Long-term stress and Helicobacter pylori infection independently induce gastric mucosal lesions in C57BL/6 mice

Cross-sectional association between long working hours and endoscopic gastritis: the Kangbuk Samsung Health Study

OBJECTIVES

This study aimed to determine the cross-sectional association between long working hours and gastritis diagnosed by endoscopy.

DESIGN

Cross-sectional study.

SETTING

Large university hospitals in Seoul and Suwon, South Korea.

PARTICIPANTS

Workers in formal employment who underwent a comprehensive health examination at the Kangbuk Samsung Hospital Total Healthcare Centre clinics in Seoul and Suwon, South Korea, between January 2011 and December 2018. Of the 386 488 participants, 168 391 full-time day workers met the inclusion criteria and were included in the analysis.

PRIMARY OUTCOME MEASURE

Endoscopic gastritis.

RESULTS

The participants were predominantly college graduates or above (88.9%), male (71.2%) and in their 30s (51.1%), and the median age was 36 (IQR 31-42). Approximately 93.2% of participants had positive endoscopic gastritis, and there was a significant association between working hours and positive findings of endoscopic gastritis. The multivariate fully adjusted prevalence ratio (PR) of endoscopic gastritis for participants working >55 hours per week compared with 35-40 hours per week was 1.011 (95% CI 1.007 to 1.015). Furthermore, endoscopic findings were classified into nine subtypes of gastritis, including superficial gastritis, erosive gastritis, atrophic gastritis, intestinal metaplasia and haemorrhagic gastritis increased with longer working hours (p for trends <0.05). Their PRs for participants working >55 hours per week compared with 35-40 hours per week were 1.019 (95% CI 1.012 to 1.026), 1.025 (95% CI 1.011 to 1.040), 1.017 (95% CI 1.008 to 1.027), 1.066 (95% CI 1.028 to 1.105) and 1.177 (95% CI 1.007 to 1.375), respectively.

CONCLUSIONS

Working over 55 hours per week was cross-sectionally associated with positive findings of endoscopic gastritis. The study findings indicated potentially increased risks of superficial gastritis, erosive gastritis, atrophic gastritis, intestinal metaplasia and haemorrhagic gastritis among workers with long working hours (>55 hours per week), supporting the need for further exploration via longitudinal studies.

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

Tocotrienol (T3) is a subfamily of vitamin E known for its wide array of medicinal properties. This review aimed to summarize the health benefits of T3, particularly in prevention or treatment of non-communicable diseases (NCDs), including cardiovascular, musculoskeletal, metabolic, gastric, and skin disorders, as well as cancers. Studies showed that T3 could prevent various NCDs, by suppressing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the mevalonate pathway, inflammatory response, oxidative stress, and alternating hormones. The efficacy of T3 in preventing/treating these NCDs is similar or greater compared to tocopherol (TF). TF may lower the efficacy of T3 because the efficacy of the combination of TF and T3 was lower than T3 alone in some studies. Data investigating the effects of T3 on osteoporosis, arthritis, and peptic ulcers in human are limited. The positive outcomes of T3 treatment obtained from the preclinical studies warrant further validation from clinical trials.

Selye's general adaptation syndrome: stress-induced gastro-duodenal ulceration and inflammatory bowel disease

Hans Selye in a note to Nature in 1936 initiated the field of stress research by showing that rats exposed to nocuous stimuli responded by way of a 'general adaptation syndrome' (GAS). One of the main features of the GAS was the 'formation of acute erosions in the digestive tract, particularly in the stomach, small intestine and appendix'. This provided experimental evidence for the view based on clinical data that gastro-duodenal (peptic) ulcers could be caused by stress. This hypothesis was challenged by Marshall and Warren's Nobel Prize (2005)-winning discovery of a causal association between Helicobacter pylori and peptic ulcers. However, clinical and experimental studies suggest that stress can cause peptic ulceration in the absence of H. pylori Predictably, the etiological pendulum of gastric and duodenal ulceration has swung from 'all stress' to 'all bacteria' followed by a sober realization that both factors play a role, separately as well as together. This raises the question as to whether stress and H. pylori interact, and if so, how? Stress has also been implicated in inflammatory bowel disease (IBD) and related disorders; however, there is no proof yet that stress is the primary etiological trigger for IBD. Central dopamine mechanisms seem to be involved in the stress induction of peptic ulceration, whereas activation of the sympathetic nervous system and central and peripheral corticotrophin-releasing factor appears to mediate stress-induced IBD.

