1 3299 112 HIGH-FAT DIET RELATED LUNG FIBROSIS-EPIGENETIC REGULATION MATTERS. PULMONARY FIBROSIS (PF) IS AN INTERSTITIAL LUNG DISEASE CHARACTERIZED BY THE DESTRUCTION OF THE PULMONARY PARENCHYMA CAUSED BY EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION. DESPITE THE WELL-KNOWN ETIOLOGICAL FACTORS SUCH AS SENESCENCE, ABERRANT EPITHELIAL CELL AND FIBROBLAST ACTIVATION, AND CHRONIC INFLAMMATION, PF HAS RECENTLY BEEN RECOGNIZED AS A METABOLIC DISEASE AND ABNORMAL LIPID SIGNATURE WAS OBSERVED BOTH IN SERUM AND BRONCHOALVEOLAR LAVAGE FLUID (BALF) OF PF PATIENTS AND MICE PF MODEL. CLINICALLY, OBSERVATIONAL STUDIES SUGGEST A SIGNIFICANT LINK BETWEEN HIGH-FAT DIET (HFD) AND PF AS MANIFESTED BY HIGH INTAKE OF SATURATED FATTY ACIDS (SFAS) AND MEAT INCREASES THE RISK OF PF AND MICE LUNG FIBROSIS. HOWEVER, THE POSSIBLE MECHANISMS BETWEEN HFD AND PF REMAIN UNCLEAR. IN THE CURRENT REVIEW WE EMPHASIZE THE DIVERSITY EFFECTS OF THE EPIGENETIC DYSREGULATION INDUCED BY HFD ON THE FIBROTIC FACTORS SUCH AS EPITHELIAL CELL INJURY, ABNORMAL FIBROBLAST ACTIVATION AND CHRONIC INFLAMMATION. FINALLY, WE DISCUSS THE POTENTIAL WAYS FOR PATIENTS TO IMPROVE THEIR CONDITIONS AND EMPHASIZE THE PROSPECT OF TARGETED THERAPY BASED ON EPIGENETIC REGULATION FOR SCIENTIFIC RESEARCHERS OR DRUG DEVELOPERS. 2023 2 6223 42 THE LEADING ROLE OF EPITHELIAL CELLS IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A RELENTLESSLY PROGRESSIVE AND DEVASTATING INTERSTITIAL LUNG DISEASE OF UNKNOWN ETIOLOGY, WHERE THE NORMAL LUNG ARCHITECTURE IS LOST AND REPLACED BY FIBROTIC TISSUE LEADING TO AN IRREVERSIBLE AND PROGRESSIVE RESPIRATORY INSUFFICIENCY. HISTORICALLY, IPF WAS CONSIDERED A CHRONIC INFLAMMATORY DISORDER, WHICH GRADUALLY PROGRESSED TO ESTABLISHED FIBROSIS. HOWEVER, STRONG CLINICAL AND EXPERIMENTAL EVIDENCE INDICATES THAT THE DISEASE REPRESENTS AN EPITHELIAL-DRIVEN DISORDER WHICH RESULTS FROM A COMPLEX INTERPLAY OF GENETIC AND ENVIRONMENTAL RISK FACTORS, AGING-ASSOCIATED PROCESSES AND A PROFIBROTIC EPIGENETIC REPROGRAMMING. THE CONVERGENCE OF THESE FACTORS RESULTS IN THE ABERRANT ACTIVATION OF EPITHELIAL CELLS THAT INITIATE THE DEVELOPMENT OF THE DISEASE, PRODUCING VIRTUALLY ALL THE MEDIATORS THAT PARTICIPATE IN THE MIGRATION, PROLIFERATION AND ACTIVATION OF FIBROBLASTS, THEIR DIFFERENTIATION TO MYOFIBROBLASTS AND THE EXCESSIVE AND CHAOTIC SECRETION OF EXTRACELLULAR MATRIX PROTEINS. ALTHOUGH PROGRESS HAS BEEN MADE IN UNDERSTANDING THE CAUSES AND CONSEQUENCES OF THIS ABNORMAL BEHAVIOR OF DISTAL AIRWAYS AND ALVEOLAR EPITHELIUM, THE MECHANISMS THAT INITIATE AND PERPETUATE THE VICIOUS CIRCLE OF MULTIDIRECTIONAL ABNORMAL COMMUNICATIONS BETWEEN THE EPITHELIUM AND FIBROBLASTS AND OTHER RESIDENT CELLS HAVE NOT BEEN ELUCIDATED. IN THIS REVIEW, WE DISCUSS THE ROLE OF EPITHELIAL CELLS AND THE MECHANISMS UNDERLYING THE FIBROTIC RESPONSE IN IPF, AND HIGHLIGHT SOME PROMISING THERAPEUTIC TARGETS FOR THESE CELLS. 2020 3 4738 35 NOVEL FIBROBLAST PHENOTYPES IN HOMEOSTASIS AND CHRONIC INFLAMMATION: FROM FUNCTIONS TO POTENTIAL REGULATORS. FIBROBLASTS ARE ESSENTIAL COMPONENTS OF THE STROMA, SUSTAINING A VARIETY OF TISSUES AND BEING KEY TO THE PROCESS OF TISSUE REPAIR AFTER INJURY. THEIR ROLE IN TISSUE REPAIR HAS BEEN ATTRIBUTED TO THEIR ABILITY TO ACQUIRE A CONTRACTILE, EXTRACELLULAR MATRIX-PRODUCING PHENOTYPE KNOWN AS MYOFIBROBLASTS. THIS PROPERTY IS PRIMARILY DEPENDENT ON THEIR RESPONSE TO THE PLEIOTROPIC CYTOKINE TRANSFORMING GROWTH FACTOR-BETA1. UNTIL RECENTLY, THE POTENTIAL ROLE OF FIBROBLASTS IN OTHER HOMEOSTATIC AND DISEASE-RELATED PROCESSES WAS LESS WELL UNDERSTOOD. ALTHOUGH IN VITRO STUDIES INDICATED THAT FIBROBLASTS ARE ABLE TO RESPOND TO AND SECRETE INFLAMMATORY