Gelsemium low doses protect against serum deprivation-induced stress on mitochondria in neuronal cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Gelsemium dynamized dilutions (GDD) are known as a remedy for a wide range of behavioral and psychological symptoms of depression and anxiety at ultra-low doses, yet the underlying mechanisms of the mode of action of G. sempervirens itself are not well understood. AIM OF THE STUDY: The present study was designed to examine the neuroprotective effects of Gelsemium preparations in counteracting stress-related mitochondrial dysfunctions in neuronal cells. MATERIALS AND METHODS: We started by studying how serum deprivation affects the mitochondrial functions of human neuroblastoma (SH-SY5Y) cells. Next, we looked into the potential of various Gelsemium dilutions to improve cell survival and ATP levels. After identifying the most effective dilutions, 3C and 5C, we tested their ability to protect SH-SY5Y cells from stress-induced mitochondrial deficits. We measured total and mitochondrial superoxide anion radicals using fluorescent dyes dihydroethidium (DHE) and the red mitochondrial superoxide indicator (MitoSOX). Additionally, we assessed total nitric oxide levels with 4,5-diaminofluorescein diacetate (DAF-2DA), examined the redox state using pRA305 cells stably transfected with a plasmid encoding a redox-sensitive green fluorescent protein, and analyzed mitochondrial network morphology using an automated high-content analysis device, Cytation3. Furthermore, we investigated bioenergetics by measuring ATP production with a bioluminescence assay (ViaLighTM HT) and evaluated mitochondrial respiration (OCR) and glycolysis (ECAR) using the Seahorse Bioscience XF24 Analyzer. Finally, we determined cell survival using an MTT reduction assay. RESULTS: Our research indicates that Gelsemium dilutions (3C and 5C) exhibited neuroprotective effects by: - Normalizing total and mitochondrial superoxide anion radicals and total nitric oxide levels. - Regulating the mitochondrial redox environment and mitochondrial networks morphology. - Increasing ATP generation as well as OCR and ECAR levels, thereby reducing the viability loss induced by serum withdrawal stress. CONCLUSIONS: These findings highlight that dynamized Gelsemium preparations may have neuroprotective effects against stress-induced cellular changes in the brain by regulating mitochondrial functions, essential for the survival, plasticity, and function of neurons in depression.

Differential Mobility Spectrometry-Based Cardiolipin Analysis.

Cardiolipins (CL) are special lipids in many respects. First of all, CL are composed of four fatty acids linked by two phosphatidic acids, which provide CL a unique molecular structure. Secondly, in eukaryotic cells they are specific to a single organelle, mitochondria, where they are also synthetized. CL are one of the most abundant lipid classes in mitochondria, mainly localized in the inner membrane. They are key determinants of mitochondrial health and homeostasis by modulating membrane integrity and fluidity, mitochondrial shapes, and metabolic pathways. Disturbances in mitochondrial CL composition can lead to tissue malfunction and diseases. It is therefore important to develop analytical tools to study the mitochondrial lipidome, and more particularly the CL. The method described here allows the quantification of cardiolipins at the sum composition level in isolated mitochondria or in liver tissue by flow injection analysis coupled to differential mobility spectrometry (FIA-DMS), also known as DMS-based shotgun lipidomics.

The evolving pathophysiology of TBI and the advantages of temporally-guided combination therapies.

Several clinical and experimental studies have demonstrated that traumatic brain injury (TBI) activates cascades of biochemical, molecular, structural, and pathological changes in the brain. These changes combine to contribute to the various outcomes observed after TBI. Given the breadth and complexity of changes, combination treatments may be an effective approach for targeting multiple detrimental pathways to yield meaningful improvements. In order to identify targets for therapy development, the temporally evolving pathophysiology of TBI needs to be elucidated in detail at both the cellular and molecular levels, as it has been shown that the mechanisms contributing to cognitive dysfunction change over time. Thus, a combination of individual mechanism-based therapies is likely to be effective when maintained based on the time courses of the cellular and molecular changes being targeted. In this review, we will discuss the temporal changes of some of the key clinical pathologies of human TBI, the underlying cellular and molecular mechanisms, and the results from preclinical and clinical studies aimed at mitigating their consequences. As most of the pathological events that occur after TBI are likely to have subsided in the chronic stage of the disease, combination treatments aimed at attenuating chronic conditions such as cognitive dysfunction may not require the initiation of individual treatments at a specific time. We propose that a combination of acute, subacute, and chronic interventions may be necessary to maximally improve health-related quality of life (HRQoL) for persons who have sustained a TBI.

