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Collaco JM, Abman SH, Austin ED, Avitabile CM, Bates A, Fineman JR, Freire GA, Handler SS, Ivy DD, Krishnan US, Mullen MP, Varghese NP, Yung D, Nies MK, Everett AD, Zimmerman KO, Simmons W, Chakraborty H, Yenokyan G, Newell‐Sturdivant A, Christensen E, Eyzaguirre LM, Hanley DF, Rosenzweig EB, Romer LH. Kids Mod PAH trial: A multicenter trial comparing mono- versus duo-therapy for initial treatment of pediatric pulmonary hypertension. Pulm Circ 2023; 13:e12305. [PMID: 37915400 PMCID: PMC10617301 DOI: 10.1002/pul2.12305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 09/20/2023] [Indexed: 11/03/2023] Open
Abstract
Pulmonary hypertension (PH) is a significant health problem that contributes to high morbidity and mortality in diverse cardiac, pulmonary, and systemic diseases in children. Evidence-based advances in PH care have been challenged by a paucity of quality endpoints for assessing clinical course and the lack of robust clinical trial data to guide pharmacologic therapies in children. While the landmark adult AMBITION trial demonstrated the benefit of up-front combination PH therapy with ambrisentan and tadalafil, it remains unknown whether upfront combination therapy leads to more rapid and sustained clinical benefits in children with various categories of PH. In this article, we describe the inception of the Kids Mod PAH Trial, a multicenter Phase III trial, to address whether upfront combination therapy (sildenafil and bosentan vs. sildenafil alone) improves PH outcomes in children, recognizing that marked differences between the etiology and therapeutic response between adults and children exist. The primary endpoint of this study is WHO functional class (FC) 12 months after initiation of study drug therapy. In addition to the primary outcome, secondary endpoints are being assessed, including a composite measure of time to clinical worsening, WHO FC at 24 months, echocardiographic assessment of PH and quantitative assessment of right ventricular function, 6-min walk distance, and NT-proBNP levels. Exploratory endpoints include selected biomarkers, actigraphy, and assessments of quality of life. This study is designed to pave the way for additional clinical trials by establishing a robust infrastructure through the development of a PPHNet Clinical Trials Network.
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Affiliation(s)
- Joseph M. Collaco
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Steven H. Abman
- Department of PediatricsChildren's Hospital ColoradoAuroraColoradoUSA
| | - Eric D. Austin
- Department of PediatricsVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Catherine M. Avitabile
- Department of Pediatrics, Children's Hospital of PhiladelphiaUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Angela Bates
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Jeffrey R. Fineman
- Department of PediatricsUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Grace A. Freire
- Department of PediatricsJohns Hopkins All Children's HospitalSt. PetersburgFloridaUSA
| | | | - Dunbar D. Ivy
- Department of PediatricsChildren's Hospital ColoradoAuroraColoradoUSA
| | - Usha S. Krishnan
- Department of Pediatrics, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Mary P. Mullen
- Department of PediatricsBoston Children's HospitalBostonMassachusettsUSA
| | - Nidhy P. Varghese
- Department of Pediatrics, Baylor College of MedicineTexas Children's HospitalHoustonTexasUSA
| | - Delphine Yung
- Department of PediatricsUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Melanie K. Nies
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Allen D. Everett
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Kanecia O. Zimmerman
- Departments of Biostatistics and Bioinformatics, Department of Pediatrics, Duke Clinical Research InstituteDuke UniversityDurhamNorth CarolinaUSA
| | - William Simmons
- Departments of Biostatistics and Bioinformatics, Department of Pediatrics, Duke Clinical Research InstituteDuke UniversityDurhamNorth CarolinaUSA
| | - Hrishikesh Chakraborty
- Departments of Biostatistics and Bioinformatics, Department of Pediatrics, Duke Clinical Research InstituteDuke UniversityDurhamNorth CarolinaUSA
| | - Gayane Yenokyan
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Allison Newell‐Sturdivant
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Neurology, Johns Hopkins School of MedicineBIOS Clinical Trials Coordinating Center (CTCC)BaltimoreMarylandUSA
| | - Eric Christensen
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Neurology, Johns Hopkins School of MedicineBIOS Clinical Trials Coordinating Center (CTCC)BaltimoreMarylandUSA
| | - Lindsay M. Eyzaguirre
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Neurology, Johns Hopkins School of MedicineBIOS Clinical Trials Coordinating Center (CTCC)BaltimoreMarylandUSA
| | - Daniel F. Hanley
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Neurology, Johns Hopkins School of MedicineBIOS Clinical Trials Coordinating Center (CTCC)BaltimoreMarylandUSA
| | - Erika B. Rosenzweig
- Department of Pediatrics, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Lewis H. Romer
- Departments of Pediatrics, Neurology, Anesthesiology and Critical Care Medicine, and BiostatisticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
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2
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Jin Q, Pandey D, Thompson CB, Lewis S, Sung HW, Nguyen TD, Kuo S, Wilson KL, Gracias DH, Romer LH. Acute downregulation of emerin alters actomyosin cytoskeleton connectivity and function. Biophys J 2023; 122:3690-3703. [PMID: 37254483 PMCID: PMC10541481 DOI: 10.1016/j.bpj.2023.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/30/2023] [Accepted: 05/22/2023] [Indexed: 06/01/2023] Open
Abstract
Fetal lung fibroblasts contribute dynamic infrastructure for the developing lung. These cells undergo dynamic mechanical transitions, including cyclic stretch and spreading, which are integral to lung growth in utero. We investigated the role of the nuclear envelope protein emerin in cellular responses to these dynamic mechanical transitions. In contrast to control cells, which briskly realigned their nuclei, actin cytoskeleton, and extracellular matrices in response to cyclic stretch, fibroblasts that were acutely downregulated for emerin showed incomplete reorientation of both nuclei and actin cytoskeleton. Emerin-downregulated fibroblasts were also aberrantly circular in contrast to the spindle-shaped controls and exhibited an altered pattern of filamentous actin organization that was disconnected from the nucleus. Emerin knockdown was also associated with reduced myosin light chain phosphorylation during cell spreading. Interestingly, emerin-downregulated fibroblasts also demonstrated reduced fibronectin fibrillogenesis and production. These findings indicate that nuclear-cytoskeletal coupling serves a role in the dynamic regulation of cytoskeletal structure and function and may also impact the transmission of traction force to the extracellular matrix microenvironment.
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Affiliation(s)
- Qianru Jin
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Deepesh Pandey
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Carol B Thompson
- Biostatistics Center, Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Shawna Lewis
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Hyun Woo Sung
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Thao D Nguyen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Scot Kuo
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland; Microscope Facility, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Katherine L Wilson
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - David H Gracias
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland; Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland; Center for MicroPhysiological Systems, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland; Department of Chemistry, Johns Hopkins University, Baltimore, Maryland; Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland
| | - Lewis H Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland; Center for Cell Dynamics, Johns Hopkins School of Medicine, Baltimore, Maryland.
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3
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Pahapale GJ, Tao J, Nikolic M, Gao S, Scarcelli G, Sun SX, Romer LH, Gracias DH. Directing Multicellular Organization by Varying the Aspect Ratio of Soft Hydrogel Microwells. Adv Sci (Weinh) 2022; 9:e2104649. [PMID: 35434926 PMCID: PMC9189654 DOI: 10.1002/advs.202104649] [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] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 03/08/2022] [Indexed: 06/03/2023]
Abstract
Multicellular organization with precise spatial definition is essential to various biological processes, including morphogenesis, development, and healing in vascular and other tissues. Gradients and patterns of chemoattractants are well-described guides of multicellular organization, but the influences of 3D geometry of soft hydrogels are less well defined. Here, the discovery of a new mode of endothelial cell self-organization guided by combinatorial effects of stiffness and geometry, independent of protein or chemical patterning, is described. Endothelial cells in 2 kPa microwells are found to be ≈30 times more likely to migrate to the edge to organize in ring-like patterns than in stiff 35 kPa microwells. This organization is independent of curvature and significantly more pronounced in 2 kPa microwells with aspect ratio (perimeter/depth) < 25. Physical factors of cells and substrates that drive this behavior are systematically investigated and a mathematical model that explains the organization by balancing the dynamic interaction between tangential cytoskeletal tension, cell-cell, and cell-substrate adhesion is presented. These findings demonstrate the importance of combinatorial effects of geometry and stiffness in complex cellular organization that can be leveraged to facilitate the engineering of bionics and integrated model organoid systems with customized nutrient vascular networks.
