CCN2 is induced by transforming growth factor-beta (TGFbeta) in fibroblasts and is overexpressed in connective tissue disease. CCN2 has been proposed to be a downstream mediator of TGFbeta action in fibroblasts; however, the role of CCN2 in regulating this process unclear. By using embryonic fibroblasts isolated from ccn2-/- mice, we showed that CCN2 is required for a subset of responses to TGFbeta. Affymetrix genome-wide expression profiling revealed that 942 transcripts were induced by TGFbeta greater than 2-fold in ccn2+/+ fibroblasts, of which 345 were not induced in ccn2-/- fibroblasts, including pro-adhesive and matrix remodeling genes. Whereas TGFbeta properly induced a generic Smad3-responsive promoter in ccn2-/- fibroblasts, TGFbeta-induced activation of focal adhesion kinase (FAK) and Akt was reduced in ccn2-/- fibroblasts. Emphasizing the importance of FAK and Akt activation in CCN2-dependent transcriptional responses to TGFbeta in fibroblasts, CCN2-dependent transcripts were not induced by TGFbeta in fak-/- fibroblasts and were reduced by wortmannin in wild-type fibroblasts. Akt1 overexpression in ccn2-/- fibroblasts rescued the TGFbeta-induced transcription of CCN2-dependent mRNA. Finally, induction of TGFbeta-induced fibroblast adhesion to fibronectin and type I collagen was significantly diminished in ccn2-/- fibroblasts. Thus in embryonic fibroblasts, CCN2 is a necessary cofactor required for TGFbeta to activate the adhesive FAK/Akt/phosphatidylinositol 3-kinase cascade, FAK/Akt-dependent genes, and adhesion to matrix.
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http://dx.doi.org/10.1074/jbc.M511343200 | DOI Listing |
Immun Inflamm Dis
November 2024
Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 6-151 61 Queen Street East, Toronto, ON, M5C 2T2, Canada.
Background: Several new treatments have recently been shown to have heart and kidney protective benefits in people with diabetes. Because these treatments were developed in parallel, it is unclear how the different molecular pathways affected by the therapies may overlap. Here, we examined the effects of the mineralocorticoid receptor antagonist finerenone in mice with comorbid diabetes, focusing on the regulation of expression of the glucagon-like peptide-1 receptor (GLP-1R), gastric inhibitory polypeptide receptor (GIPR) and glucagon receptor (GCGR), which are targets of approved or investigational therapies in diabetes.
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November 2024
Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, PR China.
Purpose: Subconjunctival fibrosis is the main cause of failure after glaucoma filtration surgery. We explored the effects of sulforaphane (SFN) on the conversion of human Tenon's fibroblasts (HTFs) into myofibroblasts, transforming growth factor (TGF)-β-induced contraction of collagen gel, and inflammation.
Methods: After treatment with the combination of TGF-β and SFN or TGF-β alone, primary HTFs were subjected to a three-dimensional collagen contraction experiment to examine their contractility.
J Oral Biosci
November 2024
College of Dentistry, University of Saskatchewan, 105 Wiggins Rd, Saskatoon, SK, Canada, S7H 2E5. Electronic address:
Background: Fibrotic responses in the gingiva are characterized by their hyperproliferative nature instead of scar tissue formation. Clinically, these conditions appear as "gingival overgrowth" (GO), which can be of drug-induced or genetic origin. Despite surgical removal, GO can recur.
View Article and Find Full Text PDFFront Immunol
September 2024
First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece.
Introduction: Crohn's disease (CD) is characterized by chronic inflammation and intestinal fibrosis leading to lifelong complications. However, the disease pathogenesis remains elusive, and the therapeutic options are limited. Here, we investigated the interaction between neutrophils and intestinal fibroblasts in the development of CD immunofibrosis, a disease mechanism predisposing to inflammatory and fibrotic complications.
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