Search Results (678)

Polycystic kidney disease (PKD) is a genetic disorder characterized by renal cyst formation and progressive renal dysfunction, where inflammation, immune responses, and metabolic dysregulation critically drive disease progression, while emerging evidence increasingly links its pathogenesis to mitochondrial dysfunction. Mitochondria, central to cellular energy production, metabolism, and redox homeostasis, exhibit profound abnormalities in PKD, contributing to disease pathogenesis. Current evidence on mitochondrial mechanisms driving PKD progression includes metabolic reprogramming, oxidative stress, disrupted mitochondrial dynamics, and impaired mitophagy. Polycystic kidney disease is caused by mutations in the PKD1 or PKD2 genes, which encode polycystin 1 and polycystin 2. The formation of dysfunctional polycystins (PC1/PC2) is a key event in the pathogenesis of this disease, triggering impaired calcium signaling, increased production of mitochondrial reactive oxygen species (ROS), and reduced oxidative phosphorylation, thereby promoting cyst growth and fibrosis. Key signaling pathways such as mTORC1 hyperactivation, AMPK suppression, and disrupted calcium homeostasis further exacerbate mitochondrial defects. Emerging therapeutic strategies targeting mitochondrial pathways, such as mitochondrial antioxidants, modulators of mitophagy, calcium signaling regulators, and metabolic reprogramming agents, show promise in preclinical models. However, challenges remain in translating these findings to clinical applications, including drug specificity and minimizing off-target effects. This review underscores mitochondria as pivotal players in PKD pathogenesis and highlights their potential as therapeutic targets to mitigate cystogenesis and disease progression. Full article

Gestational diabetes mellitus (GDM) is increasingly recognized as a complex pathology rooted in systemic and organelle-level dysfunction, specifically involving chronic low-grade inflammation (CLGI), mitochondrial impairment, and endoplasmic reticulum (ER) stress. Central to this pathophysiology is mitochondrial dysfunction, characterized by reduced respiration, impaired metabolic flexibility, and dysregulated fission/fusion machinery, which fuels a self-perpetuating cycle of reactive oxygen species (ROS) production. Concurrently, chronic ER stress triggered by hyperglycemia and lipotoxicity activates the unfolded protein response (UPR), further amplifying redox imbalance through the Endoplasmic Reticulum Oxidoreductin 1/Protein Disulfide Isomerase (ERO1/PDI) axis and bridging metabolic toxicity to inflammation via c-Jun N-terminal kinase (JNK) and nuclear factor kappa-light-chain–enhancer of activated B cells (NF-κB) signaling. The Advanced Glycation Endproducts (AGEs) and the Receptor for Advanced Glycation Endproducts (RAGE) axis act as a molecular catalyst that sequester antioxidants and drive pro-inflammatory feedback loops. These converging mechanisms culminate in profound placental maladaptation, including structural abnormalities like chorangiosis and functional defects in nutrient transport mediated by hyperactive mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review article provides insight into recent evidence to elucidate the meta-inflammatory environment of GDM, where modest but sustained elevations in biomarkers like Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) disrupt redox homeostasis and impair insulin signaling pathways through the activation of stress-sensitive kinases. By integrating these molecular perspectives, the article underscores the necessity of targeting the systemic inflammatory and oxidative continuum spanning pre-conception to the antenatal period through lifestyle interventions and emerging therapeutic strategies to mitigate GDM risk and improve maternal–fetal outcomes. Full article

A common hypoxic scenario in tumors involves unresolved acute hypoxia that eventually leads to sustained (chronic) hypoxia. This shift drives a characteristic “HIF switch”, where the key hypoxia-responsive factors change from HIF-1α to HIF-2α over time, and importantly, this switch is closely linked to stemness regulation. However, the mechanisms underlying this switch and its impact on stemness regulation are not yet fully understood. Here, we developed a mechanistic network model integrating the HIF-1/HIF-2 signaling axis with the stemness regulators OCT4 and SOX2. We found the duration and intensity of hypoxia jointly shape the dynamics of HIF-1α and HIF-2α, ultimately regulating OCT4-mediated stemness. Under physioxia, HIF-2α–mTORC2 positive feedback supports the gradual accumulation of HIF-2α toward a modest steady level and low OCT4 expression, corresponding to a primed state. Under prolonged mild hypoxia, the concurrent induction of HIF-1α, albeit at low levels, and accelerated accumulation of HIF-2α elevate OCT4 to intermediate levels, promoting stem-like traits. Under moderate hypoxia, PHD-2-mediated negative feedback triggers pulsatile HIF-1α dynamics, driving a shift toward HIF-2α dominance. Ultimately, cooperative HIF-1α/HIF-2α signaling induces REDD1 and suppresses mTORC1-dependent protein synthesis, pushing OCT4 into a high-expression state associated with differentiation. This work presents a unified framework for understanding how the HIF signaling hierarchy coordinates metabolic and transcriptional programs to direct cell fate across varying hypoxic landscapes. Full article

