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Taylor KA, Carroll MK, Short SA, Goode AP. Identifying characteristics and clinical conditions associated with hand grip strength in adults: the Project Baseline Health Study. Sci Rep 2024; 14:8937. [PMID: 38637523 PMCID: PMC11026445 DOI: 10.1038/s41598-024-55978-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/29/2024] [Indexed: 04/20/2024] Open
Abstract
Low hand grip strength (HGS) is associated with several conditions, but its value outside of the older adult population is unclear. We sought to identify the most salient factors associated with HGS from an extensive list of candidate variables while stratifying by age and sex. We used data from the initial visit from the Project Baseline Health Study (N = 2502) which captured detailed demographic, occupational, social, lifestyle, and clinical data. We applied MI-LASSO using group methods to determine variables most associated with HGS out of 175 candidate variables. We performed analyses separately for sex and age (< 65 vs. ≥ 65 years). Race was associated with HGS to varying degrees across groups. Osteoporosis and osteopenia were negatively associated with HGS in female study participants. Immune cell counts were negatively associated with HGS for male participants ≥ 65 (neutrophils) and female participants (≥ 65, monocytes; < 65, lymphocytes). Most findings were age and/or sex group-specific; few were common across all groups. Several of the variables associated with HGS in each group were novel, while others corroborate previous research. Our results support HGS as a useful indicator of a variety of clinical characteristics; however, its utility varies by age and sex.
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Affiliation(s)
- Kenneth A Taylor
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA.
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA.
| | | | | | - Adam P Goode
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA
- Duke University School of Medicine, Population Health Sciences, Durham, NC, USA
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Chen L, Liu J, Rastegarpouyani H, Janssen PML, Pinto JR, Taylor KA. Structure of mavacamten-free human cardiac thick filaments within the sarcomere by cryoelectron tomography. Proc Natl Acad Sci U S A 2024; 121:e2311883121. [PMID: 38386705 PMCID: PMC10907299 DOI: 10.1073/pnas.2311883121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
Heart muscle has the unique property that it can never rest; all cardiomyocytes contract with each heartbeat which requires a complex control mechanism to regulate cardiac output to physiological requirements. Changes in calcium concentration regulate the thin filament activation. A separate but linked mechanism regulates the thick filament activation, which frees sufficient myosin heads to bind the thin filament, thereby producing the required force. Thick filaments contain additional nonmyosin proteins, myosin-binding protein C and titin, the latter being the protein that transmits applied tension to the thick filament. How these three proteins interact to control thick filament activation is poorly understood. Here, we show using 3-D image reconstruction of frozen-hydrated human cardiac muscle myofibrils lacking exogenous drugs that the thick filament is structured to provide three levels of myosin activation corresponding to the three crowns of myosin heads in each 429Å repeat. In one crown, the myosin heads are almost completely activated and disordered. In another crown, many myosin heads are inactive, ordered into a structure called the interacting heads motif. At the third crown, the myosin heads are ordered into the interacting heads motif, but the stability of that motif is affected by myosin-binding protein C. We think that this hierarchy of control explains many of the effects of length-dependent activation as well as stretch activation in cardiac muscle control.
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Affiliation(s)
- Liang Chen
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306
| | - Jun Liu
- Microbial Sciences Institute, Yale University, West Haven, CT06516
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT06536
| | - Hosna Rastegarpouyani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Paul M. L. Janssen
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH43210
| | - Jose R. Pinto
- Department of Biomedical Sciences, Florida State College of Medicine, Florida State University, Tallahassee, FL32306
| | - Kenneth A. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306
- Department of Biological Science, Florida State University, Tallahassee, FL32306
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Yeganeh FA, Summerill C, Hu Z, Rahmani H, Taylor DW, Taylor KA. The cryo-EM 3D image reconstruction of isolated Lethocerus indicus Z-discs. J Muscle Res Cell Motil 2023; 44:271-286. [PMID: 37661214 PMCID: PMC10843718 DOI: 10.1007/s10974-023-09657-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 08/14/2023] [Indexed: 09/05/2023]
Abstract
The Z-disk of striated muscle defines the ends of the sarcomere, which repeats many times within the muscle fiber. Here we report application of cryoelectron tomography and subtomogram averaging to Z-disks isolated from the flight muscles of the large waterbug Lethocerus indicus. We use high salt solutions to remove the myosin containing filaments and use gelsolin to remove the actin filaments of the A- and I-bands leaving only the thin filaments within the Z-disk which were then frozen for cryoelectron microscopy. The Lethocerus Z-disk structure is similar in many ways to the previously studied Z-disk of the honeybee Apis mellifera. At the corners of the unit cell are positioned trimers of paired antiparallel F-actins defining a large solvent channel, whereas at the trigonal positions are positioned F-actin trimers converging slowly towards their (+) ends defining a small solvent channel through the Z-disk. These near parallel F-actins terminate at different Z-heights within the Z-disk. The two types of solvent channel in Lethocerus are similar in size compared to those of Apis which are very different in size. Two types of α-actinin crosslinks were observed between oppositely oriented actin filaments. In one of these, the α-actinin long axis is almost parallel to the F-actins it crosslinks. In the other, the α-actinins are at a small but distinctive angle with respect to the crosslinked actin filaments. The utility of isolated Z-disks for structure determination is discussed.
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Affiliation(s)
- Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Corinne Summerill
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
- Department of Life and Earth Sciences, Perimeter College, Georgia State University, 33 Gilmer Street SE, Atlanta, GA, 30303, USA
| | - Zhongjun Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
- Facebook, Inc, 1 Hacker Way, Menlo Park, CA, 94025, USA
| | - Hamidreza Rahmani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
- The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA.
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Ulmer CS, Taylor KA, Campbell AA, Sherwood A, Wu JQ, Beckham JC, Hoerle JM, Augustine AV. Response to letter to the editor: sleep breathing at the intersection of nightmares and cardiovascular risk. Sleep 2023; 46:zsad221. [PMID: 37748436 DOI: 10.1093/sleep/zsad221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023] Open
Affiliation(s)
- Christi S Ulmer
- Durham Veterans Affairs Center of Innovation to Accelerate Discovery and Practice Transformation (ADAPT), Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Kenneth A Taylor
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA
- Duke University School of Medicine, Duke Clinical Research Institute, Durham, NC, USA
| | | | - Andrew Sherwood
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Jade Q Wu
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Jean C Beckham
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Veterans Affairs VA Mid-Atlantic MIRECC Workgroup, Durham, NC, USA
| | - Jeffrey M Hoerle
- Veterans Affairs VA Mid-Atlantic MIRECC Workgroup, Durham, NC, USA
| | - Ann V Augustine
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Durham Veterans Affairs (VA) Healthcare System, Durham, NC, USA
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Abbasi Yeganeh F, Rastegarpouyani H, Li J, Taylor KA. Structure of the Drosophila melanogaster Flight Muscle Myosin Filament at 4.7 Å Resolution Reveals New Details of Non-Myosin Proteins. Int J Mol Sci 2023; 24:14936. [PMID: 37834384 PMCID: PMC10573858 DOI: 10.3390/ijms241914936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/15/2023] Open
Abstract
Striated muscle thick filaments are composed of myosin II and several non-myosin proteins which define the filament length and modify its function. Myosin II has a globular N-terminal motor domain comprising its catalytic and actin-binding activities and a long α-helical, coiled tail that forms the dense filament backbone. Myosin alone polymerizes into filaments of irregular length, but striated muscle thick filaments have defined lengths that, with thin filaments, define the sarcomere structure. The motor domain structure and function are well understood, but the myosin filament backbone is not. Here we report on the structure of the flight muscle thick filaments from Drosophila melanogaster at 4.7 Å resolution, which eliminates previous ambiguities in non-myosin densities. The full proximal S2 region is resolved, as are the connecting densities between the Ig domains of stretchin-klp. The proteins, flightin, and myofilin are resolved in sufficient detail to build an atomic model based on an AlphaFold prediction. Our results suggest a method by which flightin and myofilin cooperate to define the structure of the thick filament and explains a key myosin mutation that affects flightin incorporation. Drosophila is a genetic model organism for which our results can define strategies for functional testing.
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Affiliation(s)
- Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
| | - Hosna Rastegarpouyani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Jiawei Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
| | - Kenneth A. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
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Taylor KA, Burke C, George SZ, Danyluk S, Kingsbury CA, Kapos FP, Seebeck K, Lewis CE, Ford E, Plez C, Kosinski A, Filippo R, Brown M, Goode AP. Characterizing Acute Low Back Pain in a Community-Based Cohort. medRxiv 2023:2023.10.02.23296149. [PMID: 37873225 PMCID: PMC10592986 DOI: 10.1101/2023.10.02.23296149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Acute low back pain (LBP) is a common experience, however, the associated pain severity, pain frequency, and characteristics of individuals with acute LBP in community settings have yet to be well understood. The purpose of this manuscript is to categorize and compare acute LBP groups for differences in the following characteristics: 1) sociodemographic, 2) general and physical health, and 3) psychological. This cross-sectional study used baseline data from 131 community-based participants with acute LBP (<4 weeks duration before screening and > 30 pain-free days before acute LBP onset). Two LBP categorization definitions were used based on LBP frequency combined with either: 1) pain interference frequency (impact-based) or 2) pain intensity (intensity-based). Descriptive associations were calculated as prevalence ratios for categorical variables and Hedges' g for continuous variables. Our analyses identified several large associations for impact-based and intensity-based categories for pain interference with activity and with enjoyment in life, global mental health, STarT Back Screening Tool risk category, general health, and Fear Avoidance Beliefs Questionnaire-Physical Activity subscale. Larger associations were found with social constructs (racially and ethnically minoritized, performance of social roles, and isolation) when using the intensity-based versus impact-based categorization. This study adds to the literature by providing standard ways to characterize community-based individuals experiencing acute LBP. The robust differences observed between these categorization approaches suggest they may be used to improve the early identification of factors potentially contributing to the development of chronic LBP.
