Search Results (816)

Brown adipose tissue (BAT) and beige adipocytes play a crucial role in adaptive thermogenesis, primarily via uncoupling protein 1 (UCP1)-driven heat production. Once considered physiologically irrelevant in adults, BAT is now recognized as an active tissue that contributes to energy expenditure and metabolic homeostasis and represents a potential therapeutic target for obesity and metabolic disorders. This review provides an integrated overview of the molecular regulation of thermogenic adipocytes, emphasizing both canonical UCP1-dependent as well as non-canonical UCP1-independent mechanisms of heat generation. Key transcriptional and epigenetic regulators are discussed in the context of mitochondrial biogenesis, substrate utilization, and thermogenic gene programs. Major upstream signaling routes are further summarized, encompassing classical β-adrenergic pathways, as well as alternative regulatory nodes including AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR) together with diverse nutrient- and hormone-responsive cues that converge to activate brown and beige adipocytes. Finally, the cross-talk among neuronal, endocrine, immune, and gut microbiota-derived signals is highlighted as a key determinant of thermogenic adipocyte function. Together, these multilayered regulatory inputs provide a comprehensive framework for understanding how thermogenic adipose tissue integrates environmental, metabolic, and microbial cues to regulate systemic energy balance—knowledge that is essential for developing targeted therapies to combat obesity and metabolic diseases. Full article

Berberine (BBR), a protoberberine alkaloid with a long history of medicinal use, has consistently demonstrated benefits in glucose–lipid metabolism and inflammatory balance across both preclinical and human studies. These diverse effects are not mediated by a single molecular target but by BBR’s capacity to restore network coordination among metabolic, immune, and microbial systems. At the core of this regulation is an AMP-activated Protein Kinase (AMPK)-centered mechanistic hub, integrating signals from insulin and nutrient sensing, Sirtuin 1/3 (SIRT1/3)-mediated mitochondrial adaptation, and inflammatory pathways such as nuclear Factor Kappa-light-chain-enhancer of Activated B cells (NF-κB) and NOD-, LRR- and Pyrin Domain-containing Protein 3 (NLRP3). This hub is dynamically regulated by system-level inputs from the gut, mitochondria, and epigenome, which in turn strengthen intestinal barrier function, reshape microbial and bile-acid metabolites, improve redox balance, and potentially reverse the epigenetic imprint of metabolic stress. These interactions propagate through multi-organ axes, linking the gut, liver, adipose, and vascular systems, thus aligning local metabolic adjustments with systemic homeostasis. Within this framework, BBR functions as a negentropic modulator, reducing metabolic entropy by fostering a coordinated balance among these interconnected systems, thereby restoring physiological order. Combination strategies, such as pairing BBR with metformin, Sodium-Glucose Cotransporter 2 (SGLT2) inhibitors, and agents targeting the microbiome or inflammation, have shown enhanced efficacy and substantial translational potential. Berberine ursodeoxycholate (HTD1801), an ionic-salt derivative of BBR currently in Phase III trials and directly compared with dapagliflozin, exemplifies the therapeutic promise of such approaches. Within the hub–axis paradigm, BBR emerges as a systems-level modulator that recouples energy, immune, and microbial circuits to drive multi-organ remodeling. Full article

Background: Preeclampsia (PE) is a hypertensive disorder of pregnancy associated with oxidative stress and mitochondrial dysfunction. NRF1 and NRF2 are transcription factors that regulate mitochondrial activity and antioxidant defense. This study investigated their expression patterns in placentas from preeclamptic and severe preeclamptic pregnancies by immunohistochemical and bioinformatical methods. Methods: Placentas from 40 healthy controls, 40 PE, and 40 sPE patients were analyzed by histological and immunohistochemical techniques. Protein–protein interaction networks for NRF1, NRF2, and PE-related proteins were constructed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape software, followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis performed via ShinyGO, with significance set at false discovery rate (FDR) < 0.05. Results: NRF1 expression was significantly decreased in PE and sPE groups compared to controls, with notably negative staining in syncytial knots and fibrinoid areas. Conversely, NRF2 expression significantly increased, showing intense positivity in syncytiotrophoblasts, stromal cells, and vascular structures. Pathway analysis revealed that decreased NRF1 expression was associated with glutathione metabolism, hypoxia inducible factor-1 (HIF-1) signaling, and AMP-Activated Protein Kinase (AMPK) signaling pathways. Increased NRF2 expression was associated predominantly with inflammatory and immune response pathways, including AGE-RAGE signaling and pathogen–response pathways. Conclusions: Differential expressions of NRF1 and NRF2 in preeclamptic placentas reflect distinct yet interconnected responses to oxidative stress and inflammation. These transcription factors have potential clinical relevance as biomarkers for PE severity assessment and as targets for future therapeutic interventions. Full article

