Hypoxic preconditioning placental mesenchymal stem cells alleviate pathological lesion in mouse models with severe acute pancreatitis

Abstract

Objective To investigate the protective effect of hypoxia-preconditioned placental mesenchymal stem cells (HP-MSCs) on severe acute pancreatitis (SAP) of mice model and to explore its mechanisms. Methods Placental-derived mesenchymal stem cells (P-MSCs) were cultured in normoxia treatment(N-MSCs)(21% O2) or hypoxia preconditioning(HP-MSCs)(1% O2) for 48 h. CCK-8 and MTT assay were used to detect the viability andmigration of N-MSCs and HP-MSCs respectively. Thirty-two male C57BL/6 mice were divided into sham operation group (sham), SAP group (retrograde injection of 4% sodium taurocholate 0.1 mL/100 g into the pancreaticobiliary duct), normoxia group (N-MSCs) and hypoxia group (HP-MSCs). Six hours after the end of modeling, N-MSCs and HP-MSCs (1×106/100 g) were injected to treat SAP, with 8 rats in each group. Serum and pancreatic tissue were collected at 12 h after modeling. HE staining and microscopy were used to evaluate the degree of pancreatic tissue injury and pathological score. ELISA was used to measure the activities of serum amylase and lipase and the levels of inflammatory factors. Western blot was used to detect the expression of receptor interacting protein 3 (RIP3), MLKL, phosphorylated MLKL (p-MLKL) and NLRP3 in pancreatic tissue. Results HP-MSCs showed better viability and higher capacity proliferation than N-MSCs in vitro. In vivo, compared with SAP group, the pancreatic pathological score was significantly decreased in N-MSCs group (P＜0.05). The biological activity of amylase and lipase in serum were decreased, and the level of IL-6 and TNF-α was decreased (P＜0.05). Compared with N-MSCs group, the pancreatic pathological score and the level of TNF-α and IL-6 in HP-MSCs group were significantly decreased(P＜0.05). The expression of RIP3, p-MLKL and NLRP3 in pancreatic tissue of HP-MSCs group was significantly lower than those of SAP group and N-MSCs group (P＜0.05). Conclusions HP-MSCs can significantly alleviate SAP than N-MSCs, and the mechanism is potentially related to the inhibition of RIP1/RIP3-MLKL signaling pathway.

Keywords

• hypoxic preconditioning|placental mesenchymal stem cells|severe acute pancreatitis|receptor interacting protein 3(rip3)