Murine Model Of Diet-induced Obesity Research Articles

Daily Orange Consumption Reduces Hepatic Steatosis Prevalence in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease: Exploratory Outcomes of a Randomized Clinical Trial.

Background: Consumption of flavonoid-rich orange juice has been shown to reduce adiposity and liver steatosis in murine models of diet-induced obesity. However, little is known about the effects of whole orange intake, independent of body weight changes, on liver function and steatosis in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD). The goal is to understand the direct impact of orange consumption on metabolic health. Methods: Sixty-two men and women aged 30-65 with MASLD (Controlled Attenuation Parameter, (CAP) > 275 dB/m) were randomly assigned to consume either 400 g of whole oranges or non-citrus fruits daily for 4 weeks. Baseline evaluations included medical assessments, blood tests, and body composition. Liver health was assessed using transient elastography (FibroScan®) for steatosis and fibrosis, conducted by blinded personnel. This clinical trial was registered at ClinicalTrials.gov (NCT05558592). Results: After 4 weeks of orange supplementation, liver steatosis decreased in the treatment group, with 70.9% showing steatosis compared to 100% in controls (p < 0.004), indicating a 30% reduction in liver disease prevalence. There were no significant changes in fibrosis or plasma liver enzymes, though plasma gamma glutaril transferase (GGT) levels decreased significantly. Body weight, waist circumference, body composition, lipid profile, fasting glucose, insulin, and C-reactive protein levels remained unchanged. Dietary analysis revealed no change in caloric intake, but vitamins C, A, thiamine, and riboflavin increased in the orange group. Conclusions: Our findings suggest that phytochemical-rich foods, especially whole fruits like oranges, may enhance liver function as an adjunct treatment for MASLD. The notable reduction in liver steatosis prevalence occurred independently of body weight changes. Further studies are needed to investigate the long-term effects of orange supplementation on steatosis and fibrosis progression and to identify the specific bioactive compounds and mechanisms involved.

#1493 Upregulated miR-205 as a biomarker of diet-induced obesity-related glomerulopathy

Abstract Background and Aims Obesity is a modifiable risk factor for the development and progression of chronic kidney disease (CKD). Pathways through which obesity might cause renal disease are not completely understood, as not all obese subjects develop CKD. In terms of deepening the knowledge of the preliminary steps of obesity-related renal damage, our group has developed a diet-induced obese murine model with obesity related glomerulopathy (ORG). The objective of this study was to investigate ORG at a cellular, structural and transcriptomic level as a way to discover the triggering pathogenic phenomena of ORG and evaluate potential biomarkers. Method Thirty Wistar rats were randomized into two groups: control rats (n = 15), which were fed with standard diet (SD) and study rats (n = 15), which were fed with high-fat diet (HFD). After 10 weeks, weight, parameters of kidney function, renal histological features, transcriptomic changes, miRNA and mRNA isolation were compared. Results HFD gained significantly more weight (55.8%) than SD(29.2%), p = 0.001. Albuminuria was also significantly higher in HFD (10,384.04) compared with SD (5,845.45), p = 0.001. HFD rats showed typical lesions of early-stages of ORG, with a predominance of mesangial matrix increase (MMI) and podocyte hypertrophy (PH). All histologic lesions correlated with genes differentially expressed (DE) in kidneys of HFD group and, both MMI and PH, also correlated with specific miRNAs DE in the urine of HFD group. The functional analysis showed 4 miRNAs DE in the kidneys of HFD group that negatively regulates PTEN gene, which promotes podocyte endocytosis of lipids in ORG. The electronic microscope confirmed the spaces of lipid vacuoles in the podocytes of HFD rats. Between those 4 miRNAs DE, miR-205 was also found to be upregulated in the urine of HFD group. Conclusion Wistar rats fed with HFD for 10 weeks developed early-stages of ORG, with a specific targetome of miRNAs and gene expression. The upregulation of miR-205 in kidney and its isolation in urine is associated with lipid endocytosis of podocytes, which takes place in the early-stages of ORG and could become a plausible biomarker of early-stages of ORG and open new avenues for future therapeutics research.

