An integrated approach to identifying sex-specific genes, transcription factors, and pathways relevant to Alzheimer's disease.

BACKGROUND: Age represents a significant risk factor for the development of Alzheimer's disease (AD); however, recent research has documented an influencing role of sex in several features of AD. Understanding the impact of sex on specific molecular mechanisms associated with AD remains a critical challenge to creating tailored therapeutic interventions. METHODS: The exploration of the sex-based differential impact on disease (SDID) in AD used a systematic review to first select transcriptomic studies of AD with data regarding sex in the period covering 2002 to 2021 with a focus on the primary brain regions affected by AD - the cortex (CT) and the hippocampus (HP). A differential expression analysis for each study and two tissue-specific meta-analyses were then performed. Focusing on the CT due to the presence of significant SDID-related alterations, a comprehensive functional characterization was conducted: protein-protein network interaction and over-representation analyses to explore biological processes and pathways and a VIPER analysis to estimate transcription factor activity. RESULTS: We selected 8 CT and 5 HP studies from the Gene Expression Omnibus (GEO) repository for tissue-specific meta-analyses. We detected 389 significantly altered genes in the SDID comparison in the CT. Generally, female AD patients displayed more affected genes than males; we grouped said genes into six subsets according to their expression profile in female and male AD patients. Only subset I (repressed genes in female AD patients) displayed significant results during functional profiling. Female AD patients demonstrated more significant impairments in biological processes related to the regulation and organization of synapsis and pathways linked to neurotransmitters (glutamate and GABA) and protein folding, Aß aggregation, and accumulation compared to male AD patients. These findings could partly explain why we observe more pronounced cognitive decline in female AD patients. Finally, we detected 23 transcription factors with different activation patterns according to sex, with some associated with AD for the first time. All results generated during this study are readily available through an open web resource Metafun-AD (https://bioinfo.cipf.es/metafun-ad/). CONCLUSION: Our meta-analyses indicate the existence of differences in AD-related mechanisms in female and male patients. These sex-based differences will represent the basis for new hypotheses and could significantly impact precision medicine and improve diagnosis and clinical outcomes in AD patients.

Sex-based differences in brain morphometry under chronic stress: A pilot MRI study.

Background: Sex-based differences are known to be a significant feature of chronic stress; however, the morphological mechanisms of the brain underlying these differences remain unclear. The present study aimed to use magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) to investigate the effects of sex on gray matter volume (GMV) changes under conditions of chronic stress. Methods: A total of 32 subjects were included for analysis in the present study: 16 participants experiencing chronic stress and 16 healthy controls. T1-weighted (T1WI) images from a 3 T MRI scanner were extracted from the OpenfMRI database. Images were segmented into gray matter using VBM analysis. A two-way analysis of variance (ANOVA) with a 2 × 2 full factorial design was used to evaluate the main and interaction effects of chronic stress and sex on GMV changes, and then post hoc testing was used to verify each simple effect. Results: Two-way ANOVA showed a chronic stress × sex interaction effect on GMV. Simple effects analysis indicated that the GMV of the bilateral pre- and post-central gyri, the right cuneus and superior occipital gyrus was decreased in males, whereas that of the bilateral pre- and post-central gyri, the right superior occipital gyrus and the left middle frontal gyrus and orbital middle frontal gyrus was increased in females, under chronic stress. Additionally, in the control group, the GMV of the bilateral pre- and post-central gyri, the right cuneus and superior occipital gyrus was greater in males than females. While in the chronic stress group, the above sex-based differences were no longer significant. Conclusions: This study preliminarily shows that there are significant differences in gray matter volume changes between males and females under chronic stress. These findings provide a basis for future studies investigating the volumetric mechanisms of sex differences under chronic stress.

Investigation of sex-based differences in the immunotoxicity of silver nanoparticles.

