Lansoprazole, a proton pump inhibitor, mediates anti-inflammatory effect in gastric mucosal cells through the induction of heme oxygenase-1 via activation of NF-E2-related factor 2 and oxidation of kelch-like ECH-associating protein 1

The Role of Proton Pump Inhibitors in the Realm of Idiopathic Pulmonary Fibrosis and its Associated Comorbidities: A Systematic Review

As the global incidence of idiopathic pulmonary fibrosis (IPF) is on the rise, there is a need for better diagnostic criteria, better treatment options, early and appropriate diagnosis, adequate care, and a multidisciplinary approach to the management of patients. This systematic review explores the role of proton pump inhibitors (PPIs) in IPF and answers the question, "Does proton pump inhibitor improve only the prognosis of gastroesophageal associated idiopathic pulmonary fibrosis or for other types of idiopathic pulmonary fibrosis too?" We used PubMed (PMC) and Google Scholar for data collection for this systematic review and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for conducting this review. After in-depth literature screening and quality appraisal, 12 articles were selected for this systematic review. On the one hand, the efficacy of PPI therapy is supported by research such as the CAPACITY and ASCEND trials, a pilot randomized control trial (RCT) investigating the role of omeprazole in IPF and a bidirectional two-sample Mendelian randomization (MR) study, respectively. On the other hand, a systematic review and meta-analysis on antacid and antireflux surgery in IPF negate these results and show no statistical significance. Questions regarding the efficacy of PPI therapy must be dealt with in an adequately powered multicenter and double-blinded randomized control trial. The anti-inflammatory properties of antacids can serve as the cornerstone for future trials. In the following systematic review, antacid, antireflux therapy, omeprazole, and proton pump therapy are synonymous with stomach acid suppression therapy.

Translation of mechanistic advances in preeclampsia to the clinic: Long and winding road

As one of the leading causes of premature birth and maternal and infant mortality worldwide, preeclampsia remains a major unmet public health challenge. Preeclampsia and related hypertensive disorders of pregnancy are estimated to cause >75 000 maternal and 500 000 infant deaths globally each year. Because of rising rates of risk factors such as obesity, in vitro fertilization and advanced maternal age, the incidence of preeclampsia is going up with rates ranging from 5% to 10% of all pregnancies worldwide. A major discovery in the field was the realization that the clinical phenotypes related to preeclampsia, such as hypertension, proteinuria, and other adverse maternal/fetal events, are due to excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1, also referred to as sVEGFR-1). sFlt-1 is an endogenous anti-angiogenic protein that is made by the placenta and acts by neutralizing the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). During the last decade, this work has spawned a new era of molecular diagnostics for early detection of this condition. Antagonizing sFlt-1 either by reducing production or blocking its actions has shown salutary effects in animal models. Further, in early-stage human studies, the therapeutic removal of sFlt-1 from maternal circulation has shown promise in delaying disease progression and improving outcomes. Recently, the FDA approved the first molecular test for preterm preeclampsia (sFlt-1/PlGF ratio) for clinical use in the United States. Measuring serum sFlt-1/PlGF ratio in the acute hospital setting may aid short-term management, particularly regarding step-up or step-down of care, decision to transfer to settings better equipped to manage both the mother and the preterm neonate, appropriate timing of administration of steroids and magnesium sulfate, and in expectant management decisions. The test itself has the potential to save lives. Furthermore, the availability of a molecular test that correlates with adverse outcomes has set the stage for interventional clinical trials testing treatments for this disorder. In this review, we will discuss the role of circulating sFlt-1 and related factors in the pathogenesis of preeclampsia and specifically how this discovery is leading to concrete advances in the care of women with preeclampsia.

Lansoprazole protects hepatic cells against cisplatin-induced oxidative stress through the p38 MAPK/ARE/Nrf2 pathway

Lansoprazole, a proton pump inhibitor, can exert antioxidant effects through the induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, independently of the inhibition of acid secretion in the gastrointestinal tract. Lansoprazole has been reported to provide hepatoprotection in a drug-induced hepatitis animal model through the Nrf2/heme oxygenase-1 (HO1) pathway. We sought to investigate the molecular mechanism of cytoprotection by lansoprazole. An in vitro experimental model was conducted using cultured rat hepatic cells treated with lansoprazole to analyze the expression levels of Nrf2 and its downstream genes, the activity of Nrf2 using luciferase reporter assays, cisplatin-induced cytotoxicity, and signaling pathways involved in Nrf2 activation. Lansoprazole treatment of rat liver epithelial RL34 cells induced transactivation of Nrf2 and the expression of the Nrf2-dependent antioxidant genes encoding HO1, NAD(P)H quinone oxidoreductase-1, and glutathione S-transferase A2. Furthermore, cycloheximide chase experiments revealed that lansoprazole prolongs the half-life of the Nrf2 protein. Notably, cell viability was significantly increased by lansoprazole treatment in a cisplatin-induced cytotoxicity model. Moreover, the siRNA knockdown of Nrf2 fully abolished the cytoprotective effect of lansoprazole, whereas the inhibition of HO1 by tin-mesoporphyrin only partially abolished this. Finally, lansoprazole promoted the phosphorylation of p38 mitogen-activated protein kinase (MAPK) but not that of the extracellular signal-regulated kinase or the c-Jun N-terminal kinase. Using SB203580, a specific inhibitor for p38 MAPK, the lansoprazole-induced Nrf2/antioxidant response elements pathway activation and cytoprotective effects were shown to be exclusively p38 MAPK dependent. Lansoprazole was shown by these results to exert a cytoprotective effect on liver epithelial cells against the cisplatin-induced cytotoxicity through the p38 MAPK signaling pathway. This could have potential applications for the prevention and treatment of oxidative injury in the liver.

Association between clinical use of lansoprazole and the risk of type 2 diabetes mellitus: a pharmacoepidemiological cohort study

BACKGROUND

Proton pump inhibitors (PPIs) are common and widely used for gastrointestinal-related disorders. Lansoprazole is one of PPIs with potential benefits of anti-inflammation, reduced oxidative stress, and anti-diabetes. The aims of this study are to determine whether lansoprazole imparts differential risk of type 2 diabetes as compared with other PPIs.

METHODS

A population-based retrospective cohort study was conducted using the National Health Insurance Research Database in Taiwan. Patients who received lansoprazole more than 90 days and without records of use of other PPIs between January 1, 2000 and December 31, 2005 (the exposure period) were considered as the exposed cohort (n = 1668). In comparison, patients who received other PPIs more than 90 days and without use of lansoprazole in the exposure period were treated as the comparison cohort (n = 3336).The primary outcome was the new-onset of type 2 diabetes mellitus (T2DM). The association between use of lansoprazole and the risk of T2DM was determined by hazard ratios (HRs) and 95% confidence intervals (CIs) derived from multivariable Cox proportional hazards models.

RESULTS

The lansoprazole cohort showed a significantly reduced risk of T2DM with an adjusted HR of 0.65 (95% CI 0.56-0.76). Interestingly, the inverse association between use of lansoprazole and risk of T2DM was observed in both genders and in various age groups.

CONCLUSION

The present study findings suggest that lansoprazole was associated with a reduced risk of T2DM compared with other PPIs. Further studies are needed to determine the clinical implications of the present study.

Novel therapeutic and diagnostic approaches for preeclampsia

PURPOSE OF REVIEW

This review will summarize recent findings relating to the diagnostic approach to preeclampsia and current avenues of research aimed at modifying the underlying disease process.

RECENT FINDINGS

Growing international consensus supports a broad preeclampsia definition that incorporates maternal end-organ and uteroplacental dysfunction. Recent evidence demonstrates that this definition better identifies women and babies at risk of adverse outcomes compared to the traditional definition of hypertension and proteinuria. Multiple studies have demonstrated the usefulness and cost-effectiveness of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 and placental growth factor as a clinical adjunct to diagnose and predict severity of preeclampsia associated outcomes. Current novel therapeutic approaches to preeclampsia target pathogenic pathways (e.g. antiangiogenesis) or downstream effects such as oxidative stress and nitric oxide. Recent findings relating to these promising candidates are discussed. Multicenter clinical trials are needed to evaluate their effectiveness and ability to improve fetal and maternal outcomes.

SUMMARY

We provide an updated framework of the current approaches to define and diagnose preeclampsia. Disease modifying therapies (in particular, targeting the angiogenic pathway) are being developed for the first time and promise to revolutionize the way we manage preeclampsia.

Catalytic Asymmetric Construction of CF3-Substituted Chiral sp3 Carbon Centers

Due to the unique steric and electronic nature of the fluorine atom, organofluorine compounds have received significant attention in the fields of pharmaceuticals and agrochemicals. In particular, the CF3 group is frequently found in biologically active compounds. However, compared to aryl- and alkenyl-CF3-containing molecules, the construction of sp3 carbon-based alkyl-CF3-containing molecules, particularly via catalytic enantioselective synthesis, remains a considerable challenge in spite of their high potential in medicinal applications. This short review focuses on recent advances in this research area, and the reported strategies are categorized according to reaction types and starting substrates. In addition, chiral catalysts, substrate scope, and reaction mechanisms are briefly summarized.

