Comparative transcriptomic profiling of liver tissue from wild-type C57BL-6 mice fed a high-fat diet (HFD) supplemented with the probiotic (P) Bifidobacterium pseudocatenulatum CECT 7765.
ABSTRACT: We used Affymetrix microarrays to investigate gene expression changes in the liver of wild-type C57BL-6 mice exposed to a high-fat diet that might have been caused by the oral consumption of the probiotic B. pseudocatenulatum CECT 7765. The aim of this work was to determine whether the daily intake (by oral gavage) of the probiotic (P) B. pseudocatenulatum for seven weeks exerted any modulatory effects, at the level of gene expression, in the liver of C57BL-6 male mice exposed to a high-fat diet (HFD). Male mice were randomly assigned to four experimental groups (n= 5 animals per group) as follows: (1) control group, fed a standard diet (SD); (2) obese group, fed a high-fat diet (HFD); (3) a group that received the SD and a daily dose of the probiotic (1×109 CFU B. pseudocatenulatum CECT 7765) (SD+P); and (d) an obese group that was fed the HFD and a daily dose of the probiotic (1×109 CFU B. pseudocatenulatum CECT 7765) (HFD+P). At the end of the experimental procedure total RNA was extracted from the liver to compare differential gene expression between the groups. Liver differential gene expression after 7 weeks of supplementation between: 1) the HFD group and the SD group (effects of the high-fat diet); 2) the HFD+P and the HFD (effects of the probiotic on the consumption of a high-fat diet) and 3) the SD+P group and the SD (direct effects of the probiotic on the liver of animals consuming a normal diet).
Project description:<h4>Background</h4>Associations have been made between obesity and reduced intestinal numbers of members of the phylum Bacteroidetes, but there is no direct evidence of the role these bacteria play in obesity. Herein, the effects of Bacteroides uniformis CECT 7771 on obesity-related metabolic and immune alterations have been evaluated.<h4>Methods and findings</h4>Adult (6-8 week) male wild-type C57BL-6 mice were fed a standard diet or a high-fat-diet HFD to induce obesity, supplemented or not with B. uniformis CECT 7771 for seven weeks. Animal weight was monitored and histologic, biochemical, immunocompetent cell functions, and features of the faecal microbiota were analysed after intervention. The oral administration of B. uniformis CECT 7771 reduced body weight gain, liver steatosis and liver cholesterol and triglyceride concentrations and increased small adipocyte numbers in HFD-fed mice. The strain also reduced serum cholesterol, triglyceride, glucose, insulin and leptin levels, and improved oral tolerance to glucose in HFD fed mice. The bacterial strain also reduced dietary fat absorption, as indicated by the reduced number of fat micelles detected in enterocytes. Moreover, B. uniformis CECT 7771 improved immune defence mechanisms, impaired in obesity. HFD-induced obesity led to a decrease in TNF-? production by peritoneal macrophages stimulated with LPS, conversely, the administration of B. uniformis CECT 7771 increased TNF-? production and phagocytosis. Administering this strain also increased TNF-? production by dendritic cells (DCs) in response to LPS stimulation, which was significantly reduced by HFD. B. uniformis CECT 7771 also restored the capacity of DCs to induce a T-cell proliferation response, which was impaired in obese mice. HFD induced marked changes in gut microbiota composition, which were partially restored by the intervention.<h4>Conclusions</h4>Altogether, the findings indicate that administration of B. uniformis CECT 7771 ameliorates HFD-induced metabolic and immune dysfunction associated with intestinal dysbiosis in obese mice.
Project description:<h4>Objective</h4>To investigate the functional effects of probiotic treatment on the gut microbiota, as well as liver and adipose gene expression in diet-induced obese mice.<h4>Design</h4>Male C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks to induce obesity, and then randomized to receive HFD+probiotic (Lactobacillus curvatus HY7601 and Lactobacillus plantarum KY1032, n?=?9) or HFD+placebo (n?=?9) for another 10 weeks. Normal diet (ND) fed mice (n?=?9) served as non-obese controls.<h4>Results</h4>Diet-induced obese mice treated with probiotics showed reduced body weight gain and fat accumulation as well as lowered plasma insulin, leptin, total-cholesterol and liver toxicity biomarkers. A total of 151,061 pyrosequencing reads for fecal microbiota were analyzed with a mean of 6,564, 5,274 and 4,464 reads for the ND, HFD+placebo and HFD+probiotic groups, respectively. Gut microbiota species were shared among the experimental groups despite the different diets and treatments. The diversity of the gut microbiota and its composition were significantly altered in the diet-induced obese mice and after probiotic treatment. We observed concurrent transcriptional changes in adipose tissue and the liver. In adipose tissue, pro-inflammatory genes (TNF?, IL6, IL1? and MCP1) were down-regulated in mice receiving probiotic treatment. In the liver, fatty acid oxidation-related genes (PGC1?, CPT1, CPT2 and ACOX1) were up-regulated in mice receiving probiotic treatment.<h4>Conclusions</h4>The gut microbiota of diet-induced obese mice appears to be modulated in mice receiving probiotic treatment. Probiotic treatment might reduce diet-induced obesity and modulate genes associated with metabolism and inflammation in the liver and adipose tissue.
