Search Results (1,758)

Background: Overweight and obesity are currently a worldwide problem, with undesirable health consequences, such as type 2 diabetes. Therefore, much attention has been paid to preventing obesity through diet. Free fatty acids (FFAs) serve as signaling molecules in many biological processes, leading to increased energy expenditure and insulin secretion. Short-chain fatty acids (SCFAs) such as acetic, propionic and butyric acid are bioactive metabolites produced by gut microbes, and their beneficial effects on host metabolism are well studied. However, the effects of hexanoic acid on metabolism are poorly understood. Methods: Male C57BL/6J mice were fed a normal chow diet, a high-fat diet (HFD), an HFD containing 5% butyric acid or an HFD containing 5% hexanoic acid for 4 weeks, and the effects of hexanoic acid on their lipid and glucose metabolisms were examined. Results: Dietary supplementation of hexanoic acid or butyric acid for 4 weeks prevented HFD-induced obesity and fat accumulation in the white adipose tissues. Both FFAs also suppressed the elevated plasma non-esterified fatty acid (NEFA) levels and hepatic triglyceride content in the mice fed an HFD. In addition, butyric acid and hexanoic acid decreased the elevated expression of genes involved in fatty acid biosynthesis in the white adipose tissues under HFD conditions. Hyperinsulinemia induced by HFD feeding was attenuated by oral intake of butyric acid or hexanoic acid, whereas hyperglycemia under HFD feeding was improved only through oral administration of hexanoic acid. Hexanoic acid increased plasma glucagon-like peptide-1 (GLP-1) levels and the expression of genes associated with gluconeogenesis. The intraperitoneal glucose tolerance test (IPGTT) and the insulin tolerance test (ITT) revealed that the oral administration of hexanoic acid significantly enhanced glucose tolerance and insulin sensitivity. Conclusions: This study highlights the importance of hexanoic acid in improving lipid and glucose metabolisms. Hexanoic acid, as well as butyric acid, is a remarkable FFA with anti-obesity properties. Furthermore, hexanoic acid is more potent in maintaining glucose homeostasis than butyric acid. Thus, our findings provide insight into the development of functional foods which could prevent obesity-related diseases such as type 2 diabetes. Full article

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) encompasses a spectrum of liver conditions and involves gut–liver axis crosstalk. We aimed to evaluate whether oral vancomycin modifies liver injury and the cecal microbiota in a methionine–choline-deficient (MCD) diet model of NASH. Male C57BL/6J mice (n = 28) were block-randomized to four groups (n = 7 each) for 10 weeks: standard diet (STD); MCD diet; STD + vancomycin (VANC); and MCD + VANC (2 mg/mouse ≈ 50 mg/kg, every 72 h). After 10 weeks, liver tissues were analyzed for histological changes, cytokine levels [interleukin-6 (IL-6), interleukin-8 (IL-8), transforming growth factor beta 1 (TGF-β1)], and immunohistochemical markers [ubiquitin and cytokeratin 18 (CK18)]. Cecal microbiota composition was evaluated with 16S ribosomal RNA (rRNA) sequencing. The MCD reproduced key NASH features (macrovesicular steatosis, lobular inflammation). Vancomycin shifted steatosis toward a microvesicular pattern and reduced hepatocyte injury: CK18 and ubiquitin immunoreactivity were decreased in MCD + VANC vs. MCD, and hepatic IL-8 and TGF-β1 levels were lower in MCD + VANC vs. STD. Taxonomically, STD mice had Lactobacillus-rich microbiota. The MCD diet alone reduced alpha diversity (α-diversity), modestly lowered Firmicutes and increased Desulfobacterota/Fusobacteriota. Vancomycin alone caused a much larger collapse in richness, depleting Gram-positive commensals and promoting blooms of Escherichia–Shigella, Klebsiella, Parabacteroides, and Akkermansia. In the MCD + VANC group, vancomycin profoundly remodeled the microbiota, eliminating key commensals (e.g., Lactobacillus) and enriching Desulfobacterota, Fusobacteriota, and Campylobacterota. Oral vancomycin in the MCD model of NASH improved liver injury markers and altered steatosis morphology, but concurrently reprogrammed the gut into a low-diversity, pathobiont-enriched ecosystem with near-loss of Lactobacillus. These findings highlight a therapeutic trade-off—hepatic benefit accompanied by microbiome cost—that should guide microbiota-targeted strategies for NAFLD/NASH. Full article

