Language：English   Publisher：Biomedical Research Press  

<p>Myogenesis is required to generate skeletal muscle tissue and to maintain skeletal muscle mass. Decreased myogenesis under various pathogenic conditions results in muscular atrophy. Through a small screening of Japanese traditional (Kampo) medicines, hachimijiogan (HJG) was shown to promote the myogenic differentiation of C2C12 myoblasts through the upregulation of myogenin. In tumor-bearing cancer-cachectic mice, HJG was also found to have a protective effect against cancer-cachectic muscle wasting. This effect was significant when HJG was administered in combination with aerobic exercise by treadmill running. Moreover, HJG ameliorated the cellular atrophy of C2C12 myotubes induced by treatment with conditioned medium derived from a colon-26 cancer cell culture. In addition, HJG suppressed H2O2-dependent myotube atrophy, suggesting that HJG could reverse the atrophic phenotypes by eliminating reactive oxygen species.</p>

DOI： 10.2220/biomedres.44.199

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PubMed

Language：English   Publisher：バイオメディカルリサーチプレス  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Biomedical Research Press  

<p>A live assay tool has been established to uncover the precise molecular mechanisms underlying complex cell fusion events in myoblasts. The novel cell-based assay, HiMy (HiBiT-based myoblast fusion), utilizes a recently developed split-luciferase technology. The assay successfully detected cell fusion in differentiating C2C12 myoblast cultures. This allowed us to measure mixing of the cytoplasm, which occurred several hours after the initiation of C2C12 differentiation. Unlike what was reported earlier, the fusion was detected a few hours after the initiation of differentiation. Thus, this assay is sensitive enough to monitor fusion events before they become detectable using conventional methods. Furthermore, a panel of laboratory compounds, including a variety of inhibitors of cellular enzymes or activities, were assayed using the HiMy assay. Lovastatin, a cholesterol biogenesis inhibitor, decreased HiMy activity by approximately 50%. In contrast, mevalonolactone, a precursor for cholesterol synthesis, increased fusion activity. These results confirmed the previous finding that the amount of cellular cholesterol positively correlates with the rate of myoblast fusion during myogenesis. These results indicate that the novel cell fusion assay is a quick, accurate, and robust method to monitor intercellular fusion events.</p>

DOI： 10.2220/biomedres.43.107

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PubMed

Language：English   Publisher：バイオメディカルリサーチプレス  

スプリットルシフェラーゼ法を利用したHiMy(HiBiTに基づく筋芽細胞融合)によって、C2C12筋芽細胞培養における細胞融合を検出できたので報告した。これによりC2C12の分化開始の数時間後に起こる細胞質の混合を測定できた。以前に報告されていたのとは異なり、融合は分化開始の数時間後に検出された。本法は感度が高く、通常の方法で検出される以前に融合を検出できた。細胞酵素阻害剤などを含む化合物を、HiMyを用いて測定した。コレステロール合成阻害剤ロバスタチンはHiMy活性を約50%まで低下させ、コレステロール合成前駆体メバロノラクトンは融合活性を上昇させた。この新規細胞融合測定法は、細胞の融合を検出する迅速かつ正確な方法であると考えられた。

Language：English   Publishing type：Research paper (scientific journal)  

The morphology of the Golgi complex is influenced by the cellular context, which strictly correlates with nuclear functions; however, the mechanism underlying this association remains elusive. The inner nuclear membrane SUN proteins, SUN1 and SUN2, have diverse functions together with the outer nuclear membrane nesprin proteins, which comprise the LINC complex. We found that depletion of SUN1 leads to Golgi complex dispersion with maintenance of ministacks and retained function for vesicle transport through the Golgi complex. In addition, SUN2 associates with microtubule plus-end-directed motor KIF20A, possibly via nesprin-2. KIF20A plays a role in the Golgi dispersion in conjunction with the SUN2-nesprin-2 LINC complex in SUN1-depleted cells, suggesting that SUN1 suppresses the function of the SUN2-nesprin-2 LINC complex under a steady-state condition. Further, SUN1-knockout mice, which show impaired cerebellar development and cerebellar ataxia, presented altered Golgi morphology in Purkinje cells. These findings revealed a regulation of the Golgi organization by the LINC complex.

DOI： 10.1038/s41598-021-84750-4

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PubMed

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