Search Results (359)

While antiretroviral therapy (ART) has significantly improved the morbidity of HIV infection, ART may contribute to the pathogenesis of HIV associated neurocognitive impairment (HIV-NCI) by interfering with autophagic processes in astrocytes. Autophagy and mitophagy remove unwanted/damaged material and mitochondria from the intracellular environment, respectively. Dysregulated autophagy in astrocytes, abundant CNS cells with crucial homeostatic functions, contributes to many neurodegenerative diseases. Few studies have examined effects of ART on autophagy in astrocytes. We treated primary human astrocytes with a common ART regimen and performed LC3B-II and p62 turnover assays. ART significantly inhibited both LC3B-II and p62 turnover. Since p62, one autophagy receptor that mediates mitophagy, autophagic clearance of mitochondria, turnover was inhibited, we also examined mitophagy. While ART decreased BNIP3L/Nix homodimers, there were no changes in PINK1, Parkin, Mt-CO2, mitochondrial mass, or mitochondria–lysosome colocalization, indicating that ART did not inhibit mitophagy. We show that antiretroviral drugs have distinct effects on autophagic processes in astrocytes, which represents an alteration in their homeostasis, a major function of autophagy. This likely contributes to HIV-NCI. Understanding these impacts is important for improving ART for PWH, who have, by necessity, ongoing ART exposure. It also facilitates development of therapies for HIV-NCI that may include modulation of autophagy. Full article

Chronic binge drinking is common among patients with alcohol-associated steatohepatitis. Therefore, we tested the hypothesis that chronic binge ethanol exposure disrupts mitophagic processing and stimulates release of mitochondrial damage-associated molecular patterns (mtDAMPs), thereby promoting hepatic inflammation and fibrosis after chronic binge ethanol (CBE) exposure in mice using the National Institute of Alcohol Abuse and Alcoholism model. After CBE, hepatic steatosis, liver injury, inflammation, and hepatic stellate cell (HSC) activation occurred. Alda-1, an aldehyde dehydrogenase-2 activator, attenuated these changes. After CBE, mitochondrial depolarization (mtDepo) occurred in ~85% hepatocytes, and mitophagy-associated proteins increased, which Alda-1 blunted. By contrast, transcription factor-EB (master regulator of lysosomal biogenesis) and lysosomal markers decreased, indicating disrupted lysosomal processing. After mitophagy, mitochondrial biogenesis (MB) restores mitochondrial mass and function. After CBE, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (MB regulator), mitochondrial transcription factor-A, oxidative phosphorylation proteins, and fatty acid oxidation all decreased, which Alda-1 largely restored. After CBE, serum mtDAMPs (mitochondrial DNA and cytochrome c) increased 3- to 10-fold. In vitro, mitochondrial DNA stimulated macrophage and HSC activation, which was prevented by toll-like receptor-9 inhibition. In conclusion, CBE increases mtDepo in an acetaldehyde-dependent fashion, leading to mitophagic overburden, disruption of mitochondrial homeostasis, mtDAMP release, and ultimately development of liver inflammation and injury. Full article

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in pigs. Virulence factors, such as colonization factors and enterotoxins, bind to specific receptors on intestinal epithelial cells (IECs), impairing the integrity of the IEC barrier by inducing cell death. Pyroptosis is a newly discovered form of programmed cell death (PCD), which is widely involved in the pathogenesis of multiple infectious gastrointestinal diseases. However, it is still unclear whether pyroptosis contributes to the ETEC-mediated damage of IECs. This study demonstrated that ETEC infection activated NLRP3 inflammasome and triggered gasdermin D (GSDMD)-executed pyroptosis of mouse IECs in vitro and in vivo. Mechanistically, ETEC infection triggered endoplasmic reticulum (ER) stress response to increase the expression of thioredoxin-interacting protein (TXNIP) by upregulation of C/EBP homologous protein (CHOP), which subsequently activated NLRP3 inflammasome. Removal of ER stress by tauroursodeoxycholic acid (TUDCA) alleviated the pyroptosis of IECs that was caused by ETEC infection. In addition, the induced ER stress impaired mitochondria and led to mitochondrial reactive oxygen species (mtROS) overproduction and cytosolic release of mitochondrial DNA (mtDNA), which activated STING, another factor that contributed to ETEC-triggered pyroptosis. Chemical inhibition of STING attenuated ETEC-induced pyroptosis of IECs. Collectively, this study demonstrated that the activation of the STING/ER stress/mitochondrial impairment/NLRP3 inflammasome axis is a critical pathway in the ETEC infection-derived pyroptosis of IECs. Hence, targeting ER stress response may serve as a promising therapeutic strategy to prevent ETEC infection caused damage to IECs. Full article

