HFD-treated Mice Research Articles

Gut microbiota of miR-30a-5p-deleted mice aggravate high-fat diet-induced hepatic steatosis by regulating arachidonic acid metabolic pathway.

Patients with non-alcoholic fatty liver disease (NAFLD) often exhibit hepatic steatosis and dyslipidemia. Studies have shown that intestinal microorganisms are closely related to the occurrence of NAFLD and atherosclerosis. Our previous study has underscored the protective role of microRNA-30a-5p (miR-30a-5p) against atherosclerosis. In the present study, we aimed to elucidate the effect and underlying mechanism of the intestinal microorganisms of miR-30a-5p knockout (KO) mice on NAFLD. Our findings demonstrated that KO exacerbated high-fat diet (HFD)-induced hepatic steatosis and disrupted liver function, as evidenced by elevated levels of total cholesterol, low-density lipoprotein, alanine aminotransferase, aspartate transaminase, and total bile acids in serum. Fecal microbiota from HFD-fed KO mice induced hepatic steatosis, dyslipidemia, and higher levels of enzymes indicative of liver damage in wild-type mice. Remarkably, KO mice significantly intensified the above effects. 16s rDNA sequencing and metabolomics of the intestinal microbiota in the HFD-treated KO and WT mice showed that the loss of miR-30a-5p resulted in intestinal microbiota imbalance and was highly related to the arachidonic acid metabolic pathway. Targeted metabolomic in the liver tissues unveiled upregulation of COX-related (PGF2a, 8-iso-PGF2a and PGF2) and LOX-related (LTB4, LTD4, 12S-HETE and 15S-HETE) factors in HFD-treated KO mice. Immunohistochemistry and transcriptional analyses showed that miR-30a-5p affected arachidonic acid metabolism through the LOX/COX pathways. Besides, COX/LOX pathways and hepatic steatosis were reversed after reintroducing miR-30a-5p in HFD-treated KO mice. This study reveals the pivotal mechanism by which miR-30a-5p and intestinal microbes regulate hepatic steatosis and abnormal lipid metabolism, offering promising avenues for NAFLD and atherosclerosis therapeutics. MiR-30a-5p deletion aggravated hepatic steatosis and lipid disorder induced by an HFD in mice. Gut microbiota participated in the regulation of hepatic steatosis in the context of miR-30a-5p. Gut microbiota metabolism-related arachidonic acid metabolic pathway contributed to miR-30a-5p-regulated hepatic steatosis and lipid disorder. Reintroducing miR-30a-5p reversed hepatic steatosis and arachidonic acid metabolism disorder caused by HFD and miR-30a-5p deletion.

Multiomics analysis reveals the potential mechanism of high-fat diet in dextran sulfate sodium-induced colitis mice model.

A high-fat diet (HFD) is recognized as an important contributor to inflammatory bowel disease (IBD). However, the precise underlying mechanism of HFD on IBD remains elusive. This study aimed to investigate the potential mechanism by which HFD affects IBD using 16S rRNA-sequencing and RNA-seq technology. Results indicated that HFD-treated mice exhibited notable alternations in the structure and composition of the gut microbiota, with some of these alternations being associated with the pathogenesis of IBD. Analysis of the colon transcriptome revealed 11 hub genes and 7 hub pathways among control, DSS-induced colitis, and HFD + DSS-treated groups. Further analysis explores the relationship between the hub pathways and genes, as well as the hub genes and gut microbiota. Overall, the findings indicate that the impact of HFD on DSS-induced colitis may be linked to intestinal dysbiosis and specific genes such as Abca8b, Ace2, Apoa1, Apoa4, Apoc3, Aspa, Dpp4, Maob, Slc34a2, Slc7a9, and Trpm6. These results provide valuable insights for determining potential therapeutic targets for addressing HFD-induced IBD.

