Search Results (1,098)

This study evaluated olive leaf extract (OLE) as a multifunctional dermocosmetic candidate for sebum-related and inflammatory responses relevant to oily and acne-prone skin using an axis-aligned in vitro panel: (i) sebocyte lipogenesis, (ii) inflammatory mediator production in keratinocytes, and (iii) fibroblast-mediated collagen gel contraction. In addition, supportive mechanistic evidence for the sebum-related effects of OLE was obtained by examining signaling proteins associated with sebocyte lipogenesis, including PPAR-γ and SREBP-1. As a result, OLE significantly inhibited linoleic acid-induced lipid accumulation in SEB-1 sebocytes without cytotoxicity. In HaCaT keratinocytes, OLE significantly reduced the production of pro-inflammatory cytokines, including IL-8, TNF-α, and PGE₂, induced by Cutibacterium acnes or UVB. In dermal fibroblast-containing collagen gels, OLE enhanced fibroblast-mediated gel contraction. Additionally, analysis of the main mechanisms of lipid inhibition using SEB-1 sebocytes revealed that OLE exerts a dual regulatory role in lipid synthesis and inflammation by downregulating AKT and ERK phosphorylation and inhibiting PPAR-γ and SREBP-1 expression. Furthermore, among the tested extracts, the 70% ethanol extract (OLE70) exhibited the strongest antioxidant activity, the greatest gel contraction response, and the highest content of oleuropein, a major bioactive phenolic compound derived from olive. Like OLE, oleuropein also showed sebum-regulatory activity by reducing lipid accumulation in SEB-1 sebocytes, an inhibitory effect on IL-8 expression in HaCaT keratinocytes, and an inhibitory effect on the expression of PPAR-γ and SREBP-1, which are involved in sebum secretion. Taken together, these findings suggest that OLE and its major phenolic constituent, oleuropein, may modulate sebum-related, inflammatory, oxidative, and dermal remodeling-associated responses in skin cell models. These results should be interpreted as exploratory and provide a basis for further mechanistic and translational investigation. Full article

In this paper, we review the literature regarding metformin’s action on blood lipid concentrations in metformin-treated diabetic patients. Published data indicate that metformin reduces serum total cholesterol (T-C), LDL-cholesterol (LDL-C) and triacylglycerol (TAG) concentrations and raises serum HDL-cholesterol (HDL-C) concentrations in diabetic patients. The beneficial effect of metformin on serum lipid profiles in diabetic patients can result from (a) its action on AMP-activated protein kinase, which inhibits lipogenesis and cholesterol synthesis and stimulates fatty acid oxidation; (b) decreased plasma TAG concentrations, via promoting VLDL-TAG clearance by brown adipose tissue; (c) the inhibition of nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression, affecting lipid profile in diabetic patients; (d) the inhibition of the expression of genes encoding proprotein convertase subtilisin/kexin 9 (PCSK9) and lipogenic enzymes; (e) the downregulation of carbohydrate-response element-binding protein (ChREBP), which affects liver TAG and cholesterol synthesis from acetate formed by gut microbiota; (f) the inhibition of angiopoietin-like 3 protein (ANGPTL3) gene expression, and consequent effects on plasma TAG concentrations; (g) the activation of AMPK, which inhibits LXRα activity; and (h) reverse cholesterol transport. In conclusion, one can assume that beyond its primary antihyperglycemic effect, metformin exerts pleiotropic effects that modulate lipid metabolism and blood lipid profile in T2D patients. These beneficial effects of metformin on blood lipid profile may play a role in the reduction in cardiovascular risk in diabetic patients. Full article

