Cerri Daniel Giuliano, Rodrigues Lilian Cataldi, Alves Vani Maria, Machado Juliano, Bastos Víctor Alexandre Félix, Carmo Kettelhut Isis do, Alberici Luciane Carla, Costa Maria Cristina R, Stowell Sean R, Cummings Richard D, Dias-Baruffi Marcelo
Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café, s/n - Campus da USP, 14040-903- Ribeirão Preto, São Paulo, Brazil.
Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, 14049-900 - Ribeirão Preto, São Paulo, Brazil.
Glycobiology. 2021 Nov 18;31(10):1295-1307. doi: 10.1093/glycob/cwab071.
Skeletal muscle has the intrinsic ability to self-repair through a multifactorial process, but many aspects of its cellular and molecular mechanisms are not fully understood. There is increasing evidence that some members of the mammalian β-galactoside-binding protein family (galectins) are involved in the muscular repair process (MRP), including galectin-3 (Gal-3). However, there are many questions about the role of this protein on muscle self-repair. Here, we demonstrate that endogenous Gal-3 is required for: (i) muscle repair in vivo by using a chloride-barium myolesion mouse model and (ii) mouse primary myoblasts myogenic programming. Injured muscle from Gal-3 knockout mice (GAL3KO) showed persistent inflammation associated with compromised muscle repair and the formation of fibrotic tissue on the lesion site. In GAL3KO mice, osteopontin expression remained high even after 7 and 14 d of the myolesion, while Myoblast differentiation transcription factor (MyoD) and myogenin had decreased their expression. In GAL3KO mouse primary myoblast cell culture, Paired Box 7 (Pax7) detection seems to sustain even when cells are stimulated to differentiation and MyoD expression is drastically reduced. The detection and temporal expression levels of these transcriptional factors appear to be altered in Gal-3-deficient myoblast. Gal-3 expression in wild-type mice for GAL3KO states, both in vivo and in vitro, in sarcoplasm/cytoplasm and myonuclei; as differentiation proceeds, Gal-3 expression is drastically reduced, and its location is confined to the sarcolemma/plasma cell membrane. We also observed a change in the temporal-spatial profile of Gal-3 expression and muscle transcription factors levels during the myolesion. Overall, these results demonstrate that endogenous Gal-3 is required for the skeletal muscle repair process.
骨骼肌具有通过多因素过程进行自我修复的内在能力，但其细胞和分子机制的许多方面尚未完全了解。越来越多的证据表明，哺乳动物β-半乳糖苷结合蛋白家族（半乳凝素）的一些成员参与肌肉修复过程（MRP），包括半乳凝素-3（Gal-3）。然而，关于这种蛋白质在肌肉自我修复中的作用仍有许多问题。在这里，我们证明内源性Gal-3对于：（i）通过使用氯化钡肌损伤小鼠模型在体内进行肌肉修复，以及（ii）小鼠原代成肌细胞的肌源性编程是必需的。来自Gal-3基因敲除小鼠（GAL3KO）的损伤肌肉显示出持续的炎症，伴有受损的肌肉修复以及损伤部位纤维化组织的形成。在GAL3KO小鼠中，即使在肌损伤7天和14天后，骨桥蛋白的表达仍保持高水平，而成肌细胞分化转录因子（MyoD）和肌细胞生成素的表达则下降。在GAL3KO小鼠原代成肌细胞培养中，即使细胞被刺激分化且MyoD表达大幅降低，配对盒7（Pax7）的检测似乎仍持续存在。在Gal-3缺陷的成肌细胞中，这些转录因子的检测和时间表达水平似乎发生了改变。在野生型小鼠中，对于GAL3KO状态，Gal-3在体内和体外的肌浆/细胞质和肌核中均有表达；随着分化的进行，Gal-3的表达大幅降低，其位置局限于肌膜/质膜。我们还观察到在肌损伤过程中Gal-3表达和肌肉转录因子水平的时空分布变化。总体而言，这些结果表明内源性Gal-3是骨骼肌修复过程所必需的。
