Biology subjects

Au, W. H.

Publications and source records attributed to Au, W. H..

3 recordsLinked to original sources

bioRxiv2026

Cross-platform multi-laboratory screening identifies HUWE1, USP33 and USP20 as negative-regulators of autophagy or mitophagy with relevance to neurodegeneration

Autophagy and mitophagy are essential cellular processes implicated in neurodegenerative diseases, yet few tractable targets have been robustly validated for therapeutic modulation of these pathways. In an industry-academia consortium we carried out an extensive literature review and expert curation, leading to selection of 29 genes previously reported to enhance autophagy upon genetic or pharmacological modulation. These genes were classified based on whether downregulation or overexpression induced autophagic activity. Using siRNA knockdown, small-molecule modulators, and transient transfection approaches, we systematically screened these targets in parallel across HeLa and HEK-293 cell lines using high- and low-content phenotypic imaging. Promising candidates were further evaluated in induced pluripotent stem cell (iPSC)-derived neurons and in Drosophila models. Three targets emerged as top candidates: HUWE1 downregulation consistently enhanced autophagy and aggregate clearance, while USP33 downregulation promoted mitophagy. We also identified USP20, a close homologue of USP33, as an inhibitor of mitophagy, a role not previously assigned to this protein. These effects on autophagy/mitophagy were corroborated in Drosophila, highlighting their potential functional relevance across species. This cross-platform, multi-laboratory study establishes a framework for identifying and validating regulators of autophagy and mitophagy and provides a route which enables a comprehensive reassessment of the current target literature in this field. The validation of HUWE1, USP20, and USP33 as candidate therapeutic targets offers new opportunities for intervention in neurodegenerative diseases.

neuroscience↗

bioRxiv2024

Clu1/Clu form mitochondria-associated granules upon metabolic transitions and regulate mitochondrial protein translation via ribosome interactions

Mitochondria perform essential metabolic functions and respond rapidly to changes in metabolic and stress conditions. As the majority of mitochondrial proteins are nuclear-encoded, intricate post-transcriptional regulation is crucial to enable mitochondria to adapt to changing cellular demands. The eukaryotic Clustered mitochondria protein family has emerged as an important regulator of mitochondrial function during metabolic shifts. Here, we show that the Drosophila melanogaster and Saccharomyces cerevisiae Clu/Clu1 proteins form dynamic, membraneless granules adjacent to mitochondria in response to metabolic changes. Yeast Clu1 regulates the translation of a subset of nuclear-encoded mitochondrial protein by interacting with their mRNAs while these are engaged in translation. We further show that Clu1 regulates translation by interacting with polysomes, independently of whether it is in a diffuse or granular state. Our results demonstrate remarkable functional conservation with other members of the Clustered mitochondria protein family and suggests that Clu/Clu1 granules isolate and concentrate ribosomes engaged in translating their mRNA targets, thus, integrating metabolic signals with the regulation of mitochondrial protein synthesis.

molecular biology↗

bioRxiv2023

Activation of the Keap1/Nrf2 pathway suppresses mitochondrial dysfunction in C9orf72 ALS/FTD in vivo models and patient iNeurons

Mitochondrial dysfunction such as excess production of reactive oxygen species (ROS) and defective mitochondrial dynamics are common features of C9orf72 Amyotrophic Lateral Sclerosis/Frontotemporal Dementia (ALS/FTD), but it remains unclear whether these are causative or a consequence of the pathogenic process. To address this, we have performed a comprehensive characterisation of mitochondrial dysfunction in vivo model, analysing multiple transgenic Drosophila models of C9orf72-related pathology, which can be correlated to disease-relevant locomotor deficits. Genetic manipulations to reverse different aspects of mitochondrial disruption revealed that only genetic upregulation of antioxidants such as mitochondrial Sod2 and catalase were able to rescue C9orf72 locomotor deficits, suggesting a causative link between mitochondrial dysfunction, ROS and behavioural phenotypes. By analysing the Keap1/Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, a central antioxidant response pathway, we observed a blunted response in the C9orf72 models. However, both genetic reduction of Keap1 and its pharmacological targeting by dimethyl fumarate (DMF), was able to rescue C9orf72-related motor deficits. In addition, analysis of C9orf72 patient-derived iNeurons showed increased ROS that was suppressed by DMF treatment. These results indicate that mitochondrial oxidative stress is an upstream pathogenic mechanism leading to downstream mitochondrial dysfunction such as alterations in mitochondrial function and turnover. Consequently, our data support targeting the Keap1/Nrf2 signalling pathway as a viable therapeutic strategy for C9orf72-related ALS/FTD.

neuroscience↗