Статті в журналах з теми "Skin-to-brain signalling"

T The P.N.E.I. (Psycho-Neuro-Endocrine-Immunology) approach is represented by the interdisciplinary concept of bidirectional cross-talk between the psycho-neuro-endocrine and immune systems, which can influence the immune response. The well-known Gut-Brain Axis and the Gut-Skin Axis can be merged in a bigger network- the Gut-Brain-Skin Axis, with complex regulation by cytokines, neuro-peptides, neuro-hormones and another messenger (signalling) molecules and maybe the most important modulator of the Gut-Brain-Skin Axis/ the gut microbiota. The role of gut bacterial homeostasis is very important, and the homeostatic imbalance of the immune response may be a relevant etiologic/pathophysiologic factor for extra-intestinal and intestinal inflammatory, allergic and autoimmune diseases. The Low Dose Cytokines Medicine (LDM) is an innovative therapeutic approach. It is based on the most advanced knowledge in molecular biology and low dose pharmacology with the primary outcome. The SKA (Sequential Kinetic Activation) technology, codified and standardised by GUNA S.p.a. -Italy- makes the low doses of signalling molecules able to be active even below the minimum dose classically considered as effective and the significative efficacy of orally administered low-dose signalling molecules is the most representative aspect of LDM. The Physiologic Nutraceuticals and the Low Dose Medicine are two of the most promising approaches for the treatment of skin diseases based on the rebalance of the immune response and the recovery of gut dysbiosis.

Hereditary haemorrhagic telangiectasia (HHT) is characterised by arteriovenous malformations (AVMs). These vascular abnormalities form when arteries and veins directly connect, bypassing the local capillary system. Large AVMs may occur in the lungs, liver and brain, increasing the risk of morbidity and mortality. Smaller AVMs, known as telangiectases, are prevalent on the skin and mucosal lining of the nose, mouth and gastrointestinal tract and are prone to haemorrhage. HHT is primarily associated with a reduction in endoglin (ENG) or ACVRL1 activity due to loss-of-function mutations. ENG and ACVRL1 transmembrane receptors are expressed on endothelial cells (ECs) and bind to circulating ligands BMP9 and BMP10 with high affinity. Ligand binding to the receptor complex leads to activation of the SMAD1/5/8 signalling pathway to regulate downstream gene expression. Various genetic animal models demonstrate that disruption of this pathway in ECs results in AVMs. The vascular abnormalities underlying AVM formation result from abnormal EC responses to angiogenic and haemodynamic cues, and include increased proliferation, reduced migration against the direction of blood flow and an increased EC footprint. There is growing evidence that targeting VEGF signalling has beneficial outcomes in HHT patients and in animal models of this disease. The anti-VEGF inhibitor bevacizumab reduces epistaxis and has a normalising effect on high cardiac output in HHT patients with hepatic AVMs. Blocking VEGF signalling also reduces vascular malformations in mouse models of HHT1 and HHT2. However, VEGF signalling is complex and drives numerous downstream pathways, and it is not yet clear which pathway (or combination of pathways) is critical to target. This review will consider the recent evidence gained from HHT clinical and preclinical studies that are increasing our understanding of HHT pathobiology and informing therapeutic strategies.

Mammalian Na+/Ca2+ exchangers are members of three branches of a much larger family of transport proteins [the CaCA (Ca2+/cation antiporter) superfamily] whose main role is to provide control of Ca2+ flux across the plasma membranes or intracellular compartments. Since cytosolic levels of Ca2+ are much lower than those found extracellularly or in sequestered stores, the major function of Na+/Ca2+ exchangers is to extrude Ca2+ from the cytoplasm. The exchangers are, however, fully reversible and thus, under special conditions of subcellular localization and compartmentalized ion gradients, Na+/Ca2+ exchangers may allow Ca2+ entry and may play more specialized roles in Ca2+ movement between compartments. The NCX (Na+/Ca2+ exchanger) [SLC (solute carrier) 8] branch of Na+/Ca2+ exchangers comprises three members: NCX1 has been most extensively studied, and is broadly expressed with particular abundance in heart, brain and kidney, NCX2 is expressed in brain, and NCX3 is expressed in brain and skeletal muscle. The NCX proteins subserve a variety of roles, depending upon the site of expression. These include cardiac excitation–contraction coupling, neuronal signalling and Ca2+ reabsorption in the kidney. The NCKX (Na2+/Ca2+–K+ exchanger) (SLC24) branch of Na+/Ca2+ exchangers transport K+ and Ca2+ in exchange for Na+, and comprises five members: NCKX1 is expressed in retinal rod photoreceptors, NCKX2 is expressed in cone photoreceptors and in neurons throughout the brain, NCKX3 and NCKX4 are abundant in brain, but have a broader tissue distribution, and NCKX5 is expressed in skin, retinal epithelium and brain. The NCKX proteins probably play a particularly prominent role in regulating Ca2+ flux in environments which experience wide and frequent fluctuations in Na+ concentration. Until recently, the range of functions that NCKX proteins play was generally underappreciated. This situation is now changing rapidly as evidence emerges for roles including photoreceptor adaptation, synaptic plasticity and skin pigmentation. The CCX (Ca2+/cation exchanger) branch has only one mammalian member, NCKX6 or NCLX (Na+/Ca2+–Li+ exchanger), whose physiological function remains unclear, despite a broad pattern of expression.

The mineralocorticoid receptor (MR) mediates the actions of two important adrenal corticosteroid hormones, aldosterone and cortisol. The cell signalling roles of the MR in vivo have expanded enormously since the cloning of human MR gene 30 years ago and the first MR gene knockout in mice nearly 20 years ago. Complete ablation of the MR revealed important roles postnatally for regulation of kidney epithelial functions, with MR-null mice dying 1–2 weeks postnatally from renal salt wasting and hyperkalaemia, with elevated plasma renin and aldosterone. Generation of tissue-selective MR-deficient mice using Cre recombinase-LoxP gene targeting has made it possible to analyse mice lacking MR only in specific cell types. Targeting renal-specific MR has differentiated roles in specific compartments of the kidney. Ablating MR in neurons of the forebrain reinforced important roles of the MR in response to stress, behaviour and anxiety, but suggested a minimal role in maintaining basal HPA axis tone. Deletion of the MR in macrophages and other cell types of the cardiovascular system clearly defined important roles for the regulation of cardiovascular physiology and pathophysiology. Knockdown of MR mRNA in vivo using antisense/siRNA approaches, and similarly MR overexpression, has provided useful rodent models to study physiological roles of MR signalling in vivo. More recently, targeted mutation of specific domains of the MR such as the DBD has defined genomic vs non-genomic roles in vivo. New tissue-selective MR-null models are required to define roles of MR signalling in other regions of the brain, the eye, gastrointestinal tract, lung, skin, breast and gonadal organs.

