Mouse Model Of Obesity Research Articles

1686-P: ER Stress Aggravates Diaphragmatic Weakness through Activating PERK/JNK Signaling in Obesity Hypoventilation Syndrome

Obesity hypoventilation syndrome (OHS) is associated with reduced quality of life and increased risk of death. Diaphragmatic dysfunction has been implicated in the pathogenesis of OHS. We found that significant diaphragmatic weakness and lipid accumulation in people with obesity as well as mouse models of obesity, which was associated with activated endoplasmic reticulum (ER) stress indicated by increased PERK signaling and activation of JNK pathway. In cultured myotubes, inhibition of PERK and JNK signaling abrogated the lipids deposition and ameliorated insulin resistance, and inhibition of JNK signaling reversed the impaired elasticity of myotubes induced by lipotoxicity. Collectively, our data suggest that activation of PERK/JNK signaling is an important pathophysiological factor contributing to diaphragmatic contractile dysfunction in OHS. Disclosure X.Xiang: None. Y.Zhu: None. X.Pan: None. W.Xin: None. W.Tang: None. X.He: None. G.Shi: None. Y.Chen: None. Funding National Key R&D Program of China (2017YFA0105803); National Natural Science Foundation of China (82270886, 82070811); 5010 Clinical Research Projects of Sun Yat-sen University (2015015); Science and Technology Plan Project of Guangzhou City (202007040003, 202201020497); Key Area R&D Program of Guangdong Province (2019B020227003); Science and Technology Research Development Program of Guangzhou City (202007040003, 202201020497)

1684-P: Transgene Integration-Induced Genomic Rearrangement in a Noncoding Region of Chromosome 1 Leads to Spontaneous Obesity and Type 2 Diabetes in Mice

Obesity is a critical risk factor for type 2 diabetes (T2D) and has become a global health issue. We found that a mouse line (C57/B6J) of Floxed-stop over expression of IF1 (ATPase Inhibitory Factor 1) (hereon called FEI) develops spontaneous obesity without induction of transgenic expression. Targeted-Locus-Amplification (TLA) analyses revealed a rearrangement in upstream sequences of the transgene integration site, and a duplication downstream in a non-coding region of chromosome 1. Male and female FEI mice show early dyslipidemia before weight gain at two months, reaching 50-60 grams at 6-8 months. Body composition revealed FEI mice have markedly increased fat mass and modestly increased lean mass, consistent with morphometric findings of substantially increased peripheral fat pads. FEI mice were hyperphagic. When subjected to pair-feeding, they reverted to comparable WT body weight levels, then gained weight again when fed ad libidum. Adult FEI mice maintain comparable physical activity levels to their WT counterparts, but indirect metabolic levels among FEI mice declined. These mice exhibited glucose and insulin tolerance at six weeks of age, as well as hyperglycemia, hyper-insulinemia, and hyper-leptinemia. Histology H&E staining revealed markedly enlarged adipocytes with crown-like structures on visceral white adipose tissue sections, and increased fat deposition in liver sections. RNAseq analyses from subcutaneous white adipose tissues of 5-month-old FEI mice demonstrate upregulation of adipogenic and inflammatory genes. Isolated FEI preadipocytes exhibited increased proliferation but impaired lipid deposition. RT-PCR revealed upregulation of inflammatory genes (IFI202b, TNF-α, and IL6). Together, we show FEI mice are a novel obese mouse model. Preclinical studies using this model may help yield insights into novel pathogenic mechanisms and effective treatments for obesity. Disclosure D.White: None. S.Alahari: None. E.D.Lazartigues: None. Q.Yang: None. J.Wu: None. S.Kang: None. L.Lauterboeck: None. P.Mobasheran: None. F.Paliarin: None. T.Nguyen: None. M.Elgazzaz: None. R.Maiya: None. Funding American Diabetes Association (1-17-IBS-184 to Q.Y.)