Grain legume crops are rich in nutritional value and play a crucial role in global food sustainability. Like many other crops, they are affected by various abiotic stresses that reduce yield and seed quality, thereby threatening food security. Several strategies have been proposed to mitigate these effects and enhance yield. Among them, the use of biostimulants offers a sustainable and efficient approach to improving stress tolerance in the short term. However, the molecular mechanisms underlying the effects of individual or combined molecules remain poorly understood and could significantly influence the development of edited crops with enhanced stress tolerance in the long term. Melatonin (MT) has emerged as a versatile biostimulant, providing multiple benefits across different crop species. Given its key role in plant physiological processes, along with endogenous production, receptor identification, and signaling functions, it has been suggested to act as a hormone-like molecule. Nonetheless, the molecular response triggered by its application remains under investigation, particularly in grain legume species. This review explores the current state of MT applications for alleviating abiotic stress in grain legume crops, with emphasis on drought, salinity, metals/metalloids, and heat stress. We integrate biochemical, molecular, and physiological evidence to highlight the main scientific gaps regarding MT function in grain legumes. Finally, we discuss the biotechnological prospects of combining MT with modern breeding tools, as well as strategies for its delivery and sustainable production. Full article

Background: The pathogenesis of developing gestational diabetes mellitus (GDM) integrated with pregnancy-specific urinary incontinence (PSUI) may be related to immunological and hormonal factors. Inflammatory cytokines influence the function and regulation of the urinary tract, and changes in melatonin concentration are a predisposing factor for smooth muscle dysfunction and cystometric changes. Objective: This study examines the influence of melatonin, MT1 and MT2 receptors, and inflammatory cytokines in the blood and urine of pregnant women with GDM and PSUI. Methods: Two hundred sixty-nine pregnant women were approached during the diagnostic investigation of GDM and answered a specifically structured questionnaire about the involuntary loss of urine. According to these criteria, mothers were divided into four groups: continent normoglycemic (NG-C), incontinent normoglycemic (NG-I), continent GDM (GDM-C), and incontinent GDM (GDM-UI). Blood and urine samples were collected to determine the levels of melatonin, melatonin sulfate, melatonin receptors (MT1 and MT2), and inflammatory cytokines. Results: Blood level of melatonin and IL-10 was lower, but MT1, MT2, IL-1β, IL-8, and TNF-α were higher in GDM-UI compared with the NG-C group. The melatonin sulfate level was lower in the urine of the GDM-UI group compared with the NG-C group. Conclusions: Maternal hyperglycemia associated with urinary incontinence generates an inflammatory environment characterized by reduced melatonin and IL-10 and increased IL-1β, IL-8, and TNF-α in the blood of mothers with GDM with UI. This environmental condition may be involved in the pathogenesis of these pathologies. Full article

Mitochondrial transcription factor A (TFAM) is essential for mitochondrial DNA (mtDNA) maintenance and function, but its role in glioblastoma (GBM) remains largely unexplored. Analysis of patient astrocytomas and TCGA datasets has revealed progressive TFAM downregulation with increasing malignancy, with the lowest expression in glycolytic/plurimetabolic (GPM) subtypes. Functional and transcriptomic profiling of mesenchymal GBM cell lines showed that TFAM silencing in GPM-type U87MG cells enhanced proliferation, S-phase entry, reactive oxygen species (ROS) production, and adhesion, while reducing motility. These changes were correlated with upregulation of LDHC and TRAF2 and downregulation of androgen receptor-linked motility genes and LOXL2. By contrast, TFAM loss in mitochondrial (MTC)-type A172 cells caused minimal phenotypic alterations, associated with elevated SOD1 expression and activation of antioxidant, mitochondrial membrane, and survival pathways, alongside suppression of oxidative phosphorylation and vesicle-trafficking genes. TFAM overexpression reduced proliferation in U87MG but had a limited impact on A172 cells. Taken together, these findings establish TFAM as a subtype-specific regulator of GBM cell proliferation, redox balance, and motility. TFAM loss drives a proliferative, ROS-sensitive phenotype in GPM-type cells, while eliciting adaptive, stress-resilient programs in MTC-type cells. This study identifies TFAM and downstream effectors, TRAF2 and LOXL2, as potential therapeutic targets, supporting the development of metabolic subtype-tailored strategies for GBM treatment. Full article