Background/Objectives: Sebocytes, the primary cell type in sebaceous glands (SGs), produce a lipid mixture called sebum that is released onto the skin surface and is required for skin homeostasis. The lipid receptor Peroxisome Proliferator-Activated Receptor gamma (PPARγ) regulates sebocyte proliferation and lipid synthesis and is involved in acne development. As inhibition of PPARγ has been shown to reduce insulin-induced lipogenesis and Akt/mTOR signalling in SZ95 sebocytes, we here investigated the effects of PPARγ deletion on lipid homeostasis and autophagic stress responses and how the secretomes affect dermal fibroblasts. Methods: SZ95 sebocytes wildtype (WT) and PPARγ knockout (KO) were shifted to low serum and EGF-deficient conditions permissive for autophagy. Untargeted and targeted HPLC-MS/MS analyses were used to analyze native and oxidized lipids, respectively. Protein levels of LC3I/II and p62 were assessed using immunoblots and immunofluorescence microscopy to investigate the autophagic flux. Dermal fibroblasts were exposed to conditioned media. Results: In low serum culture media, KO SZ95 sebocytes displayed significantly altered levels of 23 lipid classes. We observed a significant increase in ether-linked fatty acids as components of complex lipids and detected elevated levels of phospholipid hydroperoxides and aldehydolipids in the KO sebocytes. KO SZ95 sebocytes failed to show the typical responses to lipoxidative stress, such as elevated p62 crosslinking or inclusion body formation, and had reduced LC3II/I ratios as compared to WT cells. PPARγ KO conditioned media promoted a trend towards an inflammatory fibroblast phenotype. Conclusions: These findings suggest that PPARγ in sebocytes may alter the lipidome, elevate redox stress, and affect the autophagic machinery, which could cause accumulation of oxidized lipids and other potentially harmful compounds in sebocytes. 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: Promoting white adipose tissue (WAT) browning into thermogenic beige adipocytes is a promising anti-obesity strategy. Yanggyeoksanhwa-tang (YST) has been used traditionally to alleviate obesity-related conditions. Catalpol and rhoifolin are major bioactive components of Rehmannia glutinosa (Gaertn.) and Lonicera japonica (Thunb.) with known metabolic or anti-inflammatory effects. However, their direct roles in adipocyte browning and the mechanisms via β3-adrenergic receptor (β3-AR) signaling are not well defined, and this study addresses this gap. Methods: To evaluate browning potential, 3T3-L1 adipocytes were treated with catalpol and rhoifolin during differentiation. The expression of browning markers and lipid metabolism or catabolism transcription factors was analyzed using Western blotting and quantitative real-time polymerase chain reaction. The involvement of the β3-AR and adenosine monophosphate–activated protein kinase (AMPK) signaling pathways was further validated using specific agonists and antagonists. Results: Both compound treatments significantly upregulated beige-specific (Cd137, Cited, Tbx1, Cidea, Fgf21, Tmem26) and mitochondrial biogenesis markers (Cox4, Nrf1, Tfam), accompanied by a marked increase in thermogenic markers (UCP1, PGC-1α, Prdm16). Concurrently, lipolysis-related genes such as Atgl, Hsl, and Plin1 were elevated, while lipogenesis targets (Fasn, Lpl, Srebf1, Acaca) were downregulated through activation of the β3-AR signaling pathway. Conclusions: These findings suggest that catalpol and rhoifolin, key phytochemicals of YST, promote WAT browning and lipolysis. Our findings indicate that these compounds induce browning and modulate metabolism via the β3-AR pathway. These results serve as a cornerstone for natural anti-obesity therapy, pending further validation in vivo and clinical studies. Full article

Previous studies have demonstrated that phloretic acid (PA), a phenolic compound, exerts beneficial effects on inflammation, oxidative stress, and aging. However, its effects on obesity and associated metabolic abnormalities, including dyslipidemia and metabolic dysfunction-associated steatotic liver disease (MASLD), remain unclear. To evaluate the effects of PA on these obesity-related metabolic alterations and explore the underlying mechanisms, male C57BL/6J mice were divided into three groups and fed for 10 weeks with a low-fat diet (10 kcal% fat), a high-fat diet (HFD, 60 kcal% fat), or an HFD containing 0.02% (w/w) PA. PA-supplemented mice showed no significant weight loss and fat loss. However, PA supplementation significantly reduced circulating levels of free fatty acid, triglyceride, and non-high-density lipoprotein cholesterol (HDL-C) while increasing HDL-C levels in HFD-fed mice. It also reduced hepatic lipid deposition and alleviated hepatocellular injury. These effects were accompanied by the coordinated modulation of hepatic lipid metabolism, including reduced lipogenesis and cholesterol esterification, enhanced fatty acid oxidation, and increased bile acid synthesis and excretion. Furthermore, PA attenuated hepatic oxidative stress and suppressed systemic and hepatic inflammation. These observations suggest that PA may counteract HFD-induced MASLD by modulating hepatic lipid metabolism, and that its anti-inflammatory and antioxidant effects may also contribute to these metabolic improvements. Full article

