Modulation of K_ATP channels by diazoxide preserves mitochondrial function and barrier integrity under...

Intestinal barrier dysfunction caused by mitochondrial stress, oxidative damage and apoptosis, are hallmarks of dysbiosis-associated gastrointestinal (GI) disorders. Staurosporine causes downstream features of dysbiosis-induced epithelial damage. K_ATP (K_ir6.x) channels act as metabolic sensors linking cellular energetics to stress adaptation. We investigated whether diazoxide preserved epithelial integrity under staurosporine-induced stress.

HCEC-1CT cells were exposed to staurosporine or in combination with diazoxide. Mitochondrial function, ROS generation, transepithelial electrical resistance (TEER), paracellular permeability, tight junction expression, K_ATP channel subunit regulation, MAPK signalling and epigenetic markers were assessed using functional assays, RT-qPCR and western blotting. K_ATP channel involvement was validated using the blocker glibenclamide.

Diazoxide restored mitochondrial function following staurosporine-induced damage in the co-treatment model, with an EC50 of 6 × 10^-5 M. Reducing ROS accumulation and preserving epithelial barrier integrity, as demonstrated by maintenance of TEER and paracellular sealing. Diazoxide enhanced SUR1/SUR2 expression and glycosylation, preserved ERK1/2 phosphorylation and sustained histone H3 lysine 27 acetylation, supporting active gene transcription under stress. Co-administration with staurosporine prevented downregulation of K_ATP channel subunits. Diazoxide also attenuated staurosporine-induced dysregulation of pro-inflammatory and apoptotic genes, reinforcing its function as a molecular stabilizer under cytotoxic stress. These protective effects were reversed by glibenclamide, indicating K_ATP channel dependence.

Diazoxide may be a potential therapeutic candidate for oxidative stress-driven barrier dysfunction in gastrointestinal diseases. Future studies incorporating physiologically relevant stressors, such as LPS or H₂S, will be important to validate these protective mechanisms in contexts more directly related to microbial dysbiosis.