Expression of ACE2, TMPRSS2, and SARS-CoV-2 nucleocapsid protein in gastrointestinal tissues from COVID-19 patients and association with gastrointestinal symptoms.

BACKGROUND: Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect the gastrointestinal (GI) tract in coronavirus disease 2019 (COVID-19) patients, the mechanism of GI tract injury is largely unknown. We aimed to study the potential factors that cause COVID-19 GI symptoms. METHODS: We investigated the expression and co-localization of angiotensin converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), SARS-CoV-2 nucleocapsid protein (NP), and the severity of inflammation in GI tissues from COVID-19 patients (n = 19) by immunofluorescence and histopathologic staining, and then studied their associations with GI symptoms. RESULTS: Infected stomach tissues showed significantly higher ACE2 expression than uninfected ones, while infected duodenum tissues showed significantly higher TMPRSS2 expression than uninfected ones. The expression of TMPRSS2 exhibited a moderate correlation with viral NP across different GI tissues, while no significant association was observed between ACE2 and viral NP. Some GI symptoms such as diarrhea and nausea, were related to the expression level of ACE2, TMPRSS2 or the severity of inflammation. Furthermore, age and elevated aspartate transaminase were major risk factors for disease progression. CONCLUSIONS: ACE2 and TMPRSS2 were essential proteins in the SARS-CoV-2 infection of GI tract, while TMPRSS2 rather than ACE2 may play a more important role. GI symptoms may derive from the host receptor expression level and pro-inflammatory response in COVID-19 patients after viral infection of GI tissues, and further exacerbate the disease. So targeting TMPRSS2 and inflammation may represent an effective strategy for treating COVID-19 patients with GI symptoms.

Helicobacter pylori promotes inflammatory factor secretion and lung injury through VacA exotoxin-mediated activation of NF-κB signaling.

Previous reports have shown that Helicobacter pylori (H. pylori) infection is associated with respiratory diseases. However, the pathogenesis remains unclear. Vacuolating cytotoxin A (VacA) is a major H. pylori exotoxin. In this study, we investigated the signaling pathways involved in the inflammatory response to H. pylori infection and VacA. Mice were treated with H. pylori and VacA, and histopathological analysis of lung tissues was performed using hematoxylin-eosin, Masson's trichrome, and periodic acid Schiff staining. The secretion of inflammatory cytokines was evaluated by enzyme-linked immunosorbent assay. The expression of VacA, nuclear factor-kappa B (NF-κB), and p65 NF-κB was analyzed by Western blotting and immunofluorescence. Cell proliferation and apoptosis were assessed using the MTS assay and flow cytometry, respectively. In mice, H. pylori infection and VacA treatment promoted the secretion of the inflammatory factors interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α), IL-6, and IL-8, increased p65 NF-κB protein phosphorylation, and induced lung injury. Furthermore, H. pylori infection promoted VacA production. In an in vitro cell model, VacA treatment significantly suppressed the proliferation of WI-38 and BEAS-2B cells, promoted apoptosis, induced TNF-α, IL-1ß, IL-6, and IL-8 secretion, and promoted p65 NF-κB protein phosphorylation and NF-κB nuclear transfer. The NF-κB inhibitor BAY11-7082 alleviated VacA-induced inflammation and apoptosis and increased cell viability. In conclusion, VacA promotes the secretion of inflammatory factors and induces lung injury through NF-κB signaling.

Dynamic of Composition and Diversity of Gut Microbiota in Triatoma rubrofasciata in Different Developmental Stages and Environmental Conditions.