Background/Objectives: Nopalea cochenillifera (L.) Salm-Dyck cladodes are rich in dietary fiber, polyphenols, and minerals, which are known to exert antioxidant and immunomodulatory effects. However, the mechanisms and active constituents have not been fully elucidated. In this study, we investigated the effects of continuous N. cochenillifera consumption on lipid metabolism, immune function, and the gut microbiota in mice. Methods: The feed was made using freeze-dried and powdered cladodes of N. cochenillifera. Male C57BL/6J mice were assigned to four groups: control diet (C), control diet plus 10% N. cochenillifera (CN), high-fat diet (FC), and high-fat diet plus 10% N. cochenillifera (FN). Results: Cactus supplementation reduced the body and liver weights that were elevated by the high-fat diet. Serum total cholesterol and free fatty acids were increased in the FC group compared with the C group, while cactus intake lowered these levels and enhanced fecal cholesterol excretion. Cactus consumption also elevated fecal total IgA and mucin contents. IL-4 expression in Peyer’s patches was significantly increased in the FN group compared with the FC group. Gut microbiota analysis showed significant differences in β-diversity, along with increased α-diversity and higher abundance of Lachnospiraceae, following cactus intake. Conclusions: These findings suggest that N. cochenillifera intake increases gut microbiota diversity, which enhances intestinal barrier function and thereby contributes to improved lipid metabolism and immune regulation. Full article

Background: Ozone (O₃) pollution disrupts pulmonary circadian rhythms, yet the molecular mechanisms remain elusive. The Notch signaling pathway, critical for lung homeostasis, may crosstalk with the circadian clock system. Objective: This study elucidates the role of the Notch signaling pathway in O₃-induced lung circadian rhythm disruption. Methods: C57BL/6J mice were acutely exposed to O₃ (1.0 ppm, 3 h). Lung tissues were collected 24 h post exposure. Transcriptome sequencing coupled with GSEA identified dysregulated pathways; IHC and RT-qPCR validated core genes; GEO dataset (GSE58244) reanalysis assessed Notch3/4 knockout effects. Results: O₃ activated Notch signaling (NES = 1.85, FDR = 0.034) and disrupted the circadian pathway (NES = 1.84, FDR = 0.029), downregulating Bmal1 while upregulating Per2/3 and Notch3/4 (p < 0.05). Strong correlations (r > 0.8) existed between core genes of both pathways. Notch3/4 knockout exacerbated circadian disruption in a time-dependent manner upon O₃ exposure. Conclusion: O₃ induces lung circadian disruption via Notch3/4 activation, which provides novel mechanistic insights into pollutant-induced lung injury. Full article

Ovarian aging is characterized by mitochondrial dysfunction, oxidative stress, and inflammation. The development of adjunctive treatments that mitigate age-related subfertility is warranted. We examined the benefits of nutraceutical supplementation (FE; Fertility Enhancer) with mitochondrial antioxidants, anti-inflammatory agents, metabolic activators, vitamins and minerals, and amino acids on ovarian aging, metabolic activity, and reproductive success in young (Y; 6-month-old) and middle-aged (O; 11-month-old) female C57BL/6J mice. The mice were fed calorie- and macronutrient-matched diets w/wo the FE supplement for three months and harem mated twice. Daily FE supplementation promoted significant body re-composition, including loss of white adipose tissue (gWAT: −36% vs. CON, p < 0.001), gain of skeletal muscle (SkM: +67% vs. CON, p < 0.001), and improved SkM/gWAT ratio (+185% vs. CON, p < 0.001). Metabolic testing showed enhanced fat oxidation (+38%, p < 0.01) and energy expenditure (+7%, p = 0.051) in FE mice. Breeding and immunoblotting data demonstrated improved reproductive success (Y-CON: 44%, Y-FE: 89%, O-CON: 0%, O-FE: 18%) and a modest attenuation of ovarian aging markers in both FE groups. We surmise that a multi-ingredient supplement, such as the Fertility Enhancer, may improve body re-composition, metabolic activity, and markers of ovarian aging, thus enhancing reproductive health and fertility in females. Full article

