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

Matrix Metalloproteinase Inspired Therapeutic Strategies for Bone Diseases

Matrix Metalloproteinases (MMPs), as a family of zinc-containing enzymes, show the function of decomposing Extracellular Matrix (ECM) and participate in the physiological processes of cell migration, growth, inflammation, and metabolism. Clinical and experimental studies have indicated that MMPs play an essential role in tissue injury and repair as well as tumor diagnosis, metastasis, and prognosis. An increasing number of researchers have paid attention to their functions and mechanisms in bone health and diseases. The present review focuses on MMPs-inspired therapeutic strategies for the treatment of bone-related diseases. We introduce the role of MMPs in bone diseases, highlight the MMPs-inspired therapeutic options, and posit MMPs as a trigger for smart cell/drug delivery.

Exosomes Isolated From Bone Marrow Mesenchymal Stem Cells Exert a Protective Effect on Osteoarthritis via lncRNA LYRM4-AS1-GRPR-miR-6515-5p

Objectives

The aim of this study was to investigate the effects of exosomes isolated from human bone marrow mesenchymal stem cells (BMSCs) on osteoarthritis (OA) and a competitive endogenous RNA (ceRNA) network.

Methods

Exosomes were isolated from human BMSCs and characterized by transmission electron microscopy (TEM), Nanosight (NTA), and western blotting. Chondrocytes were treated with interleukin-1β (IL-1β) and then transfected with exosomes. Cell viability and apoptosis were determined using Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. Cells with IL-1β and exosomes were sequenced, and differentially expressed lncRNAs (DE-lncRNAs) and miRNAs (DE-miRNAs) were identified. Thereafter, a ceRNA network (LYRM4-AS1-GRPR-miR-6515-5p) was chosen for further validation.

Results

TEM, NTA, and western blotting showed that exosomes were successfully isolated, and PKH67 staining showed that exosomes could be taken up by IL-1β-induced chondrocytes. Compared with the control group, IL-1β significantly decreased cell viability and promoted apoptosis (P < 0.05), while exosomes reversed the changes induced by IL-1β. For MMP3, AKT, and GRPR, IL-1β upregulated their expression, while exosomes downregulated their expression. For PTEN, there was no significant difference in PTEN expression between the control and IL-1β groups; however, exosomes markedly upregulated PTEN expression. By sequencing, 907 DE-lncRNAs and 25 DE-miRNAs were identified, and a ceRNA network was constructed. The dual-luciferase reporter gene indicated that LYRM4-AS1, miR-6515-5, and GRPR interacted with each other. The results of cell experiments showed that LYRM4-AS1 regulated the growth of IL-1β-induced chondrocytes by GRPR/miR-6515-5p.

Conclusion

Exosomes may alleviate OA inflammation by regulating the LYRM4-AS1/GRPR/miR-6515-5p signaling pathway.

Platelets and Matrix Metalloproteinases: A Bidirectional Interaction with Multiple Pathophysiologic Implications

Platelets contain and release several matrix metalloproteinases (MMPs), a highly conserved protein family with multiple functions in organism defense and repair. Platelet-released MMPs as well as MMPs generated by other cells within the cardiovascular system modulate platelet function in health and disease. In particular, a normal hemostatic platelet response to vessel wall injury may be transformed into pathological thrombus formation by platelet-released and/or by locally generated MMPs. However, it is becoming increasingly clear that platelets play a role not only in hemostasis but also in immune response, inflammation and allergy, atherosclerosis, and cancer development, and MMPs seem to contribute importantly to this role. A deeper understanding of these mechanisms may open the way to novel therapeutic approaches to the inhibition of their pathogenic effects and lead to significant advances in the treatment of cardiovascular, inflammatory, and neoplastic disorders.

Impact of disease activity on impaired glucose metabolism in patients with rheumatoid arthritis

Objective

To explore glucose metabolism in rheumatoid arthritis (RA) and its association with insulin resistance (IR) risk factors and disease activity indicators, including matrix metalloproteinase-3 (MMP3).

