The Experts below are selected from a list of 205722 Experts worldwide ranked by ideXlab platform
William M Pardridge - One of the best experts on this subject based on the ideXlab platform.
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igg enzyme Fusion Protein pharmacokinetics and anti drug antibody response in rhesus monkeys
Bioconjugate Chemistry, 2013Co-Authors: Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:The chronic administration of recombinant Fusion Proteins in preclinical animal models may generate an immune response and the formation of anti-drug antibodies (ADA). Such ADAs could alter the plasma pharmacokinetics of the Fusion Protein, and mask any underlying toxicity of the recombinant Fusion Protein. In the present study, a model IgG-enzyme Fusion Protein was evaluated with chronic dosing of Rhesus monkeys. The IgG domain of the Fusion Protein is a genetically engineered monoclonal antibody (MAb) against the human insulin receptor (HIR), which is shown to cross-react with the primate insulin receptor. The enzyme domain of the Fusion Protein is human iduronidase (IDUA), the lysosomal enzyme mutated in Mucopolysaccharidosis Type I (MPSI). MPSI affects the brain, but enzyme replacement therapy is not effective for the brain, because IDUA does not cross the blood-brain barrier (BBB). The HIRMAb domain of the Fusion Protein acts as a molecular Trojan horse to deliver the IDUA across the BBB. The HIRMAb-IDUA Fusion Protein was administered to Rhesus monkeys with weekly intravenous inFusions of 3–30 mg/kg for 6 months, and the pharmacokinetics, immune response, and tissue toxicology was assessed. The pharmacokinetics of plasma clearance of the Fusion Protein was determined with measurements of plasma IDUA enzyme activity. ADAs formed during the course of the 6 months of treatment, as determined by a sandwich ELISA. However, the plasma clearance of the Fusion Protein at the start and end of the 6-month study was comparable at all drug doses. Fusion Protein administration for 6 months showed no evidence of chronic tissue toxicity. These studies demonstrate that the immune response produced with chronic treatment of primates with an IgG-enzyme Fusion Protein has no effect on the pharmacokinetics of plasma clearance of the Fusion Protein.
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chronic dosing of mice with a transferrin receptor monoclonal antibody glial derived neurotrophic factor Fusion Protein
Drug Metabolism and Disposition, 2011Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potential neurotrophic factor treatment of brain disorders, including Parkinson's disease. However, GDNF does not cross the blood-brain barrier (BBB). A brain-penetrating form of GDNF, which is a Fusion Protein of human GDNF and a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR), has been engineered for the mouse and is designated the cTfRMAb-GDNF Fusion Protein. The present study examined the potential toxic side effects and immune response after treatment of mice with twice-weekly cTfRMAb-GDNF Fusion Protein at a dose of 2 mg/kg i.v. for 12 consecutive weeks. Chronic treatment with the Fusion Protein caused no change in body weight, no change in 23 serum chemistry measurements, and no histologic changes in brain and cerebellum, kidney, liver, spleen, heart, or pancreas. Chronic treatment caused a low-titer immune response against the Fusion Protein, which was directed against the variable region of the antibody part of the Fusion Protein, with no immune response directed against either the constant region of the antibody or against GDNF. A pharmacokinetics and brain uptake study was performed at the end of the 12 weeks of treatment. There was no change in clearance of the Fusion Protein mediated by the TfR in peripheral organs, and there was no change in BBB permeability to the Fusion Protein mediated by the TfR at the BBB. The study shows no toxic side effects from chronic cTfRMAb-GDNF systemic treatment and the absence of neutralizing antibodies in vivo.
