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Masaki Fukata - One of the best experts on this subject based on the ideXlab platform.
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Human Cerebrospinal Fluid Monoclonal LGI1 Autoantibodies Increase Neuronal Excitability.
Annals of Neurology, 2020Co-Authors: Hans‐christian Kornau, Yuko Fukata, Jakob Kreye, Alexander Stumpf, Daniel Parthier, Rosanna P. Sammons, Barbara Imbrosci, Sarah Kurpjuweit, Alexander B. Kowski, Masaki FukataAbstract:OBJECTIVE Leucine-rich glioma-inactivated 1 (LGI1) encephalitis is the second most common antibody-mediated encephalopathy, but insight into the intrathecal B-cell autoimmune response, including clonal relationships, isotype distribution, frequency, and pathogenic effects of single LGI1 antibodies, has remained limited. METHODS We cloned, expressed, and tested antibodies from 90 antibody-secreting cells (ASCs) and B cells from the cerebrospinal fluid (CSF) of several patients with LGI1 encephalitis. RESULTS Eighty-four percent of the ASCs and 21% of the memory B cells encoded LGI1-reactive antibodies, whereas reactivities to other brain epitopes were rare. All LGI1 antibodies were of IgG1, IgG2, or IgG4 isotype and had undergone affinity maturation. Seven of the overall 26 LGI1 antibodies efficiently blocked the interaction of LGI1 with its receptor ADAM22 in vitro, and their mean LGI1 signal on mouse brain sections was weak compared to the remaining, non-ADAM22-competing antibodies. Nevertheless, both types of LGI1 antibodies increased the intrinsic cellular excitability and glutamatergic synaptic transmission of hippocampal CA3 neurons in slice cultures. INTERPRETATION Our data show that the patients' intrathecal B-cell autoimmune response is dominated by LGI1 antibodies and that LGI1 antibodies alone are sufficient to promote neuronal excitability, a basis of seizure generation. Fundamental differences in target specificity and antibody hypermutations compared to the CSF autoantibody repertoire in N-methyl-D-aspartate receptor encephalitis underline the clinical concept that autoimmune encephalitides are very distinct entities. Ann Neurol 2020;87:405-418.
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the lgi1 ADAM22 protein complex in synaptic transmission and synaptic disorders
Neuroscience Research, 2017Co-Authors: Yuko Fukata, Norihiko Yokoi, Yuri Miyazaki, Masaki FukataAbstract:Abstract Physiological functioning of the brain requires fine-tuned synaptic transmission, and its dysfunction causes various brain disorders such as autism, dementia, and epilepsy. It is therefore extremely important to identify and characterize key regulators of synaptic function. In particular, disease-related synaptic proteins, such as autism-related neurexin–neuroligin and psychiatric disorder-related NMDA receptor, have attracted considerable attention. Recent basic and clinical research has highlighted critical roles of a ligand–receptor complex, LGI1–ADAM22, in synaptic transmission and brain function, as mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy and autoantibodies to LGI1 cause limbic encephalitis which is characterized by memory loss and seizures. Here, we will review our current knowledge about LGI1 and ADAM22, and discuss their patho-physiological roles in synaptic transmission and synaptic disorders.
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dysfunctional ADAM22 implicated in progressive encephalopathy with cortical atrophy and epilepsy
Neurology Genetics, 2016Co-Authors: Mikko Muona, Yuko Fukata, Annakaisa Anttonen, Anni Laari, Aarno Palotie, Helena Pihko, Tuula Lonnqvist, Leena Valanne, Mirja Somer, Masaki FukataAbstract:Objective: To identify the molecular genetic basis of a syndrome characterized by rapidly progressing cerebral atrophy, intractable seizures, and intellectual disability. Methods: We performed exome sequencing in the proband and whole-genome single nucleotide polymorphism genotyping (copy number variant analysis) in the proband-parent trio. We used heterologous expression systems to study the functional consequences of identified mutations. Results: The search for potentially deleterious recessive or de novo variants yielded compound heterozygous missense (c.1202G>A, p.Cys401Tyr) and frameshift deletion (c.2396delG, p.Ser799IlefsTer96) mutations in ADAM22 , which encodes a postsynaptic receptor for LGI1. The deleterious effect of the mutations was observed in cell surface binding and immunoprecipitation assays, which revealed that both mutant proteins failed to bind to LGI1. Furthermore, immunoprecipitation assays showed that the frameshift mutant ADAM22 also did not bind to the postsynaptic scaffolding protein PSD-95. Conclusions: The mutations identified abolish the LGI1-ADAM22 ligand-receptor complex and are thus a likely primary cause of the proband9s epilepsy syndrome, which is characterized by unusually rapidly progressing cortical atrophy starting at 3–4 months of age. These findings are in line with the implicated role of the LGI1-ADAM22 complex as a key player in nervous system development, specifically in functional maturation of postnatal synapses. Because the frameshift mutation affects an alternatively spliced exon with highest expression in postnatal brain, the combined effect of the mutations is likely to be hypomorphic rather than complete loss of function. This is compatible with the longer survival of the patient compared to Lgi1 −/− and ADAM22 −/− mice, which develop lethal seizures during the first postnatal weeks.