MEDIATORS, DEFINITIVE EVIDENCE OF THEIR CONTRIBUTION TO CHRONIC INFLAMMATION WAS LIMITED. HOWEVER, THE EMERGENCE OF TECHNIQUES THAT ALLOW EXPLORATION OF TISSUES AT THE SINGLE CELL LEVEL HAS CHALLENGED THE PREVIOUS PARADIGMS ON FIBROBLAST IDENTITY AND FUNCTIONS, AND HAS LED TO THE DISCOVERY OF SIGNIFICANT DIVERSITY, SHOWING THE PRESENCE OF FIBROBLASTS WITH ALTERNATE TRANSCRIPTIONAL PROFILES IN A VARIETY OF TISSUES. THESE STUDIES HAVE ALSO SUGGESTED POTENTIAL ROLES OF NOVEL FIBROBLAST SUBTYPES AS REGULATORS OF EPITHELIAL HOMEOSTASIS AND RENEWAL, INFLAMMATORY CELL INFILTRATION AND ACTIVATION, AND ANTIGEN PRESENTATION. HERE, WE PROVIDE A COMPREHENSIVE REVIEW OF THE RECENT LITERATURE ON FIBROBLAST DIVERSITY IN THE DIGESTIVE TRACT, SKIN, LUNGS AND JOINTS. WE ALSO REVIEW EVIDENCE OF THEIR CONTRIBUTION TO THE REGULATION OF HOMEOSTASIS AND CHRONIC INFLAMMATION, AS WELL AS THEIR INTERACTIONS WITH OTHER CELLS IN VARIOUS TISSUE COMPARTMENTS. WE DISCUSS EVIDENCE OF DIFFERENT FACTORS INVOLVED IN THE CONTROL OF FIBROBLAST FUNCTION, ADDRESSING THE ROLE OF VARIOUS CYTOKINES, TRANSCRIPTION FACTORS AND EPIGENETIC CHANGES, AS WELL AS MICROENVIRONMENTAL FACTORS, INCLUDING EXTRACELLULAR MATRIX STIFFNESS, HYPOXIA, AND METABOLIC SHIFTS. 2023 4 2169 32 EPIGENETIC MECHANISMS IN PARENCHYMAL LUNG DISEASES: BYSTANDERS OR THERAPEUTIC TARGETS? EPIGENETIC RESPONSES DUE TO ENVIRONMENTAL CHANGES ALTER CHROMATIN STRUCTURE, WHICH IN TURN MODIFIES THE PHENOTYPE, GENE EXPRESSION PROFILE, AND ACTIVITY OF EACH CELL TYPE THAT HAS A ROLE IN THE PATHOPHYSIOLOGY OF A DISEASE. PULMONARY DISEASES ARE ONE OF THE MAJOR CAUSES OF DEATH IN THE WORLD, INCLUDING LUNG CANCER, IDIOPATHIC PULMONARY FIBROSIS (IPF), CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), PULMONARY HYPERTENSION (PH), LUNG TUBERCULOSIS, PULMONARY EMBOLISM, AND ASTHMA. SEVERAL LINES OF EVIDENCE INDICATE THAT EPIGENETIC MODIFICATIONS MAY BE ONE OF THE MAIN FACTORS TO EXPLAIN THE INCREASING INCIDENCE AND PREVALENCE OF LUNG DISEASES INCLUDING IPF AND COPD. INTERESTINGLY, ISOLATED FIBROBLASTS AND SMOOTH MUSCLE CELLS FROM PATIENTS WITH PULMONARY DISEASES SUCH AS IPF AND PH THAT WERE CULTURED EX VIVO MAINTAINED THE DISEASE PHENOTYPE. THE CELLS OFTEN SHOW A HYPER-PROLIFERATIVE, APOPTOSIS-RESISTANT PHENOTYPE WITH INCREASED EXPRESSION OF EXTRACELLULAR MATRIX (ECM) AND ACTIVATED FOCAL ADHESIONS SUGGESTING THE PRESENCE OF AN EPIGENETICALLY IMPRINTED PHENOTYPE. MOREOVER, MANY ABNORMALITIES OBSERVED IN MOLECULAR PROCESSES IN IPF PATIENTS ARE SHOWN TO BE EPIGENETICALLY REGULATED, SUCH AS INNATE IMMUNITY, CELLULAR SENESCENCE, AND APOPTOTIC CELL DEATH. DNA METHYLATION, HISTONE MODIFICATION, AND MICRORNA REGULATION CONSTITUTE THE MOST COMMON EPIGENETIC MODIFICATION MECHANISMS. 2022 5 2337 18 EPIGENETIC REGULATION OF INFLAMMATORY RESPONSES IN THE CONTEXT OF PHYSICAL ACTIVITY. EPIGENETIC MODIFICATIONS OCCUR IN RESPONSE TO ENVIRONMENTAL CHANGES AND PLAY A FUNDAMENTAL ROLE IN THE REGULATION OF GENE EXPRESSION. PA IS FOUND TO ELICIT AN INFLAMMATORY RESPONSE, BOTH FROM THE INNATE AND ADAPTIVE DIVISIONS OF THE IMMUNOLOGICAL SYSTEM. THE INFLAMMATORY REACTION IS CONSIDERED A VITAL TRIGGER OF EPIGENETIC CHANGES THAT IN TURN MODULATE INFLAMMATORY ACTIONS. THE TISSUE RESPONSES TO PA INVOLVE LOCAL AND GENERAL CHANGES. THE EPIGENETIC MECHANISMS INVOLVED INCLUDE: DNA METHYLATION, HISTONE PROTEINS MODIFICATION AND MICRORNA. ALL OF THEM AFFECT GENETIC EXPRESSION IN AN INFLAMMATORY MILIEU IN PHYSICAL EXERCISE DEPENDING ON THE MAGNITUDE OF PHYSIOLOGICAL STRESS EXPERIENCED BY THE EXERCISER. PA MAY EVOKE ACUTE OR CHRONIC BIOCHEMICAL AND PHYSIOLOGICAL RESPONSES AND HAVE A POSITIVE OR NEGATIVE IMMUNOMODULATORY EFFECT. 