Effects of Lansoprazole on the Lipopolysaccharide-Stimulated Toll-Like Receptor 4 Signal Transduction Systems: A Study Using the 293hTLR4/MD2-CD14 Cells

The proton pump inhibitor, lansoprazole, prevents the development of non-traumatic osteonecrosis of the femoral head: an experimental and prospective clinical trial

Background

An effective prevention strategy for osteonecrosis of the femoral head (ONFH) has yet to be established. We previously reported that the innate immune system via the toll-like receptor (TLR) response induced by corticosteroids leads to the development of ONFH and that repression of IRF7 activity by an inhibitor could interfere with the development of ONFH while maintaining the therapeutic effect of the corticosteroids.

Objective

In the present study, we hypothesize that lansoprazole has the potential to suppress IRF7 activity and prevent corticosteroid-induced ONFH in rats. Furthermore, we conducted a preliminary clinical trial to prevent corticosteroid-induced ONFH in autoimmune disease patients.

Methods

Male Wistar rats were randomly divided into four groups. On Day 1, each rat was injected with TLR4 ligand (LPS) or TLR7 ligand (imiquimod), followed by methylprednisolone with or without lansoprazole on Day 2. They were killed at 1 or 14 days after the last injection.We prospectively recruited 30 patients requiring primary high-dose corticosteroid treatment for immune diseases. All patients were administered lansoprazole, starting the night before corticosteroid treatment began. MRI was performed before corticosteroid treatment, and at 4, 12 and 24 weeks afterward.

Results

In rats, co-treatment of lansoprazole with corticosteroids significantly repressed both IRF7 activity and the development of ONFH. Moreover, in the human patients, the incidence of ONFH was significantly decreased from 53.4 to 13.3%.

Conclusions

Although the present study is preliminary, the results show that co-treatment of lansoprazole with corticosteroids prevents ONFH development. Lansoprazole may be both safe and effective in preventing osteonecrosis of the femoral head in patients needing corticosteroid treatment.

Proton pump inhibitors induce changes in colonocyte gene expression that may affect Clostridium difficile infection

BACKGROUND

Proton pump inhibitors seem to promote Clostridium difficile infection (CDI). Although the current literature suggests that this association is mediated through gastric acid suppression, there has been little investigation into whether a direct effect on expression of colonocyte genes may also have a role. The aim of this study was to investigate the effect of omeprazole on genome-wide gene expression in a human colonic cell line.

METHODS

T84 cell monolayers were treated with acid-activated omeprazole at 0, 1, 10, or 100 μmol/L for 48 hours. Cells were lysed and total RNA samples were reverse transcribed and used to generate biotinylated cRNA. Whole-genome transcript expression levels were then quantified using an Illumina HT-12 BeadChip microarray targeting 25,440 genes. Transcripts with a stringent minimum absolute fold change of 1.5 and an adjusted nominal P value <.05 (false discovery) were identified as being differentially expressed.

RESULTS

Significant changes in expression were observed for 322 colonocyte transcripts, including genes with potential implications for susceptibility to CDI. These genes include roles in cell junctions, toxin susceptibility, and bile acid metabolism and transport.

CONCLUSION

Omeprazole treatment decreases the expression of genes that have important functions in colonocyte integrity. Such impairment in colonocyte function may promote CDI.

Propofol inhibits hypoxia/reoxygenation-induced human gastric epithelial cell injury by suppressing the Toll-like receptor 4 pathway

This study aimed to investigate the role of the Toll-like receptor 4 (TLR4) pathway in normal human gastric epithelial (GES-1) cells under hypoxia/reoxygenation (H/R) in vitro, and the effect of propofol on injured GES-1 cells as well as its possible mechanism. Before H/R induction, GES-1 cells were preconditioned with fat emulsion, propofol, or epigallocatechin gallate. Then cell viability, cell apoptosis, and related molecules in the cells were analyzed under experimental conditions. We found that propofol 50 μmol/L markedly inhibited the H/R injury under hypoxia 1.5 h/reoxygenation 2 hours by promoting GES-1 cell viability and decreasing cell apoptosis. The TLR4 signal may be involved in the protective effect of propofol against H/R injury. The malondialdehyde contents and superoxide dismutase activities were recovered under propofol preconditioning. In summary, propofol preconditioning may exert a protective effect on H/R injury in GES-1 cells and the mechanism may be via inhibition of the activated TLR4 signal under H/R conditions.

Toll-like receptor 4 modulation as a strategy to treat sepsis

Despite a decrease in mortality over the last decade, sepsis remains the tenth leading causes of death in western countries and one of the most common cause of death in intensive care units. The recent discovery of Toll-like receptors and their downstream signalling pathways allowed us to better understand the pathophysiology of sepsis-related disorders. Particular attention has been paid to Toll-like receptor 4, the receptor for Gram-negative bacteria outer membrane lipopolysaccharide or endotoxin. Since most of the clinical trial targeting single inflammatory cytokine in the treatment of sepsis failed, therapeutic targeting of Toll-like receptor 4, because of its central role, looks promising. The purpose of this paper is to focus on the recent data of various drugs targeting TLR4 expression and pathway and their potential role as adjunctive therapy in severe sepsis and septic shock.

Proton pump inhibitor lansoprazole is a nuclear liver X receptor agonist

The liver X receptors (LXRalpha and LXRbeta) are transcription factors that control the expression of genes primarily involved in cholesterol metabolism. In the brain, in addition to normal neuronal function, cholesterol metabolism is important for APP proteolytic cleavage, secretase activities, Abeta aggregation and clearance. Particularly significant in this respect is LXR mediated transcriptional control of APOE, which is the only proven risk factor for late onset Alzheimer's disease. Using a transactivation reporter assay for screening pharmacologically active compounds and off patent drugs we identified the proton pump inhibitor Lansoprazole as an LXR agonist. In secondary screens and counter-screening assays, it was confirmed that Lansoprazole directly activates LXR, increases the expression of LXR target genes in brain-derived human cell lines, and increases Abca1 and Apo-E protein levels in primary astrocytes derived from wild type but not LXRalpha/beta double knockout mice. Other PPIs activate LXR as well, but the efficiency of activation depends on their structural similarities to Lansoprazole. The identification of a widely used drug with LXR agonist-like activity opens the possibility for systematic preclinical testing in at least two diseases--Alzheimer's disease and atherosclerosis.