Section of Pharmacology, Department of Pharmacy-Drug Sciences, Orabona 4-Campus, University of Bari "Aldo Moro", 70125 Bari, Italy.
Section of Pharmaceutical Technologies, Department of Pharmacy-Drug Sciences, Orabona 4-Campus, University of Bari "Aldo Moro", 70125 Bari, Italy.
Biomolecules. 2021 Nov 22;11(11):1742. doi: 10.3390/biom11111742.
ROS-activated cSrc tyrosine kinase (TK) promotes the degradation of β-dystroglycan (β-DG), a dystrophin-glycoprotein complex component, which may reinforce damaging signals in Duchenne muscular dystrophy (DMD). Therefore, cSrc-TK represents a promising therapeutic target. In mice, a 4-week subcutaneous treatment with dasatinib (DAS), a pan-Src-TKs inhibitor approved as anti-leukemic agent, increased muscle β-DG, with minimal amelioration of morphofunctional indices. To address possible dose/pharmacokinetic (PK) issues, a new oral DAS/hydroxypropyl(HP)-β-cyclodextrin(CD) complex was developed and chronically administered to mice. The aim was to better assess the role of β-DG in pathology progression, meanwhile confirming DAS mechanism of action over the long-term, along with its efficacy and tolerability. The 4-week old mice underwent a 12-week treatment with DAS/HP-β-CD10% dissolved in drinking water, at 10 or 20 mg/kg/day. The outcome was evaluated via in vivo/ex vivo disease-relevant readouts. Oral DAS/HP-β-CD efficiently distributed in mice plasma and tissues in a dose-related fashion. The new DAS formulation confirmed its main upstream mechanism of action, by reducing β-DG phosphorylation and restoring its levels dose-dependently in both diaphragm and gastrocnemius muscle. However, it modestly improved in vivo neuromuscular function, ex vivo muscle force, and histopathology, although the partial recovery of muscle elasticity and the decrease of CK and LDH plasma levels suggest an increased sarcolemmal stability of dystrophic muscles. Our clinically oriented study supports the interest in this new, pediatric-suitable DAS formulation for proper exposure and safety and for enhancing β-DG expression. This latter mechanism is, however, not sufficient by itself to impact on pathology progression. In-depth analyses will be dedicated to elucidating the mechanism limiting DAS effectiveness in dystrophic settings, meanwhile assessing its potential synergy with dystrophin-based molecular therapies.
ROS 激活的 cSrc 酪氨酸激酶 (TK) 促进了β-肌营养不良糖蛋白复合物成分β-二聚糖 (β-DG) 的降解，这可能会增强杜氏肌营养不良症 (DMD) 中的损伤信号。因此，cSrc-TK 代表了一个有前途的治疗靶点。在小鼠中，用达沙替尼 (DAS) 进行为期 4 周的皮下治疗，达沙替尼是一种批准用于抗白血病的泛Src-TK 抑制剂，可增加肌肉中的β-DG，但形态功能指数的改善最小。为了解决可能的剂量/药代动力学 (PK) 问题，开发了一种新的口服 DAS/羟丙基 (HP)-β-环糊精 (CD) 复合物，并对 小鼠进行了慢性给药。目的是更好地评估 β-DG 在疾病进展中的作用，同时确认 DAS 的长期作用机制及其疗效和耐受性。4 周龄的 小鼠接受了为期 12 周的治疗，用 DAS/HP-β-CD10%溶于饮用水中，剂量为 10 或 20mg/kg/天。通过体内/体外与疾病相关的指标来评估结果。口服 DAS/HP-β-CD 以剂量相关的方式在 小鼠的血浆和组织中有效分布。新的 DAS 制剂证实了其主要的上游作用机制，通过降低β-DG 的磷酸化并以剂量依赖的方式恢复其在膈肌和比目鱼肌中的水平。然而，它适度地改善了体内神经肌肉功能、体外肌肉力量和组织病理学，尽管肌肉弹性的部分恢复以及 CK 和 LDH 血浆水平的降低表明营养不良肌肉的肌膜稳定性增加。我们的临床导向研究支持了对这种新的、适合儿科的 DAS 制剂的兴趣，以获得适当的暴露和安全性，并增强β-DG 的表达。然而，仅这一机制本身不足以影响疾病的进展。深入分析将致力于阐明限制 DAS 在营养不良环境中有效性的机制，同时评估其与基于肌营养不良蛋白的分子治疗的潜在协同作用。