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Affiliation(s)
- Gayatri J. Pahapale
- Department of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD21218USA
| | - Jiaxiang Tao
- Department of Mechanical EngineeringJohns Hopkins UniversityBaltimoreMD21218USA
| | - Milos Nikolic
- Maryland Biophysics ProgramInstitute for Physical Science and TechnologyUniversity of MarylandCollege ParkMD20742USA
| | - Sammy Gao
- Department of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD21218USA
| | - Giuliano Scarcelli
- Maryland Biophysics ProgramInstitute for Physical Science and Technology and Fischell Department of BioengineeringUniversity of MarylandCollege ParkMD20742USA
| | - Sean X. Sun
- Department of Mechanical EngineeringCell Biologyand Institute of NanoBioTechnology (INBT)Johns Hopkins UniversityBaltimoreMD21218USA
| | - Lewis H. Romer
- Department of Cell BiologyAnesthesiology and Critical Care MedicineBiomedical EngineeringPediatricsand Center for Cell DynamicsJohns Hopkins School of MedicineBaltimoreMD21205USA
| | - David H. Gracias
- Department of Chemical and Biomolecular EngineeringMaterials Science and EngineeringChemistry and Laboratory for Computational Sensing and Robotics (LCSR)Johns Hopkins UniversityBaltimoreMD21218USA
- Department of Oncology and Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMD21205USA
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4
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Machado RD, Welch CL, Haimel M, Bleda M, Colglazier E, Coulson JD, Debeljak M, Ekstein J, Fineman JR, Golden WC, Griffin EL, Hadinnapola C, Harris MA, Hirsch Y, Hoover-Fong JE, Nogee L, Romer LH, Vesel S, Gräf S, Morrell NW, Southgate L, Chung WK. Biallelic variants of ATP13A3 cause dose-dependent childhood-onset pulmonary arterial hypertension characterised by extreme morbidity and mortality. J Med Genet 2021; 59:906-911. [PMID: 34493544 PMCID: PMC9411922 DOI: 10.1136/jmedgenet-2021-107831] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 03/21/2021] [Accepted: 08/12/2021] [Indexed: 11/25/2022]
Abstract
Background The molecular genetic basis of pulmonary arterial hypertension (PAH) is heterogeneous, with at least 26 genes displaying putative evidence for disease causality. Heterozygous variants in the ATP13A3 gene were recently identified as a new cause of adult-onset PAH. However, the contribution of ATP13A3 risk alleles to child-onset PAH remains largely unexplored. Methods and results We report three families with a novel, autosomal recessive form of childhood-onset PAH due to biallelic ATP13A3 variants. Disease onset ranged from birth to 2.5 years and was characterised by high mortality. Using genome sequencing of parent–offspring trios, we identified a homozygous missense variant in one case, which was subsequently confirmed to cosegregate with disease in an affected sibling. Independently, compound heterozygous variants in ATP13A3 were identified in two affected siblings and in an unrelated third family. The variants included three loss of function variants (two frameshift, one nonsense) and two highly conserved missense substitutions located in the catalytic phosphorylation domain. The children were largely refractory to treatment and four died in early childhood. All parents were heterozygous for the variants and asymptomatic. Conclusion Our findings support biallelic predicted deleterious ATP13A3 variants in autosomal recessive, childhood-onset PAH, indicating likely semidominant dose-dependent inheritance for this gene.
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Affiliation(s)
- Rajiv D Machado
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | - Carrie L Welch
- Department of Pediatrics, Columbia University Irving Medical Center, New York, New York, USA
| | - Matthias Haimel
- NIHR Bioresource - Rare Diseases, University of Cambridge, Cambridge, Cambridgeshire, UK.,Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Marta Bleda
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Elizabeth Colglazier
- Department of Nursing, University of California San Francisco, San Francisco, California, USA
| | - John D Coulson
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Marusa Debeljak
- Clinical Institute of Special Laboratory Diagnostics, University Medical Centre Ljubljana, University Children's Hospital, Ljubljana, Slovenia.,Faculty of Medicine, Institute of Cell Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Josef Ekstein
- Dor Yeshorim, Committee for Prevention of Jewish Genetic Diseases, Brooklyn, New York, USA
| | - Jeffrey R Fineman
- Department of Pediatrics and Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, USA
| | | | - Emily L Griffin
- Department of Pediatrics, Columbia University Irving Medical Center, New York, New York, USA
| | - Charaka Hadinnapola
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | | | - Yoel Hirsch
- Dor Yeshorim, Committee for Prevention of Jewish Genetic Diseases, Brooklyn, New York, USA
| | | | - Lawrence Nogee
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lewis H Romer
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Anesthesiology and Critical Care Medicine, Cell Biology, Biomedical Engineering, and the Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Samo Vesel
- Department of Cardiology, University Medical Centre Ljubljana, University Children's Hospital, Ljubljana, Slovenia.,Department of Paediatrics, Teaching Hospital Celje, Celje, Slovenia
| | | | - Stefan Gräf
- NIHR Bioresource - Rare Diseases, University of Cambridge, Cambridge, Cambridgeshire, UK.,Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Nicholas W Morrell
- NIHR Bioresource - Rare Diseases, University of Cambridge, Cambridge, Cambridgeshire, UK.,Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Laura Southgate
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | - Wendy K Chung
- Department of Pediatrics, Columbia University Irving Medical Center, New York, New York, USA .,Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
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5
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Coleman RD, Morales-Demori R, Coulson J, Romer LH. Under Pressure - The Pulmonary Vasculature and its Role in the Pediatric CICU. Am J Respir Crit Care Med 2021; 204:391-392. [PMID: 34153208 PMCID: PMC8480239 DOI: 10.1164/rccm.202104-1044ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Ryan D Coleman
- Baylor College of Medicine, 3989, Pediatrics, Houston, Texas, United States;
| | | | - John Coulson
- Johns Hopkins University School of Medicine, 1500, Pediatrics, Baltimore, Maryland, United States
| | - Lewis H Romer
- Johns Hopkins University School of Medicine, 1500, Anesthesiology and Critical Care Medicine, Pediatrics, Cell Biology, and Biomedical Engineering, Baltimore, Maryland, United States
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6
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Weiss SL, Peters MJ, Alhazzani W, Agus MSD, Flori HR, Inwald DP, Nadel S, Schlapbach LJ, Tasker RC, Argent AC, Brierley J, Carcillo J, Carrol ED, Carroll CL, Cheifetz IM, Choong K, Cies JJ, Cruz AT, De Luca D, Deep A, Faust SN, De Oliveira CF, Hall MW, Ishimine P, Javouhey E, Joosten KFM, Joshi P, Karam O, Kneyber MCJ, Lemson J, MacLaren G, Mehta NM, Møller MH, Newth CJL, Nguyen TC, Nishisaki A, Nunnally ME, Parker MM, Paul RM, Randolph AG, Ranjit S, Romer LH, Scott HF, Tume LN, Verger JT, Williams EA, Wolf J, Wong HR, Zimmerman JJ, Kissoon N, Tissieres P. Surviving sepsis campaign international guidelines for the management of septic shock and sepsis-associated organ dysfunction in children. Intensive Care Med 2020; 46:10-67. [PMID: 32030529 PMCID: PMC7095013 DOI: 10.1007/s00134-019-05878-6] [Citation(s) in RCA: 266] [Impact Index Per Article: 66.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Objectives To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction. Design A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process. Methods The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, “in our practice” statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate. Results The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 49 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, “in our practice” statements were provided. In addition, 52 research priorities were identified. Conclusions A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.
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Affiliation(s)
- Scott L Weiss
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Mark J Peters
- Great Ormond Street Hospital for Children, London, UK
| | - Waleed Alhazzani
- Department of Medicine, Division of Critical Care, McMaster University, Hamilton, ON, Canada.,Department of Health Research Methods and Impact, McMaster University, Hamilton, ON, Canada
| | - Michael S D Agus
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | | | | | | | - Luregn J Schlapbach
- Paediatric Critical Care Research Group, The University of Queensland and Queensland Children's Hospital, Brisbane, QLD, Australia
| | - Robert C Tasker
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew C Argent
- Red Cross War Memorial Children's Hospital and University of Cape Town, Cape Town, South Africa
| | - Joe Brierley
- Great Ormond Street Hospital for Children, London, UK
| | | | | | | | | | - Karen Choong
- Department of Medicine, Division of Critical Care, McMaster University, Hamilton, ON, Canada.,Department of Health Research Methods and Impact, McMaster University, Hamilton, ON, Canada
| | - Jeffry J Cies
- St. Christopher's Hospital for Children, Philadelphia, PA, USA
| | | | - Daniele De Luca
- Paris South University Hospitals-Assistance Publique Hopitaux de Paris, Paris, France.,Physiopathology and Therapeutic Innovation Unit-INSERM U999, South Paris-Saclay University, Paris, France
| | | | - Saul N Faust
- University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
| | | | - Mark W Hall
- Nationwide Children's Hospital, Columbus, OH, USA
| | | | | | | | - Poonam Joshi
- All India Institute of Medical Sciences, New Delhi, India
| | - Oliver Karam
- Children's Hospital of Richmond at VCU, Richmond, VA, USA
| | | | - Joris Lemson
- Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Graeme MacLaren
- National University Health System, Singapore, Singapore.,Royal Children's Hospital, Melbourne, VIC, Australia
| | - Nilesh M Mehta
- Department of Anesthesiology, Critical Care and Pain, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | | | | | | | - Akira Nishisaki
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Mark E Nunnally
- New York University Langone Medical Center, New York, NY, USA
| | | | - Raina M Paul
- Advocate Children's Hospital, Park Ridge, IL, USA
| | - Adrienne G Randolph
- Department of Anesthesiology, Critical Care and Pain, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | | | | | | | | | - Judy T Verger
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,College of Nursing, University of Iowa, Iowa City, IA, USA
| | | | - Joshua Wolf
- St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | | | - Pierre Tissieres
- Paris South University Hospitals-Assistance Publique Hopitaux de Paris, Paris, France.,Institute of Integrative Biology of the Cell-CNRS, CEA, Univ Paris Sud, Gif-Sur-Yvette, France
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7
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Bachtiar EO, Erol O, Millrod M, Tao R, Gracias DH, Romer LH, Kang SH. 3D printing and characterization of a soft and biostable elastomer with high flexibility and strength for biomedical applications. J Mech Behav Biomed Mater 2020; 104:103649. [PMID: 32174407 PMCID: PMC7078069 DOI: 10.1016/j.jmbbm.2020.103649] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/26/2019] [Accepted: 01/20/2020] [Indexed: 01/09/2023]
Abstract
Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about the material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young's modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not only for PCU-Sil, but also for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.
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Affiliation(s)
- Emilio O Bachtiar
- Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Hopkins Extreme Materials Institute, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Ozan Erol
- Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Hopkins Extreme Materials Institute, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Michal Millrod
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, 600 North Wolfe St, Baltimore, MD 21205, USA
| | - Runhan Tao
- Hopkins Extreme Materials Institute, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - David H Gracias
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Lewis H Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, 600 North Wolfe St, Baltimore, MD 21205, USA; Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, USA; Departments of Cell Biology, Pediatrics, and the Center for Cell Dynamics, Johns Hopkins University, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Sung Hoon Kang
- Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Hopkins Extreme Materials Institute, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA; Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA.
