LncRNA PRNCR1 regulates CXCR4 expression to affect osteogenic differentiation and contribute to osteolysis after hip replacement.

BACKGROUND: Osteogenic differentiation plays an essential role in the pathogenesis of osteolysis, which is a complication of hip orthroplasty. The roles of lncRNA PRNCR1 in osteogenic differentiation and osteolysis were dissected in this study. METHODS: The expression of PRNCR1, miR-211-5p and C-X-C chemokine receptor-4 (CXCR4) protein in wear particles and mesenchymal stem cells (MSCs) were determined by qRT-PCR and Western blot, separately. The osteogenic differentiation degree of MSCs was assessed by ALP activity detection and ARS staining. Binding and interaction between RNA and protein were determined with RIP and RNA pull-down assay, respectively. Interaction between miR-211-5p and CXCR4 was examined by Dual luciferase reporter assay. RESULTS: PRNCR1 and CXCR4 were up-regulated in wear particles around prosthesis and in MSCs treated with PMMA, while miR-211-5p was down-regulated. Repression of PRNCR1 weakened the inhibitory effect of wear particles on osteogenic differentiation. PRNCR1 positively regulated CXCR4 through inhibiting miR-211-5p. Wear particles increased CXCR4 level through miR-211-5p to inhibit osteogenic differentiation of MSCs. Wear particles down-regulated miR-211-5p level through PRNCR1 to influence osteogenic differentiation of MSCs. CONCLUSION: LncRNA PRNCR1 up-regulates CXCR4 through targeting miR-211-5p, which affects osteogenic differentiation and thus contributing to osteolysis after hip replacement.

LncRNA PRNCR1 regulates osteogenic differentiation in osteolysis after hip replacement by targeting miR-211-5p.

Background Osteogenic differentiation and osteolysis after hip replacement are both associated with bone metabolism. Interaction between the long non-coding RNA (lncRNA) prostate cancer non-coding RNA 1 (PRNCR1) and miR-211-5p was analyzed to illuminate their roles in osteogenic differentiation and osteolysis. Methods The expression of PRNCR1, miR-211-5p and C-X-C chemokine receptor-4 (CXCR4) protein in tissues and mesenchymal stem cells (MSCs) were determined by qRT-PCR and western blot, separately. The osteogenic differentiation was assessed with Alkaline phosphatase (ALP) activity detection and ARS staining. The endogenous expressions of genes were modulated by recombinant plasmid and cell transfection. Combination condition and interaction between RNA and protein were determined with RIP and RNA pull-down assay, respectively. Interaction between miR-211-5p and CXCR4 was examined with Dual luciferase reporter assay. Results PRNCR1 and CXCR4 were up-regulated in wear particles around prosthesis and in MSCs incubated with Polymethylmethacrylate (PMMA), while miR-211-5p was down-regulated. Repression of PRNCR1 weakened the inhibitory effect of wear particles on osteogenic differentiation. PRNCR1 positively regulated CXCR4 through inhibiting miR-211-5p. Wear particles regulated CXCR4 level through miR-211-5p to affect osteogenic differentiation of MSCs. Wear particles regulated the miR-211-5p level through PRNCR1 to affect osteogenic differentiation of MSCs. Conclusion LncRNA PRNCR1 up-regulates CXCR4 through inhibiting miR-211-5p, which inhibits osteogenic differentiation and thereby leading to osteolysis after hip replacement.

miR-411 suppresses acute spinal cord injury via downregulation of Fas ligand in rats.

OBJECTIVE: To explore the role of miR-411/FasL in acute spinal cord injury (ASCI). METHODS: The ASCI rat model was established, and expression of miR-411 and Fas ligand (FasL) was examined. Basso, Beattie and Bresnahan (BBB) score was used to evaluate the rats' neurological function. PC12 oxygen-glucose deprivation (OGD) model was also established. Gene manipulation (including miR-411 mimic or inhibitor) was used to modulate gene expression. Luciferase reporter assay was conducted to confirm the targeting relationship between miR-411 and FasL. Flow cytometry was applied in the measurement of PC12 cell apoptosis. Finally, the miR-411 mimic was injected into the vertebral canal of ASCI rats to determine the effects of miR-411 in vivo. RESULTS: Compared with sham group, the expression of miR-411 and FasL was significantly decreased and increased in ASCI group, respectively (P < 0.05). Similarly, the expression of miR-411 and FasL was significantly lower and higher in OGD group than that in control group, respectively (P < 0.05). miR-411 directly controlled the FasL expression. miR-411 mimic can dramatically reduce the increased percentage of apoptosis cells caused by OGD when comparing to mimic control, which was greatly reversed by the overexpression of FasL (P < 0.05). Further, the BBB score was significantly elevated in the miR-411 mimic group when comparing to mimic control group, with decreased FasL expression (P < 0.05). CONCLUSION: miR-411 mimic suppressed PC12 cell apoptosis via FasL, and relieved ASCI in rats.