Project description:Aging and sex are major risk factors for developing late-onset Alzheimer’s disease. Compared to men, women are not only nearly twice as likely to develop Alzheimer’s, but they also experience worse neuropathological burden and cognitive decline despite living longer with the disease. It remains unclear how and when sex differences in biological aging emerge and contribute to Alzheimer’s disease pathogenesis. We hypothesized that these differences lead to distinct molecular Alzheimer’s disease signatures in males and females, which could be harnessed for therapeutic and biomarker development. We aged male and female, 3xTg-AD and B6129 control mice across their respective lifespans while longitudinally collecting brain samples. We conducted RNA sequencing analysis on bulk brain tissue and examined differentially expressed genes between 3xTg-AD and B6129 samples and across ages in each sex. 3xTg-AD males experienced an accelerated upregulation of immune-related gene expression in the brain relative to females, especially in genes involved in complement system activation, suggesting distinct inflammatory disease trajectories between the sexes. Our data demonstrate that chronic inflammation and complement activation are associated with increased mortality, revealing that age-related changes in immune response act as a primary driver of sex differences in Alzheimer’s disease trajectories.
Project description:Alzheimer’s disease (AD) and other age-related disorders associated with demyelination exhibit sex differences. Here, we used single-nuclei transcriptomics to dissect the contributions of sex chromosomes and gonads in demyelination and AD. In a mouse model of demyelination, we identified the role of sex chromosomes and gonads in modifying microglia and oligodendrocyte responses before and after myelin loss. In an AD-related mouse model expressing APOE4, XY sex chromosomes heightened interferon response and tau-induced demyelination. The X-linked gene Toll-like receptor 7 (Tlr7) regulated sex-specific interferon response to myelin. Deletion of Tlr7 dampened sex differences while protecting against demyelination. Administering TLR7 inhibitor mitigated tau-induced motor impairment and demyelination in male mice, indicating that Tlr7 plays a role in the male-biased IFN-I response in aging- and AD-related demyelination.
Project description:Alzheimer’s disease (AD) and other age-related disorders associated with demyelination exhibit sex differences. Here, we used single-nuclei transcriptomics to dissect the contributions of sex chromosomes and gonads in demyelination and AD. In a mouse model of demyelination, we identified the role of sex chromosomes and gonads in modifying microglia and oligodendrocyte responses before and after myelin loss. In an AD-related mouse model expressing APOE4, XY sex chromosomes heightened interferon response and tau-induced demyelination. The X-linked gene Toll-like receptor 7 (Tlr7) regulated sex-specific interferon response to myelin. Deletion of Tlr7 dampened sex differences while protecting against demyelination. Administering TLR7 inhibitor mitigated tau-induced motor impairment and demyelination in male mice, indicating that Tlr7 plays a role in the male-biased IFN-I response in aging- and AD-related demyelination.
Project description:Alzheimer’s disease (AD) and other age-related disorders associated with demyelination exhibit sex differences. Here, we used single-nuclei transcriptomics to dissect the contributions of sex chromosomes and gonads in demyelination and AD. In a mouse model of demyelination, we identified the role of sex chromosomes and gonads in modifying microglia and oligodendrocyte responses before and after myelin loss. In an AD-related mouse model expressing APOE4, XY sex chromosomes heightened interferon response and tau-induced demyelination. The X-linked gene Toll-like receptor 7 (Tlr7) regulated sex-specific interferon response to myelin. Deletion of Tlr7 dampened sex differences while protecting against demyelination. Administering TLR7 inhibitor mitigated tau-induced motor impairment and demyelination in male mice, indicating that Tlr7 plays a role in the male-biased IFN-I response in aging- and AD-related demyelination.
Project description:Sexual dimorphism in mammals is mostly attributable to sex-related hormonal differences in fetal and adult tissues; however, this may not be the sole determinant. Though genetically-identical for autosomal chromosomes, male and female preimplantation embryos could display sex-specific transcriptional regulation which can only be attributted to the differences in sexual chromosome dosage. We used microarrays to analyze sex-related transcriptional differences at the blastocyst stage.
