Soybean protein has high nutritional value, but its functional properties are easily affected by external factors,which limits its application in food industry. In the study, soybean protein isolate(SPI) was modified ...Soybean protein has high nutritional value, but its functional properties are easily affected by external factors,which limits its application in food industry. In the study, soybean protein isolate(SPI) was modified by dry heat glycation of galactooligosaccharides(GOS). The gel properties, antioxidant properties and structural changes of SPI-GOS conjugates were investigated. The application of SPI-GOS conjugates in noodles was also explored. The results observed that the glycation degree of SPI increased with the increasing reaction time. SDS-PAGE and spectral analysis showed the changes of spatial conformation of SPI after glycation. The antioxidant activity of SPI increased after glycation and DPPH radical scavenging activity of SPI-GOS peaked at 48 h of reaction. The hardness, elasticity and resilience of soybean protein gel reached their relative maximum at 48 h, 48 h and 12 h of glycation reaction, respectively. Moreover, the appropriate addition of glycated SPI improved the quality of noodles. The noodles with 4% addition of SPI-GOS had higher hardness, elasticity and tensile properties. This study will provide an effective method to modify soybean protein and expand the use of soybean protein in food industry.展开更多
The role of protein kinase C （PKC） activation in advanced glycation end products （AGEs）-induced epithelial-mesenchymal transition in renal proximal tubular epithelial cells was investigated. HKC cells were divided...The role of protein kinase C （PKC） activation in advanced glycation end products （AGEs）-induced epithelial-mesenchymal transition in renal proximal tubular epithelial cells was investigated. HKC cells were divided into three groups： normal group, AGE-BSA group （100 mg/L AGE-BSA） and AGE-BSA＋PKC inhibitor （10 μmol/L chelerythrine chloride） group. PKC activity was measured by PKC assay kit. The expression of Vimentin, and phosphorylated β-catenin was detected by using Western blotting, and the content of TGF-β1 was examined by ELISA method. The intracellular disposition of Vimentin was observed by fluorescence microscopy. As compared with normal group, PKC activity was increased significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was enhanced significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was significantly blocked by chelerythrine chloride. High expression of Vimentin, phosphorylated β-catenin, and TGF-β1 induced by AGE-BSA may be mediated via the activation of PKC signal transduction pathway.展开更多
Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of ...Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of hydroxyl radicals(·OH)were developed after the chicken myofibrillar protein mild glycation(MPG).Results exhibited that levels of AGEs and surface hydrophobicity(H_(0))steadily increased with the a ddition of h ydrogen peroxide(H_(2)O_(2))concentration.However,levels of s ulfhydryl group,free amino group,and particle size gradually decreased with the H_(2)O_(2)concentration.The protein carbonyl value increased in H_(2)O_(2)concentration until 10 mmol/L.Pearson's correlation indicated that MPG structure modification(unfolding and degradation)induced by protein oxidation were significantly positively correlated with AGEs concentration(P<0.05).Finally,a mechanism was proposed to hypothesize t he effect of protein oxidation on the formation of AGEs under MPG conditions.展开更多
Non-enzymatic glycation of proteins has been implicated as an important cause of the complications associated with diabetes and Alzheimer disease. It is well known that glycation involves the reactivity of, primarily,...Non-enzymatic glycation of proteins has been implicated as an important cause of the complications associated with diabetes and Alzheimer disease. It is well known that glycation involves the reactivity of, primarily, the ε-amino group of the lysines present in the protein. The immediate chemical environment of an amino group modulates the glycation reaction. In this work, several model helical peptides for protein glycation has been studied by resorting to QM:MM calculations through the ONIOM methodology. Some Conceptual DFT descriptors have been calculated that allowed the comparison of the chemical reactivity between the different model peptides in terms of the position of the Lys group and other spatially proximate amino acid residues.展开更多