We identified a thyroid hormone [3,5,3′-tri-iodothyronine (T3)]-responsive gene, ZAKI-4, in cultured human skin fibroblasts. It belongs to a family of genes that encode proteins containing a conserved motif. The motif binds to calcineurin and inhibits its phosphatase activity. In the present study, we have demonstrated three different ZAKI-4 transcripts, α, β1 and β2, in human brain by 5′- and 3′-RACE (rapid amplification of cDNA ends). The α transcript was identical with the one that we originally cloned from human fibroblasts and the other two are novel. The three transcripts are generated by alternative initiation and splicing from a single gene on the short arm of chromosome 6. It is predicted that β1 and β2 encode an identical protein product, β, which differs from α in its N-terminus. Since α and β contain an identical C-terminal region harbouring the conserved motif, both isoforms are suggested to inhibit calcineurin activity. Indeed, each isoform associates with calcineurin A and inhibits its activity in a similar manner, suggesting that the difference in N-terminus of each isoform does not affect the inhibitory function on calcineurin. An examination of the expression profile of the three transcripts in 12 human tissues revealed that the α transcript is expressed exclusively in the brain, whereas β transcripts are expressed ubiquitously, most abundantly in brain, heart, skeletal muscle and kidney. It was also demonstrated that human skin fibroblasts express both α and β transcripts, raising the question of which transcript is up-regulated by T3. It was revealed that T3 markedly induced the expression of α isoform but not of β. This T3-mediated increase in the α isoform was associated with a significant decrease in endogenous calcineurin activity. These results suggest that the expression of ZAKI-4 isoforms is subjected to distinct hormonal as well as tissue-specific regulation, constituting a complex signalling network through inhibition of calcineurin.

Abstract Background: Oncogenic variants of GNAQ and GNA11 arising in embryonic or fetal development lead to a spectrum of congenital mosaic disorders including Sturge-Weber syndrome (SWS) and Phakomatosis Pigmentovascularis (PPV). Both SWS and PPV are characterised by vascular malformations in brain, skin and eye, with worsening neurological sequelae after birth suggesting a potential treatment window. Although the genetic causes are understood, and previous data in non-disease-specific cell lines have suggested MAPK activation, the functional effects of the mutations in vascular endothelium have not been studied. The characteristic finding of intracerebral intravascular calcification led us to hypothesise that intra-cellular calcium-signalling disturbances leading to localised imbalances in calcium homeostasis may be involved in disease pathogenesis. Methods: Stable cell lines were established to study cell signalling downstream of GNAQ c.548G>A, p.(R183Q) or GNA11 c.547C>T, p.(R183C) variants in endothelial cells. We re-expressed mutant GNAQ or GNA11 alleles in HEK293 cells in which both endogenous genes had been knocked out for validation purposes. Constitutive calcium signaling was evaluated by measuring inositol-monophosphate accumulation and by a NFAT-luciferase reporter assay, while ligand-stimulated calcium signaling was monitored over time following incubation with intra-cellular calcium probe Fluo-8. In a parallel complementary study, serum calcium and related indices were assayed in 35 patients with SWS or PPV, consented for research under appropriate approvals. Results: GNAQ and GNA11 variants led to marked constitutive calcium signalling in vascular endothelial cells, but not to MAPK activation. GNAQ-mutant endothelial cells also showed aberrant calcium signalling responses to GPCR ligand, which led in turn to sustained replenishment of intracellular calcium stores from the extracellular space. These calcium signalling defects could be rescued by a specific calcium channel inhibitor. Strikingly, and previously undescribed in these diseases, 43% of patients were found to have hypocalcaemia, and 20% hyperparathyroidism, currently presumed secondary but under further investigation. Conclusions: GNAQ mosaicism leads to constitutive and ligand-induced over-activation of intracellular calcium signalling, which increases influx of calcium from the extracellular to the intracellular space and could be the explanation for systemic hypocalcaemia in a substantial proportion of patients. These data have immediate implications for clinical management of these mosaic diseases, and shed light on the in vivo pathogenic actions of of GNAQ/GNA11 oncogenic variants. Citation Format: Davide Zecchin, Nicole Knoepfel, Anna Gluck, Mark Stevenson, Kate E. Lines, Satyamaanasa Polubothu, Noreen Muwanga-Nanyonjo, Sara Barberan-Martin, Fanourios Michailidis, Dale Bryant, Ulrike Loebel, Asuka Inoue, Robert Semple, Sarah Aylett, Rajesh V. Thakker, Veronica A. Kinsler. Functional dissection of GNAQ and GNA11 oncogenic mutations identifies potential targeted therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 851.

SummaryAs the major entry receptor, signalling lymphocytic activation molecule (SLAM, CD150) essentially determines the tropism of measles virus (MV) for immune cells. This receptor is of considerable importance for the induction of immunomodulation and -suppression, and for the systemic spread of MV to organs including secondary lymphoid tissues, the skin, the respiratory tract, and the brain predominantly via infected cells of the immune system. But how does the virus cross the epithelial barrier during initiation of the infection, the blood organ barriers formed by endothelial cells, and the epithelial barrier from within, when virus will be released from the host? Additional unknown receptor(s) on CD150-negative epithelial and endothelial cells have been postulated. However, it has also been postulated (and demonstrated in macaques) that the initial infection is independent from usage of this receptor, and that the first target cells appear to be CD150-positive cells in the epithelium. For later stages of the infection, for virus release from the host, it is claimed that this unknown receptor on epithelial cells is required for crossing the barrier from within. The endothelial cell barrier must be crossed from the apical (luminal) to the basolateral (abluminal) side to carry the infection to organs and the skin. However, infected leukocytes are impaired in several functions including transmigration through endothelial cells. The infection may spread via cell contact-mediated infection of endothelial cells and basolateral virus release, or via migration of infected leukocytes.

