Blockade of Hemichannels Normalizes the Differentiation Fate of Myoblasts and Features of Skeletal Muscles from Dysferlin-Deficient Mice.
Blockade of Hemichannels Normalizes the Differentiation Fate of Myoblasts and Features of Skeletal Muscles from Dysferlin-Deficient Mice.
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DOI：
10.3390/ijms21176025
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发表时间：
2020-08-21
影响因子：
5.6
通讯作者：
Sáez JC
中科院分区：
文献类型：
--
作者：
Cea LA;Fernández G;Arias-Bravo G;Castillo-Ruiz M;Escamilla R;Brañes MC;Sáez JC
dysferlin病是由编码dysferlin的基因突变引起的肌肉营养不良，dysferlin是一种用于膜修复和运输的相关蛋白质。这些疾病是无法治疗的，可能是由于对相关分子靶点的认识不足。以前，我们已经表明，来自患者活检的人肌纤维以及来自携带突变形式的dysferlin的永生化人成肌细胞的肌管表达连接蛋白蛋白，但它们与成肌细胞命运和功能的相关性仍然未知。在目前的工作中，我们发现许多携带突变dysferlin的成肌细胞在诱导获得肌源性承诺时表达PPARγ，揭示了脂肪形成而不是肌源性承诺。这些细胞培养物呈现出许多单核细胞和脂肪积聚，并且在分化的48小时内形成较少的多核细胞。相反，用连接蛋白半通道阻断剂boldine处理的dysferlin缺陷型成肌细胞既不表达PPARγ，也不积累脂肪，并形成与野生型前体细胞相似数量的多核细胞。我们最近证明，从布拉伊小鼠（dysferlinopathies的动物模型）的骨骼肌肌纤维表达三个连接蛋白（Cx39，Cx43和Cx45），形成功能性半通道（HC）的肌膜。在有症状的布拉伊小鼠中，我们现在表明，每日剂量的boldine治疗8周后，运动活动逐渐恢复正常。在该处理结束时，骨骼肌与野生型小鼠的骨骼肌相当，血清中CK活性正常。boldine处理布拉伊小鼠的肌纤维也表现出强烈的dysferlin样免疫反应性。这些发现表明，肌肉功能障碍是由突变的dysferlin和从头表达的下游连接蛋白半通道触发的病理生理机制引起的，导致肌生成急剧减少并有利于肌肉损伤。因此，boldine可以代表一个治疗机会，治疗dysfernilopathies。
Dysferlinopathies are muscle dystrophies caused by mutations in the gene encoding dysferlin, a relevant protein for membrane repair and trafficking. These diseases are untreatable, possibly due to the poor knowledge of relevant molecular targets. Previously, we have shown that human myofibers from patient biopsies as well as myotubes derived from immortalized human myoblasts carrying a mutated form of dysferlin express connexin proteins, but their relevance in myoblasts fate and function remained unknown. In the present work, we found that numerous myoblasts bearing a mutated dysferlin when induced to acquire myogenic commitment express PPARγ, revealing adipogenic instead of myogenic commitment. These cell cultures presented many mononucleated cells with fat accumulation and within 48 h of differentiation formed fewer multinucleated cells. In contrast, dysferlin deficient myoblasts treated with boldine, a connexin hemichannels blocker, neither expressed PPARγ, nor accumulated fat and formed similar amount of multinucleated cells as wild type precursor cells. We recently demonstrated that myofibers of skeletal muscles from blAJ mice (an animal model of dysferlinopathies) express three connexins (Cx39, Cx43, and Cx45) that form functional hemichannels (HCs) in the sarcolemma. In symptomatic blAJ mice, we now show that eight-week treatment with a daily dose of boldine showed a progressive recovery of motor activity reaching normality. At the end of this treatment, skeletal muscles were comparable to those of wild type mice and presented normal CK activity in serum. Myofibers of boldine-treated blAJ mice also showed strong dysferlin-like immunoreactivity. These findings reveal that muscle dysfunction results from a pathophysiologic mechanism triggered by mutated dysferlin and downstream connexin hemichannels expressed de novo lead to a drastic reduction of myogenesis and favor muscle damage. Thus, boldine could represent a therapeutic opportunity to treat dysfernilopathies.
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影响因子：
3.5
作者：
Chiu, Yen-Hui;Hornsey, Mark A.;Bushby, Kate
通讯作者：
Bushby, Kate
影响因子：
64.5
作者：
GU, W;SCHNEIDER, JW;NADALGINARD, B
通讯作者：
NADALGINARD, B
DOI：
10.1073/pnas.0711402105
发表时间：
2008-01-29
影响因子：
11.1
作者：
Aguiari, Paola;Leo, Sara;Rizzuto, Rosario
通讯作者：
Rizzuto, Rosario
影响因子：
6.5
作者：
Haynes, Vanessa R.;Keenan, Stacey N.;Watt, Matthew J.
通讯作者：
Watt, Matthew J.
影响因子：
--
作者：
Cea LA;Bevilacqua JA;Arriagada C;Cárdenas AM;Bigot A;Mouly V;Sáez JC;Caviedes P
通讯作者：
Caviedes P