Protective effects of adipose?derived stem cells with phosphodiesterase 5 inhibition by lentivirus?mediated stable gene silencing on ischemia?reperfusion injury of renal tubular epithelial cells

Objective To explore the protective effects of adipose-derived stem cells(ADSCs) with phosphodiesterase 5 inhibition by lentivirus-mediated stable gene silencing on the proliferation and apoptosis of renal tubular epithelial cells induced by ischemia-reperfusion injury in vitro. Methods To isolate cultivate and indentify ADSCs from rats. Lentiviral expression vector of carrying PDE5 shRNA gene was transfected into ADSCs, and a negative control group was set up. Western blotting was used to detect PDE5 protein expression levels. ADSCs were co-cultured with NRK-52E in a transwell system, and NRK-52E cells were treated with ischemia/reoxygenation protocol. Edu assay was performed to evaluate the proliferation of NRK cells, flow cytometry to detect the apoptosis of NRK cells, and ELISA to quantify the protein expressions of fibroblast growth factor (FGF) and hepatocyte growth factor (HGF). The expression of E-cadherin and cytokeratin 18 (CK18) was quantified by real time PCR and flow cytometry. Results Western blotting for PDE5 protein indicated a significant reduction of PDE5 protein levels in PDE5 shRNA transduced population. After the treatment of ischemia/reoxygenation in vitro, the proliferative viability and apoptosis of NRK-52E cells co-cultured with ADSCs induced by PDE5 gene inhibition were significantly improved, compared to the normal group (all P <0.05). And the release of HGF, FGF were markedly enhanced (all P < 0.05). Moreover, the NRK-52E cells survival, the expression of E-cadherin and CK18 on PDE5 inhibited ADSCs co-cultured with I/R injured NRK cells was significantly increased compared to that in the negative control group (all P <0.05). Conclusion ADSCs preconditioned by inhibition of PDE5 can be a powerful novel approach to improve the survival of renal tubular cells following ischemia-reperfusion injury, and have an obvious tendency to transform epithelial cells. Key words: Cyclic nucleotide phosphodiesterases, type 5; Reperfusion injury; Stem cells