Search Results (124)

Ischemic stroke initiates a complex cascade of pathophysiological events—including energy failure, excitotoxicity, oxidative stress, inflammation, apoptosis, and mitochondrial dysfunction—that together lead to extensive neuronal damage. Effectively targeting these interconnected mechanisms is crucial for achieving neuroprotection. Alpinetin, known for its antioxidant, anti-inflammatory, and cytoprotective properties, has shown promise as a potential therapeutic agent for cerebral ischemia in preliminary studies. However, the exact molecular mechanisms underlying its neuroprotective effects remain unclear. Therefore, this study aimed to investigate the multifaceted actions of alpinetin in a preclinically relevant right middle cerebral artery occlusion (Rt.MCAO) rat model, focusing on its impact on neuronal survival, inflammation, oxidative stress, apoptosis, and mitochondrial function. Forty male Wistar rats were randomly assigned to four groups: sham operation, Rt.MCAO + vehicle, Rt.MCAO + piracetam (250 mg/kg BW), and Rt.MCAO + alpinetin (100 mg/kg BW). We examined glial cell morphology, protein kinase B (Akt) expression, mitochondrial superoxide dismutase (MnSOD), myeloperoxidase (MPO), anti-apoptotic proteins, mitogen-activated protein kinase (p38 MAPK) and mitofusin-2 (Mfn2). Treatment with alpinetin for 3 days exerted robust neuroprotective effects by significantly reducing astrocytic and microglial activation through the downregulation of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba-1), restoring Akt expression, decreasing MPO activity, and enhancing MnSOD activity. Additionally, alpinetin modulated apoptotic signaling by lowering pro-apoptotic markers Bcl-2 Associated X-protein (Bax) and caspase-3 while increasing the expression of the anti-apoptotic protein B-cell lymphoma-extra large (Bcl-XL). It also attenuated p38 MAPK activation and preserved mitochondrial integrity by mitigating the decline in Mfn2 levels. Overall, these findings highlight the therapeutic potential of alpinetin in targeting multiple pathological processes involved in ischemic brain injury, supporting its promise as an effective treatment for stroke. Full article

Background: Hypoxia-induced oxidative stress compromises the survival and function of transplanted islets, contributing to high rates of islet transplantation failure. Methods: This study investigated the small-molecule mitochondrial fusion agonist S89, which specifically activates mitofusin 1 (MFN1). We assessed its protective effects against hypoxia-induced oxidative stress and apoptosis in pancreatic β-cells. Results: In mouse insulinoma cells (Min6), S89 enhanced cell viability by promoting mitochondrial fusion to inhibit mitochondrial reactive oxygen species (mtROS) overaccumulation (S89 reduced mtROS by approximately 30%) and attenuated mitochondrial lipid peroxidation; furthermore, it suppressed hypoxia-induced apoptosis via downregulation of the BAX/BCL-2 ratio, thus protecting the cells from hypoxia-induced oxidative damage. Notably, S89 significantly potentiated glucose-stimulated insulin secretion (GSIS) in both the Min6 β-cell line and primary mouse islets. Critically, S89 pretreatment enhanced hypoxia resistance in islets and significantly increased graft survival upon transplantation into streptozotocin (STZ)-induced type 1 diabetic (T1D) mice, maintaining prolonged blood glucose homeostasis. Conclusions: These findings demonstrate that S89 protects β-cells from hypoxic injury, indicating its efficacy as a therapeutic approach for improving islet transplantation outcomes. Full article

