1
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Wang W, Li X, Ding X, Xiong S, Hu Z, Lu X, Zhang K, Zhang H, Hu Q, Lai KS, Chen Z, Yang J, Song H, Wang Y, Wei L, Xia Z, Zhou B, He Y, Pu J, Liu X, Ke R, Wu T, Huang C, Baldini A, Zhang M, Zhang Z. Lymphatic endothelial transcription factor Tbx1 promotes an immunosuppressive microenvironment to facilitate post-myocardial infarction repair. Immunity 2023; 56:2342-2357.e10. [PMID: 37625409 DOI: 10.1016/j.immuni.2023.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/14/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023]
Abstract
The heart is an autoimmune-prone organ. It is crucial for the heart to keep injury-induced autoimmunity in check to avoid autoimmune-mediated inflammatory disease. However, little is known about how injury-induced autoimmunity is constrained in hearts. Here, we reveal an unknown intramyocardial immunosuppressive program driven by Tbx1, a DiGeorge syndrome disease gene that encodes a T-box transcription factor (TF). We found induced profound lymphangiogenic and immunomodulatory gene expression changes in lymphatic endothelial cells (LECs) after myocardial infarction (MI). The activated LECs penetrated the infarcted area and functioned as intramyocardial immune hubs to increase the numbers of tolerogenic dendritic cells (tDCs) and regulatory T (Treg) cells through the chemokine Ccl21 and integrin Icam1, thereby inhibiting the expansion of autoreactive CD8+ T cells and promoting reparative macrophage expansion to facilitate post-MI repair. Mimicking its timing and implementation may be an additional approach to treating autoimmunity-mediated cardiac diseases.
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Affiliation(s)
- Wenfeng Wang
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Xiao Li
- Gene Editing Laboratory, The Texas Heart Institute, Houston, TX 77030, USA
| | - Xiaoning Ding
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Shanshan Xiong
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Zhenlei Hu
- Department of Cardiovascular Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Xuan Lu
- Silver Snake (Shanghai) Medical Science and Technique Co., Ltd., Shanghai 200030, China
| | - Kan Zhang
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Heng Zhang
- Shanghai Institute of Immunology and Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Qianwen Hu
- Shanghai Institute of Immunology and Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Kaa Seng Lai
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Zhongxiang Chen
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Junjie Yang
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Hejie Song
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Ye Wang
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Lu Wei
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Zeyang Xia
- Department of Neurosurgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Bin Zhou
- The State Key Laboratory of Cell Biology, CAS Center for Excellence on Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yulong He
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China
| | - Jun Pu
- State Key Laboratory for Oncogenes and Related Genes, Division of Cardiology, Renji Hospital, School of Medicine, Shanghai Cancer Institute, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Xiao Liu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Rongqin Ke
- School of Medicine and School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian 362021, China
| | - Tao Wu
- Shanghai Collaborative Innovative Center of Intelligent Medical Device and Active Health, Shanghai University of Medicine & Health Sciences, Shanghai 201318, China
| | - Chuanxin Huang
- Shanghai Institute of Immunology and Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Antonio Baldini
- Institute of Genetics and Biophysics "ABT," CNR, Naples 80131, Italy; Department of Molecular Medicine and Medical Biotechnologies, University of Naples, Federico II, Naples 80131, Italy
| | - Min Zhang
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.
| | - Zhen Zhang
- Pediatric Translational Medicine Institute and Pediatric Congenital Heart Disease Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; Shanghai Collaborative Innovative Center of Intelligent Medical Device and Active Health, Shanghai University of Medicine & Health Sciences, Shanghai 201318, China.