Triatoma rubrofasciata (T. rubrofasciata), one kind of triatomine insects, is the vector of Trypanosoma cruzi (T. cruzi), which lead to American trypanosomiasis. Although the gut microbiome may play an essential role in the development and susceptibility of triatomine, there is limited research on the gut microbiota of T. rubrofasciata. To elucidate the effect of the vector's developmental stages and environmental conditions on the gut microbiome, we employed 16S rRNA gene sequencing to profile the gut bacterial community diversity and composition of T. rubrofasciata. Significant shifts were observed in the overall gut microbe diversity and composition across the development of T. rubrofasciata and specific bacteria were detected in different stages. Serratia and Burkholderia-Caballeronia-Paraburkholderia were dominant in the 1st nymphal stage, while the abundance of Staphylococcus was low in the 1st nymphal stage. Oceanicaulis were undetectable in the adult stage and Odoribacter peaked in the 2nd nymphal stage. Moreover, Staphylococcus was correlated negatively with Serratia. Likewise, the total gut microbiota diversity and composition of T. rubrofasciata differentiated significantly by environmental conditions. The ingestion of a bloodmeal increased alpha diversity of gut bacterial communities, and Staphylococcus was more abundant in laboratory-reared bugs whereas Enterococcus enriched in wild-caught bugs. Furthermore, Pantoea was negatively correlated with Staphylococcus, and positively related to Bacillus only. The phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) algorithm showed obvious metagenomic functional differences by environmental conditions, and Chagas disease relevant pathway was enriched in wild-caught T. rubrofasciata.

Alterations of Gut Microbiome and Metabolite Profiling in Mice Infected by Schistosoma japonicum.

Schistosoma japonicum (S. japonicum) is one of the etiological agents of schistosomiasis, a widespread zoonotic parasitic disease. However, the mechanism of the balanced co-existence between the host immune system and S. japonicum as well as their complex interaction remains unclear. In this study, 16S rRNA gene sequencing, combined with metagenomic sequencing approach as well as ultraperformance liquid chromatography-mass spectrometry metabolic profiling, was applied to demonstrate changes in the gut microbiome community structure during schistosomiasis progression, the functional interactions between the gut bacteria and S. japonicum infection in BALB/c mice, and the dynamic metabolite changes of the host. The results showed that both gut microbiome and the metabolites were significantly altered at different time points after the infection. Decrease in richness and diversity as well as differed composition of the gut microbiota was observed in the infected status when compared with the uninfected status. At the phylum level, the gut microbial communities in all samples were dominated by Firmicutes, Bacteroidetes, Proteobacteria, and Deferribacteres, while at the genus level, Lactobacillus, Lachnospiraceae NK4A136 group, Bacteroides, Staphylococcus, and Alloprevotella were the most abundant. After exposure, Roseburia, and Ruminococcaceae UCG-014 decreased, while Staphylococcus, Alistipes, and Parabacteroides increased, which could raise the risk of infections. Furthermore, LEfSe demonstrated several bacterial taxa that could discriminate between each time point of S. japonicum infection. Besides that, metagenomic analysis illuminated that the AMP-activated protein kinase (AMPK) signaling pathway and the chemokine signaling pathway were significantly perturbed after the infection. Phosphatidylcholine and colfosceril palmitate in serum as well as xanthurenic acid, naphthalenesulfonic acid, and pimelylcarnitine in urine might be metabolic biomarkers due to their promising diagnostic potential at the early stage of the infection. Alterations of glycerophospholipid and purine metabolism were also discovered in the infection. The present study might provide further understanding of the mechanisms during schistosome infection in aspects of gut microbiome and metabolites, and facilitate the discovery of new targets for early diagnosis and prognostic purposes. Further validations of potential biomarkers in human populations are necessary, and the exploration of interactions among S. japonicum, gut microbiome, and metabolites is to be deepened in the future.

Myricetin Possesses Anthelmintic Activity and Attenuates Hepatic Fibrosis via Modulating TGFß1 and Akt Signaling and Shifting Th1/Th2 Balance in Schistosoma japonicum-Infected Mice.

