幽门螺杆菌毒力基因分型和宿主遗传多态性与胃病关系研究进展

幽门螺杆菌(Helicobacter pylori)感染能导致慢性胃炎、消化性溃疡、胃粘膜相关的淋巴样组织(Mu-cosa-associated lymphoid tissue,MALT)淋巴瘤和胃腺癌等疾病的发生。1994年世界卫生组织国际癌症研究中心(IARC)将H.pylori列为胃癌第一级因子。H.pylori感染引起的不同临床结局主要与H.pylori致病因子和宿主遗传易感性有关,大部分重大疾病发生在特定的细菌毒力因子(如cagA,vacA)与易感宿主遗传背景共同存在时。文章综述了H.pylori菌株的毒力基因的分型和宿主的遗传多态性对胃病发生的影响。     

Isolation and characterization of a Helicobacter sp. from the gastric mucosa of dolphins, Lagenorhynchus acutus and Delphinus delphis

Gastric ulcerations in dolphins have been reported for decades. Some of these lesions were associated with parasitic infections. However, cases of nonparasitic gastric ulcers with no clearly defined etiology also have been reported in wild and captive dolphins. Considerable speculation exists as to whether dolphins have Helicobacter-associated gastritis and peptic ulcer disease. The stomachs of seven stranded Atlantic white-sided dolphins, Lagenorhynchus acutus, and 1 common dolphin, Delphinus delphis, were assessed for the presence of Helicobacter species. Novel Helicobacter species were identified by culture in the gastric mucosa of two of the eight dolphins studied and by PCR in seven of the eight dolphins. The gram-negative organisms were urease, catalase, and oxidase positive. Spiral to fusiform bacteria were detected in gastric mucosa by Warthin Starry staining. Histopathology revealed mild to moderate diffuse lymphoplasmacytic gastritis within the superficial mucosa of the main stomach. The pyloric stomach was less inflamed, and bacteria did not extend deep into the glands. The lesions parallel those observed in Helicobacter pylori-infected humans. Bacteria from two dolphins classified by 16S rRNA analysis clustered with gastric helicobacters and represent a novel Helicobacter sp. most closely related to H. pylori. These findings suggest that a novel Helicobacter sp. may play a role in the etiopathogenesis of gastritis and gastric ulcers in dolphins. To our knowledge this represents the first isolation and characterization of a novel Helicobacter sp. from a marine mammal and emphasizes the wide host distribution and pathogenic potential of this increasingly important genus.     

宿主基因单核苷酸多态性与幽门螺杆菌相关胃癌

幽门螺杆菌相关胃癌是一种由遗传、环境、生活方式等因素共同作用所致的特殊类型胃癌。它的发病过程至少包括炎症、萎缩和癌变3个主要阶段。宿主基因单核苷酸多态性(SNP)包括炎症反应、胃酸抑制、免疫识别等相关基因SNP,可能特异性参与了幽门螺杆菌相关胃癌发生发展过程中的不同阶段。文章综述与幽门螺杆菌相关胃癌发病3个主要病理阶段相关的宿主基因SNP及其与胃癌发病风险关系的研究进展。     

Helicobacter pylori infection‐induced H3Ser10 phosphorylation in stepwise gastric carcinogenesis and its clinical implications

Background

Our previous works have demonstrated that Helicobacter pylori (Hp) infection can alter histone H3 serine 10 phosphorylation status in gastric epithelial cells. However, whether Helicobacter pylori‐induced histone H3 serine 10 phosphorylation participates in gastric carcinogenesis is unknown. We investigate the expression of histone H3 serine 10 phosphorylation in various stages of gastric disease and explore its clinical implication.

Materials and Methods

Stomach biopsy samples from 129 patients were collected and stained with histone H3 serine 10 phosphorylation, Ki67, and Helicobacter pylori by immunohistochemistry staining, expressed as labeling index. They were categorized into nonatrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, low‐grade intraepithelial neoplasia, high‐grade intraepithelial neoplasia, and intestinal‐type gastric cancer groups. Helicobacter pylori infection was determined by either ¹³C‐urea breath test or immunohistochemistry staining.