Methods

This single-center study included 127 non-diabetic subjects: 90 RA patients and 37 matched controls. IR-related risk factors, disease activity (DAS28-ESR/CRP), concentrations of inflammation markers, MMP3, glucose, specific insulin, and C-peptide (a marker of β-cell secretion) were determined. Homeostasis Model Assessment was used to establish insulin resistance (HOMA2-IR) and sensitivity (HOMA2-%S). Associations of HOMA2 indices with IR-related risk factors, inflammation markers, and RA activity were tested using multiple regression analyses.

Results

RA patients had significantly increased HOMA2-IR index than controls. In the RA group, multivariate analysis revealed DAS28-ESR, DAS28-CRP, tender joint counts, patient’s global assessment, and MMP3 level as significant positive predictors for HOMA2-IR (β = 0.206, P = 0.014; β = 0.192, P = 0.009; β = 0.121, P = 0.005; β = 0.148, P = 0.007; β = 0.075, P = 0.025, respectively), and reciprocal negative for HOMA2-%S index. According to the value of the coefficient of determination (R²), DAS28-ESR ≥ 5.1 has the largest proportion of variation in both HOMA2-IR indices. DAS28-ESR ≥ 5.1 and ESR were independent predictors for increased C-peptide concentration (β = 0.090, P = 0.022; β = 0.133, P = 0.022). Despite comparability regarding all IR-related risk factors, patients with DAS28-ESR ≥ 5.1 had higher HOMA2-IR than controls [1.7 (1.2–2.5) vs. 1.2 (0.8–1.4), P = 0.000]. There was no difference between patients with DAS28-ESR < 5.1 and controls [1.3 (0.9–1.9) vs. 1.2 (0.8–1.4), P = 0.375].

Conclusions

RA activity is an independent risk factor for impaired glucose metabolism. DAS28-ESR ≥ 5.1 was the main contributor to this metabolic disturbance, followed by MMP3 concentration, outweighing the impact of classic IR-related risk factors.

MicroRNA-497 Reduction and Increase of Its Family Member MicroRNA-424 Lead to Dysregulation of Multiple Inflammation Related Genes in Synovial Fibroblasts With Rheumatoid Arthritis

Objectives

Mounting evidence has demonstrated that microRNAs (miRNAs) participate in rheumatoid arthritis (RA). The role of highly conserved miR-15/107 family in RA has not been clarified yet, and hence investigated in this study.

Methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the expression of miRNAs and genes. Cell counting kit 8 (CCK-8) and FACS were used to detect proliferation and apoptosis. Protein expression was detected by using Western blotting. mRNA deep sequencing and cytokine antibody array were used to analyze differentially expressed genes, signaling pathways and cytokines.

Results

The expression of miR-15a, miR-103, miR-497, and miR-646 was found decreased, while miR-424 increased in RA patients. MiR-424 and miR-497 were further investigated and the results showed that they could regulate the expression of multiple genes in rheumatoid arthritis synovial fibroblast (RASF) and affect signaling pathways. At the protein level, miR-497 mimic altered all the selected inflammation-related genes while miR-424 inhibitor only affected part of genes. MiR-497 mimic, rather than miR-424 inhibitor, had significant effects on proliferation and apoptosis of RASF. DICER1 was found to positively regulate the expression of miR-424 and miR-497, while DICER1 was also negatively regulated by miR-424. The increase of miR-424 could reduce miR-497 expression, thus forming a loop, which facilitated explaining the dysregulated miR-424 and miR-497 in RA.

Conclusion

The miR-424 and miR-497 of miR-15/107 family affect cell proliferation and apoptosis in RA, and the proposed miR-424-DICER1-miR-497 feedback loop provides a novel insight into regulating miRNA expression and a candidate target for controlling RA.

