Gene Expression Changes In Liver Research Articles

Accelerated onset of diabetes in non-obese diabetic mice fed a refined high-fat diet.

Type 1 diabetes results from autoimmune events influenced by environmental variables, including changes in diet. This study investigated how feeding refined versus unrefined (aka 'chow') diets affects the onset and progression of hyperglycaemia in non-obese diabetic (NOD) mice. Female NOD mice were fed either unrefined diets or matched refined low- and high-fat diets. The onset of hyperglycaemia, glucose tolerance, food intake, energy expenditure, circulating insulin, liver gene expression and microbiome changes were measured for each dietary group. NOD mice consuming unrefined (chow) diets developed hyperglycaemia at similar frequencies. By contrast, mice consuming the defined high-fat diet had an accelerated onset of hyperglycaemia compared to the matched low-fat diet. There was no change in food intake, energy expenditure, or physical activity within each respective dietary group. Microbiome changes were driven by diet type, with chow diets clustering similarly, while refined low- and high-fat bacterial diversity also grouped closely. In the defined dietary cohort, liver gene expression changes in high-fat-fed mice were consistent with a greater frequency of hyperglycaemia and impaired glucose tolerance. Glucose intolerance is associated with an enhanced frequency of hyperglycaemia in female NOD mice fed a defined high-fat diet. Using an appropriate matched control diet is an essential experimental variable when studying changes in microbiome composition and diet as a modifier of disease risk.

Identification of Central Genes and Regulatory Pathways Associated with Hyperlipidemia in Rats.

Hyperlipidemia is an independent risk factor for cardiovascular and cerebrovascular diseases. The transcriptomic data and the gene regulatory networks of hyperlipidemia are largely unclear. We analyzed the changes in liver gene expression and the serum levels of biochemical indicators in rats with hyperlipidemia induced by high-fat diet (HFD). The body weight, liver weight, and the serum levels of TG, TC, HDL-C, LDL-C, ALT, and AST were significantly higher in the hyperlipidemic rats compared to the healthy controls (P < 0.05). In addition, HFD feeding decreased the antioxidant capacity of the liver tissues and significantly increased the arteriosclerosis index (AI) (P < 0.05). There were 584 differentially expressed genes (DEGs) in the hyperlipidemia model compared to the control, with |log2FC|≥ 1 and P-adjust ≤ 0.05 as the thresholds. GO analysis of the DEGs revealed significant enrichment of 382 biological processes (BP), 18 cellular components (CC), and 40 molecular functions (MF). In addition, pathways related to bile secretion, cholesterol metabolism, and steroid hormone biosynthesis were significantly associated with hyperlipidemia. The key genes potentially involved in the blood lipid changes were Agt, Src, Gnai3, Cyp2c7, Cyp2c11, Cyp2c22, Apoa1, Apoe, and Srebf1. The genes and pathways identified in this study are potential intervention targets for hyperlipidemia and warrant further investigation.

Adapting to stress: The effects of hibernation and hibernacula temperature on the hepatic transcriptome of Rhinolophus pusillus.

Hibernation, a survival strategy in mammals for extreme climates, induces physiological phenomena such as ischemia-reperfusion and metabolic shifts that hold great potential for advancements in modern medicine. Despite this, the molecular mechanisms underpinning hibernation remain largely unclear. This study used RNA-seq and Iso-seq techniques to investigate the changes in liver transcriptome expression of Rhinolophus pusillus during hibernation and active periods, as well as under different microhabitat temperatures. We identified 11 457 differentially expressed genes during hibernation and active periods, of which 395 showed significant differential expression. Genes associated with fatty acid catabolism were significantly upregulated during hibernation, whereas genes related to carbohydrate metabolism and glycogen synthesis were downregulated. Conversely, immune-related genes displayed differential expression patterns: genes tied to innate immunity were significantly upregulated, while those linked to adaptive immunity and inflammatory response were downregulated. The analysis of transcriptomic data obtained from different microhabitat temperatures revealed that R. pusillus exhibited an upregulation of genes associated with lipid metabolism in lower microhabitat temperature. This upregulation facilitated an enhanced utilization rate of triglyceride, ultimately resulting in increased energy provision for the organism. Additionally, R. pusillus upregulated gluconeogenesis-related genes regardless of the microhabitat temperature, demonstrating the importance of maintaining blood glucose levels during hibernation. Our transcriptomic data reveal that these changes in liver gene expression optimize energy allocation during hibernation, suggesting that liver tissue adaptively responds to the inherent stress of its function during hibernation. This study sheds light on the role of differential gene expression in promoting more efficient energy allocation during hibernation. It contributes to our understanding of how liver tissue adapts to the stressors associated with this state.

