Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Isocaloric intake of diets differing in macronutrient content (high protein or high fat) in adult rats indicate adverse effects as analysed by hepatic transcriptomics

ABSTRACT: Intake of high-protein (HP) diets has increased over the last years, mainly due to their popularity for body weight control. Liver is the main organ handling ingested macronutrients and it is associated with the beginning of different pathologies. We aimed to deepen our knowledge on molecular pathways affected by long-term intake of an HP diet. We performed a transcriptome analysis on liver of rats chronically fed with a casein-rich HP diet and analyzed molecular parameters related to liver injury. Chronic increase in the dietary protein/carbohydrate ratio up-regulated processes related with amino acid uptake/metabolism and lipid synthesis, promoting a molecular environment indicative of hepatic triacylglycerol (TG) deposition. Moreover, changes in expression of genes involved in acidâbase maintenance and oxidative stress indicate alterations in the pH balance due to the high acid load of the diet, which has been linked to liver/health damage. Up-regulation of immune-related genes was also observed. In concordance with changes at gene expression level, we observed increased liver TG content and increased serum markers of hepatic injury/inflammation (aspartate transaminase, C-reactive protein and TNF-alpha). Moreover, the HP diet strongly increased hepatic mRNA and protein levels of HSP90, a marker of liver injury. Thus, we show for the first time that long-term consumption of an HP diet, resulting in a high acid load, results in a hepatic transcriptome signature reflecting increased TG deposition and increased signs of health risk (increased inflammation, alterations in the acidâbase equilibrium and oxidative stress). Persistence of this altered metabolic status could have unhealthy consequences. Wistar wildtype male rats, aged 8 weeks, received a low fat diet, high protein or high fat diet for 4 months. After sacrification, livers were dissected, and immediately snap frozen in liquid nitrogen. Total RNA was isolated, quantified and qualified, and subsequently used for global gene expression profiling using Agilent 4x44K microarrays.

ORGANISM(S): Rattus norvegicus

SUBMITTER: Evert van Schothorst

PROVIDER: E-GEOD-57858 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Long-term intake of a high-protein diet increases liver triacylglycerol deposition pathways and hepatic signs of injury in rats.

Díaz-Rúa Rubén R Keijer Jaap J Palou Andreu A van Schothorst Evert M EM Oliver Paula P

The Journal of nutritional biochemistry 20170419

Intake of high-protein (HP) diets has increased over the last years, mainly due to their popularity for body weight control. Liver is the main organ handling ingested macronutrients and it is associated with the beginning of different pathologies. We aimed to deepen our knowledge on molecular pathways affected by long-term intake of an HP diet. We performed a transcriptome analysis on liver of rats chronically fed with a casein-rich HP diet and analyzed molecular parameters related to liver inju ...[more]

PMID: 28454041

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Project description:Gene expression studies in peripheral blood mononuclear cells (PBMC) can provide knowledge that would be difficult to obtain using other types of biological samples, as these cells can reflect overall response of the body to a specific stimulus, such as diet. Here, we aimed to study the impact of sustained intake of isocaloric diets with an unbalanced macronutrient proportion (rich in fat or protein) on PBMC gene expression in rats using transcriptomics, to better understand the effects of these diets on metabolism and health. Macronutrient diet composition (especially increased protein content) affected PBMC gene expression. An important effect was observed in immune response-related genes. High protein (HP) diet produced an activation of genes mainly related to antigen recognition/presentation, whereas the high fat (HF) diet was more related to a decreased expression of these genes. Key energy homeostasis genes (mainly involved in lipid metabolism) were also affected, reflecting a nutritional adaptive response to the diets. Decreased Dhrs3 and increased Pref-1/Dlk1 expression observed in HP-fed animals reflects a lower lipogenic capacity. In addition, HF diet affected the expression of genes related to insulin resistance/signaling (Msra/Slc9a6, Asb6), hypoxia (Akap12), cardiovascular problems (Ethe1, Lr11), cognitive impairment (Tmcc2) and tumorigenesis (Ddx17, Phb, Rnasen/Drosha, and Tsc2). HP diet also impaired the expression of genes related to glucose metabolism and insulinemia (Glut-4/Slc2a4, Sfxn5, Slc16a1), but positively affected genes involved in liver function (Clec4f and St6galnac3) and cardiovascular protection (Sort1). In conclusion, gene expression analysis in PBMC can provide information that could be useful to detect metabolic deviations and health consequences of diets with an unbalanced macronutrient composition. 2 months-old male Wistar rats received a low fat control diet, or a high fat (HF) diet, or a high protein (HP) diet for 4 months, respectively. At the end of the intervention, prior to the sacrifice of the animals, peripheral blood samples (1.5-2.5 mL) were collected from the safena vein, using heparin in NaCl (0.9%) as anticoagulant. Immediately after blood collection, peripheral blood mononuclear cells (PBMC) were isolated by Ficoll gradient separation. Total RNA was isolated from PBMC, quantified and qualified, and subsequently used for global gene expression profiling using Agilent 4x44K microarrays.

