Multi-level Proteomics Identifies CT45 as a Chemosensitivity Mediator and Immunotherapy Target in Ovarian Cancer.

Most high-grade serous ovarian cancer (HGSOC) patients develop resistance to platinum-based chemotherapy and recur, but 15% remain disease free over a decade. To discover drivers of long-term survival, we quantitatively analyzed the proteomes of platinum-resistant and -sensitive HGSOC patients from minute amounts of formalin-fixed, paraffin-embedded tumors. This revealed cancer/testis antigen 45 (CT45) as an independent prognostic factor associated with a doubling of disease-free survival in advanced-stage HGSOC. Phospho- and interaction proteomics tied CT45 to DNA damage pathways through direct interaction with the PP4 phosphatase complex. In vitro, CT45 regulated PP4 activity, and its high expression led to increased DNA damage and platinum sensitivity. CT45-derived HLA class I peptides, identified by immunopeptidomics, activate patient-derived cytotoxic T cells and promote tumor cell killing. This study highlights the power of clinical cancer proteomics to identify targets for chemo- and immunotherapy and illuminate their biological roles.

VCP promotes tTAF-target gene expression and spermatocyte differentiation by downregulating mono-ubiquitylated H2A.

Valosin-containing protein (VCP) binds and extracts ubiquitylated cargo to regulate protein homeostasis. VCP has been studied primarily in aging and disease contexts, but it also affects germline development. However, the precise molecular functions of VCP in the germline, particularly in males, are poorly understood. Using the Drosophila male germline as a model system, we find that VCP translocates from the cytosol to the nucleus as germ cells transition into the meiotic spermatocyte stage. Importantly, nuclear translocation of VCP appears to be one crucial event stimulated by testis-specific TBP-associated factors (tTAFs) to drive spermatocyte differentiation. VCP promotes the expression of several tTAF-target genes, and VCP knockdown, like tTAF loss of function, causes cells to arrest in early meiotic stages. At a molecular level, VCP activity supports spermatocyte gene expression by downregulating a repressive histone modification, mono-ubiquitylated H2A (H2Aub), during meiosis. Remarkably, experimentally blocking H2Aub in VCP-RNAi testes is sufficient to overcome the meiotic-arrest phenotype and to promote development through the spermatocyte stage. Collectively, our data highlight VCP as a downstream effector of tTAFs that downregulates H2Aub to facilitate meiotic progression.

Comparison of activity, structure, and dynamics of SF-1 and LRH-1 complexed with small molecule modulators.

Steroidogenic factor-1 (SF-1) is a phospholipid-sensing nuclear receptor expressed in the adrenal glands, gonads, and hypothalamus which controls steroidogenesis and metabolism. There is significant therapeutic interest in SF-1 because of its oncogenic properties in adrenocortical cancer. Synthetic modulators are attractive for targeting SF-1 for clinical and laboratory purposes due to the poor pharmaceutical properties of its native phospholipid ligands. While small molecule agonists targeting SF-1 have been synthesized, no crystal structures have been reported of SF-1 in complexes with synthetic compounds. This has prevented the establishment of structure-activity relationships that would enable better characterization of ligand-mediated activation and improvement in current chemical scaffolds. Here, we compare the effects of small molecules in SF-1 and its close homolog, liver receptor homolog-1 (LRH-1), and identify several molecules that specifically activate LRH-1. We also report the first crystal structure of SF-1 in complex with a synthetic agonist that displays low nanomolar affinity and potency for SF-1. We use this structure to explore the mechanistic basis for small molecule agonism of SF-1, especially compared to LRH-1, and uncover unique signaling pathways that drive LRH-1 specificity. Molecular dynamics simulations reveal differences in protein dynamics at the pocket mouth as well as ligand-mediated allosteric communication from this region to the coactivator binding interface. Our studies, therefore, shed important insight into the allostery driving SF-1 activity and show potential for modulation of LRH-1 over SF-1.

Phosphorylation in the intrinsically disordered region of F-BAR protein Imp2 regulates its contractile ring recruitment.

