Small extracellular vesicles secreted by induced pluripotent stem cell-derived mesenchymal stem cells improve postoperative cognitive dysfunction in mice with diabetes

Postoperative cognitive dysfunction(POCD)is a common surgical complication.Diabetes mellitus(DM)increases risk of developing POCD after surgery.DM patients with POCD seriously threaten the quality of patients’life,however,the intrinsic mechanism is unclear,and the effective treatment is deficiency.Previous studies have demonstrated neuronal loss and reduced neurogenesis in the hippocampus in mouse models of POCD.In this study,we constructed a mouse model of DM by intraperitoneal injection of streptozotocin,and then induced postoperative cognitive dysfunction by transient bilateral common carotid artery occlusion.We found that mouse models of DM-POCD exhibited the most serious cognitive impairment,as well as the most hippocampal neural stem cells(H-NSCs)loss and neurogenesis decline.Subsequently,we hypothesized that small extracellular vesicles secreted by induced pluripotent stem cell-derived mesenchymal stem cells(iMSC-sEVs)might promote neurogenesis and restore cognitive function in patients with DM-POCD.iMSC-sEVs were administered via the tail vein beginning on day 2 after surgery,and then once every 3 days for 1 month thereafter.Our results showed that iMSC-sEVs treatment significantly recovered compromised proliferation and neuronal-differentiation capacity in H-NSCs,and reversed cognitive impairment in mouse models of DM-POCD.Furthermore,miRNA sequencing and qPCR showed miR-21-5p and miR-486-5p were the highest expression in iMSC-sEVs.We found iMSC-sEVs mainly transferred miR-21-5p and miR-486-5p to promote H-NSCs proliferation and neurogenesis.As miR-21-5p was demonstrated to directly targete Epha4 and CDKN2C,while miR-486-5p can inhibit FoxO1 in NSCs.We then demonstrated iMSC-sEVs can transfer miR-21-5p and miR-486-5p to inhibit EphA4,CDKN2C,and FoxO1 expression in H-NSCs.Collectively,these results indicate significant H-NSC loss and neurogenesis reduction lead to DM-POCD,the application of iMSC-sEVs may represent a novel cell-free therapeutic tool for diabetic patients with postoperative cognitive dysfunction.

Effect of TRPV1 combined with lidocaine on cell state and apoptosis of U87-MG glioma cell lines

Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.