Search Results (99)

Mitochondria are central to energy production and redox regulation in spermatozoa, supporting key functions such as progressive motility, capacitation, and the acrosome reaction. These processes are essential for successful fertilization and embryo development. However, species-specific differences exist in the reliance on oxidative phosphorylation versus glycolysis. Mitochondria also generate reactive oxygen species, which at physiological levels aid in sperm function but can cause oxidative stress and damage when overproduced. Mitochondrial dysfunction and excessive ROS can impair membrane potential, induce apoptosis, and damage nuclear and mitochondrial DNA, ultimately compromising sperm quality. Sperm mitochondrial DNA is highly susceptible to mutations and deletions, contributing to reduced motility and fertility. Targeted antioxidant strategies have emerged as promising therapeutic interventions to mitigate oxidative damage. This article provides a comprehensive overview of mitochondrial regulation in spermatozoa, the consequences of redox imbalance, and the potential of mitochondria-targeted antioxidants to improve sperm function and male fertility outcomes. The paper aims to deepen our understanding of mitochondrial roles in sperm physiology and contribute to the advancement of strategies for addressing male infertility. Full article

Diabetic sensorimotor polyneuropathy (DSPN) is the most prevalent complication of diabetes, affecting nearly half of all persons with diabetes. It is characterized by nerve degeneration, progressive sensory loss and pain, with increased risk of ulceration and amputation. Despite its high prevalence, disease-modifying treatments for DSPN do not exist. Mitochondrial dysfunction and Ca²⁺ dyshomeostasis are key contributors to the pathophysiology of DSPN, disrupting neuronal energy homeostasis and initiating axonal degeneration. Recent findings have demonstrated that antagonism of the muscarinic acetylcholine type 1 receptor (M₁R) promotes restoration of mitochondrial function and axon repair in various neuropathies, including DSPN, chemotherapy-induced peripheral neuropathy (CIPN) and HIV-associated neuropathy. Pirenzepine, a selective M₁R antagonist with a well-established safety profile, is currently under clinical investigation for its potential to reverse neuropathy. The transient receptor potential melastatin-3 (TRPM3) channel, a Ca²⁺-permeable ion channel, has recently emerged as a downstream effector of G protein-coupled receptor (GPCR) pathways, including M₁R. TRPM3 activation enhanced mitochondrial Ca²⁺ uptake and bioenergetics, promoting axonal sprouting. This review highlights mitochondrial and Ca²⁺ signaling imbalances in DSPN and presents M₁R antagonism and TRPM3 activation as promising neuro-regenerative strategies that shift treatment from symptom control to nerve restoration in diabetic and other peripheral neuropathies. Full article

Glycolysis and oxidative phosphorylation are the main pathways of cellular energy production. Glucose is metabolized via glycolysis to generate pyruvate, which, under anaerobic conditions, is converted into lactate, while, under aerobic conditions, pyruvate enters mitochondria for oxidative phosphorylation to produce more energy. Accordingly, mitochondrial dysfunction disrupts the energy balance. Lactate, historically perceived as a harmful metabolic byproduct. However, emerging research indicates that lactate has diverse biological functions, encompassing energy regulation, epigenetic remodeling, and signaling activities. Notably, the 2019 study revealed the role of lactate in regulating gene expression through histone and non-histone lactylation, thereby influencing critical biological processes. Metabolic reprogramming is a key adaptive mechanism of cells responding to stresses. The Warburg effect in tumor cells exemplifies this, with glucose preferentially converted to lactate for rapid energy, accompanied by metabolic imbalances, characterized by exacerbated aerobic glycolysis, lactate accumulation, suppressed mitochondrial oxidative phosphorylation, and compromised mitochondrial function, ultimately resulting in a vicious cycle of metabolic dysregulation. As molecular bridges connecting metabolism and epigenetics, lactate and lactylation offer novel therapeutic targets for diseases like cancer and neurodegenerative diseases. This review summarizes the interplay between metabolic reprogramming and mitochondrial dysfunction, while discussing lactate and lactylation’s mechanistic in the pathogenesis of related diseases. Full article

