NELF‐A controls Drosophila healthspan by regulating heat‐shock protein‐mediated cellular protection and heterochromatin maintenance
TL;DR: In this article, the authors showed that the dosage of neuronal NELF-A affects multiple aspects of aging in Drosophila by regulating transcription of heat-shock protein (HSP) genes in the brains, suggesting that targeting transcription elongation might be a viable therapeutic strategy against ageonset diseases like neurodegeneration.
Abstract: NELF-mediated pausing of RNA polymerase II (RNAPII) constitutes a crucial step in transcription regulation. However, it remains unclear how control release of RNAPII pausing can affect the epigenome and regulate important aspects of animal physiology like aging. We found that NELF-A dosage regulates Drosophila healthspan: Halving NELF-A level in the heterozygous mutants or via neuronal-specific RNAi depletion improves their locomotor activity, stress resistance, and lifespan significantly. Conversely, NELF-A overexpression shortens fly lifespan drastically. Mechanistically, lowering NELF-A level facilitates the release of paused RNAPII for productive transcription of the heat-shock protein (Hsp) genes. The elevated HSPs expression in turn attenuates the accumulation of insoluble protein aggregates, reactive oxidative species, DNA damage and systemic inflammation in the brains of aging NELF-A depleted flies as compared to their control siblings. This pro-longevity effect is unique to NELF-A due to its higher expression level and more efficient pausing of RNAPII than other NELF subunits. Importantly, enhanced resistance to oxidative stress in NELF-A heterozygous mutants is highly conserved such that knocking down its level in human SH-SY5Y cells attenuates hydrogen peroxide-induced DNA damage and apoptosis. Depleting NELF-A reconfigures the epigenome through the maintenance of H3K9me2-enriched heterochromatin during aging, leading to the repression of specific retrotransposons like Gypsy-1 in the brains of NELF-A mutants. Taken together, we showed that the dosage of neuronal NELF-A affects multiple aspects of aging in Drosophila by regulating transcription of Hsp genes in the brains, suggesting that targeting transcription elongation might be a viable therapeutic strategy against age-onset diseases like neurodegeneration.
Citations
More filters
TL;DR: A comparative, interdisciplinary approach is taken to explore various hypotheses about how sex differences in aging arise and discusses genomic, morphological, and environmental differences between the sexes and how these relate to sex Differences in aging.
Abstract: Sex differences in aging occur in many animal species, and they include sex differences in lifespan, in the onset and progression of age‐associated decline, and in physiological and molecular markers of aging. Sex differences in aging vary greatly across the animal kingdom. For example, there are species with longer‐lived females, species where males live longer, and species lacking sex differences in lifespan. The underlying causes of sex differences in aging remain mostly unknown. Currently, we do not understand the molecular drivers of sex differences in aging, or whether they are related to the accepted hallmarks or pillars of aging or linked to other well‐characterized processes. In particular, understanding the role of sex‐determination mechanisms and sex differences in aging is relatively understudied. Here, we take a comparative, interdisciplinary approach to explore various hypotheses about how sex differences in aging arise. We discuss genomic, morphological, and environmental differences between the sexes and how these relate to sex differences in aging. Finally, we present some suggestions for future research in this area and provide recommendations for promising experimental designs.
27 citations
TL;DR: It is found that reduced level of nuclear lamin-B protein coincides with the decline in locomotor activity and stress resistance in young adult male Drosophila, and cellular thermal shift assay showed that lamination-B and CP190 insulator protein undergo significant change in their solubility during aging.
Abstract: Epigenetic alterations occur during aging, but it remains unclear what epigenetic features are associated with the onset of physiological decline in animals. Nuclear lamin-B forms the filamentous meshwork underneath the nuclear envelope, providing the structural scaffold necessary for genome organization and gene regulation. We found that reduced level of nuclear lamin-B protein coincides with the decline in locomotor activity and stress resistance in young adult male Drosophila. Ubiquitous lamin-B expression improves locomotor activity of the male flies at the expense of lower stress resistance and shorten lifespan. This observation suggests that tissue-specific expression of lamin-B may regulate different aspects of animal physiology during aging. To test this hypothesis, specific GAL-4 lines were used to drive the expression of lamin-B in specific neuronal populations and muscle tissues in male flies. Ectopic expression of lamin-B in the dopaminergic neurons within the protocerebral anterior medial region of the brain improves the locomotor activity of the male flies with little impact on their stress responses and lifespan. Interestingly, age-dependent decrease in the level of lamin-B protein is independent of its mRNA expression. Instead, cellular thermal shift assay showed that lamin-B and CP190 insulator protein undergo significant change in their solubility during aging. This suggests that the increased solubility of lamin-B protein may contribute to its reduced stability and degradation during aging.
