The Mitochondrial Lon Protease Is Required for Age-Specific and Sex-Specific Adaptation to Oxidative Stress

The influence of sex-specific factors on biological transformations and health outcomes in aging processes

The aging process demonstrates notable differences between males and females, which are key factors in disease susceptibility and lifespan. The differences in sex chromosomes are fundamental to the presence of sex bias in organisms. Moreover, sex-specific epigenetic modifications and changes in sex hormone levels impact the development of immunity differently during embryonic development and beyond. Mitochondria, telomeres, homeodynamic space, and intestinal flora are intricately connected to sex differences in aging. These elements can have diverse effects on men and women, resulting in unique biological transformations and health outcomes as they grow older. This review explores how sex interacts with these elements and shapes the aging process.

Selectively advantageous instability in biotic and pre-biotic systems and implications for evolution and aging

Rules of biology typically involve conservation of resources. For example, common patterns such as hexagons and logarithmic spirals require minimal materials, and scaling laws involve conservation of energy. Here a relationship with the opposite theme is discussed, which is the selectively advantageous instability (SAI) of one or more components of a replicating system, such as the cell. By increasing the complexity of the system, SAI can have benefits in addition to the generation of energy or the mobilization of building blocks. SAI involves a potential cost to the replicating system for the materials and/or energy required to create the unstable component, and in some cases, the energy required for its active degradation. SAI is well-studied in cells. Short-lived transcription and signaling factors enable a rapid response to a changing environment, and turnover is critical for replacement of damaged macromolecules. The minimal gene set for a viable cell includes proteases and a nuclease, suggesting SAI is essential for life. SAI promotes genetic diversity in several ways. Toxin/antitoxin systems promote maintenance of genes, and SAI of mitochondria facilitates uniparental transmission. By creating two distinct states, subject to different selective pressures, SAI can maintain genetic diversity. SAI of components of synthetic replicators favors replicator cycling, promoting emergence of replicators with increased complexity. Both classical and recent computer modeling of replicators reveals SAI. SAI may be involved at additional levels of biological organization. In summary, SAI promotes replicator genetic diversity and reproductive fitness, and may promote aging through loss of resources and maintenance of deleterious alleles.

Mild traumatic brain injury in Drosophila melanogaster alters reactive oxygen and nitrogen species in a sex-dependent manner

Traumatic brain injury (TBI) is an outside force causing a modification in brain function and/or structural brain pathology that upregulates brain inducible nitric oxide synthase (iNOS), instigating increased levels of nitric oxide activity which is implicated in secondary pathology leading to behavioral deficits (Hall et al., 2012; Garry et al., 2015; Kozlov et al., 2017). In mammals, TBI-induced NO production activates an immune response and potentiates metabolic crisis through mitochondrial dysfunction coupled with vascular dysregulation; however, the direct influence on pathology is complicated by the activation of numerous secondary cascades and activation of other reactive oxygen species. Drosophila TBI models have demonstrated key features of mammalian TBI, including temporary incapacitation, disorientation, motor deficits, activation of innate immunity (inflammation), and autophagy responses observed immediately after injury (Katzenberger et al., 2013; Barekat et al., 2016; Simon et al., 2017; Anderson et al., 2018; Buhlman et al., 2021b). We hypothesized that acute behavioral phenotypes would be associated with deficits in climbing behavior and increased oxidative stress. Because flies lack mammalian-like cardiovascular and adaptive immune systems, we were able to make our observations in the absence of vascular disruption and adaptive immune system interference in a system where highly targeted interventions can be rapidly evaluated. To demonstrate the induction of injury, ten-day-old transgenic flies received an injury of increasing angles from a modified high impact trauma (HIT) device where angle-dependent increases occurred for acute neurological behavior assessments and twenty-four-hour mortality, and survival was significantly decreased. Injury caused sex-dependent effects on climbing activity and measures of oxidative stress. Specifically, after a single 60-degree HIT, female flies exhibited significant impairments in climbing activity beyond that observed in male flies. We also found that several measures of oxidative stress, including Drosophila NOS (dNOS) expression, protein nitration, and hydrogen peroxide production were significantly decreased in female flies. Interestingly, protein nitration was also decreased in males, but surpassed sham levels with a more severe injury. We also observed decreased autophagy demand in vulnerable dopaminergic neurons in female, but not male flies. In addition, mitophagy initiation was decreased in females. Collectively, our data suggest that TBI in flies induces acute behavioral phenotypes and climbing deficits that are analogous to mammalian TBI. We also observed that various indices of oxidative stress, including dNOS expression, protein tyrosine nitration, and hydrogen peroxide levels, as well as basal levels of autophagy, are altered in response to injury, an effect that is more pronounced in female flies.

Mitochondria and Brain Disease: A Comprehensive Review of Pathological Mechanisms and Therapeutic Opportunities

Mitochondria play a vital role in maintaining cellular energy homeostasis, regulating apoptosis, and controlling redox signaling. Dysfunction of mitochondria has been implicated in the pathogenesis of various brain diseases, including neurodegenerative disorders, stroke, and psychiatric illnesses. This review paper provides a comprehensive overview of the intricate relationship between mitochondria and brain disease, focusing on the underlying pathological mechanisms and exploring potential therapeutic opportunities. The review covers key topics such as mitochondrial DNA mutations, impaired oxidative phosphorylation, mitochondrial dynamics, calcium dysregulation, and reactive oxygen species generation in the context of brain disease. Additionally, it discusses emerging strategies targeting mitochondrial dysfunction, including mitochondrial protective agents, metabolic modulators, and gene therapy approaches. By critically analysing the existing literature and recent advancements, this review aims to enhance our understanding of the multifaceted role of mitochondria in brain disease and shed light on novel therapeutic interventions.

Comparisons of lifespan and stress resistance between sexes in Drosophila melanogaster

Animals exhibit different extents of sexual dimorphism in a variety of phenotypes. Sex differences in longevity, one of the most complex life history traits, have also been reported. Although lifespan regulation has been studied extensively in the fruit fly, Drosophila melanogaster, the sex differences in lifespan have not been consistent in previous studies. To explore this issue, we revisited this question by examining the lifespan and stress resistance of both sexes among 15 inbred strains. We first found positive correlations between males and females from the same strain in terms of lifespan and resistance to starvation and desiccation stress. Although the lifespan difference between male and female flies varied greatly depending on the strain, males across all strains collectively had a longer lifespan. In contrast, females showed better resistance to starvation and desiccation stress. We also observed greater variation in lifespan and resistance to starvation and desiccation stress in females. Unexpectedly, there was no notable correlation observed between lifespan and the three types of stress resistance in either males or females. Overall, our study provides new data regarding sexual dimorphism in fly lifespan and stress resistance; this information may promote the investigation of mechanisms underlying longevity in future research.

High-Dose Photodynamic Therapy Increases Tau Protein Signals in Drosophila

Amyloid-Detection and imaging of amyloid-β plaques (Aβ) has been a focus in the field of neurodegeneration (ND) due to the high correlation with Parkinson's and Alzheimer's diseases. Here, a novel approach is being proposed and developed to induce and assess those diseases. Photodynamic therapy (PDT) is applied to the fruit fly Drosophila melanogaster as a model of systemic oxidative stress to induce rapid Aβ accumulation. Excised brains are evaluated by Brillouin-Raman spectroscopy and microscopy with UV surface emissions (MUSE) to interrogate physical property changes due to fixation and high-dose PDT. MUSE reveals reasonable autofluorescence in the spectral range of Aβ, particularly for females, with increased signal once stained. A presence of significant mechanical changes in fresh brains treated with PDT compared to healthy controls is revealed using Brillouin spectroscopy. Aβ plaque presence was confirmed with confocal analysis, with female PDT flies yielding nearly four-fold the mean intensity of controls, thus marking PDT as a potential neurodegenerative disease model. MUSE may serve as a viable early screening method for Aβ presence and quantification in a research setting. This reduces the time for sample preparation and drastically decreases the cost of Aβ quantification.

Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology

Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, preserving ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.