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8
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Jin Q, Bhatta A, Pagaduan JV, Chen X, West-Foyle H, Liu J, Hou A, Berkowitz D, Kuo SC, Askin FB, Nguyen TD, Gracias DH, Romer LH. Biomimetic human small muscular pulmonary arteries. Sci Adv 2020; 6:eaaz2598. [PMID: 32232160 PMCID: PMC7096158 DOI: 10.1126/sciadv.aaz2598] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 01/03/2020] [Indexed: 05/04/2023]
Abstract
Changes in structure and function of small muscular arteries play a major role in the pathophysiology of pulmonary hypertension, a burgeoning public health challenge. Improved anatomically mimetic in vitro models of these microvessels are urgently needed because nonhuman vessels and previous models do not accurately recapitulate the microenvironment and architecture of the human microvascular wall. Here, we describe parallel biofabrication of photopatterned self-rolled biomimetic pulmonary arterial microvessels of tunable size and infrastructure. These microvessels feature anatomically accurate layering and patterning of aligned human smooth muscle cells, extracellular matrix, and endothelial cells and exhibit notable increases in endothelial longevity and nitric oxide production. Computational image processing yielded high-resolution 3D perspectives of cells and proteins. Our studies provide a new paradigm for engineering multicellular tissues with precise 3D spatial positioning of multiple constituents in planar moieties, providing a biomimetic platform for investigation of microvascular pathobiology in human disease.
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Affiliation(s)
- Qianru Jin
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Anil Bhatta
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jayson V. Pagaduan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Xing Chen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Hoku West-Foyle
- Microscope Facility, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiayu Liu
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Annie Hou
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dan Berkowitz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Scot C. Kuo
- Microscope Facility, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Frederic B. Askin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thao D. Nguyen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - David H. Gracias
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
- Corresponding author. (D.H.G.); (L.H.R.)
| | - Lewis H. Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Corresponding author. (D.H.G.); (L.H.R.)
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9
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Weiss SL, Peters MJ, Alhazzani W, Agus MSD, Flori HR, Inwald DP, Nadel S, Schlapbach LJ, Tasker RC, Argent AC, Brierley J, Carcillo J, Carrol ED, Carroll CL, Cheifetz IM, Choong K, Cies JJ, Cruz AT, De Luca D, Deep A, Faust SN, De Oliveira CF, Hall MW, Ishimine P, Javouhey E, Joosten KFM, Joshi P, Karam O, Kneyber MCJ, Lemson J, MacLaren G, Mehta NM, Møller MH, Newth CJL, Nguyen TC, Nishisaki A, Nunnally ME, Parker MM, Paul RM, Randolph AG, Ranjit S, Romer LH, Scott HF, Tume LN, Verger JT, Williams EA, Wolf J, Wong HR, Zimmerman JJ, Kissoon N, Tissieres P. Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children. Pediatr Crit Care Med 2020; 21:e52-e106. [PMID: 32032273 DOI: 10.1097/pcc.0000000000002198] [Citation(s) in RCA: 458] [Impact Index Per Article: 114.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction. DESIGN A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process. METHODS The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate. RESULTS The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified. CONCLUSIONS A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.
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Affiliation(s)
- Scott L Weiss
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Mark J Peters
- Great Ormond Street Hospital for Children, London, United Kingdom
| | - Waleed Alhazzani
- Department of Medicine, Division of Critical Care, and Department of Health Research Methods and Impact, McMaster University, Hamilton, ON, Canada
| | - Michael S D Agus
- Department of Pediatrics (to Dr. Agus), Department of Anesthesiology, Critical Care and Pain (to Drs. Mehta and Randolph), Boston Children's Hospital and Harvard Medical School, Boston, MA
| | | | | | | | - Luregn J Schlapbach
- Paediatric Critical Care Research Group, The University of Queensland and Queensland Children's Hospital, Brisbane, QLD, Australia
| | - Robert C Tasker
- Department of Pediatrics (to Dr. Agus), Department of Anesthesiology, Critical Care and Pain (to Drs. Mehta and Randolph), Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Andrew C Argent
- Red Cross War Memorial Children's Hospital and University of Cape Town, Cape Town, South Africa
| | - Joe Brierley
- Great Ormond Street Hospital for Children, London, United Kingdom
| | | | | | | | | | - Karen Choong
- Department of Medicine, Division of Critical Care, and Department of Health Research Methods and Impact, McMaster University, Hamilton, ON, Canada
| | - Jeffry J Cies
- St. Christopher's Hospital for Children, Philadelphia, PA
| | | | - Daniele De Luca
- Paris South University Hospitals-Assistance Publique Hopitaux de Paris, Paris, France.,Physiopathology and Therapeutic Innovation Unit-INSERM U999, South Paris-Saclay University, Paris, France
| | - Akash Deep
- King's College Hospital, London, United Kingdom
| | - Saul N Faust
- University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, United Kingdom
| | | | - Mark W Hall
- Nationwide Children's Hospital, Columbus, OH
| | | | | | | | - Poonam Joshi
- All India Institute of Medical Sciences, New Delhi, India
| | - Oliver Karam
- Children's Hospital of Richmond at VCU, Richmond, VA
| | | | - Joris Lemson
- Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Graeme MacLaren
- National University Health System, Singapore, and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Nilesh M Mehta
- Department of Pediatrics (to Dr. Agus), Department of Anesthesiology, Critical Care and Pain (to Drs. Mehta and Randolph), Boston Children's Hospital and Harvard Medical School, Boston, MA
| | | | | | | | - Akira Nishisaki
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | | | | | - Adrienne G Randolph
- Department of Pediatrics (to Dr. Agus), Department of Anesthesiology, Critical Care and Pain (to Drs. Mehta and Randolph), Boston Children's Hospital and Harvard Medical School, Boston, MA
| | | | | | | | - Lyvonne N Tume
- University of the West of England, Bristol, United Kingdom
| | - Judy T Verger
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.,College of Nursing, University of Iowa, Iowa City, IA
| | | | - Joshua Wolf
- St. Jude Children's Research Hospital, Memphis, TN
| | | | | | - Niranjan Kissoon
- British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Pierre Tissieres
- Paris South University Hospitals-Assistance Publique Hopitaux de Paris, Paris, France.,Institute of Integrative Biology of the Cell-CNRS, CEA, Univ Paris Sud, Gif-sur-Yvette, France
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10
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11
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Jiang Z, Erol O, Chatterjee D, Xu W, Hibino N, Romer LH, Kang SH, Gracias DH. Direct Ink Writing of Poly(tetrafluoroethylene) (PTFE) with Tunable Mechanical Properties. ACS Appl Mater Interfaces 2019; 11:28289-28295. [PMID: 31291075 PMCID: PMC6813788 DOI: 10.1021/acsami.9b07279] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Poly(tetrafluoroethylene) (PTFE) is a unique polymer with highly desirable properties such as resistance to chemical degradation, biocompatibility, hydrophobicity, antistiction, and low friction coefficient. However, due to its high melt viscosity, it is not possible to three-dimensional (3D)-print PTFE structures using nozzle-based extrusion. Here, we report a new and versatile strategy for 3D-printing PTFE structures using direct ink writing (DIW). Our approach is based on a newly formulated PTFE nanoparticle ink and thermal treatment process. The ink was formulated by mixing an aqueous dispersion of surfactant-stabilized PTFE nanoparticles with a binding gum to optimize its shear-thinning properties required for DIW. We developed a multistage thermal treatment to fuse the PTFE nanoparticles, solidify the printed structures, and remove the additives. We have extensively characterized the rheological and mechanical properties and processing parameters of these structures using imaging, mechanical testing, and statistical design of experiments. Importantly, several of the mechanical and structural properties of the final-printed PTFE structures resemble that of compression-molded PTFE, and additionally, the mechanical properties are tunable. We anticipate that this versatile approach facilitates the production of 3D-printed PTFE components using DIW with significant potential applications in engineering and medicine.
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Affiliation(s)
- Zhuoran Jiang
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Ozan Erol
- Department of Mechanical Engineering and Hopkins Extreme Materials Institute Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Devina Chatterjee
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Weinan Xu
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Narutoshi Hibino
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins Medicine, 1800 Orleans Street, Baltimore, MD 21287, USA
| | - Lewis H. Romer
- Departments of Anesthesiology and Critical Care Medicine, Cell Biology, Biomedical Engineering, Pediatrics, and the Center for Cell Dynamics, Johns Hopkins Medicine, 1800 Orleans Street, Baltimore, MD 21287, USA
| | - Sung Hoon Kang
- Department of Mechanical Engineering and Hopkins Extreme Materials Institute Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
- Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - David H. Gracias
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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12
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Abstract
Pulmonary hypertension is a growing pediatric problem and children may present with pulmonary hypertensive crisis-a life-threatening emergency requiring acute interventions. The aim of this study was to characterize the broad spectrum of care provided in North American PICUs for children who present with pulmonary hypertensive crisis. DESIGN Electronic cross-sectional survey. Survey questions covered the following: demographics of the respondents, institution, and patient population; pulmonary hypertension diagnostic modalities; pulmonary hypertension-specific pharmacotherapies; supportive therapies, including sedation, ventilation, and inotropic support; and components of multidisciplinary teams. SETTING PICUs in the United States and Canada. SUBJECTS Faculty members from surveyed institutions. INTERVENTIONS None. MEASUREMENT AND MAIN RESULTS The response rate was 50% of 99 identified institutions. Of the respondents, 82.2% were pediatric intensivists from large units, and 73.9% had over a decade of experience beyond training. Respondents provided care for a median of 10 patients/yr with acute pulmonary hypertensive crisis. Formal echocardiography protocols existed at 61.1% of institutions with varying components reported. There were no consistent indications for cardiac catheterization during a pulmonary hypertensive crisis admission. All institutions used inhaled nitric oxide, and enteral phosphodiesterase type 5 inhibitor was the most frequently used additional targeted vasodilator therapy. Milrinone and epinephrine were the most frequently used vasoactive infusions. Results showed no preferred approach to mechanical ventilation. Fentanyl and dexmedetomidine were the preferred sedative infusions. A formal pulmonary hypertension consulting team was reported at 51.1% of institutions, and the three most common personnel were pediatric cardiologist, pediatric pulmonologist, and advanced practice nurse. CONCLUSIONS The management of critically ill children with acute pulmonary hypertensive crisis is diverse. Findings from this survey may inform formal recommendations - particularly with regard to care team composition and pulmonary vasodilator therapies - as North American guidelines are currently lacking. Additional work is needed to determine best practice, standardization of practice, and resulting impact on outcomes.