1 Introduction

2 Stereoselective Introduction of a CF3 Group

2.1 Nucleophilic Addition to Carbonyls and Imines

2.2 Electrophilic Substitution at the α Position of Carbonyls

2.3 Allylic Nucleophilic Substitution

3 Stereoselective Functionalization of CF3-Substituted Molecules

3.1 Electrophilic Substitution of α-CF3 Carbonyls

3.2 Substitution of α-Halo CF3 Compounds

3.3 Addition-Type Reactions with CF3-Substituted Alkenes

4 Conclusion and Outlook

Korean Red Ginseng Extract Inhibits IL-8 Expression via Nrf2 Activation in Helicobacter pylori-Infected Gastric Epithelial Cells

Helicobacter pylori (H. pylori) causes gastric diseases by increasing reactive oxygen species (ROS) and interleukin (IL)-8 expression in gastric epithelial cells. ROS and inflammatory responses are regulated by the activation of nuclear factor erythroid-2-related factor 2 (Nrf2) and the expression of Nrf2 target genes, superoxide dismutase (SOD) and heme oxygenase-1 (HO-1). We previously demonstrated that Korean red ginseng extract (RGE) decreases H. pylori-induced increases in ROS and monocyte chemoattractant protein 1 in gastric epithelial cells. We determined whether RGE suppresses the expression of IL-8 via Nrf2 activation and the expression of SOD and HO-1 in H. pylori-infected gastric epithelial AGS cells. H. pylori-infected cells were treated with RGE with or without ML385, an Nrf2 inhibitor, or zinc protoporphyrin (ZnPP), a HO-1 inhibitor. Levels of ROS and IL-8 expression; abundance of Keap1, HO-1, and SOD; levels of total, nuclear, and phosphorylated Nrf2; indices of mitochondrial dysfunction (reduction in mitochondrial membrane potential and ATP level); and SOD activity were determined. As a result, RGE disturbed Nrf2–Keap1 interactions and increased nuclear Nrf2 levels in uninfected cells. H. pylori infection decreased the protein levels of SOD-1 and HO-1, as well as SOD activity, which was reversed by RGE treatment. RGE reduced H. pylori-induced increases in ROS and IL-8 levels as well as mitochondrial dysfunction. ML385 or ZnPP reversed the inhibitory effect of RGE on the alterations caused by H. pylori. In conclusion, RGE suppressed IL-8 expression and mitochondrial dysfunction via Nrf2 activation, induction of SOD-1 and HO-1, and reduction of ROS in H. pylori-infected cells.

Effect of anti-reflux therapy on pulmonary function in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

Current guideline conditionally recommends regular use of anti-reflux medication in idiopathic pulmonary fibrosis (IPF). However, the effect of anti-reflux therapy in this group remains controversial. We systematically reviewed literatures to evaluate whether anti-reflux therapy could ameliorate pulmonary function in IPF.

Methods

We performed electronic search in PubMed, Embase and CENTRAL (Cochrane Central Register of Controlled Trials) to identify original articles published in English language. We included randomized controlled trials (RCTs) and observational studies regarding anti-reflux therapy on pulmonary function in IPF. Qualitative and quantitative analyses were conducted. In quantitative analysis, the inverse-variance method with fixed-effect model was used to analyze pooled data.

Results

Fifteen studies (2 RCTs and 13 observational studies) including 3,891 patients with IPF were included. Pooled analysis suggested that anti-reflux therapy did not improve forced vital capacity (FVC)% predicted [mean difference (MD) =0.88, 95% confidence interval (CI): −0.22 to 1.98, P=0.12, I² =0%, 8 studies, n=3,076], diffusing capacity of the lung for carbon monoxide (DLCO) % predicted (MD =0.75, 95% CI: −0.13 to 1.62, P=0.10, I² =0%, 8 studies, n=3,073), and FVC decline (MD =0.02, 95% CI: −0.01 to 0.04, P=0.29, I² =17%, 5 studies, n=1,586) in IPF.

Discussion

Anti-reflux therapy may not ameliorate pulmonary function in IPF. However, adequately powered studies are warranted to validate the present findings.

Lansoprazole enhances the antidiabetic effect of dapagliflozin in fortified diet-fed streptozotocin-treated diabetic rats

Dapagliflozin (DAPA) is used for treating type 2 diabetes, whereas lansoprazole (LPZ) is used as a traditional antiulcer drug. The present study investigated the possible antidiabetic effects of LPZ on fortified diet-fed streptozotocin (FDF/STZ)-induced insulin-resistant diabetic rats. On the basis of the current results, it can be concluded that LPZ could be used as an add-on drug along with the conventional treatment for T2D as it showed beneficial effects in the current experimental model of insulin resistance.

Regulation of adipocyte differentiation and metabolism by lansoprazole

AIMS

Lansoprazole (LPZ) is one of the most commonly prescribed drugs for treatment of acid-related diseases, and it is increasingly recognized for its potential application as an anti-diabetic therapy. Although LPZ target tissues remain poorly understood, possible sites of action include adipose tissue. In this study, we assessed effects of LPZ on adipocyte differentiation and function by using 3T3-L1 preadipocytes and HFD-induced obesity mice as an in vitro and in vivo model, respectively.

MAIN METHODS

Oil red O staining and intracellular triacylglycerol content were used to determine lipid accumulation. Glucose uptake was performed to measure mature adipocyte function. Expression of adipocyte genes was determined by qRT-PCR and immunoblotting.

KEY FINDINGS

LPZ has dual effects on differentiation of 3T3-L1 cells. At low concentrations, LPZ enhanced adipocyte differentiation via induction of PPARγ and C/EBPα, two master adipogenic transcription factors, as well as lipogenic proteins, ACC1 and FASN. Increasing of adipocyte number subsequently increased basal and insulin-stimulated glucose uptake, and expression of Glut4 mRNA. Conversely, high concentrations of LPZ strongly inhibited differentiation and expression of PPARγ and C/EBPα, and maintained expression of preadipocytes markers, β-catenin and Pref-1. Inhibition of adipogenesis by LPZ reduced mature adipocyte number, Glut4 mRNA expression and insulin-stimulated glucose uptake. In addition, treatment with LPZ at 200 mg/kg significantly reduced body weight gain and total fat mass in HFD-induced obese mice.

SIGNIFICANCE

These results indicate that effects of LPZ on adipocyte differentiation are dependent on concentration and are correlated with PPARγ and C/EBPα.

α-Lipoic Acid Inhibits IL-8 Expression by Activating Nrf2 Signaling in Helicobacter pylori-infected Gastric Epithelial Cells

Helicobacter pylori (H. pylori) causes gastritis and gastric cancers. Oxidative stress is involved in the pathological mechanism of H. pylori-induced gastritis and gastric cancer induction. Therefore, reducing oxidative stress may be beneficial for preventing the development of H. pylori-associated gastric diseases. Nuclear factor erythroid-2-related factor 2 (Nrf2) is a crucial regulator for the expression of antioxidant enzyme heme oxygenase-1 (HO-1), which protects cells from oxidative injury. α-Lipoic acid (α-LA), a naturally occurring dithiol, shows antioxidant and anti-inflammatory effects in various cells. In the present study, we examined the mechanism by which α-LA activates the Nrf2/HO-1 pathway, suppresses the production of pro-inflammatory cytokine interleukine-8 (IL-8), and reduces reactive oxygen species (ROS) in H. pylori-infected AGS cells. α-LA increased the level of phosphorylated and nuclear-translocated Nrf2 by decreasing the amount of Nrf2 sequestered in the cytoplasm by complex formation with Kelch-like ECH1-associated protein 1 (KEAP 1). By using exogenous inhibitors targeting Nrf2 and HO-1, we showed that up-regulation of activated Nrf2 and of HO-1 results in the α-LA-induced suppression of interleukin 8 (IL-8) and ROS. Consumption of α-LA-rich foods may prevent the development of H. pylori-associated gastric diseases by decreasing ROS-mediated IL-8 expression in gastric epithelial cells.

The Proton Pump Inhibitor Lansoprazole Has Hepatoprotective Effects in In Vitro and In Vivo Rat Models of Acute Liver Injury

BACKGROUND/AIMS

The proton pump inhibitor lansoprazole (LPZ) is clinically used to reduce gastric acid secretion, but little is known about its possible hepatoprotective effects. This study aimed to investigate the hepatoprotective effects of LPZ and its potential mechanisms using in vitro and in vivo rat models of liver injury.