Results

In Helicobacter pylori‐negative patients, labeling index of histone H3 serine 10 phosphorylation was gradually increased in nonatrophic gastritis, chronic atrophic gastritis, intestinal metaplasia groups, peaked at low‐grade intraepithelial neoplasia, and declined in high‐grade intraepithelial neoplasia and gastric cancer groups. In Helicobacter pylori‐infected patients, labeling index of histone H3 serine 10 phosphorylation followed the similar pattern as above, with increased expression over the corresponding Helicobacter pylori‐negative controls except in nonatrophic gastritis patient whose labeling index was decreased when compared with Helicobacter pylori‐negative control. Labeling index of Ki67 in Helicobacter pylori‐negative groups was higher in gastric cancer than chronic atrophic gastritis and low‐grade intraepithelial neoplasia groups, and higher in intestinal metaplasia group compared with chronic atrophic gastritis group. In Helicobacter pylori‐positive groups, Ki67 labeling index was increased stepwise from nonatrophic gastritis to gastric cancer except slightly decrease in chronic atrophic gastritis group. In addition, we noted that histone H3 serine 10 phosphorylation staining is accompanied with its location changes from gastric gland bottom expanded to whole gland as disease stage progress.

Conclusions

These results indicate that stepwise gastric carcinogenesis is associated with altered histone H3 serine 10 phosphorylation, Helicobacter pylori infection enhances histone H3 serine 10 phosphorylation expression in these processes; it is also accompanied with histone H3 serine 10 phosphorylation location change from gland bottom staining expand to whole gland expression. The results suggest that epigenetic dysregulation may play important roles in Helicobacter pylori‐induced gastric cancer.     

Comparative chemical and biological characterization of the lipopolysaccharides of gastric and enterohepatic helicobacters

BACKGROUND: The lipopolysaccharide of Helicobacter pylori plays an important role in colonization and pathogenicity. The present study sought to compare structural and biological features of lipopolysaccharides from gastric and enterohepatic Helicobacter spp. not previously characterized. MATERIALS AND METHODS: Purified lipopolysaccharides from four gastric Helicobacter spp. (H. pylori, Helicobacter felis, Helicobacter bizzozeronii and Helicobacter mustelae) and four enterohepatic Helicobacter spp. (Helicobacter hepaticus, Helicobacter bilis, 'Helicobacter sp. flexispira' and Helicobacter pullorum) were structurally characterized using electrophoretic, serological and chemical methods. RESULTS: Structural insights into all three moieties of the lipopolysaccharides, i.e. lipid A, core and O-polysaccharide chains, were gained. All species expressed lipopolysaccharides bearing an O-polysaccharide chain, but H. mustelae and H. hepaticus produced truncated semirough lipopolysaccharides. However, in contrast to lipopolysaccharides of H. pylori and H. mustelae, no blood group mimicry was detected in the other Helicobacter spp. examined. Intra-species, but not interspecies, fatty acid profiles of lipopolysaccharides were identical within the genus. Although shared lipopolysaccharide-core epitopes with H. pylori occurred, differing structural characteristics were noted in this lipopolysaccharide region of some Helicobacter spp. The lipopolysaccharides of the gastric helicobacters, H. bizzozeronii and H. mustelae, had relative Limulus amoebocyte lysate activities which clustered around that of H. pylori lipopolysaccharide, whereas H. bilis, 'Helicobacter sp. flexispira' and H. hepaticus formed a cluster with approximately 1000-10,000-fold lower activities. H. pullorum lipopolysaccharide had the highest relative Limulus amoebocyte lysate activity of all the helicobacter lipopolysaccharides (10-fold higher than that of H. pylori lipopolysaccharide), and all the lipopolysaccharides of enterohepatic Helicobacter spp. were capable of inducing nuclear factor-Kappa B(NF-kappaB) activation. CONCLUSIONS: The collective results demonstrate the structural heterogeneity and pathogenic potential of lipopolysaccharides of the Helicobacter genus as a group and these differences in lipopolysaccharides may be indicative of adaptation of the bacteria to different ecological niches.     

