Yang Jiahui, Zhong Jing, Fu Zhenyuan, He Dalian, Zhang Jing, Yuan Jin
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China.
Invest Ophthalmol Vis Sci. 2025 Jan 2;66(1):33. doi: 10.1167/iovs.66.1.33.
Fungal keratitis (FK) remains a treatment challenge, necessitating new therapeutic targets. Piezo1, a mechanosensitive ion channel, regulates calcium signaling and immune cell function. This study investigates its role in macrophage-mediated antifungal responses in FK.
Piezo1 and Pyrin expression in corneas and bone marrow-derived macrophages (BMDMs) were assessed by RNAseq, quantitative real-time PCR (qRT-PCR), Western blot, and immunofluorescence. Intracellular calcium ion concentration was detected by Fluo-4 AM fluorescent probe staining. Heterozygous Piezo1 deficiency (Piezo1+/-) mice and Yoda1 were performed to regulate the expression of Piezo1.
Our investigation demonstrates elevated expression of Piezo1 in the corneas of patients with FK and infected mice. This upregulation of Piezo1 corresponded with the swift recruitment of macrophages via the limbus. Additionally, Piezo1+/- mice exacerbate the progression of FK in the infection model. Furthermore, Piezo1 knockdown in macrophages exhibit a notable reduction phagocytic capacity, accompanied by an increase in viable colony-forming units in an in vitro model of fungal infection. Moreover, using a pharmacologic activator of Piezo1 (Yoda1), a calcium ion (Ca2+) chelator of BAPTA or Piezo1+/- mice, we demonstrate that Piezo1 activation triggers the Pyrin inflammasome via augmented calcium ion influx, which is required for protection against FK in murine hosts.
Piezo1 is crucial for innate immunity in FK, enhancing macrophage recruitment, activation, and Pyrin inflammasome-mediated antifungal activity via calcium signaling. Using Piezo1+/- mice and Yoda1, we confirm Piezo1's role in fungal clearance. Targeting Piezo1 offers a novel strategy to improve FK outcomes by boosting macrophage function and immune response.
真菌性角膜炎（FK）仍然是一个治疗难题，需要新的治疗靶点。Piezo1是一种机械敏感离子通道，可调节钙信号传导和免疫细胞功能。本研究调查其在FK中巨噬细胞介导的抗真菌反应中的作用。
通过RNA测序、定量实时聚合酶链反应（qRT-PCR）、蛋白质免疫印迹和免疫荧光评估Piezo1和吡啉在角膜和骨髓来源的巨噬细胞（BMDM）中的表达。使用Fluo-4 AM荧光探针染色检测细胞内钙离子浓度。采用杂合性Piezo1缺陷（Piezo1+/-）小鼠和Yoda1来调节Piezo1的表达。
我们的研究表明，FK患者和受感染小鼠角膜中Piezo1的表达升高。Piezo1的这种上调与巨噬细胞通过角膜缘的迅速募集相对应。此外，Piezo1+/-小鼠在感染模型中会加剧FK的进展。此外，巨噬细胞中Piezo1的敲低表现出吞噬能力显著降低，同时在真菌感染的体外模型中活菌落形成单位增加。此外，使用Piezo1的药理学激活剂（Yoda1）、BAPTA的钙离子（Ca2+）螯合剂或Piezo1+/-小鼠，我们证明Piezo1激活通过增加钙离子内流触发吡啉炎性小体，这是小鼠宿主抵抗FK所必需的。
Piezo1对FK的先天免疫至关重要，通过钙信号增强巨噬细胞募集、激活和吡啉炎性小体介导的抗真菌活性。使用Piezo1+/-小鼠和Yoda1，我们证实了Piezo1在真菌清除中的作用。靶向Piezo1提供了一种通过增强巨噬细胞功能和免疫反应来改善FK治疗效果的新策略。