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Affiliation(s)
- Meghan L Bernier
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Melania M Bembea
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
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13
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Liu J, Erol O, Pantula A, Liu W, Jiang Z, Kobayashi K, Chatterjee D, Hibino N, Romer LH, Kang SH, Nguyen TD, Gracias DH. Dual-Gel 4D Printing of Bioinspired Tubes. ACS Appl Mater Interfaces 2019; 11:8492-8498. [PMID: 30694051 PMCID: PMC6785027 DOI: 10.1021/acsami.8b17218] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The distribution of periodic patterns of materials with radial or bilateral symmetry is a universal natural design principle. Among the many biological forms, tubular shapes are a common motif in many organisms, and they are also important for bioimplants and soft robots. However, the simple design principle of strategic placement of 3D printed segments of swelling and nonswelling materials to achieve widely different functionalities is yet to be demonstrated. Here, we report the design, fabrication, and characterization of segmented 3D printed gel tubes composed of an active thermally responsive swelling gel (poly N-isopropylacrylamide) and a passive thermally nonresponsive gel (polyacrylamide). Using finite element simulations and experiments, we report a variety of shape changes including uniaxial elongation, radial expansion, bending, and gripping based on two gels. Actualization and characterization of thermally induced shape changes are of key importance to robotics and biomedical engineering. Our studies present rational approaches to engineer complex parameters with a high level of customization and tunability for additive manufacturing of dynamic gel structures.
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Affiliation(s)
- Jiayu Liu
- Department of Mechanical Engineering, Johns Hopkins
University, 3400 N Charles Street, Baltimore, MD 21218, USA
| | - Ozan Erol
- Department of Mechanical Engineering, Johns Hopkins
University, 3400 N Charles Street, Baltimore, MD 21218, USA
- Hopkins Extreme Materials Institute, 3400 N Charles Street,
Baltimore,Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
| | - Aishwarya Pantula
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
| | - Wangqu Liu
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
| | - Zhuoran Jiang
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
| | - Kunihiko Kobayashi
- JSR Corporation, 1-9-2, Higashi-Shimbashi, Minato-ku, Tokyo
105-8640, Japan
| | - Devina Chatterjee
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
| | - Narutoshi Hibino
- Division of Cardiac Surgery, Department of Surgery, 1800
Orleans Street, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | - Lewis H. Romer
- Departments of Anesthesiology and Critical Care Medicine,
Cell Biology, Pediatrics, Johns Hopkins University School of Medicine, 1800 Orleans
Street, Baltimore, MD 21287, USA
- Biomedical Engineering and the Center for Cell Dynamics,
Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD
21287, USA
| | - Sung Hoon Kang
- Department of Mechanical Engineering, Johns Hopkins
University, 3400 N Charles Street, Baltimore, MD 21218, USA
- Hopkins Extreme Materials Institute, 3400 N Charles Street,
Baltimore,Johns Hopkins University, Baltimore, MD 21218, USA
- Institute for NanoBioTechnology, Johns Hopkins University,
3400 N Charles Street, Baltimore, Baltimore, MD 21218, USA
| | - Thao D. Nguyen
- Department of Mechanical Engineering, Johns Hopkins
University, 3400 N Charles Street, Baltimore, MD 21218, USA
- Hopkins Extreme Materials Institute, 3400 N Charles Street,
Baltimore,Johns Hopkins University, Baltimore, MD 21218, USA
| | - David H. Gracias
- Department of Chemical & Biomolecular Engineering,
Johns Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218,
USA
- Department of Materials Science and Engineering, Johns
Hopkins University, 3400 N Charles Street, Baltimore, Baltimore, MD 21218, USA
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14
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Abstract
Interfacing nano/microscale elements with biological components in 3D contexts opens new possibilities for mimicry, bionics, and augmentation of organismically and anatomically inspired materials. Abiotic nanoscale elements such as plasmonic nanostructures, piezoelectric ribbons, and thin film semiconductor devices interact with electromagnetic fields to facilitate advanced capabilities such as communication at a distance, digital feedback loops, logic, and memory. Biological components such as proteins, polynucleotides, cells, and organs feature complex chemical synthetic networks that can regulate growth, change shape, adapt, and regenerate. Abiotic and biotic components can be integrated in all three dimensions in a well-ordered and programmed manner with high tunability, versatility, and resolution to produce radically new materials and hybrid devices such as sensor fabrics, anatomically mimetic microfluidic modules, artificial tissues, smart prostheses, and bionic devices. In this critical Review, applications of small scale devices in 3D hybrid integration, biomicrofluidics, advanced prostheses, and bionic organs are discussed.
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Affiliation(s)
- Jayson V Pagaduan
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Anil Bhatta
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Lewis H Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
- Department of Cell Biology, Department of Biomedical Engineering, Department of Pediatrics and the Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - David H Gracias
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
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15
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Bhatta A, Pagaduan JV, Chen X, West‐Foyle H, Hou A, Liu J, Jin Q, Nguyen TD, Kuo S, Berkowitz D, Gracias DH, Romer LH. Developing and characterizing human biomimetic arteriole for studying pulmonary hypertension. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.568.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anil Bhatta
- Anesthesiology and Critical Care MedicineJohns Hopkins UniversityBaltimoreMD
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Jayson V. Pagaduan
- Anesthesiology and Critical Care MedicineJohns Hopkins UniversityBaltimoreMD
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Xing Chen
- Anesthesiology and Critical Care MedicineJohns Hopkins UniversityBaltimoreMD
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Hoku West‐Foyle
- Biomedical EngineeringJohns Hopkins UniversityBaltimoreMD
- Cell BiologyJohns Hopkins UniversityBaltimoreMD
| | - Annie Hou
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Jiayu Liu
- Mechanical EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Qianru Jin
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Thao D. Nguyen
- Mechanical EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Scot Kuo
- Biomedical EngineeringJohns Hopkins UniversityBaltimoreMD
- Cell BiologyJohns Hopkins UniversityBaltimoreMD
| | - Dan Berkowitz
- Anesthesiology and Critical Care MedicineJohns Hopkins UniversityBaltimoreMD
- Biomedical EngineeringJohns Hopkins UniversityBaltimoreMD
| | - David H. Gracias
- Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMD
| | - Lewis H. Romer
- Anesthesiology and Critical Care MedicineJohns Hopkins UniversityBaltimoreMD
- Biomedical EngineeringJohns Hopkins UniversityBaltimoreMD
- Cell BiologyJohns Hopkins UniversityBaltimoreMD
- Pediatrics and the Center for Cell DynamicsJohns Hopkins UniversityBaltimoreMD
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16
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Bernier ML, Jacob AI, Collaco JM, McGrath-Morrow SA, Romer LH, Unegbu CC. Perioperative events in children with pulmonary hypertension undergoing non-cardiac procedures. Pulm Circ 2017; 8:2045893217738143. [PMID: 28971729 PMCID: PMC5731725 DOI: 10.1177/2045893217738143] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Prior limited research indicates that children with pulmonary hypertension (PH) have higher rates of adverse perioperative outcomes when undergoing non-cardiac procedures and cardiac catheterizations. We examined a single-center retrospective cohort of children with active or pharmacologically controlled PH who underwent cardiac catheterization or non-cardiac surgery during 2006–2014. Preoperative characteristics and perioperative courses were examined to determine relationships between the severity or etiology of PH, type of procedure, and occurrence of major and minor events. We identified 77 patients who underwent 148 procedures at a median age of six months. The most common PH etiologies were bronchopulmonary dysplasia (46.7%), congenital heart disease (29.9%), and congenital diaphragmatic hernia (14.3%). Cardiac catheterizations (39.2%), and abdominal (29.1%) and central venous access (8.9%) were the most common procedures. Major events included failed planned extubation (5.6%), postoperative cardiac arrest (4.7%), induction or intraoperative cardiac arrest (2%), and postoperative death (1.4%). Major events were more frequent in patients with severe baseline PH (P = 0.006) and the incidence was associated with procedure type (P = 0.05). Preoperative inhaled nitric oxide and prostacyclin analog therapies were associated with decreased incidence of minor events (odds ratio [OR] = 0.32, P = 0.046 and OR = 0.24, P = 0.008, respectively), but no change in the incidence of major events. PH etiology was not associated with events (P = 0.24). Children with PH have increased risk of perioperative complications; cardiac arrest and death occur more frequently in patients with severe PH and those undergoing thoracic procedures. Risk may be modified by using preoperative pulmonary vasodilator therapy and lends itself to further prospective studies.
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Affiliation(s)
- Meghan L Bernier
- 1 Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ariel I Jacob
- 1 Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joseph M Collaco
- 2 Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Lewis H Romer
- 1 Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,2 Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,3 Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,4 Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,5 Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chinwe C Unegbu
- 6 Division of Anesthesiology, Sedation and Perioperative Medicine, Children's National Health System, Washington, DC, USA
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17
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Kwag HR, Serbo JV, Korangath P, Sukumar S, Romer LH, Gracias DH. A Self-Folding Hydrogel In Vitro Model for Ductal Carcinoma. Tissue Eng Part C Methods 2016; 22:398-407. [PMID: 26831041 DOI: 10.1089/ten.tec.2015.0442] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A significant challenge in oncology is the need to develop in vitro models that accurately mimic the complex microenvironment within and around normal and diseased tissues. Here, we describe a self-folding approach to create curved hydrogel microstructures that more accurately mimic the geometry of ducts and acini within the mammary glands, as compared to existing three-dimensional block-like models or flat dishes. The microstructures are composed of photopatterned bilayers of poly (ethylene glycol) diacrylate (PEGDA), a hydrogel widely used in tissue engineering. The PEGDA bilayers of dissimilar molecular weights spontaneously curve when released from the underlying substrate due to differential swelling ratios. The photopatterns can be altered via AutoCAD-designed photomasks so that a variety of ductal and acinar mimetic structures can be mass-produced. In addition, by co-polymerizing methacrylated gelatin (methagel) with PEGDA, microstructures with increased cell adherence are synthesized. Biocompatibility and versatility of our approach is highlighted by culturing either SUM159 cells, which were seeded postfabrication, or MDA-MB-231 cells, which were encapsulated in hydrogels; cell viability is verified over 9 and 15 days, respectively. We believe that self-folding processes and associated tubular, curved, and folded constructs like the ones demonstrated here can facilitate the design of more accurate in vitro models for investigating ductal carcinoma.
