Search Results (150)

Background and Objectives: Obesity is linked to liver cancer through metabolic mechanisms and can promote tumor growth through metabolic impairment, decreased lipid metabolism, and interference of the energy balance in the liver. NAMPT is an enzyme expressed in the liver and is involved in the progression of tumors in obesogenic environments, while iNAMPT is known to be the rate-limiting enzyme in the synthesis of NAD, an essential coenzyme involved in ATP synthesis which promotes a pro-growth environment in the context of obesity. Because iNAMPT and cellular energetics, a hallmark of cancer, play an important role in liver cancer progression, it has become a target for cancer therapies focused on inhibiting its functions. The objective of this study was to determine the contribution of NAD biosynthesis in obesity-associated liver cancer progression. Methods: Cell culture studies were conducted with serum from male mice randomized to diet-induced obesity (OB) or control (CR) ± FK866 (iNAMPT inhibitor) in SNU, HepG2 human liver cancer cells, and Hepa 1-6 liver murine cells. Protein analysis of pAkt and pErk was performed via immunoblot. Cytotoxicity, reactive oxygen species (ROS), cell viability, and invasion were also measured in the cells. For the mouse model, the C57BL/6J male mice were randomized to the DIO or CR group. At 21 weeks of age, the mice were injected subcutaneously with Hepa 1-6 liver cancer cells. At 23 weeks, the mice received an I.P. injection of FK866 (30 mg/kg) for 2 weeks. The tumor and mouse weights were measured. Results: The cells exposed to OB sera showed increased proliferation, lactate dehydrogenase (LDH) secretion, ROS, and invasion. FK866 decreased proliferation, LDH secretion, ROS, and invasion for all liver cancer cells. The cells exposed to CR sera and OB + FK866 resulted in more LDH, suggesting increased apoptosis compared with OB sera. The OB sera increased phosphorylation of Akt, which was suppressed by FK866 compared with the OB group. In liver cancer cells, physiological and cellular signaling is affected differently when inhibiting NAD biosynthesis in an in vitro model of obesity and liver cancer. In vivo, the diet-induced obese (DIO) mice weighed significantly more than the mice fed a control diet. In addition, 70% of the DIO mice developed tumors, compared with 20% of the CR mice, and had tumors with greater volumes and weights. NAD inhibition blocked obesity-induced tumor growth. Conclusions: In this study, we demonstrate that inhibition of iNAMPT resulted in suppression of tumor growth in the context of obesity. Identifying pre-clinical strategies to reverse the impact of obesity on liver cancer progression is important due to the strong increased risk of liver cancer and its poor prognosis. Future translational research studies can be built from this pre-clinical foundational research. Full article

Background/Objectives: Obesity-related metabolic complications contribute to musculoskeletal disorders and are often associated with muscular fat accumulation. The AMP-activated protein kinase (AMPK) is a therapeutic target that can mitigate these effects. Methods: An in vivo study was conducted to understand the effects of Gryllus bimaculatus (GB), a potent AMPK activator, on metabolic and muscular homeostasis in diet-induced obesity (DIO). Six-week-old male C57BL/6J mice were fed either a normal diet or a high-fat diet (HFD) for eight weeks to induce DIO. Subsequently, HFD-fed mice were divided into four groups: HFD only, HFD with 100 mg/kg/day GB, HFD with 200 mg/kg/day GB, and HFD with 400 mg/kg/day GB for 16 weeks. To assess the effects of GB, we evaluated insulin resistance, muscle strength, muscular fat accumulation, and AMPK activation using an oral glucose tolerance test, grip strength test, histological assessments, serum lipid analyses, western blotting, and quantitative reverse transcription–polymerase chain reaction. Results: The low- and mid-dose GB groups showed a trend toward improved insulin resistance. GB significantly reduced muscle fat accumulation and increased muscle strength. The mid- and high-dose GB groups showed a significantly upregulated expression of the molecular markers of mitochondrial biogenesis and fatty acid oxidation in muscle tissues. Additionally, the high-dose GB group activated AMPK and inhibited the activity of acetyl-CoA carboxylase in the skeletal muscle. Conclusions: The results suggest that GB may serve as a nutraceutical candidate for the management of obesity-associated metabolic complications. Full article

