Reversion of age-related recognition memory impairment by iron chelation in rats

It is now generally accepted that iron accumulates in the brain during the ageing process. Increasing evidence demonstrate that iron accumulation in selective regions of the brain may generate free radicals, thereby possessing implications for the etiology of neurodegenerative disorders. In a previous study we have reported that aged rats present recognition memory deficits. The aim of the present study was to evaluate the effect of desferoxamine (DFO), an iron chelator agent, on age-induced memory impairment. Aged Wistar rats received intraperitoneal injections of saline or DFO (300mg/kg) for 2 weeks. The animals were submitted to a novel object recognition task 24h after the last injection. DFO-treated rats showed normal recognition memory while the saline group showed long-term recognition memory deficits. The results show that DFO is able to reverse age-induced recognition memory deficits. We also demonstrated that DFO reduced the oxidative damage to proteins in cortex and hippocampus. Thus, the present findings provide the first evidence that iron chelators might prevent age-related memory dysfunction.     

In vitro chelating, cytotoxicity, and blood compatibility of degradable poly(ethylene glycol)-based macromolecular iron chelators

Desferrioxamine (DFO) is used to treat an excess accumulation of iron in the body and is currently the most commonly used iron chelator for the treatment of 'iron overload' disorder. However, the disadvantages of DFO surround its high toxicity and very short plasma half-life. Here, the detailed in vitro evaluation of a novel class of high molecular weight iron chelators based on DFO and polyethylene glycol methacrylate is reported. Reversible addition fragment chain transfer (RAFT) copolymerization afforded polymer conjugates (P-DFO) with well-controlled molecular weight (27-127 kDa) and substitution of DFO (5-26 units per chain) along the copolymer. Human umbilical vein endothelial cell (HUVEC) based cell viability assays showed that the cytotoxicity of P-DFO decreased more than 100-fold at identical concentrations of DFO. The hemocompatibilities of various P-DFO samples were determined by measuring prothrombin time (PT), activated partial thromboplastin time (APTT), thrombelastograph parameters (TEG), complement activation, platelet activation, and red blood cell aggregation. Furthermore, the iron binding properties and chelating efficiency of P-DFO were compared to DFO by measuring the spectral properties upon binding to iron(III), while the prevention of iron(III) mediated oxidation of hemoglobin was also determined. Degradation of the P-DFO conjugates via cleavable ester linkages between the polymer backbone and the PEG side chains was evaluated using gel permeation chromatography (GPC) and NMR. Since the chelating ability of DFO remains intact after conjugation to the copolymer backbone, these macromolecular, blood compatible and degradable conjugates are promising candidates as long circulating, non-toxic iron chelators.     

铁螯合剂治疗高量输血重型β地中海贫血患者铁过载的疗效观察

目的探讨铁螯合剂治疗高量输血重型β地中海贫血铁过载的临床疗效。方法选择长期维持高量输血的重型β地中海贫血铁过载患者84例,其中不足量使用铁螯合剂患者36例,足量使用铁螯合剂患者48例。不足量使用铁螯合剂患者分为去铁胺（DFO）组、去铁酮（DFP）组、DFO联合DFP组;足量使用铁螯合剂患者分为DFO组、DFP组、地拉罗司（DFX）组、DFO联合DFP组。观察1年后血清铁蛋白（SF）的变化。结果不足量DFO、DFP组,SF均较1年前升高,DFO联合DFP组SF无明显变化;足量DFO、DFP组SF变化差异无统计学意义（P〉0.05）,DFX组、DFO联合DFP组SF下降差异均有统计学意义（P〈0.05）,其中DFX组疗效最佳,其次为DFO联合DFP组。结论高量输血重型β地中海贫血患者铁过载的治疗,应长期坚持使用足量的铁螯合剂,DFX以及DFO联合DFP祛铁效果明显。不良反应以骨关节疼痛及胃肠道反应为主。     

Iron chelation studies using desferrioxamine and the potential oral chelator, 1,2-dimethyl-3-hydroxypyrid-4-one, in normal and iron loaded rats.