Effects of Fermented Goat Milk on Adiposity and Gut Microbiota in a Diet-Induced Obesity Murine Model

The administration of goat milk fermented (FGM) with Lactobacillus delbrueckii subsp. indicus CRL1447 and supplemented with different mixes of lactobacilli strains (Mix1: Limosilactobacillus fermentum CRL1446 + Lactiplantibacillus paraplantarum CRL1449 + Lactiplantibacillus paraplantarum CRL1472; Mix2: CRL1446 + CRL1449; Mix3: CRL1446 + CRL1472; and Mix4: CRL1449 + CRL1472) was investigated regarding body weight, metabolic and inflammatory parameters, and gut microbiota (GM) composition in mice fed a high-fat diet (HFD). Body weight gain, adipocyte size, fasting blood glucose, serum triglyceride, and leptin levels were significantly reduced in the group fed FGM+Mix3 compared with the obese mice fed FGM. FGM+Mix2 and FGM+Mix3 modified the GM composition, reversing the dysbiosis caused by the HFD. Although there were no significant changes at the phylum level, the GM composition was significantly changed at the family and genus levels. Results suggest that the administration of FGM+Mix3 improves metabolic and immune profiles in obese mice while positively modulating the GM, therefore attenuating the risk factors associated with obesity.

Proteomic Profiling of Plasma- and Gut-Derived Extracellular Vesicles in Obesity.

Obesity entails metabolic alterations across multiple organs, highlighting the role of inter-organ communication in its pathogenesis. Extracellular vesicles (EVs) are communication agents in physiological and pathological conditions, and although they have been associated with obesity comorbidities, their protein cargo in this context remains largely unknown. To decipher the messages encapsulated in EVs, we isolated plasma-derived EVs from a diet-induced obese murine model. Obese plasma EVs exhibited a decline in protein diversity while control EVs revealed significant enrichment in protein-folding functions, highlighting the importance of proper folding in maintaining metabolic homeostasis. Previously, we revealed that gut-derived EVs' proteome holds particular significance in obesity. Here, we compared plasma and gut EVs and identified four proteins exclusively present in the control state of both EVs, revealing the potential for a non-invasive assessment of gut health by analyzing blood-derived EVs. Given the relevance of post-translational modifications (PTMs), we observed a shift in chromatin-related proteins from glycation to acetylation in obese gut EVs, suggesting a regulatory mechanism targeting DNA transcription during obesity. This study provides valuable insights into novel roles of EVs and protein PTMs in the intricate mechanisms underlying obesity, shedding light on potential biomarkers and pathways for future research.

Bovine Serum Albumin Elicits IL-33-Dependent Adipose Tissue Eosinophilia: Potential Relevance to Ovalbumin-induced Models of Allergic Disease.

All cells of the immune system reside in adipose tissue (AT), and increasing type 2 immune cells may be a therapeutic strategy to improve metabolic health. In our previous study using i.p. IL-5 injections to increase eosinophils, we observed that a standard vehicle control of 0.1% BSA also elicited profound AT eosinophilia. In this study, we aimed to determine whether BSA-induced AT eosinophilia results in metabolic benefits in murine models of diet-induced obesity. I.p. 0.1% BSA injections increased AT eosinophils after 4 wk. Despite elevating eosinophils to >50% of immune cells in the AT, body weight and glucose tolerance were not different between groups. Interestingly, BSA elicited epithelial IL-33 production, as well as gene expression for type 2 cytokines and IgE production that were dependent on IL-33. Moreover, multiple models of OVA sensitization also drove AT eosinophilia. Following transplantation of a donor fat pad with BSA-induced eosinophilia, OVA-sensitized recipient mice had higher numbers of bronchoalveolar lavage eosinophils that were recipient derived. Interestingly, lungs of recipient mice contained eosinophils, macrophages, and CD8 T cells from the donor AT. These trafficked similarly from BSA- and non-BSA-treated AT, suggesting even otherwise healthy AT serves as a reservoir of immune cells capable of migrating to the lungs. In conclusion, our studies suggest that i.p. injections of BSA and OVA induce an allergic response in the AT that elicits eosinophil recruitment, which may be an important consideration for those using OVA in animal models of allergic disease.

