KIAA1429 promotes gastric cancer progression by destabilizing RASD1 mRNA in an m6A-YTHDF2-dependent manner.

BACKGROUND: KIAA1429, a regulatory subunit of the N6-methyladenosine (m6A) methyltransferase complex, has been implicated in the progression of various cancers. However, the role of KIAA1429 in gastric cancer (GC) and its underlying mechanisms remain elusive. This study aimed to investigate the role of KIAA1429 in GC and to elucidate the underlying mechanisms. METHODS: The expression patterns and clinical relevance of KIAA1429 in GC were assessed using quantitative real-time PCR (qRT-PCR), Western blotting, immunohistochemistry (IHC), and bioinformatic analysis. In vitro and in vivo loss- and gain-of-function assays, m6A dot blot assays, methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNA-seq, MeRIP-qPCR, dual luciferase reporter assays, RNA stability assays, RNA immunoprecipitation (RIP) assays, and RNA pull-down assays were performed to investigate the biological functions and underlying molecular mechanisms of KIAA1429 in GC. RESULTS: Both the mRNA and protein expression of KIAA1429 were greater in GC tissues than in normal gastric tissues. High KIAA1429 expression correlated positively with poor prognosis in GC patients. KIAA1429 not only promoted GC cell proliferation, colony formation, G2/M cell cycle transition, migration, and invasion in vitro but also enhanced GC tumor growth and metastasis in vivo. Mechanistically, KIAA1429 increased the m6A level of RASD1 mRNA and enhanced its stability in an m6A-YTHDF2-dependent manner, thereby upregulating its expression. RASD1 knockdown partially rescued the KIAA1429 knockdown-induced impairment of pro­oncogenic ability in GC cells. The expression levels of KIAA1429 and RASD1 were negatively correlated in GC tissues. CONCLUSIONS: KIAA1429 plays a pro­oncogenic role in GC by downregulating RASD1 expression through destabilizing RASD1 mRNA in an m6A-YTHDF2-dependent manner. KIAA1429 may serve as a prognostic biomarker and therapeutic target for GC.

Alterations of the duodenal mucosal microbiome in patients with metabolic dysfunction-associated steatotic liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is associated with altered gut microbiota; however, there has been a focus on fecal samples, which are not representative of the entire digestive tract. Mucosal biopsies of the descending duodenum were collected. Five regions of the 16S rRNA gene were amplified and sequenced. Other assessments conducted on the study subjects included body mass index, transient elastography, liver enzymes, and lipid profile. Fifty-one subjects (36 with MASLD and 15 controls) were evaluated. There was no significant difference between the two groups regarding alpha- or beta-diversity of the duodenal mucosal microbiota. Linear discriminant analysis effect size (LEfSe) analysis showed that the genera Serratia and Aggregatibacter were more abundant in the duodenal mucosa of patients with MASLD, whereas the duodenal mucosal microbiota of the healthy controls was enriched with the genus Petrobacter. PICRUSt2 analysis revealed that genes associated with amino acid degradation and carboxylate degradation were significantly enriched in the duodenal mucosal microbiota of patients with MASLD. Our findings reveal the duodenal mucosal microbiota in patients with MASLD, which could contribute to future studies investigating the causal relationship between duodenal microbiota and MASLD.

Bypassing large submucosal vessels during peroral endoscopic myotomy reduces operative time and intraoperative blood loss in patients with achalasia.

OBJECTIVE: Peroral endoscopic myotomy (POEM), a relatively, minimally invasive endoscopic procedure, is the first-line treatment for achalasia. The aim of this study is to compare procedure-related parameters and clinical outcomes between bypassing and performing prophylactic electrocoagulation of large submucosal vessels during POEM. METHODS: We retrospectively enrolled 112 patients with achalasia who had undergone POEM at our hospital between April 2017 and March 2023. Large submucosal vessels were bypassed to avoid injury during submucosal tunneling in the bypass group; whereas, large submucosal vessels were prophylactically treated by electrocoagulation in prophylactic electrocoagulation group. Procedure-related parameters, Eckardt score, and complications were compared between the two groups. RESULTS: The bypass group showed a significant reduction in the operative time and amount of intraoperative blood loss than prophylactic electrocoagulation group (37.11 ± 9.96 min vs. 58.80 ± 17.90 min, and 1 [interquartile range: 1-2] mL vs. 5 [interquartile range: 3-8] mL; P < 0.001). Eleven (17.5%) and 44 (89.8%) patients in the bypass and prophylactic electrocoagulation groups, respectively, required hemostatic forceps (P < 0.001). Furthermore, lower operative and hospitalization costs were recorded in the bypass group than those in prophylactic electrocoagulation group (P < 0.05). No statistically significant difference was found between the two groups in terms of submucosal tunnel length, myotomy length, clinical efficacy, or complications. CONCLUSIONS: Bypassing large submucosal vessels during POEM can reduce the operative duration and intraoperative blood loss, with no difference in clinical outcomes than the prophylactic electrocoagulation treatment.

