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Tu R, Ping Z, Liu J, Tsoi ML, Song X, Liu W, Xie T. Niche Tet maintains germline stem cells independently of dioxygenase activity. EMBO J 2024; 43:1570-1590. [PMID: 38499787 PMCID: PMC11021519 DOI: 10.1038/s44318-024-00074-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/20/2024] Open
Abstract
Ten-eleven translocation (TET) proteins are dioxygenases that convert 5-methylcytosine (5mC) into 5-hydroxylmethylcytosine (5hmC) in DNA and RNA. However, their involvement in adult stem cell regulation remains unclear. Here, we identify a novel enzymatic activity-independent function of Tet in the Drosophila germline stem cell (GSC) niche. Tet activates the expression of Dpp, the fly homologue of BMP, in the ovary stem cell niche, thereby controlling GSC self-renewal. Depletion of Tet disrupts Dpp production, leading to premature GSC loss. Strikingly, both wild-type and enzyme-dead mutant Tet proteins rescue defective BMP signaling and GSC loss when expressed in the niche. Mechanistically, Tet interacts directly with Bap55 and Stat92E, facilitating recruitment of the Polybromo Brahma associated protein (PBAP) complex to the dpp enhancer and activating Dpp expression. Furthermore, human TET3 can effectively substitute for Drosophila Tet in the niche to support BMP signaling and GSC self-renewal. Our findings highlight a conserved novel catalytic activity-independent role of Tet as a scaffold protein in supporting niche signaling for adult stem cell self-renewal.
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Affiliation(s)
- Renjun Tu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Zhaohua Ping
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, USA
| | - Jian Liu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Centre, Shenzhen, Guangdong, China
| | - Man Lung Tsoi
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Chinese Academy of Sciences, New Territories, Hong Kong Special Administrative Region, China
| | - Xiaoqing Song
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, USA
| | - Wei Liu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Centre, Shenzhen, Guangdong, China
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China.
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, USA.
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2
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Tian J, Zhao T, Tu R, Zhang B, Huang Y, Shen Z, Wang Y, Du G. Achromobacter species (sp.) outbreak caused by hospital equipment containing contaminated water: risk factors for infection. J Hosp Infect 2024; 146:141-147. [PMID: 38403082 DOI: 10.1016/j.jhin.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND Nosocomial outbreaks of urinary tract infections caused by Achromobacter spp. have been rare in recent decades. AIM To identify the origin of an Achromobacter sp. outbreak, conduct multi-modal infection control measures, and finally to stop the outbreak. To this end, an epidemiological outbreak investigation and risk factor analysis were performed. METHODS Achromobacter sp. was detected in 22 patients in our urology wards and six environmental cultures of specimens obtained from the operating rooms. Strains isolated were submitted for antimicrobial susceptibility testing. An on-site epidemiological investigation, evaluation of patient medical records, and environmental sampling were performed to identify the source of the outbreak, and implementation of infection control intervention. A case-control study was performed to analyse the potential risk factors. FINDINGS Environmental sampling showed that the source of the infection for 22 patients was an ISA-IIIA-type medical pressurizer containing contaminated water. A case-control analysis showed that the risk factors for infection were: diagnosis of kidney/ureteral stones, surgery, placement of a double-J stent, and history of hospitalization in the past three months. CONCLUSION It was concluded that the outbreak occurred in patients who underwent internal lithotripsy and double-J stent placement, due to contact transmission with the contaminated sensor and connecting tubes of the ISA-IIIA-type medical pressurizer.
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Affiliation(s)
- J Tian
- Department of Infection and Management, The First People's Hospital of Guiyang, Guizhou, China
| | - T Zhao
- Department of Infection and Management, The First People's Hospital of Guiyang, Guizhou, China
| | - R Tu
- Department of Infection and Management, The First People's Hospital of Guiyang, Guizhou, China
| | - B Zhang
- Department of Infection and Management, The First People's Hospital of Guiyang, Guizhou, China
| | - Y Huang
- Department of Urology, The First People's Hospital of Guiyang, Guizhou, China
| | - Z Shen
- Department of Nursing, The First People's Hospital of Guiyang, Guizhou, China
| | - Y Wang
- Department of Clinical Laboratory, The First People's Hospital of Guiyang, Guizhou, China
| | - G Du
- Department of Infection and Management, The First People's Hospital of Guiyang, Guizhou, China.
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3
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Sun Y, Li M, Geng J, Meng S, Tu R, Zhuang Y, Sun M, Rui M, Ou M, Xing G, Johnson TK, Xie W. Neuroligin 2 governs synaptic morphology and function through RACK1-cofilin signaling in Drosophila. Commun Biol 2023; 6:1056. [PMID: 37853189 PMCID: PMC10584876 DOI: 10.1038/s42003-023-05428-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023] Open
Abstract
Neuroligins are transmembrane cell adhesion proteins well-known for their genetic links to autism spectrum disorders. Neuroligins can function by regulating the actin cytoskeleton, however the factors and mechanisms involved are still largely unknown. Here, using the Drosophila neuromuscular junction as a model, we reveal that F-Actin assembly at the Drosophila NMJ is controlled through Cofilin signaling mediated by an interaction between DNlg2 and RACK1, factors not previously known to work together. The deletion of DNlg2 displays disrupted RACK1-Cofilin signaling pathway with diminished actin cytoskeleton proteo-stasis at the terminal of the NMJ, aberrant NMJ structure, reduced synaptic transmission, and abnormal locomotion at the third-instar larval stage. Overexpression of wildtype and activated Cofilin in muscles are sufficient to rescue the morphological and physiological defects in dnlg2 mutants, while inactivated Cofilin is not. Since the DNlg2 paralog DNlg1 is known to regulate F-actin assembly mainly via a specific interaction with WAVE complex, our present work suggests that the orchestration of F-actin by Neuroligins is a diverse and complex process critical for neural connectivity.
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Affiliation(s)
- Yichen Sun
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Moyi Li
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
- Jiangsu Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
| | - Junhua Geng
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Sibie Meng
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Renjun Tu
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Yan Zhuang
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Mingkuan Sun
- The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, 211166, China
| | - Menglong Rui
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Mengzhu Ou
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Guangling Xing
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
- Department of Biochemistry and Chemistry, and La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Wei Xie
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
- Jiangsu Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
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Tu R, Tang XA, Xu R, Ping Z, Yu Z, Xie T. Gap junction-transported cAMP from the niche controls stem cell progeny differentiation. Proc Natl Acad Sci U S A 2023; 120:e2304168120. [PMID: 37603749 PMCID: PMC10468610 DOI: 10.1073/pnas.2304168120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 07/22/2023] [Indexed: 08/23/2023] Open
Abstract
The niche has been shown to control stem cell self-renewal in different tissue types and organisms. Recently, a separate niche has been proposed to control stem cell progeny differentiation, called the differentiation niche. However, it remains poorly understood whether and how the differentiation niche directly signals to stem cell progeny to control their differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells contribute to two separate niche compartments for controlling both germline stem cell (GSC) self-renewal and progeny differentiation. In this study, we show that IGS cells express Inx2 protein, which forms gap junctions (GJs) with germline-specific Zpg protein to control stepwise GSC lineage development, including GSC self-renewal, germline cyst formation, meiotic double-strand DNA break formation, and oocyte specification. Germline-specific Zpg and IGS-specific Inx2 knockdowns cause similar defects in stepwise GSC development. Additionally, secondary messenger cAMP is transported from IGS cells to GSCs and their progeny via GJs to activate PKA signaling for controlling stepwise GSC development. Therefore, this study demonstrates that the niche directly controls GSC progeny differentiation via the GJ-cAMP-PKA signaling axis, which provides important insights into niche control of stem cell differentiation and highlights the importance of GJ-transported cAMP in tissue regeneration. This may represent a general strategy for the niche to control adult stem cell development in various tissue types and organisms since GJs and cAMP are widely distributed.
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Affiliation(s)
- Renjun Tu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Xiaohan Alex Tang
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Rui Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Zhaohua Ping
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
- Stowers Institute for Medical Research, Kansas City, MO64110
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Tu R, Yu J, Zhang X, Zhu Y, Zeng G. Renal tubular acidosis and nephrogenic diabetes insipidus caused by Sjögren's syndrome with hypokalemic periodic paralysis as the first symptom: A case report. Rev Neurol (Paris) 2022; 178:861-864. [PMID: 35568514 DOI: 10.1016/j.neurol.2022.02.458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 11/19/2022]
Affiliation(s)
- R Tu
- Affiliated Hospital of North Sichuan Medical College Nanchong, 637000 Sichuan, China
| | - J Yu
- Affiliated Hospital of North Sichuan Medical College Nanchong, 637000 Sichuan, China.
| | - X Zhang
- Affiliated Hospital of North Sichuan Medical College Nanchong, 637000 Sichuan, China
| | - Y Zhu
- Affiliated Hospital of North Sichuan Medical College Nanchong, 637000 Sichuan, China
| | - G Zeng
- Affiliated Hospital of North Sichuan Medical College Nanchong, 637000 Sichuan, China
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6
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Fan K, Wei D, Liu X, He Y, Tian H, Tu R, Liu P, Nie L, Zhang L, Qiao D, Liu X, Hou J, Li L, Wang C, Huo W, Zhang G, Mao Z. Negative associations of morning serum cortisol levels with obesity: the Henan rural cohort study. J Endocrinol Invest 2021; 44:2581-2592. [PMID: 33829394 DOI: 10.1007/s40618-021-01558-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/22/2021] [Indexed: 12/19/2022]
Abstract
AIMS To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations. MATERIALS AND METHODS A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography-tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively. RESULTS After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers. CONCLUSION Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.
