Mitochondria in depression: The dysfunction of mitochondrial energy metabolism and quality control systems

Identification of mitochondrial-related causal genes for major depression disorder via integrating multi-omics

CONTEXT

Mitochondria dysfunction plays a pivotal role in major depressive disorder (MDD), but the causal link between mitochondria dysfunction and MDD remains unclear.

AIMS

This study aimed to explore the causal effects of mitochondrial-related genes (MRGs) on MDD by integrating multi-omics data.

METHODS

Summary statistics of DNA methylation, gene expression, and protein for MRGs were obtained from the corresponding quantitative trait loci in European ancestry individuals. GWAS summary statistics for MDD were sourced from the Psychiatric Genomics Consortium (PGC, discovery) and FinnGen R10 study (replication). Summary-data-based Mendelian Randomization (SMR) was performed to assess the association between DNA methylation, gene expression, and protein abundances of MRGs with the risk of MDD. Colocalization analysis was employed to assess the potential shared genetic variants between MRGs and MDD. Two-sample MR was conducted to assess the sensitivity of the SMR results. Single-nucleus RNA-sequencing (snRNA-seq) and bulk RNA-seq data were used to explore the candidate MRG expression.

RESULTS

We identified methylation levels of PPTC7 (cg08752433) and methylation levels of VRS2 (cg07945879, cg14935711, cg00244776, cg15848685, cg12457901, cg16958594) associated with a decreased risk of MDD. Conversely, the methylation levels of VRS2 (cg26784891, cg05853013, cg04966294) and MRPL46 (cg00200755) were associated with increased risk of MDD. High expression of COQ8A and TRMT10C were associated with an increased risk of MDD. Notably, COQ8A was predominantly expressed in both inhibitory and excitatory neurons in MDD patients.

CONCLUSION

This study established a causal relationship between mitochondrial dysfunction and MDD, identifying candidate MRGs, and providing potential diagnostic and therapeutic targets for MDD.

Navigating Psychiatric Concerns in a Veteran Reporting Gulf War Illness: A Case Report

Gulf War illness (GWI) is a chronic condition affecting nearly a third of Gulf War veterans and is characterized by persistent symptoms across a number of physical and neuropsychiatric domains. This case study examined a 52-year-old veteran admitted on a psychiatric hold for danger to others. The patient's symptoms, including chronic migraine, widespread musculoskeletal pain, skin sensitivities, environmental allergies, and mood and cognitive disturbances, met criteria for GWI according to 2 accepted case definitions. Initial misdiagnosis of psychosis was corrected upon evaluation, which identified severe anxiety consistent with generalized anxiety disorder. Treatment focused on providing validation of the patient's chronic symptoms and managing his anxiety through pharmacologic intervention. This case underscored the importance of recognizing GWI to ensure accurate diagnoses and targeted care for veterans.

Icariin mitigates depressive-like behavior in rats by regulating mitochondrial function

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedii Folium is a famous traditional Chinese medicine that has been utilized to treat depression, impotency and rheumatism for centuries in China. Icariin (ICA) is the primary flavonoid and quality control ingredient of Epimedii Folium.

AIMS OF THE STUDY

The objective of this investigation was to clarify the mechanisms through which ICA improved depressive-like behavior in prenatal stress (PS) offspring rats.

MATERIALS AND METHODS

Male offspring rats subjected to PS were utilized to investigate the antidepressant effect and possible mechanism of ICA. H&E staining, Nissl staining, ELISA, western blot, immunofluorescence staining and molecular docking were carried out in this work.

RESULTS

ICA treatment markedly mitigated depressive-like behavior and hippocampal neuronal damage in PS offspring rats. The hippocampal synaptic plasticity of PS offspring rats was impaired, while the abnormal expressions of synaptic plasticity proteins and the synaptic ultrastructure were restored after the administration of ICA. Importantly, ICA treatment improved disrupted mitochondrial dynamics and morphology, thereby reversing the decline in ATP level and mitochondrial membrane potential (MMP) in the hippocampus of PS offspring rats. The reduction of MMP in PS rats further induced the apoptosis of hippocampal neurons, while this trend was markedly reversed after the treatment with ICA. Concurrently, ICA reversed the decrease of mitochondrial biogenesis proteins (SIRT1, PGC-1α, NRF1, and TFAM) and the interaction between SIRT1 and PGC-1α. Further studies found that treatment with ICA notably counteracted the reduction in SIRT1 deacetylase activity and the increase in PGC-1α acetylation level in the hippocampus of PS rats. Additionally, ICA enhanced mitophagy by activating the PINK1/Parkin signaling pathway.