METHODS

For the in vitro model of liver injury, primary cultured rat hepatocytes were treated with interleukin-1β in the presence or absence of LPZ. The influence of LPZ on inducible nitric oxide synthase (iNOS) induction and nitric oxide (NO) production and on the associated signaling pathways was analyzed. For the in vivo model, rats were treated with D-galactosamine (GalN) and lipopolysaccharide (LPS). The effects of LPZ on survival and proinflammatory mediator expression (including iNOS and tumor necrosis factor-α) in these rats were examined.

RESULTS

LPZ inhibited iNOS induction partially through suppression of the nuclear factor-kappa B signaling pathway in hepatocytes, thereby reducing potential liver injury from excessive NO levels. Additionally, LPZ increased survival by 50% and decreased iNOS, tumor necrosis factor-α, and cytokine-induced neutrophil chemoattractant-1 mRNA expression in the livers of GalN/LPS-treated rats. LPZ also inhibited nuclear factor-kappa B activation by GalN/LPS.

CONCLUSIONS

LPZ inhibits the induction of several inflammatory mediators (including cytokines, chemokines, and NO) partially through suppression of nuclear factor-kappa B, resulting in the prevention of fulminant liver failure. The therapeutic potential of LPZ for liver injuries warrants further investigation.

A comparative study on the possible protective effect of esomeprazole, spirulina, wheatgrass on indomethacin-induced gastric ulcer in male albino rats

Gastric ulcer is a common problem affecting the gastrointestinal tract. Spirulina and wheatgrass are natural substances that have anti-inflammatory and antioxidant effects. The aim of the Work was to elucidate the possible protective role of spirulina and wheatgrass versus standard treatment esomeprazole on indomethacin-induced gastric ulcer in adult male albino rats. Eighty adult male albino rats were divided into eight groups: group I (the control group), group II that received indomethacin (100 mg/kg orally), group III that received esomeprazole (20 mg/kg orally), group IV that received spirulina (1000 mg/kg orally), group V that received wheatgrass (1000 mg/kg orally), group VI that received indomethacin (100 mg/kg) + esomeprazole (20 mg/kg), group VII that received indomethacin (100 mg/kg) + spirulina (1000 mg/kg) and group VIII that received indomethacin (100 mg/kg) + wheatgrass (1000 mg/kg). Six hours after indomethacin treatment, all rats were anesthetized and their stomachs obtained for measures of gastric acidity, pepsin activity, mucin content, gastrin, ulcer index, total antioxidant capacity (TAC), tumor necrosis factor -α (TNF-α), interleukin-8 (IL8), proapoptotic protein (Bax). Histological (using H&E stain, PAS reaction) and immunohistochemical (using anti Ki67 immunostain) techniques were performed. Western immunoblot analysis for heat shock protein 70 (HSP70) was also done. Moreover, a morphometric study was done for area% of positive immunoreactive cells for Ki67 and optical density and area% of PAS reaction. All performed measurements were followed by statistical analysis. Indomethacin induced loss of normal architecture of gastric mucosa with sloughing of surface epithelium and inflammatory cellular infiltration. It also led to a significant increase in gastric acidity, inflammatory mediators (TNF-α, IL-8), pro-apoptotic protein Bax and a significant decrease in TAC levels and HSP-70 expression. There was also a significant decrease in area% of Ki67 immunoreactivity and area% and optical density of PAS reaction as compared with the control group and other pre-treated rats. These disturbed parameters were associated with increased ulcer index. In pre-treatment groups, the structure of the mucosa was similar to control with marked improvement in the biochemical assay. In conclusion, Spirulina and wheatgrass can partly protect the gastric mucosa against indomethacin-induced damage to a degree similar to that of the classical treatment esomeprazole.

Protocatechuic acid-mediated DJ-1/PARK7 activation followed by PI3K/mTOR signaling pathway activation as a novel mechanism for protection against ketoprofen-induced oxidative damage in the gastrointestinal mucosa

Oxidative stress contributes to the progression of non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) cell apoptosis. In our previous study, we reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a protective role against ketoprofen-induced GI mucosal oxidative injury. Recent reports suggest that Nrf2 could exhibit antioxidative and antiapoptosis responses through up-regulation of DJ-1 (PARK7). In the current study, we proposed that induction of DJ-1 expression by protocatechuic acid (PCA) might provide a potential therapeutic approach for treating oxidative stress-associated GI ulcer diseases. The results indicated that PCA increased mRNA expression of glutathione peroxidase and heme oxygenase-1 through up-regulation of DJ-1 followed by Nrf2 translocation. Furthermore, PCA protected Int-407 cells against ketoprofen-induced oxidative stress by regulating the DJ-1, PI3K, and mTOR pathways. Pretreatment with PCA inhibited mitochondrial ROS generation, up-regulated the mitochondrial membrane potential, and down-regulated pro-apoptotic Bax as well as downstream caspase-8, caspase-9, and caspase-3 activity, and reversed impaired DJ-1 and anti-apoptotic Bcl-2 protein expression in Int-407 cells induced by ketoprofen. Similar to the in vitro results, SD rats treated with PCA before administration of ketoprofen exhibited decreased caspase-3 protein expression as well as oxidative damage, and impairment of the antioxidant system and DJ-1 protein expression in the GI mucosa were reversed. The administration of lansoprazole, a type of proton pump inhibitor (PPI), strongly inhibited ketoprofen-induced GI mucosal injuries via up-regulation of DJ-1, indicating that DJ-1 is essential for the dietary antioxidant- and PPI drug-mediated mechanism of ulcer therapy. These results suggest that DJ-1 could be a novel target for protection against ketoprofen-induced GI ulcers due to its antioxidant and anti-apoptosis characteristics.

Proton Pump Inhibitors in IPF: A Call for Clinical Trials

The recent FDA approval of two drugs, pirfenidone and nintedanib, for the treatment of idiopathic pulmonary fibrosis (IPF) has fueled interest in the development of additional drugs to treat the disease or its major clinical complications including cough and acute exacerbations. Since 2015, there are at least a dozen active interventional studies that are testing the efficacy of novel pharmacotherapies, exercise or stem cells in modifying the disease process in IPF. Additionally, there are combinatorial studies evaluating the effectiveness of pirfenidone or nintedanib in combination with other agents. However, there remains an urgent need for clinical trials to prospectively evaluate the efficacy of existing drugs with promising retrospective data, such as proton pump inhibitors (PPIs), in IPF. Several retrospective cohorts have provided tantalizing data supporting the beneficial effect of PPIs in patients with well-defined IPF. This review provides the general outlook of pharmacotherapies in IPF, and highlights preclinical and retrospective clinical data to make a case for randomized controlled clinical trials of PPIs in IPF.

Role of NRF2 in protection of the gastrointestinal tract against oxidative stress

The gastrointestinal tract is exposed to a variety of noxious factors, such as Helicobacter pylori, nonsteroidal anti-inflammatory drugs, gastric acid, ischemia-reperfusion, and mental stresses. Theses stressors generate free radicals within gastrointestinal tissues, causing organ injury and functional disturbance. Although the gastrointestinal tract can withstand such oxidative stresses to some extent by enhancing its antioxidant system via nuclear factor erythroid 2-related factor 2-Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1-mediated pathways, acute or chronic exposure to oxidative stress can cause several gastrointestinal tract disorders, such as inflammation, ulcers, cancers, and various functional disturbances. Recent studies have demonstrated that some natural compounds and drugs can upregulate the nuclear factor erythroid 2-related factor 2-mediated antioxidant system, ameliorating or preventing these disorders. Although these compounds may be useful as chemopreventive agents, sufficient evidence for their clinical efficacy has not yet been provided. In addition, it is important to note that excessive nuclear factor erythroid 2-related factor 2 stimulation can be harmful to human health, especially from the standpoint of tumor biology.

Low Soluble Fms-Like Tyrosine Kinase-1, Endoglin, and Endothelin-1 Levels in Women With Confirmed or Suspected Preeclampsia Using Proton Pump Inhibitors

Patients with preeclampsia display elevated placenta-derived sFlt-1 (soluble Fms-like tyrosine kinase-1) and endoglin levels and decreased placental growth factor levels. Proton pump inhibitors (PPIs) decrease trophoblast sFlt-1 and endoglin secretion in vitro. PPIs are used during pregnancy to combat reflux disease. Here, we investigated whether PPIs affect sFlt-1 in women with confirmed/suspected preeclampsia, making use of a prospective cohort study involving 430 women. Of these women, 40 took PPIs (6 esomeprazole, 32 omeprazole, and 2 pantoprazole) for 8 to 45 (median 29) days before sFlt-1 measurement. Measurements were only made once, at study entry between weeks 20 and 41 (median 33 weeks). PPI use was associated with lower sFlt-1 levels, with no change in placental growth factor levels, both when compared with all non-PPI users and with 80 gestational age-matched controls selected from the non-PPI users. No sFlt-1/placental growth factor alterations were observed in women using ferrous fumarate or macrogol while, as expected, women using antihypertensive medication displayed higher sFlt-1 levels and lower placental growth factor levels. The PPI use-associated decrease in sFlt-1 was independent of the application of antihypertensive drugs and also occurred when restricting our analysis to patients with hypertensive disease of pregnancy at study entry. PPI users displayed more cases with preexisting proteinuria, less gestational hypertension, and a lower number of neonatal sepsis cases. Finally, their plasma endoglin and endothelin-1 levels were lower while sFlt-1 levels correlated positively with both. In conclusion, PPI use associates with low sFlt-1, endoglin, and endothelin-1 levels, warranting prospective trials to investigate the therapeutic potential of PPIs in preeclampsia.

