Department of Ophthalmology, Faculty of Medicine, Usak University, TR-64100, Usak, Turkey.
Departments of Biophysics and Neuroscience, Neuroscience Research Center, School of Medicine, Suleyman Demirel University, TR-32260, Isparta, Turkey.
Graefes Arch Clin Exp Ophthalmol. 2022 Aug;260(8):2567-2583. doi: 10.1007/s00417-022-05731-5. Epub 2022 Jun 15.
The concentration of plasma high glucose (HGu) in diabetes mellitus (DM) induces the retinal pigment epithelial cell (ARPE19) death via the increase of inflammation, cytosolic (cytROS), and mitochondrial (mitROS) free oxygen radical generations. Transient potential melastatin 2 (TRPM2) cation channel is stimulated by cytROS and mitROS. Hence, the cytROS and mitROS-mediated excessive Ca influxes via the stimulation of TRPM2 channel cause to the induction of DM-mediated retina oxidative cytotoxicity. Because of the antioxidant role of carvacrol (CRV), it may modulate oxidative cytotoxicity via the attenuation of TRPM2 in the ARPE19. We aimed to investigate the modulator action of CRV treatment on the HGu-mediated TRPM2 stimulation, oxidative stress, and apoptosis in the ARPE19 cell model.
The ARPE19 cells were divided into four groups as normal glucose (NGu), NGu + Carv, HGu, and HGu + CRV.
The levels of cell death (propidium iodide/Hoechst rate) and apoptosis markers (caspases 3, 8, and 9), cytokine generations (IL-1β and TNF-α), ROS productions (cytROS, mitROS, and lipid peroxidation), TRPM2 currents, and intracellular free Ca (Fluo/3) were increased in the HGu group after the stimulations of hydrogen peroxide and ADP-ribose, although their levels were diminished via upregulation of glutathione and glutathione peroxidase by the treatments of CRV and TRPM2 blockers.
Current results confirmed that the HGu-induced overload Ca influx and oxidative retinal toxicity in the ARPE19 cells were induced by the stimulation of TRPM2, although they were modulated via the inhibition of TRPM2 by CRV. CRV may be noted as a potential therapeutic antioxidant to the TRPM2 activation-mediated retinal oxidative injury.
糖尿病患者血浆高葡萄糖（HGu）浓度通过增加炎症、胞浆（cytROS）和线粒体（mitROS）自由基的产生，诱导视网膜色素上皮细胞（ARPE19）死亡。瞬时电位梅拉塔林 2（TRPM2）阳离子通道被 cytROS 和 mitROS 刺激。因此，通过刺激 TRPM2 通道引起的 cytROS 和 mitROS 介导的过多 Ca 内流导致 DM 介导的视网膜氧化细胞毒性。由于香芹酚（CRV）的抗氧化作用，它可能通过在 ARPE19 中减弱 TRPM2 来调节氧化细胞毒性。我们旨在研究 CRV 处理对 HGu 介导的 TRPM2 刺激、ARPE19 细胞模型中的氧化应激和细胞凋亡的调节作用。
将 ARPE19 细胞分为四组：正常葡萄糖（NGu）、NGu+Carv、HGu 和 HGu+CRV。
在 HGu 组中，用 H2O2 和 ADP-核糖刺激后，细胞死亡（碘化丙啶/ Hoechst 率）和凋亡标志物（caspase 3、8 和 9）、细胞因子生成（IL-1β 和 TNF-α）、ROS 产生（cytROS、mitROS 和脂质过氧化）、TRPM2 电流和细胞内游离 Ca（Fluo/3）水平增加，尽管通过 CRV 和 TRPM2 阻断剂上调谷胱甘肽和谷胱甘肽过氧化物酶，这些水平降低。
目前的结果证实，HGu 诱导的 ARPE19 细胞中 Ca 过载内流和氧化视网膜毒性是由 TRPM2 刺激引起的，尽管它们通过 CRV 抑制 TRPM2 而被调节。CRV 可能被认为是一种潜在的治疗抗氧化剂，用于 TRPM2 激活介导的视网膜氧化损伤。
