Regulation of serum matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 following rituximab therapy in patients with rheumatoid arthritis refractory to anti-tumor necrosis factor blockers

Deciphering the role of ferroptosis in rheumatoid arthritis: Synovial transcriptome analysis and immune infiltration correlation

The pathogenesis of rheumatoid arthritis (RA) remains elusive. The initiation of joint degeneration is characterized by the loss of self-tolerance in peripheral joints. Ferroptosis, a form of regulated cell death, holds significant importance in the pathophysiology of inflammatory arthritis, primarily due to iron accumulation and the subsequent lipid peroxidation. The present study investigated the association between synovial lesions and ferroptosis-related genes using previously published data from rheumatoid patients. Transcriptome differential gene analysis was employed to identify ferroptosis-related differentially expressed genes (FRDEGs). To validate FRDEGs and screen hub genes, we used weighted gene co-expression network analysis (WGCNA) and receiver operating characteristic (ROC) curves. Subsequently, immune infiltration analysis and single cell analysis were conducted to investigate the relationship between various synovial tissues cells and FRDEGs. The findings were further confirmed through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunohistochemical staining, and immunofluorescence techniques. Upon intersecting DEGs with ferroptosis-related genes, we identified a total of 104 FRDEGs. Through the construction of a protein-protein interaction (PPI) network, we pinpointed the top 20 most highly concentrated genes as hub genes. Subsequent analyses using ROC curve and WGCNA validated eight FRDEGs: TIMP1, JUN, EGFR, SREBF1, ADIPOQ, SCD, AR, and FABP4. Immuno-infiltration analyses revealed significant infiltration of immune cell in RA synovial tissues and their correlations with the FRDEGs. Notably, TIMP1 demonstrated a positive correlation with various immune cell populations. Single-cell sequencing date of RA synovial tissue revealed predominant expression of TIMP1 is in fibroblasts. RT-qPCR, immunohistochemistry, and immunofluorescence analyses confirmed significant upregulation of TIMP1 at both mRNA and protein levels in RA synovial tissues and fibroblast-like synoviocytes (FLS). The findings provide novel insights into pathophysiology of peripheral immune tolerance deficiency in RA. The dysregulation of TIMP1, a gene associated with ferroptosis, was significantly observed in RA patients, suggesting its potential as a promising biomarker and therapeutic target.

Serum matrix metalloproteinase-3 levels monitor the therapeutic efficacy in Syrian patients with rheumatoid arthritis

Background

The plans for the successful treatment of rheumatoid arthritis (RA) seek to attain low disease activity or reach clinical remission.

Objective

Our study aimed to compare the serum MMP-3 levels with predictors of response to therapy of rheumatoid arthritis in Syrian patients and explore its worth as a new valuable biomarker for RA therapy outcomes in daily practice.

Methods

Serum samples were gathered from 43 RA patients at diagnosis and 12 weeks of therapy. Related clinical and laboratory tests were estimated, levels of serum MMP-3 were measured by ELISA method and the disease activity was assessed using disease activity scores in 28 joints with an erythrocyte sedimentation rate (DAS28-ESR) before and after therapy.

Results

The mean of Serum MMP-3 levels significantly decreased (322.3 ± 43.83 ng/ml) after therapy (12 weeks) in RA patients compared to its mean at baseline (486.49 ± 34.5 ng/ml). There wasn't a statistically significant difference in the mean of MMP-3 levels before and after therapy (P = 0.137) in non-responder patients. Patients who showed a good response (N = 38) presented higher MMP-3 levels at first which subsequently decreased significantly at the 12-week follow-up (P < 0.05). Also, there was a statistically significant difference in MMP-3 levels between the two groups of patients after therapy (P = 0.002). To differentiate between RA patients who responded to therapy and who did not, our results found that the cut-off value of serum MMP-3 was 317.8 ng/ml (sensitivity was 80%, specificity was 73%, AUC was 0.818, 95% CI: 1.114-112.5; P = 0.045) and the best cut-off value of DAS28-ESR was 5.325 (sensitivity 100%, specificity 100%, AUC = 100%,95% CI: 15.2 to 47203.8).

Conclusion

serum MMP-3 can be added as a novel and valuable biomarker in estimating the therapeutic response in RA patients, but it isn't better than DAS28-ESR.