Effect of alternative oxidase (AOX) expression on mouse cerebral mitochondria bioenergetics.

Alternative oxidase (AOX) is an enzyme that transfers electrons from reduced quinone directly to oxygen without proton translocation. When AOX from Ciona intestinalis is xenotopically expressed in mice, it can substitute the combined electron-transferring activity of mitochondrial complexes III/IV. Here, we used brain mitochondria from AOX-expressing mice with such a chimeric respiratory chain to study respiratory control bioenergetic mechanisms. AOX expression did not compromise the function of the mammalian respiratory chain at physiological conditions, however the complex IV inhibitor cyanide only partially blocked respiration by AOX-containing mitochondria. The relative fraction of cyanide-insensitive respiration increased at lower temperatures, indicative of a temperature-controlled attenuation of mammalian respiratory enzyme activity. As AOX does not translocate protons, the mitochondrial transmembrane potential in AOX-containing mitochondria was more sensitive to cyanide during succinate oxidation than during malate/pyruvate-supported respiration. High concentrations of cyanide fully collapsed membrane potential during oxidation of either succinate or glycerol 3-phosphate, but not during malate/pyruvate-supported respiration. This confirms AOX's electroneutral redox activity and indicates differences in the proton-translocating capacity of dehydrogenases upstream of the ubiquinone pool. Our respiration data refutes previous proposals for quinone partitioning within the supercomplexes of the respiratory chain, instead supporting the concept of a single homogeneous, freely diffusing quinone pool. Respiration with either succinate or glycerol 3-phosphate promotes reverse electron transfer (RET) towards complex I. AOX expression significantly decreased RET-induced ROS generation, with the effect more pronounced at low temperatures. Inhibitor-sensitivity analysis showed that the AOX-induced decrease in H2O2 release is due to the lower contribution of complex I to net ROS production during RET. Overall, our findings provide new insights into the role of temperature as a mechanism to control respiration and highlight the utility of AOX as a genetic tool to characterize both the distinct pathways of oxygen reduction and the role of redox control in RET.

Ultrastructural Features of Left Ventricle Cardiomyocytes in Preterm Newborn Rats.

The structure of left ventricular cardiomyocytes of 1 day preterm newborn rats was studied using transmission electron microscopy. It was shown that the relative area of the nucleus in cardiomyocytes of preterm rats is lower, and the relative area of the cytoplasm is higher than in full-term rats, while the relative areas of myofibrils and mitochondria do not differ. In cardiomyocytes of preterm rats damaged mitochondria, subsegmental myofibrillar contracture, and cytoplasmic swelling were found on the first postnatal day. Preterm birth in rats, in contrast to birth at term, is accompanied by the development of a number of ultrastructural damages in cardiomyocytes.

Type 2 diabetes mellitus and neurodegenerative disorders: The mitochondrial connection.

