1
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Li X, Davis RC, Xu Y, Wang Z, Souma N, Sotolongo G, Bell J, Ellis M, Howell D, Shen X, Lafata KJ, Barisoni L. Deep learning segmentation of glomeruli on kidney donor frozen sections. J Med Imaging (Bellingham) 2021; 8:067501. [PMID: 34950750 PMCID: PMC8685284 DOI: 10.1117/1.jmi.8.6.067501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/08/2021] [Indexed: 10/15/2023] Open
Abstract
Purpose: Recent advances in computational image analysis offer the opportunity to develop automatic quantification of histologic parameters as aid tools for practicing pathologists. We aim to develop deep learning (DL) models to quantify nonsclerotic and sclerotic glomeruli on frozen sections from donor kidney biopsies. Approach: A total of 258 whole slide images (WSI) from cadaveric donor kidney biopsies performed at our institution ( n = 123 ) and at external institutions ( n = 135 ) were used in this study. WSIs from our institution were divided at the patient level into training and validation datasets (ratio: 0.8:0.2), and external WSIs were used as an independent testing dataset. Nonsclerotic ( n = 22767 ) and sclerotic ( n = 1366 ) glomeruli were manually annotated by study pathologists on all WSIs. A nine-layer convolutional neural network based on the common U-Net architecture was developed and tested for the segmentation of nonsclerotic and sclerotic glomeruli. DL-derived, manual segmentation, and reported glomerular count (standard of care) were compared. Results: The average Dice similarity coefficient testing was 0.90 and 0.83. And the F 1 , recall, and precision scores were 0.93, 0.96, and 0.90, and 0.87, 0.93, and 0.81, for nonsclerotic and sclerotic glomeruli, respectively. DL-derived and manual segmentation-derived glomerular counts were comparable, but statistically different from reported glomerular count. Conclusions: DL segmentation is a feasible and robust approach for automatic quantification of glomeruli. We represent the first step toward new protocols for the evaluation of donor kidney biopsies.
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Affiliation(s)
- Xiang Li
- Duke University, Department of Electrical and Computer Engineering, Durham, North Carolina, United States
| | - Richard C. Davis
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
| | - Yuemei Xu
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
- Nanjing Drum Tower Hospital, Department of Pathology, Nanjing, China
| | - Zehan Wang
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Nao Souma
- Duke University, Department of Medicine, Division of Nephrology, Durham, North Carolina, United States
| | - Gina Sotolongo
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
| | - Jonathan Bell
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
| | - Matthew Ellis
- Duke University, Department of Medicine, Division of Nephrology, Durham, North Carolina, United States
- Duke University, Department of Surgery, Durham, North Carolina, United States
| | - David Howell
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
| | - Xiling Shen
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Kyle J. Lafata
- Duke University, Department of Electrical and Computer Engineering, Durham, North Carolina, United States
- Duke University, Department of Radiation Oncology, Durham, North Carolina, United States
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Laura Barisoni
- Duke University, Department of Pathology, Division of AI and Computational Pathology, Durham, North Carolina, United States
- Duke University, Department of Medicine, Division of Nephrology, Durham, North Carolina, United States
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2
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Cho PS, Escoffier N, Mao Y, Green C, Davis RC. Beyond physical entrainment: competitive and cooperative mental stances during identical joint-action tasks differently affect inter-subjective neural synchrony and judgments of agency. Soc Neurosci 2021; 15:368-379. [PMID: 32031918 DOI: 10.1080/17470919.2020.1727949] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Little work has examined how mental stance alone, apart from physical entrainment, affects between-participant neural synchrony during joint social interaction. We report the first findings on how cooperative and competitive mental stances, even during identical visuomotor joint-action tasks, result in distinct neural oscillatory signatures in low beta and theta band between-participant phase synchrony. Two participants jointly controlled a cursor and were instructed to either compete or cooperate to move it to one of three targets. The visuomotor output was identical for both the compete and cooperate conditions because participants were privately given the same target for experimental trials. Cooperation enhanced theta band between-participant phase-locking value (PLV) midtrial at 1-2 seconds, reflecting activation of systems for social coordination to move the cursor in a shared direction. Competition enhanced low beta between-participant PLV, shifting from temporal to frontal regions, indicating that participants focused only on their target and later evaluated self-agency as winner or loser. This interpretation of the neural signature was corroborated by participants' greater post-trial ratings of the degree of control over the cursor during competition. Top-down cooperative and competitive mental stances shape perceptions of social context and affect interpersonal neural synchrony important for representation of self and others' actions.
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Affiliation(s)
- Philip S Cho
- Center for Science and Engineering Applications in Social Science, Yonsei University , Seoul, Korea.,Underwood International College, Yonsei University , Seoul, Korea
| | - Nicolas Escoffier
- Department of Psychology, National University of Singapore , Singapore.,Life Sciences Institute Programme in Neurobiology and Ageing, National University of Singapore , Singapore
| | - Yinan Mao
- Department of Statistics, National University of Singapore , Singapore
| | - Christopher Green
- Diagnostic Radiology and Psychiatry, Wayne State School of Medicine , Detroit, MI, USA
| | - Richard C Davis
- School of Information Systems, Singapore Management University , Singapore, Singapore
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3
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Davis RC, Broadwater G, Foo WC, Jones CK, Havrilesky LJ, Bean SM. Evaluation of pelvic washing specimens in patients with endometrial cancer: Cytomorphological features, diagnostic agreement, and pathologist experience. Cancer Cytopathol 2021; 129:517-525. [PMID: 33481348 DOI: 10.1002/cncy.22406] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Pelvic washings for patients with endometrial cancer is recommended but not used for staging. The International System for Reporting Serous Fluid Cytology (TIS) has standardized diagnostic categories, but the criteria remain incomplete. The 3 primary goals of this study were to 1) investigate features that distinguish atypical/indeterminate from malignant specimens, 2) measure the level of agreement between chart and reviewer diagnoses, and 3) determine whether the number of years in practice had an effect on the diagnoses rendered. METHODS Pelvic washings and surgical pathology specimens for 52 patients with a chart diagnosis of atypical/indeterminate, suspicious, or malignant cytology and 52 age-matched controls with a negative chart diagnosis were included, reviewed blindly by 2 cytopathologists, and assigned a study diagnosis. Morphologic features were assessed. Agreement between original chart diagnoses and reviewer diagnoses were assessed as well as effect of years in practice. RESULTS The overall cellularity in cell block (CB) slides for the malignant category was significantly increased compared with the atypical/indeterminate category (P < .0001). In addition, the number of atypical groups in ThinPrep for malignant washings was significantly increased compared with the atypical category (P < .001) and the negative and suspicious categories (P < .0001) in the CB. Overall agreement between the original and adjudicated diagnoses was high (γ = 0.983). There was no significant difference between diagnoses rendered and years in practice. CONCLUSION The overall cellularity and number of atypical cells can be used to distinguish between malignant and atypical pelvic washing specimens. There is high reproducibility in the diagnostic categories and high agreement among pathologists, regardless of practice experience. These findings can help refine the criteria for TIS.
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Affiliation(s)
- Richard C Davis
- Department of Pathology, Duke University, Durham, North Carolina
| | - Gloria Broadwater
- Duke Cancer Institute Biostatistics, Duke University, Durham, North Carolina
| | - Wen-Chi Foo
- Department of Pathology, Duke University, Durham, North Carolina
| | - Claudia K Jones
- Department of Pathology, Duke University, Durham, North Carolina
| | - Laura J Havrilesky
- Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
| | - Sarah M Bean
- Department of Pathology, Duke University, Durham, North Carolina
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4
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Sinha SK, Miikeda A, Fouladian Z, Mehrabian M, Edillor C, Shih D, Zhou Z, Paul MK, Charugundla S, Davis RC, Rajavashisth TB, Lusis AJ. Local M-CSF (Macrophage Colony-Stimulating Factor) Expression Regulates Macrophage Proliferation and Apoptosis in Atherosclerosis. Arterioscler Thromb Vasc Biol 2021; 41:220-233. [PMID: 33086870 PMCID: PMC7769919 DOI: 10.1161/atvbaha.120.315255] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [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] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Previous studies have shown that deficiency of M-CSF (macrophage colony-stimulating factor; or CSF1 [colony stimulating factor 1]) dramatically reduces atherosclerosis in hyperlipidemic mice. We characterize the underlying mechanism and investigate the relevant sources of CSF1 in lesions. Approach and Results: We quantitatively assessed the effects of CSF1 deficiency on macrophage proliferation and apoptosis in atherosclerotic lesions. Staining of aortic lesions with markers of proliferation, Ki-67 and bromodeoxyuridine, revealed around 40% reduction in CSF1 heterozygous (Csf1+/-) as compared with WT (wild type; Csf1+/+) mice. Similarly, staining with a marker of apoptosis, activated caspase-3, revealed a 3-fold increase in apoptotic cells in Csf1+/- mice. Next, we determined the cellular sources of CSF1 contributing to lesion development. Cell-specific deletions of Csf1 in smooth muscle cells using SM22α-Cre (smooth muscle protein 22-alpha-Cre) reduced lesions by about 40%, and in endothelial cells, deletions with Cdh5-Cre (VE-cadherin-Cre) reduced lesions by about 30%. Macrophage-specific deletion with LysM-Cre (lysozyme M-Cre), on the other hand, did not significantly reduce lesions size. Transplantation of Csf1 null (Csf1-/-) mice bone marrow into Csf1+/+ mice reduced lesions by about 35%, suggesting that CSF1 from hematopoietic cells other than macrophages contributes to atherosclerosis. None of the cell-specific knockouts affected circulating CSF1 levels, and only the smooth muscle cell deletions had any effect on the percentage monocytes in the circulation. Also, Csf1+/- mice did not exhibit significant differences in Ly6Chigh/Ly6Clow monocytes as compared with Csf1+/+. CONCLUSIONS CSF1 contributes to both macrophage proliferation and survival in lesions. Local CSF1 production by smooth muscle cell and endothelial cell rather than circulating CSF1 is the primary driver of macrophage expansion in atherosclerosis.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Aorta/metabolism
- Aorta/pathology
- Apoptosis
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Atherosclerosis/prevention & control
- Cadherins/genetics
- Cadherins/metabolism
- Cell Proliferation
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Female
- Macrophage Colony-Stimulating Factor/deficiency
- Macrophage Colony-Stimulating Factor/genetics
- Macrophage Colony-Stimulating Factor/metabolism
- Macrophages/metabolism
- Macrophages/pathology
- Male
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Knockout
- Microfilament Proteins/genetics
- Microfilament Proteins/metabolism
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Signal Transduction
- Mice
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Affiliation(s)
- Satyesh K. Sinha
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
- Department of Internal Medicine, Charles R Drew University of Medicine and Science, Los Angeles, CA 90059
| | - Aika Miikeda
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Zachary Fouladian
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Margarete Mehrabian
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Chantle Edillor
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Diana Shih
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Zhiqiang Zhou
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Manash K Paul
- Pulmonary and Critical Care Medicine, University of California, Los Angeles, CA 90095
| | - Sarada Charugundla
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Richard C. Davis
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - Tripathi B. Rajavashisth
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
- Department of Internal Medicine, Charles R Drew University of Medicine and Science, Los Angeles, CA 90059
- Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Aldons J. Lusis
- Department of Microbiology, Immunology, & Molecular Genetics, Department of Medicine, Department of Human Genetics, University of California, Los Angeles, CA 90095
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5
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Song Z, Zou S, Zhou W, Huang Y, Shao L, Yuan J, Gou X, Jin W, Wang Z, Chen X, Ding X, Liu J, Yu C, Ku C, Liu C, Sun Z, Xu G, Wang Y, Zhang X, Wang D, Wang S, Xu W, Davis RC, Shi H. Clinically applicable histopathological diagnosis system for gastric cancer detection using deep learning. Nat Commun 2020; 11:4294. [PMID: 32855423 PMCID: PMC7453200 DOI: 10.1038/s41467-020-18147-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/31/2020] [Indexed: 11/28/2022] Open
Abstract
The early detection and accurate histopathological diagnosis of gastric cancer increase the chances of successful treatment. The worldwide shortage of pathologists offers a unique opportunity for the use of artificial intelligence assistance systems to alleviate the workload and increase diagnostic accuracy. Here, we report a clinically applicable system developed at the Chinese PLA General Hospital, China, using a deep convolutional neural network trained with 2,123 pixel-level annotated H&E-stained whole slide images. The model achieves a sensitivity near 100% and an average specificity of 80.6% on a real-world test dataset with 3,212 whole slide images digitalized by three scanners. We show that the system could aid pathologists in improving diagnostic accuracy and preventing misdiagnoses. Moreover, we demonstrate that our system performs robustly with 1,582 whole slide images from two other medical centres. Our study suggests the feasibility and benefits of using histopathological artificial intelligence assistance systems in routine practice scenarios.