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Hojjatian A, Taylor DW, Daneshparvar N, Fagnant PM, Trybus KM, Taylor KA. Double-headed binding of myosin II to F-actin shows the effect of strain on head structure. J Struct Biol 2023; 215:107995. [PMID: 37414375 PMCID: PMC10544818 DOI: 10.1016/j.jsb.2023.107995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/25/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Force production in muscle is achieved through the interaction of myosin and actin. Strong binding states in active muscle are associated with Mg·ADP bound to the active site; release of Mg·ADP allows rebinding of ATP and dissociation from actin. Thus, Mg·ADP binding is positioned for adaptation as a force sensor. Mechanical loads on the lever arm can affect the ability of myosin to release Mg·ADP but exactly how this is done is poorly defined. Here we use F-actin decorated with double-headed smooth muscle myosin fragments in the presence of Mg·ADP to visualize the effect of internally supplied tension on the paired lever arms using cryoEM. The interaction of the paired heads with two adjacent actin subunits is predicted to place one lever arm under positive and the other under negative strain. The converter domain is believed to be the most flexible domain within myosin head. Our results, instead, point to the segment of heavy chain between the essential and regulatory light chains as the location of the largest structural change. Moreover, our results suggest no large changes in the myosin coiled coil tail as the locus of strain relief when both heads bind F-actin. The method would be adaptable to double-headed members of the myosin family. We anticipate that the study of actin-myosin interaction using double-headed fragments enables visualization of domains that are typically noisy in decoration with single-headed fragments.
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Affiliation(s)
- Alimohammad Hojjatian
- Inst. of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, United States
| | - Dianne W Taylor
- Inst. of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, United States
| | - Nadia Daneshparvar
- Inst. of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, United States
| | - Patricia M Fagnant
- Dept of Molecular Physiology & Biophysics, University of Vermont College of Medicine, Burlington, VT 05405, United States
| | - Kathleen M Trybus
- Dept of Molecular Physiology & Biophysics, University of Vermont College of Medicine, Burlington, VT 05405, United States
| | - Kenneth A Taylor
- Inst. of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, United States.
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Luther PK, Morris EP, Parry DAD, Taylor KA. John Squire: a leader and seminal contributor to experimental and theoretical muscle research for over 50 years. J Muscle Res Cell Motil 2023; 44:123-124. [PMID: 37740044 DOI: 10.1007/s10974-023-09659-z] [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: 09/24/2023]
Affiliation(s)
- Pradeep K Luther
- Cardiac Function Section, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
| | - Edward P Morris
- School of Molecular Biosciences, University of Glasgow, Garscube Campus, Jarrett Building, 351, Bearsden Road, Glasgow, G61 1QH, UK
| | - David A D Parry
- School of Natural Sciences, Massey University, Private Bag, 11‑222, Palmerston North 4442, Palmerston North, New Zealand
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
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9
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Taylor KA. John Squire and the myosin thick filament structure in muscle. J Muscle Res Cell Motil 2023; 44:143-152. [PMID: 37099254 PMCID: PMC10686309 DOI: 10.1007/s10974-023-09646-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/22/2023] [Indexed: 04/27/2023]
Abstract
The structure of the thin, actin-containing filament of muscle is both highly conserved across a broad range of muscle types and is now well understood. The structure of the thick, myosin-containing filaments of striated muscle are quite variable and remained comparatively unknown until recently, particularly in the arrangement of the myosin tails. John Squire played a major role not only in our understanding of thin filament structure and function but also in the structure of the thick filaments. Long before much was known about the structure and composition of muscle thick filaments, he proposed a general model for how myosin filaments were constructed. His role in our current understanding the structure of striated muscle thick filaments and the extent through which his predictions have held true is the topic of this review.
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Affiliation(s)
- Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA.
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Hojjatian A, Rastegarpouyani H, Taylor DW, Taylor KA. Novel ADP State Found in Smooth Muscle Heavy Meromyosin by CryoEM. Microsc Microanal 2023; 29:912-914. [PMID: 37613403 DOI: 10.1093/micmic/ozad067.452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Alimohammad Hojjatian
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Hosna Rastegarpouyani
- Department of Biological Sciences, Florida State University, Tallahassee, FL, United States
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
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Li J, Rahmani H, Yeganeh FA, Rastegarpouyani H, Taylor DW, Wood NB, Previs MJ, Iwamoto H, Taylor KA. Structure and Arrangement of Non-myosin Proteins in the Flight Muscle Thick Filament from the Bumble Bee, Bombus ignitus by CryoEM. Microsc Microanal 2023; 29:917-919. [PMID: 37613770 DOI: 10.1093/micmic/ozad067.454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Jiawei Li
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL, USA
| | - Hamidreza Rahmani
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL, USA
| | | | | | - Dianne W Taylor
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL, USA
| | - Neil B Wood
- Department of Molecular Physiology & Biophysics, College of Medicine, University of Vermont, Burlington, VT, USA
| | - Michael J Previs
- Department of Molecular Physiology & Biophysics, College of Medicine, University of Vermont, Burlington, VT, USA
| | - Hiroyuki Iwamoto
- Scattering and Imaging Division, Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo, Japan
| | - Kenneth A Taylor
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL, USA
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Rastegarpouyani H, Yeganeh FA, Hojjatian A, Taylor KA. Optimizing the Protein Stability in Thick Filament Cryo-EM Sample Preparation Using a PEGylation Technique. Microsc Microanal 2023; 29:958-959. [PMID: 37613831 DOI: 10.1093/micmic/ozad067.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Hosna Rastegarpouyani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Alimohammad Hojjatian
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
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Campbell AA, Taylor KA, Augustine AV, Sherwood A, Wu JQ, Beckham JC, Hoerle JM, Ulmer CS. Nightmares: an independent risk factor for cardiovascular disease? Sleep 2023; 46:zsad089. [PMID: 36996027 DOI: 10.1093/sleep/zsad089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 02/13/2023] [Indexed: 03/31/2023] Open
Abstract
STUDY OBJECTIVES Prior work has established associations between post-traumatic stress disorder (PTSD), disrupted sleep, and cardiovascular disease (CVD), but few studies have examined health correlates of nightmares beyond risks conferred by PTSD. This study examined associations between nightmares and CVD in military veterans. METHODS Participants were veterans (N = 3468; 77% male) serving since September 11, 2001, aged 38 years (SD = 10.4); approximately 30% were diagnosed with PTSD. Nightmare frequency and severity were assessed using the Davidson Trauma Scale (DTS). Self-reported medical issues were assessed using the National Vietnam Veterans Readjustment Study Self-report Medical Questionnaire. Mental health disorders were established using the Structured Clinical Interview for DSM-IV. The sample was stratified by the presence or absence of PTSD. Within-group associations between nightmare frequency and severity and self-reported CVD conditions, adjusting for age, sex, race, current smoking, depression, and sleep duration. RESULTS Frequent and severe nightmares during the past week were endorsed by 32% and 35% of participants, respectively. Those endorsing nightmares that were frequent, severe, and the combination thereof were more likely to also evidence high blood pressure (ORs 1.42, OR 1.56, and OR 1.47, respectively) and heart problems (OR 1.43, OR 1.48, and OR 1.59, respectively) after adjusting for PTSD diagnosis and other covariates. CONCLUSIONS Nightmare frequency and severity among veterans are associated with cardiovascular conditions, even after controlling for PTSD diagnosis. Study findings suggest that nightmares may be an independent risk factor for CVD. Additional research is needed to validate these findings using confirmed diagnoses and explore potential mechanisms.
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Affiliation(s)
| | - Kenneth A Taylor
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA
- Duke University School of Medicine, Duke Clinical Research Institute, Durham, NC, USA
| | - Ann V Augustine
- Durham Veterans Affairs (VA) Healthcare System, Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Andrew Sherwood
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Jade Q Wu
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Jean C Beckham
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Veterans Affairs VA Mid-Atlantic MIRECC Workgroup, Durham, NC, USA
| | - Jeffrey M Hoerle
- Veterans Affairs VA Mid-Atlantic MIRECC Workgroup, Durham, NC, USA
| | - Christi S Ulmer
- Durham Veterans Affairs (VA) Healthcare System, Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Durham Veterans Affairs Center of Innovation to Accelerate Discovery and Practice Transformation (ADAPT), Durham, NC, USA
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Goode AP, Cleveland RJ, Kraus VB, Taylor KA, George SZ, Schwartz TA, Renner J, Huebner JL, Jordan JM, Golightly YM. Biomarkers and longitudinal changes in lumbar spine degeneration and low back pain: the Johnston County Osteoarthritis Project. Osteoarthritis Cartilage 2023; 31:809-818. [PMID: 36804589 DOI: 10.1016/j.joca.2023.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 02/07/2023] [Accepted: 02/12/2023] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To determine if baseline biomarkers are associated with longitudinal changes in the worsening of disc space narrowing (DSN), vertebral osteophytes (OST), and low back pain (LBP). DESIGN Paired baseline (2003-2004) and follow-up (2006-2010) lumbar spine radiographs from the Johnston County Osteoarthritis Project were graded for severity of DSN and OST. LBP severity was self-reported. Concentrations of analytes (cytokines, proteoglycans, and neuropeptides) were quantified by immunoassay. Pressure-pain threshold (PPT), a marker of sensitivity to pressure pain, was measured with a standard dolorimeter. Binary logistic regression models were used to estimate odd ratios (OR) and 95% confidence intervals (CI) of biomarker levels with DSN, OST, or LBP. Interactions were tested between biomarker levels and the number of affected lumbar spine levels or LBP. RESULTS We included participants (n = 723) with biospecimens, PPT, and paired lumbar spine radiographic data. Baseline Lumican, a proteoglycan reflective of extracellular matrix changes, was associated with longitudinal changes in DSN worsening (OR = 3.19 [95% CI 1.22, 8.01]). Baseline brain-derived neuropathic factor, a neuropeptide, (OR = 1.80 [95% CI 1.03, 3.16]) was associated with longitudinal changes in OST worsening, which may reflect osteoclast genesis. Baseline hyaluronic acid (OR = 1.31 [95% CI 1.01, 1.71]), indicative of systemic inflammation, and PPT (OR = 1.56 [95% CI 1.02, 2.31]) were associated with longitudinal increases in LBP severity. CONCLUSION These findings suggest that baseline biomarkers are associated with longitudinal changes occurring in structures of the lumbar spine (DSN vs OST). Markers of inflammation and perceived pressure pain sensitivity were associated with longitudinal worsening of LBP.