Use of some bone-related cytokines as predictors for rheumatoid arthritis severity by neural network analysis

Background. Rheumatoid arthritis (RA) is characterized by synovial membrane inflammation that results in joint damage. Many earlier studies have measured cytokines for a better diagnosis of RA. In the present study, three bone biomarkers (osteopontin, Stromelysin-1 (MMP3), and vascular endothelial growth factor-A (VEGF)) are examined for their ability to estimate the severity of disease by using artificial neural network (NN) analysis and regression analysis. Methods: The study enrolled 87 RA patients and 44 healthy control subjects. The biomarkers were measured by the enzyme-linked immunosorbent assay (ELISA) technique. Disease Activity Score (28 joints) and C-reactive protein (CRP) (DAS28-CRP) was calculated by using (DAS28-CRP) calculator. The patients with DAS28-CRP5.1 are considered as having high disease activity (HDA). While patients group with DAS28-CRP5.1 are considered as moderate disease activity (MDA). The neural network (NN) analysis was used for the differentiation between groups. Results. Results showed that the most sensitive predictor for high disease activity (HDA) of RA is MMP3, followed by osteopontin and VEGF. These three biomarkers can differentiate significantly between HDA and moderate disease activity (MDA) with a relatively high size effect (Partial 2=0.323, p0.001). HDA group has a significantly higher MMP3, CRP, RF, and anti-citrullinated protein antibodies (ACPA) than the MDA group. Conclusions. The use of the NN analysis indicated that the measured biomarkers help predict the HDA state in RA patients. MMP3 and osteopontin are diagnostic biomarkers for the severity of RA disease and related to many disease-related characteristics with a sensitivity of 88.9% and specificity of 68.4%.

Assessment of therapeutic effect of CD20-targeted immunoliposome in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a form of extranodal non-Hodgkin's B-cell lymphoma limited to the CNS. The treatment of PCNSL is ineffective partly due to the blood-brain barrier (BBB) restriction of delivery of many drugs including anti-CD20 (Rituximab; RTX) which is a standard treatment for systemic B-cell lymphomas. In this study, liposome with tween-80 surface modification was fabricated and conjugated with RTX for enhancing BBB penetration to target lymphoma cells in the CNS. Physicochemical characterizations of Lip/RTX were performed and spherical shape liposomes with narrow size distribution were demonstrated by TEM. An average diameter of Lip/RTX was 168.57 ± 1.57 nm with the percentage of RTX conjugation at 90.94. Cell internalization monitored by flow cytometry confirmed that conjugation of RTX promoted liposome entry into Raji cells expressing CD20. Antitumor activity of Lip/RTX was comparable to free RTX indicating that RTX moieties on liposome remained their therapeutic function. In addition, Lip/RTX inhibited tumor aggressiveness by limiting cell migration and invasion. Systemic administration of Lip/RTX significantly prolonged survival of mice harboring intracranial lymphoma xenografts. Taken together, Lip/RTX presents a new potential treatment for patients with PCNSL.

Summarizing current refractory disease definitions in rheumatoid arthritis and polyarticular juvenile idiopathic arthritis: systematic review

OBJECTIVES

To identify how refractory disease (or relevant terminology variations) in RA and polyarticular JIA (polyJIA) is defined and establish the key components of such definitions.

METHODS

Searches were undertaken of English-language articles within six medical databases, including manual searching, from January 1998 to March 2020 (PROSPERO: CRD42019127142). Articles were included if they incorporated a definition of refractory disease, or non-response, in RA/polyJIA, with clear components to the description. Qualitative content analysis was undertaken to describe refractory disease in RA/polyJIA and classify each component within each definition.

RESULTS

Of 6251 studies screened, 646 met the inclusion criteria; 581 of these applied non-response criteria while 65 provided refractory disease definitions/descriptions. From the non-response studies, 39 different components included various disease activity measures, emphasizing persistent disease activity and symptoms, despite treatment with one or more biologic DMARD (bDMARD). From papers with clear definitions for refractory disease, 41 components were identified and categorized into three key themes: resistance to multiple drugs with different mechanisms of action, typically two or more bDMARDs; persistence of symptoms and disease activity; and other contributing factors. The most common term used was 'refractory' (80%), while only 16.9% reported explicitly how their definition was generated (e.g. clinical experience or statistical methods).

CONCLUSION

Refractory disease is defined as resistance to multiple drugs with different mechanisms of action by persistence of physical symptoms and high disease activity, including contributing factors. A clear unifying definition needs implementing, as the plethora of different definitions makes study comparisons and appropriate identification of patients difficult.

Periodontal inflammation and distinct inflammatory profiles in saliva and gingival crevicular fluid (GCF) compared with serum and joints in rheumatoid arthritis patients

BACKGROUND

The association of periodontitis and Porphyromonas gingivalis (Pg) with rheumatoid arthritis (RA) is incompletely understood. To gain further insights, we evaluated periodontal status, oral, serum and joint inflammatory profiles, and Pg biomarkers in RA patients.