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Affiliation(s)
- Zhigang Song
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Shuangmei Zou
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100021, Beijing, China
| | - Weixun Zhou
- Department of Pathology, Peking Union Medical College Hospital, 100005, Beijing, China
| | - Yong Huang
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Liwei Shao
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Jing Yuan
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Xiangnan Gou
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Wei Jin
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Zhanbo Wang
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Xin Chen
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Xiaohui Ding
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Jinhong Liu
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China
| | - Chunkai Yu
- Department of Pathology, Beijing Shijitan Hospital, Capital Medical University, 100038, Beijing, China
| | - Calvin Ku
- Thorough Images, 100102, Beijing, China
| | | | - Zhuo Sun
- Thorough Images, 100102, Beijing, China
| | - Gang Xu
- Thorough Images, 100102, Beijing, China
| | | | | | - Dandan Wang
- Department of Pathology, Third Hospital, School of Basic Medical Sciences, Peking University Health Science Center, 100083, Beijing, China
| | - Shuhao Wang
- Thorough Images, 100102, Beijing, China.
- Institute for Interdisciplinary Information Sciences, Tsinghua University, 100084, Beijing, China.
| | - Wei Xu
- Institute for Interdisciplinary Information Sciences, Tsinghua University, 100084, Beijing, China
| | - Richard C Davis
- Department of Pathology, Duke University Medical Center, Durham, NC, 27710-1000, USA
| | - Huaiyin Shi
- Department of Pathology, The Chinese PLA General Hospital, 100853, Beijing, China.
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6
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Thompson MJ, Chwiałkowska K, Rubbi L, Lusis AJ, Davis RC, Srivastava A, Korstanje R, Churchill GA, Horvath S, Pellegrini M. A multi-tissue full lifespan epigenetic clock for mice. Aging (Albany NY) 2019; 10:2832-2854. [PMID: 30348905 PMCID: PMC6224226 DOI: 10.18632/aging.101590] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/05/2018] [Indexed: 12/11/2022]
Abstract
Human DNA-methylation data have been used to develop highly accurate biomarkers of aging ("epigenetic clocks"). Recent studies demonstrate that similar epigenetic clocks for mice (Mus Musculus) can be slowed by gold standard anti-aging interventions such as calorie restriction and growth hormone receptor knock-outs. Using DNA methylation data from previous publications with data collected in house for a total 1189 samples spanning 193,651 CpG sites, we developed 4 novel epigenetic clocks by choosing different regression models (elastic net- versus ridge regression) and by considering different sets of CpGs (all CpGs vs highly conserved CpGs). We demonstrate that accurate age estimators can be built on the basis of highly conserved CpGs. However, the most accurate clock results from applying elastic net regression to all CpGs. While the anti-aging effect of calorie restriction could be detected with all types of epigenetic clocks, only ridge regression based clocks replicated the finding of slow epigenetic aging effects in dwarf mice. Overall, this study demonstrates that there are trade-offs when it comes to epigenetic clocks in mice. Highly accurate clocks might not be optimal for detecting the beneficial effects of anti-aging interventions.
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Affiliation(s)
- Michael J Thompson
- Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Karolina Chwiałkowska
- Centre for Bioinformatics and Data Analysis, Medical University of Bialystok, Bialystok, Poland
| | - Liudmilla Rubbi
- Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Aldons J Lusis
- Department of Microbiology, Immunology and Molecular Genetics, Department of Medicine, and Department of Human Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Richard C Davis
- Department of Microbiology, Immunology and Molecular Genetics, Department of Medicine, and Department of Human Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA
| | | | - Ron Korstanje
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA
| | | | - Steve Horvath
- Department of Human Genetics and Biostatistics, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Matteo Pellegrini
- Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
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7
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Channon SB, Davis RC, Goode NT, May SA. What makes a 'good group'? Exploring the characteristics and performance of undergraduate student groups. Adv Health Sci Educ Theory Pract 2017; 22:17-41. [PMID: 27059340 DOI: 10.1007/s10459-016-9680-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/01/2016] [Indexed: 06/05/2023]
Abstract
Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a 'good group' through considering three aspects of group success: the task, the individuals, and the team. We employed a mixed methodology, combining demographic data with qualitative observations and task and peer evaluation scores. We determined associations between group dynamic and behaviour, demographic composition, member personalities and attitudes towards one another, and task success. We also employed a cluster analysis to create a model outlining the attributes of a good small group learning team in veterinary education. This model highlights that student groups differ in measures of their effectiveness as teams, independent of their task performance. On the basis of this, we suggest that groups who achieve high marks in tasks cannot be assumed to have acquired team working skills, and therefore if these are important as a learning outcome, they must be assessed directly alongside the task output.
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Affiliation(s)
- S B Channon
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London, NW1 0TU, UK.
| | - R C Davis
- Department of Academic Support and Development, The Royal Veterinary College, Hertfordshire, UK
| | - N T Goode
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London, NW1 0TU, UK
| | - S A May
- Department of Clinical Sciences and Services, The Royal Veterinary College, Hertfordshire, UK
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8
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Kurt Z, Bennett BJ, Davis RC, Pan C, Zhao Y, Codoni V, Trégouët DA, Zhang B, Lusis AJ, Yang X. Abstract 384: Integration of Aorta Network Models from Mouse Ath-HMDP with Human GWAS Reveals Novel Mechanisms of Coronary Artery Disease. Arterioscler Thromb Vasc Biol 2016. [DOI: 10.1161/atvb.36.suppl_1.384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coronary artery disease (CAD) remains one of leading causes of death worldwide. Although the genetic heritability of CAD has been estimated to be 40 to 60%, only ~10% can be explained by the genetic loci uncovered from recent large-scale human GWAS. To elucidate the missing mechanisms, we leveraged aorta transcriptome data from 372 mice profiled in an Atherosclerosis Hybrid Mouse Diversity Panel (ath-HMDP), human CAD GWAS from CARDIoGRAM+C4D, and human expression quantitative loci (eQTL) from the Genotype-Tissue Expression (GTEx) and the Cardiogenics transcriptomic studies. We first constructed aorta coexpression networks based on the ath-HMDP transcriptome data using MEGENA (Multiscale Embedded Gene Co-expression Network Analysis) and WGCNA (Weighted Gene Coexpression Network Analysis) to define coexpression modules with various levels of coherency and compactness. The coexpression modules from MEGENA and WGCNA were then correlated with the aortic lesion trait measured in ath-HMDP to reveal 29 coexpression modules demonstrating significant correlations with aortic lesions (p < 1e-3). We further integrated these aortic lesion-correlated modules with eQTLs from aortic and coronary arteries examined in the GTEx study and monocyte and macrophage eQTLs from Cardiogenics to map module genes to functional SNPs that likely affect the expression levels of these genes. When further incorporating the CARDIoGRAM+C4D CAD GWAS, 13 lesion-correlated modules in mouse ath-HMDP were enriched for functional SNPs demonstrating stronger association with CAD in humans. These modules were over-represented with genes in multiple biological pathways, including both known CAD processes (e.g., lipid & lipoprotein metabolisms, fatty acid triacylglycerol & ketone body metabolism, TCA cycle, vascular smooth muscle contraction, antigen processing, focal adhesion) and novel pathways (e.g., adipocytokine signaling, type I & II diabetes mellitus, neurotrophic factor signaling, lysosome). In conclusion, this cross-species integrative analysis that takes advantage of aorta profiling from a well-controlled mouse atherosclerosis study in conjunction with human genomics provides insights into the aorta-related mechanisms underlying CAD.
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Affiliation(s)
- Zeyneb Kurt
- Integrative Biology and Physiology, Univ of California, Los Angeles, Los Angeles, CA
| | | | - Richard C Davis
- Medicine/Div of Cardiology, Univ of California, Los Angeles, Los Angeles, CA
| | - Calvin Pan
- Genetics, Univ of California, Los Angeles, Los Angeles, CA
| | - Yuqi Zhao
- Integrative Biology and Physiology, Univ of California, Los Angeles, Los Angeles, CA
| | - Veronica Codoni
- INSERM UMR-S, Institut National pour la Santé et la Recherche Médicale (INSERM), Paris, France
| | | | - Bin Zhang
- Genetics and Genomic Sciences, Icahn Sch of Medicine at Mount Sinai, New York, NY
| | - Aldons J Lusis
- Depts of Medicine, Cardiology; Human Genetics; Microbiology, Immunology & Molecular Genetics, Univ of California, Los Angeles, Los Angeles, CA
| | - Xia Yang
- Integrative Biology and Physiology, Univ of California, Los Angeles, Los Angeles, CA
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9
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Lusis AJ, Seldin MM, Allayee H, Bennett BJ, Civelek M, Davis RC, Eskin E, Farber CR, Hui S, Mehrabian M, Norheim F, Pan C, Parks B, Rau CD, Smith DJ, Vallim T, Wang Y, Wang J. The Hybrid Mouse Diversity Panel: a resource for systems genetics analyses of metabolic and cardiovascular traits. J Lipid Res 2016; 57:925-42. [PMID: 27099397 PMCID: PMC4878195 DOI: 10.1194/jlr.r066944] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 02/07/2023] Open
Abstract
The Hybrid Mouse Diversity Panel (HMDP) is a collection of approximately 100 well-characterized inbred strains of mice that can be used to analyze the genetic and environmental factors underlying complex traits. While not nearly as powerful for mapping genetic loci contributing to the traits as human genome-wide association studies, it has some important advantages. First, environmental factors can be controlled. Second, relevant tissues are accessible for global molecular phenotyping. Finally, because inbred strains are renewable, results from separate studies can be integrated. Thus far, the HMDP has been studied for traits relevant to obesity, diabetes, atherosclerosis, osteoporosis, heart failure, immune regulation, fatty liver disease, and host-gut microbiota interactions. High-throughput technologies have been used to examine the genomes, epigenomes, transcriptomes, proteomes, metabolomes, and microbiomes of the mice under various environmental conditions. All of the published data are available and can be readily used to formulate hypotheses about genes, pathways and interactions.
