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Wang M, Chen L, He J, Xia W, Ye Z, She J. Structural insights into IL-6 signaling inhibition by therapeutic antibodies. Cell Rep 2024; 43:113819. [PMID: 38393945 DOI: 10.1016/j.celrep.2024.113819] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/14/2023] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
Antibody inhibitors of the interleukin-6 (IL-6) signaling pathway, such as tocilizumab and sarilumab, have been used to treat rheumatoid arthritis, chimeric antigen receptor T cell-induced cytokine storm, and severe COVID-19 pneumonia. Here, we solve the cryogenic electron microscopy structures of sarilumab and tocilizumab in complex with IL-6R to resolutions of 3.2 and 3.3 Å, respectively. These structures reveal that both tocilizumab and sarilumab bind to the D3 domain of IL-6R. The binding surfaces of the two antibodies largely overlap, but the detailed interactions are different. Functional studies of various mutants show results consistent with our structural analysis of the antibodies and IL-6R interactions. Structural comparisons with the IL-6/IL-6R/gp130 complex indicate that sarilumab and tocilizumab probably inhibit IL-6/IL-6R signaling by competing for the IL-6 binding site. In summary, this work reveals the antibody-blocking mechanism of the IL-6 signaling pathway and paves the way for future antibody discovery.
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Affiliation(s)
- Mingxing Wang
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Long Chen
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Jin He
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Wenqiang Xia
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, Zhejiang, China; College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Zihong Ye
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, Zhejiang, China.
| | - Ji She
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China.
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2
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Wang M, He J, Li S, Cai Q, Zhang K, She J. Structural basis of vitamin C recognition and transport by mammalian SVCT1 transporter. Nat Commun 2023; 14:1361. [PMID: 36914666 PMCID: PMC10011568 DOI: 10.1038/s41467-023-37037-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/28/2023] [Indexed: 03/15/2023] Open
Abstract
Vitamin C (L-ascorbic acid) is an essential nutrient for human health, and its deficiency has long been known to cause scurvy. Sodium-dependent vitamin C transporters (SVCTs) are responsible for vitamin C uptake and tissue distribution in mammals. Here, we present cryogenic electron microscopy structures of mouse SVCT1 in both the apo and substrate-bound states. Mouse SVCT1 forms a homodimer with each protomer containing a core domain and a gate domain. The tightly packed extracellular interfaces between the core domain and gate domain stabilize the protein in an inward-open conformation for both the apo and substrate-bound structures. Vitamin C binds at the core domain of each subunit, and two potential sodium ions are identified near the binding site. The coordination of sodium ions by vitamin C explains their coupling transport. SVCTs probably deliver substrate through an elevator mechanism in combination with local structural arrangements. Altogether, our results reveal the molecular mechanism by which SVCTs recognize vitamin C and lay a foundation for further mechanistic studies on SVCT substrate transport.
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Affiliation(s)
- Mingxing Wang
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Jin He
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Shanshan Li
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Qianwen Cai
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Kaiming Zhang
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China.
| | - Ji She
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China.
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3
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She J, Guo J, Jiang Y. Structure and Function of Plant and Mammalian TPC Channels. Handb Exp Pharmacol 2023; 278:155-180. [PMID: 35879575 DOI: 10.1007/164_2022_599] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Two-pore channels (TPCs) belong to the family of voltage-gated tetrameric cation channels and are ubiquitously expressed in organelles of animals and plants. These channels are believed to be evolutionary intermediates between homotetrameric voltage-gated potassium/sodium channels and the four-domain, single subunit, voltage-gated sodium/calcium channels. Each TPC subunit contains 12 transmembrane segments that can be divided into two homologous copies of an S1-S6 Shaker-like 6-TM domain. A functional TPC channel assembles as a dimer - the equivalent of a voltage-gated tetrameric cation channel. The plant TPC channel is localized in the vacuolar membrane and is also called the SV channel for generating the slow vacuolar (SV) current observed long before its molecular identification. Three subfamilies of mammalian TPC channels have been defined - TPC1, 2, and 3 - with the first two being ubiquitously expressed in animals and TPC3 being expressed in some animals but not in humans. Mammalian TPC1 and TPC2 are localized to the endolysosomal membrane and their functions are associated with various physiological processes. TPC3 is localized in the plasma membrane and its physiological function is not well defined.
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Affiliation(s)
- Ji She
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jiangtao Guo
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Department of Neurology, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Youxing Jiang
- Howard Hughes Medical Institute, Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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4
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She J, Zhuo B. Meta-analysis comparing impact of age, sex and renal function on the efficacy and safety of new oral anticoagulants vs. vitamin K antagonists for the treatment of acute venous thromboembolisms. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.2374] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
New direct oral anticoagulants (NOACs), as a preferable treatment option for acute venous thromboembolism (VTE) have been recommended with practical advantages as compared to Vitamin K antagonists (VKAs) in clinical practice.
Purpose
In our study, we performed a meta-analysis to determine the efficacy and safety of NOACs vs. VKAs in patients with different age, sex and renal function for the treatment of VTE.
Methods
Electronic databases (accessed October 2019) were systematically searched to identify RCTs evaluating apixaban, dabigatran, edoxaban, and rivaroxaban versus VKAs for the treatment of acute venous thromboembolism.
Results
NOACs was associated with a borderline higher efficacy in female (OR 0.79, 95% CI 0.62–1.02), and a significantly higher efficacy in patients with age more than 75 (OR 0.51, 95% CI 0.32–0.80) and creatinine clearance less than 50 mL/min (OR 0.57, 95% CI 0.32–0.99). NOACs also show advantage in terms of major or clinically relevant non-major bleeding in male (OR 0.72, 95% CI 0.60–0.86), and patients with creatinine clearance more than 50 mL/min (OR 0.75, 95% CI 0.67–0.84).
Conclusions
NOACs have exhibited clinical preference among patients with acute VTE as compared to VKA with significantly decreased thrombosis events and lower bleeding complications, especially in patients with age more than 75 and creatinine clearance less than 50 mL/min.
Funding Acknowledgement
Type of funding source: Public Institution(s). Main funding source(s): This study was supported by the National Natural Science Foundation of China (81800390) and the Natural Science Foundation of Shaanxi province (2018KW067).
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Affiliation(s)
- J She
- First Hospital of Medical College of Xi'an Jiaotong University, Xi'an, China
| | - B.Z Zhuo
- First Hospital of Medical College of Xi'an Jiaotong University, Xi'an, China
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5
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Wang Y, Han Y, She J, Nguyen NX, Mootha VK, Bai XC, Jiang Y. Structural insights into the Ca 2+-dependent gating of the human mitochondrial calcium uniporter. eLife 2020; 9:60513. [PMID: 32762847 PMCID: PMC7442490 DOI: 10.7554/elife.60513] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [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: 06/28/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial Ca2+ uptake is mediated by an inner mitochondrial membrane protein called the mitochondrial calcium uniporter. In humans, the uniporter functions as a holocomplex consisting of MCU, EMRE, MICU1 and MICU2, among which MCU and EMRE form a subcomplex and function as the conductive channel while MICU1 and MICU2 are EF-hand proteins that regulate the channel activity in a Ca2+-dependent manner. Here, we present the EM structures of the human mitochondrial calcium uniporter holocomplex (uniplex) in the presence and absence of Ca2+, revealing distinct Ca2+ dependent assembly of the uniplex. Our structural observations suggest that Ca2+ changes the dimerization interaction between MICU1 and MICU2, which in turn determines how the MICU1-MICU2 subcomplex interacts with the MCU-EMRE channel and, consequently, changes the distribution of the uniplex assemblies between the blocked and unblocked states.