β-hydroxybutyrate (BHB) serves as an alternative cellular fuel during states of low glucose availability, such as fasting or carbohydrate restriction, when the body shifts to using fats and ketone bodies for energy. While BHB has shown potential metabolic benefits, its mechanisms of action in the context of obesity are not fully understood. In this study, we examined the effects of BHB supplementation on subcutaneous adipose tissue (SAT) metabolism in a diet-induced obesity (DIO) mouse model. Adult male mice were first fed a high-fat diet for six weeks, followed by a standard diet with or without BHB supplementation for an additional six weeks. BHB supplementation led to significant body weight loss independent of food intake. This weight reduction was associated with decreased adipocyte differentiation, reflected by reduced peroxisome proliferator-activated receptor gamma (PPARγ) protein levels and lower uncoupling protein 1 (UCP1) expression, indicating altered SAT function. Transcriptomic analysis of SAT revealed upregulation of genes involved in fatty acid activation and transport (e.g., Slc27a2, Plin5, Acot4, Acsm3, Rik). Functional enrichment highlighted the activation of the PPAR signaling pathway and enrichment of peroxisomal components in the BHB group. Together, these results suggest that BHB promotes lipid remodeling in SAT, enhancing fatty acid metabolism while suppressing thermogenic pathways, and thus may represent a novel mechanism contributing to adiposity reduction and metabolic improvement. Full article

Traditional Chinese medicine has long acknowledged the therapeutic potential of Tetradium ruticarpum (A.Juss.) T.G.Hartley together with Coptis chinensis Franch in managing metabolic disorders. However, their combined anti-obesity effects and the underlying mechanisms remain poorly characterized. This study investigates the synergistic anti-obesity effects and mechanisms of a combined berberine and evodiamine treatment (BBE) in high-fat diet (HFD)-induced C57BL/6J mice and 3T3-L1 cells. In vitro, cell viability was evaluated using the Cell Counting Kit-8 (CCK-8), while lipid accumulation was assessed through Oil Red O staining and triglyceride content determination. Molecular docking simulations performed with AutoDockTools 1.5.6 software Vina predicted interactions between BBE and key proteins. The analysis of genes and proteins involved in browning and thermogenesis was conducted using quantitative reverse transcription polymerase chain reaction and Western blotting. In vivo, HFD-induced mice were assessed for serum lipids profiles, glucose, insulin, adipocytokines, fat tissue morphology (Hematoxylin and eosin staining), mitochondrial activity (flow cytometry), and protein expression (immunofluorescence). Molecular docking analysis revealed strong binding affinities between BBE and key target proteins, including UCP1, PGC-1α, PRDM16, CIDEA, FGF21, and FGFR1c. BBE significantly reduced lipid accumulation in 3T3-L1 cells, upregulated the mRNA expression of Prdm16, Cidea, Ucp1, and Dio2, elevated UCP1 and PGC-1α protein levels, and activated the FGF21/PGC-1α signaling pathway. In HFD-induced mice, BBE administration led to reduced body weight, smaller adipocyte size, increased adipocyte number, and alleviated hepatic steatosis. Furthermore, it lowered serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and levels of triglycerides (TG), while simultaneously increasing concentrations of high-density lipoprotein cholesterol (HDL-C). BBE also improved glucose tolerance, reduced fasting insulin levels, and modulated adipocytokine levels (reduced leptin, increased adiponectin), while promoting browning gene and protein expression. Overall, the combination of berberine and evodiamine mitigates obesity by enhancing browning and activating the FGF21/PGC-1α signaling pathway. Full article

