Biology of Sex Differences最新文献

Background: Both brain-derived neurotrophic factor (BDNF) and ovarian hormones are powerful neuromodulators, yet evidence of their impact on human cognition remains mixed. As prior work has studied them in isolation, examining their interacting effects presents a key empirical opportunity for explicating their effects on cognition.

Methods: We genotyped participants for the BDNF Val66Met single nucleotide polymorphism, which is associated with less efficient activity-dependent BDNF secretion and altered hippocampal function, and examined their performance on a complex learning task at two points in the menstrual cycle: early follicular (characterized by low levels of ovarian hormones) and late follicular (characterized by high estradiol).

Results: While met carriers showed advantages during the early follicular timepoint, val homozygotes outperformed them at the late follicular timepoint. Furthermore, effects in met carriers were largely driven by increased sensitivity to both absolute levels and changes in levels of estradiol.

Conclusions: The current findings provide the first evidence of BDNF Val66Met interacting with the menstrual cycle to predict cognition, demonstrate nuanced genotype- and hormone-specific outcomes, and underscore the importance of studying effects of interacting biological systems on human cognition.

Men and women exhibit well-established differences in electrolyte regulation, susceptibility to hypertension, kidney disease prevalence, and response to therapies for cardiovascular and renal disorders. Among these, plasma potassium regulation emerges as a key area of sex-specific divergence. Clinical and experimental studies consistently show that women are more susceptible to hypokalemia, while men are more prone to hyperkalemia, a pattern most evident during physiological or pathological stressors such as specific dietary patterns, exercise, medication use, and diseases like chronic kidney disease or cardiorenal syndrome. In this review, we synthesize current evidence from both human and animal studies on sex differences in potassium homeostasis and discuss their clinical implications. We also explore the physiological and molecular mechanisms underlying these differences, and highlight critical knowledge gaps. Advancing our understanding of these biological differences and their underlying mechanisms is essential to move beyond one-size-fits-all nutritional recommendations and disease management strategies.

Background: Pulmonary arterial hypertension (PAH) presents as increased pressure in the pulmonary arteries (PA) leading to cardiac right ventricular (RV) failure and death. Pulmonary arterial (PA) remodeling characterized by enhanced proliferation of pulmonary arterial smooth muscle cells (PASMC) and fibroblasts (PAFB) underlies PAH. There are currently no cures and PAH mortality remains high. PAH has a striking female-predominant incidence - 4:1 ratio - indicating that males may have a protective factor. However, to date only a few sex-biased factors in PAH have been investigated.

Methods: Analyses were performed on a publicly available microarray dataset (GSE117261), comprising human lung tissues from PAH patients and healthy controls, as well as publicly available single-cell lung atlases of humans and mice. Lung tissue, plasma, PASMC and PAFB were collected from male and female PAH patients. Cell proliferation was assessed after recombinant HGF protein stimulation. PH was induced in male and female rats by monocrotaline (MCT). Lung-specific knockdown was performed by intratracheal siRNA instillation the first two weeks after MCT injection. PA and RV function were assessed by echocardiography, RV systolic pressure by catheterization, and PA remodeling by histology.

Results: HGF was only upregulated in lungs of male PAH patients compared to male control lungs, but not in female PAH patients vs. female controls. Elevated plasma HGF correlated with favorable clinical characteristics only in male PAH patients. HGF is highly expressed in vascular SMC and FB in the lung and recombinant HGF inhibited PASMC and PAFB proliferation to a greater extent in cells isolated from male PAH patients compared to female. Lung HGF expression is increased to a higher extent and longer duration at early stage of PH in male rats in MCT model vs. female rats. Finally, knockdown of HGF in the lungs in early disease stage exacerbated PH in male rats characterized by higher mortality, worsened RV and PA function as well as enhanced PA medial thickening and adventitial fibrosis.

Conclusions: Lung HGF expression may be upregulated to counteract PAH disease progression by inhibiting proliferation of PASMC and PAFB. Elevated HGF in males might at least partially account for the lower incidence of male PAH patients.

Alternative splicing (AS) significantly enhances transcriptomic diversity, and its dysregulation is implicated in numerous human diseases. However, no public database systematically compiles sex-related AS events across human tissues. We developed SASdb (http://www.gdbioinfo.top/sasdb), a comprehensive database contains 2,951,059 AS events and 46,418 sex-biased alternative splicing (SAS) events, covering 22 human tissues. SASdb reveals extensive sex-specific splicing patterns, offering new insights into molecular sex differences. A case study on NSCLC-specific SAS events, absent in healthy tissues, highlights their enrichment in cancer-related pathways like autophagy, GPI-anchor biosynthesis, and AMPK/mTOR signaling. SASdb's intuitive visualization supports research in sex biology and precision medicine.

