A modified lipid composition in Fabry disease leads to an intracellular block of the detergent‐resistant membrane‐associated dipeptidyl peptidase IV

Abstract

Fabry disease is an X-linked lysosomal storage disorder that leads to abnormal accumulation of glycosphingolipids due to a deficiency of alpha-galactosidase A (AGAL). The consequences of these alterations on the targeting of membrane proteins are poorly understood. Glycosphingolipids are enriched in Triton-X-100- resistant lipid rafts [detergent-resistant membranes (DRMs)] and play an important role in the transport of several membrane-associated proteins. Here, we show that In fibroblasts of patients suffering from Fabry disease, the colocalization of AGAL with the lysosomal marker LAMP2 is decreased compared with wild-type fibroblasts concomitant with a reduced transport of AGAL to lysosomes. Furthermore, overall composition of membrane lipids in the patients' fibroblasts as well as in DRMs reveals a substantial increase in the concentration of glycolipids and a slight reduction of phosphatidylethanolamine (PE). The altered glycolipid composition in Fabry fibroblasts is associated with an intracellular accumulation and impaired trafficking of the Triton-X-100 DRM-associated membrane glycoprotein dipeptidyl peptidase IV (DPPIV) in transfected Fabry cells, whereas no effect could be observed on the targeting of aminopeptidase N (ApN) that is not associated with this type of DRM. We propose that changes in the lipid composition of cell membranes in Fabry disease disturb the ordered Triton X-100 DRMs and have implications on the trafficking and sorting of DRM-associated proteins and the overall protein-lipid interaction at the cell membrane. Possible consequences could be altered signalling at the cell surface triggered by DRM-associated proteins, with implications on gene regulation and subsequent protein expression.

Altered dynamics of a lipid raft associated protein in a kidney model of Fabry disease

“…Moreover, we found no difference in the steady state distribution of the raftassociated protein HA (figure 4B) or the raft-independent protein p75-GFP (figure 4C) in α-gal A silenced cells. A previous study reported changes in the subcellular localization of DPPIV in fibroblasts cultured from Fabry patients [39]. However, we found no effect of α-gal A silencing on DPPIV distribution ( figure 4D).…”

“…Furthermore, changes in raft composition have been described for some lysosomal storage disorders such as Niemann-Pick type C [33], Gaucher disease type I [34], Sandhoff disease [35], Sanfilippo disease [36], neuronal ceroid lypofuscinosis [37], and Krabbe disease [38]. Whether lipid raft structure is altered in Fabry disease is not known, however recent studies have suggested that trafficking of the glycosphingolipid lactosylceramide and of the apical glycoprotein dipeptidylpeptidase IV are perturbed in fibroblasts of Fabry disease patients compared to control fibroblasts [39,40].…”

Case study on the pathophysiology of Fabry disease: abnormalities of cellular membranes can be reversed by substrate reduction in vitro

“…Skin fibroblasts were grown in culture as previously described [7]. Treatment with 50 mM NB-DNJ was performed for 72 h, renewed in fresh medium every 24 h and cultured in Dulbecco’s Modified Eagle’s Medium, low glucose with 10% FBS and added penicillin and streptomycin at 37°C in 5% CO 2 .…”

“…In a previous study, we have shown that trafficking of a representative protein associated with detergent-resistant membranes (DRM)/lipid rafts (LRs), namely dipeptidyl peptidase IV (DPPIV), to the cell surface was hampered in fibroblasts from a Fabry patient, which may lead to altered signalling and transport at the cell surface [7]. LRs are distinct, ordered, liquid domains enriched in sphingolipids and cholesterol segregated from less ordered membrane domains composed of mainly unsaturated phospholipids.…”

Cadherin-related protein 24 induces morphological changes and partial cell polarization by facilitating direct cell-cell interactions

“…with this detergent (Alfalah et al , 2005 ) and is not affected by alterations of cholesterol or sphingolipid depletion, as in the case of TX-DRM-associated proteins (Maalouf et al , 2010 ). Therefore, the partial polarization induced by CDHR24 expression could be restricted to membrane proteins associated with TX-DRMs.…”