METHODS: Kidney IRI was performed with bilateral pediculus clamping in Swiss Background mice (3 months, 30-40g). Mice were euthanised on day one (I/R1, n=6), day eight (I/R8, n=6), and day twelve (I/R12, n=6) to exam acute and chronic episodes. Sham operation procedure was performed in the control. Tubular injury was assessed based on periodic acid- Schift (PAS) staining. Reverse transcriptase PCR (RT-PCR) was done to quantify mRNA expression of Bax, Bcl-2, and p16. Immunohistostaining (IHC) was performed to examine localisation of apoptosis (p53) and proliferation (Bcl-2).
RESULTS: RT-PCR analysis showed upregulation of mRNA expression of Bcl-2, Bax, and p16 (p<0.05). The data showed that ischemia/reperfusion induces upregulation of Bax (p=0.20), Bcl-2 (p=0.45), p16 (p=0.18). Apoptosis and proliferation occurred in the epithelial cells in acute episodes, but occurred in interstitial areas in chronic episodes.
CONCLUSIONS: Ischemia/reperfusion injury induces upregulation proliferation, apoptosis, and cellular senescence in acute kidney injury. Apoptosis reached its peak on day 1, proliferation on day 8, and cellular senescence on day 12.