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Alves PM, Barrias CC, Gomes P, Martins MCL. How can biomaterial-conjugated antimicrobial peptides fight bacteria and be protected from degradation? Acta Biomater 2024:S1742-7061(24)00226-5. [PMID: 38697382 DOI: 10.1016/j.actbio.2024.04.043] [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: 01/12/2024] [Revised: 03/19/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
The emergence of antibiotic-resistant bacteria is a serious threat to public health. Antimicrobial peptides (AMP) are a powerful alternative to antibiotics due to their low propensity to induce bacterial resistance. However, cytotoxicity and short half-lives have limited their clinical translation. To overcome these problems, AMP conjugation has gained relevance in the biomaterials field. Nevertheless, few studies describe the influence of conjugation on enzymatic protection, mechanism of action and antimicrobial efficacy. This review addresses this gap by providing a detailed comparison between conjugated and soluble AMP. Additionally, commonly employed chemical reactions and factors to consider when promoting AMP conjugation are reviewed. The overall results suggested that AMP conjugated onto biomaterials are specifically protected from degradation by trypsin and/or pepsin. However, sometimes, their antimicrobial efficacy was reduced. Due to limited conformational freedom in conjugated AMP, compared to their soluble forms, they appear to act initially by creating small protuberances on bacterial membranes that may lead to the alteration of membrane potential and/or formation of holes, triggering cell death. Overall, AMP conjugation onto biomaterials is a promising strategy to fight infection, particularly associated to the use of medical devices. Nonetheless, some details need to be addressed before conjugated AMP reach clinical practice. STATEMENT OF SIGNIFICANCE: Covalent conjugation of antimicrobial peptides (AMP) has been one of the most widely used strategies by bioengineers, in an attempt to not only protect AMP from proteolytic degradation, but also to prolong their residence time at the target tissue. However, an explanation for the mode of action of conjugated AMP is still lacking. This review extensively gathers works on AMP conjugation and puts forward a mechanism of action for AMP when conjugated onto biomaterials. The implications of AMP conjugation on antimicrobial activity, cytotoxicity and resistance to proteases are all discussed. A thorough review of commonly employed chemical reactions for this conjugation is also provided. Finally, details that need to be addressed for conjugated AMP to reach clinical practice are discussed.
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Affiliation(s)
- Pedro M Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
| | - Cristina C Barrias
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Paula Gomes
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
| | - M Cristina L Martins
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal.
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Eishi K, Eishi J, Matsumaru I, Sumi M, Obase K, Miura T. Current management of tricuspid regurgitation: a focus on the spiral suspension approach. Gen Thorac Cardiovasc Surg 2024:10.1007/s11748-024-02024-y. [PMID: 38642224 DOI: 10.1007/s11748-024-02024-y] [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: 01/17/2024] [Accepted: 03/10/2024] [Indexed: 04/22/2024]
Abstract
The indication for surgery for tricuspid regurgitation (TR) has reached a major turning point. It has become clear that the presence of moderate or severe TR alone worsens the prognosis of life, and the previous guidelines of Japanese Circulation Society, in which the indication for surgery was recommended at the timing of "right heart failure difficult to treat medically," now recommends surgery with a trigger of "repeated right heart failure" in the 2020 edition. In addition, a new repair technique targeting at subvalvular structure has been developed for end-stage TR to overcome a high TR recurrence rate that is associated with severe right ventricular enlargement and leaflet tethering. This review focuses on the spiral suspension technique, in which the papillary muscles are spirally suspended towards the septal leaflet annulus to correct tethering and enhances the understanding of its application in the context of TR management.
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Affiliation(s)
- Kiyoyuki Eishi
- Department of Cardiovascular Surgery, Nagasaki University, Nagasaki, Japan.
- Heart/Valve Center, Hakujyuji Hospital, 4-3-1 Ishimaru, Nishi-ku, Fukuoka, 819-8511, Japan.
| | - Junichiro Eishi
- Department of Cardiovascular Surgery, Nagasaki University, Nagasaki, Japan
- Heart/Valve Center, Hakujyuji Hospital, 4-3-1 Ishimaru, Nishi-ku, Fukuoka, 819-8511, Japan
| | - Ichiro Matsumaru
- Department of Cardiovascular Surgery, Nagasaki University, Nagasaki, Japan
| | - Mizuki Sumi
- Heart/Valve Center, Hakujyuji Hospital, 4-3-1 Ishimaru, Nishi-ku, Fukuoka, 819-8511, Japan
| | - Kikuko Obase
- Department of Cardiovascular Surgery, Nagasaki University, Nagasaki, Japan
- Heart/Valve Center, Hakujyuji Hospital, 4-3-1 Ishimaru, Nishi-ku, Fukuoka, 819-8511, Japan
| | - Takashi Miura
- Department of Cardiovascular Surgery, Nagasaki University, Nagasaki, Japan
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Trobisch PD, Kim HJ, Da Paz S, Alkharsawi M, Castelein R, Chang DG. Early-term outcome of apical fusion with vertebral body tethering for thoracolumbar curves in adolescent idiopathic scoliosis: a preliminary study. Eur Spine J 2024:10.1007/s00586-024-08242-5. [PMID: 38615086 DOI: 10.1007/s00586-024-08242-5] [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] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/17/2024] [Accepted: 03/27/2024] [Indexed: 04/15/2024]
Abstract
INTRODUCTION Vertebral body tethering (VBT) has become an alternative option for select patients with idiopathic scoliosis. However, studies have shown a high number of tether breakages, specifically after thoracolumbar (TL) VBT, that can have a negative impact on the outcome, when the breakage occurs within the first year after surgery. In order to overcome this problem, we have started to apply an apical fusion (AF) in combination with TL VBT for select patients. This study aims to analyze the outcome after AF plus VBT. METHODS This is a retrospective single surgeon's data analysis. All patients were included who have had TL VBT after January 2022 and a follow-up of 12 months. Patients were grouped based on whether they only had VBT or VBT + AF. RESULTS Twenty-five patients were analyzed (15 VBT, 10 VBT + AF). Both groups showed a significant curve correction for thoracic and TL curves. Minor loss of correction was observed in both groups. A significant difference was seen regarding early tether breakages, which were found in 60% of VBT patients and 10% of VBT + AF patients. CONCLUSION The preliminary data shows a significant reduction of early tether breakages when TL VBT is applied in combination with AF.
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Affiliation(s)
- Per D Trobisch
- Department of Spine Surgery, Eifelklinik St. Brigida, Simmerath, Germany.
| | - Hong-Jin Kim
- Department of Orthopedic Surgery, Inje University Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Stephanie Da Paz
- Department of Spine Surgery, Eifelklinik St. Brigida, Simmerath, Germany
| | - Mahmoud Alkharsawi
- Department of Spine Surgery, Eifelklinik St. Brigida, Simmerath, Germany
| | - Rene Castelein
- Dutch Scoliosis Center, University Medical Center Utrecht, Utrecht, Zeist, The Netherlands
| | - Dong-Gune Chang
- Department of Orthopedic Surgery, Inje University Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
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Montanaro RC, O'Connor NJ. Temporal and spatial refugia modify predation risk for non-native crabs in rocky intertidal habitats. PeerJ 2024; 12:e16852. [PMID: 38317840 PMCID: PMC10840497 DOI: 10.7717/peerj.16852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Populations of the non-native Asian shore crab, Hemigrapsus sanguineus, now dominate the rocky intertidal of southern New England, USA. High abundances suggest the recent invader may have experienced enhanced success as a result of enemy release. While larvae and juveniles may serve as a food source for ecologically important species, little is known about predation of mature H. sanguineus or the influence of habitat on predation pressure. To assess natural predation rates of adult H. sanguineus, crabs were tethered in the intertidal at Clarks Cove in New Bedford, MA. Crabs were left in situ for half of a tidal cycle then observed for signs of predation. Results of separate high and low tide trials showed that adult crabs were preyed upon at both high and low tide, though at a significantly higher rate during high tide during both daytime and nighttime, suggesting predation by aquatic species is greater than that by terrestrial species. To investigate the role of habitat as refuge from predation, a laboratory experiment manipulated the complexity of habitat provided to crabs in the presence of a native fish predator. Results indicate better refuge is provided by more complex shelter. Together, findings suggest that fish, crabs, and/or diving birds are important predators for H. sanguineus in the invaded range and that habitat refuge acts to reduce predation pressure.
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Affiliation(s)
- Renee C Montanaro
- Biology Department, University of Massachusetts at Dartmouth, Dartmouth, MA, United States of America
| | - Nancy J O'Connor
- Biology Department, University of Massachusetts at Dartmouth, Dartmouth, MA, United States of America
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Khoso MA, Zhang H, Khoso MH, Poudel TR, Wagan S, Papiashvili T, Saha S, Ali A, Murtaza G, Manghwar H, Liu F. Synergism of vesicle trafficking and cytoskeleton during regulation of plant growth and development: A mechanistic outlook. Heliyon 2023; 9:e21976. [PMID: 38034654 PMCID: PMC10682163 DOI: 10.1016/j.heliyon.2023.e21976] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023] Open
Abstract
The cytoskeleton is a fundamental component found in all eukaryotic organisms, serving as a critical factor in various essential cyto-biological mechanisms, particularly in the locomotion and morphological transformations of plant cells. The cytoskeleton is comprised of three main components: microtubules (MT), microfilaments (MF), and intermediate filaments (IF). The cytoskeleton plays a crucial role in the process of cell wall formation and remodeling throughout the growth and development of cells. It is a highly organized and regulated network composed of filamentous components. In the basic processes of intracellular transport, such as mitosis, cytokinesis, and cell polarity, the plant cytoskeleton plays a crucial role according to recent studies. The major flaws in the organization of the cytoskeletal framework are at the root of the aberrant organogenesis currently observed in plant mutants. The regulation of protein compartmentalization and abundance within cells is predominantly governed by the process of vesicle/membrane transport, which plays a crucial role in several signaling cascades.The regulation of membrane transport in eukaryotic cells is governed by a diverse array of proteins. Recent developments in genomics have provided new tools to study the evolutionary relationships between membrane proteins in different plant species. It is known that members of the GTPases, COP, SNAREs, Rabs, tethering factors, and PIN families play essential roles in vesicle transport between plant, animal, and microbial species. This Review presents the latest research on the plant cytoskeleton, focusing on recent developments related to the cytoskeleton and summarizing the role of various proteins in vesicle transport. In addition, the report predicts future research direction of plant cytoskeleton and vesicle trafficking, potential research priorities, and provides researchers with specific pointers to further investigate the significant link between cytoskeleton and vesicle trafficking.
