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Katsyuba, E.

Publications and source records attributed to Katsyuba, E..

5 recordsLinked to original sources

Genetic mapping of lifespan and mitochondrial stress response in C. elegans

The mitochondrial unfolded protein response (UPRmt) is one of the mito-nuclear regulatory circuits that restores mitochondrial function upon stress conditions, promoting metabolic health and longevity. However, the complex gene interactions that govern this pathway and its role in aging and healthspan remain to be fully elucidated. Here, we activated the UPRmt using doxycycline (Dox) in a genetically diverse C. elegans population comprising 85 strains and observed large variation in Dox-induced lifespan extension across these strains. Through multi-omic data integration, we identified an aging-related molecular signature that was partially reversed by Dox. To identify the mechanisms underlying Dox-induced lifespan extension, we applied quantitative trait locus (QTL) mapping analyses and found one UPRmt modulator, fipp-1/FIP1L1, which was functionally validated in C. elegans and humans. In the human UK Biobank, FIP1L1 was associated with metabolic homeostasis, underscoring its translational relevance. Overall, our findings demonstrate a novel UPRmt modulator across species and provide insights into potential translational research.

genetics↗

High-content phenotypic analysis of a C. elegans recombinant inbred population identifies genetic and molecular regulators of lifespan

Lifespan is influenced by complex interactions between genetic and environmental factors. Studying those factors in model organisms of a single genetic background limits their translational value for humans. Here, we mapped lifespan determinants in 85 genetically diverse C. elegans recombinant intercross advanced inbred lines (RIAILs). We assessed molecular profiles - transcriptome, proteome, and lipidome - and life-history traits, including lifespan, development, growth dynamics, and reproduction. RIAILs exhibited large variations in lifespan, which positively correlated with developmental time. Among the top candidates obtained from multi-omics data integration and QTL mapping, we validated known and novel longevity modulators, including rict-1, gfm-1 and mltn-1. We translated their relevance to humans using UK Biobank data and showed that variants in RICTOR and GFM1 are associated with an elevated risk of age-related heart disease, dementia, diabetes, kidney, and liver diseases. We organized our dataset as a resource (https://lisp-lms.shinyapps.io/RIAILs/) that allows interactive explorations for new longevity targets.

systems biology↗

Inhibition of GCN5 decreases skeletal muscle fat metabolism during high fat diet feeding

IntroductionGCN5 (Kat2a) is a lysine acetyl transferase capable of acetylating and inhibiting PGC-1 activity. As such, it is described as a negative regulator of PGC-1 and subsequently restricts mitochondrial content. However, elimination of GCN5 in skeletal muscle does not increase mitochondrial content or alter lipid metabolism under normal metabolic conditions. GCN5 levels increase with high-fat diet (HFD) feeding in rodents. Additionally, the GCN5 homolog, PCAF, has previously been shown to also acetylate and inhibit PGC-1 and therefore may possibly compensate for loss of GCN5. ObjectiveThe objective of this study was to examine if with HFD feeding that elimination of GCN5 (Kat2a gene) from skeletal muscle would elicit improvements in mitochondrial and metabolic markers. MethodsSkeletal muscle specific GCN5 knockouts (Gcn5 skm-/-) were fed an HFD. Body composition, cardio-metabolic and physical fitness outcomes were monitored. Additionally, cultured myotubes were treated with a pan-GCN5/PCAF inhibitor and examined for changes in mitochondrial markers. ResultsElimination of skeletal muscle GCN5 did not alter body composition, tissue masses, energy intake, or energy expenditure measurements of mice fed an HFD. Furthermore, whole body glucose homeostasis and cardiac measurements were not altered. There were few differences in lipid metabolism genes, relatively more glucose oxidation versus Gcn5 skm+/+ (wildtype) mice, and a reduction in Pdk4 expression. Exercise capacity and mitochondrial content levels were not altered in Gcn5 skm-/- mice. Further, elimination of GCN5 in skeletal muscle increased Kat2b (PCAF) mRNA expression; however, inhibition of GCN5/PCAF bromodomains in cultured myotubes did not increase oxidative metabolism genes and decreased expression of some mitochondrial genes and Pdk4 mRNA. ConclusionsNeither elimination of GCN5, nor simultaneous inhibition of GCN5 and its homolog PCAF improved skeletal muscle mitochondrial content under normal or HFD-fed conditions. Despite this, GCN5 may play a role in regulating macronutrient preference by regulating Pdk4 content. Thus, HFD/macronutrient excess revealed novel roles of GCN5 in skeletal muscle. Highlights- Skeletal muscle specific elimination of Gcn5/Kat2a decreases fat oxidation without 1) preventing high-fat diet induced weight gain, 2) improving whole body glucose handling, or 3) improving skeletal muscle mitochondrial content. - Inhibition of the GCN5 and PCAF bromodomains and Gcn5 ablation decreases expression of Pdk4. - Expression of Kat2b increases with Gcn5 elimination in skeletal muscle. - Inhibition of the GCN5 and PCAF bromodomains do not result in increased skeletal muscle mitochondrial content.

physiology↗

GCN5 Maintains Muscle Integrity by Acetylating YY1 to Promote Dystrophin Expression

This work identifies a novel role for the acetyltransferase GCN5 in regulating muscle integrity through inhibition of DNA binding activity of the transcriptional repressor YY1. Here we report that in mice a muscle-specific knockout of GCN5 (Gcn5skm-/-) reduces the expression of key structural muscle proteins, including dystrophin, resulting in myopathy. Supporting our observation, a meta-analysis between the differential transcriptome of Gcn5skm-/- muscle and all available open-access data sets identified top correlations with musculoskeletal diseases in humans. GCN5 was found to acetylate YY1 at two residues (K392 and K393), which disrupts the interaction between the YY1 zinc-finger region and DNA. De/acetylation mimics for these YY1 post-translational modifications modulated muscle structural gene expression and DNA binding. Analysis of human GTEx data also found positive and negative correlations between fiber diameter and GCN5 and YY1 respectively. Collectively, our results demonstrate that GCN5 acetyltransferase activity regulates YY1 DNA binding and expression of dystrophin to modulate muscle integrity.

cell biology↗

Identifying gene function and module connections by the integration of multi-species expression compendia

The functions of many eukaryotic genes are still poorly understood. We developed and validated a new method, termed GeneBridge, which is based on two linked approaches to impute gene function and bridge genes with biological processes. First, Gene-Module Association Determination (G-MAD) allows the annotation of gene function. Second, Module-Module Association Determination (M-MAD) allows predicting connectivity among modules. We applied the GeneBridge tools to large-scale multi-species expression compendia--1,700 datasets with over 300,000 samples from human, mouse, rat, fly, worm, and yeast--collected in this study. Unlike most existing bioinformatics tools, GeneBridge exploits both positive and negative gene/module-module associations. We constructed association networks, such as those bridging mitochondria and proteasome, mitochondria and histone demethylation, as well as ribosomes and lipid biosynthesis. The GeneBridge tools together with the expression compendia are available at systems-genetics.org, to facilitate the identification of connections linking genes, modules, phenotypes, and diseases.

systems biology↗