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the lgi1 ADAM22 protein complex directs synapse maturation through regulation of psd 95 function
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Kathryn L. Lovero, Yuko Fukata, Masaki Fukata, Adam J Granger, Roger A. NicollAbstract:Synapse development is coordinated by a number of transmembrane and secreted proteins that come together to form synaptic organizing complexes. Whereas a variety of synaptogenic proteins have been characterized, much less is understood about the molecular networks that support the maintenance and functional maturation of nascent synapses. Here, we demonstrate that leucine-rich, glioma-inactivated protein 1 (LGI1), a secreted protein previously shown to modulate synaptic AMPA receptors, is a paracrine signal released from pre- and postsynaptic neurons that acts specifically through a disintegrin and metalloproteinase protein 22 (ADAM22) to set postsynaptic strength. We go on to describe a novel role for ADAM22 in maintaining excitatory synapses through PSD-95/Dlg1/zo-1 (PDZ) domain interactions. Finally, we show that in the absence of LGI1, the mature synapse scaffolding protein PSD-95, but not the immature synapse scaffolding protein SAP102, is unable to modulate synaptic transmission. These results indicate that LGI1 and ADAM22 form an essential synaptic organizing complex that coordinates the maturation of excitatory synapses by regulating the functional incorporation of PSD-95.
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The LGI1–ADAM22 protein complex directs synapse maturation through regulation of PSD-95 function
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Kathryn L. Lovero, Yuko Fukata, Masaki Fukata, Adam J Granger, Roger A. NicollAbstract:Synapse development is coordinated by a number of transmembrane and secreted proteins that come together to form synaptic organizing complexes. Whereas a variety of synaptogenic proteins have been characterized, much less is understood about the molecular networks that support the maintenance and functional maturation of nascent synapses. Here, we demonstrate that leucine-rich, glioma-inactivated protein 1 (LGI1), a secreted protein previously shown to modulate synaptic AMPA receptors, is a paracrine signal released from pre- and postsynaptic neurons that acts specifically through a disintegrin and metalloproteinase protein 22 (ADAM22) to set postsynaptic strength. We go on to describe a novel role for ADAM22 in maintaining excitatory synapses through PSD-95/Dlg1/zo-1 (PDZ) domain interactions. Finally, we show that in the absence of LGI1, the mature synapse scaffolding protein PSD-95, but not the immature synapse scaffolding protein SAP102, is unable to modulate synaptic transmission. These results indicate that LGI1 and ADAM22 form an essential synaptic organizing complex that coordinates the maturation of excitatory synapses by regulating the functional incorporation of PSD-95.
Yuko Fukata - One of the best experts on this subject based on the ideXlab platform.
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Human Cerebrospinal Fluid Monoclonal LGI1 Autoantibodies Increase Neuronal Excitability.