The growing application of silver nanoparticles (AgNPs) in consumer, healthcare, and industrial products has raised concern over potential health implications due to increasing exposure. The evaluation of the immune response to nanomaterials is one of the key criteria to assess their biocompatibility. There are well-recognized sex-based differences in innate and adaptive immune responses. However, there is limited information available using human models. The aim was to investigate the potential sex-based differences in immune functions after exposure to AgNPs using human peripheral blood mononuclear cells (PBMCs) and plasma from healthy donors. These functions include inflammasome activation, cytokine expression, leukocyte proliferation, chemotaxis, plasma coagulation, and complement activation. AgNPs were characterized by dynamic light scattering and transmission electron microscopy. Inflammasome activation by AgNPs was measured after 6- and 24-hours incubations. AgNPs-induced inflammasome activation was significantly higher in the females, especially for the 6-hour exposure. No sex-based differences were observed for Ag ions controls. Younger donors exhibited significantly more inflammasome activation than older donors after 24-hours exposure. IL-10 was significantly suppressed in males and females after exposure. AgNPs suppressed leukocyte proliferation similarly in males and females. No chemoattractant effects, no alterations in plasma coagulation, or activation of the complement were observed after AgNPs exposure. In conclusion, the results highlight that there are distinct sex-based differences in inflammasome activation after exposure to AgNPs in human PBMCs. The results highlight the importance of considering sex-based differences in inflammasome activation induced by exposure to AgNPs in any future biocompatibility assessment for products containing AgNPs.

Sex-based differences in fairness norm compliance and neural circuitry.

Human behavior often aligns with fairness norms, either voluntarily or under external pressure, like sanctions. Prior research has identified distinct neural activation patterns associated with voluntary and sanction-based compliance or non-compliance with fairness norms. However, an investigation gap exists into potential neural connectivity patterns and sex-based differences. To address this, we conducted a study using a monetary allocation game and functional magnetic resonance imaging to examine how neural activity and connectivity differ between sexes across three norm compliance conditions: voluntary, sanction-based, and voluntary post-sanctions. Fifty-five adults (27 females) participated, revealing that punishment influenced decisions, leading to strategic calculations and reduced generosity in voluntary compliance post-sanctions. Moreover, there were sex-based differences in neural activation and connectivity across the different compliance conditions. Specifically, the connectivity between the right dorsolateral prefrontal cortex and right dorsal anterior insular appeared to mediate intuitive preferences, with variations across norm compliance conditions and sexes. These findings imply potential sex-based differences in intuitive motivation for diverse norm compliance conditions. Our insights contribute to a better understanding of the neural pathways involved in fairness norm compliance and clarify sex-based differences, offering implications for future investigations into psychiatric and neurological disorders characterized by atypical socialization and mentalizing.

Sex-based differences in the distribution of Aujeszky's disease-seropositive Japanese wild boar.

BACKGROUND: Aujeszky's disease virus (ADV) primarily infects domestic pigs and wild boars, causing the abortion and death of young piglets due to central nervous system disorders. In Japan, the national eradication program for ADV in domestic pigs has been successful in most prefectures; however, concern has been raised regarding ADV-infected wild boars as a source of transmission to domestic pigs. RESULTS: We assessed the nationwide seroprevalence of ADV among wild boars (Sus scrofa) in Japan. Moreover, we determined the sex-based differences in the spatial clustering of seropositive animals. Serum samples were obtained from a total of 1383 wild boars acquired by hunting in 41 prefectures in three fiscal years (April-March in 2014, 2015, and 2017). Seropositivity tests for ADV using enzyme-linked immunosorbent assay, the latex agglutination and neutralization tests showed 29 boars seropositive for ADV (29/1383, 2.1% [95% confidence interval, CI: 1.4-3.0%]), with 28 of these boars originating from three prefectures in the Kii Peninsula (28/121, 23.1% [95% CI: 16.0-31.7%]). The degree of spatial clustering of these ADV-seropositive adult boars in the Kii Peninsula was evaluated using the K-function and data from sera samples of 46 (14 seropositive) male and 54 (12 seropositive) female boars. The degree of clustering among females was significantly higher in seropositive animals than in tested animals; however, such a difference was not observed for seropositive males. CONCLUSIONS: The spatial dynamics of ADV among adult wild boars may be characterized based on sex, and is likely due to sex-based differences in behavioral patterns including dispersal among wild boars.

