Proliferation Of Synovial Cells Research Articles

Effects of Plastics on Inflammatory Bowel Disease and Arthritis - Implication for Sport and Recreation: A Review

Background: Arthritis and inflammatory bowel diseases (IBD) are autoimmune disorders marked by chronic inflammation. Arthritis affects the synovial membrane of joints, while IBD inflames the digestive system's walls. In this study, the inflammatory bowel disease (IBD) group mainly includes Crohn's disease and ulcerative colitis, while the arthritis analysed includes rheumatoid arthritis and the joint manifestations of systemic lupus erythematosus. Recent publications highlights the adverse effects of micro and nanoplastics on health, suggesting they may exacerbate these autoimmune disorders. Studies show that plastic accumulation can contribute to gastrointestinal and musculoskeletal diseases.Purpose: This review aims to summarize current knowledge on how microplastics influence the development of autoimmune disorders in the gastrointestinal and musculoskeletal systems, based on scientific literature, and examine their impact on sports and recreation health.Methods and Materials: A literature review was conducted using PubMed and Google Scholar databases with relevant keywords. An analysis of the collected data was performed.Conclusion: Ingesting micro- and nanoplastic particles disrupts immune homeostasis in the gastrointestinal tract and joints. It alters gut microbiota and metabolism, exacerbates arthritis by affecting synovial membrane cell proliferation and migration, among other effects. High plastic exposure may promote autoimmune diseases, potentially restricting individuals from professional and recreational physical activities, worsening health problems, promoting other diseases, and leading to premature death.

Exploring micro needles applications in rheumatoid arthritis: efficacy, safety, and patient benefits

The most significant organ in the body, the skin is also where many drugs are administered. Many benefits, including averting first-pass liver metabolism, maintaining a steady levels of plasma, safety, as well as complying over oral or parenteral methods, come with drug delivery via the skin. A few of the microscale physical improvements that significantly broadens the range of medications available for through the skin and intradermal application is the use of microneedles. Microneedles are delineate to pierce the stratum corneum, the topmost layer of the skin, deprive of giving rise to considerable exertion or tissue destruction. They are consistently tens to hundreds of micrometres in size. An array of goods, for instance silicon, polymers, and stainless steel, has been utilized to create solid, coated, hollow, and dissolvable microneedles. Meanwhile, because of their superior biocompatibility, reduced preparation expense, and strong mechanical qualities, biodegradable polymers have steadily emerged as the material of choice for creating MNs. The technique of creating microneedle arrays enhances safety, effectiveness, and bioavailability to enable medication delivery via the skin. The autoimmune disease known as rheumatoid arthritis (RA) is marked by chronic synovitis, reduced joint function, inflammation, proliferation of synovial cells, formation of pannus, and consequent loss of cartilage as well as bone. In recent years, microneedles have proven to be an incredibly effective therapeutic tool in the delivery of medications, genes, proteins, RNA, and vaccinations. The many kinds of MNs, the materials utilised to make them, and their characteristics in terms of administering treatments for rheumatoid arthritis are all covered in the current review.

Chemical constituents from stems and leaves of Mycetia hainanensis and their anti-rheumatoid arthritis activities

The chemical constituents from the stems and leaves of Mycetia hainanensis were isolated by silica gel, ODS gel, and Sephadex LH-20 gel column chromatography and preparative HPLC. The chemical structures of all the isolated compounds were identified on the basis of their physicochemical properties, spectroscopic data, as well as the comparison of their physicochemical and spectroscopic data with the reported data in literature. Twelve compounds were isolated from the 85% ethanol extract of the stems and leaves of M. hainanensis, and they were identified as mycehainanic acid(1), 11-methoxyviburtinal(2), isovaltrate acetoxyhydrin(3), jatamanvaltrate K(4), jatamanin C(5), sarmentol F(6), 4,5-dihydroblumenol A(7), petasitolone(8), xylaguaianol D(9), aristolan-9-en-1-one(10), 3α-hydroxycostic acid(11), and ilicic acid(12). Among them, compound 1 was a new nor-sesquiterpene, and compounds 2-12 were isolated from Mycetia for the first time. In addition, the MTS method was employed to assess the anti-rheumatoid arthritis activities of compounds 1-12 based on their anti-proliferative effects on synoviocytes in vitro. The results showed that compounds 1 and 6-12 exhibited notable anti-rheumatoid arthritis activities, showcasing inhibitory effects on the proliferation of MH7A synovial fibroblast cells with the IC_(50) ranging from(5.27±0.07) to(172.68±0.32)μmol·L~(-1), which were comparable to that of the positive control methotrexate \[IC_(50) of(132.39±0.21)μmol·L~(-1)\].