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Affiliation(s)
- Muneer Ahmed Khoso
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332000, China
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Department of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Hailong Zhang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Department of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Mir Hassan Khoso
- Department of Biochemistry, Shaheed Mohtarma Benazir Bhutto Medical University Larkana, Pakistan
| | - Tika Ram Poudel
- Feline Research Center of National Forestry and Grassland Administration, College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Sindho Wagan
- Laboratory of Pest Physiology Biochemistry and Molecular Toxicology Department of Forest Protection Northeast Forestry University Harbin 150040, China
| | - Tamar Papiashvili
- School of Economics and Management Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Sudipta Saha
- School of Forestry, Department of Silviculture, Northeast Forestry University, Harbin 150040, China
| | - Abid Ali
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Department of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Ghulam Murtaza
- Department of Biochemistry and Molecular Biology Harbin Medical University China, China
| | - Hakim Manghwar
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332000, China
| | - Fen Liu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332000, China
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Hegde S, Badikillaya V, Kanade U, Akbari K, Achar S, Reddy H. Are We Looking at a Paradigm Shift in the Management of Adolescent Idiopathic Scoliosis? Comprehensive Retrospective Analysis of 75 Patients of Nonfusion Anterior Scoliosis Correction with 2-5-Year Follow-up: A Single Center Experience. Asian Spine J 2023:asj.2022.0267. [PMID: 37211667 DOI: 10.31616/asj.2022.0267] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/04/2022] [Indexed: 05/23/2023] Open
Abstract
Study Design Retrospective cohort study. Purpose This study aimed to evaluate the clinical and radiological outcomes of nonfusion anterior scoliosis correction (NFASC) in patients with idiopathic scoliosis and comprehensively analyze its principles. Overview of Literature NFASC is a novel revolutionary motion-preserving surgery for idiopathic scoliosis. However, clinical data related to this procedure remain scarce, with no conclusive guidelines regarding case indications, proper technique, and possible complications. Methods This study included patients with adolescent idiopathic scoliosis (AIS) who were treated with NFASC for a structural major curve (Cobb angle, 40°-80°) with more than 50% flexibility on dynamic X-rays. The mean follow-up was 26±12.2 months (range, 12- 60 months). Clinical and radiological data such as skeletal maturity, curve type, Cobb angle, surgery details, and Scoliosis Research Society-22 revised (SRS-22r) questionnaire were collected. Statistically significant trends were examined by post hoc analysis following repeated measures analysis of variance test. Results A total of 75 patients (70 females, five males) were included, with a mean age of 14.96±2.69 years. The mean Risser and Sanders scores were 4.22±0.7 and 7.15±0.74, respectively. The mean main thoracic Cobb angles at the first and second follow-up (17.2°±5.36° and 16.92°±5.06°, respectively) were significantly lower than the preoperative Cobb angles (52.11°±7.74°) (p <0.05). Similarly, the mean thoracolumbar/lumbar Cobb angle significantly improved from the preoperative period (51.45°±11.26°) to the first follow-up (13.48°±5.11°) and last follow-up (14.24°±4.85°) (p <0.05). The mean preoperative and postoperative SRS-22r scores were 78.0±3.2 and 92.5±3.1, respectively (p <0.05). None of the patients had any complications until the most recent follow-up. Conclusions NFASC offers promising curve correction and curve progression stabilization in patients with AIS, with a low risk for complications and preservation of spinal mobility and sagittal parameters. Thus, it proves to be a favorable alternative to fusion modality.
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Affiliation(s)
- Sajan Hegde
- Department of Orthopaedics & Spine Surgery, Apollo Hospitals, Chennai, India
| | | | - Umesh Kanade
- Department of Orthopaedics & Spine Surgery, Apollo Hospitals, Chennai, India
| | - Keyur Akbari
- Department of Orthopaedics & Spine Surgery, Apollo Hospitals, Chennai, India
| | - Sharan Achar
- Department of Orthopaedics & Spine Surgery, Apollo Hospitals, Chennai, India
| | - Harith Reddy
- Department of Orthopaedics & Spine Surgery, Apollo Hospitals, Chennai, India
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Trobisch PD, Castelein R, Da Paz S. Radiographic outcome after vertebral body tethering of the lumbar spine. Eur Spine J 2023:10.1007/s00586-023-07740-2. [PMID: 37133761 DOI: 10.1007/s00586-023-07740-2] [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] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/21/2023] [Accepted: 04/22/2023] [Indexed: 05/04/2023]
Abstract
INTRODUCTION Multiple studies have analyzed the outcome after thoracic Vertebral Body Tethering (VBT). The results seem reproducible with most studies reporting coronal correction rates around 50% and a tether breakage rate near 20% at two years follow-up. There is a paucity of data on lumbar VBT, and no study has yet analyzed the radiographic outcome after lumbar VBT in a double tether technique at two years follow-up, which was the aim of this study. METHODS This is a retrospective, single surgeons' data analysis of all consecutive immature patients who have had VBT of the lumbar spine (to L3 or L4) between January 2019 and September 2020. Primary interest focused on coronal curve correction at two years post-operatively. Suspected tether breakages were analyzed separately and defined as an angular change of more than 5° between two adjacent screws. RESULTS Forty-one patients were eligible for this study and 35 (85%) had complete two-year follow-up data. Average age at surgery was 14.3 years. All patients had a Sanders stage of 7 or below. Average curve correction for thoracolumbar/lumbar curves at two years follow-up was 50%. 90% of patients had at least one level with a suspected tether breakage. No patient required a revision surgery within two years from surgery but two patients were surgically revised after two years. CONCLUSION VBT in the lumbar spine resulted in 50% coronal curve correction two years post-operatively despite a tether breakage in 90% of patients.
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Affiliation(s)
- Per D Trobisch
- Eifelklinik St. Brigida, Spine Surgery, Kammerbruchstr. 8, 52152, Simmerath, Germany.
| | - Rene Castelein
- University Medical Center Utrecht, Heidelberglaan 100, 3584 CZ, Utrecht, The Netherlands
| | - Stephanie Da Paz
- Eifelklinik St. Brigida, Spine Surgery, Kammerbruchstr. 8, 52152, Simmerath, Germany
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Huricha H, Horaguchi K, Shiiba Y, Tanaka S, Takeda KI. Effects of one hour daily outdoor access on lying and sleeping postures, and immune traits of tethered cows. Anim Biosci 2023:ab.23.0011. [PMID: 36915919 DOI: 10.5713/ab.23.0011] [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: 01/11/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Objective We investigated the effects of outdoor access for 1 h per day on the animal welfare (AW) of tethered cows, in terms of lying and sleeping postures, and immune function. Methods A total of five dry cows were tethered all day indoors (tethering) for 30 days and then tethered indoors with 1 h daily outdoor access (ODA-1h) for 30 days. To analyze the effects of ODA-1h, we calculated the total duration and bout frequency per day, and bout duration of lying and sleeping postures during the last five days of each treatment period. We also analyzed the populations of T cells, B cells, and NK cells in peripheral blood mononuclear cells (PBMC) by fluorescence-activated cell sorting, and determined the concanavalin A (Con A) -induced proliferation rate of T cells. Results The mean total time per day of lying during the ODA-1h treatment was significantly shorter than that during the tethering treatment (p<0.001). The Con A-induced proliferation rate of T cells during the ODA-1h treatment was significantly higher than that during the tethering treatment (p = 0.007). The proportion of NK cells in PBMC during the ODA-1h treatment tended to be higher than that during the tethering treatment (p = 0.062). Conclusion Although ODA-1h may decrease lying time, it increases the available space for tethered cows towards that typically found in grazing and free barn feeding systems. This increased available space promotes the expression of normal behaviors such as walking and social behaviors except lying, and may also improve the immune function of tethered dry cows, thereby improving their overall welfare.
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Affiliation(s)
- Huricha Huricha
- Faculty of Agriculture, Shinshu University, Kamiina, Nagano 399-4598, Japan
| | - Kyoko Horaguchi
- Graduate School of Science and Technology, Shinshu University, Kamiina, Nagano 399-4598, Japan
| | - Yuichiroh Shiiba
- Faculty of Agriculture, Shinshu University, Kamiina, Nagano 399-4598, Japan
| | - Sachi Tanaka
- Institute of Agriculture, Academic Assembly, Shinshu University, Kamiina, Nagano 399-459 Japan
| | - Ken-Ichi Takeda
- Institute of Agriculture, Academic Assembly, Shinshu University, Kamiina, Nagano 399-459 Japan
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Tahir Z, Craven C. Gastrulation and Split Cord Malformation. Adv Tech Stand Neurosurg 2023; 47:1-23. [PMID: 37640870 DOI: 10.1007/978-3-031-34981-2_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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Split cord malformation (SCM) is a rare form of closed spinal dysraphism, in which two hemi-cords are present, instead of a single spinal cord. SCM is categorised into type 1 and type 2. Type 1 SCM is defined by the presence of a bony or osseocartilaginous spur between the hemi-cords, whereas type 2 SCM has no bony spur, and the two hemi-cords are contained within a single dura. In this chapter, we present the putative mechanisms by which SCM arises, including gastrulation defects and Pang's unified theory. The typical and rare clinical presentations and variations are described. Finally, we outline the step-by-step surgical approach to both SCM 1 and 2 and the overall prognosis of both conditions.
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Affiliation(s)
- Zubair Tahir
- Great Ormond Street Children Hospital, London, UK.
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Maciuba K, Kaiser CM. Tethering Complex Proteins and Protein Complexes for Optical Tweezers Experiments. Methods Mol Biol 2022; 2478:427-460. [PMID: 36063330 PMCID: PMC9924098 DOI: 10.1007/978-1-0716-2229-2_16] [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] [Indexed: 12/24/2022]
Abstract
Tethering proteins to force probes, typically micrometer-sized beads, is a prerequisite for dissecting their properties with optical tweezers. DNA handles serve as spacers between the tethered protein of interest and the bead surface. Attachment sites of the DNA handles to both the surface of beads and to the protein of interest must be mechanically stable for optical tweezers experiments. The most prominent method for attaching DNA handles to proteins utilizes thiol chemistry, linking modified DNA to engineered cysteines in the target protein. This method, although experimentally straightforward, is impractical for the large number of proteins that endogenously contain multiple or essential cysteines at undesired positions. Here, we describe two alternative approaches that take advantage of genetically encoded tag sequences in the target protein. The first method uses the enzymes Sfp and BirA, and the second uses the more recently described SpyTag-SpyCatcher system. We outline the process of generating the DNA handles themselves, as well as how to make the DNA-protein chimeras for carrying out optical tweezers experiments. These methods have robustly worked for several diverse and complex proteins, including ones that are difficult to produce or purify, and for protein-containing complexes such as the ribosome. They will be useful in cases where chemistry-based approaches are impractical or not feasible.
