Department of Biomedical Sciences for Health, University of Milan, 20054 Segrate, Italy.
Gastroenterology and Digestive Endoscopy Unit, IRCCS Policlinico San Donato, 20097 Milan, Italy.
Int J Mol Sci. 2022 Feb 27;23(5):2624. doi: 10.3390/ijms23052624.
BMD is characterized by a marked heterogeneity of gene mutations resulting in many abnormal dystrophin proteins with different expression and residual functions. The smaller dystrophin molecules lacking a portion around exon 48 of the rod domain, named the D8 region, are related to milder phenotypes. The study aimed to determine which proteins might contribute to preserving muscle function in these patients. Patients were subdivided, based on the absence or presence of deletions in the D8 region, into two groups, BMD1 and BMD2. Muscle extracts were analyzed by 2-D DIGE, label-free LC-ESI-MS/MS, and Ingenuity pathway analysis (IPA). Increased levels of proteins typical of fast fibers and of proteins involved in the sarcomere reorganization characterize BMD2. IPA of proteomics datasets indicated in BMD2 prevalence of glycolysis and gluconeogenesis and a correct flux through the TCA cycle enabling them to maintain both metabolism and epithelial adherens junction. A 2-D DIGE analysis revealed an increase of acetylated proteoforms of moonlighting proteins aldolase, enolase, and glyceraldehyde-3-phosphate dehydrogenase that can target the nucleus promoting stem cell recruitment and muscle regeneration. In BMD2, immunoblotting indicated higher levels of myogenin and lower levels of PAX7 and SIRT1/2 associated with a set of proteins identified by proteomics as involved in muscle homeostasis maintenance.
BMD 的特征是基因突变明显异质性，导致许多异常的肌营养不良蛋白，具有不同的表达和残留功能。较小的肌营养不良蛋白缺乏杆状结构域外显子 48 周围的一部分，称为 D8 区，与较温和的表型有关。本研究旨在确定哪些蛋白质可能有助于维持这些患者的肌肉功能。根据 D8 区缺失或存在与否，将患者分为两组，BMD1 和 BMD2。通过二维 DIGE、无标记 LC-ESI-MS/MS 和 IPA 对肌肉提取物进行分析。BMD2 中典型的快肌纤维蛋白和参与肌节重排的蛋白水平升高。蛋白质组学数据集的 IPA 分析表明，BMD2 中糖酵解和糖异生占优势，并且 TCA 循环的通量正确，使它们能够维持代谢和上皮黏附连接。二维 DIGE 分析显示，醛缩酶、烯醇酶和甘油醛-3-磷酸脱氢酶等 moonlighting 蛋白的乙酰化蛋白形式增加，这些蛋白可以靶向细胞核，促进干细胞募集和肌肉再生。在 BMD2 中，免疫印迹分析表明肌细胞生成素水平较高，PAX7 和 SIRT1/2 水平较低，与蛋白质组学鉴定的一组参与肌肉稳态维持的蛋白质有关。
