Fibroblast growth factor receptor 3 regulates microtubule formation and cell surface mechanical properties in the developing organ of Corti.
Fibroblast growth factor receptor 3 regulates microtubule formation and cell surface mechanical properties in the developing organ of Corti.
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DOI：
10.4161/bioa.22332
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发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
Chadwick RS
中科院分区：
文献类型：
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作者：
Szarama KB;Stepanyan R;Petralia RS;Gavara N;Frolenkov GI;Kelley MW;Chadwick RS
成纤维细胞生长因子 (Fgf) 信号传导参与发育中的耳蜗的精致细胞模式，并且对于正常的听力功能是必需的。我们之前的数据表明，Fgf 信号传导会破坏肌动蛋白，从而影响柯蒂氏器中感觉外毛细胞 (OHC) 和非感觉支撑柱细胞 (PC) 的表面硬度。在这里，我们使用原子力显微镜 (AFM) 来测量 Fgf 受体 3 功能丧失对细胞骨架形成和细胞表面机械性能的影响。我们发现 OHC 和 PC 表面刚度均降低了 50%，并且 PC 中的微管形成受到显着破坏。此外，我们发现 Fgfr3 缺陷小鼠的 OHC 电动性没有变化。为了进一步了解 Fgf 信号对微管形成的调节，我们用 Fgf 受体激动剂 Fgf2 或拮抗剂 SU5402 处理野生型耳蜗外植体，发现两种处理都会导致 β-微管蛋白同种型 I 和 II 显着减少。为了确定 Fgf 信号传导的下游转录靶标，我们使用 QPCR 阵列探测 84 个细胞骨架调节因子。在治疗后显着上调的 5 个基因中，Clasp2、Mapre2 和 Mark2 影响微管形成。我们得出结论，微管形成是 Fgf 受体 3 的主要下游效应器，并表明该途径影响柯蒂氏器中液体空间的形成。
Fibroblast Growth Factor (Fgf) signaling is involved in the exquisite cellular patterning of the developing cochlea, and is necessary for proper hearing function. Our previous data indicate that Fgf signaling disrupts actin, which impacts the surface stiffness of sensory outer hair cells (OHCs) and non-sensory supporting pillar cells (PCs) in the organ of Corti. Here, we used Atomic Force Microscopy (AFM) to measure the impact of loss of function of Fgf-receptor 3, on cytoskeletal formation and cell surface mechanical properties. We find a 50% decrease in both OHC and PC surface stiffness, and a substantial disruption in microtubule formation in PCs. Moreover, we find no change in OHC electromotility of Fgfr3-deficient mice. To further understand the regulation by Fgf-signaling on microtubule formation, we treated wild-type cochlear explants with Fgf-receptor agonist Fgf2, or antagonist SU5402, and find that both treatments lead to a significant reduction in β-Tubulin isotypes I&II. To identify downstream transcriptional targets of Fgf-signaling, we used QPCR arrays to probe 84 cytoskeletal regulators. Of the 5 genes significantly upregulated following treatment, Clasp2, Mapre2 and Mark2 impact microtubule formation. We conclude that microtubule formation is a major downstream effector of Fgf-receptor 3, and suggest this pathway impacts the formation of fluid spaces in the organ of Corti.