AAA+ proteases: the first line of defense against mitochondrial damage

Mitochondria play essential cellular roles in Adenosine triphosphate (ATP) synthesis, calcium homeostasis, and metabolism, but these vital processes have potentially deadly side effects. The production of the reactive oxygen species (ROS) and the aggregation of misfolded mitochondrial proteins can lead to severe mitochondrial damage and even cell death. The accumulation of mitochondrial damage is strongly implicated in aging and several incurable diseases, including neurodegenerative disorders and cancer. To oppose this, metazoans utilize a variety of quality control strategies, including the degradation of the damaged mitochondrial proteins by the mitochondrial-resident proteases of the ATPase Associated with the diverse cellular Activities (AAA+) family. This mini-review focuses on the quality control mediated by the mitochondrial-resident proteases of the AAA+ family used to combat the accumulation of damaged mitochondria and on how the failure of this mitochondrial quality control contributes to diseases.

Construction of Mitochondrial Protection and Monitoring Model of Lon Protease Based on Machine Learning under Myocardial Ischemia Environment

The localization of a protein's submitochondrial structure is important for therapeutic design of associated disorders caused by mitochondrial abnormalities because many human diseases are directly tied to mitochondria. When Lon protease expression changes, glycolysis replaces respiratory metabolism in the cell, which is a common occurrence in cancer cells. The fact that protein formation is a dynamic research object makes it impossible to reproduce the unique living environment of proteins in an experimental setting, which surely makes it more challenging to determine protein function through experiments. This research suggests a model of Lon protease-based mitochondrial protection under myocardial ischemia based on ML (machine learning). To ensure the balance of all submitochondrial proteins, the data set is processed using a random oversampling method, each overlapping fixed-length subsequence that is created from the protein sequence functions as a channel in the convolution layer. The results demonstrate that applying the oversampling strategy increases the ROC value by 17.6%-21.3%. Our prediction method is successful as evidenced by the fact that ML prediction outperforms the predictions of other conventional classifiers.

How long-term air pollution and its metal constituents affect type 2 diabetes mellitus prevalence? Results from Wuhan Chronic Disease Cohort

BACKGROUND

Epidemiological evidence linking type 2 diabetes mellitus (T2DM) with air pollution is discrepant and most are restricted to the influences of air-pollutant mass concentration. This study aims to explore the effects of long-term exposure to air pollution and its metal constituents on T2DM prevalence in China.

METHODS

We used data on 10,253 adult residents from the baseline survey of Wuhan Chronic Disease Cohort in 2019. Ambient PM_2.5, PM₁₀ and NO₂ exposure were estimated at residences based on Chinese Air Quality Reanalysis Dataset. Concentrations of 10 metal constituents were measured by 976 PM_2.5 filter samples collected from four monitoring stations. Logistic regression models were employed to examine associations of T2DM prevalence with 3-year mean concentrations of each air pollutant and PM_2.5 metal constituents prior to the baseline investigation.

RESULTS

A total of 673 T2DM cases (6.6%) were identified. The 3-year mean exposures to PM_2.5, PM₁₀ and NO₂ were 50.89 μg/m³, 82.86 μg/m³, and 39.79 μg/m³, respectively. And interquartile range (IQR) of 10 metals in PM_2.5 varied from 0.03 ng/m³ to 78.30 ng/m³. For 1 μg/m³ increment in PM_2.5, PM₁₀ and NO₂, the odds of T2DM increased by 7.2% (95%CI: 1.026, 1.136), 3.1% (95%CI: 1.013, 1.050), and 2.1% (95%CI: 1.005, 1.038) after adjusting for potential confounders. Cd and Sb in PM_2.5 were significant risk factors to T2DM with odds ratios of 1.350 (95%CI: 1.089, 1.673) and 1.389 (95%CI: 1.164, 1.658) for per IQR increase, respectively. Stratification analyses indicated that males and those aged ≥45 years were more susceptive to long-term air pollution.

CONCLUSIONS

Long-term exposure to PM_2.5, PM₁₀ and NO₂ increased T2DM prevalence in a Wuhan population, especially for men and middle-aged and elderly people. Moreover, T2DM was significantly associated with Cd and Sb in PM_2.5. Further research to validate these results and to clarify the underlying mechanisms is warranted.

Neural mechanisms to exploit positional geometry for collision avoidance

Visual motion provides rich geometrical cues about the three-dimensional configuration of the world. However, how brains decode the spatial information carried by motion signals remains poorly understood. Here, we study a collision-avoidance behavior in Drosophila as a simple model of motion-based spatial vision. With simulations and psychophysics, we demonstrate that walking Drosophila exhibit a pattern of slowing to avoid collisions by exploiting the geometry of positional changes of objects on near-collision courses. This behavior requires the visual neuron LPLC1, whose tuning mirrors the behavior and whose activity drives slowing. LPLC1 pools inputs from object and motion detectors, and spatially biased inhibition tunes it to the geometry of collisions. Connectomic analyses identified circuitry downstream of LPLC1 that faithfully inherits its response properties. Overall, our results reveal how a small neural circuit solves a specific spatial vision task by combining distinct visual features to exploit universal geometrical constraints of the visual world.

Mitochondrial composition of and diffusion limiting factors of three social wasp genera Polistes, Ropalidia, and parapolybia (Hymenoptera: Vespidae)

Background

Social wasps Polistes, Ropalidia, and Parapolybia, belonging to the subfamily Polistinae, have obviously different distribution patterns, yet the factors leading to this difference remain unknown.

Results

The 17 newly sequenced mitogenomes of Polistes, Ropalidia, and Parapolybia contain 37 genes, and there are obvious differences among the compositions of the three genera. The monophyly of the genus Polistes and a monophyletic Ropalidiini: (Ropalidia + Parapolybia) are concordant with previous morphological analysis of the subfamily Polistinae. Our inferred divergence time demonstrates Polistes (at around 69 Ma) was diverged earlier than Ropalidia and Parapolybia (at around 61 Ma). The rearrangement of both trnY and trnL1 are shared by all the Polistinae. In addition, the unique rearrangement of TDRL derived at 69 Ma is detected in Polistes, and Ropalidia contains a Reversal which may derive at 61 Ma. Hereafter, the possibility is elaborated that Polistes originated in Aisa and then dispersed from Africa to South America, and Polistes and Ropalidia spread from Southeast Asia to Australia. At last, continental drift and Quaternary Ice Ages are inferred to be two main limiting factors in the current distributions of the three genera.

Conclusions

Obvious differences occur in the mitochondrial composition of Polistes, Ropalidia, and Parapolybia. According to the reconstructed time-calibrated framework, it is inquired that the continental drifts and the climate are mainly diffusion limiting factors of the three genera.

Supplementary information

The online version contains supplementary material available at 10.1186/s12862-022-02017-6.

Organismal and Cellular Stress Responses upon Disruption of Mitochondrial Lonp1 Protease

Cells engage complex surveillance mechanisms to maintain mitochondrial function and protein homeostasis. LonP1 protease is a key component of mitochondrial quality control and has been implicated in human malignancies and other pathological disorders. Here, we employed two experimental systems, the worm Caenorhabditis elegans and human cancer cells, to investigate and compare the effects of LONP-1/LonP1 deficiency at the molecular, cellular, and organismal levels. Deletion of the lonp-1 gene in worms disturbed mitochondrial function, provoked reactive oxygen species accumulation, and impaired normal processes, such as growth, behavior, and lifespan. The viability of lonp-1 mutants was dependent on the activity of the ATFS-1 transcription factor, and loss of LONP-1 evoked retrograde signaling that involved both the mitochondrial and cytoplasmic unfolded protein response (UPR^mt and UPR^cyt) pathways and ensuing diverse organismal stress responses. Exposure of worms to triterpenoid CDDO-Me, an inhibitor of human LonP1, stimulated only UPR^cyt responses. In cancer cells, CDDO-Me induced key components of the integrated stress response (ISR), the UPR^mt and UPR^cyt pathways, and the redox machinery. However, genetic knockdown of LonP1 revealed a genotype-specific cellular response and induced apoptosis similar to CDDO-Me treatment. Overall, the mitochondrial dysfunction ensued by disruption of LonP1 elicits adaptive cytoprotective mechanisms that can inhibit cancer cell survival but diversely modulate organismal stress response and aging.

