miR-106a mimics the nuclear factor-κB signalling pathway by targeting DR6 in rats with osteoarthritis.

Introduction: Osteoarthritis (OA) is a common inflammatory joint disease characterised by progressive cartilage destruction. Management of this condition remains a significant challenge, and new therapies are required. We investigated the protective effects of miR-106a mimics in a murine model of OA. Material and methods: This study was performed using both in vitro and in vivo OA models. Primary chondrocytes were isolated from female rats, with inflammation induced via treatment with lipopolysaccharide (LPS). Then the effects of a miR-106a mimic were examined based on the level of inflammatory cytokine production and apoptotic signalling following LPS stimulation. An in vivo rat model of OA was generated by injecting LPS into the anterior cruciate ligament, followed by treatment with miR-106a mimics. Then, inflammatory and apoptotic protein expression was assessed in the cartilage tissue. Results: Treatment with miR-106a mimic reduced the levels of inflammatory cytokines and apoptotic proteins in cartilage tissues following LPS-induced inflammation. Furthermore, the mimic ameliorated the expression of DR-6 mRNA and DR6, IκBα, and p65 proteins in chondrocytes. Similar effects were seen in the in vivo model, with the mimic attenuating expression of NF-κB, p65, IκBα, and DR6 proteins and improving histopathological outcomes in the chondrocytes of OA rats. Conclusions: Treatment with miR-106a mimic ameliorates inflammation in cartilage tissues of OA subjects by activating death receptor 6 via the NF-κB signalling pathway.

Comparison of short interval and low dose (SILD) with high dose of cyclophosphamide in the susceptibility to infection in SLE: a multicentrereal-world study.

OBJECTIVE: Infection is a major cause of death in patients with SLE. This study aimed to explore the infection rate in patients with SLE receiving a low dose of intravenous cyclophosphamide (IV-CYC). METHODS: Clinical parameters of 1022 patients with SLE from 24 hospitals in China were collected. Patients were divided into the short-interval and lower-dose (SILD, 400 mg every 2 weeks) IV-CYC group and the high-dose (HD, 500 mg/m2 of body surface area every month) IV-CYC group. The clinical data and infection rate between the two groups were compared. RESULTS: Compared with HD IV-CYC, the infection rate of the SILD IV-CYC group was significantly lower (13.04% vs 22.27%, p=0.001). Respiratory tract infection (10.28% vs 15.23%, p=0.046) and skin/soft tissue infection (1.78% vs 4.3%, p=0.040) were significantly decreased in the SILD IV-CYC group. Moreover, infections occurred most likely in patients with SLE with leucopenia (OR 2.266, 95% CI 1.322 to 3.887, p=0.003), pulmonary arterial hypertension (OR 2.756, 95% CI 1.249 to 6.080, p=0.012) and >15 mg/day of glucocorticoid (OR 2.220, 95% CI 1.097 to 4.489, p=0.027). CONCLUSIONS: SILD IV-CYC showed a lower frequency of infection events than high-dose IV-CYC in patients with SLE.

LncRNA CALML3-AS1 regulates chondrocyte apoptosis by acting as a sponge for miR-146a.

Chondrocyte apoptosis contributes to osteoarthritis, while miR-146a is a critical player in chondrocyte apoptosis. Our bioinformatics analysis showed that miR-146a may bind with long non-coding RNA (lncRNA) CALML3 antisense RNA 1 (CALML3-AS1). Our study was therefore carried out to investigate the interactions between lncRNA CALML3-AS1 and miR-146a in osteoarthritis. This study included 66 osteoarthritis patients who were admitted at Shanxi People's Hospital from July 2016 to June 2019. Transfections were performed to analyse gene interactions. RT-qPCR and Western blot were performed to determine the expression levels of gene and protein, respectively. Cell apoptosis of chondrocytes induced by lipopolysaccharide (LPS) was analysed by cell apoptosis assay. We found that CALML3-AS1 was downregulated, while miR-146a was upregulated in osteoarthritis. However, no significant correlation was found between them. In addition, overexpression of CALML3-AS1 or miR-146a did not affect the expression of each other. However, overexpression of CALML3-AS1 resulted in the upregulation of Smad family member 4 (Smad4), a downstream target of miR-146a. We also found that the expression of miR-146a and Smad4 were negatively correlated, while the correlation between CALML3-AS1 and smad4 was not significant. In cell apoptosis assay, overexpression of CALML3-AS1 and Smad4 resulted in decreased proliferation of chondrocytes. MiR-146a played an opposite role and reduced the effects of overexpression of CALML3-AS1 and Smad4. Therefore, CALML3-AS1 may regulate chondrocyte apoptosis by acting as a sponge for miR-146a to upregulate Smad4.

miR-22 inhibits synovial fibroblasts proliferation and proinflammatory cytokine production in RASF via targeting SIRT1.

BACKGROUND/AIMS: Rheumatoid arthritis synovial fibroblasts (RASF) play an essential role in the pathogenesis of rheumatoid arthritis (RA). This study aimed to investigate the biological effects of miR-22 on RASFs. METHODS: RT-qPCR was used to detect the expressions of miR-22 and SIRT1 in RA synovial tissue. The results of miR-22 on the proliferation of RASF were examined by MTT assay. The effects of miR-22 on the secretion of TNF-α, IL-1ß, and IL-6 in RASF were measured by ELISA. Target gene prediction and screening, and luciferase reporter assay were used to testify downstream target genes of miR-22. RT-qPCR and western blotting were used to detect the mRNA and protein expression of SIRT1. RESULTS: miR-22 was significantly decreased in RA synovial tissue, while SIRT1 was significantly increased in RA synovial tissue. Over-expression of miR-22 significantly inhibited the proliferation of RASFs and the secretions of inflammatory cytokines (TNF-α, IL-1ß, and IL-6) in RASFs. SIRT1 was identified as a direct target of miR-22. Over-expression of miR-22 reduced the expression level of SIRT1 in RASFs. Over-expression of SIRT1 reversed the effect of miR-22 on the proliferation of RASFs and the secretion of inflammatory cytokines. CONCLUSION: MIR-22 was significantly down-regulated in RASF cells, which affected the secretions of inflammatory cytokines and cell proliferation by regulating SIRT1.