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Affiliation(s)
- Aldons J Lusis
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA Microbiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA Human Genetics, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Marcus M Seldin
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Hooman Allayee
- Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Brian J Bennett
- Department of Genetics, University of North Carolina, Chapel Hill, NC
| | - Mete Civelek
- Departments of Biomedical Engineering University of Virginia, Charlottesville, VA
| | - Richard C Davis
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Eleazar Eskin
- Departments of Computer Science, University of California-Los Angeles, Los Angeles, CA
| | - Charles R Farber
- Public Health Sciences, University of Virginia, Charlottesville, VA
| | - Simon Hui
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Margarete Mehrabian
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Frode Norheim
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Calvin Pan
- Human Genetics, University of California-Los Angeles, Los Angeles, CA
| | - Brian Parks
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
| | - Christoph D Rau
- Anesthesiology, University of California-Los Angeles, Los Angeles, CA
| | - Desmond J Smith
- Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Thomas Vallim
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| | - Yibin Wang
- Anesthesiology, University of California-Los Angeles, Los Angeles, CA
| | - Jessica Wang
- Departments of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
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Bennett BJ, Davis RC, Civelek M, Orozco L, Wu J, Qi H, Pan C, Sevag Packard RR, Eskin E, Yan M, Kirchgessner T, Wang Z, Li X, Gregory JC, Hazen SL, Gargalovic PS, Lusis AJ. Correction: Genetic Architecture of Atherosclerosis in Mice: A Systems Genetics Analysis of Common Inbred Strains. PLoS Genet 2016; 12:e1005913. [PMID: 26934746 PMCID: PMC4775237 DOI: 10.1371/journal.pgen.1005913] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Bennett BJ, Davis RC, Civelek M, Orozco L, Wu J, Qi H, Pan C, Packard RRS, Eskin E, Yan M, Kirchgessner T, Wang Z, Li X, Gregory JC, Hazen SL, Gargalovic PS, Lusis AJ. Genetic Architecture of Atherosclerosis in Mice: A Systems Genetics Analysis of Common Inbred Strains. PLoS Genet 2015; 11:e1005711. [PMID: 26694027 PMCID: PMC4687930 DOI: 10.1371/journal.pgen.1005711] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/06/2015] [Indexed: 12/15/2022] Open
Abstract
Common forms of atherosclerosis involve multiple genetic and environmental factors. While human genome-wide association studies have identified numerous loci contributing to coronary artery disease and its risk factors, these studies are unable to control environmental factors or examine detailed molecular traits in relevant tissues. We now report a study of natural variations contributing to atherosclerosis and related traits in over 100 inbred strains of mice from the Hybrid Mouse Diversity Panel (HMDP). The mice were made hyperlipidemic by transgenic expression of human apolipoprotein E-Leiden (APOE-Leiden) and human cholesteryl ester transfer protein (CETP). The mice were examined for lesion size and morphology as well as plasma lipid, insulin and glucose levels, and blood cell profiles. A subset of mice was studied for plasma levels of metabolites and cytokines. We also measured global transcript levels in aorta and liver. Finally, the uptake of acetylated LDL by macrophages from HMDP mice was quantitatively examined. Loci contributing to the traits were mapped using association analysis, and relationships among traits were examined using correlation and statistical modeling. A number of conclusions emerged. First, relationships among atherosclerosis and the risk factors in mice resemble those found in humans. Second, a number of trait-loci were identified, including some overlapping with previous human and mouse studies. Third, gene expression data enabled enrichment analysis of pathways contributing to atherosclerosis and prioritization of candidate genes at associated loci in both mice and humans. Fourth, the data provided a number of mechanistic inferences; for example, we detected no association between macrophage uptake of acetylated LDL and atherosclerosis. Fifth, broad sense heritability for atherosclerosis was much larger than narrow sense heritability, indicating an important role for gene-by-gene interactions. Sixth, stepwise linear regression showed that the combined variations in plasma metabolites, including LDL/VLDL-cholesterol, trimethylamine N-oxide (TMAO), arginine, glucose and insulin, account for approximately 30 to 40% of the variation in atherosclerotic lesion area. Overall, our data provide a rich resource for studies of complex interactions underlying atherosclerosis. While recent genetic association studies in human populations have succeeded in identifying genetic loci that contribute to coronary artery disease (CAD) and related phenotypes, these loci explain only a small fraction of the genetic variation in CAD and associated traits. Here, we present a complementary approach using association analysis of atherosclerotic traits among inbred strains of mice. A strength of this approach is that it enables in-depth phenotypic characterization including gene expression and metabolic profiling across a variety of tissues, and integration of these molecular phenotypes with coronary artery disease itself. A striking finding was the large fraction of atherosclerosis that was explained by genetic interactions. Association analysis allowed us to identify genetic loci for atherosclerotic lesion area as well as transcript, cytokine and metabolite levels, and relationships among the traits were examined by correlation and network modeling. The plasma metabolites associated with atherosclerosis in mice, namely, LDL/VLDL-cholesterol, TMAO, arginine, glucose and insulin, overlapped with those observed in humans and accounted for approximately 30 to 40% of the observed variation in atherosclerotic lesion area. In summary, our data provide a detailed overview of the genetic architecture of atherosclerosis in mice and a rich resource for studies of the complex genetic and metabolic interactions that underlie the disease.
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Affiliation(s)
- Brian J. Bennett
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Richard C. Davis
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Mete Civelek
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Luz Orozco
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Judy Wu
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Hannah Qi
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Calvin Pan
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - René R. Sevag Packard
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Eleazar Eskin
- Department of Computer Science, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Mujing Yan
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb, Princeton, New Jersey, United States of America
| | - Todd Kirchgessner
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb, Princeton, New Jersey, United States of America
| | - Zeneng Wang
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Xinmin Li
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Jill C. Gregory
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Stanley L. Hazen
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Peter S. Gargalovic
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb, Princeton, New Jersey, United States of America
| | - Aldons J. Lusis
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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Wu X, Davis RC, McMillen TS, Schaeffer V, Zhou Z, Qi H, Mazandarani PN, Alialy R, Hudkins KL, Lusis AJ, LeBoeuf RC. Genetic modulation of diabetic nephropathy among mouse strains with Ins2 Akita mutation. Physiol Rep 2014; 2:2/11/e12208. [PMID: 25428948 PMCID: PMC4255814 DOI: 10.14814/phy2.12208] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diabetic nephropathy (DN) is a major complication of diabetes and the leading cause of end‐stage renal disease. DN is characterized by changes in kidney structure and function but the underlying genetic and molecular factors are poorly understood. We used a mouse diversity panel to explore the genetic basis of DN traits in mice carrying the Ins2 Akita mutation. Twenty‐eight Akita strains were generated by breeding this panel to DBA/2.Akita mice. Male F1 diabetic and nondiabetic littermates were evaluated for DN‐related traits. Urine albumin‐to‐creatinine ratios (ACRs), volume and cystatin C as well as blood urea nitrogen and lipoprotein levels varied significantly among the diabetic strains. For most Akita strains, ACR values increased 2‐ to 6‐fold over euglycemic control values. However, six strains exhibited changes in ACR exceeding 10‐fold with two strains (NOD/ShiLt and CBA) showing 50‐ to 83‐ fold increases. These increases are larger than previously reported among available DN mouse models establishing these strains as useful for additional studies of renal function. ACRs correlated with cystatin C (P = 0.0286), a measure of hyperfiltration and an interstitial tubular marker associated with DN onset in humans suggesting that tubule damage as well as podocyte‐stress contributed to reduced kidney function assessed by ACR. Although large changes were seen for ACRs, severe nephropathology was absent. However, glomerular hypertrophy and collagen IV content were found to vary significantly among strains suggesting a genetic basis for early onset features of DN. Our results define the range of DN phenotypes that occur among common inbred strains of mice. Diabetic nephropathy (DN) is characterized by changes in kidney structure and function but the underlying genetic and molecular factors are poorly understood. We used a mouse diversity panel to explore the genetic basis of DN traits in mice carrying the Ins2 Akita mutation. Twenty‐eight Akita strains on different genetic backgrounds were evaluated for DN‐related traits and the results define the range of DN phenotypes that occur among common inbred strains of mice.
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Affiliation(s)
- Xiuju Wu
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Richard C Davis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Timothy S McMillen
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Valerie Schaeffer
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Zhiqiang Zhou
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Hongxiu Qi
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Parisa N Mazandarani
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Roshanak Alialy
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Kelly L Hudkins
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Aldons J Lusis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA Department of Human Genetics, University of California, Los Angeles, Los Angeles, California, USA
| | - Renée C LeBoeuf
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
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Pearson AC, Jamieson S, Linford MR, Lunt BM, Davis RC. Oxidation of graphene 'bow tie' nanofuses for permanent, write-once-read-many data storage devices. Nanotechnology 2013; 24:135202. [PMID: 23478811 DOI: 10.1088/0957-4484/24/13/135202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We have fabricated nanoscale fuses from CVD graphene sheets with a 'bow tie' geometry for write-once-read-many data storage applications. The fuses are programmed using thermal oxidation driven by Joule heating. Fuses that were 250 nm wide with 2.5 μm between contact pads were programmed with average voltages and powers of 4.9 V and 2.1 mW, respectively. The required voltages and powers decrease with decreasing fuse sizes. Graphene shows extreme chemical and electronic stability; fuses require temperatures of about 400 °C for oxidation, indicating that they are excellent candidates for permanent data storage. To further demonstrate this stability, fuses were subjected to applied biases in excess of typical read voltages; stable currents were observed when a voltage of 10 V was applied to the devices in the off state and 1 V in the on state for 90 h each.
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Affiliation(s)
- A C Pearson
- Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, USA
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Davis RC, van Nas A, Bennett B, Orozco L, Pan C, Rau CD, Eskin E, Lusis AJ. Genome-wide association mapping of blood cell traits in mice. Mamm Genome 2013; 24:105-18. [PMID: 23417284 DOI: 10.1007/s00335-013-9448-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [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: 08/01/2012] [Accepted: 01/11/2013] [Indexed: 12/13/2022]
Abstract
Genetic variations in blood cell parameters can impact clinical traits. We report here the mapping of blood cell traits in a panel of 100 inbred strains of mice of the Hybrid Mouse Diversity Panel (HMDP) using genome-wide association (GWA). We replicated a locus previously identified in using linkage analysis in several genetic crosses for mean corpuscular volume (MCV) and a number of other red blood cell traits on distal chromosome 7. Our peak for SNP association to MCV occurred in a linkage disequilibrium (LD) block spanning from 109.38 to 111.75 Mb that includes Hbb-b1, the likely causal gene. Altogether, we identified five loci controlling red blood cell traits (on chromosomes 1, 7, 11, 12, and 16), and four of these correspond to loci for red blood cell traits reported in a recent human GWA study. For white blood cells, including granulocytes, monocytes, and lymphocytes, a total of six significant loci were identified on chromosomes 1, 6, 8, 11, 12, and 15. An average of ten candidate genes were found at each locus and those were prioritized by examining functional variants in the HMDP such as missense and expression variants. These results provide intermediate phenotypes and candidate loci for genetic studies of atherosclerosis and cancer as well as inflammatory and immune disorders in mice.
