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Cyclic tensile stretch inhibition of nitric oxide release from osteoblast‐like cells is both G protein and actin‐dependent
Author(s) -
Hara Fumihiko,
Fukuda Kanji,
Asada Shigeki,
Matsukawa Masataka,
Hamanishi Chiaki
Publication year - 2001
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1016/s0736-0266(00)00011-5
Subject(s) - osteoblast , cytochalasin d , microbiology and biotechnology , stress fiber , chemistry , protein kinase a , actin cytoskeleton , runx2 , mechanotransduction , microfilament , pertussis toxin , cytoskeleton , actin , cgmp dependent protein kinase , signal transduction , kinase , biophysics , biochemistry , g protein , biology , mitogen activated protein kinase kinase , focal adhesion , cell , in vitro
Recent reports indicate the alteration of nitric oxide (NO) synthesis with mechanical stress loaded on the osteoblast and NO is considered to have a significant role in mechanotransduction. We found the involvement of guanine‐nucleotide‐binding regulatory proteins (G proteins), especially Gi, in stress‐inhibited NO release of osteoblast‐like cells (JOR:17;593–597, 1999). To determine further the mechanism involved in this process, we measured c‐Jun N‐terminal kinase/stress‐activated protein kinase (JNK/SAPK) activity under cyclic tensile stretch loaded on osteoblast‐like cells. Cyclic stretch significantly enhanced JNK/SAPK activity and pertussis toxin clearly reversed stress‐enhanced JNK/SAPK activity. Cytochalasin D, actin microfilament disrupting reagent, also abolished the stress activation of JNK/SAPK. We propose a model for signaling events induced by cyclic tensile stretch, namely a transmembrane mechanosensor which couples Gi‐protein, actin cytoskeleton and finally activates JNK/SAPK activity of osteoblasts. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.