Small intestine-targeted endoscopic bariatrics: Current status and future perspectives.

The global obesity epidemic shows no signs of slowing down. Endoscopic bariatric and metabolic therapies (EBMTs) are being increasingly adopted as treatment options for obesity and obesity-related comorbidities, due to their minimally invasive nature and ease of delivery. According to the site of action along the gastrointestinal tract, EBMTs can be divided into two categories: gastric EBMTs, and small intestine-targeted EBMTs. Unlike gastric EBMTs, which work through a volume-restricting mechanism leading to early satiety and reduced caloric intake, small intestine-targeted EBMTs can be metabolically beneficial through foregut and/or hindgut pathways independent of weight loss, and therefore have great potential for the treatment of obesity-related metabolic comorbidities such as type 2 diabetes. Although none of the small intestine-targeted EBMTs have been approved by the US Food and Drug Administration to date, their clinical efficacy and safety have been extensively explored in investigational trials. This review aims to summarize and provide a comprehensive understanding of small intestine-targeted EBMTs in clinical and preclinical settings, and to further discuss their potential mechanisms of action.

Prospective study of a new endoscopic duodenal-jejunal bypass sleeve in obese patients with nonalcoholic fatty liver disease (with video).

OBJECTIVES: To evaluate the safety and efficacy of a new endoscopic duodenal-jejunal bypass sleeve (DJBS) in obese patients with nonalcoholic fatty liver disease (NAFLD), while in situ for 3 months, and at 6 months postexplantation. METHODS: Patients with obesity and NAFLD were enrolled in this single-center, prospective study, wherein the TONGEE DJBS (Tangji Medical, Hangzhou, China) was implanted for 3 months. Primary outcomes were weight loss and changes in hepatic steatosis. Secondary outcomes included changes in liver enzymes, glycemic control, and lipid profile and device safety. RESULTS: Twenty-six patients (age 35.2 ± 7.2 years; 61.5% women) underwent DJBS implantation. At 3 months, bodyweight change from baseline was -8.0 ± 3.6 kg (P < 0.001), corresponding to 8.9 ± 4.0% of total bodyweight. Hepatic steatosis significantly improved based on controlled attenuation parameter, hepatic steatosis index, and fatty liver index (P < 0.001). Liver enzymes, insulin resistance, and metabolic parameters were also improved. At 6 months postexplantation, weight loss and improvements in hepatic steatosis and liver enzyme levels remained statistically significant. Only one patient had a serious adverse event, namely, upper gastrointestinal hemorrhage. CONCLUSIONS: Three-month TONGEE DJBS implantation resulted in significant weight loss and improvement in hepatic steatosis, liver enzymes, insulin resistance, and metabolic parameters in obese patients with NAFLD. Randomized controlled trials are required to further elucidate these initial findings.

Prevalence of possible sarcopenia in community-dwelling older Chinese adults: a cross-sectional study.

