Sustained activation of MAPK/ERKs signaling pathway in cystic kidneys from bcl-2 -/- mice.
Cell proliferation, survival, and differentiation are carefully orchestrated processes during nephrogenesis that become aberrant during renal cyst formation. Signaling through focal adhesion kinase (FAK) impacts these processes, although its role during nephrogenesis requires further delineation. We previously demonstrated that phosphorylation of FAK and paxillin is not downregulated in cystic kidneys from B cell lymphoma/leukemia-2 (bcl-2) -/- mice. Here we examine whether FAK downstream signaling pathways are affected in these cystic kidneys. Cystic kidneys from bcl-2 -/- mice exhibited sustained phosphorylation of Src and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK, ERK1). However, similar levels of expression were noted for phosphorylated c-Jun NH(2)-terminal kinase, phosphatidylinositol-3-kinase, and its target protein kinase B/ATP-dependent tyrosine kinase in kidneys from postnatal day 20 bcl-2 +/+ and bcl-2 -/- mice. We also examined expression of the adapter protein Shc, implicated in growth and apoptosis. Expression of p66(Shc) decreases to low levels in postnatal kidneys, whereas p52/p46(Shc) was constitutively expressed during nephrogenesis. Shc expression was similar in normal and cystic kidneys. Therefore, sustained activation of MAPK/ERKs through the Src/FAK pathway may contribute to the hyperproliferation observed in cystic kidneys from bcl-2 -/- mice.
Sorenson
Christine M
CM
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin 53792, USA. cmsorenson@facstaff.wisc.edu
Sheibani
Nader
N
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002455:Cell Division / Q000502:physiology; D005260:Female; D051380:GRB2 Adaptor Protein; D048031:JNK Mitogen-Activated Protein Kinases; D007668:Kidney / Q000201:enzymology / Q000473:pathology; D052177:Kidney Diseases, Cystic / Q000378:metabolism* / Q000473:pathology*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation; D011247:Pregnancy; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D019061:src-Family Kinases / Q000096:biosynthesis / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D051380:GRB2 Adaptor Protein; C495949:Grb2 protein, mouse; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D019061:src-Family Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases