New differentially expressed genes and differential DNA methylation underlying refractory epilepsy

Ketone bodies (KBs) were known to suppress seizure. Untraditionally, neurons were recently reported to utilize fatty acids and produce KBs, but the effect of seizure on neuronal ketogenesis has not been researched. Zinc-alpha 2-glycoprotein (ZAG) was reported to suppress seizure via unclear mechanism. Interestingly, ZAG was involved in fatty acid beta-oxidation and thus may exert anti-epileptic effect by promoting ketogenesis. However, this promotive effect of ZAG on neuronal ketogenesis has not been clarified. In this study, we performed immunoprecipitation and mass spectrometry to identify potential interaction partners with ZAG. The mechanisms of how ZAG translocated into mitochondria were determined by quantitative coimmunoprecipitation after treatment with apoptozole, a heat shock cognate protein 70 (HSC70) inhibitor. ZAG level was modulated by lentivirus in neurons or adeno-associated virus in rat brains. Seizure models were induced by magnesium (Mg2+)-free artificial cerebrospinal fluid in neurons or intraperitoneal injection of pentylenetetrazole kindling in rats. Ketogenesis was determined by cyclic thio-NADH method in supernatant of neurons or brain homogenate. The effect of peroxisome proliferator-activated receptor gamma (PPAR gamma) on ZAG expression was examined by Western blot, quantitative real-time polymerase chain reaction (qRT-PCR) and chromatin immunoprecipitation qRT-PCR. We found that seizure induced ketogenesis deficiency via a ZAG-dependent mechanism. ZAG entered mitochondria through a HSC70-dependent mechanism, promoted ketogenesis by binding to four beta-subunits of long-chain L-3-hydroxyacyl-CoA dehydrogenase (HADHB) and alleviated ketogenesis impairment in a neuronal seizure model and pentylenetetrazole-kindled epileptic rats. Additionally, PPAR gamma activation up-regulated ZAG expression by binding to promoter region of AZGP1 gene and promoted ketogenesis through a ZAG-dependent mechanism.

Background: High glucose (HG) is linked to dopaminergic neuron loss and related Parkinson’s disease (PD), but the mechanism is unclear. Results: Rats and differentiated SH-SY5Y cells were used to investigate the effect of HG on dopaminergic neuronal apoptotic death. We found that a 40-day HG diet elevated cleaved caspase 3 levels and activated Fyn and mTOR/S6K signaling in the substantia nigra of rats. In vitro, 6 days of HG treatment activated Fyn, enhanced binding between Fyn and mTOR, activated mTOR/S6K signaling, and induced neuronal apoptotic death. The proapoptotic effect of HG was rescued by either the Fyn inhibitor PP1 or the mTOR inhibitor rapamycin. PP1 inhibited mTOR/S6K signaling, but rapamycin was unable to modulate Fyn activation. Conclusions: HG induces dopaminergic neuronal apoptotic death via the Fyn/mTOR/S6K pathway.