The incidence of type 2 diabetes mellitus (T2DM) has increased in our society in recent decades as the population ages, and this trend is not expected to revert. This is the same for the incidence of the main neurodegenerative disorders, including the two most common ones, which are, Alzheimer's and Parkinson's disease. Currently, no pharmacological therapies have been developed to revert or cure any of these pathologies. Interestingly, in recent years, an increased number of studies have shown a high co-morbidity between T2DM and neurodegeneration, as well as some common molecular pathways that are affected in both types of diseases. For example, while the etiopathology of T2DM and neurodegenerative disorders is highly complex, mitochondrial dysfunction has been broadly described in the early steps of both diseases; accordingly, this dysfunction has emerged as a plausible molecular link between them. In fact, the prominent role played by mitochondria in the mammalian metabolism of glucose places the physiology of the organelle in a central position to regulate many cellular processes that are affected in both T2DM and neurodegenerative disorders. In this collaborative review, we critically describe the relationship between T2DM and neurodegeneration; making a special emphasis on the mitochondrial mechanisms that could link these diseases. A better understanding of the role of mitochondria on the etiopathology of T2DM and neurodegeneration could pave the way for the development of new pharmacological therapies focused on the regulation of the physiology of the organelle. These therapies could, ultimately, contribute to increase healthspan.

Molecular composition of skeletal muscle in infants and adults: a comparative proteomic and transcriptomic study.

To gain a deeper understanding of skeletal muscle function in younger age and aging in elderly, identification of molecular signatures regulating these functions under physiological conditions is needed. Although molecular studies of healthy muscle have been conducted on adults and older subjects, there is a lack of research on infant muscle in terms of combined morphological, transcriptomic and proteomic profiles. To address this gap of knowledge, we performed RNA sequencing (RNA-seq), tandem mass spectrometry (LC-MS/MS), morphometric analysis and assays for mitochondrial maintenance in skeletal muscle biopsies from both, infants aged 4-28 months and adults aged 19-65 years. We identified differently expressed genes (DEGs) and differentially expressed proteins (DEPs) in adults compared to infants. The down-regulated genes in adults were associated with functional terms primarily related to sarcomeres, cellular maintenance, and metabolic, immunological and developmental processes. Thus, our study indicates age-related differences in the molecular signatures and associated functions of healthy skeletal muscle. Moreover, the findings assert that processes previously associated solely with aging are indeed part of development and healthy aging. Hence, combined findings of this study also indicate that age-dependent controls are crucial in muscle disease studies, as otherwise the comparative results may not be reliable.

Mitochondria-targeting Cu2-xSe-TPP with dual enzyme activity alleviates Alzheimer's disease by modulating oxidative stress.

Mitochondrial dysfunction in microglia has been implicated as a key pathogenesis of most neurodegenerative diseases including Alzheimer's disease (AD). Abnormal production of reactive oxygen species (ROS) and neuroinflammation caused by mitochondrial oxidative stress are important factors leading to neuronal death in AD. Herein, a "dual brake" strategy to synergistically halt mitochondrial dysfunction and neuroinflammation targeting mitochondria in microglia is proposed. To achieve this goal, (3-carboxypropyl) triphenyl-phosphonium bromide (TPP)-modified Cu2-xSe nanozymes (Cu2-xSe-TPP NPs) with dual enzyme-like activities was designed. Cu2-xSe-TPP NPs with superoxide dismutase-mimetic (SOD) and catalase-mimetic (CAT) activities can effectively scavenge ROS in the mitochondria of microglia and relieve mitochondrial oxidative stress. In vivo studies demonstrated that Cu2-xSe-TPP NPs can alleviate oxidative stress and promote neuroprotection in the hippocampus of AD model mice. In addition, Cu2-xSe-TPP NPs can regulate the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, promote Aß phagocytosis and reshape the AD inflammatory microenvironment, thus effectively attenuating AD neuropathology and rescuing cognitive deficits in AD model mice. Taken together, this strategy preventing mitochondrial damage and remodeling the inflammatory microenvironment will provide a new perspective for AD therapy.

Longitudinal autophagy profiling of the mammalian brain reveals sustained mitophagy throughout healthy aging.