Porphyra haitanensis glycoprotein regulates glucose homeostasis: targeting the liver.

In this study, we investigated the effects of glycoprotein (PG)-mediated regulation of Porphyra haitanensis on liver glucose metabolism in hyperglycemic mouse models, and sought to establish the underlying mechanism, as determined by the changes in liver gene expression and metabolic profiles. The results showed that 30-300 mg kg-1 PG upregulated the expression of the liver genes Ins1, Ins2, Insr, Gys2, Gpi1, Gck, and downregulated the expression of G6pc, G6pc2, and G6pc3, in a concentration-dependent manner. 300 mg kg-1 PG downregulated the concentrations of glucose-related metabolites in the liver, but upregulated lactic acid, 2-aminoacetic acid, and glucose-1-phosphate concentrations. It was assumed that PG regulated liver glucose metabolism by enriching insulin secretion, glycolysis/gluconeogenesis, and the AMPK signaling pathway, and promoting insulin secretion, glycogen synthesis, and glycolysis. Our findings supported the development of P. haitanensis and its glycoproteins as novel natural antidiabetic compounds that regulated blood glucose homeostasis.

Replacement of Dietary Fish Protein with Bacterial Protein Results in Decreased Adiposity Coupled with Liver Gene Expression Changes in Female Danio rerio

BackgroundEffective use of Danio rerio as a preclinical model requires standardization of macronutrient sources to achieve scientific reproducibility across studies and labs. ObjectiveOur objective was to evaluate a bacterial-based single-cell protein (SCP) for the production of open-source standardized diets with defined health characteristics for the zebrafish research community. MethodsWe completed a 16-wk feeding trial using juvenile D. rerio 31 d postfertilization (10 tanks per diet and 14 D. rerio per tank) with formulated diets containing either a typical fish protein ingredient [standard reference (SR) diet] or a novel bacterial SCP source [bacterial protein (BP) diet]. At the end of the feeding trial, growth metrics, body composition, reproductive success, and bulk transcriptomics of the liver (RNAseq on female D. rerio with confirmatory rtPCR) were performed for each diet treatment. ResultsD. rerio fed the BP diet had body weight gains equivalent to the D. rerio fed fish protein, and females had significantly lower total carcass lipid, indicating reduced adiposity. Reproductive success was similar between treatments, suggesting normal physiological function. Genes differentially expressed in female D. rerio fed the BP diet compared with females fed the SR diet were overrepresented in the gene ontologies of metabolism, biosynthesis of cholesterol precursors and products, and protein unfolding responses. ConclusionProtein source substantially affected body growth metrics and composition as well as gene expression. These data support the development of an open-source diet utilizing an ingredient that correlates with improved health profiles and reduced variability in notable outcomes.

(+)-CatechinAttenuatesMultipleAtherosclerosis-Associated Processes In Vitro, Modulates Disease-Associated Risk Factors in C57BL/6J Mice and Reduces Atherogenesis in LDL Receptor Deficient Mice by Inhibiting Inflammation and Increasing Markers of Plaque Stability.