Mangiferin prevents glucolipotoxicity-induced pancreatic beta-cell injury through modulation of autophagy via AMPK-mTOR signaling pathway

The aim of this study was to investigate the protective effects of Mangiferin (MG) on glucolipotoxicity-induced pancreatic beta-cell injury. In vivo administration of MG significantly reduced the level of blood glucose in high-fat diet (HFD)-fed mice. MG treatment inhibited beta-cell apoptosis in HFD-treated mice. In vitro, MG protected INS-1 cells against apoptosis and impairment of insulin secretion following High glucose/Palmitic acid (HG/PA) treatment. MG treatment enhanced autophagy flux which was blocked by HG/PA treatment. Inhibition of autophagosome formation by 3-Methyladenine or blockade of autolysosome by Chloroquine reversed the protective effects of MG on INS-1 cells. MG treatment increased AMPK phosphorylation and reduced mTOR activation in INS-1 cells. Administration of the AMPK blocker abrogated MG-induced autophagy, and similar results were observed in INS-1 cells after cotreatment with MG and mTOR activator. In conclusion, MG ameliorated pancreatic beta-cell injury induced by glucolipotoxicity through modulation of autophagy via the AMPK-mTOR pathway.

Key Considerations for Studying the Effects of High-Fat Diet on the Nulligravid Mouse Endometrium.

The obesity epidemic continues to increase, with half of US women predicted to be obese by 2030. Women with obesity are at increased risk for not only cardiovascular and liver disease, but also reproductive disorders. Although mouse models are useful in studying the effects of obesity, there is inconsistency in obesity-induction methods, diet composition, and mouse strains, and studies using female mice are limited. In this study, we sought to compare the effects of a 45% high-fat diet (HFD) versus a 60% HFD on the uterine estrous cycle of nulligravid C57BL/6J mice. For 22 weeks, we placed a total of 20 mice on either a 60% HFD, 45% HFD, or each HFD-matched control diet (CD). Both HFDs produced significant weight gain, with 60% HFD and 45% HFD gaining significant weight after 2 weeks and 15 weeks, respectively. Additionally, both HFDs led to glucose intolerance, fatty liver, and adipocyte hypertrophy. Mice fed 60% HFD displayed hyperphagia in the first 12 weeks of HFD treatment. Moreover, 60% HFD-treated mice had a longer estrous cycle length and an increased percentage of estrus stage samplings compared to CD-treated mice. Estrous cycle stage-controlled 60% HFD-treated mice displayed an increased estrogen-to-progesterone ratio and decreased ovarian corpora lutea compared to CD-treated mice, which may underlie the observed estrous cycle differences. There was no significant difference between diets regarding endometrial morphology or the percent of endometrial CD45+ immune cells. Our results indicate that consideration is needed when selecting a HFD-induced obesity mouse model for research involving female reproductive health.

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation.

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

Abstract A009: Addressing obesity’s impact on the PTEN mutant endometrium

Abstract Obesity is a rising epidemic in the United States, with approximately 50% of adult women predicted to be obese by 2030. Obesity is a risk factor for endometrial hyperplasia (EH), which is characterized by the benign overgrowth of the endometrial epithelium and is considered a precursor lesion for endometrial cancer (EC). Somatic PTEN mutations are commonly observed in EH and EC, with PTEN loss being one of the earliest mutations observed in the progression to EC. Previous obesity work in our lab utilized high-fat diet (HFD)-induced obese WT mice and found that obesity affected different cell types within the endometrium, including non-tumor prone cells. Our preliminary findings suggest that 60% HFD prolongs the estrus stage of the estrus cycle in WT mice. The aims of this study are to determine the cell-specific effects of obesity on the endometrial epithelia carrying PTEN mutations. Female PTENfl/fl; Pax8Cre/+ mutant and Pax8Cre+/+ control mice on a C57BL/6J background were fed either a 60% HFD or it’s sucrose-matched control diet (CD) for a minimum of 22 weeks. Weekly mouse and food weights were collected. Mice were tested for glucose tolerance after being on diet for at least 4.5 months. Uterus and blood were collected at estrus stage. Uteri were processed for single-cell RNA seq. PTENfl/fl; Pax8Cre/+ mice on both the HFD and CD had a diminished weight gain compared to Pax8Cre+/+ mice on the same diet. HFD-treated mice exhibited hyperphagia, weighed significantly more than the CD mice, and demonstrated glucose intolerance. H&E staining of the adipose tissue and liver revealed adipocyte hypertrophy and fatty liver infiltration in HFD mice. IHC of PTENfl/fl; Pax8Cre/+ uteri confirmed epithelial-specific loss of PTEN and displayed endometrial hyperplasia. PTENfl/fl; Pax8Cre/+ uteri had an influx of Ly6G+ neutrophils invading the endometrial epithelium compared to the Pax8Cre+/+ mice. Strikingly in PTENfl/+; Pax8Cre/+ we observe clonal loss of PTEN immunoreactivity in a subset of endometrial glands with similar phenotypic features. We propose that obesity’s impact on non-tumor cell types within the endometrium will be shaped by early genetic mutations in tumor-prone epithelia. Citation Format: Hilary J. Skalski, Shannon K. Harkins, Amelia R. Arendt, Madison MacLachlan, Katelyn Becker, Marc Wegener, Marie Adams, Galen Hostetter, Ronald L. Chandler. Addressing obesity’s impact on the PTEN mutant endometrium [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr A009.

