Molina Yessenia L, García-Seisdedos David, Babiy Bohdan, Lerma Milagros, Martínez-Botas Javier, Casarejos María J, Vallejo María T, Gómez-Coronado Diego, Lasunción Miguel A, Pastor Óscar, Busto Rebeca
Servicio de Bioquímica-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain.
Servicio de Bioquímica-Clínica, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain.
Biomedicines. 2022 Jun 3;10(6):1316. doi: 10.3390/biomedicines10061316.
Exosomes/microvesicles originate from multivesicular bodies that allow the secretion of endolysosome components out of the cell. In the present work, we investigated the effects of rottlerin, a polyphenol, on exosome/microvesicle secretion in a model of intracellular lipid trafficking impairment, and elucidated the mechanism of action. In a model of lipid trafficking impairment in C6 glia cells, rottlerin increased ceramide levels, while decreasing hexosylceramide content. This was accompanied by increased exosome/microvesicle secretion, thereby reducing the concentration of lipids in the endolysosomal compartment. The reduction of hexosylceramide levels by rottlerin was attributed to the increase of β-glucosidase (glucosylceramidase) activity, and the effects of rottlerin were abrogated by β-glucosidase inhibitors such as isofagomine D-tartrate and AMP-deoxynojirimycin. Moreover, treatment with ML-266, a potent activator of the β-glucosidase enzyme, recapitulated the effects of rottlerin on the sphingolipid profile and exosome/microvesicle secretion. Finally, inhibition of AMPK (AMP-activated protein kinase) using compound C prevented both exosome/microvesicle secretion and the elimination of endolysosome lipids, which were promoted by rottlerin. The results showed that the decrease in intracellular lipid deposition induced by rottlerin was mediated by β-glucosidase activation and exosome/microvesicle release via the AMPK pathway. Rottlerin consumption could represent an additional health benefit in lysosomal deposition diseases.
外泌体/微囊泡起源于多囊泡体，多囊泡体可使内溶酶体成分分泌到细胞外。在本研究中，我们研究了多酚化合物rottlerin对细胞内脂质转运受损模型中外泌体/微囊泡分泌的影响，并阐明了其作用机制。在C6神经胶质细胞脂质转运受损模型中，rottlerin增加了神经酰胺水平，同时降低了己糖神经酰胺含量。这伴随着外泌体/微囊泡分泌增加，从而降低了内溶酶体区室中脂质的浓度。rottlerin导致己糖神经酰胺水平降低归因于β-葡萄糖苷酶（葡糖神经酰胺酶）活性增加，并且rottlerin的作用被β-葡萄糖苷酶抑制剂如D-酒石酸异法戈明和AMP-脱氧野尻霉素所消除。此外，用β-葡萄糖苷酶的有效激活剂ML-266处理，重现了rottlerin对鞘脂谱和外泌体/微囊泡分泌的影响。最后，使用化合物C抑制AMPK（AMP激活的蛋白激酶）可阻止rottlerin促进的外泌体/微囊泡分泌和内溶酶体脂质的消除。结果表明，rottlerin诱导的细胞内脂质沉积减少是由β-葡萄糖苷酶激活以及通过AMPK途径释放外泌体/微囊泡介导的。食用rottlerin可能对溶酶体沉积疾病具有额外的健康益处。
