1
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Wu CI, Vinton EA, Pearse RV, Heo K, Aylward AJ, Hsieh YC, Bi Y, Adeleye S, Fancher S, Duong DM, Seyfried NT, Schwarz TL, Young-Pearse TL. APP and DYRK1A regulate axonal and synaptic vesicle protein networks and mediate Alzheimer's pathology in trisomy 21 neurons. Mol Psychiatry 2022; 27:1970-1989. [PMID: 35194165 PMCID: PMC9133025 DOI: 10.1038/s41380-022-01454-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 01/18/2022] [Indexed: 11/09/2022]
Abstract
Trisomy 21 (T21) causes Down syndrome and an early-onset form of Alzheimer's disease (AD). Here, we used human induced pluripotent stem cells (hiPSCs) along with CRISPR-Cas9 gene editing to investigate the contribution of chromosome 21 candidate genes to AD-relevant neuronal phenotypes. We utilized a direct neuronal differentiation protocol to bypass neurodevelopmental cell fate phenotypes caused by T21 followed by unbiased proteomics and western blotting to define the proteins dysregulated in T21 postmitotic neurons. We show that normalization of copy number of APP and DYRK1A each rescue elevated tau phosphorylation in T21 neurons, while reductions of RCAN1 and SYNJ1 do not. To determine the T21 alterations relevant to early-onset AD, we identified common pathways altered in familial Alzheimer's disease neurons and determined which of these were rescued by normalization of APP and DYRK1A copy number in T21 neurons. These studies identified disruptions in T21 neurons in both the axonal cytoskeletal network and presynaptic proteins that play critical roles in axonal transport and synaptic vesicle cycling. These alterations in the proteomic profiles have functional consequences: fAD and T21 neurons exhibit dysregulated axonal trafficking and T21 neurons display enhanced synaptic vesicle release. Taken together, our findings provide insights into the initial molecular alterations within neurons that ultimately lead to synaptic loss and axonal degeneration in Down syndrome and early-onset AD.
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Affiliation(s)
- Chun-I Wu
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Elizabeth A Vinton
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
| | - Richard V Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Keunjung Heo
- Harvard Medical School, Boston, MA, USA
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Aimee J Aylward
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
| | - Yi-Chen Hsieh
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Yan Bi
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
| | - Sopefoluwa Adeleye
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
| | - Seeley Fancher
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA
| | - Duc M Duong
- Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA
- Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA
- Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
| | - Thomas L Schwarz
- Harvard Medical School, Boston, MA, USA
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA.
- Harvard Medical School, Boston, MA, USA.
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2
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Heo K, Basu H, Gutnick A, Wei W, Shlevkov E, Schwarz TL. Serine/Threonine Protein Phosphatase 2A Regulates the Transport of Axonal Mitochondria. Front Cell Neurosci 2022; 16:852245. [PMID: 35370563 PMCID: PMC8973303 DOI: 10.3389/fncel.2022.852245] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Microtubule-based transport provides mitochondria to distant regions of neurons and is essential for neuronal health. To identify compounds that increase mitochondrial motility, we screened 1,641 small-molecules in a high-throughput screening platform. Indirubin and cantharidin increased mitochondrial motility in rat cortical neurons. Cantharidin is known to inhibit protein phosphatase 2A (PP2A). We therefore tested two other inhibitors of PP2A: LB-100 and okadaic acid. LB-100 increased mitochondrial motility, but okadaic acid did not. To resolve this discrepancy, we knocked down expression of the catalytic subunit of PP2A (PP2CA). This long-term inhibition of PP2A more than doubled retrograde transport of axonal mitochondria, confirming the importance of PP2A as a regulator of mitochondrial motility and as the likely mediator of cantharidin's effect.