Background/Objectives: Quercetin is a bitter compound with demonstrated anticancer effects in preclinical models of head and neck squamous cell carcinoma (HNSCC). In taste transduction, bitter compounds activate bitter taste receptors (T2Rs), a group of G protein-coupled receptors with downstream signaling that includes cytosolic calcium (Ca²⁺) release. T2Rs are expressed in HNSCC cells, where their activation induces apoptosis in vitro. Increased T2R expression in HNSCC also correlates with improved patient survival. The objective of this study was to investigate the role of quercetin as an anticancer T2R agonist in HNSCC cells in vitro and ex vivo. Methods: Quercetin-mediated Ca²⁺ responses were assessed using live cell Ca²⁺ imaging in the presence of the T2R14 antagonist LF1 and G-protein inhibitor YM-254980 (YM) in UM-SCC-47 and FaDu HNSCC cell lines. Cell viability was evaluated using crystal violet assays in cell lines and MTS assays in patient-derived tumor slices. Mitochondrial depolarization was measured with TMRE in the presence and absence of T2R pathway inhibitors. Results: Quercetin induced a Ca²⁺ response in HNSCC cells, which was significantly reduced by LF1 and YM. Quercetin also decreased cell viability in vitro. Ex vivo experiments showed a decrease in viability that was not statistically significant. Finally, quercetin caused mitochondrial depolarization, which was reduced in the presence of LF1 but not by YM. Conclusions: In HNSCC cells, quercetin causes a Ca²⁺ response that is likely mediated by T2R14, although genetic knockdown or knockout models are needed to more definitively support this hypothesis. Additionally, quercetin decreases viability in vitro and causes mitochondrial depolarization. Full article

Cryopreservation and transplantation of intact ovaries offer a promising approach to fertility restoration in cancer patients. However, ischemia–reperfusion injury following transplantation significantly impairs graft function. This study aimed to evaluate the protective effects of melatonin and elucidate its underlying mechanisms of action, including antioxidant and anti-inflammatory properties. Intact ovaries from 8 to 12-week-old LEWIS rats were cryopreserved and subsequently transplanted. Melatonin (25 mg/kg and 50 mg/kg) was administered daily from day 1 to day 4 postoperatively. Estrous cycle recovery and ovarian histology were examined, along with measurements of hormone concentrations, antioxidant activity, and inflammatory mediators. The oxidative stress response, particularly the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response elements (ARE) signaling pathway—including Nrf2, Kelch-like ECH-associated protein 1 (Keap1), and sMafg—was investigated to elucidate melatonin’s protective mechanisms. The roles of melatonin receptors and Nrf2 were investigated using specific receptor antagonists (Luzindole, 4P-PDOT) and an inhibitor (ML385) to confirm the involvement of the MT1/Nrf2/ARE pathway. As a result, rats treated with high-dose melatonin (50 mg/kg) exhibited accelerated estrous cycle recovery, reduced follicular loss, improved serum hormone levels, enhanced antioxidant capacity in serum and ovarian tissue, and decreased levels of inflammatory cytokines. Furthermore, melatonin exerted its antioxidant and anti-inflammatory effects through activation of the Nrf2/ARE signaling pathway via the MT1 receptor. These protective effects were abolished by the inhibition of either Nrf2 or MT1 receptor. In conclusion, these findings demonstrate that melatonin mitigates oxidative stress and inflammatory damage in intact transplanted ovaries through the MT1/Nrf2/ARE signaling axis, thereby preserving ovarian function post-transplantation. Full article

