Functional expression of smooth muscle-specific ion channels in TGF-β1-treated human adipose-derived mesenchymal stem cells

• DOI: 10.1152/ajpcell.00404.2012
• Publication Date: 2013-06-13T04:24:04Z
• Authors: Won Sun Park; Soon Chul Heo; Eun Su Jeon; Da Hye Hong; Youn Kyoung Son; Jae-Hong Ko; Hyoung Kyu Kim; Sun Young Lee; Jae Ho Kim; Jin Han
• Keywords: 0301 basic medicine; Blotting, Western; Mice, Nude; Cell Differentiation; Mesenchymal Stem Cells; Calcium Channel Blockers; Mesenchymal Stem Cell Transplantation; Ion Channels; Hindlimb; Membrane Potentials; Disease Models, Animal; Mice; 03 medical and health sciences; Adipose Tissue; Gene Expression Regulation; Ischemia; Animals; Humans; Calcium Channels; Large-Conductance Calcium-Activated Potassium Channels; Biomarkers; Cells, Cultured

Human adipose tissue-derived mesenchymal stem cells (hASCs) have the power to differentiate into various cell types including chondrocytes, osteocytes, adipocytes, neurons, cardiomyocytes, and smooth muscle cells. We characterized the functional expression of ion channels after transforming growth factor-β1 (TGF-β1)-induced differentiation of hASCs, providing insights into the differentiation of vascular smooth muscle cells. The treatment of hASCs with TGF-β1 dramatically increased the contraction of a collagen-gel lattice and the expression levels of specific genes for smooth muscle including α-smooth muscle actin, calponin, smooth mucle-myosin heavy chain, smoothelin-B, myocardin, and h-caldesmon. We observed Ca2+, big-conductance Ca2+-activated K+ (BKCa), and voltage-dependent K+ (Kv) currents in TGF-β1-induced, differentiated hASCs and not in undifferentiated hASCs. The currents share the characteristics of vascular smooth muscle cells (SMCs). RT-PCR and Western blotting revealed that the L-type (Cav1.2) and T-type (Cav3.1, 3.2, and 3.3), known to be expressed in vascular SMCs, dramatically increased along with the Cavβ1 and Cavβ3 subtypes in TGF-β1-induced, differentiated hASCs. Although the expression-level changes of the β-subtype BKCa channels varied, the major α-subtype BKCa channel (KCa1.1) clearly increased in the TGF-β1-induced, differentiated hASCs. Most of the Kv subtypes, also known to be expressed in vascular SMCs, dramatically increased in the TGF-β1-induced, differentiated hASCs. Our results suggest that TGF-β1 induces the increased expression of vascular SMC-like ion channels and the differentiation of hASCs into contractile vascular SMCs.