Activity of fibroblast-like synoviocytes in rheumatoid arthritis was impaired by dickkopf-1 targeting siRNA

BACKGROUND

Fibroblast-like synoviocytes (FLSs), resident mesenchymal cells of synovial joints, play an important role in the pathogenesis of rheumatoid arthritis (RA). Dickkopf-1 (DKK-1) has been proposed to be a master regulator of bone remodeling in inflammatory arthritis. Here, potential impairation on the activity of FLSs derived from RA to small interfering RNAs (siRNAs) targeting DKK-1 was investigated.

METHODS

siRNAs targeting DKK-1 were transfected into FLSs of patients with RA. Interleukin (IL)-1β, IL-6, IL-8, matrix metalloproteinase (MMP) 2, MMP3, MMP9, transforming growth factor (TGF)-β1, TGF-β2 and monocyte chemoattractant protein (MCP)-1 levels in the cell culture supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Invasion assay and H incorporation assay were utilized to investigate the effects of siRNAs targeting DKK-1 on FLSs invasion and cell proliferation, respectively. Western blotting was performed to analyze the expression of nuclear factor (NF)-κB, interleukin-1 receptor-associated kinase (IRAK)1, extracellular regulated protein kinases (ERK)1, Jun N-terminal kinase (JNK) and β-catenin in FLSs.

RESULTS

DKK-1 targeting siRNAs inhibited the expression of DKK-1 in FLSs (P < 0.01). siRNAs induced a significant reduction of the levels of IL-6, IL-8, MMP2, MMP3 and MMP9 in FLSs compared to the control group (P < 0.05). DKK-1 targeting siRNAs inhibited the proliferation and invasion of FLSs (P < 0.05). Important molecules of pro-inflammatory signaling in FLSs, including IRAK1 and ERK1, were decreased by the inhibition of DKK-1 in FLSs. In contrast, β-catenin, a pivotal downstream molecule of the Wnt signaling pathway was increased.

CONCLUSIONS

By inhibiting DKK-1, we were able to inhibit the proliferation, invasion and pro-inflammatory cytokine secretion of FLSs derived from RA, which was mediated by the ERK or the IRAK-1 signaling pathway. These data indicate the application of DKK-1 silencing could be a potential therapeutic approach to RA.

Aliskiren, tadalafil, and cinnamaldehyde alleviate joint destruction biomarkers; MMP-3 and RANKL; in complete Freund's adjuvant arthritis model: Downregulation of IL-6/JAK2/STAT3 signaling pathway

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease, which is accompanied by progressive joint damage and disability. The intolerability of conventional antirheumatic drugs by some patients necessitates the search for effective antirheumatic agents having better tolerability. In the current work, we aimed to investigate the efficacy of cinnamaldehyde, tadalafil, and aliskiren as potential antirheumatic candidates and to explore their modulatory effects on joint destruction, inflammatory response, and intracellular signaling. Arthritis was induced in female Wistar rats by complete Freund's adjuvant (CFA) 0.4 ml s.c. on days 1, 4, and 7. Treated groups received their respective drugs, starting from day 13, daily for 3 weeks. Methotrexate and prednisolone were the standard antirheumatic drugs, while cinnamaldehyde, tadalafil, and aliskiren were the test agents. Treatment with cinnamaldehyde, tadalafil, or aliskiren reduced serum levels of rheumatoid factor, and pro-inflammatory cytokines; tumor necrosis factor-alpha and interleukin-6 (IL-6), along with elevated level of IL-10 which is an anti-inflammatory cytokine. Besides, cartilage and bone destruction biomarkers; matrix metalloproteinase-3 (MMP-3) and receptor activator of nuclear factor-kappa B ligand (RANKL); were significantly reduced after treatment with the test agents, which was further confirmed by histopathological investigation. The elevated protein expressions of phosphorylated-Janus kinase 2 (p-JAK2), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), and inducible nitric oxide synthase (iNOS) in articular tissue were markedly attenuated after treatment with cinnamaldehyde, tadalafil, or aliskiren, while that of endothelial nitric oxide synthase (eNOS) was greatly enhanced. In addition, oxidative stress and inflammatory markers such as malondialdehyde, nitric oxide, and myeloperoxidase were reduced in joint tissue after treatment with the test agents, while glutathione content was elevated. Furthermore, the renin inhibitor aliskiren produced effects close to those of the normal and methotrexate, the gold standard antirheumatic drug, in most of the measured parameters.

