Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea.
R&D Center, BiomLogic, Inc., Seoul, South Korea.
Invest Ophthalmol Vis Sci. 2023 Sep 1;64(12):30. doi: 10.1167/iovs.64.12.30.
We hypothesized that antioxidative enzymes supplementation could be a treatment option for dry eye. We investigated the efficacy of oral administration of Bacillus-derived superoxide dismutase (Bd-SOD) in a murine experimental dry eye (EDE).
In part I, mice were randomly assigned to normal control, EDE, and mice groups that were treated with oral Bd-SOD after induction of EDE (EDE + Bd-SOD group; four mice in each group). Expression of SOD2, a major antioxidant enzyme with manganese as a cofactor, was assessed by immunofluorescence staining. In part II, mice were divided into seven groups (six mice in each group): normal control, EDE, vehicle-treated, topical 0.05% cyclosporin A (CsA)-treated, and oral Bd-SOD-treated (2.5, 5.0, and 10.0 mg/kg Bd-SOD) groups. Tear volume, tear-film break-up time (TBUT), and corneal fluorescein-staining scores (CFS) were measured at zero, five, and 10 days after treatment. Ten days after treatment, 2',7'-dichlorodihydrofluorescein diacetate for reactive oxygen species (ROS), enzyme-linked immunosorbent for malondialdehyde, and TUNEL assays for corneal apoptosis, flow cytometry inflammatory T cells, and histological assessment were performed.
Compared to the normal control group in part I, the EDE group showed significantly decreased SOD2 expression by immunofluorescence staining. However, the EDE + Bd-SOD group recovered similar to the normal control group. In part II, ROS, malondialdehyde, and corneal apoptosis were decreased in CsA and all Bd-SOD-treated groups. Corneal and conjunctival inflammatory T cells decreased, and conjunctival goblet cell density increased in CsA-treated and Bd-SOD-treated groups. Compared to the CsA-treated group, the 2.5 mg/kg Bd-SOD-treated group showed increased TBUT and decreased inflammatory T cells, and the 5.0 mg/kg Bd-SOD-treated group showed decreased CFS and increased conjunctival goblet cells.
Oral Bd-SOD administration might increase autogenous SOD2 expression in ocular surface tissue in EDE and could be developed as a complementary treatment for DE in the future.
我们假设抗氧化酶补充剂可能是干眼症的一种治疗选择。我们研究了口服芽孢杆菌来源的超氧化物歧化酶（Bd-SOD）在实验性干眼（EDE）小鼠模型中的疗效。
在第一部分中，将小鼠随机分为正常对照组、EDE 组和 EDE 后给予口服 Bd-SOD 的小鼠组（每组 4 只）。通过免疫荧光染色评估主要抗氧化酶（含锰的 SOD2）的表达。在第二部分中，将小鼠分为七组（每组 6 只）：正常对照组、EDE 组、载体处理组、局部 0.05%环孢素 A（CsA）处理组和口服 Bd-SOD 处理组（2.5、5.0 和 10.0 mg/kg Bd-SOD）。在治疗后 0、5 和 10 天测量泪液体积、泪膜破裂时间（TBUT）和角膜荧光素染色评分（CFS）。在治疗后 10 天，进行 2'，7'-二氯二氢荧光素二乙酸酯用于活性氧（ROS）、酶联免疫吸附用于丙二醛和角膜细胞凋亡的 TUNEL 检测、流式细胞术炎症性 T 细胞和组织学评估。
与第一部分的正常对照组相比，EDE 组的 SOD2 表达通过免疫荧光染色明显降低。然而，EDE + Bd-SOD 组的表达恢复到与正常对照组相似的水平。在第二部分中，ROS、丙二醛和角膜细胞凋亡在 CsA 和所有 Bd-SOD 处理组中均降低。在 CsA 处理组和 Bd-SOD 处理组中，角膜和结膜炎症性 T 细胞减少，结膜杯状细胞密度增加。与 CsA 处理组相比，2.5 mg/kg Bd-SOD 处理组的 TBUT 增加，炎症性 T 细胞减少，5.0 mg/kg Bd-SOD 处理组的 CFS 减少，结膜杯状细胞增多。
口服 Bd-SOD 给药可能会增加 EDE 眼表组织中的内源性 SOD2 表达，并可能在未来开发为干眼症的补充治疗方法。
