Related Experiment Video
Updated: May 15, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
Functional roles of TGF-β1 in intestinal epithelial cells through Smad-dependent and non-Smad pathways
Yumi Yamada1, Hirosato Mashima, Toshitaka Sakai
1Department of Gastroenterology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
Background And Aims:
Transforming growth factor-β1 (TGF-β1) is one of the growth factors expressed in the gut, and has been shown to play an important role in intestinal mucosal healing. We investigated the effects of TGF-β1 on the cellular functions of intestinal epithelial cells, and also evaluated its signaling pathways in these cells.
Methods:
We used the rat IEC-6 intestinal epithelial cell line for these studies. The expression of TGF-β1/Smad signaling molecules was examined. We evaluated the effect of TGF-β1 on the proliferation and differentiation by the BrdU incorporation assay and real-time PCR. We manipulated the expression levels of Smad2 and Smad3 using an adenovirus system and small interfering RNA to examine the signaling pathways. The expression of Smad2 and Smad3 along the crypt-villus axis was also examined in the murine intestine.
Results:
IEC-6 cells produced TGF-β1 and expressed functional TGF-β/Smad signaling molecules. The addition of TGF-β1 in the culture medium suppressed the proliferation and increased the expression of a differentiation marker of enterocytes, in a dose-dependent manner. The adenovirus-mediated and small interfering RNA-mediated studies clearly showed that the growth inhibitory effect and the promotion of differentiation were exerted through a Smad3-dependent and a Smad2-dependent pathway, respectively. IEC-6 cells exhibited upregulated expression of an inhibitory Smad (Smad7) as a form of negative feedback via a non-Smad pathway. Smad2 was predominantly expressed in villi, and Smad3 in crypts.
Conclusions:
TGF-β1 regulates the cellular functions of intestinal epithelial cells through both Smad-dependent and non-Smad pathways.
More Related Videos
11:38Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay
Published on: September 14, 2021
07:49Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-β Signaling
Published on: August 3, 2018
Related Concept Videos
TGF - β Signaling Pathway
Role Of Notch Signalling In Intestinal Stem Cell Renewal
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
Renewal of Intestinal Stem Cells
Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
Non-Canonical Wnt Signaling Pathways
NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...