "homing" to the bone marrow. - Methods: In this work, we focused on the possible internalization and release of Ruxolitinib (a JAK1/2 inhibitor by NOVARTIS Pharma) by MSC. In details, primary human MSC were isolated from bone marrow (BMMSC) of five patients diagnosed with Idiopathic Myelofibrosis or Polycythemia Vera. Diagnosis was confirmed by histopathology and molecular biology for the detection of mutations in Janus Kinase 2 receptor encoding gene, specifically for JAK2 V617F mutation. Subsequently, we evaluated the in vitro anti-proliferative effect of culture medium conditioned with Ruxolitinib on immortalized JAK2+ CD34+ SET-2 cells. Finally, a co-culture system of BMMSC and SET-2 cells treated or not with Ruxolitinib in different ratios (1:20, 1: 100 and 1: 1000) was used for estimating the relative anti-proliferative action on SET-2 cell line. - Results: Our preliminary results showed that MSCs could uptake and release Ruxolitinib in culture medium, and conditioned culture medium had more anti-proliferative effects on SET-2 cells compared to the drug alone added to the medium. In an in vitro co-culture system, the proliferation of SET-2 cells decreased by increasing MSC ratio treated with Ruxolitinib / SET-2, and BMMSC treated with Ruxolitinib had a greater anti-proliferative action on SET-2 cells compared to untreated BMMSCs. - Conclusions: Mesenchymal bone marrow stem cells could uptake and release Ruxolitinib that might increase the anti-proliferative effect of the drug on SET-2 cell line carrying the JAK2 V617F mutation. These mechanisms may contribute to amplify over time the pharmacological effects of Ruxolitinib in the bone marrow niche of Idiopathic Myelofibrosis and Polycythemia Vera patients. [edited by Author]
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“Colture in vitro di cellule staminali mesenchimali umane da tessuto adiposo e da midollo osseo: Allestimento, Caratterizzazione ed Effetti di Sr2+ sulla proliferazione e differenziazione osteogenica". “ "In vitro Coltures of Human Adipose Tissue-Derived and Bone Marrow-Derived Mesenchymal Stem Cells: Preparation, Characterization and Effects of Sr2+ on Cell Proliferation and Osteoinduction".