TY - JOUR
T1 - Integrin-Mediated Mechanotransduction Pathway of Low-Intensity Continuous Ultrasound in Human Chondrocytes
AU - Whitney, Nicholas P.
AU - Lamb, Allyson C.
AU - Louw, Tobias M.
AU - Subramanian, Anuradha
N1 - Funding Information:
The authors kindly acknowledge Dr. Sanjukta Guha Thakurta, Dr. Karl Kador, MinJeong Schneider and Leonard Akert who provided technical support for this work. Trish Fenster, Kandra Hahn, Peggy Pedersen and Karen Spath provided outstanding administrative support. This work was supported, in part, by the American Recovery and Reinvestment Act of 2009 research grant 1R21RR024437-01A1 from the Department of Health and Human Services and a State of Nebraska grant Stem Cell 2011-04 .
PY - 2012/10
Y1 - 2012/10
N2 - Chondrocytes are mechanosensitive cells that require mechanical stimulation for proper growth and function in in vitro culture systems. Ultrasound (US) has emerged as a technique to deliver mechanical stress; however, the intracellular signaling components of the mechanotransduction pathways that transmit the extracellular mechanical stimulus to gene regulatory mechanisms are not fully defined. We evaluated a possible integrin/mitogen-activated protein kinase (MAPK) mechanotransduction pathway using Western blotting with antibodies targeting specific phosphorylation sites on intracellular signaling proteins. US stimulation of chondrocytes induced phosphorylation of focal adhesion kinase (FAK), Src, p130 Crk-associated substrate (p130Cas), CrkII and extracellular-regulated kinase (Erk). Furthermore, pre-incubation with inhibitors of integrin receptors, Src and MAPK/Erk kinase (MEK) reduced US-induced Erk phosphorylation levels, indicating integrins and Src are upstream of Erk in an US-mediated mechanotransduction pathway. These findings suggest US signals through integrin receptors to the MAPK/Erk pathway via a mechanotransduction pathway involving FAK, Src, p130Cas and CrkII.
AB - Chondrocytes are mechanosensitive cells that require mechanical stimulation for proper growth and function in in vitro culture systems. Ultrasound (US) has emerged as a technique to deliver mechanical stress; however, the intracellular signaling components of the mechanotransduction pathways that transmit the extracellular mechanical stimulus to gene regulatory mechanisms are not fully defined. We evaluated a possible integrin/mitogen-activated protein kinase (MAPK) mechanotransduction pathway using Western blotting with antibodies targeting specific phosphorylation sites on intracellular signaling proteins. US stimulation of chondrocytes induced phosphorylation of focal adhesion kinase (FAK), Src, p130 Crk-associated substrate (p130Cas), CrkII and extracellular-regulated kinase (Erk). Furthermore, pre-incubation with inhibitors of integrin receptors, Src and MAPK/Erk kinase (MEK) reduced US-induced Erk phosphorylation levels, indicating integrins and Src are upstream of Erk in an US-mediated mechanotransduction pathway. These findings suggest US signals through integrin receptors to the MAPK/Erk pathway via a mechanotransduction pathway involving FAK, Src, p130Cas and CrkII.
KW - Chondrocyte
KW - CrkII
KW - Extracellular-regulated kinase (Erk)
KW - Focal adhesion kinase (FAK)
KW - Integrin
KW - Mechanotransduction
KW - P130 Crk-associated substrate (p130Cas)
KW - Src
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=84865778435&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865778435&partnerID=8YFLogxK
U2 - 10.1016/j.ultrasmedbio.2012.06.002
DO - 10.1016/j.ultrasmedbio.2012.06.002
M3 - Article
C2 - 22920546
AN - SCOPUS:84865778435
VL - 38
SP - 1734
EP - 1743
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
SN - 0301-5629
IS - 10
ER -