Effects of Mdivi-1 on Neural Mitochondrial Dysfunction and Mitochondria-Mediated Apoptosis in Ischemia-Reperfusion Injury After Stroke: A Systematic Review of Preclinical Studies

Resveratrol protects against a high-fat diet-induced neuroinflammation by suppressing mitochondrial fission via targeting SIRT1/PGC-1α

Various health issues have emerged due to consuming high-fat diets (HFD), particularly the detrimental impact they have on mitochondrial dynamics and subsequet cognition functions. Specially, mitochondrial fission can serve as an upstream signal in the regulation of cortical inflammation and neural pyroptosis. Our study was designed to verify the existence of neuroinflammation in the pathogenesis of HFD-induced cognitive dysfunction and demonstrated that resveratrol (RSV) attenuated neural deficits via regulation of cortical mitochondrial fission. A total of 50 male Sprague Dawley rats were randomly divided into five groups: control (Cont, 26 weeks on normal rodent diet); high-fat diet (HFD); dietary adjustments (HFD + ND); resveratrol intervention (HFD + R); joint intervention (HFD + ND + R) for 26 weeks. The spatial learning and memory function, spine density, NLRP3 inflammasome associated protein, mRNA and protein expression involved in mitochondrial dynamics and SIRT1/PGC-1α signaling pathway in brain were measured. Furthermore, reactive oxygen species (ROS) accumulation and resultant mitochondrial membrane potential (MMP) alteration in PC12 cells exposed to palmitic acid (PA) or Drp1 inhibitor (Mdivi-1) were detected to reflect mitochondrial function. The findings suggested that prolonged treatment of RSV improved cognitive deficits and neuronal damage induced by HFD, potentially attributed to activation of the SIRT1/PGC-1α axis. We further indicated that the activation of the NLRP3 inflammasome in PA (200 μM) treated PC12 cells could be inhibited by Mdivi-1. More importantly, Mdivi-1 (10 μM) reduced intracellular ROS levels and enhanced MMP by reversing Drp1-mediated aberrant mitochondrial fission. To summarize, those results clearly indicated that a HFD inhibited the SIRT1/PGC-1α pathway, which contributed to an imbalance in mitochondrial dynamics and the onset of NLRP3-mediated pyroptosis. This effect was mitigated by the RSV possibly through triggering the SIRT1/PGC-1α axis, prevented aberrant mitochondrial fission and thus inhibited the activation of the NLRP3 inflammatory pathway.

Mitophagy-regulated Necroptosis plays a vital role in the nephrotoxicity of Fumonisin B1 in vivo and in vitro

Fumonisin B1 (FB1), one of the most widely distributed mycotoxins found in grains and feeds as contaminants, affects many organs including the kidney once ingested. However, the nephrotoxicity of FB1 remains to be further uncovered. The connection between necroptosis and nephrotoxicity of FB1 has been investigated in this study. The results showed that mice exposed to high doses of FB1 (2.25 mg/kg b.w.) developed kidney damage, with significant increases in proinflammatory cytokines (Il-6, Il-1β), kidney injury-related markers (Ngal, Ntn-1), and gene expressions linked to necroptosis (Ripk1, Ripk3, Mlkl). The concentration-dependent damage effects of FB1 on PK-15 cells contain cytotoxicity, cellular inflammatory response, and necroptosis. These FB1-induced effects can be neutralized by pretreatment with the necroptosis inhibitor Nec-1. Additionally, FB1 caused mitochondrial damage and mitophagy in vivo and in vitro, whereas Mdivi-1, a mitophagy inhibitor, prevented these effects on PK-15 cells as well as, more crucially, necroptosis. In conclusion, the RIPK1/RIPK3/MLKL signal route of necroptosis, which may be controlled by mitophagy, mediated nephrotoxicity of FB1. Our findings clarify the underlying molecular pathways of FB1-induced nephrotoxicity.

The role of mitochondrial genes in ischemia-reperfusion injury: A systematic review of experimental studies

Mitochondrial dysfunction contributes to pathological conditions like ischemia-reperfusion (IR) injury. To address the lack of effective therapeutic interventions for IR injury and potential knowledge gaps in the current literature, we systematically reviewed 3800 experimental studies across 5 databases and identified 20 mitochondrial genes impacting IR injury in various organs. Notably, CyPD, Nrf2, and GPX4 are well-studied genes consistently influencing IR injury outcomes. Emerging genes like ALDH2, BNIP3, and OPA1 are supported by human genetic evidence, thereby warranting further investigation. Findings of this review can inform future research directions and inspire therapeutic advancements.