Idiopathic Pulmonary Fibrosis: Novel Concepts of Proton Pump Inhibitors as Antifibrotic Drugs

The prevalence of abnormal acid gastroesophageal reflux (GER) is higher in patients with idiopathic pulmonary fibrosis (IPF) than in matched control subjects. Several studies demonstrated that more than one-third of patients with IPF have abnormal esophageal acid exposures. In addition, many of these studies indicate that the majority of patients with IPF have silent reflux with no symptoms of GER. Findings of abnormal reflux persist in a large proportion of patients with IPF placed on antacid therapy such as proton pump inhibitors (PPIs). This seemingly paradoxical observation suggests that either patients with IPF are somehow resistant to PPI-based intervention or PPIs are inherently unable to suppress acid GER. By contrast, patients with IPF who undergo Nissen fundoplication surgery are effectively relieved from the complications of GER, and retrospective studies suggest improved lung function. Retrospective, anecdotal data suggest a beneficial role of PPIs in IPF including stabilization of lung function, reduction in episodes of acute exacerbation, and enhanced longevity. The recent evidence-based guidelines for treatment of IPF approved conditional recommendation of PPIs for all patients with IPF regardless of their GER status. Recently, we have reported that PPIs possess antiinflammatory and antifibrotic activities by directly suppressing proinflammatory cytokines, profibrotic proteins, and proliferation of lung fibroblasts. Our study provides an alternative explanation for the beneficial effect of PPIs in IPF. In this Perspective, we reviewed emerging progress on antifibrotic effect of PPIs using IPF as a disease model. In addition, we summarized surgical and pharmacological interventions for GER and their downstream effect on lung physiology.

Proton Pump Inhibitors Decrease Soluble fms-Like Tyrosine Kinase-1 and Soluble Endoglin Secretion, Decrease Hypertension, and Rescue Endothelial Dysfunction

Preeclampsia is a severe complication of pregnancy. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. Oxidative stress and vascular inflammation exacerbate the endothelial injury. A drug that can block these pathophysiological steps would be an attractive treatment option. Proton pump inhibitors (PPIs) are safe in pregnancy where they are prescribed for gastric reflux. We performed functional studies on primary human tissues and animal models to examine the effects of PPIs on sFlt-1 and soluble endoglin secretion, vessel dilatation, blood pressure, and endothelial dysfunction. PPIs decreased sFlt-1 and soluble endoglin secretion from trophoblast, placental explants from preeclamptic pregnancies, and endothelial cells. They also mitigated tumor necrosis factor-α-induced endothelial dysfunction: PPIs blocked endothelial vascular cell adhesion molecule-1 expression, leukocyte adhesion to endothelium, and disruption of endothelial tube formation. PPIs decreased endothelin-1 secretion and enhanced endothelial cell migration. Interestingly, the PPI esomeprazole vasodilated maternal blood vessels from normal pregnancies and cases of preterm preeclampsia, but its vasodilatory effects were lost when the vessels were denuded of their endothelium. Esomeprazole decreased blood pressure in a transgenic mouse model where human sFlt-1 was overexpressed in placenta. PPIs upregulated endogenous antioxidant defenses and decreased cytokine secretion from placental tissue and endothelial cells. We have found that PPIs decrease sFlt-1 and soluble endoglin secretion and endothelial dysfunction, dilate blood vessels, decrease blood pressure, and have antioxidant and anti-inflammatory properties. They have therapeutic potential for preeclampsia and other diseases where endothelial dysfunction is involved.

Proton Pump Inhibitors Do Not Reduce the Risk of Esophageal Adenocarcinoma in Patients with Barrett's Esophagus: A Systematic Review and Meta-Analysis

Objectives

Proton pump inhibitors (PPIs) have been used for treatment of Barrett's esophagus (BE) for many years. However, the connection between PPIs and esophageal adenocarcinoma (EAC) in patients with BE has still been controversial. The current systematic review and meta-analysis was designed to evaluate the association between PPIs and the risk of EAC or high-grade dysplasia (HGD) in patients with BE.

Methods

A systematic literature search of studies reporting the association between PPIs and the risk of EAC and/or HGD in patients with BE was conducted in PubMed, Embase, Web of Science and the Cochrane Library. Next, literature was screened using previously established criteria and relevant data were extracted from included studies. Finally, the software program Review Manage 5.2 was applied to aggregate data and analyze the results.

Results

Nine observational studies, comprising five cohort and four case-control studies (including a total of 5712 patients with BE), were identified. Upon meta-analysis, PPIs were found to have no association with the risk of EAC and/or HGD in patients with BE (unadjusted OR 0.43, 95% CI 0.17–1.08). Analysis for duration response relationship revealed no significant trend toward protection against EAC or HGD with PPIs usage for >2~3 years (one study using 7-year cutoff) when compared to usage for shorter time periods (PPIs usage >2~3 years vs. <2~3 years: OR 0.91 (95% CI 0.25–3.31) vs. 0.91 (0.40–2.07)).There also was considerable heterogeneity between studies.

Conclusion

No dysplasia- or cancer-protective effects of PPIs usage in patients with BE were identified by our analysis. Therefore, we conclude that clinicians who discuss the potential chemopreventive effects of PPIs with their patients, should be aware that such an effect, if exists, has not been proven with statistical significance.

Differentially expressed transcripts in stomach of Penaeus monodon in response to AHPND infection

Acute Hepatopancreatic Necrosis Disease (AHPND) is an emerging disease in aquacultured shrimp caused by a pathogenic strain of Vibrio parahaemolyticus. As with several pathogenic bacteria, colonization of the stomach appeared to be the initial step of the infection for AHPND-causing Vibrio. To understand the immune responses in the stomach of black tiger shrimp (Penaeus monodon), differentially expressed transcripts (DETs) in the stomach during V. parahaemolyticus strain 3HP (VP3HP) infection was examined using Ion Torrent sequencing. From the total 42,998 contigs obtained, 1585 contigs representing 1513 unigenes were significantly differentially expressed with 1122 and 391 unigenes up- and down-regulated, respectively. Among the DETs, there were 141 immune-related unigenes in 10 functional categories: antimicrobial peptide, signal transduction pathway, proPO system, oxidative stress, proteinases/proteinase inhibitors, apoptotic tumor-related protein, pathogen recognition immune regulator, blood clotting system, adhesive protein and heat shock protein. Expression profiles of 20 of 22 genes inferred from RNA sequencing were confirmed with the results from qRT-PCR. Additionally, a novel isoform of anti-lipopolysaccharide factor, PmALF7 whose transcript was induced in the stomach after challenge with VP3HP was discovered. This study provided a fundamental information on the molecular response in the shrimp stomach during the AHPND infection that would be beneficial for future research.

Localized delivery of carbon monoxide

The heme oxygenase (HO)/carbon monoxide (CO) system is a physiological feedback loop orchestrating various cell-protective effects in response to cellular stress. The therapeutic use of CO is impeded by safety challenges as a result of high CO-Hemoglobin formation following non-targeted, systemic administration jeopardizing successful CO therapies as of this biological barrier. Another caveat is the use of CO-Releasing Molecules containing toxicologically critical transition metals. An emerging number of local delivery approaches addressing these issues have recently been introduced and provide exciting new starting points for translating the fascinating preclinical potential of CO into a clinical setting. This review will discuss these approaches and link to future delivery strategies aiming at establishing CO as a safe and effective medication of tomorrow.

The dual topoisomerase inhibitor A35 preferentially and specially targets topoisomerase 2α by enhancing pre-strand and post-strand cleavage and inhibiting DNA religation

DNA topoisomerases play a key role in tumor proliferation. Chemotherapeutics targeting topoisomerases have been widely used in clinical oncology, but resistance and side effects, particularly cardiotoxicity, usually limit their application. Clinical data show that a decrease in topoisomerase (top) levels is the primary factor responsible for resistance, but in cells there is compensatory effect between the levels of top1 and top2α. Here, we validated cyclizing-berberine A35, which is a dual top inhibitor and preferentially targets top2α. The impact on the top2α catalytic cycle indicated that A35 could intercalate into DNA but did not interfere with DNA-top binding and top2α ATPase activity. A35 could facilitate DNA-top2α cleavage complex formation by enhancing pre-strand and post-strand cleavage and inhibiting religation, suggesting this compound can be a topoisomerase poison and had a district mechanism from other topoisomerase inhibitors. TARDIS and comet assays showed that A35 could induce cell DNA breakage and DNA-top complexes but had no effect on the cardiac toxicity inducer top2β. Silencing top1 augmented DNA break and silencing top2α decreased DNA break. Further validation in H9c2 cardiac cells showed A35 did not disturb cell proliferation and mitochondrial membrane potency. Additionally, an assay with nude mice further demonstrated A35 did not damage the heart. Our work identifies A35 as a novel skeleton compound dually inhibits topoisomerases, and predominantly and specially targets top2α by interfering with all cleavage steps and its no cardiac toxicity was verified by cardiac cells and mice heart. A35 could be a novel and effective targeting topoisomerase agent.

