N-Linked glycosylation of hemagglutinin(HA) has been demonstrated to regulate the virulence and receptor-binding specificity of avian influenza virus(AIV).In this study,we characterized the variation trend of naturall...N-Linked glycosylation of hemagglutinin(HA) has been demonstrated to regulate the virulence and receptor-binding specificity of avian influenza virus(AIV).In this study,we characterized the variation trend of naturally isolated H9 N2 viruses for the potential N-linked glycosylation sites in HA proteins,and explored any important role of some glycosylation sites.HA genes of 19 H9 N2 subtype AIV strains since 2001 were sequenced and analyzed for the potential glycosylation sites.The results showed that the viruses varied by losing one potential glycosylation site at residues 200 to 202,and having an additional one at residues 295 to 297 over the past few years.Further molecular and single mutation analysis revealed that the N200 Q mutation lost an N-linked glycosylation at positions 200 to 202 of the HA protein and affected the human-derived receptor affinity.We further found that this N-linked glycosylation increased viral productivity in the lung of the infected mice.These findings provide a novel insight on understanding the determinants of host adaption and virulence of H9 N2 viruses in mammals.展开更多
BACKGROUND Chronic atrophic gastritis(CAG)is a common disease of the digestive system with pathological characteristics of a decreasing number,or disappearance,of inherent glands of the gastric mucosa.CAG has been def...BACKGROUND Chronic atrophic gastritis(CAG)is a common disease of the digestive system with pathological characteristics of a decreasing number,or disappearance,of inherent glands of the gastric mucosa.CAG has been defined as a precancerous condition of gastric cancer.Intestinal metaplasia or intraepithelial neoplasia accompanying atrophied glands of the stomach is regarded as one of the most important precancerous lesions of gastric cancer.As a common malignant tumour,gastric cancer remains without a satisfactory therapy and its pathogenesis remains unclear,seriously threatening human life.Therefore,some scholars have proposed to prevent the incidence of gastric cancer by avoiding precancerous lesions.If CAG can be reversed,the incidence of gastric cancer can be substantially reduced.To reverse and prevent CAG and study its pathogenesis and therapy,it is necessary to develop an ideal,safe,stable,animal model.AIM To study a rapid,stable,and safe method of establishing a mouse model of human CAG.METHODS Six-week-old Kunming mice were divided into a phosphate buffered solution control group,a Helicobacter pylori(H.pylori)group,an N-methyl-N'-nitroguanidine(MNNG)group,an ammonia water group,and a group combining H.pylori,MNNG,and ammonia water(hereinafter referred to as the combined group).The mice were administrated with drinking water containing ammonia or infected with H.pylori through gavage.At the 30th,60th,90th,and 120th day after the last H.pylori infection,mice were selected randomly to collect their gastric mucosa for hematoxylin eosin staining,terminal nick-end labelling staining detection,and immunohistochemical staining for Bax and Bcl-2.In addition,H.pylori was isolated,cultured,and identified,and its extent of colonisation calculated.Blood was collected to detect inflammatory factors interleukin(IL)-1β,IL-8,and tumor necrosis factor(TNF)-αand immune function markers CD4 and CD8 to confirm successful establishment of the CAG model.RESULTS The combined group showed slight CAG at the 90th day and moderate CAG at the 120th day,while other groups did not show CAG at that time.CONCLUSION The combination of H.pylori,MNNG,and ammonia is an effective method of developing a mouse model of human CAG.展开更多