The alpha2-adrenergic receptor agonist clonidine protects against cerebral ischemia/reperfusion induced neuronal apoptosis in rats

Apoptosis is the crucial pathological mechanism following cerebral ischemic injury. Our previous studies demonstrated that clonidine, one agonist of alpha2-adrenergic receptor (α2-AR), could attenuate cerebral ischemic injury in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). However, it's unclear whether clonidine exerts neuroprotective effects by regulating neuronal apoptosis. In this study, we elucidated whether clonidine can exert anti-apoptotic effects in cerebral ischemic injury, and further explored the possible mechanisms. Neurological deficit score was measured to evaluate the neurological function. TTC staining was used for the measurement of brain infarct size. Hematoxylin-Eosin (HE) staining was applied to examine the cell morphology. TUNEL and DAPI fluorescent staining methods were used to analyze the cell apoptosis in brain tissue. Fluorescence quantitative real-time PCR was performed to assess the gene expression of Caspase-3 and P53. Western blotting assay was applied to detect the protein expression of Caspase-3 and P53. The results showed that clonidine improved neurological function, reduced brain infarct size, alleviated neuronal damage, and reduced the ratio of cell apoptosis in the brain with MCAO/R injury. moreover, clonidine down-regulated the gene and protein expression of Caspase-3 and P53 which were over-expressed after MCAO/R injury. Whereas, yohimbine (one selective α2-AR antagonist) mitigated the anti-apoptosis effects of clonidine, accompanied by reversed gene and protein expression changes. The results indicated that clonidine attenuated cerebral MCAO/R injury via suppressing neuronal apoptosis, which may be mediated, at least in part, by activating α2-AR.

Study on network pharmacology of Ginkgo biloba extract against ischaemic stroke mechanism and establishment of UPLC-MS/MS methods for simultaneous determination of 19 main active components

INTRODUCTION

Ginkgo biloba extract (GBE) is an effective substance from traditional Chinese medicine (TCM) G. biloba for treating ischaemic stroke (IS). However, its active ingredients and mechanism of action remain unclear.

OBJECTIVES

This study aimed to reveal the potential active component group and possible anti-IS mechanism of GBE.

MATERIALS AND METHODS

The network pharmacology method was used to reveal the possible anti-IS mechanism of these active ingredients in GBE. An ultra-high-performance liquid chromatography triple quadrupole electrospray tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous detection of the active ingredients of GBE.

RESULTS

The active components of GBE anti-IS were screened by literature integration. Network pharmacology results showed that the anti-IS effect of GBE is achieved through key active components such as protocatechuic acid, bilobalide, ginkgolide A, and so on. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the possible anti-IS mechanism of GBE is regulating the PI3K-Akt signalling pathway and other signal pathways closely related to inflammatory response and apoptosis regulation combined with AKT1, MAPK, TNF, ALB, CASP3, and other protein targets. Nineteen main constituents in seven batches of GBE were successfully analysed using the established UPLC-MS/MS method, and the results showed that the content of protocatechuic acid, gallic acid, ginkgolide A, and so forth was relatively high, which was consistent with network pharmacology results, indicating that these ingredients may be the key active anti-IS ingredients of GBE.

CONCLUSION

This study revealed the key active components and the anti-IS mechanism of GBE. It also provided a simple and sensitive method for the quality control of related preparations.

Mesenchymal stem cells overexpressing PBX1 alleviates haemorrhagic shock-induced kidney damage by inhibiting NF-κB activation

Mesenchymal stem cells (MSCs) have favourable outcomes in the treatment of kidney diseases. Pre-B-cell leukaemia transcription factor 1 (PBX1) has been reported to be a regulator of self-renewal of stem cells. Whether PBX1 is beneficial to MSCs in the treatment of haemorrhagic shock (HS)-induced kidney damage is unknown. We overexpressed PBX1 in rat bone marrow-derived mesenchymal stem cells (rBMSCs) and human bone marrow-derived mesenchymal stem cells (hBMSCs) to treat rats with HS and hypoxia-treated human proximal tubule epithelial cells (HK-2), respectively. The results indicated that PBX1 enhanced the homing capacity of rBMSCs to kidney tissues and that treatment with rBMSCs overexpressing PBX1 improved the indicators of kidney function, alleviated structural damage to kidney tissues. Furthermore, administration with rBMSCs overexpressing PBX1 inhibited HS-induced NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and the release of proinflammatory cytokines, and further attenuated apoptosis. We then determined whether NF-κB, an important factor in NLRP3 activation and the regulation of inflammation, participates in HS-induced kidney damage, and we found that rBMSCs overexpressing PBX1 inhibited NF-κB activation by decreasing the p-IκBα/IκBα and p-p65/p65 ratios and inhibiting the nuclear translocation and decreasing the DNA-binding capacity of NF-κB. hBMSCs overexpressing PBX1 also exhibited protective effects on HK-2 cells exposed to hypoxia, as shown by the increase in cell viability, the mitigation of apoptosis, the decrease in inflammation, and the inhibition of NF-κB and NLRP3 inflammasome activation. Our study demonstrates that MSCs overexpressing PBX1 ameliorates HS-induced kidney damage by inhibiting NF-κB pathway-mediated NLRP3 inflammasome activation and the inflammatory response.

