title: Overexpression of Cardiac-Specific Kinase TNNI3K Promotes Mouse Embryonic Stem Cells Differentiation into Cardiomyocytes.
abstract: Backgroud/Aims: The biological function of cardiac troponin I-interacting kinase (TNNI3K), a cardiac-specific functional kinase, is largely unknown. We investigated the effect of human TNNI3K (hTNNI3K) on the differentiation of mouse embryonic stem cells (mESCs) into cardiomyocytes.
  
  
  
  First, the time-space expression of endogenous Tnni3k was detected by real-time polymerase chain reaction (PCR) and western blotting at 16 different time-points over a period of 28 days. Further, action potentials and calcium current with/without 5 µM nifedipine were measured by patch clamp for mESC-derived cardiomyocytes. HTNNI3K and mouse-derived siRNA were transfected into mESC using lentivirus vector to induce hTNNI3K overexpression and knock-down, respectively.
  
  
  
  The number of troponin-T (cTnT) positive cells was greater in the group with TNNI3K overexpression as compared to that in control group, while less such cells were detected in the mTnni3k knock-down group as evaluated on flow cytometry (FCM) and ImageXpress Micro system. After upregulation of connexin43, cardiac troponin-I (Ctni), Ctni, Gata4 were detected in mESCs with TNNI3K overexpression; however, overexpression of α-Actinin and Mlc2v was not detected. Interestingly, Ctnt, connexin40 and connexin45, the markers of ventricular, atrial, and pacemaker cells, respectively, were detected in by real-time PCR in TNNI3K overexpression group.
  
  
  
  our study indicated that TNNI3K overexpression promoted mESC differentiating into beating cardiomyocytes and induced up-regulating expression of cTnT by PKCε signal pathway, which suggested a modulation of TNNI3K activity as a potential therapeutic approach for ischemic cardiac disease.
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Shi-Qiang
authors.initials: SQ
authors.lastname: Wang
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Wang
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Yao
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Ma
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Ding
authors.forename: Jue
authors.initials: J
authors.lastname: Ye
authors.forename: Xian-Min
authors.initials: XM
authors.lastname: Meng
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Li
authors.forename: Rui-Xia
authors.initials: RX
authors.lastname: Xu
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation; D018031:Connexin 43 / Q000378:metabolism; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D000066450:Mouse Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D051744:Protein Kinase C-epsilon / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D019210:Troponin I / Q000378:metabolism; D020107:Troponin T / Q000378:metabolism
chemical_list: D018031:Connexin 43; D034741:RNA, Small Interfering; D019210:Troponin I; D020107:Troponin T; D017346:Protein Serine-Threonine Kinases; C481078:TNNI3K protein, human; D051744:Protein Kinase C-epsilon; D020930:MAP Kinase Kinase Kinases; D002118:Calcium
keywords: Cardiomyocyte; Differentiation; TNNI3K; mESC