A novel iron chelator, 1,2-dimethyl-3-hydroxypyrid-4-one, and desferrioxamine were compared for their ability to remove iron and for their site of action in iron release in rats. Repeated intraperitoneal injections of the chelators in rats with widespread tissue labelling by 59Fe derived from transferrin showed comparable 59Fe mobilisation by each chelator in normal and iron loaded rats. Specific labelling of a chelatable "cold" iron pool in hepatocytes by 59Fe derived from ferritin showed this pool to be equally accessible to parenteral doses of both chelators and also to oral 1,2-dimethyl-3-hydroxypyrid-4-one, which is an effective oral iron chelating agent that removes iron from parenchymal cells. This and other alpha-ketohydroxypyridines need further development as potential therapeutic agents in human iron overload.     

Inhibition of corticosteroid production by pineal factor

The effect of a factor isolated from the bovine pineal gland on the blood corticosteroid level and on the ability of isolated adrenal tissue to synthesize these compounds was investigated in experiments on male Wistar rats. The method of obtaining the pineal fraction is described. Its injection in a dose of 2 mg/100 g body weight lowered the blood corticosteroid level by 74, 69, 40, 64, and 63% after 4, 5, 7, 9, and 12 days respectively. The ability of the adrenal tissue to synthesize corticosteroids was depressed. The results are evidence that the pineal gland participates in the regulation of adrenal function.Institute of Endocrinology and Metabolism, Kiev. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 8, pp. 146–147, August, 1979.     

Intranasal deferoxamine reverses iron-induced memory deficits and inhibits amyloidogenic APP processing in a transgenic mouse model of Alzheimer's disease

Increasing evidence indicates that a disturbance of normal iron homeostasis and an amyloid-β (Aβ)-iron interaction may contribute to the pathology of Alzheimer's disease (AD), whereas iron chelation could be an effective therapeutic intervention. In the present study, transgenic mice expressing amyloid precursor protein (APP) and presenilin 1 and watered with high-dose iron served as a model of AD. We evaluated the effects of intranasal administration of the high-affinity iron chelator deferoxamine (DFO) on Aβ neuropathology and spatial learning and memory deficits created in this AD model. The effects of Fe, DFO, and combined treatments were also evaluated in vitro using SHSY-5Y cells overexpressing the human APP Swedish mutation. In vivo, no significant differences in the brain concentrations of iron, copper, or zinc were found among the treatment groups. We found that high-dose iron (deionized water containing 10 mg/mL FeCl₃) administered to transgenic mice increased protein expression and phosphorylation of APP695, enhanced amyloidogenic APP cleavage and Aβ deposition, and impaired spatial learning and memory. Chelation of iron via intranasal administration of DFO (200 mg/kg once every other day for 90 days) inhibited iron-induced amyloidogenic APP processing and reversed behavioral alterations. DFO treatment reduced the expression and phosphorylation of APP protein by shifting the processing of APP to the nonamyloidogenic pathway, and the reduction was accompanied by attenuating the Aβ burden, and then significantly promoted memory retention in APP/PS1 mice. The effects of DFO on iron-induced amyloidogenic APP cleavage were further confirmed in vitro. Collectively, the present data suggest that intranasal DFO treatment may be useful in AD, and amelioration of iron homeostasis is a potential strategy for prevention and treatment of this disease.     

Iron overload enhances epithelial cell proliferation in endometriotic lesions induced in a murine model