Local production of reactive oxygen species drives vincristine-induced axon degeneration

Neurological side effects arising from chemotherapy, such as severe pain and cognitive impairment, are a major concern for cancer patients. These major side effects can lead to reduction or termination of chemotherapy medication in patients, negatively impacting their prognoses. With cancer survival rates improving dramatically, addressing side effects of cancer treatment has become pressing. Here, we use iPSC-derived human neurons to investigate the molecular mechanisms that lead to neurotoxicity induced by vincristine, a common chemotherapeutic used to treat solid tumors. Our results uncover a novel mechanism by which vincristine causes a local increase in mitochondrial proteins that produce reactive oxygen species (ROS) in the axon. Vincristine triggers a cascade of axon pathology, causing mitochondrial dysfunction that leads to elevated axonal ROS levels and SARM1-dependent axon degeneration. Importantly, we show that the neurotoxic effect of increased axonal ROS can be mitigated by the small molecule mitochondrial division inhibitor 1 (mdivi-1) and antioxidants glutathione and mitoquinone, identifying a novel therapeutic avenue to treat the neurological effects of chemotherapy.

Metabolic reprogramming regulates microglial polarization and its role in cerebral ischemia reperfusion

The brain is quite sensitive to changes in energy supply because of its high energetic demand. Even small changes in energy metabolism may be the basis of impaired brain function, leading to the occurrence and development of cerebral ischemia/reperfusion (I/R) injury. Abundant evidence supports that metabolic defects of brain energy during the post-reperfusion period, especially low glucose oxidative metabolism and elevated glycolysis levels, which play a crucial role in cerebral I/R pathophysiology. Whereas research on brain energy metabolism dysfunction under the background of cerebral I/R mainly focuses on neurons, the research on the complexity of microglia energy metabolism in cerebral I/R is just emerging. As resident immune cells of the central nervous system, microglia activate rapidly and then transform into an M1 or M2 phenotype to correspond to changes in brain homeostasis during cerebral I/R injury. M1 microglia release proinflammatory factors to promote neuroinflammation, while M2 microglia play a neuroprotective role by secreting anti-inflammatory factors. The abnormal brain microenvironment promotes the metabolic reprogramming of microglia, which further affects the polarization state of microglia and disrupts the dynamic equilibrium of M1/M2, resulting in the aggravation of cerebral I/R injury. Increasing evidence suggests that metabolic reprogramming is a key driver of microglial inflammation. For example, M1 microglia preferentially produce energy through glycolysis, while M2 microglia provide energy primarily through oxidative phosphorylation. In this review, we highlight the emerging significance of regulating microglial energy metabolism in cerebral I/R injury.

ALDH2 activation attenuates oxygen-glucose deprivation/reoxygenation-induced cell apoptosis, pyroptosis, ferroptosis and autophagy

PURPOSE

It is previously reported that aldehyde dehydrogenase 2 family member (ALDH2) shows neuroprotective effects in cerebral ischemia/reperfusion injury. However, whether the protective effects are through mediating the programmed cell death is yet to be fully elucidated.

METHODS

In vitro oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in HT22 cells and mouse cortical neurons. Subsequently, ALDH2 expression were assessed by qRT-PCR and western blot. The methylation status was examined by methylation-specific PCR (MS-PCR). Then, ALDH2 expression was promoted and suppressed to explore the role of ALDH2 in OGD/R-treated cells. CCK-8 assay was applied to detect cell viability, and flow cytometry was applied to evaluate cell apoptosis. Western blot was applied to detect the apoptosis-related proteins (Caspase 3, Bcl-2 and Bax), necroptosis-related proteins (RIP3 and MLKL), pyroptosis-related proteins (NLRP3 and GSDMD), ferroptosis-related protein (ACSL4 and GPX4), and autophagy-related proteins (LC3B, and p62). IL-1β and IL-18 production was evaluated by ELISA assay. Reactive oxygen species production and Fe2+ content were evaluated by the corresponding detection kit.

RESULTS

In OGD/R-treated cells, ALDH2 expression was decreased, which was due to the hypermethylation of ALDH2 in the promoter region. ALDH2 overexpression improved cell viability and ALDH2 knockdown suppressed cell viability in OGD/R-treated cells. We also found that ALDH2 overexpression attenuated OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy, while ALDH2 knockdown facilitated the OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy.

CONCLUSIONS

Collectively, our results implied that ALDH2 attenuated OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy to promote cell viability in HT22 cells and mouse cortical neurons.

Metformin alleviates cerebral ischemia/reperfusion injury aggravated by hyperglycemia via regulating AMPK/ULK1/PINK1/Parkin pathway-mediated mitophagy and apoptosis

Stroke remains the main leading cause of death and disabilities worldwide, with diabetes mellitus being a significant independent risk factor for it. Metformin, as an efficient hypoglycemic drug in treating type 2 diabetes, has been reported to alleviate the risk of diabetes-related stroke. However, its underlying mechanisms remain unclear. This study aimed to investigate the role of mitophagy and its regulatory pathway in the neuroprotective mechanism of metformin against cerebral ischemia/reperfusion (I/R) injury aggravated by hyperglycemia. A hyperglycemic cerebral I/R animal model and a high glucose cultured oxygen-glucose deprivation/reperfusion (OGD/R) cell model were used in the experiment. The indexes of brain injury, cell activity, mitochondrial morphology and function, mitophagy, mitochondrial pathway apoptosis and the AMPK pathway were observed. In diabetic rats, metformin treatment decreased cerebral infarction volume and neuronal apoptosis, and improved neurological symptoms following I/R injury. Additionally, metformin induced activation of the AMPK/ULK1/PINK1/Parkin mitophagy pathway to have neuroprotective effects. In vitro, high glucose culture and OGD/R treatment impaired mitochondrial morphology and function, mitochondrial membrane potential, and induced apoptosis. However, metformin activated AMPK/ULK1/PINK1/Parkin mitophagy pathway, normalized mitochondrial injury. This protection was reversed by autophagy inhibitor 3-methyladenine (3MA) and AMPK inhibitor compound C. In conclusion, our present study validates the potential mechanism of metformin in alleviating hyperglycemia aggravated cerebral I/R injury by the activation of AMPK/ULK1/PINK1/Parkin mitophagy pathway.

