Biology subjects

Das, A. P.

Publications and source records attributed to Das, A. P..

2 recordsLinked to original sources

bioRxiv2024

HIF1α controls adipose tissue growth through metabolic rechanneling

Excessive expansion of white adipose tissue occurs when energy intake exceeds demand. It creates a state of relative hypoxia that is directly linked to activation of the hypoxia-inducible factor (HIF) in obese human subjects and mouse models of obesity. Whether HIF1 function is important for the development of basal adiposity and diet-induced obesity remains unclear. In the present study, we genetically ablated Hif1 in adipocytes and analyzed the corresponding mice for both basal and diet-induced obesity-associated visceral white adipose tissue mass as well as parameters of systemic glucose homeostasis and peripheral insulin sensitivity. We found that inactivation of Hif1 in mouse adipocytes inhibited basal adiposity and suppressed nutrient-overload-induced adipose tissue growth. These changes in adiposity were associated with improved systemic glucose homeostasis and peripheral insulin sensitivity. Mechanistically, Hif1 mediated effects on adipocyte metabolism by re-routing glycolytic intermediates into the glycerolipid shunt, leading to increased de novo triacylglyceride synthesis in hypertrophic adipocytes. Our results have established key roles for HIif1 in controlling adipocyte growth and metabolism and adipose tissue expansion under basal conditions and in response to a high-fat diet, highlighting the central role of hypoxia and HIF1 in the development of obesity. Article HighlightsO_LIHif1 function is critical for basal adipose tissue mass expansion, and is also required for fat accumulation in response to high fat diet. C_LIO_LICo-option and co-activation of the glycerolipid biosynthetic pathway by glycolysis is an important modulator of visceral adiposity. C_LIO_LIThese findings reveal an important role of Hif1 in the adipose tissue through the coupling of glycolysis and lipid anabolism in response to HFD, which may provide a potential therapeutic target for type 2 diabetes in the future. C_LI

cell biology↗

bioRxiv2023

CVD-associated SNPs with regulatory potential drive pathologic non-coding RNA expression

BackgroundCardiovascular diseases (CVDs) are the leading cause of death worldwide. Genome-wide association studies (GWAS) have identified many single nucleotide polymorphisms (SNPs) appearing in non-coding genomic regions in CVDs. The SNPs may alter gene expression by modifying transcription factor (TF) binding sites and lead to functional consequences in cardiovascular traits or diseases. To understand the underlying molecular mechanisms, it is crucial to identify which variations are involved and how they affect TF binding. MethodsThe SNEEP (SNP exploration and analysis using epigenomics data) pipeline was used to identify regulatory SNPs, which alter the binding behavior of TFs and link GWAS SNPs to their potential target genes for six CVDs. The human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs), monoculture cardiac organoids (MCOs) and self-organized cardiac organoids (SCOs) were used in the study. Gene expression, cardiomyocyte size and cardiac contractility were assessed. ResultsBy using our integrative computational pipeline, we identified 1905 regulatory SNPs in CVD GWAS data. These were associated with hundreds of genes, half of them non-coding RNAs (ncRNAs), suggesting novel CVD genes. We experimentally tested 40 CVD-associated non-coding RNAs, among them RP11-98F14.11, RPL23AP92, IGBP1P1, and CTD-2383I20.1, which were upregulated in hiPSC-CMs, MCOs and SCOs under hypoxic conditions. Further experiments showed that IGBP1P1 depletion rescued expression of hypertrophic marker genes, reduced hypoxia-induced cardiomyocyte size and improved hypoxia-reduced cardiac contractility in hiPSC-CMs and MCOs. ConclusionsIGBP1P1 is a novel ncRNA with key regulatory functions in modulating cardiomyocyte size and cardiac function in our disease models. Our data suggest ncRNA IGBP1P1 as a potential therapeutic target to improve cardiac function in CVDs.

genomics↗