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Neuroprotection in experimental stroke in the rat with an IgG–erythropoietin Fusion Protein
Brain research, 2010Co-Authors: Eric Kawai Hui, Ruben J Boado, William M PardridgeAbstract:Erythropoietin (EPO) is a potent neuroprotective agent that could be developed as a new treatment for stroke. However, the blood-brain barrier (BBB) is intact in the early hours after stroke when neuroprotection is still possible, and EPO does not cross the intact BBB. To enable BBB transport, human EPO was re-engineered as an IgG-EPO Fusion Protein, wherein the IgG part is a monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb acts as a BBB molecular Trojan horse to ferry the fused EPO across the BBB via transport on the BBB insulin receptor. The HIRMAb part of the HIRMAb-EPO Fusion Protein does not recognize the rat insulin receptor. However, the EPO part of the Fusion Protein does recognize the rat EPO receptor. Therefore, the neuroprotective properties of the HIRMAb-EPO Fusion Protein were investigated with a permanent middle cerebral artery occlusion model in the rat. The HIRMAb-EPO Fusion Protein was injected into the ipsilateral brain under stereotaxic guidance. High doses of the HIRMAb-EPO Fusion Protein (61pmol) completely eliminated both cortical and sub-cortical infarction. Lower doses of the Fusion Protein (4.5pmol) eliminated the cortical infarct with no significant effect on sub-cortical infarct. The neurologic deficit was reduced by 35% and 90%, respectively, by the 4.5 and 61pmol doses of the HIRMAb-EPO Fusion Protein. In conclusion, these studies demonstrate the biological activity of the HIRMAb-EPO Fusion Protein in the brain in vivo, and that EPO retains neuroprotective properties following Fusion to the HIRMAb BBB Trojan horse.
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monoclonal antibody glial derived neurotrophic factor Fusion Protein penetrates the blood brain barrier in the mouse
Drug Metabolism and Disposition, 2010Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potent neuroprotective agent for multiple brain disorders, including Parkinson's disease. However, GDNF drug development is difficult because GDNF does not cross the blood-brain barrier (BBB). To enable future drug development of GDNF in mouse models, the neurotrophin was re-engineered as an IgG Fusion Protein to enable penetration through the BBB after intravenous administration. The 134-amino acid GDNF was fused to the heavy chain of a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) designated the cTfRMAb. This antibody undergoes receptor-mediated transport across the BBB and acts as a molecular Trojan horse to ferry the GDNF into mouse brain. The cTfRMAb-GDNF Fusion Protein was expressed by stably transfected Chinese hamster ovary cells, affinity-purified, and the biochemical identity was confirmed by mouse IgG and GDNF Western blotting. The cTfRMAb-GDNF Fusion Protein was bifunctional and bound with high affinity to both the GDNF receptor α1, ED50 = 1.7 ± 0.2 nM, and the mouse TfR, ED50 = 3.2 ± 0.3 nM. The cTfRMAb-GDNF Fusion Protein was rapidly taken up by brain, and the brain uptake was 3.1 ± 0.2% injected dose/g brain at 60 min after intravenous injection of a 1-mg/kg dose of the Fusion Protein. Brain capillary depletion analysis showed the majority of the Fusion Protein was transcytosed across the BBB with penetration into brain parenchyma. The brain uptake results indicate it is possible to achieve therapeutic elevations of GDNF in mouse brain with intravenous administration of the cTfRMAb-GDNF Fusion Protein.
Ruben J Boado - One of the best experts on this subject based on the ideXlab platform.
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igg enzyme Fusion Protein pharmacokinetics and anti drug antibody response in rhesus monkeys
Bioconjugate Chemistry, 2013Co-Authors: Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:The chronic administration of recombinant Fusion Proteins in preclinical animal models may generate an immune response and the formation of anti-drug antibodies (ADA). Such ADAs could alter the plasma pharmacokinetics of the Fusion Protein, and mask any underlying toxicity of the recombinant Fusion Protein. In the present study, a model IgG-enzyme Fusion Protein was evaluated with chronic dosing of Rhesus monkeys. The IgG domain of the Fusion Protein is a genetically engineered monoclonal antibody (MAb) against the human insulin receptor (HIR), which is shown to cross-react with the primate insulin receptor. The enzyme domain of the Fusion Protein is human iduronidase (IDUA), the lysosomal enzyme mutated in Mucopolysaccharidosis Type I (MPSI). MPSI affects the brain, but enzyme replacement therapy is not effective for the brain, because IDUA does not cross the blood-brain barrier (BBB). The HIRMAb domain of the Fusion Protein acts as a molecular Trojan horse to deliver the IDUA across the BBB. The HIRMAb-IDUA Fusion Protein was administered to Rhesus monkeys with weekly intravenous inFusions of 3–30 mg/kg for 6 months, and the pharmacokinetics, immune response, and tissue toxicology was assessed. The pharmacokinetics of plasma clearance of the Fusion Protein was determined with measurements of plasma IDUA enzyme activity. ADAs formed during the course of the 6 months of treatment, as determined by a sandwich ELISA. However, the plasma clearance of the Fusion Protein at the start and end of the 6-month study was comparable at all drug doses. Fusion Protein administration for 6 months showed no evidence of chronic tissue toxicity. These studies demonstrate that the immune response produced with chronic treatment of primates with an IgG-enzyme Fusion Protein has no effect on the pharmacokinetics of plasma clearance of the Fusion Protein.