Research Advances of Mitochondrial Dysfunction in Perioperative Neurocognitive Disorders

Perioperative neurocognitive disorders (PND) increases postoperative dementia and mortality in patients and has no effective treatment. Although the detailed pathogenesis of PND is still elusive, a large amount of evidence suggests that damaged mitochondria may play an important role in the pathogenesis of PND. A healthy mitochondrial pool not only provides energy for neuronal metabolism but also maintains neuronal activity through other mitochondrial functions. Therefore, exploring the abnormal mitochondrial function in PND is beneficial for finding promising therapeutic targets for this disease. This article summarizes the research advances of mitochondrial energy metabolism disorder, inflammatory response and oxidative stress, mitochondrial quality control, mitochondria-associated endoplasmic reticulum membranes, and cell death in the pathogenesis of PND, and briefly describes the application of mitochondria-targeted therapies in PND.

Long-term iTBS Improves Neural Functional Recovery by Reducing the Inflammatory Response and Inhibiting Neuronal Apoptosis Via miR-34c-5p/p53/Bax Signaling Pathway in Cerebral Ischemic Rats

To investigate intermittent theta-burst stimulation (iTBS) effect on ischemic stroke and the underlying mechanism of neurorehabilitation, we developed an ischemia/reperfusion (I/R) injury model in Sprague-Dawley (SD) rats using the middle cerebral artery occlusion/reperfusion (MCAO/r) method. Next, using different behavioral studies, we compared the improvement of the whole organism with and without iTBS administration for 28 days. We further explored the morphological and molecular biological alterations associated with neuronal apoptosis and neuroinflammation by TTC staining, HE staining, Nissl staining, immunofluorescence staining, ELISA, small RNA sequencing, RT-PCR, and western blot assays. The results showed that iTBS significantly protected against neurological deficits and neurological damage induced by cerebral I/R injury. iTBS also significantly decreased brain infarct volume and increased the number of surviving neurons after 28 days. Additionally, it was observed that iTBS decreased synaptic loss, suppressed activation of astrocytes and M1-polarized microglia, and simultaneously promoted M2-polarized microglial activation. Furthermore, iTBS intervention inhibited neuronal apoptosis and exerted a positive impact on the neuronal microenvironment by reducing neuroinflammation in cerebral I/R injured rats. To further investigate the iTBS mechanism, this study was conducted using small RNA transcriptome sequencing of various groups of peri-infarcted tissues. Bioinformatics analysis and RT-PCR discovered the possible involvement of miR-34c-5p in the mechanism of action. The target genes prediction and detection of dual-luciferase reporter genes confirmed that miR-34c-5p could inhibit neuronal apoptosis in cerebral I/R injured rats by regulating the p53/Bax signaling pathway. We also confirmed by RT-PCR and western blotting that miR-34c-5p inhibited Bax expression. In conclusion, our study supports that iTBS is vital in inhibiting neuronal apoptosis in cerebral I/R injured rats by mediating the miR-34c-5p involvement in regulating the p53/Bax signaling pathway.

Unveiling the potential of mitochondrial dynamics as a therapeutic strategy for acute kidney injury

Acute Kidney Injury (AKI), a critical clinical syndrome, has been strongly linked to mitochondrial malfunction. Mitochondria, vital cellular organelles, play a key role in regulating cellular energy metabolism and ensuring cell survival. Impaired mitochondrial function in AKI leads to decreased energy generation, elevated oxidative stress, and the initiation of inflammatory cascades, resulting in renal tissue damage and functional impairment. Therefore, mitochondria have gained significant research attention as a potential therapeutic target for AKI. Mitochondrial dynamics, which encompass the adaptive shifts of mitochondria within cellular environments, exert significant influence on mitochondrial function. Modulating these dynamics, such as promoting mitochondrial fusion and inhibiting mitochondrial division, offers opportunities to mitigate renal injury in AKI. Consequently, elucidating the mechanisms underlying mitochondrial dynamics has gained considerable importance, providing valuable insights into mitochondrial regulation and facilitating the development of innovative therapeutic approaches for AKI. This comprehensive review aims to highlight the latest advancements in mitochondrial dynamics research, provide an exhaustive analysis of existing studies investigating the relationship between mitochondrial dynamics and acute injury, and shed light on their implications for AKI. The ultimate goal is to advance the development of more effective therapeutic interventions for managing AKI.