Mitophagy neutralizes mitochondrial damage, thereby preventing cellular dysfunction and apoptosis. Defects in mitophagy have been strongly implicated in age-related neurodegenerative disorders such as Parkinson's and Alzheimer's disease. While mitophagy decreases throughout the lifespan of short-lived model organisms, it remains unknown whether such a decline occurs in the aging mammalian brain-a question of fundamental importance for understanding cell type- and region-specific susceptibility to neurodegeneration. Here, we define the longitudinal dynamics of basal mitophagy and macroautophagy across neuronal and non-neuronal cell types within the intact aging mouse brain in vivo. Quantitative profiling of reporter mouse cohorts from young to geriatric ages reveals cell- and tissue-specific alterations in mitophagy and macroautophagy between distinct subregions and cell populations, including dopaminergic neurons, cerebellar Purkinje cells, astrocytes, microglia and interneurons. We also find that healthy aging is hallmarked by the dynamic accumulation of differentially acidified lysosomes in several neural cell subsets. Our findings argue against any widespread age-related decline in mitophagic activity, instead demonstrating dynamic fluctuations in mitophagy across the aging trajectory, with strong implications for ongoing theragnostic development.

ER-mitochondria contact sites regulate hepatic lipogenesis via Ip3r-Grp75-Vdac complex recruiting Seipin.

BACKGROUND: Mitochondria and endoplasmic reticulum (ER) contact sites (MERCS) constitute a functional communication platform for ER and mitochondria, and they play a crucial role in the lipid homeostasis of the liver. However, it remains unclear about the exact effects of MERCs on the neutral lipid synthesis of the liver. METHODS: In this study, the role and mechanism of MERCS in palmitic acid (PA)-induced neutral lipid imbalance in the liver was explored by constructing a lipid metabolism animal model based on yellow catfish. Given that the structural integrity of MERCS cannot be disrupted by the si-mitochondrial calcium uniporter (si-mcu), the MERCS-mediated Ca2+ signaling in isolated hepatocytes was intercepted by transfecting them with si-mcu in some in vitro experiments. RESULTS: The key findings were: (1) Hepatocellular MERCs sub-proteome analysis confirmed that, via activating Ip3r-Grp75-voltage-dependent anion channel (Vdac) complexes, excessive dietary PA intake enhanced hepatic MERCs. (2) Dietary PA intake caused hepatic neutral lipid deposition by MERCs recruiting Seipin, which promoted lipid droplet biogenesis. (3) Our findings provide the first proof that MERCs recruited Seipin and controlled hepatic lipid homeostasis, depending on Ip3r-Grp75-Vdac-controlled Ca2+ signaling, apart from MERCs's structural integrity. Noteworthy, our results also confirmed these mechanisms are conservative from fish to mammals. CONCLUSIONS: The findings of this study provide a new insight into the regulatory role of MERCS-recruited SEIPIN in hepatic lipid synthesis via Ip3r-Grp75-Vdac complex-mediated Ca2+ signaling, highlighting the critical contribution of MERCS in hepatic lipid homeostasis.

Temporal alterations of the nascent proteome in response to mitochondrial stress.

Under stress, protein synthesis is attenuated to preserve energy and mitigate challenges to protein homeostasis. Here, we describe, with high temporal resolution, the dynamic landscape of changes in the abundance of proteins synthesized upon stress from transient mitochondrial inner membrane depolarization. This nascent proteome was altered when global translation was attenuated by stress and began to normalize as translation was recovering. This transition was associated with a transient desynchronization of cytosolic and mitochondrial translation and recovery of cytosolic and mitochondrial ribosomal proteins. Further, the elongation factor EEF1A1 was downregulated upon mitochondrial stress, and its silencing mimicked the stress-induced nascent proteome remodeling, including alterations in the nascent respiratory chain proteins. Unexpectedly, the stress-induced alterations in the nascent proteome were independent of physiological protein abundance and turnover. In summary, we provide insights into the physiological and pathological consequences of mitochondrial function and dysfunction.

Design and synthesis of novel mitochondria-targeted ergosterol peroxide derivatives as potential anti-cancer agents.

