Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to respiratory illness and multi-organ failure in critically ill patients. Although the virus-induced lung damage and inflammatory cytokine storm are believed to be directly associated with coronavirus disease 2019 (COVID-19) clinical manifestations, the underlying mechanisms of virus-triggered inflammatory responses are currently unknown. Here we report that SARS-CoV-2 infection activates caspase-8 to trigger cell apoptosis and inflammatory cytokine processing in the lung epithelial cells. The processed inflammatory cytokines are released through the virus-induced necroptosis pathway. Virus-induced apoptosis, necroptosis, and inflammation activation were also observed in the lung sections of SARS-CoV-2-infected HFH4-hACE2 transgenic mouse model, a valid model for studying SARS-CoV-2 pathogenesis. Furthermore, analysis of the postmortem lung sections of fatal COVID-19 patients revealed not only apoptosis and necroptosis but also massive inflammatory cell infiltration, necrotic cell debris, and pulmonary interstitial fibrosis, typical of immune pathogenesis in the lung. The SARS-CoV-2 infection triggered a dual mode of cell death pathways and caspase-8-dependent inflammatory responses may lead to the lung damage in the COVID-19 patients. These discoveries might assist the development of therapeutic strategies to treat COVID-19.
Nach 22 Jahren konnte die Totalsynthese von Azadirachtin (1) zum Abschluss gebracht werden. Die hoch konvergente Syntheseroute setzte auf eine Claisen‐Umlagerung und eine radikalische Cyclisierung in den Schlüsselschritten. Die Endphase der Synthese stützte sich auf das Intermediat 2, das sowohl auf präparative Weise als auch durch Abbau von 1 erhalten werden konnte. Bn=Benzyl, TBS=tert‐Butyldimethylsilyl.
A therosclerosis is the underlying cause of cardiovascular disease (CVD), which is the leading cause of mortality worldwide.1 CVD is initiated by the accumulation of lipids, necrotic cells, and fibrous elements in the neointima of medium and large arteries. 2,3 The primary cells that contribute to atherosclerotic lesion formation are endothelial cells, vascular smooth muscle cells, and macrophages. [4][5][6] Plaque formation results from the infiltration of circulating monocytes in the subendothelial space, where they differentiate into macrophages and subsequently internalize modified lipoproteins and further differentiate into foam cells. 7 Therefore, further clarification of the mechanisms leading to macrophage accumulation is important to prevent plaque rupture and subsequent life-threatening clinical complications, such as myocardial infarction and stroke. See accompanying editorial on page 7The nuclear receptor superfamily is composed of transcription factors that positively and negatively regulate gene expression, which not only influence lipid metabolism at the systemic level but also regulate lipid homeostasis and inflammation in macrophages, endothelial cells, and smooth muscle cells within the arterial walls. 8,9 The nuclear factor I (NFI) family of site-specific DNA-binding proteins are critical regulators of gliogenesis in the developing central nervous system.10,11 NFIA, a member of the NFI family, can modulate DNA replication and transcription through binding to duplex DNA containing the TTGGC motif or 5′-TTGGCN 5 GCCAA-3′ consensus sequence. 12 Many studies have shown that NFIA plays critical roles in specifying glial cell identity and promoting astrocyte differentiation during embryonic development. 10,11 In addition, a recent study demonstrated that NFIA was functionally required for proper adipocyte differentiation and lipid droplet formation. Overexpression of NFIA in 3T3-L1 cells could significantly result in lipid droplet formation without differentiation stimulus. Overexpression of dominantnegative NFIA or small interfering RNA (siRNA)-mediated knockdown of NFIA could markedly inhibit lipid accumulation during differentiation 13 . However, no publication has © 2014 American Heart Association, Inc. Objective-Cardiovascular disease caused by atherosclerosis is the number one cause of death in Western countries and threatens to become the major cause of morbidity and mortality worldwide. Long noncoding RNAs are emerging as new players in gene regulation, but how long noncoding RNAs operate in the development of atherosclerosis remains unclear. Approach and Results-Using microarray analysis, we found that long noncoding RNA RP5-833A20.1 expression was upregulated, whereas nuclear factor IA (NFIA) expression was downregulated in human acute monocytic leukemia macrophage-derived foam cells. Moreover, we showed that long noncoding RNA RP5-833A20.1 may decreases NFIA expression by inducing hsa-miR-382-5p expression in vitro. We found that the RP5-833A20.1/hsa-miR-382-5p/NFIA pathway is essenti...