Metabolic reprogramming allows cancer cells to proliferate rapidly, survive nutrient limitation, and resist stress, making tumor metabolism an important therapeutic target. However, pharmacological inhibition of metabolic enzymes often causes systemic toxicity and compensatory pathway activation. To overcome these limitations, recent studies have highlighted an alternative host-centered strategy based on increasing systemic energy expenditure. Recent studies highlight an alternative strategy in which the host increases energy expenditure through uncoupling protein 1 (UCP1) dependent thermogenesis, thereby lowering systemic glucose, fatty acid, and nucleotide availability for tumors. Engineered beige adipocytes overexpressing UCP1, PR domain-containing protein 16 (PRDM16), or peroxisome proliferator–activated receptor gamma coactivator 1 alpha (PPARGC1A/PGC1A) suppress tumor growth through nutrient competition, suggesting that activating endogenous UCP1 may provide a non-genetic and physiologically aligned anticancer approach. Building on this concept, natural products such as polyphenols, terpenoids, alkaloids, and carotenoids have emerged as promising UCP1 activators that stimulate beige and brown adipocyte thermogenesis through pathways involving AMP-activated protein kinase (AMPK), sirtuin 1 (SIRT1), PGC1A, PRDM16, and mitochondrial biogenesis. In parallel, computational studies further indicate that several plant-derived compounds bind directly to the central cavity of UCP1 with high affinity, offering structural support for their thermogenic action. Importantly, many of these compounds also inhibit cancer cell intrinsic metabolism by reducing glycolysis, oxidative phosphorylation, lipid synthesis, and amino acid dependent anaplerosis. This review integrates UCP1 biology, natural product mediated thermogenesis, molecular docking evidence, and tumor metabolic suppression, proposing a unified framework in which natural compounds impose coordinated metabolic pressure on cancer through both adipocyte-driven nutrient competition and direct inhibition of tumor metabolism. Full article

Mitochondrial dysfunction represents a central hallmark of aging and a broad spectrum of chronic diseases, ranging from metabolic to neurodegenerative and ocular disorders. Nicotinamide riboside (NR), a vitamin B₃ derivative and efficient precursor of NAD⁺ (nicotinamide adenine dinucleotide), and berberine (BBR), an isoquinoline alkaloid widely investigated in metabolic regulation, have independently emerged as promising mitochondrial modulators. NR enhances cellular NAD⁺ pools, thereby activating sirtuin-dependent pathways, stimulating PGC-1α–mediated mitochondrial biogenesis, and triggering the mitochondrial unfolded protein response (UPR^mt). BBR, by contrast, primarily activates AMPK (AMP-activated protein kinase) and interacts with respiratory complex I, improving bioenergetics, reducing mitochondrial reactive oxygen species, and promoting mitophagy and organelle quality control. Importantly, despite distinct upstream mechanisms, NR and BBR converge on shared signaling pathways that support mitochondrial health, including redox balance, metabolic flexibility, and immunometabolic regulation. Unlike previous reviews addressing these compounds separately, this article integrates current preclinical and clinical findings to provide a unified perspective on their converging actions. We critically discuss translational opportunities as well as limitations, including heterogeneous clinical outcomes and the need for robust biomarkers of mitochondrial function. By outlining overlapping and complementary mechanisms, we highlight NR and BBR as rational combinatorial strategies to restore mitochondrial resilience. This integrative perspective may guide the design of next-generation clinical trials and advance precision approaches in mitochondrial medicine. Full article