The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with g...The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with glucose in patients with diabetes;this modifies the structure and function of HSA.Furthermore,the advanced glycation end products produced by glycated HSA can cause pathological damage to the human body through various signaling pathways,eventually leading to complications of diabetes.Many potential glycation sites on HSA have different degrees of sensitivity to glucose concentration.This review provides a comprehensive assessment of the in vivo glycation sites of HSA;it also discusses the effects of glycation on the structure and function of HSA.Moreover,it addresses the relationship between HSA glycation and diabetes complications.Finally,it focuses on the value of non-enzymatic glycation of HSA in diabetes-related clinical applications.展开更多
A rat model of diabetes mellitus was induced by a high fat diet, followed by focal brain ischemia induced using the thread method after 0.5 month. Immunohistochemistry showed that expression of receptor for advanced g...A rat model of diabetes mellitus was induced by a high fat diet, followed by focal brain ischemia induced using the thread method after 0.5 month. Immunohistochemistry showed that expression of receptor for advanced glycation end-products was higher in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Western blot assay revealed increased phosphorylated c-Jun N-terminal kinase expression, and unchanged phosphorylated extracellular signal-regulated protein kinase protein expression in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Additionally, phosphorylated p38 mitogen-activated protein kinase protein was not detected in any rats in the two groups. Severity of limb hemiplegia was worse in diabetic rats with brain ischemia compared with ischemia alone rats. The results suggest that increased expression of receptor for advanced glycation end-products can further activate the c-Jun N-terminal kinase pathway in mitogen-activated protein kinase, thereby worsening brain injury associated with focal brain ischemia in diabetic rats.展开更多
AIM： To identify the effect and regulatory mechanism of amyloid β （Aβ） protein on retinal pigment epithelial （RPE） cells in cell proliferation and apoptosis, and clarify Aβ role in the pathogenesis of age-rela...AIM： To identify the effect and regulatory mechanism of amyloid β （Aβ） protein on retinal pigment epithelial （RPE） cells in cell proliferation and apoptosis, and clarify Aβ role in the pathogenesis of age-related macular degeneration （AMD）. METHODS： The model of Aβ25-35 protein cytotoxicity in RPE cell was successfully established to investigate the effect of Aβ protein on RPE cells in vitro. Based on Aβ protein, the specific inhibitors （HY-50682 or BAY11-7082） or activating agent （lipopolysaccharide） was used to analyze the regulatory mechanism of Aβ protein to RPE cells on cell proliferation and apoptosis by flow cytometry, real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay and dual-luciferase reporter gene assay. RESULTS： The number of RPE cells, treated with Aβ25-35 from 0.3 to 60 μmol/L, significantly reduce （P〈0.01）, and had the dose-dependent effect. Aβ protein 60 μmol/L inhibits the G1/S phase transition （P〈0.01） and down-regulated cyclin E mRNA level （P〈0.01）. Similarly, Aβ25-35 induced a significant increase of cell apoptosis, accompanied by the significantly higher level of activated caspase 3 protein. Furthermore, nuclear factor-kappaB （NF-κB） activity and hosphorylated Iκ-Ba level would significantly lower in treated RPE cells. Using specific inhibitors or activating agent based on the Aβ, the cell numbers, NF-κB activity, phosphorylated Iκ-Ba level, receptor for advanced glycation endproducts （RAGE） gene expression levels, cyclin E mRNA level and activated caspase 3 level had accordingly changed by different methods, confirming that RAGE/NF-κB signaling pathway involved in the regulation of Aβ protein on RPE cell apoptosis and proliferation. CONCLUSION： Aβ protein inhibits cell proliferation and activates apoptosis via inactivation of the RAGE/NF-κB signaling pathway in RPE cell.展开更多
