Abstract details
| Abstract-ID: | 2403 |
| Title of the paper: | Habitual aerobic exercise enhances adiponectin- and CTRP3-mediated vasorelaxation through activation of the AMPK-eNOS signaling pathway in aged mice |
| Authors: | Yamazaki, H., Fujie, S., Uchida, M., Iemitsu, M. |
| Institution: | Ritsueikan University |
| Department: | Pasuterueito2 201 |
| Country: | Japan |
| Abstract text | INTRODUCTION: Age-related fat accumulation contributes to arterial stiffness, whereas habitual aerobic exercise attenuates this effect. Adiponectin and C1q/tumor necrosis factor-related protein 3 (CTRP3), members of the CTRP family derived from white adipose tissue, have been shown to enhance endothelial function [1]. Habitual aerobic exercise increases circulating adiponectin and CTRP3 levels in middle-aged and older adults and that these levels are negatively correlated with arterial stiffness [2]. However, whether adiponectin and CTRP3 mediate exercise-induced improvements of endothelial function via endothelial nitric oxide synthase (eNOS) signaling pathway remains unclear. Therefore, we examined whether habitual aerobic exercise enhances adiponectin- and CTRP3-mediated vasorelaxation and activates eNOS signaling pathway in aged mice. METHODS: 38-week-old male SAMP1 mice were assigned to sedentary (Aged-Con, n=7) or 12-week voluntary wheel running groups (Aged-AT, n=7). 13-week-old SAMP1 mice served as young controls (Young, n=7). Vasorelaxation in response to adiponectin and CTRP3 were assessed in isolated thoracic aortic rings using wire myography. Plasma adiponectin and CTRP3 levels were measured by ELISA. Aortic adiponectin receptors (AdipoR1 and AdipoR2), phosphorylated and total AMP-activated protein kinase (AMPK) and eNOS, key regulators of NO production were analyzed by Western blotting. Arterial nitrate/nitrite (NOx, an index of NO production) concentrations were assessed with Griess assay. Statistical comparisons among groups were performed using one-way ANOVA. Statistical significance was set at p<0.05. RESULTS: Plasma adiponectin and CTRP3 levels were significantly higher in the Aged-AT group than in the Aged-Con group (p<0.05). Adiponectin- and CTRP3-induced vasorelaxation were significantly enhanced in the Aged-AT group compared with the Aged-Con group (p<0.05). Aortic AdipoR1 and AdipoR2 protein expression levels were significantly lower in the Aged-Con group than in the Young group, whereas the Aged-AT group showed significantly higher levels than in the Aged-Con group, and AdipoR2 expression was significantly higher than in both the Young and Aged-Con groups (p<0.05). Aortic AMPK, eNOS phosphorylation levels and arterial NOx levels were significantly decreased in the Aged-Con group compared with the Young group and were significantly increased in the Aged-AT group compared with the Aged-Con group (p-eNOS/t-eNOS: Young 0.850±0.04, Aged-Con 0.361±0.07, Aged-AT 0.833±0.04, respectively p<0.05). CONCLUSION: Habitual aerobic exercise enhances adiponectin and CTRP3-mediated vasorelaxation and may involve activation of the AMPK-eNOS signaling pathway in aged mice. References: 1. Arterioscler Thromb Vasc Biol. 31:2616-2623, 2011 2. Am J Physiol Regul Integr Comp Physiol. 314: R94-R101, 2018 |
| Topic: | Molecular Biology and Biochemistry |
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