Diabetes mellitus (DM) is a complex global pandemic that frequently leads to multiple complications. Diabetic cardiomyopathy (DCM) is the primary cause of heart failure in patients with type 1 and 2 diabetes and is fundamentally characterized by abnormalities in myocardial structure and function. Metabolic disorders occupy a leading role in the pathogenesis of DCM, manifesting as disrupted substrate metabolism, dysregulated signaling pathways, and energy imbalance. Given the limited benefits of conventional therapeutic strategies targeting glucolipid metabolism, increasing research efforts have focused on amino acid metabolism. Amino acids are involved in the synthesis of nitrogen-containing compounds and serve as an energy source under specific conditions. Moreover, emerging studies demonstrate that metabolic disturbances of specific amino acids—such as branched-chain amino acids (BCAAs), glutamine, and arginine—exacerbate mitochondrial dysfunction and oxidative stress, thereby promoting myocardial fibrosis and cardiomyocyte injury. Therefore, this review aims to summarize the general characteristics and regulatory pathways of amino acid metabolism, as well as the specific mechanisms by which metabolic alterations of amino acids contribute to the pathogenesis and progression of diabetic cardiomyopathy, with the hope of advancing more effective translational therapeutic approaches. Full article

Background/Objectives: In 4-octylphenol (4-OP), a toxic environmental pollutant with endocrine disruptive effect, the use of 4-OP causes pollution in the freshwater environment and poses risks to aquatic organisms. Common carps (Cyprinus carpio L.) live in freshwater and are experimental animals for studying the toxic effects of environmental pollutants on fish. Its heart is susceptible to toxicants. However, whether 4-OP has a toxic effect on common carp heart remains unknown. Methods: Here, we conducted a common carp 4-OP exposure experiment (carp treated with 17 μg/L 4-OP for 45 days), aiming to investigate whether 4-OP has a toxic effect on common carp hearts. We observed the microstructure and ultrastructure of carp heart and detected autophagy genes, mitochondrial fission genes, mitochondrial fusion genes, glycolytic enzymes, AMPK, ATPase, and oxidative stress factors, to investigate the molecular mechanism of 4-OP induced damage in common carp hearts. Results: Our results showed that 4-OP exposure caused mitochondrial damage, autophagy, and damage in common carp hearts. 4-OP exposure increased the levels of miR-144, and eight autophagy factors (Beclin1, RB1CC1, ULK1, LC3-I, LC3-II, ATG5, ATG12, and ATG13), and decreased the levels of four autophagy factors (PI3K, AKT, mTOR, and SQSTM1). Furthermore, 4-OP exposure induced the imbalance between mitochondrial fission and fusion and mitochondrial dynamics imbalance, as demonstrated by the increase in three mitochondrial fission factors (Mff, Drp1, and Fis1) and the decrease in three mitochondrial fusion factors (Mfn1, Mfn2, and Opa1). Moreover, excess 4-OP treatment caused energy metabolism disorder, as demonstrated by the reduction in four ATPase (Na⁺K⁺-ATPase, Ca²⁺Mg²⁺-ATPase, Ca²⁺-ATPase, and Mg²⁺-ATPase), elevation in four glycolysis genes (HK1, HK2, LDHA, and PGK1), reduction in glycolysis gen (PGAM2), and the elevation in energy-sensing AMPK. Finally, 4-OP treatment induced the imbalance between antioxidant and oxidant and oxidative stress, as demonstrated by the increase in oxidant H₂O₂, and the decreases in five antioxidant factors (CAT, SOD, T-AOC, Nrf2, and HO-1). Conclusions: miR-144 mediated autophagy by targeting PI3K, mTOR, and SQSTM1, and the miR-144/PI3K-AKT-mTOR/ULK1 pathway was involved in 4-OP-induced autophagy. Mff-Drp1 axis took part in 4-OP-caused mitochondrial dynamics imbalance, and mitochondrial dynamics imbalance mediated autophagy via Mfn2-SQSTM1, Mfn2/Beclin1, and Mff-LC3-II axes. Energy metabolism disorder mediated mitochondrial dynamics imbalance through the AMPK-Mff-Drp1 pathway. Oxidative stress mediated energy metabolism disorder via the H₂O₂-AMPK axis. Taken together, oxidative stress triggered energy metabolism disorder, induced mitochondrial dynamics imbalance, and caused autophagy via the H₂O₂-AMPK-Mff-LC3-II pathway. Our study provided references for the toxic effects of endocrine disruptor on common carp hearts, and provided a basis for assessing environmental pollutant-induced damage in common carp heart. We only studied the toxic effects of 4-OP on common carp, and the toxic effects of 4-OP on other fish species need to be further studied. Full article

