@article{HocherHaumannRahnenfuehreretal.2016, author = {Hocher, Berthold and Haumann, Hannah and Rahnenf{\"u}hrer, Jan and Reichetzeder, Christoph and Kalk, Philipp and Pfab, Thiemo and Tsuprykov, Oleg and Winter, Stefan and Hofmann, Ute and Li, Jian and P{\"u}schel, Gerhard Paul and Lang, Florian and Schuppan, Detlef and Schwab, Matthias and Schaeffeler, Elke}, title = {Maternal eNOS deficiency determines a fatty liver phenotype of the offspring in a sex dependent manner}, series = {Epigenetics : the official journal of the DNA Methylation Society}, volume = {11}, journal = {Epigenetics : the official journal of the DNA Methylation Society}, publisher = {Routledge, Taylor \& Francis Group}, address = {Philadelphia}, issn = {1559-2294}, doi = {10.1080/15592294.2016.1184800}, pages = {539 -- 552}, year = {2016}, abstract = {Maternal environmental factors can impact on the phenotype of the offspring via the induction of epigenetic adaptive mechanisms. The advanced fetal programming hypothesis proposes that maternal genetic variants may influence the offspring's phenotype indirectly via epigenetic modification, despite the absence of a primary genetic defect. To test this hypothesis, heterozygous female eNOS knockout mice and wild type mice were bred with male wild type mice. We then assessed the impact of maternal eNOS deficiency on the liver phenotype of wild type offspring. Birth weight of male wild type offspring born to female heterozygous eNOS knockout mice was reduced compared to offspring of wild type mice. Moreover, the offspring displayed a sex specific liver phenotype, with an increased liver weight, due to steatosis. This was accompanied by sex specific differences in expression and DNA methylation of distinct genes. Liver global DNA methylation was significantly enhanced in both male and female offspring. Also, hepatic parameters of carbohydrate metabolism were reduced in male and female offspring. In addition, male mice displayed reductions in various amino acids in the liver. Maternal genetic alterations, such as partial deletion of the eNOS gene, can affect liver metabolism of wild type offspring without transmission of the intrinsic defect. This occurs in a sex specific way, with more detrimental effects in females. This finding demonstrates that a maternal genetic defect can epigenetically alter the phenotype of the offspring, without inheritance of the defect itself. Importantly, these acquired epigenetic phenotypic changes can persist into adulthood.}, language = {en} } @article{ManowskyCamargoKippetal.2016, author = {Manowsky, Julia and Camargo, Rodolfo Gonzalez and Kipp, Anna Patricia and Henkel, Janin and P{\"u}schel, Gerhard Paul}, title = {Insulin-induced cytokine production in macrophages causes insulin resistance in hepatocytes}, series = {American journal of physiology : Endocrinology and metabolism}, volume = {310}, journal = {American journal of physiology : Endocrinology and metabolism}, publisher = {American Chemical Society}, address = {Bethesda}, issn = {0193-1849}, doi = {10.1152/ajpendo.00427.2015}, pages = {E938 -- E946}, year = {2016}, abstract = {Overweight and obesity are associated with hyperinsulinemia, insulin resistance, and a low-grade inflammation. Although hyperinsulinemia is generally thought to result from an attempt of the beta-cell to compensate for insulin resistance, there is evidence that hyperinsulinaemia itself may contribute to the development of insulin resistance and possibly the low-grade inflammation. To test this hypothesis, U937 macrophages were exposed to insulin. In these cells, insulin induced expression of the proinflammatory cytokines IL-1 beta, IL-8, CCL2, and OSM. The insulin-elicited induction of IL-1 beta was independent of the presence of endotoxin and most likely mediated by an insulin-dependent activation of NF-kappa B. Supernatants of the insulin-treated U937 macrophages rendered primary cultures of rat hepatocytes insulin resistant; they attenuated the insulin-dependent induction of glucokinase by 50\%. The cytokines contained in the supernatants of insulin-treated U937 macrophages activated ERK1/2 and IKK beta, resulting in an inhibitory serine phosphorylation of the insulin receptor substrate. In addition, STAT3 was activated and SOCS3 induced, further contributing to the interruption of the insulin receptor signal chain in hepatocytes. These results indicate that hyperinsulinemia per se might contribute to the low-grade inflammation prevailing in overweight and obese patients and thereby promote the development of insulin resistance particularly in the liver, because the insulin concentration in the portal circulation is much higher than in all other tissues.}, language = {en} }