Implication of sestrin3 in epilepsy and its comorbidities

Metabotropic glutamate receptors (mGluRs) in epileptogenesis: an update on abnormal mGluRs signaling and its therapeutic implications

Epilepsy is a neurological disorder characterized by high morbidity, high recurrence, and drug resistance. Enhanced signaling through the excitatory neurotransmitter glutamate is intricately associated with epilepsy. Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors activated by glutamate and are key regulators of neuronal and synaptic plasticity. Dysregulated mGluR signaling has been associated with various neurological disorders, and numerous studies have shown a close relationship between mGluRs expression/activity and the development of epilepsy. In this review, we first introduce the three groups of mGluRs and their associated signaling pathways. Then, we detail how these receptors influence epilepsy by describing the signaling cascades triggered by their activation and their neuroprotective or detrimental roles in epileptogenesis. In addition, strategies for pharmacological manipulation of these receptors during the treatment of epilepsy in experimental studies is also summarized. We hope that this review will provide a foundation for future studies on the development of mGluR-targeted antiepileptic drugs.

Sestrin 3 promotes oxidative stress primarily in neurons following epileptic seizures in rats

Epilepsy affects approximately 1% of the global population, with 30% of patients experiencing uncontrolled seizures despite treatment. Reactive oxygen species (ROS) and oxidative stress have been implicated in the pathogenesis of epilepsy. Sestrins are stress-inducible proteins that regulate the ROS response. In particular, Sestrin 3 (SESN3) has been implicated in ROS accumulation and the regulation of proconvulsant genes. To investigate the role of SESN3 in epilepsy, we studied its involvement in rat models of acute seizures and temporal lobe epilepsy. Our results showed that downregulation of SESN3 reduced the oxidative stress induced by seizure activity in neuronal cultures. After acute seizure activity, SESN3 protein levels temporarily increased as early as 3 h after the seizure, whereas kainic acid-induced status epilepticus led to a significant and persistent increase in SESN3 protein levels in the cortex and hippocampus for up to 2 weeks post-status epilepticus. In the chronic epilepsy phase, when spontaneous seizures emerge, SESN3 protein expression is significantly increased in both regions 6 and 12 weeks after status epilepticus. Interestingly, immunohistochemical staining showed a predominant increase in the oxidative stress marker 8-OHdG in neurons in both regions after an acute seizure, whereas following status epilepticus, the marker was detected in both neurons and astrocytes. Our findings suggest that SESN3 may contribute to the development and establishment of epilepsy, and could be a potential therapeutic target for more effective treatments.

The functions and roles of sestrins in regulating human diseases

Sestrins (Sesns), highly conserved stress-inducible metabolic proteins, are known to protect organisms against various noxious stimuli including DNA damage, oxidative stress, starvation, endoplasmic reticulum (ER) stress, and hypoxia. Sesns regulate metabolism mainly through activation of the key energy sensor AMP-dependent protein kinase (AMPK) and inhibition of mammalian target of rapamycin complex 1 (mTORC1). Sesns also play pivotal roles in autophagy activation and apoptosis inhibition in normal cells, while conversely promoting apoptosis in cancer cells. The functions of Sesns in diseases such as metabolic disorders, neurodegenerative diseases, cardiovascular diseases, and cancer have been broadly investigated in the past decades. However, there is a limited number of reviews that have summarized the functions of Sesns in the pathophysiological processes of human diseases, especially musculoskeletal system diseases. One aim of this review is to discuss the biological functions of Sesns in the pathophysiological process and phenotype of diseases. More significantly, we include some new evidence about the musculoskeletal system. Another purpose is to explore whether Sesns could be potential biomarkers or targets in the future diagnostic and therapeutic process.

Potential Roles of Sestrin2 in Alzheimer's Disease: Antioxidation, Autophagy Promotion, and Beyond

Alzheimer’s disease (AD) is the most common age-related neurodegenerative disease. It presents with progressive memory loss, worsens cognitive functions to the point of disability, and causes heavy socioeconomic burdens to patients, their families, and society as a whole. The underlying pathogenic mechanisms of AD are complex and may involve excitotoxicity, excessive generation of reactive oxygen species (ROS), aberrant cell cycle reentry, impaired mitochondrial function, and DNA damage. Up to now, there is no effective treatment available for AD, and it is therefore urgent to develop an effective therapeutic regimen for this devastating disease. Sestrin2, belonging to the sestrin family, can counteract oxidative stress, reduce activity of the mammalian/mechanistic target of rapamycin (mTOR), and improve cell survival. It may therefore play a crucial role in neurodegenerative diseases like AD. However, only limited studies of sestrin2 and AD have been conducted up to now. In this article, we discuss current experimental evidence to demonstrate the potential roles of sestrin2 in treating neurodegenerative diseases, focusing specifically on AD. Strategies for augmenting sestrin2 expression may strengthen neurons, adapting them to stressful conditions through counteracting oxidative stress, and may also adjust the autophagy process, these two effects together conferring neuronal resistance in cases of AD.