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Affiliation(s)
- Hye Rin Kwag
- 1 Department of Chemical and Biomolecular Engineering, Johns Hopkins University , Baltimore, Maryland
| | - Janna V Serbo
- 2 Department of Biomedical Engineering, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Preethi Korangath
- 3 Department of Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Saraswati Sukumar
- 3 Department of Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Lewis H Romer
- 2 Department of Biomedical Engineering, Johns Hopkins University School of Medicine , Baltimore, Maryland.,4 Department of Anesthesiology and Critical Care Medicine, Cell Biology, Pediatrics, Center for Cell Dynamics, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - David H Gracias
- 1 Department of Chemical and Biomolecular Engineering, Johns Hopkins University , Baltimore, Maryland.,5 Department of Materials Science and Engineering, Johns Hopkins University , Baltimore, Maryland
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Serbo JV, Kuo S, Lewis S, Lehmann M, Li J, Gracias DH, Romer LH. Patterning of Fibroblast and Matrix Anisotropy within 3D Confinement is Driven by the Cytoskeleton. Adv Healthc Mater 2016; 5:146-58. [PMID: 26033825 PMCID: PMC5817161 DOI: 10.1002/adhm.201500030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/12/2015] [Indexed: 12/16/2022]
Abstract
Effects of 3D confinement on cellular growth and matrix assembly are important in tissue engineering, developmental biology, and regenerative medicine. Polydimethylsiloxane wells with varying anisotropy are microfabicated using soft-lithography. Microcontact printing of bovine serum albumin is used to block cell adhesion to surfaces between wells. The orientations of fibroblast stress fibers, microtubules, and fibronectin fibrils are examined 1 day after cell seeding using laser scanning confocal microscopy, and anisotropy is quantified using a custom autocorrelation analysis. Actin, microtubules, and fibronectin exhibit higher anisotropy coefficients for cells grown in rectangular wells with aspect ratios of 1:4 and 1:8, as compared to those in wells with lower aspect ratios or in square wells. The effects of disabling individual cytoskeletal components on fibroblast responses to anisotropy are then tested by applying actin or microtubule polymerization inhibitors, Rho kinase inhibitor, or by siRNA-mediated knockdown of AXL or cofilin-1. Latrunculin A decreases cytoskeletal and matrix anisotropy, nocodazole ablates both, and Y27632 mutes cellular polarity while decreasing matrix anisotropy. AXL siRNA knockdown has little effect, as does siRNA knockdown of cofilin-1. These data identify several specific cytoskeletal strategies as targets for the manipulation of anisotropy in 3D tissue constructs.
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Affiliation(s)
- Janna V. Serbo
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Scot Kuo
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shawna Lewis
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Matthew Lehmann
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jiuru Li
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - David H. Gracias
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Lewis H. Romer
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Abstract
BACKGROUND AND OBJECTIVES Pulmonary hypertension (PH) has been associated with substantial morbidity and mortality in children, but existing analyses of inpatient care are limited to small single-institution series or focused registries representative of selected patient subgroups. We examined US national data on pediatric PH hospitalizations to determine trends in volume, demographics, procedures performed during admission, and resource utilization. METHODS Retrospective cohort study using a national administrative database of pediatric hospital discharges: the Kids' Inpatient Database. RESULTS Children with PH accounted for 0.13% of the 43 million pediatric hospitalizations in the United States between 1997 and 2012, and discharges demonstrated an increasing trend over the study period (P < .0001). Cumulative, inflation-adjusted national hospital charges for PH hospitalizations rose (P = .0003) from $926 million in 1997 to $3.12 billion in 2012. Patients with PH without associated congenital heart disease (CHD) comprised an increasing and majority (56.4%) proportion over the study period (P < .0001), children without associated CHD admitted at urban teaching hospitals comprised the fastest-growing subgroup. In-hospital, all-cause mortality was high (5.9%) in children with PH, but demonstrated a decreasing trend (P < .0001). CONCLUSIONS Morbidity and mortality of pediatric PH continue to represent substantial and growing health care burdens. Shifts in case mix toward PH not associated with CHD, toward noncardiac procedures, and toward care in urban teaching hospitals will increase pressure to manage resource utilization in this small but growing patient group and to improve expertise and define excellence in PH care across a wide range of clinical settings.
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Affiliation(s)
| | | | | | | | - Lewis H Romer
- Departments of Anesthesiology and Critical Care Medicine, Pediatrics, Biomedical Engineering, and Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Pandey D, Hori D, Kim JH, Bergman Y, Berkowitz DE, Romer LH. Abstract 575: NEDDylation Promotes Endothelial Dysfunction: A Role for HDAC2. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Emerging evidence strongly supports a role for HDAC2 in the transcriptional regulation of endothelial genes and vascular function. We have recently demonstrated that HDAC2 reciprocally regulates the transcription of Arginase2, which is itself a critical modulator of endothelial function via eNOS. Moreover HDAC2 levels are decreased in response to the atherogenic stimulus OxLDL via a mechanism that is apparently dependent upon proteasomal degradation. NEDDylation is a post-translational protein modification that is tightly linked to ubiquitination and thereby protein degradation. We propose that changes in NEDDylation may modulate vascular endothelial function in part through alterations in the proteasomal degradation of HDAC2. In HAEC, OxLDL exposure augmented global protein NEDDylation. Pre-incubation of mouse aortic rings with the NEDDylation activating enzyme inhibitor, MLN4924, prevented OxLDL-induced endothelial dysfunction. In HAEC, MLN enhanced HDAC2 abundance, decreased expression and activity of Arg2, and blocked OxLDL-mediated reduction of HDAC2. Additionally, HDAC2 was shown to be a substrate for NEDD8 conjugation and this interaction was potentiated by OxLDL. Further, HDAC2 levels were reciprocally regulated by ectopic expression of NEDD8 and the de-NEDDylating enzyme SENP8. Our findings indicate that the observed improvement in endothelial dysfunction with inhibition of NEDDylation activating enzyme is likely due to an HDAC2-dependent decrease in Arginase2. NEDDylation activating enzyme may therefore be a novel target in endothelial dysfunction and atherogenesis.
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Affiliation(s)
| | - Daijiro Hori
- Sch of Medicine, Johns Hopkins Univ, Baltimore, MD
| | - Jae H Kim
- Sch of Medicine, Johns Hopkins Univ, Baltimore, MD
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Pandey D, Hori D, Kim JH, Bergman Y, Berkowitz DE, Romer LH. NEDDylation promotes endothelial dysfunction: a role for HDAC2. J Mol Cell Cardiol 2015; 81:18-22. [PMID: 25655932 DOI: 10.1016/j.yjmcc.2015.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/23/2015] [Accepted: 01/26/2015] [Indexed: 01/25/2023]
Abstract
Emerging evidence strongly supports a role for HDAC2 in the transcriptional regulation of endothelial genes and vascular function. We have recently demonstrated that HDAC2 reciprocally regulates the transcription of Arginase2, which is itself a critical modulator of endothelial function via eNOS. Moreover HDAC2 levels are decreased in response to the atherogenic stimulus OxLDL via a mechanism that is apparently dependent upon proteasomal degradation. NEDDylation is a post-translational protein modification that is tightly linked to ubiquitination and thereby protein degradation. We propose that changes in NEDDylation may modulate vascular endothelial function in part through alterations in the proteasomal degradation of HDAC2. In HAEC, OxLDL exposure augmented global protein NEDDylation. Pre-incubation of mouse aortic rings with the NEDDylation activating enzyme inhibitor, MLN4924, prevented OxLDL-induced endothelial dysfunction. In HAEC, MLN enhanced HDAC2 abundance, decreased expression and activity of Arginase2, and blocked OxLDL-mediated reduction of HDAC2. Additionally, HDAC2 was shown to be a substrate for NEDD8 conjugation and this interaction was potentiated by OxLDL. Further, HDAC2 levels were reciprocally regulated by ectopic expression of NEDD8 and the de-NEDDylating enzyme SENP8. Our findings indicate that the observed improvement in endothelial dysfunction with inhibition of NEDDylation activating enzyme is likely due to an HDAC2-dependent decrease in Arginase2. NEDDylation activating enzyme may therefore be a novel target in endothelial dysfunction and atherogenesis.
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Affiliation(s)
- Deepesh Pandey
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA
| | - Daijiro Hori
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA
| | - Jae Hyung Kim
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA
| | - Yehudit Bergman
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA
| | - Dan E Berkowitz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA
| | - Lewis H Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA; Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA.