Influenza A virus(IAV)continues to pose a pandemic threat to public health,resulting a high mortality rate annually and during pandemic years.Posttranslational modification of viral protein plays a substantial role in...Influenza A virus(IAV)continues to pose a pandemic threat to public health,resulting a high mortality rate annually and during pandemic years.Posttranslational modification of viral protein plays a substantial role in regulating IAV infection.Here,based on immunoprecipitation(IP)-based mass spectrometry(MS)and purified virus-coupled MS,a total of 89 phosphorylation sites distributed among 10 encoded viral proteins of IAV were identified,including 60 novel phosphorylation sites.Additionally,for the first time,we provide evidence that PB2 can also be acetylated at site K187.Notably,the PB2 S181 phosphorylation site was consistently identified in both IP-based MS and purified virus-based MS.Both S181 and K187 are exposed on the surface of the PB2 protein and are highly conserved in various IAV strains,suggesting their fundamental importance in the IAV life cycle.Bioinformatic analysis results demonstrated that S181E/A and K187Q/R mimic mutations do not significantly alter the PB2 protein structure.While continuous phosphorylation mimicked by the PB2 S181E mutation substantially decreases viral fitness in mice,PB2 K187Q mimetic acetylation slightly enhances viral virulence in mice.Mechanistically,PB2 S181E substantially impairs viral polymerase activity and viral replication,remarkably dampens protein stability and nuclear accumulation of PB2,and significantly weakens IAV-induced inflammatory responses.Therefore,our study further enriches the database of phosphorylation and acetylation sites of influenza viral proteins,laying a foundation for subsequent mechanistic studies.Meanwhile,the unraveled antiviral effect of PB2 S181E mimetic phosphorylation may provide a new target for the subsequent study of antiviral drugs.展开更多
Objective To investigate the relationship between atopic allergy and depression and the role of DBP in the development of depression. Methods BALB/c mice were randomly divided into eight groups：saline;ovalbumin （OVA...Objective To investigate the relationship between atopic allergy and depression and the role of DBP in the development of depression. Methods BALB/c mice were randomly divided into eight groups：saline;ovalbumin （OVA）-immunized;saline＋DBP （0.45 mg/kg·183;d）; saline＋DBP （45 mg/kg·d）; DBP （0.45 mg/kg·d） OVA-immunized; DBP （45 mg/kg·d） OVA-immunized; saline＋hydrocortisone （30 mg/kg·d）; and hydrocortisone （30 mg/kg·d）-exposed OVA-immunized. Behavior （e.g. open-field, tail suspension, and forced swimming tests）, viscera coefficients （brain and spleen）, oxidative damage [e.g. reactive oxygen species （ROS）, malondialdehyde （MDA）, and glutathione （GSH）], as well as levels of IgE and IL-4, were then analyzed. Results In the saline and OVA groups, the degree of depression symptoms in mice increased with increasing DBP concentration. Additionally, the OVA-immunity groups were associated with more serious depressive behavior compared with the same exposure concentration in the saline group. Oxidative damage was associated with a dose-dependent increase in DBP in the different groups. IL-4 and IgE levels were associated with low-dose DBP stimulation, which changed to high-dose inhibition with increasing DBP exposure, possibly due to spleen injury seen at high DBP concentrations.Conclusion Development of an atopic allergy has the potential to increase the risk of depression in mice, and it seems that DBP helps OVA to exert its effect in our present model. Moreover, the results of our study implicate a certain connection between brain oxidative stress and depression, which deserves a further exploration.展开更多
BACKGROUND Myocardial remodeling is a key factor in the progression of cardiovascular disease to the end stage.In addition to myocardial infarction or stress overload,dietary factors have recently been considered asso...BACKGROUND Myocardial remodeling is a key factor in the progression of cardiovascular disease to the end stage.In addition to myocardial infarction or stress overload,dietary factors have recently been considered associated with myocardial remodeling.Nε-(carboxymethyl)lysine(CML)is a representative foodborne toxic product,which can be ingested via daily diet.Therefore,there is a marked need to explore the effects of dietary CML on the myocardium.AIM To explore the effects of dietary CML(dCML)on the heart.METHODS C57 BL/6 mice were divided into a control group and a dCML group.The control group and the dCML group were respectively fed a normal diet or diet supplemented with CML for 20 wk.Body weight and blood glucose were recorded every 4 wk.