Detection of non-pylori Helicobacter species in "Helicobacter heilmannii"-infected humans

BACKGROUND: A small proportion of patients suffering from chronic active gastritis are diagnosed with gastric Helicobacter species other than Helicobacter pylori. Circumstantial evidence has suggested that these bacteria, also referred to as "Helicobacter heilmannii"-like organisms (HHLO), may be transmitted through animals. The isolation of a Helicobacter bizzozeronii strain from a human patient confirmed this hypothesis. It was the aim of the present study to assess the presence of animal Helicobacter species and H. pylori in humans infected with HHLO, as diagnosed by histology. METHODS: Paraffin-embedded gastric biopsy specimens of 108 HHLO-infected patients (42 women and 66 men) from three clinical centers were screened for the presence of animal gastric Helicobacter species by polymerase chain reaction (PCR), using assays targeting the 16S rDNA region of the three known canine and feline helicobacters (H. bizzozeronii, H. salomonis and H. felis), "Candidatus H. suis", and "Candidatus H. bovis". In addition, the presence of H. pylori was evaluated by multiplex PCR analysis. RESULTS: In 63.4% of the stomachs (64/101) classification of the Helicobacter infection into the above mentioned groups was achieved. Non-pylori Helicobacter species commonly colonizing the stomachs of cats and dogs were found in 48.5% (49/101) of the patients. Fourteen (13.9%) samples tested positive for "Candidatus H. suis", and "Candidatus H. bovis" was demonstrated in 1 (0.9%) patient. The presence of H. pylori was established in 13 patients (12.9%). Eleven stomachs (10.9%) were infected with at least two different Helicobacter species. CONCLUSIONS: This study identifies animal Helicobacter species in the stomach of a large series of HHLO-infected patients, which may have clinical implications in a subset of patients with gastric disease.     

Genome Sequences of Three Helicobacter pylori Strains Isolated from Atrophic Gastritis and Gastric Ulcer Patients in China

Helicobacter pylori is a bacterial pathogen which can lead to several human gastric diseases. Here we describe the genome sequences of three strains isolated from atrophic gastritis and gastric ulcers patients in China. The data will permit genomic characterization of traits that may contribute to various gastric diseases.     

Fused and Overlapping rpoB and rpoC Genes in Helicobacters, Campylobacters, and Related Bacteria

The genes coding for the beta (rpoB) and beta' (rpoC) subunits of RNA polymerase are fused in the gastric pathogen Helicobacter pylori but separate in other taxonomic groups. To better understand how the unique fused structure evolved, we determined DNA sequences at and around the rpoB-rpoC junction in 10 gastric and nongastric species of Helicobacter and in members of the related genera Wolinella, Arcobacter, Sulfurospirillum, and Campylobacter. We found the fusion to be specific to Helicobacter and Wolinella genera; rpoB and rpoC overlap in the other genera. The fusion may have arisen by a frameshift mutation at the site of rpoB and rpoC overlap. Loss of good Shine-Dalgarno sequences might then have fixed the fusion in the Helicobacteraceae, even if fusion itself did not confer a selective advantage.     

30周糖尿病大鼠胃排空与幽门螺杆菌的检测

目的检测30周糖尿病大鼠胃排空情况幽门螺杆菌的感染状况。方法应用链脲佐菌素(Streptozotocin,STZ)建立30周糖尿病大鼠模型,然后采用酚红实验方法观察胃排空与胃幽门螺杆菌感染状况。结果30周糖尿病大鼠存在胃排空异常,中药"糖胃康"组与模型组比较有所改善,而幽门螺杆菌试纸检测呈阴性。结论30周糖尿病大鼠存在胃排空异常现象,不存在幽门螺杆菌感染。     

