Neuronal CBP-1 is Required for Enhanced Body Muscle Proteostasis in Response to Reduced Translation Downstream of mTOR.

Background: The ability to maintain muscle function decreases with age and loss of proteostatic function. Diet, drugs, and genetic interventions that restrict nutrients or nutrient signaling help preserve long-term muscle function and slow age-related decline. Previously, it was shown that attenuating protein synthesis downstream of the mechanistic target of rapamycin (mTOR) gradually increases expression of heat shock response (HSR) genes in a manner that correlates with increased resilience to protein unfolding stress.

RG/RGG repeats in the C. elegans homologs of Nucleolin and GAR1 contribute to sub-nucleolar phase separation.

The intrinsically disordered RG/RGG repeat domain is found in several nucleolar and P-granule proteins, but how it influences their phase separation into biomolecular condensates is unclear. We survey all RG/RGG repeats in C. elegans and uncover nucleolar and P-granule-specific RG/RGG motifs.

Quantification of tissue-specific protein translation in whole using O-propargyl-puromycin labeling and fluorescence microscopy.

The regulation of gene expression via protein translation is critical for growth, development, and stress response. While puromycin-based techniques have been used to quantify protein translation in , they have been limited to using lysate from whole worms. To achieve tissue-specific quantification of ribosome activity in intact , we report the application of O-propargyl-puromycin in a cuticle defective mutant followed by conjugation of an azide fluorophore for detection using fluorescent confocal microscopy.

Anabolic Function Downstream of TOR Controls Trade-offs Between Longevity and Reproduction at the Level of Specific Tissues .

As the most energetically expensive cellular process, translation must be finely tuned to environmental conditions. Dietary restriction attenuates signaling through the nutrient sensing mTOR pathway, which reduces translation and redirects resources to preserve the soma. These responses are associated with increased lifespan but also anabolic impairment, phenotypes also observed when translation is genetically suppressed.

Misexpression of genes lacking CpG islands drives degenerative changes during aging.

Cellular aging is characterized by disruption of the nuclear lamina and its associated heterochromatin. How these structural changes within the nucleus contribute to age-related degeneration of the organism is unclear. Genes lacking CpG islands (CGI genes) generally associate with heterochromatin when they are inactive.

Conserved dual-mode gene regulation programs in higher eukaryotes.

Recent genomic data analyses have revealed important underlying logics in eukaryotic gene regulation, such as CpG islands (CGIs)-dependent dual-mode gene regulation. In mammals, genes lacking CGIs at their promoters are generally regulated by interconversion between euchromatin and heterochromatin, while genes associated with CGIs constitutively remain as euchromatin. Whether a similar mode of gene regulation exists in non-mammalian species has been unknown.

A Drosophila Model to Study Wound-induced Polyploidization.

Polyploidy is a frequent phenomenon whose impact on organismal health and disease is still poorly understood. A cell is defined as polyploid if it contains more than the diploid copy of its chromosomes, which is a result of endoreplication or cell fusion. In tissue repair, wound-induced polyploidization (WIP) has been found to be a conserved healing strategy from fruit flies to vertebrates.

Cardiac injury modulates critical components of prostaglandin E signaling during zebrafish heart regeneration.

The inability to effectively stimulate cardiomyocyte proliferation remains a principle barrier to regeneration in the adult human heart. A tightly regulated, acute inflammatory response mediated by a range of cell types is required to initiate regenerative processes. Prostaglandin E (PGE), a potent lipid signaling molecule induced by inflammation, has been shown to promote regeneration and cell proliferation; however, the dynamics of PGE signaling in the context of heart regeneration remain underexplored.

Wound-induced polyploidization is driven by Myc and supports tissue repair in the presence of DNA damage.

Tissue repair usually requires either polyploid cell growth or cell division, but the molecular mechanism promoting polyploidy and limiting cell division remains poorly understood. Here, we find that injury to the adult epithelium causes cells to enter the endocycle through the activation of Yorkie-dependent genes ( and ). Myc is even sufficient to induce the endocycle in the uninjured post-mitotic epithelium.