The treatment of diabetes in the modern era, with its growing patient population, represents a significant challenge due to the wide range of adverse effects associated with medications that target complex biochemical processes. Consequently, researchers are investigating the hypoglycemic potential of existing drugs. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat pain, fever, and various inflammatory conditions. Recent studies have shown that NSAIDs, particularly salicylates, can influence glycemia through multiple mechanisms, including inhibition of gastrointestinal enzymes, blockade of K_ATP channels, activation of AMP-activated protein kinase (AMPK), and inhibition of NF-κB signaling, among others. Accordingly, this review explores the hypoglycemic potential of NSAIDs as well as their derivatives, and the diverse mechanisms through which these molecules may influence glucose homeostasis. Full article

Phosphate is emerging as an active mediator of oxidative stress and vascular injury in chronic kidney disease (CKD). This emerging pathophysiological framework, referred to as “Phosphatopathy”, describes the systemic syndrome driven by chronic phosphate overload and characterized by oxidative stress, inflammation, endothelial dysfunction, vascular calcification, cellular senescence, and metabolic imbalance. Beyond being a biochemical marker, phosphate overload triggers NOX-derived reactive oxygen species (ROS), activates Wnt/β-catenin and TGF-β signaling, and disrupts the FGF23–Klotho axis, promoting endothelial dysfunction, vascular calcification, and left ventricular hypertrophy (LVH). These pathways converge with systemic inflammation and energy imbalance, contributing to the malnutrition–inflammation–atherosclerosis (MIA) syndrome. Experimental and clinical data reveal that the phosphate/urinary urea nitrogen (P/UUN) ratio is a sensitive biomarker of inorganic phosphate load, while emerging regulators such as microRNA-125b and calciprotein particles integrate phosphate-driven oxidative and inflammatory responses. Therapeutic strategies targeting phosphate burden—rather than serum phosphate alone—include dietary restriction of inorganic phosphate, non-calcium binders, magnesium and zinc supplementation, and activation of important pathways related to the activation of antioxidant defense such as AMP-activated protein kinase (AMPK) and SIRT1. This integrative framework redefines phosphate as a modifiable upstream trigger of oxidative and metabolic stress in CKD. Controlling phosphate load and redox imbalance emerges as a convergent strategy to prevent vascular calcification, improve arterial stiffness, and reduce cardiovascular risk through personalized, mechanism-based interventions. Full article

Background: Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide and are strongly influenced by dietary habits. Beyond caloric intake, nutrients act as molecular signals that regulate cardiac metabolism, mitochondrial function, inflammation, and epigenetic remodeling. Objectives: This review aims to synthesize current evidence on how dietary patterns and specific nutritional interventions regulate cardiac metabolism and function through interconnected molecular and epigenetic mechanisms, highlighting their relevance for cardiovascular disease prevention. Methods: A narrative review of the literature was conducted using PubMed, Scopus, and Web of Science, focusing on studies published between 2006 and 2025. Experimental, translational, and clinical studies addressing diet-induced modulation of cardiac metabolic pathways, oxidative and inflammatory signaling, epigenetic regulation, and gut microbiota-derived metabolites were included. Results: The analyzed literature consistently shows that unbalanced diets rich in saturated fats and refined carbohydrates impair cardiac metabolic flexibility by disrupting key nutrient-sensing pathways, including AMP-activated protein kinase (AMPK), proliferator-activated receptor alpha (PPARα), mammalian target of rapamycin (mTOR), and sirtuin 1/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (SIRT1/PGC-1α), leading to mitochondrial dysfunction, oxidative stress, chronic inflammation, and maladaptive remodeling. In contrast, cardioprotective dietary patterns, such as caloric restriction (CR), intermittent fasting (IF), and Mediterranean and plant-based diets, enhance mitochondrial efficiency, redox balance, and metabolic adaptability. These effects are mediated by coordinated activation of AMPK-SIRT1 signaling, suppression of mTOR over-activation, modulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways, and favorable epigenetic remodeling involving DNA methylation, histone modifications, and non-coding RNAs. Emerging evidence also highlights the central role of gut microbiota-derived metabolites, particularly short-chain fatty acids, in linking diet to epigenetic and metabolic regulation of cardiac function. Conclusions: Diet quality emerges as a key determinant of cardiac metabolic health, acting through integrated molecular, epigenetic, and microbiota-mediated mechanisms. Targeted nutritional strategies can induce long-lasting cardioprotective metabolic and epigenetic adaptations, supporting the concept of diet as a modifiable molecular intervention. These findings provide a mechanistic rationale for integrating personalized nutrition into cardiovascular prevention and precision cardiology, complementing standard pharmacological therapies. Full article