Ergosterol peroxide (EP) is a natural steroid compound that has been reported to have significant antitumor activity. However, its poor water solubility and cellular uptake mean that it has weak efficacy against tumor cells. Herein, we designed and synthesized a series of EP derivatives with mitochondrial targeting properties. Of these, compound 15a showed an IC50 value of 0.32 µM against MCF-7 cells, which was 67-fold higher than that of the parental EP (IC50 = 21.46 µM), and was better than cisplatin (IC50 = 4.23 µM), had a selectivity index of 25.28 (IC50MCF-10A/IC50MCF-7). Additionally, compound 15a promoted an increase in intracellular reactive oxygen species levels and a decrease in mitochondrial membrane potential, and blocked the cell cycle in the G0/G1 phase. In a mouse model of breast cancer, 15a showed 89.85 % tumor inhibition at a dose of 20 mg/kg, which is similar to the therapeutic effect of the cisplatin. On the basis of these results, 15a could be considered for further preclinical evaluation for cancer therapy.

Mitochondrial dysfunction in diabetic neuropathy: Impaired mitophagy triggers NLRP3 inflammasome.

Diabetic neuropathy is one of the challenging complications of diabetes and is characterized by peripheral nerve damage due to hyperglycemia in diabetes. Mitochondrial dysfunction is reported as a key pathophysiological factor contributing to nerve damage in diabetic neuropathy, clinically manifesting as neurodegenerative changes, as well as functional and sensorimotor deficits. Accumulating evidence suggests a clear correlation between mitochondrial dysfunction and NLRP3 inflammasome activation. Unraveling deeper molecular aspects of mitochondrial dysfunction may provide stable and effective therapeutic alternatives. This review links mitochondrial dysfunction and appraises its role in the pathophysiology of diabetic neuropathy. We also tried to delineate the role of mitophagy in NLRP3 inflammasome activation in experimental diabetic neuropathy.

New insight for SS­31 in treating diabetic cardiomyopathy: Activation of mitoGPX4 and alleviation of mitochondria­dependent ferroptosis.

SS­31 is a mitochondria­targeting antioxidant that exhibits promising therapeutic potential for various diseases; however, its protective effect on diabetic cardiomyopathy (DCM) remains to be elucidated. At present, SS­31 is considered not only to mitigate cardiolipin oxidative damage, but also to alleviate ferroptosis. The present study aimed to explore SS­31 as a potential therapeutic strategy for improving DCM by alleviating mitochondria­dependent ferroptosis. In vitro, H9C2 cells were exposed to 35 mM glucose for 24 h to induce high glucose damage, then were simultaneously treated with 10, 20 or 50 µM SS­31. In addition, in vivo studies were conducted on diabeticC57BL/6J mice, which were induced to develop DCM over 4 weeks, followed by intraperitoneal injections with 2.5 mg/kg/day SS­31 for a further 4 weeks. The elevation of serum lactate dehydrogenase and creatine kinase isoenzymes, the reduction of fractional shortening and ejection fraction, the rupture of myocardial fibers and the deposition of collagen indicated the establishment of the DCM mouse model. The results of the present study indicated that SS­31 effectively alleviated these pathological changes and exhibited significant efficacy in ameliorating mitochondrial dysfunction, such as by promoting adenosine triphosphate generation, improving mitochondrial membrane potential and restoring the mitochondrial ultrastructure. Further experiments suggested that activation of the mitochondrial glutathione (mitoGSH)/mitochondrial glutathione peroxidase 4 (mitoGPX4) pathway and the elimination of mitochondrial ferrous ions may constitute the mechanisms by which SS­31 treats DCM. Therefore, the present study revealed that mitochondria­dependent ferroptosis could serve as a pathogenic mechanism of DCM and highlighted that the cardioprotective effects of SS­31 against DCM involves activation of the mitoGSH/mitoGPX4 pathway. Due to the safety profile and cardiac protective effects of SS­31, SS­31 was considered a promising strategy for treating DCM.

Metabolic impairments in neurodegeneration with brain iron accumulation.

