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Neither the disease mechanism nor treatments for COVID-19 are currently known. Here we present a novel molecular mechanism for COVID-19 that provides therapeutic intervention points that can be addressed with existing FDA-approved pharmaceuticals. The entry point for the virus is ACE2, which is a component of the counteracting hypotensive axis of RAS, that produces the nonapeptide angiotensin1-9 from angiotensin I. Bradykinin is a potent, but often forgotten, part of the vasopressor system that induces hypotension and vasodilation 1, and is regulated by ACE and enhanced by angiotensin1-9 2. Here we perform a completely new analysis on gene expression data from cells of bronchoalveolar lavage samples from COVID-19 patients that were used to sequence the virus, but the host information was discarded 3. Comparison with lavage samples from controls identify a critical imbalance in RAS represented by decreased expression of ACE in combination with increases in ACE2, renin (REN) , angiotensin (AGT), key RAS receptors (AGTR2, AGTR1), kinogen (KNG) and the kallikrein enzymes (KLKB1, many of KLK-1-15) that activate it, and both bradykinin receptors (BDKRB1, BDKRB2). This very atypical pattern of the RAS is predicted to elevate bradykinin levels in multiple tissues and systems that will likely cause increases in vascular dilation, vascular permeability and hypotension. These bradykinin-driven outcomes explain many of the symptoms being observed in COVID-19.

Lipid-poor high density lipoprotein apolipoproteins remove cholesterol and phospholipids from cells by an active secretory pathway controlled by an ABC transporter called ABCA1. This pathway is induced by cholesterol and cAMP analogs in a cell-specific manner. Here we provide evidence that increased plasma membrane ABCA1 accounts for the enhanced apolipoprotein-mediated lipid secretion from macrophages induced by cAMP analogs. Treatment of RAW264 macrophages with 8-bromo-cAMP caused parallel increases in apoA-I-mediated cholesterol efflux, ABCA1 mRNA and protein levels, incorporation of ABCA1 into the plasma membrane, and binding of apoA-I to cellsurface ABCA1. All of these parameters declined to near base-line values within 6 h after removal of 8-bromocAMP, indicating that ABCA1 is highly unstable and is degraded rapidly in the absence of inducer. Thus, ABCA1 is likely to be the cAMP-inducible apolipoprotein receptor that promotes removal of cholesterol and phospholipids from macrophages.

How an atherosclerotic plaque evolves from minimal diffuse intimal hyperplasia to a critical lesion is not well understood. Cellular proliferation is a relatively infrequent and modest event in both primary and restenotic coronary atherectomy specimens, leading us to believe that other processes, such as the formation of extracellular matrix, cell migration, neovascularization, and calcification might be more important for lesion formation. The investigation of proteins that are overexpressed in plaque compared with the normal vessel wall may provide clues that will help determine which of these processes are key to lesion pathogenesis. One such molecule, osteopontin (OPN), is an arginine-glycine-aspartate-containing acidic phosphoprotein recently shown to be a novel component of human atherosclerotic plaques and selectively expressed in the rat neointima following balloon angioplasty. Using in situ hybridization and immunohistochemical I dentifying the processes and molecular mediators of atherosclerotic plaque formation are currently areas of intense investigation. While focal smooth muscle cell (SMC) accumulations have been considered a hallmark of atherosclerosis and restenosis, 15 recent data suggest that the frequency of SMC replication in plaques is low. 6 -7 Thus, smooth muscle proliferation may not be a dominant event in lesion progression. Instead, other processes, such as cell migration, extracellular matrix formation, neovascularization, and calcification may be important pathophysiological events that are possibly linked to the expression of genes unique to atherosclerotic plaque and not found in the normal vessel wall. Examples of molecules that are overexpressed in the plaque compared with the normal vessel wall include platelet-derived growth factor-A, 8 bone morphogenetic protein-2a, 9 the major histocompatibility complex class II (la) antigen, 10 and the focus of the current study, osteopontin (OPN)." Although the mechanisms by which these genes are regulated are unknown, it is plausible to consider that SMC diversity plays a role, since plaque SMCs show a spectrum of phenotypes ranging from well differentiated (ie, containing abundant smooth muscle contractile proteins) to relatively undifferentiated (ie, containing little contractile apparatus but increased protein synthetic machinery), with the latter being present in the greatest numbers and commonly implicated in lesion progression. 12Using a differential cloning strategy, we have identified OPN, as well as several other genes (eg, collagen 1 [o-l], elastin), that are overexpressed in the rat neointima in vivo and that distinguish rat vascular SMC phenotypes in vitro.1314 OPN is an arginine-glycineaspartate-containing acidic phosphoprotein normally restricted to bone matrix, kidney, and epithelial lining cells and has been implicated in bone morphogenesis, tumor metastasis, bacterial resistance, immune function, and renal physiology. 15 In vitro, OPN serves as an adhesive substrate for both vascular smooth muscle and endothelial...

Single nucleotide polymorphisms (SNPs) have gained wide use in humans and model species and are becoming the marker of choice for applications in other species. Technology that was developed for work in model species may provide useful tools for SNP discovery and genotyping in non-model organisms. However, SNP discovery can be expensive, labour intensive, and introduce ascertainment bias. In addition, the most efficient approaches to SNP discovery will depend on the research questions that the markers are to resolve as well as the focal species. We discuss advantages and disadvantages of several past and recent technologies for SNP discovery and genotyping and summarize a variety of SNP discovery and genotyping studies in ecology and evolution.