The activation of high mobility group Box1 and toll-like receptor 4 is involved in clopidogrel-induced gastric injury through p38 MAPK.

Clopidogrel-induced gastric injury is an important clinical problem. However, the exact mechanism was still unclarified. This study aimed to investigate the role of high mobility group box protein 1 (HMGB1) and the toll-like receptor 4 (TLR4) pathway in normal human gastric epithelial (GES-1) cells under clopidogrel exposure. Morphological alterations of the gastric epithelial cells were observed under a microscope. A laser scanning confocal microscope was used to determine the distribution of HMGB1 and TLR4 in clopidogrel-induced injury. MTT was used to compare the viability of GES-1 cell among the pretreated Cli-095 (TLR4 inhibitor) group, pretreated ethyl pyruvate (HMGB1 inhibitor) group, clopidogrel group, and control group. Moreover, expression of the HMGB1, TLR4, tight junction (TJ) proteins occludin and the phosphorylation of the mitogen-activated protein kinases (MAPK) p38 were examined by western blot. We found the expression of HMGB1 and TLR4 in the cytoplasm increased after clopidogrel administration. Besides, inhibited TLR4, which is a receptor of HMGB1, prevented the injury and occludin reducing caused by clopidogrel challenge. Furthermore, blocking HMGB1 or TLR4 activity by ethyl pyruvate (HMGB1 inhibitor) or cli-095(TLR4 inhibitor) can partially diminish the activation of p38MAPK. Gastric mucosal damages observed by clopidogrel challenge are associated with HMGB1, TLR4, through p38MAPK signal pathway.

Esophageal bronchogenic cyst treated with submucosal tunneling endoscopic resection: two case reports.

INTRODUCTION: Although esophageal bronchogenic cysts are benign diseases, they may be accompanied by serious complications and have the possibility of recurrence. Therefore, once confirmed, it is necessary to treat the esophagobronchial cyst when the contraindication is excluded. Endoscopic treatment is usually used for lesions with small diameter and shallow origin, and has the advantages of small surgical trauma and risk, which can reduce the psychological burden of patients to a certain extent, help them to recover quickly, and lower hospital costs. CASE PRESENTATION: Case 1 is a 54-year-old Han Chinese man admitted to our hospital who complained of difficulty swallowing in the past 6 months. Case 2 is a 41-year-old Han Chinese man who was hospitalized in the past 3 months due to chest discomfort. Endoscopic ultrasound revealed a hypoechoic cystic lesion arising from the muscularis propria. Submucosal tunneling endoscopic resection was performed using a dual knife, and a cystic mass was observed between the mucosa and the muscular layers of the esophagus. On locating the cyst, an incision was made on the oral side of the lesion for evacuation. The cyst wall was excised using endoscopic argon plasma coagulation. We successfully removed the esophageal bronchogenic cyst lesion in the intrinsic muscle layer using submucosal tunneling endoscopic resection. CONCLUSION: Esophageal bronchogenic cysts are rare in clinical practice and lack specificity in clinical manifestations. Multiple methods can be used to determine the location and nature of the lesion and ultimately determine the treatment plan. Surgical resection and endoscopic treatment are two different treatment methods, and appropriate treatment plans need to be selected on the basis of the origin layer, size, and relationship with the esophagus of the lesion to reduce complications and improve prognosis.

Oral microbiota may predict the presence of esophageal squamous cell carcinoma.