Annals of Neurology, 2020Co-Authors: Hans‐christian Kornau, Yuko Fukata, Jakob Kreye, Alexander Stumpf, Daniel Parthier, Rosanna P. Sammons, Barbara Imbrosci, Sarah Kurpjuweit, Alexander B. Kowski, Masaki FukataAbstract:OBJECTIVE Leucine-rich glioma-inactivated 1 (LGI1) encephalitis is the second most common antibody-mediated encephalopathy, but insight into the intrathecal B-cell autoimmune response, including clonal relationships, isotype distribution, frequency, and pathogenic effects of single LGI1 antibodies, has remained limited. METHODS We cloned, expressed, and tested antibodies from 90 antibody-secreting cells (ASCs) and B cells from the cerebrospinal fluid (CSF) of several patients with LGI1 encephalitis. RESULTS Eighty-four percent of the ASCs and 21% of the memory B cells encoded LGI1-reactive antibodies, whereas reactivities to other brain epitopes were rare. All LGI1 antibodies were of IgG1, IgG2, or IgG4 isotype and had undergone affinity maturation. Seven of the overall 26 LGI1 antibodies efficiently blocked the interaction of LGI1 with its receptor ADAM22 in vitro, and their mean LGI1 signal on mouse brain sections was weak compared to the remaining, non-ADAM22-competing antibodies. Nevertheless, both types of LGI1 antibodies increased the intrinsic cellular excitability and glutamatergic synaptic transmission of hippocampal CA3 neurons in slice cultures. INTERPRETATION Our data show that the patients' intrathecal B-cell autoimmune response is dominated by LGI1 antibodies and that LGI1 antibodies alone are sufficient to promote neuronal excitability, a basis of seizure generation. Fundamental differences in target specificity and antibody hypermutations compared to the CSF autoantibody repertoire in N-methyl-D-aspartate receptor encephalitis underline the clinical concept that autoimmune encephalitides are very distinct entities. Ann Neurol 2020;87:405-418.
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the lgi1 ADAM22 protein complex in synaptic transmission and synaptic disorders
Neuroscience Research, 2017Co-Authors: Yuko Fukata, Norihiko Yokoi, Yuri Miyazaki, Masaki FukataAbstract:Abstract Physiological functioning of the brain requires fine-tuned synaptic transmission, and its dysfunction causes various brain disorders such as autism, dementia, and epilepsy. It is therefore extremely important to identify and characterize key regulators of synaptic function. In particular, disease-related synaptic proteins, such as autism-related neurexin–neuroligin and psychiatric disorder-related NMDA receptor, have attracted considerable attention. Recent basic and clinical research has highlighted critical roles of a ligand–receptor complex, LGI1–ADAM22, in synaptic transmission and brain function, as mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy and autoantibodies to LGI1 cause limbic encephalitis which is characterized by memory loss and seizures. Here, we will review our current knowledge about LGI1 and ADAM22, and discuss their patho-physiological roles in synaptic transmission and synaptic disorders.
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dysfunctional ADAM22 implicated in progressive encephalopathy with cortical atrophy and epilepsy
Neurology Genetics, 2016Co-Authors: Mikko Muona, Yuko Fukata, Annakaisa Anttonen, Anni Laari, Aarno Palotie, Helena Pihko, Tuula Lonnqvist, Leena Valanne, Mirja Somer, Masaki FukataAbstract:Objective: To identify the molecular genetic basis of a syndrome characterized by rapidly progressing cerebral atrophy, intractable seizures, and intellectual disability. Methods: We performed exome sequencing in the proband and whole-genome single nucleotide polymorphism genotyping (copy number variant analysis) in the proband-parent trio. We used heterologous expression systems to study the functional consequences of identified mutations. Results: The search for potentially deleterious recessive or de novo variants yielded compound heterozygous missense (c.1202G>A, p.Cys401Tyr) and frameshift deletion (c.2396delG, p.Ser799IlefsTer96) mutations in ADAM22 , which encodes a postsynaptic receptor for LGI1. The deleterious effect of the mutations was observed in cell surface binding and immunoprecipitation assays, which revealed that both mutant proteins failed to bind to LGI1. Furthermore, immunoprecipitation assays showed that the frameshift mutant ADAM22 also did not bind to the postsynaptic scaffolding protein PSD-95. Conclusions: The mutations identified abolish the LGI1-ADAM22 ligand-receptor complex and are thus a likely primary cause of the proband9s epilepsy syndrome, which is characterized by unusually rapidly progressing cortical atrophy starting at 3–4 months of age. These findings are in line with the implicated role of the LGI1-ADAM22 complex as a key player in nervous system development, specifically in functional maturation of postnatal synapses. Because the frameshift mutation affects an alternatively spliced exon with highest expression in postnatal brain, the combined effect of the mutations is likely to be hypomorphic rather than complete loss of function. This is compatible with the longer survival of the patient compared to Lgi1 −/− and ADAM22 −/− mice, which develop lethal seizures during the first postnatal weeks.