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chronic dosing of mice with a transferrin receptor monoclonal antibody glial derived neurotrophic factor Fusion Protein
Drug Metabolism and Disposition, 2011Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potential neurotrophic factor treatment of brain disorders, including Parkinson's disease. However, GDNF does not cross the blood-brain barrier (BBB). A brain-penetrating form of GDNF, which is a Fusion Protein of human GDNF and a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR), has been engineered for the mouse and is designated the cTfRMAb-GDNF Fusion Protein. The present study examined the potential toxic side effects and immune response after treatment of mice with twice-weekly cTfRMAb-GDNF Fusion Protein at a dose of 2 mg/kg i.v. for 12 consecutive weeks. Chronic treatment with the Fusion Protein caused no change in body weight, no change in 23 serum chemistry measurements, and no histologic changes in brain and cerebellum, kidney, liver, spleen, heart, or pancreas. Chronic treatment caused a low-titer immune response against the Fusion Protein, which was directed against the variable region of the antibody part of the Fusion Protein, with no immune response directed against either the constant region of the antibody or against GDNF. A pharmacokinetics and brain uptake study was performed at the end of the 12 weeks of treatment. There was no change in clearance of the Fusion Protein mediated by the TfR in peripheral organs, and there was no change in BBB permeability to the Fusion Protein mediated by the TfR at the BBB. The study shows no toxic side effects from chronic cTfRMAb-GDNF systemic treatment and the absence of neutralizing antibodies in vivo.
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Neuroprotection in experimental stroke in the rat with an IgG–erythropoietin Fusion Protein
Brain research, 2010Co-Authors: Eric Kawai Hui, Ruben J Boado, William M PardridgeAbstract:Erythropoietin (EPO) is a potent neuroprotective agent that could be developed as a new treatment for stroke. However, the blood-brain barrier (BBB) is intact in the early hours after stroke when neuroprotection is still possible, and EPO does not cross the intact BBB. To enable BBB transport, human EPO was re-engineered as an IgG-EPO Fusion Protein, wherein the IgG part is a monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb acts as a BBB molecular Trojan horse to ferry the fused EPO across the BBB via transport on the BBB insulin receptor. The HIRMAb part of the HIRMAb-EPO Fusion Protein does not recognize the rat insulin receptor. However, the EPO part of the Fusion Protein does recognize the rat EPO receptor. Therefore, the neuroprotective properties of the HIRMAb-EPO Fusion Protein were investigated with a permanent middle cerebral artery occlusion model in the rat. The HIRMAb-EPO Fusion Protein was injected into the ipsilateral brain under stereotaxic guidance. High doses of the HIRMAb-EPO Fusion Protein (61pmol) completely eliminated both cortical and sub-cortical infarction. Lower doses of the Fusion Protein (4.5pmol) eliminated the cortical infarct with no significant effect on sub-cortical infarct. The neurologic deficit was reduced by 35% and 90%, respectively, by the 4.5 and 61pmol doses of the HIRMAb-EPO Fusion Protein. In conclusion, these studies demonstrate the biological activity of the HIRMAb-EPO Fusion Protein in the brain in vivo, and that EPO retains neuroprotective properties following Fusion to the HIRMAb BBB Trojan horse.