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Affiliation(s)
- Yan Wang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Yan Han
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
| | - Nam X Nguyen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Broad Institute, Cambridge, United States
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
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6
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Guo G, Shi F, Zhu J, Shao Y, Gong W, Zhou G, Wu H, She J, Shi W. Piperine, a functional food alkaloid, exhibits inhibitory potential against TNBS-induced colitis via the inhibition of IκB-α/NF-κB and induces tight junction protein (claudin-1, occludin, and ZO-1) signaling pathway in experimental mice. Hum Exp Toxicol 2019; 39:477-491. [PMID: 31835924 DOI: 10.1177/0960327119892042] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Inflammatory bowel disease is a chronic immunoinflammatory disease of the gastrointestinal tract. Piperine, an alkaloid, has been reported to possess antioxidant, anti-inflammatory, antiapoptotic, and antiulcer potential. AIM To elucidate the plausible mechanisms of action of piperine on experimental trinitrobenzenesufonic acid (TNBS)-induced colitis by assessing various biochemical, molecular, histological, and ultrastructural modifications. METHODS Colitis was induced in male Sprague-Dawley rats via intrarectal instillation of TNBS. Then, the rats were treated with piperine (10, 20, and 40 mg/kg, p.o.) for 14 days. RESULTS TNBS induced significant (p < 0.05) colonic damage, which was assessed by disease activity index, macroscopic score, and stool consistency. The administration of piperine (20 and 40 mg/kg) significantly inhibited (p < 0.05) these damages. Treatments with piperine (20 and 40 mg/kg) notably inhibited (p < 0.05) the TNBS-induced elevation of oxido-nitrosative stress (superoxide dismutase, glutathione, malondialdehyde, and nitric oxide), 5-hydroxytryptamine, and hydroxyproline content in the colon. Furthermore, colonic inducible nitric oxide synthase (iNOs), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, interferon-gamma, and cyclooxygenase-2 (COX-2) messenger RNA (mRNA) expressions were upregulated after TNBS instillation and piperine (20 and 40 mg/kg) significantly attenuated (p < 0.05) these elevated mRNA expressions. TNBS decreased the expressions of tight junction (TJ) protein (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and increased the expressions of proapoptotic (caspase-1) protein. These expressions were markedly inhibited (p < 0.05) by piperine treatment. Histological and ultrastructural studies of transmission electron microscopy suggested that piperine significantly ameliorated (p < 0.05) TNBS-induced colonic aberrations. CONCLUSION Piperine ameliorated the progression of TNBS-induced colitis by modulating the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha/nuclear factor-kappa B signaling pathway, thus inhibiting the overexpression of proinflammatory cytokines (TNF-α and IL's), COX-2, iNOs, oxido-nitrosative stress, and proapoptotic proteins (caspase-1) that may improve the expression of TJ protein (claudin-1, occludin, and ZO-1).
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Affiliation(s)
- G Guo
- Department of Talent Highland, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China
| | - F Shi
- Department of Talent Highland, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China.,Department of General Surgery, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China
| | - J Zhu
- Department of Gastroenterology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Y Shao
- Department of Nephrology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - W Gong
- Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - G Zhou
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu, China
| | - H Wu
- Department of Talent Highland, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China
| | - J She
- Department of Talent Highland, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China.,Department of General Surgery, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China
| | - W Shi
- Department of Talent Highland, The First Affiliated Hospital of Xi'an Jiao Tong University, Xian, China.,Department of Gastroenterology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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7
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Ye Y, Luo Q, Jiang HQ, Zhang J, Wang J, She J. [Renal clear cell carcinoma transferred to infratemporal fossa and pterygopalatine fossa: A case report]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2019; 33:998-999. [PMID: 31623054 DOI: 10.13201/j.issn.1001-1781.2019.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Indexed: 11/12/2022]
Abstract
SummaryRenal clear cell carcinoma is prone to distant metastasis, especially in the head and neck, but it is rare to transfer to infratemporal fossa and pterygopalatine fossa. We reported a 62-year-old male patient with complains of numbness and burning sensation on the left side of the face for more than 3 months. Left kidney removal was performed 8 years ago due to renal cancer. Preoperative enhancement CT showed a large blood-rich occupation in the left nasopharyngeal and pterygopalatine with adjacent paranasal sinus and skull base bone destruction. Under the general anesthesia, the anterior lacrimal recess approach was used for tumor resection. Preoperative interventional embolization of the feeding artery, intraoperative pathology, frozen section showed metastasis of renal cell carcinoma, and postoperative immunohistochemical examination, confirmed metastatic renal clear cell carcinoma(infratemporal fossa and pterygopalatine fossa). The patients were transferred to the oncology department for further radiotherapy and chemotherapy.
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8
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Gong LJ, She J, Zhu L. [The role of leukotriene in the pathogenesis of cough variant asthma]. Zhonghua Jie He He Hu Xi Za Zhi 2019; 42:219-222. [PMID: 30845400 DOI: 10.3760/cma.j.issn.1001-0939.2019.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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9
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Wang Y, Nguyen NX, She J, Zeng W, Yang Y, Bai XC, Jiang Y. Structural Mechanism of EMRE-Dependent Gating of the Human Mitochondrial Calcium Uniporter. Cell 2019; 177:1252-1261.e13. [PMID: 31080062 DOI: 10.1016/j.cell.2019.03.050] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [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: 11/05/2018] [Revised: 02/09/2019] [Accepted: 03/27/2019] [Indexed: 01/06/2023]
Abstract
Mitochondrial calcium uptake is crucial to the regulation of eukaryotic Ca2+ homeostasis and is mediated by the mitochondrial calcium uniporter (MCU). While MCU alone can transport Ca2+ in primitive eukaryotes, metazoans require an essential single membrane-spanning auxiliary component called EMRE to form functional channels; however, the molecular mechanism of EMRE regulation remains elusive. Here, we present the cryo-EM structure of the human MCU-EMRE complex, which defines the interactions between MCU and EMRE as well as pinpoints the juxtamembrane loop of MCU and extended linker of EMRE as the crucial elements in the EMRE-dependent gating mechanism among metazoan MCUs. The structure also features the dimerization of two MCU-EMRE complexes along an interface at the N-terminal domain (NTD) of human MCU that is a hotspot for post-translational modifications. Thus, the human MCU-EMRE complex, which constitutes the minimal channel components among metazoans, provides a framework for future mechanistic studies on MCU.
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Affiliation(s)
- Yan Wang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nam X Nguyen
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ji She
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weizhong Zeng
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yi Yang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Youxing Jiang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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10
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Chen Q, Zeng W, She J, Bai XC, Jiang Y. Structural and functional characterization of an otopetrin family proton channel. eLife 2019; 8:46710. [PMID: 30973323 PMCID: PMC6483595 DOI: 10.7554/elife.46710] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 03/09/2019] [Accepted: 04/11/2019] [Indexed: 12/14/2022] Open
Abstract
The otopetrin (OTOP) proteins were recently characterized as proton channels. Here we present the cryo-EM structure of OTOP3 from Xenopus tropicalis (XtOTOP3) along with functional characterization of the channel. XtOTOP3 forms a homodimer with each subunit containing 12 transmembrane helices that can be divided into two structurally homologous halves; each half assembles as an α-helical barrel that could potentially serve as a proton conduction pore. Both pores open from the extracellular half before becoming occluded at a central constriction point consisting of three highly conserved residues - Gln232/585-Asp262/Asn623-Tyr322/666 (the constriction triads). Mutagenesis shows that the constriction triad from the second pore is less amenable to perturbation than that of the first pore, suggesting an unequal contribution between the two pores to proton transport. We also identified several key residues at the interface between the two pores that are functionally important, particularly Asp509, which confers intracellular pH-dependent desensitization to OTOP channels.
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Affiliation(s)
- Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
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11
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She J, Zeng W, Guo J, Chen Q, Bai XC, Jiang Y. Structural mechanisms of phospholipid activation of the human TPC2 channel. eLife 2019; 8:45222. [PMID: 30860481 PMCID: PMC6424560 DOI: 10.7554/elife.45222] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [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: 01/16/2019] [Accepted: 03/07/2019] [Indexed: 12/21/2022] Open
Abstract
Mammalian two-pore channels (TPCs) regulate the physiological functions of the endolysosome. Here we present cryo-EM structures of human TPC2 (HsTPC2), a phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2)-activated, Na+ selective channel, in the ligand-bound and apo states. The apo structure captures the closed conformation, while the ligand-bound form features the channel in both open and closed conformations. Combined with functional analysis, these structures provide insights into the mechanism of PI(3,5)P2-regulated gating of TPC2, which is distinct from that of TPC1. Specifically, the endolysosome-specific PI(3,5)P2 binds at the first 6-TM and activates the channel – independently of the membrane potential – by inducing a structural change at the pore-lining inner helix (IS6), which forms a continuous helix in the open state but breaks into two segments at Gly317 in the closed state. Additionally, structural comparison to the voltage-dependent TPC1 structure allowed us to identify Ile551 as being responsible for the loss of voltage dependence in TPC2.