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the lgi1 ADAM22 protein complex directs synapse maturation through regulation of psd 95 function
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Kathryn L. Lovero, Yuko Fukata, Masaki Fukata, Adam J Granger, Roger A. NicollAbstract:Synapse development is coordinated by a number of transmembrane and secreted proteins that come together to form synaptic organizing complexes. Whereas a variety of synaptogenic proteins have been characterized, much less is understood about the molecular networks that support the maintenance and functional maturation of nascent synapses. Here, we demonstrate that leucine-rich, glioma-inactivated protein 1 (LGI1), a secreted protein previously shown to modulate synaptic AMPA receptors, is a paracrine signal released from pre- and postsynaptic neurons that acts specifically through a disintegrin and metalloproteinase protein 22 (ADAM22) to set postsynaptic strength. We go on to describe a novel role for ADAM22 in maintaining excitatory synapses through PSD-95/Dlg1/zo-1 (PDZ) domain interactions. Finally, we show that in the absence of LGI1, the mature synapse scaffolding protein PSD-95, but not the immature synapse scaffolding protein SAP102, is unable to modulate synaptic transmission. These results indicate that LGI1 and ADAM22 form an essential synaptic organizing complex that coordinates the maturation of excitatory synapses by regulating the functional incorporation of PSD-95.
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The LGI1–ADAM22 protein complex directs synapse maturation through regulation of PSD-95 function
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Kathryn L. Lovero, Yuko Fukata, Masaki Fukata, Adam J Granger, Roger A. NicollAbstract:Synapse development is coordinated by a number of transmembrane and secreted proteins that come together to form synaptic organizing complexes. Whereas a variety of synaptogenic proteins have been characterized, much less is understood about the molecular networks that support the maintenance and functional maturation of nascent synapses. Here, we demonstrate that leucine-rich, glioma-inactivated protein 1 (LGI1), a secreted protein previously shown to modulate synaptic AMPA receptors, is a paracrine signal released from pre- and postsynaptic neurons that acts specifically through a disintegrin and metalloproteinase protein 22 (ADAM22) to set postsynaptic strength. We go on to describe a novel role for ADAM22 in maintaining excitatory synapses through PSD-95/Dlg1/zo-1 (PDZ) domain interactions. Finally, we show that in the absence of LGI1, the mature synapse scaffolding protein PSD-95, but not the immature synapse scaffolding protein SAP102, is unable to modulate synaptic transmission. These results indicate that LGI1 and ADAM22 form an essential synaptic organizing complex that coordinates the maturation of excitatory synapses by regulating the functional incorporation of PSD-95.
Atsushi Yamagata - One of the best experts on this subject based on the ideXlab platform.
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insights into the mechanisms of epilepsy from structural biology of lgi1 ADAM22
Cellular and Molecular Life Sciences, 2020Co-Authors: Atsushi Yamagata, Shuya FukaiAbstract:Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1–ADAM22.
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Insights into the mechanisms of epilepsy from structural biology of LGI1–ADAM22
Cellular and Molecular Life Sciences, 2020Co-Authors: Atsushi Yamagata, Shuya FukaiAbstract:Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1–ADAM22.
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structural basis of epilepsy related ligand receptor complex lgi1 ADAM22
Nature Communications, 2018Co-Authors: Atsushi Yamagata, Norihiko Yokoi, Yuri Miyazaki, Hideki Shigematsu, Yusuke Sato, Sakurako Gotoito, Asami Maeda, Teppei Goto, Makoto Sanbo, Masumi HirabayashiAbstract:Epilepsy is a common brain disorder throughout history. Epilepsy-related ligand–receptor complex, LGI1–ADAM22, regulates synaptic transmission and has emerged as a determinant of brain excitability, as their mutations and acquired LGI1 autoantibodies cause epileptic disorders in human. Here, we report the crystal structure of human LGI1–ADAM22 complex, revealing a 2:2 heterotetrameric assembly. The hydrophobic pocket of the C-terminal epitempin-repeat (EPTP) domain of LGI1 binds to the metalloprotease-like domain of ADAM22. The N-terminal leucine-rich repeat and EPTP domains of LGI1 mediate the intermolecular LGI1–LGI1 interaction. A pathogenic R474Q mutation of LGI1, which does not exceptionally affect either the secretion or the ADAM22 binding, is located in the LGI1–LGI1 interface and disrupts the higher-order assembly of the LGI1–ADAM22 complex in vitro and in a mouse model for familial epilepsy. These studies support the notion that the LGI1–ADAM22 complex functions as the trans-synaptic machinery for precise synaptic transmission. LGI1 is an epilepsy-related gene that encodes a secreted neuronal protein. Here the authors present the crystal structure of LGI1 bound to its receptor ADAM22, which provides structural insights into epilepsy-causing LGI1 mutations and might facilitate the development of novel anti-epilepsy drugs.
