Introduction:
MicroRNA (miRNA) is a noncoding RNA that plays an important role in many diseases. Partial bladder outlet obstruction (PBOO) is a blockage between the outlet of the neck of the bladder and the external urethral orifice secondary to prostate hyperplasia and urethral stricture, and causative of morphological and functional abnormalities in the bladder. We examine the effects of miRNA-325-3p on PBOO and related mechanisms through an in-vitro study.

Material and methods:
Primary bladder smooth muscle cells (BSMCs) were extracted from SD rats and subjected to TGF-1 stimulation to form a cell model of PBOO. Cell proliferation was measured by CCK-8 assay, and the gene and protein expression levels were measured by RT-qPCR, western blot, and immunofluorescence. The correlation between miRNA-325-3p and ILK was analyzed through a double-luciferase target experiment.

Results:
The proliferation of BSMCs in the model group increased more significantly than in the normal group (p < 0.001) with miRNA-325-3p repression, and led to activation of the ILK and the TLR4/NF-B(p65) pathway as well as significant changes in the marker proteins. With miRNA-325-3p transfection, the rate of cell proliferation of the miRNA-325-3p group was significantly suppressed with ILK repression compared with that of the model group, and led to the suppression of TLR4/NF-B(p65) activity and the regulation of protein expression. However, the miRNA-325-3p treatment’s effects disappeared as ILK was supplemented. The double-luciferase experiment helped miRNA-325-3p target ILK in BSMCs.

Conclusions:
miRNA-325-3p overexpression may play a key role in PBOO-induced cell proliferation by targeting ILK and suppressing the TLR4/NF-B(p65) signaling pathway.