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Affiliation(s)
- K Fan
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - D Wei
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - X Liu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - Y He
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - H Tian
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - R Tu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - P Liu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - L Nie
- Department of Occupational and Environmental Health Sciences, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - L Zhang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - D Qiao
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - X Liu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - J Hou
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - L Li
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - C Wang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - W Huo
- Department of Occupational and Environmental Health Sciences, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China
| | - G Zhang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China.
| | - Z Mao
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, People's Republic of China.
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Sulyaeva VS, Gatapova EY, Kozhevnikov AK, Rogilo DI, Saraev AA, Yushina IV, Khomyakov MN, Shapovalova AA, Shayapov VR, Bhaskar N, Tu R, Kosinova ML. CHEMICAL STRUCTURE AND FUNCTIONAL PROPERTIES OF AMORPHOUS BORON CARBONITRIDE FILMS. J STRUCT CHEM+ 2021. [DOI: 10.1134/s0022476621080187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Pang J, Le L, Zhou Y, Tu R, Hou Q, Tsuchiya D, Thomas N, Wang Y, Yu Z, Alexander R, Thexton M, Lewis B, Corbin T, Durnin M, Li H, Ashery-Padan R, Yan D, Xie T. NOTCH Signaling Controls Ciliary Body Morphogenesis and Secretion by Directly Regulating Nectin Protein Expression. Cell Rep 2021; 34:108603. [PMID: 33440163 DOI: 10.1016/j.celrep.2020.108603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 07/19/2020] [Revised: 11/20/2020] [Accepted: 12/14/2020] [Indexed: 11/29/2022] Open
Abstract
Anterior segment dysgenesis is often associated with cornea diseases, cataracts, and glaucoma. In the anterior segment, the ciliary body (CB) containing inner and outer ciliary epithelia (ICE and OCE) secretes aqueous humor that maintains intraocular pressure (IOP). However, CB development and function remain poorly understood. Here, this study shows that NOTCH signaling in the CB maintains the vitreous, IOP, and eye structures by regulating CB morphogenesis, aqueous humor secretion, and vitreous protein expression. Notch2 and Notch3 function via RBPJ in the CB to control ICE-OCE adhesion, CB morphogenesis, aqueous humor secretion, and protein expression, thus maintaining IOP and eye structures. Mechanistically, NOTCH signaling transcriptionally controls Nectin1 expression in the OCE to promote cell adhesion for driving CB morphogenesis and to directly stabilize Cx43 for controlling aqueous humor secretion. Finally, NOTCH signaling directly controls vitreous protein secretion in the ICE. Therefore, this study provides important insight into CB functions and involvement in eye diseases.
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Affiliation(s)
- Ji Pang
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Liang Le
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yi Zhou
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Blvd, Kansas City, KS 66160, USA
| | - Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Qiang Hou
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; State Key Laboratory and Key Laboratory of Vision Science, School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dai Tsuchiya
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Nancy Thomas
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yongfu Wang
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Zulin Yu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Richard Alexander
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Marina Thexton
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Brandy Lewis
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Timothy Corbin
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Michael Durnin
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Deyue Yan
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Blvd, Kansas City, KS 66160, USA.
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Tu R, Duan B, Song X, Chen S, Scott A, Hall K, Blanck J, DeGraffenreid D, Li H, Perera A, Haug J, Xie T. Multiple Niche Compartments Orchestrate Stepwise Germline Stem Cell Progeny Differentiation. Curr Biol 2020; 31:827-839.e3. [PMID: 33357404 DOI: 10.1016/j.cub.2020.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/17/2020] [Accepted: 12/15/2020] [Indexed: 11/28/2022]
Abstract
The niche controls stem cell self-renewal and progenitor differentiation for maintaining adult tissue homeostasis in various organisms. However, it remains unclear whether the niche is compartmentalized to control stem cell self-renewal and stepwise progeny differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells form a niche for controlling germline stem cell (GSC) progeny differentiation. In this study, we have identified four IGS subpopulations, which form linearly arranged niche compartments for controlling GSC maintenance and multi-step progeny differentiation. Single-cell analysis of the adult ovary has identified four IGS subpopulations (IGS1-IGS4), the identities and cellular locations of which have been further confirmed by fluorescent in situ hybridization. IGS1 and IGS2 physically interact with GSCs and mitotic cysts to control GSC maintenance and cyst formation, respectively, whereas IGS3 and IGS4 physically interact with 16-cell cysts to regulate meiosis, oocyte development, and cyst morphological change. Finally, one follicle cell progenitor population has also been transcriptionally defined for facilitating future studies on follicle stem cell regulation. Therefore, this study has structurally revealed that the niche is organized into multiple compartments for orchestrating stepwise adult stem cell development and has also provided useful resources and tools for further functional characterization of the niche in the future.
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Affiliation(s)
- Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Bo Duan
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Xiaoqing Song
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Allison Scott
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Kate Hall
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Jillian Blanck
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Dustin DeGraffenreid
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Anoja Perera
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Jeff Haug
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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10
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Tu R, Duan B, Song X, Xie T. Dlp-mediated Hh and Wnt signaling interdependence is critical in the niche for germline stem cell progeny differentiation. Sci Adv 2020; 6:eaaz0480. [PMID: 32426496 PMCID: PMC7220319 DOI: 10.1126/sciadv.aaz0480] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 02/28/2020] [Indexed: 05/04/2023]
Abstract
Although multiple signaling pathways work synergistically in various niches to control stem cell self-renewal and differentiation, it remains poorly understood how they cooperate with one another molecularly. In the Drosophila ovary, Hh and Wnt pathways function in the niche to promote germline stem cell (GSC) progeny differentiation. Here, we show that glypican Dlp-mediated Hh and Wnt signaling interdependence operates in the niche to promote GSC progeny differentiation by preventing BMP signaling. Hh/Wnt-mediated dlp repression is essential for their signaling interdependence in niche cells and for GSC progeny differentiation by preventing BMP signaling. Mechanistically, Hh and Wnt downstream transcription factors directly bind to the same dlp regulatory region and recruit corepressors composed of transcription factor Croc and Egg/H3K9 trimethylase to repress Dlp expression. Therefore, our study reveals a novel mechanism for Hh/Wnt signaling-mediated direct dlp repression and a novel regulatory mechanism for Dlp-mediated Hh/Wnt signaling interdependence in the GSC differentiation niche.
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Affiliation(s)
- Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Bo Duan
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Xiaoqing Song
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Corresponding author.
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11
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Mao Y, Tu R, Huang Y, Mao D, Yang Z, Lau PK, Wang J, Ni J, Guo Y, Xie T. The exocyst functions in niche cells to promote germline stem cell differentiation by directly controlling EGFR membrane trafficking. Development 2019; 146:dev.174615. [PMID: 31142545 DOI: 10.1242/dev.174615] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 12/11/2018] [Accepted: 05/14/2019] [Indexed: 12/31/2022]
Abstract
The niche controls stem cell self-renewal and differentiation in animal tissues. Although the exocyst is known to be important for protein membrane trafficking and secretion, its role in stem cells and niches has never been reported. Here, this study shows that the exocyst functions in the niche to promote germline stem cell (GSC) progeny differentiation in the Drosophila ovary by directly regulating EGFR membrane trafficking and signaling. Inactivation of exocyst components in inner germarial sheath cells, which form the differentiation niche, causes a severe GSC differentiation defect. The exocyst is required for maintaining niche cells and preventing BMP signaling in GSC progeny by promoting EGFR membrane targeting and signaling through direct association with EGFR. Finally, it is also required for EGFR membrane targeting, recycling and signaling in human cells. Therefore, this study reveals a novel function of the exocyst in niche cells to promote stem cell progeny differentiation by directly controlling EGFR membrane trafficking and signaling in vivo, and also provides important insight into how the niche controls stem cell progeny differentiation at the molecular level.