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22
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Pandey D, Bhunia A, Oh YJ, Chang F, Bergman Y, Kim JH, Serbo J, Boronina TN, Cole RN, Van Eyk J, Remaley AT, Berkowitz DE, Romer LH. OxLDL triggers retrograde translocation of arginase2 in aortic endothelial cells via ROCK and mitochondrial processing peptidase. Circ Res 2014; 115:450-9. [PMID: 24903103 PMCID: PMC8760889 DOI: 10.1161/circresaha.115.304262] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Increased arginase activity contributes to endothelial dysfunction by competition for l-arginine substrate and reciprocal regulation of nitric oxide synthase (NOS). The rapid increase in arginase activity in human aortic endothelial cells exposed to oxidized low-density lipoprotein (OxLDL) is consistent with post-translational modification or subcellular trafficking. OBJECTIVE To test the hypotheses that OxLDL triggers reverse translocation of mitochondrial arginase 2 (Arg2) to cytosol and Arg2 activation, and that this process is dependent on mitochondrial processing peptidase, lectin-like OxLDL receptor-1 receptor, and rho kinase. METHODS AND RESULTS OxLDL-triggered translocation of Arg2 from mitochondria to cytosol in human aortic endothelial cells and in murine aortic intima with a concomitant rise in arginase activity. All of these changes were abolished by inhibition of mitochondrial processing peptidase or by its siRNA-mediated knockdown. Rho kinase inhibition and the absence of the lectin-like OxLDL receptor-1 in knockout mice also ablated translocation. Aminoterminal sequencing of Arg2 revealed 2 candidate mitochondrial targeting sequences, and deletion of either of these confined Arg2 to the cytoplasm. Inhibitors of mitochondrial processing peptidase or lectin-like OxLDL receptor-1 knockout attenuated OxLDL-mediated decrements in endothelial-specific NO production and increases in superoxide generation. Finally, Arg2(-/-) mice bred on an ApoE(-/-) background showed reduced plaque load, reduced reactive oxygen species production, enhanced NO, and improved endothelial function when compared with ApoE(-/-) controls. CONCLUSIONS These data demonstrate dual distribution of Arg2, a protein with an unambiguous mitochondrial targeting sequence, in mammalian cells, and its reverse translocation to cytoplasm by alterations in the extracellular milieu. This novel molecular mechanism drives OxLDL-mediated arginase activation, endothelial NOS uncoupling, endothelial dysfunction, and atherogenesis.
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Affiliation(s)
- Deepesh Pandey
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Anil Bhunia
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Young Jun Oh
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Fumin Chang
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Yehudit Bergman
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Jae Hyung Kim
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Janna Serbo
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Tatiana N Boronina
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Robert N Cole
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Jennifer Van Eyk
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Alan T Remaley
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Dan E Berkowitz
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Lewis H Romer
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
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Teo BKK, Wong ST, Lim CK, Kung TYS, Yap CH, Ramagopal Y, Romer LH, Yim EKF. Nanotopography modulates mechanotransduction of stem cells and induces differentiation through focal adhesion kinase. ACS Nano 2013; 7:4785-98. [PMID: 23672596 DOI: 10.1021/nn304966z] [Citation(s) in RCA: 288] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Regulated biophysical cues, such as nanotopography, have been shown to be integral for tissue regeneration and embryogenesis in the stem cell niche. Tissue homeostasis involves the interaction of multipotent cells with nanoscaled topographical features in their ECM to regulate aspects of cell behavior. Synthetic nanostructures can drive specific cell differentiation, but the sensing mechanisms for nanocues remain poorly understood. Here, we report that nanotopography-induced human mesenchymal stem cell (hMSC) differentiation through cell mechanotransduction is modulated by the integrin-activated focal adhesion kinase (FAK). On nanogratings with 250 nm line width on polydimethylsiloxane, hMSCs developed aligned stress fibers and showed an upregulation of neurogenic and myogenic differentiation markers. The observed cellular focal adhesions within these cells were also significantly smaller and more elongated on the nanogratings compared to microgratings or unpatterned control. In addition, our mechanistic study confirmed that this regulation was dependent upon actomyosin contractility, suggesting a direct force-dependent mechanism. The topography-induced differentiation was observed on different ECM compositions but the response was not indicative of a direct ECM-induced hMSC differentiation pathway. FAK phosphorylation was required for topography-induced hMSC differentiation while FAK overexpression overruled the topographical cues in determining cell lineage bias. The results indicated that FAK activity had a direct impact on topography-induced gene expression, and that this effect of FAK was independent of cell shape. These findings suggest that hMSC sense and transduce nanotopographical signals through focal adhesions and actomyosin cytoskeleton contractility to induce differential gene expression.
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Affiliation(s)
- Benjamin Kim Kiat Teo
- Department of Bioengineering, National University of Singapore, 9 Engineering Drive 1, EA 03-12, Singapore 117576, Singapore
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Collaco JM, Romer LH, Stuart BD, Coulson JD, Everett AD, Lawson EE, Brenner JI, Brown AT, Nies MK, Sekar P, Nogee LM, McGrath-Morrow SA. Frontiers in pulmonary hypertension in infants and children with bronchopulmonary dysplasia. Pediatr Pulmonol 2012; 47:1042-53. [PMID: 22777709 PMCID: PMC3963167 DOI: 10.1002/ppul.22609] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 05/19/2012] [Indexed: 12/23/2022]
Abstract
Pulmonary hypertension (PH) is an increasingly recognized complication of premature birth and bronchopulmonary dysplasia (BPD), and is associated with increased morbidity and mortality. Extreme phenotypic variability exists among preterm infants of similar gestational ages, making it difficult to predict which infants are at increased risk for developing PH. Intrauterine growth retardation or drug exposures, postnatal therapy with prolonged positive pressure ventilation, cardiovascular shunts, poor postnatal lung and somatic growth, and genetic or epigenetic factors may all contribute to the development of PH in preterm infants with BPD. In addition to the variability of severity of PH, there is also qualitative variability seen in PH, such as the variable responses to vasoactive medications. To reduce the morbidity and mortality associated with PH, a multi-pronged approach is needed. First, improved screening for and increased recognition of PH may allow for earlier treatment and better clinical outcomes. Second, identification of both prenatal and postnatal risk factors for the development of PH may allow targeting of therapy and resources for those at highest risk. Third, understanding the pathophysiology of the preterm pulmonary vascular bed may help improve outcomes through recognizing pathways that are dysregulated in PH, identifying novel biomarkers, and testing novel treatments. Finally, the recognition of conditions and exposures that may exacerbate or lead to recurrent PH is needed to help with developing treatment guidelines and preventative strategies that can be used to reduce the burden of disease.
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Affiliation(s)
- Joseph M Collaco
- Eudowood Division of Pediatric Respiratory Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-2533, USA
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Brown AT, Gillespie JV, Miquel-Verges F, Holmes K, Ravekes W, Spevak P, Brady K, Easley RB, Golden WC, McNamara L, Veltri MA, Lehmann CU, McMillan KN, Schwartz JM, Romer LH. Inhaled epoprostenol therapy for pulmonary hypertension: Improves oxygenation index more consistently in neonates than in older children. Pulm Circ 2012; 2:61-6. [PMID: 22558521 PMCID: PMC3342750 DOI: 10.4103/2045-8932.94835] [Citation(s) in RCA: 17] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The purpose of this study was to determine the efficacy of inhaled epoprostenol for treatment of acute pulmonary hypertension (PH) in pediatric patients and to formulate a plan for a prospective, randomized study of pulmonary vasodilator therapy in this population. Inhaled epoprostenol is an effective treatment for pediatric PH. A retrospective chart review was conducted of all pediatric patients who received inhaled epoprostenol at a tertiary care hospital between October 2005 and August 2007. The study population was restricted to all patients under 18 years of age who received inhaled epoprostenol for greater than 1 hour and had available data for oxygenation index (OI) calculation. Arterial blood gas values and ventilator settings were collected immediately prior to epoprostenol initiation, and during epoprostenol therapy (as close to 12 hours after initiation as possible). Echocardiograms were reviewed during two time frames: Within 48 hours prior to therapy initiation and within 96 hours after initiation. Of the 20 patients in the study population, 13 were neonates, and the mean OI for these patients improved during epoprostenol administration (mean OI before and during therapy was 25.6±16.3 and 14.5±13.6, respectively, P=0.02). Mean OI for the seven patients greater than 30 days of age was not significantly different during treatment (mean OI before and during therapy was 29.6±15.0 and 25.6±17.8, P=0.56). Improvement in echocardiographic findings (evidence of decreased right-sided pressures or improved right ventricular function) was demonstrated in 20% of all patients. Inhaled epoprostenol is an effective therapy for the treatment of selected pediatric patients with acute PH. Neonates may benefit more consistently from this therapy than older infants and children. A randomized controlled trial is needed to discern the optimal role for inhaled prostanoids in the treatment of acute PH in childhood.
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Affiliation(s)
- Anna T Brown
- Department of Anesthesiology and Critical Care Medicine, Baltimore, Maryland, USA
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Soucy PA, Werbin J, Heinz W, Hoh JH, Romer LH. Microelastic properties of lung cell-derived extracellular matrix. Acta Biomater 2011; 7:96-105. [PMID: 20656080 DOI: 10.1016/j.actbio.2010.07.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 07/18/2010] [Accepted: 07/19/2010] [Indexed: 01/11/2023]
Abstract
The mechanical properties of the extracellular microenvironment regulate cell behavior, including migration, proliferation and morphogenesis. Although the elastic moduli of synthetic materials have been studied, little is known about the properties of naturally produced extracellular matrix. Here we have utilized atomic force microscopy to characterize the microelastic properties of decellularized cell-derived matrix from human pulmonary fibroblasts. This heterogeneous three-dimensional matrix had an average thickness of 5 ± 0.4 μm and a Young's modulus of 105 ± 14 Pa. Ascorbate treatment of the lung fibroblasts prior to extraction produced a twofold increase in collagen I content, but did not affect the stiffness of the matrices compared with matrices produced in standard medium. However, fibroblast-derived matrices that were crosslinked with glutaraldehyde demonstrated a 67% increase in stiffness. This work provides a microscale characterization of fibroblast-derived matrix mechanical properties. An accurate understanding of native three-dimensional extracellular microenvironments will be essential for controlling cell responses in tissue engineering applications.