A prospective study of 34492 participants shows an inverse association between (+)-catechin intake and coronary heart disease. The effects of (+)-catechin on atherosclerosis and associated risk factors are poorly understood and are investigated. (+)-Catechin attenuates reactive oxygen species production in human macrophages, endothelial cells and vascular smooth muscle cells, chemokine-driven monocytic migration, and proliferation of human macrophages and their expression of several pro-atherogenic genes. (+)-Catechin also improves oxidized LDL-mediated mitochondrial membrane depolarization in endothelial cells and attenuates growth factor-induced smooth muscle cell migration. In C57BL/6J mice fed high fat diet (HFD) for 3 weeks, (+)-catechin attenuates plasma levels of triacylglycerol and interleukin (IL)-1β and IL-2, produces anti-atherogenic changes in liver gene expression, and reduces levels of white blood cells, myeloid-derived suppressor cells, Lin- Sca+ c-Kit+ cells, and common lymphoid progenitor cells within the bone marrow. In LDL receptor deficient mice fed HFD for 12 weeks, (+)-catechin attenuates atherosclerotic plaque burden and inflammation with reduced macrophage content and increased markers of plaque stability; smooth muscle cell and collagen content. This study provides novel, detailed insights into the cardio-protective actions of (+)-catechin together with underlying molecular mechanisms and supports further assessments of its beneficial effects in human trials.

Effects of Cigarette Smoke Exposure on the Gut Microbiota and Liver Transcriptome in Mice Reveal Gut-Liver Interactions.

Cigarette smoke exposure has a harmful impact on health and increases the risk of disease. However, studies on cigarette-smoke-induced adverse effects from the perspective of the gut–liver axis are lacking. In this study, we evaluated the adverse effects of cigarette smoke exposure on mice through physiological, biochemical, and histopathological analyses and explored cigarette-smoke-induced gut microbiota imbalance and changes in liver gene expression through a multiomics analysis. We demonstrated that cigarette smoke exposure caused abnormal physiological indices (including reduced body weight, blood lipids, and food intake) in mice, which also triggered liver injury and induced disorders of the gut microbiota and liver transcriptome (especially lipid metabolism). A significant correlation between intestinal bacterial abundance and the expression of lipid-metabolism-related genes was detected, suggesting the coordinated regulation of lipid metabolism by gut microbiota and liver metabolism. Specifically, Salmonella (harmful bacterium) was negatively and positively correlated with up- (such as Acsl3 and Me1) and downregulated genes (such as Angptl4, Cyp4a12a, and Plin5) involved in lipid metabolism, while Ligilactobacillus (beneficial bacterium) showed opposite trends with these genes. Our results clarified the key role of gut microbiota in liver damage and metabolism and improved the understanding of gut–liver interactions caused by cigarette smoke exposure.

Mouse model of NASH that replicates key features of the human disease and progresses to fibrosis stage 3.

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States and the world; with no Food and Drug Administration–approved pharmacological treatment available, it remains an area of unmet medical need. In nonalcoholic steatohepatitis (NASH), the most important predictor of clinical outcome is the fibrosis stage. Moreover, the Food and Drug Administration recommends that clinical trials for drugs to treat this disease include patients with fibrosis stage 2 or greater. Therefore, when using animal models for investigating the pathophysiology of NAFLD and for the preclinical evaluation of new drugs, it is important that the animals develop substantial fibrosis. The aim of this study was to develop a mouse model of NAFLD that replicated the disease in humans, including obesity and progressive liver fibrosis. Agouti yellow mutant mice, which have hyperphagia, were fed a Western diet and water containing high‐fructose corn syrup for 16 weeks. Mice became obese and developed glucose intolerance. Their gut microbiota showed dysbiosis with changes that replicate some of the changes described in humans with NASH. They developed NASH with activity scores of 5–6 and fibrosis, which was stage 1 after 16 weeks, and stage 3 after 12 months. Changes in liver gene expression assessed by gene‐set enrichment analysis showed 90% similarity with changes in human patients with NASH. Conclusion: Ay mice, when fed a Western diet similar to that consumed by humans, develop obesity and NASH with liver histology, including fibrosis, and gene expression changes that are highly similar to the disease in humans.