METHODS

In this cross-sectional study, we evaluated 33 patients with predominantly untreated new-onset RA, 20 healthy individuals (HIs), and 20 non-RA chronic periodontitis patients. Thirteen mediators (IFN-γ, IL-10, IL-17A, IL-6, IL-8, CXCL10, TNF-α, CXCL13, IL-23, MMP-1, MMP-3, MMP-8, MMP-9) were measured in serum, synovial fluid, saliva and gingival crevicular fluid (GCF) by multiplex immunoassay. Serum Pg IgG antibodies and subgingival Pg DNA were determined.

RESULTS

Most RA patients (91%) received routine dental care; only one currently smoked. Ten (30.3%) had periodontal health, 13 (39.4%) had gingivitis, and 10 (30.3%) had periodontitis. Th1 and innate immune responses predominated in serum. Many mediators were concentrated in joints, particularly IL-6, IL-8, and CXCL10. However, salivary and GCF profiles were more restricted, emphasizing neutrophilic inflammation (IL-8, MMP-8) and MMP-9. Compared with HI, most RA patients, regardless of periodontal status, had significantly elevated oral fluid levels of these mediators, with suppression of GCF IL-10, a pattern similar to non-RA periodontitis patients. Pg antibodies or DNA however were primarily associated with clinical periodontitis.

CONCLUSIONS

Despite routine dental care, RA patients often had inflammation in oral fluids, but inflammatory profiles differed from serum and joints. Neutrophilic inflammatory profiles in oral fluids, regardless of periodontal status, suggests that gingival tissues are a common, and often unrecognized, site of extra-articular inflammation in RA.

The role of EMMPRIN/CD147 in regulating angiogenesis in patients with psoriatic arthritis

BACKGROUND

Angiogenesis plays a central role in the pathophysiology of rheumatic diseases. Patients with psoriatic arthritis (PsA) demonstrate increased vascularity over patients with rheumatoid arthritis (RA), with unknown mechanisms.

METHODS

We evaluated the serum levels of several pro- and anti-angiogenic factors in 62 PsA patients with active disease, 39 PsA patients in remission, 33 active RA patients, and 33 healthy controls (HC). Additionally, we used an in vitro co-culture system of fibroblast (HT1080) and monocytic-like (MM6) cell lines, to evaluate how their interactions affect the secretion of angiogenic factors and angiogenesis promoting abilities using scratch and tube formation assays.

RESULTS

PsA patients, regardless of disease activity, exhibited higher levels of EMMPRIN/CD147, IL-17, and TNF-α relative to RA patients or HC. Factors, such as IL-6, and the ratio between CD147 and thrombospondin-1, exhibited elevated levels in active PsA patients relative to PsA patients in remission. Secretion of CD147, VEGF, and MMP-9 was increased in vitro. CD147 neutralization with an antibody reduced these levels and the ability of endothelial cells to form tube-like structures or participate in wound healing.

CONCLUSIONS

CD147 plays a role in mediating angiogenesis in PsA, and the therapeutic possibilities of neutralizing it merit further investigation.

Tissue-inhibitors of metalloproteinase-1 and vascular-endothelial growth-factor in severe haemophilia A children on low dose prophylactic recombinant factor VIII: Relation to subclinical arthropathy

BACKGROUND

Subclinical synovitis occur long before clinical haemophilic arthropathy (HA). New biomarkers are needed for early detection of HA.

AIM

To compare the levels of tissue inhibitors of metalloproteinase-1 (TIMP-1) and vascular endothelial growth factor (VEGF)in severe haemophilia A boys on prophylaxis and on-demand therapy to healthy boys and correlate them with the haemophilia joint health score (HJHS) & the Denver magnetic resonance imaging (MRI) scale; hence, determine their values in early detection of HA.

METHODS

Haemophilia joint health score, serum TIMP-1, VEGF and Denver MRI score were assessed in 50 boys with severe haemophilia A (31 on prophylactic factor VIII therapy (62%) with a dose of 15 IU/kg/twice weekly) and 50 age-matched healthy boys.

RESULTS

Boys with severe haemophilia A had significantly higher TIMP-1 240 ng/mL, SD200-350 (P < .001) and VEGF 600 pg/mL, SD400-1100 (P < .001). Their mean HJHS was 4.5 ± 3.0 (0-11) and their mean Denver MRI score was 5.55 ± 1.6 (2.00-8.00). A significant positive correlation was found between TIMP-1 and VEGF (P < .001), BMI Z-score (P = .029), HJHS (P = .041)and total MRI score (<.001). Significant correlations were found between VEGF and age (P < .001), HJHS (P = .003) and total MRI score (P < .001). Boys with severe haemophilia A on prophylaxis therapy had significantly lower HJHS (P = .021), VEGF (P < .001), TIMP-1 (P = .002) and total MRI score (P = .021) than those on on-demand therapy. Receiver operating characteristic curve, defined a cut-off value of 160 ng/mL for TIMP-1 with a sensitivity of 90% and specificity of 60% and that of 350 pg/mL for VEGF with a sensitivity of 78% and specificity of 88% for discrimination between severe haemophilia A and healthy boys.