^(18)F-fluorodeoxyglucose(FDG)was used to trace the glucose uptake in mouse myocardium,followed by visualizing with micro-positron emission tomography(PET).Myocardial remodeling and glucose metabolism were also detected.In vitro,H9C2 cardiomyocytes were added to exogenous CML and cultured for 24 h.The effects of exogenous CML on glucose metabolism,collagen I expression,hypertrophy,and apoptosis of cardiomyocytes were analyzed.RESULTS Our results suggest that the levels of fasting blood glucose,fasting insulin,and serum CML were significantly increased after 20 wk of dCML.Micro-PET showed that ^(18)F-FDG accumulated more in the myocardium of the dCML group than in the control group.Histological staining revealed that dCML could lead to myocardial fibrosis and hypertrophy.The indexes of myocardial fibrosis,apoptosis,and hypertrophy were also increased in the dCML group,whereas the activities of glucose metabolism-related pathways and citrate synthase(CS)were significantly inhibited.In cardiomyocytes,collagen I expression and cellular size were significantly increased after the addition of exogenous CML.CML significantly promoted cellular hypertrophy and apoptosis,while pathways involved in glucose metabolism and level of Cs mRNA were significantly inhibited.CONCLUSION This study reveals that dCML alters myocardial glucose metabolism and promotes myocardial remodeling.展开更多
To understand the effects of self synthesized N-carbamylglutamate（NCG） on growth performance of ICR mice,mice were fed with the basal diet adding with 0.025%,0.05% and 0.1% NCG for 28 d.Effects of different levels o...To understand the effects of self synthesized N-carbamylglutamate（NCG） on growth performance of ICR mice,mice were fed with the basal diet adding with 0.025%,0.05% and 0.1% NCG for 28 d.Effects of different levels of NCG on body weight of mice were observed.The re-sults showed that the addition of NCG in the feed could improve the growth performance of mice,and the growth-promoting effect enhanced with the increasing dose.展开更多
Preliminary work by our research team revealed that Schisandra, a renowned traditional Chinese medicine, causes learning and memory improvements in ovariectomized mice. This activity was attributed to active ingredien...Preliminary work by our research team revealed that Schisandra, a renowned traditional Chinese medicine, causes learning and memory improvements in ovariectomized mice. This activity was attributed to active ingredients extracted with N-butyl alcohol, named Schisandra N-butanol extract. In this study, ovariectomized mice were pretreated with Schisandra N-butanol extract given by intragastric administration. This treatment led to the enhancement of learning, and an increase in hippocampal CA1 synaptic, surface and postsynaptic density. A decrease in the average size of the synaptic active zone was also observed. These experimental findings showing that Schisandra N-butanol extract improved synaptic morphology indicate an underlying mechanism by which the ability of learning is enhanced in ovariectomized mice.展开更多
Amperometric studies have indicated that substance P as well as NMDA stimulates release of NO in rat aortic rings. These data have been confirmed by functional observations of vaso-relaxant action of NMDA within norad...Amperometric studies have indicated that substance P as well as NMDA stimulates release of NO in rat aortic rings. These data have been confirmed by functional observations of vaso-relaxant action of NMDA within noradrenaline pre-contracted aortic rings, supporting the presence of NMDA receptor in rat aortic rings. It is known that the enzyme endothelial NO synthase (eNOS) mediates vasodilatation not only in rats, but also in C57BL6 mice aortic ring, indicating that in this blood vessel NO is the endogenous endothelium-derived vasodilator. In this work, amperometry together with specifically nitrites insensitive micro-biosensors have been applied to examine the effect of NMDA and substance P upon NO release in rat and in two strains of mice aortic rings. The electrochemical data monitored demonstrate that NMDA mediates vascular relaxation via NO in rats but not in mice. These results are supported by functional data, therefore they suggest that NMDA receptors are “not responding” within these experimental conditions in mice aortic rings.展开更多