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Affiliation(s)
- Kevin Maciuba
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Christian M Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.
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Bracamonte JH, Wilson JS, Soares JS. Quantification of the heterogeneous effect of static and dynamic perivascular structures on patient-specific local aortic wall mechanics using inverse finite element modeling and DENSE MRI. J Biomech 2022; 138:111119. [PMID: 35576631 PMCID: PMC9536506 DOI: 10.1016/j.jbiomech.2022.111119] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 11/30/2022]
Abstract
Recent studies have highlighted the relevance of perivascular interactions on aortic wall mechanics. Most of the approaches assume static perivascular structures; however, the beating heart dynamically displaces the neighboring aorta. We develop a model to account for the effect of periaortic interactions due to static and dynamic structures by prescribing a moving elastic foundation boundary condition (EFBC) embedded into an inverse finite element algorithm using in vivo displacements from 2D displacement encoding with stimulated echoes (DENSE) MRI as target data. We applied this method at three different locations of interest, the distal aortic arch (DAA), descending thoracic aorta (DTA), and infrarenal abdominal aorta (IAA) for a total of 27 cases in healthy humans. The model reproduces the target diastole-to-systole deformation and bulk displacement of the aortic wall with median displacement errors below 0.5mm. The EFBC showed good agreement with the location of anatomical features and was consistent among individuals of similar characteristics. Results show that an energy source acting on the adventitia is required to reproduce the displacements measured at the vicinity of the heart, but not at the abdomen. The average adventitial load as a percentage of the luminal pulse-pressure was found to increase with age and to decrease along the descending aorta, from 61% at the DAA to 37% at the DTA, and 30% at the IAA. This approach offers a patient-specific method to estimate in vivo adventitial loads and aortic wall stiffness, which can bring a better understanding of normal and pathological in vivo aortic function.
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Affiliation(s)
- Johane H Bracamonte
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, Richmond, VA 23284, United States.
| | - John S Wilson
- Department of Biomedical Engineering & Pauley Heart Center, Virginia Commonwealth University, 601 West Main Street, Richmond, VA 23284, United States.
| | - Joao S Soares
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, Richmond, VA 23284, United States.
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Koo DH, Sathishraj R, Friebe B, Gill BS. Deciphering the Mechanism of Glyphosate Resistance in Amaranthus palmeri by Cytogenomics. Cytogenet Genome Res 2022; 161:578-584. [PMID: 35021177 DOI: 10.1159/000521409] [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] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/07/2021] [Indexed: 11/19/2022] Open
Abstract
In agriculture, various chemicals are used to control the weeds. Out of which, glyphosate is an important herbicide invariably used in the cultivation of glyphosate-resistant crops to control weeds. Overuse of glyphosate results in the evolution of glyphosate-resistant weeds. Evolution of glyphosate resistance (GR) in Amaranthus palmeri (AP) is a serious concern in the USA. Investigation of the mechanism of GR in AP identified different resistance mechanisms of which 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene amplification is predominant. Molecular analysis of GR AP identified the presence of a 5- to >160-fold increase in copies of the EPSPS gene than in a glyphosate-susceptible (GS) population. This increased copy number of the EPSPS gene increased the genome size ranging from 3.5 to 11.8%, depending on the copy number compared to the genome size of GS AP. FISH analysis using a 399-kb EPSPS cassette derived from bacterial artificial chromosomes (BACs) as probes identified that amplified EPSPS copies in GR AP exist in extrachromosomal circular DNA (eccDNA) in addition to the native copy in the chromosome. The EPSPS gene-containing eccDNA having a size of ∼400 kb is termed EPSPS-eccDNA and showed somatic mosacism in size and copy number. EPSPS-eccDNA has a genetic mechanism to tether randomly to mitotic or meiotic chromosomes during cell division or gamete formation and is inherited to daughter cells or progeny generating copy number variation. These eccDNAs are stable genetic elements that can replicate and exist independently. The genomic characterization of the EPSPS locus, along with the flanking regions, identified the presence of a complex array of repeats and mobile genetic elements. The cytogenomics approach in understanding the biology of EPSPS-eccDNA sheds light on various characteristics of EPSPS-eccDNA that favor GR in AP.
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Affiliation(s)
- Dal-Hoe Koo
- Wheat Genetics Resource Center and Department of Plant Pathology, Kansas State University, Manhattan, Kansas, USA
| | - Rajendran Sathishraj
- Wheat Genetics Resource Center and Department of Plant Pathology, Kansas State University, Manhattan, Kansas, USA
| | - Bernd Friebe
- Wheat Genetics Resource Center and Department of Plant Pathology, Kansas State University, Manhattan, Kansas, USA
| | - Bikram S Gill
- Wheat Genetics Resource Center and Department of Plant Pathology, Kansas State University, Manhattan, Kansas, USA
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Larkin A, Ames A, Seman M, Ragunathan K. Investigating Mitotic Inheritance of Histone Modifications Using Tethering Strategies. Methods Mol Biol 2022; 2529:419-440. [PMID: 35733025 DOI: 10.1007/978-1-0716-2481-4_18] [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] [Indexed: 06/15/2023]
Abstract
The covalent and reversible modification of histones enables cells to establish heritable gene expression patterns without altering their genetic blueprint. Epigenetic mechanisms regulate gene expression in two separate ways: (1) establishment, which depends on sequence-specific DNA- or RNA-binding proteins that recruit histone-modifying enzymes to unique genomic loci, and (2) maintenance, which is sequence-independent and depends on the autonomous propagation of preexisting chromatin states during DNA replication. Only a subset of the vast repertoire of histone modifications in the genome is heritable. Here, we describe a synthetic biology approach to tether histone-modifying enzymes to engineer chromatin states in living cells and evaluate their potential for mitotic inheritance. In S. pombe, fusing the H3K9 methyltransferase, Clr4, to the tetracycline-inducible TetR DNA-binding domain facilitates rapid and reversible control of heterochromatin assembly. We describe a framework to successfully implement an inducible heterochromatin establishment system and evaluate its molecular properties. We anticipate that our innovative genetic strategy will be broadly applicable to the discovery of protein complexes and separation-of-function alleles of heterochromatin-associated factors with unique roles in epigenetic inheritance.
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Affiliation(s)
- Ajay Larkin
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Amanda Ames
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Melissa Seman
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Kaushik Ragunathan
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
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Shen J, Parent S. Iatrogenic dural tear after growth modulation in AIS: an unusual complication and its management. Spine Deform 2021; 9:1699-703. [PMID: 34152579 DOI: 10.1007/s43390-021-00368-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To report a case of iatrogenic durotomy with symptomatic Chiari-like deformity in a patient after undergoing anterior vertebral body growth modulation (AVBGM) in skeletally immature patients with adolescent idiopathic scoliosis (AIS). There have not been reports of iatrogenic durotomy in the literature and its management after AVBGM. METHODS A 13-year-old skeletally immature girl underwent successful AVBGM for thoracic AIS from T6 to T12. Despite uneventful post-operative hospitalization, the patient suffered from recurrent and persistent bouts of headaches that were mostly orthostatic. At 3 months post-op, an MRI was performed on the suspicion of a cerebrospinal fluid (CSF) leak due to an iatrogenic durotomy. On MRI, decreased volume of CSF and a decrease in the dural sac diameter were observed. Furthermore, a pseudo-meningocele was seen at the last level of instrumentation. RESULTS After an unsuccessfully trial of epidural blood patch combined with 5 days of supine immobilization, the patient was consented to screw revision as well as a lumbar drain. The lumbar drain was installed to redirect the CSF leak to allow the durotomy to heal. After 11 days, the drain was removed based on the favorable clinical evolution. CONCLUSION Iatrogenic durotomy is a rare complication in AVBGM. This is the first report of such a case that involves a Chiari-like deformity on initial MRI investigation. We suggest that an MRI is performed for all patients presenting with symptoms of CSF leak after AVBGM.
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Shimogawa T, Mukae N, Kanata A, Tsukamoto H, Murakami N, Kurogi A, Shono T, Suzuki SO, Morioka T. Spinal cord deformity with aggravation of tethering in saccular limited dorsal myeloschisis during the first 2 months of life. Surg Neurol Int 2021; 12:476. [PMID: 34621591 PMCID: PMC8492443 DOI: 10.25259/sni_517_2021] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/01/2021] [Indexed: 11/04/2022] Open
Abstract
Background Although the optimal timing of prophylactic untethering surgery for limited dorsal myeloschisis (LDM) with intact or subtle neurological findings diagnosed at birth remains undetermined, intentional delayed surgery is commonly used for flat and tail-like LDM. Conversely, for saccular LDM, early surgery is indicated during the postnatal period because it prevents rupture of the sac. We treated a saccular LDM patient, in whom intentional delayed surgery was selected because the sac was thickly covered with normal skin. We describe the clinical course of the case and discuss the optimal timing of the surgery. Case Description The patient had a dorsal midline sac in the upper lumbar region. Initial magnetic resonance imaging (MRI) after birth revealed a tethering tract that began at the dome of the sac and joined the lumbar cord. Dorsal bending of the cord at the stalk-cord union and invagination of the cord into the sac were noted. At 2 months, he was neurologically normal; however, the second MRI examination revealed that the cord tethering was aggravated. The cord was markedly displaced dorsally and to the left, with deviation of the cord to the sac out of the spinal canal. Following untethering surgery, the spinal cord deformity markedly improved. Conclusion Early surgery may be recommended for saccular LDM when tethering is present, including dorsal bending of the cord at the stalk-cord union and invagination of the cord into the sac observed on detailed MRI examination, even if the sac has no risk of rupture.