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Affiliation(s)
- A P Goode
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Duke Clinical Research Institute, Duke University, Durham, NC, USA; Department of Population Health Sciences, Duke University, Durham, NC, USA.
| | - R J Cleveland
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, USA; Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
| | - V B Kraus
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Duke Molecular Physiology Institute and Department of Medicine, Duke University School of Medicine, Durham, NC, USA; Duke Department of Medicine, Duke University, NC, USA.
| | - K A Taylor
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Duke Clinical Research Institute, Duke University, Durham, NC, USA.
| | - S Z George
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Duke Clinical Research Institute, Duke University, Durham, NC, USA.
| | - T A Schwartz
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, USA; Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | - J Renner
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, USA; Department of Radiology, University of North Carolina, Chapel Hill, NC, USA.
| | - J L Huebner
- Duke Molecular Physiology Institute and Department of Medicine, Duke University School of Medicine, Durham, NC, USA.
| | - J M Jordan
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, USA; Department of Medicine, University of North Carolina, Chapel Hill, NC, USA; Department of Orthopedics, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | - Y M Golightly
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA; College of Allied Health Professions, University of Nebraska Medical Center, Omaha, NE, USA.
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15
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Taylor KA, Mysliwiec V, Kimbrel NA, Augustine AV, Ulmer CS. Probable trauma associated sleep disorder in post-9/11 US Veterans. Sleep Adv 2023; 4:zpad001. [PMID: 37193287 PMCID: PMC10108646 DOI: 10.1093/sleepadvances/zpad001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/10/2022] [Indexed: 05/18/2023]
Abstract
Study Objectives The purpose of this study was to (1) estimate trauma associated sleep disorder (TASD) prevalence among post-9/11 era veterans and to describe differences in service and comorbid mental health clinical characteristics among individuals with and without probable TASD, and (2) estimate TASD prevalence and characteristics of reported traumatic experiences stratified by sex. Methods We used cross-sectional data from the post-deployment mental health study of post-9/11 veterans, which enrolled and collected baseline data from 2005 to 2018. We classified veterans as having probable TASD using self-reported measures: traumatic experiences from the traumatic life events questionnaire (TLEQ) and items from the Pittsburgh sleep quality index with Addendum for posttraumatic stress disorder (PTSD) mapped to TASD diagnostic criteria and ascertained mental health diagnoses (PTSD, major depressive disorder [MDD]) via Structured Clinical Interview for DSM-IV. We calculated effect sizes as prevalence ratios (PR) for categorical variables and Hedges' g for continuous variables. Results Our final sample included 3618 veterans (22.7% female). TASD prevalence was 12.1% (95% CI: 11.1% to 13.2%) and sex-stratified prevalence was similar for female and male veterans. Veterans with TASD had a much higher comorbid prevalence of PTSD (PR: 3.72, 95% CI: 3.41 to 4.06) and MDD (PR: 3.93, 95% CI: 3.48 to 4.43). Combat was the highest reported most distressing traumatic experience among veterans with TASD (62.6%). When stratifying by sex, female veterans with TASD had a wider variety of traumatic experiences. Conclusions Our results support the need for improved screening and evaluation for TASD in veterans, which is currently not performed in routine clinical practice.
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Affiliation(s)
- Kenneth A Taylor
- Duke University School of Medicine, Orthopaedic Surgery, Durham, NC, USA
- Duke University School of Medicine, Duke Clinical Research Institute, Durham, NC, USA
| | - Vincent Mysliwiec
- University of Texas Health Science Center at San Antonio, Department of Psychiatry and Behavioral Sciences, San Antonio, TX, USA
| | - Nathan A Kimbrel
- Durham Veterans Affairs (VA) Healthcare System, Durham, NC, USA
- VA Mid-Atlantic Mental Illness Research, Education and Clinical Center, Durham, NC, USA
- VA Health Services Research and Development, Center of Innovation to Accelerate Discovery and Practice Transformation, Durham, NC, USA
- Duke University School of Medicine, Psychiatry and Behavioral Sciences, Durham, NC, USA
| | - Ann V Augustine
- Durham Veterans Affairs (VA) Healthcare System, Durham, NC, USA
- Duke University School of Medicine, Neurology, Durham, NC, USA
| | - Christi S Ulmer
- Duke University School of Medicine, Psychiatry and Behavioral Sciences, Durham, NC, USA
- Durham Veterans Affairs (VA) Healthcare System, Center of Innovation to Accelerate Discovery and Practice Transformation (ADAPT), Durham, NC, USA
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16
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Li J, Rahmani H, Abbasi Yeganeh F, Rastegarpouyani H, Taylor DW, Wood NB, Previs MJ, Iwamoto H, Taylor KA. Structure of the Flight Muscle Thick Filament from the Bumble Bee, Bombus ignitus, at 6 Å Resolution. Int J Mol Sci 2022; 24:377. [PMID: 36613818 PMCID: PMC9820631 DOI: 10.3390/ijms24010377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/28/2022] Open
Abstract
Four insect orders have flight muscles that are both asynchronous and indirect; they are asynchronous in that the wingbeat frequency is decoupled from the frequency of nervous stimulation and indirect in that the muscles attach to the thoracic exoskeleton instead of directly to the wing. Flight muscle thick filaments from two orders, Hemiptera and Diptera, have been imaged at a subnanometer resolution, both of which revealed a myosin tail arrangement referred to as “curved molecular crystalline layers”. Here, we report a thick filament structure from the indirect flight muscles of a third insect order, Hymenoptera, the Asian bumble bee Bombus ignitus. The myosin tails are in general agreement with previous determinations from Lethocerus indicus and Drosophila melanogaster. The Skip 2 region has the same unusual structure as found in Lethocerus indicus thick filaments, an α-helix discontinuity is also seen at Skip 4, but the orientation of the Skip 1 region on the surface of the backbone is less angled with respect to the filament axis than in the other two species. The heads are disordered as in Drosophila, but we observe no non-myosin proteins on the backbone surface that might prohibit the ordering of myosin heads onto the thick filament backbone. There are strong structural similarities among the three species in their non-myosin proteins within the backbone that suggest how one previously unassigned density in Lethocerus might be assigned. Overall, the structure conforms to the previously observed pattern of high similarity in the myosin tail arrangement, but differences in the non-myosin proteins.
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Affiliation(s)
- Jiawei Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Hamidreza Rahmani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Hosna Rastegarpouyani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Dianne W. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Neil B. Wood
- Department of Molecular Physiology & Biophysics, University of Vermont, Larner College of Medicine, Burlington, VT 05405, USA
| | - Michael J. Previs
- Department of Molecular Physiology & Biophysics, University of Vermont, Larner College of Medicine, Burlington, VT 05405, USA
| | - Hiroyuki Iwamoto
- Scattering and Imaging Division, Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198, Japan
| | - Kenneth A. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
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17
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Taylor KA, Schwartz SW, Alman AC, Goode AP, Dagne GA, Sebastião YV, Foulis PR. Nightmare disorder and low back pain in veterans: cross-sectional association and effect over time. Sleep Adv 2022; 3:zpac030. [PMID: 36387301 PMCID: PMC9648406 DOI: 10.1093/sleepadvances/zpac030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 07/29/2022] [Indexed: 12/15/2022]
Abstract
Low back pain (LBP) disproportionately impacts US military veterans compared with nonveterans. Although the effect of psychological conditions on LBP is regularly studied, there is little published to date investigating nightmare disorder (NMD) and LBP. The purpose of this study was to (1) investigate whether an association exists between NMD and LBP and (2) estimate the effect of NMD diagnosis on time to LBP. We used a retrospective cohort design with oversampling of those with NMD from the Veterans Health Administration (n = 15 983). We used logistic regression to assess for a cross-sectional association between NMD and LBP and survival analysis to estimate the effect of NMD on time to LBP, up to 60-month follow-up, conditioning on age, sex, race, index year, Charlson Comorbidity Index, depression, anxiety, insomnia, combat exposure, and prisoner of war history to address confounding. Odds ratios (with 95% confidence intervals [CIs]) indicated a cross-sectional association of 1.35 (1.13 to 1.60) and 1.21 (1.02 to 1.42) for NMD and LBP within 6 months and 12 months pre- or post-NMD diagnosis, respectively. Hazard ratios (HRs) indicated the effect of NMD on time to LBP that was time-dependent-HR (with 95% CIs) 1.27 (1.02 to 1.59), 1.23 (1.03 to 1.48), 1.19 (1.01 to 1.40), and 1.10 (0.94 to 1.29) in the first 3, 6, 9, and 12 months post-diagnosis, respectively-approximating the null (1.00) at >12 months. The estimated effect of NMD on LBP suggests that improved screening for NMD among veterans may help clinicians and researchers predict (or intervene to reduce) risk of future back pain.