RasGRPs (guanine nucleotide releasing proteins) are a family of four GEFs (guanine nucleotide-exchange factors) (Ras GEFs) that positively regulate Ras and related small GTPases. RasGRP1 possesses a catalytic region consisting of a REM (Ras exchange motif) and a CDC25 (cell division cycle 25) domain. RasGRP1 also possesses a DAG (diacylglycerol)-binding C1 domain and a pair of EF hands that bind calcium. RasGRP1 is selectively expressed in lymphocytes as well as in some cells of the brain, kidney and skin. Functional analysis supports the hypothesis that RasGRP1 serves to couple TCR (T-cell receptor) stimulation and phospholipase C activation with Ras signalling. In B-cells, both RasGRP1 and RasGRP3 play a similar role downstream of the B-cell receptor. RasGRP2 acts on the Ras-related protein Rap and functions in platelet adhesion. RasGRP4 is expressed in mast cells and certain myeloid leukaemia cells. Membrane DAG regulates RasGRPs directly by recruitment to cellular membranes, as well as indirectly by protein kinase C-mediated phosphorylation. The properties of RasGRPs provide a novel view of Ras regulation in lymphocytes and explain several earlier observations. Many experimental results obtained with DAG analogues could be reviewed in light of these findings.

Despite a considerable amount of data, the molecular and cellular bases of the toxicity due to metal exposure remain unknown. Recent mechanistic models from radiobiology have emerged, pointing out that the radiation-induced nucleo-shuttling of the ATM protein (RIANS) initiates the recognition and the repair of DNA double-strand breaks (DSB) and the final response to genotoxic stress. In order to document the role of ATM-dependent DSB repair and signalling after metal exposure, we applied twelve different metal species representing nine elements (Al, Cu, Zn Ni, Pd, Cd, Pb, Cr, and Fe) to human skin, mammary, and brain cells. Our findings suggest that metals may directly or indirectly induce DSB at a rate that depends on the metal properties and concentration, and tissue type. At specific metal concentration ranges, the nucleo-shuttling of ATM can be delayed which impairs DSB recognition and repair and contributes to toxicity and carcinogenicity. Interestingly, as observed after low doses of ionizing radiation, some phenomena equivalent to the biological response observed at high metal concentrations may occur at lower concentrations. A general mechanistic model of the biological response to metal exposure based on the nucleo-shuttling of ATM is proposed to describe the metal-induced stress response and to define quantitative endpoints for toxicity and carcinogenicity.

Abstract Frontotemporal dementia and amyotrophic lateral sclerosis are clinically and pathologically overlapping disorders with shared genetic causes. We previously identified a disease locus on chromosome 16p12.1-q12.2 with genome-wide significant linkage in a large European Australian family with autosomal dominant inheritance of frontotemporal dementia and amyotrophic lateral sclerosis and no mutation in known amyotrophic lateral sclerosis or dementia genes. Here we demonstrate the segregation of a novel missense variant in CYLD (c.2155A>G, p.M719V) within the linkage region as the genetic cause of disease in this family. Immunohistochemical analysis of brain tissue from two CYLD p.M719V mutation carriers showed widespread glial CYLD immunoreactivity. Primary mouse neurons transfected with CYLDM719V exhibited increased cytoplasmic localization of TDP-43 and shortened axons. CYLD encodes a lysine 63 deubiquitinase and CYLD cutaneous syndrome, a skin tumour disorder, is caused by mutations that lead to reduced deubiquitinase activity. In contrast with CYLD cutaneous syndrome-causative mutations, CYLDM719V exhibited significantly increased lysine 63 deubiquitinase activity relative to the wild-type enzyme (paired Wilcoxon signed-rank test P = 0.005). Overexpression of CYLDM719V in HEK293 cells led to more potent inhibition of the cell signalling molecule NF-κB and impairment of autophagosome fusion to lysosomes, a key process in autophagy. Although CYLD mutations appear to be rare, CYLD’s interaction with at least three other proteins encoded by frontotemporal dementia and/or amyotrophic lateral sclerosis genes (TBK1, OPTN and SQSTM1) suggests that it may play a central role in the pathogenesis of these disorders. Mutations in several frontotemporal dementia and amyotrophic lateral sclerosis genes, including TBK1, OPTN and SQSTM1, result in a loss of autophagy function. We show here that increased CYLD activity also reduces autophagy function, highlighting the importance of autophagy regulation in the pathogenesis of frontotemporal dementia and amyotrophic lateral sclerosis.

Oestrogens are well-known proliferation and differentiation factors that play an essential role in the correct development of sex-related organs and behaviour in mammals. With the use of the ERE-Luc reporter mouse model, we show herein that throughout mouse development, oestrogen receptors (ERs) are active starting from day 12 post conception. Most interestingly, we show that prenatal luciferase expression in each organ is proportionally different in relation to the germ layer of the origin. The luciferase content is highest in ectoderm-derived organs (such as brain and skin) and is lowest in endoderm-derived organs (such as liver, lung, thymus and intestine). Consistent with the testosterone surge occurring in male mice at the end of pregnancy, in the first 2 days after birth, we observed a significant increase in the luciferase content in several organs, including the liver, bone, gonads and hindbrain. The results of the present study show a widespread transcriptional activity of ERs in developing embryos, pointing to the potential contribution of these receptors in the development of non-reproductive as well as reproductive organs. Consequently, the findings reported here might be relevant in explaining the significant differences in male and female physiopathology reported by a growing number of studies and may underline the necessity for more systematic analyses aimed at the identification of the prenatal effects of drugs interfering with ER signalling, such as aromatase inhibitors or endocrine disrupter chemicals.