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Affiliation(s)
- Takafumi Shimogawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Akiko Kanata
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Haruhisa Tsukamoto
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Ai Kurogi
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Tadahisa Shono
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
| | | | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
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Shigemitsu S, Mah K, Thompson RB, Grenier J, Lin LQ, Silmi A, Beigh MVR, Khoo NS, Colen T. Tricuspid Valve Tethering Is Associated with Residual Regurgitation after Valve Repair in Hypoplastic Left Heart Syndrome: A Three-Dimensional Echocardiographic Study. J Am Soc Echocardiogr 2021; 34:1199-1210. [PMID: 34147648 DOI: 10.1016/j.echo.2021.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Tricuspid valve regurgitation (TR) is a risk factor for morbidity and mortality in children with hypoplastic left heart syndrome (HLHS). Surgical tricuspid valve (TV) repair is common, but durable repair remains challenging. The aim of this study was to examine mechanisms of TR requiring surgery, features associated with unsuccessful repair, and TV changes after surgical repair. METHODS Thirty-six patients with HLHS requiring TV repair (TVR) and 36 matched control subjects with HLHS were assessed using two-dimensional and three-dimensional echocardiography. Using three-dimensional echocardiography, TV coordinates from the annulus, leaflet, and ventricle were used to measure annular, leaflet, prolapse, and tethering values and anterior papillary muscle angle. TR grade and ventricular size, function, and shape were assessed using two-dimensional echocardiography. RESULTS Patients requiring TVR had greater total leaflet prolapse, larger TV annular and leaflet areas, and flatter annuli, with no difference in tethering, coaptation index, or anterior papillary muscle angle. In patients with HLHS, successful TVR at follow-up (58%) was associated with preoperative total leaflet prolapse (especially posterior). Unsuccessful repair was associated with preoperative tethering of the septal leaflet. TVR in patients with HLHS caused a reduction of total annular and leaflet size and reduced prolapse and tethering of the posterior leaflet but did not affect anterior leaflet prolapse or septal leaflet tethering. CONCLUSIONS Features associated with TVR include a flattened and dilated TV annulus with leaflet prolapse. The additional presence of a tethered septal leaflet before TVR is associated with significant postoperative TR. Current surgical techniques, predominantly posterior annuloplasty and commissuroplasty, adequately address annular size and posterior leaflet pathology, but not septal leaflet tethering. Individualized and innovative surgical techniques are vital to improve surgical repair success.
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Affiliation(s)
- Sachie Shigemitsu
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Kandice Mah
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Richard B Thompson
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Justin Grenier
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Lily Q Lin
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Amal Silmi
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Mirza Vamiq Rasool Beigh
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Nee Scze Khoo
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy Colen
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
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Abstract
Anterior vertebral body tether (AVBT) is a nonfusion surgical procedure for correction of scoliosis in skeletally immature individuals. With US Food and Drug Administration approval in 2019, AVBT technology is spreading and early to midterm reports are being published. Early clinical reports are promising while precise indications, outcomes, complication profiles, and best practices are being established. Patients who are skeletally immature and wish to avoid a fusion surgery may benefit from this procedure. This article highlights the translational science foundation, early to midterm clinical reports, and future directions for this growing technique in pediatric spinal deformity surgery.
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Affiliation(s)
- Courtney E Baker
- Department of Orthopedic Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA
| | - Todd A Milbrandt
- Department of Orthopedic Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA.
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18
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Abstract
STUDY DESIGN Retrospective chart review. OBJECTIVE To report 2-4-year outcomes of anterior vertebral body tethering (AVBT) for adolescent idiopathic scoliosis (AIS). AVBT is a relatively new procedure to correct AIS spine curvature and few outcomes studies have been published. METHODS Patients from 2015 to 2017 with 2-year follow-up were included. Successful outcomes were defined as curves 35° or less without revision surgery. We also compared outcomes between thoracic and lumbar ABVT. RESULTS There were 19 AVBTs in 17 patients, 13 thoracic and 6 lumbar. Nine curves (47%) in nine patients (53%) were successful. Preoperative kyphosis averaged 26° in the successful group and 14° in the unsuccessful group (P = 0.0337). Immediate correction for lumbar ABVTs (76%) was greater than thoracic ABVTs (43%) (P = 0.0140). Correction per level per month was greater in lumbar ABVTs (2.9° vs. 0.1°) (0.0440). Preoperative Sanders Maturity Scale (SMS) was 3.7 for successful cases and 2.5 for unsuccessful cases (P = 0.0232). Final SMS was 7.7 for successful cases and 5.7 for unsuccessful cases (P = 0.0518). All successful cases and 50% of unsuccessful cases were mature at final follow-up (P = 0.0294). There were four (24%) revision procedures, and three involving lumbar AVBTs. There were nine (47%) broken tethers. CONCLUSIONS Despite several final curves > 35°, four revisions, and nine broken tethers, the majority of patients (53%) were considered successful. Lumbar ABVTs correct more intraoperatively and faster postoperatively. Patients who are tethered during or slightly after the curve acceleration phase of growth may have more successful outcomes than patients tethered prior to the curve acceleration phase. AVBT requires further study with longer outcomes to define best practices for indications, level selections, and surgical techniques. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Courtney E Baker
- Department of Orthopedics, Mayo Clinic, Rochester, MN, 55903, USA
| | - Gary M Kiebzak
- Department of Orthopaedics and Sports Medicine, Nemours Children's Hospital, 13535 Nemours Parkway, Orlando, FL, 32827, USA.
| | - Kevin M Neal
- Department of Pediatric Orthopedic Surgery, Nemours Children's Specialty Care, 807 Children's Way, Jacksonville, FL, 32207, USA
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Mishima Y, Inoue K. Tethered Function Assay to Study RNA-Regulatory Proteins in Zebrafish Embryos. Methods Mol Biol 2021; 2218:347-354. [PMID: 33606244 DOI: 10.1007/978-1-0716-0970-5_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Many proteins are assumed to mediate post-transcriptional regulation of mRNAs. However, the lack of information about their target mRNAs and functional domains hampers the detailed analysis of their molecular function. Here we describe a method to analyze the post-transcriptional effects of proteins of interest by artificially tethering the protein to a reporter mRNA in zebrafish embryos.
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Affiliation(s)
- Yuichiro Mishima
- Department of Frontier Life Sciences, Faculty of Lifesciences, Kyoto Sangyo University, Kyoto, Japan.
| | - Kunio Inoue
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Hyogo, Japan
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Ricci F, Aung N, Gallina S, Zemrak F, Fung K, Bisaccia G, Paiva JM, Khanji MY, Mantini C, Palermi S, Lee AM, Piechnik SK, Neubauer S, Petersen SE. Cardiovascular magnetic resonance reference values of mitral and tricuspid annular dimensions: the UK Biobank cohort. J Cardiovasc Magn Reson 2020; 23:5. [PMID: 33407573 PMCID: PMC7788733 DOI: 10.1186/s12968-020-00688-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 04/07/2020] [Accepted: 10/29/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Mitral valve (MV) and tricuspid valve (TV) apparatus geometry are essential to define mechanisms and etiologies of regurgitation and to inform surgical or transcatheter interventions. Given the increasing use of cardiovascular magnetic resonance (CMR) for the evaluation of valvular heart disease, we aimed to establish CMR-derived age- and sex-specific reference values for mitral annular (MA) and tricuspid annular (TA) dimensions and tethering indices derived from truly healthy Caucasian adults. METHODS 5065 consecutive UK Biobank participants underwent CMR using cine balanced steady-state free precession imaging at 1.5 T. Participants with non-Caucasian ethnicity, prevalent cardiovascular disease and other conditions known to affect cardiac chamber size and function were excluded. Absolute and indexed reference ranges for MA and TA diameters and tethering indices were stratified by gender and age (45-54, 55-64, 65-74 years). RESULTS Overall, 721 (14.2%) truly healthy participants aged 45-74 years (54% women) formed the reference cohort. Absolute MA and TA diameters, MV tenting length and MV tenting area, were significantly larger in men. Mean ± standard deviation (SD) end-diastolic and end-systolic MA diameters in the 3-chamber view (anteroposterior diameter) were 2.9 ± 0.4 cm (1.5 ± 0.2 cm/m2) and 3.3 ± 0.4 cm (1.7 ± 0.2 cm/m2) in men, and 2.6 ± 0.4 cm (1.6 ± 0.2 cm/m2) and 3.0 ± 0.4 cm (1.8 ± 0.2 cm/m2) in women, respectively. Mean ± SD end-diastolic and end-systolic TA diameters in the 4-chamber view were 3.2 ± 0.5 cm (1.6 ± 0.3 cm/m2) and 3.2 ± 0.5 cm (1.7 ± 0.3 cm/m2) in men, and 2.9 ± 0.4 cm (1.7 ± 0.2 cm/m2) and 2.8 ± 0.4 cm (1.7 ± 0.3 cm/m2) in women, respectively. With advancing age, end-diastolic TA diameter became larger and posterior MV leaflet angle smaller in both sexes. Reproducibility of measurements was good to excellent with an inter-rater intraclass correlation coefficient (ICC) between 0.92 and 0.98 and an intra-rater ICC between 0.90 and 0.97. CONCLUSIONS We described age- and sex-specific reference ranges of MA and TA dimensions and tethering indices in the largest validated healthy Caucasian population. Reference ranges presented in this study may help to improve the distinction between normal and pathological states, prompting the identification of subjects that may benefit from advanced cardiac imaging for annular sizing and planning of valvular interventions.
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Affiliation(s)
- Fabrizio Ricci
- Department of Neuroscience, Imaging and Clinical Sciences, "G.D'Annunzio" University, Chieti, Italy
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Casa Di Cura Villa Serena, 65013, Città Sant'Angelo, Pescara, Italy
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
| | - Nay Aung
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Sabina Gallina
- Department of Neuroscience, Imaging and Clinical Sciences, "G.D'Annunzio" University, Chieti, Italy
| | - Filip Zemrak
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Kenneth Fung
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Giandomenico Bisaccia
- Department of Neuroscience, Imaging and Clinical Sciences, "G.D'Annunzio" University, Chieti, Italy
| | - Jose Miguel Paiva
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Mohammed Y Khanji
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Cesare Mantini
- Department of Neuroscience, Imaging and Clinical Sciences, "G.D'Annunzio" University, Chieti, Italy
| | - Stefano Palermi
- Department of Neuroscience, Imaging and Clinical Sciences, "G.D'Annunzio" University, Chieti, Italy
| | - Aaron M Lee
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK
| | - Stefan K Piechnik
- Division of Cardiovascular Medicine, NIHR BRC Oxford, Radcliffe Department of Medicine, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, NIHR BRC Oxford, Radcliffe Department of Medicine, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK
| | - Steffen E Petersen
- William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK.
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, West Smithfield, London, UK.
