Search

Objectives: To obtain mechanistic insight into COVID-19 within a cardiovascular setting. Background: Thrombosis and vascular dysfunction are part of the complex pathology seen in severe COVID-19 and advancing age is the most significant risk factor. Little is known about age and expression of pathways utilised by the COVID-19 virus, SARS-CoV-2, in cardiovascular tissues. Methods: We used publicly available databases (GTEx, GEO and Array Express) to investigate gene expression levels, in adult tissues, of the two putative SARS-CoV-2 receptors, ACE2 and BSG along with a selected range of genes thought to be involved in virus binding/processing. Our analysis included; vessels (aorta and coronary artery), heart (atrial appendage and left ventricle), kidney (cortex), whole blood, lung, colon and spleen along with endothelial cells, nasal and bronchial epithelium and peripheral blood mononuclear cells. Gene expression levels were then analysed for age associations. Results: We found: (i) cardiovascular tissues/endothelial cells express the required genes for SARS-CoV-2 infection, (ii) SARS-CoV-2 receptor pathways, ACE2/TMPRSS2 and BSG/PPIB(A) polarise to lung/epithelium and vessel/endothelium respectively, (iii) expression of host genes are relatively stable with age and (iv) notable exceptions are ACE2 which decreases with age in some tissues and BSG which increases with age in endothelial cells. Conclusion: Our data identifies a positive correlation of BSG with age in endothelial cells. Since BSG is utilised by other pathogens and is implicated in a range of cardiovascular disease, our observations may have relevance to our understanding of mechanisms associated with other pathogens and in the diseases associated with aging respectively.

Well-orchestrated maternal-fetal crosstalk occurs via secreted ligands, interacting receptors, and coupled intracellular pathways between the conceptus and endometrium, and is essential for successful embryo implantation. However, previous studies mostly focus on either the conceptus or the endometrium in isolation. The lack of integrated analysis impedes our understanding of early maternal-fetal crosstalk. Herein, focusing on ligand–receptor complexes and coupled pathways at the maternal-fetal interface in sheep, we provide the first comprehensive proteomic map of ligand-receptor pathway cascades essential for embryo implantation. We demonstrate that these cascades are associated with cell adhesion and invasion, redox homeostasis, and the immune response. Candidate interactions and their physiological roles were further validated by functional experiments. We reveal the physical interaction of albumin and claudin 4 and their roles in facilitating embryo attachment to endometrium. We also demonstrate a novel function of enhanced conceptus glycolysis in remodeling uterine receptivity by inducing endometrial histone lactylation, a newly identified histone modification. Results from in vitro and in vivo models supported the essential role of lactate in inducing endometrial H3K18 lactylation and in regulating redox homeostasis and apoptotic balance to ensure successful implantation. By reconstructing a map of potential ligand-receptor pathway cascades at the maternal-fetal interface, our study presents new concepts for understanding molecular and cellular mechanisms that fine-tune conceptus-endometrium crosstalk during implantation. This provides more direct and accurate insights for developing potential clinical intervention strategies to improve pregnancy outcomes following both natural and assisted conception.

Background Human mesenchymal stromal cells (MSCs) phenotypically share their positive expression of the International Society for Cell and Gene Therapy (ISCT) markers CD73, CD90 and CD105 with fibroblasts. Fibroblasts are often co-isolated as an unwanted by-product from biopsy and they can rapidly overgrow the MSCs in culture. Indeed, many other surface markers have been proposed, though no unique MSC specific marker has been identified yet. Quantitative PCR (qPCR) is a precise, efficient and rapid method for gene expression analysis. To identify a marker suitable for accurate MSC characterisation, qPCR was exploited. Methods and results Two commercially obtained bone marrow (BM) derived MSCs and an hTERT immortalised BM-MSC line (MSC-TERT) have been cultured for different days and at different oxygen levels before RNA extraction. Together with RNA samples previous extracted from umbilical cord derived MSCs and MSC-TERT cells cultured in 2D or 3D, this heterogeneous sample set was quantitatively analysed for the expression levels of 18 candidate MSC marker genes. The expression levels in MSCs were compared with the expression levels in fibroblasts to verify the differentiation capability of these genes between MSCs and fibroblasts. None of the ISCT markers could differentiate between fibroblasts and MSCs. A total of six other genes (ALCAM, CLIC1, EDIL3, EPHA2, NECTIN2, and TMEM47) were identified as possible biomarkers for accurate identification of MSCs. Conclusion Justified by considerations on expression level, reliability and specificity, Activated-Leukocyte Cell Adhesion Molecule (ALCAM) was the best candidate for improving the biomarker set of MSC identification., Highlights • ALCAM showed reliable high gene expression levels in hMSCs from different sources and under different culture conditions • ALCAM gene expression can distinguish between several hMSC-lines and fibroblasts • EDIL3 and TMEM47 gene expression can aid in distinguishing between hMSCs and fibroblasts • EDIL3 and TMEM47 and ALCAM in particular, could possibly replace ENG and THY1 in improved hMSC characterisation.