RAGE is a critical factor of sex-based differences in age-induced kidney damage.

Introduction: Advanced glycation end products (AGEs) are a heterogeneous group of molecules with potential pathophysiological effects on the kidneys. Fibrosis together with the accumulation of AGEs has been investigated for its contribution to age-related decline in renal function. AGEs mediate their effects in large parts through their interactions with the receptor for AGEs (RAGE). RAGE is a transmembrane protein that belongs to the immunoglobulin superfamily and has the ability to interact with multiple pro-inflammatory/pro-oxidative ligands. The role of RAGE in aging kidneys has not been fully characterized, especially for sex-based differences. Methods: Therefore, we analyzed constitutive RAGE knockout (KO) mice in an age- and sex-dependent manner. Paraffin-embedded kidney sections were used for histological analysis and protein expression of fibrosis and damage markers. RNA expression analysis from the kidney cortex was done by qPCR for AGE receptors, kidney damage, and early inflammation/fibrosis factors. FACS analysis was used for immune cell profiling of the kidneys. Results: Histological analysis revealed enhanced infiltration of immune cells (positive for B220) in aged (>70 weeks old) KO mice in both sexes. FACS analysis revealed a similar pattern of enhanced B-1a cells in aged KO mice. There was an age-based increase in pro-fibrotic and pro-inflammatory markers (IL-6, TNF, TGF-ß1, and SNAIL1) in KO male mice that presumably contributed to renal fibrosis and renal damage (glomerular and tubular). In fact, in KO mice, there was an age-dependent increase in renal damage (assessed by NGAL and KIM1) that was accompanied by increased fibrosis (assessed by CTGF). This effect was more pronounced in male KO mice than in the female KO mice. In contrast to the KO animals, no significant increase in damage markers was detectable in wild-type animals at the age examined (>70 weeks old). Moreover, there is an age-based increase in AGEs and scavenger receptor MSR-A2 in the kidneys. Discussion: Our data suggest that the loss of the clearance receptor RAGE in male animals further accelerates age-dependent renal damage; this could be in part due to an increase in AGEs load during aging and the absence of protective female hormones. By contrast, in females, RAGE expression seems to play only a minor role when compared to tissue pathology.

Maladaptive changes in delay discounting in males during the COVID-19 pandemic: the predictive role of functional connectome.

The Coronavirus disease of 2019 (COVID-19) and measures to curb it created population-level changes in male-dominant impulsive and risky behaviors such as violent crimes and gambling. One possible explanation for this is that the pandemic has been stressful, and males, more so than females, tend to respond to stress by altering their focus on immediate versus delayed rewards, as reflected in their delay discounting rates. Delay discounting rates from healthy undergraduate students were collected twice during the pandemic. Discounting rates of males (n=190) but not of females (n=493) increased during the pandemic. Using machine learning, we show that prepandemic functional connectome predict increased discounting rates in males (n=88). Moreover, considering that delay discounting is associated with multiple psychiatric disorders, we found the same neural pattern that predicted increased discounting rates in this study, in secondary datasets of patients with major depression and schizophrenia. The findings point to sex-based differences in maladaptive delay discounting under real-world stress events, and to connectome-based neuromarkers of such effects. They can explain why there was a population-level increase in several impulsive and risky behaviors during the pandemic and point to intriguing questions about the shared underlying mechanisms of stress responses, psychiatric disorders and delay discounting.

Association between smokeless tobacco use and oral cavity cancer risk in women compared with men: a systematic review and meta-analysis.