Project description:Background and Aims: Inflammasome-mediated caspase-1 activity regulates the maturation and release of the pro-inflammatory cytokines interleukin (IL)-1M-CM-^_ and IL-18. Recently, we showed that caspase-1 deficiency strongly reduces high fat diet-induced adiposity although the mechanism is still unclear. We now aimed to elucidate the mechanism by which caspase-1 deficiency reduces modulates resistance to high fat diet-feeding fat accumulation in adipose tissue by focusing on the role of caspase-1 in the regulation of triglyceride (TG)-rich lipoprotein metabolism. Methods: Caspase-1 deficient and wild-type mice (both C57Bl/6 background) were used to determine postprandial TG kinetics, intestinal TG absorption, VLDL-TG production as well as TG clearance, all of which strongly contribute to the supply of TG for storage in adipose tissue. Micro-array and qPCR analysis were used to unravel intestinal and hepatic metabolic pathways involved. Results: Caspase-1 deficiency reduced the postprandial response to an oral lipid load, while tissue specific clearance of TG-rich lipoproteins was not changed. Indeed, an oral olive oil gavage containing [3H]TG revealed that caspase-1 deficiency significantly decreased intestinal chylomicron-TG production and reduced the uptake of [3H]TG-derived FA by liver, muscle, and adipose tissue. Similarly, caspase-1 deficiency reduced the hepatic VLDL-TG production without reducing VLDL-apoB production, despite an elevated hepatic TG content. Pathway analysis revealed that caspase-1 deficiency reduces intestinal and hepatic expression of genes involved in lipogenesis. Conclusions: Absence of caspase-1 reduces assembly and secretion of TG-rich lipoproteins, thereby reducing the availability of TG-derived FA for uptake by peripheral organs including adipose tissue. We anticipate that caspase-1 represents a novel link between innate immunity and lipid metabolism. Keywords: Expression profiling by array Wild-type (WT) and Casp1-null mice were maintained at lab chow. Animals, aged between 14 and 16 weeks (n=3 per genotype), were killed and liver and intestinal segments were removed. Livers were isolated from mice that were fasted over night, whereas intesines were removed from mice 2 hrs after they received an oral lipid load.Total RNA was isolated and subjected to gene expression profiling.

Project description:Transcriptional profiling of rat liver comparing male rats with congenital hypothyrodism (CH) vs intact at adulhood. Here we studied how CH influences liver gene expression program in adulthood. Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology but its specific influence in liver is less understood. Here we studied how CH influences liver gene expression program in adulthood. Pregnant rats were given anti-thyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as a reduction in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, feed efficiency increased in CH and this was accompanied by significant catch-up growth. On PND80, significant reduction in body mass, tail length, and circulating IGF-I remained in CH rats. On the other hand, mRNA levels of known GH targeted genes were significantly up-regulated. Serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in expression for hepatic genes involved in lipid metabolism with an increased transcription of PPAR and reduced expression of genes involved in fatty acids and cholesterol uptake, cellular sterol efflux, triglycerides assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to hypothyroidism onset in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters, and to T3 replacement with enhanced activation of lipogenic transcriptional program. In summary, we provided in vivo evidence that neonatal hypothyroidism causes long-lasting effects on hepatic transcriptional program and tissue sensitivity to hormone treatment. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood. Two conditions CH vs INTACT male rats. Biological replicates: Four independent hybridizations: 4 controls (age-matched intact rats) vs 4 CH (male rats with congenital hypothyroidism) on postnatal day 80 for a total of four arrays. One replicate per array.