The F-BAR protein Imp2 is an important contributor to cytokinesis in the fission yeast Schizosaccharomyces pombe. Because cell cycle-regulated phosphorylation of the central intrinsically disordered region (IDR) of the Imp2 paralog Cdc15 controls Cdc15 oligomerization state, localization and ability to bind protein partners, we investigated whether Imp2 is similarly phosphoregulated. We found that Imp2 is endogenously phosphorylated on 28 sites within its IDR, with the bulk of phosphorylation being constitutive. In vitro, the casein kinase 1 (CK1) isoforms Hhp1 and Hhp2 can phosphorylate 17 sites, and Cdk1 (also known as Cdc2) can phosphorylate the remaining 11 sites. Mutations that prevent Cdk1 phosphorylation result in precocious Imp2 recruitment to the cell division site, and mutations designed to mimic these phosphorylation events delay Imp2 accumulation at the contractile ring (CR). Mutations that eliminate CK1 phosphorylation sites allow CR sliding, and phosphomimetic substitutions at these sites reduce Imp2 protein levels and slow CR constriction. Thus, like Cdc15, the Imp2 IDR is phosphorylated at many sites by multiple kinases. In contrast to Cdc15, for which phosphorylation plays a major cell cycle regulatory role, Imp2 phosphorylation is primarily constitutive, with milder effects on localization and function. This article has an associated First Person interview with the first author of the paper.

Use of the Esophageal Sponge in Directing Food Reintroduction in Eosinophilic Esophagitis.

BACKGROUND & AIMS: Dietary therapy is successful in eosinophilic esophagitis (EoE) but requires multiple upper endoscopies. The aim of this study was to determine if food reintroduction in EoE can be directed by minimally-invasive esophageal sponge cytology. METHODS: In this prospective non-blinded trial, 22 responders to 6-food elimination diets underwent sequential food reintroduction guided by esophageal sponge cytology. Foods were reintroduced followed by unsedated esophageal sponge cytology assessment. A food trigger was defined by sponge cytology peak eosinophil count of ≥15 eos/high-powered field (hpf). Symptoms (EoE symptom activity index [EEsAI]), endoscopic score (EoE endoscopic reference score [EREFS]), and biopsy histology (peak eosinophil count) were collected pre-dietary therapy and post-dietary therapy, and then 4 weeks post food reintroduction. RESULTS: The EEsAI and EREFS were similar post-dietary therapy to post-food reintroduction: 12.0 (interquartile range [IQR], 0.0-27.0) vs 16.5 (IQR, 9.0-28.8) (P = .265) and 1.5 (IQR, 0.2-3.0) vs 1.0 (IQR, 0.0-2.0) (P = .185). However, the peak eosinophil count was increased post-food reintroduction compared with post-dietary therapy: 20.0 (IQR, 5.0-51.5) vs 2.0 (IQR, 1.0-4.0) (P < .001), suggesting a failure of identification of all food triggers. The peak eosinophil count was lower post-food reintroduction compared with pre-dietary therapy: 20.0 (IQR, 5.0-51.5) vs 52.0 (IQR, 30.8-76.2) (P = .008). At the post food reintroduction evaluation, sponge cytology and biopsy histology were in agreement in 59% (13/22) of cases using a cutoff of <15 eos/hpf and 68% (15/22) of cases using a cutoff of <6 eos/hpf. CONCLUSIONS: In the first study to evaluate a non-endoscopic technique in the clinical management of EoE, the esophageal sponge was moderately successful at guiding food reintroduction in EoE dietary responders in the outpatient setting. CLINICALTRIALS: gov, Number NCT02599558.

Reproductive tradeoffs govern sexually dimorphic tubular lysosome induction in Caenorhabditis elegans.