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Affiliation(s)
- Ying Mao
- PKU-THU Joint Center for Life Sciences, College of Life Sciences, School of Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Yan Huang
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Decai Mao
- PKU-THU Joint Center for Life Sciences, College of Life Sciences, School of Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Zhihao Yang
- PKU-THU Joint Center for Life Sciences, College of Life Sciences, School of Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Pik Ki Lau
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jinhui Wang
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jianquan Ni
- PKU-THU Joint Center for Life Sciences, College of Life Sciences, School of Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Yusong Guo
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
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12
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Sung H, Witzel T, Hata C, Tu R, Shen S, Lin D, Noishiki Y, Tomizawa Y, Quijano R. Development and Evaluation of a Pliable Biological Valved Conduit. Part II: Functional and Hemodynamic Evaluation. Int J Artif Organs 2018. [DOI: 10.1177/039139889301600406] [Citation(s) in RCA: 19] [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] [Indexed: 11/15/2022]
Abstract
Many congenital cardiac malformations may require a valved conduit for the reconstruction of the right ventricular outflow tract. In spite of many endeavors made in the last 25 years, the clinical results of right ventricular outflow tract reconstruction with currently available valved conduits are still not satisfactory. Specific problems encountered clinically include suboptimal hemodynamic performance, conduit kinking or compression, and fibrous peeling from the luminal surface. To address these deficiencies, we undertook the development of a biological valved conduit: a bovine external jugular vein graft with a retained native valve cross-linked with a diglycidyl ether (DE). This study, using a canine model, was to evaluate the functional and hemodynamic performance of this newly developed valved conduit. Three 14 mm conduits, implanted as bypass grafts, right ventricle to pulmonary artery, were evaluated. The evaluation was conducted with a noninvasive color Doppler flow mapping system at pre-implantation, immediately post implantation, one- and three-months post implantation, and prior to retrieval (five-months post implantation). The two-dimensional tomographic inspection of the leaflet motion at various periods post implantation showed that the valvular leaflets in the DE treated conduit was quite pliable. No cardiac failure or valvular dysfunction was observed in any of the studied cases. The color Doppler flow mapping study demonstrated that the valve in the DE treated conduit was competent, with no conduit kinking or compression observed in any of the three cases. The spectral Doppler velocity study evidenced that the transvalvular pressure gradients of the DE treated conduit were minimal as compared to those of the currently available conduits. In conclusion, from the functional and hemodynamic performance points of view, this newly developed valved conduit is superior to those currently available.
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Affiliation(s)
- H.W. Sung
- Baxter Edwards CVS Division, Irvine, California - USA
| | - T.H. Witzel
- Baxter Edwards CVS Division, Irvine, California - USA
| | - C. Hata
- Baxter Edwards CVS Division, Irvine, California - USA
| | - R. Tu
- Baxter Edwards CVS Division, Irvine, California - USA
| | - S.H. Shen
- Baxter Edwards CVS Division, Irvine, California - USA
| | - D. Lin
- Baxter Edwards CVS Division, Irvine, California - USA
| | | | - Y. Tomizawa
- Tokyo Women's Medical College, Tokyo - Japan
| | - R.C. Quijano
- Baxter Edwards CVS Division, Irvine, California - USA
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Tu R, Quijano R, Lu C, Shen S, Wang E, Hata C, Lin D. A Preliminary Study of the Fixation Mechanism of Collagen Reaction with a Polyepoxy Fixative. Int J Artif Organs 2018. [DOI: 10.1177/039139889301600707] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A new biomaterial has been developed by fixing native collagens with a polyepoxy compound (PC) fixative. Prior studies have shown that this biomaterial has comparable properties as compared to collagen fixed with glutaraldehyde (GA) and thus has a great promise for use as an implantable bioprosthesis. The purpose of this study was to understand the mechanism of the amino acids-PC reactions in the fixation process. Bovine arteries were fixed with PC under various pH, concentration and temperature conditions as a function of fixation time. Individual amino acid components in the fresh and the fixed arteries were assayed using a Beckman amino acid analyzer to determine the degree of tanning. The denaturation temperature (Td) was also measured on each sample. Since the denaturation temperature is a direct indication of cross-linking of individual amino acids with the fixative, the difference in the degree of tanning for the same increase in Td may be indicative of the quantity of the masked, non-cross-linked amino acids. The fixation reaction data indicated that not all amino acids were cross-linked upon contacting the PC fixative. Masking appeared to be more substantial with a fixation at higher pH values.
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Affiliation(s)
- R. Tu
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - R.C. Quijano
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - C.L. Lu
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - S. Shen
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - E. Wang
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - C. Hata
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
| | - D. Lin
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, California - USA
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Noishiki Y, Hata C, Tu R, Shen S, Lin D, Sung H, Witzel T, Wang E, Thyagarajan K, Tomizawa Y, Quijano R. Development and Evaluation of a Pliable Biological Valved Conduit. Part I: Preparation, Biochemical Properties, and Histological Findings. Int J Artif Organs 2018. [DOI: 10.1177/039139889301600405] [Citation(s) in RCA: 19] [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] [Indexed: 10/17/2022]
Abstract
Different types of external valved conduits have been used for the repair of complex congenital cardiac anomalies that may have otherwise been inoperable. However, an ideal conduit has yet to be found due to complications such as stenosis, thrombosis, calcification of the valve and graft wall, and “peeling” of the neointima. To address those problems, a new extracardiac valved conduit made of bovine jugular vein was developed and evaluated in a preliminary animal study. Harvested bovine vein containing a naturally existing valve was initially incorporated with protamine on the inner surface and then was cross-linked in diglycidyl ether (DE). Fixation with DE allowed the vein and its leaflets to retain a tissue-like elasticity. To provide antithrombogenicity to the graft, heparin was introduced into the lumen to bind ionically to the pre-entrapped protamine. The biological valved conduit of approximately 14 mm diameter was implanted from the right ventricle to pulmonary artery as bypass graft in three dogs. After implantation, the native main pulmonary artery was ligated between the anastomotic sites of the bypass conduit. No anticoagulant or antiplatelet drugs were administered after surgery. One DE-fixed valved conduit was retrieved at 3 months, and the others were removed at 5 months. Only small thrombus areas were found on the white luminal surfaces. The valves and the conduits maintained softness and pliability, similar to before implantation. Additionally, the collagen content, shrink temperature, and tanning index of this newly developed biological valved conduit before and after fixation were measured in the study. These preliminary results suggest that the new valved conduit fixed with DE and heparinized on the lumen may help mitigate the problems observed in the currently available conduits.
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Affiliation(s)
- Y. Noishiki
- First Department of Surgery, Yokohama City University School of Medicine, Yokohama - Japan
| | - C. Hata
- Baxter Edwards CVS Division, Irvine, California - USA
| | - R. Tu
- Baxter Edwards CVS Division, Irvine, California - USA
| | - S.H. Shen
- Baxter Edwards CVS Division, Irvine, California - USA
| | - D. Lin
- Baxter Edwards CVS Division, Irvine, California - USA
| | - H.W. Sung
- Baxter Edwards CVS Division, Irvine, California - USA
| | - T. Witzel
- Baxter Edwards CVS Division, Irvine, California - USA
| | - E. Wang
- Baxter Edwards CVS Division, Irvine, California - USA
| | | | - Y. Tomizawa
- Tokyo Women's Medical College, Tokyo - Japan
| | - R.C. Quijano
- Baxter Edwards CVS Division, Irvine, California - USA
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Wang E, Thyagarajan K, Tu R, Lin D, Hata C, Shen S, Quijano R. Evaluation of Collagen Modification and Surface Properties of a Bovine Artery via Polyepoxy Compound Fixation. Int J Artif Organs 2018. [DOI: 10.1177/039139889301600706] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Collagen of bovine internal thoracic artery (BITA) was treated with glutaraldehyde (GA) or polyepoxy compounds (PC). This study was to evaluate the surface properties as a result of tissue tanning reaction with PC. The fixation resulted in a significant reduction of available lysine, histidine, and other amino acid residues in PC fixed grafts as compared to fresh pre-fixed arteries. Among them, the lysine (Lys) content was reduced by about 80%, indicating that PC reactions mainly involve with Lys residues. Both PC and GA treatment led to crosslinking as evidenced by the increase in the denaturation temperature. The critical surface tension and the Fourier Transform Infrared Spectrum (FTIR) on a preimplant and its 96 days explant were evaluated and found to be similar. The FTIR analysis of a pre-implant and the 96 day explant indicated that there was no lipid deposition.
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Affiliation(s)
- E. Wang
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - K. Thyagarajan
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - R. Tu
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - D. Lin
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - C. Hata
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - S.H. Shen
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
| | - R.C. Quijano
- Baxter Healthcare Corporation, Edwards CVS Division, Irvine, CA - USA
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Boerboom L, Olinger G, Karas B, Lindon J, Rosen L, Thyagarajan K, Tu R. Heparinization of Biological Vascular Graft Reduces Fibrin Deposition. Int J Artif Organs 2018. [DOI: 10.1177/039139889301600506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An alternative graft is needed for coronary bypass operations in patients lacking suitable autologous vessels. We therefore studied Denaflex™, a biologic graft, in a dog ex-vivo shunt model to determine whether heparin treatment makes this graft less thrombogenic. Comparison was also made to Bioflow™, a nonheparinized biologic graft. Fibrinogen deposition during high flow (593 ± 202 ml/min) decreased from 672 ± 467 ngl mm2 in nonheparinized Denaflex grafts to 448 ± 298 ng/mm2 (p<0.05) in heparinized Denaflex grafts. At low flow (117 ± 13 ml/min), heparinization of Denaflex grafts similarly decreased fibrinogen deposition from 1102 ± 601 ng/mm2 to 703 ± 405 ng/mm2 (p<0.05). At both flow rates fibrinogen deposition in Bioflow grafts was less than in nonheparinized Denaflex, but was similar to heparinized Denaflex grafts. Platelet deposition was not influenced by heparinization of Denaflex grafts and was similar among Denaflex and Bioflow preparations. Whether Denaflex performs acceptably in vivo as a xenograft requires extensive study.