Proton pump inhibitors in IPF: beyond mere suppression of gastric acidity

Proton pump inhibitors (PPIs) are structurally composed of benzimidazole core; a pharmacologically common scaffold that makes up nearly one quarter of the hundred most selling drugs including anticancer, opioid, antihistaminic and antihelmintic drugs. In medicinal chemistry, benzimidazoles are coined as privileged scaffolds due to their ability to recognize and bind diverse biological targets. In this regard, PPIs have been linked to other extra-intestinal functions including direct modulation of airway epithelial, vascular endothelial and immune cells. PPIs have been reported to improve outcomes in idiopathic pulmonary fibrosis (IPF) including slowing the decline in measures of lung function, reducing episodes of acute exacerbations and prolonging transplant-free survival. Recently, the evidence-based guidelines for IPF treatment conditionally recommended the use of PPIs in IPF. However, no prospective clinical trial has been conducted to empirically evaluate the safety and efficacy of PPIs in IPF. Here, we discuss emerging anti-inflammatory and antifibrotic activity of PPIs in the context of IPF. We also discuss possible molecular mechanisms by which PPIs may unleash their beneficial effect in IPF.

Pharmacological treatment of eosinophilic gastrointestinal disorders

INTRODUCTION

Eosinophilic gastrointestinal disorders (EGIDs) are increasingly prevalent chronic inflammatory diseases characterized by eosinophilic infiltration of the gastrointestinal (GI) tract, in the absence of other known causes of eosinophilia.

AREAS COVERED

Clinical management of EGIDs is challenging, as there are currently limited therapeutic options available. The most common EGID is eosinophilic esophagitis (EoE), and rarer forms are eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis. Clinical presentation depends on the affected GI site. Recently duodenal eosinophilia has been recognized to commonly be present in patients with functional dyspepsia. This review will provide an overview of the pathogenesis and therapeutic management of EGIDs, with particular focus on the pharmacological strategies for these conditions. Expert commentary: Despite the considerable progress made in understanding the pathogenesis of EGIDs, there is still an urgent need for the development of specific and effective therapeutic approaches. Therapeutic management protocols are required that are based on rigorous clinical investigation in large prospective controlled trials to better understand the risks, benefits and limitations of each therapy. More well-defined and consistent end-points are also required to assess treatment outcomes, as there has been variability between patient reported outcomes, clinical outcomes, and histological outcomes in the studies to date.

ALPK1 phosphorylates myosin IIA modulating TNF-α trafficking in gout flares

Gout is characterized by the monosodium urate monohydrate (MSU)-induced arthritis. Alpha kinase-1 (ALPK1) has shown to be associated with MSU-induced inflammation and gout. Here, we used bioinformatics, proteomics, cell models, and twenty in vitro human assays to clarify some of its role in the inflammatory response to MSU. We found myosin IIA to be a frequent interacting protein partner of ALPK1, binding to its N-terminal and forming a protein complex with calmodulin and F-actin, and that MSU-induced ALPK1 phosphorylated the myosin IIA. A knockdown of endogenous ALPK1 or myosin IIA significantly reduced the MSU-induced secretion of tumour necrosis factor (TNF)-α. Furthermore, all gouty patients expressed higher basal protein levels of ALPK1, myosin IIA, and plasma TNF-α, however those medicated with colchicine has shown reduced myosin IIA and TNF-α but not ALPK1. The findings suggest ALPK1 is a kinase that participates in the regulation of Golgi-derived TNF-α trafficking through myosin IIA phosphorylation in the inflammation of gout. This novel pathway could be blocked at the level of myosin by colchicine in gout treatment.

Renoprotective effect of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats

Proton pump inhibitors (PPIs) have exhibited glucose lowering action in animal models of diabetes; however, their potential in diabetes-related complications has not yet been evaluated. Hence, the present study has been undertaken to investigate the renoprotective potential of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats. Diabetic nephropathy was induced with a single injection of streptozotocin (STZ, 45 mg/kg, i.p.). Lansoprazole (40 mg/kg; 80 mg/kg, p.o.; 4 weeks) was administered to diabetic rats after 4 weeks of STZ treatment. A battery of biochemical tests such as serum glucose, glycated hemoglobin, blood urea nitrogen (BUN), serum creatinine, albumin, and kidney weight/body weight (%) ratio were performed to evaluate the renal functions. Oxidative stress was determined by estimating renal thiobarbituric acid reactive species (TBARS) and reduced glutathione (GSH) levels. Lipid profile was assessed by determining serum cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL). The STZ-treated rats demonstrated deleterious alterations in kidney functions, enhanced oxidative stress, and disturbed lipid profile. Administration of lansoprazole to diabetic rats significantly reduced serum glucose, glycated hemoglobin, BUN, creatinine, albumin levels, and oxidative stress. Serum lipids like TC and TG were decreased, and HDL was enhanced in lansoprazole-treated STZ rats. The findings of our study indicate that renoprotective effects of lansoprazole may be attributed to its glucose-lowering, lipid-lowering, and antioxidative potential.

Pleiotropic effect of the proton pump inhibitor esomeprazole leading to suppression of lung inflammation and fibrosis

Background

The beneficial outcome associated with the use of proton pump inhibitors (PPIs) in idiopathic pulmonary fibrosis (IPF) has been reported in retrospective studies. To date, no prospective study has been conducted to confirm these outcomes. In addition, the potential mechanism by which PPIs improve measures of lung function and/or transplant-free survival in IPF has not been elucidated.

Methods

Here, we used biochemical, cell biological and preclinical studies to evaluate regulation of markers associated with inflammation and fibrosis. In our in vitro studies, we exposed primary lung fibroblasts, epithelial and endothelial cells to ionizing radiation or bleomycin; stimuli typically used to induce inflammation and fibrosis. In addition, we cultured lung fibroblasts from IPF patients and studied the effect of esomeprazole on collagen release. Our preclinical study tested efficacy of esomeprazole in a rat model of bleomycin-induced lung injury. Furthermore, we performed retrospective analysis of interstitial lung disease (ILD) databases to examine the effect of PPIs on transplant-free survival.

Results

The cell culture studies revealed that esomeprazole controls inflammation by suppressing the expression of pro-inflammatory molecules including vascular cell adhesion molecule-1, inducible nitric oxide synthase, tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1β and IL-6). The antioxidant effect is associated with strong induction of the stress-inducible cytoprotective protein heme oxygenase-1 (HO1) and the antifibrotic effect is associated with potent inhibition of fibroblast proliferation as well as downregulation of profibrotic proteins including receptors for transforming growth factor β (TGFβ), fibronectin and matrix metalloproteinases (MMPs). Furthermore, esomeprazole showed robust effect in mitigating the inflammatory and fibrotic responses in a murine model of acute lung injury. Finally, retrospective analysis of two ILD databases was performed to assess the effect of PPIs on transplant-free survival in IPF patients. Intriguingly, this data demonstrated that IPF patients on PPIs had prolonged survival over controls (median survival of 3.4 vs 2 years).

Conclusions

Overall, these data indicate the possibility that PPIs may have protective function in IPF by directly modulating the disease process and suggest that they may have other clinical utility in the treatment of extra-intestinal diseases characterized by inflammatory and/or fibrotic phases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0614-x) contains supplementary material, which is available to authorized users.

Therapeutic roles of carbon monoxide in intestinal ischemia-reperfusion injury

Intestinal ischemia-reperfusion (I-R) injury is a complex, multifactorial, pathophysiological process with high morbidity and mortality, leading to serious difficulty in treatment. The mechanisms involved in the pathogenesis of intestinal I-R injury have been examined in detail and various therapeutic approaches for intestinal I-R injury have been developed; however, existing circumstances have not yet led to a dramatic change of treatment. Carbon monoxide (CO), one of the by-products of heme degradation by heme oxygenase (HO), is considered as a candidate for treatment of intestinal I-R injury and indeed HO-1-derived endogenous CO and exogenous CO play a pivotal role in protecting the gastrointestinal tract from intestinal I-R injury. Interestingly, anti-inflammatory effects of CO have been elucidated sufficiently in various cell types including endothelial cells, circulating leukocytes, macrophages, lymphocytes, epithelial cells, fibroblast, organ-specific cells, and immune-presenting cells. In this review, we herein focus on the therapeutic roles of CO in intestinal I-R injury and the cell-specific anti-inflammatory effects of CO, clearly demonstrating future therapeutic strategies of CO for treating intestine I-R injury.