OBJECTIVES: To determine the prevalence of possible sarcopenia and its association with other conditions in older adults in Bengbu, China. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional study of 1082 community-dwelling Chinese people aged at least 60 years from March to June 2022. METHODS: Handgrip strength and information regarding associated conditions were collected. Possible sarcopenia was estimated based on handgrip strength with cut-off values (<28 kg in men; <18 kg in women) recommended by the Asia Working Group for Sarcopenia in 2019. Mann-Whitney U tests, χ2 tests and binary logistic regression analyses were used to explore relationships between possible sarcopenia and associated conditions. RESULTS: Possible sarcopenia was more prevalent in men (52.79%, n=246, age 79.43±7.33 years among men with possible sarcopenia) than in women (44.48%, n=274, age 78.90±7.71 years among women with possible sarcopenia). In men, possible sarcopenia positively correlated with high age (OR 2.658, 95% CI 1.758 to 4.019), physical inactivity (OR 2.779, 95% CI 1.646 to 4.691) and diabetes (OR 4.269, 95% CI 2.397 to 7.602), and negatively with hypertension (OR 0.586, 95% CI 0.384 to 0.893). The risk of possible sarcopenia in men decreased by 12.6% for every 1 kg/m2 increase of body mass index (OR 0.874, 95% CI 0.817 to 0.935). In women, possible sarcopenia positively correlated with high age (OR 3.821, 95% CI 2.677 to 5.455), physical inactivity (OR 2.185, 95% CI 1.488 to 3.210) and arthritis (OR 2.076, 95% CI 1.411 to 3.056). CONCLUSION: Possible sarcopenia is prevalent in older adults and the factors affecting possible sarcopenia are different in men and women. Health education about these target factors can be considered as a potential measure to prevent possible sarcopenia.

Incidence of colorectal cancer at different screening intervals after index colonoscopy and post-polypectomy: a meta-analysis of 811,181 participants.

OBJECTIVES: To examine the evidence on the incidence of colorectal cancers (CRCs) at a follow-up screening colonoscopy (after index colonoscopy and post-polypectomy) in individuals with no adenoma, low-risk adenomas, and high-risk adenomas. METHODS: We included studies reporting the incidence of CRCs at different screening intervals after index colonoscopy and post-polypectomy. The main outcome was pooled cumulative incidence rate of CRCs stratified by intervals of 3, 5, 10, and >10 years. RESULTS: Fourteen studies with 811,181 participants were analyzed, including 10 multicenter studies and 3 national CRC screening programs. The cumulative incidence of CRCs was 0.63% (95% confidence interval [CI]: 0.30, 0.97) in the high-risk-adenoma group at 3 years, 0.37% (95% CI: 0.13, 0.61) and 0.67% (95% CI: 0.36, 0.99) in the low-risk-adenoma group at 5 and 10 years, respectively, and 0.32% (95% CI: 0.20, 0.45) and 0.50% (95% CI: 0.30, 0.69) in the no-adenoma-group at 10 and >10 years, respectively. CONCLUSION: This meta-analysis summarizes the results of colonoscopy surveillance programs with detailed data support for different screening intervals. The data on date suggest that reasonable surveillance intervals are within 3 years for the high-risk-adenoma group, 5-10 years for the low-risk-adenoma group, and ≥10 years for the no-adenoma group.

Gut microbiome and microbial metabolites in NAFLD and after bariatric surgery: Correlation and causality.

Non-alcoholic fatty liver disease (NAFLD) is currently related to a heavy socioeconomic burden and increased incidence. Since obesity is the most prevalent risk factor for NAFLD, weight loss is an effective therapeutic solution. Bariatric surgery (BS), which can achieve long-term weight loss, improves the overall health of patients with NAFLD. The two most common surgeries are the Roux-en-Y gastric bypass and sleeve gastrectomy. The gut-liver axis is the complex network of cross-talking between the gut, its microbiome, and the liver. The gut microbiome, involved in the homeostasis of the gut-liver axis, is believed to play a significant role in the pathogenesis of NAFLD and the metabolic improvement after BS. Alterations in the gut microbiome in NAFLD have been confirmed compared to that in healthy individuals. The mechanisms linking the gut microbiome to NAFLD have been proposed, including increased intestinal permeability, higher energy intake, and other pathophysiological alterations. Interestingly, several correlation studies suggested that the gut microbial signatures after BS become more similar to those of lean, healthy controls than that of patients with NAFLD. The resolution of NAFLD after BS is related to changes in the gut microbiome and its metabolites. However, confirming a causal link remains challenging. This review summarizes characteristics of the gut microbiome in patients with NAFLD before and after BS and accumulates existing evidence about the underlying mechanisms of the gut microbiome.

Endoscopic Bariatric and Metabolic Therapies for Liver Disease: Mechanisms, Benefits, and Associated Risks.