Objective: Limited literature is available comparing sexes in rectal cancer. This nationwide study using real-world data was performed to evaluate sex-based differences in diagnosis, treatment and survival outcomes in rectal cancer.

Methods: Data from the Netherlands Cancer Registry were analyzed for patients diagnosed with rectal adenocarcinoma between 2015 and 2019. Patient and tumor characteristics, treatment strategies, response to neoadjuvant therapy, and survival outcomes were compared between sexes.

Results: The cohort consisted of 22251 patients (37.1% women, 62.9% men). Women more frequently presented with cT4 tumors (16% vs. 11%, P < 0.001) but no differences were observed in nodal status, distant metastases, use of neoadjuvant (chemo) radiotherapy and radicality in resections between sexes. In the total study population, 5-year survival did not differ significantly (63.6% in women vs. 61.6% in men, P=0.23). However, in surgically treated patients, survival was higher in women (77.4% vs. 75.0%, P=0.019). Female sex was an independent predictor for survival in surgically treated patients (HR 0.90; 95% CI 0.82-0.98). In the subgroup of patients who were asymptomatic at the time of diagnosis [n=1320], there were no sex-based differences in presentation, treatment, or survival (5-year overall survival: 78.8% vs. 80.4%, P=0.45).

Conclusion: Sex-based differences exist in rectal cancer presentation and outcome. Women are more likely to present a more advanced T-stage. Despite this, women have a better overall survival after surgical treatment. In contrast, men and women undergoing treatment for asymptomatic rectal cancer have comparable outcomes.

Background: Previous research on Four Core Genotypes and XY* mice has been instrumental in establishing important effects of sex-chromosome complement that cause sex differences in physiology and disease. We have generated rat models using similar modifications of the testis-determining gene Sry, to produce XX and XY rats with the same type of gonad, as well as XO, XXY and XYY rats with varying gonads. The models permit discovery of novel sex-chromosome effects (XX vs. XY) that contribute to sex differences in any rat phenotype, and test for effects of different numbers of X or Y chromosomes.

Methods: XY rats were created with an autosomal transgene of Sry, producing XX and XY progeny with testes. In other rats, CRISPR-Cas9 technology was used to remove Y chromosome factors that initiate testis differentiation, producing fertile XY gonadal females. Interbreeding of these lines produced rats with interesting combinations of sex chromosomes and gonads: XO, XX, XY, XXY rats with ovaries; and XO, XX, XY, XXY, and XYY rats with testes. These groups can be compared to detect sex differences caused by sex-chromosome complement (XX vs. XY) and/or by gonadal hormones (rats with testes vs. ovaries). Other comparisons detect the effects of X or Y chromosome number (in gonadal females: XO vs. XX, XX vs. XXY, XO vs. XY, XY vs. XXY; in gonadal males: XY vs. XXY, XY vs. XYY; XX vs. XXY, XO vs. XX, XO vs. XY).

Results: We measured numerous phenotypes to characterize these models, including gonadal histology, breeding performance, anogenital distance, levels of reproductive hormones, body and organ weights, and central nervous system sexual dimorphisms. Serum testosterone levels were comparable in adult XX and XY gonadal males. Phenotypes previously known to be sexually differentiated by the action of gonadal hormones were found to be similar in XX and XY rats with the same type of gonad, suggesting that XX and XY rats with the same type of gonad have comparable levels of gonadal hormones at various stages of development.

Conclusion: The results establish powerful new models to discriminate sex-chromosome and gonadal hormone effects that cause sex differences in rat physiology and disease.

Introduction: Hypertension is a multifactorial condition of unknown cause that affects more than 1.28 billion adults worldwide and impacts the sexes differently. The hypothalamic paraventricular nucleus (PVN) plays a central role in blood pressure (BP) regulation by modulating sympathetic tone and releasing neuropeptides that affect the cardiovascular function. In this study, we investigated the transcriptomic profile of the PVN in hypertensive strains and across sexes, aiming to identify novel sex-specific molecular pathways involved in the regulation of BP.

Methods: To accomplish this goal, we sequenced RNA from the PVNs of normotensive Wistar rats and Spontaneously Hypertensive Rats (SHR), both male and female. We also performed a cardiovascular assessment based on blood pressure (BP) measurements and their variability.