CONCLUSION

ICA exerted anti-depressive effects in PS offspring rats, partly by improving mitochondrial dynamics, biogenesis, and mitophagy.

The Ferroptosis-Mitochondrial Axis in Depression: Unraveling the Feedforward Loop of Oxidative Stress, Metabolic Homeostasis Dysregulation, and Neuroinflammation

Emerging evidence links ferroptosis-mitochondrial dysregulation to depression pathogenesis through an oxidative stress-energy deficit-neuroinflammation cycle driven by iron overload. This study demonstrates that iron accumulation initiates ferroptosis via Fenton reaction-mediated lipid peroxidation, compromising neuronal membrane integrity and disabling the GPx4 antioxidant system. Concurrent mitochondrial complex I/IV dysfunction impairs ATP synthesis, creating an AMPK/mTOR signaling imbalance and calcium dyshomeostasis that synergistically impair synaptic plasticity. Bidirectional crosstalk emerges: lipid peroxidation derivatives oxidize mitochondrial cardiolipin, while mitochondrial ROS overproduction activates ACSL4 to amplify ferroptotic susceptibility, forming a self-reinforcing neurodegenerative loop. Prefrontal-hippocampal metabolomics reveal paradoxical metabolic reprogramming with glycolytic compensation suppressing mitochondrial biogenesis (via PGC-1α/TFAM downregulation), trapping neurons in bioenergetic crisis. Clinical data further show that microglial M1 polarization through cGAS-STING activation sustains neuroinflammation via IL-6/TNF-α release. We propose a "ferroptosis-mitochondrial fragmentation-metabolic maladaptation" triad as mechanistic subtyping criteria for depression. Preclinical validation shows that combinatorial therapy (iron chelators + SIRT3 agonists) rescues neuronal viability by restoring mitochondrial integrity and energy flux. This work shifts therapeutic paradigms from monoaminergic targets toward multimodal strategies addressing iron homeostasis, organelle dynamics, and metabolic vulnerability-a framework with significant implications for developing neuroprotective antidepressants.

Study on the comorbid mechanisms of sarcopenia and late-life depression

The increasing global aging population has brought greater focus to age-related diseases, particularly muscle-brain comorbidities such as sarcopenia and late-life depression. Sarcopenia, defined by the gradual loss of muscle mass and function, is notably prevalent among older individuals, while late-life depression profoundly affects their mental health and overall well-being. Epidemiological evidence suggests a high co-occurrence of these two conditions, although the precise biological mechanisms linking them remain inadequately understood. This review synthesizes the existing body of literature on sarcopenia and late-life depression, examining their definitions, prevalence, clinical presentations, and available treatments. The goal is to clarify the potential connections between these comorbidities and offer a theoretical framework for the development of future preventive and therapeutic strategies.