Protective role of hemeoxygenase-1 in gastrointestinal diseases

Disorders and diseases of the gastrointestinal system encompass a wide array of pathogenic mechanisms as a result of genetic, infectious, neoplastic, and inflammatory conditions. Inflammatory diseases in general are rising in incidence and are emerging clinical problems in gastroenterology and hepatology. Hemeoxygenase-1 (HO-1) is a stress-inducible enzyme that has been shown to confer protection in various organ-system models. Its downstream effectors, carbon monoxide and biliverdin have also been shown to offer these beneficial effects. Many studies suggest that induction of HO-1 expression in gastrointestinal tissues and cells plays a critical role in cytoprotection and resolving inflammation as well as tissue injury. In this review, we examine the protective role of HO-1 and its downstream effectors in modulating inflammatory diseases of the upper (esophagus and stomach) and lower (small and large intestine) gastrointestinal tract, the liver, and the pancreas. Cytoprotective, anti-inflammatory, anti-proliferative, antioxidant, and anti-apoptotic activities of HO-1 make it a promising if not ideal therapeutic target for inflammatory diseases of the gastrointestinal system.

Nrf2-inducing anti-oxidation stress response in the rat liver--new beneficial effect of lansoprazole

Lansoprazole is a potent anti-gastric ulcer drug that inhibits gastric proton pump activity. We identified a novel function for lansoprazole, as an inducer of anti-oxidative stress responses in the liver. Gastric administration of lansoprazole (10–100 mg/kg) to male Wistar rats produced a dose-dependent increase in hepatic mRNA levels of nuclear factor, erythroid-derived 2, -like 2 (Nrf2), a redox-sensitive transcription factor, at 3 h and Nrf2 immunoreactivity (IR) in whole hepatic lysates at 6 h. Conversely, the levels of Kelch-like ECH-associated protein (Keap1), which sequesters Nrf2 in the cytoplasm under un-stimulated conditions, were unchanged. Translocation of Nrf2 into the nuclei of hepatocytes was observed using western blotting and immunohistochemistry. Expression of mRNAs for Nrf2-dependent antioxidant and phase II enzymes, such as heme oxygenase 1 (HO-1), NAD (P) H dehydrogenase, quinone 1 (Nqo1), glutathione S-transferase A2 (Gsta2), UDP glucuronosyltransferase 1 family polypeptide A6 (Ugt1a6), were dose-dependently up-regulated at 3 h. Furthermore, the levels of HO-1 IR were dose-dependently increased in hepatocytes at 6 h. Subcutaneous administration of lansoprazole (30 mg/kg/day) for 7 successive days resulted in up-regulation and nuclear translocation of Nrf2 IR in hepatocytes and up-regulation of HO-1 IR in the liver. Pretreatment with lansoprazole attenuated thioacetamide (500 mg/kg)-induced acute hepatic damage via both HO-1-dependent and -independent pathways. Up-stream networks related to Nrf2 expression were investigated using microarray analysis, followed by data mining with Ingenuity Pathway Analysis. Up-regulation of the aryl hydrocarbon receptor (AhR)-cytochrome P450, family 1, subfamily a, polypeptide 1 (Cyp1a1) pathway was associated with up-regulation of Nrf2 mRNA. In conclusion, lansoprazole might have an alternative indication in the prevention and treatment of oxidative hepatic damage through the induction of both phase I and phase II drug-metabolizing systems, i.e. the AhR/Cyp1a1/Nrf2 pathway in hepatocytes.

Eosinophilic oesophagitis: clinical presentation and pathogenesis

Eosinophilic oesophagitis (EoE) is an inflammatory disorder of the oesophagus which has become increasingly recognised over recent years, although it remains underdiagnosed in many centres. It is characterised histologically by a significant eosinophilic infiltration of the oesophageal mucosa (>15 eosinophils per high powered field), and clinically with features of oesophageal dysfunction such a dysphagia, food impaction, and proton pump inhibitor (PPI) resistant dyspepsia. Fibrosis and oesophageal remodelling may occur and lead to oesophageal strictures. An allergic predisposition is common in the EoE population, which appears to be primarily food antigen driven in children and aeroallergen driven in adults. Evidence suggests that the pathogenesis of EoE is due to a dysregulated immunological response to an environmental allergen, resulting in a T helper type 2 (Th2) inflammatory disease and remodelling of the oesophagus in genetically susceptible individuals. Allergen elimination and anti-inflammatory therapy with corticosteroids are currently the mainstay of treatment; however, an increasing number of studies are now focused on targeting different stages in the disease pathogenesis. A greater understanding of the underlying mechanisms resulting in EoE will allow us to improve the therapeutic options available.

Advances in prevention and treatment of chemotherapy-induced gastrointestinal mucositis with proton pump inhibitors

Proton pump inhibitors (PPIs) are potent acid-suppressive medications commonly used for management of acid-related diseases. Over the past decade, gastrointestinal injury following chemotherapy has attracted wide attention from oncologists. Two international clinical practice guidelines, the National Comprehensive Cancer Network (NCCN) and the Multinational Association of Supportive Care in Cancer (MASCC) antiemesis guidelines, recommend omeprazole for the treatment of chemotherapy-induced epigastric pain. In recent years, PPIs have been widely used for the prevention and treatment of chemotherapy-induced gastrointestinal mucositis. This paper summarizes the mechanisms by which chemotherapy causes damage to the gastrointestinal tract, the mechanisms underlying the protection afforded by PPIs against gastrointestinal injury induced by chemotherapy, and their clinical applications.

The impact of non-steroidal anti-inflammatory drugs on the small intestinal epithelium

The small intestine has been called as a dark continent of digestive tract and it had been very difficult to diagnose or treat the disease of small intestine. However recent technological development including video capsule endoscopy or balloon-assisted endoscopy has made us to aware the various diseases of small intestine. By using capsule endoscopy, many researchers reported that more than 70% of patients treated continuously with non-steroidal anti-inflammatory drugs (NSAID) exhibit the mucosal damage of small intestine. In some cases, NSAID not only causes mucosal damage but also results in life threatening bleeding from small intestine, which had not been prevented or cured by gastro-protective drug or anti-gastric acid secretion drug administration. Therefore to investigate and identify the effective drug that protects small intestine from mucosal damage is urgently expected. In spite of extensive investigation in clinical field, only a few drugs such as misoprostol, a synthetic prostaglandin E₁ analogue, has been reported as an effective one but is not satisfactory enough to fulfill the requirement of patients who suffer from NSAID-induced mucosal damage of small intestine. And now, extensive study is being performed using several gastro-mucoprotective drugs by many researchers. In this review, we introduce the current clinical situation in small intestinal injury of patients under NSAID treatment, and to summarize the molecular mechanism by which NSAID, including acetyl salicylic acid, cause small intestinal damage. In addition, we present results of clinical trials performed so far, and refer the possible preventive method or treatment in the near future.

Oligosaccharides from agar inhibit murine intestinal inflammation through the induction of heme oxygenase-1 expression

BACKGROUND

Agarose is hydrolyzed easily to yield oligosaccharides, designated as agaro-oligosaccharides (AGOs). Recently, it has been demonstrated that AGOs induce heme oxygenase-1 (HO-1) expression in macrophages and that they might lead to anti-inflammatory property. Nevertheless, the molecular mechanism of AGO-mediated HO-1 induction remains unknown, as does AGOs' ability to elicit anti-inflammatory activity in vivo. This study was undertaken to uncover the mechanism of AGO-mediated HO-1 induction and to investigate the therapeutic effect of AGOs on intestinal inflammation.

METHODS

Mice were treated with 2,4,6-trinitrobenzene sulfonic acid (TNBS) to induce colitis. The respective degrees of mucosal injury of mice that had received AGO and control mice were compared. We investigated HO-1 expression using Western blotting, quantitative real-time PCR (qRT-PCR), and immunohistochemistry. The expression of tumor necrosis factor-α (TNF-α) was measured using qRT-PCR and enzyme-linked immunosorbent assay.

RESULTS

AGO administration induced HO-1 expression in colonic mucosa. The induction was observed mainly in F4/80 positive macrophages. Increased colonic damage and myeloperoxidase activity after TNBS treatment were inhibited by AGO administration. TNBS treatment induced TNF-α expression, and AGO administration suppressed induction. However, HO inhibitor canceled AGO-mediated amelioration of colitis. In RAW264 cells, AGOs enhanced HO-1 expression time-dependently and concentration-dependently and suppressed lipopolysaccharide-induced TNF-α expression. Furthermore, agarotetraose-mediated HO-1 induction required NF-E2-related factor 2 function and phosphorylation of c-jun N-terminal kinase.

CONCLUSIONS

We infer that AGO administration inhibits TNBS-induced colitis in mice through HO-1 induction in macrophages. Consequently, oral administration of AGOs might be an important therapeutic strategy for inflammatory bowel disease.

