Search Results (300)

Bacterial infection triggered excessive inflammatory responses, yet the mechanisms linking inflammatory activation to immunometabolic adaptation remained incompletely understood. The mitochondrial translocator protein (TSPO) has been implicated in inflammatory activation and cellular metabolism. This study aimed to investigate the role of TSPO in inflammation mediated by Toll-like receptor 4 (TLR4). Herein, we integrated transcriptomic data from the human peripheral blood dataset GSE72829, and single-cell transcriptomic profiles from the CELLxGENE platform with cellular mechanistic experiments in BV2 microglia and RAW264.7 macrophages. Transcriptomic analyses revealed that TSPO expression was markedly upregulated in patients with bacterial infection (n = 52) and exhibited diagnostic potential to distinguish bacterial infection from healthy controls (HCs, n = 16) and viral infection (n = 92). TSPO-correlated genes were enriched in Toll-like receptor (TLR) signaling, inflammatory response, and immunometabolic pathways. Mechanistically, TSPO interacted with TLR4 and selectively modulated TLR4-driven inflammatory activation. TSPO deficiency augmented lipopolysaccharide (LPS) induced tumor necrosis factor‑α (TNF-α) and interleukin‑6 (IL-6) secretion, accompanied by disrupted Ca²⁺ homeostasis, impaired cholesterol balance, and compensatory metabolic remodeling characterized by elevated L-lactate and sustained Adenosine triphosphate (ATP) levels. Collectively, these findings identified TSPO as an immunometabolic regulator bridging TLR4 signaling and metabolic adaptation during inflammatory activation. Besides, TSPO represented a promising biomarker and therapeutic target to limit exaggerated inflammatory responses. Full article

Background: Translocator Protein (TSPO) is a transmembrane protein located in the mitochondrial outer membrane and highly expressed in the brain, which makes it a potential biomarker for microglial activation and neuroinflammation in neurodegenerative diseases. However, its role in neuropsychiatric disorders and its contribution to methamphetamine (METH) addiction (MA) remain unclear. Here, we aimed to investigate the association of the TSPO rs6971 with susceptibility to MA and METH-associated psychosis (MAP) and to evaluate its effect on TSPO expression. Methods: We investigated the association of TSPO/rs6971 (Ala147Thr) with susceptibility to MA and METH-associated psychosis (MAP). Genotyping was performed on 300 individuals, including 200 diagnosed with METH use disorder, with 100 of these exhibiting MAP, along with 100 healthy controls (HCs). We explored how different genotypes influence TSPO expression at both the transcript and protein levels using RT-qPCR and ELISA. Results: Age- and sex-adjusted logistic regression analysis revealed nominal associations between the rs6971 AA genotype and MAP under the recessive and co-dominant genetic models, with stronger associations observed after excluding individuals with a family history of psychiatric disorders. Within the MAP group, carriers of the A allele exhibited increased circulating TSPO levels compared to those with the GG genotype. Additionally, higher protein concentrations (p = 0.036) were observed in heterozygous individuals with MAP, compared to METH users without psychosis. Conclusions: Our findings suggest that the expression of TSPO may be influenced by genotype, with A allele carriers showing elevated TSPO expression. Overall, these exploratory findings suggest potential for TSPO-based translational strategies for patients with MA, and highlight the need for more comprehensive evaluations in future research. Full article

Background: AML cells can be defined by impairments in glycolytic metabolism, resulting in increased glucose uptake coupled with reduced glycolytic flux. Consequently, cells rely on alternative pathways such as glutamine metabolism to fuel mitochondrial respiration through anapleurosis. AML cells express upregulated levels of glutamine transporters and catabolic enzymes such as solute carrier family 1 member 5 (SLC1A5) and glutaminase 1 (GLS-1), respectively, to support metabolic needs; impairment of glutamine metabolism induces proliferative arrest. Our previous work identified plumbagin (PLB) as a selective activator of pyruvate kinase isoform M2 (PKM2), resulting in increased PKM2 tetrameric protein, impaired PKM2 nuclear translocation and suppressed c-Myc expression. Objective: Therefore, we aimed to investigate whether PLB-mediated PKM2 activation influences glutamine metabolism as a downstream effect of c-Myc suppression in AML. Methods/Results: AML cell lines treated with PLB were cultured in the presence or absence of glutamine and were compared to cell models with genetically suppressed PKM2 to assess for differences in growth. Spectrophotometric analysis revealed that PLB treatment reduces intracellular glutamine uptake, and immunoblotting indicated suppression of GLS-1 expression, ultimately leading to reduced AML cell proliferation and viability. Supplementation with glutamine partially restored cell growth, indicating that PKM2 modulation is associated with impaired glutamine uptake and utilization. Conclusion: Overall, this study explores the downstream implications of PLB-induced alterations in the c-Myc/PKM2 axis, expanding the understanding of PKM2’s function beyond glycolysis. The findings presented confirm that PKM2 activation leads to indirect consequences on glutamine metabolism in AML, providing further insight into the mechanisms of PLB-mediated AML cell death. Full article