Cognitive impairments, particularly in the context of neurodegenerative diseases, are associated with disruptions in mitochondrial function and key metabolic pathways. This study investigates the impact of short-term scopolamine exposure on mitochondrial DNA (mtDNA) stability and the kynurenine pathway (KP) in the hippocampus, a brain region central to learning and memory. We analyzed the mitochondrial D-loop region for mutations and heteroplasmy levels in hippocampal tissue from rats exposed to scopolamine (1 mg/kg/0.4 mL/cc i.p. x 14 days). Additionally, the expression of the KP enzymes kynurenine aminotransferase (KAT I, KAT II) and kynurenine 3-monooxygenase (KMO) and receptors aryl hydrocarbon receptor (Ahr) and G protein-coupled receptor 35 (GPR35) was evaluated using quantitative PCR. Neither significant mutation nor heteroplasmy changes were observed in the mtDNA D-loop region between the scopolamine-treated and control groups. Similarly, the hippocampal expression levels of the kat I, kat II, kmo and ahr and gpr35 genes remained unchanged, indicating no activation of this metabolic pathway under short-term scopolamine exposure. These findings suggest that the mitochondrial genome in the hippocampus remains stable under acute pharmacological stress induced by scopolamine, with no significant activation of the KP. These results underline the distinction between transient, reversible cognitive deficits and chronic neurodegenerative processes, providing insights for therapeutic approaches targeting specific stages of cognitive change. Full article

Canine distemper virus (CDV) is a serious and often fatal disease caused by Morbillivirus canis, which affects domestic dogs and wild carnivores, with case-fatality rates reaching up to 47%. The hemagglutinin (H) protein mediates viral adsorption and shows high genetic variability, making it a valuable molecular marker. This study aimed to detect and characterize the H gene of CDV strains from 14 dogs with fatal neurological disease in the Brazilian states of Mato Grosso and Rondônia. Brain tissue was tested via RT-PCR for the nucleocapsid gene, and positive samples were amplified for the H gene. Ten complete H-gene sequences were obtained. Phylogenetic analysis revealed two distinct clusters within the South America I/Europe lineage: one related to strains from Uruguay and Argentina (with residues 530G/549Y) and another related to Brazilian strains (530S/549Y). One sequence (MT8) showed an intermediate position in the haplotype network but clustered phylogenetically with Uruguay/Argentina-related strains. Most sequences carried 530S/549Y, a pattern linked to altered SLAM receptor usage in wildlife. These findings demonstrate the co-circulation of two CDV clusters in Central–Western Brazil, their regional and international genetic connectivity, and amino acid substitutions potentially influencing host adaptation and antigenicity. Full article

Skeletal muscle, constituting 40–50% of total body mass, is vital for mobility, posture, and systemic homeostasis. Muscle contraction heavily relies on ATP, primarily generated by mitochondrial oxidative phosphorylation. Mitochondria play a key role in decoding intracellular calcium signals. The endocannabinoid system (ECS), including CB₁ receptors (CB₁Rs), broadly influences physiological processes and, in muscles, regulates functions like energy metabolism, development, and repair. While plasma membrane CB₁Rs (pCB₁Rs) are well-established, a distinct mitochondrial CB₁R (mtCB₁R) population also exists in muscles, influencing mitochondrial oxidative activity and quality control. We investigated the role of mtCB₁Rs in skeletal muscle physiology using a novel systemic mitochondrial CB₁ deletion murine model. Our in vivo studies showed no changes in motor function, coordination, or grip strength in mtCB₁ knockout mice. However, in vitro force measurements revealed significantly reduced specific force in both fast-twitch (EDL) and slow-twitch (SOL) muscles following mtCB₁R ablation. Interestingly, knockout EDL muscles exhibited hypertrophy, suggesting a compensatory response to reduced force quality. Electron microscopy revealed significant mitochondrial morphological abnormalities, including enlargement and irregular shapes, correlating with these functional deficits. High-resolution respirometry further demonstrated impaired mitochondrial respiration, with reduced oxidative phosphorylation and electron transport system capacities in knockout mitochondria. Crucially, mitochondrial membrane potential dissipated faster in mtCB₁ knockout muscle fibers, whilst mitochondrial calcium levels were higher at rest. These findings collectively establish that mtCB₁Rs are critical for maintaining mitochondrial health and function, directly impacting muscle energy production and contractile performance. Our results provide new insights into ECS-mediated regulation of skeletal muscle function and open therapeutic opportunities for muscle disorders and aging. Full article

