scholarly journals Activation of C-Type Lectin Receptor and (RIG)-I-Like Receptors Contributes to Proinflammatory Response in Middle East Respiratory Syndrome Coronavirus-Infected Macrophages

Author(s):  
Xiaoyu Zhao ◽  
Hin Chu ◽  
Bosco Ho-Yin Wong ◽  
Man Chun Chiu ◽  
Dong Wang ◽  
...  

Abstract Background Human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) poses an ongoing threat to public health worldwide. The studies of MERS patients with severe disease and experimentally infected animals showed that robust viral replication and intensive proinflammatory response in lung tissues contribute to high pathogenicity of MERS-CoV. We sought to identify pattern recognition receptor (PRR) signaling pathway(s) that mediates the inflammatory cascade in human macrophages upon MERS-CoV infection. Methods The potential signaling pathways were manipulated individually by pharmacological inhibition, small interfering ribonucleic acid (siRNA) depletion, and antibody blocking. The MERS-CoV-induced proinflammatory response was evaluated by measuring the expression levels of key cytokines and/or chemokines. Reverse transcription-quantitative polymerase chain reaction assay, flow cytometry analysis, and Western blotting were applied to evaluate the activation of related PRRs and engagement of adaptors. Results MERS-CoV replication significantly upregulated C-type lectin receptor (CLR) macrophage-inducible Ca2+-dependent lectin receptor (Mincle). The role of Mincle for MERS-CoV-triggered cytokine/chemokine induction was established based on the results of antibody blockage, siRNA depletion of Mincle and its adaptor spleen tyrosine kinase (Syk), and Syk pharmacological inhibition. The cytokine and/or chemokine induction was significantly attenuated by siRNA depletion of retinoic acid-inducible-I-like receptors (RLR) or adaptor, indicating that RLR signaling also contributed to MERS-CoV-induced proinflammatory response. Conclusions The CLR and RLR pathways are activated and contribute to the proinflammatory response in MERS-CoV-infected macrophages.

2015 ◽  
Vol 20 (49) ◽  
Author(s):  
Daniel KW Chu ◽  
Jamiu O Oladipo ◽  
Ranawaka APM Perera ◽  
Sulaiman A Kuranga ◽  
Samuel MS Chan ◽  
...  

Evidence of current and past Middle East respiratory syndrome coronavirus (MERS-CoV) infection in dromedary camels slaughtered at an abattoir in Kano, Nigeria in January 2015, was sought by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and serology. MERS-CoV RNA was detected in 14 (11%) of 132 nasal swabs and antibody in 126 (96%) of 131 serum samples. Phylogenetic analyses demonstrate that the viruses in Nigeria are genetically distinct from those reported in the Arabian peninsula.


mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Stanley Perlman

ABSTRACT Ten years after the severe acute respiratory syndrome epidemic, a second coronavirus, the Middle East respiratory syndrome coronavirus (MERS-CoV), has been identified as the cause of a highly lethal pneumonia in patients in the Middle East and in travelers from this region. Over the past 9 months, since the virus was first isolated, much has been learned about the biology of the virus. It is now clear that MERS-CoV is transmissible from person to person, and its close relationship with several bat coronaviruses suggests that these animals may be the ultimate source of the infection. However, many key issues need to be addressed, including identification of the proximate, presumably zoonotic, source of the infection, the prevalence of the infection in human populations, details regarding clinical and pathological features of the human infection, the establishment of a small rodent model for the infection, and the virological and immune basis for the severe disease observed in most patients. Most importantly, we do not know whether a MERS-CoV epidemic is likely or not. Infection with the virus has so far resulted in only 91 cases and 46 deaths (as of 29 July 2013), but it is nonetheless setting off alarm bells among public health officials, including Margaret Chan, Director-General of the World Health Organization, who called MERS-CoV “a threat to the entire world.” This article reviews some of the progress that has been made and discusses some of the questions that need to be answered.


Author(s):  
Sara Keränen ◽  
Santeri Suutarinen ◽  
Rahul Mallick ◽  
Johanna P. Laakkonen ◽  
Diana Guo ◽  
...  

