Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany.
School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou 325015, China.
Cells. 2024 Aug 9;13(16):1329. doi: 10.3390/cells13161329.
The conjunctiva has immune-responsive properties to protect the eye from infections. Its innate immune system reacts against external pathogens, such as fungi. The complement factor C5a is an important contributor to the initial immune response. It is known that activation of transient-receptor-potential-vanilloid 1 (TRPV1) and TRP-melastatin 8 (TRPM8) channels is involved in different immune reactions and inflammation in the human body. The aim of this study was to determine if C5a and (MR) modulate Ca-signaling through changes in TRPs activity in human conjunctival epithelial cells (HCjECs). Furthermore, crosstalk was examined between C5a and MR in mediating calcium regulation. Intracellular Ca-concentration ([Ca]) was measured by fluorescence calcium imaging, and whole-cell currents were recorded using the planar-patch-clamp technique. MR was used as a purified extract. Application of C5a (0.05-50 ng/mL) increased both [Ca] and whole-cell currents, which were suppressed by either the TRPV1-blocker AMG 9810 or the TRPM8-blocker AMTB (both 20 µM). The N-terminal peptide C5L2p (20-50 ng/mL) blocked rises in [Ca] induced by C5a. Moreover, the MR-induced rise in Ca-influx was suppressed by AMG 9810 and AMTB, as well as 0.05 ng/mL C5a. In conclusion, crosstalk between C5a and MR controls human conjunctival cell function through modulating interactions between TRPV1 and TRPM8 channel activity.
结膜具有免疫反应特性，可保护眼睛免受感染。它的先天免疫系统会对真菌等外部病原体产生反应。补体因子 C5a 是初始免疫反应的重要贡献者。众所周知，瞬时受体电位香草酸 1（TRPV1）和 TRP 金属蛋白酶 8（TRPM8）通道的激活参与了人体的不同免疫反应和炎症。本研究旨在确定 C5a 和（MR）是否通过改变人结膜上皮细胞（HCjEC）中 TRP 的活性来调节 Ca 信号。此外，还研究了 C5a 和 MR 之间在调节钙方面的串扰。通过荧光钙成像测量细胞内 Ca 浓度 ([Ca])，并使用平面贴附式膜片钳技术记录全细胞电流。MR 用作纯化提取物。应用 C5a（0.05-50 ng/mL）会增加 [Ca] 和全细胞电流，这两种电流都被 TRPV1 阻断剂 AMG 9810 或 TRPM8 阻断剂 AMTB（均为 20 µM）抑制。N 端肽 C5L2p（20-50 ng/mL）可阻断 C5a 引起的 [Ca]升高。此外，MR 诱导的 Ca 内流增加被 AMG 9810 和 AMTB 以及 0.05 ng/mL C5a 抑制。总之，C5a 和 MR 之间的串扰通过调节 TRPV1 和 TRPM8 通道活性之间的相互作用来控制人结膜细胞的功能。