Nonalcoholic fatty liver disease (NAFLD), including advanced-stage nonalcoholic steatohepatitis (NASH), is currently the most common chronic liver disease worldwide and is projected to become the leading indication for liver transplantation (LT). However, there are no effective pharmacological therapies for NAFLD. Endoscopic bariatric and metabolic therapies (EBMTs) are less invasive procedures for the treatment of obesity and its metabolic comorbidities. Several recent studies have demonstrated the beneficial effects of EBMTs on NAFLD/NASH. In this review, we summarize the major EBMTs and their mechanisms of action. We further discuss the current evidence on the efficacy and safety of EBMTs in people with NAFLD/NASH and obese cirrhotic LT candidates. The potential utility of EBMTs in reducing liver volume and perioperative complications in bariatric surgery candidates is also discussed. Moreover, we review the development of liver abscesses as a common serious adverse event in duodenal-jejunal bypass liner implantation.

Effects of Bariatric Endoscopy on Non-Alcoholic Fatty Liver Disease: A Comprehensive Systematic Review and Meta-Analysis.

Background and objective: Endoscopic bariatric and metabolic therapies (EBMTs) are emerging minimally invasive therapeutic options for obesity and its related complications, including non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the effects of EBMTs on NALFD in patients with obesity. Methods: Four databases were searched until Nov 2021. Randomized controlled trials (RCTs) and observational studies reporting liver-related outcomes following Food and Drug Administration (FDA)-approved and non-FDA-approved EBMTs were included. Liver parameters, metabolic parameters, and weight loss were evaluated. Risk of bias was assessed using the "risk of bias" tool in the Cochrane Collaboration for RCTs and the Methodological Index for Non-Randomized Studies criteria for observational studies. Results: Thirty-three studies with 1710 individuals were included. Regarding the effects of EBMTs on liver fibrosis, a significant decline of NAFLD Fibrosis Score, but not transient elastography-detected liver stiffness or Fibrosis-4 Index, was observed. EBMTs significantly improved liver steatosis (control attenuation parameter and Hepatic Steatosis Index), NAFLD Activity Score, and Homeostasis Model Assessment of Insulin Resistance. EBMTs reduced serum levels of alanine transaminase, aspartate aminotransferase, and gamma-glutamyl transpeptidase considerably. Moreover, EBMTs had reducing effects on the serum levels of triglycerides and total cholesterol as well as body weight. Conclusions: Our meta-analysis suggested that EBMTs could ameliorate NAFLD based on the evidence of improved liver steatosis, liver function, and insulin resistance. Large-scale, prospective, long-term studies are warranted to clarify the role of EBMTs in patients with different stages of NAFLD.

Efficacy and Safety of Endoscopic Resection for Small Gastric Gastrointestinal Stromal Tumors in Elderly Patients.

Background: Gastrointestinal stromal tumors (GISTs) are prevalent in elderly patients. Endoscopic resection has become popular for treating small (≤5 cm) gastric GISTs. However, little is known about the outcomes of endoscopic resection in elderly patients. Aim: To assess the efficacy and safety of endoscopic resection for small (≤5 cm) gastric GISTs in elderly patients (≥65 years old). Methods: A total of 260 patients (265 lesions) with gastric GISTs treated via endoscopic resection from January 2011 to May 2020 were retrospectively analyzed. Among them, 65 patients were ≥65 years old (elderly group), and 195 patients were <65 years old (nonelderly group). Clinicopathological characteristics, postoperative complications, and tumor recurrence rates between the two age groups were compared. Results: A total of 260 patients with primary small (≤5 cm) gastric GISTs were treated with endoscopic resection. The median ages of the elderly and nonelderly groups were 68 (range 65-83) years and 55 (range 32-64) years, respectively. Elderly patients showed a higher incidence of comorbidities compared with nonelderly patients (61.5% versus 32.3%s, respectively; p < 0.001). All elderly patients and 99.0% of nonelderly patients underwent en bloc resection; only two nonelderly patients received piecemeal resection. No significant differences were found regarding postoperative complications or tumor recurrence rates between the two groups. Conclusions: Although elderly patients had more comorbidities than nonelderly patients, both groups had similar postoperative complications and recurrence rates. We suggest that endoscopic resection performed by experienced endoscopists is safe and effective for treating small (≤5 cm) gastric GISTs in elderly patients.

Comparative Study of the Nutritional Composition and Antioxidant Ability of Soups Made from Wild and Farmed Snakehead Fish (Channa Argus).

