Search Results (117)

Brown adipose tissue (BAT) has emerged as a promising therapeutic target for metabolic disorders such as type 2 diabetes and obesity. To advance research on BAT activation and elucidate the mechanisms underlying adipogenesis, it is crucial to develop a reliable in vitro model. This study aimed to optimize the differentiation of adipose-derived stem cells (ADSCs) into beige adipocytes and to validate the protocol using primary human ADSCs obtained from eight donors. Protocol optimization was first performed with commercial ADSCs, testing more than 30 combinations of adipogenic conditions. Differentiation was assessed by microscopy, Oil Red O staining, and uncoupling protein 1 (UCP1) expression via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot. Among the key adipogenic factors, rosiglitazone proved more effective than indomethacin. Extending the induction phase from 4 to 8 days and maintaining dexamethasone throughout the culture markedly enhanced differentiation efficiency. Serum concentration above 5% was inhibitory, while optimal conditions were identified as 5 μM rosiglitazone and 20 μg/mL insulin. The optimized protocol successfully induced beige adipogenesis in ADSCs from eight independent donors, though efficiency varied considerably which could be attributed to individual donor variability. These findings provide a robust in vitro model for studying beige fat biology and highlight the relevance of personalized approaches in metabolic research. Full article

Background/Objectives: Rosiglitazone (RSG), a potent PPARγ agonist for type 2 diabetes mellitus (T2DM), induces adverse adipogenic effects that limit clinical use. We investigated whether emodin (1,3,8-trihydroxy-6-methylanthraquinone, EMO), a natural anthraquinone, mitigates RSG-induced complications while enhancing its insulin-sensitizing benefits in severe obesity. Methods: Male ob/ob mice with established obesity and diabetes were treated for 4 weeks with RSG (10 mg kg⁻¹ day⁻¹), EMO (200 or 400 mg kg⁻¹ day⁻¹) or their combination. Metabolic profiling, organ function, and adipose histology were analyzed. RNA sequencing and mechanistic studies (Western blot, RT-qPCR, luciferase assays) in inguinal subcutaneous adipose tissue (iSAT), epididymal white adipose tissue (eWAT), and 3T3-L1 adipocytes were used to define EMO’s actions. Results: EMO co-treatment dose-dependently reduced RSG-induced weight gain, visceral adiposity (iSAT and eWAT mass, p < 0.05), and ectopic lipid deposition while ameliorating hepatorenal dysfunction. EMO synergistically enhanced RSG’s glucose-lowering effects. Mechanistically, EMO suppressed sterol regulatory element-binding protein 1 (SREBP1)-mediated lipogenesis (Srebp1, Acc, Fasn, Scd1; p < 0.05) and enhanced PPARγ-peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α)-driven thermogenesis via enhanced PPARγ transactivation and nuclear translocation. Thermogenic genes (Ucp1, Ppargc1a, Cidea; p < 0.05) were upregulated, with maximal uncoupling protein 1 (UCP1) induction in iSAT at 400 mg/kg EMO. Conclusions: EMO selectively enhances RSG’s glycemic benefits while attenuating its adipogenic effects in severe obesity by dual PPARγ modulation-inhibiting adipogenic pathways while amplifying thermogenesis. This strategy mitigates RSG’s adverse effects while improving insulin sensitivity, supporting the potential of EMO as a PPARγ adjunct therapy. Full article

Genipin, a natural compound derived from Gardenia jasminoides, is widely used as an inhibitor of uncoupling protein 2 (UCP2), a protein located in the inner mitochondrial membrane (IMM) that plays a crucial role in regulating oxidative stress and cellular metabolism. Pharmacological inhibition of UCP2 has been explored as a strategy to modulate reactive oxygen species (ROS) and inflammatory responses. However, the utility of genipin is limited by its relatively low bioavailability and dose-dependent toxicity. To address these limitations, we developed mito-genipin, a mitochondria-targeted genipin derivative incorporating a triphenylphosphonium (TPP⁺) moiety, designed to enhance mitochondrial accumulation and thereby increase efficacy. In macrophages, mito-genipin induced mitochondrial hyperpolarization, elevated ROS production, and amplified pro-inflammatory cytokine expression compared with control or genipin treatment. In cells lacking UCP2, mito-genipin did not enhance ROS production. Our data identify mito-genipin as an effective modulator of oxidative stress and inflammation, supporting a putative link to UCP2 inhibition and highlighting potential implications in redox biology and immunomodulation. Full article