225-LB: Reciprocal Regulatory Interactions of Adipocytes and B Lymphocytes

Obesity, a global health problem, leads to chronic inflammation of adipose tissue (AT), an immune-mediated process linked to metabolic dysfunction and disease, including type II diabetes mellitus. Adipocytes, the most abundant cellular constituent of AT, store lipids and secrete adipokines, a group of hormone-like molecules such as adiponectin and adipsin that regulate metabolism and immune cell functions. In mouse models of diet-induced obesity, distinct subsets of B lymphocytes have been implicated in both exacerbating and mitigating AT inflammation and insulin resistance, but the immunoregulatory mechanisms underlying these effects are incompletely understood. Similarly, whether B lymphocytes and adipocytes engage in regulatory interactions with each other is not known. To investigate this question, we performed in vitro co-culture studies using murine 3T3-L1 adipocytes and I.29µ+ B cells, a murine B cell lymphoma that initiates robust secretion of IgM antibodies and the anti-inflammatory cytokine interleukin (IL)-10 upon activation by lipopolysaccharide (LPS). The induction of IgM and IL-10 secretion was markedly attenuated when I.29µ+ B cells were stimulated with LPS while co-cultured in direct contact with 3T3-L1 adipocytes. This inhibitory effect was also observed, albeit to a lesser degree, when the two cell types were co-cultured but separated by a semipermeable membrane. Conversely, secretion of adiponectin and adipsin by 3T3-L1 adipocytes was reduced when the adipocytes were co-cultured with I.29µ+ B cells, both in direct contact and when separated by a semipermeable membrane. This reduction of adipokine output was observed in both the absence and presence of LPS to activate the B cells. These data support the hypothesis that B lymphocytes and adipocytes can engage in reciprocal interactions that modulate the functions of these two secretory cell types and, in turn, may influence AT homeostasis and inflammation in healthy and obese states. Disclosure J. W. Brewer: None. R. L. Judd: None. M. K. Allman: None. S. R. Carroll: None. S. Granger: None. A. Hall: None. K. Pownall: None. J. Quintana: None. N. Arellano rangel: None. J. Thomas: None. Funding Edward Via College of Osteopathic Medicine Center for One Health

854-P: ENT-03, a Centrally Acting Endogenous Spermine Bile Acid with PTP1B Inhibitory Activity, Has Potent Effects on Metabolism and Weight in a Mouse Model of Diet-Induced Obesity (DIO)

Background: We have discovered ENT-03, a spermine-bile acid of unprecedented structure in the brain of neonatal mice. ENT-03 appears postnatally at a time when the maternal supply of milk is inadequate to support maximal growth and development. ENT-03 has PTP1B inhibitory activity and acts centrally to normalize glycemia and reverse obesity. Methods: ENT-03 (25mg/kg), semaglutide (0.04mg/kg) or vehicle were administered subcutaneously twice weekly for 10 weeks to DIO mice (n=5/group). Results: In ENT-03 treated mice on a high fat diet, non-fasting glucose rapidly fell to within normal range prior to any significant weight loss (p=2×10-5), remaining normal thereafter. In contrast, in semaglutide treated mice, glucose fell in proportion to weight loss, remaining elevated throughout (p=0.2). ENT-03 treated mice were restored to lean body weight. Body weight and glucose improved partially in semaglutide treated mice. Body fat decreased by 49% in ENT-03 (p=10-5) and by 19% in semaglutide treated mice (p=0.1). Basal glucose uptake in muscle was increased 3-fold in ENT-03 treated mice compared to controls. Conclusion: ENT-03 is a novel endogenous, centrally acting mammalian steroid which rapidly normalizes glucose, independent of body weight and causes gradual but marked weight loss in DIO mice. Phase 1 studies will begin in Q2 2023. Disclosure D.Barbut: None. J.A.Baur: Consultant; Cytokinetics Inc., Pfizer Inc., Other Relationship; Elysium Health, Research Support; Pfizer Inc., Metro Biotech. P.M.Titchenell: Consultant; Alnylam, Guidepoint, AstraZeneca. J.G.Davis: None. M.B.Zemel: None. G.Fleming: Board Member; NuSirt, Consultant; Amolyt, Oramed Pharmaceuticals, Adocia, Aerami, TixiMed, Biocon, Hagar, CMC Magnetics, AdioPharm. A.C.Moses: Advisory Panel; Enterin, ViaCyte, Inc., GentiBio, TixiMed, Consultant; Virta Health Corp., ARMI (Advanced Regenerative Manufacturing Institute), Stock/Shareholder; Minutia. M.Zasloff: None.