Modulation of TNFα Activity by the microRNA Let-7 Coordinates Zebrafish Heart Regeneration.

The adult zebrafish is capable of regenerating heart muscle, resolving collagen tissue, and fully restoring heart function throughout its life. In this study, we show that the highly upregulated, epicardium-enriched microRNA let-7i functions in wound closure and cardiomyocyte proliferation. RNA sequencing experiments identified upregulated expression of members of the tumor necrosis factor (TNF) signaling pathway in the absence of let-7.

A Novel Caenorhabditis Elegans Proteinopathy Model Shows Changes in mRNA Translational Frameshifting During Aging.

Background/aims: Regulation of mRNA translation is central to protein homeostasis and is optimized for speed and accuracy. Spontaneous recoding events occur virtually at any codon but at very low frequency and are commonly assumed to increase as the cell ages.

Methods: Here, we leveraged the polyglutamine(polyQ)-frameshifting model of huntingtin exon 1 with CAG repeat length in the pathological range (Htt51Q), which undergoes enhanced non-programmed translational -1 frameshifting.

Emerging Roles for Immune Cells and MicroRNAs in Modulating the Response to Cardiac Injury.

Stimulating cardiomyocyte regeneration after an acute injury remains the central goal in cardiovascular regenerative biology. While adult mammals respond to cardiac damage with deposition of rigid scar tissue, adult zebrafish and salamander unleash a regenerative program that culminates in new cardiomyocyte formation, resolution of scar tissue, and recovery of heart function. Recent studies have shown that immune cells are key to regulating pro-inflammatory and pro-regenerative signals that shift the injury microenvironment toward regeneration.

Tumor penetrating peptides inhibiting MYC as a potent targeted therapeutic strategy for triple-negative breast cancers.

Overexpression of MYC oncogene is highly prevalent in many malignancies such as aggressive triple-negative breast cancers (TNBCs) and it is associated with very poor outcome. Despite decades of research, attempts to effectively inhibit MYC, particularly with small molecules, still remain challenging due to the featureless nature of its protein structure. Herein, we describe the engineering of the dominant-negative MYC peptide (OmoMYC) linked to a functional penetrating 'Phylomer' peptide (FPPa) as a therapeutic strategy to inhibit MYC in TNBC.

RegenDbase: a comparative database of noncoding RNA regulation of tissue regeneration circuits across multiple taxa.

Regeneration is an endogenous process of tissue repair that culminates in complete restoration of tissue and organ function. While regenerative capacity in mammals is limited to select tissues, lower vertebrates like zebrafish and salamanders are endowed with the capacity to regenerate entire limbs and most adult tissues, including heart muscle. Numerous profiling studies have been conducted using these research models in an effort to identify the genetic circuits that accompany tissue regeneration.

Implications of CpG islands on chromosomal architectures and modes of global gene regulation.

CpG islands (CGIs) have long been implicated in the regulation of vertebrate gene expression. However, the involvement of CGIs in chromosomal architectures and associated gene expression regulations has not yet been thoroughly explored. By combining large-scale integrative data analyses and experimental validations, we show that CGIs clearly reconcile two competing models explaining nuclear gene localizations.

Oxidative stress-dependent MMP-13 activity underlies glucose neurotoxicity.

Background: A complication of diabetes is neuropathy, a condition of sensory axon degeneration that originates in the epidermis. The mechanisms remain unknown but reactive oxygen species (ROS) have been implicated in this condition. In this study, we assessed the role of ROS and a candidate downstream target, MMP-13 in glucose-induced sensory axon degeneration in zebrafish and mice.

The protein tyrosine phosphatase 1B inhibitor MSI-1436 stimulates regeneration of heart and multiple other tissues.