The Z-scheme has been proven to be an effective strategy to develop a high-efficiency visible-light photocatalyst. However, the visible-light-responding active component in the Z-scheme system is usually restricted to semiconductor materials sensitive to visible light. On the other hand, noble-metal nanoparticles (such as Ag) can act as an active component for the design of high-efficiency plasmonic photocatalysts due to their strong absorption in the visible light region. In this study, H2WO4·H2O/Ag/AgCl composite nanoplates were prepared by a one-step ionic reaction between Ag8W4O16/Ag nanorods and HCl aqueous solution. The photocatalytic activity experiments indicated that the H2WO4·H2O/Ag/AgCl composite nanoplates exhibited a much higher photocatalytic activity than the one-component (H2WO4·H2O) or two-component (such as Ag/AgCl and H2WO4·H2O/Ag) photocatalysts. On the basis of photocatalytic activity and band structure analysis, a plasmonic Z-scheme photocatalytic mechanism is proposed; namely, two-step visible-light absorption is caused by the localized surface plasmon resonance of metallic Ag nanoparticles and the band gap photoexcitation of H2WO4·H2O. The present results suggest that metallic Ag nanoparticles can act as an effective active component for the construction of a Z-scheme visible-light photocatalyst. Considering the versatility and flexibility of noble-metal nanoparticles and semiconductors, this work may provide some insight into the design of novel and highly efficient Z-scheme visible-light photocatalysts.
The coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now spread to >200 countries posing a global public health concern. Patients with comorbidity, such as hypertension suffer more severe infection with elevated mortality. The development of effective antiviral drugs is in urgent need to treat COVID-19 patients. Here, we report that calcium channel blockers (CCBs), a type of antihypertensive drug that is widely used in clinics, inhibited the post-entry replication events of SARS-CoV-2 in vitro, while no in vitro anti-SARS-CoV-2 effect was observed for the two other major types of antihypertensive drugs, namely, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers. CCB combined with chloroquine showed a significantly enhanced anti-SARS-CoV-2 efficacy. A retrospective clinical investigation on hospitalized COVID-19 patients with hypertension as the only comorbidity revealed that the CCB amlodipine besylate therapy was associated with a decreased case fatality rate. The results from this study suggest that CCB administration to COVID-19 patients with hypertension as the comorbidity might improve the disease outcome.
Severe fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne infectious disease caused by a novel phlebovirus (SFTS virus, SFTSV), was listed among the top 10 priority infectious diseases by the World Health Organization due to its high fatality of 12%-50% and possibility of pandemic transmission. Currently, effective anti-SFTSV intervention remains unavailable. Here, by screening a library of FDA-approved drugs, we found that benidipine hydrochloride, a calcium channel blocker (CCB), inhibited SFTSV replication in vitro. Benidipine hydrochloride was revealed to inhibit virus infection through impairing virus internalization and genome replication. Further experiments showed that a broad panel of CCBs, including nifedipine, inhibited SFTSV infection. The anti-SFTSV effect of these two CCBs was further analyzed in a humanized mouse model in which CCB treatment resulted in reduced viral load and decreased fatality rate. Importantly, by performing a retrospective clinical investigation on a large cohort of 2087 SFTS patients, we revealed that nifedipine administration enhanced virus clearance, improved clinical recovery, and remarkably reduced the case fatality rate by >5-fold. These findings are highly valuable for developing potential host-oriented therapeutics for SFTS and other lethal acute viral infections known to be inhibited by CCBs in vitro.
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