Project description:Poor access to human left ventricular myocardium is a significant limitation in the study of heart failure (HF). Here, we utilise a carefully procured large human heart biobank of cryopreserved left ventricular myocardium to obtain direct molecular insights into ischaemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM), the most common causes of HF worldwide. We perform unbiased, deep proteomic and metabolomic analyses of 51 left ventricular (LV) samples from 44 cryopreserved human ICM and DCM hearts, compared to age-, gender-, and BMI-matched, histopathologically normal, donor controls. We report a dramatic reduction in serum amyloid A1 protein in ICM hearts, perturbed thyroid hormone signalling pathways and significant reductions in oxidoreductase co-factor riboflavin-5-monophosphate and glycolytic intermediate fructose-6-phosphate in both; unveil gender-specific changes in HF, including nitric oxide-related arginine metabolism, mitochondrial substrates, and X chromosome-linked protein and metabolite changes; and provide an interactive online application as a publicly-available resource.
Project description:The incidence of Alzheimer's Disease in females is almost double that of males. To search for sex-specific gene associations, we build a machine learning approach focused on functionally impactful coding variants. This method can detect differences between sequenced cases and controls in small cohorts. In the Alzheimer's Disease Sequencing Project with mixed sexes, this approach identified genes enriched for immune response pathways. After sex-separation, genes become specifically enriched for stress-response pathways in male and cell-cycle pathways in female. These genes improve disease risk prediction in silico and modulate Drosophila neurodegeneration in vivo. Thus, a general approach for machine learning on functionally impactful variants can uncover sex-specific candidates towards diagnostic biomarkers and therapeutic targets.
Project description:MTSS1 (metastasis suppressor 1) is an I-BAR protein that regulates cytoskeleton dynamics through interactions with actin, Rac, and actin-associated proteins. In a prior study, we identified genetic variants in a cardiac-specific enhancer upstream of MTSS1 that reduce human left ventricular (LV) MTSS1 expression and associate with protection against dilated cardiomyopathy (DCM). We sought to probe these effects further using population genomics and in vivo murine models. We crossed Mtss1-/- mice with a transgenic (Tg) murine model of human DCM caused by the D230N pathogenic mutation in Tpm1 (tropomyosin 1). In females, Tg/Mtss1+/- mice had significantly increased LV ejection fraction and reduced LV volumes relative to their Tg/Mtss1+/+ counterparts, signifying partial rescue of DCM due to Mtss1 haploinsufficiency. No differences were observed in males. To study effects in humans, we fine-mapped the MTSS1 locus with 82 cardiac magnetic resonance (CMR) traits in 22,381 UK Biobank participants. MTSS1 enhancer variants showed interaction with biological sex in their associations with several CMR traits. After stratification by biological sex, associations with CMR traits and colocalization with MTSS1 expression in the Genotype-Tissue Expression (GTEx) Project were observed principally in women and were substantially weaker in men. These findings suggest sex dimorphism in the effects of MTSS1-lowering alleles, and parallel the increased LV ejection fraction and reduced LV volumes observed female Tg/Mtss1+/- mice. Together, our findings at the MTSS1 locus suggest a genetic basis for sex dimorphism in cardiac remodeling and motivate sex-specific study of common variants associated with cardiac traits and disease.
Project description:BackgroundPlacental macrophages, Hofbauer cells (HBC) are the only fetal immune cell population within the stroma of healthy placenta along pregnancy. They are central players in maintaining immune tolerance during pregnancy. Immunometabolism emerged a few years ago as a new field that integrates cellular metabolism with immune responses, however, the immunometabolism of HBC has not been explored yet. Here we studied the sex-specific differences in the phenotypic, functional and immunometabolic profile of HBC.MethodsHBC were isolated from human term placentas (N = 31, 16 from male and 15 female neonates). Ex vivo assays were carried out to assess active metabolic and endoplasmic reticulum stress pathways by flow cytometry, confocal microscopy, gene expression and in silico approaches.ResultsHBC from female placentas displayed a stronger M2 phenotype accompanied by high rates of efferocytosis majorly sustained on lipid metabolism. On the other hand, male HBC expressed a weaker M2 phenotype with higher glycolytic metabolism. LPS stimulation reinforced the glycolytic metabolism in male but not in female HBC. Physiological endoplasmic reticulum stress activates IRE-1 differently, since its pharmacological inhibition increased lipid mobilization, accumulation and efferocytosis only in female HBC. Moreover, differential sex-associated pathways accompanying the phenotypic and functional profiles of HBC appeared related to the placental villi environment.ConclusionsThese results support sex-associated effects on the immunometabolism of the HBC and adds another layer of complexity to the intricate maternal-fetal immune interaction.