Exposure to persistent organic pollutants such as 2,3,7,8-tetrachlorodibenzodioxin (TCDD) increases metabolic disorder risk. In this study, we show that a single intraperitoneal injection of TCDD (10 μg/kg) in C57BL/6J mice induced body weight gain, lipid accumulation in the liver and adipose tissue, macrophage infiltration, and elevated hepatic and serum triglyceride levels after 12 weeks. Despite serum aryl hydrocarbon receptor (AhR) ligand levels normalizing by 12 weeks, the persistent effects suggest TCDD sequestration in fat tissue. TCDD inhibited the expression of mitochondrial proteins (COX1, TOM20, TFAM, H2AX) and reduced mitochondrial oxygen consumption. Liver-specific AhR knockout ameliorated TCDD-induced mitochondrial dysfunction, lipid accumulation, and macrophage infiltration. Mechanistically, TCDD-induced hepatic plasminogen activator inhibitor-1 (PAI-1) promoted adipocyte hypertrophy. In the liver, PAI-1 disrupted the interaction between tissue-type plasminogen activator (tPA) and apolipoprotein B (ApoB), thereby enhancing very-low-density lipoprotein (VLDL) assembly. These findings reveal that hepatocyte-derived circulating PAI-1, upregulated via hepatic AhR activation, contributes to adipocyte hypertrophy and hepatosteatosis through the intracellular modulation of the tPA–PAI-1 axis. Thus, hepatic AhR activation drives mitochondrial dysfunction and obesity, even after a single TCDD exposure. Full article

Objectives: Skin aging, often accelerated by dietary advanced glycation end products (AGEs), poses both cosmetic and health challenges. This study explores the protective effects of hydroxytyrosol (HT), a potent antioxidant found in olives, against AGEs-induced skin aging in mice. Methods: A total of forty-eight 8-month-old specific pathogen-free (SPF) male C57BL/6J mice were randomly assigned to one of four groups: control, model, low-dose hydroxytyrosol (HT25), and high-dose hydroxytyrosol (HT50). An additional group of six 6-week-old SPF male C57BL/6J mice served as the youth group. The experimental period lasted 16 weeks. Following the intervention, skin, serum, and ileum samples were collected. Results: The results demonstrated that HT50 significantly increased skin moisture, epidermal thickness, and dermal thickness (p < 0.05). HT50 also significantly elevated hydroxyproline levels as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the skin while reducing malondialdehyde (MDA) content (p < 0.05). Furthermore, HT50 significantly reduced the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) (p < 0.05). Regarding intestinal integrity, hydroxytyrosol intervention (either HT25 or HT50) significantly increased the positive staining ratios of zonula occludens-1 (ZO-1) and occludin in the ileum (p < 0.05). Conclusions: HT improves skin hydration, thickness, and collagen levels while reducing oxidative stress and inflammation. Notably, HT also enhances intestinal barrier function, suggesting a role for the gut–skin axis. These findings highlight HT’s potential as a natural intervention for skin aging. Full article

The exposure of endothelial cells to high glucose concentrations promotes angiogenesis. The present study investigated whether this pro-angiogenic effect of glucose is suitable to improve the capability of nanofat to vascularize implanted dermal substitutes. Nanofat was processed from white adipose tissue originating from green fluorescent protein (GFP)⁺ C57BL/6J donor mice and incubated for 1 h in Hank’s Balanced Salt Solution with or without (control) a high level of glucose (30 mM). The pretreated nanofat was seeded onto dermal substitutes, which were analyzed by intravital fluorescence microscopy, histology and immunohistochemistry in dorsal skinfold chambers of GFP⁻ C57BL/6J mice to assess their vivo performance over a period of 14 days. A high level of glucose-pretreated nanofat did not induce a stronger immune response when compared to the control. However, it improved the vascularization of the implants, as shown by a significantly higher density of blood-perfused microvessels in the border zones (~3.6-fold increase) and more CD31⁺/GFP⁺ microvessels (~3-fold increase) inside the implants. Accordingly, high glucose-pretreated nanofat levels also enhanced the tissue integration of the dermal substitutes, as indicated by the deposition of more type I collagen (~2.9-fold increase). These findings suggest that the short-term exposure of nanofat to a high level of glucose represents a promising and clinically feasible strategy to enhance its regenerative properties when seeded onto dermal substitutes. Full article

The glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) are ligand-activated transcription factors that regulate epidermal homeostasis, inflammation, and function. Prior studies using epidermal-specific conditional single and double knockout mice have shown their importance in skin physiology; however, clinically human disease is largely treated pharmacologically. Our objective was to examine how systemic MR/GR antagonism affects cutaneous gene expression and epidermal thickness in aged (18-month-old) C57BL/6J female mice. Mice were treated with selective GR (relacorilant), selective MR (eplerenone), or dual GR/MR (miricorilant) antagonists for 8 weeks. Quantitative RT-qPCR analysis of the skin showed that miricorilant significantly upregulated Sgk1, a GR/MR target. Miricorilant also increased the expression of keratinocyte differentiation markers and downregulated key inflammatory cytokines and Col3a1, a collagen subtype associated with tissue remodeling. Relacorilant suppressed Scnn1g, a subunit of the epithelial sodium channel. None of the antagonists significantly altered proliferation markers, epidermal thickness, or regulators of glucocorticoid activity. Our findings show that miricorilant downregulated inflammatory cytokines and increased differentiation marker expression without affecting epidermal thickness, suggesting its potential to treat inflammatory skin diseases. The results contrast with data from GR/MR knockout studies, highlighting the likely significance of receptor dynamics. Further studies of antagonist effects on receptor interactions with co-regulators appear warranted. Full article

Background: Ischemia–reperfusion injury (IRI) is a major contributor to acute kidney injury (AKI). While the precise mechanisms of AKI are still incompletely defined, extensive evidence highlights tubular cell injury and death as key factors in its development. Necroptosis has recently emerged as a critical pathway in the pathogenesis of ischemia–reperfusion-induced AKI (IR-AKI). Although sex differences in susceptibility to IR-AKI have been reported, it remains unclear whether there are sex differences in necroptosis dynamics and whether these differences underlie the observed sexual dimorphism in kidney IRI. This study aimed to address these questions. Methods: male and female C57BL/6 J mice were subjected to AKI via ischemia induced by bilateral renal pedicle clamping for 18 min at 37 °C. Plasma, urine, and kidney samples were collected at 0 h, 3 h, 6 h, 12 h, 24 h, 48 h, and 72 h post-reperfusion. Kidney injury and function were assessed by measuring plasma creatinine (PCr), blood urea nitrogen (BUN) levels, and histological damage (PAS and cleaved caspase3 staining). Necroptosis activation was assessed by quantifying phosphorylated forms of key markers: p-RIPK1 and p-MLKL. To explore the role of sex hormones in regulating necroptosis dynamics, ovariectomized female mice were subjected to the same IR-AKI protocol, and their kidney injury and functional outcomes were compared with those of intact counterparts. Results: The PCr was 0.35 ± 0.04 and 0.32 ± 0.06 mg/dL for males and females, respectively, at 3 h of IR. The levels exponentially increased to 2.05 ± 0.18 at 48 h post-reperfusion in the males but only gradually to 0.94 ± 0.13 mg/dL in females. Necroptosis activation began as early as 3 h post-IR in males but was delayed until ~6 h in females. Males exhibited stronger and more sustained necroptosis activation than females, showing elevated phosphorylation levels of pRIPK1 and pMLKL in Western blot. Female sex hormone deficiency exacerbated the female response to IR-induced injury, which reduced the sex difference in the dynamic of the necroptotic activation and subsequent kidney injury. To our knowledge, this is the first study to characterize sex differences in the initiation and progression of necroptosis and subsequent injury in a mouse model of IR-AKI. Conclusions: Our findings reveal distinct temporal patterns of programmed cell death between sexes. Necroptosis-targeted therapies require early intervention in males, which can be delayed in females after IR-AKI, highlighting the need for sex-specific therapeutic windows. Full article