The proton-pump inhibitor lansoprazole enhances amyloid beta production

A key event in the pathogenesis of Alzheimer’s disease (AD) is the accumulation of amyloid-β (Aβ) species in the brain, derived from the sequential cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. Based on a systems biology study to repurpose drugs for AD, we explore the effect of lansoprazole, and other proton-pump inhibitors (PPIs), on Aβ production in AD cellular and animal models. We found that lansoprazole enhances Aβ37, Aβ40 and Aβ42 production and lowers Aβ38 levels on amyloid cell models. Interestingly, acute lansoprazole treatment in wild type and AD transgenic mice promoted higher Aβ40 levels in brain, indicating that lansoprazole may also exacerbate Aβ production in vivo. Overall, our data presents for the first time that PPIs can affect amyloid metabolism, both in vitro and in vivo.

A possible involvement of Nrf2-mediated heme oxygenase-1 up-regulation in protective effect of the proton pump inhibitor pantoprazole against indomethacin-induced gastric damage in rats

Background

Proton pump is an integral membrane protein that is ubiquitous ATP binding cassette (ABC) involved in many transport processes in all living organisms, among which a specialized form of pump, so called p-type proton pump, exists in the parietal cells of stomach. Though proton pump inhibitors (PPIs) are frequently prescribed to prevent nonsteroidal anti-inflammatory drugs (NSAIDs)-induced gastric damage, the acid suppressive actions do not suffice to explain.

Methods

In order to document the effects of pantoprazole, one of PPIs, on the NSAIDs-induced gastric damage, in vitro and in vivo studies were performed. Immunocytochemistry, Western blot analysis, electrophoretic mobility shift assay and RT-PCR were conducted to evaluate the induction of heme oxygenase-1 (HO-1) through Nrf2 activation in normal gastric mucosal RGM-1 cells or in vivo stomach tissues from rats treated with indomethacin and/or pantoprazole.

Results

Pantoprazole activated Nrf2 through inactivation of Keap1, after which the expression of HO-1 was significantly increased in a dose-dependent manner in RGM-1 cells. Increased ARE-DNA binding activity was observed maximally at 1 h with 300 μM of pantoprazole. The expression of HO-1 induced by pantoprazole was significantly associated with the increased in vitro tube formation (P < 0.05) and angiogenic factors including VEGF, bFGF, and HIF-1α. Indomethacin markedly increased the expressions of TNF-α, IL-1ß, IL-8, NOX-1, ICAM-1 and VCAM, whereas pantoprazole significantly decreased the expressions of indomethacin-induced these inflammatory mediators in accord with pantoprazole-induced HO-1 (P < 0.05) as documented with HO-1 inhibitor. In vivo model of indomethacin-induced gastric damage could validate in vitro-drawn results that pantoprazole remarkably protected against indomethacin-induced gastric damage, in which zinc protoporphyrin (5 mg/kg, ip) significantly abolished the protective efficacy of pantoprazole.

Conclusion

These results demonstrate that Nrf2-mediated HO-1 induction of PPIs afforded a significant protective effect against NSAIDs-induced gastric damage beyond acid suppressive actions.

Revaprazan, a novel acid pump antagonist, exerts anti-inflammatory action against Helicobacter pylori-induced COX-2 expression by inactivating Akt signaling

Chronic gastric inflammation developing after Helicobacter pylori (H. pylori) infection is responsible for either dyspeptic symptom relevant to gastritis/peptic ulcer or gastric tumorigenesis, in which acid suppressants, especially proton pump inhibitors (PPIs), play role in relieving dyspepsia as well as the eradication regimen. Among several mediators engaged in propagating gastric inflammation after H. pylori infection, cyclooxygenase-2 (COX-2) might be the principal one, and several prescriptions have been made for decreasing the COX-2 levels. Multiple line of evidence are available for anti-inflammatory action of PPIs beyond acid suppression, but revaprazan, a novel acid pump antagonist launched in clinic, has also been suggested to exert significant anti-inflammatory actions as much as PPI. In the current study, we hypothesized that revaprazan could regulate H. pylori-driven COX-2 expression as one of its anti-inflammatory pharmacological actions. The changes of gastric COX-2 expression as well as responsible transcription factors were measured after H. pylori infection in the presence or absence of revaprazan. Infection of AGS cells with H. pylori induced significant up-regulation of COX-2 in time- and concentration-dependent manners, which was mediated by Akt phosphorylation. Revaprazan treatment significantly inhibited IkappaB-alpha degradation as well as Akt inactivation, resulting in attenuation of H. pylori-induced COX-2 expression. Additional rescuing action of revaprazan against H. pylori-induced cytotoxicity was noted. In conclusion, revaprazan imposed significant anti-inflammatory actions on H. pylori infection beyond acid suppression.

Proton pump inhibitors suppress iNOS-dependent DNA damage in Barrett's esophagus by increasing Mn-SOD expression

Barrett's esophagus (BE), an inflammatory disease, is a risk factor for Barrett's esophageal adenocarcinoma (BEA). Treatment of BE patients with proton pump inhibitors (PPIs) is expected to reduce the risk of BEA. We performed an immunohistochemical study to examine the formation of nitrative and oxidative DNA lesions, 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxygaunosine (8-oxodG), in normal esophageal, BE with pre- and post-treatment by PPIs and BEA tissues. We also observed the expression of an oxidant-generating enzyme (iNOS) and its transcription factor NF-κB, an antioxidant enzyme (Mn-SOD), its transcription factor (Nrf2) and an Nrf2 inhibitor (Keap1). The immunoreactivity of DNA lesions was significantly higher in the order of BEA>BE>normal tissues. iNOS expression was significantly higher in the order of BEA>BE>normal tissues, while Mn-SOD expression was significantly lower in the order of BEA<BE<normal tissues. Interestingly, Mn-SOD expression and the nuclear localization of Nrf2 were significantly increased, and the formation of DNA lesions was significantly decreased in BE tissues after PPIs treatment for 3-6months. Keap1 and iNOS expression was not significantly changed by the PPIs treatment in BE tissues. These results indicate that 8-nitroguanine and 8-oxodG play a role in BE-derived BEA. Additionally, PPIs treatment may trigger the activation and nuclear translocation of Nrf2 resulting in the expression of antioxidant genes, leading to DNA damage suppression. These DNA lesions can be useful biomarkers to predict both the risk of BEA and the efficacy of PPIs treatment to prevent BEA in BE patients.

Translocation of heme oxygenase-1 to mitochondria is a novel cytoprotective mechanism against non-steroidal anti-inflammatory drug-induced mitochondrial oxidative stress, apoptosis, and gastric mucosal injury

The mechanism of action of heme oxygenase-1 (HO-1) in mitochondrial oxidative stress (MOS)-mediated apoptotic tissue injury was investigated. MOS-mediated gastric mucosal apoptosis and injury were introduced in rat by indomethacin, a non-steroidal anti-inflammatory drug. Here, we report that HO-1 was not only induced but also translocated to mitochondria during gastric mucosal injury to favor repair mechanisms. Furthermore, mitochondrial translocation of HO-1 resulted in the prevention of MOS and mitochondrial pathology as evident from the restoration of the complex I-driven mitochondrial respiratory control ratio and transmembrane potential. Mitochondrial translocation of HO-1 also resulted in time-dependent inhibition of apoptosis. We searched for the plausible mechanisms responsible for HO-1 induction and mitochondrial localization. Free heme, the substrate for HO-1, was increased inside mitochondria during gastric injury, and mitochondrial entry of HO-1 decreased intramitochondrial free heme content, suggesting that a purpose of mitochondrial translocation of HO-1 is to detoxify accumulated heme. Heme may activate nuclear translocation of NF-E2-related factor 2 to induce HO-1 through reactive oxygen species generation. Electrophoretic mobility shift assay and chromatin immunoprecipitation studies indicated nuclear translocation of NF-E2-related factor 2 and its binding to HO-1 promoter to induce HO-1 expression during gastric injury. Inhibition of HO-1 by zinc protoporphyrin aggravated the mucosal injury and delayed healing. Zinc protoporphyrin further reduced the respiratory control ratio and transmembrane potential and enhanced MOS and apoptosis. In contrast, induction of HO-1 by cobalt protoporphyrin reduced MOS, corrected mitochondrial dysfunctions, and prevented apoptosis and gastric injury. Thus, induction and mitochondrial localization of HO-1 are a novel cytoprotective mechanism against MOS-mediated apoptotic tissue injury.

Heme oxygenase-1 system and gastrointestinal inflammation: A short review

Heme oxygenase-1 (HO-1) system catalyzes heme to biologically active products: carbon monoxide, biliverdin/bilirubin and free iron. It is involved in maintaining cellular homeostasis and many physiological and pathophysiological processes. A growing body of evidence indicates that HO-1 activation may play an important protective role in acute and chronic inflammation of gastrointestinal tract. This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal inflammation studied to date. The ability to upregulate HO-1 by pharmacological means or using gene therapy may offer therapeutic strategies for gastrointestinal inflammation in the future.