2021 6 6199 31 THE IMPORTANCE OF EPIGENETICS IN THE DEVELOPMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. IT IS GENERALLY ACCEPTED THAT GENETIC PREDISPOSITION PLAYS A ROLE IN COPD DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS. THEREFORE, MANY CANDIDATE GENES THAT COULD BE LINKED TO THE DEVELOPMENT OF DISEASE HAVE BEEN EXAMINED IN COPD. HOWEVER, INCONSISTENT RESULTS IN DIFFERENT STUDY POPULATIONS OFTEN LIMIT THIS APPROACH, SUGGESTING THAT NOT ONLY GENETICS, BUT ALSO OTHER FACTORS, MAY BE CONTRIBUTED TO THE SUSCEPTIBILITY TO COPD. EPIGENETIC MECHANISMS CAN AFFECT THE TRANSCRIPTIONAL ACTIVITY OF SPECIFIC GENES, AT DIFFERENT POINTS IN TIME, AND IN DIFFERENT ORGANS. MOREOVER, THESE MECHANISMS CAN HAVE AN EFFECT ON PEOPLE'S HEALTH. RECENTLY, THERE IS EMERGING EVIDENCE SUPPORTING A ROLE OF EPIGENETICS FOR THE REGULATION OF INFLAMMATORY GENES IN DISEASES SUCH AS ASTHMA AND COPD. MOREOVER, RECENT STUDIES SUGGEST THAT THE CURRENTLY USED TREATMENTS INCLUDING CORTICOSTEROIDS MAY WORK THROUGH EPIGENETIC MECHANISMS. EPIGENETIC REGULATION CAN BE REPROGRAMMED, POTENTIALLY AFFECTING THE RISK, AETIOLOGY AND TREATMENT OF VARIOUS DISEASE STATES. THE EPIGENETICALLY INFLUENCED PHENOTYPE COULD BE REVERSED WITH DEMETHYLATING OR DEACETYLATING AGENTS, CONSISTENT WITH EPIGENETIC PLASTICITY. THE POSTNATAL REVERSIBILITY OF THESE METHYLATION OR ACETYLATION EVENTS MAY THEREFORE PROVIDE GOOD OPPORTUNITIES FOR INTERVENTION. THE RECOGNITION OF THE ROLE OF GENETIC AND EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF COPD MAY IDENTIFY NOVEL TARGETS THAT HATCH NEW THERAPIES FOR PATIENTS WITH COPD. 2011 7 288 42 AGING AND INDUCED SENESCENCE AS FACTORS IN THE PATHOGENESIS OF LUNG EMPHYSEMA. CLASSICALLY, THE DEVELOPMENT OF EMPHYSEMA IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE IS BELIEVED TO INVOLVE INFLAMMATION INDUCED BY CIGARETTE SMOKE AND LEUKOCYTE ACTIVATION, INCLUDING OXIDANT-ANTIOXIDANT AND PROTEASE-ANTIPROTEASE IMBALANCES. WHILE THERE IS SUBSTANTIAL EVIDENCE FOR THIS, ADDITIONAL ASPECTS HAVE BEEN SUGGESTED BY A NUMBER OF CLINICAL AND EXPERIMENTAL OBSERVATIONS. SMOKERS EXHIBIT SIGNS OF PREMATURE AGING, PARTICULARLY OBVIOUS IN THE SKIN. THE LINK BETWEEN AGING AND CHRONIC DISEASE IS WELL-KNOWN, E.G., FOR THE BRAIN AND MUSCULOSKELETAL OR CARDIOVASCULAR SYSTEM, AS WELL AS THE CLINICAL LINK BETWEEN MALNUTRITION AND EMPHYSEMA, AND THE EXPERIMENTAL LINK TO CALORIC RESTRICTION. INTERESTINGLY, THIS INTERVENTION ALSO INCREASES LIFESPAN, IN PARALLEL WITH ALTERATIONS IN METABOLISM, OXIDANT BURDEN AND ENDOCRINE SIGNALING. OF SPECIAL INTEREST IS THE OBSERVATION THAT, EVEN IN THE ABSENCE OF AN INFLAMMATORY ENVIRONMENT, LUNG FIBROBLASTS FROM PATIENTS WITH EMPHYSEMA SHOW PERSISTENT ALTERATIONS, POSSIBLY BASED ON EPIGENETIC MECHANISMS. THE IMPORTANCE OF THESE MECHANISMS FOR CELLULAR REPROGRAMMING AND RESPONSE PATTERNS, INDIVIDUAL RISK PROFILE AND THERAPEUTIC OPTIONS IS BECOMING INCREASINGLY RECOGNIZED. THE SAME APPLIES TO CELLULAR SENESCENCE. RECENT FINDINGS FROM PATIENTS AND EXPERIMENTAL MODELS OPEN NOVEL VIEWS INTO THE ARENA OF GENE-ENVIRONMENT INTERACTIONS, INCLUDING THE ROLE OF SYSTEMIC ALTERATIONS, CELLULAR STRESS, TELOMERES, CDK INHIBITORS SUCH AS P16, P21, PRB, PI3K, MTOR, FOXO TRANSCRIPTION FACTORS, HISTONE MODIFICATIONS, AND SIRTUINS. THIS ARTICLE AIMS TO OUTLINE THIS EMERGING PICTURE AND TO STIMULATE THE IDENTIFICATION OF CHALLENGING QUESTIONS. SUCH INSIGHTS ALSO BEAR IMPLICATIONS FOR THE LONG-TERM COURSE OF THE DISEASE IN RELATION TO EXISTING OR FUTURE THERAPIES AND THE EXPLORATION OF POTENTIAL LUNG REGENERATION. 