Identifying Inputs to Visual Projection Neurons in Drosophila Lobula by Analyzing Connectomic Data

Electron microscopy (EM)-based connectomes provide important insights into how visual circuitry of fruit fly Drosophila computes various visual features, guiding and complementing behavioral and physiological studies. However, connectomic analyses of the lobula, a neuropil putatively dedicated to detecting object-like features, remains underdeveloped, largely because of incomplete data on the inputs to the brain region. Here, we attempted to map the columnar inputs into the Drosophila lobula neuropil by performing connectivity-based and morphology-based clustering on a densely reconstructed connectome dataset. While the dataset mostly lacked visual neuropils other than lobula, which would normally help identify inputs to lobula, our clustering analysis successfully extracted clusters of cells with homogeneous connectivity and morphology, likely representing genuine cell types. We were able to draw a correspondence between the resulting clusters and previously identified cell types, revealing previously undocumented connectivity between lobula input and output neurons. While future, more complete connectomic reconstructions are necessary to verify the results presented here, they can serve as a useful basis for formulating hypotheses on mechanisms of visual feature detection in lobula.

Prenatal Fine Particulate Matter, Maternal Micronutrient Antioxidant Intake, and Early Childhood Repeated Wheeze: Effect Modification by Race/Ethnicity and Sex

Fine particulate matter (PM2.5) potentiates in utero oxidative stress influencing fetal development while antioxidants have potential protective effects. We examined associations among prenatal PM2.5, maternal antioxidant intake, and childhood wheeze in an urban pregnancy cohort (n = 530). Daily PM2.5 exposure over gestation was estimated using a satellite-based spatiotemporally resolved model. Mothers completed the modified Block98 food frequency questionnaire. Average energy-adjusted percentile intake of β-carotene, vitamins (A, C, E), and trace minerals (zinc, magnesium, selenium) constituted an antioxidant index (AI). Maternal-reported child wheeze was ascertained up to 4.1 ± 2.8 years. Bayesian distributed lag interaction models (BDLIMs) were used to examine time-varying associations between prenatal PM2.5 and repeated wheeze (≥2 episodes) and effect modification by AI, race/ethnicity, and child sex. Covariates included maternal age, education, asthma, and temperature. Women were 39% Black and 33% Hispanic, 36% with ≤high school education; 21% of children had repeated wheeze. Higher AI was associated with decreased wheeze in Blacks (OR = 0.37 (0.19-0.73), per IQR increase). BDLIMs identified a sensitive window for PM2.5 effects on wheeze among boys born to Black mothers with low AI (at 33-40 weeks gestation; OR = 1.74 (1.19-2.54), per µg/m3 increase in PM2.5). Relationships among prenatal PM2.5, antioxidant intake, and child wheeze were modified by race/ethnicity and sex.

Sex determination gene transformer regulates the male-female difference in Drosophila fat storage via the adipokinetic hormone pathway

Sex differences in whole-body fat storage exist in many species. For example, Drosophila females store more fat than males. Yet, the mechanisms underlying this sex difference in fat storage remain incompletely understood. Here, we identify a key role for sex determination gene transformer (tra) in regulating the male-female difference in fat storage. Normally, a functional Tra protein is present only in females, where it promotes female sexual development. We show that loss of Tra in females reduced whole-body fat storage, whereas gain of Tra in males augmented fat storage. Tra's role in promoting fat storage was largely due to its function in neurons, specifically the Adipokinetic hormone (Akh)-producing cells (APCs). Our analysis of Akh pathway regulation revealed a male bias in APC activity and Akh pathway function, where this sex-biased regulation influenced the sex difference in fat storage by limiting triglyceride accumulation in males. Importantly, Tra loss in females increased Akh pathway activity, and genetically manipulating the Akh pathway rescued Tra-dependent effects on fat storage. This identifies sex-specific regulation of Akh as one mechanism underlying the male-female difference in whole-body triglyceride levels, and provides important insight into the conserved mechanisms underlying sexual dimorphism in whole-body fat storage.

Prenatal Ambient Ultrafine Particle Exposure and Childhood Asthma in the Northeastern United States

Rationale: Ambient ultrafine particles (UFPs; with an aerodynamic diameter < 0.1 μm) may exert greater toxicity than other pollution components because of their enhanced oxidative capacity and ability to translocate systemically. Studies examining associations between prenatal UFP exposure and childhood asthma remain sparse. Objectives: We used daily UFP exposure estimates to identify windows of susceptibility of prenatal UFP exposure related to asthma in children, accounting for sex-specific effects. Methods: Analyses included 376 mother-child dyads followed since pregnancy. Daily UFP exposure during pregnancy was estimated by using a spatiotemporally resolved particle number concentration prediction model. Bayesian distributed lag interaction models were used to identify windows of susceptibility for UFP exposure and examine whether effect estimates varied by sex. Incident asthma was determined at the first report of asthma (3.6 ± 3.2 yr). Covariates included maternal age, education, race, and obesity; child sex; nitrogen dioxide (NO2) and temperature averaged over gestation; and postnatal UFP exposure. Measurements and Main Results: Women were 37.8% Black and 43.9% Hispanic, with 52.9% reporting having an education at the high school level or lower; 18.4% of children developed asthma. The cumulative odds ratio (95% confidence interval) for incident asthma per doubling of the UFP exposure concentration across pregnancy was 4.28 (1.41-15.7), impacting males and females similarly. Bayesian distributed lag interaction models indicated sex differences in the windows of susceptibility, with the highest risk of asthma seen in females exposed to higher UFP concentrations during late pregnancy. Conclusions: Prenatal UFP exposure was associated with asthma development in children, independent of correlated ambient NO2 and temperature. Findings will benefit future research and policy-makers who are considering appropriate regulations to reduce the adverse effects of UFPs on child respiratory health.

University of Southern California and buck institute nathan shock center: multidimensional models of aging

The USC-Buck Nathan Shock Center of Excellence in the Biology of Aging is a new and fully integrated multi-institutional center focused on training the next generation of geroscientists and providing access to cutting-edge geroscience technologies to investigators across the nation. The USC-Buck NSC is devoted to forging a deeper understanding of how and why aging processes cause disease in order to advance the translation of basic research on aging into effective preventions and therapies. Including more than 61 NIA-supported investigators, six NIA-funded research centers, four NIA T32s, and several additional aging research centers of excellence, the USC-Buck NSC constitutes one of the largest collections of leaders in geroscience research within the USA; the unique nature of the USC-Buck NSC research infrastructure ensures an integrated organization that is representative of the wide breadth of topics encompassed by the biology of aging field. By leveraging the 25-year-long relationship, current collaborations and joint administrational activities of the University of Southern California and the Buck Institute for Aging Research, the USC-Buck NSC aims to enhance and expand promising research in the biology of aging at both at the and to make a positive impact across California, the nation and throughout the world. Specialized cores provide services to all Shock Center members, as well as provide support for services to the community at large.

Developmental mechanisms of sex differences: from cells to organisms

Male-female differences in many developmental mechanisms lead to the formation of two morphologically and physiologically distinct sexes. Although this is expected for traits with prominent differences between the sexes, such as the gonads, sex-specific processes also contribute to traits without obvious male-female differences, such as the intestine. Here, we review sex differences in developmental mechanisms that operate at several levels of biological complexity - molecular, cellular, organ and organismal - and discuss how these differences influence organ formation, function and whole-body physiology. Together, the examples we highlight show that one simple way to gain a more accurate and comprehensive understanding of animal development is to include both sexes.