The development of calvarial bones is tightly co-ordinated with the growth of the brain and needs harmonious interactions between different tissues within the calvarial sutures. Premature fusion of cranial sutures, known as craniosynostosis, presumably involves disturbance of these interactions. Mutations in the homeobox gene Msx2 as well as the FGF receptors cause human craniosynostosis syndromes. Our histological analysis of mouse calvarial development demonstrated morphological differences in the sagittal suture between embryonic and postnatal stages. In vitro culture of mouse calvaria showed that embryonic, but not postnatal, dura mater regulated suture patency. We next analysed by in situ hybridisation the expression of several genes, which are known to act in conserved signalling pathways, in the sagittal suture during embryonic (E15-E18) and postnatal stages (P1-P6). Msx1 and Msx2 were expressed in the sutural mesenchyme and the dura mater. FGFR2(BEK), as well as Bmp2 and Bmp4, were intensely expressed in the osteogenic fronts and Bmp4 also in the mesenchyme of the sagittal suture and in the dura mater. Fgf9 was expressed throughout the calvarial mesenchyme, the dura mater, the developing bones and the overlying skin, but Fgf4 was not detected in these tissues. Interestingly, Shh and Ptc started to be expressed in patched pattern along the osteogenic fronts at the end of embryonic development and, at this time, the expression of Bmp4 and sequentially those of Msx2 and Bmp2 were reduced, and they also acquired patched expression patterns. The expression of Msx2 in the dura mater disappeared after birth. <P> FGF and BMP signalling pathways were further examined in vitro, in E15 mouse calvarial explants. Interestingly, beads soaked in FGF4 accelerated sutural closure when placed on the osteogenic fronts, but had no such effect when placed on the mid-sutural mesenchyme. BMP4 beads caused an increase in tissue volume both when placed on the osteogenic fronts and on the mid-sutural area, but did not effect suture closure. BMP4 induced the expression of both Msx1 and Msx2 genes in sutural tissue, while FGF4 induced only Msx1. We suggest that the local application of FGF on the osteogenic fronts accelerating suture closure in vitro, mimics the pathogenesis of human craniosynostosis syndromes in which mutations in the FGF receptor genes apparently cause constitutive activation of the receptors. Taken together, our data suggest that conserved signalling pathways regulate tissue interactions during suture morphogenesis and intramembranous bone formation of the calvaria and that morphogenesis of mouse sagittal suture is controlled by different molecular mechanisms during the embryonic and postnatal stages. Signals from the dura mater may regulate the maintenance of sutural patency prenatally, whereas signals in the osteogenic fronts dominate after birth.

Abstract We only have a rudimentary understanding of the molecular and cellular determinants of nerve regeneration and neuropathic pain in humans. This cohort study uses the most common entrapment neuropathy (carpal tunnel syndrome) as a human model system to prospectively evaluate the cellular and molecular correlates of neural regeneration and its relationship with clinical recovery. In 60 patients undergoing carpal tunnel surgery [36 female, mean age 62.5 (standard deviation 12.2) years], we used quantitative sensory testing and nerve conduction studies to evaluate the function of large and small fibres before and 6 months after surgery. Clinical recovery was assessed with the global rating of change scale and Boston Carpal Tunnel Questionnaire. Twenty healthy participants provided normative data [14 female, mean age 58.0 (standard deviation 12.9) years]. At 6 months post-surgery, we noted significant recovery of median nerve neurophysiological parameters (P < 0.0001) and improvements in quantitative sensory testing measures of both small and large nerve fibre function (P < 0.002). Serial biopsies revealed a partial recovery of intraepidermal nerve fibre density [fibres/mm epidermis pre: 4.20 (2.83), post: 5.35 (3.34), P = 0.001], whose extent correlated with symptom improvement (r = 0.389, P = 0.001). In myelinated afferents, nodal length increased postoperatively [pre: 2.03 (0.82), post: 3.03 (1.23), P < 0.0001] suggesting that this is an adaptive phenomenon. Transcriptional profiling of the skin revealed 31 differentially expressed genes following decompression, with ADCYAP1 (encoding pituitary adenylate cyclase activating peptide, PACAP) being the most strongly upregulated (log2 fold-change 1.87, P = 0.0001) and its expression was associated with recovery of intraepidermal nerve fibres. We found that human induced pluripotent stem cell-derived sensory neurons expressed the receptor for PACAP and that this peptide could significantly enhance axon outgrowth in a dose-dependent manner in vitro [neurite length PACAP 1065.0 µm (285.5), vehicle 570.9 μm (181.8), P = 0.003]. In conclusion, carpal tunnel release is associated with significant cutaneous reinnervation, which correlates with the degree of functional improvement and is associated with a transcriptional programme relating to morphogenesis and inflammatory processes. The most highly dysregulated gene ADCYAP1 (encoding PACAP) was associated with reinnervation and, given that this peptide signals through G-protein coupled receptors, this signalling pathway provides an interesting therapeutic target for human sensory nerve regeneration.