Diabetic cardiomyopathy (DCM) is a serious complication of type 2 diabetes mellitus (T2DM), characterized by cardiac dysfunction, inflammation, and fibrosis. In this study, a T2DM mouse model was established by administering a high-fat diet (60% fat) in combination with streptozotocin injection in male C57BL/6J mice. The mice subsequently underwent an eight-week exercise intervention consisting of swimming training, resistance training, or high-intensity interval training (HIIT). The results showed that all three forms of exercise improved cardiac function and attenuated myocardial hypertrophy in DCM mice. Exercise training further downregulated the expression of pro-inflammatory cytokines, including interleukin-6, tumor necrosis factor-α, nuclear factor κB, and monocyte chemoattractant protein-1, and mitigated myocardial fibrosis by suppressing fibronectin, α-SMA, collagen type I alpha 1 chain, collagen type III alpha 1 chain, and the TGF-β1/Smad signaling pathway. Moreover, exercise inhibited the expression of PANoptosis-related genes and proteins in cardiomyocytes of DCM mice. Notably, HIIT produced the most pronounced improvements across these pathological markers. In addition, all three exercise modalities effectively suppressed the aberrant activation of the cGAS–STING signaling pathway in the myocardium. In conclusion, exercise training exerts beneficial effects against DCM by improving cardiac function and reducing inflammation, PANoptosis, and fibrosis, and HIIT emerged as the most effective strategy. Full article

Background: Iron is an essential nutrient for many bacterial pathogens and normal cellular function and homeostasis of their hosts. Studies suggest that iron deficiency or overload may contribute to the pathogenesis of several chronic conditions and modify host–microbial interactions. In this study, we assessed the impact of varying dietary iron intakes on the microbiota of the intestinal tract and lungs of wild-type mice. Methods: Male C57BL/6J mice were fed either a standard pellet chow (high iron diet), a ferrous ammonium sulfate (FeAS)-supplemented diet or an iron-deficient diet for four weeks. Tissue from the lung, duodenum and colon was collected, and 16S rRNA gene fragments were pyrosequenced. Results: Total serum iron levels were negatively associated with richness of the lung microbiome (p = 0.035). In the murine lungs, there was no association between the iron diet and the overall lung microbiota community composition, but Bacteroides spp. were significantly enriched in the lungs of mice fed the FeAS diet (LDA score > 4, p < 0.05). The community composition of the intestinal microbiota changed significantly depending on the iron diet, with increased richness in the low-iron compared to the iron-supplemented groups (p = 0.053). In the duodenum, Prevotella spp. were reduced (Mean = 7.869, SEM = 3.464, p < 0.05), and Desulfovibrio species increased (Mean = 5.343, SEM = 1.362, p < 0.001) in iron-supplemented groups compared to the low-iron-diet group. In the colon, Bifidobacterium and Bacteroides species were reduced (Mean = 7.175, SEM = 2.246, p < 0.01 and Mean = 6.967, SEM = 1.834, p < 0.01 respectively), and Pseudomonas increased (Mean = 24.03, SEM = 8.919, p < 0.05) in mice on higher-iron diets compared to the low-iron diet. Discussion: This study demonstrates that dietary iron intake significantly impacts the intestinal microbiota and has a small, yet significant, effect on the lung microbiome in C57BL/6J mice. Whilst dietary iron content per se did not significantly modulate the composition of the lung microbiota, serum iron levels had subtle impacts on the community composition of the lung microbiota. Full article

