Low-Dose Acetylsalicylic Acid and Mitochondria-Targeted Antioxidant Mitoquinone Attenuate Non-Alcoholic Steatohepatitis in Mice

Induction of mitochondrial toxicity by non-steroidal anti-inflammatory drugs (NSAIDs): The ultimate trade-off governing the therapeutic merits and demerits of these wonder drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are most extensively used over-the-counter FDA-approved analgesic medicines for treating inflammation, musculoskeletal pain, arthritis, pyrexia and menstrual cramps. Moreover, aspirin is widely used against cardiovascular complications. Owing to their non-addictive nature, NSAIDs are also commissioned as safer opioid-sparing alternatives in acute trauma and post-surgical treatments. In fact, therapeutic spectrum of NSAIDs is expanding. These "wonder-drugs" are now repurposed against lung diseases, diabetes, neurodegenerative disorders, fungal infections and most notably cancer, due to their efficacy against chemoresistance, radio-resistance and cancer stem cells. However, prolonged NSAID treatment accompany several adverse effects. Mechanistically, apart from cyclooxygenase inhibition, NSAIDs directly target mitochondria to induce cell death. Interestingly, there are also incidences of dose-dependent effects where NSAIDs are found to improve mitochondrial health thereby suggesting plausible mitohormesis. While mitochondria-targeted effects of NSAIDs are discretely studied, a comprehensive account emphasizing the multiple dimensions in which NSAIDs affect mitochondrial structure-function integrity, leading to cell death, is lacking. This review discusses the current understanding of NSAID-mitochondria interactions in the pathophysiological background. This is essential for assessing the risk-benefit trade-offs of NSAIDs for judiciously strategizing NSAID-based approaches to manage pain and inflammation as well as formulating effective anti-cancer strategies. We also discuss recent developments constituting selective mitochondria-targeted NSAIDs including theranostics, mitocans, chimeric small molecules, prodrugs and nanomedicines that rationally optimize safer application of NSAIDs. Thus, we present a comprehensive understanding of therapeutic merits and demerits of NSAIDs with mitochondria at its cross roads. This would help in NSAID-based disease management research and drug development.

Prophylactic treatment with Bacteroides uniformis and Bifidobacterium bifidum counteracts hepatic NK cell immune tolerance in nonalcoholic steatohepatitis induced by high fat diet

Hepatic immunity is one of the driving forces for the development of nonalcoholic steatohepatitis (NASH), and targeting gut microbiota is believed to affect the hepatic immune constitution. Here, we aimed to investigate the hepatic immunological state in NASH, with a specific emphasis on natural killer (NK) cells. In addition, we aimed to identify the contributing species that target hepatic immunity to provide new directions and support the feasibility of immunotherapy for NASH. A possible NASH population was determined by combination of long-term severe fatty liver, metabolic disorders and increased serum CK18 to detect serum immune factors and gut microbiota. NASH was induced in mice fed a high-fat diet to verify the prophylactic effect of the functional species on the immunopathology and development of NASH. Hepatic immunologic state was examined, and the effector functions of NK cells were detected. Hepatic transcriptome, proteomic, and fecal metagenome were performed. We observed a statistical increase in serum IL-10 (p < 0.001) and non-statistical decrease in interferon-γ and IL-6 in NASH population, hinting at the possibility of immune tolerance. Fecal Bacteroides uniformis and Bifidobacterium bifidum were abundant in healthy population but depleted in NASH patients. In NASH mice, hepatic CD8+T cells, macrophages, and dendritic cells were increased (p < 0.01), and NK cells were inhibited, which were identified with decreased granzyme B (p < 0.05). Bacteroides uniformis and Bifidobacterium bifidum improved hepatic pathological and metabolic cues, increased hepatic NK cells and reduced macrophages (p < 0.05). Bacteroides uniformis also restored hepatic NK cell function, which was identified as increased CD107a (p < 0.05). Transcriptional and translational profiling revealed that the functional species might restore the function of hepatic NK cells through multiple pathways, such as reduction of inhibitory molecules in NK cells. Bacteroides uniformis and Bifidobacterium bifidum are novel prophylactics for NASH that restore the impaired function of hepatic NK cells.