Objective: To explore the preventive effect and mechanism of melatonin on high-fructose-induced renal injury in mice. Methods: A total of forty male C57BL/6J mice aged six weeks were randomly assigned to four groups: control group (CON), melatonin group (MLT), fructose group (FRU), and fructose + melatonin group (FRU + MLT). The concentration of the fructose solution was 30%, and the dose of melatonin was 10 mg/kg/day by intragastric administration. The experiment lasts for 10 weeks. Results: Liquid intake and energy intake were comparable between the FRU and FRU + MLT, both of which were significantly higher than that in the CON and MLT. MLT inhibited fructose-induced increased levels in serum creatinine (Cre), serum urea nitrogen (BUN), serum uric acid (UA), serum triglyceride (TG), renal kidney injury molecule-1 (KIM-1), and renal TG. Hematoxylin and Eosin (H&E) staining and Oil Red O (ORO) staining showed that MLT alleviated renal tubular dilatation, loss of brush border, epithelial cell detachment and lipid accumulation. Transmission electron microscope (TEM) observations showed that MLT increased autophagic vacuoles among mitochondria. Western blot analysis showed that, compared with the FRU, the FRU + MLT had elevated expression of AMP-activated protein kinase (AMPK) phosphorylation, along with a significant increase in the expression of its downstream mitophagy-related proteins (including PINK1, Parkin, LC3 II, and Beclin1), whereas the expression of p62 was markedly decreased. Furthermore, the expression levels of FAO-related proteins (including PPARα and CPT1A) in the FRU + MLT were significantly upregulated. Conclusions: MLT alleviates renal injury caused by high-fructose exposure in male mice and its mechanism might be associated with the regulation of mitophagy and fatty acid oxidation. Full article

Glycemic control disorders, including insulin resistance (IR) and type 2 diabetes (T2D), represent a major global health challenge. Although existing therapeutic strategies demonstrate effectiveness regarding glycemic control and reduction in diabetes-associated mortality, they are often associated with limited patient tolerance and adherence. Consequently, there is growing interest in natural bioactive compounds that may support glycemic regulation while potentially posing a lower risk of adverse effects in ongoing therapy. The objective of this review is to evaluate the potential of selected natural substances in the context of blood glucose regulation. The analysis encompasses data from in vitro, in vivo, and clinical studies on compounds such as mannoheptulose, β-carotene, resveratrol, steviol glycosides, and curcumin. These agents have demonstrated the ability to modulate key metabolic pathways, enhance tissue insulin sensitivity, reduce oxidative stress, and support pancreatic β-cell function. Particularly promising effects have been observed when some of these compounds are combined with conventional antidiabetic medications, such as metformin. The review also highlights relevant molecular mechanisms, including activation of the AMP-activated protein kinase (AMPK) pathway, increased expression of glucose transporter type 4 (GLUT4), and modulation of gene expression related to insulin sensitivity. Despite encouraging findings, further clinical research is necessary to determine optimal dosages, therapeutic protocols, and the long-term safety of these substances in human populations. Natural bioactive compounds may thus represent a valuable adjunct to current strategies for managing glycemic disorders. Full article