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Affiliation(s)
- Richard C Davis
- Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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15
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Ghazalpour A, Rau CD, Farber CR, Bennett BJ, Orozco LD, van Nas A, Pan C, Allayee H, Beaven SW, Civelek M, Davis RC, Drake TA, Friedman RA, Furlotte N, Hui ST, Jentsch JD, Kostem E, Kang HM, Kang EY, Joo JW, Korshunov VA, Laughlin RE, Martin LJ, Ohmen JD, Parks BW, Pellegrini M, Reue K, Smith DJ, Tetradis S, Wang J, Wang Y, Weiss JN, Kirchgessner T, Gargalovic PS, Eskin E, Lusis AJ, LeBoeuf RC. Hybrid mouse diversity panel: a panel of inbred mouse strains suitable for analysis of complex genetic traits. Mamm Genome 2012; 23:680-92. [PMID: 22892838 DOI: 10.1007/s00335-012-9411-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 07/04/2012] [Indexed: 11/28/2022]
Abstract
We have developed an association-based approach using classical inbred strains of mice in which we correct for population structure, which is very extensive in mice, using an efficient mixed-model algorithm. Our approach includes inbred parental strains as well as recombinant inbred strains in order to capture loci with effect sizes typical of complex traits in mice (in the range of 5% of total trait variance). Over the last few years, we have typed the hybrid mouse diversity panel (HMDP) strains for a variety of clinical traits as well as intermediate phenotypes and have shown that the HMDP has sufficient power to map genes for highly complex traits with resolution that is in most cases less than a megabase. In this essay, we review our experience with the HMDP, describe various ongoing projects, and discuss how the HMDP may fit into the larger picture of common diseases and different approaches.
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Affiliation(s)
- Anatole Ghazalpour
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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Terra JK, France B, Cote CK, Jenkins A, Bozue JA, Welkos SL, Bhargava R, Ho CL, Mehrabian M, Pan C, Lusis AJ, Davis RC, LeVine SM, Bradley KA. Allelic variation on murine chromosome 11 modifies host inflammatory responses and resistance to Bacillus anthracis. PLoS Pathog 2011; 7:e1002469. [PMID: 22241984 PMCID: PMC3248472 DOI: 10.1371/journal.ppat.1002469] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 11/16/2011] [Indexed: 01/23/2023] Open
Abstract
Anthrax is a potentially fatal disease resulting from infection with Bacillus anthracis. The outcome of infection is influenced by pathogen-encoded virulence factors such as lethal toxin (LT), as well as by genetic variation within the host. To identify host genes controlling susceptibility to anthrax, a library of congenic mice consisting of strains with homozygous chromosomal segments from the LT-responsive CAST/Ei strain introgressed on a LT-resistant C57BL/6 (B6) background was screened for response to LT. Three congenic strains containing CAST/Ei regions of chromosome 11 were identified that displayed a rapid inflammatory response to LT similar to, but more severe than that driven by a LT-responsive allele of the inflammasome constituent NRLP1B. Importantly, increased response to LT in congenic mice correlated with greater resistance to infection by the Sterne strain of B. anthracis. The genomic region controlling the inflammatory response to LT was mapped to 66.36–74.67 Mb on chromosome 11, a region that encodes the LT-responsive CAST/Ei allele of Nlrp1b. However, known downstream effects of NLRP1B activation, including macrophage pyroptosis, cytokine release, and leukocyte infiltration could not fully explain the response to LT or the resistance to B. anthracis Sterne in congenic mice. Further, the exacerbated response in congenic mice is inherited in a recessive manner while the Nlrp1b-mediated response to LT is dominant. Finally, congenic mice displayed increased responsiveness in a model of sepsis compared with B6 mice. In total, these data suggest that allelic variation of one or more chromosome 11 genes in addition to Nlrp1b controls the severity of host response to multiple inflammatory stimuli and contributes to resistance to B. anthracis Sterne. Expression quantitative trait locus analysis revealed 25 genes within this region as high priority candidates for contributing to the host response to LT. We show that genetic variation within an 8.3 Mb region on mouse chromosome 11 controls host response to anthrax lethal toxin (LT) and resistance to infection by the Sterne strain of Bacillus anthracis. Specifically, congenic C57BL/6 mice in which this region of chromosome 11 is derived from a genetically divergent CAST/Ei strain presented with a rapid and strong innate immune response to LT and displayed increased survival following infection with Sterne spores. CAST/Ei chromosome 11 encodes a dominant LT-responsive allele of Nlrp1b that may partially account for the severe response to LT. However, the strength of this response was attenuated in mice with only one copy of chromosome 11 derived from CAST/Ei indicating the existence of a recessive modifier of the inflammatory response to LT. In addition, congenic mice displayed a pronounced immune response using an experimental model of sepsis, indicating that one or more genes within the chromosome 11 region control host response to multiple inflammatory stimuli. Analyzing the influence of allelic variation on gene expression identified 25 genes as candidates for controlling these responses. In summary, we report a genetic model to study inflammatory responses beneficial to the host during anthrax.
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Affiliation(s)
- Jill K Terra
- Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, California, United States of America
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Abstract
BACKGROUND Little data have been reported on the factors that are important in bilateral amputee walking ability especially the role of hip strength. STUDY DESIGN Observational, case-control study where participants were evaluated at a single point in time. OBJECTIVES The aim of this study was to investigate the factors involved in bilateral amputee walking ability by assessment of walking speed, perceived exertion, exercise intensity, physiological cost index (PCI) and hip muscle strength. METHODS For a group of 10 bilateral amputees, with different levels of amputation, and a non-pathological reference group, walking ability was assessed using the two-minute walk test. Hip muscle strength was assessed using isokinetic strength tests. RESULTS Bilateral amputees were found to have slower walking speeds and increased PCI of walking which were correlated to higher levels of amputation. Peak hip torques were reduced in the amputees, which was only significant for concentric extension torque (p = 0.029), and approaching significance for concentric flexion (p = 0.061) and abduction (p = 0.057). Bilateral amputee peak hip strength suggested a positive trend with increasing walking ability. CONCLUSIONS Bilateral amputee walking ability was reduced and mainly related to level of amputation. The role of hip strength in bilateral amputee walking ability requires further investigation.
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Affiliation(s)
- Jma Visser
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands.
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Davis RC, van Nas A, Castellani LW, Zhao Y, Zhou Z, Wen P, Yu S, Qi H, Rosales M, Schadt EE, Broman KW, Péterfy M, Lusis AJ. Systems genetics of susceptibility to obesity-induced diabetes in mice. Physiol Genomics 2011; 44:1-13. [PMID: 22010005 DOI: 10.1152/physiolgenomics.00003.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inbred strains of mice are strikingly different in susceptibility to obesity-driven diabetes. For instance, deficiency in leptin receptor (db/db) leads to hyperphagia and obesity in both C57BL/6 and DBA/2 mice, but only on the DBA/2 background do the mice develop beta-cell loss leading to severe diabetes, while C57BL/6 mice are relatively resistant. To further investigate the genetic factors predisposing to diabetes, we have studied leptin receptor-deficient offspring of an F2 cross between C57BL/6J (db/+) males and DBA/2J females. The results show that the genetics of diabetes susceptibility are enormously complex and a number of quantitative trait loci (QTL) contributing to diabetes-related traits were identified, notably on chromosomes 4, 6, 7, 9, 10, 11, 12, and 19. The Chr. 4 locus is likely due to a disruption of the Zfp69 gene in C57BL/6J mice. To identify candidate genes and to model coexpression networks, we performed global expression array analysis in livers of the F2 mice. Expression QTL (eQTL) were identified and used to prioritize candidate genes at clinical trait QTL. In several cases, clusters of eQTLs colocalized with clinical trait QTLs, suggesting a common genetic basis. We constructed coexpression networks for both 5 and 12 wk old mice and identified several modules significantly associated with clinical traits. One module in 12 wk old mice was associated with several measures of hepatic fat content as well as with other lipid- and diabetes-related traits. These results add to the understanding of the complex genetic interactions contributing to obesity-induced diabetes.
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Affiliation(s)
- Richard C Davis
- Department of Medicine, University of California, Los Angeles, California 90095-1679, USA.
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Davis RC, Marsden IT, Maloney MT, Minamide LS, Podlisny M, Selkoe DJ, Bamburg JR. Amyloid beta dimers/trimers potently induce cofilin-actin rods that are inhibited by maintaining cofilin-phosphorylation. Mol Neurodegener 2011; 6:10. [PMID: 21261978 PMCID: PMC3037337 DOI: 10.1186/1750-1326-6-10] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 01/24/2011] [Indexed: 11/10/2022] Open
Abstract
Background Previously we reported 1 μM synthetic human amyloid beta1-42 oligomers induced cofilin dephosphorylation (activation) and formation of cofilin-actin rods within rat hippocampal neurons primarily localized to the dentate gyrus. Results Here we demonstrate that a gel filtration fraction of 7PA2 cell-secreted SDS-stable human Aβ dimers and trimers (Aβd/t) induces maximal neuronal rod response at ~250 pM. This is 4,000-fold more active than traditionally prepared human Aβ oligomers, which contain SDS-stable trimers and tetramers, but are devoid of dimers. When incubated under tyrosine oxidizing conditions, synthetic human but not rodent Aβ1-42, the latter lacking tyrosine, acquires a marked increase (620 fold for EC50) in rod-inducing activity. Gel filtration of this preparation yielded two fractions containing SDS-stable dimers, trimers and tetramers. One, eluting at a similar volume to 7PA2 Aβd/t, had maximum activity at ~5 nM, whereas the other, eluting at the void volume (high-n state), lacked rod inducing activity at the same concentration. Fractions from 7PA2 medium containing Aβ monomers are not active, suggesting oxidized SDS-stable Aβ1-42 dimers in a low-n state are the most active rod-inducing species. Aβd/t-induced rods are predominantly localized to the dentate gyrus and mossy fiber tract, reach significance over controls within 2 h of treatment, and are reversible, disappearing by 24 h after Aβd/t washout. Overexpression of cofilin phosphatases increase rod formation when expressed alone and exacerbate rod formation when coupled with Aβd/t, whereas overexpression of a cofilin kinase inhibits Aβd/t-induced rod formation. Conclusions Together these data support a mechanism by which Aβd/t alters the actin cytoskeleton via effects on cofilin in neurons critical to learning and memory.
