Iron overload often occurs during blood transfusion and iron supplementation, resulting in the presence of non-transferrin-bound iron(NTBI) in host plasma and damage to multiple organs, but effects on the intestine ha...Iron overload often occurs during blood transfusion and iron supplementation, resulting in the presence of non-transferrin-bound iron(NTBI) in host plasma and damage to multiple organs, but effects on the intestine have rarely been reported. In this study, an iron overload mouse model with plasma NTBI was established by intraperitoneal injection of iron dextran. We found that plasma NTBI damaged intestinal morphology, caused intestinal oxidative stress injury and reactive oxygen species(ROS) accumulation,and induced intestinal epithelial cell apoptosis. In addition, plasma NTBI increased the relative abundance of Ileibacterium and Desulfovibrio in the cecum, while the relative abundance of Faecalibaculum and Romboutsia was reduced. Ileibacterium may be a potential microbial biomarker of plasma NTBI. Based on the function prediction analysis, plasma NTBI led to the weakening of intestinal microbiota function, significantly reducing the function of the extracellular structure. Further investigation into the mechanism of injury showed that iron absorption in the small intestine significantly increased in the iron group. Caco-2 cell monolayers were used as a model of the intestinal epithelium to study the mechanism of iron transport. By adding ferric ammonium citrate(FAC, plasma NTBI in physiological form) to the basolateral side, the apparent permeability coefficient(Papp) values from the basolateral to the apical side were greater than 3×10^(-6)cm s^(-1). Intracellular ferritin level and apical iron concentration significantly increased, and SLC39A8(ZIP8) and SLC39A14(ZIP14) were highly expressed in the FAC group.Short hairpin RNA(sh RNA) was used to knock down ZIP8 and ZIP14 in Caco-2 cells. Transfection with ZIP14-specific sh RNA decreased intracellular ferritin level and inhibited iron uptake. These results revealed that plasma NTBI may cause intestinal injury and intestinal flora dysbiosis due to the uptake of plasma NTBI from the basolateral side into the small intestine, which is probably mediated by ZIP14.展开更多
Myocardial siderosis is known as the major cause of death in thalassemia major(TM) patients since it can lead to iron overload cardiomyopathy.Although this condition can be prevented if timely effective intensive chel...Myocardial siderosis is known as the major cause of death in thalassemia major(TM) patients since it can lead to iron overload cardiomyopathy.Although this condition can be prevented if timely effective intensive chelation is given to patients,the mortality rate of iron overload cardiomyopathy still remains high due to late detection of this condition.Various direct and indirect methods of iron assessment,including serum ferritin level,echocardiogram,non-transferrin-bound iron,cardiac magnetic resonance T2*,heart rate variability,and liver biopsy and myocardial biopsy,have been proposed for early detection of cardiac iron overload in TM patients.However,controversial evidence and limitations of their use in clinical practice exist.In this review article,all of these iron assessment methods that have been proposed or used to directly or indirectly determine the cardiac iron status in TM reported from both basic and clinical studies are comprehensively summarized and presented.Since there has been growing evidence in the past decades that cardiac magnetic resonance imaging as well as cardiac autonomic status known as the heart rate variability can provide early detection of cardiac involvement in TM patients,these two methods are also presented and discussed.The existing controversy regarding the assessment of cardiac involvement in thalassemia is also discussed.展开更多
Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice....Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice.Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1|50 mg/(kg·day)| for 6 months.Blood levels of non-transferrin hound iron,labile plasma iron.ferritin(Ft) and malondialdehyde were determined.Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload.Interestingly,the mice showed a decrease in the non—transferrin bound iron,labile plasma iron and malondialdehyde levels,but not the Ft levels after continuous CM1 treatment.Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overload β—thalassemic mice.展开更多
基金supported by the National Natural Science Foundation of China (32272886)the National Key Research and Development Program of China (2022YFD1300500)。
文摘Iron overload often occurs during blood transfusion and iron supplementation, resulting in the presence of non-transferrin-bound iron(NTBI) in host plasma and damage to multiple organs, but effects on the intestine have rarely been reported. In this study, an iron overload mouse model with plasma NTBI was established by intraperitoneal injection of iron dextran. We found that plasma NTBI damaged intestinal morphology, caused intestinal oxidative stress injury and reactive oxygen species(ROS) accumulation,and induced intestinal epithelial cell apoptosis. In addition, plasma NTBI increased the relative abundance of Ileibacterium and Desulfovibrio in the cecum, while the relative abundance of Faecalibaculum and Romboutsia was reduced. Ileibacterium may be a potential microbial biomarker of plasma NTBI. Based on the function prediction analysis, plasma NTBI led to the weakening of intestinal microbiota function, significantly reducing the function of the extracellular structure. Further investigation into the mechanism of injury showed that iron absorption in the small intestine significantly increased in the iron group. Caco-2 cell monolayers were used as a model of the intestinal epithelium to study the mechanism of iron transport. By adding ferric ammonium citrate(FAC, plasma NTBI in physiological form) to the basolateral side, the apparent permeability coefficient(Papp) values from the basolateral to the apical side were greater than 3×10^(-6)cm s^(-1). Intracellular ferritin level and apical iron concentration significantly increased, and SLC39A8(ZIP8) and SLC39A14(ZIP14) were highly expressed in the FAC group.Short hairpin RNA(sh RNA) was used to knock down ZIP8 and ZIP14 in Caco-2 cells. Transfection with ZIP14-specific sh RNA decreased intracellular ferritin level and inhibited iron uptake. These results revealed that plasma NTBI may cause intestinal injury and intestinal flora dysbiosis due to the uptake of plasma NTBI from the basolateral side into the small intestine, which is probably mediated by ZIP14.
基金Supported by Thailand Research Fund grants RTA5580006 and BRG5480003
文摘Myocardial siderosis is known as the major cause of death in thalassemia major(TM) patients since it can lead to iron overload cardiomyopathy.Although this condition can be prevented if timely effective intensive chelation is given to patients,the mortality rate of iron overload cardiomyopathy still remains high due to late detection of this condition.Various direct and indirect methods of iron assessment,including serum ferritin level,echocardiogram,non-transferrin-bound iron,cardiac magnetic resonance T2*,heart rate variability,and liver biopsy and myocardial biopsy,have been proposed for early detection of cardiac iron overload in TM patients.However,controversial evidence and limitations of their use in clinical practice exist.In this review article,all of these iron assessment methods that have been proposed or used to directly or indirectly determine the cardiac iron status in TM reported from both basic and clinical studies are comprehensively summarized and presented.Since there has been growing evidence in the past decades that cardiac magnetic resonance imaging as well as cardiac autonomic status known as the heart rate variability can provide early detection of cardiac involvement in TM patients,these two methods are also presented and discussed.The existing controversy regarding the assessment of cardiac involvement in thalassemia is also discussed.
基金Supported by the Royal Golden Jubilee PhD Program.Thailand Research Fund(Grant No.PHD/0333/2551)
文摘Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice.Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1|50 mg/(kg·day)| for 6 months.Blood levels of non-transferrin hound iron,labile plasma iron.ferritin(Ft) and malondialdehyde were determined.Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload.Interestingly,the mice showed a decrease in the non—transferrin bound iron,labile plasma iron and malondialdehyde levels,but not the Ft levels after continuous CM1 treatment.Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overload β—thalassemic mice.