Mitochondrial c-Fos May Increase the Vulnerability of Neuro2a Cells to Cellular Stressors

Mitochondrial Probe for Glutathione Depletion Reveals NME3 Essentiality for Mitochondrial Redox Response

Maintenance of the mitochondrial thiol redox state is essential for cell survival. However, we lack a comprehensive understanding of the redox response to mitochondrial glutathione depletion. We developed a mitochondria-penetrating peptide, mtCDNB, to specifically deplete mitochondrial glutathione. A genome-wide CRISPR/Cas9 screen in tandem with mtCDNB treatment was employed to uncover regulators of the redox response to mitochondrial glutathione depletion. We identified nucleoside diphosphate kinase 3 (NME3) as a regulator of mitochondrial dynamics. We show that NME3 is recruited to the mitochondrial outer membrane when under redox stress. In the absence of NME3, there is impaired mitophagy, which leads to the accumulation of dysfunctional mitochondria. NME3 knockouts depleted of mitochondrial glutathione have increased mitochondrial ROS production, accumulate mtDNA lesions, and present a senescence-associated secretory phenotype. Our findings suggest a novel role for NME3 in selecting mitochondria for degradation through mitophagy under conditions of mitochondrial redox stress.

Targeting Nrf2 signaling pathway by quercetin in the prevention and treatment of neurological disorders: An overview and update on new developments

BACKGROUND

Neurological disorders (NLDs) are widely acknowledged as a significant public health concern worldwide. Stroke, Alzheimer's disease (AD), and traumatic brain injury (TBI) are three of these disorders that have sparked major study attention. Neurological dysfunction, protein buildup, oxidation and neuronal injury, and aberrant mitochondria are all prevalent neuropathological hallmarks of these disorders. The signaling cascade of nuclear factor erythroid 2 related factor 2 (Nrf2) shares all of them as a common target. Several studies have found that overexpression of Nrf2 is a promising treatment method in NLDs. Effective treatment of these disorders continues to be a universal concern regardless of various medicines. In order to treat a variety of neurological problems, organic remedies may provide an alternative treatment. It has been demonstrated that polyphenols like quercetin (Que) offer considerable capabilities for treating NLDs. One of Que's greatest key targets, Nrf2, has the capacity to control the production of a number of cytoprotective enzymes that exhibit neuroprotective, detoxifying, and antioxidative effects. Additionally, Que enhanced the expression of Nrf2 and inhibited alterations in the shape and death of neurons in the hippocampus.

OBJECTIVE

In this review, we have focused on Que's medicinal prospects as a neuroprotective drug.

METHODS

PubMed, Scopus, Science Direct, and Google Scholar were used to search articles for this study.

RESULTS

The findings of this research demonstrate that (1) Que protected the blood-brain barrier via stimulating Nrf2 in animal stroke, which alleviated ischemic reperfusion and motor dysfunction. (2) By triggering the Nrf2 pathway, Que reduced the neuroinflammation and oxidative damage brought on by TBI in the cortex. (3) In an experimental model of AD, Que enhanced cognitive function by decreasing A1-4, antioxidant activity, and Nrf2 levels in the brain.

CONCLUSION

We discuss recent research on Que-mediated Nrf2 expression in the management of several NLDs in this paper.

Gene therapy for the mitochondrial genome: Purging mutations, pacifying ailments

In the recent years, the reported cases of mitochondrial disorders have reached a colossal number. These disorders spawn a sundry of pathological conditions, which lead to pernicious symptoms and even fatality. Due to the unpredictable etiologies, mitochondrial diseases are putatively referred to as "mystondria" (mysterious diseases of mitochondria). Although present-day research has greatly improved our understanding of mitochondrial disorders, effective therapeutic interventions are still at the precursory stage. The conundrum becomes further complicated because these pathologies might occur due to either mitochondrial DNA (mtDNA) mutations or due to mutations in the nuclear DNA (nDNA), or both. While correcting nDNA mutations by using gene therapy (replacement of defective genes by delivering wild-type (WT) ones into the host cell, or silencing a dominant mutant allele that is pathogenic) has emerged as a promising strategy to address some mitochondrial diseases, the complications in correcting the defects of mtDNA in order to renovate mitochondrial functions have remained a steep challenge. In this review, we focus specifically on the selective gene therapy strategies that have demonstrated prospects in targeting the pathological mutations in the mitochondrial genome, thereby treating mitochondrial ailments.

The protection effect and mechanism of hyperbaric oxygen therapy in rat brain with traumatic injury

PURPOSE

To investigate the effect of hyperbaric oxygen therapy (HBOT) on traumatic brain injury (TBI) outcome.

METHODS

The modified Marmarou's weight drop device was used to generate non-lethal moderate TBI rat model, and further developed in vitro astrocytes culturing system. Then, we analyzed the expression changes of interested genes and protein by quantitative PCR and western blot.

RESULTS

Multiple HBO treatments significantly reduced the expression of apoptosis promoting genes, such as c-fos, c-jun, Bax and weakened the activation of Caspase-3 in model rats. On the contrary, HBOT alleviated the decrease of anti-apoptosis gene Bcl-2 and promoted the expression of neurotrophic factors (NTFs), such as NGF, BDNF, GDNF and NT-3 in vivo. As a consequent, the neuropathogenesis was remarkably relied with HBOT. Astrocytes from TBI brain or those cultured with 21% O2 density expressed higher NTFs than that of corresponding controls, from sham brain and cultured with 7% O2, respectively. The NTFs expression was the highest in astrocytes form TBI brain and cultured with 21% O2, suggesting a synergistic effect existed between TBI and the following HBO treatment in astrocytes.

CONCLUSION

Our findings provided evidence for the clinical usage of HBO treating brain damages.

Protective Effects of Quercetin on Mitochondrial Biogenesis in Experimental Traumatic Brain Injury via the Nrf2 Signaling Pathway

The present investigation was carried out to elucidate a possible molecular mechanism related to the protective effect of quercetin administration against oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in mitochondrial biogenesis. Recently, quercetin has been proved to have a protective effect against mitochondria damage after traumatic brain injury (TBI). However, its precise role and underlying mechanisms in traumatic brain injury are not yet fully understood. The aim of the present study was to investigate the effect of quercetin on the potential mechanism of these effects in a weight-drop model of TBI in male mice that were treated with quercetin or vehicle via intraperitoneal injection administrated 30 min after TBI. In this experiment, ICR mice were divided into four groups: A sham group, TBI group, TBI + vehicle group, and TBI + quercetin group. Brain samples were collected 24 h later for analysis. Quercetin treatment resulted in an upregulation of Nrf2 expression and cytochrome c, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were restored by quercetin treatment. Quercetin markedly promoted the translocation of Nrf2 protein from the cytoplasm to the nucleus. These observations suggest that quercetin improves mitochondrial function in TBI models, possibly by activating the Nrf2 pathway.