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2
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Peng X, Lai KS, She P, Kang J, Wang T, Li G, Zhou Y, Sun J, Jin D, Xu X, Liao L, Liu J, Lee E, Poss KD, Zhong TP. Corrigendum to ‘Induction of Wnt signaling antagonists and p21-activated kinase enhances cardiomyocyte proliferation during zebrafish heart regeneration’. J Mol Cell Biol 2022; 13:921. [PMID: 35092682 PMCID: PMC8800510 DOI: 10.1093/jmcb/mjab064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xiangwen Peng
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China
| | - Kaa Seng Lai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China
| | - Peilu She
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Junsu Kang
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tingting Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Guobao Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China
| | - Yating Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Jianjian Sun
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Daqing Jin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Lujian Liao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Jiandong Liu
- Department of Pathology and Laboratory Medicine, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ethan Lee
- Department of Developmental and Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kenneth D Poss
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tao P Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
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3
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Xie S, Fu W, Yu G, Hu X, Lai KS, Peng X, Zhou Y, Zhu X, Christov P, Sawyer L, Ni TT, Sulikowski GA, Yang Z, Lee E, Zeng C, Wang WE, Zhong TP. Discovering small molecules as Wnt inhibitors that promote heart regeneration and injury repair. J Mol Cell Biol 2021; 12:42-54. [PMID: 30925593 PMCID: PMC7259332 DOI: 10.1093/jmcb/mjz023] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [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: 06/15/2018] [Revised: 12/11/2018] [Accepted: 03/03/2019] [Indexed: 12/30/2022] Open
Abstract
There are intense interests in discovering proregenerative medicine leads that can promote cardiac differentiation and regeneration, as well as repair damaged heart tissues. We have combined zebrafish embryo-based screens with cardiomyogenesis assays to discover selective small molecules that modulate heart development and regeneration with minimal adverse effects. Two related compounds with novel structures, named as Cardiomogen 1 and 2 (CDMG1 and CDMG2), were identified for their capacity to promote myocardial hyperplasia through expansion of the cardiac progenitor cell population. We find that Cardiomogen acts as a Wnt inhibitor by targeting β-catenin and reducing Tcf/Lef-mediated transcription in cultured cells. CDMG treatment of amputated zebrafish hearts reduces nuclear β-catenin in injured heart tissue, increases cardiomyocyte (CM) proliferation, and expedites wound healing, thus accelerating cardiac muscle regeneration. Importantly, Cardiomogen can alleviate the functional deterioration of mammalian hearts after myocardial infarction. Injured hearts exposed to CDMG1 display increased newly formed CMs and reduced fibrotic scar tissue, which are in part attributable to the β-catenin reduction. Our findings indicate Cardiomogen as a Wnt inhibitor in enhancing injury-induced CM proliferation and heart regeneration, highlighting the values of embryo-based small molecule screens in discovery of effective and safe medicine leads.
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Affiliation(s)
- Shuying Xie
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Wenbin Fu
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Guangju Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Xueli Hu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Kaa Seng Lai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Xiangwen Peng
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Yating Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Xuejiao Zhu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Plamen Christov
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Leah Sawyer
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Terri T Ni
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Gary A Sulikowski
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Zhongzhou Yang
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Wei E Wang
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Tao P Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
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4
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She P, Zhang H, Peng X, Sun J, Gao B, Zhou Y, Zhu X, Hu X, Lai KS, Wong J, Zhou B, Wang L, Zhong TP. The Gridlock transcriptional repressor impedes vertebrate heart regeneration by restricting expression of lysine methyltransferase. Development 2020; 147:147/18/dev190678. [PMID: 32988975 PMCID: PMC7541343 DOI: 10.1242/dev.190678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 08/03/2020] [Indexed: 12/19/2022]
Abstract
Teleost zebrafish and neonatal mammalian hearts exhibit the remarkable capacity to regenerate through dedifferentiation and proliferation of pre-existing cardiomyocytes (CMs). Although many mitogenic signals that stimulate zebrafish heart regeneration have been identified, transcriptional programs that restrain injury-induced CM renewal are incompletely understood. Here, we report that mutations in gridlock (grl; also known as hey2), encoding a Hairy-related basic helix-loop-helix transcriptional repressor, enhance CM proliferation and reduce fibrosis following damage. In contrast, myocardial grl induction blunts CM dedifferentiation and regenerative responses to heart injury. RNA sequencing analyses uncover Smyd2 lysine methyltransferase (KMT) as a key transcriptional target repressed by Grl. Reduction in Grl protein levels triggered by injury induces smyd2 expression at the wound myocardium, enhancing CM proliferation. We show that Smyd2 functions as a methyltransferase and modulates the Stat3 methylation and phosphorylation activity. Inhibition of the KMT activity of Smyd2 reduces phosphorylated Stat3 at cardiac wounds, suppressing the elevated CM proliferation in injured grl mutant hearts. Our findings establish an injury-specific transcriptional repression program in governing CM renewal during heart regeneration, providing a potential strategy whereby silencing Grl repression at local regions might empower regeneration capacity to the injured mammalian heart. Highlighted Article: Novel mechanisms of the Grl-Smyd2 network govern vertebrate CM renewal and heart regeneration, which might be relevant in developing strategies for regeneration interventions in humans.
