Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterised by recurrent ischemic strokes in the deep white matter. ...Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterised by recurrent ischemic strokes in the deep white matter. Mutations in the gene encoding the cell surface receptor, Notch3, have been identified in CADASIL patients, and accumulation of the extracellular domain of Notch3 has been demonstrated in affected vessels. Almost all CADASIL mutations alter the number of cysteine residues in the epidermal growth factor (EGF)-like repeats in the extracellular domain of the protein. Abstract:Objectives: To understand the functional consequences of a recurrent CADASIL mutation on furin processing, cell surface expression, ligand binding, and activation of a downstream effector CBF1 by the Notch3 receptor. Methods: We expressed wild type and mutant Notch3 receptors in cultured cells and examined cell surface expression of the proteins. We also applied a new flow cytometry based approach to semiquantitatively measure binding to three Notch ligands. Additionally, we used a well characterised coculture system to examine ligand dependent activation of transcription from a CBF1-luciferase reporter construct. Results: These studies revealed subtle abnormalities in furin processing of the mutant receptor, although both heterodimeric and full length receptors are present on the cell surface, are capable of interacting with soluble forms of three ligands, Delta1, Delta4, and Jagged1, and retain the ability to activate CBF1 in a ligand dependent manner. Conclusions: By comparison with other mutant forms of Notch3, these data indicate that individual CADASIL mutations can have disparate effects on Notch3 expression and function.展开更多
Heterotopic ossification （HO） refers to the abnormal formation of bone in soft tissue. Although some of the underlying processes of HO have been described, there are currently no clinical tests using validated bioma...Heterotopic ossification （HO） refers to the abnormal formation of bone in soft tissue. Although some of the underlying processes of HO have been described, there are currently no clinical tests using validated biomarkers for predicting HO formation. As such, the diagnosis is made radiographically after HO has formed. To identify potential and novel biomarkers for HO, we used isobaric tags for relative and absolute quantitation （iTRAQ） and high-throughput antibody arrays to produce a semi-quantitative proteomics survey of serum and tissue from subjects with （HO ＋） and without （HO-） heterotopic ossification. The resulting data were then analyzed using a systems biology approach. We found that serum samples from subjects experiencing traumatic injuries with resulting HO have a different proteomic expression controls. Subsequent quantitative ELISA identified profile compared to those from the matched five blood serum proteins that were differentially regulated between the HO-- and HO- groups. Compared to HO- samples, the amount of insulin-like growth factor I （IGF1） was up-regulated in HO＋ samples, whereas a lower amount of osteopontin （OPN）, myeloperoxidase （MPO）, runt-related transcription factor 2 （RUNX2）,and growth differentiation factor 2 or bone morphogenetic protein 9 （BMP-9） was found in HO ＋ samples （Welch two sample t-test; P 〈 0.05）. These proteins, in combination with potential serum biomarkers previously reported, are key candidates for a serum diagnostic panel that may enable early detection of HO prior to radiographic and clinical manifestations.展开更多
文摘Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterised by recurrent ischemic strokes in the deep white matter. Mutations in the gene encoding the cell surface receptor, Notch3, have been identified in CADASIL patients, and accumulation of the extracellular domain of Notch3 has been demonstrated in affected vessels. Almost all CADASIL mutations alter the number of cysteine residues in the epidermal growth factor (EGF)-like repeats in the extracellular domain of the protein. Abstract:Objectives: To understand the functional consequences of a recurrent CADASIL mutation on furin processing, cell surface expression, ligand binding, and activation of a downstream effector CBF1 by the Notch3 receptor. Methods: We expressed wild type and mutant Notch3 receptors in cultured cells and examined cell surface expression of the proteins. We also applied a new flow cytometry based approach to semiquantitatively measure binding to three Notch ligands. Additionally, we used a well characterised coculture system to examine ligand dependent activation of transcription from a CBF1-luciferase reporter construct. Results: These studies revealed subtle abnormalities in furin processing of the mutant receptor, although both heterodimeric and full length receptors are present on the cell surface, are capable of interacting with soluble forms of three ligands, Delta1, Delta4, and Jagged1, and retain the ability to activate CBF1 in a ligand dependent manner. Conclusions: By comparison with other mutant forms of Notch3, these data indicate that individual CADASIL mutations can have disparate effects on Notch3 expression and function.
基金supported by the Department of Defense (Grant No. W81-WXH-10-20139 to LEE as Co-PI)the National Institute of General Medical Sciences of the National Institutes of Health [Grant No. U54-GM104941 (DE-CTR) to ELC]the Nemours Alfred I. du Pont Hospital for Children’s Biomedical Research Department, United States to ELC
文摘Heterotopic ossification （HO） refers to the abnormal formation of bone in soft tissue. Although some of the underlying processes of HO have been described, there are currently no clinical tests using validated biomarkers for predicting HO formation. As such, the diagnosis is made radiographically after HO has formed. To identify potential and novel biomarkers for HO, we used isobaric tags for relative and absolute quantitation （iTRAQ） and high-throughput antibody arrays to produce a semi-quantitative proteomics survey of serum and tissue from subjects with （HO ＋） and without （HO-） heterotopic ossification. The resulting data were then analyzed using a systems biology approach. We found that serum samples from subjects experiencing traumatic injuries with resulting HO have a different proteomic expression controls. Subsequent quantitative ELISA identified profile compared to those from the matched five blood serum proteins that were differentially regulated between the HO-- and HO- groups. Compared to HO- samples, the amount of insulin-like growth factor I （IGF1） was up-regulated in HO＋ samples, whereas a lower amount of osteopontin （OPN）, myeloperoxidase （MPO）, runt-related transcription factor 2 （RUNX2）,and growth differentiation factor 2 or bone morphogenetic protein 9 （BMP-9） was found in HO ＋ samples （Welch two sample t-test; P 〈 0.05）. These proteins, in combination with potential serum biomarkers previously reported, are key candidates for a serum diagnostic panel that may enable early detection of HO prior to radiographic and clinical manifestations.