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Affiliation(s)
- Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jiangtao Guo
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China.,Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
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12
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She J. P3855Dual versus single antiplatelet therapy in combination with antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention with stent implantation: a meta-analysis. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p3855] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J She
- First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, China People's Republic of
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13
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She J, Guo J, Chen Q, Zeng W, Jiang Y, Bai XC. Structural insights into the voltage and phospholipid activation of the mammalian TPC1 channel. Nature 2018; 556:130-134. [PMID: 29562233 PMCID: PMC5886804 DOI: 10.1038/nature26139] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [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: 11/21/2017] [Accepted: 02/19/2018] [Indexed: 01/09/2023]
Abstract
Organellar two-pore channels (TPCs) function as a homodimer with each subunit containing two homologous Shaker-like 6-TM repeats1. They belong to the voltage-gated ion channel superfamily2 and are ubiquitously expressed in animals and plants3,4. Mammalian TPC1 and TPC2 are localized to the endolysosomal membrane and play critical roles in regulating the physiological functions of these acidic organelles5–7. Here we present the cryo-EM structures of mouse TPC1 (MmTPC1), a voltage-dependent, phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) activated Na+ selective channel, in both the apo closed and ligand-bound open states which, combined with functional analysis, provide comprehensive structural insights into the selectivity and gating mechanisms of mammalian TPC channels. The channel has a coin slot-shaped ion pathway in the filter that defines the selectivity of mammalian TPCs. Only the voltage sensing domain from the second 6-TM domain confers voltage dependence to MmTPC1. Endolysosome-specific PtdIns(3,5)P2 binds to the first 6-TM domain and activates the channel under depolarizing membrane potential. Structural comparison between the apo and PtdIns(3,5)P2-bound structures elucidates the interplay between voltage and ligand in channel activation. In light of the emerging importance of phosphoinositide regulation of ion channels, the MmTPC1 structures exemplify the lipid binding and regulation in a 6-TM voltage-gated channel.
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Affiliation(s)
- Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Jiangtao Guo
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9039, USA
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14
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Chen J, Zhang Y, Li G, Peng F, Jie X, She J, Dongye G, Zou Z, Rong S, Chen L. Cytotoxicity in vitro, cellular uptake, localization and apoptotic mechanism studies induced by ruthenium(II) complex. J Biol Inorg Chem 2017; 23:261-275. [DOI: 10.1007/s00775-017-1528-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 12/13/2017] [Indexed: 12/22/2022]
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15
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Guo J, She J, Zeng W, Chen Q, Bai XC, Jiang Y. Structures of the calcium-activated, non-selective cation channel TRPM4. Nature 2017; 552:205-209. [PMID: 29211714 PMCID: PMC5901961 DOI: 10.1038/nature24997] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/03/2017] [Indexed: 12/12/2022]
Abstract
TRPM4 is a calcium-activated, phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) -modulated, non-selective cation channel that belongs to the family of melastatin-related transient receptor potential (TRPM) channels. Here we present the electron cryo-microscopy structures of the mouse TRPM4 channel with and without ATP. TRPM4 consists of multiple transmembrane and cytosolic domains, which assemble into a three-tiered architecture. The N-terminal nucleotide-binding domain and the C-terminal coiled-coil participate in the tetrameric assembly of the channel; ATP binds at the nucleotide-binding domain and inhibits channel activity. TRPM4 has an exceptionally wide filter but is only permeable to monovalent cations; filter residue Gln973 is essential in defining monovalent selectivity. The S1-S4 domain and the post-S6 TRP domain form the central gating apparatus that probably houses the Ca2+- and PtdIns(4,5)P2-binding sites. These structures provide an essential starting point for elucidating the complex gating mechanisms of TRPM4 and reveal the molecular architecture of the TRPM family.
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Affiliation(s)
- Jiangtao Guo
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9039, USA
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
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16
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Chen Q, She J, Zeng W, Guo J, Xu H, Bai XC, Jiang Y. Structure of mammalian endolysosomal TRPML1 channel in nanodiscs. Nature 2017; 550:415-418. [PMID: 29019981 PMCID: PMC5901962 DOI: 10.1038/nature24035] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [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: 06/05/2017] [Accepted: 08/24/2017] [Indexed: 12/14/2022]
Abstract
Transient receptor potential mucolipin 1 (TRPML1) is an endo/lysosomal cation channel ubiquitously expressed in mammalian cells1,2 and its loss-of-function mutations are the direct cause of Type IV mucolipidosis (MLIV), an autosomal recessive lysosomal storage disease3-6. Here we present the single particle cryo-electron microscopy (cryo-EM) structure of the mouse TRPML1 channel embedded in nanodiscs. Combined with mutagenesis, the TRPML1 structure reveals that phosphatidylinositol bisphosphate (PIP2) binds to the N-terminus of the channel – distal from the pore – and the helix-turn-helix extension between S2 and S3 likely couples ligand binding to pore opening. The tightly packed selectivity filter contains multiple ion binding sites and the conserved acidic residues form the luminal Ca2+ blocking site that confers luminal pH and Ca2+ modulation on channel conductance. A luminal linker domain forms a fenestrated canopy atop the channel, providing multiple luminal ion passages to the pore and also creating a negative electrostatic trap – preferably for divalent cations at the luminal entrance. The structure also reveals two equally distributed S4-S5 linker conformations in the closed channel, providing structural implication for the S4-S5 linker-mediated PIP2 gating mechanism among TRPML channels7,8.
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Affiliation(s)
- Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Jiangtao Guo
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
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17
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Lee C, Guo J, Zeng W, Kim S, She J, Cang C, Ren D, Jiang Y. The lysosomal potassium channel TMEM175 adopts a novel tetrameric architecture. Nature 2017; 547:472-475. [PMID: 28723891 PMCID: PMC5901963 DOI: 10.1038/nature23269] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [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: 04/11/2017] [Accepted: 06/06/2017] [Indexed: 11/09/2022]
Abstract
TMEM175 is a lysosomal K+ channel that is important for maintaining the membrane potential and pH stability in lysosomes. It contains two homologous copies of a six-transmembrane-helix (6-TM) domain, which has no sequence homology to the canonical tetrameric K+ channels and lacks the TVGYG selectivity filter motif found in these channels. The prokaryotic TMEM175 channel, which is present in a subset of bacteria and archaea, contains only a single 6-TM domain and functions as a tetramer. Here, we present the crystal structure of a prokaryotic TMEM175 channel from Chamaesiphon minutus, CmTMEM175, the architecture of which represents a completely different fold from that of canonical K+ channels. All six transmembrane helices of CmTMEM175 are tightly packed within each subunit without undergoing domain swapping. The highly conserved TM1 helix acts as the pore-lining inner helix, creating an hourglass-shaped ion permeation pathway in the channel tetramer. Three layers of hydrophobic residues on the carboxy-terminal half of the TM1 helices form a bottleneck along the ion conduction pathway and serve as the selectivity filter of the channel. Mutagenesis analysis suggests that the first layer of the highly conserved isoleucine residues in the filter is primarily responsible for channel selectivity. Thus, the structure of CmTMEM175 represents a novel architecture of a tetrameric cation channel whose ion selectivity mechanism appears to be distinct from that of the classical K+ channel family.
