miR­152 regulates TGF­ß1­induced epithelial­mesenchymal transition by targeting HPIP in tubular epithelial cells.

Renal fibrosis is a common pathological feature of chronic kidney diseases, and their development and progression are influenced by epigenetic modifications including aberrant microRNA (miRNA or miR) expression. miRNAs have been demonstrated to modulate the aggressiveness of various cancers and have emerged as possible therapeutic agents for the management of renal fibrosis. Transforming growth factor ß1 (TGF­ß1)­induced epithelial­mesenchymal transition (EMT) of tubular epithelial cells serves a role in the initiation and progression of renal fibrosis. Furthermore, recent results indicated that the progression of EMT is reversible. The present study aimed to clarify the role of miR­152 in EMT of the tubular epithelial cell line HK­2, stimulated by TGF­ß1, using in vitro transfection with a miR­152 mimic and to further investigate the underlying mechanism of miR­152 activity. In the present study, miR­152 expression was significantly reduced in TGF­ß1­treated HK­2 cells, accompanied by an increased expression of hematopoietic pre­B­cell leukemia transcription factor (PBX)­interacting protein (HPIP). Additionally, miR­152 overexpression inhibited TGF­ß1­induced EMT and suppressed HPIP expression by directly targeting the 3' untranslated region of HPIP in HK­2 cells. Furthermore, upregulation of HPIP reversed miR­152­mediated inhibitory effects on the EMT. Collectively, the results suggest that downregulation of miR­152 initiates the dedifferentiation of renal tubules and progression of renal fibrosis, which may provide important targets for prevention strategies of renal fibrosis.