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Affiliation(s)
- Keunjung Heo
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Himanish Basu
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Amos Gutnick
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Wei Wei
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Evgeny Shlevkov
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Thomas L Schwarz
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
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3
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Han S, Kim K, Heo K, Cho K, Kim W, Chu M. Sex Differences In The Association Between Chronotype And Depression: Results From The Seventh Korea National Health And Nutrition Examination Survey, 2016. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Ha W, Kim K, Heo K. A patient with drug-resistant epilepsy who showed seizure freedom after hemorrhage related to radiation-induced cavernous malformation. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.1802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Heo K, Lim SM, Nahm M, Kim YE, Oh KW, Park HT, Ki CS, Kim SH, Lee S. A De Novo RAPGEF2 Variant Identified in a Sporadic Amyotrophic Lateral Sclerosis Patient Impairs Microtubule Stability and Axonal Mitochondria Distribution. Exp Neurobiol 2018; 27:550-563. [PMID: 30636905 PMCID: PMC6318558 DOI: 10.5607/en.2018.27.6.550] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/24/2018] [Accepted: 11/26/2018] [Indexed: 12/23/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is frequently linked to microtubule abnormalities and mitochondrial trafficking defects. Whole exome sequencing (WES) of patient-parent trios has proven to be an efficient strategy for identifying rare de novo genetic variants responsible for sporadic ALS (sALS). Using a trio-WES approach, we identified a de novo RAPGEF2 variant (c.4069G>A, p.E1357K) in a patient with early-onset sALS. To assess the pathogenic effects of this variant, we have used patient-derived skin fibroblasts and motor neuron-specific overexpression of the RAPGEF2-E1357K mutant protein in Drosophila. Patient fibroblasts display reduced microtubule stability and defective microtubule network morphology. The intracellular distribution, ultrastructure, and function of mitochondria are also impaired in patient cells. Overexpression of the RAPGEF2 mutant in Drosophila motor neurons reduces the stability of axonal microtubules and disrupts the distribution of mitochondria to distal axons and neuromuscular junction (NMJ) synapses. We also show that the recruitment of the pro-apoptotic protein BCL2-associated X (BAX) to mitochondria is significantly increased in patient fibroblasts compared with control cells. Finally, increasing microtubule stability through pharmacological inhibition of histone deacetylase 6 (HDAC6) rescues defects in the intracellular distribution of mitochondria and BAX. Overall, our data suggest that the RAPGEF2 variant identified in this study can drive ALS-related pathogenic effects through microtubule dysregulation.
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Affiliation(s)
- Keunjung Heo
- Department of Brain and Cognitive Sciences and Dental Research Institute, Seoul National University, Seoul 08826, Korea
| | - Su Min Lim
- Department of Neurology, College of Medicine, Hanyang University, Seoul 04763, Korea
| | - Minyeop Nahm
- Department of Neurology, College of Medicine, Hanyang University, Seoul 04763, Korea
| | - Young-Eun Kim
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul 04763, Korea
| | - Ki-Wook Oh
- Department of Neurology, College of Medicine, Hanyang University, Seoul 04763, Korea
| | - Hwan Tae Park
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Korea
| | | | - Seung Hyun Kim
- Department of Neurology, College of Medicine, Hanyang University, Seoul 04763, Korea
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences and Dental Research Institute, Seoul National University, Seoul 08826, Korea
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6
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Heo K, Nahm M, Lee MJ, Kim YE, Ki CS, Kim SH, Lee S. The Rap activator Gef26 regulates synaptic growth and neuronal survival via inhibition of BMP signaling. Mol Brain 2017; 10:62. [PMID: 29282074 PMCID: PMC5745669 DOI: 10.1186/s13041-017-0342-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022] Open
Abstract
In Drosophila, precise regulation of BMP signaling is essential for normal synaptic growth at the larval neuromuscular junction (NMJ) and neuronal survival in the adult brain. However, the molecular mechanisms underlying fine-tuning of BMP signaling in neurons remain poorly understood. We show that loss of the Drosophila PDZ guanine nucleotide exchange factor Gef26 significantly increases synaptic growth at the NMJ and enhances BMP signaling in motor neurons. We further show that Gef26 functions upstream of Rap1 in motor neurons to restrain synaptic growth. Synaptic overgrowth in gef26 or rap1 mutants requires BMP signaling, indicating that Gef26 and Rap1 regulate synaptic growth via inhibition of BMP signaling. We also show that Gef26 is involved in the endocytic downregulation of surface expression of the BMP receptors thickveins (Tkv) and wishful thinking (Wit). Finally, we demonstrate that loss of Gef26 also induces progressive brain neurodegeneration through Rap1- and BMP signaling-dependent mechanisms. Taken together, these results suggest that the Gef26-Rap1 signaling pathway regulates both synaptic growth and neuronal survival by controlling BMP signaling.
