Vaspin regulated cartilage cholesterol metabolism through miR155/LXRα and participated in the occurrence of osteoarthritis in rats.

AIMS: This study intends to explore the role of Vaspin and cholesterol metabolism in the process of osteoarthritis (OA) and its mechanism in vitro and in vivo. MAIN METHODS: In vitro, chondrocytes were treated with interleukin-1ß (IL-1ß, 20 ng/mL) in combination with Vaspin at different concentrations for 48 h. The expressions of Aggrecan (ACAN), Collagen 2a1 (Col2a1), A Disintegrin And Metalloproteinase with Thrombo Spondin type 1 motifs 5 (ADAMTS 5), and Matrix metalloproteinase 13 (MMP13) were detected. In vivo, the expression of liver X receptor (LXRα) and other Cholesterol efflux related genes were detected in the rat OA knee cartilage-induced by papain. KEY FINDINGS: In vitro, in a concentration-dependent manner, Vaspin reversed the decreased expression of ACAN and Col2a1, and the increased expression of ADAMTS 5 and MMP13 caused by IL-1ß. Besides, Vaspin promoted the expression of LXRα and other Cholesterol efflux related genes in a concentration-dependent manner in chondrocytes. However, miR155 mimics reversed the Vaspin-induced expression changes of cholesterol efflux pathway in chondrocytes. In vivo, the expression of LXRα and other Cholesterol efflux related genes were decreased in the rat OA knee cartilage-induced by papain. Besides, the level of Vaspin was reduced and the miroRNA155 (miR155) expression was increased in OA knee cartilage of rats. SIGNIFICANCE: In conclusion, the decreased expression of Vaspin inhibited the expression of Cholesterol efflux pathway via miR155/LXRα. Finally, the inhibited Cholesterol efflux pathway led to the cholesterol accumulation and OA in cartilage.

miRNA-155 expression and role in pathogenesis in spinal tuberculosis-induced intervertebral disc destruction.

The current study aimed to investigate microRNA-155 (miR-155) expression in spinal tuberculosis-induced intervertebral disc destruction and its regulatory role in disease pathogenesis. A total of 26 patients with intervertebral disc destruction induced by spinal tuberculosis and 31 healthy individuals were included. Reverse transcription-quantitative polymerase chain reactions, western blot analysis and ELISA were performed to detect mRNA and protein expression levels. A bioinformatics analysis was applied to predict the upstream regulator of matrix metalloproteinase (MMP)13, which was confirmed by dual-luciferase reporter assay. Compared with the control group, mRNA and protein expression levels of MMP13 were significantly increased in the intervertebral disc of patients with spinal tuberculosis. However, miR-155 expression in the intervertebral disc of patients with spinal tuberculosis was significantly decreased compared with the control group. Dual-luciferase reporter assays suggested that miR-155 bound to the 3'-untranslated region of MMP13 to regulate gene expression. In primary annulus fibrosus cells, upregulated miR-155 expression significantly decreased MMP13 expression in the cells and culture supernatant, whereas it increased type II collagen expression. Upregulated MMP13 expression in the intervertebral disc in patients with spinal tuberculosis may be correlated with downregulated miR-155 expression. miR-155 may regulate expression levels of associated proteins in the intervertebral disc via modulating MMP13 expression, which contributes to the disease pathogenesis. The results of the current study may provide the theoretical basis for the diagnosis and treatment of disc damages caused by spinal tuberculosis.