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Haslinger K, Prather KLJ. Heterologous caffeic acid biosynthesis in Escherichia coli is affected by choice of tyrosine ammonia lyase and redox partners for bacterial Cytochrome P450. Microb Cell Fact 2020; 19:26. [PMID: 32046741 PMCID: PMC7011507 DOI: 10.1186/s12934-020-01300-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 02/05/2020] [Indexed: 01/03/2023] Open
Abstract
Background Caffeic acid is industrially recognized for its antioxidant activity and therefore its potential to be used as an anti-inflammatory, anticancer, antiviral, antidiabetic and antidepressive agent. It is traditionally isolated from lignified plant material under energy-intensive and harsh chemical extraction conditions. However, over the last decade bottom-up biosynthesis approaches in microbial cell factories have been established, that have the potential to allow for a more tailored and sustainable production. One of these approaches has been implemented in Escherichia coli and only requires a two-step conversion of supplemented l-tyrosine by the actions of a tyrosine ammonia lyase and a bacterial Cytochrome P450 monooxygenase. Although the feeding of intermediates demonstrated the great potential of this combination of heterologous enzymes compared to others, no de novo synthesis of caffeic acid from glucose has been achieved utilizing the bacterial Cytochrome P450 thus far. Results The herein described work aimed at improving the efficiency of this two-step conversion in order to establish de novo caffeic acid formation from glucose. We implemented alternative tyrosine ammonia lyases that were reported to display superior substrate binding affinity and selectivity, and increased the efficiency of the Cytochrome P450 by altering the electron-donating redox system. With this strategy we were able to achieve final titers of more than 300 µM or 47 mg/L caffeic acid over 96 h in an otherwise wild type E. coli MG1655(DE3) strain with glucose as the only carbon source. We observed that the choice and gene dose of the redox system strongly influenced the Cytochrome P450 catalysis. In addition, we were successful in applying a tethering strategy that rendered even a virtually unproductive Cytochrome P450/redox system combination productive. Conclusions The caffeic acid titer achieved in this study is about 10% higher than titers reported for other heterologous caffeic acid pathways in wildtype E. coli without l-tyrosine supplementation. The tethering strategy applied to the Cytochrome P450 appears to be particularly useful for non-natural Cytochrome P450/redox partner combinations and could be useful for other recombinant pathways utilizing bacterial Cytochromes P450.
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Affiliation(s)
- Kristina Haslinger
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, USA.
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22
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Abstract
In trypanosomatids, posttranscriptional controls are very important in regulation of individual gene expression. These are achieved through combinatorial sets of RNA-binding proteins (RBPs) which recognize RNA regulatory motifs or regions of secondary structure within RNAs. To analyze the potential functional impact of an RBP on their mRNA targets, we have applied a robust technique called tethering assay. In this method, the protein under study is attached to an mRNA reporter through an artificial RNA-protein interaction. Therefore, the functional activity of a protein can be analyzed independently of its intrinsic ability to bind to RNA. By making use of a cell line expressing a chloramphenicol acetyltransferase (CAT) reporter mRNA, we have characterized dozens of novel mRNA-fate regulators in cultured Trypanosoma brucei. After induction of the candidate fusion protein, the effect on the reporter expression is determined by a rapid CAT assay. The protocol is simple and typically takes one working day for analysis of a single protein and controls. In this chapter, we provide a description of materials and methods for the tethering method and should allow the assay to be successfully deployed in any laboratory with minimal user training.
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Affiliation(s)
- Elisha Mugo
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Esteban D Erben
- German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany.
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Brandner A, De Vecchis D, Baaden M, Cohen MM, Taly A. Structural dataset from microsecond-long simulations of yeast mitofusin Fzo1 in the context of membrane docking. Data Brief 2019; 26:104460. [PMID: 31667232 PMCID: PMC6811871 DOI: 10.1016/j.dib.2019.104460] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 08/23/2019] [Indexed: 11/15/2022] Open
Abstract
In this work we present a novel set of possible auto-oligomerisation states of yeast protein Fzo1 in the context of membrane docking. The dataset reports atomistic models and trajectories derived from a molecular dynamics study of the yeast mitofusin Fzo1, residues 101–855. The initial modelling was followed by coarse-grained molecular dynamics simulation to evaluate the stability and the dynamics of each structural model in a solvated membrane environment. Simulations were run for 1 μs and collected with GROMACS v5.0.4 using the martini v2.1 force field. For each structural model, the dataset comprises the production phase under semi-isotropic condition at 1 bar, 310 K and 150 mn NaCl. The integration step is 20 fs and coordinates have been saved every 1 ns. Each trajectory is associated with a ready-available visualization state for the VMD software. These structural detailed informations are a ready-available platform to plan integrative studies on the mitofusin Fzo1 and will aid the community to further elucidate the mitochondrial tethering process during membrane fusion. This dataset is based on the publication “Physics-based oligomeric models of the yeast mitofusin Fzo1 at the molecular scale in the context of membrane docking.” (Brandner and De Vecchis et al., 2019)”.
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Affiliation(s)
- Astrid Brandner
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.,CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Dario De Vecchis
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.,CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Marc Baaden
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.,CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Mickael M Cohen
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.,Laboratoire de Biologie Cellulaire et Moléculaire des Eucaryotes, Sorbonne Université, CNRS, 16 UMR 8226, Paris, France
| | - Antoine Taly
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.,CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
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24
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Dejgaard SY, Presley JF. Rab18: new insights into the function of an essential protein. Cell Mol Life Sci 2019; 76:1935-1945. [PMID: 30830238 DOI: 10.1007/s00018-019-03050-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [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: 12/24/2018] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 12/14/2022]
Abstract
Rab18 is one of the small number of conserved Rab proteins which have been traced to the last eukaryotic common ancestor. It is found in organisms ranging from humans to trypanosomes, and localizes to multiple organelles, including most notably endoplasmic reticulum and lipid droplets. In humans, absence of Rab18 leads to a severe illness known as Warburg-Micro syndrome. Despite this evidence that Rab18 is essential, its role in cells remains mysterious. However, recent studies identifying effectors and interactors of Rab18, are now shedding light on its mechanism of action, suggesting functions related to organelle tethering and to autophagy. In this review, we examine the variety of roles proposed for Rab18 with a focus on new evidence giving insights into the molecular mechanisms it utilizes. Based on this summary of our current understanding, we identify priority areas for further research.
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Affiliation(s)
- Selma Yilmaz Dejgaard
- Department of Medical Biology, Near East University, Nicosia, Cyprus.,Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, QC, H3A 0C7, Canada
| | - John F Presley
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, QC, H3A 0C7, Canada.
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25
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Topilsky Y, Michelena HI, Messika-Zeitoun D, Enriquez Sarano M. Doppler-Echocardiographic Assessment of Tricuspid Regurgitation. Prog Cardiovasc Dis 2018; 61:397-403. [PMID: 30447222 DOI: 10.1016/j.pcad.2018.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 11/16/2022]
Abstract
Compared with the vast literature concerning the echocardiographic assessment of mitral, or aortic disease, the data concerning the evaluation of tricuspid regurgitation (TR) is very limited. In this review we summarized the present data concerning the assessment of TR. We review the present knowledge concerning the pathogenesis of TR showing that it is extremely multi-factorial, thus, when assessing patients with TR by echocardiography it is imperative to focus on four major aspects: evaluation of severity of TR, assessment of the etiology of TR, evaluation of the mechanism of TR and suitability for surgical or per-cutaneous repair.
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Affiliation(s)
- Yan Topilsky
- The Department of Cardiology Tel Aviv Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Hector I Michelena
- The Division of Cardiology, Mayo College of Medicine, Mayo Clinic, Rochester, MN, United States of America
| | - David Messika-Zeitoun
- University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada
| | - Maurice Enriquez Sarano
- The Division of Cardiology, Mayo College of Medicine, Mayo Clinic, Rochester, MN, United States of America
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26
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Erlanson DA, Davis BJ, Jahnke W. Fragment-Based Drug Discovery: Advancing Fragments in the Absence of Crystal Structures. Cell Chem Biol 2018; 26:9-15. [PMID: 30482678 DOI: 10.1016/j.chembiol.2018.10.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/12/2018] [Accepted: 09/28/2018] [Indexed: 01/08/2023]
Abstract
Fragment-based drug discovery typically requires an interplay between screening methods, structural methods, and medicinal chemistry. X-ray crystallography is generally the method of choice to obtain three-dimensional structures of the bound ligand/protein complex, but this can sometimes be difficult, particularly for early, low-affinity fragment hits. In this Perspective, we discuss strategies to advance and evolve fragments in the absence of crystal structures of protein-fragment complexes, although the structure of the unliganded protein may be available. The strategies can involve other structural techniques, such as NMR spectroscopy, molecular modeling, or a variety of chemical approaches. Often, these strategies are aimed at guiding evolution of initial fragment hits to a stage where crystal structures can be obtained for further structure-based optimization.
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Affiliation(s)
- Daniel A Erlanson
- Carmot Therapeutics, Inc., 740 Heinz Avenue, Berkeley, CA 94710, USA.
| | - Ben J Davis
- Vernalis (R&D) Ltd, Granta Park, Cambridge, UK.
| | - Wolfgang Jahnke
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Novartis Campus, Basel, Switzerland.
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27
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Poirier LA, Gilbert STC, St-Hilaire S, Davidson J, Cox R, Quijón PA. Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors. Mar Pollut Bull 2018; 127:160-164. [PMID: 29475649 DOI: 10.1016/j.marpolbul.2017.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 06/08/2023]
Abstract
Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters (Crassostrea virginica) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species.
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Affiliation(s)
- Luke A Poirier
- Department of Biology, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada
| | - Shane T C Gilbert
- Department of Biology, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada
| | - Sophie St-Hilaire
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada
| | - Jeff Davidson
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada
| | - Ruth Cox
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada
| | - Pedro A Quijón
- Department of Biology, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada.
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Abstract
Ischemic mitral regurgitation (IMR) is a common complication of ischemic heart disease that doubles mortality after myocardial infarction and is a major driving factor increasing heart failure. IMR is caused by left ventricular (LV) remodeling which displaces the papillary muscles that tether the mitral valve leaflets and restrict their closure. IMR frequently recurs even after surgical treatment. Failed repair associates with lack of reduction or increase in LV remodeling, and increased heart failure and related readmissions. Understanding mechanistic and molecular mechanisms of IMR has largely attributed to the development of large animal models. Newly developed therapeutic interventions targeted to the primary causes can also be tested in these models. The sheep is one of the most suitable models for the development of IMR. In this chapter, we describe the protocols for inducing IMR in sheep using surgical ligation of obtuse marginal branches. After successful posterior myocardial infarction involving posterior papillary muscle, animals develop significant mitral regurgitation around 2 months after the surgery.
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Affiliation(s)
- Dae-Hee Kim
- Cardiac Imaging Center, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea
- Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Brittan Morris
- Surgical Cardiovascular Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - J Luis Guerrero
- Surgical Cardiovascular Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Suzanne M Sullivan
- Surgical Cardiovascular Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Judy Hung
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Robert A Levine
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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29
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Edel C, Erbel R, Budde T. [Hemodynamic interplay between tricuspid valve and right ventricle]. Herz 2017; 42:622-628. [PMID: 28921000 DOI: 10.1007/s00059-017-4614-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The tricuspid valve and the right ventricle are hemodynamically closely related. Pathological changes of the valve or of the ventricle itself and also various diseases beyond that can result in a downward spiral of mutual interference, which is of prognostic importance for the patient. The development of a functional tricuspid regurgitation is of great importance. Especially with the help of 3D-echocardiography, more and more changes and mechanisms have been identified that are crucial in this process. This article provides a review of the relationship between the tricuspid valve and the right ventricle emphasizing the current knowledge of the causes, the pathophysiological concepts, the underlying structural changes and the therapeutic approaches based on this.