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Affiliation(s)
- Keunjung Heo
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.,Department of Cell & Developmental Biology, Dental Research Institute, Seoul National University, Seoul, 03080, South Korea
| | - Minyeop Nahm
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, South Korea
| | - Min-Jung Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.,Department of Cell & Developmental Biology, Dental Research Institute, Seoul National University, Seoul, 03080, South Korea
| | - Young-Eun Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea
| | - Chang-Seok Ki
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, South Korea
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.
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7
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Choi Y, Yim S, Cho K, Cho YJ, Heo K, Kim Y. Relationship between sleep disordered breathing and coronary artery calcium in ischemic stroke patients. Sleep Med 2017. [DOI: 10.1016/j.sleep.2017.11.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Park CS, Kim TK, Kim HG, Kim YJ, Jeoung MH, Lee WR, Go NK, Heo K, Lee S. Therapeutic targeting of tetraspanin8 in epithelial ovarian cancer invasion and metastasis. Oncogene 2016; 35:4540-8. [PMID: 26804173 DOI: 10.1038/onc.2015.520] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/27/2015] [Accepted: 11/12/2015] [Indexed: 11/09/2022]
Abstract
Epithelial ovarian cancer (EOC) invasion and metastasis are complex phenomena that result from the coordinated action of many metastatic regulators and must be overcome to improve clinical outcomes for patients with these cancers. The identification of novel therapeutic targets is critical because of the limited success of current treatment regimens, particularly in advanced-stage ovarian cancers. In this study, we found that tetraspanin 8 (TSPAN8) is overexpressed in about 52% (14/27) of EOC tissues and correlates with poor survival. Using small interfering RNA-mediated TSPAN8 knockdown and a competition assay with purified TSPAN8 large extracellular loop (TSPAN8-LEL) protein, we identified TSPAN8-LEL as a key regulator of EOC cell invasion. Furthermore, monotherapy with TSPAN8-blocking antibody we developed shows that antibody-based modulation of TSPAN8-LEL can significantly reduce the incidence of EOC metastasis without severe toxicity in vivo. Finally, we demonstrated that the TSPAN8-blocking antibody promotes the internalization and concomitant downregulation of cell surface TSPAN8. Collectively, our data suggest TSPAN8 as a potential novel therapeutic target in EOCs and antibody targeting of TSPAN8 as an effective strategy for inhibiting invasion and metastasis of TSPAN8-expressing EOCs.
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Affiliation(s)
- C S Park
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - T-K Kim
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - H G Kim
- New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - Y-J Kim
- Specific Organs Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - M H Jeoung
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - W R Lee
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - N K Go
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - K Heo
- New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - S Lee
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
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9
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Cho K, Lee M, Lee B, Cho Y, Heo K. Morphological changes of REM-activating pedunculopontine nucleus in patients with epilepsy of sleep-predominant seizures. Sleep Med 2015. [DOI: 10.1016/j.sleep.2015.02.1400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Son Y, Heo K, Bae MJ, Lee CG, Cho WS, Kim SD, Yang K, Shin IS, Lee MY, Kim JS. Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice. Radiat Prot Dosimetry 2015; 167:316-320. [PMID: 25948832 DOI: 10.1093/rpd/ncv270] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and antisperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h(-1)) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation.