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Affiliation(s)
- L.E. Boerboom
- Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wl Irvine, CA - USA
| | - G.N. Olinger
- Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wl Irvine, CA - USA
| | - B.J. Karas
- Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wl Irvine, CA - USA
| | - J.N. Lindon
- Applied Science and Baxter Healthcare Corporation, Irvine, CA - USA
| | - L.Z. Rosen
- Applied Science and Baxter Healthcare Corporation, Irvine, CA - USA
| | - K. Thyagarajan
- Edwards Divisions, Baxter Healthcare Corporation, Irvine, CA - USA
| | - R. Tu
- Edwards Divisions, Baxter Healthcare Corporation, Irvine, CA - USA
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17
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Tu R, Qian J, Rui M, Tao N, Sun M, Zhuang Y, Lv H, Han J, Li M, Xie W. Proteolytic cleavage is required for functional neuroligin 2 maturation and trafficking in Drosophila. J Mol Cell Biol 2018; 9:231-242. [PMID: 28498949 PMCID: PMC5907836 DOI: 10.1093/jmcb/mjx015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 05/03/2017] [Indexed: 01/15/2023] Open
Abstract
Neuroligins (Nlgs) are transmembrane cell adhesion molecules playing essential roles in synapse development and function. Genetic mutations in neuroligin genes have been linked with some neurodevelopmental disorders such as autism. These mutated Nlgs are mostly retained in the endoplasmic reticulum (ER). However, the mechanisms underlying normal Nlg maturation and trafficking have remained largely unknown. Here, we found that Drosophila neuroligin 2 (DNlg2) undergoes proteolytic cleavage in the ER in a variety of Drosophila tissues throughout developmental stages. A region encompassing Y642-T698 is required for this process. The immature non-cleavable DNlg2 is retained in the ER and non-functional. The C-terminal fragment of DNlg2 instead of the full-length or non-cleavable DNlg2 is able to rescue neuromuscular junction defects and GluRIIB reduction induced by dnlg2 deletion. Intriguingly, the autism-associated R598C mutation in DNlg2 leads to similar marked defects in DNlg2 proteolytic process and ER export, revealing a potential role of the improper Nlg cleavage in autism pathogenesis. Collectively, our findings uncover a specific mechanism that controls DNlg2 maturation and trafficking via proteolytic cleavage in the ER, suggesting that the perturbed proteolytic cleavage of Nlgs likely contributes to autism disorder.
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Affiliation(s)
- Renjun Tu
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Jinjun Qian
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Menglong Rui
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Nana Tao
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Mingkuan Sun
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Yan Zhuang
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Huihui Lv
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Junhai Han
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China.,The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Moyi Li
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China.,The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
| | - Wei Xie
- Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China.,The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 SiPaiLou Road, Nanjing 210096, China
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18
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Abstract
One requirement of the mechanical parameters for an acceptable vascular prosthesis is compliance. The compliance of a vascular prosthesis is defined as the fractional change in luminal volume per unit change in applied pressure. A compliant prosthesis has been correlated to prosthesis patency and long-term efficacy in an animal study. However, there have been very few reports on how to manufacture a compliant prosthesis. It is the objective of this study to research the processing methods to manufacture a reasonably compliant vascular prosthesis. A new fixative, polyepoxy compound, was used to fix an artery. The arteries were fixed under different degrees of longitudinal retraction. By locking in the collagen micro-structure at an overly relaxed state and then crosslinking said collagen, the resulting biological prosthesis exhibited extreme compliance and pliability. A prosthesis matching its arterial origin in tensile modulus was achieved by crosslinking an artery at its 45% retraction longitudinally. This flexible prosthesis showed a volumetric compliance index of 18.4 ± 0.9 %Δ/100 mmHg and a longitudinal tensile modulus of 942 grams/cm2. Our current study indicated that a prosthesis fixed with polyepoxy compounds has shown more pliability than that with glutaraldehyde. Further animal study to correlate prostheses patency to different degrees of compliance is needed to confirm this proposed manufacturing approach.
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Affiliation(s)
- R. Tu
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
| | - E. Wang
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
| | - C. Hata
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
| | - S.H. Shen
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
| | - D. Lin
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
| | - R.C. Quijano
- Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California - USA
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Yang K, Li Y, Mao Z, Liu X, Zhang H, Liu R, Xue Y, Tu R, Liu X, Zhang X, Li W, Wang C. Relationship between spicy flavor, spicy food intake frequency, and general obesity in a rural adult Chinese population: The RuralDiab study. Nutr Metab Cardiovasc Dis 2018; 28:252-261. [PMID: 29289573 DOI: 10.1016/j.numecd.2017.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/16/2017] [Accepted: 10/22/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS The purpose of this study was to explore the association between spicy flavor, spicy food frequency, and general obesity in Chinese rural adults. METHODS AND RESULTS A total of 15,683 subjects (5907 males, 9776 females) aged 35-74 years from the RuralDiab Study were recruited for this cross-sectional study. Analysis of covariance was used to determine the differences of participant characteristics across body mass index (BMI) categories. Logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for obesity associated with the level of spicy flavor and frequency of spicy food intake. A meta-analysis was conducted to validate the result of the cross-sectional study. The crude and standardized prevalence of obesity were 16.78% and 17.57%, respectively. Compared with No spicy flavor, the adjusted ORs (95% CIs) of Mild, Middle, and Heavy spicy flavor for obesity were 1.232 (1.117-1.359), 1.463 (1.290-1.659), and 1.591 (1.293-1.958), respectively (Ptrend < 0.001). Similarly, compared with no spicy food consumption, the adjusted ORs (95% CIs) of 1 or 2 days/week, 3-5 days/week, and 6 or 7 days/week were 1.097 (0.735-1.639), 1.294 (0.932-1.796), and 1.250 (1.025-1.525), respectively (Ptrend = 0.026). The point estimate and 95% CI of mean BMI difference between the spicy food consuming group and spicy food non-consuming group was 0.37 (95% CI: 0.30-0.44) in the meta-analysis. CONCLUSION The data indicated that spicy flavor and spicy food frequency were positively associated with general obesity in Chinese rural populations.
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Affiliation(s)
- K Yang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Y Li
- Department of Clinical Pharmacology, School of Pharmaceutical Science, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Z Mao
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - X Liu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - H Zhang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - R Liu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Y Xue
- Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - R Tu
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - X Liu
- Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - X Zhang
- Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - W Li
- Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China
| | - C Wang
- Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China.
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Abstract
In this second article, we continue the review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. The discussion in this article is focused on topics pertaining to levels 4 and 5, which are the more advanced levels of competency defined by the Accreditation Council for Graduate Medical Education Neuroradiology Milestones on Health Care Economics and System Based Practice.
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Affiliation(s)
- S L Weiner
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - R Tu
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - R Javan
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - M R Taheri
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC.
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Abstract
Few resources are available in the medical literature for a comprehensive review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. Therefore, we present a comprehensive review article as a study guide for fellows to learn from and gain competence in the Accreditation Council for Graduate Medical Education neuroradiology milestones on health care economics.
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Affiliation(s)
- S L Weiner
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - R Tu
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - R Javan
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC
| | - M R Taheri
- From the Neuroradiology Section, Department of Radiology, George Washington University Hospital, Washington, DC.
