Protective Effect Of Hydrogen Sulfide Against Corticosterone-induced Neurotoxicity To PC12Cells By Modulation Of BDNF-TrkB Pathway

[Backgroud and Objective]Depression is involved in stress-induced dysregulation of hypothalamic-pituitary-adrenal (HPA) axis, which increases the level of corticosterone, resulting in serious damage on human emotion management brain regions (such as the hippocampus, etc.). Inhibited Corticosterone neurotoxicity will help reduce depression.Hydrogen Sulfide (H2S), a new type of neuroprotectant, has anti-oxidative, anti-inflammatory, and anti-apoptotic properties. We have confirmed that H2S can improve the depression behavior of depression animal. Whether dose H2S protect against the neurotoxicity of Corticosterone?Brain-derived neurotrophic factor (BDNF), an important neurotrophic factor that has a positive significance in the plasticity and injury repair of neurons, is involved in mediating the antidepressant effect of antidepressants.Therefore, in this experiment, we will use Corticosterone-induced damage in PC12cells as the vitro model about high Corticosterone levels in depression patients to observe whether H2S protect against Corticosterone-induced neurotoxicity. If H2S has a protective action, we will further explore whether BDNF is involved in the mechanism of action of H2S against Corticosterone neurotoxicity. [Methods]The activity of CBS and the content of endogenous H2S in PCI2cells were detected by methylene blue spectrophotometric method. The viability of PCl2cells was detected by CCK-8method. The expressions of CBS and BDNF in PCl2cells were determined by Western Blot. The apoptosis of PCl2cells was detected by Flow cytometry (FCM). The level of intracellular ROS in PCl2cells was determined by the NBT reduction assay. The level of mitochondria membrane potential (MMP) in PCl2cells was assessed under a confocal microscopy after JC-1staining.[Results]1.Corticosterone inhibits the endogenous generation of H2S in PCl2cellsTreatment of PCl2cells with Corticosterone (0.2,0.4,0.8mmol/L) for24h inhibited the viability of PC12cells, attenuated the protein expression and activity of CBS and reduced the content of endogenous hydrogen sulfide in cell culture medium in PC12cells in a concentration-dependent manner. These data indicated that Corticosterone-induced damage on PC12cell may be related to its inhibition of CBS/H2S.2. H2S protects PC12cells against Corticosterone-induced neurotoxicityPretreatment with H2S (0.08,0.2,0.8mmol/L) for30min obviously increased the viability of PC12cells treated Corticosterone (0.2,0.4mmol/L) for24h. Pretreatment of PC12cells with H2S (0.2mmol/L) for30min singificantly enhanced the viability of PCI2cells treated with Corticosterone (0.4mmol/L), attenuated the apoptosis of PC12cells induced by Corticosterone (0.4mmol/L), weaked the accumulation of ROS induced by exposure to0.4mmol/L Corticosterone, and inhibited the loss of MMP in PC12cells triggered by Corticosterone (0.4mmol/L) for24h. These results suggest that H2S protects PCI2cells against Corticosterone-induced neurotoxicity.3. BDNF-TrkB pathway mediates the protection of H2S in Corticosterone-induced neurotoxicityTreatment with H2S (0.08,0.2,0.8mmol/L) for24h upregulated the protein expression of BDNF in PC12cells as well as pretreatment with H2S (0.2mmol/L) for30min reduced the inhibition of BDNF expression induced by Corticosterone (0.4mmol/L) in PC12cells.Pretreatment of PC12cells with k252a (10nmol/L), a specific blockers of BDNF-TrkB pathway, markedly prevented the protective action of H2S (0.2mmol/L), implying that BDNF-TrkB pathway mediates the protection of H2S against Corticosterone-induced neurotoxicity.[Conclusion]1. Corticosterone-induced damage on PC12cell is closely related to the inhibitory effect of Corticosterone on the expression and activity of CBS and the generation of endogenous H2S.2. H2S antagonizes Corticosterone-induced neurotoxicity to PC12cells and the underlying mechanism is associated with upregulating the pathway of BDNF-TrkB.