Background/Objectives: Obesity represents a significant global health challenge. Although alternate-day fasting (ADF) has been shown to effectively improve metabolic parameters, long-term adherence to this regimen remains limited. This study aimed to investigate whether highly polymerized persimmon tannin (DP31) could serve as a practical alternative to ADF for the prevention of high-fat diet (HFD)-induced obesity in mice. Methods: Male C57BL/6J mice (n = 10 per group) were subjected to an HFD for 11 weeks, during which they concurrently received either DP31 or ADF. Body weight, fat mass, serum lipid levels, glucose tolerance, fasting glucose, and insulin levels were assessed. Additionally, hepatic transcriptomics, Western blotting, 16S rRNA sequencing, and short-chain fatty acids (SCFAs) analysis were conducted. Results: DP31 demonstrated comparable efficacy to ADF in reducing body weight gain and improving lipid profiles, while exhibiting superior effects on glucose tolerance and fasting glucose levels (p < 0.05). Both interventions effectively reversed HFD-induced hepatic gene dysregulation, leading to the upregulation of genes involved in processes related to steroid metabolism. In addition, both treatments activated the hepatic AMPK-mTORC1-Lpin1 axis, suppressed lipogenesis, upregulated PGC1α, and increased β-hydroxybutyrate levels, indicating enhanced fatty acid oxidation (p < 0.05). Notably, DP31 outperformed ADF in enriching beneficial gut genera, such as Akkermansia, and boosting SCFAs production, which may elucidate its superior glycemic control. Overall, DP31 exhibits comparable effects to ADF in preventing obesity-related metabolic disorders, while demonstrating superior effects on glucose homeostasis. Full article

Background/Objectives: Capivasertib is a selective pan-AKT inhibitor recently approved in combination with fulvestrant for the treatment of hormone receptor-positive (HR+)/HER2- breast cancer with alterations in the PI3K/AKT pathway. The PI3K/AKT/mTOR signaling cascade represents a critical indication of endocrine resistance and tumor progression in this subtype of breast cancer. The present review summarizes current clinical data regarding the efficacy of capivasertib, either as monotherapy or in combination with other therapeutic agents and discusses emerging biomarkers and mechanisms of resistance. Methods: A literature search of the PubMed database was conducted to identify clinical trials evaluating capivasertib in breast cancer. Studies on capivasertib as monotherapy or in combination with fulvestrant, paclitaxel, or olaparib were included. Results: Findings from phase I–III clinical trials indicate that capivasertib in combination with fulvestrant significantly prolongs progression-free survival in patients with HR+/HER2- advanced breast cancer, particularly in tumors containing PIK3CA, AKT1, or PTEN alterations. Drug combination approaches with paclitaxel or olaparib have demonstrated additive or synergistic effects in triple-negative and DNA repair-deficient contexts, respectively. Monotherapy studies confirm effective pathway inhibition with modest clinical benefit, primarily in AKT1-mutant tumors. Translational analyses suggest that persistent mTORC1-mediated protein synthesis and compensatory signaling activation contribute to acquired resistance. Conclusions: Capivasertib constitutes a clinically validated therapeutic approach for the inhibition of AKT signaling in breast cancer. Its efficacy is most evident when combined with endocrine therapy; however, optimization of patient selection and rational combination strategies remains necessary to overcome resistance associated with mTORC1 activation and signaling redundancy. Full article

Inadequate choline intake-induced choline metabolic stress (CMS) has been divergently linked to metabolic dysfunction-associated steatotic liver disease (MASLD), yet underlying mechanisms remain unclear. We hypothesized that CMS modifies plasma-free amino acid (PFAA) signatures to influence MASLD risk. In a nested case–control study of 125 participants, dietary choline intake and blood choline metabolites were assessed together with targeted metabolomics and transcriptomic profiling. MASLD was characterized by low choline intake, reduced plasma betaine/choline ratio (Pbcr), elevated homocysteine, increased branched-chain amino acids (BCAAs), and depleted serine/glycine, achieving strong predictive accuracy (AUC = 0.90). CMS was associated with reduced lymphocytic transcripts involved in BCAA catabolism and altered mTORC1/Akt/IRS1 signaling. Nonlinear Pbcr- and intake-dependent MASLD risk patterns were attenuated after adjustment for genetic–metabolite networks. These findings identify CMS-responsive metabolic mediators supporting precision choline interventions. Full article

