title: Megakaryocytes and platelets express nicotinic acetylcholine receptors but nicotine does not affect megakaryopoiesis or platelet function.
abstract: In our previous investigations we have shown that platelets and their precursors express nicotinic α7 acetylcholine receptors (nAChRα7) that are involved in platelet function and in vitro differentiation of the megakaryoblastic cell line MEG-01. In this study, we were interested in the expression analysis of additional nAChR and the effects of nicotine in an ex vivo model using megakaryocytic cells differentiated from cord blood derived CD34(+) cells (CBMK) and an in vivo model using blood samples from smokers. CBMK were differentiated with thrombopoietin (TPO) for up to 17 days. Quantitative real-time PCR (QRT-PCR), Western blot analysis and flow cytometry were used to investigate nAChR expression (nAChRα7, nAChRα4, nAChRβ2) and nicotine effects. In blood samples of 15 nonsmokers and 16 smokers platelet parameters (count, mean platelet volume--MPV and platelet distribution width--PDW) were determined as indicators for changes of in vivo megakaryopoiesis. Platelet function was determined by the use of whole blood aggregometry and flow cytometry. The functional role of nAChR was evaluated using specific antagonists in aggregometry. CHRNA7, CHRNA4 and CHRNB2 gene transcripts and the corresponding proteins could be identified in CBMK during all stages of differentiation. Platelets contain nAChRα7 and nAChRβ2 but not nAChRα4. Nicotine had no effect on TPO-induced differentiation of CBMK. There was no significant difference in all platelet parameters of the smokers compared to the nonsmokers. In line with this, cholinergic gene transcripts as well as the encoded proteins were equally expressed in both the study groups. Despite our observation of nAChR expression in megakaryopoiesis and platelets, we were not able to detect effects of nicotine in our ex vivo and in vivo models. Thus, the functional role of the nAChR in these cells remains open.
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Schedel
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Kaiser
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Uhlig
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Lorenz
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Anip
authors.initials: A
authors.lastname: Sarin
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Starigk
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Hassmann
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Karen
authors.initials: K
authors.lastname: Bieback
authors.affiliation: a Institute of Transfusion Medicine and Immunology, Mannheim Medical Faculty, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg - Hessen , Mannheim , Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bugert
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D016022:Case-Control Studies; D002454:Cell Differentiation / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D055016:Megakaryocyte Progenitor Cells / Q000187:drug effects / Q000378:metabolism; D008533:Megakaryocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology*; D010865:Pilot Projects; D015539:Platelet Activation; D011978:Receptors, Nicotinic / Q000097:blood*
chemical_list: D011978:Receptors, Nicotinic; D009538:Nicotine
keywords: Megakaryocytic differentiation; nicotine; nicotinic acetylcholine receptors