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Affiliation(s)
- Y Son
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - K Heo
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - M J Bae
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - C G Lee
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - W S Cho
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - S D Kim
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - K Yang
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea
| | - I S Shin
- College of Veterinary Medicine, Chonnam National University, Gwangju, South Korea
| | - M Y Lee
- College of Pharmacy, Kyungpook National University, Daegu, South Korea
| | - J S Kim
- Research Center, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), Jwadong-gil 40, Gijang-gun, Busan 619-953, South Korea College of Veterinary Medicine, Chonnam National University, Gwangju, South Korea
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11
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Park SJ, Shim JW, Park HS, Eum DY, Park MT, Mi Yi J, Choi SH, Kim SD, Son TG, Lu W, Kim ND, Yang K, Heo K. MacroH2A1 downregulation enhances the stem-like properties of bladder cancer cells by transactivation of Lin28B. Oncogene 2015; 35:1292-301. [PMID: 26028027 PMCID: PMC4791524 DOI: 10.1038/onc.2015.187] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 04/01/2015] [Accepted: 04/24/2015] [Indexed: 12/18/2022]
Abstract
The histone variant, macroH2A1, has an important role in embryonic stem cell differentiation and tumor progression in various types of tumors. However, the regulatory roles of macroH2A1 on bladder cancer progression have not been fully elucidated. Here, we show that macroH2A1 knockdown promotes stem-like properties of bladder cancer cells. The knockdown of macroH2A1 in bladder cancer cells increased tumorigenicity, radioresistance, degeneration of reactive oxygen species, increased sphere formation capability and an increase in the proportion of side populations. We found that macroH2A1 is required for the suppression of Lin28B identified as a novel downstream target of macroH2A1 in bladder cancer. Loss of macroH2A1 expression significantly correlated with the elevated levels of Lin28B expression and subsequently inhibited the mature let-7 microRNA expression. Furthermore, the stable overexpression of Lin28B enhances the several phenotypes, including tumorigenicity and sphere-forming ability, which are induced by macroH2A1 depletion. Importantly, Lin28B expression was regulated by macroH2A1-mediated reciprocal binding of p300 and EZH2/SUV39H1. Our results suggest that Lin28B/let-7 pathway is tightly regulated by macroH2A1 and its cofactors, and have a pivotal role in the bladder tumor progression and the regulation of stem-like characteristics of bladder cancer cells.
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Affiliation(s)
- S-J Park
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea.,Department of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - J W Shim
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - H S Park
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - D-Y Eum
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - M-T Park
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - J Mi Yi
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - S H Choi
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - S D Kim
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - T G Son
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
| | - W Lu
- The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA, USA
| | - N D Kim
- Department of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - K Yang
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea.,Department of Radiation Oncology, Dongnam Institute of Radiological & Medical Sciences, Busan, Republic of Korea.,Department of Radiation Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - K Heo
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Busan, Republic of Korea
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12
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Kim JM, Heo K, Choi J, Kim K, An W. The histone variant MacroH2A regulates Ca(2+) influx through TRPC3 and TRPC6 channels. Oncogenesis 2013; 2:e77. [PMID: 24165580 PMCID: PMC3816217 DOI: 10.1038/oncsis.2013.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/05/2013] [Accepted: 09/11/2013] [Indexed: 12/11/2022] Open
Abstract
The histone variant macroH2A replaces canonical H2A in the designated region of chromatin where its incorporation has the potential to establish a functionally distinct chromatin domain. The transient receptor potential canonical (TRPC) channels are a family of Ca2+-permeable cationic channels controlling changes in the cytosolic Ca2+ concentration. The proper regulation of Trpc gene expression requires chromatin remodeling, but little is known about the nature of these regulatory processes. Here, we show that macroH2A1 represses two Trpc family genes, Trpc3 and Trpc6, and attenuates Ca2+-dependent proliferative responses in bladder cancer cells. MacroH2A1 recruits histone deacetylase 1 (HDAC1) and HDAC2 to facilitate its persistent action, resulting in a compromise of histone acetylation across the Trpc3 and Trpc6 loci. Further, macroH2A1 depletion augments histone acetylation and Ca2+ influx, leading to increased cell growth and invasion. Our data provide new insights into TRPC3/TRPC6-mediated Ca2+ signaling and indicate a central role for macroH2A1 in regulating transcriptional competence of Trpc3 and Trpc6 genes.