Energy Metabolism Focused Analysis of Sexual Dimorphism in Biological Aging and Hypothesized Sex-specificity in Sirtuin Dependency

The process of biological aging or senescence refers to the gradual loss of homeostasis and subsequent loss of function - leading to higher chances of mortality. Many mechanisms and driving forces have been suggested to facilitate the evolution of a molecular circuit acting as a trade-off between survival and proliferation, resulting in senescence. A major observation on biological aging and longevity in humans and model organisms is the prevalence of significant sexual divergence in the onset, mechanisms and effects of aging associated processes. In the current account, we describe possible mechanisms by which aging, sex and reproduction are evolutionarily intertwined in order to maintain systemic energy homeostasis. We also interrogate existing literature on the sexual dimorphism of genetic, cellular, metabolic, endocrine and epigenetic processes driving cellular and systemic aging. Subsequently, based on available evidence, we propose a hypothetic model of sex-limited decoupling of female longevity from sirtuins, a major family of regulator proteins of the survival-proliferation trade-off. We also provide necessary considerations to be made in order to test the hypothesis and explore the physiological and therapeutic implications of this decoupling event in male and female longevity after reaching reproductive maturity. HYPOTHESIS STATEMENT: Sirtuins provide survival benefits in a sex-nonspecific manner but the dependency on sirtuins in driving metabolic networks after reaching reproductive maturity is evolutionarily decoupled from female longevity.

Short-term intensified training temporarily impairs mitochondrial respiratory capacity in elite endurance athletes

The maintenance of healthy and functional mitochondria is the result of a complex mitochondrial turnover and herein quality-control program that includes both mitochondrial biogenesis and autophagy of mitochondria. The aim of this study was to examine the effect of an intensified training load on skeletal muscle mitochondrial quality control in relation to changes in mitochondrial oxidative capacity, maximal oxygen consumption, and performance in highly trained endurance athletes. Elite endurance athletes (n = 27) performed high-intensity interval exercise followed by moderate-intensity continuous exercise 3 days per week for 4 wk in addition to their usual volume of training. Mitochondrial oxidative capacity, abundance of mitochondrial proteins, markers of autophagy, and antioxidant capacity of skeletal muscle were assessed in skeletal muscle biopsies before and after the intensified training period. The intensified training period increased several autophagy markers suggesting an increased turnover of mitochondrial and cytosolic proteins. In permeabilized muscle fibers, mitochondrial respiration was ∼20% lower after training although some markers of mitochondrial density increased by 5%-50%, indicative of a reduced mitochondrial quality by the intensified training intervention. The antioxidative proteins UCP3, ANT1, and SOD2 were increased after training, whereas we found an inactivation of aconitase. In agreement with the lower aconitase activity, the amount of mitochondrial LON protease that selectively degrades oxidized aconitase was doubled. Together, this suggests that mitochondrial respiratory function is impaired during the initial recovery from a period of intensified endurance training whereas mitochondrial quality control is slightly activated in highly trained skeletal muscle.NEW & NOTEWORTHY We show that mitochondrial respiration is temporarily impaired after a period of intensified exercise training in elite athletes. In parallel, proteins involved in the antioxidative response including SOD2, UCP3, and ANT2 were upregulated, whereas mitochondrial biogenesis was slightly activated. Despite the mitochondrial respiratory impairments, physical performance was improved a few days after the intense training period.

Xanthohumol prolongs lifespan and decreases stress-induced mortality in Drosophila melanogaster

Aging is a significant risk factor that links to the genesis of human diseases. The capacity to scavenge free radicals and adapt to various stresses is essential for expanding living organisms' lifespan. The evidences on the promotion of longevity by dietary supplementation are growing. Drosophila or fruit fly is one of the most effective models for the evaluation of anti-aging compounds. Xanthohumol (XN) is a potential bioactive substance for the prevention and treatment of many diseases. The previous studies have reported its potent activities as antioxidant, anticancer, anti-inflammatory, antiviral, antibacterial antiplasmodial, and antiobesity. In this study, the effect of XN supplementation on the lifespan extension was investigated in Drosophila melanogaster. The effects of XN on the improvement of the recovery from cold and heat shock, the resistance to starvation stress, and free radical-induced oxidative stress in XN-treated flies were also evaluated. Results showed that supplementation with XN at 0.5 mg/mL diet extended the mean lifespan by 14.89%. This was consistent with a significant improvement of locomotor activity of the Drosophila fed with an XN-mixed diet compared with those fed with a control diet. XN supplementation significantly increased the antioxidant enzyme activities at both 25 and 40 days. Drosophila treated with XN exhibited increased survival after exposure to hydrogen peroxide and paraquat. Finally, XN supplementation improved the recovery from cold and heat shock, the resistance to starvation stress, and acetic acid-induced stress. The present study shows that dietary supplementation with XN revealed the longevity effect and ameliorated stress-induced mortality in Drosophila.

LONP1 Regulates Mitochondrial Accumulations of HMGB1 and Caspase-3 in CA1 and PV Neurons Following Status Epilepticus

Lon protease 1 (LONP1) is a highly conserved serine peptidase that plays an important role in the protein quality control system in mammalian mitochondria. LONP1 catalyzes the degradation of oxidized, dysfunctional, and misfolded matrix proteins inside mitochondria and regulates mitochondrial gene expression and genome integrity. Therefore, LONP1 is up-regulated and suppresses cell death in response to oxidative stress, heat shock, and nutrient starvation. On the other hand, translocation of high mobility group box 1 (HMGB1) and active caspase-3 into mitochondria is involved in apoptosis of parvalbumin (PV) cells (one of the GABAergic interneurons) and necrosis of CA1 neurons in the rat hippocampus, respectively, following status epilepticus (SE). In the present study, we investigated whether LONP1 may improve neuronal viability to prevent or ameliorate translocation of active caspase-3 and HMGB1 in mitochondria within PV and CA1 neurons. Following SE, LONP1 expression was up-regulated in mitochondria of PV and CA1 neurons. LONP1 knockdown deteriorated SE-induced neuronal death with mitochondrial accumulation of active caspase-3 and HMGB1 in PV cells and CA1 neurons, respectively. LONP1 knockdown did not affect the aberrant mitochondrial machinery induced by SE. Therefore, our findings suggest, for the first time, that LONP1 may contribute to the alleviation of mitochondrial overloads of active caspase-3 and HMGB1, and the maintenance of neuronal viability against SE.

Female-biased upregulation of insulin pathway activity mediates the sex difference in Drosophila body size plasticity

Nutrient-dependent body size plasticity differs between the sexes in most species, including mammals. Previous work in Drosophila showed that body size plasticity was higher in females, yet the mechanisms underlying increased female body size plasticity remain unclear. Here, we discover that a protein-rich diet augments body size in females and not males because of a female-biased increase in activity of the conserved insulin/insulin-like growth factor signaling pathway (IIS). This sex-biased upregulation of IIS activity was triggered by a diet-induced increase in stunted mRNA in females, and required Drosophila insulin-like peptide 2, illuminating new sex-specific roles for these genes. Importantly, we show that sex determination gene transformer promotes the diet-induced increase in stunted mRNA via transcriptional coactivator Spargel to regulate the male-female difference in body size plasticity. Together, these findings provide vital insight into conserved mechanisms underlying the sex difference in nutrient-dependent body size plasticity.

The proteasome beta 5 subunit is essential for sexually divergent adaptive homeostatic responses to oxidative stress in D. melanogaster

Our studies center on the physiological phenomenon of adaptive homeostasis in which very low, signaling levels of an oxidant can induce transient expansion of the baseline homeostatic range of protective mechanisms, resulting in transient stress protection. The 20S proteasome is a major element of such inducible defense enzymes against oxidative stress but the relative importance of each of its three proteolytic subunits, β1, β2, and β5, is only poorly understood. We focused the present studies on determining the role of the β5 subunit in adaptation, survival, and lifespan. Decreased expression of the 20S proteasome β5 subunit (with RNAi) blocked the adaptive increase in the catalytic activities of the 20S proteasome response to signaling levels of H₂O₂ in female flies. Similarly, female-specific adaptive increases in survival following H₂O₂ pretreatment and subsequent toxic challenge was blocked. In contrast, direct overexpression of the 20S proteasome β5 subunit enabled an increased 20S proteasome proteolytic response, but prevented further adaptive homeostatic increases through H₂O₂ signaling, indicating there is a maximum 'ceiling' to the adaptive response. Males showed no adaptive change in proteasomal levels or activity whatsoever with H₂O₂ pretreatment and exhibited no significant impact upon the other 2 proteolytic subunits of the proteasome. However, chronic loss of the β5 subunit led to shortened lifespan in both sexes. Our exploration of the importance of the 20S proteasome β5 subunit in adaptive homeostasis highlights the interconnection between signal transduction pathways and regulated gene expression in sexually divergent responses to oxidative stimulation.