297-LB: Dorzagliatin, a Glucokinase Activator, Repairs Defective Islet Function in High-Fat Diet-Induced Diabetic Mice

The DREAM study showed long-term benefits for glucose control in newly diagnosed type 2 diabetes (T2D) patients even after withdrawal of dorzagliatin treatment, a newly approved glucokinase activator for T2D treatment, who were considered to be in the remission for diabetes. The purpose of the current study is to examine the mechanisms of dorzagliatin-induced diabetes remission by evaluating the changes in islet function over time after a period of administering dorzagliatin in high-fat diet (HFD) induced obesity and diabetes mouse models. Diabetes mice were generated after 7 months of HFD, then received dorzagliatin or vehicle controls via oral gavage once a day for 19 days (8 days of 30 mg/Kg and 11 days of 15 mg/Kg). After drug withdrawal, one group of mice remained in HFD and another group changed to a normal diet. Islets were then isolated at different time points after drug withdrawal, and the serum and liver were collected for evaluation. The glucose ramp-stimulated insulin secretion (GSIS) was evaluated in islet perifusion. Gene expression was measured by qPCR in islets and by RNA-seq in the liver. Compared to normal mouse islets, HFD-induced diabetic islets in vehicle groups have impaired GSIS with about 40% reduction in maximum insulin secretion. In contrast, GSIS was fully recovered to the levels of normal islets in 10, 18 and 38 days after dorzagliatin withdrawal, but returned to defective GSIS levels after 45 days of drug discontinuation. In addition, islet GSIS can be fully recovered after 80 days of diet change. In conclusion, the defective GSIS in HFD-induced diabetes mouse islets is reversible and can be fully restored by dorzagliatin even after a long period of drug withdrawal while still remaining in HFD. The mechanisms are likely due to increased glucokinase gene expression caused by a short treatment of dorzagliatin. Diet change alone can recover islet function but requires weight reduction and a longer duration. Disclosure D. Han: Employee; Nanjing AscendRare Pharmaceutical Technology. S. Meng: Employee; Nanjing AscendRare Pharmaceutical Technology. X. Zhou: Employee; Nanjing AscendRare Pharmaceutical Technology. R. Li: Employee; Nanjing AscendRare Pharmaceutical Technology. C. Li: Employee; Hua Medicine, Nanjing AscendRare Pharmaceutical Technology.

1679-P: L-arginine Ameliorates Polycystic Ovary Syndrome and Attenuates Intestinal Oxidative Stress by Regulating Gut Microbiota

More than half of Polycystic ovary syndrome (PCOS) women are overweight or obese, and weight gain amplifies and worsens the symptoms of PCOS. Hence, it is essential to further understand and treat PCOS women with obesity. Therefore, this study tried to use a multi-omics approach that integrates the gut microbiome, serum metabolomics, serum transcriptomics, and clinical indicators to distinguish obese PCOS from obese non-PCOS women. The stool and blood samples from 33 obese PCOS patients and 30 obese control women were collected. The sequencing results suggested there were significant differences in gut microbiome and metabolites between obese PCOS women and obese women. Of which, the level of L-arginine (Arg) in obese PCOS patients was significantly lower than that in the control group and associated with gut microbiota alterations. Further correlation analysis between metabolite and clinical phenotype showed that Arg was significantly correlated with the clinical phenotype of obese PCOS patients. In this study, C57BL/6 mice were treated with dehydroepiandrosterone (DHEA) with a high-fat diet (HFD) to induce obese PCOS mice models for 3 weeks. PCOS mice were randomly divided into four groups: Arg group, Arg + antibiotic cocktail (ABX) group, PCOS group, and PCOS + ABX group. After 3 weeks of Arg supplementation, the estrous cycle, ovarian morphology, intestinal oxidative stress and intestinal barrier integrity were improved in Arg group PCOS mice, while testosterone levels and insulin resistance levels were decreased. However, these improvements were not observed in the Arg plus ABX group, suggesting that ABX-mediated depletion of the gut microbiome would eliminate these improvements. Then the 16s rRNA sequencing was performed to determine the gut microbiota of the four groups. The results showed that Arg can ameliorate reproductive characteristics of PCOS and attenuate intestinal oxidative stress by regulating gut microbiota. Disclosure D.Dilimulati: None. M.Cai: None. Y.Zhang: None. S.Qu: None. M.Zhang: None.