Cyy-287, a novel pyrimidine-2,4-diamine derivative, efficiently mitigates inflammatory responses, fibrosis, and lipid synthesis in obesity-induced cardiac and hepatic dysfunction.

Inflammation and metabolic disorders are important factors in the occurrence and development of obesity complications. In this study, we investigated the protective effect and underlying mechanism of a novel pyrimidine-2,4-diamine derivative, Cyy-287, on mice fed a high-fat diet (HFD). The mice were randomly separated into four groups (n ≥ 7): control (regular diet), HFD, HFD with Cyy-287 (5 mg/kg), and HFD with Cyy-287 (20 mg/kg) following HFD feeding for 10 weeks. After a 10-week administration, ALT and AST enzymes, echocardiography, immunohistochemical (IHC), Western blot (WB), Masson and Sirius Red staining were used to evaluate functional and morphological changes to the heart and liver. Microsomes from the mouse liver were extracted to quantify the total amount of CYP450 enzymes after drug treatment. Cyy-287 decreased the levels of serum glucose, LDL, TC, ALT, and AST activities in HFD-treated mice. However, Cyy-287 administration increased ejection fraction (EF) and fractional shortening (FS) index of the heart. Cyy-287 inhibited histopathological changes in the heart and liver; decreased inflammatory activity; significantly diminished p38 mitogen-activated protein kinase (MAPK), the nuclear factor-kappa B (NF-κB) axis, and sterol regulatory element-binding protein-1c (SREBP-1c); and upregulated the AMP-activated protein kinase (AMPK) pathway in HFD-treated mice. Cyy-287 restored the content of hepatic CYP450 enzymes. These findings demonstrated that Cyy-287 protected heart and liver cells from obesity-induced damage by inhibiting inflammation, fibrosis, and lipid synthesis.

Effect of YC-1102 on the Improvement of Obesity in High-Fat Diet-Induced Obese Mice.

Obesity is one of the major risk factors for metabolic diseases worldwide. This study examined the effects of YC-1102, an extract derived from the roots of Rosa multiflora, on 3T3-L1 preadipocytes and high-fat diet (HFD)-induced obese mice. In vivo experiments involved the oral administration of YC-1102 (100, 150, and 200 mg/kg body weight) daily to mice for eight weeks. YC-1102 was found to downregulate the expressions of PPARγ and C/EBPα during adipogenesis, inhibiting adipocyte differentiation and upregulating the expression of PGC-1α for energy metabolism to enhance mitochondrial biogenesis and fatty acid oxidation. It has been shown that daily administration of YC-1102 to mice receiving a HFD prevented an increase in body weight and the accumulation of body fat. YC-1102 administration also reduced TG, TC, and LDL cholesterol levels, as well as glucose and leptin levels, and increased adiponectin levels, thus effectively inhibiting the metabolism of lipids. YC-1102-treated mice showed significant reductions in the mRNA expression of PPARγ and C/EBPα. The levels of PGC-1α involved in energy metabolism increased significantly in the YC-1102-treated mice when compared to the HFD-treated mice. According to the findings of this study, YC-1102 has a dual mechanism that reduces transcription factors that promote the differentiation of adipocytes and increases transcription factors that promote energy consumption.