Sex-dependent hypothalamic response in a diet-induced obesity murine model

Sex-dependent hypothalamic response in a diet-induced obesity murine model

Aqueous remote loading of setmelanotide in poly(lactic-co-glycolic acid) microspheres for long-term obesity treatment

Setmelanotide (Imcivree™) was developed as a daily injectable therapeutic peptide for the treatment of rare forms of syndromic obesity, such as POMC deficiency and leptin receptor deficiency. The important option of poly(lactic-co-glycolic acid) (PLGA) controlled release microspheres has become more attractive for this class of drugs upon the discovery that net positively charged peptides can be remote-loaded rapidly from aqueous peptide solution into blank microspheres at high loading and encapsulation efficiency. Here we sought to remote-load setmelanotide in PLGA microspheres and examine its potential for long-term controlled release and body weight control. The influence of PLGA microsphere porosity was investigated with respect to morphology, drug loading, and in vitro release profiles. Increased density of the microspheres inhibited the progress of encapsulation of the dicationic peptide. A diet-induced obese murine model was then used to determine the pharmacokinetic profile and to evaluate long-term efficacy of an optimal formulation. Remote loaded PLGA formulations encapsulated setmelanotide as high as ∼63% (∼6.3% w/w loading) and exhibited slow and continuous peptide release over ∼6 weeks in vitro largely independent of microsphere porosity. The obtained in vivo release pattern from deconvolution of the pharmacokinetics after subcutaneous microsphere injection was consistent with the in vitro release profile but with a lower initial burst release and overall slightly faster release rate. After a single injection of remote-loaded setmelanotide, continuous long-term inhibition of food intake and body weight control was observed over 17 and 30 days, respectively. The improvement in body weight control over drug-free microsphere vehicle-treated control groups matched the observed PK profile. This study provides the first report of long-acting release formulation for 1-month controlled release of setmelanotide and body weight control in a diet induced obese murine model, and supports the further development of long-acting treatment options for obese patients.

Olvanil inhibits adipocyte differentiation in 3T3-L1 cells, reduces fat accumulation and improves lipidic profile on mice with diet-induced obesity

AimThe present study is aimed to examine olvanil's effect in preadipocyte cell culture and on a murine model of diet-induced obesity. We hypothesized that olvanil by being a capsaicinoid will reduce the differentiation to mature adipocytes and reduce the weight of fat tissue in the studied mice. MethodsTo determine the effect of olvanil on adipogenesis, 3T3-L1 cells were cultured. Oil red staining was performed to determine lipid accumulation, whereas triglycerides were measured by biochemical determination. Expression of PPAR-γ and PREF-1 were measured by RT-PCR. Therefore, male C57BL/6J mice (CICUAL:2018-020B) were fed with a high-fat diet for 12 weeks to develop a murine model of diet-induced obesity (DIO). Animals were separated into 6 experimental groups: control (standard diet), DIO (high-fat diet), DIO + orlistat (10 mg/kg), DIO + olvanil (10 mg/kg), DIO + olvanil (25 mg/kg) and DIO + olvanil (50 mg/kg), olvanil was administered for 4 weeks. ResultsOlvanil inhibits adipogenesis, reduces lipid accumulation and triglycerides in 3T3-L1 adipocytes. PPAR-ɣ gene expression was suppressed while PREF-1 was increased in adipocytes treated with olvanil. Whereas protein expression of FABP4 and PPAR-ɣ decreases significantly with olvanil. The results suggest that olvanil can inhibit the differentiation of preadipocytes to adipocytes through the overexpression or maintenance of PREF-1 levels and the suppression of PPAR-ɣ, and FABP4. Therefore, in diet-induced obesity in mice, olvanil decreases fat accumulation in the body and improve lipid profile by decreasing LDL, VLDL and triglycerides in serum. ConclusionOlvanil inhibits adipocyte differentiation in 3T3-L1 cells and reduces fat accumulation and ameliorate lipid profile in diet-induced obese mice.

