Related Experiment Video
Updated: Aug 11, 2026

Affinity Precipitation of Active Rho-GEFs Using a GST-tagged Mutant Rho Protein (GST-RhoA(G17A)) from Epithelial Cell Lysates
Published on: March 31, 2012
TGF-beta1 stimulates HO-1 via the p38 mitogen-activated protein kinase in A549 pulmonary epithelial cells
Wen Ning1, Ruiping Song, Chaojun Li
1Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
Abstract:
In lung injury and progressive lung diseases, the multifunctional cytokine transforming growth factor-beta1 (TGF-beta1) modulates inflammatory responses and wound repair. Heme oxygenase-1 (HO-1) is a stress-inducible protein that has been demonstrated to confer cytoprotection against oxidative injury and provide a vital function in maintaining tissue homeostasis. Here we report that TGF-beta1 is a potent inducer of HO-1 and examined the signaling pathway by which TGF-beta1 regulates HO-1 expression in human lung epithelial cells (A549). TGF-beta1 (1-5 ng/ml) treatment resulted in a marked time-dependent induction of HO-1 mRNA in A549 cells, followed by corresponding increases in HO-1 protein and HO enzymatic activity. Actinomycin D and cycloheximide inhibited TGF-beta1-responsive HO-1 mRNA expression, indicating a requirement for transcription and de novo protein synthesis. Furthermore, TGF-beta1 rapidly activated the p38 mitogen-activated protein kinase (p38 MAPK) pathway in A549 cells. A chemical inhibitor of p38 MAPK (SB-203580) abolished TGF-beta1-inducible HO-1 mRNA expression. Both SB-203580 and expression of a dominant-negative mutant of p38 MAPK inhibited TGF-beta1-induced ho-1 gene activation, as assayed by luciferase activity of an ho-1 enhancer/luciferase fusion construct (pMHO1luc-33+SX2). These studies demonstrate the critical intermediacy of the p38 MAPK pathway in the regulation of HO-1 expression by TGF-beta1.
More Related Videos
06:02Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition
Published on: June 10, 2016
06:54Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
Related Concept Videos
Regulation of Angiogenesis and Blood Supply
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
MAPK Signaling Cascades
TGF - β Signaling Pathway
Activation and Inactivation of G Proteins
Intracellular Signaling Affects Focal Adhesions
Some...