AB0067 RHEUMATOID ARTHRITIS IS DRIVEN NOT ONLY BY INFLAMMATION BUT ALSO BY FIBROGENESIS

Background:Rheumatoid arthritis (RA) is a chronic, autoimmune disease characterized by inflammation of the synovium, cartilage and bone leading to joint swelling, tenderness, and dysfunction. The destruction of the joint tissue involves degradation of the extracellular matrix (ECM). The ECM consist of collagens and other connective proteins1. Studies have shown that elevated levels of collagen metabolites, such as those of type I, II, III and VI, are highly elevated in RA, correlated to disease activity and modulated in response to, for example tocilizumab2, baricitinib3 and methotrexate4. However, little is known about the formation of collagen, fibroblast activity, the fibrotic component of RA and how this influence likelihood of response to treatment.Objectives:We investigated the level of active fibrogenesis in a population of moderate to severe RA patients (in contrast healthy controls) by assessing blood-levels of PRO-C3 and PRO-C6 (type III and VI collagen formation markers), which have been reported to be associated with the degree and extent of fibrosis5.Methods:PRO-C3 and PRO-C6 was measured in serum of 166 RA patients (age; 54 (20-82), 83 % females, 91% white) at baseline and week 16 after treatment with an anti-IL6 receptor antibody in combination with MTX, as well as in serum of 77 donors (age; 42 (20-69), 51 % females, 66% white). Marker data was LN transformed. A general linear model was used when comparing groups.Results:The serum fibrogenesis marker PRO-C3, but not PRO-C6, was significantly elevated in RA compared to donors (2.1 vs. 2.4 ≈ 30% difference, p<0.0001, fig. 1A). None of the markers were correlated with disease measures such as DAS28, CRP, VASpain. None of the markers were modulated significantly in response to treatment. Interestingly, PRO-C3 levels were significantly higher at in non-responders (resp.) at week 16 compared to resp. (2.8 vs. 2.4 ≈ 40% difference, p=0.0018, fig. 1C). Similar trend was observed for PRO-C6 (2.2 vs. 2.0 ≈ 20% difference, p=0.061 fig. 1D).Conclusion:Active fibrosis, with activated fibroblasts, may play an unseen role in RA. Patients will elevated levels of the fibrosis markers PRO-C3 and PRO-C6 were less likely to respond to an anti-IL6R. This may also give clue why such treatment are less efficacious in diseases with a clear fibrotic component.References:[1]Karsdal et al. Rheumatoid arthritis: A case for personalized health care? ACR 2014; 66: 1273–80.[2]Bay-Jensen et al. Effect of tocilizumab combined with methotrexate on circulating biomarkers of synovium, cartilage, and bone in the LITHE study. SAR 2014; 43: 470–8.[3]Thudium et al. The Janus kinase 1/2 inhibitor baricitinib reduces biomarkers of joint destruction in moderate to severe rheumatoid arthritis. ART 2020; 22.[4]Drobinski et al. Connective tissue remodeling is differently modulated by tocilizumab versus methotrexate monotherapy in patients with early rheumatoid arthritis: the AMBITION study. ART 2021; 23.[5]Karsdal et al. Profiling and targeting connective tissue remodeling in autoimmunity - A novel paradigm for diagnosing and treating chronic diseases. AutoRev 2021; 20.Disclosure of Interests:None declared

Local Shifts in Inflammatory and Resolving Lipid Mediators in Response to Tendon Overuse

Tendon inflammation has been implicated in both adaptive connective tissue remodeling and overuse-induced tendinopathy. Lipid mediators control the initiation and resolution of inflammation, but their roles within tendon are largely unknown. Here we profiled local shifts in intratendinous lipid mediators via liquid chromatography-tandem mass spectrometry in response to synergist ablation-induced plantaris tendon overuse. Sixty-four individual lipid mediators were detected in homogenates of habitually loaded plantaris tendons from healthy ambulatory rats. This included many bioactive metabolites of the cyclooxygenase (COX), lipoxygenase (LOX), and epoxygenase (CYP) pathways. Synergist ablation induced a robust inflammatory response at day 3 post-surgery characterized by epitenon infiltration of polymorphonuclear leukocytes (PMNs) and macrophages (MΦ), heightened expression of inflammation-related genes, and increased intratendinous concentrations of the pro-inflammatory eicosanoids thromboxane B2 (TXB2) and prostaglandin E2 (PGE2). By day 7, MΦ became the predominant myeloid cell type in tendon and there were further delayed increases in other COX metabolites including PGD2, PGF2α and PGI2. Specialized pro-resolving mediators (SPMs) including protectin D1 (PD1) and resolvin D6 (RvD6), as well as related pathway markers of D-resolvins (17-HDoHE), E-resolvins (18-HEPE) and lipoxins (15-HETE) were also increased locally in response to tendon overuse, as were many anti-inflammatory fatty acid epoxides of the CYP pathway (e.g. EpETrEs). Nevertheless, intratendinous prostaglandins remained markedly increased even following 28 days of tendon overuse together with a lingering MΦ presence. These data reveal a delayed and prolonged local inflammatory response to tendon overuse characterized by an overwhelming predominance of pro-inflammatory eicosanoids and a relative lack of pro-resolving lipid mediators.