Putative effect of Helicobacter pylori and gastritis on gastric acid secretion in cat

Helicobacter pylori may increase or inhibit gastric acid. We studied acid variations and plasma gastrin in cats harboring Helicobacter felis, harboring H. pylori, or free of gastric pathogens with reference to thioperamide (H(3) receptor antagonist) and SR-27417A (PAF receptor antagonist). In cats harboring H. felis, gastric mucosa were histologically normal. After H. felis eradication, pentagastrin-stimulated acid secretion was increased (40%) compared with the situation before eradication. Thioperamide abolished this inhibitory effect of H. felis, whereas SR-27417A did not. Basal and meal-stimulated plasma gastrin levels were not affected by eradication therapy. Acid secretion was inhibited (-80%) in week 3, increased from weeks 5 to 9, and remained constant for up to 42 weeks after H. pylori infection. SR-27417A had no effect on acid secretion before week 8 but inhibited it thereafter, and thioperamide increased it (20%) only before week 7 in those cats. Helicobacter inhibits gastric acid via an H(3) receptor pathway. Inflammatory mediators are thus involved in adaptation to the inhibitory effects of H. pylori on acid secretion.     

Inflammation, Immunity, and Vaccines for Helicobacter pylori

Helicobacter pylori infects almost half of the population worldwide and represents the major cause of gastroduodenal diseases, such as duodenal and gastric ulcer, gastric adenocarcinoma, autoimmune gastritis, and B-cell lymphoma of mucosa-associated lymphoid tissue. Helicobacter pylori induces the activation of a complex and fascinating cytokine and chemokine network in the gastric mucosa. Different bacterial and environmental factors, other concomitant infections, and host genetics may influence the balance between mucosal tolerance and inflammation in the course of H. pylori infection. An inverse association between H. pylori prevalence and the frequencies of asthma and allergies was demonstrated, and the neutrophil activating protein of H. pylori was shown to inhibit the allergic inflammation of bronchial asthma. During the last year, significant progress was made on the road to the first efficient vaccine for H. pylori that will represent a novel and very important bullet against both infection and gastric cancer.     

Does Helicobacter pylori infection per se cause gastric cancer or duodenal ulcer? Inadequate evidence in Mongolian gerbils and inbred mice

A role for Helicobacter pylori infection in the development of gastric cancer in humans is well established; however, evidence for its carcinogenicity in animals remains inadequate. Mongolian gerbils and mice are commonly used to investigate the carcinogenicity of H. pylori, yet it is unclear whether H. pylori infection per se causes gastric cancer or duodenal ulcers in these animal models. Gastric adenocarcinoma in the gerbils was reported over 10 years ago, but this species has proved an unreliable model for studying H. pylori infection-associated gastric cancer. Helicobacter pylori infection alone appears insufficient to induce gastric cancer in these animals; additional carcinogenic insult is required. The development of invasive adenocarcinoma in inbred mice is rare regardless of the mouse or bacterial strain, and many long-term studies have failed to induce gastric cancer in these animals. Helicobacter pylori infection is also an established causative factor for duodenal ulcer in humans. However, few studies have attempted to develop animal models of H. pylori infection-induced duodenal ulcer. We therefore conclude that both Mongolian gerbils and inbred mice may be inadequate models for studying H. pylori infection-associated gastric cancer and that there is no animal model of H. pylori infection-induced duodenal ulcer.     

胃癌和甲状腺疾病相关性研究进展

胃癌是我国常见的恶性肿瘤之一。多种因素与胃癌的发生相关,如环境、饮食、幽门螺杆菌感染、慢性萎缩性胃炎和肠上皮化生等。随着对胃癌研究的深入,国外学者发现胃癌的发病率在碘摄入不足或者摄入过多的地区有逐渐增高的趋势,而碘是甲状腺疾病发病的重要因素。最新的研究发现,胃癌和甲状腺疾病的关系可能受到地域因素的影响,但目前缺乏对此关系的大样本临床研究。本文试对这些研究的最新进展作一综述。     

Genome sequence of Helicobacter bizzozeronii strain CIII-1, an isolate from human gastric mucosa

The canine-adapted Helicobacter bizzozeronii is the only nonpylori Helicobacter species isolated from human gastric biopsy tissue. Here we present the genome sequence of strain CIII-1, isolated from a 45-year-old female patient with severe gastric symptoms. This is the first genome sequence of nonpylori gastric Helicobacter isolated from human gastritis.     