Effects of the SLICK1 mutation in PRLR on regulation of core body temperature and global gene expression in liver in cattle

The SLICK1 mutation in bovine PRLR (c.1382del; rs517047387) is a deletion mutation resulting in a protein with a truncated intracellular domain. Cattle carrying at least one allele have a phenotype characterized by a short hair coat (slick phenotype) and increased resistance to heat stress. Given the pleiotropic nature of prolactin, the mutation may affect other physiological characteristics. The liver is one organ that could potentially be affected because of the expression of PRLR. The mutation is a dominant allele, and heterozygous animals have a similar hair coat to that of animals homozygous for the mutation. Present objectives were to determine whether inheritance of the SLICK1 mutation affects liver gene expression and if animals homozygous for the SLICK1 allele differ from heterozygotes in liver gene expression and regulation of body temperature during heat stress. In one experiment, rectal and ruminal temperatures were less for Holstein heifers that were heterozygous for the SLICK1 allele compared with wildtype heifers. There were 71 differentially expressed genes in liver, with 13 upregulated and 58 downregulated in SLICK1 heterozygotes. Among the ontologies characteristic of differentially expressed genes were those related to immune function and fatty acid and amino acid metabolism. In a prospective cohort study conducted with adult Senepol cattle, body temperature and hepatic gene expression were compared between animals heterozygous or homozygous for the SLICK1 mutation. There were no differences in ruminal temperatures between genotypes, rectal temperature was higher in animals homozygous for the SLICK1 mutation, and there was only one gene in liver that was differentially expressed. It was concluded that inheritance of the SLICK1 allele can exert functional changes beyond those related to hair growth although changes in liver gene expression were not extensive. Results are also consistent with the SLICK1 allele being dominant because there were few differences in phenotype between animals inheriting one or two copies of the allele.

Effects of Administering Exogenous Bovine Somatotropin During the First Trimester of Pregnancy Altered Uterine Hemodynamics in Suckled Beef Cows

The objective of this study was to examine the effects of recombinant bovine somatotropin (bST) administration on uterine hemodynamics and subsequent fetal programming in suckled cows during the first trimester of gestation. Crossbred beef cows (n = 152) were stratified by breed, days postpartum, parity, cyclicity status, and body condition score (BCS) before being assigned to either receive injections of bST every other week (BST; 500-mg/14 d) starting at fixed-time artificial insemination (TAI; d 0) until d 97 or to receive no bST (CTL). Blood samples were collected until d 97 for analysis of plasma concentrations of insulin-like growth factor 1 (IGF-1). Pregnancy was assessed via transrectal ultrasonography on d 41 and 173. A subset of pregnant cows (BST, n = 24; CTL, n = 28) were selected for assessment of uterine arterial blood flow (BF), pulsatility index, and resistance index (RI) of the uterine arteries ipsilateral and contralateral to the conceptus via color Doppler ultrasonography on d 97 and 233 of gestation. No differences (P = 0.99) were detected in body weight (BW) or BCS of dams; however, plasma concentrations of IGF-1 were greater (P &amp;lt; 0.001) in BST-treated cows. Color Doppler ultrasonography parameters differed whereby a treatment × day interaction (P = 0.007) was detected for RI on d 97 (P = 0.048); however, on d 233, RI did not differ (P &amp;gt; 0.10) but ipsilateral BF for BST-treated cows was greater (P = 0.0319) than controls. Mean heart girth diameter, crown-to-rump length, and neonate BW at 7 ± 5 d of calf age did not differ (P &amp;gt; 0.10). Liver tissue samples from each calf were collected for analysis of mRNA expression of target insulin-like growth factor system ligands. There was no difference in gene expression of hepatic IGF-1 between treatments (P = 0.99). A treatment × sex interaction was determined, where BST heifers had increased mRNA expression of IGFR1 compared to BST bulls (P = 0.03). Bi-weekly administration of bST until d 97 of pregnancy increased plasma concentrations of IGF-1, altered uterine hemodynamics in dams, induced sex-specific changes in liver gene expression of the offspring but failed to alter calf morphometries or calf performance until weaning.