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Affiliation(s)
- J-M Kim
- Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
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13
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Lee EK, Kim JA, Kim JS, Park SJ, Heo K, Yang KM, Son TG. Activation of de novo GSH synthesis pathway in mouse spleen after long term low-dose γ-ray irradiation. Free Radic Res 2012; 47:89-94. [PMID: 23136969 DOI: 10.3109/10715762.2012.747678] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glutathione (GSH) is an important cellular antioxidant and has a critical role in maintaining the balance of cellular redox. In this study, we investigated the GSH biosynthesis genes involved in the elevation of endogenous GSH levels using an irradiation system with an irradiation dose rate of 1.78 mGy/h, which was about 40,000 times less than the dose rates used in other studies. The results showed that GSH levels were significantly increased in the low-dose (0.02 and 0.2 Gy) irradiated group compared to those in the non-irradiated group, but enzymatic antioxidants such as superoxide dismutase and catalase were not induced at any doses tested. The elevation in GSH was accompanied by elevated expression of glutamate-cysteine ligase modifier subunit, but no changes were observed in the expression of glutamate-cysteine ligase catalytic subunit and thioredoxin in de novo GSH synthesis. In the case of genes involved in the GSH regeneration cycle, the expression of glutathione reductase was not changed after irradiation, whereas glutathione peroxidase was only increased in the 0.2 Gy irradiated group. Collectively, our results suggest that the de novo pathway, rather than the regeneration cycle, may be mainly switched on in response to stimulation with long-term low-dose radiation in the spleen.
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Affiliation(s)
- E K Lee
- Research Center, Dongnam Institute of Radiological and Medical Science , 40 Jwadong-gil, Jangan-eup, Gijang-gun, Busan, Republic of Korea
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14
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Cho Y, Lee B, Yoo J, Heo K. PO18-WE-22 Reflex epilepsies induced by playing “Go-stop” (Korean card game) or “Baduk” (Go game in Korean). J Neurol Sci 2009. [DOI: 10.1016/s0022-510x(09)70951-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Abstract
Porous materials are potential candidates for applications in various fields, such as bionanotechnology, gas separation, catalysts and micro-electronics. In particular, their applications in bionanotechnology include biosensors, biomedical implants and microdevices, biosupporters, bio-encapsules, biomolecule separations and biomedical therapy. All these bionanotechnology applications utilise the shape, size and size distribution of pores in porous materials. Therefore the controlled creation of pores with desired shape, size and size distribution is most important in the development of nanoporous materials. Accordingly, the accurate evaluation of pore structure is necessary in the development of nanoporous materials and their applications. This article reviews recent developments in analytical techniques to characterise the pore structures of nanoporous materials.