210-OR: Long-Acting GIPR Agonism Enhances Body Weight Regulation of Multiple Weight-Reducing Agents in Diet-Induced Obese Mice

The development of multi-agonists targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) has resulted in significant clinical improvements in body weight management, however the contribution of GIPR agonism to this effect is incompletely understood. Using a diet induced obese (DIO) mouse model, GIPR agonism (LAGIPRA) alone has demonstrated little to no efficacy in weight management, whereas the addition of LAGIPRA to long acting GLP-1R agonism decreased food intake and increased energy expenditure resulting in greater weight loss compared with GLP-1R agonism alone suggesting a synergistic benefit. To determine whether GIPR agonism would provide similar synergistic improvements in energy metabolism with additional pharmacologic drivers of weight loss, we treated DIO mice with various weight reducing agents plus and minus LAGIPRA in metabolic chambers. Interestingly, addition of LAGIPRA enhanced weight loss, fat mass reduction, energy expenditure, and lipid oxidation whether combined with T3, FGF21, or long-acting glucagon (IUB288); consistent with earlier experiments, it had little effect on its own. Assessment of adipose tissue engagement in these and subsequent studies suggest GIPR agonism in this tissue may enhance lipolysis, potentially enabling greater energy expenditure via release of stored lipids. These findings suggest a unique role for GIPR agonism to regulate energy expenditure when combined with molecules that reduce body weight generating a greater negative caloric balance and enhancing body weight reduction. Disclosure W.Roell: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. L.O'farrell: None. A.Regmi: Employee; Eli Lilly and Company. T.Coskun: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company.

273-LB: The Effect of Bispecific GLP-1R/GLP-2R Agonist Compared with Dual GLP-1R/GLP-2R Agonist and Dual GLP-1R/GIPR Agonist in Diet-Induced Obesity Mouse Model

Obesity is a global health challenge with few pharmacological options associated with type 2 diabetes and cardiovascular (CV) complications. MG12, a bispecific GLP-1R/GLP-2R Fc-fused agonist, was manufactured to show its potential advantage over current comparable dual incretin agonists. In this study, we observed that MG12 was superior in body weight (BW) reduction when compared to dual GLP-1R/GLP-2R agonist as well as combination therapy of GLP-1R and GLP-2R Fc-fused agonist. We predicted this as the result of the optimized state of increasing GLP-1 activity and the bispecific structural nature. Also, MG12 showed BW reduction in a dose-dependent manner. Interestingly, MG12 at a high dose showed similar BW reduction to dual GLP-1R/GIPR agonist despite a lesser decrease in food intake after the first injection. Additionally, we noted a higher reduction in fat/muscle mass ratio after the last injection in the comparable BW reduced group. Furthermore, MG12 showed a decrease in low grade inflammation biomarkers, which may indicate a potential CV outcome benefit. Therefore, MG12 may be a promising new therapeutic approach for obesity-related metabolic disorders. Disclosure T. Oh: Employee; Progen. Co., Ltd, SL Metagen. Co., Ltd. S. Yang: None. J. Roh: None. J. Sung: None.

Selective activation of PPARα maintains thermogenic capacity of beige adipocytes

Beige adipocytes are inducible thermogenic adipocytes used for anti-obesity treatment. Beige adipocytes rapidly lose their thermogenic capacity once external cues are removed. However, long-term administration of stimulants, such as PPARγ and β-adrenergic receptor agonists, is unsuitable due to various side effects. Here, we reported that PPARα pharmacological activation was the preferred target for maintaining induced beige adipocytes. Pemafibrate used in clinical practice for dyslipidemia was developed as a selective PPARα modulator (SPPARMα). Pemafibrate administration regulated the thermogenic capacity of induced beige adipocytes, repressed body weight gain, and ameliorated impaired glucose tolerance in diet-induced obese mouse models. The transcriptome analysis revealed that the E-twenty-six transcription factor ELK1 acted as a cofactor of PPARα. ELK1 was mobilized to the Ucp1 transcription regulatory region with PPARα and modulated its expression by pemafibrate. These results suggest that selective activation of PPARα by pemafibrate is advantageous to maintain the function of beige adipocytes.

