Protection of human adipose stromal vascular fraction derived culture supernatant against acute renal ischemia/reperfusion injury

Abstract

Objective To observe the effect of human adipose stromal vascular fraction (SVF) derived culture supernatant protecting kidney from acute ischemia/reperfusion injury (IRI). Methods SVF was isolated and was used for the preparation of SVF derived culture supernatant named SVF conditioned medium (SVF-CM). Hypoxia/reoxygenation (H/R) injury model of renal tubular epithelial cell (HK-2) was established for cell proliferation and apoptosis assay. Thirty-two SD rats were divided into four groups randomly: SVF-CM group, SVF group, control group, and sham group. Twenty-four hours after surgery, blood sample was collected for the detection of serum creatinine (SCr) and blood urea nitrogen (BUN). Kidney tissues were retrieved for hematoxylin and eosin (HE) and immunohistochemical staining. Results Both SVF-CM and SVF could significantly enhance the proliferative capability as well as attenuate the apoptosis of HK-2, while no significant difference could be found between the two groups for cell proliferation (P=0.781) and apoptosis (P=0.921, 0.280). At 24 h after surgery, serum levels of SCr and BUN in both SVF-CM and SVF groups were significantly lower than that in control group (P=0.000). However, there was no significant difference between the two groups (P=0.993, 0.985). Tubular damage score in both SVF-CM (1.9±0.8) and SVF (1.7±0.9) groups were significantly lower than that in control group (3.3±0.7) (P=0.000). Meanwhile, the numbers of proliferating cell nuclear antigen (PCNA) positive cells in both SVF-CM [(60.86±18.39) cells] and SVF [(62.51±20.03) cells] groups were significantly higher than that in control group [(33.61±6.91) cells] (P=0.000). Additionally, the numbers of terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) positive cells in both SVF-CM [(24.73±6.82) cells] and SVF [(22.11±5.68) cells] groups were significantly lower that in control group [(45.12±7.85) cells] (P=0.000). However, no significant difference on tubular damage score, number of proliferative cells and apoptotic cells could be found between SVF-CM and SVF groups (P=0.114, 0.875, 0.197). Conclusion Administration of SVF derived culture supernatant or SVF was equally effective in promoting the structural and functional recovery of damaged kidney. Key words: Adipose stromal vascular fraction; Culture supernatant; Acute kidney injury; Ischemia/reperfusion injury