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Tu R, Chang-Ming H, Lin J, Li P, Zheng C. Comprehensive complication index (CCI) predicts cancer-specific survival of patients with postoperative complications after curative resection of gastric cancer. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx369.030] [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: 11/12/2022] Open
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Lu J, Chang-Ming H, Zheng C, Chen Q, Tu R. The effectiveness of the 8th American Joint Committee on Cancer TNM classification in the prognosis evaluation of stage III gastric cancer patients: A comparative study between the 7th and 8th editions. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx369.083] [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: 11/13/2022] Open
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24
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Wang X, Liu D, Ning Y, Liu J, Wang X, Tu R, Shen H, Chen Q, Xiong Y. Siglec-9 is upregulated in rheumatoid arthritis and suppresses collagen-induced arthritis through reciprocal regulation of Th17-/Treg-cell differentiation. Scand J Immunol 2017; 85:433-440. [PMID: 28273363 DOI: 10.1111/sji.12543] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/02/2017] [Indexed: 12/25/2022]
Affiliation(s)
- X. Wang
- Institute of Endemic Diseases; Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission; Health Science Center; Xi'an Jiaotong University; Xi'an China
- Department of Rheumatology; Second Hospital of Lanzhou University; Lanzhou Gansu China
| | - D. Liu
- Institute of Endemic Diseases; Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission; Health Science Center; Xi'an Jiaotong University; Xi'an China
- Department of Rheumatology and Immunology; Xi'an No.5 Hospital; Xi'an Shaanxi China
| | - Y. Ning
- Department of Nephrology; Second Hospital of Lanzhou University; Lanzhou Gansu China
| | - J. Liu
- Department of Rheumatology and Immunology; Xi'an No.5 Hospital; Xi'an Shaanxi China
| | - X. Wang
- Core Research Laboratory; Second Hospital of Lanzhou University; Lanzhou Gansu China
- Department of Rheumatology; Second Hospital of Lanzhou University; Lanzhou Gansu China
| | - R. Tu
- College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - H. Shen
- Department of Rheumatology; Second Hospital of Lanzhou University; Lanzhou Gansu China
| | - Q. Chen
- Institute of Endemic Diseases; Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission; Health Science Center; Xi'an Jiaotong University; Xi'an China
| | - Y. Xiong
- Institute of Endemic Diseases; Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission; Health Science Center; Xi'an Jiaotong University; Xi'an China
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Jin J, Tang Q, Li Z, Zhao Z, Zhang Z, Lu L, Zhu T, Vanhoutte PM, Leung SW, Tu R, Shi Y. Prostaglandin E 2 regulates renal function in C57/BL6 mouse with 5/6 nephrectomy. Life Sci 2017; 174:68-76. [PMID: 28263803 DOI: 10.1016/j.lfs.2017.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/27/2017] [Accepted: 03/01/2017] [Indexed: 12/26/2022]
Abstract
AIMS To investigate the roles of cyclooxygenases (COX) and their metabolites in C57/BL6 mice with 5/6 nephrectomy, an animal model of chronic renal failure. MAIN METHODS C57/BL6 mice were grouped into sham-operated (2K), one kidney removal (1K) and 5/6 nephrectomy groups (5/6Nx). Renal resistive index was measured by ultrasonography. Blood, aortae, renal arteries and renal cortex were collected for measurement of kidney function, assessment of vascular responsiveness, Western blotting, immuohistochemistry and enzyme-linked immunosorbent assays. KEY FINDINGS After four weeks, acetylcholine-induced relaxations were blunted in renal arteries of 1K and 5/6Nx mice; indomethacin, a non-selective COX inhibitor, improved the response in 5/6Nx, but not in 1K renal arteries. In 5/6Nx renal arteries, but not in 1K preparations, the protein presence of endothelial nitric oxide synthase (eNOS) was decreased, while that of COX-2 and its products [prostacyclin and thromboxane A2] were increased. The renal resistive index was lower in 5/6Nx mice, suggesting a lower resistance in the renal microvasculature. In the renal cortex of 5/6Nx mice, eNOS protein presence was increased; while the presence of COX-2 was not detectable. The prostaglandin E2 level was lower in the 5/6Nx cortex than in the other two groups. SIGNIFICANCE The early stage of renal mass removal is associated with increased renal arterial constriction and reduced microvascular resistance. The former is due to downregulation of eNOS and upregulation of COX-2, leading to an increased production of prostacyclin and thromboxane A2. A reduced production of PGE2 in the renal cortex is important for maintaining normal renal function.
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Affiliation(s)
- J Jin
- Biomedical Research Centre, Zhongshan Hospital, Fudan University, China
| | - Q Tang
- Department of Urology, Zhongshan Hospital, Fudan University, China; Shanghai Key Laboratory of Organ Transplantation, China
| | - Z Li
- Biomedical Research Centre, Zhongshan Hospital, Fudan University, China
| | - Z Zhao
- Department of Pathology, Faculty of Medicine, Fudan University, China
| | - Z Zhang
- Department of Pathology, Faculty of Medicine, Fudan University, China
| | - L Lu
- Department of Physiology and Pathophysiology, Faculty of Medicine, Fudan University, China
| | - T Zhu
- Department of Urology, Zhongshan Hospital, Fudan University, China; Shanghai Key Laboratory of Organ Transplantation, China
| | - P M Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - S W Leung
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - R Tu
- Department of Obstetrics and Gynecology, Zhongshan Hospital, Fudan University, China.
| | - Y Shi
- Biomedical Research Centre, Zhongshan Hospital, Fudan University, China; Shanghai Key Laboratory of Organ Transplantation, China.
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Leslie-Mazwi TM, Bello JA, Tu R, Nicola GN, Donovan WD, Barr RM, Hirsch JA. Current Procedural Terminology: History, Structure, and Relationship to Valuation for the Neuroradiologist. AJNR Am J Neuroradiol 2016; 37:1972-1976. [PMID: 27418473 DOI: 10.3174/ajnr.a4863] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 05/09/2016] [Indexed: 11/07/2022]
Abstract
The year 1965 was critical for US health care policy. In that year, Medicare was created as part of the Social Security Act under President Lyndon B. Johnson after several earlier attempts by Presidents Franklin Roosevelt and Harry Truman. In 1966, the American Medical Association first published a set of standard terms and descriptors to document medical procedures, known as Current Procedural Terminology, or CPT. Fifty years later, though providers have certainly heard the term "CPT code," most would benefit from an enhanced understanding of the historical basis, current structure, and relationship to valuation of Current Procedural Terminology. This article will highlight this evolution, particularly as it relates to neuroradiology.
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Affiliation(s)
- T M Leslie-Mazwi
- From the Neuroendovascular Program (T.M.L.-M., J.A.H.), Massachusetts General Hospital, Boston, Massachusetts
| | - J A Bello
- Montefiore Medical Center (J.A.B.), Albert Einstein College of Medicine, Bronx, New York
| | - R Tu
- Progressive Radiology (R.T.), The George Washington University, Falls Church, Virginia
| | - G N Nicola
- Hackensack University Medical Center (G.N.N.), Hackensack, New Jersey
| | - W D Donovan
- Norwich Diagnostic Imaging Associates (W.D.D.), Norwich, Connecticut
| | - R M Barr
- Mecklenburg Radiology Associates P.A. (R.M.B.), Charlotte, North Carolina
| | - J A Hirsch
- From the Neuroendovascular Program (T.M.L.-M., J.A.H.), Massachusetts General Hospital, Boston, Massachusetts
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27
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Qian J, Tu R, Yuan L, Xie W. Intronic miR-932 targets the coding region of its host gene, Drosophila neuroligin2. Exp Cell Res 2016; 344:183-93. [PMID: 26844630 DOI: 10.1016/j.yexcr.2016.01.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/21/2016] [Accepted: 01/29/2016] [Indexed: 02/08/2023]
Abstract
Despite great progress for two decades in microRNAs (miRNAs), the direct regulation of host gene by intragenic (mostly intronic) miRNA is conceptually plausible but evidence-limited. Here, we report that intronic miR-932 could target its host gene via binding with coding sequence (CDS) region rather than regular 3'UTR. The conserved miR-932 is embedded in the fourth intron of Drosophila neuroligin2 (dnlg2), which encodes a synaptic cell adhesion molecule, DNlg2. In silico analysis predicted two putative miR-932 target sites locate in the CDS region of dnlg2 instead of regular 3'-UTR miRNA binding sites. Employing luciferase reporter assay, we further proved that the miR-932 regulates expression of its host gene dnlg2 via the binding CDS region of dnlg2. Consistently, we observed miR-932 downregulated expression of dnlg2 in S2 cell, and the repression of dnlg2 by miR-932 at both protein and RNA level. Furthermore, we found CDS-located site1 is dominant for regulating expression of host dnlg2 by miR-932. In addition to providing thorough examination of one intronic miRNA targeting the CDS region of its host gene, our genome-wide analysis indicated that nearly half of fruitfly and human intronic miRNAs may target their own host gene at coding region. This study would be valuable in elucidating the regulation of intronic miRNA on host gene, and provide new information about the biological context of their genomic arrangements and functions.
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Affiliation(s)
- Jinjun Qian
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Renjun Tu
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Liudi Yuan
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China; Department of Biochemistry and Molecular Biology, Medical School of Southeast University, Nanjing 210009, China.
| | - Wei Xie
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China.
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28
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Tu R, Grover H, Kotra L. Peptidyl Arginine Deiminases and Neurodegenerative Diseases. Curr Med Chem 2016; 23:104-14. [DOI: 10.2174/0929867323666151118120710] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 11/05/2015] [Accepted: 11/17/2015] [Indexed: 11/22/2022]
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Affiliation(s)
- E Ben-David
- From the Department of Radiology, George Washington University Hospital, Washington, DC
| | - R Tu
- From the Department of Radiology, George Washington University Hospital, Washington, DC.