Liver Transcriptome Dynamics During Hibernation Are Shaped by a Shifting Balance Between Transcription and RNA Stability.

Hibernators dramatically lower metabolism to save energy while fasting for months. Prolonged fasting challenges metabolic homeostasis, yet small-bodied hibernators emerge each spring ready to resume all aspects of active life, including immediate reproduction. The liver is the body’s metabolic hub, processing and detoxifying macromolecules to provide essential fuels to brain, muscle and other organs throughout the body. Here we quantify changes in liver gene expression across several distinct physiological states of hibernation in 13-lined ground squirrels, using RNA-seq to measure the steady-state transcriptome and GRO-seq to measure transcription for the first time in a hibernator. Our data capture key timepoints in both the seasonal and torpor-arousal cycles of hibernation. Strong positive correlation between transcription and the transcriptome indicates that transcriptional control dominates the known seasonal reprogramming of metabolic gene expression in liver for hibernation. During the torpor-arousal cycle, however, discordance develops between transcription and the steady-state transcriptome by at least two mechanisms: 1) although not transcribed during torpor, some transcripts are unusually stable across the torpor bout; and 2) unexpectedly, on some genes, our data suggest continuing, slow elongation with a failure to terminate transcription across the torpor bout. While the steady-state RNAs corresponding to these read through transcripts did not increase during torpor, they did increase shortly after rewarming despite their simultaneously low transcription. Both of these mechanisms would assure the immediate availability of functional transcripts upon rewarming. Integration of transcriptional, post-transcriptional and RNA stability control mechanisms, all demonstrated in these data, likely initiate a serial gene expression program across the short euthermic period that restores the tissue and prepares the animal for the next bout of torpor.

Sensitivity to Dietary Wheat Gluten in Atlantic Salmon Indicated by Gene Expression Changes in Liver and Intestine.

Feed safety is a necessity for animal health and welfare as well as prerequisite for food safety and human health. Wheat gluten (WG) is considered as a valuable protein source in fish feed due to its suitability as a feed binder, high digestibility, good amino acid profile, energy density and most importantly, due to its relatively low level of anti-nutritional factors (ANFs). The main aim of this study was to identify the impact of dietary WG on salmon health by analysing growth, feed efficiency and the hepatic and intestinal transcriptomes. The fish were fed either control diet with fishmeal (FM) as the only source of protein or diets, where 15% or 30% of the FM were replaced by WG. The fish had a mean initial weight of 223 g and approximately doubled their weight during the 9-week experiment. Salmon fed on 30% WG showed reduced feed intake compared to the 15% and FM fed groups. The liver was the less affected organ but fat content and activities of the liver health markers in plasma increased with the inclusion level of WG in the diet. Gene expression analysis showed significant changes in both, intestine and liver of fish fed with 30% WG. Especially noticeable were changes in the lipid metabolism, in particular in relation to the intestinal lipoprotein transport and sterol metabolism. Moreover, the intestinal transcriptome of WG-fed fish showed shifts in the expression of a large number of genes responsible for immunity and tissue structure and integrity. These observations implied that the fish receiving WG-containing diet were undergoing nutritional stress. Overall, the study provided evidence that a high dietary level of WG can have a negative impact on the intestinal and liver health of salmon with symptoms similar to gluten sensitivity in humans.

GH directly inhibits steatosis and liver injury in a sex-dependent and IGF1-independent manner.

