Heterogeneous expression of suppressor of cytokine signalling 2 (SOCS-2) in liver tissue.
Suppressor of cytokine signalling 2 (SOCS-2), a dual effector of growth hormone signalling, was found to be heterogeneously expressed in murine liver parenchyma. Data from Affymetrix gene arrays, confirmed by quantitative RT-PCR using preparations of periportal and pericentral hepatocyte subpopulations as well as immunohistochemical detection, showed a preferential expression of SOCS-2 in pericentral hepatocytes. Stimulation of cultured periportal and pericentral hepatocyte subpopulations by different concentrations of growth hormone for 1 h resulted at 100 ng mL(-1) in a 1.6-fold and 4.3-fold increase of SOCS-2 mRNA, respectively. Likewise, insulin-like growth factor-1, another physiological target of growth hormone, was stimulated preferentially in pericentral hepatocytes. As growth hormone receptor was found to be homogeneously expressed in mouse liver parenchyma, our data indicate that growth hormone signalling downstream of growth hormone receptor is more sensitive and/or effective in pericentral than in periportal hepatocytes. Presumably, the heterogeneous distribution of SOCS-2 may contribute to the pericentral preference of growth hormone action via differential feedback.
Zellmer
Sebastian
S
Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany. sebastian.zellmer@medizin.uni-leipzig.de
Sickinger
Stephan
S
Schmidt-Heck
Wolfgang
W
Guthke
Reinhard
R
Gebhardt
Rolf
R
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D005974:Glutamate-Ammonia Ligase / Q000096:biosynthesis / Q000235:genetics; D013006:Growth Hormone / Q000494:pharmacology; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics; D011986:Receptors, Somatotropin / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism*; D046888:Tissue Array Analysis / Q000379:methods
D012333:RNA, Messenger; D011986:Receptors, Somatotropin; C491409:Socs2 protein, mouse; D050826:Suppressor of Cytokine Signaling Proteins; C519530:insulin-like growth factor-1, mouse; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D005974:Glutamate-Ammonia Ligase