Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.

SIRT3 regulates mitochondrial biogenesis in aging-related diseases

Sirtuin 3(SIRT3),the main family member of mitochondrial deacetylase,targets the majority of substrates controlling mitochondrial biogenesis via lysine deacetylation and modulates important cellular functions such as energy metabolism,reactive oxygen species production and clearance,oxidative stress,and aging.Deletion of SIRT3 has a deleterious effect on mitochondrial biogenesis,thus leading to the defect in mitochondrial function and insufficient ATP production.Imbalance of mitochondrial dynamics leads to excessive mitochondrial biogenesis,dampening mitochondrial function.Mitochondrial dysfunction plays an important role in several diseases related to aging,such as cardiovascular disease,cancer and neurodegenerative diseases.Peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC1α)launches mitochondrial biogenesis through activating nuclear respiratory factors.These factors act on genes,transcribing and translating mitochondrial DNA to generate new mitochondria.PGC1αbuilds a bridge between SIRT3 and mitochondrial biogenesis.This review described the involvement of SIRT3 and mitochondrial dynamics,particularly mitochondrial biogenesis in agingrelated diseases,and further illustrated the role of the signaling events between SIRT3 and mitochondrial biogenesis in the pathological process of aging-related diseases.

SBC(Sanhuang Xiexin Tang combined with Baihu Tang plus Cangzhu)alleviates NAFLD by enhancing mitochondrial biogenesis and ameliorating inflammation in obese patients and mice

In the context of non-alcoholic fatty liver disease (NAFLD), characterized by dysregulated lipid metabolism in hepatocytes, the quest for safe and effective therapeutics targeting lipid metabolism has gained paramount importance. Sanhuang Xiexin Tang (SXT) and Baihu Tang (BHT) have emerged as prominent candidates for treating metabolic disorders. SXT combined with BHT plus Cangzhu (SBC) has been used clinically for Weihuochisheng obese patients. This retrospective analysis focused on assessing the anti-obesity effects of SBC in Weihuochisheng obese patients. We observed significant reductions in body weight and hepatic lipid content among obese patients following SBC treatment. To gain further insights, we investigated the effects and underlying mechanisms of SBC in HFD-fed mice. The results demonstrated that SBC treatment mitigated body weight gain and hepatic lipid accumulation in HFD-fed mice. Pharmacological network analysis suggested that SBC may affect lipid metabolism, mitochondria, inflammation, and apoptosis—a hypothesis supported by the hepatic transcriptomic analysis in HFD-fed mice treated with SBC. Notably, SBC treatment was associated with enhanced hepatic mitochondrial biogenesis and the inhibition of the c-Jun N-terminal kinase (JNK)/nuclear factor-kappa B (NF-κB) and extracellular signal-regulated kinase (ERK)/NF-κB pathways. In conclusion, SBC treatment alleviates NAFLD in both obese patients and mouse models by improving lipid metabolism, potentially through enhancing mitochondrial biogenesis. These effects, in turn, ameliorate inflammation in hepatocytes.

Mitochondrial dysfunction and quality control lie at the heart of subarachnoid hemorrhage

The dramatic increase in intracranial pressure after subarachnoid hemorrhage leads to a decrease in cerebral perfusion pressure and a reduction in cerebral blood flow.Mitochondria are directly affected by direct factors such as ischemia,hypoxia,excitotoxicity,and toxicity of free hemoglobin and its degradation products,which trigger mitochondrial dysfunction.Dysfunctional mitochondria release large amounts of reactive oxygen species,inflammatory mediators,and apoptotic proteins that activate apoptotic pathways,further damaging cells.In response to this array of damage,cells have adopted multiple mitochondrial quality control mechanisms through evolution,including mitochondrial protein quality control,mitochondrial dynamics,mitophagy,mitochondrial biogenesis,and intercellular mitochondrial transfer,to maintain mitochondrial homeostasis under pathological conditions.Specific interventions targeting mitochondrial quality control mechanisms have emerged as promising therapeutic strategies for subarachnoid hemorrhage.This review provides an overview of recent research advances in mitochondrial pathophysiological processes after subarachnoid hemorrhage,particularly mitochondrial quality control mechanisms.It also presents potential therapeutic strategies to target mitochondrial quality control in subarachnoid hemorrhage.