ASSESSMENT OF PARALLEL SIGNALING PATHWAYS IN UTERINE MYOCYTES STIMULATED WITH VARIOUS SMOOTH MUSCLE AGONISTS H.N. Aguilar, B.F. Mitchell 1 TRACTOGRAPHY: A NOVEL TECHNIQUE TO IMAGE FIBER TRACTS OF THE SPINAL CORD Fahad Alkherayf, Eve Tsai, Arturo Cardenas-Blanco, Alain Berthiaume, Brien Benoit, John Sinclair 1 MODULATION OF OSTEOCLASTOGENESIS IN INFLAMMATORY JOINT DISEASES H. Allard-Chamard, M. Durant, A.J. de Brum-Fernandes, G. Boire, S.V. Komarova, S.J. Dixon, S.M. Sims, R. Harison, M.F. Manolson 2 “THE RIGHT THING TO DO? A CRITICAL ANALYSIS OF PUBLIC HEALTH ETHICS, RIGHTS DISCOURSE, AND THE EXPANSION OF ANTIRETROVIRAL THERAPY (ART)” Berkhout, SG, Anderson, S, Tyndall, MW 2 COST-EFFECTIVENESS OF IMMEDIATE BASELINE COMPUTED TOMOGRAPHY VS. MAGNETIC RESONANCE IMAGING OF ACUTE ISCHEMIC STROKE IN ONTARIO PATIENTS WHO PRESENT WITH SYMPTOMS SUGGESTIVE OF STROKE KR Burton, G. Mery 3 CHITOSAN-MEDIATED FGF18 DELIVERY FOR ASSISTED BONE REPAIR A. Carli, M. Lavertu, C. Gao, A. Merzouki, M.D. Buschmann, J.E. Henderson, E.J.Harvey 3 ACTIVE PI3K-AKT SIGNALING PROMOTES THE METASTATIC POTENTIAL OF ASCITES-DERIVED EPITHELIAL OVARIAN CANCER CELLS Correa RJM, Ramos-Valdes Y, Bertrand M, Lanvin D, Préfontaine M, Sugimoto AK, Lewis JD, Shepherd TG, DiMattia GE 4 MECHANISMS OF K65R, D67N, K103N, V106M AND M184V RESISTANCE DEVELOPMENT IN SUBTYPE-B AND C HIV-1 Dimitrios Coutsinos, Cedric F. Invernizzi, Daniela Moisi, Maureen Oliveira, Hongtao Xu, Bluma G. Brenner, Mark A. Wainberg 4 A MODEL TO DETERMINE FACTORS INVOLVED IN THE INDUCTION OF AN IN VIVO CTL RESPONSE Dissanayake D, Ohashi PS 5 P63 ANTAGONIZES P53 TO PROMOTE THE SURVIVAL OF EMBRYONIC NEURAL PRECURSOR CELLS Sagar B. Dugani, Annie Paquin, Masashi Fujitani, David R. Kaplan, Freda D. Miller 5 SPINAL LOCOMOTOR NETWORK MODULATION BY ENDOGENOUS SEROTONIN IN THE ISOLATED NEONATAL MOUSE SPINAL CORD Dunbar MJ, Whelan PJ 6 THE TUMOR PROMOTING AND REPRESSING EFFECTS OF INTEGRIN-LINKED KINASE ARE DIFFERENTIATED BY JNK1 IN HUMAN CANCER CELLS Adam David Durbin, Gregory Edward Hannigan, David Malkin 6 INCREASED EXCITATION IN MICE OVER-EXPRESSING NEUROLIGIN-1 IS ASSOCIATED WITH IMPAIRED LONG-TERM POTENTIATION AND LEARNING AND MEMORY Brennan D Eadie, Timal Kannangara, Regina Dalhaus, Rochelle M Hines, Yu-Tian Wang, Alaa El-Husseini, Brian R Christie 7 A NOVEL ROLE FOR CDK5/P35 IN MEDULLOBLASTOMA FORMATION Friesen AN, Shin J, Law V, Lee YS, Mckinnon P, Lee KY 7 ALTERED PSYCHOSOCIAL BEHAVIOUR AND STRESS RESPONSE FOLLOWING ‘MINOR’ STROKE IN THE RAT Krista Hewlett, Meighan Kelly, Dale Corbett 8 TUMOUR PATHOLOGY PREDICTS MICROSATELLITE INSTABILITY IN COLORECTAL CANCER AJ Hyde, D Fontaine, S Stuckless, RC Green, A Pollett, M Simms, P Parfrey, HB Younghusband 8 PROTEINASE-ACTIVATED RECEPTOR-2 (PAR2) IS A POTENTIAL TARGET FOR THE ANTI-INFLAMMATORY EFFECTS OF INSULIN Eric Hyun, Rithwick Ramachandran, Nicolas Cenac, Steeve Houle, Amit Saxena, Roland S. Liblau, Morley Hollenberg, Nathalie Vergnolle 9 CHEMOSENSITIVE PROPERTIES OF THE VENTRAL MEDULLA IN VITRO Kalf Daniel J, Wilson Richard JA 9 NOVEL DOPAMINE RECEPTOR-N TYPE CALCIUM CHANNEL INTERACTIONS: POTENTIAL THERAPEUTIC TARGETS FOR DISORDERS ASSOCIATED WITH ABERRANT DOPAMINERGIC SIGNALLING Alexandra E. Kisilevsky, Sean J. Mulligan, Christophe Altier, Mircea C. Iftinca, Diego Varela, Chao Tai, Lina Chen, Shahid Hameed, Jawed Hamid, Brian A. MacVicar, Gerald W. Zamponi 10 TRUNCATION OF THE C-TERMINAL DOMAIN OF CONNEXIN43 INCREASES INFARCT VOLUME DURING STROKE Kozoriz MG, Bechberger JF, Bechberger GR, Suen MWH, Moreno AP, Maass K, Willecke K, Naus CC 10 EVALUATION OF THE DELIVERABILITY AND TOLERABILITY OF INTENSIVE WEEKLY DOUBLET ADJUVANT CHEMOTHERAPY IN NON SMALL CELL LUNG CANCER M. Sara Kuruvilla, Lorraine Martelli-Reid, J. R. Goffin, A. Arnold, Peter M. Ellis 11 A POLICY-ORIENTED SYSTEMATIC REVIEW OF THE SAFETY AND EFFICACY OF ENDOSCOPIC THERAPIES FOR THE TREATMENT OF BARRETT’S ESOPHAGUS Lau D, Menon D, Stafinski T, Topfer LA, Walker J 11 THE SRC-LIKE ADAPTOR PROTEIN, SLAP, PLAYS A ROLE IN MONOCYTE-DERIVED DENDRITIC CELL MATURATION Larissa Liontos, L Dragone, A Weiss, C J McGlade 12 SWEET PEE: A NEW MOUSE MODEL FOR GLOMERULOCYSTIC KIDNEY DISEASE AND GLUCOSURIA J Ly, J Rossant, L Oxborne, C McKerlie, A Flenniken, S Quaggin 12 CARDIOGENIC SHOCK IN ASPHYXIATED NEONATE PIGLETS: IS COMBINATION INOTROPE THERAPY BETTER THAN HIGH-DOSE DOPAMINE? N. Manouchehri, P.-Y. Cheung, C. Joynt, T. Churchill, D. Bigam 13 THE RELATIONSHIP BETWEEN FLOW-MEDIATED DILATION, HYPEREMIC SHEAR STRESS, AND VARIOUS ANTHROPOMETRIC INDICES OF OBESITY Martin BJ, Title LM, Verma S, Charbonneau F, Buithieu J, Lonn EM, Anderson TJ 13 RAPID LOCALIZATION OF NEUTROPHILS TO SITES OF CELL DEATH BY MAC1-DEPENDENT ADHESION AND INTRAVASCULAR CRAWLING McDonald B, Menezes GB, Kubes P 14 THE ROLE OF SHIP-1 IN CEACAM1-MEDIATED HOST RESPONSES TO NEISSERIA GONORRHOEAE INFECTION Gordon G McSheffrey, S D Gray-Owen 14 USING VOLTAGE-SENSITIVE DYES TO RECORD BRAIN ACTIVITY IN NATURALLY MOVING MICE McVea DA, Mohajerani MH, Fingas M, Murphy TH 15 POTENTIAL MECHANICAL INFLUENCE IN MICROVASCULAR PATHOLOGY IN THE ACL DEFICIENT RABBIT KNEE Daniel Miller 15 OSTEOBLAST MECHANOSENSITIVITY: THE ROLE OF HYDROSTATIC PRESSURE Kenneth A. Myers, Timothy Douglas, Ricarda Hess, Justin Parreno, Jerome B. Rattner, Dieter Scharnweber, Nigel G. Shrive, David A. Hart 16 ENDOTHELIAL PROGENITOR CELLS FOR HEALING AND ANGIOGENESIS IN A SEGMENTAL BONE DEFECT MODEL: A COMPARISON WITH MESENCHYMAL STEM CELLS Nauth A, Li R, Schemitsch EH 16 DELAY OF DNA METHYLATION IN PERINATAL MALE GERM CELLS IN THE ABSENCE OF DNMT3L RESULTING IN INFERTILITY Kirsten Niles, Sophie La Salle, Christopher Oakes, Jacquetta Trasler 17 INVESTIGATING CRMP4 FUNCTION IN CNS NERVE REGENERATION S. Ong Tone, S. Kanagal, A. Wilson, Y.Z. Alabed, A. Di Polo, A.E. Fournier 17 A NOVEL, DNA DAMAGE-DEPENDENT REGULATORY PATHWAY FOR AKT IN VIVO Andrew J. Perrin, W. Brent Derry 18 CHOP AS A TARGET FOR PRESERVATION OF TRANSPLANTED ISLET GRAFT MASS Potter K, Dai L, Verchere CB 18 TREATMENT OF ACHILLES TENDINOPATHY R Ram, C Patel, D Wiseman, W Meeuwisse, JP Wiley 19 PLACENTAL LACTOGEN FUNCTION IN POST-IMPLANTATION MURINE PREGNANCY Saara M. Rawn, James C. Cross 19 DECODING NEURAL SIGNALS FROM MULTIELECTRODE ARRAYS IN THE PRIMATE DORSOLATERAL PREFRONTAL CORTEX Sachs A.J, Pieper F, Martinez-Trujillo J.C. 20 THE ROLE OF TRANSFORMING GROWTH FACTOR ALPHA IN A MOUSE MODEL OF OSTEOARTHRITIS Usmani S.E, Appleton C.T.G., Welch I.D, Beier F. 20 SKIN-DERIVED STEM CELLS ACT AS FUNCTIONAL SCHWANN CELLS WHEN TRANSPLANTED INTO LESIONED PERIPHERAL NERVE Sarah K. Walsh, Rajiv Midha 21 TLR4 MEDIATES SUSCEPTIBILITY TO STREPTOZOTOCIN-INDUCED DIABETES C Westwell-Roper, G Soukhatcheva, MJH Hutton, JP Dutz, CB Verchere 21 A FUSION OF GMCSF AND IL-21 (GIFT-21) POTENTLY INDUCES INFLAMMATION AND APOPTOSIS THROUGH SIGNALS DOWNSTREAM OF THE IL-21R ALPHA CHAIN Patrick Williams, Shala Yuan, Jessica Cuerquis, Elena Birman, Kathy Ann Forner, Jacques Galipeau 22