Regenerative medicine holds substantial promise for repairing or replacing tissues and organs damaged by disease, injury, and degeneration. Much of the field has focused on development of cell-based therapeutics, gene-based therapeutics, and tissue engineering-based therapeutics. In contrast, development of small molecule regenerative medicine therapies is an emerging area.

Fosl1 overexpression directly activates trophoblast-specific gene expression programs in embryonic stem cells.

During early development in placental mammals, proper trophoblast lineage development is essential for implantation and placentation. Defects in this lineage can cause early pregnancy failures and other pregnancy disorders. However, transcription factors controlling trophoblast development remain poorly understood.

In Situ Detection of MicroRNA Expression with RNAscope Probes.

Elucidating the spatial resolution of gene transcripts provides important insight into potential gene function. MicroRNAs are short, singled-stranded noncoding RNAs that control gene expression through base-pair complementarity with target mRNAs in the 3' untranslated region (UTR) and inhibiting protein expression. However, given their small size of ~22- to 24-nt and low expression levels, standard in situ hybridization detection methods are not amendable for microRNA spatial resolution.

Assessing Health Span in Caenorhabditis elegans: Lessons From Short-Lived Mutants.

Genetic changes resulting in increased life span are often positively associated with enhanced stress resistance and somatic maintenance. A recent study found that certain long-lived Caenorhabditis elegans mutants spent a decreased proportion of total life in a healthy state compared with controls, raising concerns about how the relationship between health and longevity is assessed. We evaluated seven markers of health and two health-span models for their suitability in assessing age-associated health in invertebrates using C elegans strains not expected to outperform wild-type animals.

IKKα regulates human keratinocyte migration through surveillance of the redox environment.

Although the functions of HO in epidermal wound repair are conserved throughout evolution, the underlying signaling mechanisms are largely unknown. In this study we used human keratinocytes (HEK001) to investigate HO-dependent wound repair mechanisms. Scratch wounding led to HO production in two or three cell layers at the wound margin within ∼30 min and subsequent cysteine modification of proteins via sulfenylation.

DNA Damage-Inducible Transcript 4 Is an Innate Surveillant of Hair Follicular Stress in Vitamin D Receptor Knockout Mice and a Regulator of Wound Re-Epithelialization.

Mice and human patients with impaired vitamin D receptor (VDR) signaling have normal developmental hair growth but display aberrant post-morphogenic hair cycle progression associated with alopecia. In addition, VDR mice exhibit impaired cutaneous wound healing. We undertook experiments to determine whether the stress-inducible regulator of energy homeostasis, DNA damage-inducible transcript 4 (Ddit4), is involved in these processes.

Regulatory Conformational Coupling between CLC Anion Channel Membrane and Cytoplasmic Domains.

CLC anion channels are homodimeric proteins. Each subunit is comprised of 18 α-helices designated "A-R" and an intracellular carboxy-terminus containing two cystathionine-β-synthase (CBS1 and CBS2) domains. Conformational coupling between membrane and intracellular domains via poorly understood mechanisms is required for CLC regulation.

Role of CBS and Bateman Domains in Phosphorylation-Dependent Regulation of a CLC Anion Channel.

Eukaryotic CLC anion channels and transporters are homodimeric proteins composed of multiple α-helical membrane domains and large cytoplasmic C-termini containing two cystathionine-β-synthase domains (CBS1 and CBS2) that dimerize to form a Bateman domain. The Bateman domains of adjacent CLC subunits interact to form a Bateman domain dimer. The functions of CLC CBS and Bateman domains are poorly understood.

Leucine-rich repeat containing protein LRRC8A is essential for swelling-activated Cl- currents and embryonic development in zebrafish.

A volume-regulated anion channel (VRAC) has been electrophysiologically characterized in innumerable mammalian cell types. VRAC is activated by cell swelling and mediates the volume regulatory efflux of Cl(-) and small organic solutes from cells. Two groups recently identified the mammalian leucine-rich repeat containing protein LRRC8A as an essential VRAC component.