Carboxymethylated chitosan protects Schwann cells against hydrogen peroxide-induced apoptosis by inhibiting oxidative stress and mitochondria dependent pathway.

Carboxymethylated chitosan (CMCS) has many beneficial effects, including anti-oxidant and anti-apoptotic actions. However, the mechanisms by which CMCS protect against oxidative stress induced damage to Schwann cells (SCs) remains unclear. The present study aimed to investigate the mechanism by which CMCS protects SCs against hydrogen peroxide (H2O2) induced damage. H2O2 was used to establish a model of oxidative stress injury in SCs to mimic the development of nerve injury in vitro. Different concentrations (50, 100 and 200 µg/ml) of CMCS were added to test whether CMCS was capable of protecting SCs from H2O2 induced damage. MTT, LDH release and Annexin V/FITC assays were then performed. Levels of reactive oxygen species were detected using a reactive oxygen species assay kit, the mitochondrial membrane potential (ΔΨm) of SCs was analyzed by rhodamine123 fluorescence staining, the synthesis of Bcl-2, Bax, cytochrome c and caspase-3 were analyzed by real-time PCR and Western blot analysis. The results showed that CMCS protected SCs from apoptosis, decreased LDH release and enhanced cell viability, also decreased reactive oxygen species levels and increased ΔΨm. Additional experiments demonstrated that CMCS could decrease protein expression of Bax, cytochrome c and caspase-3, while promote Bcl-2 protein expression induced by H2O2. Taken together, the finding of this study indicated that CMCS prevented H2O2-induced damage to SCs through the mitochondrial dependent pathway.

He B ，Wu F ，Fan L ，Li XH ，Liu Y ，Liu YJ ，Ding WJ ，Deng M ，Zhou Y ... -  《-》

Neuroprotective effects of carboxymethylated chitosan on hydrogen peroxide induced apoptosis in Schwann cells.

The protective and promotion effects of Carboxymethylated chitosan (CMCS) on peripheral nerve and cultured Schwann cells (SCs) have been demonstrated, but few studies discussed the protective roles of CMCS on SCs apoptosis. We explored the anti-apoptotic activities of CMCS in SCs to enhance cells survival in this present study. Rat SCs were isolated and cultured in vitro, hydrogen peroxide (H2O2) was used to establish the apoptosis models of SCs. Cells proliferative activity was assessed by CCK-8 assay. The apoptosis of SCs was detected by flow cytometry (FCM) analysis. Superoxide dismutase (SOD) and malondialdehyde (MDA) activities were detected by the corresponding assay kit. The nuclear appearance of apoptotic SCs was observed by nuclear staining with Hoechst 33342. The real-time PCR was performed to detect the levels of Bcl-2, Bax, Caspase-3 and -9 mRNA. Detection of caspase-3 and -9 was fulfilled by using Western blot analysis. FCM assay and Hoechst33342 staining results indicated that CMCS could protect SCs from apoptosis with dose and time-dependent manner. SOD and MDA analysis results indicated that CMCS could promote SOD activity and reduce the MDA levels in H2O2 induced SCs. The decreased caspase-3, -9 and Bax activities and increased Bcl-2 activity were observed in CMCS treated SCs. The present study indicates CMCS has the neuroprotective effect on peripheral nerves and inhibit SCs apoptosis.

He B ，Tao HY ，Liu SQ 《-》

[Effect of carboxymethylated chitosan on apoptosis and expression of brain derived neurotrophic factor and glial cell line derived neurotrophic factor in oxidative stress induced Schwann cells in vitro].

He B ，Tao H ，Liu S 《-》

Crocin protects retinal ganglion cells against H2O2-induced damage through the mitochondrial pathway and activation of NF-κB.

Lv B ，Chen T ，Xu Z ，Huo F ，Wei Y ，Yang X ... -  《-》

Puerarin may protect against Schwann cell damage induced by glucose fluctuation.

Xue B ，Wang L ，Zhang Z ，Wang R ，Xia XX ，Han PP ，Cao LJ ，Liu YH ，Sun LQ ... -  《-》