Heat stress (HS) has emerged as a major environmental stressor, inducing oxidative stress and hepatic steatosis and impairing production performance and health in laying hens, with limited evidence-based nutritional interventions available. This study investigated the hepatoprotective effects of dietary silibinin (SIL) against chronic HS. In a 10-week trial, 252 43-week-old Hy-Line Brown hens were exposed to daily HS (32 ± 1 °C, temperature–humidity index [THI] > 73) and fed either a basal diet or one supplemented with 100 mg/kg SIL. SIL significantly increased laying rate (p < 0.05) and improved albumen height, Haugh units, and shell strength by week 8 (p < 0.05). Histological analysis showed a 48% reduction in non-alcoholic fatty liver disease (NAFLD) activity score, with significantly decreased hepatic triglyceride content (p < 0.05); Oil Red O staining confirmed reduced lipid droplet accumulation. SIL restored redox balance by increasing plasma, hepatic total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px) (p < 0.05), increasing hepatic catalase (CAT) and glutathione (GSH) levels while decreasing malondialdehyde (MDA) (p < 0.05). Untargeted plasma metabolomics identified 11 key metabolites related to 2-oxoglutarate and purine metabolism, while hepatic transcriptomics revealed 835 differentially expressed genes primarily in the PPAR signaling and fatty acid biosynthesis pathways. SIL suppressed de novo lipogenesis via downregulation of ACACA and FASN, and enhanced β-oxidation through upregulation of CPT1A and ACSL1 (p < 0.05). Molecular docking indicated favorable binding affinities between SIL and these targets, which was further supported by corresponding changes in protein expression via Western blotting. Correlation analysis revealed a consistent alignment between the upregulation of ACSL1/CPT1A and improvement in performance and antioxidant status, suggesting a coordinated metabolic shift. These findings emphasize the potential of SIL as a sustainable animal nutrition antioxidant additive, which can alleviate HS-induced lipid disorders in the liver of laying hens. Importantly, these hepatoprotective effects were demonstrated exclusively under chronic heat stress conditions; further studies incorporating a normothermic baseline are required to distinguish stress-specific mitigation from general metabolic stimulation. Full article

The dysregulation of intestinal lipid metabolism induced by a high-fat diet (HFD) is associated with metabolic diseases; however, the validity of intestinal organoids (IOs) as substitutes for traditional research systems remains uncertain. This study aimed to determine whether fatty acid (FA)-treated IOs accurately replicate intestinal lipid metabolism observed in HFD mice. Male C57BL/6 mice were fed either a normal chow diet (NCD) or HFD for 12 weeks, while mouse small intestinal crypt-derived IOs were treated in vitro with either an FA cocktail or a vehicle. Mice on the HFD exhibited phenotypes characteristic of metabolic syndrome, including intestinal lipid accumulation, upregulation of lipid catabolic genes, and downregulation of lipogenic genes. FA-treated IOs demonstrated enhanced budding frequency, lipid droplet accumulation, enriched lipid catabolism pathways, and suppressed lipogenesis, aligning with the in vivo findings. Omics analyses of the top 87 variable genes indicated a strong congruence between FA-treated IOs and intestinal tissues from HFD mice, with control groups clustering distinctly. The differentially expressed genes in both models were implicated in metabolic reprogramming, immune modulation, and barrier remodeling. Therefore, FA-treated IOs recapitulate key morphological and transcriptional characteristics of intestinal lipid metabolism in HFD mice, offering a valuable complementary model for investigating intestinal metabolic disorders. Full article

While diabetic retinal disease (DRD) has classically been viewed as a microvascular complication, emerging evidence places the photoreceptor at the center of its pathogenesis. Recognizing this central role provides a critical framework for resolving a major clinical paradox in diabetes: why the retina exhibits profound susceptibility to hyperglycemic damage, whereas closely related neural tissues like the brain are mostly spared. In this review, we synthesize the evidence for photoreceptor-driven DRD pathology by evaluating two primary mechanistic paradigms. In the first, hyperglycemia-induced damage to the blood vessels limits perfusion, creating an ischemic environment that selectively devastates tissues dependent on exceptionally high blood flow and energy delivery—specifically, the photoreceptors. In the second paradigm, hyperglycemia induces a direct shift in the metabolic profile of photoreceptors, triggering oxidative stress and dysregulated lipogenesis that subsequently place pathological strain on the local microvasculature. Regardless of whether the initial insult is vascular or neuronal, the photoreceptor remains the critical node of disease progression. Because current and investigational DRD treatments predominantly target downstream vascular consequences, exploring these dual mechanisms highlights an urgent need and a significant opportunity to develop novel therapies that target the photoreceptor to address DRD at its root. Full article

