Related Experiment Video
Updated: Jun 6, 2026
Isolation of Primary Myofibroblasts from Mouse and Human Colon Tissue
Published on: October 12, 2013
Interleukin-32α expression in human colonic subepithelial myofibroblasts
Yuhki Yagi1, Akira Andoh, Hirotsugu Imaeda
1Department of Medicine, Graduate School of Medicine, Shiga University of Medical Science, Seta Tukinowa, Otsu, Japan.
Abstract:
Interleukin (IL)-32 is a recently described proinflammatory cytokine, characterized by induction of nuclear factor (NF)-κB activation. We studied IL-32α expression in human colonic subepithelial myofibroblasts (SEMFs). Colonic SEMFs were isolated from normal human colon tissue. IL-32α protein expression was evaluated by Western blot analyses, and IL-32α mRNA expression was analyzed by real-time PCR. IL-32α mRNA was weakly expressed without a stimulus, and its expression was markedly enhanced by IL-1ß and TNF-α. IL-1ß and TNF-α enhanced intracellular accumulation of IL-32α protein, but IL-32α was not detected in supernatants. Each cytokine dose- and time-dependently induced IL-32α mRNA expression. An inhibitor of phosphatidylinositol 3-kinase (LY294002) significantly suppressed IL-1ß- and TNF-α-induced IL-32α mRNA expression, although MAPK inhibitors had no effect. Akt activation in response to these cytokines was confirmed by Western blotting. Blockade of NF-κB activation by an adenovirus expressing a stable mutant form of IκBα markedly suppressed IL-1ß- and TNF-α-induced IL-32α mRNA expression. Human colonic SEMFs expressed IL-32α in response to IL-1ß and TNF-α. IL-32α mRNA expression depends on the phosphatidylinositol 3-kinase and the NF-κB system.
Insights
Interleukin-32 alpha (IL-32α) is expressed in human colon cells. Its expression is triggered by inflammatory signals, involving key signaling pathways like PI3K and NF-κB.
Area of Science:
- Immunology
- Gastroenterology
- Cell Biology
Background:
- Interleukin-32 (IL-32) is a pro-inflammatory cytokine known to activate nuclear factor-kappa B (NF-κB).
- The expression and regulation of IL-32 isoforms, such as IL-32α, in specific cell types like colonic subepithelial myofibroblasts (SEMFs) remain to be fully elucidated.
Purpose of the Study:
- To investigate the expression of IL-32α in human colonic SEMFs.
- To determine the regulatory mechanisms, including signaling pathways, involved in IL-32α induction by inflammatory cytokines.
Main Methods:
- Isolation of SEMFs from normal human colon tissue.
- Analysis of IL-32α mRNA and protein expression using real-time PCR and Western blotting.
- Pharmacological inhibition of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways, and blockade of NF-κB activation.
Main Results:
- IL-32α mRNA was constitutively expressed at low levels in SEMFs, with significant upregulation by IL-1β and TNF-α.
- IL-1β and TNF-α induced intracellular IL-32α protein accumulation, dependent on dose and time.
- PI3K and NF-κB signaling pathways were identified as critical mediators of IL-1β- and TNF-α-induced IL-32α mRNA expression, while MAPK pathways were not involved.
Conclusions:
- Human colonic SEMFs express IL-32α in response to inflammatory stimuli IL-1β and TNF-α.
- The induction of IL-32α expression in these cells is regulated by the PI3K and NF-κB signaling pathways.
Related Concept Videos
01:20Inflammatory Bowel Disease II: Ulcerative Colitis
01:25Inflammatory Bowel Disease III: Crohn's Disease