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Affiliation(s)
- Richard C Davis
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA.
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Whitted AD, Stanifer JW, Dube P, Borkowski BJ, Yusuf J, Komolafe BO, Davis RC, Soberman JE, Weber KT. A dyshomeostasis of electrolytes and trace elements in acute stressor states: impact on the heart. Am J Med Sci 2010; 340:48-53. [PMID: 20610973 DOI: 10.1097/maj.0b013e3181e5945b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Acute stressor states are associated with a homeostatic activation of the hypothalamic-pituitary-adrenal axis. A hyperadrenergic state follows and leads to a dyshomeostasis of several intra- and extracellular cations, including K, Mg, and Ca. Prolongation of myocardial repolarization and corrected QT interval (QTc) of the ECG are useful biomarkers of hypokalemia and/or hypomagnesemia and should be monitored to address the adequacy of cation replacement. A dyshomeostasis of several trace elements, including Zn and Se, are also found in critically-ill patients to compromise metalloenzyme-based antioxidant defenses. Collectively, dyshomeostasis of these electrolytes and trace elements have deleterious consequences on the myocardium: atrial and ventricular arrhythmias; induction of oxidative stress with reduced antioxidant defenses; and adverse myocardial remodeling, including cardiomyocytes lost to necrosis and replaced by fibrous tissue. To minimize such consequences during hyperadrenergic states, systematic surveillance of electrolytes and trace elements, together with QTc, are warranted. Plasma K and Mg should be maintained at > or =4.0 mEq/L and > or =2.0 mg/dL, respectively (the 4 and 2 rule).
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Affiliation(s)
- Anthony D Whitted
- Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Davis RC, Castellani LW, Hosseini M, Ben-Zeev O, Mao HZ, Weinstein MM, Jung DY, Jun JY, Kim JK, Lusis AJ, Péterfy M. Early hepatic insulin resistance precedes the onset of diabetes in obese C57BLKS-db/db mice. Diabetes 2010; 59:1616-25. [PMID: 20393148 PMCID: PMC2889760 DOI: 10.2337/db09-0878] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To identify metabolic derangements contributing to diabetes susceptibility in the leptin receptor-deficient obese C57BLKS/J-db/db (BKS-db) mouse strain. RESEARCH DESIGN AND METHODS Young BKS-db mice were used to identify metabolic pathways contributing to the development of diabetes. Using the diabetes-resistant B6-db strain as a comparison, in vivo and in vitro approaches were applied to identify metabolic and molecular differences between the two strains. RESULTS Despite higher plasma insulin levels, BKS-db mice exhibit lower lipogenic gene expression, rate of lipogenesis, hepatic triglyceride and glycogen content, and impaired insulin suppression of gluconeogenic genes. Hepatic insulin receptor substrate (IRS)-1 and IRS-2 expression and insulin-stimulated Akt-phosphorylation are decreased in BKS-db primary hepatocytes. Hyperinsulinemic-euglycemic clamp studies indicate that in contrast to hepatic insulin resistance, skeletal muscle is more insulin sensitive in BKS-db than in B6-db mice. We also demonstrate that elevated plasma triglyceride levels in BKS-db mice are associated with reduced triglyceride clearance due to lower lipase activities. CONCLUSIONS Our study demonstrates the presence of metabolic derangements in BKS-db before the onset of beta-cell failure and identifies early hepatic insulin resistance as a component of the BKS-db phenotype. We propose that defects in hepatic insulin signaling contribute to the development of diabetes in the BKS-db mouse strain.
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Affiliation(s)
- Richard C. Davis
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | | | - Maryam Hosseini
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
- Lipid Research Laboratory, VA Greater Los Angeles Healthcare System, Los Angeles, California
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Osnat Ben-Zeev
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
- Lipid Research Laboratory, VA Greater Los Angeles Healthcare System, Los Angeles, California
| | - Hui Z. Mao
- Lipid Research Laboratory, VA Greater Los Angeles Healthcare System, Los Angeles, California
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Michael M. Weinstein
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Dae Young Jung
- Program in Molecular Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, Massachusetts
- Department of Cellular and Molecular Physiology, Pennsylvania State University School of Medicine, Hershey, Pennsylvania
| | - John Y. Jun
- Department of Cellular and Molecular Physiology, Pennsylvania State University School of Medicine, Hershey, Pennsylvania
| | - Jason K. Kim
- Program in Molecular Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, Massachusetts
- Department of Cellular and Molecular Physiology, Pennsylvania State University School of Medicine, Hershey, Pennsylvania
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Aldons J. Lusis
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Miklós Péterfy
- Department of Medicine, University of California, Los Angeles, Los Angeles, California
- Lipid Research Laboratory, VA Greater Los Angeles Healthcare System, Los Angeles, California
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Corresponding author: Miklos Peterfy,
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Bamburg JR, Bernstein BW, Davis RC, Goldsbury C, Maloney MT, Marsden IT, Minamide LS, Pak CW, Perry G, Podlisny MB, Selkoe DJ, Shaw AE, Siedlak SL, Whiteman IT. P2‐219: ADF/cofilin‐actin rods and synaptic loss in Alzheimer's disease. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.1268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Chi W. Pak
- Colorado State UniversityFort Collins CO USA
| | - George Perry
- University of Texas at San AntonioSan Antonio TX USA
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Pearlstein RM, Davis RC, Ditson SL. Giant circular dichroism of high molecular weight chlorophyllide-apomyoglobin complexes. Proc Natl Acad Sci U S A 2010; 79:400-2. [PMID: 16593144 PMCID: PMC345750 DOI: 10.1073/pnas.79.2.400] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chlorophyllide a and the apoprotein of myoglobin (Mb) spontaneously form three types of complex. The M (M(r) approximately 3 x 10(5)) and H (M(r) >/= 4 x 10(6)) complexes, but not the L (M(r) approximately 1.7 x 10(4)), display a circular dichroism (CD) spectrum that is highly red-shifted, nonconservative, and very intense-characteristics shared by the CD spectra of reaction center complexes from purple photosynthetic bacteria. At its 710-nm peak, the H complex CD spectrum has a larger magnitude, 0.06 differential absorbance per unit total absorbance, than has been reported for chlorophyll in any medium.
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Affiliation(s)
- R M Pearlstein
- Battelle Memorial Institute, Columbus Laboratories, Columbus, Ohio 43201
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24
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Davis RC, Maloney MT, Minamide LS, Flynn KC, Stonebraker MA, Bamburg JR. Mapping cofilin-actin rods in stressed hippocampal slices and the role of cdc42 in amyloid-beta-induced rods. J Alzheimers Dis 2010; 18:35-50. [PMID: 19542631 DOI: 10.3233/jad-2009-1122] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dissociated hippocampal neurons exposed to a variety of degenerative stimuli form neuritic cofilin-actin rods. Here we report on stimulus driven regional rod formation in organotypic hippocampal slices. Ultrastructural analysis of rods formed in slices demonstrates mitochondria and vesicles become entrapped within some rods. We developed a template for combining and mapping data from multiple slices, enabling statistical analysis for the identification of vulnerable sub-regions. Amyloid-beta (Abeta) induces rods predominantly in the dentate gyrus region, and Abeta-induced rods are reversible following washout. Rods that persist 24 h following transient (30 min) ATP-depletion are broadly distributed, whereas rods formed in response to excitotoxic glutamate localize within and nearby the pyramidal neurons. Time-lapse imaging of cofilin-GFP-expressing neurons within slices shows neuronal rod formation begins rapidly and peaks by 10 min of anoxia. In approximately 50% of responding neurons, Abeta-induced rod formation acts via cdc42, an upstream regulator of cofilin. These new observations support a role for cofilin-actin rods in stress-induced disruption of cargo transport and synaptic function within hippocampal neurons and suggest both cdc42-dependent and independent pathways modulate cofilin activity downstream from Abeta.
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Affiliation(s)
- Richard C Davis
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO, USA
| | - Michael T Maloney
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Laurie S Minamide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Kevin C Flynn
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO, USA.,Max Planck Institute of Neurobiology, Martinsreid, Munich, Germany
| | - Matthew A Stonebraker
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - James R Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO, USA
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25
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Bamburg JR, Bernstein BW, Davis RC, Flynn KC, Goldsbury C, Jensen JR, Maloney MT, Marsden IT, Minamide LS, Pak CW, Shaw AE, Whiteman I, Wiggan O. ADF/Cofilin-actin rods in neurodegenerative diseases. Curr Alzheimer Res 2010; 7:241-50. [PMID: 20088812 PMCID: PMC4458070 DOI: 10.2174/156720510791050902] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [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: 09/03/2009] [Accepted: 11/24/2009] [Indexed: 11/22/2022]
Abstract
Dephosphorylation (activation) of cofilin, an actin binding protein, is stimulated by initiators of neuronal dysfunction and degeneration including oxidative stress, excitotoxic glutamate, ischemia, and soluble forms of beta-amyloid peptide (Abeta). Hyperactive cofilin forms rod-shaped cofilin-saturated actin filament bundles (rods). Other proteins are recruited to rods but are not necessary for rod formation. Neuronal cytoplasmic rods accumulate within neurites where they disrupt synaptic function and are a likely cause of synaptic loss without neuronal loss, as occurs early in dementias. Different rod-inducing stimuli target distinct neuronal populations within the hippocampus. Rods form rapidly, often in tandem arrays, in response to stress. They accumulate phosphorylated tau that immunostains for epitopes present in "striated neuropil threads," characteristic of tau pathology in Alzheimer disease (AD) brain. Thus, rods might aid in further tau modifications or assembly into paired helical filaments, the major component of neurofibrillary tangles (NFTs). Rods can occlude neurites and block vesicle transport. Some rod-inducing treatments cause an increase in secreted Abeta. Thus rods may mediate the loss of synapses, production of excess Abeta, and formation of NFTs, all of the pathological hallmarks of AD. Cofilin-actin rods also form within the nucleus of heat-shocked neurons and are cleared from cells expressing wild type huntingtin protein but not in cells expressing mutant or silenced huntingtin, suggesting a role for nuclear rods in Huntington disease (HD). As an early event in the neurodegenerative cascade, rod formation is an ideal target for therapeutic intervention that might be useful in treatment of many different neurological diseases.
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Affiliation(s)
- J R Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, 80523, USA.
