Vandenburgh Herman, Shansky Janet, Benesch-Lee Frank, Skelly Kirsten, Spinazzola Janelle M, Saponjian Yero, Tseng Brian S
Department of Pathology, Brown Medical School-Miriam Hospital, Providence, Rhode Island, USA.
FASEB J. 2009 Oct;23(10):3325-34. doi: 10.1096/fj.09-134411. Epub 2009 Jun 1.
Identification of factors that improve muscle function in boys with Duchenne muscular dystrophy (DMD) could lead to an improved quality of life. To establish a functional in vitro assay for muscle strength, mdx murine myoblasts, the genetic homologue of DMD, were tissue engineered in 96-microwell plates into 3-dimensional muscle constructs with parallel arrays of striated muscle fibers. When electrically stimulated, they generated tetanic forces measured with an automated motion tracking system. Thirty-one compounds of interest as potential treatments for patients with DMD were tested at 3 to 6 concentrations. Eleven of the compounds (insulin-like growth factor-1, creatine, beta-hydroxy-beta-methylbutyrate, trichostatin A, lisinopril, and 6 from the glucocorticoid family) significantly increased tetanic force relative to placebo-treated controls. The glucocorticoids methylprednisolone, deflazacort, and prednisone increased tetanic forces at low doses (EC(50) of 6, 19, and 56 nM, respectively), indicating a direct muscle mechanism by which they may be benefitting DMD patients. The tetanic force assay also identified beneficial compound interactions (arginine plus deflazacort and prednisone plus creatine) as well as deleterious interactions (prednisone plus creatine inhibited by pentoxifylline) of combinatorial therapies taken by some DMD patients. Since mdx muscle in vivo and DMD patients respond in a similar manner to many of these compounds, the in vitro assay will be a useful tool for the rapid identification of new potential treatments for muscle weakness in DMD and other muscle disorders.
识别可改善杜氏肌营养不良症（DMD）男孩肌肉功能的因素，可能会提高其生活质量。为建立一种用于肌肉力量的功能性体外检测方法，将DMD的基因同源物mdx小鼠成肌细胞在96孔板中进行组织工程化，形成具有平行排列横纹肌纤维的三维肌肉构建体。当受到电刺激时，它们会产生用自动运动跟踪系统测量的强直力。对31种作为DMD患者潜在治疗药物的感兴趣化合物进行了3至6种浓度的测试。其中11种化合物（胰岛素样生长因子-1、肌酸、β-羟基-β-甲基丁酸、曲古抑菌素A、赖诺普利以及6种糖皮质激素家族化合物）相对于安慰剂处理的对照组，显著增加了强直力。糖皮质激素甲泼尼龙、地夫可特和泼尼松在低剂量时（分别为6、19和56 nM的半数有效浓度）增加了强直力，表明它们可能使DMD患者受益的直接肌肉机制。强直力检测还确定了有益的化合物相互作用（精氨酸加地夫可特以及泼尼松加肌酸）以及一些DMD患者联合治疗中的有害相互作用（泼尼松加肌酸被己酮可可碱抑制）。由于mdx小鼠体内肌肉和DMD患者对许多这些化合物的反应相似，这种体外检测将成为快速识别DMD和其他肌肉疾病肌肉无力新潜在治疗方法的有用工具。
