Canonical transient receptor potential 6 channel deficiency promotes smooth muscle cells dedifferentiation and increased proliferation after arterial injury.
Canonical transient receptor potential 6 channel deficiency promotes smooth muscle cells dedifferentiation and increased proliferation after arterial injury.
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规范瞬态受体电位6通道缺乏促进平滑肌细胞去分化并增加动脉损伤后增殖。
DOI：
10.1016/j.jvssci.2020.07.002
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Graham LM
中科院分区：
文献类型：
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作者：
Smith AH;Putta P;Driscoll EC;Chaudhuri P;Birnbaumer L;Rosenbaum MA;Graham LM
先前的研究表明，经典瞬时受体电位 6 (TRPC6) 通道缺陷有助于促进高胆固醇血症动物动脉损伤的内皮愈合。利用颈动脉线损伤模型在野生型 (WT) 和 TRPC6-/- 小鼠中进行了长期研究，以确定 TRPC6 对血管平滑肌细胞 (SMC) 表型调节和新内膜增生的影响。我们假设 TRPC6 对于维持或重新表达分化的 SMC 表型以及最大限度地减少动脉损伤后的管腔狭窄至关重要。在基线和线损伤后 4 周对 WT 和 TRPC6-/- 小鼠的颈总动脉 (CCA) 进行评估。在基线时，TRPC6-/- 小鼠的 CCA MYH11 和 SM22 染色减少、弹性蛋白层减少、管腔扩张和管壁变薄。颈动脉线损伤后，与 WT 小鼠相比，TRPC6-/- 小鼠出现明显更明显的管腔狭窄。与 WT CCA 相比，受损的 TRPC6-/- CCA 表现出增加的内侧/内膜细胞数量和活跃的细胞增殖。免疫组织化学表明，在金属丝损伤后 28 天，WT CCA 中内侧 SMC 中收缩生物标志物的表达基本上处于基线水平。相比之下，在受伤后 28 天，来自 TRPC6-/- CCA 的内侧 SMC 显示收缩生物标志物的表达相对于基线水平显着下降。为了评估 TRPC6 在全身动脉 SMC 表型调节中的作用，从 WT 和 TRPC6-/- 小鼠的胸主动脉采集 SMC 并进行表征。 TRPC6-/- SMC 显示出响应血清刺激的增强的增殖和迁移。收缩表型生物标志物 MYH11 和 SM22 的表达在 TRPC6-/- SMC 中减弱。 siRNA 介导的 TRPC6 缺陷抑制小鼠 SMC 系中收缩生物标志物的表达。这些结果表明 TRPC6 有助于损伤后动脉 SMC 收缩表型的恢复或维持。了解 TRPC6 在表型调节中的作用可能会导致基于机制的 IH 减弱疗法。血管内介入和开放性血管手术后，血管平滑肌细胞（VSMC）会进行基因表达的协调重编程，以促进动脉愈合。 VSMC 特异性收缩生物标志物（例如 SM22 和 MYH11）的下调以及促进细胞增殖、迁移和基质合成的途径的诱导是这种表型转换的标志。失调的表型转换导致新内膜增生和血管再狭窄的发生。因此，识别调节或限制 VSMC 表型调节的途径有可能减少新生内膜增生并改善血管干预后的结果。在这项研究中，我们证明非电压门控阳离子通道 TRPC6 的耗竭会促进表型转换和系统动脉 VSMC 中收缩生物标志物的损失。颈动脉线损伤后，与野生型小鼠相比，TRPC6-/- 小鼠出现更明显的管腔狭窄。这些结果表明TRPC6有助于损伤后VSMC收缩表型的恢复或维持。了解 TRPC6 在表型转换中的作用可能会导致基于机制的治疗来减轻再狭窄。
Previous studies showed the benefit of canonical transient receptor potential 6 (TRPC6) channel deficiency in promoting endothelial healing of arterial injuries in hypercholesterolemic animals. Long-term studies utilizing a carotid wire-injury model were undertaken in wild-type (WT) and TRPC6-/- mice to determine the effects of TRPC6 on phenotypic modulation of vascular smooth muscle cells (SMC) and neointimal hyperplasia. We hypothesized that TRPC6 was essential in the maintenance or reexpression of a differentiated SMC phenotype and minimized luminal stenosis following arterial injury. The common carotid arteries (CCA) of WT and TRPC6-/- mice were evaluated at baseline and 4 weeks after wire injury. At baseline, CCA of TRPC6-/- mice had reduced staining of MYH11 and SM22, fewer elastin lamina, luminal dilation, and wall thinning. After carotid wire injury, TRPC6-/- mice developed significantly more pronounced luminal stenosis compared with WT mice. Injured TRPC6-/- CCA demonstrated increased medial/intimal cell number and active cell proliferation when compared with WT CCA. Immunohistochemistry suggested that expression of contractile biomarkers in medial SMC were essentially at baseline levels in WT CCA at 28 days after wire injury. By contrast, at 28 days after injury medial SMC from TRPC6-/- CCA showed a significant decrease in the expression of contractile biomarkers relative to baseline levels. To assess the role of TRPC6 in systemic arterial SMC phenotype modulation, SMC were harvested from thoracic aortae of WT and TRPC6-/- mice and were characterized. TRPC6-/- SMC showed enhanced proliferation and migration in response to serum stimulation. Expression of contractile phenotype biomarkers, MYH11 and SM22, was attenuated in TRPC6-/- SMC. siRNA-mediated TRPC6 deficiency inhibited contractile biomarker expression in a mouse SMC line. These results suggest that TRPC6 contributes to the restoration or maintenance of arterial SMC contractile phenotype following injury. Understanding the role of TRPC6 in phenotypic modulation may lead to mechanism-based therapies for attenuation of IH. After endovascular intervention and open vascular surgery, vascular smooth muscle cells (VSMC) undergo a coordinated reprogramming of gene expression to facilitate arterial healing. Down regulation of VSMC-specific contractile biomarkers (eg, SM22 and MYH11) and induction of pathways that promote cell proliferation, migration, and matrix synthesis are hallmarks of this phenotypic switch. Dysregulated phenotypic switching leads to the development of neointimal hyperplasia and vascular restenosis. Identifying pathways that regulate or constrain VSMC phenotypic modulation, therefore, has the potential to decrease neointimal hyperplasia and improve outcomes after vascular intervention. In this study, we demonstrate that depletion of the non-voltage-gated cation channel TRPC6 promotes phenotypic switching and loss of contractile biomarkers in systemic arterial VSMC. TRPC6-/- mice developed significantly more pronounced luminal stenosis compared with wild-type mice after carotid wire injury. These results suggest that TRPC6 contributes to the restoration or maintenance of contractile phenotype in VSMC after injury. Understanding the role of TRPC6 in phenotypic switching may lead to mechanism-based therapies to mitigate restenosis.