Abstract Sturge–Weber syndrome (SWS) is a neurocutaneous disorder characterized by vascular malformations affecting skin, eyes and leptomeninges of the brain, which can lead to glaucoma, seizures and intellectual disability. The discovery of a disease-causing somatic missense mutation in the GNAQ gene, encoding an alpha chain of heterotrimeric G-proteins, has initiated efforts to understand how G-proteins contribute to SWS pathogenesis. The mutation is predominantly detected in endothelial cells and is currently believed to affect downstream MAPK signalling. In this study of six Norwegian patients with classical SWS, we aimed to identify somatic mutations through deep sequencing of DNA from skin biopsies. Surprisingly, one patient was negative for the GNAQ mutation, but instead harbored a somatic mutation in GNB2 (NM_005273.3:c.232A>G, p.Lys78Glu), which encodes a beta chain of the same G-protein complex. The positions of the mutant amino acids in the G-protein are essential for complex reassembly. Therefore, failure of reassembly and continuous signalling is a likely consequence of both mutations. Ectopic expression of mutant proteins in endothelial cells revealed that expression of either mutant reduced cellular proliferation, yet regulated MAPK signalling differently, suggesting that dysregulated MAPK signalling cannot fully explain the SWS phenotype. Instead, both mutants reduced synthesis of Yes-associated protein (YAP), a transcriptional co-activator of the Hippo signalling pathway, suggesting a key role for this pathway in the vascular pathogenesis of SWS. The discovery of the GNB2 mutation sheds novel light on the pathogenesis of SWS and suggests that future research on targets of treatment should be directed towards the YAP, rather than the MAPK, signalling pathway.

The HEDGEHOG-GLI (HH-GLI) signalling is a key pathway critical in embryonic development, stem cell biology and tissue homeostasis. In recent years, aberrant activation of HH-GLI signalling has been linked to several types of cancer, including those of the skin, brain, lungs, prostate, gastrointestinal tract and blood. HH-GLI signalling is initiated by binding of HH ligands to the transmembrane receptor PATCHED and is mediated by transcriptional effectors that belong to the GLI family, whose activity is finely tuned by a number of molecular interactions and post-translation modifications. Several reports suggest that the activity of the GLI proteins is regulated by several proliferative and oncogenic inputs, in addition or independent of upstream HH signalling. The identification of this complex crosstalk and the understanding of how the major oncogenic signalling pathways interact in cancer is a crucial step towards the establishment of efficient targeted combinatorial treatments. Here we review recent findings on the cooperative integration of HH-GLI signalling with the major oncogenic inputs and we discuss how these cues modulate the activity of the GLI proteins in cancer. We then summarise the latest advances on SMO and GLI inhibitors and alternative approaches to attenuate HH signalling through rational combinatorial therapies.

AbstractGlutamic acid is the main excitatory neurotransmitter acting both in the brain and in peripheral tissues. Abnormal distribution of glutamic acid receptors occurs in skin hyperproliferative conditions such as psoriasis and skin regeneration; however, the biological function of glutamic acid in the skin remains unclear. Using ex vivo, in vivo and in silico approaches, we showed that exogenous glutamic acid promotes hair growth and keratinocyte proliferation. Topical application of glutamic acid decreased the expression of genes related to apoptosis in the skin, whereas glutamic acid increased cell viability and proliferation in human keratinocyte cultures. In addition, we identified the keratinocyte glutamic acid excitotoxic concentration, providing evidence for the existence of a novel skin signalling pathway mediated by a neurotransmitter that controls keratinocyte and hair follicle proliferation. Thus, glutamic acid emerges as a component of the peripheral nervous system that acts to control cell growth in the skin. These results raise the perspective of the pharmacological and nutritional use of glutamic acid to treat skin diseases.

AbstractPainful or potentially tissue-damaging stimuli are detected by primary sensory afferents that innervate the skin as well as internal tissues. The neurons that give rise to sensory afferents are located in the dorsal root ganglia (DRG) and transmit sensory information to the spinal cord where it is processed and further relayed to higher brain regions to ultimately generate the perception of pain. Both the DRGs as well as the spinal cord comprise a variety of morphologically, molecularly and functionally diverse neurons. The objective of this review is to provide an overview of the different types of sensory neurons and their proposed role in pain signalling. Moreover, I will discuss how pain related sensory information is processed in the dorsal horn of the spinal cord with an emphasis on recently delineated neural circuits that mediate pain hypersensitivity in the setting of nerve injury and inflammation.