PURPOSE: Microbial imbalances have been well elucidated in esophageal adenocarcinoma (EAC), but few studies address the oral microbiota in esophageal squamous cell carcinoma (ESCC). In view of the fact, we aimed to explore the associations of oral microbiota with these patients suffering from ESCC. METHODS: In our study, a total of 109 individuals were enrolled (control = 53, ESCC = 56). We profiled the microbiota in oral swabs from individuals with control (ConT) and ESCC (ESCCT). 16S rRNA gene sequencing was applied to analyze the microbiome. The α and ß diversity differences were tested by Tukey Test and Partial Least Squares Discriminant Analysis (PLS-DA) respectively. Linear discriminant analysis effect size (LEfSe) analysis was performed to assess taxonomic differences between the two groups. RESULTS: Our results showed that the microbial richness and diversity was a slightly higher in ESCCT groups than that in ConT groups. Bacteroidota, Firmicutes, Proteobacteria, Fusobacteria, Actinobacteria and Patescibacteria were the six dominant bacteria of oral flora in the two groups. When compared with control group, increased Fusobacterioa at phylum level, Neisseriaceae at family level and Leptotrichia at genus level were detected. LEfSe analysis indicated a greater abundance of Leptotrichiaceae, Leptotrichia, Fusobacteriales, Fusobacteria and Fusobacteriota in ESCC groups. CONCLUSION: Our study suggests a potential association between oral microbiome dysbiosis and ESCC and provides insights on a potential screening marker for esophageal cancer.

Antibiotic resistance of Helicobacter pylori in Nanjing, China: a cross-section study from 2018 to 2023.

Background: The increasing prevalence of antibiotic resistance in cases of Helicobacter pylori (H. pylori) infection has emerged as a significant global issue. This study offers a comprehensive examination of the alterations in drug resistance exhibited by H. pylori in the Nanjing region of China during the preceding five years. Another important objective is to investigate the influence of levofloxacin medication history on genotypic and phenotypic resistance. Methods: This research screened 4277 individuals diagnosed with H. pylori infection between April 2018 and May 2023. The phenotype and genotypic resistance were evaluated using the Kirby-Bauer disk diffusion and PCR method. Results: The most recent primary resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone, and tetracycline were recorded at 77.23% (2385/3088), 37.24% (1150/3088), 27.72% (856/3088), 0.52% (16/3088), 0.19% (6/3088), and 0.06% (2/3088), respectively. For the recent five years, we observed a notable upsurge in the rate of metronidazole resistance and a slight elevation of clarithromycin and levofloxacin resistance. The documented resistance rates to single-drug, dual-drug, triple-drug, and quadruple-drug regimens were 35.39%, 28.32%, 25.72%, and 0.21%, respectively. The prevalence of multidrug-resistant strains escalated, rising from 37.96% in 2018 to 66.22% in 2023. The rate of phenotypic and genotypic resistance rate (57.10% and 65.57%) observed in strains obtained from patients without a levofloxacin treatment history was significantly lower than the rate in strains obtained from those with a history of levofloxacin treatment (88.73% and 94.74%). The prevailing gyrA mutations were primarily N87K (52.35%, 345/659), accompanied by D91N (13.96%, 92/659), and closely followed by D87G (10.77%, 71/659). For gyrA mutations, the 91-amino acid mutants exhibit a higher likelihood of discrepancies between phenotypic and genotypic resistance than the 87-amino acid mutants. Conclusion: The extent of antibiotic resistance within H. pylori remains substantial within the Nanjing region. If levofloxacin proves ineffective in eradicating H. pylori during the initial treatment, its use in subsequent treatments is discouraged. The employment of levofloxacin resistance genotype testing can partially substitute conventional antibiotic sensitivity testing. Notably, predicting phenotypic resistance of levofloxacin through PCR requires more attention to the mutation type of gyrA to improve prediction accuracy.

Tongue coating microbiome composition reflects disease severity in patients with COVID-19 in Nanjing, China.