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Affiliation(s)
- Peilu She
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Huifang Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Xiangwen Peng
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Jianjian Sun
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Bangjun Gao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yating Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Xuejiao Zhu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Xueli Hu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Kaa Seng Lai
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Jiemin Wong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Bin Zhou
- Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Linhui Wang
- Department of Urology, Shanghai Changzheng Hospital, Shanghai, 200003, China
| | - Tao P Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, 200241, China
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5
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Peng X, Lai KS, She P, Kang J, Wang T, Li G, Zhou Y, Sun J, Jin D, Xu X, Liao L, Liu J, Lee E, Poss KD, Zhong TP. Induction of Wnt signaling antagonists and p21-activated kinase enhances cardiomyocyte proliferation during zebrafish heart regeneration. J Mol Cell Biol 2020; 13:41-58. [PMID: 33582796 PMCID: PMC8035995 DOI: 10.1093/jmcb/mjaa046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 03/15/2020] [Revised: 08/14/2020] [Accepted: 08/16/2020] [Indexed: 12/13/2022] Open
Abstract
Heart regeneration occurs by dedifferentiation and proliferation of pre-existing cardiomyocytes (CMs). However, the signaling mechanisms by which injury induces CM renewal remain incompletely understood. Here, we find that cardiac injury in zebrafish induces expression of the secreted Wnt inhibitors, including Dickkopf 1 (Dkk1), Dkk3, secreted Frizzled-related protein 1 (sFrp1), and sFrp2, in cardiac tissue adjacent to injury sites. Experimental blocking of Wnt activity via Dkk1 overexpression enhances CM proliferation and heart regeneration, whereas ectopic activation of Wnt8 signaling blunts injury-induced CM dedifferentiation and proliferation. Although Wnt signaling is dampened upon injury, the cytoplasmic β-catenin is unexpectedly increased at disarrayed CM sarcomeres in myocardial wound edges. Our analyses indicated that p21-activated kinase 2 (Pak2) is induced at regenerating CMs, where it phosphorylates cytoplasmic β-catenin at Ser 675 and increases its stability at disassembled sarcomeres. Myocardial-specific induction of the phospho-mimetic β-catenin (S675E) enhances CM dedifferentiation and sarcomere disassembly in response to injury. Conversely, inactivation of Pak2 kinase activity reduces the Ser 675-phosphorylated β-catenin (pS675-β-catenin) and attenuates CM sarcomere disorganization and dedifferentiation. Taken together, these findings demonstrate that coordination of Wnt signaling inhibition and Pak2/pS675-β-catenin signaling enhances zebrafish heart regeneration by supporting CM dedifferentiation and proliferation.
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Affiliation(s)
- Xiangwen Peng
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Kaa Seng Lai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Peilu She
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Junsu Kang
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tingting Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Guobao Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai 200438, China
| | - Yating Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Jianjian Sun
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Daqing Jin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Lujian Liao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
| | - Jiandong Liu
- Department of Pathology and Laboratory Medicine, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ethan Lee
- Department of Developmental and Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kenneth D Poss
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tao P Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai 200241, China
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6
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Fang Y, Lai KS, She P, Sun J, Tao W, Zhong TP. Tbx20 Induction Promotes Zebrafish Heart Regeneration by Inducing Cardiomyocyte Dedifferentiation and Endocardial Expansion. Front Cell Dev Biol 2020; 8:738. [PMID: 32850848 PMCID: PMC7417483 DOI: 10.3389/fcell.2020.00738] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 04/17/2020] [Accepted: 07/16/2020] [Indexed: 12/17/2022] Open
Abstract
Heart regeneration requires replenishment of lost cardiomyocytes (CMs) and cells of the endocardial lining. However, the signaling regulation and transcriptional control of myocardial dedifferentiation and endocardial activation are incompletely understood during cardiac regeneration. Here, we report that T-Box Transcription Factor 20 (Tbx20) is induced rapidly in the myocardial wound edge in response to various sources of cardiac damages in zebrafish. Inducing Tbx20 specifically in the adult myocardium promotes injury-induced CM proliferation through CM dedifferentiation, leading to loss of CM cellular contacts and re-expression of cardiac embryonic or fetal gene programs. Unexpectedly, we identify that myocardial Tbx20 induction activates the endocardium at the injury site with enhanced endocardial cell extension and proliferation, where it induces the endocardial Bone morphogenetic protein 6 (Bmp6) signaling. Pharmacologically inactivating endocardial Bmp6 signaling reduces expression of its targets, Id1 and Id2b, attenuating the increased endocardial regeneration in tbx20-overexpressing hearts. Altogether, our study demonstrates that Tbx20 induction promotes adult heart regeneration by inducing cardiomyocyte dedifferentiation as well as non-cell-autonomously enhancing endocardial cell regeneration.