Introduction: Diabetic retinopathy (DR) is characterized by early retinal neurodegeneration accompanied by progressive alterations of the retinal microvasculature, both exacerbated by hyperglycemia-induced oxidative stress and inflammation. Mitochondrial dysfunction critically contributes to neuronal loss and vascular impairment. The 18 kDa Translocator Protein (TSPO) is a mitochondrial outer membrane protein whose expression is increased in activated retinal glial cells and represents a promising target to modulate neuroinflammation and oxidative stress. This study evaluates the therapeutic potential of the TSPO ligand PIGA-1138 in experimental models of DR. Methods: PIGA-1138 (3 µM in vitro; 10 mg/kg/day, i.p., in vivo) was evaluated in high glucose (HG)-exposed 661W retinal cells and in streptozotocin (STZ, 150 mg/kg)-induced diabetic C57BL/6J mice. Cell viability, mitochondrial function, oxidative stress, and Nrf2, HO-1, and SOD1 expression were assessed in vitro. Retinal function and morphology were evaluated in vivo by electroretinography (ERG), visual acuity testing, and optical coherence tomography (OCT) at 30 and 60 days after diabetes induction. Results: PIGA-1138 significantly improved cell viability, reducing apoptosis (TUNEL p ≤ 0.01), preserving mitochondrial membrane potential (MitoRed p ≤ 0.01), reducing oxidative damage, and enhancing Nrf2 nuclear translocation together with HO-1 (p ≤ 0.05) and SOD1 (p ≤ 0.01) expression in HG-treated retinal cells. In diabetic mice, treatment preserved ERG responses and limited retinal thinning at 60 days (p ≤ 0.01), while showing a trend toward preserving visual acuity. Conclusions: Targeting mitochondrial TSPO with PIGA-1138 attenuates key hallmarks of DR by mitigating oxidative stress, suppressing neuroinflammation, and preserving retinal structure and function. These findings support TSPO as a potential disease-modifying target for DR. Full article

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder in which systemic pathophysiological alterations significantly contribute to disease progression and non-motor manifestations, such as depression and anxiety. The microbiota–gut–brain axis represents a critical bidirectional pathway in which intestinal dysbiosis and epithelial barrier disruption catalyze central neuroinflammation. This scoping review synthesizes evidence from 43 empirical and analytical studies across 28 countries and maps the findings under the WHO International Classification of Functioning (ICF) framework. Pathophysiological data reveal a profound taxonomic shift in patients with ALS, characterized by severe depletion of neuroprotective, butyrate-producing genera (Akkermansia and Prevotella) and enrichment of pro-inflammatory Enterobacteriaceae. This dysbiotic state leads to structural damage to the intestinal mucosa, alteration of Paneth cells, and downregulation of tight junction proteins (zonulin), triggering a “leaky gut” phenomenon. Subsequent systemic translocation of lipopolysaccharides (LPS) induces TLR4-mediated endotoxemia, microglial hyperactivation, and accelerated motor neuron apoptosis. Conversely, therapeutic modulation via Fecal Microbiota Transplantation (FMT), psychobiotics, and metabolic interventions (ketogenic or Mediterranean diets) has demonstrated significant efficacy in restoring epithelial integrity, mitigating mitochondrial hypermetabolism, and reducing emotional distress. This review identifies a critical research gap in the microstructural characterization of the enteric nervous system in ALS. Incorporating microbiome-targeted biomarkers into clinical protocols is crucial for implementing a stratified, multi-systemic therapeutic strategy aimed at enhancing patient prognosis and psychological well-being. Full article