The recombinant DNA technology enabled the produ-ction of a variety of human therapeutic proteins. Accumulated clinical experience, however, indicates that the formation of antibodies against such proteins is a genera...The recombinant DNA technology enabled the produ-ction of a variety of human therapeutic proteins. Accumulated clinical experience, however, indicates that the formation of antibodies against such proteins is a general phenomenon rather than an exception. The immunogenicity of therapeutic proteins results in inefficient therapy and in the development of undesired, sometimes life-threatening, side reactions. The human proteins, designed for clinical application, usually have the same amino acid sequence as their native prototypes and it is not yet fully clear what the reasons for their immunogenicity are. In previous studies we have demonstrated for the first time that interferon-b （IFN-b） pharmaceuticals, used for treatment of patients with multiple sclerosis, do contain advanced glycation end products （AGEs） that contribute to IFN-b immunogenicity. AGEs are the fnal products of a chemical reaction known as the Maillard reaction or glycation, which implication in protein drugs’ immunogenicity has been overlooked so far. Therefore, the aim of the present article is to provide a comprehensive overview on the Maillard reaction with emphasis on experimental data and theoretical consideration telling us why the Maillard reaction warrants special attention in the context of the well-documented protein drugs’ immunogenicity.展开更多
目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至202...目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至2022年2月我院收治的100例SP患儿为研究对象,根据患儿是否发生继发性ARDS将患儿分为ARDS组(n=56)和对照组(n=44),收集患儿一般资料,采集外周血以酶联免疫吸附法进行RAGE、HMGB1、IFN-γ和IL-4表达水平检测,采用多因素logistic回归分析SP患儿继发ARDS的影响因素,采用Pearson相关性分析其与IFN-γ/IL-4的相关性,并采用受试者工作曲线(ROC)分析RAGE、HMGB1表达对SP患儿继发ARDS的预测价值。结果两组SP患儿性别、年龄、体温以及发病季节之间无显著差异,ARDS组致病菌种类多于对照组,PaO_(2)/FiO_(2)和APS评分、血清RAGE、HMGB1、IFN-γ和IL-4表达水平以及IFN-γ/IL-4比值均高于对照组(P<0.05)。经多因素logistic回归分析可知,致病菌种类、PaO_(2)/FiO_(2)、RAGE、HMGB1表达、IFN-γ、IL-4和IFN-γ/IL-4均为SP患儿继发ARDS的影响因素。经Pearson相关检验,SP患儿血清RAGE、HMGB1表达水平与IFN-γ、IL-4和IFN-γ/IL-4均呈正相关(P<0.05)。经ROC曲线分析可得,血清RAGE、HMGB1水平预测SP患儿发生ARDS的AUC分别为0.707和0.750,灵敏度分别为73.2%、64.3%,特异度分别为68.2%、77.3%,两者联合预测的AUC为0.848,灵敏度和特异度分别为80.4%和81.8%。结论SP继发ARDS患儿血清中RAGE、HMGB1表达水平较高,与IFN-γ/IL-4呈正相关,监测患儿血清RAGE、HMGB1表达对SP患儿继发ARDS的风险有一定的预测价值。展开更多
基金the National Natural Science Foundation of China (31871748)Natural Science Foundation of Henan Province (242300421317, 242300420462)+2 种基金the Project of Henan University of Technology Excellent Young Teachers (21420064)Zhengzhou Science and Technology Collaborative Innovation Project (21ZZXTCX17)China Postdoctoral Science Fundation (2021M701112) for the financial support。
文摘Soybean protein has high nutritional value, but its functional properties are easily affected by external factors,which limits its application in food industry. In the study, soybean protein isolate(SPI) was modified by dry heat glycation of galactooligosaccharides(GOS). The gel properties, antioxidant properties and structural changes of SPI-GOS conjugates were investigated. The application of SPI-GOS conjugates in noodles was also explored. The results observed that the glycation degree of SPI increased with the increasing reaction time. SDS-PAGE and spectral analysis showed the changes of spatial conformation of SPI after glycation. The antioxidant activity of SPI increased after glycation and DPPH radical scavenging activity of SPI-GOS peaked at 48 h of reaction. The hardness, elasticity and resilience of soybean protein gel reached their relative maximum at 48 h, 48 h and 12 h of glycation reaction, respectively. Moreover, the appropriate addition of glycated SPI improved the quality of noodles. The noodles with 4% addition of SPI-GOS had higher hardness, elasticity and tensile properties. This study will provide an effective method to modify soybean protein and expand the use of soybean protein in food industry.
基金supported by grants from National Natural Sciences Foundation of China (No. 30370657, No.30871172)New Century Excellent Talents Grant (No. NCET004–0712)
文摘The role of protein kinase C （PKC） activation in advanced glycation end products （AGEs）-induced epithelial-mesenchymal transition in renal proximal tubular epithelial cells was investigated. HKC cells were divided into three groups： normal group, AGE-BSA group （100 mg/L AGE-BSA） and AGE-BSA＋PKC inhibitor （10 μmol/L chelerythrine chloride） group. PKC activity was measured by PKC assay kit. The expression of Vimentin, and phosphorylated β-catenin was detected by using Western blotting, and the content of TGF-β1 was examined by ELISA method. The intracellular disposition of Vimentin was observed by fluorescence microscopy. As compared with normal group, PKC activity was increased significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was enhanced significantly in AGE-BSA group. The expression of Vimentin, phosphorylated β-catenin, and TGF-β1 was significantly blocked by chelerythrine chloride. High expression of Vimentin, phosphorylated β-catenin, and TGF-β1 induced by AGE-BSA may be mediated via the activation of PKC signal transduction pathway.