Results: Cardiovascular assessment revealed higher SBP in SHRs than in Wistar rats; while males exhibited greater autonomic regulation associated with vasomotor and neurohumoral mechanisms, while females maintained comparable SBP levels primarily through an increase in heart rate, reflecting distinct autonomic adaptations. Hypertension also impacted gene expression, with influences from both the hypertensive state and sex. Compared with female SHRs, male SHRs presented a marked increase in differentially expressed genes (DEGs). Key upregulated genes in males, including Brain-Derived Neurotrophic Factor (Bdnf) and Hypocretin (Hcrt), have already been linked to elevated BP, and Angiotensin II Receptor Type 1 (Agtr1a) is possibly associated with increased SBP-VLF variability, which serves as an indirect measure of enhanced sympathetic tone. In contrast, the female transcriptomic signature was characterized by the upregulation of anti-inflammatory pathways, with upregulation of NLR Family CARD Domain Containing 3 (Nlrc3) and Paired Ig-like Receptor B (Pirb), and downregulation of Absent in Melanoma 2 (Aim2), and S100 Calcium Binding Protein B (S100b). Notably, genes associated with neuroinflammation, such as the downregulation of Annexin A1 (Anxa1) and the upregulation of Solute Carrier Family 11 Member 1 (Slc11a1), were consistently altered in both sexes.

Conclusion: These results provide new insights into the cardiovascular and molecular basis of sex differences in hypertension, suggesting distinct neurohumoral autonomic profile in males, whereas in females a greater anti-inflammatory component. These findings offer a valuable framework for developing future sex-specific therapeutic strategies.

Background: The apolipoprotein E (APOE) ε4 allele is a risk factor for late-onset Alzheimer's disease; however, risk varies by sex and lifestyle. Regular physical activity is known to mitigate cognitive decline; whether the degree of benefit differs by APOE genotype, sex, and race remains unknown.

Methods: Analyses utilized data from 2,985 participants in the Health, Aging, and Body Composition (HABC) cohort, comprising community-dwelling black and white older adults followed for 10 years. Cognitive performance was assessed multiple times across the 10 years using the Digit Symbol Substitution Test (DSST) for executive functions and processing speed and the Modified Mini-Mental State Examination (3MS) for global cognition. APOE genotypes were categorized into ε2, ε3, and ε4 groups. Annual self-reported walking time was used to quantify physical activity. Linear mixed models and latent growth curve modeling examined the interactions between APOE genotype, sex, and walking on cognitive trajectories with adjustments for race, study location, health score, age, education attained, and body mass index.

Results: APOE ε4 carriers demonstrated steeper declines in both DSST and 3MS scores compared to ε3 carriers, irrespective of sex (all β<-0.13, all p < 0.004). APOE ε2 was protective longitudinally for 3MS in females only (β = 0.15, p < 0.002). Walking showed the strongest protective effect in APOE ε4 carriers for females and males in the rate of change of DSST and 3MS scores (all β > 0.27, all p < 0.044).

Discussion: These findings underscore the importance of public messaging about the benefits of regular physical activity for retaining cognitive function especially for persons genetically at heightened risk.

Background: Sexual differentiation of the brain is a complex ontogenetic process orchestrated by genetic and hormonal influences, leading to sex‑specific physiological and behavioral traits in adulthood. In mammals, the sex chromosome complement (SCC) contributes to this process by encoding unequal genetic information in XX and XY cells. Furthermore, SCC upregulates aromatase and estrogen receptor β (ERβ) expression in amygdala neurons of XY compared to XX embryos at embryonic day (E) 14. These molecules are critically implicated in the steroid-dependent programming of neural circuits during the subsequent critical window of sexual differentiation (E17-PN10). Since epigenetic mechanisms play a key role in specific target gene expression forming a layer of gene regulation, we aimed to contribute to a better understanding of their impact on the sexual differentiation of the brain.

Methods: Four Core Genotypes mouse model was employed to study the epigenetic machinery involved in DNA methylation and histone deacetylation in different brain regions (amygdala, hypothalamus, and cortex) to elucidate the underlying epigenetic landscape at E14 by RT-qPCR. Amygdala primary neuronal cultures were then established to evaluate the epigenetic regulation of Cyp19a1 (aromatase) and Esr2 (ERβ) expression. To assess this, pharmacological inhibition of DNA methylation, using zebularine, as well as Chromatin Immunoprecipitation (ChIP-qPCR) assays were performed.

Results: Sex-specific expression of DNA methyltransferases 3a and 3b, along with histone deacetylases 2 and 8, was higher in XX than XY embryos in a region- and developmental stage- dependent manner. Pharmacological inhibition of DNA methylation did not significantly alter aromatase expression in male or female amygdala neuronal cultures under the conditions tested. However, ChIP-qPCR assays revealed a selective enrichment of Acetyl-H4 at the Cyp19a1 promoter in male cultures that was not observed in females. No significant enrichment of the examined epigenetic marks was detected at the Esr2 promoter.

Conclusions: Acetylation of histone H4 contributes to promoting the higher Cyp19a1 expression previously observed in male neurons. Our findings support a model in which SCC plays a role in the epigenetic regulation of aromatase, a key enzyme involved in hormone-driven sexual differentiation of the male brain. Furthermore, the presence of two X chromosomes shapes a distinct epigenetic landscape in the brain during early development, highlighting the influence of chromosomal sex on the neurodevelopmental programming.