2008 8 1597 32 DNA METHYLATION REGULATED GENE EXPRESSION IN ORGAN FIBROSIS. DNA METHYLATION IS A MAJOR EPIGENETIC MECHANISM TO REGULATE GENE EXPRESSION. EPIGENETIC REGULATION, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND RNA INTERFERENCE, RESULTS IN HERITABLE CHANGES IN GENE EXPRESSION INDEPENDENT OF ALTERATIONS IN DNA SEQUENCE. EPIGENETIC REGULATION OFTEN OCCURS IN RESPONSE TO AGING AND ENVIRONMENT STIMULI, INCLUDING EXPOSURES AND DIET. STUDIES HAVE SHOWN THAT DNA METHYLATION IS CRITICAL IN THE PATHOGENESIS OF FIBROSIS INVOLVING MULTIPLE ORGAN SYSTEMS, CONTRIBUTING TO SIGNIFICANT MORBIDITY AND MORTALITY. ABERRANT DNA METHYLATION CAN SILENCE OR ACTIVATE GENE EXPRESSION PATTERNS THAT DRIVE THE FIBROSIS PROCESS. FIBROSIS IS A PATHOLOGICAL WOUND HEALING PROCESS IN RESPONSE TO CHRONIC INJURY. IT IS CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX PRODUCTION AND ACCUMULATION, WHICH EVENTUALLY AFFECTS ORGAN ARCHITECTURE AND RESULTS IN ORGAN FAILURE. FIBROSIS CAN AFFECT A WIDE RANGE OF ORGANS, INCLUDING THE HEART AND LUNGS, AND HAVE LIMITED THERAPEUTIC OPTIONS. DNA METHYLATION, LIKE OTHER EPIGENETIC PROCESS, IS REVERSIBLE, THEREFORE REGARDED AS ATTRACTIVE THERAPEUTIC INTERVENTIONS. ALTHOUGH EPIGENETIC MECHANISMS ARE HIGHLY INTERACTIVE AND OFTEN REINFORCING, THIS REVIEW DISCUSSES DNA METHYLATION-DEPENDENT MECHANISMS IN THE PATHOGENESIS OF ORGAN FIBROSIS, WITH FOCUS ON CARDIAC AND PULMONARY FIBROSIS. WE DISCUSS SPECIFIC PRO- AND ANTI-FIBROTIC GENES AND PATHWAYS REGULATED BY DNA METHYLATION IN ORGAN FIBROSIS; WE FURTHER HIGHLIGHT THE POTENTIAL BENEFITS AND SIDE-EFFECTS OF EPIGENETIC THERAPIES IN FIBROTIC DISORDERS. 2017 9 4228 23 METHYLATION OF INFLAMMATORY CELLS IN LUNG DISEASES. THIS CHAPTER OVERVIEWS ROLES OF DNA METHYLATION IN INFLAMMATORY CELL BIOLOGY WITH THE FOCUSES ON LYMPHOCYTES AND MACROPHAGES/MONOCYTES IN LUNG DISEASES, ALTHOUGH THE MOLECULAR MECHANISMS BY WHICH TARGET GENES ARE METHYLATED AND REGULATED IN LUNG DISEASES REMAIN UNCLEAR. MOST OF EPIGENETIC STUDIES ON DNA METHYLATION OF TARGET GENES IN LUNG DISEASES MAINLY DEMONSTRATED THE CORRELATION OF DNA METHYLATION OF TARGET GENES WITH THE LEVELS OF OTHER CORRESPONDING FACTORS, WITH THE SPECIFICITY OF CLINICAL PHENOMES, AND WITH THE SEVERITY OF LUNG DISEASES. THERE IS AN URGENT NEED TO IDENTIFY AND VALIDATE THE SPECIFICITY AND REGULATORY MECHANISMS OF INFLAMMATORY CELL EPIGENETICS IN DEPTH. THE EPIGENETIC HETEROGENEITY AMONG DIFFERENT SUBSETS OF T CELLS AND AMONG PROMOTERS OR NON-PROMOTERS OF TARGET GENES SHOULD BE FURTHERMORE CLARIFIED IN ACUTE OR CHRONIC LUNG DISEASES AND CANCERS. THE HYPER/HYPO-METHYLATION AND MODIFICATIONS OF CHROMOSOL AND EXTRACHROMOSOMAL DNA MAY RESULT IN ALTERNATIONS IN PROTEINS WITHIN INFLAMMATORY CELLS, WHICH CAN BE IDENTIFIED AS DISEASE-SPECIFIC BIOMARKERS AND THERAPEUTIC TARGETS. 2020 10 5258 33 PROGRESSION OF TUBULOINTERSTITIAL FIBROSIS AND THE CHRONIC KIDNEY DISEASE PHENOTYPE - ROLE OF RISK FACTORS AND EPIGENETICS. ALTHOUGH THE KIDNEY HAS CAPACITY TO REPAIR AFTER MILD INJURY, ONGOING OR SEVERE DAMAGE RESULTS IN SCARRING (FIBROSIS) AND AN ASSOCIATED PROGRESSIVE LOSS OF KIDNEY FUNCTION. HOWEVER, DESPITE ITS UNIVERSAL SIGNIFICANCE, EVIDENCE HIGHLIGHTS A POPULATION BASED HETEROGENEITY IN THE TRAJECTORY OF CHRONIC KIDNEY DISEASE (CKD) IN THESE PATIENTS. TO EXPLAIN THE HETEROGENEITY OF THE CKD PHENOTYPE REQUIRES AN UNDERSTANDING OF THE RELEVANT RISK FACTORS FOR FIBROSIS. THESE FACTORS INCLUDE BOTH THE EXTRINSIC NATURE OF INJURY, AND INTRINSIC FACTORS SUCH AS AGE, GENDER, GENETICS, AND PERPETUAL ACTIVATION OF FIBROBLASTS THROUGH PRIMING. IN MANY CASES AN ADDITIONAL LEVEL OF REGULATION IS PROVIDED BY EPIGENETIC MECHANISMS WHICH INTEGRATE THE VARIOUS PRO-FIBROTIC AND ANTI-FIBROTIC TRIGGERS IN FIBROGENESIS. IN THIS REVIEW WE THEREFORE EXAMINE THE VARIOUS MOLECULAR AND STRUCTURAL CHANGES