Shuya Fukai - One of the best experts on this subject based on the ideXlab platform.
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Insights into the mechanisms of epilepsy from structural biology of LGI1–ADAM22
Cellular and Molecular Life Sciences, 2020Co-Authors: Atsushi Yamagata, Shuya FukaiAbstract:Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1–ADAM22.
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insights into the mechanisms of epilepsy from structural biology of lgi1 ADAM22
Cellular and Molecular Life Sciences, 2020Co-Authors: Atsushi Yamagata, Shuya FukaiAbstract:Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1–ADAM22.
Leonie S. Young - One of the best experts on this subject based on the ideXlab platform.
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ADAM22 as a prognostic and therapeutic drug target in the treatment of endocrine-resistant breast cancer.
Vitamins and Hormones Series, 2020Co-Authors: Jarlath C. Bolger, Leonie S. YoungAbstract:Abstract The development of breast cancer resistance to endocrine therapies may result from an increase in cellular plasticity, permitting the emergence of a hormone-independent tumor. ADAM proteins are multidomain transmembrane proteins that have a diverse array of functions in both natural physiology and disease. A number of ADAM proteins have been implicated in the occurrence of breast cancer, including ADAM 9, ADAM12, ADAM15, ADAM17, ADAM22, and ADAM28. ADAM22 expression is driven by the coactivator protein SRC-1 in response to tamoxifen treatment in the resistant setting. ADAM22 is an ER-independent predictor of disease-free survival. LGI1 is a neuropeptide that binds ADAM22 in the nervous system. In addition to being a ligand for ADAM11, ADAM22, and ADAM23, LGI1 may play a role as a tumor suppressor. Furthermore, LGI1 may act to reduce cell migration and may impair proliferation. Therapies based on LGI1 may provide a building block for future therapies in ADAM22-positive breast cancer.
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po 507 ADAM22 as a therapeutic target for endocrine resistant metastatic breast cancer
Poster Presentation, 2018Co-Authors: B Doherty, Jarlath C. Bolger, Sinead Cocchiglia, Damir Vareslija, Sara Charmsaz, Arnold D K Hill, Leonie S. YoungAbstract:Introduction The development of endocrine resistance is a major hurdle for the treatment of oestrogen receptor positive (ER+) breast cancer. One of the key contributors to this resistant phenotype is overexpression of the nuclear receptor coactivator SRC-1, which in turn has been shown to promote metastatic disease. Using CHIP-seq and microarray studies, the neuronal protein ADAM22 (A Disintegrin And Metalloproteinase) was identified as a potential pro-metastatic SRC-1 regulated gene in endocrine resistant cell lines. ADAM22 expression promotes both migration and de-differentiation, key hallmarks of metastasis. While clinically, elevated ADAM22 expression predicts poor disease free survival. Here, both the role of ADAM22 in metastatic development and the clinical potential of ADAM22 as a biomarker and therapeutic target were explored. Material and methods The functional effect of ADAM22 modulation on anchorage independent growth and mammosphere formation was investigated using CRISPR/Cas9 knockout and lentiviral overexpression in the endocrine resistant LY2 cell line. To examine the clinical relevance of ADAM22 as a biomarker, ADAM22 expression was examined in matched primary breast and metastatic cancer tissues. A small peptide mimetic of the ADAM22 endogenous ligand LGI1 (LGIMIM) was designed and explored as a potential anti-ADAM22 therapeutic both in vitro and in vivo . Results and discussions ADAM22 expression promotes anchorage independent growth and mammosphere formation, suggesting ADAM22 contributes to both the survival of metastatic cells and their ability to colonise distant sites. ADAM22 expression was significantly higher in primary breast tumours which went on to metastasise versus primaries which did not. A significant increase in ADAM22 expression was found in brain metastatic tissue compared to matched primary tissue, suggesting ADAM22 may prime endocrine resistant cancer cells to colonise the brain. LGIMIM treatment was sufficient to inhibit ADAM22 mediated phenotypes in vitro and to reduce metastatic burden in a xenograft model of endocrine resistance in vivo . Conclusion ADAM22 is a promising biomarker and therapeutic target for endocrine resistant breast cancer.