We recently reported that a chimeric peptide (GEP44) targeting the glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y1- and Y2- receptors decreased body weight (BW), energy intake, and core temperature in diet-induced obese (DIO) male and female mice. In the current study, we tested the hypothesis that the strong reduction in body weight in response to GEP44 is partially related to the stimulation of energy expenditure (EE). To test this, rats were maintained on a high fat diet (HFD) for at least 4 months to elicit DIO prior to undergoing a sequential 2-day vehicle period, 2-day GEP44 (50 nmol/kg) period, and a minimum 2-day washout period, and detailed measures of energy homeostasis. GEP44 (50 nmol/kg) reduced EE (indirect calorimetry), respiratory exchange ratio (RER), core temperature, activity, energy intake, and BW in male and female rats. As in our previous study in mice, GEP44 reduced BW in male and female HFD-fed rats by 3.8 ± 0.2% and 2.3 ± 0.4%, respectively. These effects appear to be mediated by increased lipid oxidation and reductions in energy intake as GEP44 reduced RER and cumulative energy intake in male and female HFD-fed rats. The strong reduction in body weight in response to GEP44 is related to a robust reduction in energy intake, but not to the stimulation of EE. The paradoxical finding that GEP44 reduced EE might be secondary to a reduction in diet-induced thermogenesis or might indicate an important mechanism to limit the overall efficacy of GEP44 to prevent further weight loss. Full article

Background/Objectives: A high-energy-density (HED) diet promotes body weight gain, fat accumulation, and gut dysbiosis, contributing to obesity. The aim of this study was to characterize the initial response to HED diet consumption, as well as identify any sex differences in body composition, systemic inflammation, gut microbiome, and fecal fat excretion in rats. Methods: Male and female Sprague-Dawley rats were fed a low-energy-density (LED) diet for 10 days and were then switched to an HED diet for four weeks. Food intake, body weight, and body composition were measured routinely. Serum samples were collected to measure inflammatory cytokines/chemokines. Fecal samples were collected for microbiome analysis and lipid content. Results: After the HED diet, all rats gained body weight and fat mass, with males exhibiting increased susceptibility to weight gain. Males displayed either a diet-induced obesity phenotype (DIO-P) or a diet-resistant (DR) phenotype, as characterized by their differential body weight gain. Males showed elevated TGF-β levels, while females exhibited increases in Interferon gamma-inducible protein 10 (IP-10), regulated on activation, normal T cell expressed and secreted (RANTES) protein, and basic fibroblast growth factor (FGFb). Changes in gut microbiota composition revealed a reduction in beneficial species, like Bacteroides uniformis and Parabacteroides distasonis, and an increase in species such as Akkermansia muciniphila. Sex differences in fat metabolism were shown in the greater fecal fat excretion observed in males. Conclusions: Our study demonstrates that short-term consumption of a high-energy diet elicits notable sex-specific differences in body weight, body composition, inflammatory markers, gut microbiota, and fat excretion in Sprague-Dawley rats. While we recognize that this study has a small sample size and a short-term intervention, our findings highlight the critical role of sex as a biological variable in diet-induced obesity research. Full article

Fibroblast growth factor 21 (FGF21), a hormone-like protein, plays a crucial role in enhancing glucose and lipid metabolism, offering promising therapeutic avenues for conditions such as nonalcoholic steatohepatitis and severe hypertriglyceridemia. Despite its potential, this protein’s limited stability and brief half-life pose significant challenges for its use in clinical settings. In this study, we created an FGF21 analog (named FGF21-164) that is a mutant of FGF21 and fused it with the tandem repeat sequence of human CD164. FGF21-164, characterized by extensive glycosylation and sialylation, exhibits enhanced pharmacokinetic properties, particularly in terms of its significantly longer half-life compared to its native form. The in vitro efficacy of FGF21-164 was evaluated using 3T3-L1-induced adipocytes. The protein demonstrated a dose-dependent increase in glucose uptake and effectively decreased lipid droplet accumulation surrounding the adipocytes. The in vivo activity of FGF21-164 was evaluated in leptin-deficient (ob/ob) and diet-induced obesity (DIO) mice. A single subcutaneous dose of FGF21-164 led to a rapid decrease in blood glucose levels and sustained normal fasting glucose levels for up to 28 days. Additionally, repeated dosing of FGF21-164 significantly curbed weight gain and reduced hepatic fat accumulation in DIO mice. Full article

