Objective:a-Synuclein has been studied as a potential biomarker for Parkinson's disease(PD)with no concluding results.Accordingly,there is an urgent need to find out reliable specific biomarkers for PD.GPR37 is an...Objective:a-Synuclein has been studied as a potential biomarker for Parkinson's disease(PD)with no concluding results.Accordingly,there is an urgent need to find out reliable specific biomarkers for PD.GPR37 is an orphan G protein-coupled receptor that toxically accumulates in autosomal recessive juvenile parkinsonism.Here,we investigated whether GPR37 is upregulated in sporadic PD,and thus a suitable potential biomarker for PD.Methods:GPR37 protein density and mRNA expression in postmortem substantia nigra(SN)from PD patients were analysed by immunoblot and RT-qPCR,respectively.The presence of peptides from the N-terminus-cleaved domain of GPR37(i.e.ecto-GPR37)in human cerebrospinal fluid(CSF)was determined by liquid chromatography-mass spectrometric analysis.An engineered in-house nanoluciferase-based immunoassay was used to quantify ecto-GPR37 in CSF samples from neurological control(NC)subjects,PD patients and Alzheimer's disease(AD)patients.Results:GPR37 protein density and mRNA expression were significantly augmented in sporadic PD.Increased amounts of ecto-GPR37 peptides in the CSF samples from PD patients were identified by mass spectrometry and quantified by the in-house ELISA method.However,the CSF total a-synuclein level in PD patients did not differ from that in NC subjects.Similarly,the cortical GPR37 mRNA expression and CSF ecto-GPR37 levels in AD patients were also unaltered.Conclusion:GPR37 expression is increased in SN of sporadic PD patients.The ecto-GPR37 peptides are significantly increased in the CSF of PD patients,but not in AD patients.These results open perspectives and encourage further clinical studies to confirm the validity and utility of ecto-GPR37 as a potential PD biomarker.展开更多
Background:New fuid biomarkers for Alzheimer’s disease(AD)that reveal synaptic and neural network dysfunc‑tions are needed for clinical practice and therapeutic trial design.Dense core vesicle(DCV)cargos are promisin...Background:New fuid biomarkers for Alzheimer’s disease(AD)that reveal synaptic and neural network dysfunc‑tions are needed for clinical practice and therapeutic trial design.Dense core vesicle(DCV)cargos are promising cerebrospinal fuid(CSF)indicators of synaptic failure in AD patients.However,their value as biomarkers has not yet been determined.Methods:Immunoassays were performed to analyze the secretory proteins prohormone convertases PC1/3 and PC2,carboxypeptidase E(CPE),secretogranins SgIII and SgII,and Cystatin C in the cerebral cortex(n=45,provided by Bellvitge University Hospital)and CSF samples(n=66,provided by The Sant Pau Initiative on Neurodegeneration cohort)from AD patients(n=56)and age-matched controls(n=55).Results:In AD tissues,most DCV proteins were aberrantly accumulated in dystrophic neurites and activated astro‑cytes,whereas PC1/3,PC2 and CPE were also specifcally accumulated in hippocampal granulovacuolar degeneration bodies.AD individuals displayed an overall decline of secretory proteins in the CSF.Interestingly,in AD patients,the CSF levels of prohormone convertases strongly correlated inversely with those of neurodegeneration markers and directly with cognitive impairment status.Conclusions:These results demonstrate marked alterations of neuronal-specifc prohormone convertases in CSF and cortical tissues of AD patients.The neuronal DCV cargos are biomarker candidates for synaptic dysfunction and neurodegeneration in AD.展开更多
基金supported by Ministerio de Ciencia,Innovacion y Universidades-Agencia Estatal de Investigacion/FEDER(SAF2017-87349-R and MDM-2017-0729)ISCIII/FEDER(PIE14/00034 and PI19/00144)+5 种基金Generalitat de Catalunya(2017SGR1604,2017SGR595)Fundacio la Marato de TV3(Grant 20152031)FWO(SBO-140028)ERC consolidator grant(Progsy 649116)Stiftelsen for Strategisk Forskning and a Wallenberg Clinical Scholarship to PS.The CRG/UPF Proteomics Unit is part of the Spanish Infrastruaure for Omics Technologies(ICTS OmicsTech)is a member of the ProteoRed PRB3 consortium which is supported by grant PT17/0019 of the PEI+D+i 2013-2016 from the Instituto de Salud Carlos Ⅲ(ISCⅢ)and ERDF.