Mechanisms for remodeling of connective tissue of the pelvic floor during pregnancy, childbirth and in the postpartum period

The analysis of literature data on molecular mechanisms for remodeling of connective tissue of the female reproductive system during pregnancy, childbirth and in the postpartum period is presented. The search for publications and their analysis was conducted in PUBMED, Google Scholar, eLIBRARY.RU databases. Particular attention was given to the study of expression pattern of specific proteinases involved in the process of synthesis and combination of elastic fibers, assembly of the collagen polypeptide chains at different stages. The place of matrix metalloproteinases and their tissue inhibitors in proteolytic degradation of the extracellular matrix of connective tissue is described. Pregnancy, childbirth and postpartum period are the triggering mechanism for connective tissue remodeling, certain mechanisms of which remain unclear and require further investigation. Key words: collagen, lysyl oxidase, metalloproteinases, сonnective tissue, fibulin-5, extracellular matrix, elastic fibers

Morphological features and the functional state of connective tissue of the uterine rudiments in reproductive age patients with Mayer–Rokitansky–Küster–Hauser syndrome

Introduction. Female patients with Mayer–Rokitansky–Küster–Hauser syndrome (MRKH) have high stigma scores; the condition severely affects the reproductive system. The study aimed at specification of morphological features and assessment of the maturity of connective tissues of the uterine rudiments in MRKH. Patients and methods. The study included 42 patients with vaginal and uterine aplasia having functioning uterine rudiments and 47 patients of the control group without genital malformations. Age of the patients was 20-24 years in 67.2% of the cases, and 31.2% of the patients were aged ≤ 19, inclusive. Immunohistochemi-cal assay was applied to determine expression levels of collagen I, collagen III, ММР2, ММР9, TIMP1, fibronectin and laminin proteins within the functioning uterine rudiments in comparison with levels of the same proteins in normally developed uterine tissues. Results. Decreased expression of collagen type I and elevated levels of MMP2 and MMP9 proteins in uterine tissues were observed for the group of patients with MRKH. Conclusions. 1) Uterine rudiments in patients with MRKH show variable degree of morphological similarity with the normally developed uterus; 2) The functioning uterine rudiments are subject to the same pathological processes as the normally developed uterus (myoma, endometriosis). 3) The functioning uterine rudiments in patients with MRKH show altered patterns of connective tissue remodeling, with decreased expression of collagen type I and increased expression of matrix metalloproteinases MMP2 and MMP9. Keywords: Müllerian aplasia, uterine rudiments, metalloproteinases, connective tissue remodeling, ММР2, ММР9