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Affiliation(s)
- C Edel
- Klinik für Kardiologie, Elektrophysiologie, Gastroenterologie und Intensivmedizin, Alfried-Krupp-Krankenhaus Rüttenscheid, Alfried-Krupp-Straße 21, 45131, Essen, Deutschland.
| | - R Erbel
- Klinik für Kardiologie, Elektrophysiologie, Gastroenterologie und Intensivmedizin, Alfried-Krupp-Krankenhaus Rüttenscheid, Alfried-Krupp-Straße 21, 45131, Essen, Deutschland
| | - T Budde
- Klinik für Kardiologie, Elektrophysiologie, Gastroenterologie und Intensivmedizin, Alfried-Krupp-Krankenhaus Rüttenscheid, Alfried-Krupp-Straße 21, 45131, Essen, Deutschland
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30
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Tomatis VM, Josh P, Papadopulos A, Gormal RS, Lanoue V, Martin S, Meunier FA. ENA/VASP proteins regulate exocytosis by mediating myosin VI-dependent recruitment of secretory granules to the cortical actin network. Mol Cell Neurosci 2017; 84:100-111. [PMID: 28784263 DOI: 10.1016/j.mcn.2017.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 04/20/2017] [Revised: 07/17/2017] [Accepted: 07/27/2017] [Indexed: 10/24/2022] Open
Abstract
In neurosecretory cells, myosin VI associated with secretory granules (SGs) mediates their activity-dependent recruitment to the cortical actin network and is necessary to sustain exocytosis. The mechanism by which myosin VI interacts with SGs is unknown. Using a myosin VI pull-down assay and mass spectrometry we identified Mena, a member of the ENA/VASP family, as a myosin VI binding partner in PC12 cells, and confirmed that Mena colocalized with myosin VI on SGs. Using a knock-sideways approach to inactivate the ENA/VASP family members by mitochondrial relocation, we revealed a concomitant redistribution of myosin VI. This was ensued by a reduction in the association of myosin VI with SGs, a decreased SG mobility and density in proximity to the plasma membrane as well as decreased evoked exocytosis. These data demonstrate that ENA/VASP proteins regulate SG exocytosis through modulating the activity of myosin VI.
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Affiliation(s)
- Vanesa M Tomatis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Peter Josh
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sally Martin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.
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31
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Brewin MP, Bexon CJ, Tucker SC. A case report on the use of vibration to improve soft tissue extensibility after major trauma. J Hand Ther 2017; 30:367-371. [PMID: 28479025 DOI: 10.1016/j.jht.2016.11.012] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 10/24/2016] [Accepted: 11/21/2016] [Indexed: 02/03/2023]
Abstract
UNLABELLED This report presents a case where vibration training to the arm alone, as opposed to whole-body vibration, was used to aid rehabilitation to a serious traumatic injury. An improvement in soft tissue extensibility to a major traumatic wound to the wrist and forearm has been noted in a therapy plan including vibration under stretch. After 12 weeks of intensive therapy, a considerable improvement was seen in both the active extension of the wrist and the composite extension of all fingers. This may highlight the use of vibration, as an adjunct to therapy, to specific areas of the human body for improving outcome from traumatic injury. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Mark Paul Brewin
- Salisbury Burns Unit, Salisbury NHS Foundation Trust, Salisbury, Wiltshire, United Kingdom.
| | - Carole J Bexon
- Wessex Rehabilitation Centre, Salisbury NHS Foundation Trust, Salisbury, Wiltshire, United Kingdom
| | - Sarah C Tucker
- Plastic Surgery, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, United Kingdom
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32
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Addi C, Murschel F, Liberelle B, Riahi N, De Crescenzo G. A highly versatile adaptor protein for the tethering of growth factors to gelatin-based biomaterials. Acta Biomater 2017; 50:198-206. [PMID: 28069507 DOI: 10.1016/j.actbio.2017.01.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 12/19/2016] [Accepted: 01/05/2017] [Indexed: 02/06/2023]
Abstract
In the field of tissue engineering, the tethering of growth factors to tissue scaffolds in an oriented manner can enhance their activity and increase their half-life. We chose to investigate the capture of the basic Fibroblast Growth Factor (bFGF) and the Epidermal Growth Factor (EGF) on a gelatin layer, as a model for the functionalization of collagen-based biomaterials. Our strategy relies on the use of two high affinity interactions, that is, the one between two distinct coil peptides as well as the one occurring between a collagen-binding domain (CBD) and gelatin. We expressed a chimeric protein to be used as an adaptor that comprises one of the coil peptides and a CBD derived from the human fibronectin. We proved that it has the ability to bind simultaneously to a gelatin substrate and to form a heterodimeric coiled-coil domain with recombinant growth factors being tagged with the complementary coil peptide. The tethering of the growth factors was characterized by ELISA and surface plasmon resonance-based biosensing. The bioactivity of the immobilized bFGF and EGF was evaluated by a human umbilical vein endothelial cell proliferation assay and a vascular smooth muscle cell survival assay. We found that the tethering of EGF preserved its mitogenic and anti-apoptotic activity. In the case of bFGF, when captured via our adaptor protein, changes in its natural mode of interaction with gelatin were observed. STATEMENT OF SIGNIFICANCE In an effort to functionalize collagen/gelatin-based biomaterials with growth factors, we have designed an adaptor protein corresponding to a collagen-binding domain fused to a coil peptide. In our strategy, this adaptor protein captures growth factors being tagged with the partner coil peptide in a specific, stable and oriented manner. We have found that the tethering of the Epidermal Growth Factor preserved its mitogenic and anti-apoptotic activity. In the case of the basic Fibroblast Growth Factor, the captured growth factor remained bioactive although its tethering via this adaptor protein modified its natural mode of interaction with gelatin. Altogether this strategy is easily adaptable to the simultaneous tethering of various growth factors.
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Affiliation(s)
- Cyril Addi
- Department of Chemical Engineering, Biomedical Science and Technology Research Group, Bio-P(2) Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal (QC) H3C 3A7, Canada
| | - Frédéric Murschel
- Department of Chemical Engineering, Biomedical Science and Technology Research Group, Bio-P(2) Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal (QC) H3C 3A7, Canada
| | - Benoît Liberelle
- Department of Chemical Engineering, Biomedical Science and Technology Research Group, Bio-P(2) Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal (QC) H3C 3A7, Canada
| | - Nesrine Riahi
- Department of Chemical Engineering, Biomedical Science and Technology Research Group, Bio-P(2) Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal (QC) H3C 3A7, Canada
| | - Gregory De Crescenzo
- Department of Chemical Engineering, Biomedical Science and Technology Research Group, Bio-P(2) Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal (QC) H3C 3A7, Canada.
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Rahayu R, Ohsaki E, Omori H, Ueda K. Localization of latency-associated nuclear antigen (LANA) on mitotic chromosomes. Virology 2016; 496:51-58. [PMID: 27254595 DOI: 10.1016/j.virol.2016.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 03/24/2016] [Revised: 04/28/2016] [Accepted: 05/24/2016] [Indexed: 01/25/2023]
Abstract
In latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), viral gene expression is extremely limited and copy numbers of viral genomes remain constant. Latency-associated nuclear antigen (LANA) is known to have a role in maintaining viral genome copy numbers in growing cells. Several studies have shown that LANA is localized in particular regions on mitotic chromosomes, such as centromeres/pericentromeres. We independently examined the distinct localization of LANA on mitotic chromosomes during mitosis, using super-resolution laser confocal microscopy and correlative fluorescence microscopy-electron microscopy (FM-EM) analyses. We found that the majority of LANA were not localized at particular regions such as telomeres/peritelomeres, centromeres/pericentromeres, and cohesion sites, but at the bodies of condensed chromosomes. Thus, LANA may undergo various interactions with the host factors on the condensed chromosomes in order to tether the viral genome to mitotic chromosomes and realize faithful viral genome segregation during cell division.
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Affiliation(s)
- Retno Rahayu
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Eriko Ohsaki
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hiroko Omori
- Central Instrumentation Laboratory Research Institute for Microbial Diseases (BIKEN), Osaka University, Osaka 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
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D'Uva G, Lauriola M. Towards the emerging crosstalk: ERBB family and steroid hormones. Semin Cell Dev Biol 2015; 50:143-52. [PMID: 26582250 DOI: 10.1016/j.semcdb.2015.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [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: 10/08/2015] [Revised: 10/28/2015] [Accepted: 11/09/2015] [Indexed: 01/05/2023]
Abstract
Growth factors acting through receptor tyrosine kinases (RTKs) of ERBB family, along with steroid hormones (SH) acting through nuclear receptors (NRs), are critical signalling mediators of cellular processes. Deregulations of ERBB and steroid hormone receptors are responsible for several diseases, including cancer, thus demonstrating the central role played by both systems. This review will summarize and shed light on an emerging crosstalk between these two important receptor families. How this mutual crosstalk is attained, such as through extensive genomic and non-genomic interactions, will be addressed. In light of recent studies, we will describe how steroid hormones are able to fine-tune ERBB feedback loops, thus impacting on cellular output and providing a new key for understanding the complexity of biological processes in physiological or pathological conditions. In our understanding, the interactions between steroid hormones and RTKs deserve further attention. A system biology approach and advanced technologies for the analysis of RTK-SH crosstalk could lead to major advancements in molecular medicine, providing the basis for new routes of pharmacological intervention in several diseases, including cancer.
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Affiliation(s)
- Gabriele D'Uva
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Mattia Lauriola
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel; Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, Bologna 40138, Italy.
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35
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Sabir A, Shafiq M, Islam A, Sarwar A, Dilshad MR, Shafeeq A, Zahid Butt MT, Jamil T. Fabrication of tethered carbon nanotubes in cellulose acetate/polyethylene glycol-400 composite membranes for reverse osmosis. Carbohydr Polym 2015; 132:589-97. [PMID: 26256386 DOI: 10.1016/j.carbpol.2015.06.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [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: 04/07/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT.
