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Objective:To discuss the protective effect of carnosine(CAR)against oxygen-glucose deprivation/reoxygenation(OGD/R)-induced astrocyte(AS)injury,and to clarify its possible mechanism.Methods:The AS were divided into control group,model group(OGD/R group),OGD/R+CAR group(CAR group),and OGD/R+CAR+AMP-activated protein kinase(AMPK)activator AICAR group(CAR+AICAR group).MTT assay and green cyanine staining method were used to detect the survival rates and green cyanine staining positive rates of the AS in various groups;Annexin V-FITC/PI method and flow cytometry were used to detect the apoptotic rates of the AS in various groups;Western blotting method was used to detect the expression levels of AMPK,phosphorylated AMPK(p-AMPK),mammalian target of rapamycin(mTOR),phosphorylated mTOR(p-mTOR),microtubule-associated protein light chain 3B(LC3B),Beclin-1,and P62 proteins in the AS in various groups;immunofluorescence staining was used to observe the LC3B positive fluorescence intensities in the AS in various groups.Results:Compared with control group,the survival rate and green cyanine staining positive rate of the AS in OGD/R group were decreased(P＜0.01),the apoptotic rate of the AS was increased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were increased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were decreased(P＜0.01).Compared with OGD/R group,the survival rate and green cyanine staining positive rate of the AS in CAR group were increased(P＜0.01),the apoptotic rate of the AS was decreased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were decreased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were increased(P＜0.01).Compared with CAR group,the survival rate and green cyanine staining positive rate of the AS in CAR+AICAR group were decreased(P＜0.01),the apoptotic rate of the AS was increased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were increased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were decreased(P＜0.01).The LC3B immunofluorescence staining results were consistent with the Western blotting results.Conclusion:CAR has the protective effect on injury of the AS induced by OGD/R,and its molecular mechanism may be related to the inhibition of the AMPK/mTOR signaling pathway,thereby inhibiting autophagy.

Objective:To investigate the effects of carnosine(CAR)on the spatial learning and memory abilities of rats with vascular cognitive impairment(VCI),and to explore the roles of the Akt/mTOR pathway and autophagy in this process.Methods:Fifty male Sprague-Dawley(SD)rats were randomly divided into sham-operated(Sham)group,VCI group,VCI+CAR-L group,VCI+CAR-M group,and VCI+CAR-H group.The spatial learning and memory abilities of rats were evaluated by the Morris water maze experiment;Nissl staining was used to detect the damage in the hippocampal CA1 region;the nitroblue tetrazolium and thiobarbituric acid methods were used to measure the activities of superoxide dismutase(SOD)and malondialdehyde(MDA)content in hippocampal tissue;Western Blot was performed to determine the expression of p-Akt,p-mTOR,Beclin-1,and LC3B proteins,and immunofluorescent staining was con-ducted to detect changes in LC3B expression in the CA1 region.SH-SY5Y cells were divided into control group,oxy-gen-glucose deprivation/reperfusion(OGD/R)group,OGD/R+rapamycin(RAPA),OGD/R+CAR(1.2 mmol/L)group,and OGD/R+CAR+RAPA group.Methyl thiazolyl tetrazolium assay was used to detect neuronal survival rate;Western Blot was used to detect the levels of p-mTOR,Beclin-1,and LC3B in neuronal cells;immunofluorescent stai-ning was performed to assess the degree of autophagy.Results:CAR could improve the learning and memory abilities of VCI rats,reduce hippocampal tissue cell damage,and inhibit oxidative stress(P＜0.01).CAR increased the expres-sion of p-Akt,p-mTOR,and p62 proteins(P＜0.01 or P＜0.05)and decreased the expression of Beclin-1 and the ra-tio of LC3B Ⅱ/Ⅰ(P＜0.01 or P＜0.05).CAR significantly increased the survival rate of SH-SY5Y cells after OGD/R(P＜0.01)and inhibited autophagy in hippocampal neurons.Furthermore,the intervention with RAPA counteracted the therapeutic effect of CAR,reduced the survival rate of SH-SY5Y groups(P＜0.01),and enhanced autophagy.Conclusion:CAR can improve rat VCI injury,and its mechanism may involve inhibiting oxidative stress,activating the Akt/mTOR signaling pathway in neuronal cells,and thereby inhibiting excessive autophagy to exert a protective effect.

Objective:To investigate the effects of carnosine(CAR)on the spatial learning and memory abilities of rats with vascular cognitive impairment(VCI),and to explore the roles of the Akt/mTOR pathway and autophagy in this process.Methods:Fifty male Sprague-Dawley(SD)rats were randomly divided into sham-operated(Sham)group,VCI group,VCI+CAR-L group,VCI+CAR-M group,and VCI+CAR-H group.The spatial learning and memory abilities of rats were evaluated by the Morris water maze experiment;Nissl staining was used to detect the damage in the hippocampal CA1 region;the nitroblue tetrazolium and thiobarbituric acid methods were used to measure the activities of superoxide dismutase(SOD)and malondialdehyde(MDA)content in hippocampal tissue;Western Blot was performed to determine the expression of p-Akt,p-mTOR,Beclin-1,and LC3B proteins,and immunofluorescent staining was con-ducted to detect changes in LC3B expression in the CA1 region.SH-SY5Y cells were divided into control group,oxy-gen-glucose deprivation/reperfusion(OGD/R)group,OGD/R+rapamycin(RAPA),OGD/R+CAR(1.2 mmol/L)group,and OGD/R+CAR+RAPA group.Methyl thiazolyl tetrazolium assay was used to detect neuronal survival rate;Western Blot was used to detect the levels of p-mTOR,Beclin-1,and LC3B in neuronal cells;immunofluorescent stai-ning was performed to assess the degree of autophagy.Results:CAR could improve the learning and memory abilities of VCI rats,reduce hippocampal tissue cell damage,and inhibit oxidative stress(P＜0.01).CAR increased the expres-sion of p-Akt,p-mTOR,and p62 proteins(P＜0.01 or P＜0.05)and decreased the expression of Beclin-1 and the ra-tio of LC3B Ⅱ/Ⅰ(P＜0.01 or P＜0.05).CAR significantly increased the survival rate of SH-SY5Y cells after OGD/R(P＜0.01)and inhibited autophagy in hippocampal neurons.Furthermore,the intervention with RAPA counteracted the therapeutic effect of CAR,reduced the survival rate of SH-SY5Y groups(P＜0.01),and enhanced autophagy.Conclusion:CAR can improve rat VCI injury,and its mechanism may involve inhibiting oxidative stress,activating the Akt/mTOR signaling pathway in neuronal cells,and thereby inhibiting excessive autophagy to exert a protective effect.

In recent years, more and more researchers at home and abroad have realized that there is a certain relationship between allergic rhinitis(AR) and attention deficit hyperactivity disorder(ADHD) in children.Children with AR had higher ADHD related symptom scores than healthy children; ADHD children have a significantly increased risk of allergic diseases, such as asthma, eczema and atopic dermatitis.At present, it has been clear that they have the common characteristics of increasing prevalence year by year, genetic tendency, environmental and neuropsychological factors, and similar clinical manifestations.However, there is no final conclusion whether they are mutual cause and effect or comorbidities.This artide reviews the similarities between AR and ADHD in epidemiology, etiology, clinical manifestations and drug treatment, so as to further explore the correlation between AR and ADHD.