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.

Antibiotic resistance profile of Helicobacter pylori to 14 antibiotics: a multicenter study in Fujian, China.

Background and aim: Efficacy of Helicobacter pylori (H. pylori) eradication is related to the local antimicrobial resistance epidemiology. We aimed to investigate the antibiotic resistance of H. pylori in Fujian, China. Methods: H. pylori-infected patients in four centers were enrolled in the study from Oct 2019 to Jan 2022. The bacteria were isolated, cultured and identified from the biopsy of patients' gastric mucosa samples. Antimicrobial susceptibility testing was performed by a modified broth microdilution method for H. pylori to seven guideline-recommended antibiotics and seven potential choices for H. pylori eradication. Results: A total of 205 H. pylori strains were isolated. The resistance rates of amoxicillin (AMX), amoxicillin and clavulanate potassium (AMC), cefixime (CFM), gentamicin (GEN), tetracycline (TET), doxycycline (DOX), azithromycin (AZM), clarithromycin (CLR), levofloxacin (LVFX), sparfloxacin (SPFX), metronidazole (MTZ), tinidazole (TID), rifampicin (RFP) and furazolidone (FZD) were 11.22%, 12.20%, 7.32%, 12.20%, 4.88%, 4.39%, 44.39%, 43.90%, 30.24%, 21.46%, 40.98%, 45.85%, 5.37% and 10.24%, respectively. The rates of pan-sensitivity, single, double, triple and multiple resistance for seven guideline-recommended antibiotics were 32.68%, 30.24%, 13.17%, 7.76%, and 14.15%, respectively. The main double-resistance patterns were CLR+MTZ (10/205, 5%) and CLR+LVFX (9/205, 4%). The main triple-resistance pattern was CLR+MTZ+ LVFX (15/205, 7%). Conclusions: In Fujian, the prevalence of H. pylori resistance to AZM, CLR, LVFX, SPFX, MTZ, and TID was high, whereas that to AMX, AMC, GEN, CFM, TET, DOX, RFP and FZD was relatively low. CFM and DOX are promising new choices for H. pylori eradication.

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.

Minimum inhibitory concentrations of commonly used antibiotics against Helicobacter Pylori: A multicenter study in South China.

AIM: To determine the minimum inhibitory concentrations (MICs) of commonly used antibiotics against Helicobacter Pylori (H. pylori) in South China and compare their resistance rates by using EUCAST breakpoints and other breakpoints. METHODS: Patients who had not previously received H. pylori treatment in clinical centers in South China were enrolled in this study from 2017 to 2020. Gastric biopsies were obtained for H. pylori culture. The MICs of amoxicillin (AMX), clarithromycin (CLA), metronidazole (MTZ), levofloxacin (LEV), tetracycline (TET) and furazolidone (FZD) were tested by broth microdilution method and assessed by two different breakpoints. ATCC43504 standard strain served as a control. RESULTS: A total of 208 H. pylori strains were isolated from patients' biopsy samples. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for H. pylori were 0.0156-256mg/L (MIC50 0.125mg/L, MIC90 4mg/L), 0.0156- >256 mg/L (MIC50 0.0312mg/L, MIC90 64mg/L), 0.0156- >256mg/L (MIC50 8mg/L, MIC90 256mg/L), 0.0156-256mg/L (MIC50 0.25mg/L, MIC90 16mg/L), 0.0156-256mg/L (MIC50 0.0625mg/L, MIC90 4mg/L), and 0.0156- >256mg/L (MIC50 0.0312mg/L, MIC90 2mg/L), respectively. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for ATCC43504 strain were 0.25mg/L, 0.0625mg/L, 64mg/L, 0.5mg/L, 1mg/L and 0.25mg/L, respectively. The resistance rate of FZD was 11.05%. The overall resistance rates according to EUCAST breakpoints and other breakpoints were 57.21% and 14.90% for AMX (p<0.001), 38.94% and 38.94% for CLA (p = 1), 39.42% and 50.96% for MTZ (p<0.001), 12.98% and 10.58% for TET (p = 0.025), 35.10% and 35.10% for LEV (p = 1), respectively. CONCLUSIONS: Our results demonstrate that AMX, FZD, and TET, but not MTZ, CLR or LEV, showed good anti-H. pylori activity in vitro in South China. When different breakpoints were used, similar results were found with CLA, and LEV, but not with AMX, MTZ, or TET.

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.

Modified sequential therapy vs quadruple therapy as initial therapy in patients with Helicobacter infection.

AIM: To evaluate the efficacy and safety of modified sequential therapy and to compare modified sequential therapy with standard quadruple therapy for Helicobacter pylori (H. pylori) eradication. METHODS: In total, 200 consecutive patients who were diagnosed with H. pylori-infected chronic gastritis by electronic endoscopy and rapid urease testing from December 2012 to October 2013 were enrolled in this study. The patients had not previously received H. pylori eradication treatment, and were randomized into two groups. The patients in Group A (n = 101) were treated with ilaprazole + bismuth potassium citrate + amoxicillin and clavulanate potassium + levofloxacin, and the patients in Group B (n = 99) were administered a modified sequential therapy composed of ilaprazole at 5 mg bid and amoxicillin and clavulanate potassium at 914 mg for the first five days followed by ilaprazole at 5 mg bid, furazolidone at 100 mg bid and levofloxacin at 500 mg qid for the next five days. Four to six weeks after the end of treatment, a 14C-urea breath test was performed for all the subjects to confirm the eradication of H. pylori. The intention-to-treat and per-protocol eradication rates were determined. RESULTS: A total of 190 of the 200 patients completed the study. All 200 patients were included in the intention-to-treat analysis, whereas 190 patients were included in the per-protocol analysis. In the intention-to-treat analysis, the rates of H. pylori eradication in Groups A and B were 85.15% (86/101) and 81.82% (81/99), respectively. In the per-protocol analysis, the H. pylori eradication rates in Groups A and B were 88.66% (86/97) and 87.09% (81/93), respectively. No significant difference was observed (χ(2) = 0.109, P = 0.741) in the eradication rate between Groups A and B. The rates of adverse effects observed in the groups were similar at 6.19% (6/97) for Group A and 7.53% (7/93) for Group B (P > 0.05). No mortality or major morbidities were observed in any of the patients. Symptomatic improvements in the presentation of stomachache, acid regurgitation, and burning sensation were not significantly different between the two groups. CONCLUSION: Ilaprazole-based 10-d standard quadruple therapy does not offer an incremental benefit over modified sequential therapy for the treatment of H. pylori infection, as both treatment regimens appear to be effective, safe, and well-tolerated as initial treatment options.