文摘Objective:a-Synuclein has been studied as a potential biomarker for Parkinson's disease(PD)with no concluding results.Accordingly,there is an urgent need to find out reliable specific biomarkers for PD.GPR37 is an orphan G protein-coupled receptor that toxically accumulates in autosomal recessive juvenile parkinsonism.Here,we investigated whether GPR37 is upregulated in sporadic PD,and thus a suitable potential biomarker for PD.Methods:GPR37 protein density and mRNA expression in postmortem substantia nigra(SN)from PD patients were analysed by immunoblot and RT-qPCR,respectively.The presence of peptides from the N-terminus-cleaved domain of GPR37(i.e.ecto-GPR37)in human cerebrospinal fluid(CSF)was determined by liquid chromatography-mass spectrometric analysis.An engineered in-house nanoluciferase-based immunoassay was used to quantify ecto-GPR37 in CSF samples from neurological control(NC)subjects,PD patients and Alzheimer's disease(AD)patients.Results:GPR37 protein density and mRNA expression were significantly augmented in sporadic PD.Increased amounts of ecto-GPR37 peptides in the CSF samples from PD patients were identified by mass spectrometry and quantified by the in-house ELISA method.However,the CSF total a-synuclein level in PD patients did not differ from that in NC subjects.Similarly,the cortical GPR37 mRNA expression and CSF ecto-GPR37 levels in AD patients were also unaltered.Conclusion:GPR37 expression is increased in SN of sporadic PD patients.The ecto-GPR37 peptides are significantly increased in the CSF of PD patients,but not in AD patients.These results open perspectives and encourage further clinical studies to confirm the validity and utility of ecto-GPR37 as a potential PD biomarker.
基金This work was supported by grants from the Spanish Ministry of Economy and Competitiveness(BFU2016-80868-R,MINECO/FEDER,to FA)the Spanish Ministry of Science and Innovation(PID2019-107738RB-I00,MICINN/FEDER,to FA)+2 种基金the Catalonian Government(2017SGR1255 to FA,2014SGR-0235 to AL,PERIS SLT006/17/125 to DA)the Carlos III Institute of Health,Spain(PI18/00435 to DA,PI14/1561 and PI17/01896 to AL)and the CIBERNED program(Program 1,Alzheimer Disease to AL and IF),partly funded by Fondo Europeo de Desar‑rollo Regional(FEDER),Unión Europea,“Una manera de hacer Europa”,and BBVA Foundation(to AL)We are grateful to the Generalitat de Catalunya(NB),the Ministry of Education and Vocational Training(NB)and the Universitat de Barcelona(VP)for fnancial support.
文摘Background:New fuid biomarkers for Alzheimer’s disease(AD)that reveal synaptic and neural network dysfunc‑tions are needed for clinical practice and therapeutic trial design.Dense core vesicle(DCV)cargos are promising cerebrospinal fuid(CSF)indicators of synaptic failure in AD patients.However,their value as biomarkers has not yet been determined.Methods:Immunoassays were performed to analyze the secretory proteins prohormone convertases PC1/3 and PC2,carboxypeptidase E(CPE),secretogranins SgIII and SgII,and Cystatin C in the cerebral cortex(n=45,provided by Bellvitge University Hospital)and CSF samples(n=66,provided by The Sant Pau Initiative on Neurodegeneration cohort)from AD patients(n=56)and age-matched controls(n=55).Results:In AD tissues,most DCV proteins were aberrantly accumulated in dystrophic neurites and activated astro‑cytes,whereas PC1/3,PC2 and CPE were also specifcally accumulated in hippocampal granulovacuolar degeneration bodies.AD individuals displayed an overall decline of secretory proteins in the CSF.Interestingly,in AD patients,the CSF levels of prohormone convertases strongly correlated inversely with those of neurodegeneration markers and directly with cognitive impairment status.Conclusions:These results demonstrate marked alterations of neuronal-specifc prohormone convertases in CSF and cortical tissues of AD patients.The neuronal DCV cargos are biomarker candidates for synaptic dysfunction and neurodegeneration in AD.