Mechanisms of Modulation of Mitochondrial Architecture

Mitochondrial network architecture plays a critical role in cellular physiology. Indeed, alterations in the shape of mitochondria upon exposure to cellular stress can cause the dysfunction of these organelles. In this scenario, mitochondrial dynamics proteins and the phospholipid composition of the mitochondrial membrane are key for fine-tuning the modulation of mitochondrial architecture. In addition, several factors including post-translational modifications such as the phosphorylation, acetylation, SUMOylation, and o-GlcNAcylation of mitochondrial dynamics proteins contribute to shaping the plasticity of this architecture. In this regard, several studies have evidenced that, upon metabolic stress, mitochondrial dynamics proteins are post-translationally modified, leading to the alteration of mitochondrial architecture. Interestingly, several proteins that sustain the mitochondrial lipid composition also modulate mitochondrial morphology and organelle communication. In this context, pharmacological studies have revealed that the modulation of mitochondrial shape and function emerges as a potential therapeutic strategy for metabolic diseases. Here, we review the factors that modulate mitochondrial architecture.

Mitochondrial quality control in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury is a phenomenon in which exacerbating damage of liver cells due to restoration of blood flow following ischemia during liver surgery, especially those involving liver transplantation. Mitochondria, the energy-producing organelles, are crucial for cell survival and apoptosis and have evolved a range of quality control mechanisms to maintain homeostasis in the mitochondrial network in response to various stress conditions. Hepatic ischemia-reperfusion leads to disruption of mitochondrial quality control mechanisms, as evidenced by reduced mitochondrial autophagy, excessive division, reduced fusion, and inhibition of biogenesis. This leads to dysfunction of the mitochondrial network. The accumulation of damaged mitochondria ultimately results in apoptosis of hepatocytes due to the release of apoptotic proteins like cytochrome C. This worsens hepatic ischemia-reperfusion injury. Currently, hepatic ischemia-reperfusion injury protection is being studied using different approaches such as drug pretreatment, stem cells and exosomes, genetic interventions, and mechanical reperfusion, all aimed at targeting mitochondrial quality control mechanisms. This paper aims to provide direction for future research on combating HIRI by reviewing the latest studies that focus on targeting mitochondrial quality control mechanisms.

Mitochondrial dysfunctions induce PANoptosis and ferroptosis in cerebral ischemia/reperfusion injury: from pathology to therapeutic potential

Ischemic stroke (IS) accounts for more than 80% of the total stroke, which represents the leading cause of mortality and disability worldwide. Cerebral ischemia/reperfusion injury (CI/RI) is a cascade of pathophysiological events following the restoration of blood flow and reoxygenation, which not only directly damages brain tissue, but also enhances a series of pathological signaling cascades, contributing to inflammation, further aggravate the damage of brain tissue. Paradoxically, there are still no effective methods to prevent CI/RI, since the detailed underlying mechanisms remain vague. Mitochondrial dysfunctions, which are characterized by mitochondrial oxidative stress, Ca²⁺ overload, iron dyshomeostasis, mitochondrial DNA (mtDNA) defects and mitochondrial quality control (MQC) disruption, are closely relevant to the pathological process of CI/RI. There is increasing evidence that mitochondrial dysfunctions play vital roles in the regulation of programmed cell deaths (PCDs) such as ferroptosis and PANoptosis, a newly proposed conception of cell deaths characterized by a unique form of innate immune inflammatory cell death that regulated by multifaceted PANoptosome complexes. In the present review, we highlight the mechanisms underlying mitochondrial dysfunctions and how this key event contributes to inflammatory response as well as cell death modes during CI/RI. Neuroprotective agents targeting mitochondrial dysfunctions may serve as a promising treatment strategy to alleviate serious secondary brain injuries. A comprehensive insight into mitochondrial dysfunctions-mediated PCDs can help provide more effective strategies to guide therapies of CI/RI in IS.

Oridonin ameliorates caspase-9-mediated brain neuronal apoptosis in mouse with ischemic stroke by inhibiting RIPK3-mediated mitophagy

Neuronal loss is a primary factor in determining the outcome of ischemic stroke. Oridonin (Ori), a natural diterpenoid compound extracted from the Chinese herb Rabdosia rubescens, has been shown to exert anti-inflammatory and neuroregulatory effects in various models of neurological diseases. In this study we investigated whether Ori exerted a protective effect against reperfusion injury-induced neuronal loss and the underlying mechanisms. Mice were subjected to transient middle cerebral artery occlusion (tMCAO), and were injected with Ori (5, 10, 20 mg/kg, i.p.) at the beginning of reperfusion. We showed that Ori treatment rescued neuronal loss in a dose-dependent manner by specifically inhibiting caspase-9-mediated neuronal apoptosis and exerted neuroprotective effects against reperfusion injury. Furthermore, we found that Ori treatment reversed neuronal mitochondrial damage and loss after reperfusion injury. In N2a cells and primary neurons, Ori (1, 3, 6 μM) exerted similar protective effects against oxygen-glucose deprivation and reoxygenation (OGD/R)-induced injury. We then conducted an RNA-sequencing assay of the ipsilateral brain tissue of tMCAO mice, and identified receptor-interacting protein kinase-3 (RIPK3) as the most significantly changed apoptosis-associated gene. In N2a cells after OGD/R and in the ipsilateral brain region, we found that RIPK3 mediated excessive neuronal mitophagy by activating AMPK mitophagy signaling, which was inhibited by Ori or 3-MA. Using in vitro and in vivo RIPK3 knockdown models, we demonstrated that the anti-apoptotic and neuroprotective effects of Ori were RIPK3-dependent. Collectively, our results show that Ori effectively inhibits RIPK3-induced excessive mitophagy and thereby rescues the neuronal loss in the early stage of ischemic stroke.