Assessing the influence of curcumin in sex-specific oxidative stress, survival and behavior in Drosophila melanogaster

Oxidative stress, which occurs from an imbalance of reactive oxygen and nitrogen species (RONS) and both endogenous and exogenous antioxidants, promotes aging and underlies sex-specific differences in longevity and susceptibility to age-related neurodegeneration. Recent evidence suggests that curcumin, a yellow pigment derived from turmeric and shown to exhibit antioxidant properties as a RONS scavenger, influences the regulation of genetic elements in endogenous antioxidant pathways. To investigate the role of curcumin in sex-specific in vivo responses to oxidative stress, Drosophila were reared on media supplemented with 0.25, 2.5 or 25 mmol l-1 curcuminoids (consisting of curcumin, demethoxycurcumin and bisdemethoxycurcumin) and resistance to oxidative stress and neural parameters were assessed. High levels of curcuminoids exhibited two sex-specific effects: protection from hydrogen peroxide as an oxidative stressor and alterations in turning rate in an open field. Taken together, these results suggest that the influence of curcuminoids as antioxidants probably relies on changes in gene expression and that sexual dimorphism exists in the in vivo response to curcuminoids.

Sex differences in early transcriptomic responses to oxidative stress in the copepod Tigriopus californicus

Background

Patterns of gene expression can be dramatically different between males and females of the same species, in part due to genes on sex chromosomes. Here we test for sex differences in early transcriptomic response to oxidative stress in a species which lacks heteromorphic sex chromosomes, the copepod Tigriopus californicus.

Results

Male and female individuals were separately exposed to control conditions and pro-oxidant conditions (hydrogen peroxide and paraquat) for periods of 3 hours and 6 hours. Variance partitioning showed the greatest expression variance among individuals, highlighting the important information that can be obscured by the common practice of pooling individuals. Gene expression variance between sexes was greater than that among treatments, showing the profound effect of sex even when males and females share the same genome. Males exhibited a larger response to both pro-oxidants, differentially expressing more than four times as many genes, including up-regulation of more antioxidant genes, heat shock proteins and protease genes. While females differentially expressed fewer genes, the magnitudes of fold change were generally greater, indicating a more targeted response. Although females shared a smaller fraction of differentially expressed genes between stressors and time points, expression patterns of antioxidant and protease genes were more similar between stressors and more GO terms were shared between time points.

Conclusions

Early transcriptomic responses to the pro-oxidants H₂O₂ and paraquat in copepods revealed substantial variation among individuals and between sexes. The finding of such profound sex differences in oxidative stress response, even in the absence of sex chromosomes, highlights the importance of studying both sexes and the potential for developing sex-specific strategies to promote optimal health and aging in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-020-07179-5.

GPR39 protects against corticosterone-induced neuronal injury in hippocampal cells through the CREB-BDNF signaling pathway

BACKGROUND

The release of zinc from glutamatergic terminals in the hippocampal CA3 region can activate postsynaptic GPR39 receptors and regulate cognition and depression. However, the role and mechanism of GPR39 in the stress-induced depression is still poorly understood.

METHODS

In this study, hippocampal cells (HT-22) were treated with corticosterone (CORT). Then the effects of stress on the activity, mitochondrial function and apoptosis of HT-22 cells were observed. The effects of GPR39 on CORT-induced stress injury were analyzed by both siRNA and agonist (TC-G-1008).

RESULTS

Compared with the 500 nM CORT group, the cell viability, apoptosis, mitochondrial membrane potential, and expression levels of BCL-2, CREB and BDNF mRNA were significantly decreased in the GPR39 siRNA+500 nM CORT group, while the expression levels of caspase3, caspase9, AIF and BAX mRNA were significantly increased in the GPR39 siRNA+500 nM CORT group. Compared with the 1 μM CORTgroup, the cell viability, apoptosis, mitochondrial membrane potential, and expression levels of BCL-2, CREB and BDNF were significantly increased in the GPR39 agonist+1 μΜ CORT group, while the expression levels of caspase3, caspase9, AIF and BAX mRNA were significantly decreased in the GPR39 siRNA+500 nM CORT group. Compared with the control group, the mRNA and protein levels of GPR39, CREB and BDNF were significantly increased, and the mRNA and protein levels of CREB and BDNF were significantly decreased after 50 μM zinc sulfate treatment for 6 h.

CONCLUSIONS

GPR39 may play a neuroprotective role in CORT-induced cell injury via the improvement of CREB-BDNF expression, by inhibiting pro-apoptotic proteins and by upregulating anti-apoptotic proteins.

Birds have peramorphic skulls, too: anatomical network analyses reveal oppositional heterochronies in avian skull evolution

In contrast to the vast majority of reptiles, the skulls of adult crown birds are characterized by a high degree of integration due to bone fusion, e.g., an ontogenetic event generating a net reduction in the number of bones. To understand this process in an evolutionary context, we investigate postnatal ontogenetic changes in the skulls of crown bird and non-avian theropods using anatomical network analysis (AnNA). Due to the greater number of bones and bone contacts, early juvenile crown birds have less integrated skulls, resembling their non-avian theropod ancestors, including Archaeopteryx lithographica and Ichthyornis dispars. Phylogenetic comparisons indicate that skull bone fusion and the resulting modular integration represent a peramorphosis (developmental exaggeration of the ancestral adult trait) that evolved late during avialan evolution, at the origin of crown-birds. Succeeding the general paedomorphic shape trend, the occurrence of an additional peramorphosis reflects the mosaic complexity of the avian skull evolution.

Plateau and Foth use anatomical network analysis to study the evolution of avian skull anatomy. They report that the ontogenetic changes in the morphology and modularity of the avian skulls is comparable to evolutionary transformations from non-avian theropods to modern birds. Their work highlights the complexity of avian skull evolution.

Sex differences in the response to oxidative and proteolytic stress

Sex differences in diseases involving oxidative and proteolytic stress are common, including greater ischemic heart disease, Parkinson disease and stroke in men, and greater Alzheimer disease in women. Sex differences are also observed in stress response of cells and tissues, where female cells are generally more resistant to heat and oxidative stress-induced cell death. Studies implicate beneficial effects of estrogen, as well as cell-autonomous effects including superior mitochondrial function and increased expression of stress response genes in female cells relative to male cells. The p53 and forkhead box (FOX)-family genes, heat shock proteins (HSPs), and the apoptosis and autophagy pathways appear particularly important in mediating sex differences in stress response.

The Role of Sex and Sex Hormones in Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are a wide class of disorders of the central nervous system (CNS) with unknown etiology. Several factors were hypothesized to be involved in the pathogenesis of these diseases, including genetic and environmental factors. Many of these diseases show a sex prevalence and sex steroids were shown to have a role in the progression of specific forms of neurodegeneration. Estrogens were reported to be neuroprotective through their action on cognate nuclear and membrane receptors, while adverse effects of male hormones have been described on neuronal cells, although some data also suggest neuroprotective activities. The response of the CNS to sex steroids is a complex and integrated process that depends on (i) the type and amount of the cognate steroid receptor and (ii) the target cell type-either neurons, glia, or microglia. Moreover, the levels of sex steroids in the CNS fluctuate due to gonadal activities and to local metabolism and synthesis. Importantly, biochemical processes involved in the pathogenesis of NDs are increasingly being recognized as different between the two sexes and as influenced by sex steroids. The aim of this review is to present current state-of-the-art understanding on the potential role of sex steroids and their receptors on the onset and progression of major neurodegenerative disorders, namely, Alzheimer's disease, Parkinson's diseases, amyotrophic lateral sclerosis, and the peculiar motoneuron disease spinal and bulbar muscular atrophy, in which hormonal therapy is potentially useful as disease modifier.

Sex-specific and shared expression profiles of vulnerability and resilience to trauma in brain and blood

BACKGROUND

While post-traumatic stress disorder (PTSD) is defined by behavioral/cognitive symptoms most directly relevant to brain function, it can be considered a systemic disorder characterized by a distinct inability to reinstate homeostasis after trauma.

