Search Results (1,019)

Objective: Insulin resistance (IR) is a complex and multifactorial disorder that contributes to type 2 diabetes and cardiovascular disease. MicroRNAs (miRNAs) play important roles in diverse developmental and disease processes. However, the molecular mechanisms of IR are unclear. This paper aims to explore the role of miRNA in regulating IR and to elucidate the mechanisms responsible for these effects. Methods: IR models were created by feeding a high-fat diet (HFD) to mice or stimulating 3T3-L1 cells with palmitate. Twelve weeks of HFD trigger weight gain, leading to lipid accumulation and insulin resistance in mice. The expression profiles of miRNAs in adipose tissues (AT) from the HFD-induced mouse models were analyzed. The relationship between miR-221-3p and SOCS1 was determined using dual luciferase reporter gene assays. Metabolic alterations in AT were investigated by real-time PCR and Western blot. Results: miR-221-3p was significantly increased in AT. HFD-induced disturbances in glucose homeostasis were aggravated by miR-221-3p upregulation. The inhibition of miR-221-3p promoted insulin sensitivity including reduced lipid accumulation and the disruption of glucose metabolism. Of note, the 3′-UTR of SOCS1 was found to be a direct target of miR-221-3p. The SOCS1 inhibitor attenuated miR-221-3p-induced increases in IRS-1 phosphorylation, AKT phosphorylation, and GLUT4. miR-221-3p was considered to be involved in the PI3K/AKT signaling pathway, thus leading to increased insulin sensitivity and decreased IR in HFD-fed mice and 3T3-L1 adipocytes. Conclusions: The miR-221-3p/SOCS1 axis in AT plays a pivotal role in the regulation of glucose metabolism, providing a novel target for treating IR and diabetes. Full article

The gut microbiota plays a significant role in metabolic diseases such as obesity. We extracted and purified a new type of pectin polysaccharide (mango peel pectin, MPP) from mango (Mangifera indica L.) peel. The structural analysis results reveal that MPP has a molecular weight (Mw) of 6.76 × 10⁵ Da and the mass fractions of the main components were galacturonic acid (21.36%), glucose (8.85%), and arabinose (5.97%). The results of methylation and NMR analyses reveal that the backbone of MPP consisted of →6)-α-D-GalpAOMe-(1→ and →4)-β-D-Glcp-(1→ linkages. Based on the above structural analysis, we further explored the therapeutic effect of MPP on high-fat diet-induced obese mice. The results demonstrate that MPP significantly suppressed body weight and dyslipidemia, reduced liver damage and lipid accumulation, attenuated changes in adipocyte hypertrophy, and improved glucose homeostasis and insulin resistance, with fasting blood glucose (FBG) levels decreasing by more than 12.8%. Furthermore, the modulatory impact of MPP on gut microbiota composition was investigated. MPP treatment significantly enhanced the levels of short-chain fatty acids (SCFAs) by decreasing the amount of Bacillota and reducing the Bacillota/Bacteroidota ratio, especially with an increase in the total SCFA content of over 64%. Meanwhile, MPP treatment encouraged beneficial bacteria to grow (e.g., Bacteroidota, Akkermansia, and Nanasyncoccus), altered the gut microbiome profiles in mice, and decreased the abundance of harmful bacteria (e.g., Paralachnospira, Coproplasma, Pseudoflavonifractor, Parabacteroides, Acetatifactor, and Phocaeicola). Overall, the findings demonstrate for the first time that MPP treats obesity by alleviating dyslipidemia, improving insulin resistance, and regulating gut microbiota to improve the intestinal environment. Full article