A reduction in hepatocyte growth hormone (GH)-signaling promotes non-alcoholic fatty liver disease (NAFLD). However, debate remains as to the relative contribution of the direct effects of GH on hepatocyte function vs indirect effects, via alterations in insulin-like growth factor 1 (IGF1). To isolate the role of hepatocyte GH receptor (GHR) signaling, independent of changes in IGF1, mice with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd) were treated with a vector expressing rat IGF1 targeted specifically to hepatocytes. Compared to GHR-intact mice, aHepGHRkd reduced circulating IGF1 and elevated GH. In male aHepGHRkd, the shift in IGF1/GH did not alter plasma glucose or non-esterified fatty acids (NEFA), but was associated with increased insulin, enhanced systemic lipid oxidation and reduced white adipose tissue (WAT) mass. Livers of male aHepGHRkd exhibited steatosis associated with increased de novo lipogenesis, hepatocyte ballooning and inflammation. In female aHepGHRkd, hepatic GHR protein levels were not detectable, but moderate levels of IGF1 were maintained, with minimal alterations in systemic metabolism and no evidence of steatosis. Reconstitution of hepatocyte IGF1 in male aHepGHRkd lowered GH and normalized insulin, whole body lipid utilization and WAT mass. However, IGF1 reconstitution did not reduce steatosis or eliminate liver injury. RNAseq analysis showed IGF1 reconstitution did not impact aHepGHRkd-induced changes in liver gene expression, despite changes in systemic metabolism. These results demonstrate the impact of aHepGHRkd is sexually dimorphic and the steatosis and liver injury observed in male aHepGHRkd mice is autonomous of IGF1, suggesting GH acts directly on the adult hepatocyte to control NAFLD progression.

Characterization of indoleamine-2,3-dioxygenase 1, tryptophan-2,3-dioxygenase, and Ido1/Tdo2 knockout mice

Indoleamine-2,3-dioxygenase 1 (IDO1) and tryptophan-2,3-dioxygenase 2 (TDO2) degrade tryptophan (Trp) to kynurenine (Kyn), and these enzymes have promise as therapeutic targets. A comprehensive characterization of potential safety liabilities of IDO1 and TDO2 inhibitors using knockout (KO) mice has not been assessed, nor has the dual Ido1/Tdo2 KO been reported. Here we characterized male and female mice with KOs for Ido1, Tdo2, and Ido1/Tdo2 and compared findings to the wild type (WT) mouse strain, evaluated for 14 days, using metabolomics, transcriptional profiling, behavioral analysis, spleen immunophenotyping, comprehensive histopathological analysis, and serum clinical chemistry.Multiple metabolomic changes were seen in KO mice. For catabolism of Trp to Kyn and anthranilic acid, both substrates were decreased in liver of Tdo2 and dual KO mice. Metabolism of Trp to serotonin and its metabolites resulted in an increase in 5-Hydroxyindole-3-acetic acid in the Tdo2 and dual KO mice. Ido1 and dual KO mice displayed a Kyn reduction in plasma but not in liver. Nicotinamide synthesis and conversion of glucose to lactic acid were not impacted. A slight decrease in serum alkaline phosphatase was seen in all KOs, and small changes in liver gene expression of genes unrelated to tryptophan metabolism were observed. Regarding other parameters, no genotype-specific changes were observed.In summary, this work shows metabolomic pathway changes for metabolites downstream of tryptophan in these KO mice, and suggests that inhibition of the IDO1 and TDO2 enzymes would be well tolerated whether inhibited individually or in combination since no safety liabilities were uncovered.

Quantitative Transcriptional Biomarkers of Xenobiotic Receptor Activation in Rat Liver for the Early Assessment of Drug Safety Liabilities.