BACKGROUND: Iron deposits are characteristic of endometriotic lesions, and pelvic iron concentrations are higher in endometriosis patients than in women without endometriosis. In this study, the effect of iron overload and iron chelation on the development of endometriosis in a murine model was investigated. METHODS: Human menstrual endometrium was injected i.p. into nude mice, either alone (controls) or supplemented with erythrocytes or desferrioxamine (DFO), an iron chelator. After 5 days, the iron load of endometriosis-like lesions and peritoneal macrophages and fluid was evaluated. Lesions were quantified by immunohistochemical morphometry, and their proliferative activity was assessed. RESULTS: Injection of erythrocytes into the pelvic cavity caused iron overload in lesions (P < 0.025) and peritoneal macrophages (P < 0.01) and fluid (P < 0.05), whereas DFO effectively reduced iron status in lesions (P < 0.05) and macrophages (P < 0.01) compared with controls. No difference was observed in the number or surface area of lesions between the three groups. Erythrocytes increased (P < 0.05) and DFO significantly decreased (P < 0.01) the proliferative activity of lesions. CONCLUSIONS: Iron overload does not appear to affect lesion establishment but may contribute to the further growth of endometriosis by promoting cell proliferation of lesions. Iron chelator treatment could therefore be beneficial in endometriosis to prevent iron overload in the pelvic cavity and decrease cellular proliferation of lesions.     

复方鱼油对糖尿病大鼠主动脉粥样硬化早期病变的影响

雄性Ｗｉｓｔａｒ大鼠４２只，随机分为：正常对照组（１２只）；糖尿病对照组（１８只）；复方鱼油治疗组（１２只）。后两组静脉内注射链菌霉素导致ＤＭ，治疗组于注射ＳＴＺ第３周末开始灌饲复方鱼油。结果表明：复方鱼油可显著降低血脂水平，抑制血小板聚集，增强心房肽基因表达的降低血压，抑制主动脉粥样硬化早期病变形成。对糖尿病大鼠ＡＳ具有防治作用。     

吡咯烷二硫代氨基甲酸酯对2型糖尿病大鼠心肌的保护作用

目的: 探讨吡咯烷二硫代氨基甲酸酯(PDTC)的降糖作用及对糖尿病大鼠心肌的保护作用。方法: 37只雄性Wistar大鼠,随机分为正常对照组(NC)和高脂饮食组(HFD)。喂养8周后,高脂饮食组大鼠腹腔注射单剂量链脲佐菌素(STZ)27 mg/kg复制2型糖尿病大鼠模型。造模成功后再随机分为模型组和PDTC治疗组。PDTC治疗组大鼠每天腹腔注射PDTC(50 mg/kg)1次,模型组和正常对照组每天注射相同剂量的生理盐水,连续注射1周后,检测血糖及各种生化指标,处死大鼠。检测心肌组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活性;用透射电镜观察心肌组织的超微结构;用免疫组化观察心肌组织中诱导型一氧化氮合酶(iNOS)和硝基酪氨酸(NT)的表达。结果: 糖尿病模型组与正常对照组大鼠相比,血糖和MDA水平显著升高,SOD和GSH-Px活性明显下降(P<0.01);PDTC治疗后,血糖和MDA水平明显降低,SOD和GSH-Px活性明显升高(P＜0.01)。糖尿病组心肌变性坏死、线粒体损伤及炎症细胞浸润;PDTC治疗后线粒体损伤明显减轻。糖尿病组较正常对照组心肌中iNOS和NT的表达均明显增加;PDTC治疗后iNOS和NT的表达均明显减少。结论: 高血糖可引起氧化应激,使心肌组织中iNOS和NT生成过多,损伤了心肌细胞的结构和功能。PDTC不仅具有降糖作用,而且还可以通过减少iNOS和NT的产生,进而阻止或延缓糖尿病心肌病的发生。     