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27
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Yang CP, Leung J, Hunt EA, Serwint J, Norvell M, Keene EA, Romer LH. Pediatric residents do not feel prepared for the most unsettling situations they face in the pediatric intensive care unit. J Palliat Med 2010; 14:25-30. [PMID: 21054202 DOI: 10.1089/jpm.2010.0314] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Critical care rotations involve emotionally unsettling situations with greater frequency and intensity than those that are encountered in other portions of residency training. New approaches are needed to optimize the preparation and professionalism of postgraduate medical trainees when managing crisis management scenarios. METHODS An anonymous survey was conducted that focused on preparedness for dealing with emotionally unsettling situations, training preferences for these encounters, and the utility of resource personnel. A total of 58% of four classes of pediatric residents responded over a 2-year period. RESULTS Pediatric residents in our program identified sudden patient death and conflicts about goals of care within the team as the most unsettling situations. These were also the scenarios with which they had the least experience and for which they felt least prepared. Team discussion was designated as the most helpful educational tool, in addition to a combination of didactic educational programs and end-of-rotation sessions. CONCLUSIONS The focus and design of clinical education programming on preparation for crisis management during the care of critically ill patients benefit from the incorporation of trainee perceptions of preparedness and the efficacy of educational formats. Trainee feedback in these areas can be harnessed as a continuous quality improvement tool and as a metric of success in meeting professional training goals.
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Affiliation(s)
- Chris P Yang
- Department of Anesthesiology and Critical Care Medicine, John Hopkins University School of Medicine , Baltimore, Maryland, USA.
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28
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Ryoo S, Bhunia A, Chang F, Shoukas A, Berkowitz DE, Romer LH. OxLDL-dependent activation of arginase II is dependent on the LOX-1 receptor and downstream RhoA signaling. Atherosclerosis 2010; 214:279-87. [PMID: 21130456 DOI: 10.1016/j.atherosclerosis.2010.10.044] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/17/2010] [Accepted: 10/27/2010] [Indexed: 01/01/2023]
Abstract
AIMS Arginase II regulates NOS activity by competing for the substrate l-arginine. Oxidized LDL (OxLDL) is a proatherogenic molecule that activates arginase II. We tested the hypotheses that OxLDL-dependent arginase II activation occurs through a specific receptor, and via a Rho GTPase effector mechanism that is inhibited by statins. METHODS AND RESULTS Arginase II activation by OxLDL was attenuated following preincubation with the LOX-1 receptor-blocking antibody JTX92. This also prevented the dissociation of arginase II from microtubules. LOX-1(-/-) mice failed to exhibit the increased arginase II activity seen in WT mice fed a high cholesterol diet. Furthermore, endothelium from LOX-1(-/-) mice failed to demonstrate the diet-dependent reduction in NO and increase in ROS that were observed in WT mice. OxLDL induced Rho translocation to the membrane and Rho activation, and these effects were inhibited by pretreatment with JTX92 or statins. Transfection with siRNA for RhoA, or inhibition of ROCK both decreased OxLDL-stimulated arginase II activation. Preincubation with simvastatin or lovastatin blocked OxLDL-induced dissociation of arginase II from microtubules and prevented microtubule depolymerization. CONCLUSIONS This study provides a new focus for preventive therapy for atherosclerotic disease by delineating a clearer path from OxLDL through the endothelial cell LOX-1 receptor, RhoA, and ROCK, to the activation of arginase II, downregulation of NO, and vascular dysfunction.
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Affiliation(s)
- Sungwoo Ryoo
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904, United States
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29
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Soucy KG, Attarzadeh DO, Ramachandran R, Soucy PA, Romer LH, Shoukas AA, Berkowitz DE. Single exposure to radiation produces early anti-angiogenic effects in mouse aorta. Radiat Environ Biophys 2010; 49:397-404. [PMID: 20401726 DOI: 10.1007/s00411-010-0287-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 04/05/2010] [Indexed: 05/29/2023]
Abstract
Radiation exposure can increase the risk for many non-malignant physiological complications, including cardiovascular disease. We have previously demonstrated that ionizing radiation can induce endothelial dysfunction, which contributes to increased vascular stiffness. In this study, we demonstrate that gamma radiation exposure reduced endothelial cell viability or proliferative capacity using an in vitro aortic angiogenesis assay. Segments of mouse aorta were embedded in a Matrigel-media matrix 1 day after mice received whole-body gamma irradiation between 0 and 20 Gy. Using three-dimensional phase contrast microscopy, we quantified cellular outgrowth from the aorta. Through fluorescent imaging of embedded aortas from Tie2GFP transgenic mice, we determined that the cellular outgrowth is primarily of endothelial cell origin. Significantly less endothelial cell outgrowth was observed in aortas of mice receiving radiation of 5, 10, and 20 Gy radiation, suggesting radiation-induced endothelial injury. Following 0.5 and 1 Gy doses of whole-body irradiation, reduced outgrowth was still detected. Furthermore, outgrowth was not affected by the location of the aortic segments excised along the descending aorta. In conclusion, a single exposure to gamma radiation significantly reduces endothelial cell outgrowth in a dose-dependent manner. Consequently, radiation exposure may inhibit re-endothelialization or angiogenesis after a vascular injury, which would impede vascular recovery.
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Affiliation(s)
- Kevin G Soucy
- Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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30
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Yoshimura K, Meckel KF, Laird LS, Chia CY, Park JJ, Olino KL, Tsunedomi R, Harada T, Iizuka N, Hazama S, Kato Y, Keller JW, Thompson JM, Chang F, Romer LH, Jain A, Iacobuzio-Donahue C, Oka M, Pardoll DM, Schulick RD. Integrin alpha2 mediates selective metastasis to the liver. Cancer Res 2009; 69:7320-8. [PMID: 19738067 DOI: 10.1158/0008-5472.can-09-0315] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cancers display distinct patterns of organ-specific metastasis. Comparative analysis of a broad array of cell membrane molecules on a liver-metastasizing subline of B16 melanoma versus the parental B16-F0 revealed unique up-regulation of integrin alpha2. The direct role of integrin alpha2 in hepatic metastasis was shown by comparison of high versus low-expressing populations, antibody blockade, and ectopic expression. Integrin alpha2-mediated binding to collagen type IV (highly exposed in the liver sinusoids) and collagen type IV-dependent activation of focal adhesion kinase are both known to be important in the metastatic process. Analysis of primary colorectal cancers as well as coexisting liver and lung metastases from individual patients suggests that integrin alpha2 expression contributes to liver metastasis in human colorectal cancer. These findings define integrin alpha2 as a molecule conferring selective potential for formation of hepatic metastasis, as well as a possible target to prevent their formation.
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Affiliation(s)
- Kiyoshi Yoshimura
- Department of Surgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, 600 North Wolfe Street, Blalock 685, Baltimore, MD 21287, USA
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31
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Soucy PA, Romer LH. Endothelial cell adhesion, signaling, and morphogenesis in fibroblast-derived matrix. Matrix Biol 2009; 28:273-83. [DOI: 10.1016/j.matbio.2009.04.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 04/07/2009] [Accepted: 04/07/2009] [Indexed: 10/20/2022]
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Abstract
One powerful approach to understanding how cells process spatially variant signals is based on using micropatterned substrates to control the distribution of signaling molecules. However, quantifying spatially complex signals requires an appropriate metric. Here we propose that the Shannon information theory formalism provides a robust and useful way to quantify the organization of proteins in micropatterned systems. To demonstrate the use of informational entropy as a metric, we produced patterns of lines of fibronectin with varying information content. Fibroblasts grown on these patterns were sensitive to very small changes in informational entropy (6.6 bits), and the responses depended on the scale of the pattern.
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Affiliation(s)
- Jeffrey L Werbin
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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33
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Usatyuk PV, Romer LH, He D, Parinandi NL, Kleinberg ME, Zhan S, Jacobson JR, Dudek SM, Pendyala S, Garcia JGN, Natarajan V. Regulation of hyperoxia-induced NADPH oxidase activation in human lung endothelial cells by the actin cytoskeleton and cortactin. J Biol Chem 2007; 282:23284-95. [PMID: 17562703 DOI: 10.1074/jbc.m700535200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although the actin cytoskeleton has been implicated in the control of NADPH oxidase in phagocytosis, very little is known about the cytoskeletal regulation of endothelial NADPH oxidase assembly and activation. Here, we report a role for cortactin and the tyrosine phosphorylation of cortactin in hyperoxia-induced NADPH oxidase activation and ROS production in human pulmonary artery ECs (HPAECs). Exposure of HPAECs to hyperoxia for 3 h induced NADPH oxidase activation, as demonstrated by enhanced superoxide production. Hyperoxia also caused a thickening of the subcortical dense peripheral F-actin band and increased the localization of cortactin in the cortical regions and lamellipodia at cell-cell borders that protruded under neighboring cells. Pretreatment of HPAECs with the actin-stabilizing agent phallacidin attenuated hyperoxia-induced cortical actin thickening and ROS production, whereas cytochalasin D and latrunculin A enhanced basal and hyperoxia-induced ROS formation. In HPAECs, a 3-h hyperoxic exposure enhanced the tyrosine phosphorylation of cortactin and interaction between cortactin and p47(phox), a subcomponent of the EC NADPH oxidase, when compared with normoxic cells. Furthermore, transfection of HPAECs with cortactin small interfering RNA or myristoylated cortactin Src homology domain 3 blocking peptide attenuated ROS production and the hyperoxia-induced translocation of p47(phox) to the cell periphery. Similarly, down-regulation of Src with Src small interfering RNA attenuated the hyperoxia-mediated phosphorylation of cortactin tyrosines and blocked the association of cortactin with actin and p47(phox). In addition, the hyperoxia-induced generation of ROS was significantly lower in ECs expressing a tyrosine-deficient mutant of cortactin than in vector control or wild-type cells. These data demonstrate a novel function for cortactin and actin in hyperoxia-induced activation of NADPH oxidase and ROS generation in human lung endothelial cells.
