Dysfunction of mitochondria in intestinal epithelial cells: a key player in the pathogenesis of inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are a group of chronic gastrointestinal disorders with increasing incidence and prevalence that represent a major challenge for healthcare systems worldwide. Owing to their intricate and largely unknown etiologies, these patients are difficult to diagnose and treat. Intestinal barriers, including biological (gut microbes), chemical, and physical barriers, are crucial for maintaining normal intestinal function; thus, damage to intestinal barriers plays a role in the progression of intestinal inflammatory responses and hence in possible IBD. Intestinal epithelial cells (IECs), which contain mitochondria, play pivotal roles in intestinal barriers, which are indispensable for numerous functions, including energy production, signal transduction, cell-fate determination, epigenetic modifications, and inter-organelle crosstalk in cells. This review focuses on the current understanding of how mitochondria in IECs maintain and disturb intestinal-barrier homeostasis. We also discuss mitochondria-targeted therapeutics for IBD. These findings offer new insights into the etiological underpinnings of IBD, leading to the proposal of innovative therapeutic strategies. In the future, much remains to be done to understand the contribution of mitochondria in IECs to the functions of intestinal barriers.