The ongoing global pandemic (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a huge public health issue. Hence, we devised a multiplex reverse transcription loop-mediated isothermal amplification (mRT-LAMP) coupled with a nanoparticle-based lateral flow biosensor (LFB) assay (mRT-LAMP-LFB) for diagnosing COVID-19. Using two LAMP primer sets, the ORF1ab (opening reading frame 1a/b) and N (nucleoprotein) genes of SARS-CoV-2 were simultaneously amplified in a single-tube reaction, and detected with the diagnosis results easily interpreted by LFB. In presence of FITC (fluorescein)-/digoxin- and biotin-labeled primers, mRT-LAMP produced numerous FITC-/digoxin- and biotin-attached duplex amplicons, which were determined by LFB through immunoreactions (FITC/digoxin on the duplex and anti-FITC/digoxin on the test line of LFB) and biotin/treptavidin interaction (biotin on the duplex and strptavidin on the polymerase nanoparticle). The accumulation of nanoparticles leaded a characteristic crimson band, enabling multiplex analysis of ORF1ab and N gene without instrumentation. The limit of detection (LoD) of COVID-19 mRT-LAMP-LFB was 12 copies (for each detection target) per reaction, and no cross-reactivity was generated from non-SARS-CoV-2 templates. The analytical sensitivity of SARS-CoV-2 was 100% (33/33 oropharynx swab samples collected from COVID-19 patients), and the assay's specificity was also 100% (96/96 oropharynx swab samples collected from non-COVID-19 patients). The total diagnostic test can be completed within 1 h from sample collection to result interpretation. In sum, the COVID-19 mRT-LAMP-LFB assay is a promising tool for diagnosing SARS-CoV-2 infections in frontline public health field and clinical laboratories, especially from resource-poor regions.
Gastroesophageal reflux disease complicated by Barrett esophagus (BE) is a major risk factor for esophageal adenocarcinoma (EA). The mechanisms whereby acid reflux may accelerate the progression from BE to EA are not known. We found that NOX1 and NOX5-S were the major isoforms of NADPH oxidase in SEG1-EA cells. The expression of NOX5-S mRNA was significantly higher in these cells than in esophageal squamous epithelial cells. NOX5 mRNA was also significantly higher in Barrett tissues with high grade dysplasia than without dysplasia. Pulsed acid treatment significantly increased H 2 O 2 production in both SEG1-EA cells and BE mucosa, which was blocked by the NADPH oxidase inhibitor apocynin. In SEG1 cells, acid treatment increased mRNA expression of NOX5-S, but not NOX1, and knockdown of NOX5 by NOX5 small interfering RNA abolished acid-induced H 2 O 2 production. In addition, acid treatment increased intracellular Ca 2؉ and phosphorylation of cAMP-response element-binding protein (CREB). Acid-induced NOX5-S expression and H 2 O 2 production were significantly inhibited by removal of extracellular Ca 2؉ and by knockdown of CREB using CREB small interfering RNA. Two novel CREB-binding elements TGACGAGA and TGACGCTG were identified in the NOX5-S gene promoter. Overexpression of CREB significantly increased NOX5-S promoter activity. Knockdown of NOX5 significantly decreased [ 3 H]thymidine incorporation, which was restored by 10 ؊13 M H 2 O 2 . Knockdown of NOX5 also significantly decreased retinoblastoma protein phosphorylation and increased cell apoptosis and caspase-9 expression. In conclusion, in SEG1 EA cells NOX5-S is overexpressed and mediates acid-induced H 2 O 2 production. Acid-induced NOX5-S expression depends on an increase in intracellular Ca 2؉ and activation of CREB. NOX5-S contributes to increased cell proliferation and decreased apoptosis.Esophageal adenocarcinoma has increased in incidence over the past 3 decades (1), at a rate exceeding that of any other cancer in the last 10 years (2, 3). Esophageal adenocarcinoma is characterized by a uniformly poor prognosis, with a median survival time following diagnosis of less than 18 months, and a 5-year survival rate of less than 20% in operable tumors (4). The major risk factor for esophageal adenocarcinoma is gastroesophageal reflux disease (GERD) 2 complicated by Barrett esophagus (BE) (5). Approximately 10% of GERD patients develop BE, where esophageal squamous epithelium damaged by acid reflux is replaced by a metaplastic, intestinal type epithelium. The specialized intestinal metaplasia of BE is associated with a 30 -125-fold increased risk for the development of esophageal adenocarcinoma, with the best estimates of cancer incidence of about 0.5-1.0% per year, i.e. one cancer per 100 -200 patients for each year of observation (6 -8). A middle-aged individual with BE for 20 years or more has an estimated 10 -20% lifetime risk of developing esophageal adenocarcinoma, which is similar to the risk of lung cancer among heavy smokers or of liver cancer amo...