Abstract Background Brain arteriovenous malformations (bAVM) may rupture causing disability or death. BAVM vessels are characterized by abnormally high flow that in general triggers expansive vessel remodeling mediated by cyclo-oxygenase-2 (COX2), the target of non-steroidal anti-inflammatory drugs. We investigated whether COX2 is expressed in bAVMs and whether it associates with inflammation and haemorrhage in these lesions. Methods Tissue was obtained from surgery of 139 bAVMs and 21 normal Circle of Willis samples. The samples were studied with immunohistochemistry and real-time quantitative polymerase chain reaction (RT-PCR). Clinical data was collected from patient records. Results COX2 expression was found in 78% (109/139) of the bAVMs and localized to the vessels’ lumen or medial layer in 70% (95/135) of the bAVMs. Receptors for prostaglandin E2, a COX2-derived mediator of vascular remodeling, were found in the endothelial and smooth muscle cells and perivascular inflammatory cells of bAVMs. COX2 was expressed by infiltrating inflammatory cells and correlated with the extent of inflammation (r = .231, p = .007, Spearman rank correlation). COX2 expression did not associate with haemorrhage. Conclusion COX2 is induced in bAVMs, and possibly participates in the regulation of vessel wall remodelling and ongoing inflammation. Role of COX2 signalling in the pathobiology and clinical course of bAVMs merits further studies.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 156
Author(s):  
Mohammad Al Hasan ◽  
Patricia E. Martin ◽  
Xinhua Shu ◽  
Steven Patterson ◽  
Chris Bartholomew

GPR56 is required for the adipogenesis of preadipocytes, and the role of one of its ligands, type III collagen (ColIII), was investigated here. ColIII expression was examined by reverse transcription quantitative polymerase chain reaction, immunoblotting and immunostaining, and its function investigated by knockdown and genome editing in 3T3-L1 cells. Adipogenesis was assessed by oil red O staining of neutral cell lipids and production of established marker and regulator proteins. siRNA-mediated knockdown significantly reduced Col3a1 transcripts, ColIII protein and lipid accumulation in 3T3-L1 differentiating cells. Col3a1−/− 3T3-L1 genome-edited cell lines abolished adipogenesis, demonstrated by a dramatic reduction in adipogenic moderators: Pparγ2 (88%) and C/ebpα (96%) as well as markers aP2 (93%) and oil red O staining (80%). Col3a1−/− 3T3-L1 cells displayed reduced cell adhesion, sustained active β-catenin and deregulation of fibronectin (Fn) and collagen (Col4a1, Col6a1) extracellular matrix gene transcripts. Col3a1−/− 3T3-L1 cells also had dramatically reduced actin stress fibres. We conclude that ColIII is required for 3T3-L1 preadipocyte adipogenesis as well as the formation of actin stress fibres. The phenotype of Col3a1−/− 3T3-L1 cells is very similar to that of Gpr56−/− 3T3-L1 cells, suggesting a functional relationship between ColIII and Gpr56 in preadipocytes.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Raquel Weber ◽  
Ana Paula Santin Bertoni ◽  
Laura Walter Bessestil ◽  
Ilma Simoni Brum ◽  
Tania Weber Furlanetto

Goiter is more common in women, suggesting that estrogen could be involved in its physiopathology. The presence of classical estrogen receptors (ERαand ERβ) has been described in thyroid tissue, suggesting a direct effect of estrogen on the gland. A nonclassic estrogen receptor, the G-protein-coupled estrogen receptor (GPER1), has been described recently in several tissues. However, in goiter, the presence of this receptor has not been studied yet. We investigated GPER1 gene and protein expressions in normal thyroid and goiter using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot, respectively. In normal thyroid (n=16) and goiter (n=19), GPER1 gene was expressed in all samples, while GPER1 protein was expressed in all samples of normal thyroid (n=15) but in only 72% of goiter samples (n=13). When comparing GPER1 gene and protein levels in both conditions, gene expression and protein levels were higher in normal thyroid than in goiter, suggesting a role of this receptor in this condition. Further studies are needed to elucidate the role of GPER1 in normal thyroid and goiter.


Blood ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 1223-1229 ◽  
Author(s):  
Dehua Wang ◽  
Jenice D'Costa ◽  
Curt I. Civin ◽  
Alan D. Friedman