Schistosomiasis is a zoonotic and debilitating parasitic disease caused by Schistosoma japonicum. Praziquantel remains the choice for treating schistosomiasis, but its efficacy could be hampered by emergence of resistance. In this study, using large-scale drug screening, we selected out myricetin, a natural flavonol compound, having a good anti-schistosome effect. We found that myricetin exhibited dose and time-dependent insecticidal effect on S. japonicum in vitro, with an LC50 of 600 µM for 24 h, and inhibited female spawning. The drug mainly destroyed the body structure of the worms and induced apoptosis of the worm cells, which in turn led to death. In addition, oral administration of myricetin in mice infected with S. japonicum showed a deworming effect in vivo, as evidenced by a significant reduction in the liver egg load. H&E staining, quantitative RT-PCR, and Western blotting assays showed that myricetin significantly alleviated liver fibrosis in mice infected with S. japonicum. Myricetin also effectively inhibited the expression of TGFß1, Smad2, phospho-Smad2, Smad3, phospho-Smad3, ERK, phospho-ERK, Akt, and phospho-Akt in the liver of infected mice, suggesting that myricetin attenuated liver fibrosis in mice via modulating TGFß1 and Akt signaling. Flow cytometric analysis of Th subtypes (Th1/Th2/Th17/Treg) in the mouse spleen further revealed that myricetin significantly increased the percentage Th1 cells in infected mice and reduced the proportion of Th2 cells and Th17 cells. Immunology multiplex assay further showed that myricetin attenuated S. japonicum-induced rise in the plasma levels of IL-4, IL-5, IL-10, IL-13, and IL-17A in infected mice while increasing the plasma contents of IFN-γ, IL-12, and IL-7. In conclusion, our study provides the first direct evidence that myricin possesses potent anti-schistosome activities in vitro and in vivo, and offers new insights into the mechanisms of action by myricetin. The present findings suggest that myricetin could be further explored as a therapeutic agent for S. japonicum.

Practical Experience of Endoscope Reprocessing and Working-Platform Disinfection in COVID-19 Patients: A Report from Guangdong China during the Pandemic.

BACKGROUND: No consensus exists regarding which procedures should be performed to disinfect endoscopes and working platforms after COVID-19 patients have undergone endoscopy. METHODS: We analyzed the disinfection quality of endoscopes and working platforms after 11 COVID-19 patients had undergone endoscopy. CONCLUSIONS: For endoscopic preprocessing at the bedside, a key disinfection step is using a multienzyme stock solution. The nucleic acid tests for endoscopists, washers, endoscopes, and working platforms were all negative. Based on our experience with the 11 COVID-19 patients who had undergone endoscopy, we provide an endoscopic reprocessing method for the bedside endoscopic diagnosis and treatment of COVID-19 patients for reference.

Taxonomic integrative and phylogenetic identification of the first recorded Triatoma rubrofasciata in Zhangzhou, Fujian Province and Maoming, Guangdong Province, China.

BACKGROUND: Most species of Triatominae live exclusively in Latin America. However, one species, Triatoma rubrofasciata, has been recorded in the Americas as well as in various port areas in Africa and Asia. An increasing number of T. rubrofasciata have been reported in southern China in recent years. However, the origin of this invasive insect vector in China remains unknown, therefore, accurate identification and phylogenetic analysis of the bugs are urgently needed. METHODS: A total of seven triatomine insect specimens were found and collected from Maoming City, Guangdong Province, China (GDMM) and Zhangzhou City, Fujian Province, China (FJZZ), respectively. The obtained insect vector specimens were observed under a dissecting microscope for morphological classification and then the genomic DNA was extracted, and the 16S ribosomal RNA (rRNA), 28S rRNA as well as cytochrome oxidase subunit I (COI) genes of the species were amplified and sequenced. Subsequently, molecular phylogenetic analyses based on multiple alignments of the above genes were conducted in order to identify the species and determine the phylogenetic origin approximation accurately. RESULTS: The triatomine insects collected from GDMM and FJZZ were identified as Triatoma rubrofasciata using morphological and genetic analyses. All of the Chinese T. rubrofasciata captured in FJZZ, GDMM and other localities in southern China, together with a Vietnamese and Brazilian strain, formed a new, cohesive clade. T. rubrofasciata in GDMM and FJZZ are likely derived from strains found in Vietnam or Brazil. CONCLUSIONS: To the best of our knowledge, this is the first record of the invasive insect T. rubrofasciata, which is likely derived from strains native to Vietnam or Brazil, in both Maoming City, Guangdong Province and Zhangzhou City, Fujian Province of China. A comparison of the DNA sequences of the 16 s rRNA, 28 s rRNA and COI genes confirmed the specific identification of T. rubrofasciata, and its potential origin in China is based on the phylogenetic analyses undertaken in this study. More targeted interventions and improved entomological surveillance are urgently needed to control the spread of this haematophagous insect in China.