基金supported by National Key R&D Program of China(2021YFD2100104)griculture Research System of China(CARS-41-Z)+2 种基金Science and Technology Project of Nanjing City(202002040)Jiangsu Province Policy Guidance Program(BX2020008)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0579),China。
文摘Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of hydroxyl radicals(·OH)were developed after the chicken myofibrillar protein mild glycation(MPG).Results exhibited that levels of AGEs and surface hydrophobicity(H_(0))steadily increased with the a ddition of h ydrogen peroxide(H_(2)O_(2))concentration.However,levels of s ulfhydryl group,free amino group,and particle size gradually decreased with the H_(2)O_(2)concentration.The protein carbonyl value increased in H_(2)O_(2)concentration until 10 mmol/L.Pearson's correlation indicated that MPG structure modification(unfolding and degradation)induced by protein oxidation were significantly positively correlated with AGEs concentration(P<0.05).Finally,a mechanism was proposed to hypothesize t he effect of protein oxidation on the formation of AGEs under MPG conditions.
文摘Non-enzymatic glycation of proteins has been implicated as an important cause of the complications associated with diabetes and Alzheimer disease. It is well known that glycation involves the reactivity of, primarily, the ε-amino group of the lysines present in the protein. The immediate chemical environment of an amino group modulates the glycation reaction. In this work, several model helical peptides for protein glycation has been studied by resorting to QM:MM calculations through the ONIOM methodology. Some Conceptual DFT descriptors have been calculated that allowed the comparison of the chemical reactivity between the different model peptides in terms of the position of the Lys group and other spatially proximate amino acid residues.
基金Supported by the National Natural Science Foundation of China,No.81870593Natural Science Foundation of Shandong Province of China,No.ZR2020MH106and Medical Health Science and Technology Project of Shandong Province,No.202003060400.
文摘The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with glucose in patients with diabetes;this modifies the structure and function of HSA.Furthermore,the advanced glycation end products produced by glycated HSA can cause pathological damage to the human body through various signaling pathways,eventually leading to complications of diabetes.Many potential glycation sites on HSA have different degrees of sensitivity to glucose concentration.This review provides a comprehensive assessment of the in vivo glycation sites of HSA;it also discusses the effects of glycation on the structure and function of HSA.Moreover,it addresses the relationship between HSA glycation and diabetes complications.Finally,it focuses on the value of non-enzymatic glycation of HSA in diabetes-related clinical applications.
基金supported by the Science and Technology Development Foundation of Jilin Province,No.200905172
文摘A rat model of diabetes mellitus was induced by a high fat diet, followed by focal brain ischemia induced using the thread method after 0.5 month. Immunohistochemistry showed that expression of receptor for advanced glycation end-products was higher in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Western blot assay revealed increased phosphorylated c-Jun N-terminal kinase expression, and unchanged phosphorylated extracellular signal-regulated protein kinase protein expression in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Additionally, phosphorylated p38 mitogen-activated protein kinase protein was not detected in any rats in the two groups. Severity of limb hemiplegia was worse in diabetic rats with brain ischemia compared with ischemia alone rats. The results suggest that increased expression of receptor for advanced glycation end-products can further activate the c-Jun N-terminal kinase pathway in mitogen-activated protein kinase, thereby worsening brain injury associated with focal brain ischemia in diabetic rats.