Our purpose is to investigate the relationship between the microbiota of patients' tongue coating microbiota and the severity of COVID-19, and to identify the severity of COVID-19 patients' condition as early as possible. The participants were categorized into three groups: healthy controls (Con group) consisting of 37 individuals, patients with mild to moderate symptoms (M group) comprising 49 individuals, and patients with severe and critical symptoms (S-C group) consisting of 44 individuals. We collected oral swabs from all participants and performed 16S rRNA gene sequencing to analyze the microbiome. The α and ß diversity differences were assessed respectively. Additionally, we employed the Linear Discriminant Analysis Effect Size (LEfSe) analysis to evaluate taxonomic differences among the three groups. Our findings revealed a significantly higher richness of tongue coating microbiota in both the S-C group and M group compared to the Con group. When compared with Con group, decreased Prevotella, Neisseria, Fusobacterium and Alloprevotella, and over-expressed Streptococcus and Rothia in M and S-C group were identified. LEfSe analysis indicated a greater abundance of Pseudomonas, Acinetbacter, Lactobacillus, Corynebacterium, Rothia in S-C group. Our study suggests a potential association between tongue coating microbiome and the severity of COVID-19 patients.

Phenotype and genotype analysis for Helicobacter pylori antibiotic resistance in outpatients: a retrospective study.

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) in outpatients and to explore the consistency between genotype and phenotype of H. pylori antibiotic resistance. A retrospective study on outpatients screened with urea breath test for H. pylori infection in Nanjing First Hospital from April 2018 to January 2022. Patients who tested positive underwent a consented upper endoscopy, and the H. pylori infection was confirmed by rapid urease test (RUT) and H. pylori culture. For antibiotic resistance phenotype analysis, the H. pylori strains isolated from gastric biopsy were tested for antibiotic resistance phenotype by the Kirby-Bauer disk diffusion test. In addition, the antibiotic resistance genotype of isolated H. pylori was tested with a real-time polymerase chain reaction. A total of 4,399 patients underwent H. pylori infection screening, and 3,306 H. pylori strains were isolated. The antibiotic resistance phenotype test revealed that the resistance rates of metronidazole (MTZ), clarithromycin (CLR), levofloxacin (LEV), amoxicillin (AMX), furazolidone (FR), and tetracycline (TE) were 74.58%, 48.61%, 34.83%, 0.76%, 0.27%, and 0.09%, respectively. Additionally, the antibiotic resistance genotype test revealed that rdxA gene mutation A610G (92.96%), A91G (92.95%), C92A (93.00%), and G392A (95.07%) were predominant in H. pylori with MTZ resistance; 23S rRNA gene mutation A2143G (86.47%) occurred in most H. pylori with CLR resistance; and gyrA gene mutation 87Ile/Lys/Tyr/Arg (97.32%) and 91Asn/Gly/Tyr (90.61%) were the most popular mutations in strains with LEV resistance. The phenotypic resistance and genotypic resistance to CLR (kappa value = 0.824) and LEV (kappa value = 0.895) were in good agreement. The history of eradication with MTZ, CLR, LEV, and AMX was correlated with H. pylori resistance. In short, this study demonstrated that drug resistance of H. pylori was mainly to MTZ, CLR, and LEV in local outpatients. Three drugs can be selected for increased MICs (Minimum Inhibitory Concentration) via single chromosomal mutations. In addition, the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. IMPORTANCE Helicobacter pylori is a key bacterium that causes stomach diseases. There was a high prevalence of H. pylori in the Chinese population. We analyzed the resistance phenotype and genotype characteristics of H. pylori in 4,399 outpatients at the First Hospital of Nanjing, China. We found a higher resistance rate to metronidazole (MTZ) , clarithromycin (CLR), and levofloxacin (LEV), and the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. This study provides information on H. pylori infection and also provides guidance for clinical doctors' drug treatment.

Association of the 463G-A myeloperoxidase gene polymorphism with gastric cancer risk.