The robust transcriptional plasticity of liver mediated through xenobiotic receptors underlies its ability to respond rapidly and effectively to diverse chemical stressors. Thus, drug-induced gene expression changes in liver serve not only as biomarkers of liver injury, but also as mechanistic sentinels of adaptation in metabolism, detoxification, and tissue protection from chemicals. Modern RNA sequencing methods offer an unmatched opportunity to quantitatively monitor these processes in parallel and to contextualize the spectrum of dose-dependent stress, adaptation, protection, and injury responses induced in liver by drug treatments. Using this approach, we profiled the transcriptional changes in rat liver following daily oral administration of 120 different compounds, many of which are known to be associated with clinical risk for drug-induced liver injury by diverse mechanisms. Clustering, correlation, and linear modeling analyses were used to identify and optimize coexpressed gene signatures modulated by drug treatment. Here, we specifically focused on prioritizing 9 key signatures for their pragmatic utility for routine monitoring in initial rat tolerability studies just prior to entering drug development. These signatures are associated with 5 canonical xenobiotic nuclear receptors (AHR, CAR, PXR, PPARα, ER), 3 mediators of reactive metabolite-mediated stress responses (NRF2, NRF1, P53), and 1 liver response following activation of the innate immune response. Comparing paradigm chemical inducers of each receptor to the other compounds surveyed enabled us to identify sets of optimized gene expression panels and associated scoring algorithms proposed as quantitative mechanistic biomarkers with high sensitivity, specificity, and quantitative accuracy. These findings were further qualified using public datasets, Open TG-GATEs and DrugMatrix, and internal development compounds. With broader collaboration and additional qualification, the quantitative toxicogenomic framework described here could inform candidate selection prior to committing to drug development, as well as complement and provide a deeper understanding of the conventional toxicology study endpoints used later in drug development.

Impact of Broccoli on Molecular Biomarkers of Liver Health (P06-001-19)

ObjectivesThe diet in combination with lifestyle are contributing factors to obesity-associated diseases including type II diabetes, non-alcoholic hepatic diseases, cardiovascular disease and cancer. Broccoli, a brassica vegetable, can reduce the negative effects of a detrimental diet and sedentary lifestyle that can lead to obesity and impede the development of chronic diseases. There are no established molecular biomarkers that reflect the health benefits of dietary broccoli consumption. Thus, in this study we focused on health benefits of broccoli on liver and studied the relevance of blood metabolite profile changes and gene expression patterns in liver as indicators of liver disease development and prevention. MethodsRats (n = 3) were fed an AIN93G diet with 10% cooked freeze-dried broccoli for 14 days. We examined the impact of broccoli feeding on the plasma metabolite composition by metabolomics analysis and liver gene expression changes using Q-RT-PCR after 0, 1, 2, 4, 7, 14 days of broccoli feeding. ResultsWe identified several metabolites that changed more than 2-fold compared to the level on day 0, including metabolites that were involved in liver pathways for glutathione synthesis, amino acid metabolism and de novo fatty acid synthesis. We found that repeated broccoli consumption changes gene expression levels (CD36, CPT-1, CD68) in the liver. ConclusionsFurther characterizing health-promoting effects of broccoli in different in vivo obesity models will significantly expand our understanding of both liver health and the impact of dietary broccoli, having a broad impact on prevention of obesity-associated diseases, including NALFD and type II diabetes. Funding SourcesFunding provided by National Institute of Food and Agriculture, U.S. Department of Agriculture, College of ACES DNS 20/20 Award, USDA/AFRI Grant.

Petite Integration Factor 1 (PIF1) helicase deficiency increases weight gain in Western diet-fed female mice without increased inflammatory markers or decreased glucose clearance.

Petite Integration Factor 1 (PIF1) is a multifunctional helicase present in nuclei and mitochondria. PIF1 knock out (KO) mice exhibit accelerated weight gain and decreased wheel running on a normal chow diet. In the current study, we investigated whether Pif1 ablation alters whole body metabolism in response to weight gain. PIF1 KO and wild type (WT) C57BL/6J mice were fed a Western diet (WD) rich in fat and carbohydrates before evaluation of their metabolic phenotype. Compared with weight gain-resistant WT female mice, WD-fed PIF1 KO females, but not males, showed accelerated adipose deposition, decreased locomotor activity, and reduced whole-body energy expenditure without increased dietary intake. Surprisingly, PIF1 KO females did not show obesity-induced alterations in fasting blood glucose and glucose clearance. WD-fed PIF1 KO females developed mild hepatic steatosis and associated changes in liver gene expression that were absent in weight-matched, WD-fed female controls, linking hepatic steatosis to Pif1 ablation rather than increased body weight. WD-fed PIF1 KO females also showed decreased expression of inflammation-associated genes in adipose tissue. Collectively, these data separated weight gain from inflammation and impaired glucose homeostasis. They also support a role for Pif1 in weight gain resistance and liver metabolic dysregulation during nutrient stress.