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Affiliation(s)
- Yabo Fang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| | - Kaa Seng Lai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| | - Peilu She
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| | - Jianjian Sun
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| | - Wufan Tao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Tao P Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
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7
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Phua PB, Tan BS, Wu RF, Lai KS, Chia L, Lau E. High-average-power mid-infrared ZnGeP2 optical parametric oscillator with a wavelength-dependent polarization rotator. Opt Lett 2006; 31:489-91. [PMID: 16496896 DOI: 10.1364/ol.31.000489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A wavelength-dependent polarization rotator is used to transform the orthogonal polarizations of the signal and idler of a near-degenerate type II KTP optical parametric oscillator (OPO) into a common polarization state. This common polarization allows a single ZnGeP2 OPO to fully utilize the 2 microm signal and idler KTP OPO outputs in a mid-IR conversion. The simple design of the wavelength-dependent polarization rotator yields a compact source that simultaneously generates four mid-JR wavelengths collinearly with a total mid-IR average power of 5.5 W at a >15 kHz pulse repetition rate.
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Affiliation(s)
- P B Phua
- DSO National Laboratories, 20, Science Park Drive, S118230 Singapore.
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8
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Wu RF, Lai KS, Wong H, Xie WJ, Lim Y, Lau E. Multiwatt mid-IR output from a Nd:YALO laser pumped intracavity KTA OPO. Opt Express 2001; 8:694-698. [PMID: 19421260 DOI: 10.1364/oe.8.000694] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have achieved 4.1W of 3.5-micron output from a non-critically phasematched (NCPM), type II, KTiOAsO4 (KTA) optical parametric oscillator (OPO) pumped within the cavity of a Q-switched diode-pumped Nd: YALO laser operating at 10kHz. We adopted the simplest configuration with a compact diode-pumped Nd: YALO module pumping the singly resonant KTA OPO. Besides 4.1W of 3.5um, 10.9W of 1.5 micron and 11.3W of 1-micron radiation were obtained simultaneously.
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9
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Abstract
We present a 120-W cw diode-pumped Tm:YAG laser. The Tm:YAG rod is side pumped by three diode arrays whose radiation is coupled through compound parabolic concentrators. The maximum optical-to-optical conversion efficiency of the 2.02-mum laser output is 25.2%, with a slope efficiency of 31.2%.
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Affiliation(s)
- K S Lai
- DSO National Laboratories, 20, Science Park Drive, S118230, Singapore
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10
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Wu RF, Phua PB, Lai KS, Lim YL, Lau E, Chng A, Bonnin C, Lupinski D. Compact 21-W 2-mum intracavity optical parametric oscillator. Opt Lett 2000; 25:1460-1462. [PMID: 18066248 DOI: 10.1364/ol.25.001460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report on an intracavity optical parametric oscillator (OPO) placed within a compact diode-pumped Nd:YALO laser cavity. This OPO utilizes a pair of KTP crystals, which are diffusion bonded together in a walk-off-compensated configuration. We have generated up to 21.4 W of 2-mum radiation, operating in a few-kilohertz range.
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11
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Phua PB, Lai KS, Wu R. Multiwatt High-Repetition-Rate 2-microm Output from an Intracavity KTiOPO(4) Optical Parametric Oscillator. Appl Opt 2000; 39:1435-1439. [PMID: 18338029 DOI: 10.1364/ao.39.001435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have obtained 6.5 W of 2-mum output from a near-degenerate, type II KTiOPO(4) (KTP) optical parametric oscillator (OPO) pumped within the cavity of a Q-switched diode-pumped Nd:YAG laser that operates at 3 kHz. We adopted the simplest configuration with a compact diode-pumped Nd:YAG module pumping the doubly resonant KTP OPO in its randomly polarized resonator with an acousto-optic Q switch. Attempts to increase the 2-mum output power by pumping this intracavity KTP OPO with a polarized laser beam by use of thermal birefringence compensation configurations are discussed.
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12
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Abstract
We demonstrate a compact cw diode-pumped Nd:YAlO laser that can produce 100 W of power at 1079 nm and 18.3 W at 1341 nm. Lasing and nonlasing thermal lensing data are presented.
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Affiliation(s)
- R Wu
- DSO National Laboratories, 20 Science Park Drive, S118230 Singapore, Singapore.
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13
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Phua PB, Lai KS, Wu RF, Chong TC. High-efficiency mid-infrared ZnGeP2 optical parametric oscillator in a multimode-pumped tandem optical parametric oscillator. Appl Opt 1999; 38:563-565. [PMID: 18305647 DOI: 10.1364/ao.38.000563] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate a high-efficiency ZnGeP(2) optical parametric oscillator (OPO) pumped by another KTP OPO in a multimode-pumped tandem OPO configuration. The maximum optical-to-optical and slope efficiencies were 32% and 42.5%, respectively. Our setup also provides tunable multiband radiation in the 2.03-2.32-microm range and the 2.9-6.2-microm range simultaneously.
