SIRT1 deficiency interferes with membrane resealing after cell membrane injury
SIRT1 deficiency interferes with membrane resealing after cell membrane injury
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DOI：
10.1371/journal.pone.0218329
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发表时间：
2019-06-26
期刊：
影响因子：
3.7
通讯作者：
Horio, Yoshiyuki
中科院分区：
文献类型：
--
作者：
Fujiwara, Daisuke;Iwahara, Naotoshi;Horio, Yoshiyuki
SIRT 1（一种NAD（+）依赖性蛋白脱乙酰酶）的激活可改善δ-肌聚糖缺陷TO-2仓鼠和肌营养不良蛋白缺陷mdx小鼠的肌肉病理生理学。我们发现SIRT 1在肌肉细胞的细胞膜下高度表达。为了阐明SIRT 1对肌肉的功能作用，产生了骨骼肌特异性SIRT 1敲除小鼠（SIRT 1-MKO）。SIRT 1-MKO小鼠表现出与轻度肌营养不良相似的肌肉病理学，与野生型（WT）小鼠相比，中央有核小肌纤维数量增加，中型（2000-3001 μ m（2））肌纤维数量减少。因此，与WT小鼠相比，SIRT 1-MKO小鼠在跑步机和倒立悬挂试验中表现出显著降低的运动能力，血清肌酸激酶活性水平较高。运动后SIRT 1-MKO小鼠肌肉的伊文思蓝染料摄取量高于WT小鼠，表明SIRT 1-MKO小鼠的膜脆性。由于SIRT 1主要定位于肌细胞膜下，因此SIRT 1可能在肌细胞膜中具有新的作用。我们发现，与对照细胞相比，SIRT 1抑制剂或Sirt 1-siRNA显著增加了激光诱导C2 C12细胞膜破裂后荧光FM 1 -43染料摄入量。抑制SIRT 1或SIRT 1敲低严重扰乱了损伤部位下膜囊泡的动态聚集，但不影响膜修复蛋白的表达水平。这些数据表明，SIRT 1在膜破裂的肌肉细胞的重新密封中具有关键作用，这可能影响SIRT 1-MKO小鼠的表型。据我们所知，这份报告是第一份证明SIRT 1影响质膜修复机制的报告。
Activation of SIRT1, an NAD(+)-dependent protein deacetylase, ameliorates muscular pathophysiology of delta-sarcoglycan-deficient TO-2 hamsters and dystrophin-deficient mdx mice. We found that SIRT1 was highly expressed beneath the cellular membranes of muscle cells. To elucidate functional roles of SIRT1 on muscles, skeletal muscle-specific SIRT1 knockout mice (SIRT1-MKO) were generated. SIRT1-MKO mice showed muscular pathology similar to mild muscular dystrophies with increased numbers of centrally nucleated small myofibers and decreased numbers of middle-sized (2000-3001 mu m(2)) myofibers compared to those of wild-type (WT) mice. Accordingly, SIRT1-MKO mice showed significantly decreased exercise capacity in treadmill and inverted hanging tests with higher levels of serum creatine kinase activities compared with those in WT mice. Evans blue dye uptake after exercise was greater in the muscles of SIRT1-MKO than those of WT mice, suggesting membrane fragility in SIRT1-MKO mice. Because SIRT1 was dominantly localized beneath the membranes of muscular cells, SIRT1 may have a new role in the membranes. We found that levels of fluorescent FM1-43 dye intake after laser-induced membrane disruption in C2C12 cells were significantly increased by SIRT1 inhibitors or Sirt1-siRNA compared with those of control cells. Inhibition of SIRT1 or SIRT1-knockdown severely disturbed the dynamic aggregation of membrane vesicles under the injured site but did not affect expression levels of membrane repair proteins. These data suggested that SIRT1 had a critical role in the resealing of membrane-ruptured muscle cells, which could affect phenotypes of SIRT1-MKO mice. To our knowledge, this report is the first to demonstrate that SIRT1 affected plasma-membrane repair mechanisms.