Background Severe acute respiratory syndrome coronavirus 2 infection is associated with hypercoagulability, which predisposes to venous thromboembolism (VTE). We analyzed platelet and neutrophil activation in patients with coronavirus disease 2019 (COVID-19) and their association with VTE. Methods Hospitalized patients with COVID-19 and age- and sex-matched healthy controls were studied. Platelet and leukocyte activation, neutrophil extracellular traps (NETs), and matrix metalloproteinase 9, a neutrophil-released enzyme, were measured. Four patients were restudied after recovery. The activating effect of plasma from patients with COVID-19 on control platelets and leukocytes and the inhibiting activity of common antithrombotic agents on it were studied. Results A total of 36 patients with COVID-19 and 31 healthy controls were studied; VTE developed in 8 of 36 patients with COVID-19 (22.2%). Platelets and neutrophils were activated in patients with COVID-19. NET, but not platelet activation, biomarkers correlated with disease severity and were associated with thrombosis. Plasmatic matrix metalloproteinase 9 was significantly increased in patients with COVID-19. Platelet and neutrophil activation markers, but less so NETs, normalized after recovery. In vitro, plasma from patients with COVID-19 triggered platelet and neutrophil activation and NET formation, the latter blocked by therapeutic-dose low-molecular-weight heparin, but not by aspirin or dypiridamole. Conclusions Platelet and neutrophil activation are key features of patients with COVID-19. NET biomarkers may help to predict clinical worsening and VTE and may guide low-molecular-weight heparin treatment.
Recent advances in tiling array and high throughput analyses revealed that at least 87.3 % of the human genome is actively transcribed, though <3 % of the human genome encodes proteins. This unexpected truth suggests that most of the transcriptome is constituted by noncoding RNA. Among them, high-resolution microarray and massively parallel sequencing analyses identified long noncoding RNAs (lncRNAs) as nonprotein-coding transcripts. lncRNAs are largely polyadenylated and >200 nucleotides in length transcripts, involved in gene expression through epigenetic and transcriptional regulation, splicing, imprinting and subcellular transport. Although lncRNAs functions are largely uncharacterized, accumulating data indicate that they are involved in fundamental biological functions. Conversely, their dysregulation has increasingly been recognized to contribute to the development and progression of several human malignancies, especially lung cancer, which represents the leading cause of cancer-related deaths worldwide. We conducted a comprehensive review of the published literature focusing on lncRNAs function and disruption in nonsmall cell lung cancer biology, also highlighting their value as biomarkers and potential therapeutic targets. lncRNAs are involved in NSCLC pathogenesis, modulating fundamental cellular processes such as proliferation, cell growth, apoptosis, migration, stem cell maintenance and epithelial to mesenchymal transition, also serving as signaling transducers, molecular decoys and scaffolds. Also, lncRNAs represent very promising biomarkers in early-stage NSCLC patients and may become particularly useful in noninvasive screening protocols. lncRNAs may be used as predictive biomarkers for chemotherapy and targeted therapies sensitivity. Furthermore, selectively targeting oncogenic lncRNAs could provide a new therapeutic tool in treating NSCLC patients. lncRNAs disruption plays a pivotal role in NSCLC development and progression. These molecules also serve as diagnostic, prognostic and predictive biomarkers. Characterization of lncRNA genes and their mechanisms of action will enable us to develop a more comprehensive clinical approach, with the final goal to benefit our patients.
Since increased cholesterol levels are crucial in determining the development of atheroma, their reduction represents a mainstay in primary and secondary cardiovascular prevention. The most recent spectacular advancement in cholesterol-lowering therapy is represented by proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors. Although their benefit over currently available treatments has been ascribed primarily to their strong low-density lipoprotein (LDL)-cholesterol reducing action, several clues suggest that PCSK9 inhibitors may also influence platelet function and blood coagulation. PCSK9 knockout mice develop less venous and arterial thrombosis and show reduced in vivo platelet activation upon arterial injury. In patients with acute coronary syndromes (ACSs) treated with P2Y12 inhibitors, a direct association between PCSK9 serum levels and residual platelet reactivity was found. A direct correlation between urinary excretion of 11-dehydro-thromboxane-B2, a marker of in vivo platelet activation, and circulating PCSK9 levels was reported in patients with atrial fibrillation. Moreover, recombinant human PCSK9 added in vitro to human platelets potentiated activation induced by weak agonists. Finally, blood clotting factor VIII (FVIII), which is associated with stroke and ACS risk, is cleared from the circulation by members of the LDL receptor (LDLR) family. Given that PCSK9 degrades LDLR, it is conceivable that PCSK9 inhibitors by enhancing the expression of LDLR may slightly decrease circulating FVIII, in this way contributing to the prevention of cardiovascular events. This review aims to discuss the possible and hypothetical interactions between PCSK9 and the haemostatic system and to examine the possible pleiotropic effects of PCSK9 inhibitors in cardiovascular prevention.
Sepsis, a complex and dynamic syndrome resulting from microbial invasion and immune system dysregulation, is associated with an increased mortality, reaching up to 35% worldwide. Cholesterol metabolism is often disturbed during sepsis, with low plasma cholesterol levels being associated with poor prognosis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes degradation of the low-density lipoprotein receptor (LDLR), thus regulating intracellular and plasma cholesterol levels. PCSK9 is often upregulated during sepsis and might have a detrimental effect on immune host response and survival. Accordingly, PCSK9 reduces lipopolysaccharide uptake and clearance by human hepatocytes. Moreover, PCSK9 upregulation exacerbates organ dysfunction and tissue inflammation during sepsis, whereas a protective effect of PCSK9 deficiency has been documented in septic patients. Although a possible detrimental impact of PCSK9 on survival has been described, some beneficial effects of PCSK9 on immune response may be hypothesized. First, PCSK9 is associated with increased plasma cholesterol levels, which might be protective during sepsis. Second, PCSK9, by stimulating LDLR degradation and inhibiting reverse cholesterol transport (RCT), might promote preferential cholesterol accumulation in macrophages and other immune cells; these events might improve lipid raft composition and augment toll-like receptor function thus supporting inflammatory response. Hence, a more clear definition of the role of PCSK9 in septic states might provide additional insight in the understanding of the sepsis-associated immune dysregulation and enhance therapeutic outcomes.
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