In recent years, fish soup has become an important product for commercial processing of fish due to its health effects. In this study, nutritional composition and antioxidant ability of soups prepared from farmed and wild snakehead fish were analyzed (hereafter FS and WS soup, respectively). For the FS soup, the proximate composition of protein, fat, ash, free amino acids, and soluble peptides were 2.55%, 0.89%, 0.92%, 0.47%, and 0.62%, respectively. The total amino acid was 390.11 mg/ g, and the proportion of essential amino acid was 27.59%. The total fatty acid was 13.64 g/100 g, of which monounsaturated fatty acid was 5.78 g/100 g, n-6 polyunsaturated fatty acid 3.50 g/100 g, and n-3 polyunsaturated fatty acid 0.41 g/100 g, respectively. The contents of Zn and Ca were 9.04 mg/ kg and 1.13 mg/ g, respectively. The DPPH radical-scavenging ability, Fe2+ chelating ability, and hydroxyl radical-scavenging ability was 57.89%, 21.21%, and 25.61%, respectively. Overall, there was no obvious difference in the nutritional composition and antioxidant activity between the FS and WS soups. The protein content (1.90%) of the WS soup was relatively lower, but the total fatty acid (16.22 g/100 g), MUFA (7.17 g/100 g), and Zn (12.57 mg/ kg) contents were significantly higher.

Curcumin Improves Epithelial Barrier Integrity of Caco-2 Monolayers by Inhibiting Endoplasmic Reticulum Stress and Subsequent Apoptosis.

Curcumin is a natural polyphenol and is supposed to possess antioxidant, anti-inflammatory, anticancer, and antiapoptotic properties. Although some studies have reported the therapeutic effects of curcumin on ulcerative colitis (UC), the specific mechanism remains unclear. An in vitro coculture model of Caco-2 and differentiated THP-1 cells was established. After administration of curcumin (10 µM), Western blot analysis was performed to evaluate the protein levels of tight junction (TJ) proteins zonula occludens- (ZO-) 1 and claudin-1. Annexin V-APC/7-AAD assays and flow cytometry were conducted to assess Caco-2 cell apoptosis. The expression levels of oxidative stress and endoplasmic reticulum stress- (ERS-) related molecules were determined by Western blot analysis. Curcumin administration significantly upregulated ZO-1 and claudin-1 protein levels and reduced Caco-2 cell apoptosis. The protein levels of oxidative stress markers inducible nitric oxide synthase (iNOS) and γH2AX and ERS-induced apoptosis-related molecules C/EBP homologous protein (CHOP) and cleaved caspase-12 were significantly downregulated upon curcumin treatment. Furthermore, curcumin administration greatly blocked the protein kinase-like endoplasmic reticulum kinase- (PERK-) eukaryotic translation initiation factor 2α- (eIF2α-) activating transcription factor 4- (ATF4-) CHOP signaling pathway. Curcumin enhanced intestinal epithelial barrier integrity in the in vitro coculture model by upregulating TJ protein expressions and reducing intestinal epithelial cell apoptosis. The potential mechanisms may be suppression of ERS and subsequent apoptosis.

Genetic and antigenic heterogeneity of GI-1/Massachusetts lineage infectious bronchitis virus variants recently isolated in China.

Four GI-1/Massachusetts-type (GI-1/Mass-type) infectious bronchitis virus (IBV) strains were isolated and the complete genomes of these isolates, coupled with the Mass-type live-attenuated vaccine H120 and the Mass-type pathogenic M41 strains, were sequenced in the present study. Our results show that isolates LJL/140820 and I0306/17 may be derived from the Ma5 (another Mass-type live-attenuated vaccine strain) and H120 vaccine strains, respectively. The I1124/16 strain was found to be a M41 variant that likely resulted from nucleotide accumulated mutations in the genome. Consistently, the results of the virus neutralization test showed that isolate I1124/16 was antigenically related but slight different from the M41. Our results from the protection experiments pointed out that chickens immunized with H120 failed to eliminate viral shedding after infection with the isolate I1124/16, which was different from that of M41; this result was consistent to the field observation and further implicated that the variant IBV isolate I1124/16 was antigenic different from the M41 strain. Furthermore, the I1124/16 was found to have comparable but slightly lower pathogenicity with the M41 strain. More studies based on the reverse genetic techniques are needed to elucidate the amino acids in the S1 subunit of spike protein contributing to the altered antigenicity of the isolate I1124/16. In addition, an IBV isolate, LJL/130609, was found to be originated from recombination events between the I1124/16- and Connecticut-like strains. Our results from the virus neutralization test also showed that isolates LJL/130609 and I1124/16 were antigenic closely related. Hence, there are at least 3 different genetic evolution patterns for the circulation of the GI-1/Mass-type IBV field strains in China. The differences of vaccines used, the field conditions and genetic pressures between different flocks, likely account for the emergence, evolution patterns, and characteristics of the Mass-type IBV strains.