Mitochondrial transport systems are essential regulators of cellular bioenergetics, calcium homeostasis, and metabolic signaling, and have emerged as critical targets of environmental toxicants. Although heavy metals and pesticides act through distinct primary mechanisms, increasing evidence indicates that they converge on a common network of mitochondrial dysfunction characterized by oxidative stress, impaired metabolite transport, calcium dyshomeostasis, and sensitization to mitochondrial permeability transition. This review provides an updated overview of the major mitochondrial transport systems involved in environmental toxicity, including the adenine nucleotide translocator (ANT), phosphate carrier (PiC), mitochondrial calcium uniporter (MCU), voltage-dependent anion channel (VDAC), and F1·Fo-ATP synthase (ATP synthase). We discuss their physiological roles, the molecular mechanisms by which heavy metals and pesticides disrupt their function, and the effects on oxidative phosphorylation, reactive oxygen species (ROS) generation, cardiolipin remodeling, and mitochondrial membrane integrity. Particular attention is devoted to the debate surrounding the molecular basis of mitochondrial permeability transition pore (mPTP) formation and to the concept that permeability transition represents the integrated outcome of cumulative mitochondrial stress rather than dysfunction of a single protein. Finally, we summarize emerging therapeutic strategies aimed at preserving mitochondrial transport function, limiting mitochondrial permeability transition, and attenuating downstream inflammatory signaling. Understanding these convergent mechanisms may facilitate the development of interventions to mitigate chronic diseases associated with environmental toxicant exposure. Full article

We previously demonstrated that fatty acid-binding protein 3 (FABP3) is significantly upregulated in ischemic neurons, and its inhibition mitigates ischemic brain injury in mice and attenuates mitochondrial damage under rotenone-induced oxidative stress. These findings suggest a potential role for FABP3 in mitochondrial dysfunction in ischemic neurons, although the underlying mechanism remains unclear. In this study, we further investigated the role of FABP3 in mitochondrial injury and apoptosis in ischemic neurons. Our findings indicated that FABP3 deficiency significantly decreased infarct volume following middle cerebral artery occlusion/reperfusion (MCAO/R) in mice, improved cognitive and spontaneous activity deficits, and suppressed BAX activation and mitochondrial translocation, caspase-3 activation, and cytochrome c release. In HT22 cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R), FABP3 deficiency increased cell viability, reduced apoptosis, and alleviated the loss of mitochondrial membrane potential. Conversely, FABP3 overexpression further exacerbated mitochondrial dysfunction and apoptosis, effects that were partially reversed by the BAX inhibitor BAI1. Furthermore, FABP3 overexpression promoted abnormal mitochondrial lipid accumulation and increased lipid peroxidation. Both the mitochondria-targeted antioxidant MitoQ and the ferroptosis inhibitor Ferrostatin-1 alleviated FABP3 overexpression-induced mitochondrial damage and apoptotic signaling. Collectively, our findings suggest that FABP3 is an important promoter of cerebral ischemia–reperfusion injury. FABP3 may aggravate ischemic neuronal injury by promoting abnormal mitochondrial lipid accumulation and lipid peroxidation, thereby enhancing BAX-dependent mitochondrial apoptotic signaling. Targeting FABP3 may provide a potential therapeutic strategy for neuroprotection in ischemic stroke. Full article

Mitochondrial electron transport chain (ETC) impairment triggers mitochondrial unfolded protein response (UPR^mt) that promotes mitochondrial homeostasis, yet the nuclear factors that mediate these responses remain incompletely defined. Here, we identify GLDI-8 as a nuclear factor required for robust activation of the hsp-6p::gfp UPR^mt reporter induced by ETC dysfunction in Caenorhabditis elegans. Depletion of gldi-8 markedly compromises mitochondrial stress-induced hsp-6p::gfp reporter activation, and transgenic rescue restores the response, supporting a specific requirement for GLDI-8 in this pathway. Mitochondrial stress promotes nuclear accumulation of GLDI-8; however, a GLDI-8 transcriptional (promoter) reporter shows no detectable induction under the same conditions, suggesting that regulation occurs at the post-transcriptional level. Genetic analysis further shows that stress-induced nuclear translocation of GLDI-8 is not abolished by atfs-1 knockdown, and GLDI-8 is dispensable for DVE-1 nuclear translocation under mitochondrial stress. Together, these findings establish GLDI-8 as a mitochondrial stress-responsive nuclear factor that contributes to ETC impairment–induced transcriptional responses and adds to the complex regulatory network underlying the UPR^mt. Full article