Role and mechanism of FLT4 in high-fat diet-induced obesity in mice

The FLT4 gene plays an important role in the onset and progression of obesity and is involved in the structure and function of lymphatic vessels. By inducing a mouse obesity model with a high-fat diet and knocking out the FLT4 gene, which is associated with lymphatic vessel growth in mice, FLT4+/− mice were found to be susceptible to high-fat diet-induced obesity, with significant accumulation of visceral fat. BODIPY™ FL C16 imaging revealed dilated and branched mesenteric lymphatic vessels in FLT4+/− mice. Immunofluorescence staining showed that FLT4+/− exacerbated the morphological abnormalities of lymphatic vessels and submucosal lymphatic vessels in visceral adipose tissue of obese mice, accompanied by macrophage infiltration around lymphatic vessels. In addition, FLT4 knock down increased the proportion of M1-type macrophages in the adipose tissue of the epididymis, indicating significant chronic inflammation in FLT4+/− obese mice. These findings provide new evidence for the involvement of lymphatic vessel morphological abnormalities in the onset and progression of obesity and highlight the importance of further investigation of FLT4 to better understand the mechanism of HFD-induced obesity and to develop related treatments.

Maternal obesity alters the placental transcriptome in a fetal sex-dependent manner.

Infants born to obese mothers have an increased risk of developing obesity and metabolic diseases in childhood and adulthood. Although the molecular mechanisms linking maternal obesity during pregnancy to the development of metabolic diseases in offspring are poorly understood, evidence suggests that changes in the placental function may play a role. Using a mouse model of diet-induced obesity with fetal overgrowth, we performed RNA-seq analysis at embryonic day 18.5 to identify genes differentially expressed in the placentas of obese and normal-weight dams (controls). In male placentas, 511 genes were upregulated and 791 genes were downregulated in response to maternal obesity. In female placentas, 722 genes were downregulated and 474 genes were upregulated in response to maternal obesity. The top canonical pathway downregulated in maternal obesity in male placentas was oxidative phosphorylation. In contrast, sirtuin signaling, NF-kB signaling, phosphatidylinositol, and fatty acid degradation were upregulated. In female placentas, the top canonical pathways downregulated in maternal obesity were triacylglycerol biosynthesis, glycerophospholipid metabolism, and endocytosis. In contrast, bone morphogenetic protein, TNF, and MAPK signaling were upregulated in the female placentas of the obese group. In agreement with RNA-seq data, the expression of proteins associated with oxidative phosphorylation was downregulated in male but not female placentas of obese mice. Similarly, sex-specific changes in the protein expression of mitochondrial complexes were found in placentas collected from obese women delivering large-for-gestational-age (LGA) babies. In conclusion, maternal obesity with fetal overgrowth differentially regulates the placental transcriptome in male and female placentas, including genes involved in oxidative phosphorylation.

Semaglutide ameliorates obesity-induced cardiac inflammation and oxidative stress mediated via reduction of neutrophil Cxcl2, S100a8, and S100a9 expression.