BACKGROUND: The impact of smokeless tobacco (SLT) use on the risk of oral cavity cancer (OCC) has been confirmed; however, the sex-based difference in this association remains inconclusive. Therefore, this study aimed to estimate the association between SLT use and OCC risk in women and compared it to that in men. METHODS: PubMed, Embase, and Cochrane Library databases were systematically searched for eligible studies from their inception up to August 2020. Studies reporting the effect estimates of SLT use on OCC risk in men and women, were eligible for inclusion. The relative risk ratio (RRR) was applied to calculate the sex-based difference in the relationship between SLT use and OCC risk, and pooled analysis was conducted using a random-effects model with inverse variance weighting. RESULTS: Nineteen studies reporting a total of 6593 OCC cases were included in the final meta-analysis. The pooled relative risk (RR) suggested that SLT use was associated with an increased risk of OCC in both men (RR, 2.94; 95% confidence interval [CI], 2.05-4.20; P < 0.001) and women (RR, 6.39; 95%CI, 3.16-12.93; P < 0.001). Moreover, the SLT-use-related risk of OCC was higher in women than that in men (RRR,1.79; 95%C, 1.21-2.64; P = 0.003). The risk of OCC related to SLT use in women was still significantly higher than that in men (RRR, 1.75; 95%CI, 1.15-2.66; P = 0.008) after excluding indirect comparison results. Finally, a subgroup analysis suggested significant sex-based differences only in individuals who received chewed smokeless products, regardless of the control definition. Pooled analysis of studies with high design quality confirmed the notably higher risk of OCC in women than in men. CONCLUSIONS: This study found that SLT use was associated with a higher risk of OCC in women than in men. Further large-scale prospective cohort studies should be conducted to verify sex-based differences in the association between use of specific smokeless products and OCC risk.

Sex-based differences in bacterial meningitis in adults: Epidemiology, clinical features, and therapeutic outcomes.

BACKGROUND: To investigate the sex-based differences in clinical features, causative pathogens, and outcomes of hospital-based culture-proven adult bacterial meningitis. OBJECTIVE: This retrospective study enrolled 621 patients at a tertiary medical center. To compare changes over time, the presentation of disease among the enrolled patients was divided into two equal time periods: the first study period (1986-2002) and the second study period (2003-2019). RESULTS: Of the 621 patients enrolled in this study, 396 were males and 225 were females. The overall case fatality rate was 30.4% with 30.1% and 31.1% in males and females, respectively. Regarding the causative pathogens, there was a rising incidence of coagulase-negative staphylococcal infections and a decreasing incidence of Klebsiella pneumoniae infection in both male and female in the second study period. The prevalence of patients with nosocomial infection in a postneurosurgical state were 41.9% (68/162) in the first study period and 58.1% (94/162) in the second study period in male group, and 34.8% (32/92) in the first study period and 65.2% (60/92) in the second study period in female group, respectively. Significant factors between the sexes difference included age (P = 0.004), traumatic brain injury (P = 0.01), alcoholism (P < 0.001), brain tumor (P < 0.001), systemic lupus erythematosus (SLE) (P = 0.004), presence of diabetic ketoacidosis/hyperglycemic hyperosmolar state (P = 0.033), brain abscess (P = 0.042), and total protein (P = 0.002) and white blood cell count (P = 0.036) of cerebrospinal fluid data. CONCLUSION: Our study revealed an increase in the number of patients with nosocomial infection with a postneurosurgical state in both male and female in the second study period. Males were younger and frequently presented with a history of head trauma and alcoholism with concomitant brain abscesses while females presented with SLE and brain tumor. The therapeutic outcome did not show differences between the sexes.

Fetal Zone Steroids and Estrogen Show Sex Specific Effects on Oligodendrocyte Precursor Cells in Response to Oxidative Damage.

Oxygen causes white matter damage in preterm infants and male sex is a major risk factor for poor neurological outcome, which speculates the role of steroid hormones in sex-based differences. Preterm birth is accompanied by a drop in 17ß-estradiol (E2) and progesterone along with increased levels of fetal zone steroids (FZS). We performed a sex-based analysis on the FZS concentration differences in urine samples collected from preterm and term infants. We show that, in preterm urine samples, the total concentration of FZS, and in particular the 16α-OH-DHEA concentration, is significantly higher in ill female infants as compared to males. Since we previously identified Nup133 as a novel target protein affected by hyperoxia, here we studied the effect of FZS, allopregnanolone (Allo) and E2 on differentiation and Nup133 signaling using mouse-derived primary oligodendrocyte progenitor cells (OPCs). We show that the steroids could reverse the effect of hyperoxia-mediated downregulation of Nup133 in cultured male OPCs. The addition of FZS and E2 protected cells from oxidative stress. However, E2, in presence of 16α-OH-DHEA, showed a negative effect on male cells. These results assert the importance of sex-based differences and their potential implications in preterm stress response.

