ABSTRACT
Increasing evidence indicates that amyloid aggregates, including oligomers, protofibrils or fibrils, are pivotal toxins in the pathogenesis of many amyloidoses such as Alzheimer's disease (AD), Parkinson's disease, Huntington's disease, prion-related diseases, type 2 diabetes and hereditary renal amyloidosis. Various oligomers assembled from different amyloid proteins share common structures and epitopes. Here we present data indicating that two oligomer-specific single chain variable fragment (scFv) antibodies isolated from a naïve human scFv library could conformation-dependently recognize oligomers assembled from α-synuclein, amylin, insulin, Aß1-40, prion peptide 106-126 and lysozyme, and fibrils from lysozyme. Further investigation showed that both scFvs inhibited the fibrillization of α-synuclein, amylin, insulin, Aß1-40 and prion peptide 106-126, and disaggregated their preformed fibrils. However, they both promoted the aggregation of lysozyme. Nevertheless, the two scFv antibodies could attenuate the cytotoxicity of all amyloids tested. Moreover, the scFvs recognized the amyloid oligomers in all types of plaques, Lewy bodies and amylin deposits in the brain tissues of AD and PD patients and the pancreas of type 2 diabetes patients respectively, and showed that most amyloid fibril deposits were colocalized with oligomers in the tissues. Such conformation-dependent scFv antibodies may have potential application in the investigation of aggregate structures, the mechanisms of aggregation and cytotoxicity of various amyloids, and in the development of diagnostic and therapeutic reagents for many amyloidoses.
Subject(s)
Amyloid/immunology , Amyloid/metabolism , Amyloidosis/metabolism , Protein Interaction Domains and Motifs/immunology , Single-Chain Antibodies/metabolism , Amyloid/chemistry , Amyloidosis/pathology , Antigen-Antibody Reactions , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Humans , Lewy Bodies/metabolism , Lewy Bodies/pathology , Multiprotein Complexes/immunology , Multiprotein Complexes/metabolism , Protein Binding , Protein Conformation , Protein Folding , Protein Multimerization/immunology , Single-Chain Antibodies/immunology , Tissue Distribution , Tumor Cells, CulturedABSTRACT
The recognition of recurrent aberrant regions in cancer is important to the discovery of candidate cancer related genes. Here we first constructed a genome-wide gene expression map of squamous lung carcinoma from the Stanford Microarray Database. High-resolution detection of aberrant chromosomal regions was performed by using moving-median method. 84% (27 of 32) of our results were consistent with the previous studies of comparative genomic hybridization or loss of heterozygosity. One overrepresented region in Xq28 was newly discovered to be related to squamous cell lung carcinoma. These observations could be of great interest for further studies.
Subject(s)
Carcinoma, Squamous Cell/genetics , Chromosome Aberrations , Gene Expression Regulation, Neoplastic/genetics , Genome, Human/genetics , Lung Neoplasms/genetics , Chromosomes, Human, Pair 3/genetics , HumansABSTRACT
OBJECTIVE: To study the association between Alzheimer' s disease (AD) and apolipoprotein E (apoE) polymorphism and apoE epsilon4 allele; and to investigate the role of apoE in senile plaque formation. METHODS: During the period from 1982 to 2003, 27 portmortem cases of AD from the archival files of Department of Pathology of Beijing Hospital, diagnosed according to the consortium to establish a registry for Alzheimer's disease (CERAD) criteria, were enrolled into this study. Among the 27 cases studied, there were 23 cases of definite AD and 4 cases of probable AD. Postmortem brain tissues from 67 neurologically unremarkable deceased were used as age-matched controls. Immunohistochemical study for beta-amyloid (Abeta) and Tau protein, as well as immunohistochemical study for Abeta/apoE, were performed in all AD cases using streptavidin-peroxidase (SP) and double immunostaining ( SP/ABC) methods, respectively. Senile plaques and neurofibrillary tangles in the 23 cases of definite AD were further quantified. The apoE genotypes in all cases were analyzed by polymerase chain reaction and restriction fragment length polymorphism technologies. RESULTS: Immunohistochemical study for Abeta distinguished 4 different types of senile plaques: diffuse non-neuritic plaques, diffuse neuritic plaques, dense-core neuritic plaques and dense-core non-neuritic plaques. Double immunohistochemistry for Abeta/apoE showed that some senile plaques were positive for both Abeta and apoE. The expression rates for Abeta and apoE in these 4 different types of senile plaques were 4. 28%, 84. 71%, 8.50% and 2.51%, respectively. The positivity rate for Abeta/apoE in diffuse neuritic plaques were significantly higher than those in other 3 types (P < 0.01). The frequency of occurrence of apoE epsilon4 allele in AD was significantly higher than that in the control group (P < 0.01). The numbers of senile plaques and neurofibrillary tangles in AD cases with apoE epsilon4 allele were also significantly higher than those in AD cases without apoE epsilon4 allele (P < 0.01). CONCLUSIONS: ApoE polymorphism is associated with AD. The presence of apoE epsilon4 allele carries a higher risk for the development of AD. ApoE may also play an important role in the transformation of diffuse non-neuritic plaques to diffuse neuritic plaques.