Mono(2-ethylhexyl) phthalate (MEHP), a bioactive metabolite of di(2-ethylhexyl) phthalate (DEHP), has been detected in the placenta and urine of pregnant women and is linked to adverse pregnancy outcomes. However, its effects on mitochondrial homeostasis in trophoblast cells remain incompletely understood. This study examined the impact of MEHP (0.5–200 µM) on mitochondrial function, dynamics, and biogenesis in human HTR-8/SVneo trophoblast cells. MEHP (≥5 µM) reduced MTT conversion without compromising membrane integrity, suggesting early metabolic or redox imbalance. A dose-dependent loss of mitochondrial membrane potential was observed, with increased reactive oxygen species (ROS) generation only at 200 µM. MEHP modulated the expression of mitochondrial dynamics genes, with a more pronounced mitofusin 1 (MFN1) induction at low doses and increased mitochondrial DNA content, suggesting a compensatory response to mild stress. Conversely, high doses more strongly induced fission and mitochondrial 1 (FIS1) expression, suggesting mitochondrial fragmentation. Both concentrations induced the expression of the mitochondrial biogenesis regulators peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and nuclear factor erythroid 2–related factor 2 (Nrf2), while sirtuin 1 (SIRT1) expression and activity declined progressively with dose. These results demonstrate that MEHP disrupts mitochondrial homeostasis in trophoblast cells at concentrations spanning the estimated human exposure range. The dose-dependent effects, from adaptive responses to overt dysfunction, may help explain the associations between MEHP exposure and placental pathology observed in epidemiological studies. Full article

Lead (Pb) exposure poses a significant public health concern due to its neurotoxic effects. While mitochondrial dysfunction is implicated in lead neurotoxicity, the precise molecular mechanisms, particularly the role of non-coding RNA-mediated competing endogenous RNA networks, remain underexplored. SH-SY5Y neuroblastoma cells were treated with 10 μM lead acetate. Cell viability was assessed by Cell Counting Kit-8 (CCK-8). Mitochondrial ultrastructure and quantity were analyzed via transmission electron microscopy (TEM). Key mitochondrial dynamics proteins were examined by Western blot. Comprehensive transcriptome sequencing, including long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), microRNAs (miRNAs) and mRNAs, was performed followed by functional enrichment and ceRNA network construction. Selected RNAs and hub genes were validated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Lead exposure significantly reduced SH-SY5Y cell viability and induced mitochondrial damage (decreased quantity, swelling, fragmentation). Western blot confirmed an imbalance in mitochondrial dynamics, as indicated by decreased mitofusin 2 (MFN2), increased total and phosphorylated dynamin-related protein 1 (DRP1). Transcriptomic analysis revealed widespread differential expression of lncRNAs, circRNAs, miRNAs, and mRNAs. Enrichment analysis highlighted mitochondrial function and oxidative stress pathways. A ceRNA network identified five key hub genes: SLC7A11, FOS, HMOX1, HGF, and NR4A1. All validated RNA and hub gene expression patterns were consistent with sequencing results. Our study demonstrates that lead exposure significantly impairs mitochondrial quantity and morphology in SH-SY5Y cells, likely via disrupted mitochondrial dynamics. We reveal the potential regulatory mechanisms of lead-induced neurotoxicity involving ceRNA networks, identifying hub genes crucial for cellular stress response. This research provides a foundational framework for developing therapeutic strategies against lead-induced neurotoxicity. Full article