BACKGROUND/AIMS: To explore the association between polymorphism of myeloperoxidase (MPO) gene and the susceptibility to gastric cancer. METHODOLOGY: A case control study of 117 gastric cancer patients and 105 controls was conducted to investigate the polymorphism of MPO gene 463G-A using the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The association between polymorphism and the risk of gastric cancer was examined by a multivariate analysis. Stratification analysis by age, gender, smoking status, H. pylori (Hp) infection and family history of gastric cancer was performed. RESULTS: In gastric cancer group the frequencies of the cases caring genotype G/G, G/A, A/A were 70.94%, 25.64% and 3.42%, respectively. In healthy control group, the frequency of genotype G/G, G/A, A/A was 51.43%, 37.14% and 11.43%, respectively. The frequency of genotype G/A and A/A in cancer group was found significantly higher than that in healthy control group (p<0.05). Compared with the MPO-463 G/G genotype, individuals with GA/AA genotype had a significantly decreased risk of gastric cancer (OR=0.50, 95%CI=0.28-0.90). In the stratification analysis, patients younger than 60 years old, male, Hp-IgG negative and with no family history of gastric cancer with genotype GA/AA had lower risk than those with genotype G/G. CONCLUSIONS: MPO gene polymorphism is associated with susceptibility of gastric cancer. It is conceivable that carriers of the A allele may be at reduced risk of gastric cancer.

Antibiotic resistance of Helicobacter pylori isolated from patients in Nanjing, China: A cross-section study from 2018 to 2021.

The increasing antibiotic resistance of Helicobacter pylori infection is a globally urging problem. To investigate the H. pylori resistance situation in Nanjing, China, we enrolled patients in Nanjing First Hospital from January 2018 to May 2021. H. pylori strains were isolated from patients who had at least one positive 13C-urea breath or rapid urease result. Subsequently, we performed antibiotic susceptibility tests on the isolated strains to clarithromycin, metronidazole, levofloxacin, amoxicillin, furazolidone and tetracycline. ARMS-PCR was conducted to determine H. pylori clarithromycin resistance gene mutation. Our results demonstrated that the primary resistance rates of metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone and tetracycline were 67.19% (1417/2109), 35.99% (759/2109), 24.23% (511/2109), 0.76% (16/2109), 0.28% (6/2109) and 0.09% (2/2109), respectively. The resistance rates of metronidazole, clarithromycin and levofloxacin elevated significantly after treatment and the three antibiotics composed the majority of multi-resistance patterns. However, the resistance rates of amoxicillin, furazolidone and tetracycline were still in low levels after treatment. ARMS-PCR showed a rather good consistency with antibiotic susceptibility test in detecting clarithromycin resistance, with a kappa value of 0.79. Overall, this study revealed the latest complex situation of antibiotic resistance of H. pylori infection in Nanjing and offered suggestions on clinical medication for curing H. pylori.

Characterization of Esophageal Microbiota in Patients With Esophagitis and Esophageal Squamous Cell Carcinoma.

Microbial imbalances have been well elucidated in esophageal adenocarcinoma. However, few studies address the microbiota in esophageal squamous cell carcinoma (ESCC) and esophagitis (ES). We aimed to explore the association of esophageal microbiota with these patients. Esophageal tissues were obtained from healthy controls and ES and ESCC patients undergoing upper endoscopy. 16S rRNA gene sequencing was applied to analyze the microbiome. The α and ß diversity differences were tested by Tukey test and partial least squares-discriminant analysis (PLS-DA), respectively. Linear discriminant analysis effect size (LEfSe) analysis was performed to assess taxonomic differences between groups. A total of 68 individuals were enrolled (control = 21, ES = 15, ESCC = 32). Microbial diversity was significantly different between the ESCC patients and healthy controls by Chao1 index, Shannon index, and PLS-DA. Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria were the five dominant bacterial phyla among the three groups. Megamonas, Collinsella, Roseburia, and Ruminococcus_2 showed a significantly continuous decreasing trend from the control group to the ESCC group at the genus level. When compared with the control group, decreased Fusobacteria at phylum level and Faecalibacterium, Bacteroides, Curvibacter, and Blautia at genus level were detected. ESCC samples also displayed a striking reduction of Bacteroidetes, Faecalibacterium, Bacteroides, and Blautia in comparison with the ES patients. LEfSe analysis indicated a greater abundance of Streptococcus, Actinobacillus, Peptostreptococcus, Fusobacterium, and Prevotella in the ESCC group. Our study suggests a potential association between esophageal microbiome dysbiosis and ESCC and provides insights into potential screening markers for esophageal cancer.