Latest assessment methods for mitochondrial homeostasis in cognitive diseases

Mitochondria play an essential role in neural function,such as supporting normal energy metabolism,regulating reactive oxygen species,buffering physiological calcium loads,and maintaining the balance of morphology,subcellular distribution,and overall health through mitochondrial dynamics.Given the recent technological advances in the assessment of mitochondrial structure and functions,mitochondrial dysfunction has been regarded as the early and key pathophysiological mechanism of cognitive disorders such as Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,mild cognitive impairment,and postoperative cognitive dysfunction.This review will focus on the recent advances in mitochondrial medicine and research methodology in the field of cognitive sciences,from the perspectives of energy metabolism,oxidative stress,calcium homeostasis,and mitochondrial dynamics(including fission-fusion,transport,and mitophagy).

Lycium barbarum Polysaccharides Promotes Mitochondrial Biogenesis and Energy Balance in NAFLD Cell Model

Objective:To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides(LBP)in a non-alcoholic fatty liver disease(NAFLD)cell model.Methods:Normal human hepatocyte LO2 cells were treated with 1 mmol/L free fatty acids(FFA)mixture for 24 h to induce NAFLD cell model.Cells were divided into 5 groups,including control,model,low-,medium-and high dose LBP(30,100and 300μg/mL)groups.The monosaccharide components of LBP were analyzed with high performance liquid chromatography.Effects of LBP on cell viability and intracellular lipid accumulation were assessed by cell counting Kit-8 assay and oil red O staining,respectively.Triglyceride(TG),alanine aminotransferase(ALT),aspartate aminotransferase(AST),adenosine triphosphate(ATP)and oxidative stress indicators were evaluated.Energy balance and mitochondrial biogenesis related mRNA and proteins were determined by quantitative real-time polymerase chain reaction and Western blot,respectively.Results:Heteropolysaccharides with mannose and glucose are the main components of LBP.LBP treatment significantly decreased intracellular lipid accumulation as well as TG,ALT,AST and malondialdehyde levels(P<0.05 or P<0.01),increased the levels of superoxide dismutase,phospholipid hydroperoxide glutathione peroxidase,catalase,and ATP in NAFLD cell model(P<0.05).Meanwhile,the expression of uncoupling protein 2 was down-regulated and peroxisome proliferator-activated receptor gamma coactivator-1α/nuclear respiratory factor 1/mitochondrial transcription factor A pathway was up-regulated(P<0.05).Conclusion:LBP promotes mitochondrial biogenesis and improves energy balance in NAFLD cell model.

Mitochondrial biogenesis of astrocytes is increased under experimental septic conditions

Background Mitochondrial dysfunction has been reported to be one of the contributing factors of sepsis-associated encephalopathy （SAE）.Mitochondrial biogenesis controls mitochondrial homeostasis and responds to changes in cellular energy demand.In addition,it is enhanced or decreased due to mitochondrial dysfunction during SAE.The aim of this study was to explore the changes of mitochondrial biogenesis of astrocytes under septic conditions.Methods Lipopolysaccharide （LPS; 50 ng/ml） and interferon-γ （IFN-γ; 200 U/ml） were incubated with astrocytes to model the effects of a septic insult on astrocytes in vitro.The mitochondrial ultrastructure and volume density were evaluated by transmission electron microscopy.Intracellular adenosine triphosphate （ATP） levels were detected by the firefly luciferase system.The expression of protein markers of mitochondrial biogenesis and the binding ability of mitochondrial transcription factor A （TFAM） were determined by western blot and electrophoretic mobility shift assays,respectively.The mitochondrial DNA （mtDNA） content was detected by real-time polymerase chain reaction.Results The number of mildly damaged mitochondria was found to be significantly greater after treatment for 6 hours,as compared with at 0 hour （P＜0.05）.The mitochondrial volume density was significantly elevated at 24 hours,as compared with at 0 hour （P＜0.05）.The ATP levels at 6 hours,12 hours,and 24 hours were significantly greater than those at 0 hour （P＜0.05）.The protein markers of mitochondrial biogenesis were significantly increased at 6 hours and 12 hours,as compared with at 0 hour （P＜0.05）.The TFAM binding activity was not significantly changed among the four time points analyzed.The mtDNA contents were significantly increased at 12 hours and 24 hours,as compared with at 0 hour （P＜0.05）.Conclusions Under septic conditions,mitochonddal biogenesis of astrocytes increased to meet the high-energy demand and to promote mitochondrial recovery.Furthermore,the TFAM-DNA binding ability was not sensitive to sepsis-induced injury.