Acne vulgaris is a chronic inflammatory disease of the pilosabaceous unit with a multifactorial pathogenesis involving sebaceous gland activity, follicular hyperkeratinization, microbial dysbiosis, and immune dysregulation. Increasing attention has been given to the role of the skin and gut microbiome, as well as the gut–skin axis, although their clinical significance has not yet been fully explained. This review critically evaluates the current evidence regarding the use of probiotics, prebiotics, and synbiotics in the treatment of acne. Available studies suggest that microbiome-targeted interventions may influence inflammatory pathways, microbial composition, and metabolic regulators such as IGF-1 and mTORC1. Some clinical trials indicate improvements in acne severity and skin parameters following oral or local interventions. However, the evidence is heterogeneous and limited by small sample sizes, short study durations, and variability in formulations and outcomes. Therefore, although microbiome-based strategies may have potential as adjunctive therapy, their clinical efficacy remains uncertain. Further, well-designed, large-scale studies are needed to determine their role in dermatological practice. Full article

Mulibrey nanism is a rare autosomal recessive multisystem disorder caused by biallelic loss of function variants in TRIM37 encoding a peroxisomal E3 ubiquitin ligase. Initially described in Finland, where it remains most prevalent due to a founder mutation, the condition is now recognized worldwide and is characterized by severe prenatal-onset growth failure, distinctive craniofacial features, radiological abnormalities, ocular findings, and hepatopathy. Although its clinical spectrum extends far beyond these core manifestations, the major determinant of morbidity and mortality is progressive cardiovascular disease, including constrictive pericarditis and restrictive cardiomyopathy. Additional features include metabolic dysfunction such as insulin resistance and type 2 diabetes, gonadal insufficiency, skeletal abnormalities including fibrous dysplasia, and an increased risk of benign and malignant tumours. The clinical course evolves across the lifespan from early growth and developmental abnormalities to progressive multisystem disease in adolescence and adulthood. Recent advances have expanded understanding of TRIM37 function, linking it to mTORC1 TFEB signalling autophagy, centrosome integrity, extracellular matrix regulation, and immune cell function, providing mechanistic insights into tumour predisposition, skeletal pathology, and immune dysregulation. Management remains supportive and requires multidisciplinary care with emphasis on early recognition and treatment of cardiac disease, metabolic complications, and malignancy risk. Prognosis is variable but improves with early diagnosis and appropriate surveillance. This review summarises the clinical spectrum molecular mechanisms and current management of Mulibrey nanism and highlights priorities for future research. Full article

Background/Objectives: The development of non-alcoholic fatty liver disease (NAFLD) is closely linked to oxidative stress and inflammation. Aerobic exercise has been shown to improve NAFLD, although its underlying mechanisms remain incompletely understood. This study utilized ApoE^-/- mice to investigate the role of Sestrin2 in aerobic exercise-induced amelioration of NAFLD. Methods: Random assignment of C57BL/6J and ApoE^-/- mice yielded four groups: C (control), CE (aerobic exercise), AS (ApoE^-/- control), and AE (ApoE^-/- aerobic exercise). Aerobic exercise lasting 12 weeks was administered to the CE and AE groups. Serum biomarkers were analyzed by ELISA, liver tissue morphology was assessed via HE and ORO staining, and macrophage polarization was evaluated through immunofluorescence. Additionally, mRNA and protein expression levels were measured by qPCR and Western blot. Results: Aerobic exercise reduced liver wet weight, lipid accumulation, and steatosis in ApoE^-/- mice. Aerobic exercise attenuates hepatic oxidative stress, and upregulated the expression of regulation oxidative stress related gene and proteins of Nrf2, HO-1, CAT, and SOD1 in ApoE^-/- mice. Aerobic exercise promoted a shift in macrophage polarization from the pro-inflammatory M1 phenotype toward the anti-inflammatory M2 phenotype in the liver, and significantly reduced TNF-α and IL-1β levels, accompanied by upregulation of Sestrin2 expression, enhanced AMPK phosphorylation, inhibited mTORC1 in the liver. Conclusions: These findings suggest that aerobic exercise alleviates oxidative stress and inflammation in NAFLD, with Sestrin2 activation playing a central role. Full article