Background/Objectives: Mitochondria are dynamic organelles that continuously undergo balanced cycles of fusion and division to maintain optimal function. Mitochondrial division is mediated by Dynamin-Related Protein 1 (DRP1), a cytosolic large GTPase whose phosphorylation at serine 616 (DRP1-S616Ⓟ) promotes its translocation to the outer mitochondrial membrane and organelle division. Dysregulated mitochondrial division disrupts cellular homeostasis and contributes to disease pathogenesis, including cancer. Our prior work demonstrated that the oncogene-induced mitogen-activated protein kinase (MAPK) pathway constitutively phosphorylates DRP1 at serine 616, which is essential to cellular transformation and correlates with oncogene status in patient tissues. Similarly, DRP1-S616Ⓟ is subject to pharmacologic control by targeted therapies against oncogenic MAPK signaling. Methods: Building upon this foundation, we developed and characterized a recombinant murine monoclonal antibody (referred to as 3G11) with high specificity for human DRP1-S616Ⓟ, raised against a peptide derived from the human DRP1 sequence. Results: Using diverse experimental platforms, we demonstrate the robust utility of 3G11 to detect DRP1-S616Ⓟ in melanoma cell extracts and isolated organelles. Immunofluorescence revealed that pharmacologic inhibition of oncogenic MAPK signaling reduces DRP1-S616Ⓟ levels, which correlates with mitochondrial hyperfusion, while immunohistochemistry showed that elevated DRP1-S616Ⓟ expression in human tissues correlates with BRAF^V600E disease. Conclusions: 3G11 is a new recombinant antibody for detecting DRP1-S616Ⓟ and supports studies of mitochondrial division in cancer. Together, these findings establish 3G11 as a specific, versatile, renewable, and cost-effective tool for studying mitochondrial division, with strong potential for clinical applications. Full article

(1) Background: Mild traumatic brain injury (mTBI), the most prevalent form of traumatic brain injury, often results from repetitive impacts to the head and is associated with long-term neurological impairment. The pathophysiology of mTBI is multifactorial and involves alterations in mitochondrial bioenergetics, a key determinant of neuronal function and survival. Although mitochondrial dysfunction is recognized as a hallmark of mTBI, its long-term effects on bioenergetics and the roles of regulatory cytosolic and mitochondrial proteins remain poorly understood. We hypothesized that repeated mTBI (rmTBI) induces sustained deficits in mitochondrial bioenergetics that are associated with long-term changes in key bioenergetic and other regulatory proteins. (2) Methods: Using the repeated CHIMERA injury model in adult male rats, randomly assigned to sham or rmTBI groups, we assessed mitochondrial respiration in isolated mitochondria and whole cerebral cortex homogenates using a Clark O₂ electrode and an Oroboros O₂k respirometer at time points ranging from 1 day to 2 months post-injury. Western blotting was performed for expression of regulatory proteins HKI, DRP1, MFN2, VDAC1, and ANT2. (3) Results: At 2 months post-rmTBI, respiration was faster and uncoupled, while ATP synthesis was significantly slowed compared with sham rats. This was accompanied by decreased expression of mitochondrial MFN2 and ANT2, by increased mitochondrial expression of DRP1, and by decreased translocation of HKI to mitochondria. There was no significant difference in VDAC1 expression. Earlier time points showed no significant differences in bioenergetics or protein expression, but neuro-inflammatory markers (GFAP and Iba1) were significantly elevated at these earlier time points of post-injury. (4) Conclusions: These findings indicate that rmTBI leads to a delayed long-term impairment of mitochondrial bioenergetics associated with alterations in proteins critical for bioenergetic regulation and mitochondrial control. This suggests a pathophysiologic mechanism for the persistent cognitive and behavioral deficits observed following rmTBI. Full article

