Vloga monocitov in poškodbe DNA v vnetnih procesih pri bolnikih s sistemsko sklerozo ter vpletenost adiponektina in resolvina v razvoj fibroze

Brezovec, Neža (author), Čučnik, Saša (mentor), Lakota, Katja (comentor)

Sistemska skleroza (SSc) je sistemska avtoimunska revmatska bolezen, katere patogeneza ni popolnoma razjasnjena, tudi obvladovanje glavnih kliničnih znakov, kot sta vnetje in fibroza, s farmakoterapijo pogosto ni učinkovito. Z namenom boljšega razumevanja patogeneze in odkrivanja novih terapevtskih učinkovin smo proučevali oksidativni stres in migracijo monocitov pri bolnikih s SSc ter učinke adiponektina in resolvina D1 na vnetje in fibrozo. Metodološki pristop je zajemal delo na vzorcih bolnikov s SSc in zdravih oseb, celičnih kulturah in živalskem modelu. Pri bolnikih s SSc smo izmerili povišan indeks oksidativnega stresa (na osnovi povišanih serumskih reaktivnih kisikovih metabolitov in/ali antioksidantne kapacitete), več prelomov DNA v levkocitih ter oslabljene popravljalne mehanizme poškodb DNA. Na površini monocitov bolnikov s SSc smo dokazali povečano izražanje adhezijske molekule CD62L, katere izražanje je bilo spodbujeno s komponentami seruma bolnikov. Spremembe v oksidativnem stanju in migratornem fenotipu monocitov so pri bolnikih s SSc sovpadale s pljučno prizadetostjo, prisotnostjo avtoprotiteles in uporabo farmakoterapije. Na skeletnomišičnih celicah in skeletnomišičnih fibroblastih smo pokazali, da se adiponektin vpleta v vnetje in mišično regeneracijo z aktivacijo znotrajceličnih signalnih poti ter s spodbujanjem izločanja interlevkina-6 in sfingozin-1-fosfata, kot možne posledice povečane ceramidazne aktivnosti adiponektinskih receptorjev. AdipoRon, analog adiponektina, primerljivih učinkov ni izkazal. Resolvin D1 je na mišjem modelu peritonealne fibroze znižal delež polimorfonuklearnih celic v sistemskem krvnem obtoku, medtem ko vpliva na lokalno vnetje in fibrozo v trebušni steni ni imel. Negativno je vplival na izražanje hemerina, regulatorja vnetnih procesov, ki se veže na isti receptor kot resolvin E1. V doktorski disertaciji smo pokazali, kako obsežnejše stanje oksidativnega stresa in večji potencial migracije monocitov pri SSc sovpada s klinično sliko bolezni ter tako pripomogli k boljšemu razumevanju patogeneze. Obenem smo dokazali, da ima adiponektin učinke na mišično vnetje in regeneracijo, resolvin D1 pa potencial obvladovanja vnetja v fibrotičnih boleznih tudi z regulacijo izražanja ligandov resolvinskih receptorjev.

• Language: Slovenian
• Keywords: sistemska skleroza, vnetje, fibroza, monociti, oksidativni stres, poškodbe DNA, adiponektin, AdipoRon, resolvin D1
• Work type: Doctoral dissertation
• Organization: FFA - Faculty of Pharmacy
• Year: 2023
• PID: 20.500.12556/RUL-144918
• Publication date in RUL: 23.03.2023

Secondary language

• Language: English
• Title: The role of monocytes and DNA damage in inflammation of patients with systematic sclerosis and involvement of adiponectina and resolvin in fibrotic development

Abstract

Systemic sclerosis (SSc) is a systemic autoimmune rheumatic disease whose pathogenesis remains poorly understood, and pharmacotherapy for the major clinical manifestations - inflammation and fibrosis - is often ineffective. To better understand the pathogenesis and find new therapeutic options, we investigated oxidative stress and monocyte migration in SSc and effects of adiponectin and resolvin D1 on inflammation and fibrosis. Our methodological approach included work with samples from SSc patients, cell cultures, and animal models. SSc patients exhibited a higher oxidative stress index (based on increased serum reactive oxygen metabolites and/or antioxidant capacity), more DNA breaks in leukocytes, and impaired DNA damage repair mechanisms. We found increased surface expression of the adhesion molecule CD62L on SSc monocytes and showed that CD62L expression is stimulated by SSc serum components. Both the altered oxidative status and monocyte phenotype were consistent with lung involvement, autoantibodies, and pharmacotherapy in SSc patients. In skeletal muscle cells and skeletal muscle fibroblasts, adiponectin acted on inflammation and muscle regeneration by activating intracellular signalling pathways and stimulating secretion of interleukin-6 and sphingosine-1-phosphate, possibly due to increased ceramidase activity of adiponectin receptors. AdipoRon, an adiponectin analogue, did not show comparable effects. In a mouse model of peritoneal fibrosis, resolvin D1 decreased the proportion of polymorphonuclear cells in the systemic circulation, whereas locally in the abdominal wall it had no effect on inflammation and fibrosis. It also downregulated the expression of chemerin, an important regulator of inflammation that binds to the same receptor as resolvin E1. In our work, we show that oxidative stress and increased migratory potential of monocytes in SSc correspond to the clinical picture of the disease. We show that adiponectin has effects on muscle inflammation and regeneration and that resolvin D1 has the potential to promote resolution of inflammation by regulating the expression of other resolvin receptor ligands.

• Keywords: systemic sclerosis, inflammation, fibrosis, monocytes, oxidative stress, DNA damage, adiponectin, AdipoRon, resolvin D1