Chronic liver injury is characterized by sustained activation of transforming growth factor-β (TGF-β) signaling within the fibrotic microenvironment, yet the contribution of TGF-β-associated metabolic remodeling to hepatic stellate cell (HSC) activation remains incompletely understood. Here, we investigated whether TGF-β signaling is associated with lipid metabolic remodeling in HSCs and whether pirfenidone (PFD) interferes with this process. We found that TGF-β1 was spatially associated with lipid accumulation in fibrotic liver tissue and that TGF-β1/2 promoted HSC proliferation. In vitro, TGF-β1/2 coordinately upregulated sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN), accompanied by increased intracellular lipid accumulation and enhanced oleic acid (OA)-associated lipid responses. Low-dose OA further activated AKT/ERK/p70 S6K signaling in HSCs, whereas PFD attenuated these signaling events. In parallel, PFD suppressed TGF-β-associated lipid accumulation in vitro, reduced SREBP1/FASN expression in activated HSC-rich regions in vivo, and alleviated CCl₄-induced liver fibrosis. Together, these findings support a model in which TGF-β-associated lipogenic remodeling contributes to HSC activation and suggest that interference with this metabolic state may represent one component of the antifibrotic action of pirfenidone. Full article

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive hepatic lipid accumulation and can progress to severe liver injury. Kaempferol (KPF), a plant-derived flavonoid, exhibits lipid-regulatory properties. Tripartite motif-containing protein 56 (TRIM56), an E3 ubiquitin ligase, has been reported to interact with fatty acid synthase (FASN) and limit hepatic lipogenesis. This study investigated whether KPF alleviates NAFLD through modulation of TRIM56-associated lipid metabolic pathways. Molecular docking, molecular dynamics simulations, and cellular thermal shift assays (CETSA) were employed to evaluate the interaction between KPF and TRIM56. High-fat diet-induced NAFLD mice and fatty acid-treated HepG2 cells were used to assess the effects of KPF on hepatic lipid accumulation. Histological analysis, lipid profiling, Oil Red O staining, Western blotting, immunofluorescence, and quantitative PCR were performed. Endogenous co-immunoprecipitation examined the association between TRIM56 and FASN, and siRNA-mediated knockdown of TRIM56 evaluated its functional contribution. KPF significantly reduced serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels, ameliorated hepatic steatosis in vivo, and decreased intracellular lipid accumulation in vitro. In silico and CETSA analyses supported the engagement of TRIM56 by KPF. KPF restored TRIM56 expression under steatotic conditions, whereas TRIM56 silencing attenuated its lipid-lowering effects. TRIM56 was confirmed to associate with FASN, and KPF treatment suppressed multiple lipogenic enzymes. These findings indicate that KPF alleviates hepatic steatosis, at least in part, through modulation of TRIM56-associated lipogenic pathways, highlighting TRIM56 as a potential therapeutic target in NAFLD. Full article

The most common complication of active brucellosis in humans is osteoarticular injury. In the bone marrow microenvironment, mesenchymal stem cells (MSCs) can differentiate into either adipocytes or osteoblasts, and this balance is tightly regulated because an increase in adipogenesis may negatively affect bone formation and favor bone loss. The differentiation of MSCs into adipocytes or osteoblasts is tightly regulated by mechanisms that promote cell fate toward one lineage while repressing the other. Our study demonstrated that Brucella abortus infects MSCs but does not affect the deposition of organic and mineral matrix during osteoblast differentiation. However, the infection upregulates Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) expression in osteoblasts, which may contribute to osteoclast activation and bone resorption. Conversely, B. abortus infection significantly influences adipocyte differentiation by modulating lipolysis, lipogenesis, and interactions between lipid droplets and mitochondria. This leads to increased cellular cholesterol levels and reduced intracellular triglycerides, accompanied by glycerol release. These changes result in more differentiated adipocytes and larger lipid droplets. Consequently, we observed increased IL-6 secretion and a higher leptin/adiponectin ratio. Importantly, these effects were independent of a functional type IV secretion system (T4SS), as purified Brucella DNA fully reproduced the adipogenic phenotype. Moreover, inhibition of TLR9—the primary sensor of bacterial DNA—significantly reduced the DNA-induced adipogenic response, demonstrating that adipocyte modulation is at least in part mediated through TLR9 signaling. In summary, B. abortus promotes MSC differentiation toward an inflammatory adipocyte phenotype. It involves a TLR-9-mediated DNA detection. It may contribute to osteoarticular injury and infection-associated bone resorption. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of chronic liver disease worldwide and arises from systemic metabolic dysregulation and insulin resistance. Despite its increasing prevalence, effective pharmacological interventions remain limited. Recent evidence has identified sirtuin 6 (SIRT6), an NAD⁺-dependent epigenetic regulator, as an important modulator of hepatic metabolic and stress-responsive pathways. This review summarizes current knowledge regarding the role of SIRT6 in liver physiology and MASLD pathogenesis. Accumulating evidence indicates that SIRT6 suppresses lipogenic transcriptional programs while enhancing mitochondrial oxidative capacity and fatty acid oxidation, thereby maintaining metabolic homeostasis. Beyond lipid metabolism, SIRT6 is implicated in the regulation of endoplasmic reticulum stress responses, inflammatory signaling, and chromatin accessibility, which are the processes that collectively influence hepatocellular injury and disease progression. In addition, emerging data suggest that SIRT6 modulates hepatic stellate cell activation and fibrogenic signaling pathways, thereby linking epigenetic regulation to the development of liver fibrosis. A reduction in hepatic SIRT6 expression and activity has been reported in metabolic disorders, including MASLD. We further discuss the therapeutic potential of targeting SIRT6, including the development of selective small-molecule activators and naturally derived compounds aimed at restoring SIRT6 activity. Together, the available evidence positions SIRT6 as an important regulatory node in MASLD and a promising candidate for future therapeutic intervention. Full article