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monoclonal antibody glial derived neurotrophic factor Fusion Protein penetrates the blood brain barrier in the mouse
Drug Metabolism and Disposition, 2010Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potent neuroprotective agent for multiple brain disorders, including Parkinson's disease. However, GDNF drug development is difficult because GDNF does not cross the blood-brain barrier (BBB). To enable future drug development of GDNF in mouse models, the neurotrophin was re-engineered as an IgG Fusion Protein to enable penetration through the BBB after intravenous administration. The 134-amino acid GDNF was fused to the heavy chain of a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) designated the cTfRMAb. This antibody undergoes receptor-mediated transport across the BBB and acts as a molecular Trojan horse to ferry the GDNF into mouse brain. The cTfRMAb-GDNF Fusion Protein was expressed by stably transfected Chinese hamster ovary cells, affinity-purified, and the biochemical identity was confirmed by mouse IgG and GDNF Western blotting. The cTfRMAb-GDNF Fusion Protein was bifunctional and bound with high affinity to both the GDNF receptor α1, ED50 = 1.7 ± 0.2 nM, and the mouse TfR, ED50 = 3.2 ± 0.3 nM. The cTfRMAb-GDNF Fusion Protein was rapidly taken up by brain, and the brain uptake was 3.1 ± 0.2% injected dose/g brain at 60 min after intravenous injection of a 1-mg/kg dose of the Fusion Protein. Brain capillary depletion analysis showed the majority of the Fusion Protein was transcytosed across the BBB with penetration into brain parenchyma. The brain uptake results indicate it is possible to achieve therapeutic elevations of GDNF in mouse brain with intravenous administration of the cTfRMAb-GDNF Fusion Protein.
Eric Kawai Hui - One of the best experts on this subject based on the ideXlab platform.
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igg enzyme Fusion Protein pharmacokinetics and anti drug antibody response in rhesus monkeys
Bioconjugate Chemistry, 2013Co-Authors: Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:The chronic administration of recombinant Fusion Proteins in preclinical animal models may generate an immune response and the formation of anti-drug antibodies (ADA). Such ADAs could alter the plasma pharmacokinetics of the Fusion Protein, and mask any underlying toxicity of the recombinant Fusion Protein. In the present study, a model IgG-enzyme Fusion Protein was evaluated with chronic dosing of Rhesus monkeys. The IgG domain of the Fusion Protein is a genetically engineered monoclonal antibody (MAb) against the human insulin receptor (HIR), which is shown to cross-react with the primate insulin receptor. The enzyme domain of the Fusion Protein is human iduronidase (IDUA), the lysosomal enzyme mutated in Mucopolysaccharidosis Type I (MPSI). MPSI affects the brain, but enzyme replacement therapy is not effective for the brain, because IDUA does not cross the blood-brain barrier (BBB). The HIRMAb domain of the Fusion Protein acts as a molecular Trojan horse to deliver the IDUA across the BBB. The HIRMAb-IDUA Fusion Protein was administered to Rhesus monkeys with weekly intravenous inFusions of 3–30 mg/kg for 6 months, and the pharmacokinetics, immune response, and tissue toxicology was assessed. The pharmacokinetics of plasma clearance of the Fusion Protein was determined with measurements of plasma IDUA enzyme activity. ADAs formed during the course of the 6 months of treatment, as determined by a sandwich ELISA. However, the plasma clearance of the Fusion Protein at the start and end of the 6-month study was comparable at all drug doses. Fusion Protein administration for 6 months showed no evidence of chronic tissue toxicity. These studies demonstrate that the immune response produced with chronic treatment of primates with an IgG-enzyme Fusion Protein has no effect on the pharmacokinetics of plasma clearance of the Fusion Protein.
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chronic dosing of mice with a transferrin receptor monoclonal antibody glial derived neurotrophic factor Fusion Protein
Drug Metabolism and Disposition, 2011Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potential neurotrophic factor treatment of brain disorders, including Parkinson's disease. However, GDNF does not cross the blood-brain barrier (BBB). A brain-penetrating form of GDNF, which is a Fusion Protein of human GDNF and a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR), has been engineered for the mouse and is designated the cTfRMAb-GDNF Fusion Protein. The present study examined the potential toxic side effects and immune response after treatment of mice with twice-weekly cTfRMAb-GDNF Fusion Protein at a dose of 2 mg/kg i.v. for 12 consecutive weeks. Chronic treatment with the Fusion Protein caused no change in body weight, no change in 23 serum chemistry measurements, and no histologic changes in brain and cerebellum, kidney, liver, spleen, heart, or pancreas. Chronic treatment caused a low-titer immune response against the Fusion Protein, which was directed against the variable region of the antibody part of the Fusion Protein, with no immune response directed against either the constant region of the antibody or against GDNF. A pharmacokinetics and brain uptake study was performed at the end of the 12 weeks of treatment. There was no change in clearance of the Fusion Protein mediated by the TfR in peripheral organs, and there was no change in BBB permeability to the Fusion Protein mediated by the TfR at the BBB. The study shows no toxic side effects from chronic cTfRMAb-GDNF systemic treatment and the absence of neutralizing antibodies in vivo.