Insomnia is a common and complex disorder, rooted in the dysregulation of circadian rhythms, impaired neurotransmitter function, and disturbances in sleep–wake homeostasis. While conventional hypnotics such as benzodiazepines and Z-drugs are effective in the short term, their use is limited by a high potential for dependence, cognitive side effects, and withdrawal symptoms. In contrast, melatonergic receptor agonists—melatonin, ramelteon, tasimelteon, and agomelatine—represent a pharmacologically targeted alternative that modulates MT1 and MT2 receptors, which are pivotal to the regulation of circadian timing and sleep initiation. Clinical evidence supports the efficacy of these agents in reducing sleep onset latency, extending total sleep duration, and re-aligning disrupted circadian rhythms, particularly among older individuals and patients with non-24 h sleep–wake disorders. Notably, agomelatine offers additional antidepressant properties through selective antagonism of the 5-HT_2C receptor in micromolar concentrations. In contrast, its agonistic activity at melatonergic receptors is observed in the low sub-nanomolar range, which illustrates the complexity of this drug’s interactions with the human body. All compounds reviewed demonstrate a generally favorable safety and tolerability profile. Accumulating evidence highlights that selected medicinal plants, such as chamomilla, lemon balm, black cumin, valeriana, passionflower and lavender, may exert relevant hypnotic or anxiolytic effects, thus complementing melatonergic strategies in the management of insomnia. This structured narrative review presents a comprehensive analysis of the molecular pharmacology, receptor affinity, signaling pathways, and clinical outcomes associated with melatonergic agents. It also examines their functional interplay with serotonergic, GABAergic, dopaminergic, and orexinergic systems involved in arousal and sleep regulation. Through comparative synthesis of pharmacokinetics and neurochemical mechanisms, this work aims to inform the development of evidence-based strategies for the treatment of insomnia and circadian rhythm sleep–wake disorders. Full article

Male fertility has declined over the years, partly due to metabolic disorders such as obesity and Type 2 diabetes. Antidiabetic drugs, including GLP-1 receptor agonists like liraglutide, are widely used to manage these conditions and aid in weight loss. Within the male reproductive tract, Leydig cells (LCs) are essential since they produce testosterone. Notably, the influence of antidiabetics on LCs remains a subject of limited investigation. Herein, we aimed to evaluate the effect of liraglutide on the physiology of LCs. To this end, we cultured LCs (BLTK1 cell line) without (control) or in the presence of selected concentrations of liraglutide. We then assessed their metabolic viability, cell proliferation, LDH release, ROS production, mitochondrial membrane potential, and in vivo mitochondrial cell performance, as well as the number of mtDNA copies. We also measured androstenedione production. Our results showed that liraglutide at pharmacological and supra-pharmacological concentrations increased the metabolic viability of LCs and reduced ROS production at all concentrations. Furthermore, the pharmacological concentration of liraglutide increased the basal respiration, maximal respiration, proton leak, and oxygen consumption rate related to ATP-linked production. Androstenedione production remained unchanged, which may be related to the inherent limitations of the cell line in supporting steroidogenesis. Overall, our findings suggest that liraglutide exhibits a potential protective effect on LC function, particularly by enhancing metabolic viability, reducing oxidative stress, and improving mitochondrial performance, highlighting its potential beyond the established role in diabetes and weight management. Full article