人脐带间充质干细胞肌肉注射健康大鼠心肌组织微血管及胶原纤维的表达

BACKGROUND:To date, it is still unclear whether the intramuscular injection of heterogeneous umbilical cord mesenchymal stem cells (UC-MSC) can cause cardiac ectopic pathological angiogenesis as well as increase collagen synthesis to promote myocardial fibrosis. OBJECTIVE:To explore the effects of intramuscular injection of human UC-MSCs on myocardial micrangium and collagen expression in normal Wistar rats. METHODS:After 2 weeks of feeding, 60 male SPF Wistar rats were randomly assigned to receive intramuscular injection of PBS (normal group), DMEM (culture medium group), human UC-MSCs supernatant (supernatant group), 0.25×10⁵, 1.0×10⁵, 4.0×10⁵ human UC-MSCs (low-, moderate- and high-dose groups), respectively (n=10 per group). All the rats were subjected to second injection (same dose) at 4 weeks after first intramuscular injection. Then, the rats were killed under anesthesia at 4 weeks after second injection, to take heart tissues from the left ventricle for pathological observation, immunohistochemical examination and Masson staining. RESULTS AND CONCLUSION: No alteration of the response, activity, victualage, faeces, weight growth, and fur was found, and there was no death in rats during the experiment. All the rats had no symptoms of molt, inflammation, skin ulcer, scleroma. Strong positive expression of CD34 for the micrangium in the myocardial tissue was observed, and positive expression of the collagen in the myocardial tissue observed by Masson staining. There were no significant differences in the microvessel density and collagen expression in the myocardium among the groups (F=0.110 and 0.585, P > 0.05). To conclude, hUC-MSCs or its supernatant via intramuscular injection has no effect on the micrangium and collagen expression in normal rats.     

Renal urea clearance in normal and adrenalectomized rats after exercise

In groups of male Wistar rats, blood level, urinary excretion of urea, and renal urea clearance were determined in resting conditions or during 48-60 h after swimming for 30 min with an additional load of 10% of body weight as well as after swimming for 3 or 10 h without additional load. Both types of swimming exercise caused a significant increase in the blood level, urinary excretion, and renal clearance of urea. After 10-h swimming, the increase of renal urea clearance was observed only from the second period (0-12 h) of urine collection. In this type of exercise, an elevation of blood level of corticosterone was obtained after 6-h restitution. The increased urinary excretion and renal urea clearance persisted for a longer time than was necessary for the normalization of the blood level. A significant rise in blood urea level and a drop in renal urea clearance occurred after adrenalectomy. In adrenalectomized rats, increased urea excretion and renal clearance were observed 12-24 h after 3-h swimming, but the level of renal clearance obtained in sedentary normal rats was not achieved. The blood level of urea did not increase. This suggested that the glucocorticoids play a role both in urea formation during exercise and in its elevated renal clearance after exercise.     

脐血内皮祖细胞尾静脉与局部注射治疗糖尿病下肢缺血

背景：内皮祖细胞治疗糖尿病下肢缺血临床及动物实验多采用局部肌肉注射。 目的：比较脐血内皮祖细胞鼠尾静脉与局部注射治疗糖尿病下肢缺血效果的差异。 方法：取Wistar雄性大鼠分成5组：①糖尿病射线照射后结扎双后肢股动脉,尾静脉注射内皮祖细胞(DLV)。②糖尿病结扎双后肢股动脉左后肢局部肌肉注射PBS(DLC),右后肢局部肌肉注射内皮祖细胞(DLM)。③正常大鼠射线照射后结扎双后肢,尾静脉注射内皮祖细胞(NLV)。④糖尿病不结扎不注射内皮祖细胞(DC)。用绿色荧光示踪内皮祖细胞,苏木精-伊红染色检测肌纤维间毛细血管数,RT-PCR检测双后肢肌肉血管内皮生长因子mRNA水平。 结果与结论：DLV组与DLM组比较,右后肢腓肠肌溃疡及缺血好转明显,二者无明显区别;有明显荧光,差别不明显,Ⅷ因子免疫组织化学染色肌纤维间毛细血管数多,相互间无明显差别;腓肠肌血管内皮生长因子表达差异无显著性意义(P > 0.05)。提示脐血内皮祖细胞治疗糖尿病大鼠下肢缺血尾静脉注射与局部肌肉注射效果相当。     

A role for hypoxia-inducible factor-1alpha in desferoxamine neuroprotection

The newborn brain has increased vulnerability to hypoxia-ischemia from maturational differences in the oxidative stress response. We hypothesized that desferoxamine (DFO), an iron chelator, would provide protection in an in vitro model of ischemia in part through activation of the hypoxia-inducible gene hypoxia-inducible factor-1alpha (HIF-1alpha). Hippocampal neurons from E16 CD1 mice were exposed to 3 h of oxygen and glucose deprivation with and without pretreatment with 10 mmol/L DFO in the presence and absence of 2 micromol/L antisense oligonucleotides specific for HIF-1alpha (antiHIF-1alpha). DFO pretreatment resulted in 45% reduction in cell death (p = 0.006). This protection was diminished with transfection of antiHIF-1alpha (p = 0.049). Blocking HIF-1alpha reduces DFO protection suggesting that DFO protects through iron chelation and HIF-1alpha induction.     