Background/Objectives: Epicardial adipose tissue (EAT) is metabolically active and is in dynamic crosstalk with the surrounding cardiomyocytes, modulating their function and metabolism. Oxidative stress is a key contributor to cell death and cardiac remodeling, is a hallmark of diabetes (DM) and cardiovascular disease, such as coronary artery disease (CAD). However, little is known about these processes in EAT from patients undergoing cardiac surgery. This study investigates changes in mitochondrial dynamics, reactive oxygen species (ROS) production, and antioxidant defense levels in EAT compared to subcutaneous adipose tissue (SAT) in patients undergoing cardiac surgery, with a focus on the impact of DM and CAD. Methods: Adipose tissue biopsies were collected from 128 patients undergoing surgical cardiac intervention. Mitochondrial dynamics and oxidative stress markers were analyzed. Results: EAT exhibited increased expression of mitochondrial fusion markers [mitofusin 1 (p ≤ 0.001), mitofusin 2 (p = 0.038), and optic atrophy 1 (p ≤ 0.001)], as well as fission markers [fission 1 (p ≤ 0.001) and dynamin-related protein 1 (p ≤ 0.001)] relative to SAT. Additionally, ROS levels (dihydroethidium, p = 0.004) were elevated, while lipid peroxidation (malondialdehyde, p ≤ 0.001) was reduced in EAT compared to SAT. Reduced glutathione (GSH) levels (p ≤ 0.001) and the redox buffer ratio between reduced and oxidized glutathione (GSH/GSSG, p ≤ 0.001) were significantly increased in EAT. Interestingly, glutathione peroxidase activity (p ≤ 0.001) and the antioxidant defense markers catalase (p ≤ 0.001) and superoxide dismutase 2 (p = 0.001) were significantly reduced in EAT compared to SAT. Conclusions: The findings provide a unique molecular insight into the mitochondrial dynamics and oxidative stress profiles of EAT, highlighting potential avenues for a novel diagnostic method and therapeutic strategies for cardiac disease. Full article

Cardiotoxicity related to anthracyclines and trastuzumab represents a significant clinical challenge in cancer therapy, often limiting treatment efficacy and patient survival. The underlying mechanisms of cardiotoxicity involve the activation of NLRP3 and the MyD88-dependent signaling pathway. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), such as inclisiran, are known for their lipid-lowering effects, but emerging data indicate that they may also exert pleiotropic benefits beyond cholesterol reduction. This study investigates whether inclisiran can mitigate the cardiotoxic effects of anthracyclines and trastuzumab through reduction of NLRP3 activation and MyD88 signaling, independently of its effects on dyslipidemia. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were exposed to subclinical concentrations of doxorubicin (1 µM) and trastuzumab in sequential therapy (200 nM), alone or in combination with inclisiran (100 nM) for 24 h. After the incubation period, we performed the following tests: determination of cardiomyocytes apoptosis, analysis of intracellular reactive oxygen species, lipid peroxidation products (including malondialdehyde and 4-hydroxynonenal), intracellular mitofusin-2 and Ca⁺⁺ levels. Troponin and BNP were quantified through selective ELISA methods. A confocal laser scanning microscope was used to study cardiomyocyte morphology and F-actin staining after treatments. Moreover, pro-inflammatory studies were also performed, including the intracellular expression of NLRP-3, MyD-88 and twelve cytokines/growth factors involved in cardiotoxicity (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL17-α, IFN-γ, TNF-α, G-CSF, GM-CSF). Inclisiran co-incubated with doxorubicin and trastuzumab exerts significant cardioprotective effects, enhancing cell viability by 88.9% compared to only DOXO/TRA treated cells (p < 0.001 for all). Significant reduction of oxidative stress, and intracellular levels of NLRP-3, MyD88, IL-1α, IL-1β, IL-6, IL-12, IL17-α, TNF-α, G-CSF were seen in the inclisiran group vs. only DOXO/TRA (p < 0.001). For the first time, PCSK9i inclisiran has been shown to exert significant anti-inflammatory effects to reduce anthracycline-HER-2 blocking agent-mediated cardiotoxicity through NLRP-3 and Myd-88 related pathways. The overall conclusions of the study warrant further investigation of the use of PCSK9i in primary prevention of CTRCD in cancer patients, independently from dyslipidemia. Full article