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Affiliation(s)
- K Heo
- National Research Laboratory for Polymer Synthesis & Physics, Department of Chemistry, Center for Integrated Molecular Systems, Polymer Research Institute, Pohang University of Science and Technology (Postech), Pohang 790-784, Republic of Korea
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Park SA, Lim SR, Kim GS, Heo K, Park SC, Chang JW, Chung SS, Choi JU, Kim TS, Lee BI. Ictal electrocorticographic findings related with surgical outcomes in nonlesional neocortical epilepsy. Epilepsy Res 2002; 48:199-206. [PMID: 11904238 DOI: 10.1016/s0920-1211(02)00006-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE To characterize ictal electrocorticographic features related to surgical outcomes in nonlesional neocortical epilepsy (NE). METHODS We analyzed 187 ictal electrocorticograms (ECoG) obtained from 18 patients who had undergone presurgical evaluation and subsequent neocortical resections (frontal: seven, parietal: one, occipital: four, multilobar: six). None of them had any MRI-detectable lesions. Various ECoG data sets recorded from eight patients who achieved a favorable surgical outcome (either seizure free or more than 90% reduction of seizure frequencies) were compared with that from ten patients with unfavorable outcome (less than 90% reduction of seizure frequencies) (follow up duration: 47+/-11 months). RESULTS Reproducible ictal onset zone (IOZ) in recurrent seizures (P=0.013) and persistent ictal discharges in IOZ from the onset to the end of seizure (P=0.004) were found more frequently in the patients with good outcome. Ictal onset patterns consisting of low voltage fast or high amplitude beta spikes predicted a good surgical outcome while rhythmic sinusoidal activity or rhythmic spike/sharp waves of slow frequency were predictive of poor outcome (P=0.01). The ictal onset rhythm consisting of gamma or beta frequencies was more prevalent in the favorable group (P=0.015). CONCLUSIONS The presence of stable ictal circuit suggested by the consistent earliest activation of specific electrodes in the repetitive seizures (reproducible IOZ) and the active participation of IOZ throughout the attack were valuable prognostic factors in addition to the morphology and frequency of ictal onset rhythm.
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Affiliation(s)
- S A Park
- Department of Neurology, Yonsei University College of Medicine, Severance Hospital, CPO Box 8044, Seoul, South Korea
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Abstract
Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.
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Affiliation(s)
- S W Seo
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
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18
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Abstract
PURPOSE To describe the possible mechanism of ictal automatisms with preserved responsiveness (APRs) in a patient with left mesial temporal lobe epilepsy, which had not been reported previously. METHODS Ictal EEGs recorded from bilateral foramen ovale electrodes with scalp-sphenoidal electrodes were analyzed in respect to the ictal semiology. RESULTS The patient had a right hemispheric language dominance in the dextral. Electroclinical analysis revealed that the onset of oroalimentary automatisms coincided with the involvement of the left mesial and lateral temporal structures by spreading ictal discharges. The ictal discharge spreading was limited to the ipsilateral hemisphere throughout the seizure, which explained the intact consciousness and preserved responsiveness of the patient. CONCLUSIONS This case suggests that APRs take place in seizures originating from the nondominant temporal lobe, during which ipsilateral mesial and lateral temporal structures are diffusely involved without spreading to the contralateral side.
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Affiliation(s)
- S A Park
- Departments of Neurology, Yonsei University College of Medicine, Seoul, Korea
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19
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Heo K, Lin X, Odle J, Han IK. Kinetics of carnitine palmitoyltransferase-I are altered by dietary variables and suggest a metabolic need for supplemental carnitine in young pigs. J Nutr 2000; 130:2467-70. [PMID: 11015474 DOI: 10.1093/jn/130.10.2467] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To examine the kinetics of carnitine palmitoyltransferase-I (CPT-I) and the influence of dietary variables, young pigs (18 kg, n = 20) were fed corn-soybean meal diets supplemented with 40 g soy oil/kg and containing either 136 or 180 g crude protein/kg and either 0 or 500 mg/kg L-carnitine (2 x 2 factorial design). Diets were offered for 10 d (85% of ad libitum); CPT-I activities in liver and skeletal muscle mitochondria were determined, and enzyme kinetic constants (V:(max) and K:(m) for carnitine) were estimated. Kinetics of CPT-I in muscle were not affected by diet (P: > 0.1; carnitine K:(m) = 480 +/- 44 micromol/L). In contrast, the K:(m) for carnitine in liver was increased from 164 to 216 +/- 20 micromol/L by dietary L-carnitine supplementation (P: < 0.01) and from 169 to 211 +/- 20 micromol/L by high protein feeding (P: < 0.05). Dietary L-carnitine increased muscle and liver free carnitine concentrations by 72 and 158% over control concentrations (770 and 80 micro;mol/kg wet muscle and liver, respectively). Because tissue carnitine concentrations were within the range of the respective K:(m) for both liver and muscle tissue, it is inferred that alteration of tissue carnitine concentrations via dietary supplementation could modulate CPT-I activity in young pigs.
