Proton Pump Inhibitors in IPF: A Call for Clinical Trials

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.

Radiation-induced gastric injury during radiotherapy: molecular mechanisms and clinical treatment

Radiotherapy (RT) has been the standard of care for treating a multitude of cancer types. Radiation-induced gastric injury (RIGI) is a common complication of RT for thoracic and abdominal tumors. It manifests acutely as radiation gastritis or gastric ulcers, and chronically as chronic atrophic gastritis or intestinal metaplasia. In recent years, studies have shown that intracellular signals such as oxidative stress response, p38/MAPK pathway and transforming growth factor-β signaling pathway are involved in the progression of RIGI. This review also summarized the risk factors, diagnosis and treatment of this disease. However, the root of therapeutic challenges lies in the incomplete understanding of the mechanisms. Here, we also highlight the potential mechanistic, diagnostic and therapeutic directions of RIGI.

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.

Esomeprazole attenuates inflammatory and fibrotic response in lung cells through the MAPK/Nrf2/HO1 pathway

Introduction

Idiopathic pulmonary fibrosis (IPF) is an orphan disease characterized by progressive loss of lung function resulting in shortness of breath and often death within 3–4 years of diagnosis. Repetitive lung injury in susceptible individuals is believed to promote chronic oxidative stress, inflammation, and uncontrolled collagen deposition. Several preclinical and retrospective clinical studies in IPF have reported beneficial outcomes associated with the use of proton pump inhibitors (PPIs) such as esomeprazole. Accordingly, we sought to investigate molecular mechanism(s) by which PPIs favorably regulate the disease process.

Methods

We stimulated oxidative stress, pro-inflammatory and profibrotic phenotypes in primary human lung epithelial cells and fibroblasts upon treatment with bleomycin or transforming growth factor β (TGFβ) and assessed the effect of a prototype PPI, esomeprazole, in regulating these processes.

Results

Our study shows that esomeprazole controls pro-inflammatory and profibrotic molecules through nuclear translocation of the transcription factor nuclear factor-like 2 (Nrf2) and induction of the cytoprotective molecule heme oxygenase 1 (HO1). Genetic deletion of Nrf2 or pharmacological inhibition of HO1 impaired esomeprazole-mediated regulation of proinflammatory and profibrotic molecules. Additional studies indicate that activation of Mitogen Activated Protein Kinase (MAPK) pathway is involved in the process. Our experimental data was corroborated by bioinformatics studies of an NIH chemical library which hosts gene expression profiles of IPF lung fibroblasts treated with over 20,000 compounds including esomeprazole. Intriguingly, we found 45 genes that are upregulated in IPF but downregulated by esomeprazole. Pathway analysis showed that these genes are enriched for profibrotic processes. Unbiased high throughput RNA-seq study supported antifibrotic effect of esomeprazole and revealed several novel targets.

Conclusions

Taken together, PPIs may play antifibrotic role in IPF through direct regulation of the MAPK/Nrf2/HO1 pathway to favorably influence the disease process in IPF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12950-021-00284-6.

Is it possible to use Proton Pump Inhibitors in COVID-19 treatment and prophylaxis?

Coronaviruses (CoV), discovered after 1960, caused human life-threatening outbreaks. SARS-CoV2, which appeared in Wuhan, China in December 2019, causing Severe Acute Respiratory Syndrome and has different features than other coronaviruses, has been determined and the disease caused by the virus has been called "Coronavirus Disease-2019" (COVID-19). This disease activates both the natural and acquired immune system. The cytokin storm, in which blood levels of proinflammatory cytokines are detected excessively high is developing and the uncontrolled inflammatory response causes local and systemic tissue damages. Although a spesific drug has not been found yet, the medications currently in use for other indications, whose pharmacokinetic- pharmacodynamic properties and toxic doses are already known; are included in the treatment practice of COVID-19. These drugs affect the entry of the virus into the cell and its intracellular distribution. They also have anti-inflammatory and immunomodulating effects too. Therefore, we think that Proton Pump Inhibitors (PPI's) with similar mechanisms of action may also be involved in COVID-19 treatment and prophylaxis.

Dose and time-dependent toxicological impact of pantoprazole on vascular endothelium and renal tissue

Proton pump inhibitors (PPIs) have wide pleiotropic action in addition to their therapeutic potential in gastroesophageal reflux diseases. Conversely, recent reports revealed a significant incidence of toxic events of PPIs including nephritis, osteoporosis, and cardiac damage. Thus, the study was designed to reconcile the deceptive contraindications. The present investigation targeted to reveal the toxic impact of sub-acute and sub-chronic administration of pantoprazole (PPZ) with different concentrations (low dose 4 mg/kg, medium-dose 8 mg/kg and high dose 16 mg/kg once a day) on normal vascular endothelium and renal tissue of rats. Vascular endothelial dysfunction (VED) was estimated by the contractility of an isolated aortic ring, nitrite/nitrate concentration, oxidative stress, and integrity of the endothelium layer. Moreover, the renal abnormalities were further confirmed by an increased level of serum creatinine, blood urea nitrogen (BUN), the incidence of microproteinuria, and structural alteration. Sub-acute administration of PPZ treatment did not produce any toxicological impact on endothelium and renal tissue. Whereas, sub-chronic administration of PPZ treatment causes moderate VED and renal dysfunction in a dose-dependent manner. Sub-chronic treatment of PPZ also influences the mitigation of NO and elevation of oxidative stress. Collecting all the evidence, it concludes that decreased nitric oxide availability and increased levels of oxidative stress may be a possible underlying mechanism of causing VED and renal abnormalities from high-dose PPZ treatment.