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Affiliation(s)
- Kenneth A Taylor
- Corresponding author. Kenneth A. Taylor, Duke Clinical Research Institute, 300 West Morgan Street, Ste 800, Durham, NC 27701, USA.
| | - Skai W Schwartz
- College of Public Health, University of South Florida, Tampa, FL, USA
| | - Amy C Alman
- College of Public Health, University of South Florida, Tampa, FL, USA
| | - Adam P Goode
- Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA,Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA,Population Health Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Getachew A Dagne
- College of Public Health, University of South Florida, Tampa, FL, USA
| | - Yuri V Sebastião
- Division of Global Women’s Health, Department of Obstetrics and Gynecology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Philip R Foulis
- Morsani College of Medicine, University of South Florida, Tampa, FL, USA,Pathology and Laboratory Medicine, James A. Haley Veterans’ Hospital, Tampa, FL, USA
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18
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Dasari AKR, Dillard L, Yi S, Viverette E, Hojjatian A, Sengupta U, Kayed R, Taylor KA, Borgnia MJ, Lim KH. Untwisted α-Synuclein Filaments Formed in the Presence of Lipid Vesicles. Biochemistry 2022; 61:1766-1773. [PMID: 36001818 DOI: 10.1021/acs.biochem.2c00283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Accumulation of filamentous aggregates of α-synuclein is a pathological hallmark of several neurodegenerative diseases, including Parkinson's disease (PD). The interaction between α-synuclein and phospholipids has been shown to play a critical role in the aggregation of α-synuclein. Most structural studies have, however, been focused on α-synuclein filaments formed in the absence of lipids. Here, we report the structural investigation of α-synuclein filaments assembled under the quiescent condition in the presence of anionic lipid vesicles using electron microscopy (EM), including cryogenic electron microscopy (cryo-EM). Our transmission electron microscopy (TEM) analyses reveal that α-synuclein forms curly protofilaments at an early stage of aggregation. The flexible protofilaments were then converted to long filaments after a longer incubation of 30 days. More detailed structural analyses using cryo-EM reveal that the long filaments adopt untwisted structures with different diameters, which have not been observed in previous α-synuclein fibrils formed in vitro. The untwisted filaments are rather similar to straight filaments with no observable twist that are extracted from patients with dementia with Lewy bodies. Our structural studies highlight the conformational diversity of α-synuclein filaments, requiring additional structural investigation of not only more ex vivo α-synuclein filaments but also in vitro α-synuclein filaments formed in the presence of diverse cofactors to better understand the molecular basis of diverse molecular conformations of α-synuclein filaments.
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Affiliation(s)
- Anvesh K R Dasari
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Lucas Dillard
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, United States
| | - Sujung Yi
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Elizabeth Viverette
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, United States
| | - Alimohammad Hojjatian
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380, United States
| | - Urmi Sengupta
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Rakez Kayed
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380, United States
| | - Mario Juan Borgnia
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, United States
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
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19
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Rastegarpouyani H, Taylor DW, Yeganeh FA, Hojjatian A, Taylor KA. Cryo-EM sample preparation of native myosin filament from striated muscle. Acta Crystallogr A Found Adv 2022. [DOI: 10.1107/s2053273322099570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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20
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Goode AP, Hu D, George SZ, Schwartz TA, Kraus VB, Huebner JL, Cleveland RJ, Taylor KA, Jordan JM, Golightly YM. Biomarker clusters differentiate phenotypes of lumbar spine degeneration and low back pain: The Johnston County Osteoarthritis Project. Osteoarthritis and Cartilage Open 2022; 4. [PMID: 35991624 PMCID: PMC9387345 DOI: 10.1016/j.ocarto.2022.100270] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective: Describe the association between biomarkers and lumbar spine degeneration (vertebral osteophytes [OST], facet joint osteoarthritis [FOA], and disc space narrowing [DSN]), for persons with and without low back pain (LBP) and determine whether clusters based on biomarkers differentiate lumbar spine structure with and without LBP. Methods: Using data from the Johnston County Osteoarthritis Project (2006–2010), we measured serum N-cadherin, Keratin-19, Lumican, CXCL6, RANTES, HA, IL-6, BDNF, OPG, and NPY, and urinary CTX-II. Biomarkers were used to group participants using k-means cluster analysis. Logistic regression models were used to compare biomarker clusters. Results: The sample consisted of 731 participants with biospecimens and lumbar spine radiographic data. Three biomarker subgroups were identified: one characterized by structural degenerative changes; another characterized by structural degenerative changes and inflammation, with pain; and a referent cluster with lower levels of biomarkers, pain, and structural degenerative changes. Compared to the referent subgroup, the structural change subgroup was associated with DSN (OR = 1.94, 95% CI 1.30–2.90) and FOA (OR = 1.72, 95% CI 1.12–2.62), and the subgroup with structural degenerative change, inflammation, and pain was associated with OST with LBP (OR = 1.60, 95% CI 1.04–2.46), FOA with LBP (OR = 1.59, 95% CI 1.04–2.45), and LBP (OR = 1.63, 95% CI 1.11–2.41). The subgroup with structural degenerative changes was more likely to have OST (OR = 1.82, 95% CI 1.06–3.13) and less likely to have FOA with LBP (OR = 0.62, 95% CI 0.40–0.96) compared to the group with inflammation and pain. Conclusion: Clustering by biomarkers may assist in differentiating patients for specific clinical interventions aimed at decreasing LBP.
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21
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Li J, Rahmani H, Abbasi Yeganeh F, Rastegarpouyani H, Taylor DW, Iwamoto H, Taylor KA. Cryo-EM structure of the asynchronous flight muscle thick filament from the bumble bee, Bombus ignitius, at 6 Å resolution. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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22
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Hojjatian A, Dasari AKR, Sengupta U, Taylor D, Daneshparvar N, Yeganeh FA, Dillard L, Michael B, Griffin RG, Borgnia MJ, Kayed R, Taylor KA, Lim KH. Tau induces formation of α-synuclein filaments with distinct molecular conformations. Biochem Biophys Res Commun 2021; 554:145-150. [PMID: 33798940 PMCID: PMC8062303 DOI: 10.1016/j.bbrc.2021.03.091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/17/2021] [Indexed: 11/17/2022]
Abstract
Recent structural investigation of amyloid filaments extracted from human patients demonstrated that the ex vivo filaments associated with different disease phenotypes adopt diverse molecular conformations, which are different from those of in vitro amyloid filaments. A very recent cryo-EM structural study also revealed that ex vivo α-synuclein filaments extracted from multiple system atrophy patients adopt distinct molecular structures from those of in vitro α-synuclein filaments, suggesting the presence of co-factors for α-synuclein aggregation in vivo. Here, we report structural characterizations of α-synuclein filaments formed in the presence of a potential co-factor, tau, using cryo-EM and solid-state NMR. Our cryo-EM structure of the tau-promoted α-synuclein filaments reveals some similarities to one of the previously reported polymorphs of in vitro α-synuclein filaments in the core region, while illustrating distinct conformations in the N- and C-terminal regions. The structural study highlights the conformational plasticity of α-synuclein filaments and the importance of the co-factors, requiring additional structural investigation of not only more ex vivo α-synuclein filaments, but also in vitro α-synuclein filaments formed in the presence of diverse co-factors. The comparative structural analyses will help better understand molecular basis of diverse structures of α-synuclein filaments and possible relevance of each structure to the disease phenotype.
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Affiliation(s)
- Alimohammad Hojjatian
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Anvesh K R Dasari
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
| | - Urmi Sengupta
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Dianne Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Nadia Daneshparvar
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Lucas Dillard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Brian Michael
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Mario J Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Rakez Kayed
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA.
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Rahmani H, Ma W, Hu Z, Daneshparvar N, Taylor DW, McCammon JA, Irving TC, Edwards RJ, Taylor KA. The myosin II coiled-coil domain atomic structure in its native environment. Proc Natl Acad Sci U S A 2021; 118:e2024151118. [PMID: 33782130 PMCID: PMC8040620 DOI: 10.1073/pnas.2024151118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The atomic structure of the complete myosin tail within thick filaments isolated from Lethocerus indicus flight muscle is described and compared to crystal structures of recombinant, human cardiac myosin tail segments. Overall, the agreement is good with three exceptions: the proximal S2, in which the filament has heads attached but the crystal structure doesn't, and skip regions 2 and 4. At the head-tail junction, the tail α-helices are asymmetrically structured encompassing well-defined unfolding of 12 residues for one myosin tail, ∼4 residues of the other, and different degrees of α-helix unwinding for both tail α-helices, thereby providing an atomic resolution description of coiled-coil "uncoiling" at the head-tail junction. Asymmetry is observed in the nonhelical C termini; one C-terminal segment is intercalated between ribbons of myosin tails, the other apparently terminating at Skip 4 of another myosin tail. Between skip residues, crystal and filament structures agree well. Skips 1 and 3 also agree well and show the expected α-helix unwinding and coiled-coil untwisting in response to skip residue insertion. Skips 2 and 4 are different. Skip 2 is accommodated in an unusual manner through an increase in α-helix radius and corresponding reduction in rise/residue. Skip 4 remains helical in one chain, with the other chain unfolded, apparently influenced by the acidic myosin C terminus. The atomic model may shed some light on thick filament mechanosensing and is a step in understanding the complex roles that thick filaments of all species undergo during muscle contraction.