Obesity, which is driven by inflammation and oxidative stress, is a risk factor for cardiovascular disease. Semaglutide, a glucagon-like peptide-1 receptor agonist, is an antidiabetic drug with major effects on weight loss. In this study, single-cell transcriptomics was used to examine non-cardiomyocytes to uncover the mechanism of obesity-induced myocardial damage and the cardioprotective impact of semaglutide. We constructed obese mouse models and measured Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6), Reactive Oxygen Species (ROS), and Malonic dialdehyde (MDA) levels in serum and heart tissue to determine the levels of inflammation and oxidative stress in obesity and the effect of semaglutide on these levels. Then, utilizing single-cell transcriptomes to screen for key cell populations and differentially expressed genes (DEGs), we assessed the effects of obesity and semaglutide on non-cardiac cells. Finally, a DEG localization analysis was performed to explore DEGs as well as cell types associated with inflammation and oxidative stress. Semaglutide reduced increased TNF-α, IL-6, ROS, and MDA levels in serum and cardiac tissues in obese mouse. Several genes are closely associated with inflammation and oxidative stress. Chemokine (C-X-C motif) ligand 2 (Cxcl2), S100 calcium binding protein A8 (S100a8), and S100 calcium binding protein A9 (S100a9), which were elevated in obesity but decreased following semaglutide treatment, were also expressed particularly in neutrophils. Finally, by decreasing neutrophil Cxcl2, S100a8, and S100a9 expressions, semaglutide may help to reduce cardiac inflammation and oxidative stress. Semaglutide significantly reduced body weight in obese mice as well as exerted anti-inflammatory and antioxidant effects possibly by inhibiting the expression of S100a8, S100a9, and Cxcl2 in neutrophils. These discoveries are expected to reveal new molecular mechanisms underlying obesity-related heart damage and semaglutide's cardioprotective properties.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 106 Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.

Maternal high-fat diet increases airway sensory innervation and reflex bronchoconstriction in adult offspring.

Children born to obese mothers are prone to develop asthma and airway hyperresponsiveness, but the mechanisms behind this are unclear. Here we developed a mouse model of maternal diet-induced obesity that recapitulates metabolic abnormalities seen in humans born to obese mothers. Offspring of dams fed a high-fat diet (HFD) showed increased adiposity, hyperinsulinemia, and insulin resistance at 16 wk of age despite being fed only a regular diet (RD). Bronchoconstriction induced by inhaled 5-hydroxytriptamine was also significantly increased in offspring of HFD-fed versus RD-fed dams. Increased bronchoconstriction was blocked by vagotomy, indicating this reflex was mediated by airway nerves. Three-dimensional (3-D) confocal imaging of tracheas collected from 16-wk-old offspring showed that both epithelial sensory innervation and substance P expression were increased in the offspring of HFD-fed dams compared with offspring of RD-fed dams. For the first time, we show that maternal high-fat diet increases airway sensory innervation in offspring, leading to reflex airway hyperresponsiveness.NEW & NOTEWORTHY Our study reveals a novel potential mechanism, by which maternal high-fat diet increases the risk and severity of asthma in offspring. We found that exposure to maternal high-fat diet in mice leads to hyperinnervation of airway sensory nerves and increased reflex bronchoconstriction in offspring fed a regular diet only. These findings have important clinical implications and provide new insights into the pathophysiology of asthma, highlighting the need for preventive strategies in this patient population.

Characterization of lipid signatures in the plasma and insulin-sensitive tissues of the C57BL/6J mice fed on obesogenic diets

Diet-induced obesity mouse models are widely utilized to investigate the underlying mechanisms of dyslipidemia, glucose intolerance, insulin resistance, hepatic steatosis, and type 2 diabetes mellitus (T2DM), as well as for screening potential drug compounds. However, there is limited knowledge regarding specific signature lipids that accurately reflect dietary disorders. In this study, we aimed to identify key lipid signatures using LC/MS-based untargeted lipidomics in the plasma, liver, adipose tissue (AT), and skeletal muscle tissues (SKM) of male C57BL/6J mice that were fed chow, LFD, or obesogenic diets (HFD, HFHF, and HFCD) for a duration of 20 weeks. Furthermore, we conducted a comprehensive lipid analysis to assess similarities and differences with human lipid profiles. The mice fed obesogenic diets exhibited weight gain, glucose intolerance, elevated BMI, glucose and insulin levels, and a fatty liver, resembling characteristics of T2DM and obesity in humans. In total, we identified approximately 368 lipids in plasma, 433 in the liver, 493 in AT, and 624 in SKM. Glycerolipids displayed distinct patterns across the tissues, differing from human findings. However, changes in sphingolipids, phospholipids, and the expression of inflammatory and fibrotic genes showed similarities to reported human findings. Significantly modulated pathways in the obesogenic diet-fed groups included ceramide de novo synthesis, sphingolipid remodeling, and the carboxylesterase pathway, while lipoprotein-mediated pathways were minimally affected. This study provides a tissue-specific comparison of lipid composition, highlighting the usefulness of DIO models in preclinical research. However, caution is warranted when extrapolating findings from these models to dyslipidemia-associated pathologies and their complications in humans.