Mitochondria maintain cellular homeostasis through the dynamic balance of fusion and fission, which relies on nuclear-encoded mitochondrial fusion proteins, mitofusins 1 and 2 (Mfn1, Mfn2). Changes in Mfn1 and Mfn2 expression significantly affect mitochondrial fusion and fission, thereby affecting cellular metabolism. This study investigated the effect of Mfn1 expression on cell proliferation, apoptosis, and mitochondrial function by overexpressing Mfn1 (in OE-Mfn1 cells) and silencing Mfn1 using short hairpin RNA (shRNA) (in shMfn1 cells). Cell proliferation capacity, mitochondrial membrane potential, and mitochondrial ATP content were measured. To investigate the effects of Mfn1 on cellular metabolism and epigenetic modifications, the levels of metabolites α-KG, A-CoA, and SAM, as well as the levels of cellular methylation and acetylation, were detected by ELISA. Differentially expressed genes and metabolites were assessed by RNA-seq and LC-MS. This study demonstrates that alterations in Mfn1 gene expression can significantly affect mitochondrial metabolism and cell proliferation and apoptosis. In addition, Mfn1 affects the expression of genes encoding enzymes that are responsible for histone methylation and acetylation, thereby regulating these modifications. These findings provide a theoretical basis for further elucidation of the mechanisms by which Mfn1 affects cell proliferation, regulates metabolites, and modulates chromatin epigenetic modification. Full article

Stroke is still considered a predominant cause of morbidity and mortality, for which research on prevention and cure has been sought to prevent neuronal damage after a stroke incident. In this research, we evaluated the protective effects of virgin coconut oil (VCO) using behavioral, morphophysiological, and gene expression parameters using an ischemic stroke surgical rat model using Sprague Dawley (SD) rats. Eight-week-old SD rats were subjected to repeated oral administration (5 mL/kg/day) of either 1% Tween 80 or VCO. For behavioral and morphophysiological parameters, surgery was performed for each group, after which neurological scoring was performed at 4 h, 24 h, 48 h, 5 d, and 10 d. Further, hematological and brain morphology assessment was performed after euthanasia and necropsy of the animals. For gene expression studies, surgery was performed with animals sacrificed at different time points (baseline, before surgery, 4 h, 24 h, and 48 h after surgery) to collect the brain. Results of the study showed that there are differences in the neurological scores between the two treatments 24 h, 48 h, and 5 d after surgery. Brain morphology assessment also showed favorable results for VCO for infarct size, edema, and hypoxic neurons. Gene expression studies also showed positive results with an increase in the relative expression of angiogenin (Ang), angiopoietin (Angpt 1), Parkin, dynamin-related protein 1 (Drp 1), mitofusin 2 (Mfn 2), and mitochondrial rho (Miro) and decreased relative expression of caspase 3, receptor for advanced glycation end-product (Rage), and glyceraldehyde-3-phosphate dehydrogenase (Gapdh). In summary, the current study shows that VCO may have protective effects on the brain after stroke, which may be explained by the results of the gene expression studies. Full article

As high-quality sheep germplasm resources in China, Hu sheep are characterized by fast growth and development, high fecundity, and tolerance to drought and cold. Tibetan sheep, adapted to high-altitude environments, have developed strong environmental adaptability. To explore the differences in the interaction among rumen microbial flora, hepatic gluconeogenesis, and mitochondrial function between Tibetan sheep and Hu sheep in the Qinghai–Tibet Plateau, this study systematically compared and analyzed the rumen flora density, key enzyme activities related to hepatic gluconeogenesis and mitochondrial function, and the expression levels of related genes in Tibetan sheep and Hu sheep under identical feeding management conditions, followed by correlation analysis. The results showed that Hu sheep had significantly higher densities of Ruminobacteramylophilus (Ram) and Fibrobacter succinogenes (Fs) associated with starch and protein degradation (p < 0.01). The expression levels of Forkhead box O1 (FOXO1), pyruvate carboxylase (PC) activity, and adenosine triphosphate (ATP) content were also significantly higher than those in Tibetan sheep (p < 0.01). In contrast, Tibetan sheep had higher densities of Butyrivibrio fibrisolvens (Bf), Ruminococcus albus (Ra), Ruminococcus flavefaciens (Rf), etc., related to cellulose degradation (p < 0.01). The gluconeogenesis-related genes, Glucose-6-phosphatase catalytic subunit 1 (G6PC1) and phosphoenolpyruvate carboxykinase1 (PCK1), and the activities of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FBPase) were significantly higher in Tibetan sheep than in Hu sheep (p < 0.01). Mitochondrial function-related genes Mitofusin-1 (Mfn1), Mitofusin-2 (Mfn2), subunit 6 of ATP synthase (ATP6), cytochrome b (Cytb), etc., also showed significantly higher expression in Tibetan sheep (p < 0.01). While no significant differences were observed in the contents of citric acid (CA), pyruvic acid (PA), glucose (Glu), etc. (p > 0.05). Correlation analysis indicated that rumen flora was associated with the key enzyme activities and gene expressions of hepatic gluconeogenesis and mitochondrial function to varying degrees. In summary, Tibetan sheep exhibit strong fiber degradation capacity, the efficient utilization of gluconeogenic intermediates, and mitochondrial oxidative phosphorylation (OXPHOS) ability, forming adaptive strategies for high-altitude environments. By contrast, Hu sheep show efficient protein and starch degradation capacity, thereby enhancing the supply of gluconeogenic precursors. It is indicated that when introducing Hu sheep to high-altitude areas, dietary intervention can be used to regulate rumen microorganisms, such as increasing fiber-decomposing bacteria or enhancing mitochondrial oxidative capacity, to counteract metabolic limitations induced by hypoxia. Full article