Sex-specific differences in animal behavior commonly reflect unique reproductive interests. In the nematode Caenorhabditis elegans, hermaphrodites can reproduce without a mate and thus prioritize feeding to satisfy the high energetic costs of reproduction. However, males, which must mate to reproduce, sacrifice feeding to prioritize mate-searching behavior. Here, we demonstrate that these behavioral differences influence sexual dimorphism at the organelle level; young males raised on a rich food source show constitutive induction of gut tubular lysosomes, a non-canonical lysosome morphology that forms in the gut of hermaphrodites when food is limited or as animals age. We found that constitutive induction of gut tubular lysosomes in males results from self-imposed dietary restriction through DAF-7/TGFß, which promotes exploratory behavior. In contrast, age-dependent induction of gut tubular lysosomes in hermaphrodites is stimulated by self-fertilization activity. Thus, separate reproductive tradeoffs influence tubular lysosome induction in each sex, potentially supporting different requirements for reproductive success.

Development of a new class of liver receptor homolog-1 (LRH-1) agonists by photoredox conjugate addition.

LRH-1 is a nuclear receptor that regulates lipid metabolism and homeostasis, making it an attractive target for the treatment of diabetes and non-alcoholic fatty liver disease. Building on recent structural information about ligand binding from our labs, we have designed a series of new LRH-1 agonists that further engage LRH-1 through added polar interactions. While the current synthetic approach to this scaffold has, in large part, allowed for decoration of the agonist core, significant variation of the bridgehead substituent is mechanistically precluded. We have developed a new synthetic approach to overcome this limitation, identified that bridgehead substitution is necessary for LRH-1 activation, and described an alternative class of bridgehead substituents for effective LRH-1 agonist development. We determined the crystal structure of LRH-1 bound to a bridgehead-modified compound, revealing a promising opportunity to target novel regions of the ligand binding pocket to alter LRH-1 target gene expression.

Fundamentals of Arthroscopic Surgery Training Program Improves Knee Arthroscopy Simulator Performance in Arthroscopic Trainees.

PURPOSE: To determine the effectiveness of a nonanatomic simulator in developing basic arthroscopy motor skills transferable to an anatomic model. METHODS: Forty-three arthroscopy novice individuals currently enrolled in medical school were recruited to perform a diagnostic knee arthroscopy using a high-fidelity virtual reality arthroscopic simulator providing haptic feedback after viewing a video of an expert performing an identical procedure. Students were then randomized into an experimental or control group. The experimental group then completed a series of self-guided training modules using the fundamentals of arthroscopy simulator training nonanatomic modules including camera centering, tracking, periscoping, palpation, and collecting stars in a three-dimensional space. Both groups completed another diagnostic knee arthroscopy between 1 and 2 weeks later. Camera path length, time, tibia and femur cartilage damage, as well as a composite score were recorded by the simulator on each attempt. RESULTS: The experimental group (n = 22) showed superior performance in composite score (30.09 vs 24, P = .046) and camera path length (71.51 cm vs 109.07 cm, P = .0274) at the time of the second diagnostic knee arthroscope compared with the control group (n = 21). The experimental group also showed significantly greater improvement in composite score between the first and second arthroscopes compared with the control group (14.27 vs 4.95, P < .01). Femoral and tibial cartilage damage were not significantly improved between arthroscopy attempts (-0.86% vs -1.45%, P = .40) and (-1.10 vs -1.27%, P = .83), respectively. CONCLUSIONS: The virtual reality-based fundamentals of arthroscopy simulator training nonanatomic simulator is beneficial in developing basic motor skills in arthroscopy novice individuals resulting in significantly greater composite performance in an anatomic knee model. Based on the results of this study, it appears that there may be benefit from nonanatomic simulators in general as part of an arthroscopy training program. LEVEL OF EVIDENCE: Level II, randomized trial.

Dma1 ubiquitinates the SIN scaffold, Sid4, to impede the mitotic localization of Plo1 kinase.