Zhuanggu Jianxi Decoction reduces synovial tissue inflammation in human knee osteoarthritis by regulating LXRs/NF-κB signaling pathway

This study aims to explore the mechanism of Zhuanggu Jianxi Decoction in reducing synovial tissue inflammation in human knee osteoarthritis(KOA) via the liver X receptors(LXRs)/nuclear factor(NF)-κB signaling pathway. The synovial tissue samples were collected from 5 healthy volunteers and 30 KOA synovitis patients and cultured in vitro. The samples from the heathy volunteers were set as the normal group, and those from KOA synovitis patients were randomized into synovitis, Zhuanggu Jianxi Decoction, LXRα inhibitor, and N-CoR inhibitor groups. The synovitis tissue samples of the 5 groups were treated with 10% blank serum, 10% blank serum, 10% drug-containing serum, 10% drug-containing serum+LXRα inhibitor, and 10% drug-containing serum+N-CoR inhibitor, respectively, for 7 days. After intervention, the synovial tissue samples of each group were collected and stained with hematoxylin-eosin for observation and scoring of the pathological changes. The expression intensity of the fibroblast-specific marker α-smooth musle actin(α-SMA) in the synovial tissue was observed by immunofluorescence staining. The levels of interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), matrix metalloproteinase-3(MMP-3), and matrix metalloproteinase-13(MMP-13) in the supernatant of synovium homogenate were determined by ELISA. The mRNA and protein levels of LXRα, N-CoR, P50, and P65 in the synovial tissue were determined by RT-qPCR and Western blot, respectively. The results showed that compared with the normal group, the synovitis group showcased obvious synovial lining cell proliferation, inflammatory cell infiltration, synovial cell disarrangement, increased histopathological score(P<0.05), enhanced α-SMA fluorescence intensity and increased number of synovial fibroblasts(P<0.05), elevated levels of IL-1β, TNF-α, MMP-3, and MMP-13 in the synovial tissue(P<0.05), down-regulated mRNA and protein levels of LXRα and N-CoR, and up-regulated mRNA and protein levels of P50 and P65(P<0.05). Compared with the synovitis group, the Zhuanggu Jianxi Decoction group showed alleviated pathological changes, declined histopathological score of the synovial tissue(P<0.05), decreased α-SMA fluorescence intensity and number of synovial fibroblasts(P<0.05), lowered levels of IL-1β, TNF-α, MMP-3, and MMP-13(P<0.05), up-regulated mRNA and protein levels of LXRα and N-CoR, and down-regulated mRNA and protein levels of P50 and P65(P<0.05) in the synovial tissue. Compared with the Zhuanggu Jianxi Decoction group, the LXRα inhibitor group and N-CoR inhibitor group showed aggravated pathological changes, risen histopathological score of the synovial tissue(P<0.05), enhanced α-SMA fluorescence intensity and increased number of synovial fibroblasts(P<0.05), elevated levels of IL-1β, TNF-α, MMP-3, and MMP-13(P<0.05), down-regulated mRNA and protein levels of LXRα and N-CoR, and up-regulated mRNA and protein levels of P50 and P65(P<0.05). The results above indicated that Zhuanggu Jianxi Decoction could alleviate the synovial tissue inflammation in KOA patients by upregulating the mRNA and protein levels of LXRα and N-CoR in the LXRs/NF-κB pathway to downregulate the mRNA and protein levels of P50 and P65 and reduce the activity of the NF-κB pathway in the synovial tissue.

Targeted isolation of lignans and triterpenoids from kadsura coccinea by molecular networking and anti-RA-FLS activity

In this study, six compounds (four triterpenoids named heilaohutriterpenes A-D and two lignans name heilaohusuins F and G) together with 21 known compounds were isolated from roots of Kadsura coccinea (Lem.) A. C. Smith guided by molecular networking. Their structures were determined using a combination of HR-ESI-MS, 1D, 2D-NMR anatysis, NMR calculation, and electronic circular dichroism (ECD) calculations. Moreover, the ability of the isolated compounds to inhibit the proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells was evaluated in vitro. Heilaohutriterpene B (2), heilaohutriterpene D (4), coccinone B (7), and kadsuralignan H (24) demonstrated significant inhibitory activities against RA-FLS cells, with IC50 values of 9.57 ± 0.84, 16.22 ± 1.71, 3.08 ± 1.59, and 19.09 ± 2.42 μM, respectively. Meanwhile, western blotting analysis revealed that compound 2 down-regulated the level of P–NF-κB p65 and up-regulated that of Bax and IκBα. These results collectively suggest that compound 2 promoted the apoptosis of RA-FLS cells by inhibiting the NF-κB pathway. Taken together, this study contributed to the structural diversity of compounds derived from K. coccinea and lays a basis for further anti-RA-related studies.