5 citations
TL;DR: The assembly of stress- induced MLOs and the stress-induced modification of existing MLOs in eukaryotes, yeasts, and prokaryotes in response to various stress factors are described.
Abstract: The discovery of intrinsically disordered proteins (IDPs) that do not have an ordered structure and nevertheless perform essential functions has opened a new era in the understanding of cellular compartmentalization. It threw the bridge from the mostly mechanistic model of the organization of the living matter to the idea of highly dynamic and functional “soft matter”. This paradigm is based on the notion of the major role of liquid-liquid phase separation (LLPS) of biopolymers in the spatial-temporal organization of intracellular space. The LLPS leads to the formation of self-assembled membrane-less organelles (MLOs). MLOs are multicomponent and multifunctional biological condensates, highly dynamic in structure and composition, that allow them to fine-tune the regulation of various intracellular processes. IDPs play a central role in the assembly and functioning of MLOs. The LLPS importance for the regulation of chemical reactions inside the cell is clearly illustrated by the reorganization of the intracellular space during stress response. As a reaction to various types of stresses, stress-induced MLOs appear in the cell, enabling the preservation of the genetic and protein material during unfavourable conditions. In addition, stress causes structural, functional, and compositional changes in the MLOs permanently present inside the cells. In this review, we describe the assembly of stress-induced MLOs and the stress-induced modification of existing MLOs in eukaryotes, yeasts, and prokaryotes in response to various stress factors.
2 citations
TL;DR: Ngian et al. as discussed by the authors corrected the following: NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance.
Abstract: Aging CellEarly View e13547 ErratumOpen Access Erratum to: NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance This article corrects the following: NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance Zhen-Kai Ngian, Wei-Qi Lin, Chin-Tong Ong, Volume 20Issue 5Aging Cell First Published online: March 31, 2021 First published: 17 January 2022 https://doi.org/10.1111/acel.13547AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Zhen-Kai Ngian, Wei-Qi Lin, Chin-Tong Ong, Aging Cell, 20, e13348. https://doi.org/10.1111/acel.13348 In the published version of Ngian et al. (2021), the authors noticed that the panel label (f) was incorrectly placed, and label (g) was missing in Figure 3. The corrected version of Figure 3 was shown below. The authors would like to apologize for the inconvenience caused. Reference Ngian, Z.-K., Lin, W.-Q., & Ong, C.-T. (2021). NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance. Aging Cell, 20, e13348. https://doi.org/10.1111/acel.13348Wiley Online LibraryCASPubMedWeb of Science®Google Scholar Early ViewOnline Version of Record before inclusion in an issuee13547 ReferencesRelatedInformation
References
More filters
TL;DR: Global run-on sequencing, GRO-seq, shows that peaks of promoter-proximal polymerase reside on ∼30% of human genes, transcription extends beyond pre-messenger RNA 3′ cleavage, and antisense transcription is prevalent.
Abstract: RNA polymerases are highly regulated molecular machines. We present a method (global run-on sequencing, GRO-seq) that maps the position, amount, and orientation of transcriptionally engaged RNA polymerases genome-wide. In this method, nuclear run-on RNA molecules are subjected to large-scale parallel sequencing and mapped to the genome. We show that peaks of promoter-proximal polymerase reside on ∼30% of human genes, transcription extends beyond pre-messenger RNA 3′ cleavage, and antisense transcription is prevalent. Additionally, most promoters have an engaged polymerase upstream and in an orientation opposite to the annotated gene. This divergent polymerase is associated with active genes but does not elongate effectively beyond the promoter. These results imply that the interplay between polymerases and regulators over broad promoter regions dictates the orientation and efficiency of productive transcription.