Reduced SARS-CoV-2 mRNA vaccine immunogenicity and protection in mice with diet-induced obesity and insulin resistance

Obesity and type 2 diabetes mellitus (T2DM) are associated with an increased risk of severe outcomes from infectious diseases, including coronavirus disease 2019. These conditions are also associated with distinct responses to immunization, including an impaired response to widely used severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines. We sought to establish a connection between reduced immunization efficacy via modeling the effects of metabolic diseases on vaccine immunogenicity that is essential for the development of more effective vaccines for this distinct vulnerable population. A murine model of diet-induced obesity and insulin resistance was used to model the effects of comorbid T2DM and obesity on vaccine immunogenicity and protection. Mice fed a high-fat diet (HFD) developed obesity, hyperinsulinemia, and glucose intolerance. Relative to mice fed a normal diet, HFD mice vaccinated with a SARS-CoV-2 mRNA vaccine exhibited significantly lower anti-spike IgG titers, predominantly in the IgG2c subclass, associated with a lower type 1 response, along with a 3.83-fold decrease in neutralizing titers. Furthermore, enhanced vaccine-induced spike-specific CD8+ T-cell activation and protection from lung infection against SARS-CoV-2 challenge were seen only in mice fed a normal diet but not in HFD mice. The study demonstrated impaired immunity following SARS-CoV-2 mRNA immunization in a murine model of comorbid T2DM and obesity, supporting the need for further research into the basis for impaired anti-SARS-CoV-2 immunity in T2DM and investigation of novel approaches to enhance vaccine immunogenicity among those with metabolic diseases.

Host obesity alters the ovarian tumor immune microenvironment and impacts response to standard of care chemotherapy

BackgroundThe majority of women with epithelial ovarian cancer (OvCa) are diagnosed with metastatic disease, resulting in a poor 5-year survival of 31%. Obesity is a recognized non-infectious pandemic that increases OvCa incidence, enhances metastatic success and reduces survival. We have previously demonstrated a link between obesity and OvCa metastatic success in a diet-induced obesity mouse model wherein a significantly enhanced tumor burden was associated with a decreased M1/M2 tumor-associated macrophage ratio (Liu Y et al. Can, Res. 2015; 75:5046–57).MethodsThe objective of this study was to use pre-clinical murine models of diet-induced obesity to evaluate the effect of a high fat diet (HFD) on response to standard of care chemotherapy and to assess obesity-associated changes in the tumor microenvironment. Archived tumor tissues from ovarian cancer patients of defined body mass index (BMI) were also evaluated using multiplexed immunofluorescence analysis of immune markers.ResultsWe observed a significantly diminished response to standard of care paclitaxel/carboplatin chemotherapy in HFD mice relative to low fat diet (LFD) controls. A corresponding decrease in the M1/M2 macrophage ratio and enhanced tumor fibrosis were observed both in murine DIO studies and in human tumors from women with BMI > 30.ConclusionsOur data suggest that the reported negative impact of obesity on OvCa patient survival may be due in part to the effect of the altered M1/M2 tumor-associated macrophage ratio and enhanced fibrosis on chemosensitivity. These data demonstrate a contribution of host obesity to ovarian tumor progression and therapeutic response and support future combination strategies targeting macrophage polarization and/or fibrosis in the obese host.

Discovery of a novel, liver-targeted thyroid hormone receptor-β agonist, CS271011, in the treatment of lipid metabolism disorders.

Thyroid hormone receptor β (THR-β) plays a critical role in metabolism regulation and has become an attractive target for treating lipid metabolism disorders in recent years. Thus, in this study, we discovered CS271011, a novel THR-β agonist, and assessed the safety and efficiency of CS271011 compared to MGL-3196 in vitro and in vivo. We conducted luciferase reporter gene assays to assess the activation of THR-β and α in vitro. C57BL/6J mice were fed a high-fat diet for 12 weeks, CS271011 was administered by gavage at the dose of 1 mg/kg and 3 mg/kg, and MGL-3196 was administered at the dose of 3 mg/kg for 10 weeks. Body weight, food intake, serum and hepatic parameters, histological analysis, pharmacokinetic studies, RNA sequencing of the liver and heart, and expression of hepatic lipid-metabolic genes were determined to evaluate the safety and efficiency of CS271011. Compared with MGL-3196, CS271011 showed higher THR-β activation in vitro. In the diet-induced obesity mice model, CS271011 demonstrated favourable pharmacokinetic properties in mice and was enriched in the liver. Finally, CS271011 improved dyslipidaemia and reduced liver steatosis in the diet-induced obesity murine model. Mechanistically, CS271011 and MGL-3196 showed potent regulation of lipid metabolism-related genes. CS271011 is a potent and liver-targeted THR-β agonist for treating lipid metabolism disorders.