Neuroinflammation and Natural Antidepressants: Balancing Fire with Flora

Background/Objectives: Major depressive disorder (MDD) is a major global health concern that is intimately linked to neuroinflammation, oxidative stress, mitochondrial dysfunction, and complicated metabolic abnormalities. Traditional antidepressants frequently fall short, highlighting the urgent need for new, safer, and more acceptable therapeutic techniques. Phytochemicals, i.e., natural antidepressants derived from plants, are emerging as powerful plant-based therapies capable of targeting many pathogenic pathways at the same time. Summary: This narrative review synthesizes evidence from preclinical and clinical studies on the efficacy of phytochemicals such as curcumin, polyphenols, flavonoids, and alkaloids in lowering depressed symptoms. Consistent data show that these substances have neuroprotective, anti-inflammatory, and antioxidant properties, altering neuroimmune interactions, reducing oxidative damage, and improving mitochondrial resilience. Particularly, polyphenols and flavonoids have great therapeutic potential because of their capacity to penetrate the blood-brain barrier, inhibit cytokine activity, and encourage neuroplasticity mediated by brain-derived neurotrophic factor (BDNF). Despite promising results, the heterogeneity in study designs, phytochemical formulations, and patient demographics highlights the importance of thorough, standardized clinical studies. Conclusions: This review identifies phytochemicals as compelling adjuvant or independent therapies in depression treatment, providing multimodal mechanisms and enhanced tolerability. Additional research into improved dosage, pharmacokinetics, long-term safety, and integrative therapy approaches is essential. Using phytotherapeutics could considerably improve holistic and customized depression care, encouraging new research routes in integrative neuroscience and clinical psychiatry.

Association between depressive symptoms and premature death: An exploratory mediation analysis via mitochondrial function

BACKGROUND

Depression is a common mental health issue that can lead to various physical and psychological diseases. However, the relationship between depressive symptoms and premature death remains unclear.

METHODS

In this study, we used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 to assess the relationship between depressive symptoms and premature mortality and the potential influence of mitochondrial function on this relationship. The Patient Health Questionnaire-9 (PHQ-9) was used to assess the severity of depressive symptoms. Mortality data were obtained from the National Death Index (NDI). Mitochondrial function was assessed by measuring methylmalonic acid (MMA) levels. Multivariate logistic regression was used to assess the association between depressive symptoms and premature mortality, controlling for demographic, lifestyle, and disease-related factors. Restricted cubic splines were plotted, and propensity score matching (PSM) was used to create balanced groups. Finally, mediation analysis was performed to investigate the mediating role of MMA in the association between depressive symptoms and premature mortality.

RESULTS

This study included a total of 6599 participants. The results showed a substantial positive association (odds ratio [OR] = 1.452; 95 % confidence interval [CI], 1.038-2.031; p < 0.05) between depressive symptoms and premature mortality. The significance of this relationship was maintained after PSM analysis (OR = 2.370; 95 % CI, 1.749-3.212; p < 0.01). Mediation analysis showed that MMA partially mediated this relationship, with a mediation proportion of 4.1 %.

CONCLUSION

This study indicates that depressive symptoms significantly increases the risk of premature death and mitochondrial dysfunction partially mediates this positive relationship. Additional prospective and experimental studies are warranted to verify these findings.

Restoration of mitochondrial energy metabolism by electroconvulsive therapy in adolescent and juvenile mice

Background

Adolescent depression is an increasingly serious public health issue, and traditional treatment methods often have side effects or limited efficacy. Electroconvulsive therapy (ECT), a widely used treatment for severe depression, has recently gained attention for its potential in treating adolescent depression. Previous studies suggest that mitochondrial dysfunction is closely related to the onset of depression. Therefore, investigating the mechanism by which ECT alleviates depressive symptoms through the improvement of mitochondrial energy metabolism is of great significance.

Methods

This study employed the chronic unpredictable mild stress (CUMS) mouse model to assess the effects of ECT on depression-like behaviors through the sucrose preference test, open field test, and tail suspension test. Additionally, mitochondrial energy metabolism markers, including ATP levels, oxygen consumption rate (OCR), lactate, and pyruvate, were measured in both mouse and human plasma to evaluate the effects of ECT on mitochondrial function.

Results

The results showed that ECT significantly improved depression-like and anxiety-like behaviors in mice, as evidenced by the reversal of abnormal behaviors in the sucrose preference test, open field test, and tail suspension test. Analysis of plasma mitochondrial energy metabolism markers revealed that ECT significantly increased ATP levels, restored OCR, reduced lactate accumulation, and increased pyruvate levels. These findings suggest that ECT alleviates depressive symptoms by restoring mitochondrial energy metabolism and improving brain energy supply.