Identification and Experimental Verification of PDK4 as a Potential Biomarker for Diagnosis and Treatment in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disorder marked by sustained joint inflammation, with an etiology that remains elusive. Achieving an early and precise diagnosis poses significant challenges. This study aims to elucidate the molecular pathways involved in RA pathogenesis by screening genes associated with its occurrence, analyzing the related molecular activities, and ultimately developing more effective molecular-level treatments for RA. Microarray expression profiling datasets GSE1919, GSE10500, GSE15573, GSE77298, GSE206848, and GSE236924 were sourced from the Gene Expression Omnibus (GEO) database. Samples were divided into experimental (RA) and control (normal) groups. Differentially expressed genes (DEGs) were identified using R software packages such as limma, glmnet, e1071 as well as randomForest. Cross-validation of DEGs was conducted using lasso regression and the random forest (RF) algorithm in R software to pinpoint intersecting genes that met the criteria. Among these, one gene was selected as the target for correlation analysis to identify DEGs related to the target gene. Enrichment analysis utilized the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases and Gene Ontology (GO) data. Gene Set Enrichment Analysis (GSEA) was performed to compare the expression levels of the target gene (PDK4) across various biological pathways and functions in groups with high and low expression. The relationship between target gene expression levels and cellular immune function was assessed using the immune function score technique. The discrepancy in immune cell distribution between the control and experimental groups, as well as their correlation with target gene expression levels, was elucidated using CIBERSORT. The relationships between mRNA, lncRNA, and miRNA were depicted in the ceRNA regulation network. The expression levels of the target gene were validated using Western blot and qRT-PCR. In this study, six intersecting genes meeting the criteria were identified through cross-validation, and PDK4 was chosen as the target gene for further investigation. Functional analysis using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) revealed that PDK4-associated DEGs are primarily enriched in the PPAR signaling pathway, thereby regulating synovial cell proliferation and migration, ultimately influencing the onset and progression of rheumatoid arthritis (RA). Immune infiltration analysis suggested that eosinophil quantity may influence the progression of RA. Experimental results from PCR and Western blot confirmed the downregulation of PDK4 in the RA group. The significant downregulation of PDK4 expression in patients diagnosed with rheumatoid arthritis (RA) was confirmed. PDK4 may function as a novel regulatory factor in the onset and progression of RA, with potential applications as a diagnostic biomarker for the condition.

Synoviocyte detachment: an overlooked yet crucial histological aspect in rheumatoid arthritis

ObjectiveRheumatoid arthritis (RA) is a prevalent autoimmune disorder that leads to chronic joint inflammation, deformity, disability, and systemic complications. This study aimed to analyze the clinical characteristics and synovial pathology of RA patients with synoviocyte detachment, and explore the factors associated with this phenomenon.MethodsThis was a retrospective cohort study included RA patients who underwent synovial biopsy at our center from April to September 2023. Demographic, clinical, laboratory, and synovial histological data were retrospectively collected from medical records at the time of joint synovial biopsy in patients. Microscopic examination of hematoxylin and eosin (HE)-stained synovial tissue sections categorized the samples into synoviocyte detachment and no-synoviocyte detachment groups. Clinical characteristics and synovial pathological changes were compared between the two groups, and the factors associated with synoviocyte detachment were explored through logistic regression analysis.ResultsFifty-five RA patients were enrolled; 45 were females, and the mean age was 53.4 ± 11.8 years. Nine RA patients exhibited synoviocyte detachment. A total of 46 RA patients in the no-synoviocyte detachment group (15 with a normal lining layer and 31 with synovial cell proliferation) were included. Compared with the no-synoviocyte detachment group, the synoviocyte detachment group presented higher RF, ESR, CRP and DAS28-CRP levels (P < 0.05). The synoviocyte detachment group exhibited more prominent neovascularization (P < 0.05). ESR, DAS28-CRP and synovial neovascularization were risk factors associated with synoviocyte detachment in RA patients.ConclusionRA patients with synoviocyte detachment exhibit elevated clinical disease activity, marked by pronounced synovial pathology featuring increased neovascularization and less inflammatory cell infiltration. A significant reduction in lymphocyte count compared with patients with synovial cell proliferation was also observed.