Neurodegeneration with brain iron accumulation (NBIA) is a broad, heterogeneous group of rare inherited diseases (1-3 patients/1,000,000 people) characterized by progressive symptoms associated with excessive abnormal iron deposition in the brain. Approximately 15,000-20,000 individuals worldwide are estimated to be affected by NBIA. NBIA is usually associated with slowly progressive pyramidal and extrapyramidal symptoms, axonal motor neuropathy, optic nerve atrophy, cognitive impairment and neuropsychiatric disorders. To date, eleven subtypes of NBIA have been described and the most common ones include pantothenate kinase-associated neurodegeneration (PKAN), PLA2G6-associated neurodegeneration (PLAN), mitochondrial membrane protein-associated neurodegeneration (MPAN) and beta-propeller protein-associated neurodegeneration (BPAN). We present a comprehensive overview of the evidence for disturbed cellular homeostasis and metabolic alterations in NBIA variants, with a careful focus on mitochondrial bioenergetics and lipid metabolism which drives a new perspective in understanding the course of this infrequent malady.

Hypoxia-induced mitochondrial fission regulates the fate of bone marrow mesenchymal stem cells by maintaining HIF1α stabilization.

For mesenchymal stem cells derived from bone marrow, a controlled reduction in ambient oxygen concentration has been recognized as a facilitator of osteogenic differentiation and the formation of calcium nodules. However, the specific molecular mechanisms underlying this phenotype remain unclear. The aim of this study was to elucidate the impact of hypoxia on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and to explore the involvement of mitophagy and the regulation of mitochondrial dynamics mediated by the mitochondrial dynamic regulatory factor FUN14 domain-containing 1 (FUNDC1). Our findings suggest that FUNDC1 is required for promoting osteogenic differentiation in BMSCs under hypoxic conditions. However, this effect was not dependent on FUNDC1-mediated mitophagy but rather on FUNDC1-mediated regulation of mitochondrial fission. At the mechanistic level, FUNDC1 binds more DNM1L and less OPA1 under hypoxic conditions, leading to an upsurge in mitochondrial division. This heightened mitochondrial division culminates in the increased translocation of Parkin to mitochondria, diminishing its interactions with HIF1α in the cytoplasm and consequently facilitating HIF1α deubiquitination and stabilization. In summary, FUNDC1-regulated mitochondrial division in hypoxic culture emerges as a critical determinant for the translocation of Parkin to mitochondria, ultimately maintaining HIF1α stabilization and promoting osteogenic differentiation.

Downregulation of glucose-energy metabolism via AMPK signaling pathway in granulosa cells of diminished ovarian reserve patients.

Glucose metabolism plays a crucial role in the function of granulosa cells (GCs) and the development of follicles. In cases of diminished ovarian reserve (DOR), alterations in these processes can impact female fertility. This study aims to investigate changes in glucose-energy metabolism in GCs of young DOR patients aged 20 to 35 years and their correlation with the onset and progression of DOR. 72 DOR cases and 75 women with normal ovarian reserve (NOR) as controls were included based on the POSEIDON and Bologna criteria. Samples of GCs and follicular fluid (FF) were collected for a comprehensive analysis involving transcriptomics, metabolomics, RT-qPCR, JC-1 staining, and flow cytometry. The study identified differentially expressed genes and metabolites in GCs of DOR and NOR groups, revealing 7 common pathways related to glucose-energy metabolism, along with 11 downregulated genes and 14 metabolites. Key substances in the glucose-energy metabolism pathway, such as succinate, lactate, NADP, ATP, and ADP, showed decreased levels, with the DOR group exhibiting a reduced ADP/ATP ratio. Downregulation of genes involved in glycolysis (HK, PGK, LDH1), the TCA cycle (CS), and gluconeogenesis (PCK) was observed, along with reduced glucose content and expression of glucose transporter genes (GLUT1 and GLUT3) in DOR GCs. Additionally, decreased AMPK pathway activity and impaired mitochondrial function in DOR suggest a connection between mitochondrial dysfunction and disrupted energy metabolism. Above all, the decline in glucose-energy metabolism in DOR is closely associated with its onset and progression. Reduced glucose uptake and impaired mitochondrial function in DOR GCs lead to internal energy imbalances, hindering the AMPK signaling pathway, limiting energy production and supply, and ultimately impacting follicle development and maturation.