Background: Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal death and neurodevelopmental disorders, and its pathological mechanisms are closely related to disturbed energy metabolism and lipid remodeling. Exploring the spatial heterogeneity of metabolomics is essential to analyze the pathological process of HIE. Methods: In this study, we established a neonatal mouse hypoxic-ischemic brain damage (HIBD) model by the modified Rice method, and analyzed various metabolic pathways such as the tricarboxylic acid (TCA) cycle, purine metabolism, and lipid metabolism in the ischemic edema area, with contralateral and control brain tissues using matrix-assisted laser desorption mass spectrometry imaging (MALDI-MSI) with a spatial resolution of 50 μm. Results: In the HIBD model, key metabolites of the tricarboxylic acid (TCA) cycle (citrate, succinate, L-glutamate, glucose, aspartate, and glutamine) were significantly enriched in the edematous area compared with the control (fold change: 1.52–2.82), which suggests a blockage of mitochondrial function; ATP/ADP/AMP levels were reduced by 53–73% in the edematous area, and xanthine was abnormally accumulated in the hippocampus of the affected side, suggesting energy depletion and altered purine metabolism; lipid remodeling showed regional specificity: some unsaturated fatty acids, such as docosahexaenoic acid, were abnormally accumulated in the hippocampus. In contrast, pentadecanoic acid levels were reduced across the entire brain in the HIBD model, with a more pronounced decrease in the ipsilateral hippocampus, suggesting impaired membrane stability. Conclusions: The neonatal mouse HIBD model exhibits reprogramming of energy metabolism, characterized by a blockage in the tricarboxylic acid (TCA) cycle and ATP depletion, along with an abnormal spatial distribution of lipids. By targeting xanthine metabolic pathways, restoring mitochondrial function, and intervening in region-specific lipid remodeling, brain energy homeostasis may be improved and neurological damage attenuated. Further studies should validate the clinical feasibility of xanthine and lipid imbalance as diagnostic markers of HIBD and explore the critical time window for metabolic intervention to optimize therapeutic strategies. Full article

Heat stress (HS), an important environmental stressor for healthy poultry farming, has been shown to have a detrimental effect on production performance and induce serious diseases through immune system damage. As the avian peripheral immune system’s primary organ, spleen is subject to complex biological processes in response to HS injury. Histopathological characterization demonstrated that HS resulted in the destruction of the splenic red and white medulla, a decrease in cell density and organ atrophy. These changes directly impaired pathogen clearance and immune surveillance. At the physiological level, the impact of HS is characterized by disrupted metabolic homeostasis through interrupting neuroendocrine function. This, in turn, results in a significant suppression of humoral immune response. The oxidative-inflammatory cascade constitutes the core pathology of this disease. Energy metabolism disorder triggered by mitochondrial dysfunction and redox imbalance form a vicious circle, which promotes apoptosis signaling cascade. Meanwhile, over-activation of intrinsic immune system triggers a series of inflammatory factors, which further amplifies effects of tissue damage. The present prevention and control strategies are centered on synergistic anti-inflammatory and antioxidant interventions with nutrient modulators and plant actives. Nevertheless, it is imperative for future studies to incorporate multi-omics technologies in order to analyze the metabolic mechanisms and patterns of stress and establish a precise intervention strategy based on immune homeostatic regulation. This review systematically investigated the multilevel regulatory mechanisms of HS-induced spleen injury, which provides a theoretical basis for the mechanistic analysis and technological innovation of the prevention and control of HS syndrome in poultry. Full article

Heart failure represents the terminal stage in the development of many cardiovascular diseases, and its pathological mechanisms are closely related to disturbances in energy metabolism and mitochondrial dysfunction in cardiomyocytes. In recent years, nicotinamide adenine dinucleotide (NAD⁺), a core coenzyme involved in cellular energy metabolism and redox homeostasis, has been shown to potentially ameliorate heart failure through the regulation of mitochondrial function. This review systematically investigates four core mechanisms of mitochondrial dysfunction in heart failure: imbalance of mitochondrial dynamics, excessive accumulation of reactive oxygen species (ROS) leading to oxidative stress injury, dysfunction of mitochondrial autophagy, and disturbance of Ca²⁺ homeostasis. These abnormalities collectively exacerbate the progression of heart failure by disrupting ATP production and inducing apoptosis and myocardial fibrosis. NAD⁺ has been shown to regulate mitochondrial biosynthesis and antioxidant defences through the activation of the deacetylase family (e.g., silent information regulator 2 homolog 1 (SIRT1) and SIRT3) and to increase mitochondrial autophagy to remove damaged mitochondria, thus restoring energy metabolism and redox balance in cardiomyocytes. In addition, the inhibition of NAD⁺-degrading enzymes (e.g., poly ADP-ribose polymerase (PARP), cluster of differentiation 38 (CD38), and selective androgen receptor modulators (SARMs)) increases the tissue intracellular NAD⁺ content, and supplementation with NAD⁺ precursors (e.g., β-nicotinamide mononucleotide (NMN), nicotinamide riboside, etc.) also significantly elevates myocardial NAD⁺ levels to ameliorate heart failure. This study provides a theoretical basis for understanding the central role of NAD⁺ in mitochondrial homeostasis and for the development of targeted therapies for heart failure. Full article

