Modelling idiopathic intracranial hypertension in rats: contributions of high fat diet and testosterone to intracranial pressure and cerebrospinal fluid production
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ABSTRACT: Female Wistar rats were either fed nutrient source-matched control diet (control) or a high fat diet (HFD). HFD-fed rats presented with increased ICP, which was not accompanied by altered CSF dynamics or modified choroid plexus function. HFD-induced ICP elevation in experimental rats did not originate from an increased rate of CSF secretion.
Project description:Idiopathic intracranial hypertension (IIH) is a syndrome exhibiting elevated intracranial pressure (ICP), visual disturbances, and severe headache. IIH primarily affects young obese women, though it can occur in individuals of any age, BMI, and sex. IIH is characterized by systemic metabolic dysregulation with a profile of increased androgen hormones. However, the contributions of obesity/hormonal perturbations to cerebrospinal fluid (CSF) dynamics remains unresolved. We employed obese female Zucker rats and adjuvant testosterone to reveal IIH causal drivers. ICP and CSF dynamics were determined with in vivo experimentation and magnetic resonance imaging, testosterone levels assessed with mass spectrometry, and choroid plexus function revealed with transcriptomics. Obese rats had undisturbed CSF testosterone levels and no changes in ICP or CSF dynamics. Chronic adjuvant testosterone treatment of obese rats elevated the CSF secretion rate, although with no effect on the ICP, due to the elevated CSF drainage capacity of these rats. Obesity in itself therefore does not suffice to recapitulate the IIH symptoms, but modulation of CSF dynamics comes about with adjuvant testosterone treatment, mimicking the androgen excess observed in female IIH patients. Obesity-induced androgen dysregulation may thus play a crucial role in the disease mechanism of IIH.
Project description:Modelling idiopathic intracranial hypertension in rats: contributions of high fat diet and testosterone to intracranial pressure and cerebrospinal fluid production
Project description:The impact of intra-uterine growth retardation (IUGR) was analyzed on gene expression of the colonic epithelial cells from adults rats fed a standard or a high-fat diet. The hypothesis tested in this study was that IUGR induces sustainable effects on colonocyte transcriptome that may alter further nutritional adaptations at adulthood, especially to high-fat diet. Total RNA extracted from control (C) and IUGR (R) rats fed chow (Normal Diet, ND) or high-fat diet (HFD).
Project description:Whole genome expression profilling were undertaken in high fat diet (HFD)-fed obese rats to identify the genetic factors associated with metabolic dysfunction, insulin resistance and obesity.
Project description:The purpose of this study was to investigate whether paternal high-fat diet (HFD) transgenerationally remodeled the hepatic transcriptome of F2 female rats Liver mRNA expression profiling of F2-female from F0-founders fed either a chow or a chronic HFD challenged. Adult females were challenge or not a high-fat diet for 12 weeks. Liver was dissected at an endpoint experiment. Rats were subjected to 4 hours fasting prior to anesthesia with pentobarbital and tissue collection.
Project description:PURPOSE: To examine if a parental high fat diet (HFD) influences metabolic health in two generations of offspring, and alters the germ cell (GC) transcriptome. PROCEDURE: GC-eGFP Sprague Dawley rats were weaned onto HFD (45% fat) or Control Diet (CD; 10% fat). After metabolic testing, founders (F0) were bred with controls, establishing the F1 generation. Germ cells from F0 males were isolated and their RNA sequenced. F1 rats were bred with control rats at 17 weeks to generate F2 offspring. FINDINGS: HFD resulted in 9.7% and 14.7% increased weight in male and female F0 respectively. F1 offspring of HFD mothers were heavier than controls. F1 daughters of HFD-fed males were also heavier. F2 male offspring derived from HFD-fed maternal grandfathers were 7.2% heavier, and exhibited increases of 31% in adiposity, 97% in plasma leptin and 300% in luteinising hormone to testosterone ratio. HFD exposure did not alter the F0 GC transcriptome. CONTROLS: Matched CD was consumed by all animals not consuming the HFD. Animals were compared to a parallel cohort of CD rats. CONCLUSIONS: HFD consumption by maternal grandfathers results in a disrupted metabolic phenotype in grandsons. This effect is not mediated by alterations to the GC transcriptome.
Project description:Whole genome expression profilling were undertaken in high fat diet (HFD)-fed obese rats to identify the genetic factors associated with metabolic dysfunction, insulin resistance and obesity. Sprague dawley male rats were maintained on HFD for 12 weeks ad libitum regimen. Liver being the principal organ for glucose homeostasis is targeted for microarray profilling. We could identify genes/factors associated with obesity induced metabolic dysfunction. Custom Rat Whole Genome 8x60k Gene Expression Microarray (AMADID:030192 ) designed by Genotypic Technology Private Limited.
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.
Project description:The purpose of this study was to investigate whether grandpaternal high-fat diet (HFD) transgenerationally remodels the transcriptome of skeletal muscle EDL muscle mRNA expression profiling of F2-female offspring from F0-founders fed either a chow or a chronic HFD challenged. Adult females were challenge or not a high-fat diet for 12 weeks. EDL muscle was dissected at an endpoint experiment. Rats were subjected to 4 hours fasting prior to anesthesia with pentobarbital and tissue collection.
Project description:Background:The objective of this study was to investigate obesity-related glomerulopathy (ORG) at a cellular, structural and transcriptomic level. Methods:Thirty Wistar rats were randomized into two groups: control rats(n=15), which were fed a standard diet(SD) and study rats(n=15), which were fed a high-fat diet (HFD). After 10 weeks, weight, parameters of kidney function, renal histological features, transcriptomic changes, miRNA and mRNA isolation were compared. Results:HFD gained more weight(55.8%) than SD(29.2%), p<0.001. Albuminuria was also significantly higher in HFD(10,384.04 ng/ml) compared with SD(5,845.45 ng/ml), p<0.001. HFD showed typical lesions of early stages of ORG, with a predominance of mesangial matrix increase (MMI) and podocyte hypertrophy (PH). All histologic lesions correlated with genes differentially expressed (DE) in kidneys of HFD group and PH, also correlated with specific miRNAs DE in the urine of HFD. The functional analysis showed 4 miRNAs DE in the kidneys of HFD group that negatively regulates PTEN gene, which promotes podocyte endocytosis of lipids in ORG. The electronic microscope confirmed the spaces of lipid vacuoles in the podocytes of HFD. Between those 4 miRNAs DE, miR-205 was also found to be upregulated in the urine of HFD group. Conclusions: Wistar rats fed a HFD developed early-stages of ORG, with a specific targetome of miRNAs and gene expression. The upregulation of miR-205 in kidney and its isolation in urine is associated with lipid endocytosis of podocytes, which could become a plausible biomarker of early-stages of ORG and open new avenues for future therapeutics research. Translational Statement: The findings of the basic research in this study can be replicated in human models of obesity. The results of the study on miRNA in humans may contribute to improving the understanding of the pathophysiology of obesity-related glomerulopathy, aiding in the search for early biomarkers, and exploring new therapeutic targets. Keywords: MicroRNA, Biomarker, targetome, obesity-related glomerulopathy, mesangial matrix increase, podocyte hypertrophy, Wistar rats