Abstract:
Diabetic retinopathy (DR) affects over 140 million people globally. The mechanisms that lead to blindness are still enigmatic but there is evidence that sustained inflammation and hypoxia contribute to vascular damage. Despite efforts to understand the role of inflammation and microglia in DR\'s pathology, the contribution of astrocytes to hypoxic responses is less clear. To investigate the role of astrocytes in hypoxia-induced retinopathy, we utilized a 7-day systemic hypoxia model using the GFAP-CreERT2:Rosa26iDTR transgenic mouse line. This allows for the induction of inflammatory reactive astrogliosis following tamoxifen and diphtheria toxin administration. We hypothesize that DTx-induced astrogliosis is neuroprotective during hypoxia-induced retinopathy. Glial, neuronal, and vascular responses were quantified using immunostaining, with antibodies against GFAP, vimentin, IBA-1, NeuN, fibrinogen, and CD31. Cytokine responses were measured in both the brain and serum. We report that while both DTx and hypoxia induced a phenotype of reduced microglia morphological activation, DTx, but not hypoxia, induced an increase in the Müller glia marker vimentin. We did not observe that the combination of DTx and hypoxic treatments exacerbated the signs of reactive glial cells, nor did we observe a significant change in the expression immunomodulatory mediators IL-1β, IL2, IL-4, IL-5, IL-6, IL-10, IL-18, CCL17, TGF-β1, GM-CSF, TNF-α, and IFN-γ. Overall, our results suggest that, in this hypoxia model, reactive astrogliosis does not alter the inflammatory responses or cause vascular damage in the retina.
摘要:
糖尿病视网膜病变(DR)影响全球超过1.4亿人。导致失明的机制仍然是神秘的,但有证据表明持续的炎症和缺氧会导致血管损伤。尽管努力了解炎症和小胶质细胞在DR病理中的作用,星形胶质细胞对缺氧反应的贡献尚不清楚.探讨星形胶质细胞在缺氧诱导视网膜病变中的作用,我们使用GFAP-CreERT2:Rosa26iDTR转基因小鼠系,建立了7天全身缺氧模型.这允许在他莫昔芬和白喉毒素施用后诱导炎性反应性星形胶质细胞增生。我们假设DTx诱导的星形胶质细胞增生在缺氧诱导的视网膜病变期间具有神经保护作用。Glial,神经元,使用免疫染色对血管反应进行定量,具有抗GFAP的抗体,波形蛋白,IBA-1,NeuN,纤维蛋白原,CD31在脑和血清中测量细胞因子反应。我们报告说,虽然DTx和缺氧都诱导了小胶质细胞形态激活减少的表型,DTx,但不是缺氧,诱导了Müller胶质细胞标记波形蛋白的增加。我们没有观察到DTx和低氧治疗的组合会加剧反应性神经胶质细胞的症状,我们也没有观察到免疫调节介质IL-1β表达的显著变化,IL2,IL-4,IL-5,IL-6,IL-10,IL-18,CCL17,TGF-β1,GM-CSF,TNF-α,和IFN-γ。总的来说,我们的结果表明,在这个缺氧模型中,反应性星形胶质增生不改变炎症反应或引起视网膜血管损伤。