Background: Obesity has emerged as a significant public health challenge largely attributed to excessive dietary fat consumption. A growing body of evidence indicates that soluble dietary fiber (SDF) can prevent high-fat-diet (HFD)-induced obesity by modulating the gut microbiota. Our previous studies have shown that SDF derived from highland barley bran exhibits favorable lipid-lowering activity in vitro, but its lipid-lowering effect in vivo remains to be elucidated. Methods: This study aimed to investigate the lipid-lowering effects of SDF from highland barley bran in HFD-fed mice based on the gut microbiota. Mice were fed an HFD, and the intervention effects of SDF on hepatic lipid metabolism and its underlying molecular mechanisms were systematically evaluated using liver lipidomics, 16S rDNA sequencing, molecular biological techniques, and fecal microbiota transplantation (FMT). Results: Liver lipidomics analysis revealed that potential lipid biomarkers responsive to barley bran-derived SDF included phosphatidylethanolamines (PE, 18:2–20:3), phosphatidylserine (PS, 18:0–18:2), and PS (18:1–22:3). Furthermore, SDF modulated the composition and structure of the gut microbiota in HFD-fed mice. Notably, SDF increased the abundance of short-chain fatty acid (SCFA)-producing bacteria, particularly Dubosiella, as well as elevated SCFA levels. Conclusions: The increase in SCFAs activated the hepatic AMP-activated protein kinase α (AMPK) signaling pathway, thereby ameliorating HFD-induced disturbances in lipid metabolism, reducing hepatic lipid accumulation, and lowering serum lipid concentrations. Full article

Obesity is linked to metabolic dysfunction-associated steatotic liver disease (MASLD), but the molecular mechanisms and effective treatments remain unclear. This study investigated whether ST32db, an inducer of activating transcription factor 3 (ATF3), affects lipid metabolism in MASLD. An in vitro model was established involving the treatment of HepG2 cells with 1 mM oleic acid (OA) with or without 20 µM ST32db. In an in vivo model, C57BL/6 mice were fed a high-fat diet (HFD) for 18 weeks to induce obesity and treated or not with ST32db (1 mg kg⁻¹). ST32db significantly decreased intracellular lipid accumulation in OA-treated HepG2 cells. In these cells, ST32db remarkably decreased mRNA and protein levels of adipogenesis- and lipogenesis-related genes and increased mRNA levels of adipose triglyceride lipase (ATGL), a lipolytic enzyme. In HFD-fed mice, the ST32db treatment significantly decreased the liver weight, serum triglycerides, and fat vacuole and triglyceride accumulation in the liver. Livers from these mice also showed significantly decreased CCAAT/enhancer-binding protein β mRNA and protein levels, increased ATF3 mRNA and protein and ATGL mRNA levels, and increased levels of phosphorylated AMP-activated protein kinase (AMPK) and protein kinase A (PKA). These findings suggest that ST32db may exert protective effects against MASLD through activating hepatic AMPK and PKA pathways. Full article

Static cold storage (SCS) remains the most widely used method of liver graft preservation due to its simplicity, accessibility, and reduced cost in transplantation practice. Since the invention of the University of Wisconsin (UW) solution, several alternative preservation solutions—including histidine–tryptophan–ketoglutarate (HTK), Celsior, and more recently IGL-1 and IGL-2—have been formulated to optimize cellular and vascular protection during cold ischemia. More recently, the introduction of dynamic perfusion techniques, such as hypothermic oxygenated perfusion (HOPE) and normothermic machine perfusion (NMP), approximately fifteen years ago, has further enhanced transplantation protocols, being applied either alone or in combination with traditional SCS to ensure optimal graft preservation prior to implantation. Despite these technological advances, achieving fully effective dynamic perfusion remains a key challenge for improving outcomes in vulnerable grafts, particularly steatotic or marginal livers. This review details how Polyethylene Glycol 35 (PEG35)-based solutions activate multiple cytoprotective pathways during SCS, including AMP-activated protein kinase (AMPK), nitric oxide (NO) production, and the antioxidant transcription factor Nrf2. We propose that these molecular mechanisms serve as a form of preconditioning that is synergistically leveraged by HOPE to preserve mitochondrial function, endothelial glycocalyx integrity, and microvascular homeostasis. Furthermore, the oncotic and rheological properties of PEG35 reduce perfusate viscosity, mitigating shear stress and microcirculatory damage during dynamic perfusion—effects that are further enhanced by NO- and AMPK-mediated protection initiated during the SCS phase. This integrated approach provides a strong rationale for combining PEG35-mediated SCS with HOPE, particularly for grafts with high susceptibility to ischemia–reperfusion injury, such as fatty livers. Finally, we highlight emerging avenues in graft preservation, including the design of unified perfusion solutions that optimize endothelial, mitochondrial, and redox protection, with the potential to improve post-transplant outcomes and extend applicability to other solid organ grafts. Full article