O-GlcNAcylation Is Required for the Survival of Cerebellar Purkinje Cells by Inhibiting ROS Generation

Purkinje cells (PCs), as a unique type of neurons output from the cerebellar cortex, are essential for the development and physiological function of the cerebellum. However, the intricate mechanisms underlying the maintenance of Purkinje cells are unclear. The O-GlcNAcylation (O-GlcNAc) of proteins is an emerging regulator of brain function that maintains normal development and neuronal circuity. In this study, we demonstrate that the O-GlcNAc transferase (OGT) in PCs maintains the survival of PCs. Furthermore, a loss of OGT in PCs induces severe ataxia, extensor rigidity and posture abnormalities in mice. Mechanistically, OGT regulates the survival of PCs by inhibiting the generation of intracellular reactive oxygen species (ROS). These data reveal a critical role of O-GlcNAc signaling in the survival and maintenance of cerebellar PCs.

Mitochondrial dynamics in vascular remodeling and target-organ damage

Vascular remodeling is the pathological basis for the development of many cardiovascular diseases. The mechanisms underlying endothelial cell dysfunction, smooth muscle cell phenotypic switching, fibroblast activation, and inflammatory macrophage differentiation during vascular remodeling remain elusive. Mitochondria are highly dynamic organelles. Recent studies showed that mitochondrial fusion and fission play crucial roles in vascular remodeling and that the delicate balance of fusion-fission may be more important than individual processes. In addition, vascular remodeling may also lead to target-organ damage by interfering with the blood supply to major body organs such as the heart, brain, and kidney. The protective effect of mitochondrial dynamics modulators on target-organs has been demonstrated in numerous studies, but whether they can be used for the treatment of related cardiovascular diseases needs to be verified in future clinical studies. Herein, we summarize recent advances regarding mitochondrial dynamics in multiple cells involved in vascular remodeling and associated target-organ damage.

Research progress on the protective mechanism of a novel soluble epoxide hydrolase inhibitor TPPU on ischemic stroke

Arachidonic Acid (AA) is the precursor of cerebrovascular active substances in the human body, and its metabolites are closely associated with the pathogenesis of cerebrovascular diseases. In recent years, the cytochrome P450 (CYP) metabolic pathway of AA has become a research hotspot. Furthermore, the CYP metabolic pathway of AA is regulated by soluble epoxide hydrolase (sEH). 1-trifluoromethoxyphenyl-3(1-propionylpiperidin-4-yl) urea (TPPU) is a novel sEH inhibitor that exerts cerebrovascular protective activity. This article reviews the mechanism of TPPU's protective effect on ischemic stroke disease.

Electroacupuncture ameliorates surgery-induced spatial memory deficits by promoting mitophagy in rats

Background

This study sought to explore the mechanism underlying the therapeutic effects of electroacupuncture (EA) on spatial memory deficits caused by surgery.

Methods

Hepatic apex resection was performed under propofol-based total intravenous anesthesia. Male Sprague-Dawley rats were subjected to EA treatment or EA + mitochondrial division inhibitor-1 (mdivi-1) treatment once a day for three consecutive days after surgery. The Morris water maze test was used to evaluate the spatial memory of the rats after surgery. Tissue from the hippocampus of each rat was frozen and used for transcriptomic and proteomic analyses to identify potential targets for EA treatment. Western blotting was used to confirm the protein expression levels. The levels of reactive oxygen species (ROS) and adenosine triphosphate (ATP) were detected using commercial kits. The rat mitochondria were then isolated, and the activity of mitochondrial complex V was assessed.

Results

EA attenuated surgery-induced spatial memory deficits on postoperative day 3, while these effects were reversed by treatment with the mdivi-1 (P<0.05). Ribonucleic acid (RNA)-sequencing revealed that EA upregulated multiple metabolic pathways and the phosphatidylinositol 3‑kinas/protein kinase B signaling pathway. The proteomic and western blotting results suggested that the EA treatment substantially downregulated coiled-coil-helix-coiled-coil-helix domain containing 3 (ChChd3) expression in the hippocampus. The EA treatment significantly increased the autophagy-related protein levels, including phosphatase and tensin homolog-induced kinase 1, Parkin, MAP1LC3 (LC3), and Beclin1, and inhibited the production of ROS and inflammatory cytokine interleukin-1β in the hippocampus (P<0.05).

Conclusions

These results suggest that EA ameliorates postoperative spatial memory deficits and protects hippocampus from oxidative stress and inflammation through enhanced autophagy in an animal model of perioperative neurocognitive disorders (PNDs).