Collagen Peptide Exerts an Anti-Obesity Effect by Influencing the Firmicutes/Bacteroidetes Ratio in the Gut.

Alterations in the intestinal microbial flora are known to cause various diseases, and many people routinely consume probiotics or prebiotics to balance intestinal microorganisms and the growth of beneficial bacteria. In this study, we selected a peptide from fish (tilapia) skin that induces significant changes in the intestinal microflora of mice and reduces the Firmicutes/Bacteroidetes ratio, which is linked to obesity. We attempted to verify the anti-obesity effect of selected fish collagen peptides in a high-fat-diet-based obese mouse model. As anticipated, the collagen peptide co-administered with a high-fat diet significantly inhibited the increase in the Firmicutes/Bacteroidetes ratio. It increased specific bacterial taxa, including Clostridium_sensu_stricto_1, Faecalibaculum, Bacteroides, and Streptococcus, known for their anti-obesity effects. Consequently, alterations in the gut microbiota resulted in the activation of metabolic pathways, such as polysaccharide degradation and essential amino acid synthesis, which are associated with obesity inhibition. In addition, collagen peptide also effectively reduced all obesity signs caused by a high-fat diet, such as abdominal fat accumulation, high blood glucose levels, and weight gain. Ingestion of collagen peptides derived from fish skin induced significant changes in the intestinal microflora and is a potential auxiliary therapeutic agent to suppress the onset of obesity.

Fish-Derived Protein Hydrolysates Increase Insulin Sensitivity and Alter Intestinal Microbiome in High-Fat-Induced Obese Mice

Obesity and type 2 diabetes are characterized by low-grade systemic inflammation and glucose intolerance, which can be partially controlled with nutritional interventions. Protein-containing nutritional supplements possess health-promoting benefits. Herein, we examined the effect of dietary supplementation with protein hydrolysates derived from fish sidestreams on obesity and diabetes, utilizing a mouse model of High-Fat Diet-induced obesity and type 2 diabetes. We examined the effect of protein hydrolysates from salmon and mackerel backbone (HSB and HMB, respectively), salmon and mackerel heads (HSH and HMH, respectively), and fish collagen. The results showed that none of the dietary supplements affected weight gain, but HSH partially suppressed glucose intolerance, while HMB and HMH suppressed leptin increase in the adipose tissue. We further analyzed the gut microbiome, which contributes to the metabolic disease implicated in the development of type 2 diabetes, and found that supplementation with selected protein hydrolysates resulted in distinct changes in gut microbiome composition. The most prominent changes occurred when the diet was supplemented with fish collagen since it increased the abundance of beneficial bacteria and restricted the presence of harmful ones. Overall, the results suggest that protein hydrolysates derived from fish sidestreams can be utilized as dietary supplements with significant health benefits in the context of type 2 diabetes and diet-induced changes in the gut microbiome.

Obesity-induced inflammation exacerbates clonal hematopoiesis.

Characterized by the accumulation of somatic mutations in blood cell lineages, clonal hematopoiesis of indeterminate potential (CHIP) is frequent in aging and involves the expansion of mutated hematopoietic stem and progenitor cells (HSC/Ps) that leads to an increased risk of hematologic malignancy. However, the risk factors that contribute to CHIP-associated clonal hematopoiesis (CH) are poorly understood. Obesity induces a proinflammatory state and fatty bone marrow (FBM), which may influence CHIP-associated pathologies. We analyzed exome sequencing and clinical data for 47,466 individuals with validated CHIP in the UK Biobank. CHIP was present in 5.8% of the study population and was associated with a significant increase in the waist-to-hip ratio (WHR). Mouse models of obesity and CHIP driven by heterozygosity of Tet2, Dnmt3a, Asxl1, and Jak2 resulted in exacerbated expansion of mutant HSC/Ps due in part to excessive inflammation. Our results show that obesity is highly associated with CHIP and that a proinflammatory state could potentiate the progression of CHIP to more significant hematologic neoplasia. The calcium channel blockers nifedipine and SKF-96365, either alone or in combination with metformin, MCC950, or anakinra (IL-1 receptor antagonist), suppressed the growth of mutant CHIP cells and partially restored normal hematopoiesis. Targeting CHIP-mutant cells with these drugs could be a potential therapeutic approach to treat CH and its associated abnormalities in individuals with obesity.