Au/Ag@ZnS yolk-shell photocatalysts enhanced with noble metals and hyaluronic acid for efficient hydrogen production in rheumatoid arthritis therapy

Rheumatoid arthritis, characterized by the abnormal proliferation of synovial cells and extensive macrophage infiltration, is a chronic inflammatory disease. Molecular hydrogen, known for its antioxidant properties, has shown promise in eliminating reactive oxygen species. However, the low solubility and bioavailability of hydrogen limit the effectiveness of this therapy. To overcome these issues, we developed a novel yolk-shell heterostructure, H-AAZS (Au/Ag@ZnS modified hyaluronic acid), utilizing a hydrothermal cation exchange process. Through ion doping, semiconductor hybridization, and Schottky barriers in H-AAZS, photocatalysis for hydrogen generation has been successfully implemented using 660 nm laser irradiation. Additionally, the H-AAZS demonstrate the capacity for mild photothermal therapy, inducing apoptosis in synovial cells with Au's hot electrons with 660 nm laser irradiation. This strategy not only improves the abnormal proliferation of synovial cells but also avoids the exacerbation of inflammation caused by thermal stimulation. Both in vitro and in vivo experiments validate the synergistic effects of hydrogen production mediated anti-inflammatory responses, macrophage polarization and photothermal therapy. Therefore, this work represents a significant advancement as it ingeniously harnesses photocatalysis to modulate the synovial microenvironment while mitigating the side effects associated with photothermal therapy. This nanocrystal provides new and valuable insights into the potential treatment of Rheumatoid arthritis.

Xuetongsu ameliorates synovial inflammatory hyperplasia in rheumatoid arthritis by inhibiting JAK2/STAT3 and NF-κB signaling pathways

Ethnopharmacological relevanceSynovial inflammatory hyperplasia is the key pathological process that leads to further joint damage in rheumatoid arthritis (RA) progress. Kadsura heteroclita (Roxb) Craib, also called Xuetong in Chinese Tujia ethnomedicine, is utilized for its medicinal properties, including promoting blood circulation, dispelling “wind evil”, and relieving “damp evil”. It has been used in the treatment of arthralgia and RA, within Tujia ethnomedicinal practices. Xuetongsu (XTS), the main component of Xuetong, has been shown to inhibit the proliferation of RA fibroblast-like synovial cells (RAFLS) cells. However, the molecular mechanism of XTS in RA treatment requires further investigation. Aim of the studyTo observe the therapeutic effect of XTS on synovial inflammatory hyperplasia in rheumatoid arthritis, focusing on its underlying molecular mechanisms involving the janus kinase 2 (JAK2)/transducer/activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-κB) signaling pathways. Materials and methodsProtein-protein interaction (PPI) and molecular docking were used to find the main targets of XTS treatment for RA. In lipopolysaccharide (LPS)-induced RAFLS and RAW264.7 cells in vitro models, the levels of inflammatory cytokines were analyzed using enzyme linked immunosorbent assay (ELISA), and the expression of JAK2, STAT3, and NF-κB signaling pathways, as well as cyclooxygenase-2 (COX-2), were analyzed through western blotting test. A hemolysis assay was used to certify the biosecurity of XTS. A model of adjuvant arthritis (AIA) was established in 40 male rats, and different doses of XTS were administered, followed by an automatic blood routine, ELISA assay, hematoxylin and eosin (H&E) staining, and radiological analysis of the effect of no XTS on blood cytokines, histological changes, and improvement of posterior paw bone destruction in AIA rats. The protein levels of inflammatory cytokines were analyzed by immunofluorescence, immunohistochemistry, or Western blot. Finally, H&E staining was used to detect the damage of XTS on the heart, liver, spleen, lung, and kidney of AIA rats. ResultsOur results demonstrate that XTS effectively inhibited LPS-induced inflammatory responses in RAFLS and RAW264.7 cells by modulating the JAK2/STAT3 and NF-κB signaling pathways. Moreover, XTS administration in the AIA rats model significantly ameliorated paw swelling. Histological analysis revealed that XTS also suppressed the inflammatory response in paw tissue by modulating the JAK2/STAT3 and NF-κB signaling pathways. Importantly, during the treatment, XTS exhibited excellent safety profiles, as it did not induce any abnormalities in blood routine parameters or cause organ damage in the rats. ConclusionsOur findings highlight XTS as a promising natural agent for inhibiting synovial hyperplasia in RA. XTS holds great potential as an unprecedented natural agent for developing novel therapeutic strategies to target synovial hyperplasia in RA.