Vitamin E: a potential therapy for gastric mucosal injury

CONTEXT

Many scientific reports have shown the involvement of oxidative stress and inflammation as well as diminished gastroprotective substances in the pathogenesis of gastric lesions using various models. Therefore, treatment with antioxidants like tocopherol and tocotrienol may afford beneficial effects in attentuating the formation of the gastric lesions.

OBJECTIVE

The aim of this work was to summarize documented reports on the effects of vitamin E on various models of gastric lesion.

METHODS

A literature search was performed from databases in Medline (PubMed), Web of Science, ScienceDirect, and Googlescholar from June to December 2013.

RESULTS AND CONCLUSION

The potential roles of tocopherol and tocotrienol in modifying the effects of ulcerogenic agents are discussed in this review. The protective effects of the vitamin E might involve ameliorating oxidative stress and inflammation as well as restoration of endogenous gastroprotective substances. This vitamin has the potential to be used as a therapy for gastric mucosal injury.

Peptic ulcers after the Great East Japan earthquake and tsunami: possible existence of psychosocial stress ulcers in humans

BACKGROUND

Societal stress derived from an event that affects the whole society, e. g., a natural disaster, provides a unique, indirect way of determining the relationship between psychological stress and peptic ulcer disease in humans. In this study, we investigated the changing patterns of the incidence of peptic ulcers before and after the Great East Japan earthquake, which occurred on 11 March, 2011.

METHODS

Clinical data of patients with peptic ulcers were retrospectively collected during the 3 months after the earthquake (2011) from 7 major hospitals in the middle of the stricken area, and were compared with the data for the same period of the previous year (2010). The eligible subjects were classified into four groups according to Helicobacter pylori infection status and intake of nonsteroidal anti-inflammatory drugs (NSAIDs).

RESULTS

The incidence of all types of peptic ulcers was 1.5-fold increased after the earthquake, and in particular, the incidence of hemorrhagic ulcers was 2.2-fold increased; the gastric ulcer/duodenal ulcer ratio in hemorrhagic ulcers was also significantly increased (p < 0.05). Regarding the etiology of the peptic ulcers, the proportion of non-H. pylori and non-NSAID ulcers was significantly increased, from 13 % in 2010 to 24 % in 2011 after the earthquake (p < 0.05).

CONCLUSION

In addition to the increased incidence of peptic ulcers, compositional changes in the disease were observed after the Great East Japan earthquake. The significant increase in the proportion of non-H. pylori and non-NSAID ulcers after the earthquake indicated that psychological stress alone induced peptic ulcers in humans independently of H. pylori infection and NSAID intake.

Cathelicidin protects against Helicobacter pylori colonization and the associated gastritis in mice

Cathelicidin, an antimicrobial peptide of the innate immune system, has been shown to modulate microbial growth, wound healing and inflammation. However, whether cathelicidin controls Helicobacter pylori infection in vivo remains unexplored. This study sought to elucidate the role of endogenous and exogenous mouse cathelicidin (CRAMP) in the protection against H. pylori infection and the associated gastritis in mice. Results showed that genetic ablation of CRAMP in mice significantly increased the susceptibility of H. pylori colonization and the associated gastritis as compared with the wild-type control. Furthermore, replenishment with exogenous CRAMP, delivered via a bioengineered CRAMP-secreting strain of Lactococcus lactis, reduced H. pylori density in the stomach as well as the associated inflammatory cell infiltration and cytokine production. Collectively, these findings indicate that cathelicidin protects against H. pylori infection and its associated gastritis in vivo. Our study also demonstrates the feasibility of using the transformed food-grade bacteria to deliver cathelicidin, which may have potential clinical applications in the treatment of H. pylori infection in humans.