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Affiliation(s)
- K Heo
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695-7621, USA
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20
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Heo K, Odle J, Han IK, Cho W, Seo S, van Heugten E, Pilkington DH. Dietary L-carnitine improves nitrogen utilization in growing pigs fed low energy, fat-containing diets. J Nutr 2000; 130:1809-14. [PMID: 10867055 DOI: 10.1093/jn/130.7.1809] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Growing pigs (n = 25; 17.8 +/- 0.1 kg) were used to study the effects of L-carnitine and protein intake on nitrogen (N) balance and body composition. Fat-supplemented (40 g soy oil/kg diet), corn-soybean meal basal diets containing low or high protein (136 or 180 g/diet) were formulated so that protein accretion would be limited by metabolizable energy (ME). Each basal diet was supplemented with 0 or 500 mg/kg L-carnitine and fed to pigs for 10 d in a nutrient balance trial. Final body composition was compared with weight and age-matched pigs measured on d 0 to calculate nutrient accretion rates. High protein feeding increased (P < 0.01) average daily gain (ADG) by 34%, as well as nitrogen digestibility (4.4%), retention (5.2%), urinary excretion (29%) and crude protein (CP) accretion (33%). Total-body carnitine accretion rate was 4.5 fold greater and total body carnitine concentration was almost 100% greater than in unsupplemented controls (P < 0.01). Irrespective of protein level, carnitine increased ADG (by 7.3%, P < 0.10) and CP accretion rate (9%, P < 0.10). Congruently, carnitine supplementation improved the efficiency of nitrogen retention (P < 0. 05) and reduced urinary nitrogen excretion (14%, P < 0.10). Carcass fat content also was reduced in carnitine-supplemented pigs (P < 0. 10). Collectively, these data support the hypothesis that carnitine can improve the efficiency of nitrogen utilization in 20-kg pigs fed energy-limited, fat-containing diets. We conclude that endogenous carnitine biosynthesis may be adequate to maintain sufficient tissue levels during growth, but that supplemental dietary carnitine (at 500 mg/kg) may be retained sufficiently so as to alter nutrient partitioning and thus body composition of 20-kg pigs.
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Affiliation(s)
- K Heo
- Departments of Animal Science, North Carolina State University, Raleigh, NC 27695-7621, USA
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21
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Hwang JI, Heo K, Shin KJ, Kim E, Yun C, Ryu SH, Shin HS, Suh PG. Regulation of phospholipase C-beta 3 activity by Na+/H+ exchanger regulatory factor 2. J Biol Chem 2000; 275:16632-7. [PMID: 10748023 DOI: 10.1074/jbc.m001410200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Among the phospholipase C that catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate, four mammalian phospholipase C-beta (PLC-beta) isotypes (isotypes 1-4) are activated through G protein-coupled receptors (GPCRs). Although the regulation of the PLC-betas by GPCRs and heterotrimeric G proteins has been extensively studied, little is known about the molecular determinants that regulate their activity. The PLC-beta isozymes carry a putative PSD-95/Dlg/ZO-1 (PDZ) binding motif (X(S/T)X(V/L)COOH) at their carboxyl terminus, which is implicated in specific interactions with anchor proteins. Using the yeast two-hybrid system, we identified Na(+)/H(+) exchanger regulatory factor 2 (NHERF2) as a protein that interacted with a C-terminal heptapeptide of PLC-beta3. Immunoprecipitation studies revealed that NHERF2 interacts specifically with PLC-beta3, but not with other PLC-beta isotypes. Furthermore, PLC-beta3 interacted with NHERF2 rather than with other PDZ-containing proteins. This interaction required the COOH-terminal NTQL sequence of PLC-beta3 and the second PDZ domain of NHERF2. Interestingly, NHERF2 potentiated the PLC-beta activation by carbachol in COS7 and HeLa cells, while mutant NHERF2, lacking the second PDZ domain, had no such effect. Taken together, the data suggest that NHERF2 may act as a modulator underlying the process of PLC-beta3-mediated signaling.