Brown adipose tissue (BAT) has shifted from being considered a transient thermogenic organ of infancy to a metabolically dynamic and multifunctional tissue throughout life. Histologically and developmentally distinct from white and beige adipocytes, BAT originates from a myogenic lineage and is characterised by a high mitochondrial density, multilocular lipid droplets, and abundant sympathetic innervation. Its defining function, non-shivering thermogenesis, is mediated by uncoupling protein 1 (UCP1) and complemented by alternative mechanisms such as futile creatine and calcium cycling. Beyond heat production, thermogenic fat is crucial in regulating whole-body metabolism. It contributes to glucose, lipid, and branched-chain amino acid homeostasis, and engages in endocrine and paracrine signalling through a rich secretome of batokines, lipid mediators, and extracellular vesicle-bound microRNAs. These signals orchestrate crosstalk with the liver, skeletal muscle, pancreas, and immune system, enhancing insulin sensitivity, vascularisation, and anti-inflammatory responses. Brown/Beige fat also exhibits notable anti-fibrotic properties and supports adipose tissue remodelling, maintaining structural and functional plasticity under metabolic stress. This review offers a comprehensive synthesis of thermogenic adipose tissue biology, integrating its structural, developmental, and molecular features with its expanding physiological functions, highlighting its pivotal role in energy balance as well as its emerging therapeutic potential in obesity, type 2 diabetes, and related metabolic disorders. Full article

Ectopic lipid accumulation is a core contributor to insulin resistance and metabolic diseases, including type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease. Conventional therapies have primarily focused on redistributing lipid burden across tissues or modulating specific pathways. However, this often causes compensatory responses that merely shift the burden rather than resolve the underlying lipid excess. In this review, we introduce the concept of the ballooning effect, wherein single-target interventions inadvertently exacerbate lipid accumulation in non-target tissues. We then explore fundamental strategies for true lipid disposal, which aim either to prevent lipid influx or to promote complete lipid oxidation. Among these, mild mitochondrial uncoupling emerges as a promising solution. By dissipating substrate energy as heat, mitochondrial uncoupling reduces ectopic lipid burden without relying on redistribution. Recent advances have yielded safer chemical uncouplers and novel endogenous protein-based mechanisms that enable controlled uncoupling with minimal toxicity. Together, these provide a new framework for next-generation metabolic therapies that move beyond lipid redistribution and aim for a true lipid disposal, potentially offering a safe and effective strategy. Full article

Oxidative stress poses a significant challenge in livestock production, impairing intestinal function, nutrient absorption, and overall animal performance. Uncoupling protein 2 (UCP2) is a mitochondrial regulator known for its protective effects against oxidative damage, but its specific function in porcine intestinal epithelial cells and its regulation by genipin—a natural UCP2 inhibitor with potential therapeutic properties—remains unclear. In this study, we cloned and overexpressed the porcine UCP2 gene in intestinal porcine epithelial cells (IPEC-J2), generating a stable UCP2-overexpressing cell line (IPEC-J2-UCP2). Under hydrogen peroxide-induced oxidative stress, UCP2 overexpression significantly improved cell viability, reduced reactive oxygen species (ROS) levels, and enhanced antioxidant enzyme activities (SOD, GPx, and CAT). Additionally, UCP2 upregulated the anti-apoptotic gene Bcl-2 and downregulated pro-apoptotic genes (Fas, Caspase-3, and Bax), indicating a protective role against oxidative stress-induced apoptosis. We also investigated the regulatory effects of genipin on UCP2. Under non-stress conditions, genipin mildly promoted anti-apoptotic gene expression. However, under oxidative stress, genipin strongly inhibited UCP2 expression, exacerbated ROS accumulation, reduced cell viability, and increased expression of pro-apoptotic markers, particularly Caspase-3 and Bax. These findings reveal that UCP2 plays a critical role in protecting porcine intestinal epithelial cells from oxidative injury and that genipin exerts context-dependent effects on cell fate by modulating UCP2. This study provides a mechanistic basis for targeting UCP2 to manage oxidative stress and improve intestinal health and performance in pigs. Full article