Exposure to low-intensity noise exacerbates nonalcoholic fatty liver disease by activating hypothalamus pituitary adrenal axis

Noise exposure induces metabolic disorders, in a latent, chronic and complex way. However, there is no direct evidence elucidating the relationship between low-intensity noise exposure and nonalcoholic fatty liver disease (NAFLD). Male mice (n = 5) on high-fat diet (HFD) were exposed to an average of 75 dB SPL noise for 3 months to reveal the effect of noise exposure on NAFLD, where the potential mechanisms were explored. In vivo (n = 5) and in vitro models challenged with dexamethasone (DEX) were used to verify the role of hypothalamus pituitary adrenal (HPA) axis activation in hepatic lipid metabolism. Typical chronic-restraint stress (CRS, n = 8) was used to explore the role of depression in modifying activity of HPA axis. Finally, animal experiment (n = 8) was repeated to validate the roles of depression and HPA axis activation in NAFLD development. Chronic low-intensity noise exposure exacerbated NAFLD in mice on HFD characterized by hepatocyte steatosis, modified lipid metabolism and inflammation level. Plasma ACTH in H + N group was 1.5-fold higher than that in HFD group. Transcription of glucocorticoid receptor target genes was increased by chronic low-intensity noise exposure in HFD-treated mice. Excessive glucocorticoids mimicking HPA axis activation induced NAFLD in vivo and in vitro. Plasma ACTH increase and lipid storage also occurred in depressive mice stressed by CRS. More interestingly, the same noise exposure simultaneously induced depression in mice, disrupted the HPA axis homeostasis and exacerbated NAFLD in a repeated experiment. Thus, three-month exposure to 75 dB SPL noise was sufficient to exacerbate NAFLD progress in mice, where activation of HPA axis played a critical role. Depression played an intermediate role and contributed to HPA axis activation up-stream of the exacerbation.

Effects of the Phytocompound Combination against Dysbiosis Induced by AGE-Rich High-fat Diet in Mice

Background and Aims: The composition of the Microbiota can be influenced by various lifestyle and environmental factors, including diet. We designed a study to investigate the improving effects of plant extract, the combination of turmeric, ginger, boswellia, and cat’s claw on the abundance of key members of the gut microbiota, Bacteroidetes, Akkermansia muciniphila (A. muciniphila), Faecalibacterium prausnitzii (F. prausnitzii), Firmicutes and Bifidobacterium in mice treated with advanced glycation end products (AGE) rich high-fat diet (HFD).
 Materials and Methods: Eighteen 2-month age male C57BL/6 mice were adopted to a regular diet for 1 week and then fed with an HFD or regular diet. After 8 weeks of diet, animals received plant extract concurrently with HFD for 8 weeks. Stools were taken, DNA of stool samples was extracted, and qPCR of 16s rDNA universal primers was performed. Then the effect of plant extract on dysbiosis induced by AGE-rich HFD was accessed.
 Results: Our results revealed the frequencies of Bacteroidetes (p=0.001), A. muciniphila (p= 0.0005), F. prausnitzii (p<0.0001), and Bifidobacterium (p= 0.0008) were reduced, whereas the frequency of Firmicute was increased in the AGE-rich HFD group. A significant increase in the F/B ratio was observed in the HFD group than in the regular diet group (p= 0.0003). plant extract reduced the F/B ratio and improved gut microbiota homeostasis. 
 Conclusion: Plant extract restored gut microbiota patterns in HFD-treated mice. It seems more studies are required to prove the application of plant extracts for modulating the gut microbiota as a promising new biomarker with potential for therapeutic applications.