Project description:Systemic acute inflammatory signals can cause profound anorexia by disrupting the physiological appetite regulation in the hypothalamic milieu. Conversely, obesity related chronic inflammation of the hypothalamus can disturb anorexigenic signals and promote abnormal body weight control. The aim of the present study was to compare the global hypothalamic endophenotype in C57/Bl6 mice exposed to a high-fat diet or with acute illness mediated by LPS. Ten-week old male C57/Bl6 mice (n=18) were randomly divided into four groups; the control 1 group (n =3) was fed a normal diet whereas the high-fat diet (HFD) group (n =6) was fed a high-fat diet for eight weeks. The control 2 group (n=3) received an intraperitoneal injection of saline whereas the LPS group (n=6) received an intraperitoneal injection of LPS. Mice were sacrificed 18-hr post-injection. Both control 2 and LPS groups were fed a normal diet for eight weeks before the injection. The hypothalamic regions were removed and analysed using a 2D LC-MS methodology. The proteomic analysis profiled 9,235 proteins (q<0.05) across all biological states, of which 522 proteins were found modulated in the HFD group and another 579 in the LPS group. The proteomic profiles demonstrated that the systemic acute inflammation linked with anorexia induced a negative feedback loop of appetite control in the hypothalamus, suggesting an effort to re-establish homeostasis. By contrast, the chronic inflammation associated with obesity initiated a “perpetual cycle” of positive feedback enhancement of appetite regulation further exacerbating positive energy balance.
Project description:The purpose of this study was to investigate the effect of Qutanhuoxue decoction on AQP7 and AQP9 expression in nonalcoholic fatty liver model rats. Nighty male SD rats (six weeks old, 250 ± 10?g) were randomly divided into 5 groups: normal diet group (ND group), high-fat diet (HFD group), HFD + low dose Qd group, HFD + middle dose Qd group, and HFD + high dose Qd group. Rats in ND group were fed with a regular diet, while rats in other groups were fed with high-fat diet. After the success of the molding, HFD + low dose Qd group, HFD + middle dose Qd group, and HFD + high dose Qd group were, respectively, gavaged by Qutanhuoxue decoction with concentration of 4.5g.kg-1.d-1, 9.0g.kg-1.d-1, and 18g.kg-1.d-1. The ND group and HFD group were gavaged by the same volume of physiological saline lavage, once a day. During the period of gavaging, the other four groups continue to be fed with high-fat fodder except ND group. All rats were killed at 14d, 21d, and 28d, respectively. HE staining was used to observe the pathological changes of liver tissues and serum level of ALT AST GGT and TC TG was detected by automatic analyzer. The expression levels of liver AQP9 mRNA and adipose tissue AQP7 mRNA were detected by real-time PCR. Quhuoxue decoction can significantly reduce the liver function (ALT, AST, and GGT) and blood fat (TG, TC) levels of NAFLD rats and reduce the degree of liver fat degeneration. The effect was the best in the HFD + high dose Qd group of 28d. Qutanhuoxue decoction can decrease the expression of liver AQP9 mRNA and increase the expression of adipose tissue AQP7 mRNA. In conclusion, Qutanhuoxue decoction can reduce the degree of hepatic steatosis, which may be closely related to the increase of AQP7 expression in adipose tissue and the decrease of AQP9 expression in liver.
Project description:The present study aimed to examine the effect of high-fat diet prior to pregnancy on the liver of mouse offspring. Female C57BL/6J mice were fed a normal chow (15.2% fat by energy) (CTR and CTR-PP groups) or a high-fat chow (31.2% fat by energy) (HFD and HFD-PP groups) for 3−4 weeks and then mated with male C57BL/6J mice fed normal chow. Some mothers continued on the same diet until pups reached 21 days of age (CTR and HFD), and others were fed the different chows from gestational day 0 (CTR-PP and HFD-PP) to determine the effects of a high-fat diet during the pre-pregnancy period in HFD-PP/CTR and HFD/CTR-PP comparisons. RNA sample was taken from liver of 3-week-old mouse prenatally received high-fat diet prior to pregnancy, during pregnancy and lactation, or through prior to and during pregnancy and lactation, while control RNA was taken from control counterpart prenatally received normal diet alone. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.