Diabetes is increasingly recognized as a chronic inflammatory disease marked by systemic metabolic disturbances, with endothelial dysfunction playing a central role in its complications. Hyperglycemia, a hallmark of diabetes, drives endothelial damage by inducing excessive reactive oxygen species (ROS) production, particularly hydrogen peroxide (H₂O₂). This oxidative stress impairs endothelial cells, which are vital for vascular health, leading to severe complications such as diabetic nephropathy, retinopathy, and coronary artery disease—major causes of morbidity and mortality in diabetic patients. Recent studies have highlighted the therapeutic potential of placenta-derived mesenchymal stem cells (pMSCs), in mitigating these complications. pMSCs exhibit anti-inflammatory, antioxidant, and tissue-repair properties, showing promise in reversing endothelial damage in laboratory settings. To explore their efficacy in a more physiologically relevant context, we used a streptozotocin (STZ)-induced diabetic mouse model, which mimics type 1 diabetes by destroying pancreatic beta cells and causing hyperglycemia. pMSCs were administered via intra-peritoneal injections, and their effects on endothelial injury and tissue damage were assessed. Metabolic tests, including glucose tolerance tests (GTTs) and insulin tolerance tests (ITTs) revealed that pMSCs did not restore metabolic homeostasis or improve glucose regulation. However, histopathological kidney, heart, and eye tissue analyses demonstrated significant protective effects. pMSCs preserved glomerular structure in the kidneys, protected cardiac blood vessels, and maintained retinal integrity, suggesting their potential to address diabetes-related tissue injuries. Although these findings underscore the therapeutic potential of pMSCs for diabetic complications, further research is needed to optimize dosing, elucidate molecular mechanisms, and evaluate long-term safety and efficacy. Combining pMSCs with other therapies may enhance their benefits, paving the way for future clinical applications. Full article

The pregnane X receptor (PXR), a ligand-activated nuclear receptor, plays a central role in regulating the metabolism of both endogenous substances and xenobiotics. In recent years, increasing evidence has highlighted its involvement in chronic diseases, particularly metabolic disorders and cancer. PXR modulates drug-metabolizing enzymes, transporters, inflammatory factors, lipid metabolism, and immune-related pathways, contributing to the maintenance of hepatic–intestinal barrier homeostasis, energy metabolism, and inflammatory responses. Specifically, in type 2 diabetes mellitus (T2DM), PXR influences disease progression by regulating glucose metabolism and insulin sensitivity. In obesity, it affects adipogenesis and inflammatory processes. In atherosclerosis (AS), PXR exerts protective effects through cholesterol metabolism and anti-inflammatory actions. In metabolic dysfunction-associated steatotic liver disease (MASLD), it is closely associated with lipid synthesis, oxidative stress, and gut microbiota balance. Moreover, PXR plays dual roles in various cancers, including hepatocellular carcinoma, colorectal cancer, and breast cancer. Currently, PXR-targeted strategies, such as small molecule agonists and antagonists, represent promising therapeutic avenues for treating metabolic diseases and cancer. This review comprehensively summarizes the structural features, signaling pathways, and gene regulatory functions of PXR, as well as its role in metabolic diseases and cancer, providing insights into its therapeutic potential and future drug development challenges. Full article

Regular physical activity induces a dynamic crosstalk between skeletal muscle and adipose tissue, modulating the key molecular pathways that underlie metabolic flexibility, mitochondrial function, and inflammation. This review highlights the role of myokines and adipokines—particularly IL-6, irisin, leptin, and adiponectin—in orchestrating muscle–adipose tissue communication during exercise. Exercise stimulates AMPK, PGC-1α, and SIRT1 signaling, promoting mitochondrial biogenesis, fatty acid oxidation, and autophagy, while also regulating muscle hypertrophy through the PI3K/Akt/mTOR and Wnt/β-catenin pathways. Simultaneously, adipose-derived factors like leptin and adiponectin modulate skeletal muscle metabolism via JAK/STAT3 and AdipoR1-mediated AMPK activation. Additionally, emerging exercise mimetics such as the mitochondrial-derived peptide MOTS-c and myostatin inhibitors are highlighted for their roles in increasing muscle mass, the browning of white adipose tissue, and improving systemic metabolic function. The review also addresses the role of anti-inflammatory compounds, including omega-3 polyunsaturated fatty acids and low-dose aspirin, in mitigating NF-κB and IL-6 signaling to protect mitochondrial health. The resulting metabolic flexibility, defined as the ability to efficiently switch between lipid and glucose oxidation, is enhanced through repeated exercise, counteracting age- and disease-related mitochondrial and functional decline. Together, these adaptations demonstrate the importance of inter-tissue signaling in maintaining energy homeostasis and preventing sarcopenia, obesity, and insulin resistance. Finally, here we propose a stratified treatment algorithm based on common age-related comorbidities, offering a framework for precision-based interventions that may offer a promising strategy to preserve metabolic plasticity and delay the age-associated decline in cardiometabolic health. Full article

