Effect of Kruppel-like factor 4 on PTZ-induced acute seizure mice.

Kruppel-like factor 4 (Klf4) is a transcription factor that is involved in neuronal regeneration and the development of glutamatergic systems. However, it is unknown whether Klf4 is involved in acute seizure. To investigate the potential role of Klf4 in pentylenetetrazol (PTZ)-induced seizure, western blotting, immunofluorescence, behaviour test and electrophysiology were conducted in this study. We found that Klf4 protein and mRNA expression were increased in both the hippocampus (HP) and prefrontal cortex (PFC) after PTZ-induced seizure in mice. HP-specific knockout (KO) of Klf4 in mice decreased protein expression of Klf4 and the down-stream Klf4 target tumour protein 53 (TP53/P53). These molecular changes are accompanied by increased seizure latency, reduced immobility time in the forced swimming test and tail suspension test. Reduced hippocampal protein levels for synaptic proteins, including glutamate receptor 1 (GRIA1/GLUA1) and postsynaptic density protein 95 (DLG4/PSD95), were also observed after Klf4-KO, while increased mRNA levels of complement proteins were observed for complement component 1q subcomponent A (C1qa), complement component 1q subcomponent B (C1qb), complement component 1q subcomponent C (C1qc), complement component 3 (C3), complement component 4A (C4a) and complement component 4B (C4b). Moreover, c-Fos expression induced by PTZ was reduced by hippocampal conditional KO of Klf4. Electrophysiology showed that PTZ-induced action potential frequency was decreased by overexpression of Klf4. In conclusion, these findings suggest that Klf4 plays an important role in regulating PTZ-induced seizures and therefore constitutes a new molecular target that should be explored for the development of antiepileptic drugs.

Ginsenoside Re Prevents Depression-like Behaviors via Inhibition of Inflammation, Oxidative Stress, and Activating BDNF/TrkB/ERK/CREB Signaling: An In Vivo and In Vitro Study.

Depression is a widespread disease, with high mortality and recurrence rates. Recent studies have shown that elevated cytokine levels are implicated in the molecular mechanisms of depression. Oxidative stress contributes to the stimulation of cytokine production. Growing evidence suggests that ginsenoside Re (Gs-Re) exerts a neuroprotective effect on the hippocampus by suppressing oxidative stress and inflammation. However, the effect and mechanism of Gs-Re in the treatment of depression remain understudied. This study aimed to evaluate the neuroprotective and antidepressant-like effects of Gs-Re and the possible underlying mechanisms. In this article, the antidepressant-like effect of the Gs-Re was studied both in vitro (H2O2-induced oxidative stress in HT-22 cells) and in vivo (reserpine-induced depressive model mice). Our results indicated that, at the cellular level, Gs-Re effectively enhanced cell survival following H2O2 stimulation, inhibited the mass production of oxidative stress markers (MDA and ROS), and prevented the occurrence of apoptosis. Moreover, Gs-Re significantly reduced the levels of proinflammatory cytokines IL-1ß, IL-6, and TNF-α and restored the abnormal mitochondrial membrane potential. Subsequently, Gs-Re treatment reversed reserpine-induced neuroinflammation and depressive-like behaviors in vivo and inhibited microglia overactivation. Furthermore, the alterations in the BDNF/TrkB/ERK/CREB signaling pathway induced by H2O2 or reserpine in HT-22 cells or in the mouse hippocampus were significantly reversed by Gs-Re. K252a blocked the improvement of Gs-Re on depression-like behavior and eliminated the inhibition of oxidative stress and neuroinflammation in vivo. This study suggested that Gs-Re produces neuroprotective and depressive effects by inhibiting oxidative stress and inflammation and activating the BDNF/TrkB/ERK/CREB pathway.