Predictive Value of Anastomotic Blood Supply for Anastomotic Stricture After Esophagectomy in Esophageal Cancer.

BACKGROUND: Insufficient blood supply in the gastric tube is considered as a risk factor for postoperative anastomotic strictures in patients receiving esophagectomy, but the direct evidence is lacking. AIMS: We aimed to investigate the correlation between perioperative blood supply in the anastomotic area of the gastric tube and the formation of anastomotic strictures in the patients undergoing esophagectomy. METHODS: This prospective study included 60 patients with esophageal squamous cell carcinoma undergoing Ivor Lewis esophagectomy between March 2014 and February 2016, which were divided into stricture group (n = 13) and non-stricture group (n = 47) based on their severity of anastomotic strictures at 3 months post-operation. The perioperative anastomotic blood supply was measured using a laser Doppler flowmetry. The gastric intramucosal pH (pHi) was measured by a gastric tonometer within 72 h post-operation. The perfusion index and gastric pHi were compared between groups. RESULTS: The stricture group had a significantly lower blood flow index (P < 0.001) and gastric pHi values from day 1 to day 3 post-operation than the non-stricture group (all P < 0.001). In addition, Pearson correlation analysis showed that both the perfusion index and gastric pHi were significantly correlated with stricture size and stricture scores, respectively (r = 0.65 - 0.32, all P < 0.05). Furthermore, the multivariate logistic regression analysis showed that perfusion index was an influential factor associated with postoperative anastomotic strictures (OR 0.84. 95% CI 0.72-0.98, P = 0.026). CONCLUSION: These results suggested that poor blood supply in the anastomotic area of the gastric tube in the perioperative period was a risk factor for postoperative anastomotic strictures.

Down-regulation of lncTCF7 inhibits cell migration and invasion in colorectal cancer via inhibiting TCF7 expression.

The prognosis of colorectal cancer (CRC) is still very poor, owing to the high incidence of metastasis. Long noncoding RNA TCF7 (lncTCF7) has been shown to play critical roles in human CRC development and progression, but the molecular mechanisms of lncTCF7 in CRC are still unknown. This study aimed to explore the functions and molecular mechanisms of lncTCF7 on the migration and invasion of CRC cells. Notably, lncTCF7 was highly expressed in CRC cell lines relative to normal colonic epithelial cells. LncTCF7 knockdown significantly inhibited migration and invasion of CRC cells. In addition, TCF7 was highly expressed in CRC cell lines relative to that in normal colonic epithelial cells and its expression was significantly decreased in CRC cells transfected with si-lncTCF7. RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays showed that LncTCF7 recruits BAF170 to activate the TCF7 promoter and regulate TCF7 expression. TCF7 overexpression could promote migration and invasion in CRC cells transfected with si-lncTCF7, which reversed the effect of lncTCF7 on the migration and invasion of CRC cells. In conclusion, our data indicate that the downregulation of lncTCF7 significantly inhibits migration and invasion of CRC cells by inhibiting TCF7 expression, suggesting that lncTCF7 may be a potential target for CRC therapy.