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Affiliation(s)
- Changkeun Lee
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815-6789, USA
| | - Jiangtao Guo
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Weizhong Zeng
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815-6789, USA
| | - Sunghoon Kim
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815-6789, USA
| | - Ji She
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Chunlei Cang
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Youxing Jiang
- Department of Physiology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815-6789, USA
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18
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Lodd E, She J, Fleming TH, Nawroth PP, Kroll J. Glo1-/- zebrafish mutants display differential susceptibility of vascular and renal systems. DIABETOL STOFFWECHS 2017. [DOI: 10.1055/s-0037-1601764] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- E Lodd
- Center for Biomedicine and Medical Technology Mannheim, Vascular Biology and Tumor Angiogenesis, Mannheim, Germany
| | - J She
- Center for Biomedicine and Medical Technology Mannheim, Vascular Biology and Tumor Angiogenesis, Mannheim, Germany
| | - TH Fleming
- Department of Medicine I and Clinical Chemistry, Heidelberg, Germany
| | - PP Nawroth
- Department of Medicine I and Clinical Chemistry, Heidelberg, Germany
| | - J Kroll
- Center for Biomedicine and Medical Technology Mannheim, Vascular Biology and Tumor Angiogenesis, Mannheim, Germany
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19
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She J, Wang F, Zhou J. A Novel Sensor Selection and Power Allocation Algorithm for Multiple-Target Tracking in an LPI Radar Network. Sensors (Basel) 2016; 16:s16122193. [PMID: 28009819 PMCID: PMC5191172 DOI: 10.3390/s16122193] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 12/07/2016] [Accepted: 12/09/2016] [Indexed: 11/25/2022]
Abstract
Radar networks are proven to have numerous advantages over traditional monostatic and bistatic radar. With recent developments, radar networks have become an attractive platform due to their low probability of intercept (LPI) performance for target tracking. In this paper, a joint sensor selection and power allocation algorithm for multiple-target tracking in a radar network based on LPI is proposed. It is found that this algorithm can minimize the total transmitted power of a radar network on the basis of a predetermined mutual information (MI) threshold between the target impulse response and the reflected signal. The MI is required by the radar network system to estimate target parameters, and it can be calculated predictively with the estimation of target state. The optimization problem of sensor selection and power allocation, which contains two variables, is non-convex and it can be solved by separating power allocation problem from sensor selection problem. To be specific, the optimization problem of power allocation can be solved by using the bisection method for each sensor selection scheme. Also, the optimization problem of sensor selection can be solved by a lower complexity algorithm based on the allocated powers. According to the simulation results, it can be found that the proposed algorithm can effectively reduce the total transmitted power of a radar network, which can be conducive to improving LPI performance.
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Affiliation(s)
- Ji She
- Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.
| | - Fei Wang
- Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.
| | - Jianjiang Zhou
- Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.
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20
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Dong H, Wang Y, Ou Y, She J, Shen X, Li J, Zhang C, Liu L. Preparation of molecularly imprinted polymer for chiral recognition of racemic 1,1′-binaphthalene-2,2′-diamine by HPLC. ACTA CHROMATOGR 2014. [DOI: 10.1556/achrom.26.2014.4.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Song J, Xue K, She J, Ding F, Li S, Shangguan R, Dai Y, Du L, Li N. A mammary repopulating cell population characterized in mammary anlagen reveals essential mammary stroma for morphogenesis. Exp Cell Res 2014; 327:123-34. [DOI: 10.1016/j.yexcr.2014.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 04/30/2014] [Accepted: 06/12/2014] [Indexed: 11/29/2022]
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22
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She J, Han Z, Zhou B, Chai J. Structural basis for differential recognition of brassinolide by its receptors. Protein Cell 2013; 4:475-82. [PMID: 23709366 DOI: 10.1007/s13238-013-3027-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/22/2013] [Indexed: 10/26/2022] Open
Abstract
Brassinosteroids, a group of plant steroid hormones, regulate many aspects of plant growth and development. We and other have previously solved the crystal structures of BRI1(LRR) in complex with brassinolide, the most active brassinosteroid identified thus far. Although these studies provide a structural basis for the recognition of brassinolide by its receptor BRI1, it still remains poorly understood how the hormone differentiates among its conserved receptors. Here we present the crystal structure of the BRI1 homolog BRL1 in complex with brassinolide. The structure shows that subtle differences around the brassinolide binding site can generate a striking effect on its recognition by the BRI1 family of receptors. Structural comparison of BRL1 and BRI1 in their brassinolide-bound forms reveals the molecular basis for differential binding of brassinolide to its different receptors, which can be used for more efficient design of plant growth regulators for agricultural practice. On the basis of our structural studies and others' data, we also suggest possible mechanisms for the activation of BRI1 family receptors.
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Affiliation(s)
- Ji She
- School of Life Sciences, Peking University, Beijing, 100871, China
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23
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Liu T, Liu Z, Song C, Hu Y, Han Z, She J, Fan F, Wang J, Jin C, Chang J, Zhou JM, Chai J. Chitin-induced dimerization activates a plant immune receptor. Science 2012; 336:1160-4. [PMID: 22654057 DOI: 10.1126/science.1218867] [Citation(s) in RCA: 402] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Pattern recognition receptors confer plant resistance to pathogen infection by recognizing the conserved pathogen-associated molecular patterns. The cell surface receptor chitin elicitor receptor kinase 1 of Arabidopsis (AtCERK1) directly binds chitin through its lysine motif (LysM)-containing ectodomain (AtCERK1-ECD) to activate immune responses. The crystal structure that we solved of an AtCERK1-ECD complexed with a chitin pentamer reveals that their interaction is primarily mediated by a LysM and three chitin residues. By acting as a bivalent ligand, a chitin octamer induces AtCERK1-ECD dimerization that is inhibited by shorter chitin oligomers. A mutation attenuating chitin-induced AtCERK1-ECD dimerization or formation of nonproductive AtCERK1 dimer by overexpression of AtCERK1-ECD compromises AtCERK1-mediated signaling in plant cells. Together, our data support the notion that chitin-induced AtCERK1 dimerization is critical for its activation.
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Affiliation(s)
- Tingting Liu
- Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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24
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Salami F, Abels M, Hyöty H, Vaziri-Sani F, Aronsson C, Vehik K, Delli A, Hagopian W, Rewers M, Ziegler A, Simell O, Akolkar B, Krischer J, She J, Lernmark A. DETECTION OF LACTOBACILLI IN MONTHLY MAIL-IN STOOL SAMPLES FROM 3-18 MONTHS OLD INFANTS AT GENETIC RISK FOR TYPE 1 DIABETES. Int J Probiotics Prebiotics 2012; 7:135-144. [PMID: 25045339 PMCID: PMC4101081] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The feasibility to detect lactobacilli in mail-in infant stools collected monthly from 3-18 months old children was investigated. The aim was to determine total lactobacilli and Lactobacillus plantarum (L. plantarum) content (ng/g feces) in 50 infants each from Colorado (648 samples), Finland (624 samples) and Sweden (685 samples) who participated in the TEDDY (The Environmental Determinants of Diabetes in the Young) study. Total lactobacilli content varied markedly between 5 and 16,800 ng/g feces in the three clinical sites within and between individuals especially in infants. L.plantarum also varied markedly intra- and inter-individually from <0.5 - 736 ng/g feces. A higher variability of total lactobacilli was found before 10 months of age than after in the three different clinical sites. Sweden had the lowest total lactobacilli content compared to Colorado and Finland while the L.plantarum content was higher in Sweden. Mail-in stool samples from infants should prove useful in analyzing probiotics in childhood.
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Affiliation(s)
- F Salami
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
| | - M Abels
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
| | - H Hyöty
- Department of Virology, Tampere University Hospital, Tampere, Finland
| | - F Vaziri-Sani
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
| | - Ca Aronsson
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
| | - K Vehik
- Morsani College of Medicine, Pediatrics Epidemiology Center, University of South Florida, Tampa, FL, USA
| | - A Delli
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
| | - Wa Hagopian
- Pacific Northwest Diabetes Research Institute, Seattle, WA, USA
| | - M Rewers
- Barbara Davis Center for Childhood Diabetes, University of Colorado, Aurora, CO, USA
| | - Ag Ziegler
- Diabetes Research Institute, Technische Universität München, Munich, Germany
| | - O Simell
- Department of Pediatrics, University of Turku, Turku, Finland
| | | | - J Krischer
- Morsani College of Medicine, Pediatrics Epidemiology Center, University of South Florida, Tampa, FL, USA
| | - J She
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA, USA
| | - A Lernmark
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmö, Sweden
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25
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Wang M, Bush S, Ghamande SA, She J. Prognostic value of serum protein biomarkers in patients with epithelial ovarian cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.10567] [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: 11/20/2022] Open
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27
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Bai C, She J, Goolaerts A, Song Y, Shen C, Shen J, Hong Q. Stress failure plays a major role in the development of high-altitude pulmonary oedema in rats. Eur Respir J 2009; 35:584-91. [PMID: 19741034 DOI: 10.1183/09031936.00001709] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Hypoxia and exertion are considered as the two main factors in the development of high-altitude pulmonary oedema (HAPE), however its pathophysiology remains unclear. Therefore, we established a model in which 32 Sprague-Dawley rats were randomly assigned to normoxic rest, hypoxic rest, normoxic exercise and hypoxic exercise. An altitude of 4,700 m was simulated using hypobaric hypoxia, while exercise consisted 48 h walk with 15-20 min breaks every 4 h. Arterial blood gas, bronchoalveolar lavage (BAL), lung wet-to-dry weight (W/D) ratio and histological measurements were conducted on each animal. In rats exercising in hypoxia, BAL protein and lung W/D ratio were significantly increased but no changes in BAL leukotriene B(4) and immunoglobulin M were observed. In the same group, lung histology showed typical haemorrhagic lung oedema and disruption of both alveolar epithelium and capillary endothelium while hypoxia or exertion alone only induced slight endothelium and epithelium swelling/disruption. Our study established a direct link between histological and physiological evidence of HAPE-like symptoms and we demonstrated that hypoxia and exertion can synergistically induce HAPE-like symptoms in Sprague-Dawley rats without inducing lung inflammation. We therefore propose that alveolar epithelium and capillary endothelium stress failure play a major role in the development of HAPE.