基金supported by the National Key R&D Program of China(2016YFD0500201)the Natural Science Foundation of Shandong Province,China(ZR2017BC094)+1 种基金the earmarked fund for China Agriculture Research System(CARS-41-Z10)the High-Level Talents and Innovative Team Recruitment Program of the Shandong Academy of Agricultural Sciences,China
文摘N-Linked glycosylation of hemagglutinin(HA) has been demonstrated to regulate the virulence and receptor-binding specificity of avian influenza virus(AIV).In this study,we characterized the variation trend of naturally isolated H9 N2 viruses for the potential N-linked glycosylation sites in HA proteins,and explored any important role of some glycosylation sites.HA genes of 19 H9 N2 subtype AIV strains since 2001 were sequenced and analyzed for the potential glycosylation sites.The results showed that the viruses varied by losing one potential glycosylation site at residues 200 to 202,and having an additional one at residues 295 to 297 over the past few years.Further molecular and single mutation analysis revealed that the N200 Q mutation lost an N-linked glycosylation at positions 200 to 202 of the HA protein and affected the human-derived receptor affinity.We further found that this N-linked glycosylation increased viral productivity in the lung of the infected mice.These findings provide a novel insight on understanding the determinants of host adaption and virulence of H9 N2 viruses in mammals.
基金Supported by National Natural Science Foundation of China,No.31460023Science Research and Technology Development Project of Guangxi,No.1598025-33
文摘BACKGROUND Chronic atrophic gastritis(CAG)is a common disease of the digestive system with pathological characteristics of a decreasing number,or disappearance,of inherent glands of the gastric mucosa.CAG has been defined as a precancerous condition of gastric cancer.Intestinal metaplasia or intraepithelial neoplasia accompanying atrophied glands of the stomach is regarded as one of the most important precancerous lesions of gastric cancer.As a common malignant tumour,gastric cancer remains without a satisfactory therapy and its pathogenesis remains unclear,seriously threatening human life.Therefore,some scholars have proposed to prevent the incidence of gastric cancer by avoiding precancerous lesions.If CAG can be reversed,the incidence of gastric cancer can be substantially reduced.To reverse and prevent CAG and study its pathogenesis and therapy,it is necessary to develop an ideal,safe,stable,animal model.AIM To study a rapid,stable,and safe method of establishing a mouse model of human CAG.METHODS Six-week-old Kunming mice were divided into a phosphate buffered solution control group,a Helicobacter pylori(H.pylori)group,an N-methyl-N'-nitroguanidine(MNNG)group,an ammonia water group,and a group combining H.pylori,MNNG,and ammonia water(hereinafter referred to as the combined group).The mice were administrated with drinking water containing ammonia or infected with H.pylori through gavage.At the 30th,60th,90th,and 120th day after the last H.pylori infection,mice were selected randomly to collect their gastric mucosa for hematoxylin eosin staining,terminal nick-end labelling staining detection,and immunohistochemical staining for Bax and Bcl-2.In addition,H.pylori was isolated,cultured,and identified,and its extent of colonisation calculated.Blood was collected to detect inflammatory factors interleukin(IL)-1β,IL-8,and tumor necrosis factor(TNF)-αand immune function markers CD4 and CD8 to confirm successful establishment of the CAG model.RESULTS The combined group showed slight CAG at the 90th day and moderate CAG at the 120th day,while other groups did not show CAG at that time.CONCLUSION The combination of H.pylori,MNNG,and ammonia is an effective method of developing a mouse model of human CAG.