Anthracyclines and human epidermal growth factor receptor 2 (HER-2) inhibitors are cornerstone therapies for breast cancer but are associated with significant cardiotoxicity. While sodium–glucose cotransporter 2 (SGLT2) inhibitors such as dapagliflozin have demonstrated cardio–renal protective effects during anthracycline treatment, their efficacy in preventing cardiotoxicity from sequential anthracycline and HER-2 blockade remains poorly understood. This study investigates the cardioprotective role of dapagliflozin in a preclinical model of chemotherapy-induced cardiotoxicity. Female C57Bl/6 mice were divided into four groups and treated for 10 days as follows: (1) a normal control group receiving saline (sham); (2) a model control group receiving doxorubicin (2.17 mg/kg/day for 5 days) followed by HER-2-blocking monoclonal antibody (2.25 mg/kg/day for 5 days); (3) a dapagliflozin-only group (10 mg/kg/day via oral gavage); and (4) a treatment group receiving the combination of doxorubicin, HER-2 inhibitor, and dapagliflozin. Cardiac function was assessed using echocardiography (VEVO 2100). Biomarkers of myocardial injury and inflammation (NLRP3, MyD88, CXCR4, H-FABP, troponin-T, and cytokines) were quantified via ELISA and immunohistochemistry. Circulating markers such as mitofusin-2, cardiac myosin light chain, malondialdehyde (MDA), and 4-hydroxy-2-nonenal (4-HNE) were also measured. Dapagliflozin significantly preserved the ejection fraction and reduced both radial and longitudinal strain impairment in mice treated with the doxorubicin–HER-2 inhibitor combination (p < 0.001). Levels of myocardial NLRP3, MyD88, CXCR4, H-FABP, interleukin-1β, and troponin-T were significantly lower in the dapagliflozin-treated group compared to the chemotherapy-only group. Serum markers of oxidative stress and cardiac injury, including mitofusin-2, MDA, 4-HNE, BNP, and high-sensitivity C-reactive protein (hs-CRP), were also reduced by dapagliflozin treatment. Our findings demonstrate that dapagliflozin effectively mitigates early cardiac dysfunction and injury in a preclinical model of sequential doxorubicin and HER-2 inhibitor therapy. Full article