Amelioration of obesity-induced white adipose tissue inflammation by Bacillus coagulans T4 in a high-fat diet-induced obese murine model

AimFresh evidence suggests that B. coagulans can be regarded as a promising therapeutic alternative for metabolic disorders. However, the possible effects of this probiotic on obesity-induced adipose tissue inflammation are unknown. MethodsC57BL/6j male mice were assigned to a normal-chow diet (NCD) or a high-fat diet (HFD) for 10 weeks. After this period, HFD-fed mice were randomly divided into two groups; HFD control group and HFD plus B. coagulans T4 (IBRC-N10791) for another 8 weeks. B. coagulans T4 was administrated daily by oral intragastric gavage (1 × 109 colony-forming units). Key findingsHere, we found that B. coagulans successfully mitigated obesity and related metabolic disorder, as indicated by reduced body weight gain, decreased adiposity, and improved glucose tolerance. B. coagulans T4 administration also inhibited HFD-induced macrophage accumulation in white adipose tissue and switched M1 to M2 macrophages. In parallel, B. coagulans T4 treatment attenuated HFD-induced alteration in mRNA expression of pro/anti-inflammatory cytokines and Tlr4 in white adipose tissue. Moreover, B. coagulans T4 supplementation reduced the Firmicutes/Bacteriodetes ratio and increased the number of Lactobacillus and Faecalibacterium compared to the HFD group. Additionally, a significant increase in propionate and acetate levels in the HFD group was seen following B. coagulans T4 administration. SignificanceTaken together, the present study provides evidence that B. coagulans T4 supplementation exerts anti-obesity effects in part through attenuating inflammation in adipose tissue. The present study will have significant implications for obesity management.

Vitamin A preserves cardiac energetic gene expression in a murine model of diet-induced obesity.

Perturbed vitamin-A metabolism is associated with type 2 diabetes and mitochondrial dysfunction that are pathophysiologically linked to the development of diabetic cardiomyopathy (DCM). However, the mechanism, by which vitamin A might regulate mitochondrial energetics in DCM has previously not been explored. To test the hypothesis that vitamin-A deficiency accelerates the onset of cardiomyopathy in diet-induced obesity (DIO), we subjected mice with lecithin retinol acyltransferase (Lrat) germline deletion, which exhibit impaired vitamin-A stores, to vitamin A-deficient high-fat diet (HFD) feeding. Wild-type mice fed with a vitamin A-sufficient HFD served as controls. Cardiac structure, contractile function, and mitochondrial respiratory capacity were preserved despite vitamin-A deficiency following 20 wk of HFD feeding. Gene profiling by RNA sequencing revealed that vitamin A is required for the expression of genes involved in cardiac fatty acid oxidation, glycolysis, tricarboxylic acid cycle, and mitochondrial oxidative phosphorylation in DIO as expression of these genes was relatively preserved under vitamin A-sufficient HFD conditions. Together, these data identify a transcriptional program, by which vitamin A preserves cardiac energetic gene expression in DIO that might attenuate subsequent onset of mitochondrial and contractile dysfunction.NEW & NOTEWORTHY The relationship between vitamin-A status and the pathogenesis of diabetic cardiomyopathy has not been studied in detail. We assessed cardiac mitochondrial respiratory capacity, contractile function, and gene expression by RNA sequencing in a murine model of combined vitamin-A deficiency and diet-induced obesity. Our study identifies a role for vitamin A in preserving cardiac energetic gene expression that might attenuate subsequent development of mitochondrial and contractile dysfunction in diet-induced obesity.

ODP005 Molecular Characterization of Early Adipose Tissue Remodeling and Fibrosis in a Murine Model of Diet-Induced Obesity.

