Effects of umbilical cord mesenchymal stem cells on regulating renal inflammatory microenvironment of kidney in mice with acute kidney injury

doi:10.3969/j.issn.1672-8521.2014.02.004

Abstract：Objective:To observe the effect of exogenous umbilical cord mesenchymal stem cells (UC-MSCs)on inflammatory microenvironment and repair of kidney tissue in mice with acute kidney inj ury (AKI)induced by is-chemia/reperfusion injury. Methods:UC-MSCs were isolated from umbilical cords of pregnant C57BL/6 mice and cultured. Sixty healthy female C57BL/6 mice were randomly divided into normal control group,AKI group,and AKI+MSC group (n=20). AKI model was replicated by clamping bilateral renal pedicles for 45 minutes followed by release of clamping. Meanwhile,1×106 UC-MSCs were injected intraperitoneally in the AKI+MSC group, and 0.2 ml normal saline was injected instead of UC-MSCs in AKI group. On 2,7 days after the model estab-lished,10 mice of each group were sacrificed respectively,blood and renal tissues were sampled for detecting ser-um creatinine (SCr)and blood urea nitrogen (BUN)levels,or assessing the pathological changes in renal tissue after HE staining. The levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interferon-1 (IFN-1 ), basic fibroblast growth factor (bFGF),interleukin-10 (IL-10),B lymphocyte tumor-2 (Bcl-2 )of renal tissue homogenate were determined by enzyme-linked immunoadsorbent assay (ELISA). Results:On day 2 ,the lev-els of BUN and SCr in AKI group were much higher than those in the normal control group,and pathological changes in renal tubule showed significant swelling and vacuolation of epithelial cells,but they were all alleviated on day 7. Compared to those in the AKI group,the levels of BUN and SCr in AKI+MSC were much lower (P<0.01),while pathological changes were mild in AKI+MSC group on day 2,and they recoverd on day 7. ELISA showed that the levels of pro-inflammatory factors (IL-1β,TNF-α,IFN-1 )in kidney tissue of AKI group in-creased significantly (P<0.05 or P<0.01),while the levels of anti-inflammatory factors (bFGF,IL-10,Bcl-2) decreased significantly compared to the normal control group,especially on day 2. While inj ection of UC-MSCs could lower the levels of pro-inflammatory factors and increase the levels of anti-inflammatory factors,however, the difference was still sighificant as compared with that of the normal control group (P<0.05 or P<0.01). Con-clusions:UC-MSCs can regulate cytokines secretion via inflammatory microenvironmental regulation mechanisms in mice with acute kidney inj ury,thus contributing to protection against acute inj ury to the kidney.