Resveratrol synergizes with cisplatin in antineoplastic effects against AGS gastric cancer cells by inducing endoplasmic reticulum stress­mediated apoptosis and G2/M phase arrest.

Gastric cancer (GC) is a common gastrointestinal malignancy, and cisplatin (DDP) is an important component of chemotherapeutic regimens for GC. However, the application of DDP is limited by its dose­dependent systemic toxicity. Resveratrol (RES) is a natural polyphenol compound that has chemopreventive and therapeutic effects against various cancers, including GC. However, whether RES can sensitize GC cells to DDP remains unknown. Following RES/DDP combination treatment, cell viability was determined by Cell Counting Kit­8 and colony­forming assays, and cell apoptosis and the cell cycle were detected by FITC­Annexin V/PI staining assay and PI staining assay, respectively, followed by flow cytometry. Moreover, western blotting was performed to evaluate the protein expression levels, and the intracellular free Ca2+ concentration was determined by a Fluo­4 AM probe after cell cotreatment with RES and DDP. The present results demonstrated that RES/DDP combination treatment significantly inhibited cell viability, promoted cell apoptosis and induced G2/M phase arrest in AGS cells. In addition, it was determined that RES combined with DDP significantly increased the levels of Bax, cleaved poly­ADP­ribose polymerase (PARP), glucose­regulated protein 78 (GRP78), PRKR­like ER kinase (PERK), p­eukaryotic translation initiation factor 2α (p­eIF2α), CCAAT/enhancer binding protein homologous protein (CHOP) and cleaved caspase­12, whereas Bcl­2 expression was downregulated following RES/DDP cotreatment. Moreover, RES/DDP cotreatment significantly upregulated phosphorylated cyclin­dependent kinase 1 (p­CDK1, Tyr15), p21Waf1/Cip1 and p27Kip1 protein levels and downregulated Cdc25C protein levels. In conclusion, RES and DDP synergistically inhibited the growth of the gastric adenocarcinoma cell line AGS by inducing endoplasmic reticulum stress­mediated apoptosis and G2/M phase arrest via activation of the PERK/eIF2α/activating transcription factor 4 (ATF4)/CHOP signaling pathway and caspase­12 and by inactivating the CDK1­cyclin B1 complex. These results indicated that RES is a promising adjuvant for DDP during GC chemotherapy.

Genetic, Antigenic, and Pathogenic Characteristics of Infectious Bronchitis Virus GI-7/TW-II in China.

Nine infectious bronchitis virus (IBV) strains belonging to the GI-7 lineage were isolated between 2009 and 2017 in China. Phylogenetic analysis and comparisons of full-length sequences of the S1 gene suggested that the GI-7 lineage should be further classified as Taiwan (TW)-I and TW-II sublineages, which correspond to the previous TW-I and TW-II genotypes. The nine IBV strains were clustered in the TW-II sublineage. Further investigation revealed that viruses in the TW-I and TW-II were not only genetically but also antigenically different. Moreover, the TW-II sublineage contained various clades and recombinants. A recombinant was found to originate from recombination events between field strains (TW-II ck/CH/LJL/090608- and GI-19 ck/ CH/LDL/091022-like viruses) in which the recombination in the S1 subunit coding sequences had led to changes in antigenicity of the viruses. A more in-depth investigation demonstrated that TW-II viruses appear to have undergone a significant evolution following introduction in mainland China, which resulted in the viruses diverging into different clades. The viruses between the different clades in TW-II sublineage exhibited a significant change in genetic and antigenic characteristics. In addition, the five TW-II viruses selected on the basis of the results of S1 nucleotide sequence phylogenetic trees showed different pathogenicity to specific-pathogen-free chickens, although they could induce nephritis in the infected chickens and thus were identified as nephropathogenic strains.

