title: Involvement of TRPV2 and SOCE in calcium influx disorder in DMD primary human myotubes with a specific contribution of α1-syntrophin and PLC/PKC in SOCE regulation.
abstract: Calcium homeostasis is critical for several vital functions in excitable and nonexcitable cells and has been shown to be impaired in many pathologies including Duchenne muscular dystrophy (DMD). Various studies using murine models showed the implication of calcium entry in the dystrophic phenotype. However, alteration of store-operated calcium entry (SOCE) and transient receptor potential vanilloid 2 (TRPV2)-dependant cation entry has not been investigated yet in human skeletal muscle cells. We pharmacologically characterized basal and store-operated cation entries in primary cultures of myotubes prepared from muscle of normal and DMD patients and found, for the first time, an increased SOCE in DMD myotubes. Moreover, this increase cannot be explained by an over expression of the well-known SOCE actors: TRPC1/4, Orai1, and stromal interaction molecule 1 (STIM1) mRNA and proteins. Thus we investigated the modes of regulation of this cation entry. We firstly demonstrated the important role of the scaffolding protein α1-syntrophin, which regulates SOCE in primary human myotubes through its PDZ domain. We also studied the implication of phospholipase C (PLC) and protein kinase C (PKC) in SOCE and showed that their inhibition restores normal levels of SOCE in DMD human myotubes. In addition, the involvement of TRPV2 in calcium deregulation in DMD human myotubes was explored. We showed an abnormal elevation of TRPV2-dependant cation entry in dystrophic primary human myotubes compared with normal ones. These findings show that calcium homeostasis mishandling in DMD myotubes depends on SOCE under the influence of Ca(2+)/PLC/PKC pathway and α1-syntrophin regulation as well as on TRPV2-dependant cation influx.
authors: Institut de Physiologie et Biologie Cellulaires, Université de Poitiers/Centre National de la Recherche Scientifique FRE-3511 Poitiers, France.
authors: Rania
authors: R
authors: Harisseh
authors: Aurélien
authors: A
authors: Chatelier
authors: Christophe
authors: C
authors: Magaud
authors: Nadine
authors: N
authors: Déliot
authors: Bruno
authors: B
authors: Constantin
mesh_terms: D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D020013:Calcium Signaling; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D004963:Estrenes / Q000494:pharmacology; D005682:Gadolinium / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism*; D020388:Muscular Dystrophy, Duchenne / Q000378:metabolism* / Q000473:pathology; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D000071740:ORAI1 Protein; D018408:Patch-Clamp Techniques; D061251:Primary Cell Culture; D011493:Protein Kinase C / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D000071737:Stromal Interaction Molecule 1; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism; D050916:TRPV Cation Channels / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002135:Calcium-Binding Proteins; D004963:Estrenes; D007093:Imidazoles; D007211:Indoles; D008301:Maleimides; D008565:Membrane Proteins; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D011760:Pyrrolidinones; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D050052:TRPC Cation Channels; C489571:TRPC4 ion channel; D050916:TRPV Cation Channels; C400769:TRPV2 protein, human; C091825:syntrophin alpha1; C096351:transient receptor potential cation channel, subfamily C, member 1; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D005682:Gadolinium; D011493:Protein Kinase C; D010738:Type C Phospholipases; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D009543:Nifedipine; C070515:bisindolylmaleimide I
keywords: Ca2+/PLC/PKC; DMD; SOCE; TRPV2; human primary myotubes; α1-syntrophin