Mustapha, Sagir and Azemi, Ahmad Khusairi and Ahmad, Wan Amir Nizam Wan and Rasool, Aida Hanum Ghulam and Mustafa, Mohd Rais and Mokhtar, Siti Safiah (2022) Inhibition of endoplasmic reticulum stress improves acetylcholine-mediated relaxation in the aorta of type-2 diabetic rats. Molecules, 27 (16). ISSN 1420-3049, DOI https://doi.org/10.3390/molecules27165107.
Full text not available from this repository.Abstract
Endoplasmic reticulum (ER) stress contributes to insulin resistance and macro- and microvascular complications associated with diabetes. This study aimed to evaluate the effect of ER stress inhibition on endothelial function in the aorta of type-2 diabetic rats. Type-2 diabetes was developed in male Sprague-Dawley rats using a high-fat diet and low-dose streptozotocin. Rat aortic tissues were harvested to study endothelial-dependent relaxation. The mechanisms for acetylcholine-mediated relaxation were investigated using pharmacological blockers, Western blotting, oxidative stress, and inflammatory markers. Acetylcholine-mediated relaxation was diminished in the aorta of diabetic rats compared to control rats; supplementation with TUDCA improved relaxation. In the aortas of control and diabetic rats receiving TUDCA, the relaxation was mediated via eNOS/PI3K/Akt, NAD(P)H, and the K-ATP channel. In diabetic rats, acetylcholine-mediated relaxation involved eNOS/PI3K/Akt and NAD(P)H, but not the K-ATP channel. The expression of ER stress markers was upregulated in the aorta of diabetic rats and reduced with TUDCA supplementation. The expression of eNOS and Akt were lower in diabetic rats but were upregulated after supplementation with TUDCA. The levels of MDA, IL-6, and SOD activity were higher in the aorta of the diabetic rats compared to control rats. This study demonstrated that endothelial function was impaired in diabetes, however, supplementation with TUDCA improved the function via eNOS/Akt/PI3K, NAD(P)H, and the K-ATP channel. The improvement of endothelial function was associated with increased expressions of eNOS and Akt. Thus, ER stress plays a crucial role in the impairment of endothelial-dependent relaxation. Mitigating ER stress could be a potential strategy for improving endothelial dysfunction in type-2 diabetes.
| Item Type: | Article |
|---|---|
| Funders: | Malaysian Ministry of Higher Education [FRGS/1/2018/SKK08/USM/02/11] |
| Uncontrolled Keywords: | Endothelial function; ER stress; Tauro-ursodeoxycholic acid (TUDCA); Type-2 diabetes; Vasculopathy |
| Subjects: | Q Science > QD Chemistry R Medicine |
| Divisions: | Faculty of Medicine |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 21 Sep 2023 06:25 |
| Last Modified: | 21 Sep 2023 06:25 |
| URI: | http://eprints.um.edu.my/id/eprint/41388 |
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