TY - JOUR
T1 - Shear stress induces cell apoptosis via a c-Src-phospholipase D-mTOR signaling pathway in cultured podocytes
AU - Huang, Chunfa
AU - Bruggeman, Leslie A.
AU - Hydo, Lindsey M.
AU - Miller, R. Tyler
N1 - Funding Information:
This work was supported by grants from VA Merit Reviews (C.H. and R.T.M.), and the National Institutes of Health (R.T.M. DK083592 ).
PY - 2012/6/10
Y1 - 2012/6/10
N2 - The glomerular capillary wall, composed of endothelial cells, the glomerular basement membrane and the podocytes, is continually subjected to hemodynamic force arising from tractional stress due to blood pressure and shear stress due to blood flow. Exposure of glomeruli to abnormal hemodynamic force such as hyperfiltration is associated with glomerular injury and progressive renal disease, and the conversion of mechanical stimuli to chemical signals in the regulation of the process is poorly understood in podocytes. By examining DNA fragmentation, apoptotic nuclear changes and cytochrome c release, we found that shear stress induced cell apoptosis in cultured podocytes. Meanwhile, podocytes exposed to shear stress also stimulated c-Src phosphorylation, phospholipase D (PLD) activation and mammalian target of rapamycin (mTOR) signaling. Using the antibodies against c-Src, PLD1, and PLD2 to perform reciprocal co-immunoprecipitations and in vitro PLD activity assay, our data indicated that c-Src interacted with and activated PLD1 but not PLD2. The inhibition of shear stress-induced c-Src phosphorylation by PP2 (a specific inhibitor of c-Src kinase) resulted in reduced PLD activity. Phosphatidic acid, produced by shear stress-induced PLD activation, stimulated mTOR signaling, and caused podocyte hypertrophy and apoptosis.
AB - The glomerular capillary wall, composed of endothelial cells, the glomerular basement membrane and the podocytes, is continually subjected to hemodynamic force arising from tractional stress due to blood pressure and shear stress due to blood flow. Exposure of glomeruli to abnormal hemodynamic force such as hyperfiltration is associated with glomerular injury and progressive renal disease, and the conversion of mechanical stimuli to chemical signals in the regulation of the process is poorly understood in podocytes. By examining DNA fragmentation, apoptotic nuclear changes and cytochrome c release, we found that shear stress induced cell apoptosis in cultured podocytes. Meanwhile, podocytes exposed to shear stress also stimulated c-Src phosphorylation, phospholipase D (PLD) activation and mammalian target of rapamycin (mTOR) signaling. Using the antibodies against c-Src, PLD1, and PLD2 to perform reciprocal co-immunoprecipitations and in vitro PLD activity assay, our data indicated that c-Src interacted with and activated PLD1 but not PLD2. The inhibition of shear stress-induced c-Src phosphorylation by PP2 (a specific inhibitor of c-Src kinase) resulted in reduced PLD activity. Phosphatidic acid, produced by shear stress-induced PLD activation, stimulated mTOR signaling, and caused podocyte hypertrophy and apoptosis.
KW - Apoptosis
KW - C-Src
KW - MTOR
KW - Phospholipase D
KW - Podocytes
KW - Shear stress
UR - http://www.scopus.com/inward/record.url?scp=84860370772&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860370772&partnerID=8YFLogxK
U2 - 10.1016/j.yexcr.2012.03.011
DO - 10.1016/j.yexcr.2012.03.011
M3 - Article
C2 - 22472346
AN - SCOPUS:84860370772
SN - 0014-4827
VL - 318
SP - 1075
EP - 1085
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 10
ER -