Multiple sclerosis (MS) is a chronic autoimmune disease characterised by inflammation, demyelination, and neurodegeneration within the central nervous system. The pathogenesis of MS involves an immune-mediated attack on myelin and neurons, accompanied by blood–brain barrier dysfunction and chronic CNS inflammation. Central to MS pathology is dysregulation of the kynurenine pathway, which metabolises tryptophan into neuroactive compounds. Kynurenine pathway (KP) activation, driven by inflammatory cytokines, leads to the production of both neuroprotective (e.g., kynurenic acid, KYNA) and neurotoxic (e.g., quinolinic acid, QUIN) metabolites. Imbalance between these metabolites, particularly increased QUIN production, exacerbates glutamate excitotoxicity, oxidative stress, and mitochondrial dysfunction, contributing to neuronal and oligodendrocyte damage. Mitochondrial dysfunction plays a critical role in the pathophysiology of MS, exacerbating neurodegeneration through impaired energy metabolism and oxidative stress. This review integrates the current understanding of KP dysregulation in multiple sclerosis across disease stages. In RRMS, heightened KP activity correlates with inflammation and neuroprotection attempts through increased KYNA production. In contrast, SPMS and PPMS are associated with a shift towards a more neurotoxic KP profile, marked by elevated QUIN levels and reduced KYNA, exacerbating neurodegeneration and disability progression. Understanding these mechanisms offers insights into potential biomarkers and therapeutic targets for MS, emphasising the need for strategies to rebalance KP metabolism and mitigate neurotoxicity in progressive disease stages. Full article

Mitochondria play a central role in energy metabolism and continuously adapt through dynamic processes such as fusion and fission. When the balance between these processes is disrupted, it can lead to mitochondrial dysfunction and increased oxidative stress, contributing to the development and progression of various cardiometabolic diseases (CMDs). Their role is crucial in diabetes mellitus (DM), since their dysfunction drives β-cell apoptosis, immune activation, and chronic inflammation through excessive ROS production, worsening endogenous insulin secretion. Moreover, sympathetic nervous system activation and altered dynamics, contribute to hypertension through oxidative stress, impaired mitophagy, endothelial dysfunction, and cardiomyocyte hypertrophy. Furthermore, the role of mitochondria is catalytic in endothelial dysfunction through excessive reactive oxygen species (ROS) production, disrupting the vascular tone, permeability, and apoptosis, while impairing antioxidant defense and promoting inflammatory processes. Mitochondrial oxidative stress, resulting from an imbalance between ROS/Reactive nitrogen species (RNS) imbalance, promotes atherosclerotic alterations and oxidative modification of oxidizing low-density lipoprotein (LDL). Mitochondrial DNA (mtDNA), situated in close proximity to the inner mitochondrial membrane where ROS are generated, is particularly susceptible to oxidative damage. ROS activate redox-sensitive inflammatory signaling pathways, notably the nuclear factor kappa B (NF-κB) pathway, leading to the transcriptional upregulation of proinflammatory cytokines, chemokines, and adhesion molecules. This proinflammatory milieu promotes endothelial activation and monocyte recruitment, thereby perpetuating local inflammation and enhancing atherogenesis. Additionally, mitochondrial disruptions in heart failure promote further ischemic injury and excessive oxidative stress release and impair ATP production and Ca²⁺ dysregulation, contributing to cell death, fibrosis, and decreased cardiac performance. This narrative review aims to investigate the intricate relationship between mitochondrial dysfunction and CMDs. Full article

: Alzheimer’s disease (AD) is a neurodegenerative disorder closely associated with aging, and its pathogenesis involves the interaction of multidimensional pathophysiologic processes. This review outlines the core mechanisms linking aging and AD. The amyloid cascade hypothesis emphasizes that abnormal deposition of amyloid-β (Aβ) triggers neuronal damage and synaptic dysfunction, which is exacerbated by aging-associated declines in protein clearance. Neuroinflammation, a synergistic pathogenetic factor in AD, is mediated by microglia activation, creating a vicious cycle with Aβ and tau pathology. The cholinergic hypothesis states that the degeneration of cholinergic neurons in the basal forebrain can lead to acetylcholine deficiency, which is directly associated with cognitive decline. Endothelial disorders promote neuroinflammation and metabolic waste accumulation through blood–brain barrier dysfunction and cerebral vascular abnormalities. In addition, glutamate-mediated excitotoxicity and mitochondrial dysfunction (e.g., oxidative stress and energy metabolism imbalance) further lead to neuronal death, and aging-associated declines in mitochondrial autophagy exacerbate such damage. This review also explores the application of animal models that mimic AD and aging in studying these mechanisms and summarizes therapeutic strategies targeting these pathways. Future studies need to integrate multi-targeted therapies and focus on the role of the aging microenvironment in regulating AD pathology in order to develop more effective early diagnosis and treatment options. Full article

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. Full article

Type 2 diabetes is a significant risk factor for cardiovascular disease, particularly coronary heart disease, heart failure, and diabetic cardiomyopathy. Diabetic cardiomyopathy, characterized by heart dysfunction in the absence of coronary artery disease or hypertension, is triggered by various mechanisms, including hyperinsulinemia, insulin resistance, and inflammation. At the cellular level, increased insulin resistance leads to an imbalance in lipid and glucose metabolism, causing oxidative stress, mitochondrial dysfunction, and excess production of reactive oxygen species (ROS). This disrupts normal heart function, leading to fibrosis, hypertrophy, and cardiac remodeling. In diabetic patients, the excessive accumulation of fatty acids, advanced glycation end products (AGEs), and other metabolic disturbances further contribute to endothelial dysfunction and inflammatory responses. This inflammatory environment promotes structural damage, apoptosis, and calcium-handling abnormalities, resulting in heart failure. Additionally, diabetes increases the risk of arrhythmias, such as atrial fibrillation, which worsens cardiac outcomes. New insights into these molecular mechanisms have led to improvements in diabetes management, focusing on mitigating complications and understanding the cellular processes involved. Recent therapeutic advances, such as SGLT-2 inhibitors, have shown promise in addressing the energy imbalance and cardiac dysfunction seen in diabetic cardiomyopathy, offering new hope for better cardiovascular outcomes. Full article

This review examines the impact of heat stress (HS) on carcass traits, meat quality, and nutritional composition in monogastric animals, specifically poultry and swine, and evaluates targeted nutritional strategies for mitigation. With rising global temperatures and intensified heat waves, HS has emerged as a key threat to animal welfare, production efficiency, and meat quality. Physiological disturbances induced by HS, including oxidative stress, protein denaturation, mitochondrial dysfunction, and hormonal imbalances, contribute to reduced carcass yield, muscle degradation, and inferior sensory attributes such as tenderness, juiciness, and flavour. HS also diminishes the nutritional value of meat by depleting essential amino acids, polyunsaturated fatty acids, and antioxidant micronutrients. This review highlights nutritional interventions, including antioxidant supplementation (e.g., vitamin E, selenium, polyphenols), osmolytes (e.g., betaine, taurine), probiotics, prebiotics, and optimised energy-to-protein ratios, as promising tools to enhance thermotolerance and meat quality. Emerging feed additives such as phytochemicals also show potential for protecting muscle integrity and improving oxidative stability. Given species-specific responses and production system variability, integrating these dietary approaches with stage-specific management is essential for resilience under climate stress. Future research should focus on the precision nutrition, biomarker identification, and validation of synergistic nutritional strategies that safeguard performance and meat quality in monogastric production systems. Full article

Low back pain is a widespread condition that significantly impacts quality of life, with intervertebral disc degeneration (IDD) being a major contributing factor. However, the underlying mechanisms of IDD remain poorly understood, necessitating further investigation. Environmental risk factors, such as mechanical stress and cigarette smoke, elevate reactive oxygen species levels from both endogenous and exogenous sources, leading to redox imbalance and oxidative stress. The endoplasmic reticulum (ER) and mitochondria, two key organelles responsible for protein folding and energy production, respectively, are particularly vulnerable to oxidative stress. Under oxidative stress conditions, ER stress and mitochondrial dysfunction occur, resulting in unfolded protein response activation, impaired biosynthetic processes, and disruptions in the tricarboxylic acid cycle and electron transport chain, ultimately compromising energy metabolism. Prolonged and excessive ER stress can further trigger apoptosis through ER–mitochondrial crosstalk. Given the unique microenvironment of the intervertebral disc (IVD)—characterized by hypoxia, glucose starvation, and region-specific cellular heterogeneity—the differential effects of environmental stressors on distinct IVD cell populations require further investigation. This review explores the potential mechanisms through which environmental risk factors alter IVD cell activities, contributing to IDD progression, and discusses future therapeutic strategies aimed at mitigating disc degeneration. Full article