Meehan Daniel T, Brockhouse Julia, Connell Katherine, Madison Jacob, Gratton Michael Anne, Cosgrove Dominic
Boys Town National Research Hospital, Omaha NE, USA.
Boys Town National Research Hospital, Omaha NE, USA.
Hear Res. 2025 Aug 5;466:109383. doi: 10.1016/j.heares.2025.109383.
We previously demonstrated that endothelin A receptor (ETR) signaling plays a major role in regulating strial pathology in the COL4A3 knockout mouse model for Alport syndrome. Blocking the receptor prevented accumulation of extracellular matrix (ECM) in the strial capillary basement membranes (SCBMs) including laminin α2. Herein, we explored whether α-dystroglycan receptors for laminin α2 are present on cultured strial pericytes, marginal cells, and intermediate cells, as well as in intact stria vascularis. We performed comparative analysis of gene expression in isolated glomeruli and stria vascularis from wild type and Alport mice using RNA-seq. We examined the effects of endothelin treatment of pericytes on cytoskeletal dynamics and CDC42 activation using immunofluorescence, and on cell signaling using phosphoantibody microarrays. mRNA encoding α-dystroglycan receptors are present in strial cell lines as well as RNA from micro dissected stria vascularis. These same receptors were found adjacent to the capillary basement membranes on strial endothelial cells, marginal cells, intermediate cells, and pericytes in vivo by immunofluorescence. RNA-seq analysis of RNA from wild type and Alport glomeruli and stria vascularis revealed similar regulation of genes implicated in the pathogenesis of both organs. Treatment of pericytes with endothelin-1 (ET-1) resulted in changes in cell signaling consistent with observed reduction of filamentous to globular actin ratios and cell adhesion. Therefore, the induction of laminin α2 likely contributes to strial pathology in Alport syndrome via signaling through α-dystroglycan receptors. ET-1 activation of ETRs directly contributes to altered cell signaling in strial pericytes, resulting in changes in actin cytoskeletal dynamics.
我们之前证明，在内皮素A受体（ETR）信号传导在调节Alport综合征的COL4A3基因敲除小鼠模型的螺旋韧带病理过程中起主要作用。阻断该受体可防止包括层粘连蛋白α2在内的螺旋韧带毛细血管基底膜（SCBMs）中细胞外基质（ECM）的积累。在此，我们探究了层粘连蛋白α2的α - 肌营养不良蛋白聚糖受体是否存在于培养的螺旋韧带周细胞、边缘细胞和中间细胞以及完整的血管纹中。我们使用RNA测序对野生型和Alport小鼠分离的肾小球和血管纹中的基因表达进行了比较分析。我们使用免疫荧光检查了内皮素处理周细胞对细胞骨架动力学和CDC42激活的影响，并使用磷酸化抗体微阵列检查了对细胞信号传导的影响。编码α - 肌营养不良蛋白聚糖受体的mRNA存在于螺旋韧带细胞系以及显微解剖的血管纹RNA中。通过免疫荧光在体内发现这些相同的受体位于螺旋韧带内皮细胞、边缘细胞、中间细胞和周细胞的毛细血管基底膜附近。对野生型和Alport肾小球及血管纹的RNA进行RNA测序分析，揭示了与两个器官发病机制相关基因的相似调控。用内皮素 - 1（ET - 1）处理周细胞导致细胞信号传导发生变化，这与观察到的丝状肌动蛋白与球状肌动蛋白比例降低和细胞粘附一致。因此，层粘连蛋白α2的诱导可能通过α - 肌营养不良蛋白聚糖受体信号传导导致Alport综合征的螺旋韧带病理。ETR的ET - 1激活直接导致螺旋韧带周细胞中细胞信号传导改变，从而导致肌动蛋白细胞骨架动力学变化。