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abstract p3 05 02 global characterisation of the src 1 transcriptome and rational drug design results in the identification of a novel peptide targeting ADAM22 in endocrine resistance
Cancer Research, 2015Co-Authors: Jarlath C. Bolger, Damir Vareslija, Arnold D K Hill, Damian Mccartan, Ailis Fagan, Christopher Byrne, Marie Mcilroy, Peadar Ogaora, Leonie S. YoungAbstract:In spite of therapeutic advances, up to 25% of luminal breast cancers will eventually develop resistance to endocrine therapy and develop metastatic disease. The underlying mechanism causing ER-positive, steroid responsive tumours to develop a resistant, metastatic phenotype remains unresolved. Previous work from our group and others has identified the P160 protein SRC-1 as a significant predictor of recurrence on endocrine therapy. The purpose of this study is to further examine downstream SRC-1 targets in the context of endocrine resistant breast cancer. We adopted a global approach to define the transcriptional targets of SRC-1. SRC-1 ChIP sequencing in endocrine resistant luminal B breast cancer cells was combined with SRC-1 gene expression array analysis. This identified a number of pathways significantly elevated following tamoxifen treatment, including a number involved in cellular adhesion. From these pathways, A Disintegrin And Metalloproteinase-22 (ADAM22) was selected for further study. Knockout studies confirmed ADAM22 as a tamoxifen dependent SRC-1 target gene. Functional assays including migration, three dimensional cell culture and adhesion independence growth assays confirmed a role for ADAM22 in promoting a migratory, aggressive phenotype. Samples from two separate TMAs comprising over 1,000 patients confirmed that ADAM22 is associated with poor disease free survival in breast cancer patients. LGI1 is a naturally occurring neuropeptide which acts on an inhibitory manner on ADAM22 in the central nervous system. Using molecular modelling, a novel peptide mimetic targeting the disintegrin binding domain of ADAM22 was designed. Treatment with this peptide mimetic restored endocrine resistant cells to a less aggressive, sensitive phenotype, similar to the effect seen with knockdown of ADAM22. Moreover in an endocrine resistant xenograft model, treatment with the LGI1 mimetic significantly reduced primary and metastatic tumour burden in tamoxifen treated animals. We have used next-generation sequencing techniques to identify a novel therapeutic target in endocrine resistant, metastatic breast cancer. Rational drug design has been used to manufacture a therapeutic peptide against ADAM22. A combination of in vitro, in vivo and patient studies has confirmed a role for ADAM22 in metastatic breast cancer. Our novel peptide mimetic may form a future basis for targeting ADAM22 in endocrine resistant disease. Citation Format: Jarlath C Bolger, Damian McCartan, Damir Vareslija, Ailis Fagan, Christopher Byrne, Marie McIlroy, Peadar O9Gaora, Arnold D Hill, Leonie S Young. Global characterisation of the SRC-1 transcriptome and rational drug design results in the identification of a novel peptide targeting ADAM22 in endocrine resistance [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-05-02.
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global characterization of the src 1 transcriptome identifies ADAM22 as an er independent mediator of endocrine resistant breast cancer
Cancer Research, 2012Co-Authors: Damian Mccartan, Jarlath C. Bolger, Arnold D K Hill, Ailis Fagan, Christopher Byrne, Marie Mcilroy, Jianming Xu, Peadar O Gaora, Leonie S. YoungAbstract:The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity that permits the emergence of a hormone independent tumor. The steroid coactivator protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumor adaptability. In this discovery study we identified ADAM22, a non-protease member of the ADAM family of disintegrins, as a direct ER-independent target of SRC-1. We confirmed SRC-1 as a regulator of ADAM22 by molecular, cellular and in vivo studies. ADAM22 functioned in cellular migration and differentiation and its levels were increased endocrine resistant tumors compared to endocrine sensitive tumors in a mouse xenograft models of human breast cancer. Clinically ADAM22 was found to serve as an independent predictor of poor disease-free survival. Taken together, our findings suggest that SRC-1 switches steroid-responsive tumors to a steroid resistant state in which the SRC-1 target gene ADAM22 has a critical role, suggesting this molecule as a prognostic and therapeutic drug target that could help improve the treatment of endocrine-resistant breast cancer.