1608-P: Phenotype of Liver-Specific MC3R Knockout Mice

The melanocortin 3 receptor (MC3R) is a key regulator of energy homeostasis and feeding behavior. Global Mc3r knockout mice exhibit greater fat mass and reduced lean mass. Our previous research has found that Mc3r transcripts can be detected in liver and the MC3R deficiency phenotype is partially reversed in liver-specific MC3R recovery mice on a chow diet, in both male and female mice, and high fat diet, in females only. To further examine the role of hepatic MC3R, we produced a liver-specific Mc3r knockout model by crossing mice expressing albumin-Cre recombinase (Alb-Cre+/+) to mice with a floxed Mc3r gene (LoxP+/+), and placed them on a 45 kcal% energy from fat diet for 12 weeks. Female liver-specific Mc3r-deficient mice with diet-induced obesity displayed nonsignificant trends towards worsened glucose tolerance during a glucose tolerance test (glucose AUC Lox+/+, Alb-Cre+/+: n=10, 24036±1644; Alb-Cre+/+: n=10, 19745±1364; BL/6: n=11, 21072±1152 min*mg/dL, p=0.059) and insulin resistance during a glucose tolerance test (glucose AUC LoxP+/+, Alb-Cre+/+: n=10, 14938±812.2;Alb-Cre+/+: n=14, 13062±850; BL/6: n=11, 11725±1024 min*mg/dL, p=0.12), but no differences in morning serum C-peptide (LoxP+/+, Alb-Cre+/+: n=8, 0.74±0.07; Alb-Cre+/+: n=4, 0.55±0.15; BL/6: n=8, 0.29±0.05 ng/mL, p=0.32). Similar patterns were observed for total food consumption (LoxP+/+, Alb-Cre+/+: n=10, 37.2±1.2; Alb-Cre+/+: n=15, 34.5±0.7; BL/6: n=10, 35.7±1.4 g/15 days, p=0.082), with no differences in feeding efficiency (LoxP+/+, Alb-Cre+/+: n=10, 0.027±0.008; Alb-Cre+/+: n=15, 0.009±0.011; BL/6: n=10, 0.017±0.025 g/kcal, p=0.19). No notable trends were observed in male mice. These data suggest that hepatic Mc3r deficiency alone is at most a minor contributor to the obesity phenotypes associated with HFD-treated Mc3r-deficient mice. Additional analysis of tissue samples from these mice and future studies examining Mc3r function in the liver will further elucidate the role of hepatic MC3R. Disclosure J.Chen: None. J.K.Elmquist: Research Support; Regeneron Pharmaceuticals Inc. J.A.Yanovski: Research Support; Hikma Pharmaceuticals, Rhythm Pharmaceuticals, Inc., Soleno Therapeutics, Inc., Versanis Bio Inc. T.P.Patel: None. A.Jain: None. D.Elizondo: None. E.K.Altman: None. N.Tugarinov: None. M.Hollis: None. R.Roberson: None. A.Caron: None.

Salidroside protects mice from high-fat diet-induced obesity by modulating the gut microbiota

Obesity is a systemic disease with multisystem inflammation associated with gut dysbiosis. Salidroside (SAL) which is a major glycoside extracted from Rhodiola rosea L. has a wide range of pharmacological effects, but the role of gut microbiota in the protective effects of SAL on obesity has not been studied. Herein, we aim to explore whether SAL could ameliorate high-fat diet (HFD)-induced obesity in mice by modulating microbiota. Results showed that oral treatment with SAL alleviated HFD-induced obesity in mice as evidenced by body weight and fat weight. SAL supplementation effectively attenuated fat accumulation, lipid synthesis genes expression, liver inflammation, and metabolic endotoxemia. In addition, SAL treatment alleviated intestinal damage and increased the expression of mucin protein (Mucin-2) and tight junction (TJ) proteins (Occludin and Zonula Occludens-1). 16S rRNA sequencing analysis revealed that the gut microbiota of obese mice was also partly improved by SAL via restoring the microbial community structure and diversity. A fecal microbiota transplantation (FMT) study was designed to verify the causality. Compared with fecal transplantation (FM) from the HFD-treated mice, FM from the SAL-treated mice significantly mitigate the symptoms of obese mice, including decreasing body weight, fat accumulation, and attenuating pathological damage in the gut. Thus, SAL could be a remarkable candidate to prevent obesity.

Fucoidan from Sargassum thunbergii obtained via step gradient ethanol precipitation indicate potential anti-obesity and anti-hepatic steatosis in vitro 3T3-L1 and HepG2 cells and in vivo high-fat diet-induced obesity mice.

