Genetics and Molecular Pathology, SA Pathology at Women's and Children's Hospital, North Adelaide, South Australia, Australia; and.
Genetics and Molecular Pathology, SA Pathology at Women's and Children's Hospital, North Adelaide, South Australia, Australia; and; Department of Pediatrics, University of Adelaide, Adelaide, South Australia, Australia.
J Lipid Res. 2013 Jun;54(6):1691-1697. doi: 10.1194/jlr.M038232. Epub 2013 Apr 6.
Bis(monoacylglycero)phosphate (BMP) assists lysosomal function by facilitating interaction of hydrolases and activator proteins with sphingolipid substrates. Impaired lysosomal degradation of the sphingolipid glucosylceramide (GC) occurs in Gaucher disease due to an inherited deficiency of acid β-glucosidase, with secondary BMP alterations. We investigated the nature of BMP accumulation and whether its correction reduced the storage burden in a THP-1 macrophage model of Gaucher disease. Using sucrose gradients and detergent solubility, 98% of BMP resided in the detergent-soluble membranes (DSM) rather than in the detergent-resistant membranes (DRM) where 73% of GC predominated. There was a 2-fold widespread elevation in BMP, including the saturated, mono- and polyunsaturated species. Linoleic acid in the culture media selectively reduced BMP from 4.2 nmol/mg to 0.49 nmol/mg (except 18:1/18:2) and prevented up to one third of GC, dihexosylceramide (DHC), and trihexosylceramide (THC) from accumulating. The 2-fold reduction in these sphingolipids occurred only in the DRM and did not reduce 18:1/16:0. However, once GC had accumulated, linoleic acid could not reverse it, DHC, or THC, despite effectively reducing BMP. These results imply a causative link for BMP in the pathobiology of Gaucher disease and demonstrate that linoleic acid can shield the cell from excessive substrate accumulation.
双(单酰基甘油)磷酸(BMP)通过促进水解酶和激活蛋白与鞘脂底物的相互作用来辅助溶酶体功能。由于酸性β-葡萄糖苷酶的遗传性缺乏,导致鞘糖脂葡萄糖脑苷脂(GC)的溶酶体降解受损,从而发生戈谢病,随之而来的是 BMP 改变。我们研究了 BMP 积累的性质,以及其校正是否可以减少戈谢病 THP-1 巨噬细胞模型中的储存负担。使用蔗糖梯度和去污剂溶解度,98%的 BMP 存在于去污剂可溶性膜(DSM)中,而不是在 73%的 GC 占优势的去污剂抗性膜(DRM)中。BMP 广泛增加了 2 倍,包括饱和、单不饱和和多不饱和物种。培养基中的亚油酸选择性地将 BMP 从 4.2 nmol/mg 降低到 0.49 nmol/mg(除 18:1/18:2 外),并阻止高达三分之一的 GC、二己糖神经酰胺(DHC)和三己糖神经酰胺(THC)积累。这些鞘脂的 2 倍减少仅发生在 DRM 中,不会减少 18:1/16:0。然而,一旦 GC 积累,亚油酸就无法逆转它、DHC 或 THC,尽管它有效地降低了 BMP。这些结果意味着 BMP 在戈谢病的病理生物学中存在因果关系,并表明亚油酸可以保护细胞免受过多底物积累的影响。