Long noncoding RNAs (lncRNAs) have been reported to play an important role in
diabetic nephropathy (DN). However, the molecular mechanism involved in this process remains poorly understood. Thus, the present study aimed to explore the function and molecular mechanism of dysregulated
lncRNA X-inactive specific transcript (XIST) in DN. DN mouse models were established by
streptozotocin treatment, and human renal tubular epithelial HK-2 cells were exposed to high
glucose to produce an in vitro model. XIST was highly expressed in renal tissues of patients with DN, mice with DN, and high
glucose-exposed HK-2 cells. To identify the interaction among XIST, miR-93-5p, and
cyclin-dependent kinase inhibitor 1A (CDKN1A) and to analyze the functional significance of their interaction in renal interstitial
fibrosis, we altered endogenous expression of XIST and miR-93-5p and CDKN1A. Dual-
luciferase reporter assay results suggested that XIST was highly expressed in the kidney tissue of DN mice and high
glucose-exposed HK-2 cells. XIST was identified to be a
lncRNA that could bind to miR-93-5p, and CDKN1A was a target of miR-93-5p. Downregulated expression of XIST led to an increase in miR-93-5p expression, thereby decreasing CDKN1A and suppressing renal interstitial
fibrosis in DN. Consistently, XIST knockdown reduced the expression of
fibrosis markers (
fibronectin,
collagen type IV, and
transforming growth factor-β1). Restoration of CDKN1A or decreasing miR-93-5p yielded a reversed effect on renal interstitial
fibrosis. In conclusion, our study demonstrated that silenced XIST inducing miR-93-5p-dependent CDKN1A inhibition was beneficial for preventing renal interstitial
fibrosis in DN, which may provide a future strategy to prevent the progression of DN.