Analysis of the Primary and Post-Treatment Antibiotic Resistance of Helicobacter pylori in the Nanjing Area.

BACKGROUND: Resistance of Helicobacter pylori (H. pylori) to antibiotics is increasing worldwide. The study was aimed to understand the current situation of antibiotic resistance in Nanjing and to provide a reasonable basis for clinical selection of antibiotics to cure H. pylori. OBJECTIVE: To investigate the current status of H. pylori antibiotics resistance in the Nanjing area, and analyze the primary and post-treatment antibiotic resistance of H. pylori in this area. METHODS: During the period from July 2017 to December 2019, 1533 gastric mucosal specimens from patients with positive H. pylori confirmed by a breath test or rapid urease test were collected for isolation and identification of H. pylori. The agar dilution method was used for the antibiotic resistance test. RESULTS: The result showed that the resistance rates of H. pylori to amoxicillin, clarithromycin, levofloxacin, furazolidone, tetracycline and metronidazole were 2.74%, 47.03%, 33.59%, 0.91%, 0.52% and 80.76%, respectively in the period of July 2017 to December 2019. The resistance rates of H. pylori (primary vs. post-treatment) to amoxicillin, clarithromycin, levofloxacin, furazolidone, tetracycline and metronidazole were 1.83% vs. 6.08%, 38.62% vs. 77.81%, 27.41% vs. 56.23%, 0.58% vs. 2.13%, 0.33% vs. 1.22%, 78.57% vs. 88.75%, respectively. CONCLUSION: Antibiotic resistance of H. pylori remained a problem for the effective eradication of this pathogen and its associated diseases in the Nanjing area. For post-treatment eradication patients, clinicians should take into account regional antibiotic resistance rate, personal antibiotic exposure history, economic benefit ratio, adverse antibiotic reactions, antibiotic availability and other aspects.

circRNA RNF111 regulates the growth, migration and invasion of gastric cancer cells by binding to miR­27b­3p.

hsa_circ_0001982 [circRNA ring finger protein 111 (RNF111)] has been found to promote cancer growth; however, its role in gastric cancer (GC) remains unclear. The present study examined the effects of circR­RNF111 on the growth, migration and invasion of GC cells and aimed to elucidate the underlying molecular mechanisms. The expression levels of circR­RNF111 and miR­27b­3p in GC tissues and GC cell lines were detected by reverse transcription­quantitative PCR (RT­qPCR). StarBase v2.0 and dual­luciferase assay were used to predict and analyze the association between circR­RNF111 and miR­27b­3p. The effects of circR­RNF111 and miR­27b­3p on cell growth, apoptosis, migration and invasion were detected by cell counting kit­8 (CCK­8) assay, colony formation assay, flow cytometry, wound­healing assay and Transwell assay, respectively. In addition, western blot analysis was performed to determine the expression levels of genes related to cell apoptosis and epithelial­mesenchymal transition (EMT). The results revealed that circR­RNF111 and miR­27b­3p were closely related to the clinicopathological characteristics of GC, and that circR­RNF111 and miR­27b­3p negatively correlated and were abnormally expressed in GC. circR­RNF111 acted as a sponge of miR­27b­3p. The silencing of circR­RNF111 significantly inhibited GC cell viability, colony formation, migration and invasion, and exerted a pro­apoptotic effect. miR­27b­3p inhibitor promoted the proliferation, migration and invasion of GC cells, and inhibited cell apoptosis. In addition, circR­RNF111 silencing significantly decreased the expression levels of Bcl2, Vimentin and N­cadherin, and increased those of cleaved caspase­3 and E­cadherin. Furthermore, miR­27b­3p inhibition reversed the regulatory effects of circR­RNF111 silencing on the GC cells. On the whole, the findings of the present study demonstrate that circR­RNF111 is involved in the regulation of growth, migration and invasion of GC cells by binding to miR­27b­3p.

