title: Functional constituents of a local serotonergic system, intrinsic to the human coronary artery smooth muscle cells.
abstract: Human coronary artery smooth muscle cells (HCASMCs) play an important role in the pathogenesis of coronary atherosclerosis and coronary artery diseases (CAD). Serotonin is a mediator known to produce vascular smooth muscle cell mitogenesis and contribute to coronary atherosclerosis. We hypothesize that the HCASMC possesses certain functional constituents of the serotonergic system such as: tryptophan hydroxylase and serotonin transporter. Our aim was to examine the presence of functional tryptophan hydroxylase-1 (TPH1) and serotonin transporter (SERT) in HCASMCs. The mRNA transcripts by qPCR and protein expression by Western blot of TPH1 and SERT were examined. The specificity and accuracy of the primers were verified using DNA gel electrophoresis and sequencing of qPCR products. The functionality of SERT was examined using a fluorescence dye-based serotonin transporter assay. The enzymatic activity of TPH was evaluated using UPLC. The HCASMCs expressed both mRNA transcripts and protein of SERT and TPH. The qPCR showed a single melt curve peak for both transcripts and in sequence analysis the amplicons were aligned with the respective genes. SERT and TPH enzymatic activity was present in the HCASMCs. Taken together, both TPH and SERT are functionally expressed in HCASMCs. These findings are novel and represent an initial step in examining the clinical relevance of the serotonergic system in HCASMCs and its role in the pathogenesis of coronary atherosclerosis and CAD.
authors: Center for Clinical and Translational Science, Creighton University School of Medicine, CRISS II Room 510, 2500 California Plaza, Omaha, NE, 68178, USA.
authors: Kannan
authors: K
authors: Baskar
authors: Swastika
authors: S
authors: Sur
authors: Vithyalakshmi
authors: V
authors: Selvaraj
authors: Devendra K
authors: DK
authors: Agrawal
mesh_terms: D001158:Arteries / Q000201:enzymology / Q000378:metabolism*; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000201:enzymology / Q000378:metabolism*; D057075:Enzyme Assays; D015870:Gene Expression; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D014365:Tryptophan Hydroxylase / Q000235:genetics / Q000378:metabolism*
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C497467:TPH1 protein, human; D014365:Tryptophan Hydroxylase