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26
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Minamide LS, Maiti S, Boyle JA, Davis RC, Coppinger JA, Bao Y, Huang TY, Yates J, Bokoch GM, Bamburg JR. Isolation and characterization of cytoplasmic cofilin-actin rods. J Biol Chem 2010; 285:5450-60. [PMID: 20022956 PMCID: PMC2820773 DOI: 10.1074/jbc.m109.063768] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [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: 09/08/2009] [Revised: 12/11/2009] [Indexed: 12/20/2022] Open
Abstract
Cofilin-actin bundles (rods), which form in axons and dendrites of stressed neurons, lead to synaptic dysfunction and may mediate cognitive deficits in dementias. Rods form abundantly in the cytoplasm of non-neuronal cells in response to many treatments that induce rods in neurons. Rods in cell lysates are not stable in detergents or with added calcium. Rods induced by ATP-depletion and released from cells by mechanical lysis were first isolated from two cell lines expressing chimeric actin-depolymerizing factor (ADF)/cofilin fluorescent proteins by differential and equilibrium sedimentation on OptiPrep gradients and then from neuronal and non-neuronal cells expressing only endogenous proteins. Rods contain ADF/cofilin and actin in a 1:1 ratio. Isolated rods are stable in dithiothreitol, EGTA, Ca(2+), and ATP. Cofilin-GFP-containing rods are stable in 500 mM NaCl, whereas rods formed from endogenous proteins are significantly less stable in high salt. Proteomic analysis of rods formed from endogenous proteins identified other potential components whose presence in rods was examined by immunofluorescence staining of cells. Only actin and ADF/cofilin are in rods during all phases of their formation; furthermore, the rapid assembly of rods in vitro from these purified proteins at physiological concentration shows that they are the only proteins necessary for rod formation. Cytoplasmic rod formation is inhibited by cytochalasin D and jasplakinolide. Time lapse imaging of rod formation shows abundant small needle-shaped rods that coalesce over time. Rod filament lengths measured by ultrastructural tomography ranged from 22 to 1480 nm. These results suggest rods form by assembly of cofilin-actin subunits, followed by self-association of ADF/cofilin-saturated F-actin.
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Affiliation(s)
| | - Sankar Maiti
- From the Department of Biochemistry and Molecular Biology and
| | - Judith A. Boyle
- From the Department of Biochemistry and Molecular Biology and
| | | | | | - Yunhe Bao
- From the Department of Biochemistry and Molecular Biology and
| | | | - John Yates
- The Scripps Research Institute, La Jolla, California 92037
| | - Gary M. Bokoch
- The Scripps Research Institute, La Jolla, California 92037
| | - James R. Bamburg
- From the Department of Biochemistry and Molecular Biology and
- the Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado 80523-1870 and
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Gale GD, Yazdi RD, Khan AH, Lusis AJ, Davis RC, Smith DJ. A genome-wide panel of congenic mice reveals widespread epistasis of behavior quantitative trait loci. Mol Psychiatry 2009; 14:631-45. [PMID: 18379576 PMCID: PMC3014058 DOI: 10.1038/mp.2008.4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Understanding the genetics of behavioral variation remains a fascinating but difficult problem with considerable theoretical and practical implications. We used the genome-tagged mice (GTM) and an extensive test battery of well-validated behavioral assays to scan the genome for behavioral quantitative trait loci (QTLs). The GTM are a panel of 'speed congenic' mice consisting of over 60 strains spanning the entire autosomal genome. Each strain harbors a small (approximately 23 cM) DBA/2J donor segment on a uniform C57BL/6J background. The panel allows for mapping to regions as small as 5 cM and provides a powerful new tool for increasing mapping power and replicability in the analysis of QTLs. A total of 97 loci were mapped for a variety of complex behavioral traits including hyperactivity, anxiety, prepulse inhibition, avoidance and conditional fear. A larger number of loci were recovered than generally attained from standard mapping crosses. In addition, a surprisingly high proportion of loci, 63%, showed phenotypes unlike either of the parental strains. These data suggest that epistasis decreases sensitivity of locus detection in traditional crosses and demonstrate the utility of the GTM for mapping complex behavioral traits with high sensitivity and precision.
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Affiliation(s)
- GD Gale
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - RD Yazdi
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - AH Khan
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - AJ Lusis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - RC Davis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - DJ Smith
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
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28
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Bhasin KKS, van Nas A, Martin LJ, Davis RC, Devaskar SU, Lusis AJ. Maternal low-protein diet or hypercholesterolemia reduces circulating essential amino acids and leads to intrauterine growth restriction. Diabetes 2009; 58:559-66. [PMID: 19073773 PMCID: PMC2646054 DOI: 10.2337/db07-1530] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We have examined maternal mechanisms for adult-onset glucose intolerance, increased adiposity, and atherosclerosis using two mouse models for intrauterine growth restriction (IUGR): maternal protein restriction and hypercholesterolemia. RESEARCH DESIGN AND METHODS For these studies, we measured the amino acid levels in dams from two mouse models for IUGR: 1) feeding C57BL/6J dams a protein-restricted diet and 2) feeding C57BL/6J LDL receptor-null (LDLR(-/-)) dams a high-fat (Western) diet. RESULTS Both protein-restricted and hypercholesterolemic dams exhibited significantly decreased concentrations of the essential amino acid phenylalanine and the essential branched chain amino acids leucine, isoleucine, and valine. The protein-restricted diet for pregnant dams resulted in litters with significant IUGR. Protein-restricted male offspring exhibited catch-up growth by 8 weeks of age and developed increased adiposity and glucose intolerance by 32 weeks of age. LDLR(-/-) pregnant dams on a Western diet also had litters with significant IUGR. Male and female LDLR(-/-) Western-diet offspring developed significantly larger atherosclerotic lesions by 90 days compared with chow-diet offspring. CONCLUSIONS In two mouse models of IUGR, we found reduced concentrations of essential amino acids in the experimental dams. This indicated that shared mechanisms may underlie the phenotypic effects of maternal hypercholesterolemia and maternal protein restriction on the offspring.
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Affiliation(s)
- Kum Kum S Bhasin
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
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29
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Abstract
Hirano bodies are actin-rich inclusions reported most frequently in the hippocampus in association with a variety of conditions including neurodegenerative diseases, and aging. We have developed a model system for formation of Hirano bodies in Dictyostelium and cultured mammalian cells to permit detailed studies of the dynamics of these structures in living cells. Model Hirano bodies are frequently observed in membrane-enclosed vesicles in mammalian cells consistent with a role of autophagy in the degradation of these structures. Clearance of Hirano bodies by an exocytotic process is supported by images from electron microscopy showing extracellular release of Hirano bodies, and observation of Hirano bodies in the culture medium of Dictyostelium and mammalian cells. An autophagosome marker protein Atg8-GFP, was co-localized with model Hirano bodies in wild type Dictyostelium cells, but not in atg5(-) or atg1-1 autophagy mutant strains. Induction of model Hirano bodies in Dictyostelium with a high level expression of 34 kDa DeltaEF1 from the inducible discoidin promoter resulted in larger Hirano bodies and a cessation of cell doubling. The degradation of model Hirano bodies still occurred rapidly in autophagy mutant (atg5(-)) Dictyostelium, suggesting that other mechanisms such as the ubiquitin-mediated proteasome pathway could contribute to the degradation of Hirano bodies. Chemical inhibition of the proteasome pathway with lactacystin, significantly decreased the turnover of Hirano bodies in Dictyostelium providing direct evidence that autophagy and the proteasome can both contribute to degradation of Hirano bodies. Short term treatment of mammalian cells with either lactacystin or 3-methyl adenine results in higher levels of Hirano bodies and a lower level of viable cells in the cultures, supporting the conclusion that both autophagy and the proteasome contribute to degradation of Hirano bodies.
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Affiliation(s)
- Dong-Hwan Kim
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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30
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Affiliation(s)
- Manesh Thomas
- Department of Internal Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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Kopf D, Cheng LSC, Blandau P, Hsueh W, Raffel LJ, Buchanan TA, Xiang AH, Davis RC, Rotter JI, Lehnert H. Association of insulin sensitivity and glucose tolerance with the c.825C>T variant of the G protein beta-3 subunit gene. J Diabetes Complications 2008; 22:205-9. [PMID: 18413224 PMCID: PMC2695761 DOI: 10.1016/j.jdiacomp.2006.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Revised: 11/17/2006] [Accepted: 12/19/2006] [Indexed: 10/22/2022]
Abstract
UNLABELLED The risk of macrovascular complications of diabetes mellitus is greatly enhanced by the presence of high blood pressure. In addition, hypertension and diabetes share insulin resistance as a common pathophysiological mechanism. Despite evidence for a common molecular genetic background of insulin resistance, glucose intolerance, and hypertension, few candidate genes have been shown to influence all of these features simultaneously. We examined the association of insulin sensitivity with the c.825C>T variant of the g-protein beta-3 subunit (GNB3), a candidate gene of hypertension, in families of Mexican-American hypertensive patients. METHODS One hundred eighty subjects enrolled in a family study of Mexican-American hypertensive patients were recruited from hypertension clinics in Los Angeles. Subjects underwent pretreatment blood pressure recording, an oral glucose tolerance test, euglycemic hyperinsulinemic clamp, and anthropometric measurements. DNA from peripheral blood leukocytes was genotyped by polymerase chain reaction and restriction enzyme digest with BseD1 (GNB). Statistical analysis was performed by transmission disequilibrium testing. RESULTS In carriers of the T-allele, blood glucose was significantly lower [(mean+S.D.) fasting: 96.7+22.9 vs. 106.7+51.7mg/dl, P=.009; oral glucose tolerance test (oGTT) 120 min: 131.7+48.7 vs. 137.8+64.9 mg/dl, P=.036], and insulin sensitivity was significantly higher (229.0+108.7 vs. 188.5+94.2 mg/kg per minute, P=.037) than in homozygous carriers of the C-allele. Blood pressure did not differ significantly between the phenotypes. CONCLUSION In a Mexican-American hypertensive population, we found evidence for higher insulin sensitivity in carriers of the T allele of the c.825C>T variant of GNB3.
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Affiliation(s)
- Daniel Kopf
- Department of Endocrinology and Metabolism, University of Magdeburg, Magdeburg, Germany.
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Mahadevan G, Davis RC, Frenneaux MP, Hobbs FDR, Lip GYH, Sanderson JE, Davies MK. Left ventricular ejection fraction: are the revised cut-off points for defining systolic dysfunction sufficiently evidence based? Heart 2008; 94:426-8. [PMID: 18347374 DOI: 10.1136/hrt.2007.123877] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- G Mahadevan
- Department of Cardiovascular Medicine, University of Birmingham, 21 Metchley Park Road, Edgbaston, Birmingham B15 2PQ, UK.
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McLin JP, Thompson LM, Lusis AJ, Davis RC, Steward O. Genes on distal chromosome 18 determine vulnerability to excitotoxic neurodegeneration following status epilepticus, but not striatal neurodegeneration induced by quinolinic acid. Neurobiol Dis 2008; 29:391-9. [DOI: 10.1016/j.nbd.2007.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/24/2007] [Accepted: 10/03/2007] [Indexed: 10/22/2022] Open
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Davis RC, Furukawa R, Fechheimer M. A cell culture model for investigation of Hirano bodies. Acta Neuropathol 2008; 115:205-17. [PMID: 17978823 DOI: 10.1007/s00401-007-0275-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 07/24/2007] [Accepted: 07/26/2007] [Indexed: 11/28/2022]
Abstract
Hirano bodies are paracrystalline F-actin-rich aggregations associated with a variety of conditions including aging, and neurodegenerative diseases. The composition and structure of these inclusions have been described by immunohistochemistry and ultrastructure, respectively. However, studies of the physiological function and dynamics of Hirano bodies have been hindered due to lack of a facile in vitro experimental system. We have developed a model for formation of Hirano bodies in mammalian cell cultures by expression of the carboxy-terminal fragment (CT) of a 34-kDa actin-bundling protein. Expression of the CT protein induces F-actin rearrangement in HEK 293, HeLa, Cos7 cells, neuroblastoma and astrocytic cells, and in primary neurons. We have termed these structures model Hirano bodies, since their composition and ultrastructure is quite similar to that reported in vivo. Model Hirano bodies in cell cultures sometimes appeared to be formed of a number of smaller domains, suggesting that small aggregates are intermediates in the formation of Hirano bodies. Stable lines expressing CT and bearing model Hirano bodies exhibit normal growth, morphology, and motility. This model provides a valuable system for the study of the dynamics of Hirano bodies, and their role in disease processes.
