Upregulation of p16, Bax and Bcl-2 mRNA Expression Associated with Epithelial Apoptosis and Myofibroblast Proliferation in Kidney Fibrosis Model in Mice

Background. Cellular senescence may play a role in the development of kidney fibrosis, but its specific association with apoptosis or proliferation have yet to be determined.
Objectives. This study aims to determine the effects of unilateral ureteral obstruction (UUO) on proliferation, cellular senescence and apoptosis in kidney fibrosis. Methods. A unilateral ureteral obstruction (UUO) procedure was performed to induce kidney fibrosis in 24 Swiss mice (3 months old, 30 g–40 g). Mice were sacrificed on day 3 (UUO3, n = 6), day 7 (UUO7, n = 6) and day 14 (UUO14, n = 6). Sham operation (SO) procedures were performed on the control group. The expression of Bcl-2, p16 and Bax mRNA was quantified with reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical (IHC) staining with anti-Bcl-2 and p53 antibodies was used to determine the localisation of proliferation and apoptosis. Data were analysed using one-way ANOVA followed by a post hoc least significant difference (LSD) test (P < 0.05). Results. RT-PCR analysis showed higher mRNA expression of Bcl-2, p16 and Bax in the UUO groups compared with SO group (P < 0.05). Immunostaining showed that Bcl-2 and p53 expression in tubular epithelium in the UUO groups, except Bcl-2 expression was found in interstitial areas of UUO14 group. Conclusion. Senescence in UUO might be associated with epithelial apoptosis and myofibroblast proliferation.