Diabetes-induced disruption of gap junction pathways within the retinal microvasculature.
Diabetes-induced disruption of gap junction pathways within the retinal microvasculature.
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发表时间：
2001-07
影响因子：
4.4
通讯作者：
H. Oku;Tatsuo Kodama;K. Sakagami;D. Puro;D. Puro
中科院分区：
文献类型：
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作者：
H. Oku;Tatsuo Kodama;K. Sakagami;D. Puro;D. Puro
糖尿病引起的微血管损伤是视力下降的主要原因。在糖尿病视网膜病变的早期发现事件可能有助于理解并预防这种疾病。对视网膜微血管内细胞间通讯可能在糖尿病发作后不久受到影响的假设进行了测试。方法采用链脲佐菌素诱导大鼠糖尿病模型。为了评估细胞-细胞偶联，通过膜片移液管将差距连接渗透示踪剂神经生物素递送至位于从糖尿病和对照动物的视网膜新鲜分离的微血管上的周细胞中。随后，免疫组织化学方法揭示了示踪剂的细胞间扩散的程度。电生理学方法也被用来检测细胞间通讯。结果在对照组大鼠视网膜微血管中，神经生物素从载有示踪剂的周细胞扩散数百微米。然而，在糖尿病发作后的几天内，这种细胞与细胞的耦合显着减少。相比之下，胰岛素治疗的糖尿病大鼠的微血管没有表现出明显的细胞间通讯的损失。与蛋白激酶C（PKC）在糖尿病诱导的间隙连接途径抑制中发挥作用一致，暴露于PKC激活剂（佛波醇肉豆蔻酸酯乙酸酯）的微血管显着减少示踪剂偶联。结论：在视网膜微血管内存在广泛的细胞间偶联，在链脲佐菌素诱导的糖尿病发病后不久，这种偶联明显减少。缝隙连接通路的关闭破坏了视网膜微血管的多细胞组织，并可能导致血管功能障碍。
PURPOSE Microvascular damage caused by diabetes is a leading cause of visual loss. Identifying events early in the course of diabetic retinopathy may help in understanding and, perhaps, preventing this disorder. The hypothesis that cell-to-cell communication within the retinal microvasculature may be affected soon after the onset of diabetes was tested. METHODS Streptozotocin was used to induce diabetes in rats. To assess cell-to-cell coupling the gap junction-permeant tracer, Neurobiotin, was delivered via patch pipettes into pericytes located on microvessels freshly isolated from the retinas of diabetic and control animals. Subsequently, immunohistochemical methods revealed the extent of the intercellular spread of the tracer. Electrophysiological methods were also used to detect intercellular communication. RESULTS In retinal microvessels of control rats, Neurobiotin spread hundreds of micrometers from the tracer-loaded pericytes. However, within days after the onset of diabetes, this cell-to-cell coupling was dramatically reduced. In contrast, microvessels of insulin-treated diabetic rats showed no significant loss of intercellular communication. Consistent with protein kinase C (PKC) playing a role in the diabetes-induced inhibition of gap junction pathways, exposure of microvessels to a PKC activator (phorbol myristate acetate) markedly reduced tracer coupling. CONCLUSIONS Within retinal microvessels there is extensive cell-to-cell coupling, which is markedly reduced soon after the onset of streptozotocin-induced diabetes. The closure of gap junction pathways disrupts the multicellular organization of retinal microvessels and may contribute to vascular dysfunction.