Aquaporins have multiple distinct roles in mammalian physiology. Phenotype analysis of aquaporin-knockout mice has confirmed the predicted role of aquaporins in osmotically driven transepithelial fluid transport, as occurs in the urinary concentrating mechanism and glandular fluid secretion. Aquaporins also facilitate water movement into and out of the brain in various pathologies such as stroke, tumour, infection and hydrocephalus. A major, unexpected cellular role of aquaporins was revealed by analysis of knockout mice: aquaporins facilitate cell migration, as occurs in angiogenesis, tumour metastasis, wound healing, and glial scar formation. Another unexpected role of aquaporins is in neural function – in sensory signalling and seizure activity. The water-transporting function of aquaporins is likely responsible for these roles. A subset of aquaporins that transport both water and glycerol, the ‘aquaglyceroporins’, regulate glycerol content in epidermal, fat and other tissues. Mice lacking various aquaglyceroporins have several interesting phenotypes, including dry skin, resistance to skin carcinogenesis, impaired cell proliferation, and altered fat metabolism. The various roles of aquaporins might be exploited clinically by development of drugs to alter aquaporin expression or function, which could serve as diuretics, and in the treatment of brain swelling, glaucoma, epilepsy, obesity and cancer.

Poster presentation Tuesday 8 October Background En coup de sabre (ECDS) is a form of linear scleroderma characterised by skin induration followed by unilateral pigmentation dysregulation over the frontoparietal region with associated scarring. Parry Romberg syndrome (PRS) is a sporadic neurocutaneous disease characterised by slow and progressive hemifacial atrophy of the skin, muscles, and bony structures. Both conditions are associated with neurological symptoms such as headache and seizures. A wide variety of magnetic resonance findings associated with these conditions have been described. However, to date, attempts to identify predictors of MRI abnormalities have remained unsuccessful. The aim of this study was to: (i) describe the abnormalities seen on MRI in a large group of children with PRS/ECDS; and (ii) identify demographic, clinical, and laboratory predictors of MRI abnormalities. Methods This was a single centre (Great Ormond Street Hospital, London) retrospective case series of patients with PRS/ECDS seen from 2001-2018. We identified patients with cutaneous symptoms consistent with the clinical descriptions of PRS/ECDS: lateral forehead scleroderma with/without hemifacial atrophy. Presenting clinical, immunological, and MR brain findings are reported. Results are expressed as medians and ranges or frequencies and percentages. Fisher’s exact test was used to identify clinical associations with MRI abnormalities. Results A total of 17 patients were identified: 7 males and 10 females; median age 13 years (range 3 – 23). Non-cutaneous manifestations included seizures, headaches, stroke, cranial nerve dysfunction, anxiety, hypertension, hypermobility, Raynaud’s, myositis, and gastro-oesophageal reflux. The positive MR findings included ipsilateral enhanced white matter signalling, mineral deposition, lateral ventricle dilation, leptomeningeal enhancement, cavernomas, generalised atrophy, and loss of cortical gyration. The presence of seizures and the PRS phenotype were significantly associated with an abnormal MRI (p < 0.05) and showed trends towards significance with ipsilateral enhanced white matter signalling (p = 0.09). Conclusion The development of seizures and the PRS phenotype predict abnormalities in MR brain imaging in childhood PRS/ECDS. Baseline and regular monitoring MR brain scans should be carried out in all patients with PRS/ECDS to identify abnormalities associated with the development of seizures. Conflicts of Interest The authors declare no conflicts of interest.

AbstractNeuroinflammation, in which activated microglia are involved, appears to contribute to the development of Parkinson’s disease (PD). However, the role of microglial activation and the mechanisms governing this process remain uncertain. We focused on one inhibitory mechanism involved in the control of microglial activation, the microglia inhibitory receptor CD200R1, and its ligand CD200, mainly expressed by neurons. The human CD200R1 gene encodes two membrane-associated and two soluble protein isoforms and the human CD200 gene encodes full-length proteins (CD200full) but also truncated (CD200tr) proteins which act as CD200R1 antagonists. Little is known about their expression in the human brain under pathological conditions. We used human peripheral blood monocytes and monocyte-derived microglia-like cells from control subjects to characterize the expression of the CD200R1 mRNA variants, which showed stimulus-specific responses. We provide evidence of increased CD200R1 (mRNA variants and protein isoforms) and CD200 expression (CD200tr mRNA) in brain tissue of PD patients, mainly in the hippocampus, as well as increased CD200 expression (CD200full and CD200tr mRNAs) in iPSCs-derived dopaminergic neurons generated from skin fibroblasts of PD patients. Our results suggest that CD200-CD200R1 signalling is altered in PD, which may affect the microglial function and constitute a potential target in therapeutic strategies for PD.

Young Sepia officinalis (0-5 months) were studied in the laboratory and in the sea, and their appearance and behaviour compared with that of adult animals. Cuttlefish lay large eggs and the hatchlings are miniature replicas of the adults. From the moment of hatching they show body patterns as complex as those of adults and far more elaborate than those shown by most juvenile cephalopods. There are 13 body patterns: 6 of these are ‘chronic’ (lasting for minutes or hours) and 7 are ‘acute’ (lasting for seconds or minutes). The patterns are built up from no fewer than 34 chromatic, 6 textural, 8 postural and 6 locomotor components, used in varying combinations and intensities of expression. Nearly all these components occur in young animals: 26 of the chromatic, all the textural and locomotor, and 6 of the postural components. Nevertheless, patterning does change with age and we have recorded this and correlated the changes with behaviour. The components are built up from units, which themselves comprise four elements organized in precise relation to one another: chromatophores, iridophores, leucophores and skin muscles. The chromatophores are always especially important: they are muscular organs innervated directly from the brain and controlled ultimately by the highest centres (optic lobes). The areas in the Sepia brain that control patterning are already well developed at hatching, for the appearance of the skin is as much part of the brain’s motor program as is the attitude of the arms or fins, or the posture of the entire animal. The iridophores and leucophores develop later and are especially important constituents of many adult patterns, notably the Intense Zebra of the mature male. Experiments confirm that patterning is neurally controlled and apparently mediated exclusively by the visual system. Young cuttlefish use patterning primarily for concealment, utilizing such strategies as general colour resemblance, disruptive coloration, obliterative shading, shadow elimination, disguise and adaptive behaviour. Older animals also conceal themselves but increasingly use patterns for signalling, both interspecifically (warning or ‘deimatic’ displays) and intraspecifically (sexual signalling). Laboratory-reared cuttlefish were released in the sea and observed underwater. They quickly and effectively concealed themselves on the substrate; it was easy for the human observer to lose them and many passing fish behaved as if they were not there. One local predator, Serranus cabrilla , was observed to attack them and no fewer than 35 attacks were recorded, only six of which were successful. Laboratory-reared cuttlefish apparently distinguished between these predators and other, non-predatory, fish the first time they encountered them in nature.