Increased expression of tight junction protein occludin is associated with the protective effect of mosapride against aspirin-induced gastric injury.

Mosapride is known to affect gastric motility, however whether mosapride has anti-ulcergenic effects in gastric mucosal injury is unclear. The aim of the present study was to investigate the effects of mosapride on aspirin-induced gastric injuries. GES-1 cells were cultured and divided into 5 groups: Control group, aspirin injury group (treated with 18.2 mmol/l aspirin) and mosapride pretreatment groups (treated with 0.4, 0.5, or 0.6 µmol/l mosapride). Cell proliferation was evaluated via MTT assay and cell apoptosis was investigated via flow cytometry. The expression of occludin was determined by western blot analysis. A total of 40 male Sprague-Dawley rats were randomized into five groups: Control group, aspirin injury group (150 mg/kg) and mosapride pretreatment groups (0.25, 0.50 or 0.75 mg/kg). Gastric mucosal lesions were induced by administering 200 mg/kg aspirin daily for 4 days. Rats in the mosapride groups were pretreated with mosapride 1 h prior to aspirin administration. Histological changes were evaluated under a light microscope and gastric epithelial TJs were observed via transmission electron microscopy. The results revealed that cell apoptosis was significantly increased in the aspirin injury group compared with the control (P<0.05), whereas apoptosis was significantly decreased in the mosapride pretreatment groups compared with the aspirin group (P<0.05). Cell viability was significantly increased in the mosapride pretreatment groups compared with the aspirin injury group (P<0.05), and that of the aspirin injury group was significantly decreased compared with the control group (P<0.05). Compared with the aspirin injury group, occludin expression was significantly increased in the three mosapride pre-treatment groups (all P<0.05). It was also demonstrated that gastric damage was significantly attenuated in the mosapride pretreatment groups compared with the aspirin injury group (P<0.05). Impaired TJ integrity was observed in aspirin injury group, whereas TJs in the mosapride groups were almost intact. In conclusion, the results of the present study suggest that mosapride exerts a gastroprotective action on aspirin-induced gastric mucosal injury at least in part via attenuating cell apoptosis and increasing occludin expression.

Proton-pump inhibitors can decrease gastrointestinal bleeding after percutaneous coronary intervention.

BACKGROUND: Current medical therapies for patients who have an acute coronary syndrome (ACS) focus on the coagulation cascade and platelet inhibition. These, coupled with early use of cardiac catheterization and revascularization, have decreased morbidity and mortality rates in patients who have acute ischemic heart disease with risk of bleeding. OBJECTIVE: The study aimed to determine the incidence of gastrointestinal bleeding after percutaneous coronary intervention (PCI). The effect of proton-pump inhibitor (PPI) treatment was also analyzed. METHODS: This case-control study evaluated gastrointestinal bleeding within a year of PCI for stable angina and acute coronary syndromes at Nanjing First Hospital between 2008 and 2011. Cases were identified and outcomes assessed using linkage analysis of data from cardiology and gastroenterology department databases. Analysis of the case and control groups for both risk and protective factors was performed using independent two-sample Student's t-test with Fisher's exact P value and logistic regression. RESULTS: The incidence of gastrointestinal bleeding following PCI was 1.3% (35/2680 patients). The risk factors for gastrointestinal bleeding were advanced age, female gender, smoking, drinking, previous peptic ulcer and previous gastrointestinal bleeding. PPI use after PCI (P=0.000) was accompanied by a lower risk of gastrointestinal bleeding, with only a few cases of gastrointestinal bleeding events reported. CONCLUSION: The incidence of gastrointestinal bleeding associated with the combination of aspirin and clopidogrel therapy was estimated to be 1.3%. Advanced age, being female, smokers, drinkers, previous peptic ulcer and previous gastrointestinal bleeding were significant independent risk factors. PPI for the prevention and treatment of gastrointestinal bleeding induced by the combination of aspirin and clopidogrel in patients after PCI was safe and effective.