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Affiliation(s)
- C Bai
- Dept of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.
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28
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Wang Y, She J, Xiang H, Li Y, Liu J, Li D, Yu M. Improving auscultatory blood pressure measurement with electronic and computer technology: the visual auscultation method. Am J Hypertens 2009; 22:624-9. [PMID: 19265786 DOI: 10.1038/ajh.2009.30] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The auscultatory method is used as the reference standard in all prevalent protocols for validation of noninvasive blood pressure measuring devices, and a validation study is essentially based on the comparison between the device and observer measurements. Thus, the objectivity and accuracy of observer measurements are crucial to the validation result. METHODS To provide observers with more objective information about an auscultatory measurement so that sufficient information to make measurements with greater potential objectivity and accuracy can be available, a computerized data acquisition and analysis system has been developed. It cannot only acquire and store Korotkoff sound, cuff pressure, and oscillometric pulse signals, as well as the sphygmomanometer image, but it also can display the waveforms of the three signals and the sphygmomanometer video while playing the synchronous Korotkoff sounds. With this system, observers can make their measurements via the visual auscultation method, that is to say, by watching those waveforms, instead of the sphygmomanometer, while listening for synchronized Korotkoff sounds. The system was validated according to the International Protocol (IP). RESULTS The result showed that all the differences between system measurements by the visual auscultation method and observer measurements by the conventional auscultatory method were within 4 mm Hg. CONCLUSIONS The visual auscultation method achieved a high degree of accuracy, and human observers can be replaced by the system in the validation study of blood pressure measuring devices.
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She J, Forsberg E, Ao XY, He SL. High-efficiency polarization beam splitters based on a two-dimensional polymer photonic crystal. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1464-4258/8/3/019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
The reaction of 4, 6-O-benzylidene-d-pyranosides with a stoichiometric amount of TsCl, AcCl, and BzCl in the presence of silver(I) oxide and a catalytic amount of potassium iodide led to monosubstituted derivatives in high regioselectivity and in good yields.
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Affiliation(s)
- Haisheng Wang
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Science, Peking University, Xue Yuan Road #38, Beijing 100083, P. R. China
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Abstract
As an important neurotoxin, aluminium can cause cognitive dysfunctions and mental diseases. Previous studies have reported that aluminium impaired long-term potentiation (LTP) in vivo and in vitro. Here, we utilise two models of synaptic plasticity, LTP and long-term depression (LTD) to study the effects of aluminium on synaptic plasticity in vivo. Neonatal Wistar rats were chronically exposed to aluminium from birth to weaning via the milk of dams fed with 0.3% aluminium chloride solution. Excitatory postsynaptic potential (EPSP) and population spikes (PS) were recorded from the dentate gyrus (DG) of adult rats by electrically stimulating the perforant path. THE FOLLOWING RESULTS WERE OBTAINED: (1) The input/output function indicated that, as compared to controls, aluminium increased the baseline amplitude of the PS, but decreased the baseline slope of EPSP. (2) Aluminium significantly prevented LTD in PS (controls: 77.36+/-6.7%, n=7; aluminium-exposed: 102.01+/-9.1%, n=7; P<0.05) and decreased the LTD amplitude in EPSP (controls: 76.61+/-4.1%, n=7; aluminium-exposed: 94.31+/-7.9% n=7, P<0.05). (3) Aluminium reduced the amplitude of LTP in both PS (controls: 190+/-16.1%, n=7; aluminium-exposed: 135+/-9.7%, n=7; P<0.05) and EPSP (control: 132+/-9.3%, n=7; aluminium-exposed: 115+/-10.6%, n=7; P<0.05). As for LTD and LTP, PS was impaired more seriously than EPSP in aluminium-exposed rats. (4) Aluminium exposure decreased the paired-pulse facilitation (PPF) of PS at 30-150 ms interpulse interval (IPI), and reduced 93.5% of PPF at 80 ms IPI in PS (controls: 243.4+/-39.8%, n=7; aluminium-exposed: 149.9+/-12.3%, n=7). There was no significant difference in EPSP of PPF. From these results we conclude that aluminium exposure in neonatal rats thus reduces the amplitude of LTP and PPF and blocks the induction of LTD in the DG. We suggest that aluminium affects both presynaptic and postsynaptic mechanisms of synaptic transmission.
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Affiliation(s)
- J Chen
- School of Life Science, University of Science and Technology of China, P.O. Box 4, Hefei, Anhui 230027, China
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Liu XG, Liang NC, Liu W, She J, Mo LE. [Inhibitory effect and kinetic analysis of sodium quercetin-7,4'-disulphate on recombinant human protein kinase CK2 holoenzyme]. Yao Xue Xue Bao 2002; 37:165-8. [PMID: 12579753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To study the direct effect and kinetics of sodium quercetin-7,4'-disulphate (SQDS) on recombinant human protein kinase CK2 holoenzyme. METHODS The recombinant human CK2 holoenzyme activity was assayed by detecting incorporation of 32P of [gamma-32P] ATP into the substrate in various conditions. RESULTS The recombinant human CK2 was a second messenger (Ca2+, cAMP and cGMP) independent protein kinase. The characterization and function of the reconstituted holoenzyme were consistent with those of native CK2. SQDS was shown to strongly inhibit the holoenzyme activity of recombinant human protein kinase CK2 with an IC50 of 4.4 mumol.L-1, which was more effective than DRB and A3, known CK2 special inhibitors. Kinetic studies of SQDS on recombinant human CK2 showed: the inhibition was competitive with ATP and noncompetitive with casein. CONCLUSION SQDS is a potent inhibitor of protein kinase CK2. This study provide experimental basis for the development of more effective inhibitors of CK2 and for clinical application of SQDS in the future.
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Affiliation(s)
- Xin-guang Liu
- Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang 524023, China.
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33
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She J, Liu HX. [Relation of the four famous doctors in Beijing and integrated traditional Chinese and Western medicine]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2001; 21:803-5. [PMID: 12575367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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34
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She J. Promoting the development of traditional Chinese medicine in the new century. J TRADIT CHIN MED 2001; 21:3-6. [PMID: 11360534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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35
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She J, Liu H. [Clinical epidemiological principle and method should be taken as an important measure in scientific research of traditional Chinese medicine]. Zhongguo Zhong Xi Yi Jie He Za Zhi 1999; 19:548-9. [PMID: 11783191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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36
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Liu W, Song ZJ, Liang NC, She J, Mo LE. Inhibitory effects of sodium quercetin monosulfate on pig platelet aggregation induced by thrombin. Zhongguo Yao Li Xue Bao 1999; 20:623-6. [PMID: 10678126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
AIM To study the inhibitory effects of sodium quercetin monosulfate (SQMS) on pig platelet aggregation induced by thrombin. METHODS Platelet aggregation was analyzed by turbidimetry. Cytosolic free calcium concentration ([Ca2+]i) was determined by Fura-2 fluorescence. Activity of protein kinase C (PKC) was assayed by incubating PKC with histone III S and [gamma-32 P] ATP. The cytoskeletal proteins were precipitated by Triton X-100 and separated by SDS-PAGE. RESULTS SQMS inhibited the platelet aggregation induced by thrombin 500 U.L-1 with IC50 132 (50-347) mumol.L-1. SQMS inhibited Ca2+ influx in blood platelets induced by thrombin 500 U.L-1 in the presence of extracellular Ca2+ 1 mmol.L-1 with IC50 20 (9-46) mumol.L-1; SQMS inhibited the internal Ca2+ release in the absence of extracellular Ca2+. SQMS also decreased [Ca2+]i level in quiescent blood platelets. SQMS (10-160 mumol.L-1) inhibited the activity of cytosolic PKC from blood platelets in a concentration-dependent manner, but had no effect on membrane PKC. SQMS (20-80 mumol.L-1) inhibited the actin polymerization induced by thrombin 500 U.L-1 inblood platelets in a concentration-dependent manner. CONCLUSION SQMS inhibited pig platelet aggregation induced by thrombin and its mechanism might be due to its inhibitions of Ca2+ influx, internal Ca2- release, PKC activity, and actin polymerization.