ASSESSMENT OF MACROPHAGE INFLAMMATORY ACTIVITY ON VISCERAL ADIPOSE TISSUE IN HIGH-FAT DIET-INDUCED OBESE MICE BY 18F- FDG PET/CT

Objective: Obesity induced inflamed visceral adipose tissue (VAT) secretes pro-inflammatory cytokines thereby promoting systemic inflammation and insulin resistance which further exacerbate obesity-related cardiovascular disease (CVD). Macrophages are the key players in the development of obesity-associated VAT inflammation. Extensive clinical studies have reported that 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) can be used to evaluate the macrophage inflammatory activity on VAT in human beings. However, due to difficulty in human VAT biopsy, pathologic correlations were lacking and there was a few study on preclinical animal models. Here, we investigated whether 18F-FDG PET/CT could reflect the macrophage inflammatory activity on VAT in high-fat diet-induced obese mice. Design and method: Obese animal models were induced by a high-fat diet (60% fat) for 20 weeks using the male C57BL/6 mice. Insulin tolerance test was performed to evaluate the status of insulin resistance and C-reactive protein (CRP) was measured to assess the status of systemic inflammation. All animals underwent 18F-FDG PET/CT before sacrifice. Macrophage inflammatory activity was evaluated using the maximum standardized uptake value (SUVmax). Flow cytometry-, histological-, and molecular analyses were performed on harvested VAT. Results: All obese animals showed insulin resistance which resembled the human metabolic syndrome, a key pathophysiological process that contributes to increase CVD risk. VAT SUVmax was increased in obese mice and significantly correlated with the levels of CRP. Furthermore, VAT from obese mice showed increased macrophage infiltration, compared to normal mice. Conclusions: 18F-FDG PET/CT could visualize and evaluate the macrophage inflammatory activity on obesity-driven inflamed VAT in obese mice model. Our preclinical study strongly supports the clinical application of 18F-FDG PET/CT in the assessment of VAT inflammation to patients who are vulnerable to CVD.

Non-Cardiotoxic Tetradecanoic Acid-2,4-Dinitrophenol Ester Nanomicelles in Microneedles Exert Potent Anti-Obesity Effect by Regulating Adipocyte Browning and Lipogenesis.

Sustained oral uncoupler 2,4-dinitrophenol (DNP) administration exerts prominent anti-obesity effects, but the adipose tissue off-target disadvantage leads to systemic adverse effects. A novel non-cardiotoxicity DNP delivery method using a biocompatible microneedles patch containing the amphiphilic tetradecanoic acid-DNP ester (TADNP) is described, which is synthesized via esterification on the phenolic hydroxyl of DNP. The TADNP is self-assembled as nanomicelles, which enhance the endocytosis rate of DNP by adipocytes and its permeation in isolated adipose tissues. The microenvironment of adipose tissues promotes the massive release of DNP and plasma and simulated gastrointestinal fluids. The microneedles-delivered TADNP nanomicelles (MN-TADNP) effectively deliver DNP in treated adipose tissues and reduce DNP content in off-target organs. Both oral and MN patch-delivered TADNP micelles effectively exert anti-obesity effects in a mouse model of high-fat diet-induced obesity; and noteworthily, MN-TADNPexhibit more satisfactory biosafety than oral administration. Here, a smart MN patch loaded with tetradecanoic acid-modified DNP is reported, which enhances its accumulation in adipose tissues and exerts an anti-obesity effect without causing any systemic toxicity.