Proper cell division requires strict coordination between mitotic exit and cytokinesis. In the event of a mitotic error, cytokinesis must be inhibited to ensure equal partitioning of genetic material. In the fission yeast, Schizosaccharomyces pombe, the checkpoint protein and E3 ubiquitin ligase, Dma1, delays cytokinesis by inhibiting the septation initiation network (SIN) when chromosomes are not attached to the mitotic spindle. To elucidate the mechanism by which Dma1 inhibits the SIN, we screened all SIN components as potential Dma1 substrates and found that the SIN scaffold protein, Sid4, is ubiquitinated in vivo in a Dma1-dependent manner. To investigate the role of Sid4 ubiquitination in checkpoint function, a ubiquitination deficient sid4 allele was generated and our data indicate that Sid4 ubiquitination by Dma1 is required to prevent cytokinesis during a mitotic checkpoint arrest. Furthermore, Sid4 ubiquitination delays recruitment of the Polo-like kinase and SIN activator, Plo1, to spindle pole bodies (SPBs), while at the same time prolonging residence of the SIN inhibitor, Byr4, providing a mechanistic link between Dma1 activity and cytokinesis inhibition.

Metformin inhibits ovarian cancer growth and increases sensitivity to paclitaxel in mouse models.

OBJECTIVE: There is increasing preclinical evidence indicating that metformin, a medication commonly used for type 2 diabetes mellitus, may protect against cancer. Motivated by this emerging evidence we asked 2 questions: (1) can metformin prevent ovarian cancer growth by altering metabolism and (2) will metformin increase sensitivity to chemotherapy. STUDY DESIGN: The effect of metformin in ovarian cancer was tested in vitro and with 2 different mouse models. In vitro, cell lines (n = 6) were treated with metformin (10-40 mmol/L) or phosphate-buffered saline solution and cellular proliferation and metabolic alterations (adenosine monophosphate-activated protein kinase activity, glycolysis, and lipid synthesis) were compared between the 2 groups. In mouse models, a prevention study was performed by treating mice with metformin (250 mg/kg/d intraperitoneally) or placebo for 2 weeks followed by intraperitoneal injection of the SKOV3ip1 human ovarian cancer cell line, and the mean number of tumor implants in each treatment group was compared. In a treatment study, the LSL-K-ras(G12D/+)/PTEN(floxP/floxP) genetic mouse model of ovarian cancer was used. Mice were treated with placebo, paclitaxel (3 mg/kg/wk intraperitoneally for 7 weeks), metformin (100 mg/kg/d in water for 7 weeks), or paclitaxel plus metformin, and tumor volume was compared among treatment groups. RESULTS: In vitro, metformin decreased proliferation of ovarian cancer cell lines and induced cell cycle arrest, but not apoptosis. Further analysis showed that metformin altered several aspects of metabolism including adenosine monophosphate-activated protein kinase activity, glycolysis, and lipid synthesis. In the prevention mouse model, mice that were pretreated with metformin had 60% fewer tumor implants compared with controls (P < .005). In the treatment study, mice that were treated with paclitaxel plus metformin had a 60% reduction in tumor weight compared with controls (P = .02), which is a level of tumor reduction greater than that resulting from either paclitaxel or metformin alone. CONCLUSION: Based on these results, we conclude that metformin alters metabolism in ovarian cancer cells, prevents tumor growth, and increases sensitivity to chemotherapy in vitro and in mouse models. These preclinical findings suggest that metformin warrants further investigation for use as an ovarian cancer therapeutic.

DAF-16/FOXO and HLH-30/TFEB comprise a cooperative regulatory axis controlling tubular lysosome induction in C. elegans.

