Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0344329 (collapse)
 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Colchicine and nocodazole, both established microtubule disruptors, are useful tools to investigate cytoskeletal-dependent signaling cascades and the associated downstream transcriptional targets. Since cytoskeletal events impact pathophysiologic consequences in the vascular system, the signaling requirements underlying colchicine-stimulated expression of PAI-1 and CTGF, two prominent cell deformation-sensitive fibrosis-initiating proteins, were evaluated in vascular smooth muscle cells. Microtubule disruption rapidly induced EGFR transactivation (at the src kinase-sensitive EGFR(Y845) site) in a ROS-dependent manner. Genetic deficiency of EGFR, inhibition of EGFR signaling with AG1478 or introduction of a kinase-deficient EGFR construct effectively blocked colchicine-stimulated PAI-1 and CTGF expression. MEK/ERK involvement downstream of ROS generation was critical for PAI-1, but not CTGF, expression following cytoskeletal perturbation suggesting bifurcation of signaling pathways downstream of EGFR activation. Colchicine also stimulated SMAD2/3 phosphorylation by a Rho/ROCK-dependent mechanism independent of TGF-beta1 release or receptor activity. Rho/ROCK signaling initiated by tubulin network collapse was required for both CTGF and PAI-1 induction. Colchicine-initiated SMAD3 phosphorylation, however, was essential for PAI-1, but not CTGF, expression further highlighting divergence of signaling events downstream of Rho/ROCK that mediate microtubule deformation-associated changes in profibrotic gene transcription.
 ...
PMID:Differential requirement for MEK/ERK and SMAD signaling in PAI-1 and CTGF expression in response to microtubule disruption. 1924 54

Vascular smooth muscle cells (VSMCs) are subject to changing hemodynamic stimuli that alter cytoskeletal dynamics, cellular architecture, and structure-associated signal transduction. Tensional stress, force application, and structural perturbations are sensed by VSMCs and impact the physiological as well as pathophysiological responses of the vasculature. Microtubule-targeting drugs provide useful tools to analyze cytoskeletal-associated signaling pathways and their linkages to pathological outcomes. Architecture-based controls on a subset of profibrotic genes commonly expressed in vascular disease are highlighted by their frequent induction in mechanically manipulated cells and with associated changes in cytoskeletal dynamics. VSMCs respond to biomechanical cues by activating several kinase cascades, leading to gene reprogramming. It is apparent that a significant fraction of the vast repertoire of signaling intermediates, moreover, are sequestered on the cytoskeletal framework in an "inactive state." Reorganization within these networks due to fluctuating mechanical forces could release these effectors from their cytoskeletal anchors, thus alleviating the "repressive state" resulting in downstream signaling. Indeed, recent findings indicate that microtubule disruption in VSMCs rapidly stimulates pp60c-src kinase activation and epidermal growth factor receptor (EGFR) transphosphorylation at Y845, a src kinase target residue. EGFR genetic deficiency, pharmacological inhibition of EGFR signaling, or adenoviral delivery of the kinase-deficient EGFRK721A construct effectively blocked colchicine-stimulated expression of two prominent vascular profibrotic genes, plasminogen activator inhibitor type-1 (PAI-1; SERPINE1) and connective tissue growth factor (CTGF; CCN2). Signaling intermediates involved in microtubule collapse-initiated PAI-1/CTGF induction in VSMCs include the MEK/ERK, Rho/ROCK, and SMAD2/3 pathways. This review highlights commonalities and differences in signaling events that facilitate expression of vascular disease-relevant genes initiated as a consequence of loss of microtubular integrity.
 ...
PMID:The Cytoskeletal Network Regulates Expression of the Profibrotic Genes PAI-1 and CTGF in Vascular Smooth Muscle Cells. 2931 Aug 4

Involution returns the lactating mammary gland to a quiescent state after weaning. The mechanism of involution involves collapse of the mammary epithelial cell compartment. To test whether the cJUN NH2-terminal kinase (JNK) signal transduction pathway contributes to involution, we established mice with JNK deficiency in the mammary epithelium. We found that JNK is required for efficient involution. JNK deficiency did not alter the STAT3/5 or SMAD2/3 signaling pathways that have been previously implicated in this process. Nevertheless, JNK promotes the expression of genes that drive involution, including matrix metalloproteases, cathepsins, and BH3-only proteins. These data demonstrate that JNK has a key role in mammary gland involution post lactation.
 ...
PMID:The cJUN NH2-terminal kinase (JNK) pathway contributes to mouse mammary gland remodeling during involution. 2951 38