Conclusion

This study systematically explored the potential mechanism by which ECT alleviates adolescent depression through the improvement of mitochondrial energy metabolism. The results indicate that ECT not only effectively alleviates depressive symptoms but also provides new insights and experimental evidence for the treatment of adolescent depression through mitochondrial function restoration. Future research could further investigate how to combine drug treatments to enhance mitochondrial function, improve ECT efficacy, and evaluate the effects of ECT in different depression subtypes, providing guidance for personalized clinical treatment.

Integrative bioinformatics analysis reveals mitochondrial-Immune crosstalk in depression and stroke: a multi-omics mechanistic exploration

Stroke, a leading cause of disability and mortality globally, often cooccurs with depression or poststroke depression (PSD). The intricate interplay between mitochondrial metabolism and immune-related inflammation in depression and stroke remains a pivotal yet unresolved area. This study harnessed bioinformatics to elucidate the distinct contributions of mitochondrial metabolism and the immune microenvironment, as well as their complex interactions, to the pathogenesis of depression and stroke. By analyzing gene expression profiles from depression and stroke datasets alongside mitochondrial gene data, differentially expressed genes (DEGs) were meticulously identified, with a particular focus on mitochondria-related DEGs (MitoDEGs). Comprehensive functional investigations of common DEGs were conducted through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A robust protein-protein interaction (PPI) network was constructed, pinpointing ten hub-MitoDEGs intricately linked to depression and stroke. Furthermore, leveraging single-cell RNA sequencing analysis has shed light on gene expression across a myriad of cell types. Notably, these findings demonstrated immune cell dysregulation, revealing significant alterations in neutrophil and CD8+ T-cell infiltration within both the depression and stroke contexts. Correlation analyses revealed profound associations of the hub-MitoDEGs with mitochondrial metabolism, immune-related genes, and immunocytes. Importantly, this study also delineated ten potential drugs that target key genes implicated in depression and stroke, identifying promising avenues for innovative therapeutic interventions in these debilitating disorders.

Ginkgo biloba L. leaf extract (EGb 761) alleviates reserpine-induced depression-like symptoms in aged rats by enhancing serotonin/norepinephrine levels and reducing oxidative/nitrosative stress

Along with accelerated aging, the prevalence of late-life depression (LLD) exacerbates. Older people are more vulnerable to the adverse effects of antidepressants than the young. Therefore, creating antidepressants from medicinal herbs that are more effective and safer is inevitable. Ginkgo biloba L. leaf extract (EGb761) is broadly applied for treating various neuronal dysfunctions. The present study aimed to evaluate the ameliorative and antidepressant effects of EGb761 against reserpine (RES)-induced depression like symptoms and associated comorbidities in aged female rats. Besides, it compared its efficacy with the antidepressant duloxetine (DULX), offering a more comprehensive understanding of therapeutic potential of EGb 761. Rats grouped into control group, EGb 761-H group, RES group, RES plus either EGb 761-L, EGb 761-H, or DULX groups. The antidepressant effects of EGb 761 were evaluated through a series of behavioral tests, measurement of depression biochemical markers, performing neuronal histopathology and immunohistochemical analyses. EGb 761 significantly attenuated behavioral deficits in the open field test and reduced immobility time in the forced swimming test. Moreover, EGb 761 exerted antidepressant-like actions by ameliorating neurotransmitter imbalances, restoring redox homeostasis in cortical region. Also, EGb 761 increased level of ATP, diminished DNA fragmentation, decreased caspase-3 immunoreactivity and increased immunoreactivity of synaptophysin in the cerebral cortex, besides it enhanced the histological architecture of this region. Overall, EGb 761 has the potential effects to manage LLD focus on the role of both serotonergic and noradrenergic systems in mediating these effects, alongside the impact on oxidative/nitrosative stress.