Intramuscular fat (IMF) marbling is a key determinant of beef quality, yet predicting how breed-specific gene expression translates into tissue-scale fat patterning remains a major challenge. Using a small public transcriptomic dataset (n = 3 per breed), this study presents a proof-of-concept omics-to-tissue modeling framework that converts RNA-seq data into biophysically interpretable parameters governing intramuscular adipogenesis. Using transcriptomic profiles from GSE161967 (Japanese Black Wagyu versus Chinese Red Steppes), we derived composite indices capturing the adipogenic commitment (φ) and lipid droplet capacity (ψ) from curated gene modules. These indices were mapped via calibrated linear functions to a Cellular Potts Model (CPM), parameterizing the fibro-adipogenic progenitor (FAP) differentiation probability, lipogenesis rate, adipocyte cohesion, and progenitor abundance. The gene-derived parameters placed Wagyu in a high-adipogenic regime ($p_{F\to A}^{\mathrm{base}}$ = 0.65; $k_{lipogenesis}$ = 0.12), while Chinese Red Steppes resided in a low-adipogenic regime (0.25; 0.04). The CPM simulations revealed a sharp, predictive threshold at $p_{F\to A}^{\mathrm{base}}$ ≈ 0.55, below which IMF remained negligible and above which stable adipocyte clusters and 8–9% IMF emerged. Without post hoc tuning, the gene-derived parameters correctly predicted robust marbling in Wagyu and a lean phenotype in Chinese Red Steppes. A sensitivity analysis identified the adipogenic commitment as the primary control parameter, with lipogenesis acting as an amplifier. Together, these results demonstrate that transcriptomic measurements can quantitatively predict emergent marbling phenotypes through a small set of interpretable biophysical parameters, establishing a generalizable framework for forecasting complex tissue traits from omics data. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by hepatic triglyceride accumulation in the setting of obesity and insulin resistance. Although apolipoprotein C-III (APOC3) is a well-established regulator of plasma triglyceride metabolism, its hepatocyte-intrinsic role in intracellular lipid accumulation remains unclear. In this study, we investigated whether APOC3 contributes to hepatocellular triglyceride synthesis during early metabolic dysfunction. In 6-week-old db/db mice, early hepatic lipid accumulation was observed without detectable fibrosis. Transcriptomic profiling identified APOC3 as an upregulated gene associated with lipid metabolic pathways, and its hepatic upregulation was confirmed at both mRNA and protein levels. Gain- and loss-of-function experiments in HepG2 cells demonstrated that APOC3 overexpression significantly increased intracellular triglyceride content, whereas APOC3 knockdown reduced triglyceride accumulation. Mechanistically, APOC3 selectively regulated diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step of triglyceride synthesis, without significantly affecting major lipogenic transcription factors. Furthermore, under de novo lipogenesis-inducing conditions triggered by the liver X receptor agonist T0901317 and insulin, APOC3 markedly amplified DGAT2 expression and triglyceride accumulation. Collectively, these findings suggest a hepatocyte-intrinsic role for APOC3 in promoting triglyceride accumulation through DGAT2-dependent mechanisms. The APOC3–DGAT2 axis may represent a relevant pathway contributing to hepatic lipid accumulation in metabolic liver disease. Full article