Cigarette smoking contributes to vascular aging through oxidative stress, inflammation, and extracellular matrix (ECM) remodeling. Cellular senescence has been recognized as an important mechanism linking tobacco exposure to vascular dysfunction, but effective pharmacological strategies targeting this process remain scarce. In this study, we examined whether Rapalink-1, a dual inhibitor of mechanistic target of rapamycin complex 1 and complex 2 (mTORC1 and mTORC2), modulates smoke condensate (SC)-induced senescence in vascular cells. Human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (SMCs) were exposed to SC with or without Rapalink-1. SC increased intracellular reactive oxygen species, induced DNA damage, and promoted senescence-associated changes, including increased senescence-associated β-galactosidase (SA-β-gal) activity, reduced Lamin B1, and elevated p21 expression. These effects were accompanied by increased expression of inflammatory and matrix-remodeling genes associated with the senescence-associated secretory phenotype (SASP). Rapalink-1 co-treatment reduced oxidative stress and DNA damage, attenuated senescence markers, and partially normalized SASP-related and ECM-associated gene expression. Mechanistically, SC activated nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling and increased downstream mTOR pathway activity, whereas Rapalink-1 dampened these signaling responses. Together, these findings indicate that dual mTORC1/2 inhibition by Rapalink-1 mitigates smoke condensate-induced senescence and inflammatory responses in vascular cells. Full article

The MiT/TFE family transcription factors play a critical role in lysosomal biogenesis, autophagy, mitochondrial turnover and lipid catabolism by regulating the Coordinated Lysosomal Expression and Regulation (CLEAR)gene network. The dysregulation of MiT/TFE activity has been implicated in the onset and progression of cancer and neurodegeneration, but its functions in association with pulmonary diseases remain poorly understood. In this review, we systematically summarize the findings from human pulmonary diseases and associated genetic disorders, such as asthma, cancer, Birt–Hogg–Dube (BHD) syndrome, and lung injury models that implicate MiT/TFE dysregulation in pathogenic progression. We also discussed MiT/TFE regulation and signaling through pathways involving mTORC1, AMPK, and lysosomal stress in different cellular contexts. Finally, we discussed significant mechanistic gaps, such as the absence of in vivo models targeting the combined activity of TFEB and TFE3 in disease progression and prevention. In conclusion, these insights seek to offer a comprehensive framework for understanding MiT/TFE signaling in human lung diseases and could present a promising opportunity for directing future mechanistic and translational research. Full article

Background/Objectives: Brain metastasis (BM) represents a significant clinical challenge in advanced breast cancer, yet the molecular mechanisms driving breast cancer brain metastasis (BCBM) remain incompletely characterized. This study aims to identify key molecular pathways and hub genes specifically associated with BCBM through comprehensive bioinformatic analyses. Methods: Gene Set Enrichment Analysis (GSEA), differential gene expression analysis, and weighted gene co-expression network analysis (WGCNA) were performed using two independent GEO datasets (GSE191230 and GSE43837). Protein–protein interaction (PPI) networks were constructed to visualize functional interconnections among dysregulated genes. Survival analyses were conducted using the Kaplan–Meier Plotter database to evaluate the prognostic significance of identified hub genes. Results: GSEA revealed significant upregulation of metabolic pathways (mTORC1 signaling, glycolysis, oxidative phosphorylation) and downregulation of immune-related pathways in BCBM compared to primary tumors. Integrative analysis identified 34 consistently dysregulated genes across datasets, from which 12 hub genes were validated. Among these, RRM2, CDCA8, CCNB1, LMNB2, FANCI, NCAPH, YWHAZ, and ESPL1 demonstrated brain-specific over-expression compared to other metastatic sites. Functional enrichment analysis highlighted cell cycle dysregulation as a critical mechanism in BCBM, and all hub genes showed significant association with poor prognosis in breast cancer patients. Conclusions: This study identifies a unique molecular profile of BCBM characterized by cell cycle dysregulation, metabolic reprogramming, and immune microenvironment alterations. The brain-specific expression patterns of these hub genes represent potential biomarkers for BCBM risk assessment and novel therapeutic targets, providing a basis for precision medicine development. Full article