Interruption of mitochondrial symbiosis is associated with the development of osteoporosis

Mitochondria maintain bacterial traits because of their endosymbiotic origins, yet the host cell recognizes them as non-threatening since the organelles are compartmentalized. Nevertheless, the controlled release of mitochondrial components into the cytoplasm can initiate cell death, activate innate immunity, and provoke inflammation. This selective interruption of endosymbiosis as early as 2 billion years ago allowed mitochondria to become intracellular signaling hubs. Recent studies have found that the interruption of mitochondrial symbiosis may be closely related to the occurrence of various diseases, especially osteoporosis (OP). OP is a systemic bone disease characterized by reduced bone mass, impaired bone microstructure, elevated bone fragility, and susceptibility to fracture. The interruption of intra-mitochondrial symbiosis affects the energy metabolism of bone cells, leads to the imbalance of bone formation and bone absorption, and promotes the occurrence of osteoporosis. In this paper, we reviewed the mechanism of mitochondrial intersymbiosis interruption in OP, discussed the relationship between mitochondrial intersymbiosis interruption and bone marrow mesenchymal stem cells, osteoblasts and osteoclasts, as well as the inheritance and adaptation in the evolutionary process, and prospected the future research direction to provide new ideas for clinical treatment.

Comparative Transcriptomic Analysis Reveals New Insights into Spawn Aging in Agaricus bisporus: Mitochondrial Dysfunction

Spawn aging poses a substantial challenge to the Agaricus bisporus industry. This study focuses on the role of mitochondrial dysfunction in the aging process of A. bisporus spawn. We conducted a comprehensive comparative transcriptome analysis to elucidate the molecular mechanisms underlying A. bisporus spawn aging. A total of 1620 genes with significant expression changes between the normal and aged spawn were identified, including 917 up-regulated genes and 703 down-regulated genes. Our results revealed a notable down-regulation of genes involved in carbohydrate metabolism, mitochondrial energy metabolism, reactive oxygen species (ROS) scavenging, repair mechanisms for oxidative stress-induced damage, fatty acid β-oxidation, and amino acid degradation in aged A. bisporus spawn. Additionally, we observed a decreased expression of genes involved in critical signal transduction pathways associated with mitochondrial function in aged mycelium as well as genes responsible for maintaining mitochondrial stability. The up-regulated genes in aged spawn mainly affect mitochondrial fission and programmed cell death, impacting mitochondrial function. Overall, the present study first provides evidence for the pivotal role of mitochondrial dysfunction in the aging process of A. bisporus spawn and contributes to the development of targeted strategies to enhance mitochondrial function, mitigate spawn aging, and improve the yield and quality of A. bisporus cultivation.

Bibliometric insights into astrocytic roles in depression and treatment

Objective

Depression is a mental disorder that significantly impairs both physical and mental health. Recent studies have shown that reactive astrogliosis have gained significant attention for their involvement in the pathophysiology of depression. However, there is no bibliometric analysis in this research field. This study aims to provide a comprehensive overview of the knowledge structure and research hotspots regarding the role of astrocytes in the mechanisms and treatment of depression through bibliometric analysis. The scope of the literature review encompasses both basic and clinical research.

Methods

Publications related to astrocytes in depression and treatment from 2014 to 2023 were searched in the Web of Science Core Collection (WoSCC) database. VOSviewer, CiteSpace, and the R package "bibliometrix" were used to conduct this bibliometric analysis.

Results

From 2014 to 2023, a total of 1,502 documents from 78 countries on astrocytes in depression and treatment were analyzed from 169 journals, with the most co-cited journals being the Journal of Neuroscience and PNAS. China Medical University was the most productive institution. The analysis identified key authors like Verkhratsky Alexei and Baoman Li, and major co-cited references by Rajkowska and Liddelow. Keywords such as "synaptic plasticity," "astrocytes," and "neuroinflammation" revealed research trends focusing on molecular mechanisms, gut microbiota, and inflammation.

Conclusion

This is the first bibliometric study to comprehensively summarize the research trends and advancements regarding astrocytes in depression and its treatment. Through this bibliometric analysis, we aim to enhance the understanding of the significance of astrocytes in depression research and provide new perspectives and insights for future investigations. We hope that this study will facilitate a broader integration of basic and clinical research, offering novel approaches for the treatment of depression.