Background: Pleurotus salmoneostramineus is acknowledged as a reliable source of high-quality protein, with its protein concentrates, hydrolysates, and peptides potentially offering health benefits to humans. However, studies validating the medicinal effects of P. salmoneostramineus proteins, particularly the pink chromoprotein, are currently absent. Methods: This study explores anticancer peptides from the chromoprotein of P. salmoneostramineus, evaluating their ability to bind UCP2 via in silico analysis. Additionally, it assesses the protein hydrolysate from P. salmoneostramineus (PSPs) effect on HepG2 cell proliferation and mitochondrial metabolism, focusing on uncoupling protein activity. Results: Eight peptides were identified as potential UCP2 inhibitors. According to mACPpred2.0 and CSM-peptides servers, the peptides TSMQSSL, QEGQKL, SEDSGEA, and GRNSL exhibit promising anticancer properties. These anticancer peptides yielded the following docking scores (kcal/mol) when tested against UCP2: TSMQSSL (−166.75), QEGQKL (−126.06), SEDSGEA (−99.93), and GRNSL (−137.93). Molecular dynamics simulations have shown that the peptides establish stable interactions with UCP2 through salt bridges, hydrophobic interactions, and hydrogen bonds, implying that hydrogen bonding with RRR88 and FVW92 causes conformational changes in UCP2. Moreover, the outcomes of this study indicated that PSPs possess an antiproliferative effect on HepG2 cells and lower mitochondrial bioenergetics, especially UCP2 activity. Conclusions: These findings suggest that peptides from P.salmoneostramineus can inhibit UCP2, offering a promising approach for cancer prevention, playing therapeutic roles in treatment, and providing a basis for designing peptide-based cancer therapies. Full article

Uncoupling protein 2 (UCP2) plays an important role in normal cells because it mitigates the cytotoxic effect of reactive oxygen species (ROS). However, its overexpression in cancer cells is related to drug resistance and increased cell proliferation due to a decrease in ROS production. In this context, molecules that regulate or block UCP2 have potential as anticancer agents. (-)-Epicatechin, a flavonoid that inhibits cell proliferation, increases ROS, and induces apoptosis in cancerous cells, was evaluated for its effects on UCP2 gene expression. For this purpose, the real-time quantitative polymerase chain reaction (qRT–PCR) and Western blotting were performed in MDA-MB-231 and MCF-10A cells to determine the effects of (-)-epicatechin on UCP2 expression. Furthermore, the impact of (-)-epicatechin on cell viability was also determined. To analyze the transcriptional regulation of the UCP2 gene by (-)-epicatechin, a 5′-region of the human UCP2 gene (−2093/+297) was amplified, sequenced, cloned, and inserted into a reporter plasmid. To analyze the promoter activity and regulatory motif involved in the effects of (-)-epicatechin, several deletions of the UCP2 promoter were generated and transfected into MDA-MB-231 and MCF-10A cells. An electrophoretic mobility shift assay (EMSA) was carried out to detect the interaction between DNA and proteins involved in the effect of (-)-epicatechin. The increased expression of the UCP2 gene in MDA-MB-231 cells was decreased by (-)-epicatechin, and the opposite effect was observed in MCF-10A cells. The promoter region of the human UCP2 gene (−2093/+297) showed activity, which was decreased by (-)-epicatechin. A sequence of 117 bp located at position −109 b to +8 b has a fragment of 90 bp that is related to the (-)-epicatechin effect. Bioinformatics analysis and EMSA of this sequence revealed the presence of a regulatory site for a protein with zinc fingers. The presence of a response element to (-)-epicatechin in the human UCP2 promoter revealed that the inhibition of this gene in MDA-MB-231 breast cancer cells occurred at the transcriptional level. In this study, we propose the mechanism of action of (-)-epicatechin that could aid in cancer treatment. Full article

Six isoforms of uncoupling proteins (UCPs) exist, spanning from UCP1 to UCP6. A precise physiological function has only been established for UCP1, which is involved in non-shivering thermogenesis, but the functions of other UCPs are still not fully defined. Therefore, the purpose of the present study is to search for indications of the involvement of nine polymorphic variants of UCP1-6 genes in human adaptation to cold climates using four criteria: (1) the presence of associations of polymorphic variants of UCP genes with levels of thyroid-stimulating hormone, free triiodothyronine, and free thyroxine; (2) the presence of associations of polymorphic variants of UCP genes with changes in thyroid homeostasis (SPINA); (3) the presence of associations of polymorphic variants of UCP genes with body surface area; (4) the presence of signals of directional selection to cold climate for polymorphic variants of UCP genes. As a result of the evaluation, the highest scores for cold adaptation traits were recorded for polymorphic variants rs3811787 of the UCP1 gene and rs1800849 of the UCP3 gene. We suggest that the results obtained indicate the importance of uncoupling proteins UCP1 and UCP3 in human adaptation to cold through processes of non-shivering and shivering thermogenesis. Full article