Depletion of neutrophils in IL-10(-/-) mice delays clearance of gastric Helicobacter infection and decreases the Th1 immune response to Helicobacter

Gastric infection with Helicobacter induces a lymphocyte-rich mucosal inflammation that contains a minor population of neutrophilic granulocytes. The function of neutrophils in the local immune response to gastric Helicobacter infection remains unknown. To investigate this issue, we conducted experiments in neutrophil-depleted control wild-type (wt) and IL-10(-/-) mice infected with Helicobacter felis by gastric lavage. Infection of wt mice elicited a mild, focal gastritis and a Helicobacter-specific Th1 immune response. In wt mice Helicobacter colonization of the stomach was persistent and progressively increased during the 29 days of observation. Infection of IL-10(-/-) mice with H. felis elicited a severe chronic gastritis and a greatly enhanced Helicobacter-specific Th1 immune response, as compared with wt mice. After initial colonization, the IL-0(-/-) mice completely cleared Helicobacter from the stomach by day 8. The gastric inflammation in wt and IL-10(-/-) mice contained modest numbers of neutrophils. The intensity of gastric inflammation and the extent of Helicobacter colonization were similar in control and in neutrophil-depleted wt mice. In contrast, neutrophil depletion of Helicobacter-infected IL-10(-/-) mice decreased the severity of gastritis, modulated the Helicobacter-specific Th1 immune response, and delayed the clearance of bacteria from the stomach. These studies identify a role for neutrophils in the local and systemic immune response to gastric Helicobacter in IL-10(-/-) mice.     

Concurrent enteric helminth infection modulates inflammation and gastric immune responses and reduces helicobacter-induced gastric atrophy

Helicobacter pylori is causally associated with gastritis and gastric cancer. Some developing countries with a high prevalence of infection have high gastric cancer rates, whereas in others, these rates are low. The progression of helicobacter-induced gastritis and gastric atrophy mediated by type 1 T-helper cells may be modulated by concurrent parasitic infection. Here, in mice with concurrent helminth infection, helicobacter-associated gastric atrophy was reduced considerably despite chronic inflammation and high helicobacter colonization. This correlated with a substantial reduction in mRNA for cytokines and chemokines associated with a gastric inflammatory response of type 1 T-helper cells. Thus, concurrent enteric helminth infection can attenuate gastric atrophy, a premalignant lesion.     

Spatial Distribution of Helicobacter spp. in the Gastrointestinal Tract of Dogs

Background:  In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. We sought to determine the spatial distribution of Helicobacter spp. in the gastrointestinal tract and the hepatobiliary system of dogs using culture-independent methods.
Materials and methods:  Samples of stomach, duodenum, ileum, cecum, colon, pancreas, liver, and bile from six dogs were evaluated for Helicobacter spp. by genus, gastric, and enterohepatic Helicobacter spp. Polymerase chain reaction, 16S rRNA gene sequence analysis, immunohistochemistry, and fluorescence in situ hybridization (FISH).
Results:  In the stomach, Helicobacter spp. DNA was detected in all six dogs, with H. bizzozeronii and H. felis identified by specific polymerase chain reaction. Helicobacter organisms were localized within the surface mucus, the lumen of gastric glands, and inside parietal cells. The small intestine harbored gastric and enterohepatic Helicobacter spp. DNA/antigen in low amounts. In the cecum and colon, Helicobacter spp. DNA, with highest similarity to H. bilis /flexispira taxon 8, H. cinaedi , and H. canis, was detected in all six dogs. Helicobacter organisms were localized at the mucosal surface and within the crypts. Gastric Helicobacter spp. DNA was detected occasionally in the large intestine, but no gastric Helicobacter spp. were present in clone libraries or detected by FISH.
Conclusions:  This study demonstrates that in addition to the stomach, the large intestine of dogs is also abundantly colonized by Helicobacter spp. Additional studies are necessary to investigate the association between enterohepatic Helicobacter spp. and presence of intestinal inflammatory or proliferative disorders in dogs.     