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Affiliation(s)
- Hamidreza Rahmani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
- Department of Physics, Florida State University, Tallahassee, FL 32306-4380
| | - Wen Ma
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Zhongjun Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
| | - Nadia Daneshparvar
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
- Department of Physics, Florida State University, Tallahassee, FL 32306-4380
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Thomas C Irving
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL 60616
| | - Robert J Edwards
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27607
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380;
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24
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Affiliation(s)
- Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA.
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25
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Rahmani H, Daneshparvar N, Taylor DW, Ma W, Taylor KA. The Atomic Model for Myosin II Coiled-Coil Shows Novel Observations and Insights into Muscle Contraction. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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26
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Daneshparvar N, Taylor DW, O'Leary TS, Rahmani H, Abbasiyeganeh F, Previs MJ, Taylor KA. CryoEM structure of Drosophila flight muscle thick filaments at 7 Å resolution. Life Sci Alliance 2020; 3:3/8/e202000823. [PMID: 32718994 PMCID: PMC7391215 DOI: 10.26508/lsa.202000823] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 06/22/2020] [Revised: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 11/24/2022] Open
Abstract
Striated muscle thick filaments are composed of myosin II and several non-myosin proteins. Myosin II's long α-helical coiled-coil tail forms the dense protein backbone of filaments, whereas its N-terminal globular head containing the catalytic and actin-binding activities extends outward from the backbone. Here, we report the structure of thick filaments of the flight muscle of the fruit fly Drosophila melanogaster at 7 Å resolution. Its myosin tails are arranged in curved molecular crystalline layers identical to flight muscles of the giant water bug Lethocerus indicus Four non-myosin densities are observed, three of which correspond to ones found in Lethocerus; one new density, possibly stretchin-mlck, is found on the backbone outer surface. Surprisingly, the myosin heads are disordered rather than ordered along the filament backbone. Our results show striking myosin tail similarity within flight muscle filaments of two insect orders separated by several hundred million years of evolution.
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Affiliation(s)
- Nadia Daneshparvar
- Department of Physics, Florida State University, Tallahassee, FL, USA.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
| | - Thomas S O'Leary
- Department of Molecular Physiology & Biophysics, University of Vermont College of Medicine, Burlington, VT, USA
| | - Hamidreza Rahmani
- Department of Physics, Florida State University, Tallahassee, FL, USA.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
| | | | - Michael J Previs
- Department of Molecular Physiology & Biophysics, University of Vermont College of Medicine, Burlington, VT, USA
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
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Gross M, Patel R, Schwartz SW, Sebastião YV, Foulis P, Scheer D, Taylor KA, Anderson W. 0806 Prescription Correlates of Nightmare Disorder Among Veterans. Sleep 2020. [DOI: 10.1093/sleep/zsaa056.802] [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: 11/14/2022] Open
Abstract
Abstract
Introduction
In the James A. Haley Veterans Administration (JAHVA) Vista database, the ICD-9 code 307.47 for Nightmare disorder (ND) is infrequently used and appears independently of codes for PTSD. We wanted to determine if certain drugs that may affect sleep are associated with ND.
Methods
All patients with ND visiting JAHVA between 2007 and 2011 were selected along with control patients who visited JAHVA on one of 20 random days, one day each quarter year. Controls were assigned an index date reflecting their selection quarter. Associations with prescriptions for opioids, antidepressants (SSRI’s, SSNI’s, Tricyclics), antihistamines and benzodiazepine/Z-drugs were initially investigated. Two analyses were performed: risk factor analysis- patients with ND diagnosis dates (cases) or index dates (controls) prior to 2008 were excluded and only prescription dates that preceded the ND diagnosis or index date were considered; treatment analysis- cases and controls with a ND diagnosis date or index date after 2010 were excluded and only prescription dates that were subsequent to the ND diagnosis or index date respectively were considered. Logistic regression adjusting for age, gender, race and Hispanic ethnicity was used to determine the association between drug groups and ND.
Results
In risk factor analysis (667 cases, 14,739 controls), opioids and antihistamines were significantly less prevalent among would-be ND patients than controls (OR=0.627 and 0.610 respectively); no drug group was predictive of ND. In contrast, all drug groups were significantly associated with ND in treatment analysis (803 cases, 15,530 controls). The strongest associations were seen with benzodiazepine (OR=3.026; 95% CI: 2.472, 3.703) and SSRI (OR=2.789; 95% CI=2.316, 3.358) prescriptions.
Conclusion
Our data suggest that some JAHVA providers may be treating ND with medication, most notably with benzodiazepines/Z-drugs and antidepressants. The role of anti-histamine and opioid prescriptions needs further elucidation. The ramifications of these treatment decisions should be explored.
Support
This material is the result of work supported with resources and the use of facilities at the James A. Haley Veterans’ Hospital.
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Affiliation(s)
- M Gross
- University of South Florida, College of Public Health, Tampa, FL
| | - R Patel
- University of South Florida, College of Public Health, Tampa, FL
- James A. Haley Veteran’s Hospital, Tampa, FL
| | - S W Schwartz
- University of South Florida, College of Public Health, Tampa, FL
| | | | - P Foulis
- University of South Florida, College of Public Health, Tampa, FL
- James A. Haley Veteran’s Hospital, Tampa, FL
| | - D Scheer
- University of South Florida, College of Public Health, Tampa, FL
- Biotech Research Group Inc., Tampa, FL
| | - K A Taylor
- University of South Florida, College of Public Health, Tampa, FL
- Gannon University, Ruskin, FL
| | - W Anderson
- University of South Florida, College of Public Health, Tampa, FL
- James A. Haley Veteran’s Hospital, Tampa, FL
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Taylor KA, Schwartz SW, Sebastião YV, Anderson WM, Foulis PR. 0667 Positive Airway Pressure Non-Adherence Interacts With Post-Traumatic Stress Disorder to Increase Risk of Back Pain. Sleep 2020. [DOI: 10.1093/sleep/zsaa056.663] [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: 11/13/2022] Open
Abstract
Abstract
Introduction
Altered sleep, as is associated with obstructive sleep apnea (OSA), may increase the risk of back pain (BP). However, little to no evidence regarding the effect of OSA on musculoskeletal pain is currently available, let alone the effect of positive airway pressure (PAP) treatment non-adherence. The purpose of this analysis is to investigate the effect of PAP non-adherence on future BP diagnosis.
Methods
A sample of 1,662 veterans who had a sleep study between January 2003 and October 2006 and receiving PAP treatment for OSA were used for analysis. Measures at baseline included demographic and OSA symptom severity data. Up to 3 weeks of PAP adherence data were collected and patient chart data was collected through May 2010 to determine outcomes. Time was calculated from PAP treatment start to BP diagnosis or censoring, which occurred at date of death or last recorded encounter. Survival analysis was conducted to obtain the hazard ratios (HR) for the effect of PAP non-adherence on BP diagnosis and to investigate whether post-traumatic stress disorder (PTSD) is an effect modifier of this relationship.
Results
PAP treatment non-adherence significantly increased the risk of BP diagnosis (HR 1.88 [95% CI: 1.08, 3.27]) among veterans with PTSD, while non-adherence among veterans without PTSD was not a statistically significant risk factor. Relative excess risk due to interaction (RERI) was 0.97 (95% CI: -0.07, 2.02; p-value=0.068). These estimates are independent of age, sex, race, body mass index, apnea severity (based on Apnea-Hypopnea Index), PTSD diagnosis, income level, and marital status.
Conclusion
PAP treatment non-adherence among veterans with PTSD appears to result in a significant increase in risk of future BP diagnosis. The interaction between PAP non-adherence and PTSD appears to be borderline synergistic. Therefore, improving PAP adherence among veterans with PTSD may decrease risk of future BP diagnosis.
Support
This material is the result of work supported with resources and the use of facilities at the James A. Haley Veterans’ Hospital.
