Upregulated long noncoding RNA LOC105375913 induces tubulointerstitial fibrosis in focal segmental glomerulosclerosis.

Tubulointerstitial fibrosis impacts renal prognosis of focal segmental glomerulosclerosis (FSGS). Based on transcriptomic analysis, we found that the level of LOC105375913 was increased in tubular cells of FSGS patients. C3a induced the expression of LOC105375913, which promoted the expression of fibronectin and collagen I in tubular cells. Silence of snail reversed the level of fibronectin and collagen I in cells overexpressing LOC105375913. MiR-27b was predicted and confirmed to regulate the expression of snail in tubular cells, and LOC105375913 contained the response element of miR-27b. The competitive binding between LOC105375913 and miR-27b increased the level of snail and promoted fibrogenesis in tubular cells. Upstream, p38 and XBP-1s regulated the expression of LOC105375913. Inhibition of p38 or silence of XBP-1s decreased the level of LOC105375913, and suppressed the expression of snail, fibronectin and collagen I in tubular cells treated with C3a. Overexpression of LOC105375913 decreased the level of miR-27b, increased the level of snail and caused tubulointerstitial fibrosis in mice. In conclusion, the activation of C3a/p38/XBP-1s pathway induces the expression of LOC105375913 in tubular cells, and LOC105375913 increases the level of snail and induces tubulointerstitial fibrosis through competitive binding of miR-27b in tubular cells of FSGS patients.