Astrocytic YAP protects the optic nerve and retina in an experimental autoimmune encephalomyelitis model through TGF-β signaling.
Astrocytic YAP protects the optic nerve and retina in an experimental autoimmune encephalomyelitis model through TGF-β signaling.
复制标题
星形胶质细胞YAP通过TGF-β信号传导在实验性自身免疫性脑脊髓炎模型中保护视神经和视网膜。
DOI：
10.7150/thno.60031
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发表时间：
2021
期刊：
影响因子：
12.4
通讯作者：
Huang Z
中科院分区：
文献类型：
--
作者：
Wu Q;Miao X;Zhang J;Xiang L;Li X;Bao X;Du S;Wang M;Miao S;Fan Y;Wang W;Xu X;Shen X;Yang D;Wang X;Fang Y;Hu L;Pan X;Dong H;Wang H;Wang Y;Li J;Huang Z
理论基础：视神经炎是多发性硬化症(MS)的主要症状之一，可导致视力障碍。星形胶质细胞是MS神经炎症的关键调节因子，而星形胶质细胞YAP在神经炎症中起关键作用。同时，YAP信号参与了包括青光眼、视网膜脉络膜萎缩和视网膜脱离在内的视力损害。然而，星形细胞YAP在MS相关视神经炎(MS-ON)的神经炎症和脱髓鞘中的作用和潜在机制仍不清楚。方法：建立实验性自身免疫性脑脊髓炎(EAE)模型，并成功建立星形胶质细胞YAP条件性基因敲除(CKO)小鼠YAPGFAP-CKO小鼠，以评价YAP在MS-ON中的作用。采用行为学、免疫染色、尼氏染色、苏木精-伊红(HE)染色、TUNEL染色、LFB染色、电子显微镜(EM)、实时定量聚合酶链式反应(QPCR)、基因集浓缩分析(GSEA)和RNA测序基因集变异分析(GSVA)等方法，研究YAP信号转导功能及其机制。为了进一步探讨YAP信号在EAE中的潜在治疗作用，用多种药物治疗EAE小鼠，包括转化生长因子-β(β)途径激动剂SRI-011381和抑制河马MST1/2激活YAP的XMU-MP-1。结果：我们发现YAP在EAE小鼠视神经星形胶质细胞中显著上调和激活。条件性敲除星形胶质细胞中的YAP基因可导致EAE小鼠视神经炎症浸润和脱髓鞘加重，视网膜神经节细胞(RGCs)损伤。此外，星形胶质细胞中YAP的缺失促进了EAE小鼠视神经星形胶质细胞和小胶质细胞的激活，但抑制了视神经星形胶质细胞的增殖。从机制上讲，星形胶质细胞YAP缺失后，转化生长因子-β信号通路显著下调。此外，定量聚合酶链式反应和免疫荧光检测均证实YAPGFAP-CKO EAE小鼠转化生长因子-β信号通路减少。有趣的是，SRI-011381部分挽救了YAPGFAP-CKO EAE小鼠视神经和视网膜的缺失。最后，XMU-MP-1激活YAP信号可减轻EAE小鼠视神经的炎症和脱髓鞘。结论：星形细胞YAP可能通过上调转化生长因子-β信号通路来预防神经炎性浸润和脱髓鞘，为针对MS-ON制定治疗策略提供靶点。
Rationale: Optic neuritis is one of main symptoms in multiple sclerosis (MS) that causes visual disability. Astrocytes are pivotal regulators of neuroinflammation in MS, and astrocytic yes-associated protein (YAP) plays a critical role in neuroinflammation. Meanwhile, YAP signaling is involved in visual impairment, including glaucoma, retinal choroidal atrophy and retinal detachment. However, the roles and underlying mechanisms of astrocytic YAP in neuroinflammation and demyelination of MS-related optic neuritis (MS-ON) remains unclear. Methods: To assess the functions of YAP in MS-ON, experimental autoimmune encephalomyelitis (EAE, a common model of MS) was established, and mice that conditional knockout (CKO) of YAP in astrocytes, YAPGFAP-CKO mice, were successfully generated. Behavior tests, immunostaining, Nissl staining, Hematoxylin-Eosin (HE) staining, TUNEL staining, Luxol Fast Blue (LFB) staining, electron microscopy (EM), quantitative real-time PCR (qPCR), gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) by RNA sequencing were used to examine the function and mechanism of YAP signaling based on these YAPGFAP-CKO mice and EAE model mice. To further explore the potential treatment of YAP signaling in EAE, EAE mice were treated with various drugs, including SRI-011381 that is an agonist of transforming growth factor-β (TGF-β) pathway, and XMU-MP-1 which inhibits Hippo kinase MST1/2 to activate YAP. Results: We found that YAP was significantly upregulated and activated in the astrocytes of optic nerve in EAE mice. Conditional knockout of YAP in astrocytes caused more severe inflammatory infiltration and demyelination in optic nerve, and damage of retinal ganglion cells (RGCs) in EAE mice. Moreover, YAP deletion in astrocytes promoted the activation of astrocytes and microglia, but inhibited the proliferation of astrocytes of optic nerve in EAE mice. Mechanically, TGF-β signaling pathway was significantly down-regulated after YAP deletion in astrocytes. Additionally, both qPCR and immunofluorescence assays confirmed the reduction of TGF-β signaling pathway in YAPGFAP-CKO EAE mice. Interestingly, SRI-011381 partially rescued the deficits in optic nerve and retina of YAPGFAP-CKO EAE mice. Finally, activation of YAP signaling by XMU-MP-1 relieved the neuroinflammation and demyelination in optic nerve of EAE mice. Conclusions: These results suggest astrocytic YAP may prevent the neuroinflammatory infiltration and demyelination through upregulation of TGF-β signaling and provide targets for the development of therapeutic strategies tailored for MS-ON.