Targeting mitochondrial biogenesis for preventing and treating insulin resistance in diabetes and obesity:Hope from natural mitochondrial nutrients

Insulin resistance is an important feature of type 2 diabetes and obesity. The underlying mechanisms of insulin resistance are still unclear. Mitochondrial dysfunction,

Mitochondria in Huntington’s disease:implications in pathogenesis and mitochondrial-targeted therapeutic strategies

Huntington’s disease is a genetic disease caused by expanded CAG repeats on exon 1 of the huntingtin gene located on chromosome 4.Compelling evidence implicates impaired mitochondrial energetics,altered mitochondrial biogenesis and quality control,disturbed mitochondrial trafficking,oxidative stress and mitochondrial calcium dyshomeostasis in the pathogenesis of the disorder.Unfortunately,conventional mitochondrial-targeted molecules,such as cysteamine,creatine,coenzyme Q10,or triheptanoin,yielded negative or inconclusive results.However,future therapeutic strategies,aiming to restore mitochondrial biogenesis,improving the fission/fusion balance,and improving mitochondrial trafficking,could prove useful tools in improving the phenotype of Huntington’s disease and,used in combination with genome-editing methods,could lead to a cure for the disease.

PGC-1α overexpression promotes mitochondrial biogenesis to protect auditory cells against cisplatin-induced cytotoxicity

Cisplatin(CDDP)-induced ototoxicity is one of the common adverse effects of cisplatin chemotherapy.Thus far,effective approaches for attenuating hearing loss are unavailable in clinical practice.Mitochondrial biogenesis acts as a master element of mitochondrial health and is necessary for mitochondrial quality control.The current study examined whether mitochondrial biogenesis is involved in CDDP-induced ototoxicity.Herein,we showed that CDDP damaged mitochondrial function and caused death of House Ear Institute-Organ of Corti 1(HEI-OC1)cells by impairing mitochondrial biogenesis.Moreover,overexpression of peroxisome proliferatoractivated receptor-g coactivator-1a,a key factor in mitochondrial biogenesis,promoted mitochondrial biogenesis in HEI-OC1 cells and protected them against CDDP-induced cytotoxicity.These findings suggest that mitochondrial biogenesis is involved in the pathology of CDDP cytotoxicity of HEI-OC1 cells,and activation of peroxisome proliferator-activated receptor-g coactivator-1a can be considered a potential therapeutic strategy to attenuate CDDP-mediated ototoxicity.

Targeting mitochondrial transcription factor A sensitizes pancreatic cancer cell to gemcitabine

Background:The survival of pancreatic cancer cells,particularly cancer stem cells which are responsible for tumor relapse,depends on mitochondrial function.Mitochondrial transcription factor A(TFAM)is critical for the regulation of mitochondrial DNA and thus mitochondrial function.However,the possible involvement of TFAM in pancreatic cancer is unknown.Methods:Human samples were obtained from pancreatic cancers and their adjacent tissues;human pancreatic cell lines were cultured in RPMI1640 medium.TFAM expressions in pancreatic tissues and cultured cells were determined using immunohistochemistry,ELISA,and reverse transcription polymerase chain reaction(RT-PCR).The effect of TFAM on cell growth,migration,colony formation and apoptosis were evaluated.Mitochondrial biogenesis in pancreatic cancer and normal cells were examined.Results:The majority of pancreatic cancer tissues exhibited higher TFAM expression compared to the adjacent counterparts.Consistently,TFAM mRNA and protein levels were higher in pancreatic cancer cell lines than in immortalized normal pancreatic epithelial cells.There was no difference on TFAM level between gemcitabine-sensitive and resistant pancreatic cancer cells.Functional analysis demonstrated that TFAM overexpression activated pancreatic normal and tumor cells whereas TFAM inhibition effectively inhibited the growth of pancreatic cancer cells.TFAM inhibition enhanced gemcitabine’s cytotoxicity and suppressed growth,anchorage-independent colony formation and survival of gemcitabine-resistant pancreatic cancer cells.Mechanistic studies showed that TFAM inhibition resulted in remarkable mitochondrial dysfunction and energy crisis followed by oxidative stress.The basal mitochondrial biogenesis level correlated well with TFAM level in pancreatic cancer cells.Conclusions:TFAM played essential roles in pancreatic cancer via regulating mitochondrial functions which highlighted the therapeutic value of inhibiting TFAM to overcome gemcitabine resistance.