Abstract One of the many pathophysiological changes associated with obesity is the build up of structural and physiochemical extracellular matrix components in adipose depots, known as adipose tissue fibrosis. Like liver fibrosis, adipose tissue fibrosis occurs as a response to chronic injury and inflammation and can perpetuate inflammation and impede proper tissue functioning. Key adipose tissue fibrosis markers have been identified in obese adipose tissue, including collagen VI and its cleavage product endotrophin, however, adipose tissue fibrosis remains poorly characterized, particularly in its initiating phases. We have developed and characterized a murine model of diet-induced obesity (12 weeks of high fat feeding), insulin resistance, and early fibrotic development in both sexes. While diagnosable fibrosis was absent, as determined by picrosirius red staining, we detected elevated collagen VI, TGF-β, TNF-α, and TIMP-1 mRNA in gonadal white adipose of both sexes. TIMP-4 was decreased in males but elevated in females. Immunohistochemical analysis revealed pericellular build up of collagen VI immunoreactivity in males only, co-localized with immunoreactivity of its protease MMP-14, which is known to generate the pro-fibrotic fragment endotrophin. This work identifies key sex differences and fibrosis markers present during the initiation of adipose tissue fibrosis, earlier than diagnosable fibrosis can be detected, highlighting their potential as therapeutic targets for prevention or reversal of fibrosis in the treatment of obesity and insulin resistance. Presentation: No date and time listed

Functional Complementation of Anti-Adipogenic Phytonutrients for Obesity Prevention and Management.

Obesity is an established risk factor for metabolic disease. This study explores the functional complementation of anti-adipogenic phytonutrients for obesity prevention and management. Nine phytonutrients were selected based on their ability to affect the expression of one or more selected adipogenic biomarker proteins. The phytonutrients include berberine, luteolin, resveratrol, fisetin, quercetin, fucoidan, epigallocatechin gallate, hesperidin, and curcumin. The selected adipogenic biomarker proteins include PPARɣ, SREBP1c, FASN, PLIN1, FABP4, and β-catenin. Individually, phytonutrients had variable effects on the expression level of selected adipogenic biomarker proteins. Collectively, the functional complementation of nine phytonutrients suppressed de novo fatty acid biosynthesis via the negative regulation of PPARɣ, FASN, PLIN1, and FABP4 expression; activated glycolysis via the positive regulation of SREBP1c expression; and preserved cell–cell adhesion via the inhibition of β-catenin degradation. In primary human subcutaneous preadipocytes, the composition of nine phytonutrients had more potent and longer lasting anti-adipogenic effects compared to individual phytonutrients. In a diet-induced obesity murine model, the composition of nine phytonutrients improved glucose tolerance and reduced weight gain, liver steatosis, visceral adiposity, circulating triglycerides, low-density lipoprotein cholesterol, and inflammatory cytokines and chemokines. The functional complementation of anti-adipogenic phytonutrients provides an effective approach toward engineering novel therapeutics for the prevention and management of obesity and metabolic syndrome.

A Composition of Phytonutrients for Glycemic and Weight Management.

Maintaining healthy body weight is an important component of any effective diabetes management plan. However, glycemic management using insulin generally leads to weight gain. In addition, weight loss medications prescribed for diabetes management are often associated with adverse side effects, which limit their long-term usage. Alternatively, nutrition intervention provides a safe, readily accessible, and inexpensive option for diabetes management. This study describes a composition of phytonutrients comprising berberine, cinnamaldehyde, and curcumin for glycemic and weight management. Functional complementarity between berberine, cinnamaldehyde, and curcumin provides an effective means to improve insulin sensitivity without increasing adiposity. In primary human omental preadipocytes, cinnamaldehyde and curcumin additively enhance insulin-stimulated activation of Akt2 and glucose uptake, whereas berberine inhibits de novo fatty acid biosynthesis and fat cell differentiation. In a diet-induced obesity murine model, a dietary supplement with berberine, cinnamaldehyde, and curcumin prevents weight gain, improves glucose tolerance, and reduces HbA1c, blood lipids, visceral adiposity, and liver steatosis. Collectively, the composition of phytonutrients comprising berberine, cinnamaldehyde, and curcumin protects against obesity and pre-diabetic conditions in a diet-induced obesity murine model. Safety and efficacy assessment of nutrition intervention using combined berberine, cinnamaldehyde, and curcumin for glycemic and weight management in future clinical trials are warranted.

