Project description:Bordering the central nervous system (CNS) parenchyma are the pia mater enveloping the brain and the choroid underlying the retina. Although in close proximity to the neural parenchyma, the pia mater and choroid are external to the immune privileged environment of the brain and retina and are distinct immune compartments. This study generated a single cell transcriptomic atlas of immune cells within the healthy adult mouse pia and choroid. Comparative analysis of immune populations within these tissues revealed heterogeneous subtypes of T cells, B cells, monocytes/macrophages and dendritic cells, which displayed tissue-specific transcriptomic signatures and potential functional specialisations. Single cell RNA-sequencing of choroidal immune cells from human eye tissue identified populations with similar transcriptional profiles to mouse choroidal immune cells. This study provides a detailed understanding of the molecular signatures of immune cells within the bordering tissues of the brain and retina, and their potential roles in CNS immune surveillance.
Project description:Normal aging is accompanied by escalating systemic inflammation. To comprehensively characterize the impact of aging on immune cells in the brain and periphery, we harvested immune cells from mouse spleen and brain tissues. Single cell sequencing was performed to compare the genetic signatures in these isolated immune cell subsets from spleen and brain tissues in young and aged mice. Our results demonstrate increased accumulations of immune cells such as natural killer (NK) cells in the aged brain as compared to the young brain. In addition, NK cells in the aged brain display augmented proliferation activity and cytotoxicity. RNA-sequencing of neuroblasts isolated from the aged brain revealed that aging induces dysregulated expression of genes related to DNA damage response and upregulation of senescence signatures.
Project description:Normal aging is accompanied by escalating systemic inflammation. To comprehensively characterize the impact of aging on immune cells in the brain and periphery, we harvested immune cells from mouse spleen and brain tissues. Single cell sequencing was performed to compare the genetic signatures in these isolated immune cell subsets from spleen and brain tissues in young and aged mice. Our results demonstrate increased accumulations of immune cells such as natural killer (NK) cells in the aged brain as compared to the young brain. In addition, NK cells in the aged brain display augmented proliferation activity and cytotoxicity. RNA-sequencing of neuroblasts isolated from the aged brain revealed that aging induces dysregulated expression of genes related to DNA damage response and upregulation of senescence signatures.
Project description:Using a canine custom retinal cDNA microarray our aim is to identify normal gene expression profiling for retina and frontal, occipital and temporal brain cortices Keywords: retina-brain comparisons
Project description:Control of neural organogenesis is a complex process and the epigenetic contribution is largely unknown. Here we have followed the genome-wide distribution of two important histone H3 modifications, H3K4me2 and H3K27me3 during late mouse retina development. We found that genes expressed only in mature rod photoreceptors, have a unique signature consisting of de-novo accumulation of H3K4me2 both at the transcription start site (TSS) and over the whole gene that correlates with the increase in transcription, but no accumulation of H3K27me3 at any stage. We also found that distribution of H3K4me2 and H3K27me3 on the genes widely expressed is not always associated with their transcriptional levels. Genes without H3K4me2 and H3K27me3 accumulation at any stage represent a group of transcripts never expressed in retina. The epigenetic signatures defined by H3K4me2 and H3K27me3 can distinguish cell-type specific genes from widespread transcripts and may be reflective of cell specificity during retina maturation. Examination of 2 different histone modifications during late mouse retina development.
Project description:Using a canine custom retinal cDNA microarray our aim is to identify normal gene expression profiling for retina and frontal, occipital and temporal brain cortices Total RNA was isolated using Trizol reagent (Invitrogen, Carlsbad, CA) and further purified by Rneasy mini kit (Qiagen, Valencia, CA). Purity and RNA quality were evaluated by absorbance at 260 nm and by denaturing formaldehyde agarose gel electrophoresis. High quality RNAs with A260/280 ratio over 1.8 and intact 28S and 18S RNA bands were used for microarray analysis. To generate an RNA reference sample for microarray hybridizations, we pooled equal amounts of total RNA from the occipital, temporal, and frontal brain regions collected from three 16-week-old beagles to achieve a homogeneous pool of transcripts. The pooled RNA was divided into aliquots (2μg/μl) and stored at -80 °C until use. For the purpose of this work, four tissue groups have been established, containing five biological replicates for normal retina and three for each respective brain region. After initial validation of reproducibility, only one microarray experiment was used for each sample.
Project description:There is a growing need to better characterise senescent cells in the CNS and retina. The recently published SenMayo gene panel was developed to identify transcriptomic signatures of senescence across multiple organ systems, but the retina was not included. While other approaches have identified senescent signatures in the retina, these have largely focused on experimental models in young animals. We therefore conducted a detailed single-cell RNA-seq analysis to identify senescent cell populations in the retina of different aged mice and compared these with five comprehensive human and mouse retina and brain transcriptome datasets. Transcriptomic signatures of senescence were most apparent in mouse and human retinal glial cells, with IL4, 13 and 10 and the AP1 pathway being the most prominent markers involved. Similar levels of transcriptional senescence were observed in the retinal glia of young and old mice, whereas the human retina showed significantly increased enrichment scores with advancing age.