GKLF, a transcriptional activator of Txnip, drives microglia activation in kainic acid-induced murine models of epileptic seizures

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.

Krüppel-like factors: potential roles in blood-brain barrier dysfunction and epileptogenesis

Epilepsy is a chronic and debilitating neurological disorder, known for the occurrence of spontaneous and recurrent seizures. Despite the availability of antiseizure drugs, 30% of people with epilepsy experience uncontrolled seizures and drug resistance, evidencing that new therapeutic options are required. The process of epileptogenesis involves the development and expansion of tissue capable of generating spontaneous recurrent seizures, during which numerous events take place, namely blood-brain barrier (BBB) dysfunction, and neuroinflammation. The consequent cerebrovascular dysfunction results in a lower seizure threshold, seizure recurrence, and chronic epilepsy. This suggests that improving cerebrovascular health may interrupt the pathological cycle responsible for disease development and progression. Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors, encountered in brain endothelial cells, glial cells, and neurons. KLFs are known to regulate vascular function and changes in their expression are associated with neuroinflammation and human diseases, including epilepsy. Hence, KLFs have demonstrated various roles in cerebrovascular dysfunction and epileptogenesis. This review critically discusses the purpose of KLFs in epileptogenic mechanisms and BBB dysfunction, as well as the potential of their pharmacological modulation as therapeutic approach for epilepsy treatment.

An explanation of the role of pyroptosis playing in epilepsy

Epilepsy is a severe central nervous system disorder characterized by an imbalance between neuronal excitation and inhibition, resulting in heightened neuronal excitability, particularly within the hippocampus. About one-third of individuals with epilepsy experience difficult-to-manage seizures, known as refractory epilepsy. Epilepsy is closely linked to inflammatory immune response, with elevated levels of inflammatory mediators observed in individuals with this condition. This inflammation of the brain can lead to seizures of various types and is further exacerbated by the release of inflammatory factors, which heighten the excitability of peripheral neurons and worsen the progression of epilepsy. Pyroptosis is an inflammatory programmed cell death which has been shown to be involved in the pathological process of epilepsy. Inflammatory factors released during pyroptosis increase neuronal excitability and promote abnormal discharge in epilepsy, increasing susceptibility to epilepsy. This article provides an overview of the current knowledge on cell pyroptosis and its potential mechanisms, including both canonical and noncanonical pathways. Additionally, we discuss the potential mechanisms of pyroptosis occurrence in epilepsy and the potential therapeutic drugs targeting pyroptosis as a treatment strategy. In summary, this review highlights the promising potential of pyroptosis as a target for developing innovative therapies for epilepsy.

Minocycline alleviates LPS-induced cognitive dysfunction in mice by inhibiting the NLRP3/caspase-1 pathway

BACKGROUND

Growing experimental evidence indicates that cognitive impairment is linked to neuroinflammation. Minocycline (MINO), an antibiotic known for its anti-inflammatory, has shown promise in alleviating cognitive impairment. Nonetheless, the exact mechanism through which MINO improves cognitive impairment is not yet understood.

METHODS

A neuroinflammatory model was establish by utilizing lipopolysaccharide. The assessment of mice's cognitive and learning abilities was conducted through the MWM and Y-maze tests. The evaluation of hippocampal neuronal injury and microglial activation were achieved by performing HE staining and IHC, respectively. To evaluate BV2 cell viability and apoptosis, the CCK-8 and Hoechst 33342/PI staining assays were employed. In order to assess the protein and RNA expression levels of NLRP3, caspase-1, IL-1β, IL-18, Iba-1, and Bcl2/Bax, WB and RT-qPCR were utilized. Additionally, the inhibitory effect of MINO on apoptosis by targeting the NLRP3/caspase-1 pathway was investigated using Nigericin.

RESULTS

MINO was effective in reducing the time it took for mice to escape from the test, increasing the number of platforms they crossed, and mitigating damage to the hippocampus while also suppressing microglial activation and the expression of Iba-1 in a neuroinflammatory model caused by LPS. Furthermore, MINO improved the viability of BV2 cell and reduced apoptosis. It also had the effect of reducing the expression levels of NLRP3/Caspase-1, IL-1β, IL-18, and BAX, while upregulating the expression of Bcl2. Additionally, MINO was found to downregulate the NLRP3 expression, which is specifically activated by nigericin.

CONCLUSION

The protective effect of MINO relies on the crucial involvement of the NLRP3/caspase-1 pathway.