Project description:Individualized outcome prediction classifiers were successfully constructed through expression profiling of a total of 779 genes in microglial cells from 36 mice, which had been consecutively operated on within a defined short period of time
Project description:The prevalence of cardiovascular disease varies with sex, and the impact of intrinsic sex-based differences on vasculature is not well understood. Animal models can provide important insight into some aspects of human biology, however not all discoveries in animal systems translate well to humans. To explore the impact of chromosomal sex on proteomic phenotypes, we used iPSC-derived vascular smooth muscle cells from healthy donors of both sexes to identify sex-based proteomic differences and their possible effects on cardiovascular pathophysiology. Our analysis confirmed that differentiated cells have a proteomic profile more similar to healthy primary aortic smooth muscle than iPSCs. We also identified sex-based differences in iPSC-derived vascular smooth muscle in pathways related to ATP binding, glycogen metabolic process, and cadherin binding as well as multiple proteins relevant to cardiovascular pathophysiology and disease. Additionally, we explored the role of autosomal and sex chromosomes in protein regulation, identifying that proteins on autosomal chromosomes also show sex-based regulation that may affect the protein expression of proteins from autosomal chromosomes. This work supports the biological relevance of iPSC-derived vascular smooth muscle cells as a model for disease, and further exploration of the pathways identified here can lead to the discovery of sex-specific pharmacological targets for cardiovascular disease.
Project description:Background: Women represent the majority of Alzheimer’s disease patients and show typical symptoms. Genetic, hormonal and behavioral mechanisms have been proposed to explain gender differences in dementia prevalence. Whether sex differences exist in the epigenetic landscape of neuronal tissue during the progression of the disease is unknown. Methods: To investigate the differences of histone H3 modifications important for transcription we determined the ge-nome-wide profiles in K4me3, K27ac and K27me3 from brain cortexes of an Alzheimer mouse model (PSAPP). Gastrocnemius muscles were also tested since they are known to be different in the two sexes and are affected during the disease progression. Results: Correlation analysis dis-tinguished the samples based on sex for H3K4me3 and H3K27met3 but not for H3K27ac. The analysis of TSS signal distribution and of bounding sites revealed that the epigenetic landscape of gastrocnemius is more influenced than brain by sex, with the exception of H3K27me3 distribution on the X chromosome which showed sex-related differences in promoters belonging to behavior and cellular/ neuronal spheres in mice cortexes. Conclusions: The epigenetic landscape is slightly affected by sex in brain, with the exception of H3K27me3. On the other hand, a higher number of differences can be found in gastrocnemius.
Project description:Mouse models of Alzheimer’s Disease (AD), which show progression through various AD stages reflective of human pathology, like 5XFAD, are well established tools for uncovering novel AD related pathways. In addition, they permit temporal examination of the intermingling of AD related pathways and can be used to potentially dissect initiating and propagating events in AD, which are critical for developing biomarkers or designing interventions in early stages of the disease. The present research offers a robust and exhaustive tandem MS examination of a familial AD mice model with a design including variables of: time (three, six, and nine months), genetic background (5XFAD vs. WT), and sex (equal males and females).
Project description:Sexual dimorphism in mammals is mostly attributable to sex-related hormonal differences in fetal and adult tissues; however, this may not be the sole determinant. Though genetically-identical for autosomal chromosomes, male and female preimplantation embryos could display sex-specific transcriptional regulation which can only be attributted to the differences in sexual chromosome dosage. We used microarrays to analyze sex-related transcriptional differences at the blastocyst stage. Day 7 bovine in vitro produced bovine blastocysts produced with sorted semen from 3 different bulls. Pooled RNA from 60 blastocysts of one sex and produced with one bull was used per chip. Three replicates of each sex per bull. In total, 18 Bovine GeneChip (Affymetrix) were used (3 replicates X 3 bulls X 2 sexes).