Tirzepatide induces a thermogenic-like amino acid signature in brown adipose tissue

ObjectivesTirzepatide, a dual GIP and GLP-1 receptor agonist, delivered superior glycemic control and weight loss compared to selective GLP-1 receptor (GLP-1R) agonism in patients with type 2 diabetes (T2D). These results have fueled mechanistic studies focused on understanding how tirzepatide achieves its therapeutic efficacy. Recently, we found that treatment with tirzepatide improves insulin sensitivity in humans with T2D and obese mice in concert with a reduction in circulating levels of branched-chain amino (BCAAs) and keto (BCKAs) acids, metabolites associated with development of systemic insulin resistance (IR) and T2D. Importantly, these systemic effects were found to be coupled to increased expression of BCAA catabolic genes in thermogenic brown adipose tissue (BAT) in mice. These findings led us to hypothesize that tirzepatide may lower circulating BCAAs/BCKAs by promoting their catabolism in BAT. MethodsTo address this question, we utilized a murine model of diet-induced obesity and employed stable-isotope tracer studies in combination with metabolomic analyses in BAT and other tissues. ResultsTreatment with tirzepatide stimulated catabolism of BCAAs/BCKAs in BAT, as demonstrated by increased labeling of BCKA-derived metabolites, and increases in levels of byproducts of BCAA breakdown, including glutamate, alanine, and 3-hydroxyisobutyric acid (3-HIB). Further, chronic administration of tirzepatide increased levels of multiple amino acids in BAT that have previously been shown to be elevated in response to cold exposure. Finally, chronic treatment with tirzepatide led to a substantial increase in several TCA cycle intermediates (α-ketoglutarate, fumarate, and malate) in BAT. ConclusionsThese findings suggest that tirzepatide induces a thermogenic-like amino acid profile in BAT, an effect that may account for reduced systemic levels of BCAAs in obese IR mice.

Abstract 2189: The role of generational obesity on the ovarian metastatic niche

Abstract Obesity is a worldwide epidemic associated with many cancer types due to persistent inflammation, hyperglycemia and hyperinsulinemia providing an abundance of nutrients and growth factors to cancer cells resulting in an ideal microenvironment. Maternal obesity often results in an increased risk of offspring developing obesity. Chronic inflammation and immunosuppression found in obese patients have been linked to ovarian cancer (OvCa). OvCa is the most lethal gynecological malignancy among women and approximately 12% of OvCa patients are obese. Poor survival rates are attributable to women presenting with advanced disease with disseminated intraperitoneal (i.p) metastasis at diagnosis. Metastatic tumor cells shed from the primary tumor and preferentially home to the mesothelium of the omentum and other peritoneal organs producing secondary lesions. Developmental programming suggests that perinatal nutritional influences can alter gene expression in offspring. A pre-clinical murine model of diet-induced obesity that included maternal cohorts of C57BL/6 mice (dam) with intact host immunity fed either a control diet (CD; 10% fat) or a high-fat diet (HFD; 40% fat) and the resulting offspring fed either diet was utilized to explore diet induced genetic and physical modifications. Body composition analysis revealed differences in weight and lean mass was dependent on offspring diet alone and fat mass was dam diet dependent among CD fed offspring. Second harmonic generation microscopy demonstrated a larger area of collagen mesh-work between fenestrations in the omentum of HFD fed mice as well as an increase in anisotropy. Additionally, a tumor study was performed using either CD or HFD fed offspring to quantify site-specific metastatic success to the adipose-rich tissues of the peritoneal cavity. Mice were injected i.p. with fluorescently tagged syngeneic ID8 murine OvCa cells and disease progression was tracked for 8 weeks. Abdominal organs were dissected, imaged, and organ-specific tumor burden quantified. Overall, offspring fed a HFD displayed an increase in organ-specific tumor burden relative to offspring fed a CD, regardless of dam diet. Furthermore, HFD offspring from HFD dams displayed higher omental tumor burden than HFD offspring from CD dams. In addition, HFD fed mice accumulated more ascites fluid than CD fed mice, however variances were independent of dam diet. Comparison of ascites cytokine expression revealed CXCL13, a dominant chemokine in adipocytes, was significantly increased in mice only exposed to a HFD suggesting an additive effect of both maternal and offspring obesity. Interestingly, increased CXCL13 expression has been reported in OvCa cell lines and in clinical samples. Together, the results suggest maternal obesity or subsequent exposure to a HFD can influence ovarian cancer metastasis. Citation Format: Tyvette Hilliard, Phillip Petrasko, Yueying Liu, Jing Yang, Marwa Asem, Jeff Johnson, Gifty Marfowaa, Brooke Kowalski, Elinor Schnautz, Morgan McCabe, M. Sharon Stack. The role of generational obesity on the ovarian metastatic niche [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2189.