This study investigated the potential lipid inhibitory and anti-obesity effects of compounds derived from Sargassum thunbergii in vitro and in vivo. We prepared a Celluclast-assisted hydrolysate from Sargassum thunbergii (STC) and three fractional ethanol precipitates (STCF1, STCF2, STCF3). We investigated their proximate composition, and anti-obesity effects in vitro and in vivo. STC and STCFs all significantly reduced intracellular lipid accumulation in PA-treated 3T3-L1 and HepG2 cells. STC, STCF1, and STCF3 had profound anti-obesity effects on high fat diet (HFD)-fed obesity model mice. Oral administration of STC, STCF1, and STCF3 significantly reduced body weight and white adipose tissue (WAT) mass. Furthermore, serum lipid levels were significantly decreased. Additionally, adipose specific hormone levels (adiponectin and fibroblast growth factor-21 (FGF-21)) were significantly decreased, and serum insulin levels were also decreased by STC, STCF1, and STCF3 treatment. A mechanistic study revealed that the adipogenesis and lipolysis associated proteins in epididymal adipose tissue, and free fatty acid oxidation in liver tissues were effectively regulated by STC, STCF1, and STCF3. Overall, our findings show the potent anti-obesity effects of STC, STCF1, and STCF3, achieved by regulation of adipogenesis, lipolysis, and the fatty acid oxidation pathway in HFD-treated obesity model mice.

Which housekeeping gene is the best choice for RT-qPCR analysis in mice fed with a high-fat diet? Studies in the liver, kidney, pancreas, and intestines

High-fat diet (HFD)-induced obesity in rodents in association with Reverse Transcription and real-time Polymerase Chain Reaction (RT-qPCR) analysis have been extensively used to investigate the gene expression regulation in metabolic syndrome. qPCR requires careful standardization, and the commonly chosen housekeeping genes (HKGs) are involved in basal metabolic pathways, which makes the choice of HKG more difficult in obesity-related studies. In this study, we investigated the expression and stability of putative HKGs, such as Ppia, Tubb2a, Tfrc, Tbp, Mrpl32, Gusb, Rn18s, Rplp0, Hprt-1, B2m, Gapdh and Actb in the liver, kidney, endocrine and exocrine pancreas, small and large intestines of HFD-treated mice. The Ct values were used to determine the stability of HKG expression by RefFinder, comparing the GeNorm, NormFinder, BestKeeper, and comparative delta-Ct method algorithms. The influence of the diet on putative HKGs expression was also evaluated by 2-ΔΔCt analysis. The most stable HKGs were: Tbp and Mrpl32 in the liver, Mrpl32 and Tubb2a in the kidney, Hrpt-1 and Gapdh in the pancreatic islets and cecum, Tbp and Ppia for the exocrine pancreas, and Rn18s, Hrpt-1, and Actb for jejunum. On the contrary, Tubb2a|Trfc must be avoided to normalize the qPCR data from the HFD liver, B2m from the kidney, Trfc|Ppia and Tubb2a|B2m from the endocrine and exocrine pancreas, respectively, B2m from the jejunum, and Rn18s and Actb from the cecum portion of the large intestine. We provided the best and worse HKGs to use in the RT-qPCR analysis of tissues involved in the regulation of energy metabolism in the HFD mice model.

Acute high-fat diet impairs macrophage-supported intestinal damage resolution.

Chronic exposure to high-fat diets (HFD) worsens intestinal disease pathology, but acute effects of HFD in tissue damage remain unclear. Here, we used short-term HFD feeding in a model of intestinal injury and found sustained damage with increased cecal dead neutrophil accumulation, along with dietary lipid accumulation. Neutrophil depletion rescued enhanced pathology. Macrophages from HFD-treated mice showed reduced capacity to engulf dead neutrophils. Macrophage clearance of dead neutrophils activates critical barrier repair and antiinflammatory pathways, including IL-10, which was lost after acute HFD feeding and intestinal injury. IL-10 overexpression restored intestinal repair after HFD feeding and intestinal injury. Macrophage exposure to lipids from the HFD prevented tethering and uptake of apoptotic cells and Il10 induction. Milk fat globule-EGF factor 8 (MFGE8) is a bridging molecule that facilitates macrophage uptake of dead cells. MFGE8 also facilitates lipid uptake, and we demonstrate that dietary lipids interfere with MFGE8-mediated macrophage apoptotic neutrophil uptake and subsequent Il10 production. Our findings demonstrate that HFD promotes intestinal pathology by interfering with macrophage clearance of dead neutrophils, leading to unresolved tissue damage.

