1 5323 80 PULMONARY INVOLVEMENT IN SYSTEMIC SCLEROSIS: EXPLORING CELLULAR, GENETIC AND EPIGENETIC MECHANISMS. SYSTEMIC SCLEROSIS (SSC) IS A CHRONIC PROGRESSIVE AUTOIMMUNE DISEASE CHARACTERIZED BY IMMUNE INFLAMMATION, VASCULOPATHY, AND FIBROSIS. THERE ARE STILL NUMEROUS UNCERTAINTIES IN THE UNDERSTANDING OF DISEASE INITIATION AND PROGRESSION. PULMONARY INVOLVEMENT IN SSC, AND PARTICULARLY PULMONARY FIBROSIS, IS CRITICAL FOR ALL ORGAN SYSTEMS AFFECTIONS IN THIS DISEASE. THIS REVIEW IS AIMED TO DESCRIBE AND ANALYZE NEW FINDINGS IN THE PATHOPHYSIOLOGY OF SSC-ASSOCIATED PULMONARY INVOLVEMENT AND TO EXPLORE PERSPECTIVE DIAGNOSTIC AND THERAPEUTIC STRATEGIES. A MYRIAD OF CELLULAR INTERACTIONS IS EXPLORED IN THE DYNAMICS OF PROGRESSIVE INTERSTITIAL LUNG DISEASE (ILD) AND PULMONARY HYPERTENSION (PH) IN SSC. THE ROLE OF EXOSOMES, MICROVESICLES, AND APOPTOTIC BODIES IS EXAMINED AND THE IMPACT OF MICRO AND LONG NON-CODING RNAS, DNA METHYLATION, AND HISTONE MODIFICATION IN SSC IS DISCUSSED. 2020 2 2988 20 GENETIC FACTORS AND SYSTEMIC SCLEROSIS. SYSTEMIC SCLEROSIS (SSC) IS A RARE CONNECTIVE TISSUE DISEASE OF UNKNOWN ETIOLOGY CHARACTERIZED BY CHRONIC INFLAMMATION AND FIBROSIS OF THE SKIN, VASCULAR ABNORMALITIES, AND VARIABLE INVOLVEMENT OF ORGANS INCLUDING KIDNEYS, GASTROINTESTINAL TRACT, HEART, AND LUNGS. SSC SHOWS A COMPLEX ETIOLOGY IN WHICH BOTH ENVIRONMENTAL AND GENETIC FACTORS SEEM TO INFLUENCE THE ONSET AND OUTCOME OF THE DISEASE. WE PROVIDE AN EXTENSIVE OVERVIEW OF THE GENETIC FACTORS AND EPIGENETIC MODIFICATIONS AND WHAT THEIR KNOWLEDGE HAS REVEALED IN TERMS OF ETIOPATHOGENESIS OF SSC. 2016 3 2684 21 EVALUATION OF X CHROMOSOME INACTIVATION WITH RESPECT TO HLA GENETIC SUSCEPTIBILITY IN RHEUMATOID ARTHRITIS AND SYSTEMIC SCLEROSIS. BACKGROUND: AUTOIMMUNE DISEASES, INCLUDING RHEUMATOID ARTHRITIS (RA) AND SYSTEMIC SCLEROSIS (SSC) ARE CHARACTERIZED BY A STRONG GENETIC SUSCEPTIBILITY FROM THE HUMAN LEUCOCYTE ANTIGEN (HLA) LOCUS. ADDITIONALLY, DISORDERS OF EPIGENETIC PROCESSES, IN PARTICULAR NON-RANDOM X CHROMOSOME INACTIVATION (XCI), HAVE BEEN REPORTED IN MANY FEMALE-PREDOMINANT AUTOIMMUNE DISEASES. HERE WE TEST THE HYPOTHESIS THAT WOMEN WITH RA OR SSC WHO ARE STRONGLY GENETICALLY PREDISPOSED ARE LESS SUSCEPTIBLE TO XCI BIAS. METHODS: USING METHYLATION SENSITIVE GENOTYPING OF THE ANDROGEN RECEPTOR (AR) GENE, XCI PROFILES WERE PERFORMED IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM 161 WOMEN WITH RA, 96 WOMEN WITH SSC AND 100 HEALTHY WOMEN. HLA-DRB1 AND DQB1 WERE GENOTYPED. PRESENCE OF SPECIFIC AUTOANTIBODIES WAS DOCUMENTED FOR PATIENTS. XCI SKEWING WAS DEFINED AS HAVING A RATIO >/= 80:20 OF CELLS INACTIVATING THE SAME X CHROMOSOME. RESULTS: 110 WOMEN WITH RA, 68 WOMEN WITH SSC, AND 69 CONTROLS WERE INFORMATIVE FOR THE AR POLYMORPHISM. AMONG THEM 40.9% OF RA PATIENTS AND 36.8% OF SSC PATIENTS HAD SKEWED XCI COMPARED TO 17.4% OF HEALTHY WOMEN (P = 0.002 AND 0.018, RESPECTIVELY). PRESENCE OF RA-SUSCEPTIBILITY ALLELES CODING FOR THE "SHARED EPITOPE" CORRELATED WITH HIGHER SKEWING AMONG RA PATIENTS (P = 0.002) AND SUCH CORRELATION WAS NOT OBSERVED IN OTHER WOMEN, HEALTHY OR WITH SSC. PRESENCE OF SSC-SUSCEPTIBILITY ALLELES DID NOT CORRELATE WITH XCI PATTERNS AMONG SSC PATIENTS. CONCLUSION: DATA DEMONSTRATE XCI SKEWING IN BOTH RA AND SSC COMPARED TO HEALTHY WOMEN. UNEXPECTEDLY, SKEWED XCI OCCURS MORE OFTEN IN WOMEN WITH RA CARRYING THE SHARED EPITOPE, WHICH USUALLY REFLECTS SEVERE DISEASE. THIS REINFORCES THE VIEW THAT LOSS OF MOSAICISM IN PERIPHERAL BLOOD MAY BE A CONSEQUENCE OF CHRONIC AUTOIMMUNITY. 2016 4 827 27 CHARACTERIZATION OF LONG NON-CODING RNAS IN SYSTEMIC SCLEROSIS MONOCYTES: A POTENTIAL ROLE FOR PSMB8-AS1 IN ALTERED CYTOKINE SECRETION. SYSTEMIC SCLEROSIS (SSC) IS A CHRONIC AUTOIMMUNE DISEASE MAINLY AFFECTING THE CONNECTIVE TISSUE. IN SSC PATIENTS, MONOCYTES ARE INCREASED IN CIRCULATION, INFILTRATE AFFECTED TISSUES, AND SHOW A PRO-INFLAMMATORY ACTIVATION STATUS, INCLUDING THE SO-CALLED INTERFERON (IFN) SIGNATURE. WE PREVIOUSLY DEMONSTRATED THAT THE DYSREGULATION OF THE IFN RESPONSE IN SSC MONOCYTES IS SUSTAINED BY ALTERED EPIGENETIC FACTORS AS WELL AS BY UPREGULATION OF THE LONG NON-CODING RNA (LNCRNA) NRIR. CONSIDERING THE ENORMOUSLY DIVERSE MOLECULAR FUNCTIONS OF LNCRNAS IN IMMUNE REGULATION, THE PRESENT STUDY INVESTIGATED THE GENOME-WIDE PROFILE OF LNCRNAS IN SSC MONOCYTES, WITH THE AIM TO FURTHER UNRAVEL THEIR POSSIBLE ROLE IN MONOCYTE DYSREGULATION AND DISEASE PATHOGENESIS. TRANSCRIPTOMIC DATA FROM TWO INDEPENDENT COHORTS OF SSC PATIENTS IDENTIFIED 886 LNCRNAS WITH AN ALTERED EXPRESSION IN SSC MONOCYTES. DIFFERENTIALLY EXPRESSED LNCRNAS WERE CORRELATED WITH