L-Glutamate (L-Glu) and its salt derivatives are widely used in the food industry as flavor enhancers. Although the consumption of these compounds is generally considered safe, some studies suggest that chronically consuming L-Glu may be associated with various disorders. In this study, Wistar pregnant rats were treated daily with 1 g/L of L-Glu in their drinking water throughout the gestational period. OPA-1, DRP-1, and mitofusin 2—key proteins involved in mitochondrial fusion and fission—were analyzed by Western blot. The results showed that L-Glu exposure significantly decreased DRP-1 levels, while OPA-1 and mitofusin 2 levels were unaffected. This was accompanied by a notable decrease in mitochondrial complexes III and V. The activities of Mg²⁺-ATPase and Na⁺/K⁺-ATPase were also analyzed in fetal cerebellar plasma membranes. Maternal L-Glu intake significantly increased Mg²⁺-ATPase activity. Regarding Na⁺/K⁺-ATPase, the data showed that L-Glu exposure did not modulate the protein level or its activity. However, a positive interaction with glutamate receptors was observed in both activities, although neither AMPA nor NMDA receptors appeared to be involved. These results suggest that chronic maternal L-Glu intake during gestation modulates Mg²⁺-ATPase activity and protein markers of mitochondrial dynamics in the fetal cerebellum, which could affect neonatal development. Full article

Objective: Joint injury precipitates post-traumatic osteoarthritis (PTOA) via chondrocyte mitochondrial oxidative damage. Carbon monoxide (CO) is a small molecule with potent antioxidant and mitochondrial benefits in other tissues that have not been explored in healthy chondrocytes. We hypothesized that CO would subvert the mitochondrial effects of articular cartilage injuries upon resident chondrocytes. Design: We evaluated intra-articular delivery of a novel carbon monoxide-containing foam (COF). We used in vitro impact injuries to explore mitochondrial and redox endpoints after CO exposure. We then applied intra-articular injections of COF or control room air foam (RAF) to assess safety, efficacy, and other intra-articular responses. Results: COF increased the expression of HO1 and mitofusin-1 within 1 h and this increase was sustained for 12 h in vitro. COF increased chondrocyte mitochondrial respiration by 40% and increased reduced (not oxidized) thiols by 50% following in vitro injury to osteochondral explants. After cartilage injury, COF prevented the formation of 3-nitrotyrosine and the loss of articular chondrocyte mitochondria. When injected intra-articularly, COF was retained for 24 h post-injection in mouse stifle joints. It increased HO1 in those joints, enhanced reduced thiol levels in rabbit stifle joints, and exhibited no toxicity 1 and 4 weeks after injection. Conclusions: This study supports the hypothesis that CO functions as an antioxidant for articular chondrocytes by supporting mitochondria and intracellular GSH in the presence or absence of cartilage injury. Challenges in delivering exogenous CO have limited its preclinical development, but new CO-releasing materials like COF may enable new examinations of this promising small molecule. Full article

Background: Mitochondria are highly dynamic organelles that undergo fusion/fission dynamics, and emerging evidence has established that mitochondrial dynamics plays a crucial regulatory role in the process of viral infection. Nevertheless, the function of mitochondria dynamics during pseudorabies (PRV) infection remains uncertain. Methods: Our investigation commenced with examining PRV-induced alterations in mitochondrial dynamics, focusing on morphological changes and the expression levels of fusion/fission proteins. We then restored mitochondrial dynamics through Mfn1 (Mitofusin 1)/Mfn2 (Mitofusin 2) overexpression and mdivi-1 (mitochondrial division inhibitor-1) treatment to assess their impact on PRV replication and mitochondrial damage. Results: We found a downregulation of the mitochondrial fusion proteins Mfn1, Mfn2, and OPA1 (optic atrophy 1), along with the activation of the fission protein Drp-1 (dynamin-related protein 1) upon PRV infection. Restoring the function of mitochondrial fusion inhibited PRV infection. Furthermore, elevated mitochondrial membrane potential (MMP), decreased reactive oxygen species (ROS) levels, and an increased mitochondrial number were observed after overexpressing Mfns or treatment with mdivi-1. Conclusions: PRV infection impairs mitochondrial dynamics by altering mitochondrial fusion and fission proteins, and the promotion of Mfn-mediated mitochondrial fusion inhibits PRV replication. Full article