Prebiotic properties of the polysaccharide from Rosa roxburghii Tratt fruit and its protective effects in high-fat diet-induced intestinal barrier dysfunction: A fecal microbiota transplantation study

Polysaccharide from Rosa roxburghii Tratt fruit (RTFP) ameliorates high-fat diet (HFD)-induced colitis in mice. However, it is still unknown whether the gut microbiota can mediate the anti-colitis effects of RTFP in mice. This research aims to investigate the role of gut microbes in modulating RTFP in colitis mice through fecal microbiota transplantation (FMT). The findings demonstrated that RTFP exhibited prebiotic effects on HFD-induced colitis mice. After FMT treatment (transplatation of the microbiota from the fecal sample to each recipient daily), the fecal microbiota of RTFP-treated donor mice remarkably alleviated colitis-related symptoms (e.g., colonic inflammation, loss of body weight, gut microbiota dysbiosis, and loss of barrier integrity) and upregulated the expression of tight junction proteins compared to the HFD-treated donor mice. Overall, RTFP can reduce the severity of HFD-induced colitis by regulating gut microbiota.

Polyphenol-Rich Liupao Tea Extract Prevents High-Fat Diet-Induced MAFLD by Modulating the Gut Microbiota.

The modulation of gut microbiota dysbiosis might regulate the progression of metabolic-associated fatty liver disease (MAFLD). Here, we found that polyphenol-rich Liupao tea extract (PLE) prevents high-fat diet (HFD)-induced MAFLD in ApoE-/- male mice accompanied by protection of the intestinal barrier and downregulation of lipopolysaccharide (LPS)-related Toll-like receptor 4 (TLR4)-myeloid differentiation primary response 88 (MyD88) signaling in the liver. Fecal microbiome transplantation (FMT) from PLE-and-HFD-treated mice delayed MAFLD development significantly compared with FMT from HFD-treated mice. In this case, 16S rRNA gene sequencing revealed that Rikenellaceae and Odoribacter were significantly enriched and that Helicobacter was significantly decreased in not only the HFD+PLE group but also the HFD+PLE-FMT group. Furthermore, the level of 3-sulfodeoxycholic acid was significantly decreased in the HFD+PLE-FMT group compared with the HFD-FMT group. In conclusion, our data demonstrate that PLE could modulate the MAFLD phenotype in mice and that this effect is partly mediated through modulation of the gut microbiota.

ApoE isoform-dependent effects of xanthohumol on high fat diet-induced cognitive impairments and hippocampal metabolic pathways.

Consumption of a high fat diet (HFD) is linked to metabolic syndrome and cognitive impairments. This is exacerbated in age-related cognitive decline (ACD) and in individuals with a genetic risk for Alzheimer’s disease (AD). Apolipoprotein E (apoE) is involved in cholesterol metabolism. In humans, there are three major isoforms, E2, E3, and E4. Compared to E3, E4 increases ACD and AD risk and vulnerability to the deleterious cognitive effects of a HFD. The plant compound Xanthohumol (XN) had beneficial effects on cognition and metabolism in C57BL/6J wild-type (WT) male mice put on a HFD at 9 weeks of age for 13 weeks. As the effects of XN in the context of a HFD in older WT, E3, and E4 female and male mice are not known, in the current study male and female WT, E3, and E4 mice were fed a HFD alone or a HFD containing 0.07% XN for 10 or 19 weeks, starting at 6 months of age, prior to the beginning of behavioral and cognitive testing. XN showed sex- and ApoE isoform-dependent effects on cognitive performance. XN-treated E4 and WT, but not E3, mice had higher glucose transporter protein levels in the hippocampus and cortex than HFD-treated mice. E3 and E4 mice had higher glucose transporter protein levels in the hippocampus and lower glucose transporter protein levels in the cortex than WT mice. In the standard experiment, regardless of XN treatment, E4 mice had nearly double as high ceramide and sphingomyelin levels than E3 mice and male mice had higher level of glycosylated ceramide than female mice. When the differential effects of HFD in E3 and E4 males were assessed, the arginine and proline metabolism pathway was affected. In the extended exposure experiment, in E3 males XN treatment affected the arginine and proline metabolism and the glycine, serine, and threonine metabolism. Myristic acid levels were decreased in XN-treated E3 males but not E3 females. These data support the therapeutic potential for XN to ameliorate HFD-induced cognitive impairments and highlight the importance of considering sex and ApoE isoform in determining who might most benefit from this dietary supplement.