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Affiliation(s)
- K A Taylor
- University of South Florida, Tampa, FL
- Gannon University, Ruskin, FL
| | | | | | - W M Anderson
- University of South Florida, Tampa, FL
- James A. Haley Veterans’ Hospital, Tampa, FL
| | - P R Foulis
- James A. Haley Veterans’ Hospital, Tampa, FL
- University of South Florida, Tampa, FL
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Daneshparvar N, Previs M, O’Leary T, Taylor D, Rahmani H, Abbasiyeganeh F, Taylor KA. Why the Interacting Heads Motif is not Observed in Isolated, Relaxed Thick Filaments of Drosophila Melanogaster. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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30
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Hojjatian A, Dasari AK, Taylor D, Daneshparvar N, Abbasi Yeganeh FA, Hun Lim K, Taylor KA. Single Particle Cryo-EM Structure of Alpha-Synuclein Fibrils Interacting with Tau. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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31
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Banerjee C, Dutta M, Liu X, Roux KH, Taylor KA. Segmentation by classification: A novel and reliable approach for semi-automatic selection of HIV/SIV envelope spikes. J Struct Biol 2020; 209:107426. [PMID: 31733279 DOI: 10.1016/j.jsb.2019.107426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 09/28/2019] [Accepted: 11/12/2019] [Indexed: 11/30/2022]
Abstract
We describe a semiautomated approach to segment Env spikes from the membrane envelope of Simian Immunodeficiency Virus visualized by cryoelectron tomography of frozen-hydrated specimens. Multivariate data analysis is applied to a large set of overlapping subvolumes extracted semiautomatically from the viral envelope and does not utilize a template of the target structure. The major manual step used in the method involves determination of six points that define an ellipsoid approximating the virion shape. The approach is robust to departures of the actual virion from this starting ellipsoid. A point cage of sufficient density is generated to ensure that any spike-like protein is identified multiple times. Subsequently translational alignment of class averages to a cylindrical reference on a curved surface separates subvolumes with spikes from those without. Spike containing subvolumes identified multiple times are removed by proximity analysis. Slightly different procedures segment spikes in the equatorial and the polar regions. Once all spikes are segmented, further alignment of class averages using separately the polar and spin angles produces recognizable spike images. Our approach localized 96% of the equatorial spikes and 85% of all spikes identified manually; it identifies a significant number of additional spikes missed by manual selection. Two types of spike shapes were segmented, one with near 3-fold symmetry resembling the conventional spike, the other had a T-shape resembling the spike structure obtained when antibodies such as PG9 bind to HIV Env. The approach should be applicable to segmentation of any protein spikes extending from a cellular or virion envelope.
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Affiliation(s)
- Chaity Banerjee
- Department of Computer Science, Florida State University, Tallahassee, FL 32306-4530, United States.
| | - Moumita Dutta
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, United States.
| | - Xiuwen Liu
- Department of Computer Science, Florida State University, Tallahassee, FL 32306-4530, United States.
| | - Kenneth H Roux
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, United States.
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, United States.
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32
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Burgoyne T, Heumann JM, Morris EP, Knupp C, Liu J, Reedy MK, Taylor KA, Wang K, Luther PK. Three-dimensional structure of the basketweave Z-band in midshipman fish sonic muscle. Proc Natl Acad Sci U S A 2019; 116:15534-15539. [PMID: 31320587 PMCID: PMC6681754 DOI: 10.1073/pnas.1902235116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Striated muscle enables movement in all animals by the contraction of myriads of sarcomeres joined end to end by the Z-bands. The contraction is due to tension generated in each sarcomere between overlapping arrays of actin and myosin filaments. At the Z-band, actin filaments from adjoining sarcomeres overlap and are cross-linked in a regular pattern mainly by the protein α-actinin. The Z-band is dynamic, reflected by the 2 regular patterns seen in transverse section electron micrographs; the so-called small-square and basketweave forms. Although these forms are attributed, respectively, to relaxed and actively contracting muscles, the basketweave form occurs in certain relaxed muscles as in the muscle studied here. We used electron tomography and subtomogram averaging to derive the 3D structure of the Z-band in the swimbladder sonic muscle of type I male plainfin midshipman fish (Porichthys notatus), into which we docked the crystallographic structures of actin and α-actinin. The α-actinin links run diagonally between connected pairs of antiparallel actin filaments and are oriented at an angle of about 25° away from the actin filament axes. The slightly curved and flattened structure of the α-actinin rod has a distinct fit into the map. The Z-band model provides a detailed understanding of the role of α-actinin in transmitting tension between actin filaments in adjoining sarcomeres.
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Affiliation(s)
- Thomas Burgoyne
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, SW7 2AZ London, United Kingdom
| | - John M Heumann
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309-0347
| | - Edward P Morris
- Division of Structural Biology, Institute of Cancer Research, SW7 3RP London, United Kingdom
| | - Carlo Knupp
- School of Optometry and Vision Sciences, Cardiff University, CF10 3AT Cardiff, United Kingdom
| | - Jun Liu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
| | - Michael K Reedy
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380
| | - Kuan Wang
- Laboratory of Muscle Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD 20892
- College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
| | - Pradeep K Luther
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, SW7 2AZ London, United Kingdom;
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Taylor KA, Schwartz SW, Sebastião YV, Anderson WM, Foulis PR. 0866 Does Obstructive Sleep Apnea Mediate the Relationship Between Post-Traumatic Stress Disorder and Low Back Pain in Veterans? Sleep 2019. [DOI: 10.1093/sleep/zsz067.864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Introduction
Low back pain (LBP) is a common complaint among veterans, leading to notable limits in function, quality of life, and an increase in healthcare cost. The incidence and prevalence of LBP have been increasing in the veterans over the past several years. Obstructive sleep apnea (OSA) has been shown to be associated with LBP and there are notable associations among post-traumatic stress disorder (PTSD), OSA and LBP in this population.
Methods
A random sample of veterans stratified by quarter was taken between 2007 and 2011 (index date), collecting records from 2006 to 2016. Veterans were excluded if they had a prevalent case of LBP, and/or OSA in the year of or year before to their index date (index period), or PTSD, OSA and/or LBP prior to the index period. Associations among the PTSD, LBP, and OSA were calculated using SAS PROC LOGISTIC. SAS PROC PHREG was used to calculate hazard ratios (HR) for mediation analysis and the percent of 4-year LBP risk explained by OSA in those with PTSD.
Results
PTSD predicted LBP diagnosis (OR 1.52 [95% CI: 1.27, 1.83]) and OSA diagnosis (OR 2.06 [1.48, 2.88]). Additionally, OSA diagnosis was predictive of LBP diagnosis (OR 8.99 [95% CI: 7.07, 11.35]). The HR for the effect of PTSD on the risk LBP diagnosis was 1.47 (95% CI: 1.25, 1.74) without adjustment for OSA. The HR for the effect of PTSD on the risk LBP diagnosis adjusted for the mediator was 1.35 (95% CI: 1.15, 1.60). The resulting percent of excess LBP risk explained by OSA is 25.5% (95% CI: 19.6%,31.1%). All analyses were adjusted for potential confounders.
Conclusion
OSA may mediate a significant amount of the risk of LBP diagnosis in veterans with PTSD. Prevention of OSA among veterans with PTSD may significantly reduce the risk of future LBP in veterans with PTSD.
Support (If Any)
This material is the result of work supported with resources and the use of facilities at the James A. Haley Veterans’ Hospital.
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Affiliation(s)
- Kenneth A Taylor
- Doctor of Physical Therapy Program, Gannon University, Ruskin, FL, USA
- University of South Florida, Tampa, FL, USA
| | | | - Yuri V Sebastião
- Center for Surgical Outcomes Research, Nationwide Children’s Hospital, Columbus, OH, USA
| | - William McD Anderson
- University of South Florida, Tampa, FL, USA
- James A. Haley Veterans' Hospital, Tampa, FL, USA
| | - Phillip R Foulis
- James A. Haley Veterans' Hospital, Tampa, FL, USA
- University of South Florida, Tampa, FL, USA
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34
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Taylor KA, Rahmani H, Edwards RJ, Reedy MK. Insights into Actin-Myosin Interactions within Muscle from 3D Electron Microscopy. Int J Mol Sci 2019; 20:ijms20071703. [PMID: 30959804 PMCID: PMC6479483 DOI: 10.3390/ijms20071703] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 01/12/2023] Open
Abstract
Much has been learned about the interaction between myosin and actin through biochemistry, in vitro motility assays and cryo-electron microscopy (cryoEM) of F-actin, decorated with myosin heads. Comparatively less is known about actin-myosin interactions within the filament lattice of muscle, where myosin heads function as independent force generators and thus most measurements report an average signal from multiple biochemical and mechanical states. All of the 3D imaging by electron microscopy (EM) that has revealed the interplay of the regular array of actin subunits and myosin heads within the filament lattice has been accomplished using the flight muscle of the large water bug Lethocerus sp. The Lethocerus flight muscle possesses a particularly favorable filament arrangement that enables all the myosin cross-bridges contacting the actin filament to be visualized in a thin section. This review covers the history of this effort and the progress toward visualizing the complex set of conformational changes that myosin heads make when binding to actin in several static states, as well as the fast frozen actively contracting muscle. The efforts have revealed a consistent pattern of changes to the myosin head structures as determined by X-ray crystallography needed to explain the structure of the different actomyosin interactions observed in situ.
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Affiliation(s)
- Kenneth A Taylor
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL 32306-4380, USA.
| | - Hamidreza Rahmani
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL 32306-4380, USA.
| | - Robert J Edwards
- Duke University Medical Center, Department of Cell Biology, Durham, NC 27607, USA.
| | - Michael K Reedy
- Duke University Medical Center, Department of Cell Biology, Durham, NC 27607, USA.
