Biology subjects

Waller-Evans, H.

Publications and source records attributed to Waller-Evans, H..

3 recordsLinked to original sources

bioRxiv2025

Niemann-Pick C-like endo-lysosomal dysfunction in DHDDS patient cells, a congenital disorder of glycosylation, can be treated with miglustat

DHDDS (dehydrodolichol diphosphate synthetase) and NgBR (Nogo-B Receptor) collectively form an enzymatic complex important for the synthesis of dolichol - a key component of protein N-glycosylation. Mutations in DHDDS and the gene encoding NgBR (NUS1) are associated with neurodevelopmental disorders that clinically present with epilepsy, motor impairments, and developmental delay. Previous work has demonstrated both DHDDS and NgBR can also interact with NPC2 (Niemann-Pick C (NPC) type 2) - a protein which functions to traffic cholesterol out of the lysosome and, when mutated, can cause a lysosomal storage disorder (NPC disease) characterised by an accumulation of cholesterol and glycosphingolipids. Abnormal cholesterol accumulation has also been reported in cells from individuals and animal models with mutations in NUS1, and suspected lipid storage has been shown in biopsies from individuals with mutations in DHDDS. Our findings provide further evidence for overlap between NPC2 and DHDDS disorders, showing that DHDDS patient fibroblasts have increased lysosomal volume, store cholesterol and ganglioside GM1, and have altered lysosomal Ca2+ homeostasis. Treatment of DHDDS cells - with the approved NPC small molecule therapy miglustat - improves these disease-associated phenotypes, identifying a possible therapeutic option for DHDDS patients. These data suggest that treatment options currently approved for NPC disease may be translatable to DHDDS/NUS1 patients.

biochemistry↗

bioRxiv2024

Inhibition of acid ceramidase as a therapeutic strategy for Niemann-Pick C disease

Lysosomal storage disorders (LSDs) are a group of individually rare diseases that as a group constitute the most common forms of childhood neurodegeneration. These life limiting and life shortening diseases have the largest economic burden per patient of any rare disease with the majority being orphan diseases with no disease modifying therapy. Whilst there is significant development in the area of gene therapies for LSDs, these can only be used to treat individual diseases, are expensive, and in recent times many companies have abandoned their gene therapy pipelines. Small molecules on the other hand can be developed to target common mechanisms of pathogenesis or common central disease phenotypes providing therapies that can treat multiple diseases. In this study we report acid ceramidase as a novel therapeutic target for treating Niemann-Pick type C (NPC) disease. Using siRNA, and the literature tool compound carmofur, we observed a reduction in lysosomal area and reduced accumulation of the lipids cholesterol and LBPA in an NPC cellular model. These lipids are known to accumulate as secondary storage molecules across many lysosomal diseases, particularly primary sphingolipid storage disorders where lyso-sphingolipids are known to accumulate via the action of acid ceramidase. As acid ceramidase has also been shown to be a therapeutic target for Krabbe disease, our findings indicate that this is a novel target for the potential treatment of multiple LSDs with primary or secondary storage of sphingolipids.

cell biology↗

bioRxiv2017

Effects Of Curcumin Nanoformulations On Cellular Function In Niemann-Pick Disease Type C Astrocytes

Niemann-Pick disease type C1 (NPC disease) is a neurodegenerative multi-lipid lysosomal storage disease caused by mutations in the NPC1 gene presenting with reduced lysosomal Ca2+ signalling and inhibited late endosome-lysosome transport. Elevating cytosolic Ca2+ levels in NPC cells has been shown to reduce lysosomal lipid storage. Treating Npc1-/- mice with the Ca2+ modulator curcumin led to reduced lipid storage, improved life expectancy and function. These studies led to reported utilisation of curcumin supplements by NPC disease families despite there being no clinical evidence of benefit and a report indicating no benefit of nanoformulated curcumin in Npc1-/- mice. The aim of this study was to determine whether various commercially available curcumin nanoformulations were capable of reproducing the findings obtained with unformulated pharmaceutical grade curcumin. We compared seven curcumin nanoformulations in Npc1-/- mouse astrocytes. All the nanoformulations elevate cytosolic Ca2+ levels but only two lowered lysosomal lipid storage. Importantly, some caused elevations in NPC lysosomal storage and/or decreased cellular viability. Although this is an in vitro study, our findings suggest that care should be taken when contemplating the use of curcumin supplements for NPC disease.

pharmacology and toxicology↗