ANGPTL8 promotes adipogenic differentiation of mesenchymal stem cells: potential role in ectopic lipid deposition.

BackgroundEctopic lipid deposition plays a promoting role in many chronic metabolic diseases. Abnormal adipogenic differentiation of mesenchymal stem cells (MSCs) is an important cause of lipid deposition in organs. Studies have shown that serum angiopoietin-like protein 8 (ANGPTL8) levels are increased in patients with many chronic metabolic diseases (such as type 2 diabetes, obesity, and hepatic steatosis), while the role of ANGPTL8 in ectopic lipid accumulation has not been reported.MethodsWe used the Gene Expression Omnibus (GEO) database to analyze the expression of ANGPTL8 in subcutaneous adipose tissue of obese patients and qPCR to analyze the expression of ANGPTL8 in the liver of high-fat diet (HFD)-induced obese mice. To explore the potential roles of ANGPTL8 in the progression of ectopic lipid deposition, ANGPTL8 knockout (KO) mice were constructed, and obesity models were induced by diet and ovariectomy (OVX). We analyzed lipid deposition (TG) in the liver, kidney, and heart tissues of different groups of mice by Oil Red O, Sudan black B staining, and the single reagent GPO-PAP method. We isolated and characterized MSCs to analyze the regulatory effect of ANGPTL8 on Wnt/β-Catenin, a key pathway in adipogenic differentiation. Finally, we used the pathway activator LiCl and a GSK3β inhibitor (i.e., CHIR99021) to analyze the regulatory mechanism of this pathway by ANGPTL8.ResultsANGPTL8 is highly expressed in the subcutaneous adipose tissue of obese patients and the liver of HFD-induced obese mice. Both normal chow diet (NCD)- and HFD-treated ANGPTL8 KO male mice gained significantly less weight than wild-type (WT) male mice and reduced ectopic lipid deposition in organs. However, the female mice of ANGPTL8 KO, especially the HFD group, did not show differences in body weight or ectopic lipid deposition because HFD could induce estrogen overexpression and then downregulate ANGPTL8 expression, thereby counteracting the reduction in HFD-induced ectopic lipid deposition by ANGPTL8 deletion, and this result was also further proven by the OVX model. Mechanistic studies demonstrated that ANGPTL8 could promote the differentiation of MSCs into adipocytes by inhibiting the Wnt/β-Catenin pathway and upregulating PPARγ and c/EBPα mRNA expression.ConclusionsANGPTL8 promotes the differentiation of MSCs into adipocytes, suggesting that ANGPTL8 may be a new target for the prevention and treatment of ectopic lipid deposition in males.

The anti-obesity effects of a water-soluble glucan from Grifola frondosa via the modulation of chronic inflammation.

Polysaccharides from Grifola frondosa (G. frondosa) have anti-obesity and anti-inflammatory activities. In this study, the major type, molecular weight, homogeneity and structure of a polysaccharide purified from G. frondosa (denoted GFPA) were determined. In high-fat diet (HFD)-treated mice, 8 weeks of GFPA administration efficiently decreased body weight and blood glucose concentration and counteracted hyperlipidemia. GFPA efficiently decreased adipocyte size and ameliorated inflammatory infiltration in the three types of white adipose tissue and alleviated steatosis, fat accumulation and inflammatory infiltration in the livers of HFD-fed mice. GFPA also decreased the concentrations of aspartate aminotransferase, alanine aminotransferase and pro-inflammatory factors in the sera and livers of HFD-treated mice. Furthermore, GFPA was found to regulate lipid metabolism via the inhibition of ceramide levels in HFD-treated mice. GFPA exhibited strong anti-obesity effects via the modulation of chronic inflammation through Toll-like receptor 4/nuclear factor kappa-B signaling, which supports the use of GFPA for the treatment of obesity.