Comparative analysis of growth performance and liver transcriptome response of juvenile Ancherythroculter nigrocauda fed diets with different protein levels

This study aimed at investigating the effects of dietary protein levels on the growth and liver transcriptome in juvenile Ancherythroculter nigrocauda. Six semi-purified diets were formulated containing 25 (control), 30, 35, 40, 45, and 50% protein. Each diet was fed to three groups of 35 fish (mean initial weight: 5.86 ± 0.10 g) for 56 days. The rate of weight gain and specific growth rate increased with dietary protein levels from 25% to 40%, but remained unchanged when fed with 45 or 50% dietary protein. The feed conversion ratio was significantly influenced by the dietary protein levels, being the lowest in fish fed 40% protein. Illumina RNA-seq analysis was performed to investigate liver gene expression changes under different dietary protein treatments. A total of 367.78 million clean reads were obtained from the six libraries. Compared with 25% protein treatment library, there were 734, 1946, 1755, 2726, and 1523 upregulated genes, and 407, 1882, 1865, 2216 and 1624 downregulated genes in the 30, 35, 40, 45, and 50% protein treatment libraries, respectively. Trend analysis of these differentially expressed genes (DEGs) identified six statistically significant trends. A series of DEGs that related to protein metabolism, growth and development, lipid metabolism and immune and stress response were identified. Moreover, gene ontology enrichment analysis of the DEGs demonstrated that cellular process, single-organism process, metabolic process and biological regulation were the most highly overrepresented biological processes. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that protein processing in endoplasmic reticulum, PPAR signaling pathway, complement and coagulation cascades, and cytochrome P450 (CYP450s) were significantly enriched in the dietary protein treatment groups. Furthermore, qPCR results showed excellent agreement on those of RNA-seq for both up- and down-regulated genes (including fasn, accα, SCD, CPT-I, igf1, ST, AST, trdmt1, hsp70, cyp450, MHC-II, C4, tgfβ, ube4b, apoE and abcb7). Thus, our results provide the baseline information for the feed formulation and nutritional research for A. nigrocauda.

Significant changes in hepatic transcriptome and circulating miRNAs are associated with diet-induced metabolic syndrome in apoE3L.CETP mice.

Long-term exposure to excess dietary fat leads to obesity and the metabolic syndrome (MetS). The purpose of the present study was to identify global changes in liver gene expression and circulating miRNAs in a humanized mouse model of diet-induced MetS. Male apoE3L.CETP mice received a high-fat diet (HFD) or a low-fat diet (LFD) for different time periods and the progression of MetS pathology was monitored. A separate group of mice was divided into responders (R) or nonresponders (NR) and received HFD for 16 weeks. We found that mice receiving the HFD developed manifestations of MetS and displayed an increasing number of differentially expressed transcripts at 4, 8, and 12 weeks compared with mice receiving the LFD. Significantly changed genes were functionally annotated to metabolic diseases and pathway analysis revealed the downregulation of genes in cholesterol and fatty acid biosynthesis and upregulation of genes related to lipid droplet formation, which was in line with the development of hepatic steatosis. In the serum of the apoE3L.CETP mice we identified three miRNAs that were upregulated specifically in the HFD group. We found that responder mice have a distinct gene signature that differentiates them from nonresponders. Comparison of the two diet intervention studies revealed a limited number of common differentially expressed genes but the expression of these common genes was affected in a similar way in both studies. In conclusion, the characteristic hepatic gene signatures and serum miRNAs identified in the present study provide novel insights to MetS pathology and could be exploited for diagnostic or therapeutic purposes.

Suppressed hepatic bile acid signalling despite elevated production of primary and secondary bile acids in NAFLD

ObjectiveBile acids are regulators of lipid and glucose metabolism, and modulate inflammation in the liver and other tissues. Primary bile acids such as cholic acid and chenodeoxycholic acid (CDCA) are...