Project description:Sex hormones are essential for neural circuit development and sex-specific behaviors. Male behaviors require both testosterone and estrogen, but it is unclear how the two hormonal pathways intersect. Circulating testosterone activates the androgen receptor (AR) and is also converted into estrogen in the brain via aromatase. We demonstrate extensive sexual dimorphism in the number and projections of aromatase-expressing neurons. The masculinization of these cells is independent of AR but can be induced in females by either testosterone or estrogen, indicating a role for aromatase in sexual differentiation of these neurons. We provide evidence suggesting that aromatase is also important in activating male-specific aggression and urine marking because these behaviors can be elicited by testosterone in males mutant for AR and in females subjected to neonatal estrogen exposure. Our results suggest that aromatization of testosterone into estrogen is important for the development and activation of neural circuits that control male territorial behaviors.
Project description:Myocardial tissue samples were explanted from the explanted left ventricle of heart failure patients with DCM (n=4), left ventricular infarct, peri-, and non-infarct regions of HF patients with ICM (n=4) at the time of their heart transplant surgeries, and the left ventricle of age- and sex-matched non-failing controls (NFC, n=4). Comparative quantitative analysis was performed on three independent sets (DCM vs. NFC, infarct vs. non-infarct, and peri- vs. non-infarct) labeled with 10-plex tandem mass tags. Following enrichment of phosphorylated peptides, the flow-through and eluted fractions were collected separately and subjected to LC-MS/MS (liquid chromatography-tandem mass spectrometry) on a Q-Exactive HF for global proteomics and phosphoproteomics profiling respectively.
Project description:Women affected by Dilated Cardiomyopathy (DCM) experience better outcomes compared to men. Whether a more pronounced Left Ventricular Reverse Remodelling (LVRR) might explain this is still unknown. We investigated the relationship between LVRR and sex and its long-term outcomes. A cohort of 605 DCM patients with available follow-up data was consecutively enrolled. LVRR was defined, at 24-month follow-up evaluation, as an increase in left ventricular ejection fraction (LVEF) ≥ 10% or a LVEF > 50% and a decrease ≥ 10% in indexed left ventricular end-diastolic diameter (LVEDDi) or an LVEDDi ≤ 33 mm/m2. Outcome measures were a composite of all-cause mortality/heart transplantation (HTx) or ventricular assist device (VAD) and a composite of Sudden Cardiac Death (SCD) or Major Ventricular Arrhythmias (MVA). 181 patients (30%) experienced LVRR. The cumulative incidence of LVRR at 24-months evaluation was comparable between sexes (33% vs. 29%; p = 0.26). During a median follow-up of 149 months, women experiencing LVRR had the lowest rate of main outcome measure (global p = 0.03) with a 71% relative risk reduction compared to men with LVRR, without significant difference between women without LVRR and males. A trend towards the same results was found regarding SCD/MVA (global p = 0.06). Applying a multi-state model, male sex emerged as an independent adverse prognostic factor even after LVRR completion. Although the rate of LVRR was comparable between sexes, females experiencing LVRR showed the best outcomes in the long term follow up compared to males and females without LVRR. Further studies are advocated to explain this difference in outcomes between sexes.