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Neuroprotection in experimental stroke in the rat with an IgG–erythropoietin Fusion Protein
Brain research, 2010Co-Authors: Eric Kawai Hui, Ruben J Boado, William M PardridgeAbstract:Erythropoietin (EPO) is a potent neuroprotective agent that could be developed as a new treatment for stroke. However, the blood-brain barrier (BBB) is intact in the early hours after stroke when neuroprotection is still possible, and EPO does not cross the intact BBB. To enable BBB transport, human EPO was re-engineered as an IgG-EPO Fusion Protein, wherein the IgG part is a monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb acts as a BBB molecular Trojan horse to ferry the fused EPO across the BBB via transport on the BBB insulin receptor. The HIRMAb part of the HIRMAb-EPO Fusion Protein does not recognize the rat insulin receptor. However, the EPO part of the Fusion Protein does recognize the rat EPO receptor. Therefore, the neuroprotective properties of the HIRMAb-EPO Fusion Protein were investigated with a permanent middle cerebral artery occlusion model in the rat. The HIRMAb-EPO Fusion Protein was injected into the ipsilateral brain under stereotaxic guidance. High doses of the HIRMAb-EPO Fusion Protein (61pmol) completely eliminated both cortical and sub-cortical infarction. Lower doses of the Fusion Protein (4.5pmol) eliminated the cortical infarct with no significant effect on sub-cortical infarct. The neurologic deficit was reduced by 35% and 90%, respectively, by the 4.5 and 61pmol doses of the HIRMAb-EPO Fusion Protein. In conclusion, these studies demonstrate the biological activity of the HIRMAb-EPO Fusion Protein in the brain in vivo, and that EPO retains neuroprotective properties following Fusion to the HIRMAb BBB Trojan horse.
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monoclonal antibody glial derived neurotrophic factor Fusion Protein penetrates the blood brain barrier in the mouse
Drug Metabolism and Disposition, 2010Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potent neuroprotective agent for multiple brain disorders, including Parkinson's disease. However, GDNF drug development is difficult because GDNF does not cross the blood-brain barrier (BBB). To enable future drug development of GDNF in mouse models, the neurotrophin was re-engineered as an IgG Fusion Protein to enable penetration through the BBB after intravenous administration. The 134-amino acid GDNF was fused to the heavy chain of a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) designated the cTfRMAb. This antibody undergoes receptor-mediated transport across the BBB and acts as a molecular Trojan horse to ferry the GDNF into mouse brain. The cTfRMAb-GDNF Fusion Protein was expressed by stably transfected Chinese hamster ovary cells, affinity-purified, and the biochemical identity was confirmed by mouse IgG and GDNF Western blotting. The cTfRMAb-GDNF Fusion Protein was bifunctional and bound with high affinity to both the GDNF receptor α1, ED50 = 1.7 ± 0.2 nM, and the mouse TfR, ED50 = 3.2 ± 0.3 nM. The cTfRMAb-GDNF Fusion Protein was rapidly taken up by brain, and the brain uptake was 3.1 ± 0.2% injected dose/g brain at 60 min after intravenous injection of a 1-mg/kg dose of the Fusion Protein. Brain capillary depletion analysis showed the majority of the Fusion Protein was transcytosed across the BBB with penetration into brain parenchyma. The brain uptake results indicate it is possible to achieve therapeutic elevations of GDNF in mouse brain with intravenous administration of the cTfRMAb-GDNF Fusion Protein.
Yves Labelle - One of the best experts on this subject based on the ideXlab platform.
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Identification of genes regulated by the EWS/NR4A3 Fusion Protein in extraskeletal myxoid chondrosarcoma
Tumor Biology, 2012Co-Authors: Christine Filion, Yves LabelleAbstract:Approximately 75 % of extraskeletal myxoid chondrosarcoma tumors (EMC) harbor a t(9;22) chromosome translocation generating an EWS/NR4A3 Fusion Protein that is thought to be instrumental in the tumoral process. Current evidence suggests that one function of the Fusion Protein is to overexpress target genes. We have generated an in vitro human cellular model in which the Fusion Protein is expressed in mesenchymal bone marrow stem cells. We have performed microarray analyses of these cells and identified several genes overexpressed in the presence of EWS/NR4A3 which are also overexpressed in EMC tumors. These genes and their products represent potential therapeutic targets for EMC tumors.