Pink1/Parkin signaling mediates pineal mitochondrial autophagy dysfunction and its biological role in a comorbid rat model of depression and insomnia

Using a chronic unpredictable mild stress (CUMS) combined with multi-platform water environment sleep deprivation (SD) as an animal model, the occurrence and development of human depression combined with insomnia were simulated. The abnormal mitochondrial autophagy signaling caused by the putative kinase 1/Parkin E3 ubiquitin protein ligase (Pink1/Parkin) signaling pathway directly affects the normal secretion of melatonin by the pineal gland, which may explain the pathogenesis of depression combined with insomnia. This study aims to explore the depression-like behavior, sleep changes, central oxidative stress response, pineal mitochondrial autophagy damage, melatonin secretion, histopathological changes of the pineal gland, and the expression of Pink1/Parkin signaling-related factors in CUMS+SD rats. The results showed that the levels of reactive oxygen species (ROS) in cerebrospinal fluid of CUMS+SD rats significantly increased along with the inflammatory factors Interleukin-1β (IL-1β) and nuclear factor kappa-B (NF-κB) in cerebrospinal fluid. In addition, the number of pineal gland cells significantly decreased, cell boundaries became blurred, cell volume shrank, and apoptotic bodies appeared in the pineal gland tissue under HE staining, indicating pineal gland inflammation. Sleep deprivation further disrupted the levels of autophagy damage factors, including histamine (MDA), glutathione (GSH), and catalase (CAT), in the cerebrospinal fluid of CUMS+ SD rats. Transmission electron microscopy of the pineal gland in CUMS+SD rats revealed damage to mitochondrial autophagy. The levels of 5-hydroxytryptamine (5-HT) and aromatic amine-N-acetyltransferase (AANAT) in the cerebrospinal fluid, as well as melatonin levels in the pineal gland, were significantly decreased. Additionally, the expression of IL-1β, NF-κB, Pink1, and Parkin in the pineal gland of CUMS+SD rats significantly increased. The expression of microtubule-associated protein 1 light chain 3-β (LC3), selective autophagy adaptor protein (P62), cytochrome c oxidase IV (COXIV), and mitochondrial outer membrane translocation enzyme 20 (TOM20) proteins downstream of the Pink1/Parkin signaling pathway was enhanced, while the expression of downstream brain-derived neurotrophic factor (BDNF), Beclin 1, and BCL2 interacting protein 3 (BNIP3) proteins was negatively regulated. Pink1/Parkin signaling may specifically respond to mitochondrial autophagy damage in the pineal gland, affecting the normal synthesis and secretion of melatonin in the pineal gland. In summary, mitochondrial autophagy damage in the pineal gland affects the normal secretion of melatonin in CUMS+SD rats, which is closely related to the specific autophagy signaling impairment of Pink1/Parkin pathway, which may mediate the occurrence of depression combined with insomnia.

One-Week Maternal Separation Caused Sex-Specific Changes in Behavior and Hippocampal Metabolomics of Offspring Rats

To investigate the effects of one-week maternal separation (MS) on anxiety- and depression-like behaviors in adolescent and adulthood as well as adult hippocampal metabolomics simultaneously in offspring female and male rats. In the MS group, newborn SD rats were separated from their mothers for 3 h per day from postnatal days (PND) 2 to 8. The open field test (OFT), elevated plus mazes (EPM), novelty suppressed feeding test (NSFT), and forced swimming test (FST) were conducted during adolescence and adulthood. Serum corticosterone, mRNA expression of hippocampal inflammatory cytokines, and hippocampal untargeted metabolomics of offspring adult rats were examined using an assay kit, qRT-PCR, and UPLC-Q-TOF/MS. Both MS female and male rats showed similar behaviors in OFT, EPM, NSFT, and SPT, except for the latency to feeding during adolescence and the open arm entries during adulthood, showed statistical significance only in MS female rats. Serum corticosterone and hippocampal pro-inflammatory cytokines IFN-γ were significantly elevated in both female and male rats, and IL-1β and TNF-α were significantly increased only in female rats. In hippocampal metabolism, the identification of differential metabolites displayed 53 and 37 in female rats and male rats, respectively (with 35 common metabolites), which were involved in 33 and 30 metabolic pathways with 28 common pathways. One-week MS induced sex-specific anxiety- and depression-like behaviors in female and male offspring rats during adolescence and adulthood, as well as sex-differentiated characteristics in the hippocampus inflammatory cytokines and metabolomics of adult MS rats. From the experimental data, the effects of MS on the female offspring rats were more severe than those of the male offspring rats.

