Biology subjects

Raedschelders, K.

Publications and source records attributed to Raedschelders, K..

3 recordsLinked to original sources

bioRxiv2021

Protective role of the Atg8 1 homologue Gabarapl1 in regulating cardiomyocyte glycophagy in diabetic heart disease

Diabetic heart disease is highly prevalent and characterized by diastolic dysfunction. The mechanisms of diabetic heart disease are poorly understood and no targeted therapies are available. Here we show that the diabetic myocardium (type 1 and type 2) is characterized by marked glycogen elevation and ectopic cellular localization - a paradoxical metabolic pathology given suppressed cardiomyocyte glucose uptake in diabetes. We demonstrate involvement of a glycogen-selective autophagy pathway ( glycophagy) defect in mediating this pathology. Genetically manipulated deficiency of Gabarapl1, an Atg8 autophagy homologue, induces cardiac glycogen accumulation and diastolic dysfunction. Stbd1, the Gabarapl1 cognate autophagosome partner is identified as a unique component of the early glycoproteome response to hyperglycemia in cardiac, but not skeletal muscle. Cardiac-targeted in vivo Gabarapl1 gene delivery normalizes glycogen levels, diastolic function and cardiomyocyte mechanics. These findings reveal that cardiac glycophagy is a key metabolic homeostatic process perturbed in diabetes that can be remediated by Gabarapl1 intervention.

molecular biology↗

bioRxiv2021

Standardized workflow for precise mid- and high-throughput proteomics of blood biofluids

BackgroundAccurate discovery assay workflows are critical for identifying authentic circulating protein biomarkers in diverse blood matrices. Maximizing the commonalities in the proteomic workflows between different biofluids simplifies the approach and increases the likelihood for reproducibility. We developed a workflow that allows flexibility for high and mid-throughput analysis for three blood-based proteomes: naive plasma, plasma depleted of the 14 most abundant proteins, and dried blood. MethodsOptimal conditions for sample preparation and DIA-MS analysis were established in plasma then automated and adapted for depleted plasma and whole blood. The MS workflow was modified to facilitate sensitive high-throughput or deep profile analysis with mid-throughput analysis. Analytical performance was evaluated from 5 complete workflows repeated over 3 days as well as a linearity analysis of a 5-6-point dilution curve. ResultUsing our high-throughput workflow, 74%, 93%, 87% of peptides displayed an inter-day CV<30% in plasma, depleted plasma and whole blood. While the mid-throughput workflow had 67%, 90%, 78% of peptides in plasma, depleted plasma and whole blood meeting the CV<30% standard. Lower limits of detection and quantitation were determined for proteins and peptides observed in each biofluid and workflow. Combining the analysis of both high-throughput plasma fractions exceeded the number of reliably identified proteins for individual biofluids in the mid-throughput workflows. ConclusionThe workflow established here allowed for reliable detection of proteins covering a broad dynamic range. We envisage that implementation of this standard workflow on a large scale will facilitate the translation of candidate markers into clinical use.

biochemistry↗

bioRxiv2020

Oncometabolism Drives Autophagy Activation in Skeletal Muscle

About 20-30% of cancer-associated deaths are due to complications from cachexia which is characterized by skeletal muscle atrophy. Metabolic reprogramming in cancer cells causes body-wide metabolic and proteomic remodeling, which remain poorly understood. Here, we present evidence that the oncometabolite D-2-hydroxylgutarate (D2-HG) impairs NAD+ redox homeostasis in skeletal myotubes, causing atrophy via deacetylation of LC3-II by the nuclear deacetylase Sirt1. Overexpression of p300 or silencing of Sirt1 abrogate its interaction with LC3, and subsequently reduced levels of LC3 lipidation. Using RNA-sequencing and mass spectrometry-based metabolomics and proteomics, we demonstrate that prolonged treatment with the oncometabolite D2-HG in mice promotes cachexia in vivo and increases the abundance of proteins and metabolites, which are involved in energy substrate metabolism, chromatin acetylation and autophagy regulation. We further show that D2-HG promotes a sex-dependent adaptation in skeletal muscle using network modeling and machine learning algorithms. Our multi-omics approach exposes new metabolic vulnerabilities in response to D2-HG in skeletal muscle and provides a conceptual framework for identifying therapeutic targets in cachexia.

systems biology↗