Isoflurane is a widely used volatile anesthetic with context-dependent effects on neuronal survival, particularly in neurodegenerative conditions. Increasing evidence suggests that brief, sublethal stress exposure can induce adaptive cellular responses through hormesis-based preconditioning mechanisms. In this study, we investigated whether isoflurane preconditioning enhances neuronal tolerance to amyloid-β (Aβ)-induced toxicity and explored the underlying redox-dependent molecular pathways. Using HT-22 murine hippocampal neuronal cells, we demonstrate that short-term exposure to low-dose isoflurane induces a delayed neuroprotective phenotype characterized by improved cell viability, reduced apoptotic signaling, and maintained mitochondrial membrane potential following Aβ challenge. Mechanistically, isoflurane preconditioning elicited a mild and transient increase in intracellular reactive oxygen species (ROS), which is critical for the activation of the PI3K/Akt signaling pathway. Pharmacological scavenging of reactive oxygen species abolished Akt phosphorylation and reduced the protective effects of preconditioning, supporting a hormetic signaling model rather than direct antioxidant action. Following Akt activation, isoflurane preconditioning promoted the inhibitory phosphorylation of glycogen synthase kinase-3β (GSK-3β), decreased Keap1 protein levels, and facilitated nuclear translocation and transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Consequently, the expression of Nrf2-regulated antioxidant genes, including heme oxygenase-1, NAD(P)H quinone dehydrogenase 1 (NQO1), superoxide dismutase 1 and 2 (SOD1/2), and catalase, was significantly upregulated. Collectively, these findings indicate that isoflurane preconditioning confers neuroprotection through hormesis-like mild oxidative signaling and coordinated activation of endogenous antioxidant defenses rather than via direct antioxidant scavenging. Full article

The mitochondrial anti-viral signaling protein, MAVS, is a central regulator of innate anti-viral immunity. Recently, we demonstrated that MAVS is overexpressed in cancer, where its downregulation resulted in reduced cell proliferation and the expression and nuclear translocation of proteins associated with transcriptional regulation and inflammation. In this study, we demonstrate that CRISPR/Cas9-mediated MAVS depletion in PC-3 prostate cancer cells suppresses proliferation, disrupts immune evasion, and alters the tumor microenvironment. Proteomic profiling of the MAVS-KO cells by LC-MS/MS revealed changes in the expression of proteins associated with immunity, cell signaling, mitochondrial function, metabolism, protein synthesis and degradation, and epigenetic regulation. In contrast to MAVS-expressing cells, MAVS-KO cells implanted subcutaneously in mice formed very small tumors. This inhibited tumor growth was linked to reduced proliferation, and enhanced apoptosis, as indicated by strong TUNEL staining and elevated activated caspase-3. Importantly, the small “tumors” derived from MAVS-KO cells displayed a distinct morphology: diminished cancer stem-cell populations, an altered tumor microenvironment and inflammatory response, increased immune cell infiltration, and reduced PD-L1 expression. Together, these findings establish MAVS as a key mediator of cancer-cell survival, inflammation, and immune regulation, and, thus, its upregulation in tumors makes it a potential anti-cancer target. Full article

Prostate cancer (PCa) progression is critically driven by androgen receptor (AR) signaling, which integrates hormonal cues with metabolic programs supporting tumor growth, survival, and therapy resistance. Emerging evidence suggests that intermittent fasting (IF) and related dietary interventions—such as time-restricted eating (TRE), alternate-day fasting (ADF), and fasting-mimicking diet (FMD)—modulate systemic metabolism, including reductions in insulin and insulin-like growth factor 1 (IGF-1), and induce intracellular nutrient stress that can influence AR activity, splice variant expression (e.g., AR-V7), and downstream metabolic pathways. This systematic literature review (Scopus, PubMed, Web of Science; publications up to December 2025; search terms: “prostate cancer,” “androgen receptor,” “AR splice variants,” “intermittent fasting,” “fasting mimicking diet”, “metabolism,” “therapy resistance”) summarizes preclinical and clinical studies addressing the impact of IF on AR signaling, lipogenesis, mitochondrial function, redox homeostasis, and therapy response. Preclinical studies indicate that IF can reduce AR expression, impair nuclear translocation, modulate AR splice variants such as AR-V7 via nutrient-sensitive splicing mechanisms, and enhance sensitivity to androgen deprivation therapy and AR-targeted agents. Mechanistically, IF-induced metabolic stress engages AMP-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), and sirtuin pathways, alters lipid and mitochondrial metabolism, and transiently increases reactive oxygen species (ROS), creating vulnerabilities in prostate tumor cells. Translational evidence suggests potential benefits of integrating IF with standard therapy, but effects may depend on fasting regimen, caloric intake, macronutrient composition, and patient metabolic context, including risk of lean mass loss. This review highlights the metabolic crosstalk between IF and AR signaling and emphasizes the need for future clinical studies incorporating biomarker-guided approaches and body composition monitoring to fully exploit this intersection for improved therapeutic outcomes in prostate cancer. Full article

