scholarly journals Inactivation of Smad-Transforming Growth Factor β Signaling by Ca2+-Calmodulin-Dependent Protein Kinase II

2000 ◽  
Vol 20 (21) ◽  
pp. 8103-8111 ◽  
Author(s):  
Stephen J. Wicks ◽  
Stephen Lui ◽  
Nadia Abdel-Wahab ◽  
Roger M. Mason ◽  
Andrew Chantry
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Transforming Growth Factor Β ◽  
Cam Kinase Ii ◽  
Cam Kinase ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Β Receptor

ABSTRACT Members of the transforming growth factor β (TGF-β) family transduce signals through Smad proteins. Smad signaling can be regulated by the Ras/Erk/mitogen-activated protein pathway in response to receptor tyrosine kinase activation and the gamma interferon pathway and also by the functional interaction of Smad2 with Ca2+-calmodulin. Here we report that Smad–TGF-β-dependent transcriptional responses are prevented by expression of a constitutively activated Ca2+-calmodulin-dependent protein kinase II (Cam kinase II). Smad2 is a target substrate for Cam kinase II in vitro at serine-110, -240, and -260. Cam kinase II induces in vivo phosphorylation of Smad2 and Smad4 and, to a lesser extent, Smad3. A phosphopeptide antiserum raised against Smad2 phosphoserine-240 reacted with Smad2 in vivo when coexpressed with Cam kinase II and by activation of the platelet-derived growth factor receptor, the epidermal growth factor receptor, HER2 (c-erbB2), and the TGF-β receptor. Furthermore, Cam kinase II blocked nuclear accumulation of a Smad2 and induced Smad2-Smad4 hetero-oligomerization independently of TGF-β receptor activation, while preventing TGF-β-dependent Smad2-Smad3 interactions. These findings provide a novel cross-talk mechanism by which Ca2+-dependent kinases activated downstream of multiple growth factor receptors antagonize cell responses to TGF-β.

scholarly journals Characterization of human PDGFR-β-positive pericytes from IPF and non-IPF lungs

2018 ◽  
Vol 315 (6) ◽  
pp. L991-L1002 ◽  
Author(s):  
Carole L. Wilson ◽  
Sarah E. Stephenson ◽  
Jean Paul Higuero ◽  
Carol Feghali-Bostwick ◽  
Chi F. Hung ◽  
...  
Keyword(s):  
Growth Factor ◽  
Lung Fibrosis ◽  
Transforming Growth Factor ◽  
Human Lung ◽  
Smooth Muscle Actin ◽  
Growth Factor Receptor ◽  
Transforming Growth Factor Β ◽  
Marker Profile ◽  
Molecular Patterns

Pericytes are key regulators of the microvasculature through their close interactions with the endothelium. However, pericytes play additional roles in tissue homeostasis and repair, in part by transitioning into myofibroblasts. Accumulation of myofibroblasts is a hallmark of fibrotic diseases such as idiopathic pulmonary fibrosis (IPF). To understand the contribution and role of pericytes in human lung fibrosis, we isolated these cells from non-IPF control and IPF lung tissues based on expression of platelet-derived growth factor receptor-β (PDGFR-β), a common marker of pericytes. When cultured in a specialized growth medium, PDGFR-β+ cells retain the morphology and marker profile typical of pericytes. We found that IPF pericytes migrated more rapidly and invaded a basement membrane matrix more readily than control pericytes. Exposure of cells to transforming growth factor-β, a major fibrosis-inducing cytokine, increased expression of α-smooth muscle actin and extracellular matrix genes in both control and IPF pericytes. Given that pericytes are uniquely positioned in vivo to respond to danger signals of both systemic and tissue origin, we stimulated human lung pericytes with agonists having pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). Both control and IPF lung pericytes increased expression of proinflammatory chemokines in response to specific PAMPs and DAMPs released from necrotic cells. Our results suggest that control and IPF lung pericytes are poised to react to tissue damage, as well as microbial and fibrotic stimuli. However, IPF pericytes are primed for migration and matrix invasion, features that may contribute to the function of these cells in lung fibrosis.

N-glycans of growth factor receptors: their role in receptor function and disease implications

2016 ◽  
Vol 130 (20) ◽  
pp. 1781-1792 ◽  
Author(s):  
Motoko Takahashi ◽  
Yoshihiro Hasegawa ◽  
Congxiao Gao ◽  
Yoshio Kuroki ◽  
Naoyuki Taniguchi
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Cell Signalling ◽  
Growth Factor Receptor ◽  
Transforming Growth Factor Β ◽  
Cellular Events ◽  
Functional Regulation ◽  
Epidermal Growth ◽  
Β Receptor ◽  
Novel Strategy

Numerous signal-transduction-related molecules are secreted proteins or membrane proteins, and the mechanism by which these molecules are regulated by glycan chains is a very important issue for developing an understanding of the cellular events that transpire. This review covers the functional regulation of epidermal growth factor receptor (EGFR), ErbB3 and the transforming growth factor β (TGF-β) receptor by N-glycans. This review shows that the N-glycans play important roles in regulating protein conformation and interactions with carbohydrate recognition molecules. These results point to the possibility of a novel strategy for controlling cell signalling and developing novel glycan-based therapeutics.

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