Discovery of CYP2E1 as a novel target in rheumatoid arthritis and validation by a new specific CYP2E1 inhibitor

Considerable evidence indicates that CYP2E1 is associated with a variety of inflammatory diseases. Here we evaluated CYP2E1 as a potential therapeutic target for rheumatoid arthritis (RA) and established the protective effect of a new CYP2E1 inhibitor. Gene-expression datasets were used to analyze the change in expression of CYP2E1 in RA patients; CYP2E1 activity in collagen-induced arthritis (CIA) rats was determined by HPLC. We further evaluated the protective effects of Cyp2e1 knockout and a CYP2E1-specific inhibitor, Q11, synthesized by our group, in CIA and adjuvant-induced arthritis (AIA) rats. The expression of CYP2E1 in synovial tissue was elevated in RA patients and in CIA rats and the activity of CYP2E1 in vivo and in vitro in CIA rats was greater than that of controls. Cyp2e1 knockout significantly reduced the incidence of CIA and alleviated the severity of symptoms. Treatment with different doses of Q11 decreased paw thickness, volume and arthritis scores and reduced the serum levels of IL‐6, TNF‐α, IL‐1β and MDA, and increased the level of GSH in CIA rats. A similar inhibitory effect was exhibited for Q11 in the AIA rats. Moreover, Q11 significantly impeded proliferation, migration, and invasion of human rheumatoid arthritis synovial fibroblasts cells. Q11 decreased the release of ROS and enhanced Nrf2 nuclear translocation and HO-1 expression in the cell nucleus. Overall, our results indicated that CYP2E1 may be a new target for RA and Q11 has potential protective effects against RA by reducing oxidative stress and opposing the inflammatory response via the ROS/Nrf2/HO-1 signaling pathway.

Combination of HDAC and FYN inhibitors in synovial sarcoma treatment.

The SS18-SSX fusion protein is an oncogenic driver in synovial sarcoma. At the molecular level, SS18-SSX functions as both an activator and a repressor to coordinate transcription of different genes responsible for tumorigenesis. Here, we identify the proto-oncogene FYN as a new SS18-SSX target gene and examine its relation to synovial sarcoma therapy. FYN is a tyrosine kinase that promotes cancer growth, metastasis and therapeutic resistance, but SS18-SSX appears to negatively regulate FYN expression in synovial sarcoma cells. Using both genetic and histone deacetylase inhibitor (HDACi)-based pharmacologic approaches, we show that suppression of SS18-SSX leads to FYN reactivation. In support of this notion, we find that blockade of FYN activity synergistically enhances HDACi action to reduce synovial sarcoma cell proliferation and migration. Our results support a role for FYN in attenuation of anti-cancer activity upon inhibition of SS18-SSX function and demonstrate the feasibility of targeting FYN to improve the effectiveness of HDACi treatment against synovial sarcoma.

Immunophenotypic Landscape of synovial tissue in rheumatoid arthritis: Insights from ACPA status

ObjectiveTo examine the clinical features and synovial pathologies in rheumatoid arthritis (RA) patients across varying titers of circulating anti-citrullinated protein antibodies (ACPA). MethodologyWe devised a negative pressure suction and rebound synovial biopsy tool to enhance the yield of synovial biopsies, noted for its ease and safety of use. This research involved a retrospective examination of 60 active RA patients who underwent synovial biopsies with this tool from June to November 2023 at our institution. A range of disease activity markers were collected, including DAS28-CRP, ESR, CRP, count of swollen and tender joints, VAS pain scale, and so forth. Synovial tissue underwent HE staining and immunohistochemistry, including synovitis grading (GSS) and counting of B cells (CD20), T cells (CD3), macrophages (CD68), and plasma cells (CD138). Participantswere categorized into three groups as per ACPA titers: ACPA-negative (0–5U/mL), low-titer (5–20U/mL), and high-titer (above 20U/mL). The study compared the clinical features and synovial pathologies across these groups. ResultsOf the 60 RA patients, they were segregated into three groups based on ACPA titers: 20 in ACPA-negative, 9 in the low-titer group, and 31 in the high-titer group. No significant differences were observed in GSS scores, synovial cell proliferation and loss, matrix activation, inflammatory infiltration, and neovascularization among these groups (P > 0.05). The high-titer ACPA group demonstrated significantly increased counts of CD3+ T cells, CD20+ B cells, and CD68+ macrophages in synovial tissues compared to the ACPA-negative and low-titer groups (p < 0.05), along with a higher incidence of ectopic lymphoid neogenesis (p < 0.05). Ordinal logistic regression revealed that rheumatoid factor (RF), and counts of synovial T cells, B cells, macrophages, and ectopic lymphoid neogenesis correlated with ACPA titers (P < 0.05), particularly lymphoid neogenesis (OR = 3.63, P = 0.023). ConclusionRA patients with high-titer ACPA demonstrate elevated levels of inflammatory cell infiltration in synovial tissues, with ectopic lymphoid neogenesis showing a strong correlation with high ACPA positivity.

