A key role for ROCK in TNF-α-mediated diabetic microvascular damage
| Autor: | Shintaro Nakao, Ali Hafezi-Moghadam, Shigeo Yoshida, Tatsuro Ishibashi, Takeshi Kita, Shuhei Kawahara, Ryoichi Arita, Hiroshi Enaida, Ryo Asato |
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| Rok vydání: | 2013 |
| Předmět: |
Male
medicine.medical_specialty Endothelium Nitric Oxide Synthase Type III Neutrophils CD18 CD11a Receptors Tumor Necrosis Factor Myosin-Light-Chain Phosphatase Enos Internal medicine medicine Humans Phosphorylation Protein Kinase Inhibitors Cells Cultured Aged Aged 80 and over rho-Associated Kinases Diabetic Retinopathy biology business.industry Tumor Necrosis Factor-alpha Fasudil Endothelial Cells Middle Aged biology.organism_classification Intercellular Adhesion Molecule-1 medicine.anatomical_structure Endocrinology Integrin alpha M biology.protein Tumor necrosis factor alpha Female Endothelium Vascular business Diabetic Angiopathies |
| Zdroj: | Investigative ophthalmologyvisual science. 54(3) |
| ISSN: | 1552-5783 |
| Popis: | Purpose Leukocyte adhesion releases tumor necrosis factor (TNF)-α that contributes to endothelial damage in early diabetic retinopathy (DR). Rho/Rho-kinase (ROCK) signaling mediates retinal endothelial damage in early DR. However, whether ROCK regulates TNF-α-mediated diabetic vascular damage is unknown. Here, the contribution of ROCK to TNF-α-mediated microvascular damage is investigated. Methods In DR patients and nondiabetic control subjects, the levels of membranous (m) TNF-α on neutrophils, soluble (s) TNF-α and its receptors in sera, were measured. In cultured microvascular endothelial cells, phosphorylation of myosin phosphatase target protein (MYPT)-1, a downstream target of ROCK, was investigated with TNF-α or DR sera pretreatment. TNF-α-induced intercellular adhesion molecule-1 (ICAM-1) and endothelial nitric oxide synthase (eNOS) phosphorylation were measured with and without ROCK inhibition by fasudil or ROCK-specific small-interfering RNA (siRNA). In isolated neutrophils from control subjects, MYPT-1 phosphorylation was investigated in the presence of TNF-α. The impact of ROCK inhibition by fasudil on TNF-α-induced integrin (CD18, CD11a, CD11b) and intracellular cytoskeletal changes were investigated. Results The serum levels of mTNF-α, sTNF-α, and its receptors were significantly elevated in DR patients. TNF-α as well as DR sera promoted MYPT-1 phosphorylation in endothelial cells, which was significantly reduced by anti-TNF-α neutralizing antibody. TNF-α-induced ICAM-1 expression, eNOS dephosphorylation, cytoskeletal changes, and CD11b/18 expression in neutrophils were significantly suppressed by fasudil as well as ROCK-specific siRNA. Conclusions ROCK is a key mediator of TNF-α signaling in diabetic microvessels. The important role of TNF-α in early DR provides a new rationale for ROCK inhibition beyond the previously shown mechanisms. |
| Databáze: | OpenAIRE |
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