Collectively, these findings led to the assumption that the downregulation of IL-6/JAK2/STAT3 signaling by cinnamaldehyde, tadalafil, and aliskiren could alleviate joint destruction by MMP-3 and RANKL, reduce iNOS, and enhance eNOS expressions. Moreover, aliskiren could be a promising therapeutic agent for RA, because of its ability to normalize most of the measured parameters after CFA-induced arthritis.

Matrix metalloproteinase 3 as a valuable marker for patients with COVID-19

The situation of the coronavirus disease 2019 (COVID‐19) continues to evolve, our study explored the significance of serum levels of matrix metalloproteinase 3 (MMP3) as a marker for patients with COVID‐19. Sixty‐two COVID‐19 patients in the First Hospital of Hunan University of Chinese Medicine and Loudi Center for Diseases Prevention and Control, from January to March 2020, were sampled as the novel coronavirus pneumonia infected group. One hundred and thirty‐one cases from the First Hospital of Hunan University of Chinese Medicine, including 67 healthy individuals and 64 non‐COVID‐19 inpatients, served as the noninfected group. Approximately every 5 days, sera from 20 cases were collected and analyzed three times, using an automatic biochemical analyzer, to detect serum MMP3 concentrations. Correlation was analyzed between MMP3 and other proinflammatory cytokines. Following normality tests, differences in serum MMP3 levels between the infected and noninfected group were analyzed via SPSS (version 25.0) software, using the Wilcoxon rank sum test. The MMP3 concentration was 44.44 (23.46 ~ 72.12) ng/mL in the infected group and 32.42 (28.16 ~ 41.21) ng/mL in the noninfected group. The difference between the two groups was statistically significant (Z = −2.799, P = .005 < .05). A positive correlation was found between MMP3 and interleukin 1β (IL‐1β; r = .681, P = .000 < .05), and IL‐6 (r = .529, P = .002 < .05). Serum MMP3 concentration, measured over three separate time points, were 55.98 (30.80 ~ 75.97) ng/mL, 34.84 (0.00 ~ 51.84) ng/mL, and 5.71 (0.00 ~ 40.46) ng/mL, respectively. Detection of serum MMP3 levels may play an important role in the development of therapeutic approaches for COVID‐19 and may indicate the severity of disease.

Inhibition of BMP3 increases the inflammatory response of fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a persistent autoimmune disease. Fibroblast-like synoviocytes (FLS) are a key component of invasive pannus and a pathogenetic mechanism in RA. Expression of bone morphogenetic protein 3 (BMP3) mRNA is reportedly decreased in the arthritic synovium. We previously showed that BMP3 expression is significantly downregulated in the synovial tissues of RA patients and models of adjuvant-induced arthritis (AIA). In the present study, we explored the association between BMP3 and FLS migration and secretion of proinflammatory factors in RA. We found that inhibition of BMP3 expression using BMP3 siRNA increased the proinflammatory chemokines and migration of FLS stimulated with TNF-α. Inhibition of BMP3 expression also increased expression of IL-6, IL-1β, IL-17A, CCL-2, CCL-3, VCAM-1, MMP-3, and MMP-9, but not TIMP-1, in AIA and RA FLS. Correspondingly, induction of BMP3 overexpression through intra-articular injection of ad-BMP3 diminished arthritis severity in AIA rats. We also found that BMP3 may inhibit activation of TGF-β1/Smad signaling. These data indicate that BMP3 may suppress the proliferation and migration of FLS via the TGF-β1/Smad signaling pathway.