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30
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Zhang X, Tu R, Yin W, Zhou X, Li X, Hu D. Micro-computerized tomography assessment of fluorescence aided caries excavation (FACE) technology: comparison with three other caries removal techniques. Aust Dent J 2013; 58:461-7. [PMID: 24320903 DOI: 10.1111/adj.12106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2013] [Indexed: 02/05/2023]
Abstract
BACKGROUND The aim of this study was to determine the caries removal effectiveness (CRE) and minimal invasiveness potential (MIP) of four dentine caries removal methods. METHODS After carious molars were scanned using micro-computerized tomography (micro-CT), dentine caries were removed by fluorescence aided caries excavation (FACE) technology, laser induced fluorescence (LIF), chemomechanical excavation (CME), and conventional excavation (CE). Micro-CT was then repeated. CRE was determined based on the volume of residual caries/initial caries (RC/IC) and the mean mineral density (MD) at the cavity floor. MIP was determined by measuring the volume of the prepared cavity/initial cavity (PC/IC). RESULTS Among the four groups, the LIF group had the smallest RC/IC (0.08), the highest mean MD at the cavity floor (1.32 g/cm(3) ) and the highest MIP (4.47). The CME group had the highest RC/IC (0.24), the lowest mean MD (1.01 g/cm(3) ) and the lowest MIP (2.23). The CE group exhibited a more acceptable CRE (RC/IC = 0.13, mean MD = 1.21 g/cm(3) ) but had a higher MIP (3.95). Both the CRE and MIP parameters of FACE technology were the second most acceptable (RC/IC = 0.12, mean MD = 1.13 g/cm(3) , MIP = 3.20) and did not differ significantly from the most acceptable. CONCLUSIONS FACE is an effective caries removal technology for removing infected dentine without significantly increasing cavity size.
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Affiliation(s)
- X Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China; West China Hospital of Stomatology, Sichuan University, Chengdu, China
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31
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Tu R, Hai N, Rothenberg S, Charafeddine R, Williams T. MicroDose Digital Mammography: Lowest Dose Innovation in Breast Cancer Screening. Technology Review and Implications to a Screening Population. Pract Radiat Oncol 2013; 3:S12. [DOI: 10.1016/j.prro.2013.01.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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Sun L, Zhang H, Yuan H, Tu R, Wang Q, Ma Y. A double-enzyme-coupled assay for high-throughput screening of succinic acid-producing strains. J Appl Microbiol 2013; 114:1696-701. [DOI: 10.1111/jam.12175] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 02/21/2013] [Accepted: 02/21/2013] [Indexed: 12/01/2022]
Affiliation(s)
- L. Sun
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
- College of Life Sciences; University of Chinese Academy of Sciences; Beijing China
| | - H. Zhang
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
| | - H. Yuan
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
| | - R. Tu
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
| | - Q. Wang
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
| | - Y. Ma
- Key Laboratory of Systems Microbial Biotechnology; Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin China
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Qi X, Zhang Y, Tu R, Lin Y, Li X, Wang Q. High-throughput screening and characterization of xylose-utilizing, ethanol-tolerant thermophilic bacteria for bioethanol production. J Appl Microbiol 2011; 110:1584-91. [DOI: 10.1111/j.1365-2672.2011.05014.x] [Citation(s) in RCA: 12] [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: 11/27/2022]
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34
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Jin HJ, Tu R, Xu F, Chen SF. Identification of nitrogen-fixing Paenibacillus from different plant rhizospheres and a novel nifH gene detected in the P. stellifer. Microbiology (Reading) 2011. [DOI: 10.1134/s0026261711010097] [Citation(s) in RCA: 6] [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: 11/23/2022] Open
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35
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Jin HJ, Tu R, Xu F, Chen SF. Identification of nitrogen-fixing Paenibacillus from different plant rhizospheres and a novel nifH gene detected in the P. stellifer. Mikrobiologiia 2011; 80:121-128. [PMID: 21513217] [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: 05/30/2023]
Abstract
A total of 534 isolates were selectively obtained from different plant rhizospheres based on their growth on nitrogen-free medium and their resistance to 80 degrees C for 15 min. Of the 534 isolates, 23 isolates had nifH gene and exhibited nitrogenase activities. Based on 16S rDNA sequence, G + C content assay and DNA-DNA hybridization, by the 23 isolates, which were divided into four monophyletic clusters, all belonged to the Paenibacillus genus. NifH gene deduced amino acid alignment analysis revealed that cluster I, including 15 isolates, showed the highest NifH identity with Paenibacillus genus; while cluster II identified as P stellifer by DNA-DNA hybridization was consistent with four uncultured bacterial clones. This study suggested that the nitrogen-fixing Paenibacillus were distributed in various ecosystems and prevalent in different plant rhizospheres. It was the first demonstration that nitrogen fixation existed in P. jamilae and P. stellifer. In eight isolates identified as P. stellfer species, a novel nifH gene was detected in Paenibacillus.
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Affiliation(s)
- H J Jin
- State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China
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36
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Tu R, Prodanovic R, Blanusa M, Ostafe R, Niehaus F, Eck J, Schwaneberg U. Flow cytometry based high throughput screening system for screening and improving industrially important enzymes. N Biotechnol 2009. [DOI: 10.1016/j.nbt.2009.06.474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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37
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Lin CS, Chow S, Lau A, Tu R, Lue TF. Human PDE5A gene encodes three PDE5 isoforms from two alternate promoters. Int J Impot Res 2002; 14:15-24. [PMID: 11896473 DOI: 10.1038/sj.ijir.3900802] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2001] [Revised: 08/30/2001] [Accepted: 10/06/2001] [Indexed: 11/10/2022]
Abstract
Sildenafil improves erectile function by inhibiting the cGMP-catalytic activity of phosphodiesterase type V (PDE5). We used rapid amplification of cDNA Ends-polymerase chain reaction (RACE-PCR) to isolate three PDE5 isoforms from human corpus cavernosum. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis on eight human cavernous tissue samples showed that all samples expressed the PDE5A1 at a lower level than the PDE5A2 isoform. Five samples expressed the PDE5A3 isoform at various levels while the other three did not. Analysis on non-penile tissues showed that all tissues expressed the A1 and A2 isoforms while only those that have substantial amounts of smooth muscle expressed the A3 isoform. Cloning and sequencing of the PDE5A gene showed that the isoform-specific 5'-ends of the PDE5 mRNAs are encoded from three alternative first exons arranged in the order of A1-A3-A2. Promoter activities were detected upstream from the A1-specific exon and in the intron preceding the A2-specific exon. The upstream PDE5A promoter is expected to direct the expression of all three PDE5 isoforms while the intronic PDE5A2 promoter only the A2 isoform. Both promoters were upregulated by increasing concentrations of either cAMP or cGMP. Several transcription factor AP2 and Sp1-binding sequences identified in the promoters are likely to be the mediators of cAMP/cGMP-responsiveness.
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Affiliation(s)
- C-S Lin
- Knuppe Molecular Urology Laboratory, School of Medicine, University of California, San Francisco, CA 94143-1695, USA.
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Abstract
Protein kinase G-I (PKG-I) activation is essential for vascular relaxation; however, its quantitative analysis in intact cells has been difficult. To overcome this difficulty, a monoclonal antibody, VASP-16C2, was recently developed that detects phosphorylated serine residue 239 of vasodilator-stimulated phosphoprotein (VASP), a substrate of PKG-I. In this study, we used this antibody to examine (i) possible functional differences between the alpha and beta isoforms of PKG-I, (ii) ability of cAMP to activate PKG-I, as compared to cGMP, the principal PKG-I-activating cyclic nucleotide, and (iii) time course and levels of PKG-I activation in vascular smooth muscle cells (VSMC) of young and old rats. We created COS-7 cell clones that overexpressed PKG-Ialpha or PKG-Ibeta, treated them with cAMP or cGMP, and analyzed their cell lysates for reactivity with VASP-16C2. The results showed that PKG-Ialpha phosphorylated VASP at a higher level than PKG-Ibeta, and cAMP was slightly weaker than cGMP in PKG-I activation. VSMC of young rats responded to cAMP or cGMP stimulation in a dose-dependent manner with increasing levels of PKG-I activation. The response was detected within 10 min and continued for at least 24 h. In contrast, VSMC of old rats showed no PKG-I activation during the first hour of cAMP or cGMP stimulation and, at 24 h these cells showed only low-level PKG-I activation. We propose that the reduced PKG-I activation may explain why vascular relaxation is decreased in older individuals.
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Affiliation(s)
- C S Lin
- Knuppe Molecular Urology Laboratory, University of California, San Francisco, CA 94143-1695, USA.
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39
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Abstract
PDE5A gene encodes type 5 phosphodiesterase (PDE5), the principal cGMP-catalyzing enzyme in the penis and the primary target of sildenafil (Viagra). We have isolated a 3.7-kb DNA fragment that contains the human PDE5A gene promoter. The DNA fragment contains a sequence of 234 nucleotides at its 3' end that corresponds to most of the untranslated region of the PDE5A1 mRNA. The remaining 3.5-kb upstream flanking sequence contains no apparent TATA box but has several sequences that resemble binding sequences for transcription factors such as androgen receptor (AR), AP1, AP2, AP4, Sp1, MyoD, Myc, and CArG. In search of promoter activities, we used a luciferase reporter system to examine 10 DNA fragments that cover various regions of the 3.7-kb fragment. We found that a full basal promoter activity was confined to a 139-bp region that includes 78 bp of the PDE5A1-specific first exon. A lesser basal promoter activity was still detectable in a 94-bp fragment that contains the same 78-bp PDE5A1-specific exon plus 16 bp of upstream sequence. Either the 139-bp or the 94-bp promoter fragment responded minimally to cAMP or cGMP (2 mM) stimulation. Longer fragments that contain either a 308-bp 5' extension (from the 138-bp fragment) or a 156-bp 3' extension (all exon sequence) responded at higher levels to cAMP and cGMP stimulation. The 5' and 3' extensions cooperated with each other to provide the highest level of responses to cAMP and cGMP stimulation. DNase I footprint analysis identified four AP2- and two Sp1-binding sites in the 5' extension and four Sp1-binding sites in the 3' extensions. Cyclic AMP and cGMP had similar stimulatory effects on the PDE5A promoter.