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Affiliation(s)
- W Liu
- Institute of Medical Biochemistry, Guangdong Medical College, Zhanjiang, China
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37
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She J, Ruzek MC, Velupillai P, de Aos I, Wang B, Harn DA, Sancho J, Biron CA, Terhorst C. Generation of antigen-specific cytotoxic T lymphocytes and regulation of cytokine production takes place in the absence of CD3zeta. Int Immunol 1999; 11:845-57. [PMID: 10330289 DOI: 10.1093/intimm/11.5.845] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The TCR-associated protein CD3zeta plays a major role in regulating the state of responsiveness to peptide-MHC complexes on the surface of antigen-presenting cells. In this paper the requirement of CD3zeta in the generation of cytotoxic T cells was compared with its requirement in cytokine gene activation in two mutant mice: ZKO mice with a disrupted CD3zeta gene and ZTG mice in which a truncated CD3zeta segment was expressed as a transgene on the ZKO background. Upon infection of ZTG mice with lymphocytic choriomeningitis virus (LCMV), antigen-specific cytotoxic T lymphocyte (CTL) responses were detected, identical to responses in wild-type mice. In addition, antigen-specific CTL responses to allogeneic class I and class II MHC in ZTG animals were indistinguishable from those in wild-type animals. However, CTL responses to the same major antigens were not detectable in ZKO mice. We conclude that the signal transduction pathways leading to CTL development and cytokine production can be triggered through TCR in the absence of functional CD3zeta, provided the remainder of the TCR-CD3 complex is expressed at high levels on the cell surface. Surprisingly, IFN-gamma production in response to LCMV followed the same kinetics in ZKO, ZTG and wild-type mice. However, in vitro studies showed that cytokine production in general was abnormally regulated in T lymphocytes from ZKO mice, in contrast to ZTG T cells. Taken together, these studies support the hypothesis that development of CTL can take place in the absence of functional CD3zeta. However, CTL development requires stronger TCR-initiated signal transduction events than induction of cytokine genes.
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MESH Headings
- Abatacept
- Animals
- Antigens, CD
- Antigens, Differentiation/physiology
- CD28 Antigens/physiology
- CTLA-4 Antigen
- Cytokines/biosynthesis
- Cytokines/genetics
- Immunoconjugates
- Membrane Proteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Receptor-CD3 Complex, Antigen, T-Cell/physiology
- Receptors, Antigen, T-Cell/physiology
- Signal Transduction
- T-Lymphocytes, Cytotoxic/physiology
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Affiliation(s)
- J She
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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Wang B, Wang N, Whitehurst CE, She J, Chen J, Terhorst C. T lymphocyte development in the absence of CD3 epsilon or CD3 gamma delta epsilon zeta. J Immunol 1999; 162:88-94. [PMID: 9886373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
CD3 gamma, delta, epsilon, and zeta proteins together with the pre-TCR alpha-chain (pT alpha) and a rearranged TCR beta-chain assemble to form the pre-TCR that controls the double negative (DN) to double positive (DP) stages of thymopoiesis. The CD3 proteins are expressed before pT alpha and TCR beta-chains in prothymocytes and are expressed intracellularly in precursor NK cells, suggesting that the CD3 complex may function independent of pT alpha and TCR beta. In this report, both the role of CD3 epsilon exclusively, and the role of CD3 proteins collectively, in thymocyte and NK cell development were examined. In a mouse strain termed E delta P, a neomycin cassette inserted within the CD3 epsilon promoter abolishes CD3 epsilon and delta expression and also abolishes CD3 gamma expression in all but a small minority (< or =1%) of prothymocytes. These prothymocytes became deficient in CD3 epsilon alone upon reconstitution of CD3 delta expression and were severely, but not completely, arrested at the DN stage, as small numbers of double positive thymocytes were detected. In de facto CD3 gamma delta epsilon zeta(null) mice generated by crossing the epsilon delta P mice with CD3 zeta-/- mice, thymopoiesis were arrested at the CD44-CD25+ DN stage as observed in RAG-/- mice, DJ and VDJ recombination at the TCR beta locus was functional, and normal numbers of NK cells were detected. Together, the findings demonstrate that during thymocyte development, the CD3 complex collectively is not essential until the critical CD44-CD25+ DN stage in which pre-TCR begins to function, whereas CD3 epsilon is critical for the assembly of pre-TCR. Moreover, CD3 proteins are dispensable for NK cell development.
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MESH Headings
- Animals
- CD3 Complex
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
- Humans
- Killer Cells, Natural/cytology
- Killer Cells, Natural/metabolism
- Lymphocyte Count
- Mice
- Mice, Knockout
- Mice, Transgenic
- Models, Biological
- Receptor-CD3 Complex, Antigen, T-Cell/biosynthesis
- Receptor-CD3 Complex, Antigen, T-Cell/deficiency
- Receptor-CD3 Complex, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/biosynthesis
- Receptors, Antigen, T-Cell/deficiency
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Stem Cells/cytology
- Stem Cells/immunology
- Stem Cells/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Thymus Gland/cytology
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Affiliation(s)
- B Wang
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Hooper K, Petreas MX, Chuvakova T, Kazbekova G, Druz N, Seminova G, Sharmanov T, Hayward D, She J, Visita P, Winkler J, McKinney M, Wade TJ, Grassman J, Stephens RD. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakstan: high levels of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) in agricultural villages of southern Kazakstan. Environ Health Perspect 1998; 106:797-806. [PMID: 9831540 PMCID: PMC1533246 DOI: 10.1289/ehp.98106797] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To assess levels of chlorinated contaminants in breast milk, we measured organochlorine pesticides, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in breast milk samples collected in 1994 according to the World Health Organization protocol from 92 donors that were representative of regional populations in southern Kazakstan. High levels (10-120 pg/g fat) of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic of the PCDD/PCDF congeners, were found in breast milk samples from an agricultural region. TCDD was the major contributor (75%) to the international toxicity equivalents of these samples. The same distinctive PCDD/PCDF congener pattern was found in 15 breast milk samples and 4 serum samples collected in 1996 in a follow-up study, and has now been confirmed by three analytical laboratories.
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Affiliation(s)
- K Hooper
- Hazardous Materials Laboratory, California Environmental Protection Agency, Berkeley, CA 94707 USA
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Wang N, Wang B, Salio M, Allen D, She J, Terhorst C. Expression of a CD3 epsilon transgene in CD3 epsilon(null) mice does not restore CD3 gamma and delta expression but efficiently rescues T cell development from a subpopulation of prothymocytes. Int Immunol 1998; 10:1777-88. [PMID: 9885898 DOI: 10.1093/intimm/10.12.1777] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [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: 11/12/2022] Open
Abstract
The TCR-associated CD3 complex consists of four subunits, i.e. CD3 gamma, delta, epsilon and zeta, which are expressed very early in T cell development prior to the expression of the TCR and the pre-TCR alpha chain. It is unclear whether the expression of each CD3 protein is independent of, or is influenced by, other CD3 subunits. To study whether CD3 epsilon regulates expression of CD3 gamma and delta genes, we generated a strain of CD3 epsilon-deficient mice termed CD3 epsilon(delta P/delta P) (epsilon(delta P)), in which the promoter of CD3E was disrupted, and subsequently reconstituted these mice with a CD3 epsilon transgene. In the epsilon(delta P) mice, T cell development is arrested at the double-negative stage and targeting the CD3 epsilon gene caused severe inhibition of CD3 gamma and delta gene expression. Introduction of the CD3 epsilon transgene did not restore CD3 gamma and delta expression. However, a very small fraction of prothymocytes that expressed CD3 gamma and delta was rescued upon reconstitution of the CD3 epsilon transgene. Remarkably, this rescue led to a very efficient differentiation and maturation of thymocytes, resulting in a significant T cell population in the periphery. These results demonstrate that CD3 epsilon does not regulate expression of CD3 gamma and delta genes, and underscore the capacity of each prothymocyte to give rise to a large number of mature peripheral T cells.
