Aberrant expression and DNA methylation of lipid metabolism genes in PCOS: a new insight into its pathogenesis

Abstract In a previous study we reported that prediabetic rats have a unique gene signature that was apparent even in neonates. Several of the changes we observed, including enhanced expression of pro-inflammatory genes and dysregulated UPR and metabolism genes were first observed in the liver followed by the pancreas. In the present study we investigated further early changes in hepatic innate immunity and metabolism in two models of type 1 diabetes (T1D), the BBdp rat and NOD mouse. There was a striking increase in lipid deposits in liver, particularly in neonatal BBdp rats, with a less striking but significant increase in neonatal NOD mice in association with dysregulated expression of lipid metabolism genes. This was associated with a decreased number of extramedullary hematopoietic clusters as well as CD68+ macrophages in the liver of both models. In addition, PPARɣ and phosphorylated AMPKα protein were decreased in neonatal BBdp rats. BBdp rats displayed decreased expression of antimicrobial genes in neonates and decreased M2 genes at 30 days. This suggests hepatic steatosis could be a common early feature in development of T1D that impacts metabolic homeostasis and tolerogenic phenotype in the prediabetic liver.

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Neuroblastoma and the epigenome

Cancer and Metastasis Reviews ◽

10.1007/s10555-020-09946-y ◽

2021 ◽

Author(s):

Irfete S. Fetahu ◽

Sabine Taschner-Mandl

Keyword(s):

Dna Methylation ◽

Histone Modifications ◽

Disease Diagnosis ◽

Dna Methyltransferases ◽

Epigenetic Alterations ◽

Aberrant Expression ◽

Tet Proteins ◽

Relative Paucity ◽

Underlying Causes ◽

Aberrant Dna Methylation

AbstractNeuroblastoma (NB) is a pediatric cancer of the sympathetic nervous system and one of the most common solid tumors in infancy. Amplification of MYCN, copy number alterations, numerical and segmental chromosomal aberrations, mutations, and rearrangements on a handful of genes, such as ALK, ATRX, TP53, RAS/MAPK pathway genes, and TERT, are attributed as underlying causes that give rise to NB. However, the heterogeneous nature of the disease—along with the relative paucity of recurrent somatic mutations—reinforces the need to understand the interplay of genetic factors and epigenetic alterations in the context of NB. Epigenetic mechanisms tightly control gene expression, embryogenesis, imprinting, chromosomal stability, and tumorigenesis, thereby playing a pivotal role in physio- and pathological settings. The main epigenetic alterations include aberrant DNA methylation, disrupted patterns of posttranslational histone modifications, alterations in chromatin composition and/or architecture, and aberrant expression of non-coding RNAs. DNA methylation and demethylation are mediated by DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) proteins, respectively, while histone modifications are coordinated by histone acetyltransferases and deacetylases (HATs, HDACs), and histone methyltransferases and demethylases (HMTs, HDMs). This article focuses predominately on the crosstalk between the epigenome and NB, and the implications it has on disease diagnosis and treatment.

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DNA methylation and lipid metabolism: an EWAS of 226 metabolic measures

Clinical Epigenetics ◽

10.1186/s13148-020-00957-8 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Monica del C. Gomez-Alonso ◽

Anja Kretschmer ◽

Rory Wilson ◽

Liliane Pfeiffer ◽

Ville Karhunen ◽

...

Keyword(s):

Dna Methylation ◽

Lipid Metabolism ◽

Population Based ◽

Total Serum ◽

Resonance Spectroscopy ◽

Metabolic Disturbances ◽

Cpg Sites ◽

Gene Transcripts

Abstract Background The discovery of robust and trans-ethnically replicated DNA methylation markers of metabolic phenotypes, has hinted at a potential role of epigenetic mechanisms in lipid metabolism. However, DNA methylation and the lipid compositions and lipid concentrations of lipoprotein sizes have been scarcely studied. Here, we present an epigenome-wide association study (EWAS) (N = 5414 total) of mostly lipid-related metabolic measures, including a fine profiling of lipoproteins. As lipoproteins are the main players in the different stages of lipid metabolism, examination of epigenetic markers of detailed lipoprotein features might improve the diagnosis, prognosis, and treatment of metabolic disturbances. Results We conducted an EWAS of leukocyte DNA methylation and 226 metabolic measurements determined by nuclear magnetic resonance spectroscopy in the population-based KORA F4 study (N = 1662) and replicated the results in the LOLIPOP, NFBC1966, and YFS cohorts (N = 3752). Follow-up analyses in the discovery cohort included investigations into gene transcripts, metabolic-measure ratios for pathway analysis, and disease endpoints. We identified 161 associations (p value < 4.7 × 10−10), covering 16 CpG sites at 11 loci and 57 metabolic measures. Identified metabolic measures were primarily medium and small lipoproteins, and fatty acids. For apolipoprotein B-containing lipoproteins, the associations mainly involved triglyceride composition and concentrations of cholesterol esters, triglycerides, free cholesterol, and phospholipids. All associations for HDL lipoproteins involved triglyceride measures only. Associated metabolic measure ratios, proxies of enzymatic activity, highlight amino acid, glucose, and lipid pathways as being potentially epigenetically implicated. Five CpG sites in four genes were associated with differential expression of transcripts in blood or adipose tissue. CpG sites in ABCG1 and PHGDH showed associations with metabolic measures, gene transcription, and metabolic measure ratios and were additionally linked to obesity or previous myocardial infarction, extending previously reported observations. Conclusion Our study provides evidence of a link between DNA methylation and the lipid compositions and lipid concentrations of different lipoprotein size subclasses, thus offering in-depth insights into well-known associations of DNA methylation with total serum lipids. The results support detailed profiling of lipid metabolism to improve the molecular understanding of dyslipidemia and related disease mechanisms.