Características genéticas, antigénicas y patógenas del virus de la bronquitis infecciosa GI-7/TW-II en China. Nueve cepas del virus de la bronquitis infecciosa (IBV) que pertenecen al linaje GI-7 se aislaron entre 2009 y 2017 en China. El análisis filogenético y las comparaciones de las secuencias completas del gene S1 sugirieron que el linaje GI-7 debería ser clasificado además como sublinajes TW-I y TW-II, que corresponden a los anteriores genotipos TW-T y TW-II. Las nueve cepas del virus de la bronquitis infecciosa se agruparon en el sublinaje TW-II. La investigación adicional reveló que los virus en TW-I y TW-II no solo eran tanto genéticamente como antigénicamente diferentes. Además, el sublinaje TW-II contenía varios clados y recombinantes. Se descubrió que un recombinante se originaba a partir de eventos de recombinación entre cepas de campo (virus similares a las cepas TW-II ck/CH/LJL/090608 y GI-19 ck/CH/LDL/091022) en los que la recombinación en las secuencias de codificación de la subunidad de S1 condujo a cambios en la antigenicidad de los virus. Una investigación más profunda demostró que los virus TW-II parecen haber experimentado una evolución significativa después de su introducción en China continental, lo que resultó en la divergencia de los virus en diferentes clados. Los virus entre los diferentes clados en el sublinaje TW-II exhibieron un cambio significativo en las características genéticas y antigénicas. Además, los cinco virus TW-II seleccionados con base en los resultados de los árboles filogenéticos de las secuencias de nucleótidos de S1 mostraron patogenicidad diferente en los pollos libres de patógenos específicos, aunque pudieron inducir nefritis en los pollos infectados y, por lo tanto, se identificaron como cepas nefropatógenas.

A highly pathogenic GI-19 lineage infectious bronchitis virus originated from multiple recombination events with broad tissue tropism.

In the present study, an IBV strain I0305/19 was isolated from a diseased commercial broiler flock in 2019 in China with high morbidity and mortality. The isolate I0305/19 was clustered together with viruses in sublineage D of GI-19 lineage on the basis of the complete S1 sequence analysis. Isolate I0305/19 and other GI-19 viruses isolated in China have the amino acid sequence MIA at positions 110-112 in the S protein. Further analysis based on the complete genomic sequence showed that the isolate emerged through at least four recombination events between GI-19 ck/CH/LJS/120848- and GI-13 4/91-like strains, in which the S gene was found to be similar to that of the GI-19 ck/CH/LJS/120848-like strain. Pathological assessment showed the isolate was a nephropathogenic IBV strain that caused high morbidity of 100 % and mortality of 80 % in 1-day-old specific-pathogen-free (SPF) chicks. The isolate I0305/19 exhibited broader tropisms in different tissues, including tracheas, lungs, bursa of Fabricius, spleen, liver, kidneys, proventriculus, small intestines, large intestines, cecum, and cecal tonsils. Furthermore, subpopulations of the virus were found in tissues of infected chickens; this finding is important in understanding how the virulent IBV strains can potentially replicate and evolve to cause disease. This information is also valuable for understanding the mechanisms of replication and evolution of other coronaviruses such as the newly emerged SARS-CoV-2.

Multiple recombination events between field and vaccine strains resulted in the emergence of a novel infectious bronchitis virus with decreased pathogenicity and altered replication capacity.

In this study, we isolated and identified 2 infectious bronchitis virus (IBV) strains from layer chickens soon after vaccination with the Massachusetts-Connecticut bivalent vaccine (Conn) and H120 and 4/91 booster vaccines in China in 2011. The results of cross-virus-neutralization tests and phylogenetic analysis of the S1 subunit of spike gene of these vaccine strains and other reference strains showed that strain LJL/110302 was of GI-19 lineage, whereas LLN/111169 was of the GI-1 lineage of the Conn serotype. Further comparative genomic analysis revealed that LLN/111169, an IBV strain with novel traits, originated from multiple recombination events (at least 3 recombination sites) between GI-19 and the Conn and 4/91 vaccine strains. LLN/111169 was pathogenic to specific pathogen-free (SPF) chickens. This is of prime importance because while IBV prevention measures worldwide are mainly dependent on modified live vaccine strains, our results showed that recombination between field and vaccine strains has produced a novel pathogenic IBV strain. In addition, LLN/111169 showed relatively broad tissue tropism (trachea, lungs, kidneys, and cecal tonsils) in infected SPF chickens. These results emphasize the importance of IBV surveillance in chicken flocks.