Pivotal Role of mTOR in Non-Skin Manifestations of Psoriasis.

Psoriasis is a chronic inflammatory condition affecting 2% of the Western population. It includes diverse manifestations influenced by genetic predisposition, environmental factors, and immune status. The sustained activation of mTOR is a key element in psoriasis pathogenesis, leading to an uncontrolled proliferation of cytokines. Furthermore, mTOR activation has been linked with the transition from psoriasis to non-skin manifestations such as psoriatic arthritis and cardiovascular events. While therapies targeting pro-inflammatory cytokines have shown efficacy, additional pathways may offer therapeutic potential. The PI3K/Akt/mTOR pathway, known for its role in cell growth, proliferation, and metabolism, has emerged as a potential therapeutic target in psoriasis. This review explores the relevance of mTOR in psoriasis pathophysiology, focusing on its involvement in cutaneous and atheromatous plaque proliferation, psoriatic arthritis, and cardiovascular disease. The activation of mTOR promotes keratinocyte and synovial cell proliferation, contributing to plaque formation and joint inflammation. Moreover, mTOR activation may exacerbate the cardiovascular risk by promoting pro-inflammatory cytokine production and dysregulation lipid and glucose metabolism. The inhibition of mTOR has shown promise in preclinical studies, reducing skin inflammation and plaque proliferation. Furthermore, mTOR inhibition may mitigate cardiovascular risk by modulating cholesterol metabolism and attenuating atherosclerosis progression. Understanding the role of mTOR in psoriasis, psoriatic arthritis, and cardiovascular disease provides insight into the potential treatment avenues and sheds light on the complex interplay of the immune and metabolic pathways in these conditions.

Mid1 promotes synovitis in rheumatoid arthritis via ubiquitin-dependent post-translational modification

IntroductionCurrent anti-rheumatic drugs are primarily modulating immune cell activation, yet their effectiveness remained suboptimal. Therefore, novel therapeutics targeting alternative mechanisms, such as synovial activation, is urgently needed. ObjectivesTo explore the role of Midline-1 (Mid1) in synovial activation. MethodsNOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice were used to establish a subcutaneous xenograft model. Wild-type C57BL/6, Mid1-/-, Dpp4-/-, and Mid1-/-Dpp4-/- mice were used to establish a collagen-induced arthritis model. Cell viability, cell cycle, qPCR and western blotting analysis were used to detect MH7A proliferation, dipeptidyl peptidase-4 (DPP4) and Mid1 levels. Co-immunoprecipitation and proteomic analysis identified the candidate protein of Mid1 substrates. Ubiquitination assays were used to determine DPP4 ubiquitination status. ResultsAn increase in Mid1, an E3 ubiquitin ligase, was observed in human RA synovial tissue by GEO dataset analysis, and this elevation was confirmed in a collagen-induced mouse arthritis model. Notably, deletion of Mid1 in a collagen-induced arthritis model completely protected mice from developing arthritis. Subsequent overexpression and knockdown experiments on MH7A, a human synoviocyte cell line, unveiled a previously unrecognized role of Mid1 in synoviocyte proliferation and migration, the key aspects of synovial activation. Co-immunoprecipitation and proteomic analysis identified DPP4 as the most significant candidate of Mid1 substrates. Mechanistically, Mid1 promoted synoviocyte proliferation and migration by inducing ubiquitin-mediated proteasomal degradation of DPP4. DPP4 deficiency led to increased proliferation, migration, and inflammatory cytokine production in MH7A, while reconstitution of DPP4 significantly abolished Mid1-induced augmentation of cell proliferation and activation. Additionally, double knockout model showed that DPP4 deficiency abolished the protective effect of Mid1 defect on arthritis. ConclusionOverall, our findings suggest that the ubiquitination of DPP4 by Mid1 promotes synovial cell proliferation and invasion, exacerbating synovitis in RA. These results reveal a novel mechanism that controls synovial activation, positioning Mid1 as a promising target for therapeutic intervention in RA.