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identification of genes regulated by the ews nr4a3 Fusion Protein in extraskeletal myxoid chondrosarcoma
Tumor Biology, 2012Co-Authors: Christine Filion, Yves LabelleAbstract:Approximately 75 % of extraskeletal myxoid chondrosarcoma tumors (EMC) harbor a t(9;22) chromosome translocation generating an EWS/NR4A3 Fusion Protein that is thought to be instrumental in the tumoral process. Current evidence suggests that one function of the Fusion Protein is to overexpress target genes. We have generated an in vitro human cellular model in which the Fusion Protein is expressed in mesenchymal bone marrow stem cells. We have performed microarray analyses of these cells and identified several genes overexpressed in the presence of EWS/NR4A3 which are also overexpressed in EMC tumors. These genes and their products represent potential therapeutic targets for EMC tumors.
Qinghui Zhou - One of the best experts on this subject based on the ideXlab platform.
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chronic dosing of mice with a transferrin receptor monoclonal antibody glial derived neurotrophic factor Fusion Protein
Drug Metabolism and Disposition, 2011Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potential neurotrophic factor treatment of brain disorders, including Parkinson's disease. However, GDNF does not cross the blood-brain barrier (BBB). A brain-penetrating form of GDNF, which is a Fusion Protein of human GDNF and a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR), has been engineered for the mouse and is designated the cTfRMAb-GDNF Fusion Protein. The present study examined the potential toxic side effects and immune response after treatment of mice with twice-weekly cTfRMAb-GDNF Fusion Protein at a dose of 2 mg/kg i.v. for 12 consecutive weeks. Chronic treatment with the Fusion Protein caused no change in body weight, no change in 23 serum chemistry measurements, and no histologic changes in brain and cerebellum, kidney, liver, spleen, heart, or pancreas. Chronic treatment caused a low-titer immune response against the Fusion Protein, which was directed against the variable region of the antibody part of the Fusion Protein, with no immune response directed against either the constant region of the antibody or against GDNF. A pharmacokinetics and brain uptake study was performed at the end of the 12 weeks of treatment. There was no change in clearance of the Fusion Protein mediated by the TfR in peripheral organs, and there was no change in BBB permeability to the Fusion Protein mediated by the TfR at the BBB. The study shows no toxic side effects from chronic cTfRMAb-GDNF systemic treatment and the absence of neutralizing antibodies in vivo.
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monoclonal antibody glial derived neurotrophic factor Fusion Protein penetrates the blood brain barrier in the mouse
Drug Metabolism and Disposition, 2010Co-Authors: Qinghui Zhou, Ruben J Boado, Eric Kawai Hui, William M PardridgeAbstract:Glial-derived neurotrophic factor (GDNF) is a potent neuroprotective agent for multiple brain disorders, including Parkinson's disease. However, GDNF drug development is difficult because GDNF does not cross the blood-brain barrier (BBB). To enable future drug development of GDNF in mouse models, the neurotrophin was re-engineered as an IgG Fusion Protein to enable penetration through the BBB after intravenous administration. The 134-amino acid GDNF was fused to the heavy chain of a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) designated the cTfRMAb. This antibody undergoes receptor-mediated transport across the BBB and acts as a molecular Trojan horse to ferry the GDNF into mouse brain. The cTfRMAb-GDNF Fusion Protein was expressed by stably transfected Chinese hamster ovary cells, affinity-purified, and the biochemical identity was confirmed by mouse IgG and GDNF Western blotting. The cTfRMAb-GDNF Fusion Protein was bifunctional and bound with high affinity to both the GDNF receptor α1, ED50 = 1.7 ± 0.2 nM, and the mouse TfR, ED50 = 3.2 ± 0.3 nM. The cTfRMAb-GDNF Fusion Protein was rapidly taken up by brain, and the brain uptake was 3.1 ± 0.2% injected dose/g brain at 60 min after intravenous injection of a 1-mg/kg dose of the Fusion Protein. Brain capillary depletion analysis showed the majority of the Fusion Protein was transcytosed across the BBB with penetration into brain parenchyma. The brain uptake results indicate it is possible to achieve therapeutic elevations of GDNF in mouse brain with intravenous administration of the cTfRMAb-GDNF Fusion Protein.