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35
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Daneshparvar N, Taylor D, Rahmani H, Taylor KA. Structure of Thick Filaments from Drosophila Indirect Flight Muscle by Cryo-EM. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.2182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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36
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Rahmani H, Daneshparvar N, Hu Z, Taylor D, Edwards RJ, Taylor KA. A Complete Atomic Model for Lethocerus Flight Muscle Myosin Filament. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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37
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Taylor KA, Hu Z, Taylor DW, Edwards RJ. Is the Myosin Head Conformation Coupled to the Thick Filament Backbone Structure? Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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38
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Yeganeh FA, Summerill C, Hu Z, Rahmani H, Taylor DW, Taylor KA. 3-D Structure of Z-Disks Isolated from the Flight Muscle of Lethocerus Indicus. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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39
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Hu G, Taylor DW, Liu J, Taylor KA. Identification of interfaces involved in weak interactions with application to F-actin-aldolase rafts. J Struct Biol 2017; 201:199-209. [PMID: 29146292 DOI: 10.1016/j.jsb.2017.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/09/2017] [Accepted: 11/12/2017] [Indexed: 10/18/2022]
Abstract
Macromolecular interactions occur with widely varying affinities. Strong interactions form well defined interfaces but weak interactions are more dynamic and variable. Weak interactions can collectively lead to large structures such as microvilli via cooperativity and are often the precursors of much stronger interactions, e.g. the initial actin-myosin interaction during muscle contraction. Electron tomography combined with subvolume alignment and classification is an ideal method for the study of weak interactions because a 3-D image is obtained for the individual interactions, which subsequently are characterized collectively. Here we describe a method to characterize heterogeneous F-actin-aldolase interactions in 2-D rafts using electron tomography. By forming separate averages of the two constituents and fitting an atomic structure to each average, together with the alignment information which relates the raw motif to the average, an atomic model of each crosslink is determined and a frequency map of contact residues is computed. The approach should be applicable to any large structure composed of constituents that interact weakly and heterogeneously.
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Affiliation(s)
- Guiqing Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Jun Liu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, United States.
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40
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Banerjee C, Hu Z, Huang Z, Warrington JA, Taylor DW, Trybus KM, Lowey S, Taylor KA. The structure of the actin-smooth muscle myosin motor domain complex in the rigor state. J Struct Biol 2017; 200:325-333. [PMID: 29038012 DOI: 10.1016/j.jsb.2017.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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: 05/01/2017] [Revised: 10/11/2017] [Accepted: 10/12/2017] [Indexed: 01/08/2023]
Abstract
Myosin-based motility utilizes catalysis of ATP to drive the relative sliding of F-actin and myosin. The earliest detailed model based on cryo-electron microscopy (cryoEM) and X-ray crystallography postulated that higher actin affinity and lever arm movement were coupled to closure of a feature of the myosin head dubbed the actin-binding cleft. Several studies since then using crystallography of myosin-V and cryoEM structures of F-actin bound myosin-I, -II and -V have provided details of this model. The smooth muscle myosin II interaction with F-actin may differ from those for striated and non-muscle myosin II due in part to different lengths of important surface loops. Here we report a ∼6 Å resolution reconstruction of F-actin decorated with the nucleotide-free recombinant smooth muscle myosin-II motor domain (MD) from images recorded using a direct electron detector. Resolution is highest for F-actin and the actin-myosin interface (3.5-4 Å) and lowest (∼6-7 Å) for those parts of the MD at the highest radius. Atomic models built into the F-actin density are quite comparable to those previously reported for rabbit muscle actin and show density from the bound ADP. The atomic model of the MD, is quite similar to a recently published structure of vertebrate non-muscle myosin II bound to F-actin and a crystal structure of nucleotide free myosin-V. Larger differences are observed when compared to the cryoEM structure of F-actin decorated with rabbit skeletal muscle myosin subfragment 1. The differences suggest less closure of the 50 kDa domain in the actin bound skeletal muscle myosin structure.
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Affiliation(s)
- Chaity Banerjee
- Department of Computer Science, Florida State University, Tallahassee, FL 32306-4530, United States
| | - Zhongjun Hu
- Institute of Molecular Biophysics, Kasha Laboratory, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Zhong Huang
- Institute of Molecular Biophysics, Kasha Laboratory, Florida State University, Tallahassee, FL 32306-4380, United States
| | - J Anthony Warrington
- Institute of Molecular Biophysics, Kasha Laboratory, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Kasha Laboratory, Florida State University, Tallahassee, FL 32306-4380, United States
| | - Kathleen M Trybus
- Health Science Research Facility 130, 149 Beaumont Avenue, Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, United States
| | - Susan Lowey
- Health Science Research Facility 130, 149 Beaumont Avenue, Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Kasha Laboratory, Florida State University, Tallahassee, FL 32306-4380, United States.
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41
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Taylor KA, Durrheim D, Heller J, O'Rourke B, Hope K, Merritt T, Freeman P, Chicken C, Carrick J, Branley J, Massey P. Equine chlamydiosis-An emerging infectious disease requiring a one health surveillance approach. Zoonoses Public Health 2017; 65:218-221. [PMID: 28984040 DOI: 10.1111/zph.12391] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Indexed: 12/19/2022]
Abstract
Psittacosis is a rare but potentially fatal zoonosis caused by Chlamydia psittaci, an organism that is typically associated with bird contact. However C. psittaci is capable of infecting other non-avian hosts, such as horses, sheep, cattle and goats. Stud staff and veterinarians have significant exposure to parturient animals and reproductive materials in their routine work. To investigate the zoonotic potential associated with the emergence of C. psittaci as an abortifacient agent in horses, we established a programme of joint human and animal surveillance in a sentinel horse-breeding region in Australia. This programme comprised cross-notification of equine cases to public health agencies, and active follow-up of known human contacts, including stud workers, foaling staff, veterinarians and laboratory staff. We identified no confirmed cases of acute psittacosis despite intensive surveillance and testing of heavily exposed contacts; however, further work in the area is needed.
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Affiliation(s)
- K A Taylor
- Population Health Unit, Hunter New England Local Health, Wallsend, NSW, Australia
| | - D Durrheim
- Population Health Unit, Hunter New England Local Health, Wallsend, NSW, Australia.,School of Public Health and Medical Practice, University of Newcastle, Newcastle, NSW, Australia
| | - J Heller
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - B O'Rourke
- Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Menangle, NSW, Australia
| | - K Hope
- Health Protection, New South Wales Ministry of Health, North Sydney, NSW, Australia
| | - T Merritt
- Population Health Unit, Hunter New England Local Health, Wallsend, NSW, Australia
| | - P Freeman
- New South Wales Department of Primary Industries, Wollongbar, NSW, Australia
| | - C Chicken
- Scone Equine Hospital, Scone, NSW, Australia
| | - J Carrick
- Equine Specialist Consulting, Scone, NSW, Australia
| | - J Branley
- Westmead Clinical School, Nepean Hospital, Nepean, NSW, Australia
| | - P Massey
- Population Health Unit, Hunter New England Local Health, Wallsend, NSW, Australia
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42
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Hu Z, Taylor DW, Edwards RJ, Taylor KA. Coupling between myosin head conformation and the thick filament backbone structure. J Struct Biol 2017; 200:334-342. [PMID: 28964844 DOI: 10.1016/j.jsb.2017.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 05/01/2017] [Revised: 09/01/2017] [Accepted: 09/26/2017] [Indexed: 12/19/2022]
Abstract
The recent high-resolution structure of the thick filament from Lethocerus asynchronous flight muscle shows aspects of thick filament structure never before revealed that may shed some light on how striated muscles function. The phenomenon of stretch activation underlies the function of asynchronous flight muscle. It is most highly developed in flight muscle, but is also observed in other striated muscles such as cardiac muscle. Although stretch activation is likely to be complex, involving more than a single structural aspect of striated muscle, the thick filament itself, would be a prime site for regulatory function because it must bear all of the tension produced by both its associated myosin motors and any externally applied force. Here we show the first structural evidence that the arrangement of myosin heads within the interacting heads motif is coupled to the structure of the thick filament backbone. We find that a change in helical angle of 0.16° disorders the blocked head preferentially within the Lethocerus interacting heads motif. This observation suggests a mechanism for how tension affects the dynamics of the myosin heads leading to a detailed hypothesis for stretch activation and shortening deactivation, in which the blocked head preferentially binds the thin filament followed by the free head when force production occurs.
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Affiliation(s)
- Zhongjun Hu
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL 32306-4380, USA
| | - Dianne W Taylor
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL 32306-4380, USA
| | - Robert J Edwards
- Duke University Medical Center, Department of Cell Biology, Durham, NC 27607, UK
| | - Kenneth A Taylor
- Florida State University, Institute of Molecular Biophysics, Tallahassee, FL 32306-4380, USA.
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Abstract
The Z-disk is a complex structure comprising some 40 proteins that are involved in the transmission of force developed during muscle contraction and in important signalling pathways that govern muscle homeostasis. In the Z-disk the ends of antiparallel thin filaments from adjacent sarcomeres are crosslinked by α-actinin. The structure of the Z-disk lattice varies greatly throughout the animal kingdom. In vertebrates the thin filaments form a tetragonal lattice, whereas invertebrate flight muscle has a hexagonal lattice. The width of the Z-disk varies considerably and correlates with the number of α-actinin bridges. A detailed description at a high resolution of the Z-disk lattice is needed in order to better understand muscle function and disease. The molecular architecture of the Z-disk lattice in honeybee (Apis mellifera) is known from plastic embedded thin sections to a resolution of 7 nm, which is not sufficient to dock component protein crystal structures. It has been shown that sectioning is a damaging process that leads to the loss of finer details present in biological specimens. However, the Apis Z-disk is a thin structure (120 nm) suitable for cryo EM. We have isolated intact honeybee Z-disks from indirect flight muscle, thus obviating the need of plastic sectioning. We have employed cryo electron tomography and image processing to investigate the arrangement of proteins within the hexagonal lattice of the Apis Z-disk. The resolution obtained, ~6 nm, was probably limited by damage caused by the harshness of the conditions used to extract the myofibrils and isolate the Z-disks.
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Affiliation(s)
- Mara Rusu
- Astbury Center, University of Leeds, Leeds, LS2 9JT, UK
| | - Zhongjun Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA
| | - John Trinick
- Astbury Center, University of Leeds, Leeds, LS2 9JT, UK.