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Affiliation(s)
- Aneela Sabir
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54590, Pakistan.
| | - Muhammad Shafiq
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54590, Pakistan
| | - Atif Islam
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54590, Pakistan
| | - Afsheen Sarwar
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54590, Pakistan
| | - Muhammad Rizwan Dilshad
- Institute of Chemical Engineering and Technology (ICET), University of the Punjab, Lahore 54590, Pakistan
| | - Amir Shafeeq
- Institute of Chemical Engineering and Technology (ICET), University of the Punjab, Lahore 54590, Pakistan
| | | | - Tahir Jamil
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54590, Pakistan
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Abstract
The HOPS multisubunit tethering factor (MTC) is a macromolecular protein complex composed of six different subunits. It is one of the key components in the perception and subsequent fusion of multivesicular bodies and vacuoles. Electron microscopy studies indicate structural flexibility of the purified HOPS complex. Inducing higher rigidity into HOPS by biochemically modifying the complex declines the potential to mediate SNARE-driven membrane fusion. Thus, we propose that integral flexibility seems to be not only a feature, but of essential need for the function of HOPS. This review focuses on the general features of membrane tethering and fusion. For this purpose, we compare the structure and mode of action of different tethering factors to highlight their common central features and mechanisms.
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Affiliation(s)
- Anne Kuhlee
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Christian Ungermann
- Department of Biology, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
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Deng M, Hui SCN, Yu FWP, Lam TP, Qiu Y, Ng BKW, Cheng JCY, Chu WCW. MRI-based morphological evidence of spinal cord tethering predicts curve progression in adolescent idiopathic scoliosis. Spine J 2015; 15:1391-401. [PMID: 25725365 DOI: 10.1016/j.spinee.2015.02.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 02/04/2015] [Accepted: 02/18/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Existing prognostic factors for adolescent idiopathic scoliosis (AIS) patients have focused mainly on curve, maturity, and bone-related factors. Previous studies have shown significant associations between curve severity and morphological evidences of relative shorter spinal cord tethering in AIS, and increased prevalence of abnormal somatosensory cortical-evoked potentials and low-lying cerebellar tonsil in severe AIS. Earlier evidence suggests that there might be neural morphological predictors for curve progression. PURPOSE The purpose of this study was to identify any morphological predictors associated with cord tethering, as measured by magnetic resonance imaging (MRI), for curve progression in AIS patients. STUDY DESIGN/SETTING This is a prospective cohort study. PATIENT SAMPLE A total of 81 female AIS subjects between 10 and 14 years were included, without surgical intervention during the follow-up period. OUTCOME MEASURES Magnetic resonance imaging scans of hindbrain and whole spine and areal bone mineral density (BMD) at bilateral femoral necks were performed. METHODS All AIS patients were longitudinally followed up starting from initiation of bracing beyond skeletal maturity in 6-month intervals. Clinical and radiographic data were recorded at each clinic visit. Bone mineral density and MRI measurements including ratio of spinal cord to vertebral column length, ratio of anteroposterior (AP) and transverse (TS) diameter of cord, lateral cord space (LCS) ratio, cerebellar tonsil level, and conus medullaris position were obtained at baseline. Only compliant patients with a minimum 2-year follow-up were analyzed. Adolescent idiopathic scoliosis girls were assigned into three groups according to bracing outcome: Group A, nonprogression (curvature increase of less than or equal to 5°); Group B, progression (curvature increase of greater than or equal to 6°); Group C, progression with surgery indication (Cobb angle of greater than or equal to 50° after skeletal maturity despite bracing). The predictors for curve progression were evaluated using univariate analysis and multivariate ordinal regression model. RESULTS The average duration of follow-up was 3.4 (range, 2.0-5.6) years. There were 46 girls (57%) in Group A, 19 (23%) in Group B, and 16 (20%) in Group C. No significant intergroup differences were found in spinal cord length, tonsil level, and conus position. Group C had significantly longer vertebral column length, smaller cord-vertebral length ratio, and higher AP/TS cord ratio compared with Group A, whereas LCS ratio in Group C was significantly increased compared with both Group A and Group B. In regression model, five significant independent predictors including cord-vertebral length ratio (odds ratio [OR]: 1.993 [95% confidence interval {CI}: 1.053-3.771], p=.034), LCS ratio (OR: 2.639 [95% CI: 1.128-6.174], p=.025), initial Cobb angle (OR: 1.156 [95% CI: 1.043-1.281], p=.006), menarche age (OR: 1.688 [95% CI: 1.010-2.823], p=.046), and BMD (OR: 2.960 [95% CI: 1.301-6.731], p=.010) and a marginally significant predictor namely AP/TS cord ratio (OR: 1.463 [95% CI: 0.791-2.706], p=.096) were obtained. CONCLUSIONS On baseline MRI measurement, cord-vertebral length ratio and LCS ratio are identified as new significant independent predictors for curve progression in AIS, whereas AP/TS cord ratio is suggested as a potential predictor requiring further validations. The earlier MRI parameters can be taken into accounts for prognostication of bracing outcome.
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Affiliation(s)
- Min Deng
- Department of Imaging and Interventional Radiology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Steve C N Hui
- Department of Imaging and Interventional Radiology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Fiona W P Yu
- Department of Orthopaedics and Traumatology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Tsz-Ping Lam
- Department of Orthopaedics and Traumatology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China; Joint Scoliosis Research Center of the Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Yong Qiu
- Joint Scoliosis Research Center of the Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China; Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road 321, Nanjing, China
| | - Bobby K W Ng
- Department of Orthopaedics and Traumatology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Jack C Y Cheng
- Department of Orthopaedics and Traumatology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China; Joint Scoliosis Research Center of the Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China
| | - Winnie C W Chu
- Department of Imaging and Interventional Radiology, Chinese University of HongKong, Pince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, China.
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38
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Nampanzira DK, Kabasa JD, Nalule SA, Nakalembe I, Tabuti JRS. Characterization of the goat feeding system among rural small holder farmers in the semi-arid regions of Uganda. Springerplus 2015; 4:188. [PMID: 25932373 PMCID: PMC4408307 DOI: 10.1186/s40064-015-0961-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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: 09/12/2014] [Accepted: 04/01/2015] [Indexed: 12/03/2022]
Abstract
Goats (Capra hircus) are widely distributed in Africa and Asia, and are important to the subsistence and economic livelihoods of many people in these areas. The goat feeding system among rural small holder farmers in Buyende district (Uganda) was characterised by determining the goat rearing practices, feed resources fed on by goats and availability of browse species mentioned by small holder farmers. Data was gathered using ethnobotanical and ecological approaches. Results from the ethnobotanical survey revealed that farmers were rearing indigenous goat breeds that are managed by tethering in natural pastures during the rainy season but free ranging during the dry season (i.e. when no crops are susceptible of damage). Major challenges facing goat production in the study area were diseases, shortage of land and inadequate pastures. The reduction of grazing land due to crop farming, has led to tethering of animals which in turn leads to restricted feeding. Goats were known to feed on 48 plant species distributed in 18 families and 39 genera dominated by trees and shrubs. Browse species were known to stay longer in the dry season when the grass and herbaceous species were no longer available. The most frequently mentioned browse species were Ficus natalensis, Harrisonia abyssinica, Acalypha psilostachya, Artocarpus heterophyllus and Lantana camara while Panicum maximum and Impeata cylindrica were the most mentioned herbaceous species. 31 browse species were encountered in the ecological survey. These were dominated by Combretum molle, L. camara, A. zygia, M. indica, and Albizia coriaria. In conclusion, the rearing practices of goats in Buyende district are comprised of indigenous goats tethered in natural pastures especially browses which stay longer through the dry season. However, most of the preferred browses are rare according to the computed IVI (i.e. less than 30%).
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Affiliation(s)
- Dorothy Kalule Nampanzira
- Department of Livestock and Industrial Resources, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - John David Kabasa
- Department of Biosecurity, Ecosystems & Veterinary Public Health, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - Sara Agnes Nalule
- Department of Wildlife and Aquatic animal resources, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - Immaculate Nakalembe
- Department of Environmental management, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - John Robert Stephen Tabuti
- Department of Bio molecular resources and Biolab Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
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39
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Michel K, Müller JA, Oprişoreanu AM, Schoch S. The presynaptic active zone: A dynamic scaffold that regulates synaptic efficacy. Exp Cell Res 2015; 335:157-64. [PMID: 25720549 DOI: 10.1016/j.yexcr.2015.02.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 02/01/2015] [Accepted: 02/10/2015] [Indexed: 12/30/2022]
Abstract
Before fusing with the presynaptic plasma membrane to release neurotransmitter into the synaptic cleft synaptic vesicles have to be recruited to and docked at a specialized area of the presynaptic nerve terminal, the active zone. Exocytosis of synaptic vesicles is restricted to the presynaptic active zone, which is characterized by a unique and highly interconnected set of proteins. The protein network at the active zone is integrally involved in this process and also mediates changes in release properties, for example in response to alterations in the level of neuronal network activity. In recent years the development of novel techniques has greatly advanced our understanding of the molecular identity of respective active zone components as well as of the ultrastructure of this membranous subcompartment and of the SV release machinery. Furthermore, active zones are now viewed as dynamic structures whose composition and size are correlated with synaptic efficacy. Therefore, the dynamic remodeling of the protein network at the active zone has emerged as one potential mechanism underlying acute and long-term synaptic plasticity. Here, we will discuss this recent progress and its implications for our view of the role of the AZ in synaptic function.
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Affiliation(s)
- Katrin Michel
- Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, 53105 Bonn, Germany
| | - Johannes Alexander Müller
- Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, 53105 Bonn, Germany
| | - Ana-Maria Oprişoreanu
- Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, 53105 Bonn, Germany
| | - Susanne Schoch
- Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, 53105 Bonn, Germany; Department of Epileptology University of Bonn Medical Center, 53105 Bonn, Germany.
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40
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Lürick A, Kuhlee A, Bröcker C, Kümmel D, Raunser S, Ungermann C. The Habc domain of the SNARE Vam3 interacts with the HOPS tethering complex to facilitate vacuole fusion. J Biol Chem 2015; 290:5405-13. [PMID: 25564619 DOI: 10.1074/jbc.m114.631465] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Membrane fusion at vacuoles requires a consecutive action of the HOPS tethering complex, which is recruited by the Rab GTPase Ypt7, and vacuolar SNAREs to drive membrane fusion. It is assumed that the Sec1/Munc18-like Vps33 within the HOPS complex is largely responsible for SNARE chaperoning. Here, we present direct evidence for HOPS binding to SNAREs and the Habc domain of the Vam3 SNARE protein, which may explain its function during fusion. We show that HOPS interacts strongly with the Vam3 Habc domain, assembled Q-SNAREs, and the R-SNARE Ykt6, but not the Q-SNARE Vti1 or the Vam3 SNARE domain. Electron microscopy combined with Nanogold labeling reveals that the binding sites for vacuolar SNAREs and the Habc domain are located in the large head of the HOPS complex, where Vps16 and Vps33 have been identified before. Competition experiments suggest that HOPS bound to the Habc domain can still interact with assembled Q-SNAREs, whereas Q-SNARE binding prevents recognition of the Habc domain. In agreement, membranes carrying Vam3ΔHabc fuse poorly unless an excess of HOPS is provided. These data suggest that the Habc domain of Vam3 facilitates the assembly of the HOPS/SNARE machinery at fusion sites and thus supports efficient membrane fusion.