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MESH Headings
- Animals
- CD3 Complex/biosynthesis
- CD3 Complex/genetics
- CD3 Complex/immunology
- Exons
- Gene Expression Regulation/immunology
- Humans
- Macromolecular Substances
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mutagenesis, Insertional
- Promoter Regions, Genetic
- Receptors, Antigen, T-Cell, gamma-delta/biosynthesis
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Stem Cells/cytology
- Stem Cells/immunology
- Stem Cells/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Transgenes/immunology
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Affiliation(s)
- N Wang
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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41
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She J, Matsui K, Terhorst C, Ju ST. Activation-induced apoptosis of mature T cells is dependent upon the level of surface TCR but not on the presence of the CD3 zeta ITAM. Int Immunol 1998; 10:1733-40. [PMID: 9846702 DOI: 10.1093/intimm/10.11.1733] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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] [Indexed: 11/14/2022] Open
Abstract
Activation-induced cell death (AICD) occurs primarily in recently activated T cells after a second TCR triggering. Since a threshold in the activation status may be critical for AICD, it is likely that the CD3 ITAM, docking sites for tyrosine kinases, regulate AICD. A 'threshold model' for AICD was tested by using two targeted mutant mouse strains lacking either the zeta chain (CD3zeta-/-) or the ITAM of the zeta chain (CD3zeta-/-:Tgzetadelta67-150). Although the T cells from the CD3zeta-/- mice express extremely low levels of surface TCR, a subpopulation (approximately 18%) of activated T cells could be induced to express TCR/FcepsilonRI gamma by using a powerful polyclonal activation protocol. These activated TCR/FcRI gamma T cells were capable of undergoing AICD, but its induction required 10 times as much anti-CD3epsilon mAb as that required for AICD of wild-type T cells. Thus, the intensity of AICD correlated with the level of CD3 expression and was less efficient with activated, CD3zeta(-/-)-derived T cells. By contrast, AICD of T cells from the CD3zeta-/-:Tgzetadelta67-150 mice could be induced with low doses of anti-CD3epsilon mAb and the extent of AICD was comparable to T cells from wild-type mice. The AICD induced in T cells from CD3-/-, CD3zeta-/-:Tgzetadelta67-150 and normal controls was specifically inhibited by Fas-Ig fusion proteins. Our data support the 'threshold model' of AICD by demonstrating that AICD is controlled by the strength of T cell activation.
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Affiliation(s)
- J She
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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42
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Wang B, Wang N, Salio M, Sharpe A, Allen D, She J, Terhorst C. Essential and partially overlapping role of CD3gamma and CD3delta for development of alphabeta and gammadelta T lymphocytes. J Exp Med 1998; 188:1375-80. [PMID: 9763617 PMCID: PMC2212484 DOI: 10.1084/jem.188.7.1375] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1998] [Revised: 07/22/1998] [Indexed: 11/22/2022] Open
Abstract
CD3gamma and CD3delta are two highly related components of the T cell receptor (TCR)-CD3 complex which is essential for the assembly and signal transduction of the T cell receptor on mature T cells. In gene knockout mice deficient in either CD3delta or CD3gamma, early thymic development mediated by pre-TCR was either undisturbed or severely blocked, respectively, and small numbers of TCR-alphabeta+ T cells were detected in the periphery of both mice. gammadelta T cell development was either normal in CD3delta-/- mice or partially blocked in CD3gamma-/- mice. To examine the collective role of CD3gamma and CD3delta in the assembly and function of pre-TCR and in the development of gammadelta T cells, we generated a mouse strain with a disruption in both CD3gamma and CD3delta genes (CD3gammadelta-/-). In contrast to mice deficient in either CD3gamma or CD3delta chains, early thymic development mediated by pre-TCR is completely blocked, and TCR-alphabeta+ or TCR-gammadelta+ T cells were absent in the CD3gammadelta-/- mice. Taken together, these studies demonstrated that CD3gamma and CD3delta play an essential, yet partially overlapping, role in the development of both alphabeta and gammadelta T cell lineages.
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Affiliation(s)
- B Wang
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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43
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She J, Petreas MX, Visita P, McKinney M, Sy FJ, Winkler JJ, Hooper K, Stephens RD. Congener-specific analysis of PCBs in human milk from Kazakhstan. Chemosphere 1998; 37:431-442. [PMID: 9661274 DOI: 10.1016/s0045-6535(98)00059-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have characterized the spectrum of PCB contaminants in human milk samples from 95 women in Kazakhstan using GC/MS congener specific analysis. In these samples, 12 PCBs comprised 83% of total PCB concentration, and were similar to the major PCBs reported in other published human milk studies. By summing concentration levels of 80 PCB congeners in the Kazakhstan samples, a mean total PCB concentration of 368 ng/g fat was obtained. This is lower than levels reported in human milk samples from Western Europe. Six indicator PCBs were summed in Kazakh milk samples; their aggregate value was similar to literature values published for human milk from the former Soviet Union. Using WHO's recent TEF scheme, the mean sum of PCDD/F, coplanar PCB, mono-ortho PCB, and di-ortho PCB TEQ is 42 pg TEQ/g fat.
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Affiliation(s)
- J She
- Hazardous Materials Laboratory, California Public Health Foundation, Berkeley 94704, USA
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44
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Hooper K, Hopper K, Petreas MX, She J, Visita P, Winkler J, McKinney M, Mok M, Sy F, Garcha J, Gill M, Stephens RD, Semenova G, Sharmanov T, Chuvakova T, Hopper K. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakstan: PCBs and organochlorine pesticides in southern Kazakstan. Environ Health Perspect 1997; 105:1250-4. [PMID: 9370517 PMCID: PMC1470329 DOI: 10.1289/ehp.971051250] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Organochlorine pesticides (OC) and polychlorinated biphenyls (PCBs) were measured in samples of breast milk taken from 92 donors representative of regional populations in southern Kazakstan. The World Health Organization protocol for assessing levels of chlorinated contaminants in breast milk was followed. The most prevalent OC residues were beta-hexachlorocyclohexane (beta-HCH), p,p'-DDE, p,p'-DDT, hexachlorobenzene, and alpha-HCH. The measured levels of beta-HCH were among the highest reported in the published literature. Data from Aralsk, near the Aral Sea, indicated continuing DDT exposure. Overall PCB-toxic equivalent levels (22 pg/g fat) were similar to those reported in industrialized European countries. PCBs were highest in Atyrau in the Caspian oilfields.
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Affiliation(s)
- K Hooper
- Hazardous Materials Laboratory, California EPA, Berkeley, CA 94704-1011, USA
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45
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She J, Simpson SJ, Gupta A, Holländer G, Levelt C, Liu CP, Allen D, van Houten N, Wang B, Terhorst C. CD16-expressing CD8alpha alpha+ T lymphocytes in the intestinal epithelium: possible precursors of Fc gammaR-CD8alpha alpha+ T cells. J Immunol 1997; 158:4678-87. [PMID: 9144480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
T lymphocytes normally express their Ag receptors in association with the CD3 proteins, which include CD3zeta. In CD3zeta eta(null) mice thymic and peripheral T lymphocytes do not express the TCR/CD3 complex on their surface due to retention in the endoplasmic reticulum of the remaining polypeptide chains. However, intestinal intraepithelial lymphocytes (iIEL) of CD3zeta eta(null) mice do express surface TCR, because the Fc epsilonRI gamma chain replaced the CD3zeta chain in the TCR/CD3 complex. Here we report that in a subset of CD8alpha alpha+ iIEL the presence of the Fc epsilonRI gamma chain could be accounted for by the surface expression of the Fc gammaRIII(CD16) complex. Because in wild-type (wt) mice only CD16+ iIEL coexpressed Fc epsilonRI gamma and CD3zeta, we concluded that the presence of Fc epsilonRI gamma was dictated by its required participation of CD16 complex. CD8alpha alpha+ iIEL bearing CD16 and B220 were also detected in the intestinal mucosa of RAG-2(null) mice from 12 days after birth onward. Two independent experimental settings were used in an attempt to demonstrate that CD16+ iIEL matured into CD16- T cells. First, in the RAG-2(null) mice, iIEL responded to in vivo administration of an anti-CD3epsilon mAb by progression to a more mature stage of development, characterized by a loss of CD16 and B220. Secondly, a conversion to CD16- iIEL occurred upon transfer of wt CD16+ iIEL into RAG-2(null) mice. We conclude from these experiments that in both RAG-2(null) and wt mice, a precursor/progeny relationship may exists between CD16+ B220+ CD8alpha alpha+ and CD16- B220- CD8alpha alpha+ iIEL.