Background/Objectives: The cerebral cortex is critical for neurological functions that are strongly affected by the aging process. Astrocytes play a central role in maintaining neurotransmitter balance and regulating antioxidant and anti-inflammatory responses, but these physiological functions may also decline with age. This study aimed to investigate the effects of melatonin, a molecule with known antioxidant, anti-inflammatory and neuroprotective properties, on astrocytes of mature cortical tissue obtained from adult Wistar rats. Methods: Primary cortical astrocyte cultures were obtained from neonatal and 90-day-old Wistar rats and treated with melatonin (300 µM for 24 h). We assessed cell viability and metabolism (MTT and extracellular lactate levels), glutamine synthetase (GS) activity, glutathione (GSH) content, release of cytokines, and the expression of genes and proteins associated with oxidative stress and inflammation by RT-qPCR and Western blotting. Results: Melatonin did not affect cell viability or lactate production. Moreover, there were no changes in GS activity, a key enzyme in glutamate metabolism, or in GSH levels, an antioxidant defense molecule synthesized by astrocytes. However, melatonin significantly reduced the expression of the nuclear factor NFκB, cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS), while increasing interleukin 6 and 10 levels. Melatonin also upregulated the gene expression of the transcriptional factors Nrf2 and sirtuin 1 (SIRT1) and downregulated AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), while PGC-1α protein levels remained unchanged. A complementary analysis of astrocytes obtained from neonatal rats showed that melatonin did not change metabolic or redox parameters under basal conditions. Conclusions: Melatonin exerted anti-inflammatory effects on adult astrocyte cultures, likely through modulation of protective signaling pathways, such as Nrf2/SIRT1. These findings highlight the potential role of melatonin in preserving astrocytic function and mitigating age-related neuroinflammatory processes. Full article

Background and Objectives: The quality of cumulus cells (CCs) is a major determinant of germinal vesicle (GV) oocyte maturation, yet the reciprocal effect of GV oocytes on cumulus cell function remains unclear. Materials and Methods: GV oocytes were cultured with or without cumulus cells (only oocytes or Oocytes–CCs), and GVBD rates were evaluated after 24 h. In parallel, cumulus cells were cultured either alone (only cumulus) or with oocytes (CCs + Oocytes). Cell morphology, growth, intracellular reactive oxygen species (ROS), and AMP-activated protein kinase (AMPK) expression were assessed by fluorescence and immunocytochemistry. Results: GVBD rates were significantly higher in Oocytes + CCs than in only oocytes (66.7% vs. 18.2%, p < 0.05). Cumulus cells co-cultured with oocytes exhibited improved growth, tighter cell connections, and greater extracellular matrix formation. ROS levels were reduced in CCs + Oocytes compared with only the cumulus group (12.1% vs. 21.9%, p < 0.01), whereas AMPK expression increased markedly (229% of CCs–Oocytes, p < 0.0001). Conclusions: In vitro co-culture underscores not only the supportive role of cumulus cells in oocyte maturation but also a reciprocal, beneficial effect of oocytes on cumulus cell viability and function, revealing the bidirectional nature of oocyte–cumulus interactions. Full article