Mitophagy in acute central nervous system injuries:regulatory mechanisms and therapeutic potentials

Acute central nervous system injuries,including ischemic stro ke,intracerebral hemorrhage,subarachnoid hemorrhage,traumatic brain injury,and spinal co rd injury,are a major global health challenge.Identifying optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent priorities.Mitochondria are susceptible to damage after acute central nervous system injury,and this leads to the release of toxic levels of reactive oxygen species,which induce cell death.Mitophagy,a selective form of autophagy,is crucial in eliminating redundant or damaged mitochondria during these events.Recent evidence has highlighted the significant role of mitophagy in acute central nervous system injuries.In this review,we provide a comprehensive overview of the process,classification,and related mechanisms of mitophagy.We also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate mitophagy.In the final section of this review,we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

Reactive oxygen species promote endurance exercise-induced adaptations in skeletal muscles

The discovery that contracting skeletal muscle generates reactive oxygen species(ROS)was first reported over 40 years ago.The prevailing view in the 1980s was that exercise-induced ROS production promotes oxidation of proteins and lipids resulting in muscle damage.However,a paradigm shift occurred in the 1990s as growing research revealed that ROS are signaling molecules,capable of activating transcriptional activators/coactivators and promoting exercise-induced muscle adaptation.Growing evidence supports the notion that reduction-oxidation(redox)signaling pathways play an important role in the muscle remodeling that occurs in response to endurance exercise training.This review examines the specific role that redox signaling plays in this endurance exercise-induced skeletal muscle adaptation.We begin with a discussion of the primary sites of ROS production in contracting muscle fibers followed by a summary of the antioxidant enzymes involved in the regulation of ROS levels in the cell.We then discuss which redox-sensitive signaling pathways promote endurance exercise-induced muscle adaptation and debate the strength of the evidence supporting the notion that redox signaling plays an essential role in muscle adaptation to endurance exercise training.In hopes of stimulating future research,we highlight several important unanswered questions in this field.

Modulation of mitochondrial bioenergetics as a therapeutic strategy in Alzheimer＇s disease

Alzheimer’s disease （AD） is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved success in preclinical models addressing the pathological hallmarks of the disease, these efforts have not translated into any effective disease-modifying therapies. This could be because interventions are being tested too late in the disease process. While existing therapies provide symptomatic and clinical benefit, they do not fully address the molecular abnormalities that occur in AD neurons. The pathophysiology of AD is complex; mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress are antecedent and potentially play a causal role in the disease pathogenesis. Dysfunctional mitochondria accumulate from the combination of impaired mitophagy, which can also induce injurious inflammatory responses, and inadequate neuronal mitochondrial biogenesis. Altering the metabolic capacity of the brain by modulating/potentiating its mitochondrial bioenergetics may be a strategy for disease prevention and treatment. We present insights into the mechanisms of mitochondrial dysfunction in AD brain as well as an overview of emerging treatments with the potential to prevent, delay or reverse the neurodegenerative process by targeting mitochondria.

Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells

Mitochondrial dysfunction and endoplasmic reticulum stress(ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide(NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca^(2+) flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstratedthe need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies.

Anti-cancer effects of sitagliptin,vildagliptin,and exendin-4 on triple-negative breast cancer cells via mitochondrial modulation

Triple-negative breast cancer(TNBC)cell line MDA-MB-231 is known for Warburg metabolism and defects in mitochondria.On the other hand,dipeptidyl peptidase-IV(DPP-IV)inhibitors such as sitagliptin and vildagliptin and GLP-1 agonist exendin-4 are known to improve mitochondrial functions as well as biogenesis,but no study has evaluated the influence of these drugs on mitochondrial biogenesis on metastatic breast cancer cell line.We have recently reported anticancer effects of 5-aminoimidazole-4-carboxamide riboside on MDA-MB-231 cells via activation of AMP-dependent kinase(AMPK),which activates the downstream transcription factors PGC-1α,PGC-1β,or FOXO1 for mitochondrial biogenesis;above-mentioned incretin-based therapies are also known to activate AMPK.This study evaluated the effects of sitagliptin,vildagliptin,and exendin-4 on MDA-MB-231 cells and the underlying changes in mitochondrial biogenesis,were examined.Treatment with sitagliptin(100μM),vildagliptin(100μM),and exendin-4(10 nM)for 72 h to MDA-MB-231 cells led to a decrease in viability indicated by MTT assay,cell migration by scratch,and transwell migration assays,accompanied with marginal reduction in cell numbers along with the apoptotic appearance,the rate of apoptosis,and decreased lactate content in conditioned medium.These changes in the cancer phenotype were accompanied by an increase in the mitochondrial DNA to nuclear DNA ratio,increased MitoTracker green and red staining,and increased expression of transcription factors PGC-1α,NRF-1,NRF-2,TFAM,and HO-1.Pre-treatment of cells with these incretin-based drugs followed by 48 h treatment with 1μM doxorubicin increased doxorubicin sensitivity as observed by a decrease in viability by MTT assay.Thus,sitagliptin,vildagliptin,and exendin-4 exert their beneficial effects on TNBC cells via an increase in mitochondrial biogenesis that helps to switch Warburg metabolism into anti-Warburg effect.Therapeutic response was in the order of:sitagliptin>vildagliptin>exendin-4.