Proteomic analysis of human synovial fluid reveals potential diagnostic biomarkers for ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease affecting the axial skeleton and peripheral joints. The etiology of this disease remains poorly understood, but interactions between genetic and environmental factors have been implicated. The present study identified differentially expressed proteins in the synovial fluid (SF) of AS patients to elucidate the underlying cause of AS.

METHODS

A cohort of 40 SF samples from 10 AS and 10 each of rheumatoid arthritis (RA), gout, and osteoarthritis (OA) patients were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify differentially expressed proteins specific to AS. The label-free LC-MS/MS results were verified by western blotting.

RESULTS

We identified 8 proteins that were > 1.5-fold upregulated in the SF of AS patients compared to that of the disease control groups, including HP, MMP1, MMP3, serum amyloid P-component (APCS), complement factor H-related protein 5 (CFHR5), mannose-binding lectin 2 (MBL2), complement component C9 (C9), and complement C4-A (C4A). CFHR5 and C9 were previously found in serum from AS patients, while APCS was previously found in SF as well as in serum. However, the present study has identified C4A, and MBL2 as potential AS biomarkers for the first time. The expression levels of MMP3, C9, and CFHR5 were verified in AS SF using western blotting.

CONCLUSION

We performed quantitative comparative proteomic analysis using by LC-MS/MS of the SF from four disease states: RA, gout, and OA. This systematic comparison revealed novel differentially expressed proteins in AS SF, as well as two previously reported candidate biomarkers. We further verified the expression of MMP3, C9 and CFHR5 by western blot. These proteins may serve as diagnostic or prognostic biomarkers in patients with AS, and may thus improve the clinical outcomes of this serious disease.

Humulus japonicus extract ameliorates collagen‑induced arthritis in mice through regulation of overall articular inflammation

Humulus japonicus (HJ) is a widely used herbal medicine in Asia with anti-oxidative, anti-microbial, and anti-inflammatory effects. We investigated the potential therapeutic effects of HJ in rheumatoid arthritis (RA) using a mouse model of collagen-induced arthritis (CIA) and a lipopolysaccharide-stimulated murine macrophage cell line (RAW 264.7). The CIA mice were administered 300 mg/kg HJ orally starting 3 days prior to second immunization. The clinical and histopathological findings were assessed in the paw of CIA mice. The levels of autoantibodies and inflammatory markers were determined in the plasma and cell culture supernatant, respectively. The expression at mRNA and protein levels was analyzed by reverse transcription quantitative-PCR and western blot analysis, respectively. HJ significantly decreased the gross arthritic scores and paw swelling in CIA mice. Furthermore, synovial inflammation, cartilage destruction, and bone erosion were markedly reduced by HJ. It also decreased the expression of inflammatory enzymes in both the paw of mice and RAW 264.7 cells. Moreover, the expression of genes related to all macrophages and pro-inflammatory M1 macrophage were significantly decreased, whereas the expression of anti-inflammatory M2 macrophage marker was markedly increased in the paw of HJ-treated CIA mice. In addition, HJ suppressed the levels of plasma anti-type II collagen antibody following the decreased expression of T helper type 1 (Th1) and Th2 cell-associated surface markers and cytokines in the paw. HJ also significantly inhibited the expression of IL-6 both in vitro and in vivo, followed by reduced STAT3 phosphorylation and expression in the paw of CIA mice. Finally, the expression of osteoclast-related genes was decreased in the paw of HJ-treated CIA mice. These findings suggest that HJ can play a role in suppressing the development of CIA by overall regulation of articular inflammation. This study should provide new insights into the use of HJ as a therapeutically effective natural product against RA.