Laboratorio de Endocrinología Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.
Departamento de Ciencias Morfológicas, Universidad de Santiago de Compostela (USC), Santiago de Compostela, Spain.
J Cachexia Sarcopenia Muscle. 2018 Dec;9(6):1063-1078. doi: 10.1002/jcsm.12338. Epub 2018 Sep 14.
This study was performed to test the therapeutic potential of obestatin, an autocrine anabolic factor regulating skeletal muscle repair, to ameliorate the Duchenne muscular dystrophy (DMD) phenotype.
Using a multidisciplinary approach, we characterized the ageing-related preproghrelin/GPR39 expression patterns in tibialis anterior (TA) muscles of 4-, 8-, and 18-week-old mdx mice (n = 3/group) and established the effects of obestatin administration at this level in 8-week-old mdx mice (n = 5/group). The findings were extended to in vitro effects on human immortalized DMD myotubes. An analysis of TAs revealed an age-related loss of preproghrelin expression, as precursor of obestatin, in mdx mice. Administration of obestatin resulted in a significant increase in tetanic specific force (33.0% ± 1.5%, P < 0.05), compared with control mdx mice. Obestatin-treated TAs were characterized by reduction of fibres with centrally located nuclei (10.0% ± 1.2%, P < 0.05) together with an increase in the number of type I fibres (25.2% ± 1.7%, P < 0.05) associated to histone deacetylases/myocyte enhancer factor-2 and peroxisome proliferator-activated receptor-gamma coactivator 1α axis, and down-regulation of ubiquitin E3-ligases by inactivation of FoxO1/4, indexes of muscle atrophy. Obestatin reduced the level of contractile damage and tissue fibrosis. These observations correlated with decline in serum creatine kinase (58.8 ± 15.2, P < 0.05). Obestatin led to stabilization of the sarcolemma by up-regulation of utrophin, α-syntrophin, β-dystroglycan, and α7β1-integrin proteins. These pathways were also operative in human DMD myotubes.
These results highlight the potential of obestatin as a peptide therapeutic for preserving muscle integrity in DMD, thus allowing a better efficiency of gene or cell therapy in a combined therapeutic approach.
本研究旨在测试自分泌合成代谢因子肥胖素（obestatin）的治疗潜力，以改善杜氏肌营养不良症（DMD）表型。
我们采用多学科方法，研究了 4、8 和 18 周龄 mdx 小鼠（每组 3 只）胫骨前肌（TA）中前胃泌素/GPR39 表达模式的老化相关情况，并在 8 周龄 mdx 小鼠（每组 5 只）中确定了肥胖素的给药效果。研究结果还扩展到了对人类永生化 DMD 肌管的体外作用。TA 分析显示，mdx 小鼠中作为肥胖素前体的前胃泌素表达随年龄增长而丧失。与对照组 mdx 小鼠相比，肥胖素治疗组的强直收缩力显著增加（33.0%±1.5%，P<0.05）。肥胖素处理的 TA 表现为纤维中中心核的数量减少（10.0%±1.2%，P<0.05），同时 I 型纤维数量增加（25.2%±1.7%，P<0.05），与组蛋白去乙酰化酶/肌细胞增强因子-2 和过氧化物酶体增殖物激活受体-γ共激活因子 1α 轴有关，FoxO1/4 失活导致泛素 E3 连接酶下调，这些都是肌肉萎缩的指标。肥胖素降低了收缩损伤和组织纤维化的程度。这些观察结果与血清肌酸激酶水平的下降相关（58.8±15.2，P<0.05）。肥胖素通过上调 utrophin、α- 合成素、β- 肌营养不良蛋白和 α7β1-整联蛋白蛋白来稳定肌膜。这些途径在人类 DMD 肌管中也是有效的。
这些结果强调了肥胖素作为一种肽类治疗药物的潜力，可用于维持 DMD 肌肉的完整性，从而在联合治疗方法中提高基因或细胞治疗的效率。