基金supported by the National Natural Science Foundation of China(32072832,32372976)by the National Key Research and Development Project of China(2021YFD1800202)+3 种基金by Jiangsu Province Agricultural Science&Technology Independent Innovation Funds[CX(21)3141]by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_3553 and KYCX21_3277)by the Earmarked Fund for China Agriculture Research System(CARS-40)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Influenza A virus(IAV)continues to pose a pandemic threat to public health,resulting a high mortality rate annually and during pandemic years.Posttranslational modification of viral protein plays a substantial role in regulating IAV infection.Here,based on immunoprecipitation(IP)-based mass spectrometry(MS)and purified virus-coupled MS,a total of 89 phosphorylation sites distributed among 10 encoded viral proteins of IAV were identified,including 60 novel phosphorylation sites.Additionally,for the first time,we provide evidence that PB2 can also be acetylated at site K187.Notably,the PB2 S181 phosphorylation site was consistently identified in both IP-based MS and purified virus-based MS.Both S181 and K187 are exposed on the surface of the PB2 protein and are highly conserved in various IAV strains,suggesting their fundamental importance in the IAV life cycle.Bioinformatic analysis results demonstrated that S181E/A and K187Q/R mimic mutations do not significantly alter the PB2 protein structure.While continuous phosphorylation mimicked by the PB2 S181E mutation substantially decreases viral fitness in mice,PB2 K187Q mimetic acetylation slightly enhances viral virulence in mice.Mechanistically,PB2 S181E substantially impairs viral polymerase activity and viral replication,remarkably dampens protein stability and nuclear accumulation of PB2,and significantly weakens IAV-induced inflammatory responses.Therefore,our study further enriches the database of phosphorylation and acetylation sites of influenza viral proteins,laying a foundation for subsequent mechanistic studies.Meanwhile,the unraveled antiviral effect of PB2 S181E mimetic phosphorylation may provide a new target for the subsequent study of antiviral drugs.
基金financially supported by the Key Project of International Cooperation from the Chinese Ministry of Science and Technology(2010DFA31790)the China National Natural Science Foundation of China(51136002)China Key Technologies R&D Program(2012BAJ02B03)
文摘Objective To investigate the relationship between atopic allergy and depression and the role of DBP in the development of depression. Methods BALB/c mice were randomly divided into eight groups：saline;ovalbumin （OVA）-immunized;saline＋DBP （0.45 mg/kg·183;d）; saline＋DBP （45 mg/kg·d）; DBP （0.45 mg/kg·d） OVA-immunized; DBP （45 mg/kg·d） OVA-immunized; saline＋hydrocortisone （30 mg/kg·d）; and hydrocortisone （30 mg/kg·d）-exposed OVA-immunized. Behavior （e.g. open-field, tail suspension, and forced swimming tests）, viscera coefficients （brain and spleen）, oxidative damage [e.g. reactive oxygen species （ROS）, malondialdehyde （MDA）, and glutathione （GSH）], as well as levels of IgE and IL-4, were then analyzed. Results In the saline and OVA groups, the degree of depression symptoms in mice increased with increasing DBP concentration. Additionally, the OVA-immunity groups were associated with more serious depressive behavior compared with the same exposure concentration in the saline group. Oxidative damage was associated with a dose-dependent increase in DBP in the different groups. IL-4 and IgE levels were associated with low-dose DBP stimulation, which changed to high-dose inhibition with increasing DBP exposure, possibly due to spleen injury seen at high DBP concentrations.Conclusion Development of an atopic allergy has the potential to increase the risk of depression in mice, and it seems that DBP helps OVA to exert its effect in our present model. Moreover, the results of our study implicate a certain connection between brain oxidative stress and depression, which deserves a further exploration.