小檗碱对糖尿病肾病大鼠C反应蛋白的影响

目的:观察小檗碱对糖尿病肾病大鼠C反应蛋白的影响。方法:将48只雄性SD大鼠随机分为空白对照组、模型组、小檗碱75、150及300mg.kg-1组、罗格列酮组六组,每组8只。除正常对照组外,其余各组大鼠腹腔注射链脲佐菌素(STZ,55mg.kg-1),成功造模后小檗碱各组及罗格列酮组分别灌胃给予75、150、300mg.kg-1小檗碱以及4mg.kg-1罗格列酮,连续6w后检测大鼠血糖、体重,HE染色检测肾脏病理改变,ELISA法检测C反应蛋白活性。结果:与正常对照组相比,糖尿病组血糖与C反应蛋白活性明显升高(P<0.05),与模型组比较,小檗碱各组血糖与C反应蛋白活性明显降低(P<0.05),有统计学意义。结论:小檗碱可降低糖尿病大鼠血糖和C反应蛋白,减轻糖尿病肾病。     

骨髓腔内输注脐带血及间充质干细胞对大鼠免疫重建影响

目的探讨骨髓腔内（IBM）输注脐带血及骨髓间充质干细胞（BMSC）对移植后大鼠免疫重建的影响。方法雌性F344胎鼠及新生鼠外周血（FNPB）及雄性F344大鼠BMSC共移植经致死量60Coγ射线辐照的雌性Wistar大鼠,其中FNPB均由IBM输注,BMSC则通过IBM或尾静脉（IV）注射。观察受鼠存活状况、供体造血干细胞（HSC）植入水平、免疫细胞及功能恢复、移植物抗宿主病（GVHD）表现,并用PCR检测受鼠供体BMSC来源Y染色体。结果两共移植组60d均100%存活,生存率和供体HSC植入水平差异无统计学意义,但明显优于单纯FNPB移植组;骨髓腔共移植组外周血白细胞及粒单系细胞集落形成单位（CFU-GM）、混合集落形成单位（CFU-GEMM）集落产率恢复较快,14d显著高于其他组（P〈0.05）。而单纯FNPB移植组各检测时点集落计数均明显低于共移植组（P〈0.05）,30dCD19＋细胞比例亦明显低于正常;30d各移植组PHA、LPS诱导淋巴细胞增殖实验及单向混合淋巴细胞培养无明显差异;60d两共移植组存活受鼠均检测到供体BMSC来源Y染色体。结论 HSC与BMSC联合输注可促进受者免疫重建,尤以IBM输注为佳。     

吗啡吸入成瘾大鼠模型的建立

目的建立吗啡吸入成瘾大鼠模型,从而减少进行功能影像学检测时的干扰因素,更好地了解成瘾强化环路。方法将30只SD雄性大鼠随机分成吸入对照组、吸入成瘾组以及注射成瘾组,利用超声雾化吸入的方式建立吸入成瘾模型,将该模型与吸入对照组、注射成瘾组进行戒断反应对比,并将吸入组各组大鼠尿液、血液样本进行吗啡检测。结果吸入成瘾组各戒断反应与吸入对照组相比具有显著性差异,P<0.01;吸入成瘾组与注射成瘾组戒断反应比较无明显显著性差异;尿检及血液吗啡胶体金法检测,吸入成瘾组吗啡定性阳性。结论通过超声雾化吸入的方式建立吗啡吸入成瘾大鼠模型是切实可行的。     