Obesity arises from a complex interplay of genetic and environmental factors. Even among individuals with the same genetic predisposition, diet-induced obesity (DIO) exhibits varying degrees of susceptibility, which are categorized as DIO and diet-induced obesity resistance (DR). The hypothalamus plays a pivotal role in regulating energy homeostasis. This study performed a comparative hypothalamic proteomic analysis in DIO and DR rats to identify differentially expressed proteins (DEPs) associated with alterations in body weight. Male Sprague Dawley rats were fed either a standard chow diet or a high-fat diet for 12 weeks. DIO rats exhibited the most rapid weight gain compared to both the control and DR rats. Despite consuming similar caloric intake, DR rats exhibited less weight gain relative to DIO rats. Proteomic analysis revealed 31 DEPs in the hypothalamus of DR rats compared to DIO rats (with a false discovery rate (FDR) < 1%). Notably, 14 proteins were upregulated and 17 proteins were downregulated in DR rats. Gene ontology analysis revealed an enrichment of ion-binding proteins, such as those binding to Fe²⁺, Zn²⁺, Ca²⁺, and Se, as well as proteins involved in neuronal activity and function, potentially enhancing neuronal development and cognition in DR rats. The DEPs pathway analysis via the Kyoto Encyclopedia of Genes and Genomes (KEGG) implicated starch and sucrose metabolism, antigen processing and presentation, and the regulation of inflammatory mediator affecting TRP channels. Western blotting confirmed the proteomic findings for TRPV4, CaMKV, RSBN1, and BASP1, which were consistent with those obtained from Tandem Mass tag (TMT) proteomic analysis. In conclusion, our study highlights the hypothalamic proteome as a critical determinant in the susceptibility to DIO and provides novel targets for obesity prevention and treatment. Full article

Background: Obesity and aging are associated with the progressive loss of brown adipose tissue (BAT), an increase in visceral white adipose tissue (vWAT), and a reduction in subcutaneous white adipose tissue (sWAT). The progressive expansion of visceral obesity promotes a low grade of systemic chronic inflammation (meta-inflammation), contributing to the onset of comorbidities such as type 2 diabetes mellitus (T2DM), metabolic syndrome, and even cancer. Thus, preserving the thermogenic activity of adipose tissue and improving the metabolic flexibility of sWAT could be an effective strategy to prevent the development of metabolic chronic diseases and promote healthy aging. Precision nutrition has emerged as a complementary approach to control the metabolic alterations associated with unhealthy obesity and aging. In a previous work, we described that a silymarin-enriched extract from milk thistle (Mthistle) increased markers of browning and thermogenesis in vitro in human differentiated adipocytes (SGBS). Objectives/Methods: Therefore, this study aims to evaluate the potential of Mthistle to activate thermogenesis in a preclinical model of high-fat diet (HFD)-induced obesity (DIO). Results: Our results demonstrate that Mthistle increases systemic energy expenditure (EE), preserves body temperature after cold exposure, improves insulin resistance, and reduces inflammatory markers in WAT. Conclusions: Based on these results, silymarin-enriched extract from Mthistle may be proposed as a nutraceutical for the management of metabolic chronic diseases and/or accelerated aging. Full article

Background; obesity and nonalcoholic fatty liver disease (NAFLD) reduce life expectancy; nonoperative interventions show poor results. Individually, chitosan (1% w/w), acetic acid (AA 0.3–6.5% w/w), and sepiolite clay (5% w/w) attenuate high-fat-diet-induced obesity (DIO) via reduced energy digestibility and increased energy expenditure. Objectives; therefore, we hypothesized that a chitosan–sepiolite biocomposite suspended in AA would attenuate DIO and NAFLD to a greater extent than AA alone via its more substantial adsorption of nonpolar molecules. Methods; we tested this dietary supplement in C57BL/6J mice fed a high-fat diet (HFD) compared to an unsupplemented HFD and an HFD supplemented with a bile acid sequestrant (cholestyramine) or standalone AA. Results; biocomposite supplementation reduced DIO gain by 60% and abolished hepatic liver accumulation, whereas standalone AA showed mild attenuation of DIO gain and did not prevent HFD-induced hepatic fat accumulation. The biocomposite intake was accompanied by a lower digestibility (−4 point %) counterbalanced by increased intake; hence, it did not affect energy absorption. Therefore, DIO attenuation was suggested to be related to higher energy expenditure, a phenomenon not found with AA alone, as supported by calculated energy expenditure using the energy balance method. Conclusions; these results support further investigation of the biocomposite’s efficacy in attenuating obesity and NAFLD, specifically when applied with a restricted diet. Future studies are needed to determine this biocomposite’s safety, mechanism of action, and efficacy compared to its components given separately or combined with other ingredients. Full article