OF FIBROSIS, AND HOW THEY ARE INFLUENCED BY EXTRINSIC AND INTRINSIC FACTORS. OUR AIM IS TO PROVIDE A UNIFYING HYPOTHESIS TO HELP EXPLAIN THE TRANSITION FROM ACUTE TO CKD. 2017 11 5456 23 RESEARCH ADVANCES ON DNA METHYLATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC COMPLEX LUNG DISEASE WITH NO SPECIFIC TREATMENT AND POOR PROGNOSIS, CHARACTERIZED BY THE PULMONARY PROGRESSIVE FIBROSIS AND DYSFUNCTIONS THAT LEAD TO RESPIRATORY FAILURE. SEVERAL FACTORS MAY IMPACT THE PROGRESS OF IPF, INCLUDING AGE, CIGARETTE SMOKING, AND DUSTS, OF WHICH GENETIC AND EPIGENETIC FACTORS MAINLY CONTRIBUTE TO LUNG TISSUE FIBROSIS. DNA METHYLATION IS ONE OF EPIGENETIC PROCESSES THAT OCCUR IN MANY DISEASES AND REGULATE CHROMOSOMAL AND EXTRACHROMOSOMAL DNA FUNCTIONS IN RESPONSE TO ENVIRONMENTAL EXPOSURES. THE METHYLATION PLAYS PIVOTAL ROLES IN REGULATION OF GENE EXPRESSION TO FACILITATE THE FORMATION OF FIBROBLASTIC FOCI AND LUNG FIBROSIS. THIS CHAPTER WILL DESCRIBE ALTERATIONS AND EFFECTS OF THE DNA METHYLATION ON GENE EXPRESSION, THE POTENTIAL APPLICATION OF DNA METHYLATION AS A BIOMARKER, AND SIGNIFICANCE AS THERAPEUTIC TARGETS. THOSE UNDERSTANDING WILL PROVIDE US NEW INSIGHT INTO THE TREATMENT AND PROGNOSIS OF IPF. 2020 12 5738 32 SMOKING AND LUNG CANCER: THE ROLE OF INFLAMMATION. WORLDWIDE OVER 1 MILLION PEOPLE DIE DUE TO LUNG CANCER EACH YEAR. IT IS ESTIMATED THAT CIGARETTE SMOKING EXPLAINS ALMOST 90% OF LUNG CANCER RISK IN MEN AND 70 TO 80% IN WOMEN. CLINICALLY EVIDENT LUNG CANCERS HAVE MULTIPLE GENETIC AND EPIGENETIC ABNORMALITIES. THESE ABNORMALITIES MAY RESULT IN ACTIVATION OF ONCOGENES AND INACTIVATION OF TUMOR-SUPPRESSOR GENES. CHRONIC INFLAMMATION, WHICH IS KNOWN TO PROMOTE CANCER, MAY RESULT BOTH FROM SMOKING AND FROM GENETIC ABNORMALITIES. THESE MEDIATORS IN TURN MAY BE RESPONSIBLE FOR INCREASED MACROPHAGE RECRUITMENT, DELAYED NEUTROPHIL CLEARANCE, AND INCREASE IN REACTIVE OXYGEN SPECIES (ROS). THUS, THE PULMONARY ENVIRONMENT PRESENTS A UNIQUE MILIEU IN WHICH LUNG CARCINOGENESIS PROCEEDS IN COMPLICITY WITH THE HOST CELLULAR NETWORK. THE PULMONARY DISEASES THAT ARE ASSOCIATED WITH THE GREATEST RISK FOR LUNG CANCER ARE CHARACTERIZED BY ABUNDANT AND DEREGULATED INFLAMMATION. PULMONARY DISORDERS SUCH AS CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)/EMPHYSEMA ARE CHARACTERIZED BY PROFOUND ABNORMALITIES IN INFLAMMATORY AND FIBROTIC PATHWAYS. THE CYTOKINES AND GROWTH FACTORS ABERRANTLY PRODUCED IN COPD AND THE DEVELOPING TUMOR MICROENVIRONMENT HAVE BEEN FOUND TO HAVE DELETERIOUS PROPERTIES THAT SIMULTANEOUSLY PAVE THE WAY FOR BOTH EPITHELIAL-MESENCHYMAL TRANSITION (EMT) AND DESTRUCTION OF SPECIFIC HOST CELL-MEDIATED IMMUNE RESPONSES. FULL DEFINITION OF THESE PATHWAYS WILL AFFORD THE OPPORTUNITY TO INTERVENE IN SPECIFIC INFLAMMATORY EVENTS MEDIATING LUNG TUMORIGENESIS AND RESISTANCE TO THERAPY. 2008 13 4882 31 OVERVIEW OF THE CELLULAR AND MOLECULAR BASIS OF KIDNEY FIBROSIS. THE COMMON PATHOGENETIC PATHWAY OF PROGRESSIVE INJURY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) IS EPITOMIZED AS NORMAL KIDNEY PARENCHYMAL DESTRUCTION DUE TO SCARRING (FIBROSIS). UNDERSTANDING THE FUNDAMENTAL PATHWAYS THAT LEAD TO RENAL FIBROSIS IS ESSENTIAL IN ORDER TO DEVELOP BETTER THERAPEUTIC OPTIONS FOR HUMAN CKD. ALTHOUGH COMPLEX, FOUR CELLULAR RESPONSES ARE PIVOTAL. (1) AN INTERSTITIAL INFLAMMATORY RESPONSE THAT HAS MULTIPLE CONSEQUENCES-SOME HARMFUL AND OTHERS HEALING. (2) THE APPEARANCE OF A UNIQUE INTERSTITIAL CELL POPULATION OF MYOFIBROBLASTS, PRIMARILY DERIVED FROM KIDNEY STROMAL CELLS (FIBROBLASTS AND PERICYTES), THAT ARE THE PRIMARY SOURCE OF THE VARIOUS EXTRACELLULAR MATRIX PROTEINS THAT FORM INTERSTITIAL SCARS. (3) TUBULAR EPITHELIAL