Rab11a Regulates the Development of Cilia and Establishment of Planar Cell Polarity in Mammalian Vestibular Hair Cells.
Rab11a Regulates the Development of Cilia and Establishment of Planar Cell Polarity in Mammalian Vestibular Hair Cells.
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Rab11a 调节哺乳动物前庭毛细胞纤毛的发育和平面细胞极性的建立。
DOI：
10.3389/fnmol.2021.762916
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发表时间：
2021
影响因子：
4.8
通讯作者：
Ren DD
中科院分区：
文献类型：
--
作者：
Chen BJ;Qian XQ;Yang XY;Jiang T;Wang YM;Lyu JH;Chi FL;Chen P;Ren DD
Rab 11 a单突变和Rab 11 a/IFT 88双突变椭圆囊纹外毛细胞静纤毛的形态学变化(A)小鼠左内耳的内侧视图及其五个前庭感觉器官（灰色）。放大的胞果显示了它们的分支，LPR（黄线）和条纹（蓝色）。LES，外侧纹状体; MES，内侧纹状体; LPR，极性反转线。(B)前庭毛细胞示意图。Kinocilium标记有Ace-微管蛋白。基体以γ-微管蛋白标记。（C、C1、D、D1）野生型对照的纹外毛细胞的静纤毛的正常外观。（E、E1、F、F1）Rab 11aCKO/CKO动物的形态学改变。（G，G1，H，H1）Rab 11aCKO/CKO/IFT 88 CKO/+小鼠静纤毛形态学变化更严重。(I-L)毛细胞的共聚焦图像的高倍放大。(M-P)野生型对照和Rab 11 a突变体毛细胞的扫描电子显微镜图像。（I，M）正常形态。野生型对照的毛细胞。（J，N）Rab 11 a突变体中单个毛细胞上的静纤毛数量减少。（K，O）与野生型对照相比，突变体中的静纤毛较短。（L，P）Rab 11 a突变小鼠毛细胞的阶梯状毛束结构丢失。(Q)将在纹状体外区域中具有静态纤毛束的异常发育的毛细胞的百分比计数为占总毛细胞的百分比（n = 5）。Rab 11aCKO/CKO、IPT 88 CKO/+小鼠毛细胞异常率高于Rab 11aCKO/CKO小鼠。单、双基因敲除毛细胞的异常率分别为42.1 ± 5.7和71.5 ± 10.4。在（A-J）中，对于所有初级图，毛细胞静纤毛束用鬼笔环肽（绿色）标记，毛细胞的富含肌动蛋白的表皮板用β-血影蛋白（红色）标记，而毛细胞的基体用γ-微管蛋白（蓝色）标记。比例尺：10 μm（C-H1），5 μm（J-N）。*P < 0.05。前庭器官具有独特的平面细胞极性（图1A），其正常发育和功能依赖于纤毛的规则极性（图1B）要求。Rab 11 a是一种小G蛋白，参与极性形成所需的细胞内和细胞外物质的运输;然而，我们对Rab 11 a在前庭器官中的作用机制的理解是有限的。在这里，我们发现，在Rab 11aCKO/CKO小鼠的椭圆囊的一般形状是异常的。这些小鼠还表现出静纤毛束的异常形态，其长度和数量均减少，以及组织水平极性紊乱。Rab 11 a影响极性蛋白在前庭器官中的分布，表明纤毛的正常发育需要Rab 11 a和鞭毛内运输。此外，在纤毛的正常发育中，小G蛋白的迁移与鞭毛内运输一起起作用。
Morphological changes of stereocilia in the extrastriolar hair cells from Rab11a single or Rab11a/IFT88 double-mutant utricles. (A) Medial view of a mouse left inner ear with its five vestibular sensory organs (gray). Enlarged are the utricle showing their subdivisions, LPR (yellow line), and striola (blue). LES, lateral extrastriola; MES, medial extrastriola; LPR, line of polarity reversal. (B) Schematic view of vestibular hair cell. Kinocilium is marked with ace-tubulin. Basal body is marked with γ-tubulin. (C,C1,D,D1) Normal appearance of the stereocilia of extrastriolar hair cells of wild-type controls. (E,E1,F,F1) Altered morphology in Rab11aCKO/CKO animals. (G,G1,H,H1) The changes in the stereocilia morphology were more severe in Rab11aCKO/CKO/IFT 88CKO/+ mice. (I–L) Higher magnification of confocal images of hair cells. (M–P) Scanning electron microscopy images of hair cells from wild-type controls and Rab11a mutants. (I,M) Morphology of normal. hair cells of wild-type controls. (J,N) The number of stereocilia on a single hair cell was deceased in the Rab11a mutant. (K,O) Stereocilia were shorter in mutants compared to the wild-type controls. (L,P) The staircase-like hair bundle architecture of hair cells was lost in Rab11a mutant mice. (Q) The percentage of hair cells with abnormal development of static cilia bundles in the extrastriola region was counted as a percentage of the total (n = 5). The percentage of abnormal hair cells was higher in Rab11aCKO/CKO, IFT88CKO/+ mice compared to Rab11aCKO/CKO. The abnormal ratios of single and double knockout hair cells were 42.1 ± 5.7 and 71.5 ± 10.4, respectively. In (A–J), for all primary panels, hair cell stereociliary bundles were marked with phalloidin (green), the actin-rich cuticular plate of hair cells was labeled with β-spectrin (red), while the basal body of the hair cell was labeled with γ-tubulin (blue). Scale bars: 10 μm (C–H1), 5 μm (J–N). *P < 0.05. Vestibular organs have unique planar cell polarity (Figure 1A), and their normal development and function are dependent on the regular polarity of cilia (Figure 1B) requires. Rab11a is a small G protein that participates in the transportation of intracellular and extracellular materials required for polarity formation; however, our understanding of the mechanisms of the actions of Rab11a in vestibular organs is limited. Here, we showed that the general shape of the utricle was abnormal in Rab11aCKO/CKO mice. These mice also showed abnormal morphology of the stereocilia bundles, which were reduced in both length and number, as well as disturbed tissue-level polarity. Rab11a affected the distribution of polarity proteins in the vestibular organs, indicating that the normal development of cilia requires Rab11a and intraflagellar transportation. Furthermore, small G protein migration works together with intraflagellar transportation in the normal development of cilia.