NSAID-induced injury of gastric epithelial cells is reversible: roles of mitochondria, AMP kinase, NGF, and PGE₂

Abstract

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac (DFN) and indomethacin (INDO) are extensively used worldwide. Their main side effects are injury of the gastrointestinal tract, including erosions, ulcers, and bleeding. Since gastric epithelial cells (GEPCs) are crucial for mucosal defense and are the major target of injury, we examined the extent to which DFN- and INDO-induced GEPC injury can be reversed by nerve growth factor (NGF), 16,16 dimethyl prostaglandin E2 (dmPGE2), and 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), the pharmacological activator of the metabolic sensor AMP kinase (AMPK). Cultured normal rat gastric mucosal epithelial (RGM1) cells were treated with PBS (control), NGF, dmPGE2, AICAR, and/or NSAID (DFN or INDO) for 1–4 h. We examined cell injury by confocal microscopy, cell death/survival using calcein AM, mitochondrial membrane potential using MitoTracker, and phosphorylation of AMPK by Western blotting. DFN and INDO treatment of RGM1 cells for 2 h decreased mitochondrial membrane potential and cell viability. NGF posttreatment (initiated 1 or 2 h after DFN or INDO) reversed the dissipation of mitochondrial membrane potential and cell injury caused by DFN and INDO and increased cell viability versus cells treated for 4 h with NSAID alone. Pretreatment with dmPGE2 and AICAR significantly protected these cells from DFN- and INDO-induced injury, whereas dmPGE2 and AICAR posttreatment (initiated 1 h after NSAID treatment) reversed cell injury and significantly increased cell viability and rescued the cells from NSAID-induced mitochondrial membrane potential reduction. DFN and INDO induce extensive mitochondrial injury and GEPC death, which can be significantly reversed by NGF, dmPGE2, and AICAR. NEW & NOTEWORTHY This study demonstrated that mitochondria are key targets of diclofenac- and indomethacin-induced injury of gastric epithelial cells and that diclofenac and indomethacin injury can be prevented and, importantly, also reversed by treatment with nerve growth factor, 16,16 dimethyl prostaglandin E2, and 5-aminoimidazole-4-carboxamide ribonucleotide.

Gastroprotective effect of topiramate on indomethacin‐induced peptic ulcer in rats: Biochemical and histological analyses

“…In this regard, pharmacologic substances rescuing mitochondrial function should therefore protect cells from this injury and subsequent cell death. 52 It has been reported previously that topiramate could inhibit the mitochondrial permeability transition pore, 14,53 and this interesting property of this drug may be involved in the observed protective effects in the current study. Although this effect was not investigated in the present study and this was one of the limitations of our study, we suggest that in future studies the effects of this drug on mitochondrial function in the indomethacin-induced gastric ulcer model be investigated.…”

“…Therefore, alterations of mitochondrial function are early events preceding cell injury. In this regard, pharmacologic substances rescuing mitochondrial function should therefore protect cells from this injury and subsequent cell death 52 . It has been reported previously that topiramate could inhibit the mitochondrial permeability transition pore, 14,53 and this interesting property of this drug may be involved in the observed protective effects in the current study.…”

The Protective Effect of Walnut Oligopeptides against Indomethacin-Induced Gastric Ulcer in Rats

“…An NSAIDs-induced deleterious action was always accompanied by the excessive generation of oxygen free radicals and proinflammatory factors, such as superoxide radical anions, hydroxyl radicals, tumor necrosis factor α (TNF-α), and interleukin (IL)-1β (IL-1β) [ 36 ]. These mechanisms, in combination with those linked to PG inhibition, influence the pathogenesis of gastric mucosal injury associated with gastrointestinal damage caused by NSAIDs [ 37 ]. Oxidative stress participates in the development of an NSAIDs-related gastric ulcer via a prostaglandin-independent mechanism [ 5 ].…”