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Taylor KA, Hu Z, Taylor D, Reedy MK, Edwards RJ. An Atomic Model for a Complete Myosin Molecule within a Native Thick Filament. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.1809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Abstract
Platelets are the primary cellular determinants of haemostasis and pathological thrombus formation leading to myocardial infarction and stroke. Following vascular injury or atherosclerotic plaque rupture, platelets are recruited to sites of damage and undergo activation induced by a variety of soluble and/or insoluble agonists. Platelet activation is a multi-step process culminating in the formation of thrombi, which contribute to the haemostatic process. Zinc (Zn(2+)) is acknowledged as an important signalling molecule in a diverse range of cellular systems, however there is limited understanding of the influence of Zn(2+) on platelet behaviour during thrombus formation. This review evaluates the contributions of exogenous and intracellular Zn(2+) to platelet function and assesses the potential pathophysiological implications of Zn(2+) signalling. We also provide a speculative assessment of the mechanisms by which platelets could respond to changes in extracellular and intracellular Zn(2+) concentration.
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Affiliation(s)
- K A Taylor
- Department of Biomedical and Forensic Sciences, Faculty of Science and Technology, Anglia Ruskin University, Cambridge, CB1 1PT, UK.
| | - N Pugh
- Department of Biomedical and Forensic Sciences, Faculty of Science and Technology, Anglia Ruskin University, Cambridge, CB1 1PT, UK.
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Hu Z, Taylor DW, Reedy MK, Edwards RJ, Taylor KA. Structure of myosin filaments from relaxed Lethocerus flight muscle by cryo-EM at 6 Å resolution. Sci Adv 2016; 2:e1600058. [PMID: 27704041 PMCID: PMC5045269 DOI: 10.1126/sciadv.1600058] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 08/23/2016] [Indexed: 05/09/2023]
Abstract
We describe a cryo-electron microscopy three-dimensional image reconstruction of relaxed myosin II-containing thick filaments from the flight muscle of the giant water bug Lethocerus indicus. The relaxed thick filament structure is a key element of muscle physiology because it facilitates the reextension process following contraction. Conversely, the myosin heads must disrupt their relaxed arrangement to drive contraction. Previous models predicted that Lethocerus myosin was unique in having an intermolecular head-head interaction, as opposed to the intramolecular head-head interaction observed in all other species. In contrast to the predicted model, we find an intramolecular head-head interaction, which is similar to that of other thick filaments but oriented in a distinctly different way. The arrangement of myosin's long α-helical coiled-coil rod domain has been hypothesized as either curved layers or helical subfilaments. Our reconstruction is the first report having sufficient resolution to track the rod α helices in their native environment at resolutions ~5.5 Å, and it shows that the layer arrangement is correct for Lethocerus. Threading separate paths through the forest of myosin coiled coils are four nonmyosin peptides. We suggest that the unusual position of the heads and the rod arrangement separated by nonmyosin peptides are adaptations for mechanical signal transduction whereby applied tension disrupts the myosin heads as a component of stretch activation.
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Affiliation(s)
- Zhongjun Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306–4380, USA
| | - Dianne W. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306–4380, USA
| | - Michael K. Reedy
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27607, USA
| | - Robert J. Edwards
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27607, USA
| | - Kenneth A. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306–4380, USA
- Corresponding author.
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Dai A, Ye F, Taylor DW, Hu G, Ginsberg MH, Taylor KA. The Structure of a Full-length Membrane-embedded Integrin Bound to a Physiological Ligand. J Biol Chem 2015; 290:27168-27175. [PMID: 26391523 DOI: 10.1074/jbc.m115.682377] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Indexed: 11/06/2022] Open
Abstract
Increased ligand binding to integrin ("activation") underpins many biological processes, such as leukocyte trafficking, cell migration, host-pathogen interaction, and hemostasis. Integrins exist in several conformations, ranging from compact and bent to extended and open. However, the exact conformation of membrane-embedded, full-length integrin bound to its physiological macromolecular ligand is still unclear. Integrin αIIbβ3, the most abundant integrin in platelets, has been a prototype for integrin activation studies. Using negative stain electron microscopy and nanodisc-embedding to provide a membrane-like environment, we visualized the conformation of full-length αIIbβ3 in both a Mn(2+)-activated, ligand-free state and a Mn(2+)-activated, fibrin-bound state. Activated but ligand-free integrins exist mainly in the compact conformation, whereas fibrin-bound αIIbβ3 predominantly exists in a fully extended, headpiece open conformation. Our results show that membrane-embedded, full-length integrin adopts an extended and open conformation when bound to its physiological macromolecular ligand.
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Affiliation(s)
- Aguang Dai
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380 and
| | - Feng Ye
- Department of Hematology and Oncology, University of California at San Diego, La Jolla, California 92093-0726
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380 and
| | - Guiqing Hu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380 and
| | - Mark H Ginsberg
- Department of Hematology and Oncology, University of California at San Diego, La Jolla, California 92093-0726
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380 and.
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Taylor KA, Wright JR, Vial C, Evans RJ, Mahaut-Smith MP. Amplification of human platelet activation by surface pannexin-1 channels. J Thromb Haemost 2014; 12:987-98. [PMID: 24655807 PMCID: PMC4238786 DOI: 10.1111/jth.12566] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [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: 10/22/2013] [Accepted: 03/04/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND Pannexin-1 (Panx1) forms an anion-selective channel with a permeability up to ~1 kDa and represents a non-lytic, non-vesicular ATP release pathway in erythrocytes, leukocytes and neurons. Related connexin gap junction proteins have been reported in platelets; however, the expression and function of the pannexins remain unknown. OBJECTIVE To determine the expression and function of pannexins in human plate-lets, using molecular, cellular and functional techniques. METHODS Panx1 expression in human platelets was det-ermined using qPCR and antibody-based techniques. Contributions of Panx1 to agonist-evoked efflux of cytoplasmic calcein, Ca(2+) influx, ATP release and aggregation were assessed in washed platelets under conditions where the P2X1 receptor response was preserved (0.32 U mL(-1) apyrase). Thrombus formation in whole blood was assessed in vitro using a shear chamber assay. Two structurally unrelated and widely used Panx1 inhibitors, probenecid and carbenoxolone, were used throughout this study, at concentrations that do not affect connexin channels. RESULTS PANX1, but not PANX2 or PANX3, mRNA was detected in human platelets. Furthermore, Panx1 protein is glycosylated and present on the plasma membrane of platelets, and displays weak physical association with P2X1 receptors. Panx1 inhibition blocked thrombin-evoked efflux of calcein, and reduced Ca(2+) influx, ATP release, platelet aggregation and thrombus formation under arterial shear rates in vitro. The Panx1-dependent contribution was not additive to that of P2X1 receptors. CONCLUSIONS Panx1 is expressed on human platelets and amplifies Ca(2+) influx, ATP release and aggregation through the secondary activation of P2X1 receptors. We propose that Panx1 represents a novel target for the management of arterial thrombosis.
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Affiliation(s)
- K A Taylor
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, UK
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Taylor KA, Feig M, Brooks CL, Fagnant PM, Lowey S, Trybus KM. Role of the Essential Light Chain in the Activation of Smooth Muscle Myosin by Regulatory Light Chain Phosphorylation. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.4006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Silverman S, Miller P, Sebba A, Weitz M, Wan X, Alam J, Masica D, Taylor KA, Ruff VA, Krohn K. The Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) study: 2-year nonvertebral fragility fracture results. Osteoporos Int 2013; 24:2309-17. [PMID: 23404615 PMCID: PMC3706736 DOI: 10.1007/s00198-013-2284-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 01/03/2013] [Indexed: 11/04/2022]
Abstract
UNLABELLED This observational study evaluated the occurrence of nonvertebral fragility fractures (NVFX) in over 4,000 men and women with osteoporosis treated with teriparatide (TPTD). The incidence of new NVFX decreased for patients receiving TPTD treatment for greater than 6 months. No new significant safety findings were observed in this large trial. INTRODUCTION The Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) study evaluated the occurrence of NVFX in patients receiving TPTD for osteoporosis in a real-world setting. METHODS DANCE is a multicenter, prospective, observational trial that examined the long-term effectiveness of TPTD in men and women with osteoporosis whom study physicians judged to be suitable for TPTD therapy. Patients received 20 μg TPTD per day by subcutaneous injection for up to 24 months and were followed for 24 months after treatment cessation. The incidence of patients experiencing a new NVFX, defined as a fracture associated with low trauma, was evaluated during four 6-month periods in both the treatment and cessation phases with >0 to ≤6 months serving as the reference. We also observed the spectrum and occurrence of serious adverse events. RESULTS Of the 4,167 patients enrolled, 4,085 took one or more doses of TPTD (safety population); 3,720 were included in the efficacy analysis. The incidence of patients experiencing a NVFX was 1.42, 0.91, 0.70, and 0.81 % for the four treatment periods, respectively, and 0.80, 0.68, 0.33, and 0.33 % for the four periods after treatment cessation. Differences for each period were statistically significant compared with the reference period (first 6-month interval, each p < 0.05). No new significant safety findings were observed. CONCLUSIONS In this study, the incidence of NVFX decreased for patients receiving TPTD for all three treatment periods >6 months compared to 0 to ≤6 months, and this trend persisted throughout the cessation phase. TPTD was generally well tolerated.
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Affiliation(s)
- S Silverman
- Cedars-Sinai/UCLA Medical Center and OMC Clinical Research Center, 8641 Wilshire Blvd, Suite 301, Beverly Hills, CA 90211, USA.
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