Sphingosylphosphorylcholine Induces Differentiation of Human Mesenchymal Stem Cells into Smooth-muscle-like Cells Through a Tgf-beta-dependent Mechanism.
From: Medical Research Center for Ischemic Tissue Regeneration of Pusan National University and the Medical Research Institute, College of Medicine, Pusan National University, Busan 602-739, Republic of Korea.
Journal of cell science
- Publish Date: Dec 2006
- ISSN: 0021-9533
- Volume: 119
- Issue: Pt 23
- Pages: 4994-5005
- Medium: Print
- Language: English
- Citation (JAMA): Jeon Eun Su, Moon Hyun Jung, Lee Mi Jeong, et al. Sphingosylphosphorylcholine Induces Differentiation of Human Mesenchymal Stem Cells into Smooth-muscle-like Cells Through a Tgf-beta-dependent Mechanism.. J. Cell. Sci. Dec 2006;119:4994-5005
Abstract
Mesenchymal stem cells (MSCs) can differentiate into diverse cell types including adipogenic, osteogenic, chondrogenic and myogenic lineages. In the present study, we demonstrated for the first time that sphingosylphosphorylcholine (SPC) induces differentiation of human adipose-tissue-derived mesenchymal stem cells (hATSCs) to smooth-muscle-like cell types. SPC increased the expression levels of several smooth-muscle-specific genes, such as those for alpha-smooth-muscle actin (alpha-SMA), h1-calponin and SM22alpha, as effectively as transforming growth factor beta (TGF-beta1) and TGF-beta3. SPC elicited delayed phosphorylation of Smad2 after 24 hours exposure, in contrast to rapid phosphorylation of Smad2 induced by TGF-beta treatment for 10 minutes. Pretreatment of the cells with pertussis toxin or U0126, an MEK inhibitor, markedly attenuated the SPC-induced expression of beta-SMA and delayed phosphorylation of Smad2, suggesting that the Gi/o-ERK pathway is involved in the increased expression of alpha-SMA through induction of delayed Smad2 activation. In addition, SPC increased secretion of TGF-beta1 through an ERK-dependent pathway, and the SPC-induced expression of alpha-SMA and delayed phosphorylation of Smad2 were blocked by SB-431542, a TGF-beta type I receptor kinase inhibitor, or anti-TGF-beta1 neutralizing antibody. Silencing of Smad2 expression with small interfering RNA (siRNA) abrogated the SPC-induced expression of alpha-SMA. These results suggest that SPC-stimulated secretion of TGF-beta1 plays a crucial role in SPC-induced smooth muscle cell (SMC) differentiation through a Smad2-dependent pathway. Both SPC and TGF-beta increased the expression levels of serum-response factor (SRF) and myocardin, transcription factors involved in smooth muscle differentiation. siRNA-mediated depletion of SRF or myocardin abolished the alpha-SMA expression induced by SPC or TGF-beta. These results suggest that SPC induces differentiation of hATSCs to smooth-muscle-like cell types through G(i/o)-ERK-dependent autocrine secretion of TGF-beta, which activates a Smad2-SRF/myocardin-dependent pathway.
Mesh Headings (Keywords): Actins, Cell Differentiation, Cells, Cultured, Extracellular Signal-Regulated MAP Kinases, GTP-Binding Protein alpha Subunits, Gi-Go, Humans, Mesenchymal Stem Cells, Muscle, Smooth, Myocytes, Smooth Muscle, Nuclear Proteins, Phosphorylation, Phosphorylcholine, Serum Response Factor, Signal Transduction, Smad2 Protein, Sphingosine, Stress Fibers, Subcutaneous Fat, Trans-Activators, Transforming Growth Factor beta, Transforming Growth Factor beta1
Check for Full Text / PubMed Unique Identifier (PMID): 17105765
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