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Affiliation(s)
- J She
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
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She J, Simpson SJ, Gupta A, Holländer G, Levelt C, Liu CP, Allen D, van Houten N, Wang B, Terhorst C. CD16-expressing CD8alpha alpha+ T lymphocytes in the intestinal epithelium: possible precursors of Fc gammaR-CD8alpha alpha+ T cells. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.10.4678] [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: 01/01/2023]
Abstract
Abstract
T lymphocytes normally express their Ag receptors in association with the CD3 proteins, which include CD3zeta. In CD3zeta eta(null) mice thymic and peripheral T lymphocytes do not express the TCR/CD3 complex on their surface due to retention in the endoplasmic reticulum of the remaining polypeptide chains. However, intestinal intraepithelial lymphocytes (iIEL) of CD3zeta eta(null) mice do express surface TCR, because the Fc epsilonRI gamma chain replaced the CD3zeta chain in the TCR/CD3 complex. Here we report that in a subset of CD8alpha alpha+ iIEL the presence of the Fc epsilonRI gamma chain could be accounted for by the surface expression of the Fc gammaRIII(CD16) complex. Because in wild-type (wt) mice only CD16+ iIEL coexpressed Fc epsilonRI gamma and CD3zeta, we concluded that the presence of Fc epsilonRI gamma was dictated by its required participation of CD16 complex. CD8alpha alpha+ iIEL bearing CD16 and B220 were also detected in the intestinal mucosa of RAG-2(null) mice from 12 days after birth onward. Two independent experimental settings were used in an attempt to demonstrate that CD16+ iIEL matured into CD16- T cells. First, in the RAG-2(null) mice, iIEL responded to in vivo administration of an anti-CD3epsilon mAb by progression to a more mature stage of development, characterized by a loss of CD16 and B220. Secondly, a conversion to CD16- iIEL occurred upon transfer of wt CD16+ iIEL into RAG-2(null) mice. We conclude from these experiments that in both RAG-2(null) and wt mice, a precursor/progeny relationship may exists between CD16+ B220+ CD8alpha alpha+ and CD16- B220- CD8alpha alpha+ iIEL.
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Affiliation(s)
- J She
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - S J Simpson
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - A Gupta
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - G Holländer
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - C Levelt
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - C P Liu
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - D Allen
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - N van Houten
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - B Wang
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
| | - C Terhorst
- Division of Immunology, Beth Israel Hospital, Boston, MA 02115, USA
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Wang B, She J, Salio M, Allen D, Lacy E, Lonberg N, Terhorst C. CD3-epsilon overexpressed in prothymocytes acts as an oncogene. Mol Med 1997; 3:72-81. [PMID: 9132282 PMCID: PMC2230102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Upon engagement of the T cell receptor for antigen, its associated CD3 proteins recruit signal transduction molecules, which in turn regulate T lymphocyte proliferation, apoptosis, and thymocyte development. Because some signal transducing molecules recruited by CD3-epsilon, i.e., p56lck and p59fyn, are oncogenic and since we previously found that overexpression of CD3-epsilon transgenes causes a block in T lymphocyte and NK cell development, we tested the hypothesis that aberrant CD3-epsilon signaling leads both to abnormal T lymphocyte death and lymphomagenesis. MATERIALS AND METHODS Ten independently derived transgenic mouse lines were generated with four different genomic CD3-epsilon constructs. Mice either homozygous or hemizygous for each transgene were analyzed for an arrest in T lymphocyte development and for the occurrence of T cell lymphomas. RESULTS Aggressive clonal T cell lymphomas developed at very high frequencies in seven mouse lines with intermediate levels of copies of CD3-epsilon derived transgenes. However, these lymphomas were not found when high copy numbers of CD3-epsilon transgenes caused a complete block in early thymic development or when a transgene was used in which the exons coding for the CD3-epsilon protein were deleted. Analyses of a series of double mutant mice, tgCD3-epsilon x RAG-2null, indicated that lymphomagenesis was initiated in lineage-committed prothymocytes, i.e., before rearrangement of the T cell receptor genes. In addition, the transgene coding for the CD3-epsilon cytoplasmic domain and its transmembrane region induced a T cell differentiation signal in premalignant tgCD3-epsilon x RAG-2null mice. CONCLUSION The nonenzymatic CD3-epsilon protein acted as a potent oncogene when overexpressed early in T lymphocyte development. Lymphomagenesis was dependent on signal transduction events initiated by the cytoplasmic domain of CD3-epsilon.
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Affiliation(s)
- B Wang
- Beth Israel Deaconess Medical Center, Division of Immunology, Boston, MA 02215, USA
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Abstract
Collapsible-tube flow with self-excited oscillations has been extensively investigated. Though physiologically relevant, forced oscillation coupled with self-excited oscillation has received little attention in this context. Based on an ODE model of collapsible-tube flow, the present study applies modern dynamics methods to investigate numerically the responses of forced oscillation to a limit-cycle oscillation which has topological characteristics discovered in previous unforced experiments. A devil's staircase and period-doubling cascades are presented with forcing frequency and amplitude as control parameters. In both cases, details are provided in a bifurcation diagram. Poincaré sections, a frequency spectrum and the largest Lyapunov exponents verify the existence of chaos in some circumstances. The thin fractal structure found in the strange attractors is believed to be a result of high damping and low stiffness in such systems.
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Affiliation(s)
- J She
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia
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Zhou X, Qiu C, She J, Zhou W. [Induced-expression of MHC-DR molecules on mice islet cells]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1996; 18:84-8. [PMID: 9208594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The correlation of induced-expression of MHC-DR molecules with insulin release in cultured mice islet cells has been studied. The results showed that, (1) No detectable induced-expression of MHC-DR molecules by TNF-alpha alone at the concentration of 50-100 U/ml has been assayed, but the induced-expression of MHC-DR molecules has been identified in a few islet cells (8.5 +/- 2.9%) with IFN-r alone at concentration of 50-100 U/ml. (2) The induced-expression of MHC-DR molecules has been detected in as high as 80% of cultured islet cells with TNF-alpha and IFN-r combined at different concentrations. (3) Insulin released from cultured islet cells was enhanced by IFN-r and TNF-alpha either alone or combined at different concentrations. These results suggest that the induced-expression of MHC-DR molecules themselves does not damage the function for insulin release in cultured islet cells.
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Affiliation(s)
- X Zhou
- Institute of Basic Medical Sciences, CAMS and PUMC, Beijing
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Bertram CD, She J. Analysis of the effects of measurement errors on the evaluation of propagation coefficients, in rubber tubes and canine aorta in vivo. Technol Health Care 1995; 3:161-84. [PMID: 8749864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Published measurements of canine arterial propagation coefficients show large disparities in pulse wave attenuation and considerable variation with frequency, suggesting both random and systematic error. Here we devise methods of assessing the likely magnitude of each measurement error source, and calculate the individual and cumulative effects on the propagation coefficients derived using three different schemes to compensate for reflections: the three-point method (3PT), the total occlusion method (OCC) and the general iterative method applied to Cox's arrangement of four transducers (GEN). Results from measurements using impulse excitation in a latex tube show that each method accumulates error in a characteristic frequency pattern. The predicted error bands for OCC are very small except at the fundamental, and clearly exclude a significant further error component. The predicted 3PT error is large at low and at high frequency, and the error bands are better predictors of actual error than in the OCC case. Transducer position error is less than any one of the three pressure measurement errors. The predicted GEN error increases with frequency and when averaged across frequency is of magnitude intermediate between those for OCC and 3PT. Results for the OCC and GEN methods from the canine aorta in vivo generally confirm these trends, but the concentration of natural pulse wave energy at low frequencies acts to reduce low-frequency error and increase high-frequency error.
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Affiliation(s)
- C D Bertram
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia
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