(1) Background: Following the discovery of the adipokine/hormone asprosin, a substantial amount of research has provided evidence for its role in the regulation of glucose homeostasis, as well as appetite, and insulin sensitivity. Its levels are dysregulated in certain disease states, including breast cancer. To date, little is known about its role in endometrial cancer (EC). The present study investigated the effects of asprosin on the transcriptome of the Ishikawa and NOU-1 EC cell lines, and assessed the expression of asprosin’s candidate receptors (TLR4, PTPRD, and OR4M1) in health and disease. (2) Methods: tissue culture, RNA extraction, RNA sequencing, reverse transcription-quantitative PCR, gene enrichment and in silico analyses were used for this study. (3) Results: TLR4 and PTPRD were significantly downregulated in EC when compared to healthy controls. TLR4 appeared to have a prognostic role in terms of overall survival (OS) in EC patients (i.e., higher expression, better OS). RNA sequencing revealed that asprosin affected 289 differentially expressed genes (DEGs) in Ishikawa cells and 307 DEGs in NOU-1 cells. Pathway enrichment included apoptosis, glycolysis, hypoxia, and PI3K/AKT/ mTOR/NOTCH signalling for Ishikawa-treated cells. In NOU-1, enriched processes included inflammatory response, epithelial-mesenchymal transition, reactive oxygen species pathways, and interferon gamma responses. Other signalling pathways included mTORC1, DNA repair, and p53, amongst others. (4) Conclusions: These findings underscore the importance of understanding receptor dynamics and signalling pathways in the context of asprosin’s role in EC, and provide evidence for a potential role of TLR4 as a diagnostic biomarker. Full article

Type 2 diabetes (T2D), a growing global health concern, is closely linked to obesity and sedentary behavior. Central to its development are insulin resistance and impaired glucose metabolism in peripheral tissues, particularly skeletal muscle, which plays a key role in energy expenditure, glucose uptake, and insulin sensitivity. Notably, increased accumulation of lipid metabolites in skeletal muscle is observed both in endurance exercise—associated with improved insulin sensitivity—and in high-fat diets that induce insulin resistance. The review examines the contrasting metabolic adaptations of skeletal muscle to these opposing conditions and highlights the key signaling molecules involved. The focus then shifts to the role of the stress kinase p38α mitogen-activated protein kinase (MAPK) in skeletal muscle adaptation to overnutrition and endurance exercise. p38α enhances mitochondrial oxidative capacity and regulates nutrient utilization, both critical for maintaining metabolic homeostasis. During exercise, it cooperates with AMP-activated protein kinase (AMPK) to boost glucose uptake and fatty acid oxidation, key mechanisms for improving insulin sensitivity. The co-activation of p38α and AMPK in skeletal muscle emerges as a promising therapeutic avenue to combat insulin resistance and T2D. The review explores strategies for selectively enhancing p38α activity in skeletal muscle. In conclusion, it advocates a comprehensive approach to T2D prevention and treatment, combining established caloric intake-reducing therapies, such as GLP-1 receptor agonists, with interventions aimed at increasing energy expenditure via activation of p38α and AMPK signaling pathways. Full article