文摘AIM： To identify the effect and regulatory mechanism of amyloid β （Aβ） protein on retinal pigment epithelial （RPE） cells in cell proliferation and apoptosis, and clarify Aβ role in the pathogenesis of age-related macular degeneration （AMD）. METHODS： The model of Aβ25-35 protein cytotoxicity in RPE cell was successfully established to investigate the effect of Aβ protein on RPE cells in vitro. Based on Aβ protein, the specific inhibitors （HY-50682 or BAY11-7082） or activating agent （lipopolysaccharide） was used to analyze the regulatory mechanism of Aβ protein to RPE cells on cell proliferation and apoptosis by flow cytometry, real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay and dual-luciferase reporter gene assay. RESULTS： The number of RPE cells, treated with Aβ25-35 from 0.3 to 60 μmol/L, significantly reduce （P〈0.01）, and had the dose-dependent effect. Aβ protein 60 μmol/L inhibits the G1/S phase transition （P〈0.01） and down-regulated cyclin E mRNA level （P〈0.01）. Similarly, Aβ25-35 induced a significant increase of cell apoptosis, accompanied by the significantly higher level of activated caspase 3 protein. Furthermore, nuclear factor-kappaB （NF-κB） activity and hosphorylated Iκ-Ba level would significantly lower in treated RPE cells. Using specific inhibitors or activating agent based on the Aβ, the cell numbers, NF-κB activity, phosphorylated Iκ-Ba level, receptor for advanced glycation endproducts （RAGE） gene expression levels, cyclin E mRNA level and activated caspase 3 level had accordingly changed by different methods, confirming that RAGE/NF-κB signaling pathway involved in the regulation of Aβ protein on RPE cell apoptosis and proliferation. CONCLUSION： Aβ protein inhibits cell proliferation and activates apoptosis via inactivation of the RAGE/NF-κB signaling pathway in RPE cell.
文摘The recombinant DNA technology enabled the produ-ction of a variety of human therapeutic proteins. Accumulated clinical experience, however, indicates that the formation of antibodies against such proteins is a general phenomenon rather than an exception. The immunogenicity of therapeutic proteins results in inefficient therapy and in the development of undesired, sometimes life-threatening, side reactions. The human proteins, designed for clinical application, usually have the same amino acid sequence as their native prototypes and it is not yet fully clear what the reasons for their immunogenicity are. In previous studies we have demonstrated for the first time that interferon-b （IFN-b） pharmaceuticals, used for treatment of patients with multiple sclerosis, do contain advanced glycation end products （AGEs） that contribute to IFN-b immunogenicity. AGEs are the fnal products of a chemical reaction known as the Maillard reaction or glycation, which implication in protein drugs’ immunogenicity has been overlooked so far. Therefore, the aim of the present article is to provide a comprehensive overview on the Maillard reaction with emphasis on experimental data and theoretical consideration telling us why the Maillard reaction warrants special attention in the context of the well-documented protein drugs’ immunogenicity.
文摘目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至2022年2月我院收治的100例SP患儿为研究对象,根据患儿是否发生继发性ARDS将患儿分为ARDS组(n=56)和对照组(n=44),收集患儿一般资料,采集外周血以酶联免疫吸附法进行RAGE、HMGB1、IFN-γ和IL-4表达水平检测,采用多因素logistic回归分析SP患儿继发ARDS的影响因素,采用Pearson相关性分析其与IFN-γ/IL-4的相关性,并采用受试者工作曲线(ROC)分析RAGE、HMGB1表达对SP患儿继发ARDS的预测价值。结果两组SP患儿性别、年龄、体温以及发病季节之间无显著差异,ARDS组致病菌种类多于对照组,PaO_(2)/FiO_(2)和APS评分、血清RAGE、HMGB1、IFN-γ和IL-4表达水平以及IFN-γ/IL-4比值均高于对照组(P<0.05)。经多因素logistic回归分析可知,致病菌种类、PaO_(2)/FiO_(2)、RAGE、HMGB1表达、IFN-γ、IL-4和IFN-γ/IL-4均为SP患儿继发ARDS的影响因素。经Pearson相关检验,SP患儿血清RAGE、HMGB1表达水平与IFN-γ、IL-4和IFN-γ/IL-4均呈正相关(P<0.05)。经ROC曲线分析可得,血清RAGE、HMGB1水平预测SP患儿发生ARDS的AUC分别为0.707和0.750,灵敏度分别为73.2%、64.3%,特异度分别为68.2%、77.3%,两者联合预测的AUC为0.848,灵敏度和特异度分别为80.4%和81.8%。结论SP继发ARDS患儿血清中RAGE、HMGB1表达水平较高,与IFN-γ/IL-4呈正相关,监测患儿血清RAGE、HMGB1表达对SP患儿继发ARDS的风险有一定的预测价值。