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Affiliation(s)
- J I Hwang
- Department of Life Science, National Creative Research Initiative Center for Calcium and Learning, Division of Molecular and Life Science and School of Environmental Engineering, Pohang University of Science and Technology, Pohang 790-784, South Korea
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Abstract
The change in neuronal nitric oxide synthase (nNOS) expression after status epilepticus induced by kainate was examined in the rat cerebral cortex. Expressional change was assessed using nNOS immunohistochemistry and reverse transcription-polymerase chain reaction for nNOS mRNA. Constitutive nNOS-positive neurons was observed in the cerebral cortex of the control group. At 1 and 3 days after status epilepticus, nNOS-positive neurons were present in a deep layer of various cortical regions such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, parietal association cortex, insular cortex, ectorhinal cortex, temporal association cortex, auditory cortex and visual cortex. The level of nNOS mRNA increased at 1, 3, 6 and 12 days after status epilepticus compared to controls. This report provides the first morphological evidence that nNOS are induced in neurons of the cerebral cortex following seizure.
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Affiliation(s)
- Y Huh
- Department of Anatomy, College of Medicine, Kyunghee University, Hoeki-Dong 1, Dongdaemun-Gu, Seoul, South Korea.
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Abstract
This study was designed to investigate the effect of endothelin-1 (ET-1) on clonidine-induced cardiovascular effects in urethane-anesthetized rabbits and to clarify the mechanism of its action. Clonidine (5, 10, and 20 micrograms/kg) given into a femoral vein (i.v.) produced a marked dose-dependent fall in arterial blood pressure and heart rate, but intracerebroventricular (i.c.v.) clonidine (2, 4, and 8 micrograms/kg) induced a slight depressor effect and bradycardia. Intravenous clonidine-induced hypotension was significantly enhanced by pretreatment with ET-1 or sarafotoxin, but the bradycardia was not affected. Intracerebroventricular clonidine-induced depressor responses were greatly inhibited by sarafotoxin pretreatment but not by ET-1. Both i.v. and i.c.v. ET-1 and sarafotoxin elicited marked hypotensive responses, with a slight decrease in heart rate. The depressor action evoked by i.v. ET-1 and sarafotoxin was significantly inhibited by nitroprusside but not by phentolamine or sodium acetylsalicylate. Furthermore, the weak bradycardia induced by ET-1 or sarafotoxin was not influenced by pretreatment with phentolamine, nitroprusside, or sodium acetylsalicylate. Taken together, these experimental data suggest that ET-1 potentiates clonidine-induced hypotensive responses in the urethane-anesthetized rabbit through facilitation of nitric oxide release, which appears to be associated with endothelin receptors.
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Affiliation(s)
- D Y Lim
- Department of Pharmacology, College of Medicine, Chosun University, Kwangju, Korea
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Heo K, Kim SJ, Kim JH, Kim OK, Cho HK. False lateralization of seizure perceived by a patient with infarction of the right parietal lobe who showed the neglect syndrome. Epilepsia 1997; 38:122-3. [PMID: 9024194 DOI: 10.1111/j.1528-1157.1997.tb01087.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A 66-year-old right-handed man developed seizures characterized by an electric sensation and convulsive movements involving the left arm, which sometimes secondarily generalized. The patient, however, reported that the seizures occurred in his right arm. Neurological examination showed many features of left hemineglect, including allesthesia, secondary to acute infarction of the right parietal lobe. Although allesthetic response was not documented during the seizure, it is likely that sensory symptoms of the seizures were localized inappropriately or that he had false memory for lateralization of seizures. In this case, the neglect syndrome caused by infarction of the right parietal lobe extended to symptoms of the seizure itself.
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Affiliation(s)
- K Heo
- Department of Neurology, Pusan-Paik Hospital, Inje University College of Medicine, Pusan, Korea
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