Obesity promotes metabolic diseases such as type 2 diabetes and cardiovascular disease. PKCδI is a serine/threonine kinase which regulates cell growth, differentiation, and survival. Caspase-3 cleavage of PKCδI releases the C-terminal catalytic fragment (PKCδI_C), which promotes inflammation and apoptosis. We previously demonstrated an increase in PKCδI_C in human obese adipose tissue (AT) and adipocytes. Subsequently, we designed a small molecule drug called NP627 and demonstrated that NP627 specifically inhibited the release of PKCδI_C in vitro. Here, we evaluate the in vivo safety and efficacy of NP627 in a diet-induced obese (DIO) mouse model. The results demonstrate that NP627 treatment in DIO mice increased glucose uptake and inhibited the cleavage of PKCδI_C in the AT as well as in the kidney, spleen, and liver. Next, RNAseq analysis was performed on the AT from the NP627-treated DIO mice. The results show increases in ADIPOQ and CIDEC, upregulation of AMPK, PI3K-AKT, and insulin signaling pathways, while inflammatory pathways were decreased post-NP627 administration. Further, levels of lncRNAs associated with metabolic pathways were affected by NP627 treatment. In conclusion, the study demonstrates that NP627, a small-molecule inhibitor of PKCδI activity, is not toxic and that it improves the metabolic function of DIO mice in vivo. Full article

The circular RNA circH19 has been implicated in the regulation of gene expression and various biological processes, including obesity. Objectives: This study aimed to elucidate the metabolic changes in plasma after circH19 knockdown in a diet-induced obese (DIO) mouse model. Methods: Plasma samples were collected following the intervention and subjected to non-targeted metabolomics analysis using liquid chromatography–mass spectrometry (LC-MS). Metabolic profiling was performed to identify and quantify metabolites, followed by multivariate statistical analysis to discern differential metabolic signatures. Results: A total of 1250 features were quantified, resulting in the upregulation of 564 metabolites and the downregulation of 686 metabolites in the circH19 knockdown group compared to the control mice. Metabolic pathway analysis revealed disruptions in lipid metabolism, amino acid turnover, and energy production pathways. Notably, the intervention led to a substantial decrease in circulating lipids and alterations in the plasma amino acid profile, indicative of an impact on protein catabolism and anabolic processes. The observed shifts in lipid and amino acid metabolism suggest potential therapeutic avenues for obesity and related metabolic disorders. Conclusions: The circH19 knockdown in DIO mice led to significant alterations in plasma metabolites, highlighting its potential role in the regulation of obesity and metabolic disorders. Full article

Background/Objectives: The inflammatory response has evolved as a protective mechanism against pathogens and tissue damage. However, chronic inflammation can occur, potentially leading to severe disease. Low-grade chronic inflammation is associated with obesity, and the Th1 cytokine profile plays an important role in this proinflammatory environment. Diet-induced obesity (DIO) can lead to persistent dysbiosis and maintain high concentrations of circulating lipopolysaccharides (LPSs) over prolonged periods of time, resulting in metabolic endotoxemia. In this context, the study of natural immunomodulators has recently increased. Objective: The aim of this study is improve scientific evidence for the immunomodulatory role of L-Alliin in obesity and inflammation. Methods: In the present work, we describe the effect of L-Alliin on serum levels of cytokines in DIO mice after an acute inflammatory challenge. L-Alliin is the main organosulfurized molecule of garlic that has been studied for its numerous beneficial physiological effects in health and disease and is beginning to be considered a nutraceutical. Two situations are simulated in this experimental model, health and chronic, low-grade inflammation that occurs in obesity, both of which are confronted with an acute, inflammation-inducing challenge. Results: Based on our findings, L-Alliin seems to somehow stimulate the cellular chemotaxis by eliciting the release of key molecules, including IL-2, IFN-γ, TNF-α, MCP-1, IL-6, IL-9, and G-CSF. However, the molecular mechanism involved remains unknown. This, in turn, mitigates the risk of severe inflammatory symptoms by preventing the release of IL-1β and its downstream molecules such as IL-1α, GM-CSF, and RANTES. Conclusions: Taken together, these results indicate that L-Alliin can boost immunity in healthy organisms and act as an immunomodulator in low-grade inflammation. Full article

