The expression of response gene to complement 32 on renal ischemia reperfusion injury in rat

To investigate the expression of response gene to complement 32 (RGC32) in rat with acute kidney injury (AKI) and to explore the role of RGC32 in renal injury and repair induced by ischemia reperfusion. Rats were randomly divided into two groups, including sham operation group (n = 48) and acute ischemia reperfusion injury (IRI) group (n = 48). Rats were sacrificed following reperfusion 2 h, 6 h, 24 h, 48 h, 72 h, 1 week (w), 2 w, and 4 w. The distribution and expression of RGC32 in renal tissue were observed by means of immunohistochemistry. The mean density of the images detected by Image-Pro Plus 6 was designated as the representative RGC32 expression levels. Meanwhile, RGC32 mRNA expression was measured by qPCR. RGC32 mainly expressed in cytoplasm of proximal tubular epithelial cells. However, RGC32 did not express in renal interstitium and vessels. The expression levels of RGC32 measured by immunohistochemistry at different reperfusion time were 0.0168 ± 0.0029, 0.0156 ± 0.0021, 0.0065 ± 0.0013, 0.0075 ± 0.0013, 0.0096 ± 0.0014, 0.0132 ± 0.0016, 0.0169 ± 0.0014, 0.0179 ± 0.0022, respectively. Compared with the sham group, the level of RGC32 expression in IRI group was significant lower at 24 h, 48 h, 72 h after IRI (p < 0.05). The expression levels of RGC32 mRNA at different reperfusion time measured by qPCR were corroborated the immunohistochemistry finding. The in vitro experiments show the expression of α-SMA and extracellular matrix expression increased signification when the RGC32 was silenced. Our data showed that the RGC32 expression in AKI rat decreased significantly reduces with different reperfusion time and performs a time-dependent manner. RGC32 may play an important role in the pathogenesis of AKI following IRI and repair in rat.