Heme oxygenase-1: a novel therapeutic target for gastrointestinal diseases

Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the catabolism of heme, followed by production of biliverdin, free iron and carbon monoxide (CO). HO-1 is a stress-responsive protein induced by various oxidative agents. Recent studies demonstrate that the expression of HO-1 in response to different inflammatory mediators may contribute to the resolution of inflammation and has protective effects in several organs against oxidative injury. Although the mechanism underlying the anti-inflammatory actions of HO-1 remains poorly defined, both CO and biliverdin/bilirubin have been implicated in this response. In the gastrointestinal tract, HO-1 is shown to be transcriptionally induced in response to oxidative stress, preconditioning and acute inflammation. Recent studies suggest that the induction of HO-1 expression plays a critical protective role in intestinal damage models induced by ischemia-reperfusion, indomethacin, lipopolysaccharide-associated sepsis, trinitrobenzene sulfonic acid, and dextran sulfate sodium, indicating that activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in the gastrointestinal tract. In addition, CO derived from HO-1 is shown to be involved in the regulation in gastro-intestinal motility. These in vitro and in vivo data suggest that HO-1 may be a novel therapeutic target in patients with gastrointestinal diseases.

Carbon monoxide involved in modulating HCO3- secretion in rat duodenum

We examined the effect of the tricarbonyl-dichlororuthenium (II) dimer (CORM-2), a carbon monoxide (CO) donor, on duodenal HCO(3)(-) secretion in rats and investigated whether endogenous CO produced by heme oxygenase (HO) is involved in the regulation of this secretion. Under urethane anesthesia, a duodenal loop was perfused with saline, and HCO(3)(-) secretion was measured at pH 7.0 using a pH stat method. CORM-2, biliverdin, FeCl(2), or ruthenium (III) chloride hydrate (RuCl(3)) was applied to the loop for 5 min. The mucosal application of CORM-2 dose-dependently increased HCO(3)(-) secretion, whereas neither RuCl(3), FeCl(2), nor biliverdin had an effect. The stimulatory effect was significantly attenuated by indomethacin but not N(G)-nitro-L-arginine methyl ester. The application of CORM-2 increased the mucosal prostaglandin (PG) E(2) content of the duodenum. The acid-induced HCO(3)(-) response was markedly inhibited by indomethacin and Sn(IV) protoporphyrin IX dichloride (SnPP; an inhibitor of HO) but not Cu(II) protoporphyrin dichloride, and the inhibitory effect of SnPP was significantly reversed by pretreatment with hemin, a substrate of HO. Perfusion of the duodenal loop with 100 mM HCl for 2 h caused a few hemorrhagic lesions in the mucosa, and this response was significantly worsened by the prior administration of SnPP and indomethacin. The expression of HO-1 but not HO-2 protein was up-regulated in the duodenum after the acid treatment. These results suggest that CO, generated endogenously or exogenously, stimulates HCO(3)(-) secretion in the duodenum, and this effect is mediated by endogenous PGs. It is assumed that HO/CO plays a role in maintaining the integrity of the duodenal mucosa.

Effects of lansoprazole on the expression of VEGF and cellular proliferation in a rat model of acetic acid-induced gastric ulcer

BACKGROUND

A recent study reported that in addition to their inhibitory effect on gastric acid secretion, some proton pump inhibitors also exert a cytoprotective effect on the gastric mucosa. We investigated the effects of lansoprazole (LPZ) on the epithelial cell cycle, and on the expressions of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2).

METHODS

We examined the effects of 25 and 5 mg/kg LPZ on ulcer healing in an acetic acid-induced ulcer model in rats with and without indomethacin (IND) treatment. On days 14 and 28 after ulcer formation, we compared the ulcer diameter, bromodeoxyuridine (BrdU) uptake, apoptosis, vascular density, and the expressions of VEGF and MMP-2 in the different groups.

RESULTS

LPZ administration increased the BrdU uptake that was reduced by IND administration. LPZ administration also increased VEGF expression at the ulcer margin in a dose-dependent manner. However, LPZ administration did not increase VEGF expression following IND pretreatment. Administration of IND alone significantly decreased MMP-2 expression at the ulcer margin; on the other hand, subsequent administration of LPZ increased the MMP-2 expression.

CONCLUSION

One of the mechanisms of ulcer healing brought about by LPZ may be the involvement of endogenous prostaglandin (PG) secretion. The effect of endogenous PG secretion may be related to the induction of VEGF expression. On the other hand, LPZ administration increased MMP-2 expression, and this effect was not influenced by the inhibition of PG synthesis. The mechanisms of LPZ on ulcer healing may be involved by VEGF expression through endogenous PGs secretion. Additionally, the stimulated expression of MMP-2, which is not secreted by endogenous PGs, is another important factor for ulcer healing by LPZ.

Novel application of proton pump inhibitor for the prevention of colitis-induced colorectal carcinogenesis beyond acid suppression

Colitis-associated cancers arise in the setting of chronic inflammation wherein an "inflammation-dysplasia-carcinoma" sequence prevails. Based on our previous findings in which the proton pump inhibitor could impose significant levels of anti-inflammatory, antiangiogenic, and selective apoptosis induction beyond gastric acid suppression, we investigated whether omeprazole could prevent the development of colitis-associated cancer in a mouse model induced by repeated bouts of colitis. Omeprazole, 10 mg/kg, was given i.p. all through the experimental periods for colitis-associated carcinogenesis. Molecular changes regarding inflammation and carcinogenesis were compared between control groups and colitis-associated cancer groups treated with omeprazole in addition to chemopreventive outcome. Nine of 12 (75.0%) mice in the control group developed multiple colorectal tumors, whereas tumors were noted in only 3 of 12 (25.0%) mice treated with daily injections of omeprazole. The cancer-preventive results of omeprazole treatment was based on significant decreases in the levels of nitric oxide, thiobarbituric acid-reactive substance, and interleukin-6 accompanied with attenuated expressions of tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2. The expressions of matrix metalloproteinase (MMP)-9, MMP-11, and MT1-MMMP were significantly decreased in mice treated with omeprazole in accordance with significant decreases in the number of beta-catenin-accumulated crypts. A significant induction of apoptosis was observed in tumor tissue treated with omeprazole. Omeprazole could block the trophic effect of gastrin in colon epithelial cells. The significant anti-inflammatory, antioxidative, and antimutagenic activities of omeprazole played a cancer-preventive role against colitis-induced carcinogenesis, and our novel in vivo evidence is suggestive of chemopreventive action independent of gastric acid suppression.

Sofalcone, a gastric mucosa protective agent, increases vascular endothelial growth factor via the Nrf2-heme-oxygenase-1 dependent pathway in gastric epithelial cells

Sofalcone, 2'-carboxymethoxy-4,4-bis(3-methyl-2-butenyloxy)chalcone, is an anti-ulcer agent that is classified as a gastric mucosa protective agent. Recent studies indicate heat shock proteins such as HSP32, also known as heme-oxygenase-1(HO-1), play important roles in protecting gastrointestinal tissues from several stresses. We have previously reported that sofalcone increases the expression of HO-1 in adipocytes and pre-adipocytes, although the effect of sofalcone on HO-1 induction in gastrointestinal tissues is not clear. In the current study, we investigated the effects of sofalcone on the expression of HO-1 and its functional role in rat gastric epithelial (RGM-1) cells. We found that sofalcone increased HO-1 expression in RGM-1 cells in both time- and concentration-dependent manners. The HO-1 induction was associated with the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in RGM-1 cells. We also observed that sofalcone increased vascular endothelial growth factor (VEGF) production in the culture medium. Treatment of RGM-1 cells with an HO-1 inhibitor (tin-protoporphyrin), or HO-1 siRNA inhibited sofalcone-induced VEGF production, suggesting that the effect of sofalcone on VEGF expression is mediated by the HO-1 pathway. These results suggest that the gastroprotective effects of sofalcone are partly exerted via Nrf2-HO-1 activation followed by VEGF production.

The expression of heme oxygenase-1 induced by lansoprazole

Our previous studies have demonstrated that lansoprazole inhibits acute inflammatory reactions as well as intestinal mucosal injuries induced by ischemia-reperfusion or indomethacin administration in rats. Thus, proton pump inhibitors such as lansoprazole have been demonstrated to prevent gastrointestinal mucosal injury by mechanisms independent of acid inhibition. In our in vitro study, lansoprazole induced the expression of heme oxygenase-1 (HO-1) on rat gastric epithelial cells (RGM-1 cells), and exerted anti-inflammatory effect on the dependent of HO-1 expression. Furthermore, NF-E2-related factor-2 (Nrf2) played an important role in HO-1 expression induced by lansoprazole. In this review, we focused on lansoprazole-induced HO-1 expression, its anti-inflammatory action, and the role of Nrf2 in its expression.