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Affiliation(s)
- Richard C Davis
- Department of Cellular Biology, University of Georgia, 724 Biological Sciences, Athens, GA 30602, USA
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Abstract
The primary and modifier genes that regulate normal maxillofacial development are unknown. Previous quantitative trait locus (QTL) analyses using the F2 progeny of 2 mouse strains, DBA/2J (short snout/wide face) and C57BL/6J (long snout/narrow face), revealed a significant logarithm-of-odds (LOD) score for snout length on mouse chromosome 12 at 44 centimorgan (cM). We further sought to validate this locus contributing to anterior-posterior dimensions of the upper mid-face at the D12Mit7 marker in a 44-centimorgan portion of chromosome 12. Congenic mice carrying introgressed DNA from DBA/2J on a C57BL/6J background were selected for submental vertex cephalometric imaging. Results confirmed QTLs, determining that short snout length (P < 0.05) and face width relative to snout length (P < 0.01) were present in the 44-cM region of chromosome 12. We conclude that one or more genes contributing to the shape of the maxillary complex are located near 44 cM of mouse chromosome 12.
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Affiliation(s)
- J Oh
- Section of Orthodontics, UCLA School of Dentistry, 43-091 Center for the Health Sciences, Box 951668, Los Angeles, CA 90095-1668, USA
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Péterfy M, Davis RC, Lusis AJ. Metabolic syndrome as a modifier of atherosclerosis in murine models. Curr Drug Targets 2007; 8:1215-20. [PMID: 18045100 DOI: 10.2174/138945007782403838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Metabolic Syndrome is a common metabolic disease associated with an increased risk for atherosclerotic cardiovascular disease and mortality. In contrast to "traditional" risk factors for atherosclerosis, such as low-density lipoprotein cholesterol, the Metabolic Syndrome represents a network of interacting risk factors stemming from the metabolic complexity of this disease. For this reason, dissection of the cellular and molecular pathways underlying atherosclerosis-susceptibility in the Metabolic Syndrome has been difficult. To facilitate this endeavor, several murine models have been recently developed. Despite their imperfect representation of the Metabolic Syndrome and atherosclerosis in humans, these models have provided important mechanistic insights and revealed novel molecular pathways. Furthermore, murine models are invaluable for the evaluation of therapeutic approaches and will no doubt facilitate the genetic dissection of atherosclerosis-susceptibility in the Metabolic Syndrome.
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Affiliation(s)
- Miklós Péterfy
- Department of Medicine, UCLA School of Medicine, Los Angeles, CA 90073, USA.
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Sharma N, Bryant J, Wloga D, Donaldson R, Davis RC, Jerka-Dziadosz M, Gaertig J. Katanin regulates dynamics of microtubules and biogenesis of motile cilia. ACTA ACUST UNITED AC 2007; 178:1065-79. [PMID: 17846175 PMCID: PMC2064628 DOI: 10.1083/jcb.200704021] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The in vivo significance of microtubule severing and the mechanisms governing its spatial regulation are not well understood. In Tetrahymena, a cell type with elaborate microtubule arrays, we engineered null mutations in subunits of the microtubule-severing complex, katanin. We show that katanin activity is essential. The net effect of katanin on the polymer mass depends on the microtubule type and location. Although katanin reduces the polymer mass and destabilizes the internal network of microtubules, its activity increases the mass of ciliary microtubules. We also show that katanin reduces the levels of several types of post-translational modifications on tubulin of internal and cortical microtubules. Furthermore, katanin deficiencies phenocopy a mutation of β-tubulin that prevents deposition of polymodifications (glutamylation and glycylation) on microtubules. We propose that katanin preferentially severs older, post-translationally modified segments of microtubules.
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Affiliation(s)
- Neeraj Sharma
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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Newman KP, Bhattacharya SK, Munir A, Davis RC, Soberman JE, Ramanathan KB. Macro- and micronutrients in patients with congestive heart failure, particularly African-Americans. Vasc Health Risk Manag 2007; 3:743-7. [PMID: 18078025 PMCID: PMC2291318] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Not all patients with heart failure, defined as a reduced ejection fraction, will have an activation of the RAAS, salt and water retention, or the congestive heart failure (CHF) syndrome. Beyond this cardiorenal perspective, CHF is accompanied by a systemic illness that includes oxidative stress, a proinflammatory phenotype, and a wasting of soft tissues and bone. A dyshomeostasis of calcium, magnesium, zinc, selenium, and vitamin D contribute to the appearance of oxidative stress and to compromised endogenous defenses that combat it. A propensity for hypovitaminosis D, given that melanin is a natural sunscreen, and for secondary hyperparathyroidism in African-Americans make them more susceptible to these systemic manifestations of CHF-a situation which is further threatened by the calcium and magnesium wasting that accompanies the secondary aldosteronism of CHF and the use of loop diuretics.
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Affiliation(s)
- Kevin P Newman
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA
| | - Syamal K Bhattacharya
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA,Department of Surgery, University of Tennessee Health Science CenterMemphis, Tennessee, USA
| | - Ahmad Munir
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA
| | - Richard C Davis
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA
| | - Judith E Soberman
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA
| | - Kodangudi B Ramanathan
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, Tennessee, USA
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Davis RC, Jin A, Rosales M, Yu S, Xia X, Ranola K, Schadt EE, Lusis AJ. A genome-wide set of congenic mouse strains derived from CAST/Ei on a C57BL/6 background. Genomics 2007; 90:306-13. [PMID: 17600671 DOI: 10.1016/j.ygeno.2007.05.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [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: 01/30/2007] [Revised: 05/16/2007] [Accepted: 05/21/2007] [Indexed: 01/09/2023]
Abstract
We previously reported the construction of two sets of heterozygous congenic strains spanning the mouse genome. For both sets, C57BL/6J was employed as the background strain while DNA from either DBA/2 or CAST/Ei was introgressed to form the congenic region. We have subsequently bred most of these strains to produce homozygous breeding stocks. Here, we report the characterization of the strain set based on CAST/Ei. CAST/Ei is the most genetically distant strain within the Mus mus species and many trait variations relevant to common diseases have been identified in CAST/Ei mice. Despite breeding difficulties for some congenic regions, presumably due to incompatible allelic variations between CAST/Ei and C57BL/6, the resulting congenic strains cover about 80% of the autosomal chromosomes and will be useful as a resource for the further analysis of quantitative trait loci between the strains.
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Affiliation(s)
- Richard C Davis
- Department of Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA 90095-1679, USA.
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Hsueh W, Abel ED, Breslow JL, Maeda N, Davis RC, Fisher EA, Dansky H, McClain DA, McIndoe R, Wassef MK, Rabadán-Diehl C, Goldberg IJ. Recipes for creating animal models of diabetic cardiovascular disease. Circ Res 2007; 100:1415-27. [PMID: 17525381 DOI: 10.1161/01.res.0000266449.37396.1f] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For more than 50 years, investigators have unsuccessfully tried to recreate in experimental animals the cardiovascular complications of diabetes seen in humans. In particular, accelerated atherosclerosis and dilated cardiomyopathy, the major causes of mortality in patients with diabetes, have been conspicuously absent in many mouse models of the disease. Under the auspices of the NIH, the Animal Models of Diabetic Complications Consortium has worked to address this issue. This effort has focused on the development of mouse models because of the high level of genomic information available and the many well-developed genetic manipulations that may be performed in mice. Importantly, the consortium has also worked to standardize many methods to assess metabolic and cardiovascular end points for measurement of the diabetic state and its macrovascular complications. Finally, for maximum benefits from these animal models in the study of atherosclerosis and of other diabetic complications, the consortium has created a system for sharing both the animal models and the accumulated phenotypic data with the greater scientific community.
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Affiliation(s)
- Willa Hsueh
- Division of Endocrinology, Diabetes, and Hypertension, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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Zagol BW, Wodi LA, Davis RC, Newman KP. A hyperactive pulmonary vasculature in response to chronic mitral regurgitation. Am J Med Sci 2007; 333:390-3. [PMID: 17570995 DOI: 10.1097/maj.0b013e318065b65d] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A subset of patients with mitral valve disease has a marked rise in pulmonary vascular resistance (PVR) that is disproportionate to elevations in pulmonary venous pressure. Termed a "hyperactive" pulmonary vasculature, the elevation in PVR falls promptly and dramatically in response to mitral valve replacement. We report a 55-year-old man with progressive, exertional dyspnea of several months' duration who had signs of congestive heart failure (CHF) with moderate mitral valvular regurgitation and aortic stenosis by echocardiographic interrogation. These lesions in combination, together with his CHF and disproportionate elevation in pulmonary artery systolic pressure (90 mm Hg) and PVR (527 dyne x s x cm(-5)), raised the prospect of valvular replacement. There followed a normalization of PVR and marked improvement in his symptoms and signs of CHF in response to pharmacologic management with an ACE inhibitor, loop diuretic, and aldosterone receptor antagonist to negate any further consideration of surgery.
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Affiliation(s)
- Brian W Zagol
- Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Lee YJ, Romanek CS, Mills GL, Davis RC, Whitman WB, Wiegel J. Gracilibacter thermotolerans gen. nov., sp. nov., an anaerobic, thermotolerant bacterium from a constructed wetland receiving acid sulfate water. Int J Syst Evol Microbiol 2006; 56:2089-2093. [PMID: 16957104 DOI: 10.1099/ijs.0.64040-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An obligatorily anaerobic, thermotolerant, asporogenic bacterium, strain JW/YJL-S1T, was isolated from a sediment sample of a constructed wetland system receiving acid sulfate water (pH 1.6–3.0). Cells of strain JW/YJL-S1T were straight to curved rods 0.2–0.4 μm in diameter and 2.0–7.0 μm in length, and stained Gram-negative. Growth of strain JW/YJL-S1T was observed at 25–54 °C (no growth at or below 20 or at or above 58 °C), with an optimum temperature range for growth of 42.5–46.5 °C. The pH25 °C range for growth was 6.0–8.25 (no growth at or below pH 5.7 or at or above pH 8.5), with optimum growth at pH 6.8–7.75. The salinity range for growth was 0–1.5 % (w/v) NaCl, with an optimum at 0–0.5 %. During growth on glucose the isolate produced acetate, lactate and ethanol as main fermentation end products. The fatty acid composition was dominated by branched-chain compounds: i15 : 0, a15 : 0, i16 : 0 and i17 : 0. The G+C content of the genomic DNA was 42.8 mol% (HPLC). Strain JW/YJL-S1T showed polymorphism of the 16S rRNA gene. Its closest relative was the thermophilic Clostridium thermosuccinogenes DSM 5807T (a member of Clostridium cluster III) (a blastn search revealed Clostridium pascui DSM 10365T to have 92.7 % gene sequence similarity, the highest value). The inferred phylogenetic trees placed strain JW/YJL-S1T between Clostridium clusters I/II and III. Based on the morphological and phylogenetic data presented, JW/YJL-S1T (=DSM 17427T=ATCC BAA-1219T) is proposed as the type strain of a novel species in a new genus, Gracilibacter thermotolerans gen. nov., sp. nov.