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Affiliation(s)
- P B Phua
- DSO National Laboratories, 20 Science Park Drive, Singapore.
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14
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Maccabee PJ, Nagarajan SS, Amassian VE, Durand DM, Szabo AZ, Ahad AB, Cracco RQ, Lai KS, Eberle LP. Influence of pulse sequence, polarity and amplitude on magnetic stimulation of human and porcine peripheral nerve. J Physiol 1998; 513 ( Pt 2):571-85. [PMID: 9807005 PMCID: PMC2231292 DOI: 10.1111/j.1469-7793.1998.571bb.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/1997] [Accepted: 08/13/1998] [Indexed: 10/26/2022] Open
Abstract
1. Mammalian phrenic nerve, in a trough filled with saline, was excited by magnetic coil (MC)-induced stimuli at defined stimulation sites, including the negative-going first spatial derivative of the induced electric field along a straight nerve, at a bend in the nerve, and at a cut nerve ending. At all such sites, the largest amplitude response for a given stimulator output setting was elicited by an induced damped polyphasic pulse consisting of an initial quarter-cycle hyperpolarization followed by a half-cycle depolarization compared with a predominantly 'monophasic' quarter-cycle depolarization. 2. Simulation studies demonstrated that the increased efficacy of the induced quarter-cycle hyperpolarizing-half-cycle depolarizing polyphasic pulse was mainly attributed to the greater duration of the outward membrane current phase, resulting in a greater outward charge transfer afforded by the half-cycle (i.e. quarter-cycles 2 and 3). The advantage of a fast rising initial quarter-cycle depolarization was more than offset by the slower rising, but longer duration depolarizing half-cycle. 3. Simulation further revealed that the quarter-cycle hyperpolarization-half-cycle depolarization showed only a 2.6 % lowering of peak outward current and a 3.5 % lowering of outward charge transfer at threshold, compared with a half-cycle depolarization alone. Presumably, this slight increase in efficacy reflects modest reversal of Na+ inactivation by the very brief initial hyperpolarization. 4. In vitro, at low bath temperature, the nerve response to an initial quarter-cycle depolarization declined in amplitude as the second hyperpolarizing phase progressively increased in amplitude and duration. This 'pull-down' phenomenon nearly disappeared as the bath temperature approached 37 C. Possibly, at the reduced temperature, delay in generation of the action potential permitted the hyperpolarization phase to reduce excitation. 5. Pull-down was not observed in the thenar muscle responses to median nerve stimulation in a normal human at normal temperature. However, pull-down emerged when the median nerve was cooled by placing ice over the forearm. 6. In a nerve at subnormal temperature straddled with non-conducting inhomogeneities, polyphasic pulses of either polarity elicited the largest responses. This was also seen when stimulating distal median nerve at normal temperature. These results imply excitation by hyperpolarizing-depolarizing pulse sequences at two separate sites. Similarly, polyphasic pulses elicited the largest responses from nerve roots and motor cortex. 7. The pull-down phenomenon has a possible clinical application in detecting pathologically slowed activation of Na+ channels. The current direction of the polyphasic waveform may become a significant factor with the increasing use of repetitive magnetic stimulators which, for technical reasons, induce a cosine-shaped half-cycle, preceded and followed by quarter-cycles of opposite polarity.
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Affiliation(s)
- P J Maccabee
- Departments of Neurology and Physiology, State University of New York, Health Science Centre at Brooklyn, 450 Clarkson Avenue, Brooklyn, NY 11203-2098,
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15
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Phua PB, Lai KS, Wu RF, Chong TC. Coupled tandem optical parametric oscillator (OPO): an OPO within an OPO. Opt Lett 1998; 23:1262-1264. [PMID: 18087492 DOI: 10.1364/ol.23.001262] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have demonstrated, for the first time to our knowledge, a coupled tandem optical parametric oscillator (OPO) configuration in which a second ZnGeP(2) OPO is placed within the resonator of the first, KTiOPO(4), OPO. A significant enhancement in the overall cascaded efficiency of this OPO compared with standard two-stage OPO's was observed. With a multimode Nd:YAG laser, an overall optical-to-optical efficiency (from 1.06 microm to the mid IR) of 5.2% was obtained from operating only ~1.4 times above oscillation threshold. The measured overall slope efficiency was attractively high at 35%. With a single set of mirrors we obtained a broad wavelength-tuning range from 2.7 to 8 microm.