CONNECTIVE TISSUE METABOLISM IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS: 10-YEAR FOLLOW-UP STUDY

CONNECTIVE TISSUE METABOLISM IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS: 10-YEAR FOLLOW-UP STUDYShevchenko N.S., Panko N.O., Rakovska L.O., Holovko T.O. Connective tissue remodeling is essential for progressive course of juvenile idiopathic arthritis (JIA), therefore changes in glucosaminoglycans (GAGs) fractions with time in patients with JIA have been studied during 10-year follow-up. The study involved 22 healthy children (controls) and 83 patients with JIA aged from 2 to 18. The follow‑up study was yearly held for 10 years and initially included 14 patients with JIA investigated for connective tissue metabolism. Proteoglycans metabolism in children with JIA is characterized by a decrease in the total GAGs, mainly by means of low levels of chondroitin-4-sulfate and highly sulphonated GAGs. This redistribution was more specific for children with prolonged disease duration (more than 5 years). Slowing of proteoglycans metabolism in reducing the excretion of uronic acids was the most common for up to 2 years of disease duration as compared to later stages. The severity of metabolic imbalance of proteoglycans depends on the duration of JIA and has the most unfavorable period of 5 years and later after the onset of the disease.Keywords: juvenile idiopathic arthritis, connective tissue metabolism. МЕТАБОЛІЗМ СПОЛУЧНОЇ ТКАНИНИ У ПАЦІЄНТІВ ІЗ ЮВЕНІЛЬНИМ ІДІОПАТИЧНИМ АРТРИТОМ: 10-РІЧНИЙ КАТАМНЕЗ.Шевченко Н.С., Панько Н.О., Раковська Л.О., Головко Т.О. Ремоделювання сполучної тканини є важливою складовою прогресуючого перебігу ювенільного ідіопатичного артриту (ЮІА), тому метою даного дослідження було вивчення динаміки змін з боку окремих фракцій глюкозаміногліканів (ГАГ) у пацієнтів з ЮІА впродовж 10 років. Дослідження включало 83 пацієнта з ЮІА віком від 2 до 18 років і 22 здорові дитини порівнюваних за віком та статтю. Катамнестичне спостереження проводилося протягом 10 років і спочатку стартувало з обстеження сполучнотканинного обміну у 14 хворих на ЮІА, показники якого у подальшому контролювалися в динаміці. В результаті дослідження було виявлено, що метаболізм протеогліканів у дітей з ЮІА характеризувався зниженням загального рівня ГАГ, в основному за рахунок хондроїтин-4-сульфату і високосульфанізованих ГАГ. Дана тенденція була найбільш характерною для доволі пізніх строків розвитку ЮІА (при анамнезі більше 5 років). Уповільнення обміну протеогліканів, про що свідчило зниження екскреції уронових кислот, найбільш часто виявлялося в період до 2 років у порівнянні з більш пізніми термінами перебігу хвороби.Таким чином, зміни сполучнотканинного обміну залежали від тривалості захворювання і були найбільш виражені в період 5 років і більше від початку захворювання.Ключові слова: ювенільний ідіопатичний артрит, обмін сполучної тканини. МЕТАБОЛИЗМ СОЕДИНИТЕЛЬНОЙ ТКАНИ У ПАЦИЕНТОВ С ЮВЕНИЛЬНЫМ ИДИОПАТИЧЕСКИМ АРТРИТОМ: 10-ЛЕТНИЙ КАТАМНЕЗ.Шевченко Н.С., Панько Н.А., Раковская Л.А., Головко Т.А. Ремоделирование соединительной ткани является важной составляющей прогрессирующего течения ювенильного идиопатического артрита (ЮИА), поэтому целью данного исследования было изучение динамики изменений со стороны отдельных фракций глюкозаминогликанов (ГАГ) у пациентов с ЮИА на протяжении 10 лет.Исследование включало 83 пациента с ЮИА возрастом от 2 до 18 лет и 22 здоровых ребенка сопоставимых по возрасту и полу. Катамнестическое наблюдение проводилось в течение 10 лет и изначально стартовало с обследования соединительно-тканного обмена у 14 детей с ЮИА, который в последующем контролировался в динамике. В результате исследования было выявлено, что метаболизм протеогликанов у детей с ЮИА характеризуется снижением общего уровня ГАГ, в основном за счет хондроитин-4-сульфата и высокосульфанизированных ГАГ. Данная тенденция была наиболее характерной для более позних сроков ЮИА (при анамнезе более 5 лет). Замедление обмена протеогликанов, о чем свидетельствовало снижение экскреции уроновых кислот, наиболее часто выявлялось в период до 2 лет в сравнении с более поздними сроками развития болезни.Таким образом, изменения соединительно-тканного обмена зависели от длительности заболевания и были наиболее выражены в период 5 лет и более от начала заболевания. Ключевые слова: ювенильный идиопатический артрит, обмен соединительной ткани.

Functional implications of the utero-placental relaxin (RLN) system in the dog throughout pregnancy and at term

Relaxin (RLN) is a key hormone of pregnancy in mammals best known for its involvement in connective tissue remodeling. In the domestic dog, placental RLN is the only known endocrine marker of pregnancy. However, knowledge is sparse regarding the spatio-temporal expression of RLN and its receptors (RXFP1 and RXFP2) in the canine uterus and placenta. Here, their expression was investigated in the pre-implantation uterus and utero-placental compartments (UtPl) at selected time points during gestation: post-implantation, mid-gestation, and at normal and antigestagen-induced luteolysis/abortion. Immunohistochemistry with newly generated, canine-specific antisera,in situhybridization and semi-quantitative PCR were applied. In compartmentalization studies, placental and endometrialRLNincreased continuously toward prepartum. The placentalRXFP1was time-related and highest during post-implantation and decreased together withRXFP2at prepartum luteolysis. The endometrial levels of both receptors did not vary greatly, but myometrialRXFP2decreased from mid-gestation to prepartum luteolysis. Antigestagen treatment resulted in suppression ofRLNin UtPl and decreasedRXFP1andRXFP2in the uterus. The placental RLN was localized mainly in the cytotrophoblast. Additionally, RXFP1 stained strongly in placental endothelial cells while RXFP2 was found mainly in maternal decidual cells. Uterine staining for all targets was found in epithelial cellular constituents and in myometrium. Finally, besides its endocrine functions, RLN seems to be involved in auto-/paracrine regulation of utero-placental functions in dogs in a time-dependent manner. New insights into feto-maternal communication was provided, in particular regarding the localization of RXFP2 in the maternal decidual cells, implying functional roles of RLN during the decidualization process.

Analysis of MMP-3 polymorphism in osseointegrated implant failure

Polymorphisms in matrix metalloproteinases (MMPs) genes have been associated with several pathologies, including dental implant loss. MMP-3 is crucial to the connective tissue remodeling process. The objective of this study was to investigate the possible relationship between -1612 MMP-3 polymorphism and the early implant failure. A sample of 240 non-smokers was divided: test group 120 patients with one or more early failed implants and control group 120 patients with one or more healthy implants. Genomic DNA from oral mucosa was analyzed by PCR-RFLP. No association of early implant loss with genotypes and alleles of the -1612 polymorphism in MMP-3 were found by the Chi-squared test. Only the presence of the -1612 polymorphism of MMP-3 is not a genetic risk factor for early loss of implants.