Diabetes mellitus (DM) is a common metabolic disease that poses a severe threat to human health. Despite a range of therapeutic approaches, there remains a lack of effective and safe therapies with the existing drugs. Therefore, there is an urgent need to develop novel, effective, and safe therapeutic strategies for DM. Free fatty acid receptor 4 (FFAR4), also known as GPR120, is a member of the G protein-coupled receptor family, which has received considerable attention as an attractive new therapeutic target for treating DM. In the present study, based on the structure of TUG-891, which has excellent activity and selectivity, a series of novel FFAR4 agonists was designed by replacing the phenylpropanoic acid β position carbon atom with an oxygen atom, while replacing the linking oxymethylene with an amide-linking group. The target compounds were evaluated for FFAR4 agonistic activity, and the preferred compounds were evaluated for selectivity, oral glucose tolerance in normal ICR mice, antidiabetic activity in diet-induced obese (DIO) mice, pharmacokinetic properties in ICR mice and molecular modeling studies. The results showed that compound 10f possessed excellent FFAR4 agonistic activity and selectivity, significantly improved glucose tolerance in normal ICR mice, lowered blood glucose and promoted insulin secretion in a dose-dependent manner in DIO mice, and showed favorable pharmacokinetic properties. These results indicate that compound 10f may be a promising compound that deserves further structure–activity relationship and pharmacological studies for the development of antidiabetic drugs. Full article

Recent studies have indicated that hindbrain [fourth ventricle (4V)] administration of the neurohypophyseal hormone, oxytocin (OT), reduces body weight, energy intake and stimulates interscapular brown adipose tissue temperature (T_IBAT) in male diet-induced obese (DIO) rats. What remains unclear is whether chronic hindbrain (4V) OT can impact body weight in female high fat diet-fed (HFD) rodents and whether this involves activation of brown adipose tissue (BAT). We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of interscapular brown adipose tissue (IBAT) contributes to its ability to activate BAT and reduce body weight in female high HFD-fed rats. To test this hypothesis, we determined the effect of disrupting SNS activation of IBAT on OT-elicited stimulation of T_IBAT and reduction of body weight in DIO rats. We first measured the impact of bilateral surgical SNS denervation to IBAT on the ability of acute 4V OT (0.5, 1, and 5 µg ≈ 0.5, 0.99, and 4.96 nmol) to stimulate T_IBAT in female HFD-fed rats. We found that the high dose of 4V OT (5 µg ≈ 4.96 nmol) stimulated T_IBAT similarly between sham rats and denervated rats (p = NS). We subsequently measured the effect of bilateral surgical denervation of IBAT on the effect of chronic 4V OT (16 nmol/day ≈ 16.1 μg/day) or vehicle infusion to reduce body weight, adiposity and energy intake in female HFD-fed rats (N = 7–8/group). Chronic 4V OT reduced body weight gain (sham: −18.0 ± 4.9 g; denervation: −15.9 ± 3.7 g) and adiposity (sham: −13.9 ± 3.7 g; denervation: −13.6 ± 2.4 g) relative to vehicle treatment (p < 0.05) and these effects were similar between groups (p = NS). These effects were attributed, in part, to reduced energy intake evident during weeks 2 (p < 0.05) and 3 (p < 0.05). To test whether these results translate to other female rodent species, we also examined the effect of chronic 4V infusion of OT on body weight and adiposity in two strains of female HFD-fed mice. Similar to what we found in the HFD-fed rat model, we also found that chronic 4V OT (16 nmol/day) infusion resulted in reduced body weight gain, adiposity and energy intake in female DIO C57BL/6J and DBA/2J mice (p < 0.05 vs. vehicle). Together, these findings suggest that (1) sympathetic innervation of IBAT is not necessary for OT-elicited increases in BAT thermogenesis and weight loss in female HFD-fed rats and (2) the effects of OT to reduce weight gain and adiposity translate to other female mouse models of diet-induced obesity (DIO). Full article