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Zhou Y, Chin MK, Lai KS, Wong CC. Low-loss measurement in partially buried opticalwaveguideson glass with a plastic prism. Appl Opt 1997; 36:5089-5090. [PMID: 18259320 DOI: 10.1364/ao.36.005089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Surface and buried planar waveguides have been fabricated in glass microscope slides with purely thermal potassium and sodium ion-exchange techniques. We measured propagation loss as low as 0.08 dB/cm in the partially buried waveguides using an improved two-prism coupling method. The method includes a plastic prism and involves applying heat to soften the base of the outcoupling plastic prism so that the prism is temporarily in extremely close contact with the waveguide surface.
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Hoffman SM, Lai KS, Tomfohrde J, Bowcock A, Gordon LA, Mohrenweiser HW. JAK3 maps to human chromosome 19p12 within a cluster of proto-oncogenes and transcription factors. Genomics 1997; 43:109-11. [PMID: 9226382 DOI: 10.1006/geno.1997.4792] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- S M Hoffman
- Human Genome Center, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
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Lai KS, Jin Y, Graham DK, Witthuhn BA, Ihle JN, Liu ET. A kinase-deficient splice variant of the human JAK3 is expressed in hematopoietic and epithelial cancer cells. J Biol Chem 1995; 270:25028-36. [PMID: 7559633 DOI: 10.1074/jbc.270.42.25028] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Signal transduction of cytokine receptors is mediated by the JAK family of tyrosine kinases. Recently, the kinase partners for the interleukin (IL)-2 receptor have been identified as JAK1 and JAK3. In this study, we report the identification of splice variants that may modulate JAK3 signaling. Three splice variants were isolated from different mRNA sources: breast (B), spleen (S), and activated monocytes (M). Sequence analysis revealed that the splice variants contain identical NH2-terminal regions but diverge at the COOH termini. Analyses of expression of the JAK3 splice isoforms by reverse transcriptase-polymerase chain reaction on a panel of cell lines show splice preferences in different cell lines: the S-form is more commonly seen in hematopoietic lines, whereas the B- and M-forms are detected in cells both of hematopoietic and epithelial origins. Antibodies raised against peptides to the B-form splice variant confirmed that the 125-kDa JAK3B protein product is found abundantly in hematopoietic as well as epithelial cells, including primary breast cancers. The lack of subdomain XI in the tyrosine kinase core of the B-form JAK3 protein suggests that it is a defective kinase. This is supported by the lack of detected autokinase activity of the B-form JAK3. Intriguingly, both the S and B splice isoforms of JAK3 appear to co-immunoprecipitate with the IL-2 receptor from HUT-78 cell lysates. This and the presence of multiple COOH-terminal splice variants coexpressed in the same cells suggest that the JAK3 splice isoforms are functional in JAK3 signaling and may enrich the complexity of the intracellular responses functional in IL-2 or cytokine signaling.
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Affiliation(s)
- K S Lai
- Department of Biology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill 27599-7295, USA
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Witthuhn BA, Silvennoinen O, Miura O, Lai KS, Cwik C, Liu ET, Ihle JN. Involvement of the Jak-3 Janus kinase in signalling by interleukins 2 and 4 in lymphoid and myeloid cells. Nature 1994; 370:153-7. [PMID: 8022486 DOI: 10.1038/370153a0] [Citation(s) in RCA: 527] [Impact Index Per Article: 17.6] [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: 01/28/2023]
Abstract
Many cytokines function through interaction with receptors of the cytokine receptor superfamily. Although lacking catalytic domains, cytokine receptors couple ligand binding to induction of protein tyrosine phosphorylation. Recent studies have shown that one or more of the Janus kinase family members (Jaks) associate with cytokine receptors and are tyrosine phosphorylated and activated following ligand binding. Here we describe a new Jak family kinase, Jak-3, and demonstrate that Jak-3, and to a lesser extent Jak-1, are tyrosine phosphorylated and Jak-3 is activated in the responses to interleukin-2 and interleukin-4 in T cells and myeloid cells. Jak-3 activation requires the serine-rich, membrane-proximal domain of the interleukin-2 receptor beta-chain, but does not require the acidic domain that is required for association and activation of Src family kinases.