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MESH Headings
- 3',5'-Cyclic-GMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-GMP Phosphodiesterases/genetics
- Animals
- Base Sequence
- Binding Sites/genetics
- COS Cells
- Cloning, Molecular
- Cyclic AMP/pharmacology
- Cyclic GMP/pharmacology
- Cyclic Nucleotide Phosphodiesterases, Type 5
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Deoxyribonuclease I
- Genes, Reporter
- Humans
- Luciferases/genetics
- Male
- Molecular Sequence Data
- Phosphodiesterase Inhibitors/pharmacology
- Piperazines/pharmacology
- Polymorphism, Genetic
- Promoter Regions, Genetic/drug effects
- Purines
- Restriction Mapping
- Sequence Homology, Nucleic Acid
- Sildenafil Citrate
- Sulfones
- Transcription Factors/metabolism
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Affiliation(s)
- C S Lin
- Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California, San Francisco, California 94143-1695, USA
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Lin CS, Chow S, Lau A, Tu R, Lue TF. Regulation of human PDE5A2 intronic promoter by cAMP and cGMP: identification of a critical Sp1-binding site. Biochem Biophys Res Commun 2001; 280:693-9. [PMID: 11162576 DOI: 10.1006/bbrc.2000.4221] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [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: 11/22/2022]
Abstract
PDE5A gene encodes type 5 phosphodiesterase (PDE5), the principal cGMP-catalyzing enzyme in the penis and the primary target of sildenafil (Viagra). We have previously reported the isolation of three alternatively spliced PDE5A isoforms in humans. We also reported the identification of three corresponding alternative first exons and an intronic promoter in the human PDE5A gene. The intronic promoter is situated upstream from the PDE5A2-specific first exon but downstream from the PDE5A1- and A3-specific first exons. In the current study we showed that the intronic promoter could be upregulated by either cAMP or cGMP. In order to identify possible regulatory elements in the promoter, we created deletion and base-substitution mutants targeting one AP2- and four Sp1-binding sequences. Loss of function of these mutants to bind to the respective transcription factors was verified by DNase I footprint analysis, and changes in promoter function were analyzed with a luciferase reporter system. Mutation of the AP2-binding sequence and deletion of the 3'-most Sp1-binding site (within the exon) had little effects on the basal or the cyclic nucleotide-inducible promoter functions. Mutation of the 5'-most Sp1-binding site had much more severe effects on the basal and the cyclic nucleotide-inducible promoter functions. Mutation of a neighboring site that contains two overlapping Sp1-binding sequences completely nullified the basal and cyclic nucleotide-inducible promoter activities. Thus, the PDE5A2 intronic promoter depends on the overlapping Sp1-binding site for basal and cyclic nucleotide-inducible functions.
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Affiliation(s)
- C S Lin
- Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California, San Francisco, California 94143-1695, USA
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Abstract
The functional role of the abundant Zn(2+) found in some hippocampal synapses has been an enigma. We show here, using N-[6-methoxy-8-quinolyl]-P-toluenesulfonamide (TSQ) staining, that chelatable-Zn(2+) can be removed from hippocampal synaptic boutons using dietary depletion or with Zn(2+) chelators. A chronic dietary deficiency of bouton Zn(2+) resulted in the impairment of long-term potentiation (LTP) at mossy fiber-CA3 synapses. The averaged normalized fEPSP slope 30 min after tetanus was 209 +/- 28% of baseline value in control (mean +/- SEM, n = 10), and 118 +/- 12% in Zn(2+)-deficient rats (mean +/- SEM, n = 12, P < 0.01). In the deficient rats with Zn(2+) supplements, mossy fiber LTP returned to normal levels. The acute depletion of bouton Zn(2+) in the hippocampal slice with membrane-permeable Zn(2+) chelators, dithizone, or diethyldithiocarbamic acid (DEDTC) blocked the induction of mossy fiber LTP. The mean amplitudes of EPSCs after tetanus were 194 +/- 22% of baseline value in control (n = 5), compared to 108 +/- 14% in dithizone (n = 6) and 101 +/- 12% in DEDTC (n = 5). The averaged value of LTP, at the associational commisural fiber-CA3 synapses, was 193 +/- 20% in the control (n = 6), compared to 182 +/- 21% (n = 6, P > 0.1) in the presence of dithizone. The blockade of mossy fiber LTP by dithizone was reversible after washout. In addition, normal LTP could be induced by tetanus if exogenous Zn(2+) was applied immediately following dithizone. Our results indicate that the endogenous Zn(2+) is specifically required for LTP induction at the mossy fiber input into CA3 neurons.
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Affiliation(s)
- Y M Lu
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
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Grossman RI, Rubin DL, Hunter G, Haughton VM, Lee D, Sze G, Kuhn MJ, Maravilla K, Tu R, Heindel W, Wippold FJ, Leeds N, Zelch J, Jinkins JR, Grodd W, Truwit C, Kanal E, Provenzale JM, Ramsey R, Simon J, Brunberg JA, Stevens GR, Kristy RM. Magnetic resonance imaging in patients with central nervous system pathology: a comparison of OptiMARK (Gd-DTPA-BMEA) and Magnevist (Gd-DTPA). Invest Radiol 2000; 35:412-9. [PMID: 10901102 DOI: 10.1097/00004424-200007000-00003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES The objective of the two pivotal phase 3 studies was to evaluate the safety and efficacy of OptiMARK (Gd-DTPA-bis(methoxyethylamide) [Gd-DTPA-BMEA]) compared with Magnevist (Gd-DTPA) in magnetic resonance imaging of the central nervous system. METHODS Two multicenter, randomized, double-blind, parallel group studies were conducted in 395 patients with known or suspected central nervous system pathology. Subjects were randomized to receive a single 0.1 mmol/kg intravenous injection of either Gd-DTPA-BMEA or Gd-DTPA. The safety of Gd-DTPA-BMEA and Gd-DTPA was monitored for up to 72 hours after study drug administration. Precontrast and postcontrast administration magnetic resonance scans were acquired using identical imaging planes and techniques. RESULTS No deaths or unexpected adverse events were reported in either group. A comparison of adverse events by intensity and relation demonstrated no statistically significant differences between the two groups. Gd-DTPA-BMEA and Gd-DTPA were equivalent with respect to confidence in diagnosis, conspicuity, and border delineation. CONCLUSIONS Gd-DTPA-BMEA and Gd-DTPA demonstrated comparable efficacy profiles, and the safety profiles were considered similar.
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Affiliation(s)
- R I Grossman
- University of Pennsylvania Medical Center, Philadelphia, USA
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Sievert KD, Bakircioglu ME, Nunes L, Tu R, Dahiya R, Tanagho EA. Homologous acellular matrix graft for urethral reconstruction in the rabbit: histological and functional evaluation. J Urol 2000; 163:1958-65. [PMID: 10799239] [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: 02/16/2023]
Abstract
OBJECTIVE To evaluate urethral replacement by a free homologous graft of acellular urethral matrix in a rabbit model. MATERIALS AND METHODS In 30 male New Zealand rabbits, a 0.8 to 1.1 cm. segment of the urethra was resected, replaced with an acellular matrix graft of 1.0 to 1.5 cm. (mean 1.3 cm.), and placed on an 8F feeding tube. Additionally 4 animals underwent sham operation. At varying intervals before sacrifice (from 10 days to 8 months), the animals underwent urodynamic evaluation and retrograde urethrography (for which 4 untreated rabbits served as control). The grafted specimens were prepared for evaluation histologically and by reverse-transcription polymerase chain reaction (RT-PCR). RESULTS In all animals, the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 3 months, smooth muscle bundles were first observed infiltrating the matrix at the end-to-end anastomosis; after 6 months, the smooth muscle bundles had grown into one-third of the matrix. Urodynamics did not detect any difference between the control and matrix-grafted animals in bladder volume, leak-point pressure and residual volume. RT-PCR detected an increase in IGF mRNA in the graft between week 3 and month 6 and in HB-EGF mRNA after day 10 through month 3. TGF-alpha mRNA was not detected; TGF-beta mRNA was unchanged from normal urethral tissue. By 8 months, the host and implant could not be differentiated by urethrography. CONCLUSION The acellular urethral matrix allows single-stage urethral reconstruction. All tissue components were seen in the grafted matrix after 3 months, with further improvement over time; however, the smooth muscle in the matrix was less than in normal rabbit urethra and was not well oriented. RT-PCR revealed the importance of time-dependent growth factor influences during regeneration.