Attenuated expression of the tight junction proteins is involved in clopidogrel-induced gastric injury through p38 MAPK activation.

Bleeding complications and delayed healing of gastric ulcer associated with use of clopidogrel is a common clinical concern; however, the underlying mechanisms remain to be determined. This study aimed to clarify whether clopidogrel could cause the damage of the human gastric epithelial cells and to further elucidate the mechanisms involved. After human gastric epithelial cell line GES-1 had been treated with clopidogrel (0.5-2.5 mM), the cell proliferation was examined by MTT assay, apoptosis was measured with DAPI staining and flow cytometry analysis, and the barrier function of the tight junctions (TJ) was evaluated by permeability measurement and transmission electron microscopy. Moreover, expression of the TJ proteins occludin and ZO-1 and the phosphorylation of the mitogen-activated protein kinases (MAPK) p38, ERK, and JNK were examined by western blot. In addition, three MAPK inhibitors specific to p38, ERK and JNK were used, respectively, to verify the signaling pathways responsible for regulating the expression of the TJ proteins being tested. Results showed that clopidogrel significantly increased dextran permeability, induced apoptosis, suppressed GES-1 cell viability, and reduced the expression of the TJ proteins (occludin and ZO-1), acting through p38 MAPK phosphorylation. Furthermore, these observed effects were partially abolished by SB-203580 (a p38 MAPK inhibitor), rather than by either U-0126 (an ERK inhibitor) or SP-600125 (a JNK inhibitor), suggesting that clopidogrel-induced disruption in the gastric epithelial cells is mediated by the p38 MAPK pathway. It is concluded that attenuated expression of the TJ proteins occludin and ZO-1 in human gastric epithelial cells could be involved in clopidogrel-induced gastric mucosal injury through activation of the p38 MAPK pathway.

Increased endoplasmic reticulum stress response is involved in clopidogrel-induced apoptosis of gastric epithelial cells.

BACKGROUND: The widespread use of clopidogrel alone or in combination with aspirin may result in gastrointestinal mucosal injury, clinically represented as recurrent ulceration and bleeding complications. Our recent work suggested that clopidogrel significantly induced human gastric epithelial cell (GES-1) apoptosis and disrupted gastric mucosal barrier, and that a p38 MAPK inhibitor could attenuate such injury. However, their exact mechanisms are largely unknown. METHODS: The GES-1 cells were used as a model system, the effects of clopidogrel on the whole gene expression profile were evaluated by human gene expression microarray and gene ontology analysis, changes of the mRNA and protein expression were determined by real-time PCR and Western blot analysis, and cell viability and apoptosis were measured by MTT assay and flow cytometry analysis, respectively. RESULTS: Gene microarray analysis identified 79 genes that were differentially expressed (P<0.05 and fold-change >3) when cells were treated with or without clopidogrel. Gene ontology analysis revealed that response to stress and cell apoptosis dysfunction were ranked in the top 10 cellular events being affected, and that the major components of endoplasmic reticulum stress-mediated apoptosis pathway - CHOP and TRIB3- were up-regulated in a concentration- and time-dependent manner when cells were treated with clopidogrel. Pathway analysis demonstrated that multiple MAPK kinases were phosphorylated in clopidogrel-treated GES-1 cells, but that only SB-203580 (a p38-specific MAPK inhibitor) attenuated cell apoptosis and CHOP over-expression, both of which were induced by clopidogrel. CONCLUSIONS: Increased endoplasmic reticulum stress response is involved in clopidogrel-induced gastric mucosal injury, acting through p38 MAPK activation.