Cho Chan-Ho, Roh Kug-Hwan, Lim Na-Young, Park Sung Jae, Park SaeGwang, Kim Hyun Woong
Department of Ophthalmology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, 48108, Korea.
Department of Microbiology and Immunology, Inje University College of Medicine, Busan, 47392, Korea.
Graefes Arch Clin Exp Ophthalmol. 2022 Nov;260(11):3553-3563. doi: 10.1007/s00417-022-05694-7. Epub 2022 May 23.
The Janus tyrosine kinase and signal transducers and activators of transcription (JAK/STAT) pathway is involved in vascular endothelial growth factor (VEGF) expression, but the role of this pathway in diabetic retinopathy (DR) remains unclear. We investigated the role of the JAK/STAT pathway on DR and VEGF expression using a streptozotocin (STZ)-induced DR mouse model.
Cultured ARPE-19 cells were exposed to high-glucose conditions and treated with JAK/STAT inhibitors (JAK inhibitor I [JAKiI], tofacitinib, STAT3 inhibitor [STAT3i]) for 48 h. Reverse-transcription polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were used to investigate p-JAK/STAT and VEGF expression. Diabetes was induced by intraperitoneal injection of STZ (50 mg/kg) in C57BL/6 mice for 5 days. DR development was evaluated every 4 weeks. JAK/STAT inhibitors were administered for 8 weeks. Immunofluorescence was used to measure the activation status of the JAK/STAT pathway and VEGF production in the retinal tissue.
In ARPE-19 cells exposed to high-glucose conditions, the mRNA and secretory protein levels of VEGF, p-JAK1, p-JAK2, p-STAT3, and p-STAT5 levels were significantly increased. Treatment with JAKiI, tofacitinib, and STAT3i significantly suppressed VEGF to basal levels at both the mRNA and secretory levels in vitro. In STZ-induced mice, retinal vascular leakage, p-JAK1, p-JAK2, p-JAK3, p-STAT3, and VEGF were significantly increased after diabetes induction. Diabetes-induced retinal vascular leakage was significantly reduced by treatment with JAKiI and tofacitinib. Increased p-JAK1 and VEGF in STZ-induced mice were significantly reduced by JAKiI (p < 0.05, p < 0.001) and tofacitinib (p < 0.001, respectively).
JAK1 may be more involved in VEGF production and DR progression in mice than JAK2, JAK3, and STAT3.
Janus酪氨酸激酶和信号转导及转录激活因子（JAK/STAT）通路参与血管内皮生长因子（VEGF）的表达，但该通路在糖尿病视网膜病变（DR）中的作用仍不清楚。我们使用链脲佐菌素（STZ）诱导的DR小鼠模型研究JAK/STAT通路对DR和VEGF表达的作用。
将培养的ARPE - 19细胞暴露于高糖环境，并分别用JAK/STAT抑制剂（JAK抑制剂I [JAKiI]、托法替布、STAT3抑制剂[STAT3i]）处理48小时。采用逆转录聚合酶链反应、蛋白质印迹法和酶联免疫吸附测定法研究磷酸化JAK/STAT和VEGF的表达。通过对C57BL/6小鼠腹腔注射STZ（50 mg/kg）持续5天诱导糖尿病。每4周评估一次DR的发展情况。给予JAK/STAT抑制剂8周。采用免疫荧光法检测视网膜组织中JAK/STAT通路的激活状态和VEGF的产生。
在暴露于高糖环境的ARPE - 19细胞中，VEGF、磷酸化JAK1、磷酸化JAK2、磷酸化STAT3和磷酸化STAT5的mRNA及分泌蛋白水平显著升高。在体外，用JAKiI、托法替布和STAT3i处理可将VEGF在mRNA和分泌水平均显著抑制至基础水平。在STZ诱导的小鼠中，糖尿病诱导后视网膜血管渗漏、磷酸化JAK1、磷酸化JAK2、磷酸化JAK3、磷酸化STAT3和VEGF均显著增加。用JAKiI和托法替布处理可显著减少糖尿病诱导的视网膜血管渗漏。JAKiI（p < 0.05，p < 0.001）和托法替布（分别为p < 0.001）可显著降低STZ诱导小鼠中升高的磷酸化JAK1和VEGF水平。
与JAK2、JAK3和STAT3相比，JAK1可能在小鼠VEGF产生和DR进展中发挥更重要的作用。
