During this reporting period the Laboratory of Genetics and Physiology has made progress in the understanding of mechanisms used by cytokines to control the physiology of liver and the hypothalamus.? ? Liver? Previously we had established that cytokine signaling (possibly growth hormone) through the transcription factor STAT5 is essential to protect the liver from hepatosteatosis (fatty liver) and its ability to regenerate. We have now performed and published additional studies on underlying molecular mechanisms. In particular, we have identified signaling cascades downstream of STAT5 that control the growth hormone - mediated physiology of hepatocytes.? ? Energy balance and metabolism? It had been known that cytokines can control energy balance by targeting certain cell populations in the CNS. For example, it is well established that leptin controls the energy balance through the transcription factor STAT3. It had also been known that another cytokine, GM-CSF, can control feeding behavior but its molecular underpinnings were elusive. GM-CSF, like many other cytokines, can activate STAT5 and we addressed the relevance of this observation. LGP scientists deleted the STAT5 genes from the mouse CNS and observed that these mice displayed an altered energy balance and developed obesity. Molecular and physiological studies in neurons of these mice linked GM-CSF signaling through STAT5 to food intake, thermoregulation and maintenance of body weight. These studies contribute to the general understanding on how cytokines control neurons and thus our apetite.

Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2008
Total Cost
$648,816
Indirect Cost
City
State
Country
United States
Zip Code
Tan, Dunyong; Chen, KuanHui E; Deng, Changhui et al. (2014) An N-terminal splice variant of human Stat5a that interacts with different transcription factors is the dominant form expressed in invasive ductal carcinoma. Cancer Lett 346:148-57
Hosui, Atsushi; Klover, Peter; Tatsumi, Tomohide et al. (2012) Suppression of signal transducers and activators of transcription 1 in hepatocellular carcinoma is associated with tumor progression. Int J Cancer 131:2774-84
Kim, Yong Deuk; Kim, Yong-Hoon; Tadi, Surendar et al. (2012) Metformin inhibits growth hormone-mediated hepatic PDK4 gene expression through induction of orphan nuclear receptor small heterodimer partner. Diabetes 61:2484-94
Huang, Kuang-tzu; Walker, Ameae M (2010) Long term increased expression of the short form 1b prolactin receptor in PC-3 human prostate cancer cells decreases cell growth and migration, and causes multiple changes in gene expression consistent with reduced invasive capacity. Prostate 70:37-47
Hosui, Atsushi; Kimura, Akiko; Yamaji, Daisuke et al. (2009) Loss of STAT5 causes liver fibrosis and cancer development through increased TGF-{beta} and STAT3 activation. J Exp Med 206:819-31
Klover, Peter; Chen, Weiping; Zhu, Bing-Mei et al. (2009) Skeletal muscle growth and fiber composition in mice are regulated through the transcription factors STAT5a/b: linking growth hormone to the androgen receptor. FASEB J 23:3140-8
Hosui, Atsushi; Hennighausen, Lothar (2008) Genomic dissection of the cytokine-controlled STAT5 signaling network in liver. Physiol Genomics 34:135-43
Lee, Ji-Yeon; Muenzberg, Heike; Gavrilova, Oksana et al. (2008) Loss of cytokine-STAT5 signaling in the CNS and pituitary gland alters energy balance and leads to obesity. PLoS ONE 3:e1639
Engblom, David; Kornfeld, Jan-Wilhelm; Schwake, Lukas et al. (2007) Direct glucocorticoid receptor-Stat5 interaction in hepatocytes controls body size and maturation-related gene expression. Genes Dev 21:1157-62
Holloway, Minita G; Cui, Yongzhi; Laz, Ekaterina V et al. (2007) Loss of sexually dimorphic liver gene expression upon hepatocyte-specific deletion of Stat5a-Stat5b locus. Endocrinology 148:1977-86

Showing the most recent 10 out of 12 publications