[PDF][PDF] Alterations in expression of angiopoietins and the Tie-2 receptor in the retina of streptozotocin induced diabetic rats

H Ohashi, H Takagi, S Koyama, H Oh, D Watanabe… - Mol Vis, 2004 - molvis.org
H Ohashi, H Takagi, S Koyama, H Oh, D Watanabe, DA Antonetti, T Matsubara, K Nagai…
Mol Vis, 2004molvis.org
Purpose: The angiopoietin (Ang)/Tie-2 system may play a role in vascular integrity and
angiogenesis. In this study, we investigated alterations of the gene expression of Ang-1 and
Ang-2 in the retinas of streptozotocin (STZ) induced diabetic rats. Methods: In situ
hybridization, reverse transcriptase polymerase chain reaction (RT-PCR) and western blot
analyses were performed to determine the mRNA and protein content for Ang-1 and Ang-2
and the Tie2 receptor in the retinas of STZ diabetic and age matched control rats. Results …
Purpose: The angiopoietin (Ang)/Tie-2 system may play a role in vascular integrity and angiogenesis. In this study, we investigated alterations of the gene expression of Ang-1 and Ang-2 in the retinas of streptozotocin (STZ) induced diabetic rats.
Methods: In situ hybridization, reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analyses were performed to determine the mRNA and protein content for Ang-1 and Ang-2 and the Tie2 receptor in the retinas of STZ diabetic and age matched control rats.
Results: Using in situ hybridization analysis, Ang-1, Ang-2, and Tie2 mRNA expression was observed in the ganglion cell layer (GCL) and the inner nuclear layer (INL). While Ang-2 mRNA expression did not changed after 2 weeks, 1 month, or 3 months of STZ induced diabetes, it was increased in the GCL and slightly elevated in the INL after 6 months of diabetes. In contrast, Ang-1 and Tie2 mRNA expression was stable at every timepoint during 6 months of STZ induced diabetes. RT-PCR and western blot analyses confirmed the increase of Ang-2 expression after 6 months of diabetes. Furthermore, double staining of alpha-smooth muscle actin (αSMA) and Ang-2 mRNA demonstrated that the SMA positive cells surrounding Ang-2-expressing cells were decreased in the GCL. Conclusions: Diabetes increases Ang-2 expression in the GCL accompanied by a reduction of αSMA positive perivascular cells. These changes may suggest a role for Ang-2 in the mechanism of pericyte loss in diabetic retinopathy.
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