METHODS

In this study, we conducted a secondary analysis of gene expression profiles in key PTSD-relevant tissues, namely blood, amygdala, and hippocampus, from a rat model of PTSD, to identify sex-specific and shared processes associated with individual differences in response to recent trauma exposure.

RESULTS

Our findings suggest both shared and sex-specific mechanisms underlying individual differences associated with vulnerability and resilience to trauma in hippocampus, amygdala, and blood. By disentangling cell composition from transcriptional changes, we found higher proportions of hippocampal oligodendrocytes in the PTSD-like, extreme behavioral response (EBR) group for both sexes and also identified modules for transcriptional activity associated with group differences (i.e., response to trauma) in the hippocampus that appeared to be sex-specific. By contrast, we found prominent sex differences, but no group differences, in amygdalar cell composition, and both shared and sex-specific modules representing PTSD-relevant transcriptional activity in the amygdala. Across amygdala and hippocampus, both sex-specific and shared processes were relevant to an overarching framework for EBR implicating disrupted TNFα/NFκΒ signaling and excitatory/inhibitory imbalance in dysregulated synaptic/structural plasticity with important implications for fear learning and memory. Our main finding in peripheral blood was consistent with the human literature and identified wound healing processes and hemostasis to be upregulated in the resilient, minimal behavioral response (MBR) group across sexes, but disrupted in a sexually dimorphic manner in the EBR group.

CONCLUSION

In contrast to the varied characterization of the PTSD-like EBR group, characterization of MBR across blood, amygdala, and hippocampus suggests a common theme of upregulated wound healing and extracellular matrix (ECM) remodeling shared between sexes. In all, we identified differential oligodendrocyte proportions in hippocampus between PTSD-like EBR and resilient MBR, and identified processes and pathways that characterize the EBR and MBR-associated transcriptional changes across hippocampus, amygdala, and blood. The sex-specific mechanisms involved in EBR may contribute to the pronounced disparity in risk for PTSD, with women much more likely to develop PTSD.

The biology of Lonp1: More than a mitochondrial protease

Initially discovered as a protease responsible for degradation of misfolded or damaged proteins, the mitochondrial Lon protease (Lonp1) turned out to be a multifaceted enzyme, that displays at least three different functions (proteolysis, chaperone activity, binding of mtDNA) and that finely regulates several cellular processes, within and without mitochondria. Indeed, LONP1 in humans is ubiquitously expressed, and is involved in regulation of response to oxidative stress and, heat shock, in the maintenance of mtDNA, in the regulation of mitophagy. Furthermore, its proteolytic activity can regulate several biochemical pathways occurring totally or partially within mitochondria, such as TCA cycle, oxidative phosphorylation, steroid and heme biosynthesis and glutamine production. Because of these multiple activities, Lon protease is highly conserved throughout evolution, and mutations occurring in its gene determines severe diseases in humans, including a rare syndrome characterized by Cerebral, Ocular, Dental, Auricular and Skeletal anomalies (CODAS). Finally, alterations of LONP1 regulation in humans can favor tumor progression and aggressiveness, further highlighting the crucial role of this enzyme in mitochondrial and cellular homeostasis.

Age-dependent expression profiles of two adaptogenic systems and thermotolerance in Drosophila melanogaster

Here, we monitored the expression of three genes (hsp70, hsp22, and hsf1) involved in heat shock response in Drosophila melanogaster in males and females of different age. Also, we investigated age- and sex-dependent expression of three major genes participating in the production of hydrogen sulfide (H2S) (cse, cbs, and mst), implicated in stress resistance and aging. In addition to the control strain, we monitored the expression of all of these genes in a cbs knockout strain (cbs-/-) generated using the CRISPR technique. The tested strains differ in the induction capacities of the studied genes. Relative to the control strain, under normal conditions, the cbs-/- strain expresses all of the studied genes more abundantly, especially hsp22. In the control strain, aging leads to a dramatic increase in hsp22 synthesis, whereas in the cbs-/- strain, hsp22 induction is not pronounced. Furthermore, in 30-day-old cbs-/- flies, the constitutive expression of hsp70 and mst is decreased. Surprisingly, in the cbs-/- strain, we detected an upregulation of hsf1 transcription in the 30-day-old females. After heat shock in the control strain, hsp70 and hsp22 induction decreased with age in males and hsp22 decreased in females, while in the cbs-/- strain, a pronounced drop in the induction capacity of both hsp genes was seen in 30-day-old males and females. However, in most cases, the expression levels of hsf1 and H2S-producing genes do not exhibit pronounced changes depending on sex, age, or heat shock. Flies of control and cbs-/- strain exhibited strong reduction in basal thermotolerance with age. Our data suggest a cross-talk between the two studied ancient and universal adaptive systems.

Widespread sex dimorphism in aging and age-related diseases

Although aging is a conserved phenomenon across evolutionary distant species, aspects of the aging process have been found to differ between males and females of the same species. Indeed, observations across mammalian studies have revealed the existence of longevity and health disparities between sexes, including in humans (i.e. with a female or male advantage). However, the underlying mechanisms for these sex differences in health and lifespan remain poorly understood, and it is unclear which aspects of this dimorphism stem from hormonal differences (i.e. predominance of estrogens vs. androgens) or from karyotypic differences (i.e. XX vs. XY sex chromosome complement). In this review, we discuss the state of the knowledge in terms of sex dimorphism in various aspects of aging and in human age-related diseases. Where the interplay between sex differences and age-related differences has not been explored fully, we present the state of the field to highlight important future research directions. We also discuss various dietary, drug or genetic interventions that were shown to improve longevity in a sex-dimorphic fashion. Finally, emerging tools and models that can be leveraged to decipher the mechanisms underlying sex differences in aging are also briefly discussed.

Temperature-Sensitive Reproduction and the Physiological and Evolutionary Potential for Mother's Curse

Strict maternal transmission of mitochondrial DNA (mtDNA) is hypothesized to permit the accumulation of mitochondrial variants that are deleterious to males but not females, a phenomenon called mother’s curse. However, direct evidence that mtDNA mutations exhibit such sexually antagonistic fitness effects is sparse. Male-specific mutational effects can occur when the physiological requirements of the mitochondria differ between the sexes. Such male-specific effects could potentially occur if sex-specific cell types or tissues have energy requirements that are differentially impacted by mutations affecting energy metabolism. Here we summarize findings from a model mitochondrial–nuclear incompatibility in the fruit fly Drosophila that demonstrates sex-biased effects, but with deleterious effects that are generally larger in females. We present new results showing that the mitochondrial–nuclear incompatibility does negatively affect male fertility, but only when males are developed at high temperatures. The temperature-dependent male sterility can be partially rescued by diet, suggesting an energetic basis. Finally, we discuss fruitful paths forward in understanding the physiological scope for sex-specific effects of mitochondrial mutations in the context of the recent discovery that many aspects of metabolism are sexually dimorphic and downstream of sex-determination pathways in Drosophila. A key parameter of these models that remains to be quantified is the fraction of mitochondrial mutations with truly male-limited fitness effects across extrinsic and intrinsic environments. Given the energy demands of reproduction in females, only a small fraction of the mitochondrial mutational spectrum may have the potential to contribute to mother’s curse in natural populations.

The Mitochondrial Lon Protease: Novel Functions off the Beaten Track?

To maintain organellar function, mitochondria contain an elaborate endogenous protein quality control system. As one of the two soluble energy-dependent proteolytic enzymes in the matrix compartment, the protease Lon is a major component of this system, responsible for the degradation of misfolded proteins, in particular under oxidative stress conditions. Lon defects have been shown to negatively affect energy production by oxidative phosphorylation but also mitochondrial gene expression. In this review, recent studies on the role of Lon in mammalian cells, in particular on its protective action under diverse stress conditions and its relationship to important human diseases are summarized and commented.