NEIGHBORING PROTEIN CODING GENES IMPLICATED IN THE REGULATION OF IFN RESPONSES AND APOPTOTIC SIGNALING IN SSC MONOCYTES. IN PARALLEL, GENE CO-EXPRESSION NETWORK ANALYSIS IDENTIFIED THE LNCRNA PSMB8-AS1 AS A TOP-RANKING HUB GENE IN CO-EXPRESSION MODULES IMPLICATED IN CELL ACTIVATION AND RESPONSE TO VIRAL AND EXTERNAL STIMULI. FUNCTIONAL CHARACTERIZATION OF PSMB8-AS1 IN MONOCYTES DEMONSTRATED THAT THIS LNCRNA IS INVOLVED IN THE SECRETION OF IL-6 AND TNFALPHA, TWO PIVOTAL PRO-INFLAMMATORY CYTOKINES ALTERED IN THE CIRCULATION OF SSC PATIENTS AND ASSOCIATED WITH FIBROSIS AND DISEASE SEVERITY. COLLECTIVELY, OUR DATA SHOWED THAT LNCRNAS ARE LINKED TO MONOCYTE DYSREGULATION IN SSC, AND HIGHLIGHT THEIR POTENTIAL CONTRIBUTION TO DISEASE PATHOGENESIS. 2021 5 5639 27 SERUM MICRORNAS IN SYSTEMIC SCLEROSIS, ASSOCIATIONS WITH DIGITAL VASCULOPATHY AND LUNG INVOLVEMENT. BACKGROUND AND AIMS: SYSTEMIC SCLEROSIS (SSC) IS AN AUTOIMMUNE, RARE MULTISYSTEM CHRONIC DISEASE THAT IS STILL NOT WELL-UNDERSTOOD AETIOLOGICALLY AND IS CHALLENGING DIAGNOSTICALLY. IN THE LITERATURE, THERE ARE EVER-INCREASING ASSUMPTIONS REGARDING THE EPIGENETIC MECHANISMS INVOLVED IN SSC DEVELOPMENT; ONE OF THEM IS CIRCULATING MICRORNAS. MANY OF THEM REGULATE TLR PATHWAYS AND ARE SIGNIFICANT IN AUTOIMMUNE BALANCE. THE AIM OF THIS STUDY WAS TO DETERMINE PROFILE EXPRESSION OF SELECTED MICRORNAS IN SSC PATIENTS, INCLUDING MIR-126, -132, -143, -145, -155, -181A, -29A AND -3148, IN COMPARISON TO HEALTHY CONTROLS. METHODS: SERUM MICRORNAS WERE ISOLATED FROM 45 PATIENTS WITH SSC AND 57 HEALTHY DONORS (HC). ADDITIONALLY, SSC PATIENTS WERE CONSIDERED IN THE ASPECT OF DISEASE SUBTYPE, INCLUDING DIFFUSE SYSTEMIC SCLEROSIS (DCSSC) AND LIMITED SYSTEMIC SCLEROSIS (LCSSC). RESULTS: MIR-3148 WAS DETECTED NEITHER IN THE SERUM OF HC NOR IN SSC PATIENTS. ALL OF THE REST OF THE ANALYZED MICRORNAS, EXCLUDING MIR-126, MIR-29A AND MIR-181A, WERE SIGNIFICANTLY UPREGULATED IN SSC PATIENTS IN COMPARISON TO HC. HOWEVER, MIR-181A HAS BEEN REVEALED ONLY IN THE SERUM OF PATIENTS WITH LCSSC BUT NOT DCSSC. MODERATE POSITIVE CORRELATIONS BETWEEN THE TRANSFER FACTOR OF THE LUNG FOR CARBON MONOXIDE (TLCO) AND MIR-126 AND MIR-145 WERE OBSERVED. A SIGNIFICANT CORRELATION HAS BEEN FOUND BETWEEN SERUM MIR-143 LEVEL AND FORCED VITAL CAPACITY (FVC). SSC PATIENTS WITH FVC