CELLS THAT HAVE VARIABLE AND TIME-DEPENDENT ROLES AS EARLY RESPONDERS TO INJURY AND LATER AS VICTIMS OF FIBROSIS DUE TO THE LOSS OF THEIR REGENERATIVE ABILITIES. (4) LOSS OF INTERSTITIAL CAPILLARY INTEGRITY THAT COMPROMISES OXYGEN DELIVERY AND LEADS TO A VICIOUS CASCADE OF HYPOXIA-OXIDANT STRESS THAT ACCENTUATES INJURY AND FIBROSIS. IN THE ABSENCE OF ADEQUATE ANGIOGENIC RESPONSES, A HEALTHY INTERSTITIAL CAPILLARY NETWORK IS NOT MAINTAINED. THE FIBROTIC 'SCAR' THAT TYPIFIES CKD IS AN INTERESTING CONSORTIUM OF MULTIFUNCTIONAL MACROMOLECULES THAT NOT ONLY CHANGE IN COMPOSITION AND STRUCTURE OVER TIME, BUT CAN BE DEGRADED VIA EXTRACELLULAR AND INTRACELLULAR PROTEASES. ALTHOUGH TRANSFORMING GROWTH FACTOR BETA APPEARS TO BE THE PRIMARY DRIVER OF KIDNEY FIBROSIS, A VAST ARRAY OF ADDITIONAL MOLECULES MAY HAVE MODULATING ROLES. THE IMPORTANCE OF GENETIC AND EPIGENETIC FACTORS IS INCREASINGLY APPRECIATED. AN INTRIGUING BUT INCOMPLETELY UNDERSTOOD CARDIORENAL SYNDROME UNDERLIES THE HIGH MORBIDITY AND MORTALITY RATES THAT DEVELOP IN ASSOCIATION WITH PROGRESSIVE KIDNEY FIBROSIS. 2014 14 4043 30 MACROPHAGES IN CHRONIC LIVER FAILURE: DIVERSITY, PLASTICITY AND THERAPEUTIC TARGETING. CHRONIC LIVER INJURY RESULTS IN IMMUNE-DRIVEN PROGRESSIVE FIBROSIS, WITH RISK OF CIRRHOSIS DEVELOPMENT AND IMPACT ON MORBIDITY AND MORTALITY. PERSISTENT LIVER CELL DAMAGE AND DEATH CAUSES IMMUNE CELL ACTIVATION AND INFLAMMATION. PATIENTS WITH ADVANCED CIRRHOSIS ADDITIONALLY EXPERIENCE PATHOLOGICAL BACTERIAL TRANSLOCATION, EXPOSURE TO MICROBIAL PRODUCTS AND CHRONIC ENGAGEMENT OF THE IMMUNE SYSTEM. BACTERIAL INFECTIONS HAVE A HIGH INCIDENCE IN CIRRHOSIS, WITH SPONTANEOUS BACTERIAL PERITONITIS BEING THE MOST COMMON, WHILE THE SUBSEQUENT SYSTEMIC INFLAMMATION, ORGAN FAILURE AND IMMUNE DYSREGULATION INCREASE THE MORTALITY RISK. TISSUE-RESIDENT AND RECRUITED MACROPHAGES PLAY A CENTRAL PART IN THE DEVELOPMENT OF INFLAMMATION AND FIBROSIS PROGRESSION. IN THE LIVER, ADIPOSE TISSUE, PERITONEUM AND INTESTINES, DIVERSE MACROPHAGE POPULATIONS EXHIBIT GREAT PHENOTYPIC AND FUNCTIONAL PLASTICITY DETERMINED BY THEIR ONTOGENY, EPIGENETIC PROGRAMMING AND LOCAL MICROENVIRONMENT. THESE CHANGES CAN, AT DIFFERENT TIMES, PROMOTE OR AMELIORATE DISEASE STATES AND THEREFORE REPRESENT POTENTIAL TARGETS FOR MACROPHAGE-DIRECTED THERAPIES. IN THIS REVIEW, WE DISCUSS THE EVIDENCE FOR MACROPHAGE PHENOTYPIC AND FUNCTIONAL ALTERATIONS IN TISSUE COMPARTMENTS DURING THE DEVELOPMENT AND PROGRESSION OF CHRONIC LIVER FAILURE IN DIFFERENT AETIOLOGIES AND HIGHLIGHT THE POTENTIAL OF MACROPHAGE MODULATION AS A THERAPEUTIC STRATEGY FOR LIVER DISEASE. 2021 15 4038 29 MACROPHAGE IMPLICATION IN IPF: UPDATES ON IMMUNE, EPIGENETIC, AND METABOLIC PATHWAYS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A LETHAL INTERSTITIAL LUNG DISEASE OF UNKNOWN ETIOLOGY WITH A POOR PROGNOSIS. IT IS A CHRONIC AND PROGRESSIVE DISEASE THAT HAS A DISTINCT RADIOLOGICAL AND PATHOLOGICAL PATTERN FROM COMMON INTERSTITIAL PNEUMONIA. THE USE OF IMMUNOSUPPRESSIVE MEDICATION WAS SHOWN TO BE COMPLETELY INEFFECTIVE IN CLINICAL TRIALS, RESULTING IN YEARS OF NEGLECT OF THE IMMUNE COMPONENT. HOWEVER, RECENT DEVELOPMENTS IN FUNDAMENTAL AND TRANSLATIONAL SCIENCE DEMONSTRATE THAT IMMUNE CELLS PLAY A SIGNIFICANT REGULATORY ROLE IN IPF, AND MACROPHAGES APPEAR TO BE AMONG THE MOST CRUCIAL. THESE HIGHLY PLASTIC CELLS GENERATE MULTIPLE GROWTH FACTORS AND MEDIATORS THAT HIGHLY AFFECT THE INITIATION AND PROGRESSION OF IPF. IN THIS REVIEW, WE WILL PROVIDE AN UPDATE ON THE ROLE OF MACROPHAGES IN IPF THROUGH A SYSTEMIC DISCUSSION OF VARIOUS REGULATORY MECHANISMS INVOLVING IMMUNE RECEPTORS, CYTOKINES, METABOLISM, AND EPIGENETICS. 