Highlights Patients in the experimental group received intravenous ribavirin versus supportive care only in the control group. Ribavirin was not associated with reduced negative conversion time of SARS-CoV-2 PCR test compared with the control group. Ribavirin did not reduce the mortality rate compared with the control group.

Endothelial cells (ECs) and macrophages engage in tight and specific interactions that play critical roles in cardiovascular homeostasis and the pathogenesis of atherosclerosis. Extracellular vesicles (EVs) are circular membrane fragments released from the endosomal compartment as exosomes or shed from the surfaces of the membranes of most cell types. Increasing evidence indicates that EVs play a pivotal role in cell-to-cell communication. However, the contribution of EVs, as determine by oxidized low-density lipoprotein (ox-LDL)-exposed and/or Kruppel-like factor 2 (KLF2)-transduced ECs in the interaction between vascular ECs and monocytes/macrophages, which is a key event in atherosclerotic plaque development, has remained elusive. This study demonstrates the characteristic impact of EVs from ox-LDL-treated and/or KLF2-transduced ECs on the monocyte/macrophage phenotype in vitro and in vivo.Q-PCR showed that both the atherosclerosis inducer ox-LDL and atheroprotective factor KLF2 regulated inflammation-associated microRNA-155 (miR-155) expression in human umbilical vein endothelial cells (HUVECs). Moreover, coculture, immunofluorescence and flow cytometry revealed that miR-155 was enriched in ox-LDL-induced ECs-EVs and subsequently transferred to human monocytic THP1 cells, in which these vesicles enhance monocyte activation by shifting the monocytes/macrophages balance from anti-inflammatory M2 macrophages towards proinflammatory M1 macrophages; EVs from KLF2-expressing ECs suppressed monocyte activation by enhancing immunomodulatory responses and diminishing proinflammatory responses, which indicate the potent anti-inflammatory activities of these cells. Furthermore, oil red staining showed that atherosclerotic lesions were reduced in mice that received EVs from KLF2-transduced ECs with decreased proinflammatory M1 macrophages and increased anti-inflammatory M2 macrophages, and this effect is at least partly due to the decreased expression of inflammation-associated miR-155, confirming our in vitro findings. In summary, this study provides novel insights into the pathophysiological effects of altered EV secretion and/or microRNA content and their influence on modulating monocyte activation depending on the environment surrounding EVs-releasing ECs.

Background-MicroRNAs (miRs) and inflammatory monocytes participate in many cardiac pathophysiological processes including acute myocardial infarction (AMI). Recently, we observed that miR-150 is downregulated in injured mouse plasma after AMI as well as in human infarcted monocytes. However, the precise functional role of miR-150 in response to AMI remains unknown. Methods and Results-In a mouse model of AMI and in human subjects with AMI, we found that miR-150 expression was reduced in monocytes. In vitro studies showed that ectopic expression of miR-150 markedly reduced monocyte migration and proinflammatory cytokine production, whereas blockade of miR-150 had opposing effects. In vivo studies showed that overexpression of miR-150 in mice resulted in improved cardiac function, reduced myocardial infarction size, inhibition of apoptosis, and reduced inflammatory Ly-6C high monocyte invasion levels after AMI. Wild-type mice transplanted with miR-150 null (−/−) bone marrow cells could reverse this protective effect. Mechanistic studies demonstrated that miR-150 inhibited the expression of chemokine receptor 4 (CXCR4), thereby promoting monocyte migration. Conclusions-Our findings indicate that miR-150 acts as a critical regulator of monocyte cell migration and production of proinflammatory cytokines, leading to cardioprotective effects against AMI-induced injury. Thus, miR-150 may be a suitable target for therapeutic intervention in the setting of ischemic heart disease. (Circ Cardiovasc Genet. 2015;8:11-20.