Mitophagy in ototoxicity

Mitochondrial dysfunction is associated with ototoxicity, which is caused by external factors. Mitophagy plays a key role in maintaining mitochondrial homeostasis and function and is regulated by a series of key mitophagy regulatory proteins and signaling pathways. The results of ototoxicity models indicate the importance of this process in the etiology of ototoxicity. A number of recent investigations of the control of cell fate by mitophagy have enhanced our understanding of the mechanisms by which mitophagy regulates ototoxicity and other hearing-related diseases, providing opportunities for targeting mitochondria to treat ototoxicity.

Robust intervention for oxidative stress-induced injury in periodontitis via controllably released nanoparticles that regulate the ROS-PINK1-Parkin pathway

Oxidative stress in periodontitis has emerged as one of the greatest barriers to periodontal tissue restoration. In this study, we synthesized controlled drug release nanoparticles (MitoQ@PssL NPs) by encasing mitoquinone (MitoQ; an autophagy enhancer) into tailor-made reactive oxygen species (ROS)-cleavable amphiphilic polymer nanoparticles (PssL NPs) to regulate the periodontitis microenvironment. Once exposed to reactive oxygen species, which were substantially overproduced under oxidative stress conditions, the ROS-cleavable PssL was disintegrated, promoting the release of the encapsulated MitoQ. The released mitoquinone efficiently induced mitophagy through the PINK1-Parkin pathway and successfully reduced oxidative stress by decreasing the amount of reactive oxygen species. With the gradual decrease in the reactive oxygen species level, which was insufficient to disintegrate PssL, the release of mitoquinone was reduced and eventually eliminated, which contributed to a redox homeostasis condition and facilitated the regeneration of periodontal tissue. MitoQ@PssL NPs have great potential in the treatment of periodontitis via microenvironment-controlled drug release, which will provide a new avenue for periodontal regeneration and diseases related to imbalanced redox metabolism.

Cerium oxide nanoparticles with antioxidative neurorestoration for ischemic stroke

Oxidative stress and mitochondrial damage are the main mechanisms of ischemia-reperfusion injury in ischemic stroke. Herein, cerium oxide nanoparticles with powerful free radical scavenging ability were used as carriers to load dl-3-n-butylphthalide (NBP-CeO2 NPs) for the combined treatment of ischemic stroke. NBP-CeO2 NPs could eliminate reactive oxygen species (ROS) in mouse brain microvascular endothelial cells and hippocampal neurons after oxygen-glucose deprivation/reoxygenation (OGD/R), and also save mitochondrial membrane potential, morphology, and function, thus alleviating the in vitro blood brain barrier (BBB) disruption and neuronal apoptosis. In the middle cerebral artery embolization/recanalization (MCAO/R) mouse model, the NBP-CeO2 NPs also possessed superior ROS scavenging ability, protected mitochondria, and preserved BBB integrity, thereby reducing cerebral infarction and cerebral edema and inhibiting neuroinflammation and neuronal apoptosis. The long-term neurobehavioral tests indicated that the NBP-CeO2 NPs significantly improved sensorimotor function and spatial learning ability by promoting angiogenesis after ischemic stroke. Therefore, the NBP-CeO2 NPs provided a novel therapeutic approach for ischemic stroke by combining antioxidant and neurovascular repair abilities, highlighting its wide application in ischemia-reperfusion injury.

Neuroprotective Effect of miR-483-5p Against Cardiac Arrest-Induced Mitochondrial Dysfunction Mediated Through the TNFSF8/AMPK/JNK Signaling Pathway

Substantial morbidity and mortality are associated with postcardiac arrest brain injury (PCABI). MicroRNAs(miRNAs) are essential regulators of neuronal metabolism processes and have been shown to contribute to alleviated neurological injury after cardiac arrest. In this study, we identified miRNAs related to the prognosis of patients with neurological dysfunction after cardiopulmonary resuscitation based on data obtained from the Gene Expression Omnibus (GEO) database. Then, we explored the effects of miR-483-5p on mitochondrial biogenesis, mitochondrial-dependent apoptosis, and oxidative stress levels after ischemia‒reperfusion injury in vitro and in vivo. MiR-483-5p was downregulated in PC12 cells and hippocampal samples compared with that in normal group cells and hippocampi. Overexpression of miR-483-5p increased the viability of PC12 cells after ischemia‒reperfusion injury and reduced the proportion of dead cells. A western blot analysis showed that miR-483-5p increased the protein expression of PCG-1, NRF1, and TFAM and reduced the protein expression of Bax and cleaved caspase 3, inhibiting the release of cytochrome c from mitochondria and alleviating oxidative stress injury by inhibiting the production of ROS and reducing MDA activity. We confirmed that miR-483-5p targeted TNFSF8 to regulate the AMPK/JNK pathway, thereby playing a neuroprotective role after cardiopulmonary resuscitation. Hence, this study provides further insights into strategies for inhibiting neurological impairment after cardiopulmonary resuscitation and suggests a potential therapeutic target for PCABI.

