{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,7]],"date-time":"2026-02-07T11:35:07Z","timestamp":1770464107041,"version":"3.49.0"},"reference-count":40,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2023,8,15]],"date-time":"2023-08-15T00:00:00Z","timestamp":1692057600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["21K07875"],"award-info":[{"award-number":["21K07875"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["JP20ek0109442h0001"],"award-info":[{"award-number":["JP20ek0109442h0001"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J cachexia sarcopenia muscle"],"published-print":{"date-parts":[[2023,10]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Myostatin, encoded by the <jats:italic>MSTN<\/jats:italic> gene comprising 3 exons, is a potent negative regulator of skeletal muscle growth. Although a variety of myostatin inhibitors have been invented for increasing muscle mass in muscle wasting diseases, no effective inhibitor is currently available for clinical use. Myostatin isoforms in several animals have been reported to inhibit myostatin, but an isoform has never been identified for the human <jats:italic>MSTN<\/jats:italic> gene, a conserved gene among animals. Here, a splice variant of the human <jats:italic>MSTN<\/jats:italic> gene was explored.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Transcripts and proteins were analysed by reverse transcription\u2010PCR amplification and western blotting, respectively. Proteins were expressed from expression plasmid. Myostatin signalling was assayed by the SMAD\u2010responsive luciferase activity. Cell proliferation was assayed by the Cell Counting Kit\u20108 (CCK\u20108) assay and cell counting. Cell cycle was analysed by the FastFUCCI system.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Reverse transcription\u2010PCR amplification of the full\u2010length <jats:italic>MSTN<\/jats:italic> transcript in CRL\u20102061 rhabdomyosarcoma cells revealed two bands consisting of a thick expected\u2010size product and a thin additional small\u2010size product. Sequencing of the small\u2010size product showed a 963\u2010bp deletion in the 5\u2032 end of exon 3, creating exon 3s, which contained unusual splice acceptor TG dinucleotides. The novel variant was identified in other human cell lines, although it was not identified in skeletal muscle. The 251\u2010amino acid isoform encoded by the novel variant (myostatin\u2010b) was identified in CRL\u20102061 rhabdomyosarcoma cells. Transfection of a myostatin\u2010b expression plasmid into CRL\u20102061 and myoblast cells inhibited endogenous myostatin signalling (44%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.001 and 63%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.001, respectively). Furthermore, myostatin\u2010b inhibited myostatin signalling induced by recombinant myostatin (68.8%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.001). In remarkable contrast, myostatin\u2010b did not inhibit the myostatin signalling induced by recombinant growth differentiation factor 11 (9.2%, <jats:italic>P<\/jats:italic>\u00a0=\u00a00.70), transforming growth factor \u03b2 (+3.1%, <jats:italic>P<\/jats:italic>\u00a0=\u00a00.83) or activin A (+1.1%, <jats:italic>P<\/jats:italic>\u00a0=\u00a00.96). These results indicate the myostatin\u2010specific inhibitory effect of myostatin\u2010b. Notably, the expression of myostatin\u2010b in myoblasts significantly enhanced cell proliferation higher than the mock\u2010transfected cells by the CCK\u20108 and direct cell counting assays (60%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.05 and 39%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.05, respectively). Myostatin\u2010b increased the percentage of S\u2010phase cells significantly higher than that of the mock\u2010transfected cells (53% vs. 80%, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a00.05).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>We cloned a novel human <jats:italic>MSTN<\/jats:italic> variant produced by unorthodox splicing. The variant encoded a novel myostatin isoform, myostatin\u2010b, that inhibited myostatin signalling by myostatin\u2010specific manner and enhanced myoblast proliferation by shifting cell cycle. Myostatin\u2010b, which has myostatin\u2010specific inhibitory activity, could be developed as a natural myostatin inhibitor.