Myeloid PGC1ß attenuates high-fat-diet induced inflammation via mitochondrial fission/mtDNA/Nlrp3 pathway.

Peroxisome proliferator-activated receptor gamma coactivators 1ß (PGC1ß) is essential in mitochondrial oxidative phosphorylation and alternative macrophages activation. To determine the contribution of PGC1ß in obesity induced inflammation, Ppargc1b (PGC1ß coding gene) myeloid conditional knockout mice (cKO) were fed with high fat diet (HFD) to examine the following effects. We found that HFD-fed cKO mice gained more fat with increased serum triglyceride (TG), low density lipoprotein (LDL), adiponectin, and leptin. Adipogenesis was stimulated while lipolysis was retarded in HFD-fed cKO mice adipose. Gluconeogenesis, lipogenesis, and fatty acid uptake were provoked while lipolysis was inhibited in HFD-fed cKO liver. Serum alanine transaminase (ALT) level, indicating fatty liver, also increased. Inflammatory cytokine including tumor necrosis factor-α (TNF-α), IL-1ß, and IL-6 was elevated in cKO mice, accompanied with glucose intolerant and insulin resistance. Energy expenditure was decreased in HFD-fed cKO mice. Further evidence showed that cKO macrophages were prone to repolarize into M1 inflammatory type in vitro. In addition to mitochondrial biogenesis and oxidative respiration, PGC1ß also modulated mitochondrial fission and cytosolic mitochondrial DNA (mtDNA) release, contributing to NLR family pyrin domain containing 3 (Nlrp3) inflammasome priming and activation. Treatment of mitochondrial fission inhibitor abolished the increased mRNA levels of Nlrp3 and IL-1ß induced by PGC1ß depletion. Nlrp3 knockdown restored the induced IL-1ß mRNA expression by PGC1ß deficiency. Myeloid PGC1ß regulated adipocyte adipogenesis and lipolysis. PGC1ß loss-of-function and mtDNA abundance correlated with obesity and diabetes. These observations uncovered the protective role of PGC1ß against obesity induced systemic inflammation. Enhancing myeloid PGC1ß function may be a potential strategy for the intervention of obesity and related diseases.

Prenatal and progressive coenzyme Q10 administration to mitigate muscle dysfunction in mitochondrial disease.

BACKGROUND: ADCK genes encode aarF domain-containing mitochondrial kinases involved in coenzyme Q (CoQ) biosynthesis and regulation. Haploinsufficiency of ADCK2 in humans leads to adult-onset physical incapacity with reduced mitochondrial CoQ levels in skeletal muscle, resulting in mitochondrial myopathy and alterations in fatty acid ß-oxidation. The sole current treatment for CoQ deficiencies is oral administration of CoQ10, which causes only partial recovery with postnatal treatment, underscoring the importance of early diagnosis for successful intervention. METHODS: We used Adck2 heterozygous mice to examine the influence of this gene on muscle structure, function and regeneration throughout development, growth and ageing. This investigation involved techniques including immunohistochemistry, analysis of CoQ levels, mitochondrial respiratory content, muscle transcriptome analysis and functional tests. RESULTS: We demonstrated that Adck2 heterozygous mice exhibit defects from embryonic development, particularly in skeletal muscle (1102 genes deregulated). Adck2 heterozygous embryos were 7% smaller in size and displayed signs of delayed development. Prenatal administration of CoQ10 could mitigate these embryonic defects. Heterozygous Adck2 mice also showed a decrease in myogenic cell differentiation, with more severe consequences in 'aged' mice (41.63% smaller) (P < 0.01). Consequently, heterozygous Adck2 mice displayed accelerated muscle wasting associated with ageing in muscle structure (P < 0.05), muscle function (less grip strength capacity) (P < 0.001) and muscle mitochondrial respiration (P < 0.001). Furthermore, progressive CoQ10 administration conferred protective effects on mitochondrial function (P < 0.0001) and skeletal muscle (P < 0.05). CONCLUSIONS: Our work uncovered novel aspects of CoQ deficiencies, revealing defects during embryonic development in mammals for the first time. Additionally, we identified the gradual establishment and progression of the deleterious Adck2 mouse phenotype. Importantly, CoQ10 supplementation demonstrated a protective effect when initiated during development.