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Affiliation(s)
- K D Sievert
- Department of Urology, University of California School of Medicine, San Francisco, California, USA
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Abstract
In the accompanying paper we present evidence for the existence of three PDE5A isoforms that differed only in the 5' end of the mRNAs. In this paper we present evidence that the three isoform-specific 5' ends were encoded by three alternative first exons that were arranged in the order of A1-A3-A2. Because the isoform-specific mRNAs could be transcribed from individual promoters, DNA fragments of the two intronic regions (A1-A3 and A3-A2) were tested for possible promoter activities. The intron between A1- and A3-specific exons did not exhibit any promoter activities even in smooth muscle cells that expressed the A3 isoform (see accompanying paper). In contrast, the intron between A3- and A2-specific exons had promoter activities in PDE5A2-expressing COS-7 and smooth muscle cells. This intronic promoter was bound by transcription factors AP-2 and Sp1, but not by AP-1, as shown by DNase I footprint analysis. However, the sequence bound by AP-2 (5'-GGGAAACGCTCGCGGGAGAGTTGG) is unusual in that it bears little resemblance to the consensus AP-2-binding sequence.
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Affiliation(s)
- C S Lin
- Knuppe Molecular Urology Laboratory, Department of Urology, University of California, San Francisco, California 94143-1695, USA.
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Lin CS, Lau A, Tu R, Lue TF. Expression of three isoforms of cGMP-binding cGMP-specific phosphodiesterase (PDE5) in human penile cavernosum. Biochem Biophys Res Commun 2000; 268:628-35. [PMID: 10679255 DOI: 10.1006/bbrc.2000.2187] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inhibition of cGMP-specific phosphodiesterase type V (PDE5) has been shown to improve penile erection in patients with erectile dysfunction. We report here the cloning of three PDE5 isoforms from human penile tissues. Two of the isoforms were identical to PDE5A1 and PDE5A2, respectively, which had been isolated from nonpenile tissues. The third isoform was novel and hence called PDE5A3. The deduced amino acid sequence of PDE5A3 was the same as the C-terminal 823-residue sequence of PDE5A1 and PDE5A2. While PDE5A1 and A2 isoforms were expressed in all tissues examined, the A3 isoform was confined to tissues with a smooth muscle or cardiac muscle component. When expressed in COS-7 cells, PDE5A1, A2, and A3 isoforms had similar cGMP-catalytic activities with K(m) of 6.2, 5.75, and 6.06 microM, respectively. Their cGMP-catalytic activities were inhibited by zaprinast with IC(50) values of 3.2 microM, 1.3 microM, and 1.6 microM, respectively, and by sildenafil with IC(50) of 28, 14, and 13 nM, respectively.
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Affiliation(s)
- C S Lin
- Knuppe Molecular Urology Laboratory, Department of Urology, University of California, San Francisco, California 94143-1695, USA.
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Shen SH, Sung HW, Tu R, Hata C, Lin D, Noishiki Y, Quijano RC. Characterization of a polyepoxy compound fixed porcine heart valve bioprosthesis. J Appl Biomater 1999; 5:159-62. [PMID: 10147176 DOI: 10.1002/jab.770050209] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Concerns with the currently available bioprostheses are calcification, long-term durability, and suboptimal hemodynamic performance. It is well known that these concerns are all more or less related to the cross-linking reagent, glutaraldehyde or formaldehyde, used in fixing bioprostheses. To address these concerns, we undertook the development of a porcine bioprosthesis fixed with a polyepoxy compound. In the development of this polyepoxy compound valve, it was found that the porcine leaflets fixed with polyepoxy compound were softer and more pliable than those fixed with glutaraldehyde. In this study, a special microtoming technique was developed to section the biological tissue so that the fixation uniformity in distinct layers of porcine aortic wall could be characterized. The fixation index and the denaturation temperature measurements in distinct layers of aortic walls showed that the cross-linking density was uniform throughout the entire aortic wall for the polyepoxy compound fixed porcine valve. It was also noted that the fixation index of the polyepoxy compound fixed aortic wall (91.5 +/- 0.5, n = 3) was not significantly different from that of its valvular leaflet (90.6 +/- 0.8, n = 3). Similarly, the denaturation temperature of the polyepoxy compound fixed aortic wall (80.4 +/- 0.9 degrees C, n = 5) was statistically comparable to that of its valvular leaflet (79.0 +/- 0.5 degrees C, n = 5). The results of this study indicated that polyepoxy compound can adequately fix the entire porcine aortic wall as well as its valvular leaflets.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S H Shen
- Baxter Edwards CVS Division, Irvine, California
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47
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Lin CS, Lau A, Bakircioglu E, Tu R, Wu F, Week S, Nunes L, Lue TF. Analysis of neuronal nitric oxide synthase isoform expression and identification of human nNOS-mu. Biochem Biophys Res Commun 1998; 253:388-94. [PMID: 9878547 DOI: 10.1006/bbrc.1998.9658] [Citation(s) in RCA: 20] [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: 11/22/2022]
Abstract
The neuronal form of nitric oxide synthase (nNOS) is responsible for the production of NO, which acts as a neurotransmitter for penile erection and urethra relaxation. An nNOS splice variant form, nNOS-mu, was first reported to be specifically expressed in skeletal muscle and heart in the rat, but later also identified in rat penile cavernosum. We report here an apparently universal expression of nNOS-mu mRNA in rat tissues, including brain, which was previously reported to be lacking nNOS-mu. Immunoblot analysis revealed that some commercially available nNOS antibodies had high levels of nonspecific activities, which could lead to the appearance of seemingly multiple forms of nNOS. Immunohistochemical analysis with these antibodies also produced nonspecific stainings. In humans, nNOS-mu; expression appeared to be confined to skeletal muscle and heart. Human penile tissues obtained from patients with erectile dysfunction did not express nNOS-mu. The human nNOS-mu-specific cDNA sequence was 89% homologous to its rat counterpart.
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Affiliation(s)
- C S Lin
- Department of Urology, University of California, San Francisco 94143, USA
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Pavlovic J, Nawrath M, Tu R, Heinicke T, Moelling K. Anti-tumor immunity is involved in the thymidine kinase-mediated killing of tumors induced by activated Ki-ras(G12V). Gene Ther 1996; 3:635-43. [PMID: 8818652] [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
We have established a syngeneic mouse tumor model to test the efficacy of the drug-sensitizing enzyme thymidine kinase from herpes simplex virus (HSVtk) in vivo. Activated mutant Ki-ras(G12V) is frequently found in human colon cancer and adenocarcinomas of the lung and pancreas. We have transformed BALB/c-3T3 cells by stable transfection of a plasmid directing the expression of the mutant Ki-ras cDNA. To transfer the HSVtk gene into tumor cells we used a Moloney murine leukemia virus (MoMLV)-based retroviral vector that carries the HSVtk gene. In this study we show that the activity of HSV-TK inhibits tumor growth in immune-compromised nude mice following GCV treatment for up to 50 days but is not sufficient to completely eliminate all tumor cells in these mice as evidenced by the occurrence of tumors between 40 and 50 days after tumor cell implantation. By contrast, immune-competent BALB/c mice develop a long-lasting antitumor immunity in response to HSVtk transduction and GCV treatment, indicating that the immune system is important for the long-term tumor suppression in vivo. In the presence of GCV co-culturing of tumor cells with HSVtk transfected cells leads to the efficient killing of HSVtk negative tumor cells. While this retroviral vector independent HSV-TK/GCV-mediated bystander effect is not sufficient to inhibit tumor formation in athymic animals it is very efficient in immune-competent syngeneic mice. Taken together the data indicate that the antitumor activity of HSV-TK is enhanced by an intact immune system.
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Affiliation(s)
- J Pavlovic
- Institute for Medical Virology, University of Zürich, Switzerland
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Affiliation(s)
- D R Fitzgibbon
- Department of Anesthesiology, University of Washington, Seattle 98195, USA
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50
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Abstract
Ultra violet (UV) light-inactivated measles virus was used for the lymphocyte proliferation assay, where it caused consistently adult human peripheral blood monolymphocytes (PBML) proliferation which was not dependent on the measles virus complement fixation titre in the donor's sera. When the cord blood lymphocytes from newborn baby and spleen lymphocytes from unprimed Balb/c, C57bl and CBA mice were used in the proliferation assay, all the lymphocytes were stimulated by the UV-inactivated measles virus in a dose-dependent manner. These results suggest that: (1) lymphotropic measles virus can also activate lymphocytes in vitro, and (2) this activation appeared to be neither species- nor major histocompatibility complex (MHC)-restricted. These results may have important implications for measles vaccination and the understanding of the immunopathogenesis of measles virus infection.
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Affiliation(s)
- R Tu
- Department of Immunology, Laboratoire National de Santé, Grand-Duché de Luxembourg
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