Psychological stress enhances the colonization of the stomach by Helicobacter pylori in the BALB/c mouse

Helicobacter pylori infection is a risk factor for development of peptic ulcers, and psychological stress (PS) may have a role in the pathogenesis of this condition. However, no interaction between PS and H. pylori infection (HI) has been established in the development of peptic ulcer, because colonization by H. pylori is the first step in the infection of the gastric mucosa, we examined H. pylori colonization of the stomach in BALB/c mice after PS. The mice were subjected to PS in a communication box test, in which they observed other mice experiencing a physical stressor (electrical) before they were inoculated with H. pylori. We found that the H. pylori colonization in the stomach of psychologically stressed mice was significantly greater than in the control mice (P < 0.05), and histological examination showed that the gastric mucosal injury in the stressed mice was more extensive than in the control mice (P < 0.05). To explore the underlying mechanisms, we administered RU486 (a type II glucocorticoid (GC) receptor antagonist) to antagonize the effect of endogenous corticosterone: this treatment decreased colonization by H. pylori in the psychologically stressed mice. We conclude that HI of the stomach of BALB/c mice is enhanced by PS, and the effect may be mediated by GCs.

Gender-specific association between iron status and the history of attempted suicide: implications for gender paradox of suicide behaviors

PURPOSE

Iron deficiency (ID) has been linked with high impulsivity, and an increased risk of ID was reported among suicide attempters. We hypothesized that poor iron status might be prevalent among suicide attempters, who have high impulsivity.

METHODS

As a part of the third National Health and Nutrition Examination Survey (1988-1994), a set of iron indices were measured in 2598 men and 2975 women aged 17-39 years, who completed a mental disorder diagnostic interview.

RESULTS

Using non-attempters as reference within each gender, we observed a gender-dependent association between poor iron status and the history of attempted suicide. For male attempters (n=74), the prevalence ratios (PR) of abnormal serum ferritin, serum iron and protoporphyrin were 18.3 (95%CI=3.3-101.7), 3.2 (1.1-9.4) and 5.4(1.8-15.6). In contrast, the PR of abnormal serum ferritin for female attempters (n=217) was 0.3 (0.1-0.6). The hematological indices did not differ significantly between attempters and non-attempters among either men or women. Compared with non-attempters, male attempters were prone to a higher odds [17.5 (4.2-72.4)] while female attempters to a lower odds [0.6 (0.3-1.1)] of ID.

CONCLUSION

These data suggest new opportunities for exploring biological bases of gender paradox of suicidal behaviors and a novel way to enhance therapeutic and preventive interventions against suicide.

Salt and stress synergize H. pylori-induced gastric lesions, cell proliferation, and p21 expression in Mongolian gerbils

Our aim was to determine if salt and stress enhance Helicobacter pylori (Hp) lesions in Meriones unguiculatus. Two hundred seventy-eight pathogen-free gerbils were allocated to seven groups: Hp-Sydney strain (45), 8% higher-salt diet (38), stress (60% space reduction/water immersion; 36), Hp + salt (33), Hp + stress (34), N-methyl-N-nitro-N-nitrosoguanidine (34), and sham (58). Gerbils were sacrificed at 1 week (67), 12 weeks (73), 52 weeks (65), and 68 weeks (73). Sydney, Padova, and Lauren classifications were blindly used. Proliferation, p53, p21, and apoptosis were assessed. Follicular active gastritis (grade 2/3) was observed in 10% of Hp gerbils, 38% of Hp + salt gerbils, and 29% of Hp + stress gerbils at 52 weeks and 67%, 83%, and 43% at 68 weeks (P < 0.05). Heterotopic proliferative glands were identified in synergy groups from 52 weeks, with increases in their number and size by 68 weeks. Higher proliferative rates were observed in Hp+salt gerbils (P < 0.0001), and p21 overexpression in Hp+salt and Hp+stress gerbils (both P's < 0.0001), by 68 weeks, without p53 increases. We conclude that salt and stress synergize Hp damage and increase pseudo-invasive gland foci.