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Affiliation(s)
- B A Witthuhn
- Department of Biochemistry, St Jude Children's Research Hospital, Memphis, Tennessee 38105
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Zhao Z, France RH, Lai KS, Gai M, Wilds EL, Kryger RA, Winger JA, Beard KB. Study of the beta-delayed alpha-particle emission of 16N. Phys Rev C Nucl Phys 1993; 48:429-432. [PMID: 9968837 DOI: 10.1103/physrevc.48.429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Zhao Z, France RH, Lai KS, Rugari SL, Gai M, Wilds EL. Astrophysical S factor of 12C( alpha, gamma )16O from the beta-delayed alpha-particle emission of 16N. Phys Rev Lett 1993; 70:2066-2069. [PMID: 10053462 DOI: 10.1103/physrevlett.70.2066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Lai KS, Jaweed MM, Seestead R, Herbison GJ, Ditunno JF, McCully K, Chance B. Changes in nerve conduction and Pi/PCr ratio during denervation-reinnervation of the gastrocsoleus muscles of rats. Arch Phys Med Rehabil 1992; 73:1155-9. [PMID: 1463379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this investigation was to study the changes in nerve conduction and phosphate metabolites of the gastrocsoleus muscles of rats during denervation-reinnervation. Sixteen male Sprague-Dawley rats underwent unilateral crush-denervation of the left sciatic nerves at the sciatic notch. Six rats were used for measurement of motor conduction latency and action potential amplitude of the gastrocsoleus muscle by stimulating the sciatic nerve at one, two and eight weeks after nerve crush. The other ten rats were designated for evaluation of the ratio of inorganic phosphorous (Pi) to phosphocreatine (PCr) by a 31P-phosphoenergetic spectrometer at two weeks and eight weeks after nerve crush. None of the sciatic nerves showed conduction to the gastrocsoleus at one or two weeks after nerve crush. At eight weeks postcrush, the motor conduction latency returned to within normal limits, whereas the action potential amplitude was only 55% of the normal. For the eight-week period of study, the Pi/PCr ratio of the normal control muscles ranged between 0.09 +/- 0.02 and 0.11 +/- 0.02 (mean +/- SD). The denervated muscles showed an increase of Pi/PCr ratio by 54% at two weeks postcrush, compared to the respective contralateral control sides. The ratios returned to the normal value by eight weeks postcrush. In summary, these data suggested that the metabolic recovery of the crush-denervated muscle followed the same pattern as the parameters of nerve conduction.
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Affiliation(s)
- K S Lai
- Department of Rehabilitation Medicine, Thomas Jefferson University Hospital, Philadelphia
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Abstract
The subcellular distribution of Giardia lamblia virus RNA in infected G. lamblia trophozoites was examined by in situ hybridization using biotinylated DNA probe and riboprobe. In G. lamblia Portland I strain, which is chronically infected by G. lamblia viruses, the viral RNA was detected in the cytoplasm as well as in the twin nuclei. When riboprobe was used to examine the course of virus infection in WB strain, accumulation of viral RNA was detected only in the cytoplasm prior to the first 72 hr of infection. Using DNA probe, further accumulation of viral RNA in increasing number of cells occurred after the 72nd hr of infection, with the RNA found in both the cytoplasm and nuclei. Eventually, the cell nuclei showed damaged morphology that deteriorated rapidly toward the final stage of infection. These observations indicate that early phase of viral RNA replication may take place in the cytoplasm of infected G. lamblia, but the nuclei are also involved during the late phase of viral replication.
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Affiliation(s)
- J H Tai
- Molecular Parasitology Laboratory, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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Maccabee PJ, Amassian VE, Eberle LP, Rudell AP, Cracco RQ, Lai KS, Somasundarum M. Measurement of the electric field induced into inhomogeneous volume conductors by magnetic coils: application to human spinal neurogeometry. Electroencephalogr Clin Neurophysiol 1991; 81:224-37. [PMID: 1710972 DOI: 10.1016/0168-5597(91)90076-a] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We measured the electric fields induced by round and figure "8" magnetic coils (MCs) in homogeneous and inhomogeneous volume conductors. In homogeneous media, the round MC held tangential (i.e., flat) to the volume conductor induced an annular electric field. When the round MC was held on-edge (i.e., orthogonal) to the volume conductor, the induced electric field consisted of two loops mainly parallel to the surface of the volume conductor and which approximated each other directly under the contacting edge of the MC. The tangentially oriented figure "8" MC similarly induced two electric field loops which approximated one another maximally under the region of the junction in its long axis. In a complex inhomogeneous volume conductor, such as a segment of human cervical-thoracic vertebral spine located eccentrically within a large cylindrical tank and submerged in isotonic saline, the direction of electric fields within the spinal canal and across the intervertebral neuroforamina was similar to that observed in the homogeneous volume conductor. However, in and near a single neuroforamen, the electric field and especially its first spatial derivative were markedly elevated compared to that recorded within the long central axis of the vertebral canal. Motor unit and compound muscle action potentials elicited in limb muscles by MC stimulation of human cervical spine confirmed predictions derived from the physical model. The predictions included: (1) absence of spinal cord stimulation compared to relative ease of nerve root stimulation by current that is most likely concentrated at the neuroforamina. When stimulating current is directed towards the periphery, the most likely low threshold site of stimulation is inferred to be just distal to the neuroforamina. It is emphasized that with supramaximal stimulation, more distal sites of excitation may occur; (2) invariant latency shifts at threshold intensities when moving the MC along the rostrocaudal axis of the cervical vertebral column; (3) significant effect (on motor unit activation thresholds) of the direction of induced current flow across the neuroforamina; (4) reduced stimulation when the targeted nerve roots are close to the null point of the electric field, i.e., between locations of high electric field intensity, of opposite polarity; and (5) relatively focal nerve root stimulation by the junction of a transversely orientated figure "8" MC, i.e., parallel to the nerve roots.