1392-P: Gut Microbiota Contributes to the Beneficial Metabolic Effects of Gelesis Hydrogel Technology

Gelesis' Oral superabsorbent hydrogels (OSH) are crosslinked cellulose-based materials that expand upon hydration in the gastrointestinal tract and are engineered to mimic the mechanical properties of masticated vegetables. One OSH prototype, denoted Gel-B, was tested in both preventative and treatment settings in murine models of diet-induced obesity. Gel-B administration blunted weight gain, reversed gut atrophy, improved metabolic parameters (glucose and insulin tolerance tests; GTT and ITT) and restored barrier function. Here, we investigated the functional role of the gut microbiome to partially explain these protective metabolic effects. Metabolic disease was induced in both Donor (n=24) and Recipient (n=24) C57BL6/J mice via consumption of a high fat and high cholesterol/carbohydrate (HFHCC) diet for weeks (wks) . Donor mice continued on HFHCC or were treated with HFHCC+Gel-B (2 or 4%) for an additional 6 wks. After 2 wks treatment, Donor fecal samples were processed every other day for intestinal microbiota transplantation (IMT) . Recipient mice continued HFHCC and received IMT derived from either HFHCC or Gel-B (2 or 4%) treated Donors via gavage every other day for 4 wks. At 4 wks, the HFHCC-corrected % body weight difference in Recipients was -10.8% and -9.6% for the 2% Gel-B-derived IMT (p=0.02) , and 4% Gel-B-derived IMT (p= 0.02) respectively. Glucose excursions, AUC 0-2h from GTT, were significantly reduced in both Recipient groups (p=0.for both 2% and 4% Gel-B-derived IMT) . The AUC 0-2h from ITT were significantly increased in the 4% Gel-B-derived IMT Recipients (p=0.04) and trended for the 2% Gel-B-derived IMT group (p=0.13) . The present study demonstrates for the first time that IMT from Gel-B treated Donors confers beneficial metabolic effects in HFHCC treated mice. Future experiments will define Gel-B associated microbiota and examine engraftment and durability of IMT. Disclosure A.Silvestri: None. A.Gil-gomez: None. E.Chiquette: Employee; Gelesis. C.Demitri: Stock/Shareholder; Gelesis. B.W.Jones: Employee; Gelesis. A.Sannino: None. M.Rescigno: Research Support; Gelesis.

Pep19 Has a Positive Effect on Insulin Sensitivity and Ameliorates Both Hepatic and Adipose Tissue Phenotype of Diet-Induced Obese Mice.

Peptide DIIADDEPLT (Pep19) has been previously suggested to improve metabolic parameters, without adverse central nervous system effects, in a murine model of diet-induced obesity. Here, we aimed to further evaluate whether Pep19 oral administration has anti-obesogenic effects, in a well-established high-fat diet-induced obesity model. Male Swiss mice, fed either a standard diet (SD) or high-fat diet (HFD), were orally administrated for 30 consecutive days, once a day, with saline vehicle or Pep19 (1 mg/kg). Next, several metabolic, morphological, and behavioral parameters were evaluated. Oral administration of Pep19 attenuated HFD body-weight gain, reduced in approximately 40% the absolute mass of the endocrine pancreas, and improved the relationship between circulating insulin and peripheral insulin sensitivity. Pep19 treatment of HFD-fed mice attenuated liver inflammation, hepatic fat distribution and accumulation, and lowered plasma alanine aminotransferase activity. The inguinal fat depot from the SD group treated with Pep19 showed multilocular brown-fat-like cells and increased mRNA expression of uncoupling protein 1 (UCP1), suggesting browning on inguinal white adipose cells. Morphological analysis of brown adipose tissue (BAT) from HFD mice showed the presence of larger white-like unilocular cells, compared to BAT from SD, Pep19-treated SD or HFD mice. Pep19 treatment produced no alterations in mice behavior. Oral administration of Pep19 ameliorates some metabolic traits altered by diet-induced obesity in a Swiss mice model.