Effects of nitric oxide on gastric ulceration induced by nicotine and cold-restraint stress

AIM: Stress induces gastric ulceration in human and experimental animals. People tend to smoke more cigarettes when under stress. Nitric oxide (NO) and nicotine have opposing effects on gastric integrity. The present study examined the possible therapeutic benefit of NO in nicotine-treated rats with stress-induced gastric ulceration.

METHODS: Rats drank a nicotine solution while control rats drank tap water for 20 days. The alkoloid was then replaced by water with or without supplementation of isosorbide dinitrate (NO donor) for an additional 10 days. Isosorbide dinitrate was given twice shortly before experiments (acute) or three times daily by oral gavages for 10 days after the rats stopped drinking nicotine solution. At the end of experiments, ulcer index, gastric adhesion mucus content and MPO activity were measured and analysed.

RESULTS: Nicotine treatment decreased gastric mucus content and intensified stress-induced gastric ulcer. A higher ulcer index persisted even after the rats stopped drinking nicotine solution for 10 days. Acute NO donor showed no benefit on both mucus and ulcer index in nicotine treatment or/and stress condition. Chronic NO donor treatment reversed the worsening action of nicotine in stomach. Stress increased gastric mucosal myeloperoxidase (MPO) activity, which was antagonized by chronic NO treatment. However, nicotine was unlikely to change mucosal MPO activity.

CONCLUSION: The intensifying action of nicotine on stress-induced gastric ulceration persists for 10 days after cessation. Nicotine treatment significantly decreases gastric mucus content that can be restored by chronic NO donor treatment. The present study suggests that NO antagonizes the ulcerogenic action of nicotine through a cytoprotective way.

Gastroduodenal mucosal defense: an integrated protective response

PURPOSE OF REVIEW

The remarkable resistance of the mucosal lining the upper gastrointestinal tract to concentrated gastric acid remains one of the biggest unsolved mysteries of upper gastrointestinal physiology. Even with the discovery of the involvement of Helicobacter pylori in gastroduodenal injury, the mechanism by which the organism causes injury remains unresolved. In the past year, there have been striking findings regarding trefoil peptides, the protective effect of regulatory peptides such as adrenomedullin, and the influence of H. pylori on the junctions that join the epithelial cells.

RECENT FINDINGS

Trefoil peptide-2-deficient mice were more susceptible to gastric injury from nonsteroidal anti-inflammatory agents, confirming that trefoil peptides increased the barrier properties of the pre-epithelial mucus gel. With regard to H. pylori, the gastric mucosa of mice deficient in the tyrosine phosphatase receptor type Z were not damaged by H. pylori vacuolating cytotoxin. Proton pump inhibition appears to be equally or more effective in upper gastrointestinal mucosal protection compared with other interventions such as exogenous prostaglandins or H. pylori eradication.

SUMMARY

Peptic ulcer disease, although declining in prevalence, appears to be increasing in virulence, perhaps because of the overall aging of the population and improved intensive care unit care. Although H. pylori and nonsteroidal anti-inflammatory drugs have been identified as key pro-ulcerogenic factors, many ulcers may also result from a deficiency of other, unknown host protective factors. A more detailed understanding of the host factors involved in mucosal protection will thus help identify novel therapeutic targets aimed at the prevention and treatment of upper gastrointestinal mucosal injury.