Although life expectancy has increased, longer lifespans do not always align with prolonged healthspans and, as a result, the occurrence of age-related degenerative diseases continues to increase. Thus, biomedical research has been shifting focus to strategies that enhance both lifespan and healthspan concurrently. Two major transcription factors that have been heavily studied in the context of aging and longevity are DAF-16/FOXO and HLH-30/TFEB; however, how these two factors coordinate to promote longevity is still not fully understood. In this study, we reveal a new facet of their cooperation that supports healthier aging in C. elegans. Namely, we demonstrate that the combinatorial effect of daf-16 and hlh-30 is required to trigger robust lysosomal tubulation, which contributes to systemic health benefits in late age by enhancing cross-tissue proteostasis mechanisms. Remarkably, this change in lysosomal morphology can be artificially induced via overexpression of SVIP, a previously characterized tubular lysosome stimulator, even when one of the key transcription factors, DAF-16, is absent. This adds to growing evidence that SVIP could be utilized to employ tubular lysosome activity in adverse conditions or disease states. Mechanistically, intestinal overexpression of SVIP leads to nuclear accumulation of HLH-30 in gut and non-gut tissues and triggers global gene expression changes that promotes systemic health benefits. Collectively, our work reveals a new cellular process that is under the control of DAF-16 and HLH-30 and provides further insight into how these two transcription factors may be exerting their pro-health effects.

The Montana Interfacility Blood Network: A Novel Lifesaving "Hand-off" for the Optimal Care of Rural Patients.

Purpose: The state of Montana encompasses and defines rural health care as it is known in the United States (US) today. This vast area is punctuated by pockets of health care availability with varying access to blood products for transfusion. Furthermore, timely transport is frequently challenged by weather that may limit air transportation options, resulting in multiple hours in ground transport to definitive care. Patients and Methods: The Montana State Trauma Care Committee (MT-STCC) developed the Montana Interfacility Blood Network (MT-IBN) to ensure blood availability in geographically distanced cases where patients may otherwise not survive. The index case that led to the formal development of the MT-IBN is described, followed by a second case illustrating the IBN process. Results: This process and development manuscript details the innovative efforts of MT-STCC to develop this fledgling idea unique to rural US health care. We review guidelines that have been developed to define broad aspects of the MT-IBN including the reason to share resources, proper packaging, paperwork necessary for transfer, and how to provide resources directly to the patient. Finally, we describe implementation within the state. Conclusion: The MT-IBN was developed by MT-STCC to facilitate the hand-off of lifesaving blood to patients being transported by ground to definitive care in Montana without having to stop at an intermediary facility. This has already led to lives saved in areas that are limited in blood availability due to rurality.

Restricting bioenergetic efficiency enhances longevity and mitochondrial redox capacity in Drosophila melanogaster.

Mitochondria are essential for survival and as such, impairments in organelle homeostasis significantly accelerate age-related morbidity and mortality. Here, we determined the contribution of bioenergetic efficiency to life span and health span in Drosophila melanogaster utilizing the mitochondrial uncoupler BAM15. Life span was determined in flies fed a normal diet (ND) or high fat diet (HFD) supplemented with vehicle or BAM15. Locomotor function was determined by negative geotaxis assay in middle-aged flies fed vehicle or BAM15 under ND or HFD conditions. Redox capacity (high-resolution respirometry/fluorometry), citrate synthase (enzyme activity), mtDNA content (qPCR), gene expression (qPCR), and protein expression (western blot) were assessed in flight muscle homogenates of middle-aged flies fed vehicle or BAM15 ND. The molar ratio of H2O2 and O2 (H2O2:O2) in a defined respiratory state was calculated as a measure of redox balance. BAM15 extended life span by 9% on ND and 25% on HFD and improved locomotor activity by 125% on ND and 53% on HFD. Additionally, BAM15 enhanced oxidative phosphorylation capacity supported by pyruvate + malate, proline, and glycerol 3-phosphate. Concurrently, BAM15 enhanced the mitochondrial H2O2 production rate, reverse electron flow from mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) to Complex I, mGPDH, and Complex I without altering the H2O2:O2 ratio. BAM15 upregulated transcriptional signatures associated with mitochondrial function and fitness as well as antioxidant defense. BAM15-mediated restriction of bioenergetic efficiency prolongs life span and health span in Drosophila fed a ND or HFD. Improvements in life span and health span in ND were supported by synergistic enhancement of muscular redox capacity.

Fission yeast Dma1 requires RING domain dimerization for its ubiquitin ligase activity and mitotic checkpoint function.