Colon Transcriptomics Reveals Sex-Dependent Metabolic Signatures in Response to 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Treatment in C57BL/6N Mice.

Diets high in red meats, particularly meats cooked at high temperature, increase the risk of colon cancer due to a production of heterocyclic aromatic amines (HAAs). Of the identified HAAs, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most mass abundant colon carcinogen in charred meat or fish. Here, we comprehensively examined sex-dependent colon transcriptome signatures in response to PhIP treatment to identify biological discrepancies. Eight-week-old male and female C57BL/6N mice were intraperitoneally injected with PhIP (10 mg/kg of body weight) and colon tissues were harvested 24 h after PhIP injection, followed by colon transcriptomics analysis. A list of differentially expressed genes (DEGs) was utilized for computational bioinformatic analyses. Specifically, overrepresentation test using the Protein Analysis Through Evolutionary Relationships tool was carried out to annotate sex-dependent changes in transcriptome signatures after PhIP treatment. Additionally, the most significantly affected canonical pathways by PhIP treatment were predicted using the Ingenuity Pathway Analysis. As results, male and female mice presented different metabolic signatures in the colon transcriptome. In the male mice, oxidative phosphorylation in the mitochondrial respiratory chain was the pathway impacted the most; this might be due to a shortage of ATP for DNA repair. On the other hand, the female mice showed concurrent activation of lipolysis and adipogenesis. The present study provides the foundational information for future studies of PhIP effects on underlying sex-dependent mechanisms.

Non-statin interventions in the prevention of cardiovascular events: Sex-based meta-analysis.

OBJECTIVE: To explore the sex-specific association of non-statin classes of drugs in reducing cardiovascular outcomes. METHODS: Published data search up to November 2019 reporting primary outcomes that approximate with major vascular events (MVEs) after treatment with non-statin group of drugs was performed. The primary outcome was the sex-specific association with MVEs. Random-effects meta-analysis was performed to estimate relative risk (RR) of the individual classes of therapies. RESULTS: Seven Randomized Clinical Trials (RCTs) including 122,164 patients were included in our analysis. Four studies compared the Triglyceride (TG)-lowering group of drugs with placebo and 3 studies compared low-density lipoprotein cholesterol (LDL-c) lowering drugs with placebo. Overall, with non-statin drugs, there was no difference in the risk reduction of cardiovascular (CV) events between men (RR 0.86; 95% CI 0.79-0.94, p-value <0.001) and women (RR 0.88; 95% CI 0.83-0.93, p-value 0.91). However, TG targeting interventions showed no cardiovascular outcome benefits in men (RR 0.85; 95% CI 0.71-1.02, p-value <0.001) while no significant benefit was seen in women (RR 0.87; 95% CI 0.77-0.98, p value = 0.85). No such difference existed in non-statin LDL-c lowering group of drugs in between men (RR 0.88; 95% CI 0.81-0.94, p value = 0.18) and women (RR 0.88; 95% CI 0.82-0.94, p value = 0.46). However, lowering of TG was only associated with a higher risk reduction of CV events (RR 0.86; 95% CI 0.77-0.95, p value = 0.03) in the entire study population. CONCLUSION: Non-statin group of drugs was effective in reducing adverse CV outcomes for both sexes. Lowering TG was associated with higher risk reduction in CV events in general.

Metabolic and immunological responses of male and female new Zealand Greenshell™ mussels (Perna canaliculus) infected with Vibrio sp.