Mesenchymal stem cell-derived extracellular vesicles suppress the fibroblast proliferation by downregulating FZD6 expression in fibroblasts via micrRNA-29b-3p in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF), a progressive and fatal lung disease, usually leads to an irreversible distortion of the pulmonary structure. The functional roles of bone marrow-derived mesenchymal stem cells (BMSC)-secreted extracellular vesicles (EVs) in fibroblasts have been implicated, yet their actions in the treatment of IPF are not fully understood. This study investigated the roles of BMSC-derived EVs expressing miR-29b-3p in fibroblasts in IPF treatment. EVs derived from BMSCs were successfully isolated and could be internalized by pulmonary fibroblasts, and Cell Counting Kit-8 (CCK-8) and Transwell assay results identified that EVs inhibited the activation of fibroblast in IPF. miR-29b-3p, frizzled 6 (FZD6), α-skeletal muscle actin (α-SMA), and Collagen I expressions were examined, which revealed that miR-29b-3p was poorly expressed and FZD6, α-SMA, and Collagen I were overexpressed in pulmonary tissues. Dual-luciferase reporter assay results demonstrated that miR-29b-3p could inversely target FZD6 expression. The gain- and loss-of-function assays were conducted to determine regulatory effects of FZD6 and miR-29b-3p on IPF. CCK-8 and Transwell assays results displayed that BMSCs-derived EVs overexpressing miR-29b-3p contributed to inhibited pulmonary interstitial fibroblast proliferation, migration, invasion, and differentiation. Furthermore, the effects of BMSCs-derived EVs overexpressing miR-29b-3p on IPF progression were assessed in vivo, which confirmed the repressive effects of BMSCs-derived EVs overexpressing miR-29b-3p on IPF progression. Collectively, BMSCs-derived EVs overexpressing miR-29b-3p relieve IPF through FZD6.

Omeprazole Increases the Efficacy of Acyclovir Against Herpes Simplex Virus Type 1 and 2

Omeprazole was shown to improve the anti-cancer effects of the nucleoside analogue 5-fluorouracil. Here, we combined omeprazole with the antiviral nucleoside analogues ribavirin and acyclovir. Omeprazole did not affect the antiviral effects of ribavirin in non-toxic concentrations up to 80 μg/mL but increased the acyclovir-mediated effects on herpes simplex virus 1 and 2 (HSV-1 and -2) replication in a dose-dependent manner. Omeprazole alone reduced HSV-1 and -2 titers [but not HSV-induced formation of cytopathogenic effects (CPE)] at concentrations ≥40 μg/mL. However, it exerted substantially stronger effects on acyclovir activity and also increased acyclovir activity at lower concentrations that did not directly interfere with HSV replication. Omeprazole 80 μg/mL caused a 10.8-fold (Vero cells) and 47.7-fold (HaCaT cells) decrease of the acyclovir concentrations that reduced HSV-1-induced CPE formation by 50% (IC₅₀). In HSV-2-infected cells, omeprazole 80 μg/mL reduced the acyclovir IC₅₀ by 7.3- (Vero cells) and 12.9-fold (HaCaT cells). In HaCaT cells, omeprazole 80 μg/mL reduced the HSV-1 titer in the presence of acyclovir 1 μg/mL by 1.6 × 10⁵-fold and the HSV-2 titer in the presence of acyclovir 2 μg/mL by 9.2 × 10³-fold. The proton pump inhibitors pantoprazole, rabeprazole, lansoprazole, and dexlansoprazole increased the antiviral effects of acyclovir in a similar fashion as omeprazole, indicating this to be a drug class effect. In conclusion, proton pump inhibitors increase the anti-HSV activity of acyclovir and are candidates for antiviral therapies in combination with acyclovir, in particular for topical preparations for the treatment of immunocompromised individuals who are more likely to suffer from severe complications.

Efficacy and Safety of Switching to Teneligliptin in Patients with Type 2 Diabetes Inadequately Controlled with Dipeptidyl Peptidase-4 Inhibitors: A 12-Week Interim Report

INTRODUCTION

Teneligliptin, an antidiabetic agent classified as a class III dipeptidyl peptidase-4 (DPP-4) inhibitor, has a unique structural feature that provides strong binding to DPP-4 enzymes. We investigated the efficacy and safety of switching patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control on a stable dose of other DPP-4 inhibitors to teneligliptin.

METHODS

Patients with T2DM whose glycosylated hemoglobin (HbA1c) levels were ≥ 7% despite taking DPP-4 inhibitors other than teneligliptin, with or without other hypoglycemic agents, for at least 3 months were enrolled. The DPP-4 inhibitors taken before participating in the study were switched to 20 mg qd teneligliptin, and this was to be maintained for 52 weeks. The primary end point was the change in HbA1c levels after 12 weeks. Metabolic parameters including fasting plasma glucose (FPG) and blood lipids were assessed also. To assess safety, adverse and hypoglycemic events were monitored. The data from baseline to week 12 were used for analysis in this interim report.

RESULTS

The mean change in HbA1c levels from baseline to week 12 was - 0.44%. At week 12, the percentage of patients achieving HbA1c < 7.0% was 31.6% and that of achieving HbA1c < 6.5% was 11.4%, respectively. In 41.2% of patients, the HbA1c levels decreased by at least 0.5% at 12 weeks. The mean change in FPG levels from baseline to week 12 was - 11.5 mg/dl. No severe hypoglycemia was reported.

CONCLUSION

After switching to teneligliptin, HbA1c levels decreased significantly in patients with T2DM inadequately controlled with other DPP-4 inhibitors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03793023.

FUNDING

Handok Inc.