Cover Story Current Issue

Chronic intake of high-energy diets alters the physiological response to food and favors overconsumption. Feeding, especially of palatable food, leads to dopamine (DA) release in the Nucleus Accumbens (NAc, in the ventral striatum), prefrontal cortex (PFC) and dorsal striatum. The mesocortical (ventral tegmental area (VTA) projecting to NAc) DA system has been implicated in motivational drive and food seeking while the nigrostriatal DA (projections from the substantia nigra (SN) to the dorsal striatum) pathway plays a role in both food anticipatory behavior and reinforcement. In humans, hypersensitivity to food-associated reward may predispose to weight gain, however as obesity progresses deficit in reward signaling emerges. Individuals with obesity have reduced DRD2 availability in prefrontal brain regions compared to lean counterparts. 

Jiyoung S. Kim, Kevin C. Williams, Rebecca A. Kirkland, Ruth Schade, ... Claire B. de La Serre

Full text

 

Current Issue

Differences in DNA methylation of HAMP in blood cells predicts the development of type 2 diabetes

Meriem Ouni, Fabian Eichelmann, Markus Jähnert, Christin Krause, ... Annette Schürmann

Differences in DNA methylation of HAMP in blood cells predicts the development of type 2 diabetes

Objectives

Better disease management can be achieved with earlier detection through robust, sensitive, and easily accessible biomarkers. The aim of the current study was to identify novel epigenetic biomarkers determining the risk of type 2 diabetes (T2D).

Methods

Livers of 10-week-old female New Zealand Obese (NZO) mice, slightly differing in their degree of hyperglycemia and liver fat content and thereby in their diabetes susceptibility were used for expression and methylation profiling. We screened for differences in hepatic expression and DNA methylation in diabetes-prone and -resistant mice, and verified a candidate (HAMP) in human livers and blood cells. Hamp expression was manipulated in primary hepatocytes and insulin-stimulated pAKT was detected. Luciferase reporter assays were conducted in a murine liver cell line to test the impact of DNA methylation on promoter activity.

Results

In livers of NZO mice, the overlap of methylome and transcriptome analyses revealed a potential transcriptional dysregulation of 12 hepatokines. The strongest effect with a 52% decreased expression in livers of diabetes-prone mice was detected for the Hamp gene, mediated by elevated DNA methylation of two CpG sites located in the promoter. Hamp encodes the iron-regulatory hormone hepcidin, which had a lower abundance in the livers of mice prone to developing diabetes. Suppression of Hamp reduces the levels of pAKT in insulin-treated hepatocytes. In liver biopsies of obese insulin-resistant women, HAMP expression was significantly downregulated along with increased DNA methylation of a homologous CpG site. In blood cells of incident T2D cases from the prospective EPIC-Potsdam cohort, higher DNA methylation of two CpG sites was related to increased risk of incident diabetes.

Conclusions

We identified epigenetic changes in the HAMP gene which may be used as an early marker preceding T2D.

Articles in Press

Differences in DNA methylation of HAMP in blood cells predicts the development of type 2 diabetes

Meriem Ouni, Fabian Eichelmann, Markus Jähnert, Christin Krause, ... Annette Schürmann

Differences in DNA methylation of HAMP in blood cells predicts the development of type 2 diabetes

Objectives

Better disease management can be achieved with earlier detection through robust, sensitive, and easily accessible biomarkers. The aim of the current study was to identify novel epigenetic biomarkers determining the risk of type 2 diabetes (T2D).

Methods

Livers of 10-week-old female New Zealand Obese (NZO) mice, slightly differing in their degree of hyperglycemia and liver fat content and thereby in their diabetes susceptibility were used for expression and methylation profiling. We screened for differences in hepatic expression and DNA methylation in diabetes-prone and -resistant mice, and verified a candidate (HAMP) in human livers and blood cells. Hamp expression was manipulated in primary hepatocytes and insulin-stimulated pAKT was detected. Luciferase reporter assays were conducted in a murine liver cell line to test the impact of DNA methylation on promoter activity.

Results

In livers of NZO mice, the overlap of methylome and transcriptome analyses revealed a potential transcriptional dysregulation of 12 hepatokines. The strongest effect with a 52% decreased expression in livers of diabetes-prone mice was detected for the Hamp gene, mediated by elevated DNA methylation of two CpG sites located in the promoter. Hamp encodes the iron-regulatory hormone hepcidin, which had a lower abundance in the livers of mice prone to developing diabetes. Suppression of Hamp reduces the levels of pAKT in insulin-treated hepatocytes. In liver biopsies of obese insulin-resistant women, HAMP expression was significantly downregulated along with increased DNA methylation of a homologous CpG site. In blood cells of incident T2D cases from the prospective EPIC-Potsdam cohort, higher DNA methylation of two CpG sites was related to increased risk of incident diabetes.

Conclusions

We identified epigenetic changes in the HAMP gene which may be used as an early marker preceding T2D.

2021 impact factor: 8.568

You are what you eat

Here is a video of Vimeo. When the iframes is activated, a connection to Vimeo is established and, if necessary, cookies from Vimeo are also used. For further information on cookies policy click here.

Auf Werbeinhalte, die vor, während oder nach Videos von WEBSITE-URL eingeblendet werden, hat WEBSITE-URL keinen Einfluss. Wir übernehmen keine Gewähr für diese Inhalte. Weitere Informationen finden Sie hier.