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Affiliation(s)
- P J Maccabee
- Department of Neurology, SUNY Health Science Center, Brooklyn 11203
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Chang KW, Chang CS, Lai KS, Chou MJ, Choo KB. High prevalence of human papillomavirus infection and possible association with betel quid chewing and smoking in oral epidermoid carcinomas in Taiwan. J Med Virol 1989; 28:57-61. [PMID: 2542446 DOI: 10.1002/jmv.1890280113] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.0] [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: 01/01/2023]
Abstract
Seventeen oral epidermoid carcinomas, three oral papillomas, and 17 normal gingival tissues were tested for the presence of human papillomavirus (HPV) types 6, 11, 16, and 18 sequences by Southern blot hybridization. Episomal HPV-16 sequences in various amounts were detected in 76.4% of the oral carcinomas and in all three cases of papilloma. However, only one of the 17 normal tissues was HPV positive with an unknown type. None of the samples contained HPV-6, -11, or -18 sequences. Examination of the habits of the patients showed that 59% of the patients were betel quid chewers and 82% were smokers. Thus, the concurrent incidence of HPV infection and betal quid chewing and/or smoking habits in oral carcinoma patients observed in Taiwan is consistent with the view that both viral and chemical factors may be involved in the process of carcinogenesis.
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Affiliation(s)
- K W Chang
- Department of Medical Research, Veterans General Hospital, Taipei, Taiwan, Republic of China
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Abstract
The appearance of rapidly flowing blood on imaging (MRI) was evaluated using flow phantoms and dye infusion experiments. Laminar flow can be maintained at high velocities in small-diameter vessels. Under such conditions, flow-related enhancement may be observed several slices into a multislice imaging volume. Decreasing cross-sectional area of the unsaturated protons in the midstream is noted on slices further removed from the entry surface. As the velocity increases, turbulence occurs. The increased random motion of the protons causes loss of intensity on the first-echo image, although rephasing with increased intensity can be noted on the second-echo image. The flow pattern of a simple intraluminal obstruction is demonstrated by MRI and dye infusion experiments. Rephasing is noted within the eddy downstream from the obstruction. Clinical examples of the phantom findings are shown and applications are discussed.
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Abstract
A case is presented of the rare adult form of Niemann-Pick disease occurring in a Cantonese. The diagnosis was verified by biochemical analysis of the affected tissues.
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Pearson GP, Lai KS, Jones DF. Effect of barium sulphate on strength of bone cement. Lancet 1976; 2:207. [PMID: 73834 DOI: 10.1016/s0140-6736(76)92388-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Lee SP, Lai KS. Exocrine pancreatic function in hepatic cirrhosis. Am J Gastroenterol 1976; 65:244-8. [PMID: 937324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Exocrine pancreatic function was assessed by the standard test meal method of Lundh in a control group, and 13 patients with nonalcoholic, postnecrotic cirrhosis of the liver. In six of these patients, splenorenal shunts were performed and exocrine pancreatic function was assessed before and three months after operation. In three of the six, the secretin-pancreozymin stimulation test was also performed. An increased volume but normal trypsin output was observed in the unoperated cirrhotic patients. An increase both in volume and in trypsin was found in the cirrhotic patients after shunting using the test meal stimulation. There was no appreciable difference, however, when tested with secretin and pancreozymin. Hypersecretion in cirrhotics, with or without shunts, is probably due to a by-pass of the hepatic degradation of normal pancreatic secretogogues produced by the intestine.
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