Lysosomal disruption, mitochondrial impairment, histopathological and oxidative stress in rat's nervous system after exposure to a neonicotinoid (imidacloprid).

Imidacloprid (IMI), a neonicotinoid pesticide, has been widely used due to its high efficiency against insect pests. However, its prolonged exposure may pose significant risks to non-target organisms, including mammals. Recent studies have raised concerns about its potential neurotoxicity, yet the underlying mechanisms remain poorly understood. This study aimed to assess the neurotoxic effects of chronic Imidacloprid exposure in Wistar rats, focusing on oxidative stress, mitochondrial dysfunction, and lysosomal disruption. Wistar rats were orally administered two doses of Imidacloprid (5 mg/kg and 50 mg/kg body weight) for three months. Neurotoxic effects were assessed by measuring key biochemical markers such as the enzymatic activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and glutathione S-transferase (GST). Non-enzymatic markers, including glutathione (GSH) levels and malondialdehyde (MDA) index, were also evaluated. Mitochondrial function was assessed by analyzing oxygen consumption, swelling, and membrane permeability and histopathological changes. Lysosomal stability was examined using the Neutral Red Retention Time (NRRT) assay. Neutral red is a dye that accumulates in the acidic environment of lysosomes. Healthy lysosomes retain the dye, while compromised lysosomes lose it, indicating destabilization. By measuring the amount of neutral red retained in lysosomes, the NRRT assay assesses lysosomal integrity. Lysosomal pH variations were also monitored to evaluate functional changes. Microscopic analysis provided insight into structural changes in lysosomes and other cell components. Lysosomal destabilization was further confirmed by morphological alterations observed through light microscopy, revealing a progressive, time-dependent degeneration of lysosomal structures, including lysosomal expansion, neutral red dye leakage, and cell rounding. These changes reflected a temporal evolution of lysosomal damage, progressing from minor structural disruptions to more severe alterations as exposure continued, observable at the microscopic level. During the study, clinical observations of intoxicated rats included symptoms such as lethargy, reduced activity levels, and impaired motor coordination. High-dose Imidacloprid exposure led to noticeable behavioral changes, including decreased exploratory behavior and altered grooming patterns. Additionally, signs of neurotoxic effects, such as tremors or ataxia, were observed in the rats exposed to the higher dose, reflecting the systemic impact of chronic pesticide exposure. The results revealed a significant decrease in the enzymatic activities of CAT, GPx, and SOD, accompanied by an increase in GST activity. A notable reduction in glutathione levels and a rise in MDA index were observed, indicating enhanced oxidative stress in the brain. Mitochondrial impairment was evidenced by disturbances in oxygen consumption, increased swelling, and altered membrane permeability. Lysosomal destabilization was confirmed by reduced retention of neutral red dye, structural changes in lysosomes, and a significant rise in lysosomal pH in the IMI-exposed groups. In addition, the histopathological features indicate that imidacloprid at the given dose and exposure duration may have caused notable neurotoxic effects in Wistar rat brain tissue. Chronic exposure to Imidacloprid induces oxidative stress, mitochondrial dysfunction, lysosomal disruption and histopathological alterations in the central nervous system of Wistar rats. These findings provide valuable insights into the neurotoxic mechanisms of neonicotinoid pesticides, highlighting the need for further research to understand the long-term effects of Imidacloprid exposure on mammalian health.