脂肪间充质干细胞移植治疗1型糖尿病模型大鼠的作用

背景:干细胞移植是1型糖尿病比较有前景的治疗方法,脂肪间充质干细胞是继骨髓间充质干细胞后的又一研究热点。目的:观察脂肪间充质干细胞移植对1型糖尿病大鼠的治疗作用。方法:将45只SD大鼠随机分为正常组、模型组和细胞移植组,后2组采用链脲菌素腹腔注射建立1型糖尿病模型。造模后7 d,正常组腹腔静脉注射生理盐水,模型组腹腔静脉注射无血清的DMEM培养液,细胞移植组腹腔静脉注射脂肪间充质干细胞悬液。移植后2周,监测各组大鼠体质量、血糖水平,ELISA法检测各组大鼠胰岛素分泌量,RT-PCR检测胰腺组织PDX-1 m RNA的表达。结果与结论:(1)移植前细胞移植组与模型组的体质量均低于正常组,移植后2周细胞移植组大鼠体质量逐渐增加,而模型组的体质量持续下降;(2)与正常组比较,模型组大鼠空腹血糖维持在较高水平(P<0.05),与模型组相比,细胞移植组大鼠空腹血糖水平显著下降(P<0.05);(3)与正常组比较,模型组胰岛素水平明显降低(P<0.05),与模型组比较,细胞移植组胰岛素水平则显著增加(P<0.05);(4)正常组胰腺组织PDX-1 mR NA表达最高,模型组最低,各组间比较差异有显著性意义(P<0.05);(5)结果表明,脂肪间充质干细胞移植促进胰岛组织PDX-1表达,改善了大鼠的高血糖状态。     

Iron-dependent regulation of frataxin expression: implications for treatment of Friedreich ataxia

Friedreich ataxia (FA) is a progressive neurodegenerative disease caused by expansion of a trinucleotide repeat within the first intron of the gene that encodes frataxin. In our study, we investigated the regulation of frataxin expression by iron and demonstrated that frataxin mRNA levels decrease significantly in multiple human cell lines treated with the iron chelator, desferal (DFO). In addition, frataxin mRNA and protein levels decrease in fibroblast and lymphoblast cells derived from both normal controls and from patients with FA when treated with DFO. Lymphoblasts and fibroblasts of FA patients have evidence of cytosolic iron depletion, as indicated by increased levels of iron regulatory protein 2 (IRP2) and/or increased IRE-binding activity of IRP1. We postulate that this inferred cytosolic iron depletion occurs as frataxin-deficient cells overload their mitochondria with iron, a downstream regulatory effect that has been observed previously when mitochondrial iron-sulfur cluster assembly is disrupted. The mitochondrial iron overload and presumed cytosolic iron depletion potentially further compromise function in frataxin-deficient cells by decreasing frataxin expression. Thus, our results imply that therapeutic efforts should focus on an approach that combines iron removal from mitochondria with a treatment that increases cytosolic iron levels to maximize residual frataxin expression in FA patients.     

Classification of different degrees of adiposity in sedentary rats

In experimental studies, several parameters, such as body weight, body mass index, adiposity index, and dual-energy X-ray absorptiometry, have commonly been used to demonstrate increased adiposity and investigate the mechanisms underlying obesity and sedentary lifestyles. However, these investigations have not classified the degree of adiposity nor defined adiposity categories for rats, such as normal, overweight, and obese. The aim of the study was to characterize the degree of adiposity in rats fed a high-fat diet using cluster analysis and to create adiposity intervals in an experimental model of obesity. Thirty-day-old male Wistar rats were fed a normal (n=41) or a high-fat (n=43) diet for 15 weeks. Obesity was defined based on the adiposity index; and the degree of adiposity was evaluated using cluster analysis. Cluster analysis allowed the rats to be classified into two groups (overweight and obese). The obese group displayed significantly higher total body fat and a higher adiposity index compared with those of the overweight group. No differences in systolic blood pressure or nonesterified fatty acid, glucose, total cholesterol, or triglyceride levels were observed between the obese and overweight groups. The adiposity index of the obese group was positively correlated with final body weight, total body fat, and leptin levels. Despite the classification of sedentary rats into overweight and obese groups, it was not possible to identify differences in the comorbidities between the two groups.