Kupffer cells (KCs) play a pivotal role in the progression of metabolic-associated steatohepatitis (MASH). This study evaluated the impact of short-term KC depletion induced by gadolinium chloride (GdCl₃) in a rat model of MASH. The intervention with GdCl₃ effectively reduced KC markers CD68 and Clec4f, together with pro-inflammatory cytokines (IL-1β, TNFα, NOS2), without affecting anti-inflammatory markers (IL-10, MRC1). Histologically, GdCl₃ reduced hepatocyte ballooning and NAS despite persistent steatosis. KC depletion was associated with decreased oxidative stress markers (TBARS, 3-nitrotyrosine) and antioxidant enzyme activity (SOD, catalase). Additionally, markers of endoplasmic reticulum stress (ATF4, GRP78, CHOP, P58^IPK) and apoptosis (BAX/BCL2 ratio, cleaved caspase-3) were diminished. Despite these improvements, GdCl₃ had no effect on lipid or glucose metabolism in the liver, associated with persistent elevation of PTP1B expression induced by SRD intake. KC depletion, however, increased FGF21 expression. GdCl₃ treatment improved systemic insulin sensitivity and reduced fasting glucose and NEFA serum levels. In white adipose tissue, the treatment decreased adipocyte size, restored insulin signaling, and inhibited lipolysis (ATGL expression) without altering macrophage infiltration (IBA) or thermogenic protein levels (UCP1) in SRD rats. These findings suggest that KC depletion modulates liver-to-adipose tissue crosstalk, potentially through FGF21 signaling, contributing to improved systemic metabolic homeostasis of SRD animals. Full article

Type 2 diabetes (T2D) is a chronic metabolic disorder requiring effective management to avoid complications. Metformin is a first-line drug agent and is routinely prescribed for the control of glycemia, but its underlying dynamics are complicated and not fully quantified. This paper formulates a control-oriented and interpretable mathematical model that integrates metformin dynamics into a classic beta-cell–insulin–glucose (BIG) regulation system. The paper’s applicability to theoretical and clinical settings is enhanced by rigorous mathematical analysis, which guarantees the model is globally bounded, well-posed, and biologically meaningful. One of the key features of the study is its global stability analysis using Lyapunov functions, which demonstrates the asymptotic stability of critical equilibrium points under realistic physiological constraints. These findings support the predictive reliability of the model in explaining long-term glycemic regulation. Bifurcation analysis also clarifies the dynamic interplay between glucose production and utilization by identifying parameter thresholds that signify transitions between homeostasis and pathological states. Residual analysis, which detects Gaussian-distributed errors, underlines the robustness of the fitting process and suggests possible refinements by including temporal effects. Sensitivity analysis highlights the predominant effect of the initial dose of metformin on long-term glucose regulation and provides practical guidance for optimizing individual treatment. Furthermore, changing the two considered metformin parameters from their optimal values—altering the dose by ±50% and the decay rate by ±20%—demonstrates the flexibility of the model in simulating glycemic responses, confirming its adaptability and its potential for optimizing personalized treatment strategies. Full article

Heme, an essential prosthetic group involved in mitochondrial respiration and transcriptional regulation, is synthesized via the rate-limiting enzyme 5-aminolevulinic acid synthase (ALAS). Utilizing heterozygous mouse models for ALAS1 and ALAS2, our studies have revealed diverse systemic consequences of chronic heme deficiency. ALAS1-heterozygous (ALAS1+/−) mice develop metabolic dysfunction characterized by insulin resistance, glucose intolerance, and abnormal glycogen accumulation, linked mechanistically to reduced AMP-activated protein kinase (AMPK) signaling. These mice also exhibit pronounced mitochondrial dysfunction, impaired autophagy, and accelerated aging phenotypes, including sarcopenia and metabolic decline, highlighting heme’s role as a critical metabolic regulator. Additionally, ALAS2 heterozygosity (ALAS2+/−) leads to impaired erythropoiesis, resulting in anemia and ineffective iron utilization. Importantly, supplementation with the heme precursor 5-aminolevulinic acid (5-ALA) significantly mitigates ALAS1+/− phenotypes, restoring metabolic function, mitochondrial health, autophagy, and immune competence. This review encapsulates key findings from our group’s research together with advances made by multiple research groups over the past decade, collectively establishing heme homeostasis as a central regulator of systemic physiology and highlighting the therapeutic potential of 5-ALA in treating heme-deficient pathologies. Full article

