title: Increased expression of transient receptor potential canonical 6 (TRPC6) in differentiating human megakaryocytes.
abstract: Members of the transient receptor potential (TRP) family of cation conducting channels are found in several tissues and cell types where they have different physiological functions. The canonical TRP channel 6 (TRPC6) is present on the platelet membrane and appears to participate in calcium influx during platelet activation. However, limited information is available on the importance of TRPC channels in megakaryocytes (MKs), the precursor cells of platelets. We determined the mRNA and protein expression of TRPC family members and investigated the role of TRPC6 for proliferation and differentiation of human MKs derived from CD34+ progenitor cells. TRPC6 transcripts were highly expressed during the differentiation of MKs and TRPC6 protein was detectable in MK cytoplasm by confocal staining. TRPC6 channel activity was modulated by pharmacological approaches using flufenamic acid (FFA) for activation and SKF96365 for inhibition. Upon FFA stimulation in MKs, an increase in intracellular calcium was observed, which was blocked by SKF96365 at 10 µM concentration. Incubation of MKs with SKF96365 resulted in a reduction in thrombopoietin-stimulated cell proliferation. Our results suggest a role of TRPC6 in calcium homeostasis during MK development, particularly for cell proliferation.
authors.affiliation: Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Gajalakshmi
authors.initials: G
authors.lastname: Ramanathan
authors.affiliation: Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Mannhalter
mesh_terms: D001692:Biological Transport; D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D008533:Megakaryocytes / Q000378:metabolism* / Q000473:pathology; D015539:Platelet Activation / Q000502:physiology; D050052:TRPC Cation Channels / Q000096:biosynthesis* / Q000235:genetics; D000074287:TRPC6 Cation Channel; D059467:Transcriptome
chemical_list: D015220:Calcium Channels; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C117032:TRPC6 protein, human; D002118:Calcium
keywords: calcium; cell proliferation; megakaryocyte; non-store-operated calcium entry; platelet; transient receptor potential C6