Amyloid-beta clearance plays a key role in the pathogenesis of Alzheimer's disease.H oweve r,the variation in functional proteins involved in amyloid-beta clearance and their correlation with amyloid-beta levels r...Amyloid-beta clearance plays a key role in the pathogenesis of Alzheimer's disease.H oweve r,the variation in functional proteins involved in amyloid-beta clearance and their correlation with amyloid-beta levels remain unclea r.In this study,we conducted meta-analyses and a systematic review using studies from the PubMed,Embase,Web of Science,and Cochrane Library databases,including journal articles published from inception to J une 30,2023.The inclusion criteria included studies comparing the levels of functional proteins associated with amyloid-beta clearance in the blood,cere b rospinal fluid,and brain of healthy controls,patients with mild cognitive impairment,and patients with Alzheimer's disease.Additionally,we analyzed the correlation between these functional proteins and amyloid-beta levels in patients with Alzheimer's disease.The methodological quality of the studies was assessed via the Newcastle-Ottawa Scale.Owing to heterogeneity,we utilized either a fixed-effect or random-effect model to assess the 95%confidence interval(CI)of the standard mean difference(SMD)among healthy controls,patients with mild cognitive impairment,and patients with Alzheimer's disease.The findings revealed significant alterations in the levels of insulin-degrading enzymes,neprilysin,matrix metalloproteinase-9,cathepsin D,receptor for advanced glycation end products,and P-glycoprotein in the brains of patients with Alzheimer's disease,patients with mild cognitive impairment,and healthy controls.In cerebrospinal fluid,the levels of triggering receptor expressed on myeloid cells 2 and ubiquitin C-terminal hydrolase L1 are altered,whereas the levels of TREM2,CD40,CD40L,CD14,CD22,cathepsin D,cystatin C,andα2 M in peripheral blood differ.Notably,TREM2 and cathepsin D showed changes in both brain(SMD=0.31,95%CI:0.16-0.47,P<0.001,I^(2)=78.4%;SMD=1.24,95%CI:0.01-2.48,P=0.048,I^(2)=90.1%)and peripheral blood(SMD=1.01,95%CI:0.35-1.66,P=0.003,I^(2)=96.5%;SMD=7.55,95%CI:3.92-11.18,P<0.001,I^(2)=98.2%)samples.Furthermore,correlations were observed between amyloid-beta levels and the levels of TREM2(r=0.16,95%CI:0.04-0.28,P=0.009,I^(2)=74.7%),neprilysin(r=-0.47,95%CI:-0.80-0.14,P=0.005,I^(2)=76.1%),and P-glycoprotein(r=-0.31,95%CI:-0.51-0.11,P=0.002,I^(2)=0.0%)in patients with Alzheimer's disease.These findings suggest that triggering receptor expressed on myeloid cells 2 and cathepsin D could serve as potential diagnostic biomarkers for Alzheimer's disease,whereas triggering receptor expressed on myeloid cells 2,neprilysin,and P-glycoprotein may represent potential therapeutic targets.展开更多
基金supported by the National Natural Science Foundation of China,No.81571046(to KZ)Key Project of Educational Department of Liaoning Province,No.LJKZ0755(to KZ)+2 种基金Project of Department of Science&Technology of Liaoning Province,No.2023JH2/20200116(to KZ)Shenyang Young and Middleaged Innovative Talents Support Program,No.RC210240(to KZ)the 345 Talent Project of Shengjing Hospital of China Medical University(to LH)。
文摘Amyloid-beta clearance plays a key role in the pathogenesis of Alzheimer's disease.H oweve r,the variation in functional proteins involved in amyloid-beta clearance and their correlation with amyloid-beta levels remain unclea r.In this study,we conducted meta-analyses and a systematic review using studies from the PubMed,Embase,Web of Science,and Cochrane Library databases,including journal articles published from inception to J une 30,2023.The inclusion criteria included studies comparing the levels of functional proteins associated with amyloid-beta clearance in the blood,cere b rospinal fluid,and brain of healthy controls,patients with mild cognitive impairment,and patients with Alzheimer's disease.Additionally,we analyzed the correlation between these functional proteins and amyloid-beta levels in patients with Alzheimer's disease.The methodological quality of the studies was assessed via the Newcastle-Ottawa Scale.Owing to heterogeneity,we utilized either a fixed-effect or random-effect model to assess the 95%confidence interval(CI)of the standard mean difference(SMD)among healthy controls,patients with mild cognitive impairment,and patients with Alzheimer's disease.The findings revealed significant alterations in the levels of insulin-degrading enzymes,neprilysin,matrix metalloproteinase-9,cathepsin D,receptor for advanced glycation end products,and P-glycoprotein in the brains of patients with Alzheimer's disease,patients with mild cognitive impairment,and healthy controls.In cerebrospinal fluid,the levels of triggering receptor expressed on myeloid cells 2 and ubiquitin C-terminal hydrolase L1 are altered,whereas the levels of TREM2,CD40,CD40L,CD14,CD22,cathepsin D,cystatin C,andα2 M in peripheral blood differ.Notably,TREM2 and cathepsin D showed changes in both brain(SMD=0.31,95%CI:0.16-0.47,P<0.001,I^(2)=78.4%;SMD=1.24,95%CI:0.01-2.48,P=0.048,I^(2)=90.1%)and peripheral blood(SMD=1.01,95%CI:0.35-1.66,P=0.003,I^(2)=96.5%;SMD=7.55,95%CI:3.92-11.18,P<0.001,I^(2)=98.2%)samples.Furthermore,correlations were observed between amyloid-beta levels and the levels of TREM2(r=0.16,95%CI:0.04-0.28,P=0.009,I^(2)=74.7%),neprilysin(r=-0.47,95%CI:-0.80-0.14,P=0.005,I^(2)=76.1%),and P-glycoprotein(r=-0.31,95%CI:-0.51-0.11,P=0.002,I^(2)=0.0%)in patients with Alzheimer's disease.These findings suggest that triggering receptor expressed on myeloid cells 2 and cathepsin D could serve as potential diagnostic biomarkers for Alzheimer's disease,whereas triggering receptor expressed on myeloid cells 2,neprilysin,and P-glycoprotein may represent potential therapeutic targets.