In fission yeast (Schizosaccharomyces pombe), the E3 ubiquitin ligase Dma1 delays cytokinesis if chromosomes are not properly attached to the mitotic spindle. Dma1 contains a C-terminal RING domain, and we have found that the Dma1 RING domain forms a stable homodimer. Although the RING domain is required for dimerization, residues in the C-terminal tail are also required to help form or stabilize the dimeric structure because mutation of specific residues in this region disrupts Dma1 dimerization. Further analyses showed that Dma1 dimerization is required for proper localization at spindle pole bodies and the cell division site, E3 ligase activity, and mitotic checkpoint function. Thus, Dma1 forms an obligate dimer via its RING domain, which is essential for efficient transfer of ubiquitin to its substrate(s). This study further supports the mechanistic paradigm that many RING E3 ligases function as RING dimers.

A global census of fission yeast deubiquitinating enzyme localization and interaction networks reveals distinct compartmentalization profiles and overlapping functions in endocytosis and polarity.

Ubiquitination and deubiquitination are reciprocal processes that tune protein stability, function, and/or localization. The removal of ubiquitin and remodeling of ubiquitin chains is catalyzed by deubiquitinating enzymes (DUBs), which are cysteine proteases or metalloproteases. Although ubiquitination has been extensively studied for decades, the complexity of cellular roles for deubiquitinating enzymes has only recently been explored, and there are still several gaps in our understanding of when, where, and how these enzymes function to modulate the fate of polypeptides. To address these questions we performed a systematic analysis of the 20 Schizosaccharomyces pombe DUBs using confocal microscopy, proteomics, and enzymatic activity assays. Our results reveal that S. pombe DUBs are present in almost all cell compartments, and the majority are part of stable protein complexes essential for their function. Interestingly, DUB partners identified by our study include the homolog of a putative tumor suppressor gene not previously linked to the ubiquitin pathway, and two conserved tryptophan-aspartate (WD) repeat proteins that regulate Ubp9, a DUB that we show participates in endocytosis, actin dynamics, and cell polarity. In order to understand how DUB activity affects these processes we constructed multiple DUB mutants and find that a quintuple deletion of ubp4 ubp5 ubp9 ubp15 sst2/amsh displays severe growth, polarity, and endocytosis defects. This mutant allowed the identification of two common substrates for five cytoplasmic DUBs. Through these studies, a common regulatory theme emerged in which DUB localization and/or activity is modulated by interacting partners. Despite apparently distinct cytoplasmic localization patterns, several DUBs cooperate in regulating endocytosis and cell polarity. These studies provide a framework for dissecting DUB signaling pathways in S. pombe and may shed light on DUB functions in metazoans.

Rbp4-Gal4, a germline driver that activates in meiosis, reveals functions for VCP in spermatid development.

Valosin-containing protein (VCP) is a versatile and ubiquitously expressed AAA+ ATPase that regulates multiple stages of Drosophila spermatogenesis. While VCP has documented roles in mitotic spermatogonia and meiotic spermatocytes, it is also highly expressed in post-meiotic spermatids, suggesting potential late-stage developmental functions as well. However, tools to assess late-stage activities of pleiotropic spermatogenesis genes such as VCP are lacking. Available germline-specific Gal4 drivers activate in stem cells or spermatogonia; consequently, knocking down VCP using one of these drivers disrupts or blocks early germ-cell development, precluding analysis of VCP in later stages. A Gal4 driver that activates later in development, such as at the meiotic spermatocyte stage, may permit functional analyses of VCP and other factors in post-meiotic stages. Here, we describe a germline-specific Gal4 driver, Rbp4-Gal4, which drives transgene expression beginning in the early spermatocyte stage. We find that Rbp4-Gal4-driven knockdown of VCP causes defects in spermatid chromatin condensation and individualization without affecting earlier developmental stages. Interestingly, the defect in chromatin condensation appears linked to errors in the histone-to-protamine transition, a key event in spermatid development. Overall, our study reveals roles for VCP in spermatid development and establishes a powerful tool to dissect the functions of pleiotropic spermatogenesis genes.