Crosstalk among N6-methyladenosine modification and RNAs in central nervous system injuries

Central nervous system (CNS) injuries, including traumatic brain injury (TBI), intracerebral hemorrhage (ICH) and ischemic stroke, are the most common cause of death and disability around the world. As the most common modification on ribonucleic acids (RNAs), N6-methyladenosine (m6A) modification has recently attracted great attentions due to its functions in determining the fate of RNAs through changes in splicing, translation, degradation and stability. A large number of studies have suggested that m6A modification played an important role in brain development and involved in many neurological disorders, particularly in CNS injuries. It has been proposed that m6A modification could improve neurological impairment, inhibit apoptosis, suppress inflammation, reduce pyroptosis and attenuate ferroptosis in CNS injuries via different molecules including phosphatase and tensin homolog (PTEN), NLR family pyrin domain containing 3 (NLRP3), B-cell lymphoma 2 (Bcl-2), glutathione peroxidase 4 (GPX4), and long non-coding RNA (lncRNA). Therefore, m6A modification showed great promise as potential targets in CNS injuries. In this article, we present a review highlighting the role of m6A modification in CNS injuries. Hence, on the basis of these properties and effects, m6A modification may be developed as therapeutic agents for CNS injury patients.

Breviscapine remodels myocardial glucose and lipid metabolism by regulating serotonin to alleviate doxorubicin-induced cardiotoxicity

Aims: The broad-spectrum anticancer drug doxorubicin (Dox) is associated with a high incidence of cardiotoxicity, which severely affects the clinical application of the drug and patients’ quality of life. Here, we assess how Dox modulates myocardial energy and contractile function and this could aid the development of relevant protective drugs.

Methods: Mice were subjected to doxorubicin and breviscapine treatment. Cardiac function was analyzed by echocardiography, and Dox-mediated signaling was assessed in isolated cardiomyocytes. The dual cardio-protective and anti-tumor actions of breviscapine were assessed in mouse breast tumor models.

Results: We found that Dox disrupts myocardial energy metabolism by decreasing glucose uptake and increasing fatty acid oxidation, leading to a decrease in ATP production rate, an increase in oxygen consumption rate and oxidative stress, and further energy deficits to enhance myocardial fatty acid uptake and drive DIC development. Interestingly, breviscapine increases the efficiency of ATP production and restores myocardial energy homeostasis by modulating the serotonin-glucose-myocardial PI3K/AKT loop, increasing glucose utilization by the heart and reducing lipid oxidation. It enhances mitochondrial autophagy via the PINK1/Parkin pathway, eliminates damaged mitochondrial accumulation caused by Dox, reduces the degree of cardiac fibrosis and inflammation, and restores cardiac micro-environmental homeostasis. Importantly, its low inflammation levels reduce myeloid immunosuppressive cell infiltration, and this effect is synergistic with the anti-tumor effect of Dox.

Conclusion: Our findings suggest that disruption of the cardiac metabolic network by Dox is an important driver of its cardiotoxicity and that serotonin is an important regulator of myocardial glucose and lipid metabolism. Myocardial energy homeostasis and timely clearance of damaged mitochondria synergistically contribute to the prevention of anthracycline-induced cardiotoxicity and improve the efficiency of tumor treatment.

Cdk5 Promotes Mitochondrial Fission via Drp1 Phosphorylation at S616 in Chronic Ethanol Exposure-Induced Cognitive Impairment

Excessive alcohol consumption can lead to alterations in brain structure and function, even causing irreversible learning and memory disorders. The hippocampus is one of the most sensitive areas to alcohol neurotoxicity in the brain. Accumulating evidence indicates that mitochondrial dysfunction contributes to alcohol neurotoxicity. However, little is known about the underlying molecular mechanisms. In this study, we found that chronic exposure to ethanol caused abnormal mitochondrial fission/fusion and morphology by activating the mitochondrial fission protein dynamin-related protein 1 (Drp1) and upregulating Drp1 receptors, such as fission protein 1 (Fis1), mitochondrial dynamics protein of 49 kDa (Mid49), and mitochondrial fission factor (Mff), combined with decreasing optic atrophy 1 (Opa1) and mitochondrial fusion protein mitofusin 1 (Mfn1) levels. In addition, mitochondrial division inhibitor 1 (mdivi-1) abrogated ethanol-induced mitochondrial dysfunction and improved hippocampal synapses and cognitive function in ethanol-exposed mice. Chronic ethanol exposure also resulted in cyclin-dependent kinase 5 (Cdk5) overactivation, as shown by the increase in the levels of Cdk5 and its activator P25 in the hippocampus. Furthermore, a Cdk5/P25 inhibitor (roscovitine) or Cdk5 knockdown using small interfering RNA (LVi-Cdk5) exerted neuroprotection by inhibiting abnormal mitochondrial fission through Drp1 phosphorylation at Ser616 and mitochondrial translocation after chronic ethanol exposure. Taken together, the present study demonstrated that inhibition of aberrant Cdk5 activation attenuates hippocampal neuron injury and cognitive deficits induced by chronic exposure to ethanol through Drp1-mediated mitochondrial fission and mitochondrial dysfunction. Interfering with this pathway might serve as a potential therapeutic approach to prevent ethanol-induced neurotoxicity in the brain.