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Affiliation(s)
- Anna Lürick
- From the Department of Biology/Chemistry, Biochemistry Section and
| | - Anne Kuhlee
- the Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Cornelia Bröcker
- From the Department of Biology/Chemistry, Biochemistry Section and
| | - Daniel Kümmel
- the Department of Biology/Chemistry, Structural Biology, University of Osnabrück, 49076 Osnabrück, Germany and
| | - Stefan Raunser
- the Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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41
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Naon D, Scorrano L. At the right distance: ER-mitochondria juxtaposition in cell life and death. Biochim Biophys Acta 2014; 1843:2184-94. [PMID: 24875902 DOI: 10.1016/j.bbamcr.2014.05.011] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/18/2014] [Accepted: 05/19/2014] [Indexed: 11/29/2022]
Abstract
The interface between mitochondria and the endoplasmic reticulum is emerging as a crucial hub for calcium signalling, apoptosis, autophagy and lipid biosynthesis, with far reaching implications in cell life and death and in the regulation of mitochondrial and endoplasmic reticulum function. Here we review our current knowledge on the structural and functional aspects of this interorganellar juxtaposition. This article is part of a Special Issue entitled: Calcium Signaling In Health and Disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Deborah Naon
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy; Department of Biology, University of Padua, Via G. Colombo 3, 35121 Padua, Italy
| | - Luca Scorrano
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy; Department of Biology, University of Padua, Via G. Colombo 3, 35121 Padua, Italy.
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42
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Messenger SW, Falkowski MA, Groblewski GE. Ca²⁺-regulated secretory granule exocytosis in pancreatic and parotid acinar cells. Cell Calcium 2014; 55:369-75. [PMID: 24742357 DOI: 10.1016/j.ceca.2014.03.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/04/2014] [Accepted: 03/09/2014] [Indexed: 01/09/2023]
Abstract
Protein secretion from acinar cells of the pancreas and parotid glands is controlled by G-protein coupled receptor activation and generation of the cellular messengers Ca(2+), diacylglycerol and cAMP. Secretory granule (SG) exocytosis shares some common characteristics with nerve, neuroendocrine and endocrine cells which are regulated mainly by elevated cell Ca(2+). However, in addition to diverse signaling pathways, acinar cells have large ∼1 μm diameter SGs (∼30 fold larger diameter than synaptic vesicles), respond to stimulation at slower rates (seconds versus milliseconds), demonstrate significant constitutive secretion, and in isolated acini, undergo sequential compound SG-SG exocytosis at the apical membrane. Exocytosis proceeds as an initial rapid phase that peaks and declines over 3 min followed by a prolonged phase that decays to near basal levels over 20-30 min. Studies indicate the early phase is triggered by Ca(2+) and involves the SG proteins VAMP2 (vesicle associated membrane protein2), Ca(2+)-sensing protein synatotagmin 1 (syt1) and the accessory protein complexin 2. The molecular details for regulation of VAMP8-mediated SG exocytosis and the prolonged phase of secretion are still emerging. Here we review the known regulatory molecules that impact the sequential exocytic process of SG tethering, docking, priming and fusion in acinar cells.
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Affiliation(s)
- Scott W Messenger
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States
| | - Michelle A Falkowski
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States
| | - Guy E Groblewski
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States.
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43
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Horenkamp FA, Mukherjee S, Alix E, Schauder CM, Hubber AM, Roy CR, Reinisch KM. Legionella pneumophila subversion of host vesicular transport by SidC effector proteins. Traffic 2014; 15:488-99. [PMID: 24483784 DOI: 10.1111/tra.12158] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 12/21/2022]
Abstract
Tethering proteins play a key role in vesicular transport, ensuring that cargo arrives at a specific destination. The bacterial effector protein SidC and its paralog SdcA have been described as tethering factors encoded by the intracellular pathogen Legionella pneumophila. Here, we demonstrate that SidC proteins are important for early events unique to maturation of vacuoles containing Legionella and discover monoubiquitination of Rab1 as a new SidC-dependent activity. The crystal structure of the SidC N-terminus revealed a novel fold that is important for function and could be involved in Legionella adaptations to evolutionarily divergent host cells it encounters in natural environments.
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Affiliation(s)
- Florian A Horenkamp
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
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44
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Abstract
Protein and lipid transport along the endolysosomal system of eukaryotic cells depends on multiple fusion and fission events. Over the past few years, the molecular constituents of both fission and fusion machineries have been identified. Here, we focus on the mechanism of membrane fusion at endosomes, vacuoles and lysosomes, and in particular on the role of the two homologous tethering complexes called CORVET and HOPS. Both complexes are heterohexamers; they share four subunits, interact with Rab GTPases and soluble NSF attachment protein receptors (SNAREs) and can tether membranes. Owing to the presence of specific subunits, CORVET is a Rab5 effector complex, whereas HOPS can bind efficiently to late endosomes and lysosomes through Rab7. Based on the recently described overall structure of the HOPS complex and a number of in vivo and in vitro analyses, important insights into their function have been obtained. Here, we discuss the general function of both complexes in yeast and in metazoan cells in the context of endosomal biogenesis and maturation.
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Affiliation(s)
- Henning J kleine Balderhaar
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry Section, Barbarastrasse 13, 49076 Osnabrück, Germany
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45
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Sckolnick M, Krementsova EB, Warshaw DM, Trybus KM. More than just a cargo adapter, melanophilin prolongs and slows processive runs of myosin Va. J Biol Chem 2013; 288:29313-22. [PMID: 23979131 DOI: 10.1074/jbc.m113.476929] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myosin Va (myoVa) is a molecular motor that processively transports cargo along actin tracks. One well studied cargo in vivo is the melanosome, a pigment organelle that is moved first by kinesin on microtubules and then handed off to myoVa for transport in the actin-rich dendritic periphery of melanocytes. Melanophilin (Mlph) is the adapter protein that links Rab27a-melanosomes to myoVa. Using total internal reflection fluorescence microscopy and quantum dot-labeled full-length myoVa, we show at the single-molecule level that Mlph increases the number of processively moving myoVa motors by 17-fold. Surprisingly, myoVa-Mlph moves ~4-fold slower than myoVa alone and with twice the run length. These two changes greatly increase the time spent on actin, a property likely to enhance the transfer of melanosomes to the adjacent keratinocyte. In contrast to the variable stepping pattern of full-length myoVa, the myoVa-Mlph complex shows a normal gating pattern between the heads typical of a fully active motor and consistent with a cargo-dependent activation mechanism. The Mlph-dependent changes in myoVa depend on a positively charged cluster of amino acids in the actin binding domain of Mlph, suggesting that Mlph acts as a "tether" that links the motor to the track. Our results provide a molecular explanation for the uncharacteristically slow speed of melanosome movement by myoVa in vivo. More generally, these data show that proteins that link motors to cargo can modify motor properties to enhance their biological role.
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Affiliation(s)
- Maria Sckolnick
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405
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46
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Abstract
The papillomavirus E2 proteins are pivotal to the viral life cycle and have well characterized functions in transcriptional regulation, initiation of DNA replication and partitioning the viral genome. The E2 proteins also function in vegetative DNA replication, post-transcriptional processes and possibly packaging. This review describes structural and functional aspects of the E2 proteins and their binding sites on the viral genome. It is intended to be a reference guide to this viral protein.
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Affiliation(s)
- Alison A McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA.
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47
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Henry M. Pseudotendon formation causing painful tethering of ruptured flexor carpi radialis tendons. J Hand Microsurg 2012; 5:1-3. [PMID: 24426661 DOI: 10.1007/s12593-012-0077-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 09/07/2012] [Indexed: 10/27/2022] Open
Abstract
Six patients (five male, one female) between 51 and 64 years of age sustained ruptures of the right dominant flexor carpi radialis (FCR) tendon. Prior to rupture, within the past 3 months to 1 year, each had received one or two corticosteroid injections of the FCR tendon sheath for stenosing tenosynovitis. Three of six patients demonstrated radiographic findings but none had clinical symptoms of osteoarthritis at the scaphoid-trapezium-trapezoid joint. The pain and disability declared by these patients appeared out of proportion to the relatively innocuous nature of a ruptured FCR tendon, with an average pre-operative Disabilities of the Arm, Shoulder, and Hand (DASH) score of 32. In all patients there was a palpable, tender mass of retracted, ruptured FCR tendon around 6 cm proximal to the wrist crease as well as a palpable cord of pseudotendon formed within the residual sheath. Pain along the course of the pseudotendon was consistently provoked by wrist extension and gripping. The patients were initially treated non-surgically with stretching, manual therapy, ultrasound, and oral medications for 2-4 months. None obtained sufficient relief, and the patients requested more definitive care. The painful tethering of the ruptured FCR was solved by complete excision of both pseudotendon and the retracted tendon stump, resulting in complete relief of symptoms with an average post-operative DASH score of 3. Pre-operative and post-operative DASH scores were analyzed with the paired Student's t-test, using a p-value of 0.05, and found to have a statistically significant difference.
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Affiliation(s)
- Mark Henry
- Hand and Wrist Center of Houston, 1200 Binz Street, 13th Floor, Houston, TX 77004 USA
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48
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Nishiga M, Izumi C, Matsutani H, Hashiwada S, Takahashi S, Hayama Y, Nakajima S, Sakamoto J, Hanazawa K, Miyake M, Tamura T, Kondo H, Motooka M, Kaitani K, Nakagawa Y. A case of significantly increased mitral regurgitation early after atrial septal defect closure. J Echocardiogr 2012; 10:69-71. [PMID: 27278048 DOI: 10.1007/s12574-012-0123-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
Abstract
We report a rare case in which mitral regurgitation (MR) was exacerbated to a severe level early after atrial septal defect (ASD) closure, even though the female patient had preoperatively mild MR and mild changes in mitral valve (MV) and sinus rhythm. The mechanism of increased MR was considered as poor coaptation and tethering of the MV due to the restricted motion of the posterior leaflet in addition to geometric changes of the left ventricle (LV) after ASD closure.
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