Modular Splicing Is Linked to Evolution in the Synapse-Specificity Molecule Kirrel3.

Kirrel3 is a cell-adhesion molecule that instructs the formation of specific synapses during brain development in mouse and Kirrel3 variants may be risk factors for autism and intellectual disabilities in humans. Kirrel3 is predicted to undergo alternative splicing but brain isoforms have not been studied. Here, we present the first in-depth characterization of Kirrel3 isoform diversity in brain using targeted, long-read mRNA sequencing of mouse hippocampus. We identified 19 isoforms with predicted transmembrane and secreted forms and show that even rare isoforms generate detectable protein in the brain. We also analyzed publicly-available long-read mRNA databases from human brain tissue and found 11 Kirrel3 isoforms that, similar to mouse, encode transmembrane and secreted forms. In mice and humans, Kirrel3 diversity arises from alternative, independent use of protein-domain coding exons and alternative early translation-stop signals. Intriguingly, the alternatively spliced exons appear at branch points in the chordate phylogenetic tree, including one exon only found in humans and their closest living relatives, the great apes. Together, these results validate a simple pipeline for analyzing isoform diversity in genes with low expression and suggest that Kirrel3 function is fine-tuned by alternative splicing and may play a role in brain evolution.

A familial natural short sleep mutation promotes healthy aging and extends lifespan in Drosophila.

Sleep loss typically imposes negative effects on animal health. However, humans with a rare genetic mutation in the dec2 gene (dec2P384R) present an exception; these individuals sleep less without the usual effects associated with sleep deprivation. Thus, it has been suggested that the dec2P384R mutation activates compensatory mechanisms that allows these individuals to thrive with less sleep. To test this directly, we used a Drosophila model to study the effects of the dec2P384R mutation on animal health. Expression of human dec2P384R in fly sleep neurons was sufficient to mimic the short sleep phenotype and, remarkably, dec2P384R mutants lived significantly longer with improved health despite sleeping less. The improved physiological effects were enabled, in part, by enhanced mitochondrial fitness and upregulation of multiple stress response pathways. Moreover, we provide evidence that upregulation of pro-health pathways also contributes to the short sleep phenotype, and this phenomenon may extend to other pro-longevity models.

Tubular lysosome induction couples animal starvation to healthy aging.

Dietary restriction promotes longevity in several species via autophagy activation. However, changes to lysosomes underlying this effect remain unclear. Here using the nematode Caenorhabditis elegans, we show that the induction of autophagic tubular lysosomes (TLs), which occurs upon dietary restriction or mechanistic target of rapamycin inhibition, is a critical event linking reduced food intake to lifespan extension. We find that starvation induces TLs not only in affected individuals but also in well-fed descendants, and the presence of gut TLs in well-fed progeny is predictive of enhanced lifespan. Furthermore, we demonstrate that expression of Drosophila small VCP-interacting protein, a TL activator in flies, artificially induces TLs in well-fed worms and improves C. elegans health in old age. These findings identify TLs as a new class of lysosomes that couples starvation to healthy aging.

A familial natural short sleep mutation promotes healthy aging and extends lifespan in Drosophila.

Sleep loss typically imposes negative effects on animal health. However, humans with a rare genetic mutation in the dec2 gene ( dec2 P384R ) present an exception; these individuals sleep less without the usual effects associated with sleep deprivation. Thus, it has been suggested that the dec2 P384R mutation activates compensatory mechanisms that allows these individuals to thrive with less sleep. To test this directly, we used a Drosophila model to study the effects of the dec2 P384R mutation on animal health. Expression of human dec2 P384R in fly sleep neurons was sufficient to mimic the short sleep phenotype and, remarkably, dec2 P384R mutants lived significantly longer with improved health despite sleeping less. The improved physiological effects were enabled, in part, by enhanced mitochondrial fitness and upregulation of multiple stress response pathways. Moreover, we provide evidence that upregulation of pro-health pathways also contributes to the short sleep phenotype, and this phenomenon may extend to other pro-longevity models.