Proteasome-Independent Protein Knockdown by Small-Molecule Inhibitor for the Undruggable Lung Adenocarcinoma

Therapeutic target identification and corresponding drug development is a demanding task for the treatment of lung adenocarcinoma, especially the most malignant proximal-proliferative subtype without druggable protein kinase mutations. Using a cell-SELEX-generated aptamer, we discovered a new tumor driver protein, leucine-rich pentatricopeptide repeat-containing protein (LRPPRC), which is specifically overexpressed in the most lethal subtype of lung adenocarcinoma. Targeted LRPPRC protein knockdown is a promising therapeutic strategy for the undruggable LUAD (lung adenocarcinoma). Nevertheless, LRPPRC is mainly located in mitochondria and degraded by protease. Current protein knockdown approaches, such as proteolysis-targeting chimeras (PROTACs), have limitations in their applications to the proteins degraded through proteasome-independent ways. Here, we designed an aptamer-assisted high-throughput method to screen small molecules that could bind to LRPPRC directly, disrupt the interaction of LRPPRC with its stabilizing chaperon protein, and lead to LRPPRC degradation by mitochondrial protease. The screened compound, gossypolacetic acid (GAA), is an old medicine that can accomplish the new function for targeted LRPPRC knockdown. It showed significant antitumor effects even with the LRPPRC-positive patient-derived tumor xenograft (PDX) model. This work not only extended the application of aptamers to screen small-molecule inhibitors for the undruggable lung cancers, but more importantly provided a new strategy to develop protein knockdown methods beyond the proteasome system.

A chromosome-level genome assembly of Cydia pomonella provides insights into chemical ecology and insecticide resistance

The codling moth Cydia pomonella, a major invasive pest of pome fruit, has spread around the globe in the last half century. We generated a chromosome-level scaffold assembly including the Z chromosome and a portion of the W chromosome. This assembly reveals the duplication of an olfactory receptor gene (OR3), which we demonstrate enhances the ability of C. pomonella to exploit kairomones and pheromones in locating both host plants and mates. Genome-wide association studies contrasting insecticide-resistant and susceptible strains identify hundreds of single nucleotide polymorphisms (SNPs) potentially associated with insecticide resistance, including three SNPs found in the promoter of CYP6B2. RNAi knockdown of CYP6B2 increases C. pomonella sensitivity to two insecticides, deltamethrin and azinphos methyl. The high-quality genome assembly of C. pomonella informs the genetic basis of its invasiveness, suggesting the codling moth has distinctive capabilities and adaptive potential that may explain its worldwide expansion.

The codling moth, Cydia pomonella, is one of the major pests of pome fruit (apples and pears) and walnuts. Here, the authors sequence and analyze its genome, providing insights on olfactory and detoxification processes that may underlie its worldwide expansion.

Sex-specific neuroprotection by inhibition of the Y-chromosome gene, SRY, in experimental Parkinson's disease

Parkinson's disease (PD) is a debilitating neurodegenerative disorder caused by the loss of midbrain dopamine (DA) neurons. While the cause of DA cell loss in PD is unknown, male sex is a strong risk factor. Aside from the protective actions of sex hormones in females, emerging evidence suggests that sex-chromosome genes contribute to the male bias in PD. We previously showed that the Y-chromosome gene, SRY, directly regulates adult brain function in males independent of gonadal hormone influence. SRY protein colocalizes with DA neurons in the male substantia nigra, where it regulates DA biosynthesis and voluntary movement. Here we demonstrate that nigral SRY expression is highly and persistently up-regulated in animal and human cell culture models of PD. Remarkably, lowering nigral SRY expression with antisense oligonucleotides in male rats diminished motor deficits and nigral DA cell loss in 6-hydroxydopamine (6-OHDA)-induced and rotenone-induced rat models of PD. The protective effect of the SRY antisense oligonucleotides was associated with male-specific attenuation of DNA damage, mitochondrial degradation, and neuroinflammation in the toxin-induced rat models of PD. Moreover, reducing nigral SRY expression diminished or removed the male bias in nigrostriatal degeneration, mitochondrial degradation, DNA damage, and neuroinflammation in the 6-OHDA rat model of PD, suggesting that SRY directly contributes to the sex differences in PD. These findings demonstrate that SRY directs a previously unrecognized male-specific mechanism of DA cell death and suggests that suppressing nigral Sry synthesis represents a sex-specific strategy to slow or prevent DA cell loss in PD.

TDP-43 induces mitochondrial damage and activates the mitochondrial unfolded protein response

Mutations in or dys-regulation of the TDP-43 gene have been associated with TDP-43 proteinopathy, a spectrum of neurodegenerative diseases including Frontotemporal Lobar Degeneration (FTLD) and Amyotrophic Lateral Sclerosis (ALS). The underlying molecular and cellular defects, however, remain unclear. Here, we report a systematic study combining analyses of patient brain samples with cellular and animal models for TDP-43 proteinopathy. Electron microscopy (EM) analyses of patient samples revealed prominent mitochondrial impairment, including abnormal cristae and a loss of cristae; these ultrastructural changes were consistently observed in both cellular and animal models of TDP-43 proteinopathy. In these models, increased TDP-43 expression induced mitochondrial dysfunction, including decreased mitochondrial membrane potential and elevated production of reactive oxygen species (ROS). TDP-43 expression suppressed mitochondrial complex I activity and reduced mitochondrial ATP synthesis. Importantly, TDP-43 activated the mitochondrial unfolded protein response (UPR^mt) in both cellular and animal models. Down-regulating mitochondrial protease LonP1 increased mitochondrial TDP-43 levels and exacerbated TDP-43-induced mitochondrial damage as well as neurodegeneration. Together, our results demonstrate that TDP-43 induced mitochondrial impairment is a critical aspect in TDP-43 proteinopathy. Our work has not only uncovered a previously unknown role of LonP1 in regulating mitochondrial TDP-43 levels, but also advanced our understanding of the pathogenic mechanisms for TDP-43 proteinopathy. Our study suggests that blocking or reversing mitochondrial damage may provide a potential therapeutic approach to these devastating diseases.

TDP-43 proteinopathy is a group of fatal neurological diseases. Here, we report a systematic examination of the role of mitochondrial damage in TDP-43 proteinopathy using patient brain tissues, as well as cellular and animal models. Our data show that TDP-43 induces severe mitochondrial damage, accompanied by activation of UPR^mt in both cellular and animal models of TDP-43 proteinopathy. LonP1, one of the key mitochondrial proteases in UPR^mt, protects against TDP-43 induced cytotoxicity and neurodegeneration. Our study uncovers LonP1 as a modifier gene for TDP-43 proteinopathy and suggests protecting against or reversing mitochondrial damage as a potential therapeutic approach to these neurodegenerative disorders.

Multi-level remodeling of transcriptional landscapes in aging and longevity

In multi-cellular organisms, the control of gene expression is key not only for development, but also for adult cellular homeostasis, and gene expression has been observed to be deregulated with aging. In this review, we discuss the current knowledge on the transcriptional alterations that have been described to occur with age in metazoans. First, we discuss age-related transcriptional changes in protein-coding genes, the expected functional impact of such changes, and how known pro-longevity interventions impact these changes. Second, we discuss the changes and impact of emerging aspects of transcription in aging, including age-related changes in splicing, lncRNAs and circRNAs. Third, we discuss the changes and potential impact of transcription of transposable elements with aging. Fourth, we highlight small ncRNAs and their potential impact on the regulation of aging phenotypes. Understanding the aging transcriptome will be key to identify important regulatory targets, and ultimately slow-down or reverse aging and extend healthy lifespan in humans.

Epigenetic regulator G9a provides glucose as a sweet key to stress resistance

The ability to adapt to acute and chronic stress is important for organisms to thrive in evolutionary niches and for cells to survive in adverse conditions. The regulatory networks that control stress responses are evolutionarily conserved, and many factors that selectively activate stress responses have been identified. Less well understood are mechanisms that guard against unnecessary induction of cytoprotective factors and that connect stress responses with cellular metabolism to control energy expenditure during stress. The work of Riahi and colleagues represents important progress in this regard because it identifies the histone methyltransferase G9a as a modulator of oxidative stress responses. G9a dampens the expression of antioxidant genes, thus preventing inappropriate energy consumption. Moreover, G9a promotes the well-paced catabolism of storage glycogen and fat during stress. The importance of energy availability during stress is further evidenced by exogenous glucose rescuing the vulnerability of the G9a mutant to oxidative stress. Prior work in multiple model systems has implicated G9a in several other adaptive responses. Therefore, its role in pacing energy consumption and in restraining excessive stress response gene expression under stress may extend to other adaptive responses across species.