Project description:Chronic stress leads post-traumatic stress disorder (PTSD) and to metabolic complications, including fatty liver. It is feasible, that stress immediately initiates molecular mechanisms to alter energy metabolism and glucose homeostasis which interfere with hepatic lipid accumulation after stress recovery. We aim to elucidate these molecular mechanisms of long term stress effects on metabolism and focus on physiological adaptation and the role of FGF21, which is protective in hepatic lipid accumulation. Methods FGF21 knockout and control mice were exposed to chronic variable stress (Cvs) and recovered for 3 months to simulate PTSD. We determined in vivo and ex vivo energy metabolism, mitochondrial function by extracellular flux analysis, alterations in DNA modifying enzymes and gene regulation immediately after stress and after the recovery period to determine long term alterations. Results Chronic stress leads to reduced insulin sensitivity and hepatic lipid accumulation with increased fatty acid uptake (FAU), stress-induced lipolysis, and reduction in NAD+/NAD ratio and Sirt activity. Immediately after stress, PPARa and SREBP-1 target genes are differentially regulated and are involved in the development of stress-induced fatty liver. After recovery, insulin sensitivity increases but insulin-induced de novo lipogenesis (DNL) is reduced and FAU is increased. HDAC and MT activity are suppressed, whereas HAT activity increases, linking metabolic adjustments to transcriptional regulators. Thus, key metabolic genes are differentially regulated and secreted proteins indicate the activation of liver disease by Cvs only in FGF21WT. GR binding to the Cd36 promoter is altered. After stress recovery, serum FGF21 is increased and protects against lipid accumulation. FGF21 interacts by attenuating DNL, increasing FAU and HAT activity, and balancing mitochondrial activity. Higher long-term stress-induced activation and binding of GR to the FGF21 promoter may contribute to the prolonged FGF21 release. Conclusions We show that previous stress exposure determines predisposition to fatty liver disease is regulated by FGF21. Immediately after Cvs, altered gene regulation and activity of DNA-modifying enzymes determine the metabolic late effects seen in PTSD. FGF21 functions after chronic stress exposure i) to protect against hepatic lipid accumulation, ii) to maintain mitochondrial capacity, and iii) to mediate in the modulation of DNA-modifying enzymes. These findings highlight the protective role of FGF21 even in stress-induced hepatic lipid accumulation.

Project description:A high phosphorus (HP) diet causes disorders of renal function, bone metabolism, and vascular function. We previously demonstrated that DNA microarray analysis is an appropriate method to comprehensively evaluate the effects of a HP diet on kidney dysfunction such as calcification, fibrillization, and inflammation. We reported that type IIb sodium-dependent phosphate transporter is significantly up-regulated in this context. In the present study, we performed DNA microarray analysis to investigate the effects of a HP diet on the liver, which plays a pivotal role in energy metabolism. DNA microarray analysis was performed with total RNA isolated from the livers of rats fed a control diet (containing 0.3% phosphorus) or a HP diet (containing 1.2% phosphorus). Gene Ontology analysis of differentially expressed genes (DEGs) revealed that the HP diet induced down-regulation of genes involved in hepatic amino acid catabolism and lipogenesis, while genes related to fatty acid β-oxidation process were up-regulated. Although genes related to fatty acid biosynthesis were down-regulated in HP diet-fed rats, genes important for the elongation and desaturation reactions of omega-3 and -6 fatty acids were up-regulated. Concentrations of hepatic arachidonic acid and eicosapentaenoic acid were increased in HP diet-fed rats. These essential fatty acids activate peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor for fatty acid β-oxidation. Evaluation of the upstream regulators of DEGs using Ingenuity Pathway Analysis indicated that PPARα was activated in the livers of HP diet-fed rats. Furthermore, the serum concentration of fibroblast growth factor 21, a hormone secreted from the liver that promotes fatty acid utilization in adipose tissue as a PPARα target gene, was higher (p = 0.054) in HP diet-fed rats than in control diet-fed rats. These data suggest that a HP diet enhances energy expenditure through the utilization of free fatty acids released via lipolysis of white adipose tissue.

Dataset Information

Isocaloric intake of diets differing in macronutrient content (high protein or high fat) in adult rats indicate adverse effects as analysed by hepatic transcriptomics

Publications

Long-term intake of a high-protein diet increases liver triacylglycerol deposition pathways and hepatic signs of injury in rats.

Similar Datasets

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