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Affiliation(s)
- Yong-Jin Lee
- Savannah River Ecology Laboratory, Aiken, SC 29802, USA
- Department of Microbiology, The University of Georgia, Athens, GA 30602, USA
| | - Christopher S Romanek
- Department of Geology, The University of Georgia, Athens, GA 30602, USA
- Savannah River Ecology Laboratory, Aiken, SC 29802, USA
| | - Gary L Mills
- Savannah River Ecology Laboratory, Aiken, SC 29802, USA
| | - Richard C Davis
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602, USA
| | - William B Whitman
- Department of Microbiology, The University of Georgia, Athens, GA 30602, USA
| | - Juergen Wiegel
- Department of Microbiology, The University of Georgia, Athens, GA 30602, USA
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Estrada-Smith D, Collins AR, Wang X, Crockett C, Castellani L, Lusis AJ, Davis RC. Impact of chromosome 2 obesity loci on cardiovascular complications of insulin resistance in LDL receptor-deficient C57BL/6 mice. Diabetes 2006; 55:2265-71. [PMID: 16873689 DOI: 10.2337/db06-0377] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Previous characterization of mouse chromosome 2 identified genomic intervals that influence obesity, insulin resistance, and dyslipidemia. For this, resistant CAST/Ei (CAST) alleles were introgressed onto a susceptible C57BL/6J background to generate congenic strains with CAST alleles encompassing 67-162 Mb (multigenic obesity 6 [MOB6]) and 84-180 Mb (MOB5) from mouse chromosome 2. To examine the effects of each congenic locus on atherosclerosis and glucose disposal, we bred each strain onto a sensitizing LDL receptor-null (LDLR(-/-)) C57BL/6J background to predispose them to hypercholesterolemia and insulin resistance. LDLR(-/-) congenics and controls were characterized for measures of atherogenesis, insulin sensitivity, and obesity. We identified a genomic interval unique to the MOB6 congenic (72-84 Mb) that dramatically decreased atherosclerosis by approximately threefold and decreased insulin resistance. This region also reduced adiposity twofold. Conversely, the congenic region unique to MOB5 (162-180 Mb) increased insulin resistance but had little effect on atherosclerosis and adiposity. The MOB congenic intervals are concordant to human and rat quantitative trait loci influencing diabetes and atherosclerosis traits. Thus, our results define a strategy for studying the poorly understood interactions between diabetes and atherosclerosis and for identifying genes underlying the cardiovascular complications of insulin resistance.
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Abstract
Increasingly, the mouse is becoming the standard model for mammalian physiology and disease. It can be genetically analyzed and manipulated with relative ease. Moreover, the endogenous genetic variation that exists among inbred mouse strains can be exploited to identify genetic control of complex physiologic processes involved in diabetes and the metabolic syndrome, among other conditions relevant to human disease. Recent advances in genetics and gene expression technology have greatly increased the knowledge to be derived from this approach when applied to traditional genetic studies.
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Affiliation(s)
- Thomas A Drake
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095-1732, USA.
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Davis RC, Schadt EE, Smith DJ, Hsieh EWY, Cervino ACL, van Nas A, Rosales M, Doss S, Meng H, Allayee H, Lusis AJ. A genome-wide set of congenic mouse strains derived from DBA/2J on a C57BL/6J background. Genomics 2005; 86:259-70. [PMID: 16039824 DOI: 10.1016/j.ygeno.2005.05.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 05/17/2005] [Accepted: 05/26/2005] [Indexed: 11/22/2022]
Abstract
In the analysis of complex traits, congenic strains are powerful tools because they allow characterization of a single locus in the absence of genetic variation throughout the remainder of the genome. Here, we report the construction and initial characterization of a genome-wide panel of congenic strains derived from the donor strain DBA/2J on the background strain C57BL/6J. For many strains, we have carried out high-density SNP genotyping to precisely map the congenic interval and to identify any contaminating regions. Certain strains exhibit striking variation in litter size and in the ratio of females to males. We illustrate the utility of the set by "Mendelizing" the complex trait of myocardial calcification. These 65 strains cover more than 95% of the autosomal genome and should facilitate the analysis of the many genetic trait differences that have been reported between these parental strains.
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Affiliation(s)
- Richard C Davis
- Department of Microbiology, Immunology and Molecular Genetics, Department of Medicine, and Department of Human Genetics, University of California, Los Angeles, CA 90095-1679, USA.
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Davis RC, Schadt EE, Cervino ACL, Péterfy M, Lusis AJ. Ultrafine mapping of SNPs from mouse strains C57BL/6J, DBA/2J, and C57BLKS/J for loci contributing to diabetes and atherosclerosis susceptibility. Diabetes 2005; 54:1191-9. [PMID: 15793261 DOI: 10.2337/diabetes.54.4.1191] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The inbred mouse strain C57BLKS/J (BKS) carrying a mutation of the leptin receptor lepr(-/-) (BKS-db) is a classic mouse model of type 2 diabetes. While BKS was originally presumed to be a substrain of C57BL/6J (B6), it has become apparent that its genome contains introgressed regions from a DBA/2 (DBA)-like strain and perhaps other unidentified sources. It has been hypothesized that the strikingly enhanced diabetes susceptibility of BKS-db compared with B6-db is conferred by this introgressed DNA. Using high-density single nucleotide polymorphisms, we have mapped the DBA and other contaminating DNA regions present in BKS. Thus, approximately 70% of its genome appears to derive from B6, with approximately 20% from DBA and another 9% from an unidentified donor. Comparison with 56 diverse inbred strains suggests that this donor may be a less common inbred strain or an outbred or wild strain. Using expression data from a B6 x DBA cross, we identified differentially regulated genes between these two strains. Those cis-regulated genes located on DBA-like blocks in BKS constitute primary candidates for genes contributing to diabetes susceptibility in the BKS-db strain. To further prioritize these candidates, we identified those cis-acting expression quantitative trait loci whose expression significantly correlates with diabetes-related phenotypes.
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Affiliation(s)
- Richard C Davis
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, 47-123 CHS, Los Angeles, CA 90095-1679, USA.
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Khouzam RN, Schwender FT, Rehman FU, Davis RC. Central cyanosis and clubbing in an 18-year-old postpartum woman presenting with a stroke. Am J Med Sci 2005; 329:153-6. [PMID: 15767823 DOI: 10.1097/00000441-200503000-00009] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
An 18-year-old woman without previously documented medical history delivered a healthy 32-week-old preterm infant. Severe bleeding occurred during week 1 postpartum secondary to ruptured vaginal condylomas. The consequent anemia was accompanied by complaints of exercise intolerance that resolved with blood transfusion. Six weeks later, the patient was brought to the emergency department of the regional medical center, where she was found to be unresponsive, with a left-sided hemiparesis and with hypoxemia that failed to correct with assisted ventilation and 100% oxygen. A cardiology consultation was obtained, which identified the patient as having central cyanosis and heretofore unappreciated marked clubbing of fingers and toes. This suggested a diagnosis of right-to-left shunting, likely at the cardiac level, together with presumptive embolic stroke, which was documented by magnetic resonance imaging and magnetic resonance angiography as a left pontine infarct. Transthoracic and transesophageal echocardiography identified anomalous drainage of the inferior vena cava into the left atrium, which was confirmed by a three-dimensional computed tomographic angiogram. Corrective surgery in the form of atrial septostomy and redirection of the inferior vena cava to the right atrium was performed. The patient was subsequently discharged and is in stable condition 3 months later without effort intolerance and with normal arterial oxygen saturation on room air.
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Affiliation(s)
- Rami N Khouzam
- Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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Hobbs FDR, Davis RC, Roalfe AK, Hare R, Davies MK. Reliability of N-terminal proBNP assay in diagnosis of left ventricular systolic dysfunction within representative and high risk populations. Heart 2004; 90:866-70. [PMID: 15253955 PMCID: PMC1768355 DOI: 10.1136/hrt.2003.014258] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To determine the performance of a new NT-proBNP assay in comparison with brain natriuretic peptide (BNP) in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations. METHODS Blood samples were taken prospectively in the community from 591 randomly sampled individuals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failure; patients on diuretics; and patients deemed at high risk of heart failure). Definite heart failure (left ventricular ejection fraction (LVEF) < 40%) was identified in 33 people. Samples were handled as though in routine clinical practice. The laboratories undertaking the assays were blinded. RESULTS Using NT-proBNP to diagnose LVEF < 40% in the general population, a level of > 40 pmol/l had 80% sensitivity, 73% specificity, 5% positive predictive value (PPV), 100% negative predictive value (NPV), and an area under the receiver-operator characteristic curve (AUC) of 76% (95% confidence interval (CI) 46% to 100%). For BNP to diagnose LVSD, a cut off level of > 33 pmol/l had 80% sensitivity, 88% specificity, 10% PPV, 100% NPV, and AUC of 88% (95% CI 75% to 100%). Similar NPVs were found for patients randomly screened from the three other populations. CONCLUSIONS Both NT-proBNP and BNP have value in diagnosing LVSD in a community setting, with similar sensitivities and specificities. Using a high cut off for positivity will confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.
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Affiliation(s)
- F D R Hobbs
- Department of Primary Care and General Practice, Primary Care Clinical Sciences Building, University of Birmingham, Birmingham B15 2TT, UK.
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Liu D, Singh RP, Khan AH, Lusis AJ, Davis RC, Smith DJ. Mapping behavioral traits by use of genome-tagged mice. Am J Geriatr Psychiatry 2004; 12:158-65. [PMID: 15010345] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
OBJECTIVE Complex trait mapping has been widely used to analyze the genetics of behavior. However, the approach has some disadvantages, including poor gene localization and low replicability. Genome-tagged mice (GTMs) are sets of congenic mouse strains that span the entire mouse genome and are a promising reagent for localization of genes contributing to behavior. METHODS In order to map behavioral loci of interest, a GTM was investigated in which the middle region of Chromosome 1 from DBA/2J was introgressed onto a C57BL/6J background. The GTM was analyzed for behaviors related to sensorimotor gating, anxiety, depression, pain sensitivity, and learning and memory. RESULTS The GTM was found to harbor a locus contributing to learning and memory, replicating results from complex trait analysis. CONCLUSIONS The GTMs should be a valuable resource for mapping and confirmation of loci contributing to complex behavioral traits in the mouse, with ultimate implications for human genomic-based research, as well.
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Affiliation(s)
- Dahai Liu
- Department of Molecular and Medical Pharmacology and Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095-1735, USA
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