Rapamycin suppresses rheumatoid arthritis fibroblast synovial cell proliferation and induces apoptosis via the AKT/mTORC1 pathway

AbstractBackgroundRheumatoid arthritis (RA) is an autoimmune disease characterized by the overproliferation of synovial fibroblast‐like synoviocytes (FLSs) in the lining, leading to chronic inflammation and progressive joint damage. RA pathogenesis involves lymphocyte infiltration, increased synovial cell proliferation, and impaired cell death. This study investigated the effects of rapamycin on RA‐FLSs and explored the underlying molecular mechanisms.MethodsThe optimal drug concentration and time for rapamycin administration were determined using a cell counting kit‐8 assay. The concentration of rapamycin varied from 1 to 25 nmol/L. The mRNA expression levels of protein kinase B (AKT), mammalian target of rapamycin (mTOR), B cell lymphoma 2 (Bcl‐2), and Bcl‐2‐associated X protein (Bax) were quantified by real‐time polymerase chain reaction. Protein expression (p‐AKT, AKT, p‐mTOR, mTOR, pS6 kinase [S6K], S6K, p‐4E‐binding protein 1 [4EBP1], 4EBP1, Bcl‐2, Bax, caspase 3, caspase 9, cyclin‐dependent kinase 2 [CDK2], and CD1) were detected by Western blotting analysis.ResultsRapamycin suppresses RA‐FLS proliferation and induces apoptosis in a dose‐dependent manner. Rapamycin significantly elevated the protein expression of Bax (p &lt; 0.01), caspase 3 (p &lt; 0.05), and caspase 9 (p &lt; 0.001), and downregulated Bcl‐2 expression (p &lt; 0.01). Rapamycin increased Bax mRNA expression (p &lt; 0.01) and decreased Bcl‐2 (p &lt; 0.05), AKT (p &lt; 0.05), and mTOR (p &lt; 0.05) expression. Additionally, there was a marked reduction in the expression levels of p‐AKT(Ser473) (p &lt; 0.01), p‐mTOR (Ser2448) (p &lt; 0.01), p‐S6K1 (p &lt; 0.01), and p‐4EBP1, CDK2, and CD1 (p &lt; 0.01).ConclusionsRapamycin effectively inhibited proliferation and induced apoptosis of RA‐FLSs by targeting the AKT/mTORC1 pathway. These findings underscore the potential of rapamycin as a therapeutic candidate for addressing the dysregulated proliferation and inflammatory characteristics of RA. Further clinical investigations are required to validate its application in the management of RA.

FAM83D acts as an oncogene by regulating cell cycle progression via multiple pathways in synovial sarcoma: a potential novel downstream target oncogene of anlotinib

ObjectiveSynovial Sarcoma (SS), a highly malignant mesenchymal neoplasm, typically carries a grim prognosis for patients presenting with high-grade or metastatic disease. Although Anlotinib, a new agent for treating soft tissue sarcomas, holds promise, its underlying mechanism remains incompletely understood. This investigation aims to delineate Anlotinib’s anticancer effectiveness and potential mechanistic underpinnings in patients suffering from advanced, refractory SS.Materials and methodsEmploying microarray assay, we examined the potential downstream targets of Anlotinib in SS therapy. A shRNA-based high-content screening was performed to identify candidate genes with the greatest influence on SW982 cell proliferation. The knockdown efficacy of selected genes within SW982 cells was confirmed using RT-qPCR as well as western blot analysis. To assess the effect of putative downstream elimination of genes with synovial sarcoma cells, cell proliferation, and apoptotic assays were carried out. Gene chip microarray as well as bioinformatics techniques were utilized to scrutinize potential signaling networks associated with the candidate downstream gene.ResultsQPCR verified high expression of FAM83D in SW982 cells, shRNA was designed to silence FAM83D by lentivirus transfection, apoptosis assay, and cell cycle arrest showing that FAM83D downregulation augments apoptosis in SW982 cells and arrests cell cycle progression in the S stage. Inhibition of FAM83D expression upregulated STAT1 while downregulated BIRC5, MCM2, and CDK1 genes in vitro.ConclusionsThis experimental study identified FAM83D as a critical regulator that contributes to the proliferation and progression of SS, suggesting that FAM83D-regulated signaling pathway may serve as a prospective target in SS management.

The Hippo-YAP Signaling Pathway in Osteoarthritis and Rheumatoid Arthritis.

Arthritis is the most prevalent joint disease and is characterized by articular cartilage degradation, synovial inflammation, and changes in periarticular and subchondral bone. Recent studies have reported that Yes-associated protein (YAP) and the transcriptional coactivator with PDZ-binding motif (TAZ) have significant effects on the proliferation, migration, and survival of chondrocytes and fibroblast-like synovial cells (FLSs). YAP/TAZ signaling pathway, as well as the related Hippo-YAP signaling pathway, are responsible for the condition of cells and articular cartilage in joints. They are tightly regulated to maintain metabolism in chondrocytes and FLSs because abnormal expression may result in cartilage damage. However, the roles and mechanisms of the Hippo-YAP pathway in arthritis remain largely unknown. This review summarizes the roles and key functions of YAP/TAZ and the Hippo-YAP signaling pathway in FLSs and chondrocytes for the induction of proliferation, migration, survival, and differentiation in rheumatoid arthritis (RA) and osteoarthritis (OA) research. We also discuss the therapeutic strategies involving YAP/TAZ and the related Hippo-YAP signaling pathway involved in OA.