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Colorectal Cancer that Highly Express Both ACE2 and TMPRSS2, Suggesting Severe Symptoms to SARS-CoV-2 Infection

Pathology & Oncology Research ◽

10.3389/pore.2021.612969 ◽

2021 ◽

Vol 27 ◽

Author(s):

Huai Wang ◽

Jiankang Yang

Keyword(s):

Colorectal Cancer ◽

Dna Methylation ◽

Viral Entry ◽

Colon Adenocarcinoma ◽

The Novel ◽

Aberrant Expression ◽

Systematic Analysis ◽

More Care ◽

Novel Coronavirus ◽

Colorectal Cancer Patients

The epidemic of the novel, pathogenic SARS-coronavirus 2 (SARS-CoV-2) in the world pose a global health emergency. Cancer has been identified as a risk factor for the novel Coronavirus disease 2019 (COVID-19). The ACE2 and TMPRSS2 have been implicated in SARS-CoV-2 infection for mediating viral entry into the host cell. However, a systematic analysis of aberrant expression of ACE2 and TMPRSS2 was not yet reported in multiple human cancers. Here, we analyzed gene expression of ACE2 and TMPRSS2 across 31 types of tumors. Notably, overexpression of ACE2 and TMPRSS2 have been observed in colorectal cancer including colon adenocarcinoma (COAD), and rectum adenocarcinoma (READ). In addition, the colorectal tumors with upregulated gene expressing presented with decreased DNA methylation levels. DNA methylation might be one of the reasons for abnormal expression of ACE2 and TMPRSS2. Conclusively, colorectal cancer was the only cancer with the upregulated expression of ACE2 and TMPRSS2. More care of colorectal cancer patients is needed in multiple cancers affected by the COVID-19 outbreak.

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Effects of an alpha‐linolenic acid enriched diet on mRNA expression of lipid metabolism genes in bovine milk somatic cells

The FASEB Journal ◽

10.1096/fasebj.23.1_supplement.546.10 ◽

2009 ◽

Vol 23 (S1) ◽

Author(s):

Katherine M Hunt ◽

Kevin G Carnahan ◽

Brent P Hatch ◽

Kelleen O Parnell ◽

Janet E Williams ◽

...

Keyword(s):

Lipid Metabolism ◽

Mrna Expression ◽

Linolenic Acid ◽

Somatic Cells ◽

Bovine Milk ◽

Alpha Linolenic Acid ◽

Milk Somatic Cells ◽

Lipid Metabolism Genes

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Glial Hedgehog and lipid metabolism regulate neural stem cell proliferation in Drosophila

10.1101/2020.05.18.100990 ◽

2020 ◽

Author(s):

Qian Dong ◽

Michael Zavortink ◽

Francesca Froldi ◽

Sofya Golenkina ◽

Tammy Lam ◽

...

Keyword(s):

Lipid Metabolism ◽

Cell Cycle Progression ◽

De Novo ◽

De Novo Lipogenesis ◽

Post Translational Modification ◽

Final Size ◽

Neural Lineage ◽

Signalling Molecule ◽

Lipid Metabolism Genes ◽

And Function

AbstractThe final size and function of the adult central nervous system (CNS) is determined by neuronal lineages generated by neural stem cells (NSCs) in the developing brain. In Drosophila, NSCs called neuroblasts (NBs) reside within a specialised microenvironment called the glial niche. Here, we explore non-autonomous glial regulation of NB proliferation. We show that lipid droplets (LDs) which reside within the glial niche are closely associated with the signalling molecule Hedgehog (Hh). Under physiological conditions, cortex glial Hh is autonomously required to sustain niche chamber formation, and non-autonomously restrained to prevent ectopic Hh signalling in the NBs. In the context of cortex glial overgrowth, induced by Fibroblast Growth Factor (FGF) activation, Hh and lipid storage regulators Lsd-2 and Fasn1 were upregulated, resulting in activation of Hh signalling in the NBs; which in turn disrupted NB cell cycle progression and reduced neuronal production. We show that the LD regulator Lsd-2 modulates Hh’s ability to signal to NBs, and de novo lipogenesis gene Fasn1 regulates Hh post-translational modification via palmitoylation. Together, our data suggest that the glial niche non-autonomously regulates NB proliferation and neural lineage size via Hh signaling that is modulated by lipid metabolism genes.

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