Project description:Obesity is tightly associated with an increased risk of nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanisms of obesity-induced fatty liver remain largely unknown.In order to identify genes that are potentially involved in dysfunctional hepatic lipid homeostasis in obesity, we performed a clustering analysis of Affymetrix arrays,which revealed that a number of mRNAs were dys-regulated in the livers of mice fed a high-fat diet (HFD), compared with mice fed a normal chow diet (ND). To identify genes that are potentially involved in dysfunctional hepatic lipid homeostasis in obesity, male C57BL/6 mice aged 8 weeks were fed a normal diet (ND) or high-fat-diet (HFD) containing 60 Kcal% of fat for 12 weeks. Then mice were sacrificed and total RNAs were isoloated from hepatic tissues. Affymetrix array hybridisation and scanning were performed using Mouse Genome 430 2.0 chips.Total RNA samples obtained from six mice per group (ND and HFD) and pooled by each of the two were used for microarray analysis.
Project description:This study aimed to investigate the mechanism of SYT on lipid metabolism and insulin sensitivity in high-fat diet (HFD)-induced obese mice by means of combining lipidomics and proteomics. The obese mice models were developed via HFD feeding for 20 consecutive weeks. Mice in the treatment group were given metformin and SYT respectively, and the effects of SYT on body weight, blood glucose, insulin sensitivity, fat accumulation in the organs, and pathological changes in the liver were monitored. Lipid metabolism was examined by lipidomics. Further determination of signaling pathways was detected by proteomics. The biological contributions of the compounds detected in SYT's chemical fingerprint were predicted by network pharmacology. Overall, our study provides supportive evidence for the mechanism of SYT's therapeutic effect on dysregulated lipid metabolism in diabesity.
Project description:Perfluorooctanesulfonic acid (PFOS) is a persistent, bio-accumulative pollutant that has been used for the last 60+ years in numerous industrial and commercial applications. In mice, PFOS administration is known to induce hepatomegaly and hepatic steatosis. The aim of the present study was to evaluate potential PFOS and diet interactions and explore the mechanism of PFOS induced liver lipid accumulation. Prior to PFOS administration, mice were fed either a standard chow diet (SD) or 60% kCal high fat diet (HFD) for 4 weeks to establish significant body weight increase. After 4 weeks of diet acclimation, the treatment groups received 0.0003% PFOS in diet for an additional 10 weeks. In addition, a subset of the mice fed HFD were switched to a SD (H-SD) to mimic weight-loss induced improvement of hepatic steatosis. A total of six treatment groups: i) SD, ii) HSD, iii) HFD (H), iv) SD +PFOS(SDP), v) H-SD +PFOS (HSDP), and vi) HFD +PFOS (HP) were included. PFOS and lipid concentrations were measured in both serum and liver. Relative liver mRNA expression was determined by targeted bead array and proteins were quantified using untargeted mass spectrometry. PFOS exposure increased liver weight, and in the HFD increased liver triglycerides and liver cholesterol content. Gene and protein expression in the liver demonstrated that PFOS exposure induced lipid utilization and xenobiotic metabolism pathways, and in a HFD, induced lipid synthesis. The data suggests that PFOS exposure acts on lipid utilization genes and exacerbates hepatic steatosis in mice fed a HFD.
Project description:The literature describes a close correlation between metabolic disorders and abnormal immune responses, like low-grade inflammation (LGI), which may be one mechanistic link between obesity and various comorbidities, including non-alcoholic fatty liver disease (NAFLD). In our study, we investigated the influence of dietary composition on obesity-derived LGI in the liver. We used a dietary induced obesity mouse model of C57BL/6J mice fed with high fat diet (HFD, 60% fat, 20% protein, 20% carbohydrates) and two different controls. One was rich in carbohydrates (10% fat, 20% protein, 70% carbohydrates), further referred to as the control diet (CD), and the other one is referred to as the standard diet (SD), with a more balanced macronutrient content (9% fat, 33% protein, 58% carbohydrates). Our results showed a significant increased NAFLD activity score in HFD compared to both controls, but livers of the CD group also differed in their macroscopic appearance from healthy livers. Hepatic fat content showed significantly elevated cholesterol concentrations in the CD group. Histologic analysis of the cellular immune response in the liver showed no difference between HFD and CD and expression analysis of immunologic mediators like interleukin (IL)-1?, IL-6, IL-10 and tumor necrosis factor alpha also point towards a pro-inflammatory response to CD, comparable to LGI in HFD. Therefore, when studying diet-induced obesity with a focus on inflammatory processes, we encourage researchers to carefully select controls and not use a control diet disproportionally rich in carbohydrates.
Project description:To identify molecular mechanism underlying the protection from diet-induced hepatic steatosis in AHNAK deficiency mice, we examined microarray analysis with liver sample from HFD-fed AHNAK KO and WT mice. Two-condition experiment, regular chow (CD) -fed WT vs. CD-fed AHNAK KO and High fat diet(HFD)-fed WT vs. HFD-fed AHNAK KO mice. Biological replicates: 3 control, One replicate per array.