2023 16 1604 30 DNA METHYLATION SUSTAINS "INFLAMED" MEMORY OF PERIPHERAL IMMUNE CELLS AGGRAVATING KIDNEY INFLAMMATORY RESPONSE IN CHRONIC KIDNEY DISEASE. THE INCIDENCE OF CHRONIC KIDNEY DISEASE (CKD) HAS RAPIDLY INCREASED IN THE PAST DECADES. A PROGRESSIVE LOSS OF KIDNEY FUNCTION CHARACTERIZES A PART OF CKD EVEN WITH INTENSIVE SUPPORTIVE TREATMENT. IRRESPECTIVE OF ITS ETIOLOGY, CKD PROGRESSION IS GENERALLY ACCOMPANIED WITH THE DEVELOPMENT OF CHRONIC KIDNEY INFLAMMATION THAT IS PATHOLOGICALLY FEATURED BY THE LOW-GRADE BUT CHRONIC ACTIVATION OF RECRUITED IMMUNE CELLS. CUMULATIVE EVIDENCE SUPPORT THAT ABERRANT DNA METHYLATION PATTERN OF DIVERSE PERIPHERAL IMMUNE CELLS, INCLUDING T CELLS AND MONOCYTES, IS CLOSELY ASSOCIATED WITH CKD DEVELOPMENT IN MANY CHRONIC DISEASE SETTINGS. THE CHANGE OF DNA METHYLATION PROFILE CAN SUSTAIN FOR A LONG TIME AND AFFECT THE FUTURE GENES EXPRESSION IN THE CIRCULATING IMMUNE CELLS EVEN AFTER THEY MIGRATE FROM THE CIRCULATION INTO THE INVOLVED KIDNEY. IT IS OF CLINICAL INTEREST TO REVEAL THE UNDERLYING MECHANISM OF HOW ALTERED DNA METHYLATION REGULATES THE INTENSITY AND THE TIME LENGTH OF THE INFLAMMATORY RESPONSE IN THE RECRUITED EFFECTOR CELLS. WE AND OTHERS RECENTLY DEMONSTRATED THAT ALTERED DNA METHYLATION OCCURS IN PERIPHERAL IMMUNE CELLS AND PROFOUNDLY CONTRIBUTES TO CKD DEVELOPMENT IN SYSTEMIC CHRONIC DISEASES, SUCH AS DIABETES AND HYPERTENSION. THIS REVIEW WILL SUMMARIZE THE CURRENT FINDINGS ABOUT THE INFLUENCE OF ABERRANT DNA METHYLATION ON CIRCULATING IMMUNE CELLS AND HOW IT POTENTIALLY DETERMINES THE OUTCOME OF CKD. 2021 17 5581 24 ROLE OF NF-KAPPAB IN AGEING AND AGE-RELATED DISEASES: LESSONS FROM GENETICALLY MODIFIED MOUSE MODELS. AGEING IS A COMPLEX PROCESS, INDUCED BY MULTIFACETED INTERACTION OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. IT IS MANIFESTED BY A DECLINE IN THE PHYSIOLOGICAL FUNCTIONS OF ORGANISMS AND ASSOCIATED TO THE DEVELOPMENT OF AGE-RELATED CHRONIC DISEASES AND CANCER DEVELOPMENT. IT IS CONSIDERED THAT AGEING FOLLOWS A STRICTLY-REGULATED PROGRAM, IN WHICH SOME SIGNALING PATHWAYS CRITICALLY CONTRIBUTE TO THE ESTABLISHMENT AND MAINTENANCE OF THE AGED STATE. CHRONIC INFLAMMATION IS A MAJOR MECHANISM THAT PROMOTES THE BIOLOGICAL AGEING PROCESS AND COMORBIDITY, WITH THE TRANSCRIPTION FACTOR NF-KAPPAB (NUCLEAR FACTOR KAPPA-LIGHT-CHAIN-ENHANCER OF ACTIVATED B CELLS) AS A CRUCIAL MEDIATOR OF INFLAMMATORY RESPONSES. THIS, TOGETHER WITH THE FINDING THAT THE ACTIVATION OR INHIBITION OF NF-KAPPAB CAN INDUCE OR REVERSE RESPECTIVELY THE MAIN FEATURES OF AGED ORGANISMS, HAS BROUGHT IT UNDER CONSIDERATION AS A KEY TRANSCRIPTION FACTOR THAT ACTS AS A DRIVER OF AGEING. IN THIS REVIEW, WE FOCUSED ON THE DATA OBTAINED ENTIRELY THROUGH THE GENERATION OF KNOCKOUT AND TRANSGENIC MOUSE MODELS OF EITHER PROTEIN INVOLVED IN THE NF-KAPPAB SIGNALING PATHWAY THAT HAVE PROVIDED RELEVANT INFORMATION ABOUT THE INTRICATE PROCESSES OR MOLECULAR MECHANISMS THAT CONTROL AGEING. WE HAVE REVIEWED THE RELATIONSHIP OF NF-KAPPAB AND PREMATURE AGEING; THE DEVELOPMENT OF CANCER ASSOCIATED WITH AGEING AND THE IMPLICATION OF NF-KAPPAB ACTIVATION IN THE DEVELOPMENT OF AGE-RELATED DISEASES, SOME OF WHICH GREATLY INCREASE THE RISK OF DEVELOPING CANCER. 