基金Supported by the National Natural Science Foundation of China,No.82070455Natural Science Foundation of Jiangsu Province,No.BK20201225+1 种基金Medical Innovation Team Project of Jiangsu Province,No.CXTDA2017010Research and Innovation Funding Project for College Students in Experimental Animal Center of Jiangsu University。
文摘BACKGROUND Myocardial remodeling is a key factor in the progression of cardiovascular disease to the end stage.In addition to myocardial infarction or stress overload,dietary factors have recently been considered associated with myocardial remodeling.Nε-(carboxymethyl)lysine(CML)is a representative foodborne toxic product,which can be ingested via daily diet.Therefore,there is a marked need to explore the effects of dietary CML on the myocardium.AIM To explore the effects of dietary CML(dCML)on the heart.METHODS C57 BL/6 mice were divided into a control group and a dCML group.The control group and the dCML group were respectively fed a normal diet or diet supplemented with CML for 20 wk.Body weight and blood glucose were recorded every 4 wk.^(18)F-fluorodeoxyglucose(FDG)was used to trace the glucose uptake in mouse myocardium,followed by visualizing with micro-positron emission tomography(PET).Myocardial remodeling and glucose metabolism were also detected.In vitro,H9C2 cardiomyocytes were added to exogenous CML and cultured for 24 h.The effects of exogenous CML on glucose metabolism,collagen I expression,hypertrophy,and apoptosis of cardiomyocytes were analyzed.RESULTS Our results suggest that the levels of fasting blood glucose,fasting insulin,and serum CML were significantly increased after 20 wk of dCML.Micro-PET showed that ^(18)F-FDG accumulated more in the myocardium of the dCML group than in the control group.Histological staining revealed that dCML could lead to myocardial fibrosis and hypertrophy.The indexes of myocardial fibrosis,apoptosis,and hypertrophy were also increased in the dCML group,whereas the activities of glucose metabolism-related pathways and citrate synthase(CS)were significantly inhibited.In cardiomyocytes,collagen I expression and cellular size were significantly increased after the addition of exogenous CML.CML significantly promoted cellular hypertrophy and apoptosis,while pathways involved in glucose metabolism and level of Cs mRNA were significantly inhibited.CONCLUSION This study reveals that dCML alters myocardial glucose metabolism and promotes myocardial remodeling.
基金Supported by Jiangsu Provincial Training Program of Innovation and Entrepreneurship for Undergraduates(201712806031H)Natural Science Foundation of Jiangsu Agri-animal Husbandry Vocational College(NSFPT201715)
文摘To understand the effects of self synthesized N-carbamylglutamate（NCG） on growth performance of ICR mice,mice were fed with the basal diet adding with 0.025%,0.05% and 0.1% NCG for 28 d.Effects of different levels of NCG on body weight of mice were observed.The re-sults showed that the addition of NCG in the feed could improve the growth performance of mice,and the growth-promoting effect enhanced with the increasing dose.
文摘Preliminary work by our research team revealed that Schisandra, a renowned traditional Chinese medicine, causes learning and memory improvements in ovariectomized mice. This activity was attributed to active ingredients extracted with N-butyl alcohol, named Schisandra N-butanol extract. In this study, ovariectomized mice were pretreated with Schisandra N-butanol extract given by intragastric administration. This treatment led to the enhancement of learning, and an increase in hippocampal CA1 synaptic, surface and postsynaptic density. A decrease in the average size of the synaptic active zone was also observed. These experimental findings showing that Schisandra N-butanol extract improved synaptic morphology indicate an underlying mechanism by which the ability of learning is enhanced in ovariectomized mice.
文摘Amperometric studies have indicated that substance P as well as NMDA stimulates release of NO in rat aortic rings. These data have been confirmed by functional observations of vaso-relaxant action of NMDA within noradrenaline pre-contracted aortic rings, supporting the presence of NMDA receptor in rat aortic rings. It is known that the enzyme endothelial NO synthase (eNOS) mediates vasodilatation not only in rats, but also in C57BL6 mice aortic ring, indicating that in this blood vessel NO is the endogenous endothelium-derived vasodilator. In this work, amperometry together with specifically nitrites insensitive micro-biosensors have been applied to examine the effect of NMDA and substance P upon NO release in rat and in two strains of mice aortic rings. The electrochemical data monitored demonstrate that NMDA mediates vascular relaxation via NO in rats but not in mice. These results are supported by functional data, therefore they suggest that NMDA receptors are “not responding” within these experimental conditions in mice aortic rings.