Hormonal orchestra: mastering mitochondria's role in health and disease

Mitochondria is a subcellular organelle involved in the pathogenesis of cellular stress, immune responses, differentiation, metabolic disorders, aging, and death by regulating process of fission, fusion, mitophagy, and transport. However, an increased interest in mitochondria as powerhouse for ATP production, the mechanisms of mitochondria-mediated cellular dysfunction in response to hormonal interaction remains unknown. Mitochondrial matrix contains chaperones and proteases that regulate intrinsic apoptosis pathway through pro-apoptotic Bcl-2 family's proteins Bax/Bak, and Cyt C release, and induces caspase-dependent and independent cells death. Energy and growth regulators such as thyroid hormones have profound effect on mitochondrial inner membrane protein and lipid compositions, ATP production by regulating oxidative phosphorylation system. Mitochondria contain cholesterol side-chain cleavage enzyme, P450scc, ferredoxin, and ferredoxin reductase providing an essential site for steroid hormones biosynthesis. In line with this, neurohormones such as oxytocin, vasopressin, and melatonin are correlated with mitochondrial integrity, displaying therapeutic implications for inflammatory and immune responses. Melatonin's also displayed protective role against oxidative stress and mitochondrial synthesis of ROS, suggesting a defense mechanism against aging-related diseases. An imbalance in mitochondrial bioenergetics can cause neurodegenerative disorders, cardiovascular diseases, and cancers. Hormone-induced PGC-1α stimulates mitochondrial biogenesis via activation of NRF1 and NRF2, which in turn triggers mtTFA in brown adipose and cardiac myocytes. Mitochondria can be transferred through cells merging, exosome-mediated transfer, and tunneling through nanotubes. By delineating the underlying molecular mechanism of hormonal mitochondrial interaction, this study reviews the dynamics mechanisms of mitochondria and its effects on cellular level, health, diseases, and therapeutic strategies targeting mitochondrial diseases.

Up-regulated succinylation modifications induce a senescence phenotype in microglia by altering mitochondrial energy metabolism

The aging of the central nervous system(CNS) is a primary contributor to neurodegenerative diseases in older individuals and significantly impacts their quality of life. Neuroinflammation, characterized by activation of microglia(MG) and release of cytokines, is closely associated with the onset of these neurodegenerative diseases. The activated status of MG is modulated by specifically programmed metabolic changes under various conditions. Succinylation, a novel post-translational modification(PTM) mainly involved in regulating mitochondrial energy metabolism pathways, remains unknown in its role in MG activation and aging. In the present study, we found that succinylation levels were significantly increased both during aging and upon lipopolysaccharide-induced(LPS-induced) MG activation undergoing metabolic reprogramming. Up-regulated succinylation induced by sirtuin 5 knockdown(Sirt5 KD) in microglial cell line BV2 resulted in significant up-regulation of aging-related genes, accompanied by impaired mitochondrial adaptability and a shift towards glycolysis as a major metabolic pathway. Furthermore, after LPS treatment, Sirt5 KD BV2 cells exhibited increased generation of reactive oxygen species(ROS), accumulation of lipid droplets, and elevated levels of lipid peroxidation. By employing immunoprecipitation, introducing point mutation to critical succinylation sites, and conducting enzyme activity assays for succinate dehydrogenase(SDH) and trifunctional enzyme subunit alpha(ECHA), we demonstrated that succinylation plays a regulatory role in modulating the activities of these mitochondrial enzymes. Finally, down-regulation the succinylation levels achieved through administration of succinyl phosphonate(SP) led to amelioration of MG senescence in vitro and neuroinflammation in vivo. To our knowledge, our data provide preliminary evidence indicating that up-regulated succinylation modifications elicit a senescence phenotype in MG through alterations in energy metabolism. Moreover, these findings suggest that manipulation of succinylation levels may offer valuable insights into the treatment of aging-related neuroinflammation.