2021 18 1188 36 COPD: A MULTIFACTORIAL SYSTEMIC DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) HAS TRADITIONALLY BEEN CONSIDERED A DISEASE OF THE LUNGS SECONDARY TO CIGARETTE SMOKING AND CHARACTERIZED BY AIRFLOW OBSTRUCTION DUE TO ABNORMALITIES OF BOTH AIRWAY (BRONCHITIS) AND LUNG PARENCHYMA (EMPHYSEMA). IT IS NOW WELL KNOWN THAT COPD IS ASSOCIATED WITH SIGNIFICANT SYSTEMIC ABNORMALITIES, SUCH AS RENAL AND HORMONAL ABNORMALITIES, MALNUTRITION, MUSCLE WASTING, OSTEOPOROSIS, AND ANEMIA. HOWEVER, IT IS STILL UNCLEAR WHETHER THEY REPRESENT CONSEQUENCES OF THE PULMONARY DISORDER, OR WHETHER COPD SHOULD BE CONSIDERED AS A SYSTEMIC DISEASE. THESE SYSTEMIC ABNORMALITIES HAVE BEEN ATTRIBUTED TO AN INCREASED LEVEL OF SYSTEMIC INFLAMMATION. CHRONIC INFLAMMATION, HOWEVER, MAY NOT BE THE ONLY CAUSE OF THE SYSTEMIC EFFECTS OF COPD. RECENT DATA FROM HUMANS AND ANIMAL MODELS SUPPORT THE VIEW THAT EMPHYSEMA MAY BE A VASCULAR DISEASE. OTHER STUDIES HAVE HIGHLIGHTED THE ROLE OF REPAIR FAILURE, BONE MARROW ABNORMALITY, GENETIC AND EPIGENETIC FACTORS, IMMUNOLOGICAL DISORDERS AND INFECTIONS AS POTENTIAL CAUSES OF COPD SYSTEMIC MANIFESTATIONS. BASED ON THIS NEW EVIDENCE, IT IS REASONABLE TO CONSIDER COPD, AND EMPHYSEMA IN PARTICULAR, AS 'A DISEASE WITH A SIGNIFICANT SYSTEMIC COMPONENT' IF NOT A 'SYSTEMIC DISEASE' PER SE. THE AIM OF THIS REVIEW IS TO GIVE AN OVERVIEW OF THE MOST RELEVANT AND INNOVATIVE HYPOTHESIS ABOUT THE EXTRAPULMONARY MANIFESTATIONS OF COPD. 2011 19 2232 31 EPIGENETIC MODIFICATIONS OF MIRNAS IN OSTEOARTHRITIS: A SYSTEMATIC REVIEW ON THEIR METHYLATION LEVELS AND EFFECTS ON CHONDROCYTES, EXTRACELLULAR MATRIX AND JOINT INFLAMMATION. OSTEOARTHRITIS (OA) IS A JOINT DISORDER CHARACTERIZED BY PROGRESSIVE DEGENERATION OF CARTILAGE EXTRACELLULAR MATRIX (ECM), CHONDROCYTE HYPERTROPHY AND APOPTOSIS AND INFLAMMATION. THE CURRENT TREATMENTS MAINLY CONCERN PAIN CONTROL AND REDUCTION OF INFLAMMATION, BUT NO THERAPEUTIC STRATEGY HAS BEEN IDENTIFIED AS A DISEASE-MODIFYING TREATMENT. THEREFORE, IDENTIFYING SPECIFIC BIOMARKERS USEFUL TO PREVENT, TREAT OR DISTINGUISH THE STAGES OF OA DISEASE HAS BECOME AN IMMEDIATE NEED OF CLINICAL PRACTICE. THE ROLE OF MICRORNAS (MIRNAS) IN OA HAS BEEN INVESTIGATED IN THE LAST DECADE, AND INCREASING EVIDENCE HAS EMERGED THAT THE INFLUENCE OF THE ENVIRONMENT ON GENE EXPRESSION THROUGH EPIGENETIC PROCESSES CONTRIBUTES TO THE DEVELOPMENT, PROGRESSION AND AGGRESSIVENESS OF OA, IN PARTICULAR ACTING ON THE MICROENVIRONMENT MODULATIONS. THE EFFECTS OF EPIGENETIC REGULATION, PARTICULARLY DIFFERENT MIRNA METHYLATION DURING OA DISEASE, WERE HIGHLIGHTED IN THE PRESENT SYSTEMATIC REVIEW. THE EVIDENCE ARISING FROM THIS STUDY OF THE LITERATURE CONDUCTED IN THREE DATABASES (PUBMED, SCOPUS, WEB OF SCIENCE) SUGGESTED THAT MIRNA METHYLATION STATE ALREADY STRONGLY IMPACTS OA PROGRESSION, DRIVING CHONDROCYTES AND SYNOVIOCYTE PROLIFERATION, APOPTOSIS, INFLAMMATION AND ECM DEPOSITION. HOWEVER, THE POSSIBILITY OF UNDERSTANDING THE MECHANISM BY WHICH DIFFERENT EPIGENETIC MODIFICATIONS OF MIRNA OR PRE-MIRNA SEQUENCES DRIVE THE AGGRESSIVENESS OF OA COULD BE THE NEW FOCUS OF FUTURE INVESTIGATIONS. 2023 20 3703 26 INFLAMMATORY SIGNALLING AS MEDIATOR OF EPIGENETIC MODULATION IN TISSUE-SPECIFIC CHRONIC INFLAMMATION. RECENT SUCCESSES OF THERAPEUTIC INTERVENTION IN CHRONIC INFLAMMATORY DISEASES USING EPIGENETIC MODIFIERS SUCH AS HISTONE DEACETYLASE INHIBITORS AND INHIBITORS OF DNA METHYLATION SUGGEST THAT EPIGENETIC REPROGRAMMING PLAYS A ROLE IN THE AETIOLOGY OF THESE DISEASES. THE EPIGENETIC SIGNATURE OF A GIVEN IMMUNE CELL IS REFLECTED IN THE HISTORY OF MODIFICATIONS FROM DIFFERENT SIGNALS THE CELL HAS BEEN SUBJECTED TO DURING DIFFERENTIATION. LIKE OTHER CELLS, DIFFERENTIATING IMMUNE CELLS ARE DEPENDENT ON A COMPLEX COMBINATION OF INTER- AND INTRACELL SIGNALLING AS WELL AS TRANSCRIPTION MACHINERIES TO MODULATE THEIR EPIGENOMES IN ORDER TO MEDIATE DIFFERENTIATION. DESPITE EXTENSIVE RESEARCH INTO THESE PROCESSES, THE LINK BETWEEN CELLULAR SIGNALLING AND EPIGENETIC MODULATION REMAINS POORLY UNDERSTOOD. HERE, WE REVIEW RECENT PROGRESS AND DISCUSS KEY FACTORS DRIVING EPIGENETIC MODULATION IN CHRONIC INFLAMMATION. 2009