CpG‐DNA and its related synthetic CpG oligodeoxynucleotides (CpG‐ODNs) play an important role in immune cell survival. It has been suggested that Akt is one of the CpG‐DNA‐responsive serine/threonine kinases; however, the target protein of CpG‐DNA that leads to Akt activation has not been elucidated. Here, we report that ex vivo stimulation of bone marrow‐derived macrophages (BMDMs) from mice lacking the catalytic subunit of DNA‐dependent protein kinase (DNA‐PKcs) results in defective phosphorylation and activation of Akt by CpG‐DNA. Unexpectedly, loss of the Toll‐like receptor 9 has a minimal effect on Akt activation in response to CpG‐DNA. Further in vitro analysis using purified DNA‐PK and recombinant Akt proteins reveals that DNA‐PK directly induces phosphorylation and activation of Akt. In addition, in BMDMs, DNA‐PKcs associates with Akt upon CpG‐DNA stimulation and triggers transient nuclear translocation of Akt. Thus, our findings establish a novel role for DNA‐PKcs in CpG‐DNA signaling and define a CpG‐DNA/DNA‐PKcs/Akt pathway.
AA amyloidosis is one of the principal causes of morbidity and mortality in captive cheetahs (Acinonyx jubatus), which are in danger of extinction, but little is known about the underlying mechanisms. Given the transmissible characteristics of AA amyloidosis, transmission between captive cheetahs may be a possible mechanism involved in the high incidence of AA amyloidosis. In this study of animals with AA amyloidosis, we found that cheetah feces contained AA amyloid fibrils that were different from those of the liver with regard to molecular weight and shape and had greater transmissibility. The infectious activity of fecal AA amyloid fibrils was reduced or abolished by the protein denaturants 6 M guanidine⅐HCl and formic acid or by AA immunodepletion. Thus, we propose that feces are a vehicle of transmission that may accelerate AA amyloidosis in captive cheetah populations. These results provide a pathogenesis for AA amyloidosis and suggest possible measures for rescuing cheetahs from extinction.feces ͉ transmissibility
Highlights d Loss of METTL3 inhibits proliferation and differentiation of hematopoietic stem cells d Depletion of m 6 A results in aberrant dsRNA formation of long m 6 A-modified transcripts d Loss of METTL3 induces deleterious innate immune responses in hematopoiesis d Mavs and Rnasel depletion partially rescue defects in Vav-Cre + -Mettl3 fl/
Background Cumulative data has shown that microRNAs (miRNAs) are involved in the etiology and prognosis of colorectal cancer (CRC). Genetic polymorphisms in pre-miRNA genes may influence the biogenesis and functions of their host miRNAs. However, whether these polymorphisms are associated with CRC prognosis remains unknown. Methods We analyzed the effects of seven single nucleotide polymorphisms (SNPs) in pre-miRNA genes on the prognosis of a Chinese population with 408 CRC patients with surgically-resected adenocarcinoma. Results Two SNPs were identified to be significantly associated with recurrence-free survival and overall survival of the patients. The most significant SNP was rs6505162 in pre-miR-423. Compared to the homozygous wild-type genotype, the variant-containing genotypes of this SNP were significantly associated with both the overall survival (HR=2.12, 95% CI1.34–3.34, P=0.001) and the recurrence-free survival (HR=1.59, 95% CI1.08–2.36, P=0.019). Another SNP, rs4919510 in pre-miR-608, was also associated with altered recurrence-free survival (HR=0.61, 95% CI 0.41–0.92, P=0.017). These effects were evident only in patients receiving chemotherapy but not in those without chemotherapy. In addition, the combined analysis of the two SNPs conferred a 2.84-fold (95% CI 1.50–5.37, P=0.001) increased risk of recurrence and/or death. Similarly, this effect was only prominent in those receiving chemotherapy (P<0.001) but not in those without chemotherapy (P=0.999). Conclusions Our data suggest that genetic polymorphisms in pre-miRNA genes may impact CRC prognosis especially in patients receiving chemotherapy, a finding that warrants further independent validation. Impact This is one of the first studies showing a prognostic role of pre-miRNA gene SNPs in CRC.
Veterans Affairs Center for Health Equity Research and Promotion.
, and develop few if any amyloid deposits spontaneously. 10 months after amyloid injection, deposits were detected in the tongue, stomach, intestine, lungs, heart, liver, and kidneys. The intensity of deposition increased thereafter, whereas no amyloid was detected in distilled water-injected SAMR1 mice, even after 20 months. The deposited amyloid was composed of endogenous APOAIIB with a different amyloid fibril conformation. The injection of these amyloid fibrils of APOAIIB (AApoAII(B)) induced earlier and more severe amyloidosis in SAMR1 mice than the injection of AApoAII(C) amyloid fibrils. Thus, AApoAII(C) from amyloidogenic mice could induce a conformational change of less amyloidogenic APOAIIB to a different amyloid fibril structure, which could also induce amyloidosis in the less amyloidogenic strain. These results provide important insights into the pathogenesis of amyloid diseases.
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