The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid （ALA）-based photodynamic therapy （PDT）. The purpose of this study is to compare the effect of two kinds of iron chelators, desfe...The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid （ALA）-based photodynamic therapy （PDT）. The purpose of this study is to compare the effect of two kinds of iron chelators, desferrioxamine （DFO） and ethylenediaminetetraacetic acid （EDTA） on the enhancement of ALA-PDT. HaCat cells were cultured in medium containing 2.0 mmol/L of ALA and 0.5 mmol/L of DFO or EDTA. After 3-h incubation in the dark, the concentration of cellular pro-toporphyrin Ⅸ （PpⅨ） was detected by high performance liquid chromatography （HPLC）, and the fluorescence of PpⅨ was observed at 630 nm emission under confocal laser scanning microscope. For PDT, HaCat cells were irradiated using 632.8 nm laser, and the fractions of apoptotic and necrotic cells were flow cytometrically assayed. Related differences in morphology and ultrastructure of Ha-Cat cells were observed using optical microscope or transmission electron microscope. Compared to incubation with ALA alone, the addition of DFO or EDTA increased the concentration of cellular PpⅨ and the fluorescent density of PpⅨ, and also increased cell death ratio after PDT. PDT using ALA plus DFO produced the highest cellular PpⅨ level, greatest cell death ratio and most severe structural damage to the cells. It was concluded that both DFO and EDTA could enhance ALA-based PpⅨ production and PDT. Compared to the non-specific iron chelator of EDTA, the specific chelator, DFO, showed more potential for the enhancement.展开更多
BACKGROUND： Studies on febrile convulsion （FC）-caused brain injury are disputed in many aspects. How FC cause nervous system injury in the developmental period and what are the characteristics of these pathological...BACKGROUND： Studies on febrile convulsion （FC）-caused brain injury are disputed in many aspects. How FC cause nervous system injury in the developmental period and what are the characteristics of these pathological injury are unknown. The current studies have demonstrated that berne oxygenase-1 （HO-1） exerts effects on brain injury mainly by catalyzing hemoglobin to produce degradation products, and HO-1 not only has neuroprotective effects, but also has neurotoxic effects during the FC-caused brain injury. Study on the effect of zinc protoporphyrin （ZnPP） on brain injury is still in the stage of animal experiment. OBJECTIVE： To observe the effects of ZnPP on carbon monoxide （CO）/HO-1 system of rats subjected to FC, and to analyze the action pathway of ZnPP in brain protective effect. DESIGN： A randomized controlled animal experiment. SETTING： Department of Pediatrics, First Hospital Affiliated to Jiamusi University. MATERIALS： Sixty-five Wistar rats, of either gender, were involved in this study. They were randomized into normal control group（ n =14, 37℃ water bath） and febrile treatment group （n =51, 44.5℃ hot water bath）. Febrile treatment group was sub-divided into febrile non-convulsion group （FNC group, n =16） and FC group （n =35）. FC group was further sub-divided into simple convulsion group （n =20） and ZnPP treatment group （n =15）. HO-1 mRNA in situ hybridization kit was provided by Boster Bioengineering Co.,Ltd. ZnPP（dark brown powder） was the product of Jingmei Bioengineering Company. METHODS： This study was carried out in the postgraduate laboratory of Jiamusi University between January 2004 and January 2007. Rats in the febrile treatment group were placed in the 44.5℃ hot water bath box. If rats did not convulse in the water within 5 minutes, they were taken out, namely FNC group （n = 16）, and those, which were convulsed within 5 minutes, were taken out immediately when they presented such a phenomenon, namely FC group （n =35）. Convulsion induction was conducted once every other day, totally 10 times. Rats were euthanized for analysis at 24 hours after the last induction. Rats in the control group were placed in the 37℃ water. Rats in the ZnPP treatment group were intraperitoneally injected with ZnPP at 45 μ mol/kg before FC attack. Rats in the simple convulsion group were only induced to be convulsed but not administrated. MAIN OUTCOME MEASURES： CO level in the brain tissue homogenate and plasma of rats in each group was detected with a spectrophotometer. HO-1 mRNA expression in the hippocampal CAI region, CA3 region and dentate gyrus of rats was observed by in situ hybridization technique. RESULTS： Sixty-five Wistar rats were involved in the study. Two rats died respectively due to drowning and convulsion in the FC group. One rat died due to convulsion drowning in the ZnPP treatment group. ①Plasma CO concentration of control group and ZnPP treatment group was significantly lower than that of the FC group （P 〈 0.01）, and was significantly higher in the ZnPP treatment group than in the FNC group （P 〈 0.05）. ②CO level in the brain tissue homogenate was significantly lower in the control group and ZnPP treatment group than in the FC group （P 〈 0.01）, and was very significantly higher in the ZnPP treatment group than in the control group （P 〈 0.01）. ③HO-1 mRNA expressions in the neuron of hippocampal CAl region, CA3 region and dentate gyrus of the control group were the lowerest, and those in the FC group were the highest. HO-1 mRNA expression in the neuron of dentate gyrus in the FC group was significantly higher than that in the ZnPP treatment group （P 〈 0.01）, and those in the FNC group and control group was significantly lower than that in the ZnPP treatment group （P 〈 0.01）. CONCLUSION： FC can cause brain injury. Over-expression of HO-I mRNA and the increase of CO are involved in the patho-physiological process of FC. ZnPP can inhibit HO-lmRNA activity and decrease CO level, which is one of pathways for protecting brain.展开更多
文摘The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid （ALA）-based photodynamic therapy （PDT）. The purpose of this study is to compare the effect of two kinds of iron chelators, desferrioxamine （DFO） and ethylenediaminetetraacetic acid （EDTA） on the enhancement of ALA-PDT. HaCat cells were cultured in medium containing 2.0 mmol/L of ALA and 0.5 mmol/L of DFO or EDTA. After 3-h incubation in the dark, the concentration of cellular pro-toporphyrin Ⅸ （PpⅨ） was detected by high performance liquid chromatography （HPLC）, and the fluorescence of PpⅨ was observed at 630 nm emission under confocal laser scanning microscope. For PDT, HaCat cells were irradiated using 632.8 nm laser, and the fractions of apoptotic and necrotic cells were flow cytometrically assayed. Related differences in morphology and ultrastructure of Ha-Cat cells were observed using optical microscope or transmission electron microscope. Compared to incubation with ALA alone, the addition of DFO or EDTA increased the concentration of cellular PpⅨ and the fluorescent density of PpⅨ, and also increased cell death ratio after PDT. PDT using ALA plus DFO produced the highest cellular PpⅨ level, greatest cell death ratio and most severe structural damage to the cells. It was concluded that both DFO and EDTA could enhance ALA-based PpⅨ production and PDT. Compared to the non-specific iron chelator of EDTA, the specific chelator, DFO, showed more potential for the enhancement.