Translocator protein (TSPO) regulates mitochondrial function, inflammation, and oxidative stress; however, its role in acute myocardial injury (MI) remains incompletely understood. While previous studies have examined TSPO ligands in cardiac injury, the interplay between TSPO modulation and nitric oxide (NO) signaling in AMI has not been systematically investigated. The aim of this study was to investigate the effects of TSPO modulation by PK11195, alone or in combination with nitric oxide synthase (NOS) inhibition by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME), on cardiometabolic, inflammatory, oxidative stress, and histopathological parameters in an experimental model of isoprenaline-induced MI in rats. Male Wistar albino rats were divided into four groups: control (C); isoprenaline + saline-treated (ISO); isoprenaline + PK11195-treated (IP); and isoprenaline + PK11195 + L-NAME-treated (IPLN) groups. Isoprenaline administration induced MI, evidenced by elevated cardiac biomarkers, electrocardiographic (ECG) alterations, and histopathological damage. PK11195 treatment significantly attenuated MI and reduced pro-inflammatory cytokine levels while increasing anti-inflammatory cytokine levels, indicating protective effects. Nevertheless, TSPO modulation was associated with adverse metabolic effects, notably elevated fibrinogen and plasma homocysteine levels. Co-administration of L-NAME mechanistically demonstrated that NO availability is essential for PK11195 cardioprotective effects, as NOS inhibition partially abolished cardioprotection and modified oxidative stress parameters. Overall, TSPO modulation exerts complex actions in acute MI through regulating mitochondrial function, inflammatory signaling, and NO pathways, suggesting that TSPO is a potential, multifaceted therapeutic target. Full article

Background: This study is part of the HEAL ITALIA partnership, funded by the National Recovery and Resilience Plan (PNRR) and the European Union. Heart failure (HF) is a serious health problem, with a reduced density of the β1-adrenergic receptor (β1-AR) in the myocardium as a hallmark. It is unclear whether this downregulation causes dysfunction or represents an epiphenomenon. Recent evidence implicates oxidative stress and mitochondrial signaling, particularly through the 18 kDa translocator protein (TSPO), in the regulation of the β1-AR, with possible modulation by estrogen. Objectives: To determine (1) the role of β1-AR desensitization in the onset and development of HF; (2) whether monocytes can represent a suitable ex vivo model for sex-oriented mechanistic studies in the cardiac field; (3) whether monocytes isolated from peripheral blood of patients can represent a diagnostic and/or therapy response biomarker by monitoring β1-AR density; (4) whether and how the mitochondrial receptor TSPO is involved in the β1-AR dysregulation observed in HF; and (5) whether the mechanisms linked to the onset of HF are regulated in a sex-specific manner through the effect of estrogen and/or the X chromosome on the expression of specific microRNAs. Methods: Using an integrated in vitro-ex vivo-in vivo methodological approach, we will evaluate the density of β1/β2-AR receptors, the downstream signaling (GRK2/β-arrestin), mitochondrial and redox parameters, and miRNA profiles in human monocytes and cardiomyocytes, and in mouse hearts after HF following pressure overload. Conclusions: The goal is to better understand the mechanisms underlying β1-AR desensitization, verify monocytes as peripheral markers of disease progression and response to therapy, and provide potentially useful information for the development of gender-specific therapies for heart failure. Full article