The effect of caloric restriction on genetical pathways

Energy restriction is defined as reducing nutrient intake without dragging the organism into malnutrition. Energy restriction is preferred because it is a non-genetic intervention that increases life expectancy. Nicotinamide adenine dinucleotide(NAD~+)and adenosine monophosphate(AMP)levels, which are the indicators of intracellular energy deficiency, increase with energy restriction. The increase in NAD~+ level stimulates sirtuin(SIRT)enzymes, and the increase in AMP level stimulates AMP-activated protein kinase(AMPK). Various mechanisms are regulated by stimulating these enzymes. By Forkhead box O(FoxO)transcription factors, the ability of resistance to oxidative stress increases, and antioxidant genes, DNA repair, and autophagy genes are stimulated. Apoptosis is induced by stimulation of the p53 protein, and tumor growth is suppressed by the disruption of aging cells. The suppression of phosphoinositide 3-kinase(PI3K)-/-Akt, and therefore mTOR signal stimulates autophagy and mitophagia, and cleanses damaged cells and organelles. Mitochondrial biogenesis is stimulated, antioxidant capacity increases, and inflammatory response decreases. Adipose tissue and lipid metabolism are regulated by the regulation of fatty acid synthesis and oxidation. As a consequence, the effects of caloric restriction on cellular metabolism are regulated through the genetic pathways.

Activation of the PGC-1α-mediated mitochondrial glutamine metabolism pathway attenuates female offspring osteoarthritis induced by prenatal excessive prednisone

Osteoarthritis is a chronic,age-related joint disease.Previous studies have shown that osteoarthritis develops during intrauterine development.Prednisone is frequently used to treat pregnancies complicated by autoimmune diseases.However,limited research has been conducted on the enduring effects of prednisone use during pregnancy on the offspring.In this study,we investigated the effect of excessive prednisone exposure on cartilage development and susceptibility to osteoarthritis in the offspring.We found that prenatal prednisone exposure(PPE)impaired cartilage extracellular matrix(ECM)synthesis,resulting in poor cartilage pathology in female offspring during the adult period,which was further exacerbated after long-distance running stimulation.Additionally,PPE suppressed cartilage development during the intrauterine period.Tracing back to the intrauterine period,we found that Pred,rather than prednisone,decreased glutamine metabolic flux,which resulted in increased oxidative stress,and decreased histone acetylation,and expression of cartilage phenotypic genes.Further,PGC-1α-mediated mitochondrial biogenesis,while PPE caused hypermethylation in the promoter region of PGC-1αand decreased its expression in fetal cartilage by activating the glucocorticoid receptor,resulting in a reduction of glutamine flux controlled by mitochondrial biogenesis.Additionally,overexpression of PGC-1α(either pharmacological or through lentiviral transfection)reversed PPEand Pred-induced cartilage ECM synthesis impairment.In summary,this study demonstrated that PPE causes chondrodysplasia in female offspring and increases their susceptibility to postnatal osteoarthritis.Hence,targeting PGC-1αearly on could be a potential intervention strategy for PPE-induced osteoarthritis susceptibility.

Regulation of neuronal bioenergetics as a therapeutic strategy in neurodegenerative diseases

Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are a heterogeneous group of debilitating disorders with multifactorial etiologies and pathogeneses that manifest distinct molecular mechanisms and clinical manifestations with abnormal protein dynamics and impaired bioenergetics. Mitochondrial dysfunction is emerging as an important feature in the etiopathogenesis of these age-related neurodegenerative diseases. The prevalence and incidence of these diseases is on the rise with the increasing global population and average lifespan. Although many therapeutic approaches have been tested, there are currently no effective treatment routes for the prevention or cure of these diseases. We present the current status of our knowledge and understanding of the involvement of mitochondrial dysfunction in these diseases and highlight recent advances in novel therapeutic strategies targeting neuronal bioenergetics as potential approach for treating these diseases.

Honokiol alleviated neurodegeneration by reducing oxidative stress and improving mitochondrial function in mutant SOD1 cellular and mouse models of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease affecting both upper and lower motor neurons(MNs)with large unmet medical needs.Multiple pathological mechanisms are considered to contribute to the progression of ALS,including neuronal oxidative stress and mitochondrial dysfunction.Honokiol(HNK)has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke,Alzheimer’s disease and Parkinson’s disease.Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo.Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins(SOD1-G93A cells for short).Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione(GSH)synthesis and activating the nuclear factor erythroid 2-related factor 2(NRF2)-antioxidant response element(ARE)pathway.Also,honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells.Importantly,honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function.The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice.Overall,honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.