CONCLUSION

Vascular endothelial growth factor and TIMP-1 can be used for early detection of HA. Further prospective studies should include larger study populations. In addition, studies should address the role of various anti-VEGFs as potential therapy for HA and their impact on prevention and treatment of HA.

MMP3 is a reliable marker for disease activity, radiological monitoring, disease outcome predictability, and therapeutic response in rheumatoid arthritis

Matrix metalloproteinase-3 or MMP3 also known as stromelysin-1 is an enzyme that is actively involved in joint destruction in rheumatoid arthritis (RA) patients. Screening the last three decades, it appears that serum levels of MMP3 reflect positively RA disease activity, joint and bone injury, and radiological erosion and predict disease outcome and drug responsiveness as summarized in several publications reporting outcomes on more than 8000 patients with RA. MMP-3 monitoring should be embedded in the routine assessment and accompany therapeutic modalities, in personalized medical RA management.

Lysyl oxidase is involved in synovial hyperplasia and angiogenesis in rats with collagen‑induced arthritis

Lysyl oxidase (LOX) serves an important role in remodeling the extracellular matrix and angiogenesis in various types of cancer; however, whether LOX is involved in the pathogenesis of rheumatoid arthritis remains unknown. In order to investigate this in the present study, β-aminopropionitrile, an inhibitor of LOX, was injected intraperitoneally into rats with type II collagen-induced arthritis (CIA). Subsequently, synovial hyperplasia was examined by hematoxyl in and eosin staining, and the microvascular density (MVD) and expression levels of LOX, matrix metalloproteinase (MMP)-2 and MMP-9 in the synovial membrane and fluid were determined by immunohistochemistry and ELISA, respectively. The enzyme activity of LOX was evaluated by the Amplex Red Hydrogen Peroxide method. The results demonstrated an increased amount of rough synovial membranes, higher MVD in these membranes and more synovial cell layers in CIA rats compared with in the control rats. In addition, higher enzymatic activity of LOX and higher expression levels of MMP-2 and MMP-9 were revealed in CIA rats compared with in the control rats. Notably, β-aminopropionitrile inhibited paw swelling and the decreased the arthritis index, the MVD in the synovial membranes and the expression levels of MMP-2 and MMP-9. Furthermore, the expression level of LOX in the synovial membranes was positively associated with the MVD and the expression levels of MMP-2 and MMP-9, suggesting that LOX promotes synovial hyperplasia and angiogenesis and that LOX may be a potential therapeutic target for rheumatoid arthritis.

Rituximab in Minimal Change Disease: Mechanisms of Action and Hypotheses for Future Studies

Treatment with rituximab, a monoclonal antibody against the B-lymphocyte surface protein CD20, leads to the depletion of B cells. Recently, rituximab was reported to effectively prevent relapses of glucocorticoid-dependent or frequently relapsing minimal change disease (MCD). MCD is thought to be T-cell mediated; how rituximab controls MCD is not understood. In this review, we summarize key clinical studies demonstrating the efficacy of rituximab in idiopathic nephrotic syndrome, mainly MCD. We then discuss immunological features of this disease and potential mechanisms of action of rituximab in its treatment based on what is known about the therapeutic action of rituximab in other immune-mediated disorders. We believe that studies aimed at understanding the mechanisms of action of rituximab in MCD will provide a novel approach to resolve the elusive immune pathophysiology of MCD.

Interleukin-21 induces migration and invasion of fibroblast-like synoviocytes from patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial fibroblast hyperplasia and bone erosion. Fibroblast-like synoviocytes (FLS) play a pivotal role in RA pathogenesis through aggressive migration and matrix invasion, and certain proinflammatory cytokines may affect synoviocyte invasion. Whether interleukin (IL)-21 influences this process remains controversial. Here, we evaluated the potential regulatory effect of IL-21 on the migration, invasion and matrix metalloproteinase (MMP) expression in RA-FLS. We found that IL-21 promoted the migration, invasion and MMP (MMP-2, MMP-3, MMP-9, MMP-13) production in RA-FLS. Moreover, IL-21 induced activation of the phosphoinositide 3-kinase (PI3K), signal transducer and activator of transcription-3 (STAT-3) and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) pathways, and blockage of these pathways [PI3K/protein kinase B (AKT) inhibitor LY294002, STAT-3 inhibitor STA-21 and ERK1/2 inhibitor PD98059] attenuated IL-21-induced migration and secretion of MMP-3 and MMP-9. In conclusion, our results suggest that IL-21 promotes migration and invasion of RA-FLS. Therefore, therapeutic strategies targeting IL-21 might be effective for the treatment of RA.