Massive mortalities due to pathogens are routinely reported in bivalve cultivation that have significant economic consequences for the global aquaculture industry. However, host-pathogen interactions and infection mechanisms that mediate these interactions are poorly understood. In addition, gender-specific immunological responses have been reported for some species, but the reasons for such differences have not been elucidated. In this study, we used a GC/MS-based metabolomics platform and flow cytometry approach to characterize metabolic and immunological responses in haemolymph of male and female mussels (Perna canaliculus) experimentally infected with Vibrio sp. Sex-based differences in immunological responses were identified, with male mussels displaying higher mortality, oxidative stress and apoptosis after pathogen exposure. However, central metabolic processes appeared to be similar between sexes at 24 h post injection with Vibrio sp. DO1. Significant alterations in relative levels of 37 metabolites were detected between infected and uninfected mussels. These metabolites are involved in major perturbations on the host's innate immune system. In addition, there were alterations of seven metabolites in profiles of mussels sampled on the second day and mussels that survived six days after exposure. These metabolites include itaconic acid, isoleucine, phenylalanine, creatinine, malonic acid, glutaric acid and hydroxyproline. Among these, itaconic acid has the potential to be an important biomarker for Vibrio sp. DO1 infection. These findings provide new insights on the mechanistic relationship between a bivalve host and a pathogenic bacterium and highlight the need to consider host sex as a biological variable in future immunological studies.

Sex-Based Differences as a Predictor of Recovery Trajectories in Young Athletes After a Sports-Related Concussion.

BACKGROUND: To date, few studies have delineated clear sex-based differences in symptom resolution after a sports-related concussion (SRC), and equivocal results have been identified in sex-based differences on baseline assessments. PURPOSE: To assess whether female athletes displayed prolonged recovery and more symptoms at baseline and after an SRC compared with male athletes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The current study assessed 135 male and 41 female athletes (10-18 years old) who participated in high-impact sports in metropolitan Atlanta middle and high schools. All athletes completed a baseline assessment and at least 1 postconcussion assessment from the Immediate Post-Concussion Assessment and Cognitive Testing battery. Longitudinal hierarchical linear modeling was employed to examine individual-level variables and their associations with adolescents' rates of recovery in concussive symptoms after controlling for age and number of prior concussions. RESULTS: Aggregate symptoms were rated as higher in female athletes compared with male athletes at baseline (mean ± SD: females, 13.49 ± 11.20; males, 4.88 ± 8.74; F(1,175) = 10.59, P < .001) and immediately after a concussion (females: 16.75 ± 18.08; males: 10.58 ± 14.21; F(1,175) = 3.99, P = .05). There were no group differences in the slope of recovery between male and female athletes, indicating generally similar trajectories of change for both groups. Post hoc analyses revealed higher baseline levels of migraine and neuropsychological symptoms in female athletes. CONCLUSION: Although female athletes in the current study reported increased symptoms, identical recovery patterns were observed in both sexes, suggesting that sex-based differences in concussion recovery are better explained by increased symptom frequency among female athletes when compared with their male counterparts.

Determination of sex-based differences in serum γ-linolenic [corrected] acid and dihomo-γ-linolenic [corrected] acid using gas chromatography-mass spectrometry.

Because serum unsaturated fatty acids can provide useful information on disease diagnosis, the simultaneous determination of several fatty acids in small volumes of human serum would be beneficial for clinical applications. In the present study, serum fatty acids were extracted with n-heptane/chloroform from 10µL of serum collected from 26 healthy Japanese subjects (11 men, ages 23-37 years; 15 women, ages 18-37 years) after deproteinization with perchloric acid, derivatization to their methyl ester using p-toluenesulfonic acid as an acid catalyst, and subsequent separation and measurement by gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. Nine types of fatty acids (palmitoleic acid [PLA], oleic acid [OA], linoleic [corrected] acid [LA], γ-linolenic acid [GLA], α-linolenic acid [ALA], dihomo-GLA [DGLA], arachidonic acid [AA], eicosapentaenoic acid [EPA], and docosahexaenoic acid [DHA]) were analyzed in the serum within 35 min by GC-MS. The concentrations of these fatty acids in serum ranged from 3.64±0.38µM (GLA) to 413±26.3 µM (LA). Among these nine fatty acids, GLA and DGLA levels were significantly lower in women than in men (p=0.0034 and 0.0012, respectively), suggesting that there may be sex-based differences in the biosynthetic production or metabolic processes of GLA and DGLA in humans.