基金Key Program of Science and Technology Research of Heilongjiang Province in 2006, No.11511400
文摘BACKGROUND： Studies on febrile convulsion （FC）-caused brain injury are disputed in many aspects. How FC cause nervous system injury in the developmental period and what are the characteristics of these pathological injury are unknown. The current studies have demonstrated that berne oxygenase-1 （HO-1） exerts effects on brain injury mainly by catalyzing hemoglobin to produce degradation products, and HO-1 not only has neuroprotective effects, but also has neurotoxic effects during the FC-caused brain injury. Study on the effect of zinc protoporphyrin （ZnPP） on brain injury is still in the stage of animal experiment. OBJECTIVE： To observe the effects of ZnPP on carbon monoxide （CO）/HO-1 system of rats subjected to FC, and to analyze the action pathway of ZnPP in brain protective effect. DESIGN： A randomized controlled animal experiment. SETTING： Department of Pediatrics, First Hospital Affiliated to Jiamusi University. MATERIALS： Sixty-five Wistar rats, of either gender, were involved in this study. They were randomized into normal control group（ n =14, 37℃ water bath） and febrile treatment group （n =51, 44.5℃ hot water bath）. Febrile treatment group was sub-divided into febrile non-convulsion group （FNC group, n =16） and FC group （n =35）. FC group was further sub-divided into simple convulsion group （n =20） and ZnPP treatment group （n =15）. HO-1 mRNA in situ hybridization kit was provided by Boster Bioengineering Co.,Ltd. ZnPP（dark brown powder） was the product of Jingmei Bioengineering Company. METHODS： This study was carried out in the postgraduate laboratory of Jiamusi University between January 2004 and January 2007. Rats in the febrile treatment group were placed in the 44.5℃ hot water bath box. If rats did not convulse in the water within 5 minutes, they were taken out, namely FNC group （n = 16）, and those, which were convulsed within 5 minutes, were taken out immediately when they presented such a phenomenon, namely FC group （n =35）. Convulsion induction was conducted once every other day, totally 10 times. Rats were euthanized for analysis at 24 hours after the last induction. Rats in the control group were placed in the 37℃ water. Rats in the ZnPP treatment group were intraperitoneally injected with ZnPP at 45 μ mol/kg before FC attack. Rats in the simple convulsion group were only induced to be convulsed but not administrated. MAIN OUTCOME MEASURES： CO level in the brain tissue homogenate and plasma of rats in each group was detected with a spectrophotometer. HO-1 mRNA expression in the hippocampal CAI region, CA3 region and dentate gyrus of rats was observed by in situ hybridization technique. RESULTS： Sixty-five Wistar rats were involved in the study. Two rats died respectively due to drowning and convulsion in the FC group. One rat died due to convulsion drowning in the ZnPP treatment group. ①Plasma CO concentration of control group and ZnPP treatment group was significantly lower than that of the FC group （P 〈 0.01）, and was significantly higher in the ZnPP treatment group than in the FNC group （P 〈 0.05）. ②CO level in the brain tissue homogenate was significantly lower in the control group and ZnPP treatment group than in the FC group （P 〈 0.01）, and was very significantly higher in the ZnPP treatment group than in the control group （P 〈 0.01）. ③HO-1 mRNA expressions in the neuron of hippocampal CAl region, CA3 region and dentate gyrus of the control group were the lowerest, and those in the FC group were the highest. HO-1 mRNA expression in the neuron of dentate gyrus in the FC group was significantly higher than that in the ZnPP treatment group （P 〈 0.01）, and those in the FNC group and control group was significantly lower than that in the ZnPP treatment group （P 〈 0.01）. CONCLUSION： FC can cause brain injury. Over-expression of HO-I mRNA and the increase of CO are involved in the patho-physiological process of FC. ZnPP can inhibit HO-lmRNA activity and decrease CO level, which is one of pathways for protecting brain.