FNDC4 reduces inflammation, proliferation, invasion and migration of rheumatoid synovial cells by inhibiting CCL2/ERK signaling

BackgroundRheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation. Fibronectin type III domain-containing protein 4 (FNDC4) is a secretory factor that can regulate inflammatory diseases. However, the role of FNDC4 in RA has not been reported so far. MethodsThe expression of FNDC4 in synovial tissues of RA was analyzed by GEO database (GSE55235 dataset). Then, the expression of FNDC4 in RA fibroblast-like synoviocytes (RA-FLSs) was detected by RT-qPCR and western blot. After constructing FNDC4 overexpression plasmid, cell proliferation and apoptosis were detected. Wound healing and transwell tests were used to detect cell migration and invasion. Then we examined the expression of cytokines related to cell inflammation. Subsequently, the regulatory mechanism of FNDC4 was further discussed. We detected the expression of CCL2 and ERK signaling pathway related proteins downstream of FNDC4. Finally, the mechanism was discussed through the overexpression of FNDC4 and CCL2 and the addition of ERK pathway activator tBHQ. ResultsGEO database showed that FNDC4 expression decreased in synovial tissues of RA. And FNDC4 expression also decreased in RA-FLSs. Overexpression of FNDC4 inhibited the proliferation, invasion and migration of RA-FLSs and promoted its apoptosis. Overexpression of FNDC4 inhibited the release of RA-FLSs inflammatory factors. The regulatory effect of FNDC4 is achieved by inhibiting the CCL2/ERK signaling pathway. ConclusionFNDC4 reduces inflammation, proliferation, invasion and migration of RA-FLSs in RA by inhibiting CCL2/ERK signaling.

Elucidating the mechanism of the Tibetan medicine sanguotang in treating gouty arthritis through network pharmacology and in vivo experiments

BackgroundWe explored the mechanisms of Sanguotang (SGT), a Tibetan medicine, in treating gout arthritis (GA). MethodsThe main active components, action targets, and disease targets of SGT were identified through TCMSP databases. The gene functions were analyzed using protein interaction (PPI) networks, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and molecular docking. A GA model induced by monosodium urate was established in rats. The ankle joint swelling was observed. The levels of uric acid (UA) and albumin (ALB) in rat serum were measured. Hematoxylin and eosin (HE) staining was conducted to examine the pathological changes in rat ankle joints. ResultsTwenty-nine active components of SGT with proven efficacy and 66 intersection targets were identified, primarily involved in inflammation and immune regulation pathways. The PPI results revealed that the key targets of SGT against GA included ALB, IL6, TNF, TP53, and PTGS. Molecular docking showed favorable binding energy between the ALB protein and the active components. The results from animal experiments demonstrated that SGT effectively alleviated the inflammatory reaction in ankle joints, and decreased UA and ALB levels. Furthermore, SGT effectively inhibited the proliferation of synovial cells in the ankle joint cavity, prevented infiltration of inflammatory cells, and protected synovial tissue, thereby improving GA. ConclusionsSGT comprehensively contributes to the treatment of GA by regulating UA metabolism, reducing the release of inflammatory factors, and modulating immune and inflammatory pathways.

Live macrophages loaded with Fe3O4 and sulfasalazine for ferroptosis and photothermal therapy of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by the infiltration of inflammatory cells and proliferation of synovial cells. It can cause cartilage and bone damage as well as disability and is regarded as an incurable chronic disease. Available therapies cannot prevent the development of diseases due to the high toxicity of the therapeutic agents and the inefficient drug delivery. Ferroptosis, an iron-dependent manner of lipid peroxidative cell death, indicates great potential for RA therapy due to ability to damage the infiltrated inflammatory cells and proliferated fibroblast-like synoviocytes. Here, we use macrophages as vector to deliver Fe3O4 nanoparticles and sulfasalazine (SSZ) for ferroptosis and photothermal therapy of RA. The inherent property of migration towards the inflamed joints under the guidance of inflammatory factors enables macrophages to targetedly deliver the payload into the RA. Upon the irradiation of the near infrared light, the Fe3O4 nanoparticles convert the light into heat to damage the proliferated synovium. Meanwhile, the iron released from Fe3O4 nanoparticles works with SSZ to generate synergetic ferroptosis effect. The resident inflammatory cells and proliferated synovium are efficiently damaged by the ferroptosis and photothermal effect, showing pronounced therapeutic effect for RA.