<\/jats:p><\/jats:sec>","DOI":"10.1002\/jcsm.13314","type":"journal-article","created":{"date-parts":[[2023,8,19]],"date-time":"2023-08-19T04:39:46Z","timestamp":1692419986000},"page":"2289-2300","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["A novel splice variant of the human <i>MSTN<\/i> gene encodes a myostatin\u2010specific myostatin inhibitor"],"prefix":"10.1002","volume":"14","author":[{"given":"Kazuhiro","family":"Maeta","sequence":"first","affiliation":[{"name":"KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation Kobe Gakuin University  Kobe Japan"},{"name":"Research Center for Locomotion Biology Kobe Gakuin University  Kobe Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manal","family":"Farea","sequence":"additional","affiliation":[{"name":"KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation Kobe Gakuin University  Kobe Japan"},{"name":"Research Center for Locomotion Biology Kobe Gakuin University  Kobe Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hisahide","family":"Nishio","sequence":"additional","affiliation":[{"name":"Research Center for Locomotion Biology Kobe Gakuin University  Kobe Japan"},{"name":"Department of Occupational Therapy, Faculty of Rehabilitation Kobe Gakuin University  Kobe Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6747-7194","authenticated-orcid":false,"given":"Masafumi","family":"Matsuo","sequence":"additional","affiliation":[{"name":"KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation Kobe Gakuin University  Kobe Japan"},{"name":"Research Center for Locomotion Biology Kobe Gakuin University  Kobe Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2023,8,15]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.cellbio.20.012103.135836"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.95.25.14938"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.151270098"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.2174\/187152210793663748"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1038\/387083a0"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.94.23.12457"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1038\/ng0997-71"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1038\/ng1810"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pgen.0030079"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa040933"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1097\/SPC.0000000000000013"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-981-13-1435-3_8"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1186\/1755-8794-4-36"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13395-017-0141-y"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.3390\/cells9122657"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajhg.2017.11.002"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cbd.2011.04.002"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.00187.2015"},{"key":"e_1_2_9_20_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0081713"},{"key":"e_1_2_9_21_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijms20184617"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0188821"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-74157-y"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1172\/JCI115244"},{"key":"e_1_2_9_25_1","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.2001.281.6.E1159"},{"key":"e_1_2_9_26_1","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/15.17.7155"},{"key":"e_1_2_9_27_1","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.273.33.21145"},{"key":"e_1_2_9_28_1","doi-asserted-by":"publisher","DOI":"10.1242\/jcs.195164"},{"key":"e_1_2_9_29_1","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkn073"},{"key":"e_1_2_9_30_1","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gku744"},{"key":"e_1_2_9_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cellsig.2011.05.003"},{"key":"e_1_2_9_32_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-017-01486-4"},{"key":"e_1_2_9_33_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2004.075069"},{"key":"e_1_2_9_34_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00439-017-1790-y"},{"key":"e_1_2_9_35_1","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.200207056"},{"key":"e_1_2_9_36_1","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M004356200"},{"key":"e_1_2_9_37_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbrc.2004.01.085"},{"key":"e_1_2_9_38_1","doi-asserted-by":"publisher","DOI":"10.1038\/s12276-020-00516-4"},{"key":"e_1_2_9_39_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0133713"},{"key":"e_1_2_9_40_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-81669-8"},{"key":"e_1_2_9_41_1","doi-asserted-by":"publisher","DOI":"10.1002\/jcsm.12899"}],"container-title":["Journal of Cachexia, Sarcopenia and Muscle"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jcsm.13314","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,13]],"date-time":"2023-10-13T01:45:23Z","timestamp":1697161523000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jcsm.13314"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,15]]},"references-count":40,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2023,10]]}},"alternative-id":["10.1002\/jcsm.13314"],"URL":"https:\/\/doi.org\/10.1002\/jcsm.13314","archive":["Portico"],"relation":{},"ISSN":["2190-5991","2190-6009"],"issn-type":[{"value":"2190-5991","type":"print"},{"value":"2190-6009","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,15]]},"assertion":[{"value":"2021-07-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-07-11","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-08-15","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}