1,945 citations
TL;DR: The data show thatmiR-133, and possibly miR-1, are key regulators of cardiac hypertrophy, suggesting their therapeutic application in heart disease.
Abstract: Growing evidence indicates that microRNAs (miRNAs or miRs) are involved in basic cell functions and oncogenesis. Here we report that miR-133 has a critical role in determining cardiomyocyte hypertrophy. We observed decreased expression of both miR-133 and miR-1, which belong to the same transcriptional unit, in mouse and human models of cardiac hypertrophy. In vitro overexpression of miR-133 or miR-1 inhibited cardiac hypertrophy. In contrast, suppression of miR-133 by 'decoy' sequences induced hypertrophy, which was more pronounced than that after stimulation with conventional inducers of hypertrophy. In vivo inhibition of miR-133 by a single infusion of an antagomir caused marked and sustained cardiac hypertrophy. We identified specific targets of miR-133: RhoA, a GDP-GTP exchange protein regulating cardiac hypertrophy; Cdc42, a signal transduction kinase implicated in hypertrophy; and Nelf-A/WHSC2, a nuclear factor involved in cardiogenesis. Our data show that miR-133, and possibly miR-1, are key regulators of cardiac hypertrophy, suggesting their therapeutic application in heart disease.
1,738 citations
TL;DR: This Review summarizes the concepts of the protective Hsp network, and the most conserved Hsps are molecular chaperones that prevent the formation of nonspecific protein aggregates and assist proteins in the acquisition of their native structures.
1,570 citations
TL;DR: It is shown that directed expression of the molecular chaperone HSP70 suppresses polyglutamine-induced neurodegeneration in vivo, indicating that polyglUTamine toxicity can be dissociated from formation of large aggregates.
Abstract: At least eight inherited human neurodegenerative diseases are caused by expansion of a polyglutamine domain within the respective proteins. This confers dominant toxicity on the proteins, leading to dysfunction and loss of neurons. Expanded polyglutamine proteins form aggregates, including nuclear inclusions (NI), within neurons, possibly due to misfolding of the proteins. NI are ubiquitinated and sequester molecular chaperone proteins and proteasome components, suggesting that disease pathogenesis includes activation of cellular stress pathways to help refold, disaggregate or degrade the mutant disease proteins. Overexpression of specific chaperone proteins reduces polyglutamine aggregation in transfected cells, but whether this alters toxicity is unknown. Using a Drosophila melanogaster model of polyglutamine disease, we show that directed expression of the molecular chaperone HSP70 suppresses polyglutamine-induced neurodegeneration in vivo. Suppression by HSP70 occurred without a visible effect on NI formation, indicating that polyglutamine toxicity can be dissociated from formation of large aggregates. Our studies indicate that HSP70 or related molecular chaperones may provide a means of treating these and other neurodegenerative diseases associated with abnormal protein conformation and toxicity.
852 citations
TL;DR: It is demonstrated here that dFOXO regulates D. melanogaster ageing when activated in the adult pericerebral fat body and reduces expression of the Drosophila insulin-like peptide dilp-2 synthesized in neurons, and represses endogenous insulin-dependent signalling in peripheral fat body.
Abstract: In Drosophila melanogaster, ageing is slowed when insulin-like signalling is reduced: life expectancy is extended by more than 50% when the insulin-like receptor (InR) or its receptor substrate (chico) are mutated, or when insulin-producing cells are ablated. But we have yet to resolve when insulin affects ageing, or whether insulin signals regulate ageing directly or indirectly through secondary hormones. Caenorhabditis elegans lifespan is also extended when insulin signalling is inhibited in certain tissues, or when repressed in adult worms, and this requires the forkhead transcription factor (FOXO) encoded by daf-16 (ref. 6). The D. melanogaster insulin-like receptor mediates phosphorylation of dFOXO, the equivalent of nematode daf-16 and mammalian FOXO3a. We demonstrate here that dFOXO regulates D. melanogaster ageing when activated in the adult pericerebral fat body. We further show that this limited activation of dFOXO reduces expression of the Drosophila insulin-like peptide dilp-2 synthesized in neurons, and represses endogenous insulin-dependent signalling in peripheral fat body. These findings suggest that autonomous and non-autonomous roles of insulin signalling combine to control ageing.
840 citations