Abstract Background While computed tomography (CT) exams are the major cause of medical exposure to ionising radiation, the radiation-induced risks must be documented. We investigated the impact of the cellular models and individual factor on the deoxyribonucleic acid double-strand breaks (DSB) recognition and repair in human skin fibroblasts and brain astrocytes exposed to current head CT scan conditions. Method Nine human primary fibroblasts and four human astrocyte cell lines with different levels of radiosensitivity/susceptibility were exposed to a standard head CT scan exam using adapted phantoms. Cells were exposed to a single-helical (37.4 mGy) and double-helical (37.4 mGy + 5 min + 37.4 mGy) examination. DSB signalling and repair was assessed through anti-γH2AX and anti-pATM immunofluorescence. Results Head CT scan induced a significant number of γH2AX and pATM foci. The kinetics of both biomarkers were found strongly dependent on the individual factor. Particularly, in cells from radiosensitive/susceptible patients, DSB may be significantly less recognised and/or repaired, whatever the CT scan exposure conditions. Similar conclusions were reached with astrocytes. Conclusions Our results highlight the importance of both individual and tissue factors in the recognition and repair of DSB after current head CT scan exams. Further investigations are needed to better define the radiosensitivity/susceptibility of individual humans.

Abstract Background/Aims Simultaneous analysis of multiple proteins in biological fluids offers insight into the pathogenesis of SSc. Here, we report a proteomic analysis of plasma and dermal interstitial fluid in SSc compared with healthy controls (HC). Methods The prospectively collected BIOPSY cohort recruited 52 SSc patients (21 early dcSSc, 15 established dcSSc,16 lcSSc) and 16 HC. Mean baseline skin score (MRSS) for early dcSSc was 21 (sd 11.2). This analysis utilised forearm skin blister fluid obtained using the dermal suction blister method and paired simultaneous plasma samples from early dcSSc and HC at baseline. These were assayed using the Olink antibody platform(www.olink.com) and reported as normalised protein expression (NPX), corresponding to log2 (expression). T-test with FDR correction (p &lt; 0.05) assessed statistical significance. Pathway analysis was conducted by STRING consortium 2020. Results 1,196 proteins were analysed in paired blister/plasma samples from 14 early dcSSc patients and 16 HC. 447 proteins were significantly different in the blister fluid of early dcSSc patients compared with HC (Table 1), whereas only 183 proteins in plasma. Of these, 130 proteins were simultaneously different in both blister fluid and plasma of early dcSSc including key cytokines associated with fibrosis and vasculopathy such as IL-6,VEGF-1, MCP-1, COL4A1, COMP, Thy1 and THBS4. No correlation was seen between these proteins and MRSS. 310 proteins were significantly elevated in blister fluid alone in early dcSSc patients compared to HC. These included cytokines (IL7,IL18, OSM), chemokines (CCL7,CCL18, CCL3), matricellular proteins (CYR61 and osteopontin). KEGG pathway analysis of the significantly elevated proteins in blister fluid in early dcSSc compared to HC highlighted pathways including cytokine-cytokine receptor interaction, cell adhesion molecules, MAPK signalling pathway and PI3K-AKT signalling pathway (FDR&lt;0.01) P154 Table 1:Protein symbolRaw mean NPXFold ChangeAdjusted p valueDetails of proteinHCdcSScKLK42.69815.9260.004Kallikrein-related peptidase 4IL616.13815.1070.008Interleukin 6NT-proBNP33.60712.8570.018N-terminal pro-brain natriuretic peptideAREG12.74711.9780.017AmphiregulinLTBP24.59311.7990.015Latent-TGF beta-binding protein 2SFRP181.10710.4040.025Secreted Frizzled Related Protein 1TNC18.0128.7280.010Tenascin CCPXM12.1477.4650.002Probable carboxypeptidase X1CYR6110.4936.1060.011Cysteine-rich angiogenic inducer 61 (CCN1)PAPPA10.2675.4800.008Pregnancy-associated plasma protein AEDA2R11.4795.4070.008Ectodysplasin-A2 rceptorNOV61.6385.1190.003Nephroblastoma overexpressed protein (CCN3)GDF-1520.8074.5400.002growth/differentiation factor 15SCARF211.8684.3770.008Scavenger Receptor Class F Member 2CXCL1071.6204.1960.028interferon-γ inducible protein 10THBS4110.6824.1630.008Thrombospondin 4CXCL1324.2564.0470.011C-X-C Motif Chemokine Ligand 13MAPT1.6614.0410.015Microtubule-associated protein tauCOL4A116.7054.0090.003Collagen type IV alpha 1MCP-11128.943.6510.016Monocyte chemoattractant protein-1Top 20 most upregulated proteins in skin blister fluid for early dcSSc (n = 14) compared with healthy control (HC, n = 16). Conclusion Numerous dysregulated proteins were identified in dermal blister fluid and plasma of early dcSSc patients. Substantially more were identified in dermal blister fluid, highlighting its potential for providing detailed information on local pathologic processes. A subset of proteins were dysregulated in both plasma and blister fluid, suggesting these may reflect systemic abnormalities. Further work will utilise this cohort to integrate gene and protein expression across the full spectrum of early dcSSc, established dcSSc and lcSSc Disclosure K.E. Clark: None. C. Campochiaro: None. E. Csomor: Corporate appointments; employee of GSK. A. Taylor: Corporate appointments; employee of GSK. K. Nevin: Corporate appointments; employee of GSK. M.A. Morse: Corporate appointments; employee of GSK. V.H. Ong: None. E. Derrett-Smith: None. N. Wisniacki: Corporate appointments; employee of GSK. S. Flint: Corporate appointments; employee of GSK. C.P. Denton: Consultancies; Actelion, GlaxoSmithKline, Bayer, Sanofi, lnventiva, Boehringer Ingelheim, Roche, Bristol Myers Squibb, CSL Behring, UCB, Leadiant Biosciences, Corbus, Servier, Arxx Therapeutics.