Project description:Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiac disease with a prevalence of 1:500 to 1:200. While most patients show obstructive HCM and a relatively stable clinical phenotype (stage II), a small group of patients progresses to end-stage HCM (stage IV) within a relatively brief period. Previous research has shown sex-differences in stage II HCM with more diastolic dysfunction in female than in male patients. Moreover, female patients more often show progression to heart failure. Here we investigated if differences in functional and structural properties of the heart may underlie sex-differences in disease progression from stage II to stage IV HCM. Cardiac tissue from stage II and IV patients was obtained during myectomy (n = 54) and heart transplantation (n = 10), respectively. Isometric force was measured in membrane-permeabilized cardiomyocytes to define active and passive myofilament force development. Titin isoform composition was assessed using gel electrophoresis, and the amount of fibrosis and capillary density were determined with histology. In accordance with disease stage-dependent adverse cardiac remodeling end-stage patients showed a thinner interventricular septal wall and larger left ventricular and atrial diameters compared to stage II patients. Cardiomyocyte contractile properties and fibrosis were comparable between stage II and IV, while capillary density was significantly lower in stage IV compared to stage II. Women showed more adverse cellular remodeling compared to men at stage II, evident from more compliant titin, more fibrosis and lower capillary density. However, the disease stage-dependent reduction in capillary density was largest in men. In conclusion, the more severe cellular remodeling in female compared to male stage II patients suggests a more advanced disease stage at the time of myectomy in women. Changes in cardiomyocyte contractile properties do not explain the progression of stage II to stage IV, while reduced capillary density may underlie disease progression to end-stage heart failure.
Project description:Project Description(50 to 5000 characters):Phospholamban (PLN) plays a central role in Ca2+ homeostasis in cardiac myocytes through its regulation of the SERCA2A Ca2+ pump. An inherited mutation converting arginine residue 9 in PLN to cysteine (R9C) results in dilated cardiomyopathy (DCM) in both humans and transgenic mice, but the downstream signaling defects leading to heart failure are poorly understood. Here, we used precision tandem mass spectrometry to gain unbiased insights into the global phosphorylation dynamics of 2041 cardiac phosphoproteins in early affected heart tissue in the transgenic R9C mouse model of DCM compared to wild type littermates. 251 dysregulated phosphorylation sites were quantified after affinity capture and identification of 4337 phosphopeptides from fractionated whole heart homogenates. Enrichment analysis of the differential phosphoprotein patterns revealed dozens of signaling pathways regulating cardiovascular activity that are selectively impaired in early stages of DCM. Strikingly, dysregulated signaling through the Notch-1 receptor, recently linked to cardiomyogenesis and embryonic cardiac stem cell development and differentiation but never directly implicated in DCM before, was one of the most prominently perturbed pathways. We verified dysregulation of Notch1 downstream components in early symptomatic R9C transgenic mouse hearts compared to wild type by immunoblot analysis and confocal immunofluorescence microscopy. These data reveal unexpected connections between protein kinases, cell signaling networks and downstream effectors essential for proper cardiac function
Project description:BackgroundNeural tube defects (NTDs) are failure of neural tube closure, which includes multiple central nervous system phenotypes. More than 300 mouse mutant strains exhibits NTDs phenotypes and give us some clues to establish association between biological functions and subphenotypes. However, the knowledge about association in human remains still very poor.MethodsHigh throughput targeted genome DNA sequencing were performed on 280 neural tube closure-related genes in 355 NTDs cases and 225 ethnicity matched controls, RESULTS: We explored that potential damaging rare variants in genes functioning in chromatin modification, apoptosis, retinoid metabolism and lipid metabolism are associated with human NTDs. Importantly, our data indicate that except for planar cell polarity pathway, craniorachischisis is also genetically related with chromatin modification and retinoid metabolism. Furthermore, single phenotype in cranial or spinal regions displays significant association with specific biological function, such as anencephaly is associated with potentially damaging rare variants in genes functioning in chromatin modification, encephalocele is associated with apoptosis, retinoid metabolism and one carbon metabolism, spina bifida aperta and spina bifida cystica are associated with apoptosis; lumbar sacral spina bifida aperta and spina bifida occulta are associated with lipid metabolism. By contrast, complex phenotypes in both cranial and spinal regions display association with various biological functions given the different phenotypes.ConclusionsOur study links genetic variant to subphenotypes of human NTDs and provides a preliminary but direct clue to investigate pathogenic mechanism for human NTDs.