Molecular Mechanisms Of Iron Overload And Endoplasmic Reticulum Stress In The Development Of Liver Diseases

Drug-induced liver injury(DILI)is a serious and common complication in modern medicine,and can cause liver failure or even death in severe cases,gravely threatening human health.The treatment of drug-induced liver injury remains a clinical challenge,mainly due to the lack of efficient and accurate diagnosis.Therefore,developing an accurate diagnosis approach is imperative to boost the timely treatment for DILI.Endoplasmic reticulum is the site of intracellular protein synthesis,folding,transport and maturation.Hepatocytes are as rich in endoplasmic reticulum,especially endoplasmic reticulum stress,which plays a key role in liver cell injury.It is worth noting that,as the primary organ of iron storage,liver functions are tightly regulated by iron homeostasis.Therefore,endoplasmic reticulum stress-mediated iron overload is closely related to the occurrence and development of many liver diseases.What’s more,the change in the concentration of chloride ions that maintains the osmotic pressure of the cells during the iron deposition is unknown,and the change of HC1O the downstream product of Cl-,is also undiscovered.A large amount of deposited iron reacted with active oxygen can give rise to lipid peroxidation,which will lead ferroptosis.Whether the dynamic changes of chloride ion and hypochlorous acid are related to the occurrence of ferroptosis is worth further study.Therefore,investigating endoplasmic reticulum stress-mediated fluctuation of ferrous ions during drug-induced liver injury and monitoring changes in chloride and hypochlorous acid during iron deposition can further study the relationship between Cl-and HClO with ferroptosis.It is expected to provide new ideas for the relief of liver injury,and further explain the relationship with the occurrence and development of liver diseaseTo solve the above issue,we constructed a ferrous ion near-infrared fluorescent probe,and a new dual detection fluorescent probe to image Cl-and HClO,successfully achieved the visualization of the dynamic changes of the three in drug-induced liver injury.The specific work carried out in this paper as follows:1.NIR fluorescence imaging analysis of ferrous mediated by endoplasmic reticulum stress in drug-induced liver injuryA new near-infrared fluorescent probe(LCy7)was designed that enables real-time visualizing of Fe2+in drug-induced liver injury.In the structure of LCy7,a pentadentaten N4O ligand with stringent specificity and high affinity for Fe2+ acts as the recognition group,and the cyanine QCy7 with a high fluorescence quantum yield is chosen as a fluorophore.When the N4O ligand in LCy7 bonded to Fe2+,the C-O bond would break in the presence of O2,restoring the masked QCy7 with bright nearinfrared fluorescence.Utilizing LCy7,the increase in Fe2+was distinctly witnessed in hepatocytes under endoplasmic reticulum stress by acetaminophen(APAP)stimulation.In vivo near-infrared fluorescence imaging revealed the conspicuous rise in Fe2+in the liver of mice during APAP-induced liver injury.We further unprecedentedly disclosed that endoplasmic reticulum stress was accompanied by the overload of Fe2+ in injured liver of these mice.Collectively,this work will facilitate a greater understanding of the pathogenesis of DILI,and also provide a powerful new tool for DILI diagnosis and treatment2.Design,synthesis and application of fluorescent probes for simultaneous imaging chloride and hypochloriteA dual-detection fluorescent probe was constructed that can be used to detect both chloride and hypochlorite.In this probe,quinoline and fluorescein act as the fluorophore,in which the derivative of 6-methoxyquinoline can be used as the recognition group of Cl-,and C=N in the 5(6)-carboxyfluorescein derivative can reacted with HClO by addition reaction,so as to achieve rapid identification of HClO.After the probe reacts with Cl" and HCIO at the same time,it generates fluorescent signals with two colors of blue and green respectively,which can effectively realize the rapid recognition of chloride ion and hypochlorous acid.The probe is expected to realize the simultaneous and rapid detection of chloride and hypochlorous acid in cells and living,which is of great significance to explore the relationship between ferroptosis and liver injury,and maybe provide new ideas for relieving drug liver injury.