LC-MS based metabolomics reveals metabolic pathway disturbance in retinal pigment epithelial cells exposed to hydroxychloroquine.

Hydroxychloroquine (HCQ) is frequently used medications for many auto-immunity diseases. However, HCQ induced retinal toxicity, which might result in irreversible retinopathy, is one of the most important complications of HCQ. However, the molecular mechanism underlying the HCQ retinal toxicity is still not well known. Retinal pigment epithelium, in which HCQ is highly enriched due to the tissue-specific affinity of HCQ, is considered to play important role in HCQ retinopathy. Herein, we used a metabolomics approach based on liquid chromatography-mass spectrometry to investigate the metabolic changes in retinal pigment epithelial cells (ARPE-19) with HCQ exposure at 6 h and 24 h. ARPE-19 cells were treated with HCQ at sub-lethal concentration 20 (IC 20), which was determined with MTT assay. Untargeted metabolic profiling revealed 9 and 15 metabolites that were significantly different between control group and HCQ exposure group at 6 h and 24 h, respectively. Enrichment and pathway analysis highlighted ascorbate and aldarate metabolism, d-Glutamine and d-glutamate metabolism and C5-Branched dibasic acid metabolism were disturbed after HCQ exposure. These findings increased our knowledge about the metabolic perturbation induced by HCQ exposure and indicated that metabolic profiling in the ARPE-19 cells might be helpful in understanding the mechanism of HCQ retinal toxicity and exploring potential biomarker.