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| Untersuchte Arbeit: Seite: 22, Zeilen: 21-42 |
Quelle: BelAiba et al 2006 Seite(n): 828, 829, Zeilen: 828: r.col: 4ff; 829: l.col: 1ff |
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| The serum- and glucocorticoid-inducible kinase-1, SGK1, is a known downstream effector of the PI3K cascade. SGK1 belongs to the “AGC” family of serine-threonine kinases and shares approximately 45% to 55% homology with Akt in its catalytic domain.
In contrast to Akt, SGK1 is also regulated at the transcriptional level in response to various hormones, growth factors, and extracellular stresses in a cell type – dependent manner, allowing sgk1 to be available for its targets only when needed. SGK1 was originally cloned from murine mammary tumor cells as a glucocorticoid-responsive gene. Human SGK1 was subsequently cloned as a cell volume-sensitive gene upregulated by hypertonic cell shrinkage. Increasing evidence suggests that expression, enzymatic activity, and cellular localization of SGK1 are regulated in response to various stimuli controlling not only cell volume and epithelial transport, but also cardiac action potential and cell proliferation, survival, and apoptosis. Excessive transcription of SGK1 has been shown to parallel diabetic nephropathy, glomerulonephritis, hepatic cirrhosis, pulmonary fibrosis, and polymorphisms of the SGK1 gene correlated with hypertension. Despite the wide tissue distribution of sgk1 and its sensitivity to various stimuli, the role of SGK-1 in the cardiovascular and pulmonary system remained ill defined. Because heparin, an inhibitor of thrombin formation, has been shown to decrease SGK1 mRNA in aortic smooth muscle cells, we hypothesized that SGK1 may play a role in thrombin signaling in human pulmonary artery smooth muscle cells (PASMC). We found that SGK1 is activated and induced by thrombin, that it regulates TF expression and activity in PASMC, and that it is present in remodeled pulmonary vessels with media hypertrophy associated with ph (Rachida S. et al., (2006) Circ Res). |
The serum- and glucocorticoid-inducible kinase-1, Sgk-1, is a known downstream effector of the PI3K cascade. Sgk-1 belongs to the “AGC” family of serine-threonine kinases and shares approximately 45% to 55% homology with Akt in its catalytic domain.6 In contrast to Akt, Sgk-1 is also regulated at the transcriptional level in response to various hormones, growth factors, and extracellular stresses in a cell type– dependent manner, allowing Sgk-1 to be available for its targets only when needed.7,8
Sgk-1 was originally cloned from murine mammary tumor cells as a glucocorticoid-responsive gene.6 Human Sgk-1 was subsequently cloned as a cell volume-sensitive gene upregulated by hypertonic cell shrinkage.9 Increasing evidence [page 829] suggests that expression, enzymatic activity, and cellular localization of Sgk-1 are regulated in response to various stimuli controlling not only cell volume and epithelial transport, but also cardiac action potential and cell proliferation, survival, and apoptosis.7,8 Excessive transcription of Sgk-1 has been shown to parallel diabetic nephropathy,10 glomerulonephritis,11 hepatic cirrhosis,12 pulmonary fibrosis,13 and polymorphisms of the Sgk-1 gene correlated with hypertension.14 Despite the wide tissue distribution of Sgk-1 and its sensitivity to various stimuli, the role of Sgk-1 in the cardiovascular and pulmonary system remained ill defined. Because heparin, an inhibitor of thrombin formation, has been shown to decrease Sgk-1 mRNA in aortic smooth muscle cells,15 we hypothesized that Sgk-1 may play a role in thrombin signaling in human pulmonary artery smooth muscle cells (PASMC), the main cell type involved in PH. We found that Sgk-1 is activated and induced by thrombin, that it regulates TF expression and activity in PASMC, and that it is present in remodeled pulmonary vessels with media hypertrophy associated with PH. 6. Webster MK, Goya L, Ge Y, Maiyar AC, Firestone GL. Characterization of sgk, a novel member of the serine/threonine protein kinase gene family which is transcriptionally induced by glucocorticoids and serum. Mol Cell Biol. 1993;13:2031–2040. 7. Firestone GL, Giampaolo JR, O’Keeffe BA. Stimulus-dependent regulation of serum and glucocorticoid inducible protein kinase (SGK) transcription, subcellular localization and enzymatic activity. Cell Physiol Biochem. 2003;13:1–12. 8. Lang F, Cohen P. Regulation and physiological roles of serum- and glucocorticoid-induced protein kinase isoforms. Sci STKE. 2001; 108:RE17. 9. Waldegger S, Barth P, Raber G, Lang F. Cloning and characterization of a putative human serine/threonine protein kinase transcriptionally modified during anisotonic and isotonic alterations of cell volume. Proc Natl Acad Sci U S A. 1997;94:4440–4445. 10. Kumar JM, Brooks DP, Olson BA, Laping NJ. Sgk, a putative serine/ threonine kinase, is differentially expressed in the kidney of diabetic mice and humans. J Am Soc Nephrol. 1999;10:2488–2494. 11. Friedrich B, Warntges S, Klingel K, Sauter M, Kandolf R, Risler T, Muller GA, Witzgall R, Kriz W, Grone HJ, Lang F. Up-regulation of the human serum and glucocorticoid-dependent kinase 1 in glomerulonephritis. Kidney Blood Press Res. 2002;25:303–307. 12. Fillon S, Klingel K, Warntges S, Sauter M, Gabrysch S, Pestel S, Tanneur V, Waldegger S, Zipfel A, Viebahn R, Haussinger D, Broer S, Kandolf R, Lang F. Expression of the serine/threonine kinase hSGK1 in chronic viral hepatitis. Cell Physiol Biochem. 2002;12:47–54. 13. Waerntges S, Klingel K, Weigert C, Fillon S, Buck M, Schleicher E, Rodemann HP, Knabbe C, Kandolf R, Lang F. Excessive transcription of the human serum and glucocorticoid dependent kinase hSGK1 in lung fibrosis. Cell Physiol Biochem. 2002;12:135–142. 14. Busjahn A, Aydin A, Uhlmann R, Krasko C, Bahring S, Szelestei T, Feng Y, Dahm S, Sharma AM, Luft FC, Lang F. Serum- and glucocorticoidregulated kinase (SGK1) gene and blood pressure. Hypertension. 2002; 40:256–260. 15. Delmolino LM, Castellot JJ Jr. Heparin suppresses sgk, an early response gene in proliferating vascular smooth muscle cells. J Cell Physiol. 1997; 173:371–379. |
The reference to "Rachida S. et al., (2006) Circ Res" potentially indicates the source, as the first author of the source is named "Rachida S. BelAiba". No such entry cannot be found in the bibliography, and nothing indicates that text spanning two paragraphs has been copied from it, mostly verbatim. |
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