Restoration of autophagy in endothelial cells from patients with diabetes mellitus improves nitric oxide signaling
| Autor: | Jessica L. Fetterman, Orian S. Shirihai, Melissa G. Farb, Monica Holbrook, Noyan Gokce, Naomi M. Hamburg, Erika A Linder, Joseph A. Vita, Brittany D Berk, Rosa Bretόn-Romero, Mai-Ann Duess, Bihua Feng, Nir Flint |
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| Rok vydání: | 2016 |
| Předmět: |
Adult
Male 0301 basic medicine medicine.medical_specialty Adenosine Nitric Oxide Synthase Type III Spermidine Cell Separation Biology Diabetic angiopathy Nitric Oxide Article Nitric oxide 03 medical and health sciences chemistry.chemical_compound Insulin resistance Enos Internal medicine Diabetes mellitus Autophagy medicine Humans Endothelial dysfunction Cells Cultured Aged Endothelial Cells Middle Aged medicine.disease biology.organism_classification 030104 developmental biology Endocrinology Diabetes Mellitus Type 2 chemistry Case-Control Studies Female Macrolides Cardiology and Cardiovascular Medicine Biomarkers Diabetic Angiopathies Signal Transduction |
| Zdroj: | Atherosclerosis. 247:207-217 |
| ISSN: | 0021-9150 |
| Popis: | Background Endothelial dysfunction contributes to cardiovascular disease in diabetes mellitus. Autophagy is a multistep mechanism for the removal of damaged proteins and organelles from the cell. Under diabetic conditions, inadequate autophagy promotes cellular dysfunction and insulin resistance in non-vascular tissue. We hypothesized that impaired autophagy contributes to endothelial dysfunction in diabetes mellitus. Methods and results We measured autophagy markers and endothelial nitric oxide synthase (eNOS) activation in freshly isolated endothelial cells from diabetic subjects (n = 45) and non-diabetic controls (n = 41). p62 levels were higher in cells from diabetics (34.2 ± 3.6 vs. 20.0 ± 1.6, P = 0.001), indicating reduced autophagic flux. Bafilomycin inhibited insulin-induced activation of eNOS (64.7 ± 22% to −47.8 ± 8%, P = 0.04) in cells from controls, confirming that intact autophagy is necessary for eNOS signaling. In endothelial cells from diabetics, activation of autophagy with spermidine restored eNOS activation, suggesting that impaired autophagy contributes to endothelial dysfunction (P = 0.01). Indicators of autophagy initiation including the number of LC3-bound puncta and beclin 1 expression were similar in diabetics and controls, whereas an autophagy terminal phase indicator, the lysosomal protein Lamp2a, was higher in diabetics. In endothelial cells under diabetic conditions, the beneficial effect of spermidine on eNOS activation was blocked by autophagy inhibitors bafilomycin or 3-methyladenine. Blocking the terminal stage of autophagy with bafilomycin increased p62 (P = 0.01) in cells from diabetics to a lesser extent than in cells from controls (P = 0.04), suggesting ongoing, but inadequate autophagic clearance. Conclusion Inadequate autophagy contributes to endothelial dysfunction in patients with diabetes and may be a target for therapy of diabetic vascular disease. |
| Databáze: | OpenAIRE |
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