Hydrogen Sulfide Antagonizes Formaldehyde-induced Neurotoxicity By Inhibition Of Autophagy Via Upregulation Of Leptin In PC12 Cells

Backgroud and Objective: Formaldehyde(FA) has neurotoxicity and we have previously demonstrated that hydrogen sulfide(H2S), the third gasotransmitter, antagonizes FA-induced neurotoxicity. However, the exact mechanisms underlying this protection remain largely unknown. It has been confirmed that excessive autophagy leads to apoptosis and cytotoxicity eventually and that leptin involves in neuroprotective regulating. The purpose of study is to investigate the mediatory role of autophagy in H2 S antagonizing FA-induced neurotoxicity and whether leptin involves in this protection effect.Methods: Cell Counting Kit-8 assay was used for cell viability; Flow cytometry was used for cell apoptosis analysis; Cleaved caspase-3 was measured by Enzyme-linked immunosorbent assay; Western blot analysis was used for leptin, beclin-1, LC-3 and PARP expression; LC-3 was measured by immunofluorescence.Results : 1. FA induced neurotoxicity and autophagy in PC12 cells. PC12 cells were treated with different concentration of formaldehydefor 24 hs,The results shows that formaldehyde could induced autophagy and led to apoptosis in PC12 cells. Autophagy and apoptosis rate were positively correlated with the concentration of formaldehyde. 2. H2 S offered protection effect against FA-induced apoptosis and cytotoxicity by regulation of autophagy. PC12 cells were pre-treated with Na HS for 30 min, and co-treated with formaldehyde for 24 hs, The results suggested that H2 S could reduced the apoptosis rate and autophagy in PC12 cells which induced by formaldehyde. 3. H2 S up-regulates the expression of leptin in PC12 cells. PC12 cells were pre-treated with Na HS for 30 min, and co-treated with formaldehyde for 24 hs, Compared with formaldehyde-treated group, H2 S restored the activity of leptin. 4. leptin TA(leptin inhibitor) reverses the neuroprotective effects of H2 S on FA-induced neurotoxicity and autophagy. PC12 cells were pre-treated with leptin TA for 30 min, then treated with Na HS for 30 min, and co-treated with formaldehyde for 24 hs. leptin TA reverses the neuroprotective effects of H2 S on FA-induced neurotoxicity and autophagy.Conclusions: H2 S antagonizes FA-induced apoptosis and cytotoxicity in PC12 cells by inhibition of autophagy via upregulation of leptin.