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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Actinin, Caco-2 Cells, Cell Proliferation, Cytoskeleton, Humans, Mitogen-Activated Protein Kinase 1, Mitogen-Activated Protein Kinase 3, Phosphorylation, Signal Transduction.
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Does cytoskeletal signaling by way of alpha-actinin-1 mediate ERK1/2 activation by repetitive deformation in human Caco2 intestinal epithelial cells? Context: Repetitive deformation stimulates proliferation in human Caco2 intestinal epithelial cells by way of an ERK1/2-dependent pathway. We examined the effects of cytoskeletal perturbation on deformation-induced signaling in Caco2 cells. The Caco2 cell cytoskeleton was disrupted with either cytochalasin D, phalloidin, colchicine, or paclitaxel. Levels of alpha-actinin-1 and -4 and paxillin were reduced by specific small interfering RNA. Cells on collagen I-precoated membranes were subjected to 10% repetitive deformation at 10 cycles/min. After 1 hour, cells were lysed for Western blot analysis. Strain-activated ERK1/2, focal adhesion kinase, and Src phosphorylation in dimethyl sulfoxide- and/or nontargeting small interfering RNA-treated control cell populations. Cytochalasin D and paclitaxel, but not phalloidin and colchicine, blocked ERK1/2 phosphorylation. A decrease in alpha-actinin-1, but not in alpha-actinin-4 or paxillin, inhibited ERK1/2 and focal adhesion kinase phosphorylation, whereas Src activation appears to be independent of these effects.
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The intestinal epithelial cell cytoskeleton may transduce mechanical signals by way of alpha-actinin-1 into the focal adhesion complex, culminating in ERK1/2 activation and proliferation. Final Decision: yes