Genetic, antigenic and pathogenic characterization of avian coronaviruses isolated from pheasants (Phasianus colchicus) in China.

Two viruses were isolated in 2017 from commercial pheasants with severe clinical signs and mortality in Shandong and Anhui provinces, China, respectively. We examined the pathogenic effects of the viruses in chicken embryos and the size and morphology of the virus particles, performed phylogenetic analysis based on the S1 gene and complete genomic sequences, and examined the antibody responses against infectious bronchitis virus (IBV). The results suggested that the viruses I0623/17 and I0710/17 were avian coronaviruses and were identified as pheasant coronaviruses (PhCoV), with greatest similarity to IBV. Further investigations of the antigenicity, complete genome organization, substitutions in multiple genes, and viral pathogenicity, replication, and shedding in chickens and pheasants showed obvious differences between PhCoV and IBV in terms of antigenicity, and viral pathogenicity, replication, and shedding in chickens and pheasants. The close genetic relationship, but obvious differences between PhCoVs and IBVs suggested the IBVs could be the ancestors of PhCoVs, and that PhCoVs isolated from different outbreaks may have evolved independently from IBVs circulating in the specific region by adaption in pheasants. This hypothesis was supported by analysis of the S1 gene fragments of the two PhCoVs isolated in the current study, as well as PhCoVs isolated in the UK and selected IBV strains. Such analyses indicated different evolution patterns and different tissue tropisms between PhCoVs isolated in different outbreaks. Further studies are needed to confirm this hypothesis by studying the complete genomic sequences of PhCoVs from different outbreaks and the pathogenicity of IBVs in pheasants to compare and clarify the relationships between PhCoVs and IBVs.

Blockage of ETS homologous factor inhibits the proliferation and invasion of gastric cancer cells through the c-Met pathway.

BACKGROUND: Gastric cancer (GC) is one of the most common and deadliest types of cancer worldwide due to its delayed diagnosis and high metastatic frequency, but its exact pathogenesis has not been fully elucidated. ETS homologous factor (EHF) is an important member of the ETS family and contributes to the pathogenesis of multiple malignant tumors. To date, whether EHF participates in the development of GC via the c-Met signaling pathway remains unclear. AIM: To investigate the role and mechanism of EHF in the occurrence and development of GC. METHODS: The expression of EHF mRNA in GC tissues and cell lines was measured by quantitative PCR. Western blotting was performed to determine the protein expression of EHF, c-Met, and its downstream signal molecules. The EHF expression in GC tissues was further detected by immunohistochemical staining. To investigate the role of EHF in GC oncogenesis, small interfering RNA (siRNA) against EHF was transfected into GC cells. The cell proliferation of GC cells was determined by Cell Counting Kit-8 and colony formation assays. Flow cytometry was performed following Annexin V/propidium iodide (PI) to identify apoptotic cells and PI staining to analyze the cell cycle. Cell migration and invasion were assessed by transwell assays. RESULTS: The data showed that EHF was upregulated in GC tissues and cell lines in which increased expression of c-Met was also observed. Silencing of EHF by siRNA reduced the proliferation of GC cells. Inhibition of EHF induced significant apoptosis and cell cycle arrest in GC cells. Cell migration and invasion were significantly inhibited. EHF silencing led to c-Met downregulation and further blocked the Ras/c-Raf/extracellular signal-related kinase 1/2 (Erk1/2) pathway. Additionally, phosphatase and tensin homolog was upregulated and glycogen synthase kinase 3 beta was deactivated. Moreover, inactivation of signal transducer and activator of transcription 3 was detected following EHF inhibition, leading to inhibition of the epithelial-to-mesenchymal transition (EMT). CONCLUSION: These results suggest that EHF plays a key role in cell proliferation, invasion, apoptosis, the cell cycle and EMT via the c-Met pathway. Therefore, EHF may serve as an antineoplastic target for the diagnosis and treatment of GC.