Vitamin D has emerged as a modulatory factor in the pathogenesis and management of diabetes mellitus due to its influence on pancreatic β-cell function, immune regulation, and inflammatory pathways. This narrative review critically examines mechanistic and clinical evidence linking vitamin D status with type 1 diabetes (T1DM), type 2 diabetes (T2DM), and gestational diabetes (GDM). In T1DM, vitamin D’s immunomodulatory effects are thought to protect β-cells from autoimmune destruction; epidemiological studies associate vitamin D sufficiency with lower T1DM incidence and improved glycemic control, although causality remains under investigation. In T2DM, vitamin D deficiency is associated with worsened metabolic control and may contribute to disease development in at-risk individuals; however, it does not influence the initial onset of T2DM in patients who are already diagnosed. Intervention trials indicate that correcting the deficiency can modestly improve insulin sensitivity, β-cell function, and metabolic parameters. GDM has similarly been linked to hypovitaminosis D, with low maternal vitamin D levels associated with higher GDM risk and adverse perinatal outcomes; mechanistic insights suggest that adequate vitamin D supports glucose homeostasis in pregnancy, and emerging trials demonstrate improved insulin resistance with maternal vitamin D supplementation. Across these diabetes subtypes, maintaining sufficient vitamin D levels appears to confer metabolic benefits and may serve as an adjunct to current preventive and therapeutic strategies. However, definitive evidence from large-scale trials is required to establish optimal vitamin D supplementation protocols and confirm its efficacy in diabetes care. Full article

Circadian rhythms are intrinsic 24 h cycles that regulate metabolic processes across multiple tissues, with skeletal muscle emerging as a central node in this temporal network. Muscle clocks govern gene expression, fuel utilisation, mitochondrial function, and insulin sensitivity, thereby maintaining systemic energy homeostasis. However, circadian misalignment, whether due to behavioural disruption, nutrient excess, or metabolic disease, impairs these rhythms and contributes to insulin resistance, and the development of obesity, and type 2 diabetes mellitus. Notably, the muscle clock remains responsive to non-photic cues, particularly exercise, which can reset and amplify circadian rhythms even in metabolically impaired states. This work synthesises multi-level evidence from rodent models, human trials, and in vitro studies to elucidate the role of skeletal muscle clocks in circadian metabolic health. It explores how exercise entrains the muscle clock via molecular pathways involving AMPK, SIRT1, and PGC-1α, and highlights the time-of-day dependency of these effects. Emerging data demonstrate that optimally timed exercise enhances glucose uptake, mitochondrial biogenesis, and circadian gene expression more effectively than time-agnostic training, especially in individuals with metabolic dysfunction. Finally, findings are integrated from multi-omic approaches that have uncovered dynamic, time-dependent molecular signatures that underpin circadian regulation and its disruption in obesity. These technologies are uncovering biomarkers and signalling nodes that may inform personalised, temporally targeted interventions. By combining mechanistic insights with translational implications, this review positions skeletal muscle clocks as both regulators and therapeutic targets in metabolic disease. It offers a conceptual framework for chrono-exercise strategies and highlights the promise of multi-omics in developing precision chrono-medicine approaches aimed at restoring circadian alignment and improving metabolic health outcomes. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) begins with hepatic lipid accumulation and triggers insulin resistance. Hibiscus leaf extract exhibits antioxidant and anti-atherosclerotic activities, and is rich in (−)-epicatechin gallate (ECG). Despite ECG’s well-known pharmacological activities and its total antioxidant capacity being stronger than that of other catechins, its regulatory effects on MASLD have not been fully described previously. Therefore, this study attempted to evaluate the anti-MASLD potential of ECG isolated from Hibiscus leaves on abnormal lipid and glucose metabolism in hepatocytes. First, oleic acid (OA) was used as an experimental model to induce lipid dysmetabolism in human primary hepatocytes. Treatment with ECG can significantly (p < 0.05) reduce the OA-induced cellular lipid accumulation. Nile red staining revealed, compared to the OA group, the inhibition percentages of 29, 61, and 82% at the tested doses of ECG, respectively. The beneficial effects of ECG were associated with the downregulation of SREBPs/HMGCR and upregulation of PPARα/CPT1 through targeting AMPK. Also, ECG at 0.4 µM produced a significant (p < 0.01) decrease in oxidative stress by 83%, and a marked (p < 0.05) increase in glycogen synthesis by 145% on the OA-exposed hepatocytes with insulin signaling blockade. Mechanistic assays indicated lipid and glucose metabolic homeostasis of ECG might be mediated via regulation of lipogenesis, fatty acid β-oxidation, and insulin resistance, as confirmed by an AMPK inhibitor. These results suggest ECG is a dual modulator of lipid and carbohydrate dysmetabolism in hepatocytes. Full article