Background: Excessive formation of neutrophil extracellular traps (NETs) leads to NETosis, accompanied by the release of citrullinated histone H3 (CitH3), a key mediator of septic inflammation. However, the role of CitH3 in sterile inflammation, such as acute myocardial infarction (MI) and post-MI heart failure, remains incompletely understood. Methods and Results: We investigated the role of CitH3, a byproduct of NETosis, in myocardial ischemia/reperfusion (I/R) injury using a murine MI model. C57BL/6J mice were subjected to left coronary artery (LCA) occlusion followed by reperfusion and treated with either a humanized anti-CitH3 monoclonal antibody (hCitH3-mAb) or control human IgG. In mice undergoing 40 min of LCA occlusion and 24 h of reperfusion, hCitH3-mAb administered 10 min before reperfusion significantly reduced infarct size by 36% compared to control (p < 0.05). Plasma levels of CitH3, IL-1β, and interferon-β were significantly elevated following MI but were attenuated by hCitH3-mAb. In addition, plasma and cardiac tissue from treated mice showed significantly lower levels of citrate synthase, a marker of mitochondrial injury, suggesting that hCitH3-mAb preserved mitochondrial integrity after MI. In mice undergoing 50 min of LCA occlusion and 21 days of reperfusion, longitudinal echocardiography revealed preservation of left ventricular ejection fraction (LVEF) in hCitH3-mAb-treated mice, with significant improvement observed on days 7, 14, and 21 post-MI (p < 0.05 vs. control). hCitH3-mAb also mitigated myocardial fibrosis and preserved tissue architecture. Conclusions: These findings demonstrated CitH3 as a critical mediator of myocardial injury and adverse remodeling following acute MI. Neutralization of CitH3 via hCitH3-mAb attenuates I/R injury and preserves cardiac function by mitigating inflammation and protecting mitochondrial integrity. Targeting CitH3 represents a promising therapeutic strategy to prevent heart failure following MI. Full article

Currently regulated per- and polyfluoroalkyl substances (PFAS) have been associated with immune, endocrine, and neurotoxicity following gestational exposures. As a result, industries have effectively replaced them with next-generation PFAS, including perfluorohexanoic acid (PFHxA). PFHxA is increasingly found in the serum of pregnant women and in breast milk, and adult human post-mortem studies indicate that PFHxA is found in the brain, with the highest concentrations in the cerebellum and hypothalamus. Despite evidence of gestational, lactational, and nervous system exposure to PFHxA, developmental neurotoxicity (DNT) testing in mammals has not been conducted. For DNT evaluation, we exposed pregnant C57Bl/6J mice daily from gestational day 0 through postnatal day (P) 21 to two PFHxA exposure levels (a lower (0.32 mg/kg of body weight (bw), or higher (50 mg/kg of bw) dose of PFHxA)) or ddH₂O using treat-based administration. Given the high PFHxA levels in the cerebellum in post-mortem studies and the cerebellum’s protracted developmental window, we assessed acute transcriptional dysregulation and cellular morphology in this brain region on the last day of exposure at P21. Using bulk-RNA sequencing, we found that PFHxA exposure had subtle effects on transcripts related to neurons and glia, with females having a greater number of dysregulated transcripts than males. Using immunohistochemistry, we found that Purkinje cell linear frequency was increased in specific lobules in the higher-exposure group and that microglial morphology underwent subtle changes in specific cerebellar layers in the lower-exposure group in both sexes. Together these data suggest that PFHxA exposure may have lobule-specific impacts on the development of both neurons and glia in the cerebellum, highlighting the importance of studying the neurotoxicity of PFHxA in both sexes. Full article

Background: Obesity-associated liver dysfunction is a key feature of metabolic syndrome. Marine by-products, such as fish oils, offer promising dietary interventions. In this study, we aimed to assess the anti-obesity and hepatoprotective effects of herring–saury by-product-derived fermented fish oil—Gwamegi oil (GmO)—and the same oil fermented with Lactobacillus brevis KCCM13538P (GmOLb) in a high-fat-diet (HFD)-induced obese mouse model. Methods: GmO was extracted and fermented. Anti-obesity and hepatoprotective effects were assessed using in vitro and in vivo studies. For the in vivo study, female C57BL/6J mice were fed an HFD supplemented with lard (control), GmO, or GmOLb for 60 days. Metabolic and liver function parameters were assessed. Results: In 3T3-L1 adipocytes, GmOLb significantly reduced lipid accumulation and intracellular triglyceride (TG) levels compared with GmO. In HFD-fed mice, GmOLb significantly reduced body weight gain, ovarian fat mass, serum TG, low-density lipoprotein cholesterol, leptin concentration, atherogenic indices, and cardiac risk factor ratio. Furthermore, it reduced liver damage indicators, including alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels. Conclusions: Fermenting herring–saury oil with L. brevis KCCM13538P enhanced its anti-obesity and hepatoprotective effects in HFD-fed mice. GmOLb shows strong potential as a functional dietary lipid for preventing and managing metabolic disorders. Full article