Stress responses are important for survival and evolutionary adaptation. This Primer explores a study showing that the fruit fly histone methyltransferase G9a (EHMT1/2) couples energy availability to finely tuned regulation of the stress response.

Zinc inhibited LPS-induced inflammatory responses by upregulating A20 expression in microglia BV2 cells

BACKGROUND

Our previous studies have proved that zinc supplement effectively alleviate depression symptoms in mice, but the mechanisms are still uncertain. Neuroinflammation is considered as an important aspect in pathogenesis of depression. To elucidate the role of zinc on neuroinflammation, in this study, we investigated effects of zinc on lipopolysaccharide (LPS)-induced inflammation in BV2 microglia cells, a kind of innate immune cells in central nervous system.

METHODS

BV2 cells were treated by 100 ng/ml LPS to induce inflammatory responses and the effects of zinc sulfate (ZnSO₄) addition on LPS-induced inflammation were observed. Besides, through culturing HT-22 hippocampus cells by using medium transferred from zinc-intervened BV2 cells, the protective roles of zinc on hippocampus cells were identified.

RESULTS

LPS treatment up-regulated expressions of CD11b, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) and level of reactive oxygen species (ROS). Meaningfully, zinc was capable of blocking ROS generation and reducing expressions of the above inflammatory cytokines at both 10 μM and 30 μM. In addition, it was proved that zinc intervention to BV2 cells could increase the viabilities of hippocampal HT-22 cells cultured by medium of BV2 cells. Furthermore, the zinc-finger protein A20, an anti-inflammation factor, was increased by zinc supplement, while levels of p65, p-IκB and p-p65 were significantly decreased.

LIMITATIONS

More compelling proofs were needed to ensure roles of A20 in anti-inflammatory effects of zinc.

CONCLUSIONS

The present results suggested that zinc inhibits inflammatory responses mediated by microglia cells via upregulation of zinc-finger A20. It was proposed that this anti-inflammatory action might be underlying mechanism of previously observed anti-depressive effects of zinc.

Limitations to adaptive homeostasis in an hyperoxia-induced model of accelerated ageing

The Nrf2 signal transduction pathway plays a major role in adaptive responses to oxidative stress and in maintaining adaptive homeostasis, yet Nrf2 signaling undergoes a significant age-dependent decline that is still poorly understood. We used mouse embryonic fibroblasts (MEFs) cultured under hyperoxic conditions of 40% O₂, as a model of accelerated ageing. Hyperoxia increased baseline levels of Nrf2 and multiple transcriptional targets (20S Proteasome, Immunoproteasome, Lon protease, NQO1, and HO-1), but resulted in loss of cellular ability to adapt to signaling levels (1.0 μM) of H₂O₂. In contrast, MEFs cultured at physiologically relevant conditions of 5% O₂ exhibited a transient induction of Nrf2 Phase II target genes and stress-protective enzymes (the Lon protease and OXR1) following H₂O₂ treatment. Importantly, all of these effects have been seen in older cells and organisms. Levels of Two major Nrf2 inhibitors, Bach1 and c-Myc, were strongly elevated by hyperoxia and appeared to exert a ceiling on Nrf2 signaling. Bach1 and c-Myc also increase during ageing and may thus be the mechanism by which adaptive homeostasis is compromised with age.

Does Bach1 & c-Myc dependent redox dysregulation of Nrf2 & adaptive homeostasis decrease cancer risk in ageing?

The Keap1-Nrf2 signal transduction pathway plays a major role in oxidant and electrophile induction of adaptive homeostasis that transiently and reversibly increases cellular and organismal protection from stress. By expanding (and then contracting) the normal homeostatic range of expression of stress-protective genes, Nrf2 allows us to cope with fluctuations in stress levels. Two major inhibitors of Nrf2 are Bach1 and c-Myc which normally serve the important function of turning off adaptation when appropriate. We have found, however, that both Bach1 and c-Myc levels increase substantially with age and that older human cells, worms, flies, and mice loose Nrf2-dependent signaling and adaptive homeostasis. Nrf2 has also been linked with increased risk of cancers, and cancer incidence certainly increases with age. Here we propose that the age-dependent increase in Bach1 and c-Myc may actually cause the age-dependent decline in Nrf2 signaling and adaptive homeostasis, and that this is a coordinated attempt to minimize the age-dependent increase in cancer incidence. In other words, we may trade off adaptive homeostasis for a lower risk of cancer by increasing Bach1 and c-Myc in ageing.

Multi-level remodeling of transcriptional landscapes in aging and longevity

In multi-cellular organisms, the control of gene expression is key not only for development, but also for adult cellular homeostasis, and gene expression has been observed to be deregulated with aging. In this review, we discuss the current knowledge on the transcriptional alterations that have been described to occur with age in metazoans. First, we discuss age-related transcriptional changes in protein-coding genes, the expected functional impact of such changes, and how known pro-longevity interventions impact these changes. Second, we discuss the changes and impact of emerging aspects of transcription in aging, including age-related changes in splicing, lncRNAs and circRNAs. Third, we discuss the changes and potential impact of transcription of transposable elements with aging. Fourth, we highlight small ncRNAs and their potential impact on the regulation of aging phenotypes. Understanding the aging transcriptome will be key to identify important regulatory targets, and ultimately slow-down or reverse aging and extend healthy lifespan in humans. [BMB Reports 2019; 52(1): 86-108].

Characterization of the mitochondrial genome of Arge bella Wei & Du sp. nov. (Hymenoptera: Argidae)

We describe Arge bella Wei & Du sp. nov., a large and beautiful species of Argidae from south China, and report its mitochondrial genome based on high-throughput sequencing data. We present the gene order, nucleotide composition of protein-coding genes (PCGs), and the secondary structures of RNA genes. The nearly complete mitochondrial genome of A. bella has a length of 15,576 bp and a typical set of 37 genes (22 tRNAs, 13 PCGs, and 2 rRNAs). Three tRNAs are rearranged in the A. bella mitochondrial genome as compared to the ancestral type in insects: trnM and trnQ are shuffled, while trnW is translocated from the trnW-trnC-trnY cluster to a location downstream of trnI. All PCGs are initiated by ATN codons, and terminated with TAA, TA or T as stop codons. All tRNAs have a typical cloverleaf secondary structure, except for trnS1. H821 of rrnS and H976 of rrnL are redundant. A phylogenetic analysis based on mitochondrial genome sequences of A. bella, 21 other symphytan species, two apocritan representatives, and four outgroup taxa supports the placement of Argidae as sister to the Pergidae within the symphytan superfamily Tenthredinoidea.

Differences between Men and Women in Mortality and the Health Dimensions of the Morbidity Process

BACKGROUND

Do men have worse health than women? This question is addressed by examining sex differences in mortality and the health dimensions of the morbidity process that characterize health change with age. We also discuss health differences across historical time and between countries.

CONTENT

Results from national-level surveys and data systems are used to identify male/female differences in mortality rates, prevalence of diseases, physical functioning, and indicators of physiological status. Male/female differences in health outcomes depend on epidemiological and social circumstances and behaviors, and many are not consistent across historical time and between countries. In all countries, male life expectancy is now lower than female life expectancy, but this was not true in the past. In most countries, women have more problems performing instrumental activities of daily living, and men do better in measured performance of functioning. Men tend to have more cardiovascular diseases; women, more inflammatory-related diseases. Sex differences in major cardiovascular risk factors vary between countries-men tend to have more hypertension; women, more raised lipids. Indicators of physiological dysregulation indicate greater inflammatory activity for women and generally higher cardiovascular risk for men, although women have higher or similar cardiovascular risk in some markers depending on the historical time and country.

SUMMARY

In some aspects of health, men do worse; in others, women do worse. The lack of consistency across historical times and between countries in sex differences in health points to the complexity and the substantial challenges in extrapolating future trends in sex differences.