PURPOSE: The purpose of this study was to characterize the endothelial (EC) F-actin cytoskeleton at different orders of the retinal microvasculature in the normal and diabetic rat and determine if changes in F-actin are associated with different stages of diabetes. METHODS: The EC F-actin cytoskeleton distribution, nuclei shape, and capillary diameter in the retinal vasculature of rats after 5 and 28 weeks of streptozotocin (STZ)-induced diabetes were compared to those in age-matched controls. The eyes were enucleated, arterially perfused, and labeled for F-actin cytoskeleton and nuclei (YO-PRO-1) or microvascular leakage (FITC-dextran). Retinal whole mounts were then examined by confocal microscopy. RESULTS: The EC F-actin distribution and nuclear size and shape were highly dependent on the location down the vascular tree. The retinal arterial system in the rat shows a high level of F-actin stress fibre (SF) staining. Peripheral border (PB) staining was present in the ECs of all vessels. Diffuse F-actin staining was observed in endothelial cytoplasm in capillaries, venules, and veins. EC nuclei became distinctly less elongated down the vascular tree. In diabetic rats at 5 weeks, at the capillary level the F-actin staining was more diffuse, and areas of F-actin loss were evident. Both dot-like and diffuse leakage was detected in retinal capillaries, and these leakage types were closely associated with the degree of F-actin changes. In diabetic rats at 28 weeks, there was an increased level of SF staining in the arterial system in addition to capillary F-actin changes. CONCLUSIONS: The EC F-actin cytoskeleton and nuclei shape retinal microvasculature of the normal rat change with location along the vascular tree. In the early stages of diabetes, there are changes to the F-actin cytoskeleton that are clearly associated with microvascular leakage. F-actin distribution could indicate important structural changes in the pathogenesis of diabetic retinopathy.
PURPOSE: The purpose of this study was to characterize the endothelial (EC) F-actin cytoskeleton at different orders of the retinal microvasculature in the normal and diabeticrat and determine if changes in F-actin are associated with different stages of diabetes. METHODS: The EC F-actin cytoskeleton distribution, nuclei shape, and capillary diameter in the retinal vasculature of rats after 5 and 28 weeks of streptozotocin (STZ)-induced diabetes were compared to those in age-matched controls. The eyes were enucleated, arterially perfused, and labeled for F-actin cytoskeleton and nuclei (YO-PRO-1) or microvascular leakage (FITC-dextran). Retinal whole mounts were then examined by confocal microscopy. RESULTS: The EC F-actin distribution and nuclear size and shape were highly dependent on the location down the vascular tree. The retinal arterial system in the rat shows a high level of F-actin stress fibre (SF) staining. Peripheral border (PB) staining was present in the ECs of all vessels. Diffuse F-actin staining was observed in endothelial cytoplasm in capillaries, venules, and veins. EC nuclei became distinctly less elongated down the vascular tree. In diabeticrats at 5 weeks, at the capillary level the F-actin staining was more diffuse, and areas of F-actin loss were evident. Both dot-like and diffuse leakage was detected in retinal capillaries, and these leakage types were closely associated with the degree of F-actin changes. In diabeticrats at 28 weeks, there was an increased level of SF staining in the arterial system in addition to capillary F-actin changes. CONCLUSIONS: The EC F-actin cytoskeleton and nuclei shape retinal microvasculature of the normal rat change with location along the vascular tree. In the early stages of diabetes, there are changes to the F-actin cytoskeleton that are clearly associated with microvascular leakage. F-actin distribution could indicate important structural changes in the pathogenesis of diabetic retinopathy.
Authors: Padma Bhonagiri; Guruprasad R Pattar; Emily M Horvath; Kirk M Habegger; Alicia M McCarthy; Jeffrey S Elmendorf Journal: Endocrinology Date: 2008-11-26 Impact factor: 4.736
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Authors: Anthony Dobi; Sarah Rosanaly; Anne Devin; Pascal Baret; Olivier Meilhac; G Jean Harry; Christian Lefebvre d'Hellencourt; Philippe Rondeau Journal: Microvasc Res Date: 2020-10-17 Impact factor: 3.514