Iglesias-Fortes S, Lockwood A C, González-Blanco C, Lozano D, García-Aguilar A, Palomino O, García G, Fernández-Millán E, Benito M, Guillén C
Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, Ciudad Universitaria, 28040 Madrid, Spain.
Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, Ciudad Universitaria, 28040 Madrid, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, 28040 Madrid, Spain; Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Complutense University of Madrid, IdISSC, Madrid, Spain.
Biochim Biophys Acta Mol Basis Dis. 2025 Apr;1871(4):167699. doi: 10.1016/j.bbadis.2025.167699. Epub 2025 Jan 30.
Type 2 diabetes mellitus is a disease which initiates with insulin resistance. Then, pancreatic β cells start to counteract this situation by increasing insulin secretion, which is known as pre-diabetic state. Amylin protein or islet amyloid polypeptide (IAPP), has multiple physiological roles such as the regulation of satiety and avoiding gastric emptying. However, amylin is able to aggregate, forming insoluble structures that affects pancreatic β cell survival. Interestingly, not all the amylin from the different species has this aggregate-prone capacity. There are species, which possesses non-amyloidogenic capacity and does not aggregate such as the rodents. However, there are versions of the protein, for instance from humans and primates, which can aggregate. Previously, we observed that small oligomers could be found in extracellular vesicles (EVs). Now, we have used a pancreatic β cell which overexpresses human amylin (hIAPP) (INS1E-hIAPP) and we have explored the capacity of amylin to be incorporated into EVs and how amylin could affect to different essential signaling pathways such as the mammalian target of rapamycin complex 1, endoplasmic-reticulum stress and senescence. Here, we report that amylin can be incorporated into EVs in an endosomal sorting complexes required for transport (ESCRT)-dependent manner. When we treated the cells with the neutral sphingomyelinase inhibitor, GW4869, one of the pathways for EV biogenesis and under high glucose conditions, there was an increased incorporation of soluble amylin into vesicles. Interestingly in this condition, when we isolated the EVs, we clearly observed that the size of the vesicles was higher, compatible with microvesicles (MVs). Resveratrol increased a pro-senescent phenotype but, it was able to revert either the high glucose or GW4869-associated senescent. In summary, these results indicate that amylin can be recruited in an ESCRT-dependent manner into EVs and, resveratrol presents an important role in inducing senescence in INS1E-hIAPP pancreatic β cells.
2型糖尿病是一种始于胰岛素抵抗的疾病。随后，胰腺β细胞开始通过增加胰岛素分泌来应对这种情况，这被称为糖尿病前期状态。胰淀素蛋白或胰岛淀粉样多肽（IAPP）具有多种生理作用，如调节饱腹感和防止胃排空。然而，胰淀素能够聚集，形成影响胰腺β细胞存活的不溶性结构。有趣的是，并非来自不同物种的所有胰淀素都具有这种易于聚集的能力。有些物种，如啮齿动物，具有非淀粉样生成能力且不会聚集。然而，该蛋白的某些变体，例如来自人类和灵长类动物的变体，能够聚集。此前，我们观察到在细胞外囊泡（EVs）中可以发现小寡聚物。现在，我们使用了一种过表达人胰淀素（hIAPP）的胰腺β细胞（INS1E-hIAPP），并研究了胰淀素被纳入EVs的能力以及胰淀素如何影响不同的重要信号通路，如雷帕霉素复合物1的哺乳动物靶点、内质网应激和衰老。在此，我们报告胰淀素可以以内体分选转运所需复合物（ESCRT）依赖的方式被纳入EVs。当我们用中性鞘磷脂酶抑制剂GW4869处理细胞时，这是EV生物发生的途径之一，并且在高糖条件下，可溶性胰淀素向囊泡中的掺入增加。有趣的是，在这种情况下，当我们分离EVs时，我们清楚地观察到囊泡的尺寸更大，与微囊泡（MVs）相符。白藜芦醇增加了促衰老表型，但它能够逆转高糖或GW4869相关的衰老。总之，这些结果表明胰淀素可以以ESCRT依赖的方式被募集到EVs中，并且白藜芦醇在诱导INS1E-hIAPP胰腺β细胞衰老中发挥重要作用。