Oxidative stress, a pivotal driver of neurodegenerative diseases, results from an imbalance between the generation of reactive oxygen species (ROS) and cellular antioxidant defenses. This review provides a comprehensive analysis of key oxidative stress sources, focusing on NADPH oxidase (NOX) hyperactivity and mitochondrial Uncoupling Protein (UCP) downregulation. Critically, we examine the therapeutic potential of phytochemicals in mitigating NOX-mediated ROS generation through direct enzyme inhibition, including impacts on NOX subunit assembly and gene expression. Furthermore, we explore the ability of phytochemicals to bolster cellular antioxidant defenses by activating the Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway, elucidating the upregulation of antioxidant genes, such as GPx, SOD, CAT, and HO-1. This review expands beyond confined overviews; emphasizes specific molecular interactions between phytochemicals and target proteins, including NOX isoforms; and provides an in-depth analysis of the specific antioxidant genes upregulated via Nrf2. This approach aims to pave the way for targeted and translatable therapeutic strategies in neurodegenerative diseases. Ultimately, this review illuminates the intricate molecular dynamics of oxidative stress in neurodegenerative diseases; underscores the potential of phytochemicals to restore redox homeostasis and reverse pathological conditions through precise modulation of key signaling pathways. Full article

Adaptive thermogenesis comprises shivering thermogenesis dependent on skeletal muscles and non-shivering thermogenesis (NST) mediated by uncoupling protein 1 (UCP1). Although the thermogenic function of UCP1 was adopted early in some placental mammals, positive selection predominantly occurred in the ancestral branches of small-bodied species. Some previous studies have revealed that rodents living in northern or high mountain regions adapt to cold environments by increasing NST, whereas those living in tropical and subtropical regions that are not exposed to cold stress express low concentrations of UCP1, indicating that UCP1 may have evolved to adapt to ambient temperatures. In this study, we explored the evolution of UCP1 and its significance to temperature adaptation by performing detailed evolutionary and statistical analyses on 64 rodents with known genomes. As a result, a total of 71 UCP1 gene sequences were obtained, including 47 intact genes, 22 partial genes, and 2 pseudogenes. Further, 47 intact genes and 3 previously published intact UCP1 genes were incorporated into evolutionary analyses, and correlation analyses between evolutionary rate and ambient temperatures (including average annual temperature, maximum temperature, and minimum temperature) of the rodent survives were conducted. The results show that UCP1 is under purifying selection (ω = 0.11), and among rodents with intact UCP1 sequences, Urocitellus parryii and Dicrostonyx groenlandicus—the two species with the lowest ambient temperatures among the rodents used here—have higher evolutionary rates than others. In the statistical analyses, in addition to ambient temperatures, body weight and weight at birth were also taken into account since weight was previously proposed to be linked to UCP1 evolution. The results showed that after controlling for the phylogenetic effect, the maximum temperature was significantly negatively correlated with the evolutionary rate of UCP1, whereas weight did not have a relationship with UCP1 evolutionary rate. Consequently, it is suggested that ambient temperature can drive the evolution of rodent UCP1, thereby enhancing NST adaptation to cold stress. Full article

Previous reports have described a statistical association between high-density lipoproteins (HDL) subclasses and the expression of genes coding for pro-calcifying proteins in the epicardial adipose tissue of patients with coronary artery disease (CAD) and aortic valvular stenosis (AVS). These results suggest a causal relationship between HDL and the regulation of gene expression in epicardial adipose tissue. However, there is no experimental evidence that supports this causal relationship. Therefore, we explored the effect of HDL isolated from CAD or AVS patients on the expression of OPN, BMP2, and BMP4, genes coding for proteins related to calcification, osteopontin, and bone morphogenetic proteins -2 and -4, respectively, and LEP, UCP, and PER, coding for leptin, uncoupling protein-1, and perilipin-2, respectively, proteins that confer phenotypic characteristics to adipocytes. The experiments were performed using a novel model of cardiac adipocytes differentiated in vitro from stromal cells of rabbit cardiac adipose tissue. AVS or CAD patients’ HDL differentially modulated the expression of BMP4 and LEP, whereas HDL from both kinds of patients upregulated the OPN gene expression. A high concentration of triglycerides associated to small HDL and a higher concentration of phospholipids of large HDL from CAD patients than those from AVS individuals were the most remarkable structural differences. Finally, we demonstrated that cholesterol from reconstituted HDL was internalized to the adipocytes. The regulation of genes related to the secretory activity of cardiac adipocytes mediated by HDL has clinical implications as a potential therapeutic target for the prevention and treatment of CAD and AVS. In summary, the HDL isolated from the CAD and AVS patients differentially regulated gene expression in adipocytes by a mechanism that seems to be dependent on HDL lipid internalization to the cells and structural characteristics of the lipoproteins. Full article