Background/Objectives: Ascorbic acid (AA)is a micronutrient with concentration-dependent anticancer properties, acting either as a reactive oxygen species (ROS) scavenger or inducer. Methods: Conventional redox-based assays such as MTS/MTT often overestimate cell proliferation due to AA’s interaction with tetrazolium salts, leading to increased formazan production. To overcome this limitation, we employed the Propidium Iodide Triton X-100 (PI/TX-100) assay to evaluate AA’s cytotoxic effects across a diverse panel of cancer and normal cell lines, including prostate (22Rv1, C4-2B, DU-145, LNCaP), breast (MCF-7, MDA-MB-231, MDA-MB-453), lung (A549), liver (HepG2, SK-HEP-1, Huh7), and kidney (Vero) cells. Results: AA significantly suppressed cancer cell viability compared to normal cells (RWPE1 and Vero), with the strongest effects observed in hormone receptor-positive lines. The relative sensitivity to AA followed distinct patterns within each cancer type. Mechanistically, AA-induced cell death involved ROS generation, lipid peroxidation, cell cycle arrest, ferroptosis, apoptosis, and downregulation of pyruvate dehydrogenase kinase 1 (PDHK1). Conclusions: These findings further support the potential of AA as a selective anticancer agent and highlight the importance of assay choice in evaluating its therapeutic efficacy. Full article

Rhabdomyolysis is characterized by the breakdown of skeletal muscle tissue, frequently leading to acute kidney injury (AKI). Traditional conservative treatments have shown limited effectiveness in modifying the disease course, thereby necessitating targeted pharmacological approaches. Zileuton (Z), a selective inhibitor of 5-lipoxygenase (5-LOX), has demonstrated efficacy in enhancing renal function recovery in animal models of AKI induced by agents such as cisplatin, aminoglycosides, and polymyxins. The present study aimed to evaluate the therapeutic potential of a single dose of Z in mitigating rhabdomyolysis-induced AKI (RI-AKI) via modulation of myeloid-derived suppressor cells (MDSCs). Male C57BL/6 mice were assigned to four experimental groups: Sham (intraperitoneal administration of 0.9% saline), Z (single intraperitoneal injection of Z at 30 mg/kg body weight), glycerol (Gly; single intramuscular dose of 50% glycerol at 8 mL/kg), and glycerol plus Z (Z + Gly; concurrent administration of glycerol intramuscularly and Z intraperitoneally). Animals were sacrificed 24 h post-glycerol injection for analysis. Zileuton administration significantly improved renal function, as indicated by reductions in blood urea nitrogen (BUN) levels (129.7 ± 17.9 mg/dL in the Gly group versus 101.7 ± 6.8 mg/dL in the Z + Gly group, p < 0.05) and serum creatinine (Cr) levels (2.2 ± 0.3 mg/dL in the Gly group versus 0.9 ± 0.3 mg/dL in the Gly + Z group p < 0.05). Histopathological assessment revealed a marked decrease in tubular injury scores in the Z + Gly group compared to the Gly group. Molecular analyses demonstrated that Z treatment downregulated mRNA expression of macrophage-inducible C-type lectin (mincle) and associated macrophage infiltration-related factors, including Areg-1, Cx3cl1, and Cx3CR1, which were elevated 24 h following glycerol administration. Furthermore, the expression of NLRP-3, significantly upregulated post-glycerol injection, was attenuated by concurrent Z treatment. Markers of mitochondrial biogenesis, such as mitochondrial DNA (mtDNA), transcription factor A mitochondrial (TFAM), and carnitine palmitoyltransferase 1 alpha (CPT1α), were diminished 24 h after glycerol injection; however, their expression was restored upon simultaneous Z administration. Additionally, Z reduced protein levels of BNIP3, a marker of mitochondrial autophagy, while enhancing the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), suggesting that Z ameliorates RI-AKI severity through the regulation of mitochondrial quality control mechanisms. Zileuton also decreased infiltration of CD11b(+) Gr-1(+) MDSCs and downregulated mRNA levels of MDSC-associated markers, including transforming growth factor-beta (TGF-β), arginase-1 (Arg-1), inducible nitric oxide synthase (iNOS), and iron regulatory protein 4 (Irp4), in glycerol-injured kidneys relative to controls. These markers were elevated 24 h post-glycerol injection but were normalized following concurrent Z treatment. Collectively, these findings suggest that Zileuton confers reno-protective effects in a murine model of RI-AKI, potentially through modulation of mitochondrial dynamics and suppression of MDSC-mediated inflammatory pathways. Further research is warranted to elucidate the precise mechanisms by which Z regulates MDSCs and to assess its therapeutic potential in clinical contexts. Full article