Abstract C/EBPα is required for generation of granulocyte-monocyte progenitors, but the subsequent role of C/EBPα in myeloid lineage commitment remains uncertain. We transduced murine marrow cells with C/EBPα-estradiol receptor (ER) or empty vector and subjected these to lineage depletion just prior to culture in estradiol with myeloid cytokines. This protocol limits biases due to lineage-specific effects on developmental kinetics, proliferation, and apoptosis. Also, lowering the dose of estradiol reduced activated C/EBPα-ER to near the physiologic range. C/EBPα-ER increased Mac1+/Gr1–/MPO–/low monocytes 1.9-fold while reducing Mac1+/Gr1+/MPOhi granulocytes 2.5-fold at 48 hours, even in 0.01 μM estradiol. This pattern was confirmed morphologically and by quantitative polymerase chain reaction (PCR) assay of lineage markers. To directly assess effects on immature progenitors, transduced cells were cultured for 1 day with and then in methylcellulose without estradiol. A 2-fold increase in monocytic compared with granulocytic colonies was observed in IL-3/IL-6/SCF or GM-CSF, but not G-CSF, even in 0.01 μM estradiol. C/EBPα-ER induced PU.1 mRNA, and PU.1-ER stimulated monocytic development, suggesting that transcriptional induction of PU.1 by C/EBPα contributes to monopoiesis. A C/EBPα variant incapable of zippering with c-Jun did not induce monopoiesis, and a variant unable to bind NF-κB p50 stimulated granulopoiesis, suggesting their cooperation with C/EBPα during monocytic commitment.


2007 ◽  
Vol 137 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Bradford A. Woodworth ◽  
Rachel Wood ◽  
John E. Baatz ◽  
Rodney J. Schlosser

OBJECTIVE: To measure alterations in SPA1, A2, and D gene expression in various forms of inflammatory chronic rhinosinusitis (CRS). STUDY DESIGN AND SETTING: Sinus mucosal biopsies were performed in patients with allergic fungal rhinosinusitis (AFS), CRS with nasal polyposis, cystic fibrosis (CF), and controls. SP mRNA was measured with quantitative polymerase chain reaction. RESULTS: Patients with CF (n = 4) showed significantly increased SPA1 (82-fold), SPA2 (100-fold), and SPD (47-fold) mRNA ( P < 0.05) when compared with controls (n = 5). Patients with CRS with nasal polyposis (n = 5) also demonstrated elevated SPA1 (27-fold), SPA2 (13-fold), and SPD (13-fold). Patients with AFS (n = 7) had increased SPA1 (5-fold), SPA2 (9-fold), and SPD (17-fold), but were not statistically significant. CONCLUSION: SPA1, A2, and D are upregulated in various forms of CRS, but are significantly elevated in cystic fibrosis CRS. SIGNIFICANCE: Understanding the role of SPs in CRS will help develop novel treatment approaches for sinonasal pathoses.


2016 ◽  
Vol 184 (6) ◽  
pp. 460-464 ◽  
Author(s):  
Caitlin M. Rivers ◽  
Maimuna S. Majumder ◽  
Eric T. Lofgren

2020 ◽  
Author(s):  
Michael G. Ison

Coronaviruses (CoVs) are a group of viral pathogens that infect mammals and birds. The presentation in humans is typically that of a mild upper respiratory tract infection, similar to the common cold. However, in recent years, dramatic attention has arisen for more lethal members of this viral family (e.g., severe acute respiratory syndrome [SARS-CoV], Middle East respiratory syndrome [MERS-CoV], and coronavirus disease 2019 [COVID-19]). The epidemiology, clinical presentation, diagnosis, and management of these viruses are discussed in this review. Importantly, new guideline tables from the Centers for Disease Control and Prevention, as well as the World Health Organization are provided at the conclusion of the review. This review contains 12 tables, 3 figure and 48 references. Keywords: Coronavirus, severe acute respiratory distress syndrome (SARS), Middle East respiratory syndrome (MERS), COVID-19, respiratory infection, antiviral, real-time polymerase chain reaction


2020 ◽  
Author(s):  
Michael G. Ison

Coronaviruses (CoVs) are a group of viral pathogens that infect mammals and birds. The presentation in humans is typically that of a mild upper respiratory tract infection, similar to the common cold. However, in recent years, dramatic attention has arisen for more lethal members of this viral family (e.g., severe acute respiratory syndrome [SARS-CoV], Middle East respiratory syndrome [MERS-CoV], and coronavirus disease 2019 [COVID-19]). The epidemiology, clinical presentation, diagnosis, and management of these viruses are discussed in this review. Importantly, new guideline tables from the Centers for Disease Control and Prevention, as well as the World Health Organization are provided at the conclusion of the review. This review contains 12 tables, 3 figure and 48 references. Keywords: Coronavirus, severe acute respiratory distress syndrome (SARS), Middle East respiratory syndrome (MERS), COVID-19, respiratory infection, antiviral, real-time polymerase chain reaction


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