Soybean leaves, by-products of soybeans, are functional food supplements for overall health, displaying nutritional superiority and various functionalities; they are widely used for both consumption and as functional materials. This study analyzed the physiological activity (efficacy) of 47 soybean leaves harvested in 2019 and 2020. Differences based on cultivation year (2 years), seed coat color (three varieties), and the interaction of soybean cultivation year × seed coat color were determined using analysis of variance (ANOVA). DPPH radical scavenging activity varied with seed coat color, while uncoupling protein-1 (UCP-1) and nitric oxide (NO) exhibited significant differences by cultivation year. Items that displayed greater increases in 2020 than in 2019 among the six measures of physiological activity (efficacy) were estrogen receptor alpha, UCP-1, and NO production inhibitory activity, whereas ABTS and DPPH radical scavenging activities as well as estrogen activity declined. ANOVA confirmed significant differences in DPPH radical scavenging activity according to seed coat color as well as in UCP-1 and NO production inhibitory activity by cultivation year. Annual comparisons in the correlations of efficacy with ABTS and DPPH radical scavenging activities exhibited strong correlations at 2 years, despite climatic variation, thus potentially being classifiable as analysis items with high cultivation stability. However, other efficacies displayed vast differences in correlation between years. Climate change may affect the added value of agricultural products by reducing the production of by-product soybean leaves and changing their bioactive properties, so various countermeasures are needed. This annual variation may largely be attributed to climatic variations owing to open field cultivation. Geomjeong Kong-5 (black color), B16 Neoljeokseoritae (black color), Sorok Kong (yellow color), and Gangwonyanggu-1994-3709 (green–black color) were selected as superior soybean leaf sources with minimal annual variation and high stability against cultivation environments. Further research is needed to ensure that the leaves of the soybean can be used as a sustainable resource for the agricultural industry. The data from this study can be used as a basis for breeding and cultivating soybean leaves while maintaining high efficacy, regardless of the instability of the growing environment due to climatic variations. Full article

Survival rates for childhood cancer survivors (CCS) have improved, although they display a risk for early frailty due to the long-term effects of chemo/radiotherapy, including early aging. This study investigates antioxidant defenses and oxidative damage in mononuclear cells (MNCs) from CCS, comparing them with those from age-matched and elderly healthy individuals. Results show impaired antioxidant responses and increased oxidative stress in CCS MNCs, which exhibited uncoupled oxidative phosphorylation, leading to higher production of reactive oxygen species, similar to metabolic issues seen in elderly individuals. Key antioxidant enzymes, namely glucose-6-phosphate dehydrogenase, hexose-6-phosphate dehydrogenase, glutathione reductase, glutathione peroxidase, catalase, and superoxide dismutase, showed reduced activity, likely due to lower expression of nuclear factor erythroid 2–related factor 2 (Nrf2). This imbalance caused significant damage to lipids, proteins, and DNA, potentially contributing to cellular dysfunction and a higher risk of cancer recurrence. These oxidative and metabolic dysfunctions persist over time, regardless of cancer type or treatment. However, treatment with N-acetylcysteine improved Nrf2 expression, boosted antioxidant defenses, reduced oxidative damage, and restored oxidative phosphorylation efficiency, suggesting that targeting the redox imbalance could enhance long-term CCS health. Full article

Ubiquitin-specific protease 2 (USP2) maintains mitochondrial integrity in culture myoblasts. In this study, we investigated the molecular mechanisms underlying the protective role of USP2 in mitochondria. The knockout (KO) of the Usp2 gene or the chemical inhibition of USP2 induced a robust accumulation of mitochondrial reactive oxygen species (ROS), accompanied by defects in mitochondrial membrane potential, in C2C12 myoblasts. ROS removal by N-acetyl-L-cysteine restored the mitochondrial dysfunction induced by USP2 deficiency. Comprehensive RT-qPCR screening and following protein analysis indicated that both the genetic and chemical inhibition of USP2 elicited a decrease in uncoupling protein 2 (UCP2) at mRNA and protein levels. Accordingly, the introduction of a Ucp2-expressing construct effectively recovered the mitochondrial membrane potential, entailing an increment in the intracellular ATP level in Usp2KO C2C12 cells. In contrast, USP2 deficiency also decreased peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) protein in C2C12 cells, while it upregulated Ppargc1a mRNA. Overexpression studies indicated that USP2 potentially stabilizes PGC1α in an isopeptidase-dependent manner. Given that PGC1α is an inducer of UCP2 in C2C12 cells, USP2 might ameliorate mitochondrial ROS by maintaining the PGC1α–UCP2 axis in myoblasts. Full article