Objectives: Paratubal cysts (PTCs) are embryological remnants and are potentially hormonally responsive. Since hyperandrogenism (HA) is representative of polycystic ovary syndrome (PCOS), we examined whether biochemical hyperandrogenism is associated with PTCs in women with PCOS and if body mass index (BMI) and insulin resistance (IR) mediate this association. Methods: This retrospective study included 577 women diagnosed with PCOS at a tertiary academic center from 2010 to 2018. Clinical data included age at diagnosis, BMI, and diagnoses of hypertension, non-alcoholic fatty liver disease, and metabolic syndrome. Laboratory measures included total testosterone, sex hormone-binding globulin, anti-Müllerian hormone, luteinizing hormone, fasting glucose, insulin, and triglycerides (TG). Derived indices included a free androgen index (FAI), homeostasis model assessment of insulin resistance (HOMA-IR), and fasting glucose-to-insulin ratio. PTCs were identified through imaging or surgical findings. Structural equation modeling (SEM) assessed direct and indirect relationships between FAI, BMI, HOMA-IR, and PTCs, while adjusting for diagnostic age. Results: PTCs were identified in 2.77% of participants. BMI, FAI, TG, and IR indices were significantly higher for women with PTCs than those without PTCs. SEM revealed significant indirect effects of FAI on PTCs via BMI and HOMA-IR. The direct effect was negative, resulting in a non-significant total effect. A sensitivity model using HOMA-IR as the predictor showed a significant direct effect on PTCs without mediation via FAI. Conclusions: Biochemical HA may influence PTC development in PCOS through metabolic pathways, establishing the need to consider metabolic context when evaluating adnexal cysts in hyperandrogenic women. Full article

Blood flow restriction training (BFRT) offers notable advantages, including simplicity and time efficiency. However, no meta-analysis has yet comprehensively evaluated its effects on glucose and lipid metabolism in overweight or obese adults. This meta-analysis examines the potential efficacy of BFRT in improving glycemic and lipid control in overweight/obese adults. The literature was searched in six databases, with the search period up to 31 March 2025. A total of eight randomized controlled trials involving 267 participants were identified. Data were analyzed using Stata 18.0 and RevMan 5.4 with random effects models. Outcomes included fasting blood glucose (FBG), homeostasis model assessment of insulin resistance (HOMA-IR), and lipid profiles, and risk of bias and publication bias (Egger’s test) were assessed. BFRT significantly reduced FBG (Hedges’ g = −1.13, 95% CI: −1.65 to −0.62, p < 0.01; I² = 66.34%) and HOMA-IR (Hedges’ g = −0.98, 95% CI: −1.35 to −0.61, p < 0.01; I² = 17.33%) compared with the controls. However, no significant changes were observed in lipid profiles. Our analysis demonstrates that BFRT exhibits the favorable effect of improving glucose metabolism in overweight/obese adults; however, current evidence does not support significant advantages of BFRT for lipid metabolism improvement. Full article