Astrocytes undergo pronounced reactivity during traumatic brain injury (TBI); however, the temporal dynamics of this response and the signaling mechanisms regulating astrocyte proliferation remain incompletely defined. In this study, we characterized the spatiotemporal profile of astrocyte reactivity and proliferation in the hippocampus during TBI and investigated the involvement of mammalian target of rapamycin complex 1 (mTORC1) signaling in these processes. Using a mouse model of TBI, we found that injury triggered a rapid astrocytic response in the hippocampus, characterized by increased glial fibrillary acidic protein (GFAP) expression and morphological hypertrophy as early as 4 h post-injury. Astrocyte proliferation emerged subsequently, peaked during the acute phase (48 and 72 h), and declined to baseline levels at 7 days post-trauma, indicating a transient proliferative response during TBI. Concurrently, mTORC1 signaling was robustly activated in reactive astrocytes in the hippocampus and was specifically associated with proliferative reactive astrocytes during injury. Pharmacological inhibition of mTORC1 signaling with rapamycin significantly reduced reactive astrocyte proliferation during TBI without altering astrocytic hypertrophy. Together, these findings demonstrate that TBI induces a rapid but transient astrocyte activation and proliferation response in the hippocampus and that mTORC1 activation is required for the proliferation, but not the hypertrophic activation, of reactive astrocytes during traumatic brain injury. Full article

Scopolamine, also known as hyoscine, is a naturally occurring tropane alkaloid derived from plants of the Solanaceae family. Clinically, the compound has long been used for the prevention of motion sickness and postoperative nausea and vomiting, as well as for ophthalmological procedures requiring mydriasis and cycloplegia. However, beyond these established indications, increasing attention has been directed toward its broader neuropharmacological actions. This narrative review aims to summarise current knowledge regarding the pharmacological properties of scopolamine, with particular emphasis on its mechanisms of action and emerging implications in neuroscience and neuropsychiatric disorders. Scopolamine acts as a non-selective antagonist of muscarinic receptor subtypes M1–M5, interfering with cholinergic neurotransmission. Experimental and clinical studies demonstrate that scopolamine induces transient cognitive impairment. This property has led to its widespread use as a pharmacological model of Alzheimer’s disease, enabling investigation of cholinergic contributions to cognitive decline. More recently, several early clinical studies suggested that intravenous administration may produce rapid reductions in depressive symptoms, possibly through modulation of glutamatergic neurotransmission and activation of mTORC1-dependent synaptic plasticity pathways in the prefrontal cortex. Nevertheless, subsequent trials have yielded inconsistent results, and the therapeutic relevance of these findings remains uncertain. Current evidence indicates that scopolamine’s neuropsychiatric effects likely arise from complex interactions between cholinergic, glutamatergic, and neurotrophic signalling systems. Taken together, scopolamine represents both a valuable experimental tool for studying cholinergic function and a mechanistic framework for the development of novel therapeutics targeting rapid neuroplastic processes in neuropsychiatric disorders. Full article

Oleaginous microorganisms usually accumulate large amounts of lipids under nitrogen limitation and in a carbon-abundant environment. However, how cells sense changes in nitrogen and carbon levels in the culture medium remains a research hotspot. Previous studies have found that the target of rapamycin complex 1 (TORC1) plays a core role in lipid accumulation in oleaginous microorganisms. The results of the Kog1 (the member proteins of TORC1) knockout strain constructed earlier by our group showed that the Kog1 negatively regulated lipid accumulation in the oleaginous fungus Mucor circinelloides. In this study, transcriptomic analysis of the knockout and control strains under nitrogen-limited and nitrogen-sufficient culture was carried out to investigate significant differences in lipid accumulation. Kog1 knockout led to a significant decrease in cell dry weight and an increase in lipid content in M. circinelloides. The transcriptomic results showed that genes encoding the glyoxylic acid cycle and genes encoding acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and Δ9 desaturase in lipid synthesis were upregulated to varying degrees under both conditions, indicating enhanced lipid metabolism that ultimately led to increased lipid accumulation. The knockout of the Kog1 gene also activated the pyruvate–acetaldehyde–acetate metabolic axis and significantly modified the branched-chain amino acid metabolic network, suggesting that Kog1 knockout reprograms the pathway of branched-chain amino acid synthesis and degradation, shifting the carbon flux from amino acid metabolism to acetyl-CoA accumulation. In addition, the gene encoding the SSK1p transcription factor, which participates in the nutrient stress response, was upregulated 41.9- and 51.9-fold in the Kog1 knockout strain compared with the control strain under nitrogen-limited and nitrogen-sufficient conditions, respectively. Full article