Vemurafenib is a BRAF (rapidly accelerated fibrosarcoma B-type)-targeted therapy used to treat patients with advanced, unresectable melanoma. It inhibits the MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated kinase) pathway and tumor proliferation in BRAF^V600E-mutated melanoma cells. Resistance to vemurafenib has been reported in melanoma patients due to secondary NRAS (neuroblastoma RAS viral oncogene homolog) mutations, which lead to paradoxical MAPK pathway activation and tumor proliferation. However, the impact of this paradoxical activation on mitochondrial dynamics and function in NRAS-mutated melanoma is unclear. Here, we investigated the effects of vemurafenib on NRAS^Q61R-mutated melanoma cells, focusing on mitochondrial dynamics and function. As expected, vemurafenib did not exhibit cytotoxicity in SK-MEL-147 NRAS^Q61R-mutated melanoma cells, even after 72 h of incubation. However, it significantly enhanced the MAPK/ERK signaling through paradoxical activation, accompanied by decreased expression of mitochondrial fusion proteins and activation of the fission protein DRP1 (dynamin-related protein 1), leading to small, rounded mitochondrial morphology. These observations were corroborated by transcriptome data obtained from NRAS-mutated melanoma patients, showing MFN1 (mitofusin 1) and OPA1 (optic atrophy 1) downregulation and DNM1L (DRP1 gene) upregulation. Interestingly, inhibition of mitochondrial fission with mdivi-1 or modulation of oxidative phosphorylation via respiratory chain inhibition or uncoupling significantly sensitized NRAS^Q61R-mutated melanoma cells to vemurafenib. Despite vemurafenib’s low cytotoxicity in NRAS-mutated melanoma, targeting mitochondrial dynamics and/or oxidative phosphorylation may offer a promising strategy for combined therapy. Full article

A prenatal low-protein (LP) diet disrupts glucose homeostasis in adult offspring. Skeletal muscles are one of the main sites of glucose clearance, and mitochondria residing in the muscle fibers are central to glucose homeostasis. Our previous studies indicated that impaired mitochondrial health is central to dysregulated glucose metabolism in the gastrocnemius muscle of the LP-programmed female rats. In addition, dysfunctional mitochondria are often an indicator of underlying irregularities in energy metabolism and metabolic inflexibility. Therefore, this study examined the mitochondrial function and metabolic flexibility in the skeletal muscles of prenatal LP-programmed adult male rats. Pregnant Wistar rats were randomly allotted to a control diet (20% protein) or an isocaloric LP diet (6% protein). Standard laboratory rat chow was given to the dams and the pups after delivery and weaning. Gene and protein expressions, mtDNA copy number, and electron microscopy were assessed in gastrocnemius (GS) muscle, and the mitochondrial oxygen consumption rate was determined using isolated flexor digitorum brevis muscle fibers. The genes associated with mitochondrial outer membrane fusion, mitofusin1 and 2 (Mfn1 and Mfn2), fission (Fis1), and biogenesis (Pgc1B, Nrf1, and Esrra) were lower in the LP group. Further, our functional studies showed that the ATP-linked oxygen consumption rate (OCR), maximal, spare respiratory, and non-mitochondrial respiration-associated OCRs were lower in the LP rats. Further, the mRNA and protein expressions of Ndufb8, a key factor involved in the complex-I catalytic activity, were downregulated in the LP group. In addition, the expression of genes linked to mitochondrial pyruvate transport (Mpc1) and metabolism (Pdha1) was lower in the LP group. In contrast, the expression of mitochondrial fatty acid transporters (Cpt1a and Cpt2) was higher in the LP when compared to the control group. However, electron microscopic analysis exhibited no difference in the mitochondrial ultrastructure in the LP muscle compared to the control. Altogether, our results indicate that the LP diet affects the mitochondrial complex-I integrity and dynamics and leads to altered expression of genes associated with substrate oxidation and mitochondrial dysfunction in the skeletal muscle of the male LP offspring. Full article