Non-Helicobacter pylori helicobacters detected in the stomach of humans comprise several naturally occurring Helicobacter species in animals

Besides the well-known gastric pathogen Helicobacter pylori , other Helicobacter species with a spiral morphology have been detected in a minority of human patients who have undergone gastroscopy. The very fastidious nature of these non- Helicobacter pylori helicobacters (NHPH) makes their in vitro isolation difficult. These organisms have been designated ' Helicobacter heilmannii '. However, sequencing of several genes detected in NHPH-infected tissues has shown that the ' H. heilmannii ' group comprises at least five different Helicobacter species, all of them known to colonize the stomach of animals. Recent investigations have indicated that Helicobacter suis is the most prevalent NHPH species in human. This species has only recently been isolated in vitro from porcine stomach mucosa. Other NHPH that colonize the human stomach are Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis and ' Candidatus Helicobacter heilmannii'. In numerous case reports of human gastric NHPH infections, no substantial information is available about the species status of the infecting strain, making it difficult to link the species with certain pathologies. This review aims to clarify the complex nomenclature of NHPH species associated with human gastric disease and their possible animal origin. It is proposed to use the term 'gastric NHPH' to designate gastric spirals that are morphologically different from H. pylori when no identification is available at the species level. Species designations should be reserved for those situations in which the species is defined.     

幽门螺杆菌保护性抗原研究进展

幽门螺杆菌是一种与慢性胃炎、胃溃疡及胃癌的发生密切相关的致病菌。疫苗是预防和控制传染病的有效途径,筛选出幽门螺杆菌保护性抗原是设计和构建幽门螺杆菌疫苗的关键。本对与幽门螺杆菌粘附、定植及与其毒素相关的保护性抗原做一概述。     

Isolation and characterization of novel Helicobacter spp. from the gastric mucosa of harp seals Phoca groenlandica

Since the recent discovery of Helicobacter cetorum in cetaceans and its role in the development of gastritis, speculation has existed as to whether pinnipeds have Helicobacter spp. associated gastritis and peptic ulcer disease. The gastric mucosa of 4 stranded harp seals Phoca groenlandica from the Massachusetts coastline were assessed for Helicobacter spp. by culture and PCR. We cultured 2 novel Helicobacter spp. from the pyloric antrum of 1 of the 4 harp seals studied, and identified these by PCR in 2 of the 4 seals. Both gram-negative bacterial isolates were catalase- and oxidase-positive. However, a fusiform helicobacter with flexispira morphology was urease-positive, and a spiral-shaped helicobacter was urease-negative. Slender, spiral and fusiform-shaped bacteria were detected in the gastric mucosa by the Warthin-Starry stain. Histopathologic analysis revealed mild diffuse lymphoplasmacytic gastritis within the superficial mucosa of the pyloric antrum of both infected seals. The 2 bacterial isolates were classified by 16S rRNA analysis; they clustered with other enteric helicobacters and represent 2 novel Helicobacter spp. The urease-negative bacterial isolate clustered with H. canis and the urease-positive isolate clustered with an isolate from a sea lion and isolates from sea otters. This cluster of pinniped isolates has 97 % similarity to a number of Helicobacter species, but appears to be most closely related to other helicobacters with flexispira morphology. These findings suggest that the novel Helicobacter spp. may play a role in the etiopathogenesis of gastrointestinal diseases in pinnipeds. To our knowledge, this represents the first isolation and characterization of a novel Helicobacter spp. from pinnipeds.