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Affiliation(s)
- Peter V Usatyuk
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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34
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Shin S, Paul-Satyaseela M, Lee JS, Romer LH, Kim KS. Corrigendum to “Focal adhesion is involved in type III group B streptococcal invasion of human brain microvascular endothelial cells”. Microb Pathog 2007. [DOI: 10.1016/j.micpath.2006.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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35
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Rundqvist J, Mendoza B, Werbin JL, Heinz WF, Lemmon C, Romer LH, Haviland DB, Hoh JH. High Fidelity Functional Patterns of an Extracellular Matrix Protein by Electron Beam-Based Inactivation. J Am Chem Soc 2006; 129:59-67. [PMID: 17199283 DOI: 10.1021/ja063698a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Controlling the organization of proteins on surfaces provides a powerful biochemical tool for determining how cells interpret the spatial distribution of local signaling molecules. Here, we describe a general high fidelity approach based on electron beam writing to pattern the functional properties of protein-coated surfaces at length scales ranging from tens of nanometers to millimeters. A silicon substrate is first coated with the extracellular matrix protein fibronectin, which is then locally inactivated by exposure to a highly focused electron beam. Biochemical inactivation of the protein is established by the loss of antibody binding to the fibronectin. Functional inactivation is determined by the inability of cells to spread or form focal adhesions on the inactivated substrate, resulting in cell shapes constrained to the pattern, while they do both (and are unconstrained) on the remaining fibronectin. These protein patterns have very high fidelity, and typical patterns agree with the input dimensions of the pattern to within 2%. Further, the feature edges are well defined and approach molecular dimensions in roughness. Inactivation is shown to be dose dependent with observable suppression of the specific binding at 2 microC cm(-2) and complete removal of biochemical activity at approximately 50 microC cm(-2) for 5 keV electrons. The critical dose for inactivation also depends on accelerating voltage, and complete loss of antibody binding was achieved at approximately 4-7 microC cm(-2) for 1 keV electrons, which corresponds to approximately 50-90 electrons per cross-sectional area of a whole fibronectin dimer and ~2-4 electrons per type III fibronectin domain. AFM analysis of the pattern surfaces revealed that electron beam exposure does not remove appreciable amounts of material from the surface, suggesting that the patterning mechanism involves local inactivation rather than the ablation that has been observed in several organic thin film systems.
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Affiliation(s)
- Jonas Rundqvist
- Nanostructure Physics, Royal Institute of Technology, AlbaNova University Center, Roslagsvägen 30B, SE-106 91 Stockholm, Sweden
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36
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Abstract
FAK, a cytoplasmic protein tyrosine kinase, is activated and localized to focal adhesions upon cell attachment to extracellular matrix. FAK null cells spread poorly and exhibit altered focal adhesion turnover. Rac1 is a member of the Rho-family GTPases that promotes membrane ruffling, leading edge extension, and cell spreading. We investigated the activation and subcellular location of Rac1 in FAK null and FAK reexpressing fibroblasts. FAK reexpressers had a more robust pattern of Rac1 activation after cell adhesion to fibronectin than the FAK null cells. Translocation of Rac1 to focal adhesions was observed in FAK reexpressers, but seldom in FAK null cells. Experiments with constitutively active L61Rac1 and dominant negative N17Rac1 indicated that the activation state of Rac1 regulated its localization to focal adhesions. We demonstrated that FAK tyrosine-phosphorylated betaPIX and thereby increased its binding to Rac1. In addition, betaPIX facilitated the targeting of activated Rac1 to focal adhesions and the efficiency of cell spreading. These data indicate that FAK has a role in the activation and focal adhesion translocation of Rac1 through the tyrosine phosphorylation of betaPIX.
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Affiliation(s)
- Fumin Chang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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37
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Ryoo S, Lemmon CA, Soucy KG, Gupta G, White AR, Nyhan D, Shoukas A, Romer LH, Berkowitz DE. Oxidized low-density lipoprotein-dependent endothelial arginase II activation contributes to impaired nitric oxide signaling. Circ Res 2006; 99:951-60. [PMID: 17008605 DOI: 10.1161/01.res.0000247034.24662.b4] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oxidized low-density lipoprotein (OxLDL) impairs NO signaling and endothelial function, and contributes to the pathogenesis of atherosclerosis. Arginase reciprocally regulates NO levels in endothelial cells by competing with NO synthase for the substrate l-arginine. In human aortic endothelial cells, OxLDL stimulation increased arginase enzyme activity in a time- and dose-dependent manner. Arginase activity reached its maximum as early as 5 minutes, was maintained for a period of more than 48 hours, and was associated with a reciprocal decrease in NO metabolite (NOx [nitrite and nitrate]) production. Furthermore, OxLDL induced arginase II mRNA expression after 4 hours. Small interfering RNA targeted to arginase II decreased both the quantity and the activity of arginase from baseline, prevented OxLDL-dependent increases in arginase activity, and induced an increase in NOx production. Immunofluorescence analysis revealed an association of arginase II with the microtubule cytoskeleton. Microtubule disruption with nocodazole caused a dramatic redistribution of arginase II to a diffuse cytosolic pattern, increased arginase activity, and decreased NOx production, which was restored in the presence of the specific arginase inhibitor (S)-(2-boronoethyl)-l-cysteine (BEC). On the other hand, epothilone B prevented microtubule disruption and inhibited OxLDL-dependent increases in arginase activity and attenuated OxLDL-dependent decreases in NOx. Preincubation of rat aortic rings with OxLDL resulted in an increase in arginase activity and a decrease in NOx production. This was reversed by arginase inhibition with the BEC. Thus, OxLDLs increase arginase activity by a sequence of regulatory events that involve early activation through decreased association with microtubules and a later increase in transcription. Furthermore, increased arginase activity contributes to OxLDL-dependent impairment of NOx production. Arginase, therefore, represents a novel target for therapy in atherosclerosis.
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Affiliation(s)
- Sungwoo Ryoo
- Department of Anesthesiology, The Johns Hopkins Medical Institutions, Baltimore, MD, USA
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38
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Shin S, Paul-Satyaseela M, Maneesh PS, Lee JS, Romer LH, Kim KS. Focal adhesion kinase is involved in type III group B streptococcal invasion of human brain microvascular endothelial cells. Microb Pathog 2006; 41:168-73. [PMID: 16949788 DOI: 10.1016/j.micpath.2006.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 06/08/2006] [Accepted: 07/07/2006] [Indexed: 11/26/2022]
Abstract
Group B streptococcus (GBS), the leading cause of neonatal meningitis, has been shown to invade human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. GBS invasion of HBMEC has been shown to require the host cell actin cytoskeleton rearrangements. The present study examined the mechanisms underlying actin cytoskeleton rearrangements that are involved in type III GBS invasion of HBMEC. We showed that type III GBS invasion was inhibited by genistein, a general tyrosine kinase inhibitor (mean 54% invasion decrease at 100 microM), and LY294002, a phosphatidylinositol 3 (PI3) kinase inhibitor (mean 70% invasion decrease at 50 microM), but not by PP2, an inhibitor of the Src family tyrosine kinases. We subsequently showed that the focal adhesion kinase (FAK) was the one of the host proteins tyrosine phosphorylated by type III GBS. Over-expression of a dominant negative form of the FAK C-terminal domain significantly decreased type III GBS invasion of HBMEC (mean 51% invasion decrease). In addition, we showed that FAK phosphorylation correlated with its association of paxillin, an adapter protein of actin filament, and PI3-kinase subunit p85. This is the first demonstration that FAK phosphorylation and its association with paxillin and PI3 kinase play a key role in type III GBS invasion of HBMEC.
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Affiliation(s)
- Sooan Shin
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Park 256, Baltimore, MD 21287, USA
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39
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Pirone DM, Liu WF, Ruiz SA, Gao L, Raghavan S, Lemmon CA, Romer LH, Chen CS. An inhibitory role for FAK in regulating proliferation: a link between limited adhesion and RhoA-ROCK signaling. ACTA ACUST UNITED AC 2006; 174:277-88. [PMID: 16847103 PMCID: PMC2064187 DOI: 10.1083/jcb.200510062] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Focal adhesion kinase (FAK) transduces cell adhesion to the extracellular matrix into proliferative signals. We show that FAK overexpression induced proliferation in endothelial cells, which are normally growth arrested by limited adhesion. Interestingly, displacement of FAK from adhesions by using a FAK−/− cell line or by expressing the C-terminal fragment FRNK also caused an escape of adhesion-regulated growth arrest, suggesting dual positive and negative roles for FAK in growth regulation. Expressing kinase-dead FAK-Y397F in FAK−/− cells prevented uncontrolled growth, demonstrating the antiproliferative function of inactive FAK. Unlike FAK overexpression–induced growth, loss of growth control in FAK−/− or FRNK-expressing cells increased RhoA activity, cytoskeletal tension, and focal adhesion formation. ROCK inhibition rescued adhesion-dependent growth control in these cells, and expression of constitutively active RhoA or ROCK dysregulated growth. These findings demonstrate the ability of FAK to suppress and promote growth, and underscore the importance of multiple mechanisms, even from one molecule, to control cell proliferation.
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Affiliation(s)
- Dana M Pirone
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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40
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Abstract
The vascular wall contains intimal endothelium and medial smooth muscle that act as contiguous tissues with tight spatial and functional coordination in response to tonic and episodic input from the bloodstream and the surrounding parenchyma. Focal adhesions are molecular bridges between the intracellular and extracellular spaces that integrate a variety of environmental stimuli and mediate 2-way crosstalk between the extracellular matrix and the cytoskeleton. Focal adhesion components are targets for biochemical and mechanical stimuli that evoke crucial developmental and injury response mechanisms including cell growth, movement, and differentiation, and tailoring of the extracellular microenvironment. Focal adhesions provide the vascular wall constituents with flexible and specific tools for exchanging cues in a complex system. The molecular mechanisms that underlie these vital communications are detailed in this review with the goal of defining future targets for vascular tissue engineering and for the therapeutic modulation of disordered vascular growth, inflammation, thrombosis, and angiogenesis.
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Affiliation(s)
- Lewis H Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4904, USA.
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41
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Wadgaonkar R, Dudek SM, Zaiman AL, Linz-McGillem L, Verin AD, Nurmukhambetova S, Romer LH, Garcia JGN. Intracellular interaction of myosin light chain kinase with macrophage migration inhibition factor (MIF) in endothelium. J Cell Biochem 2005; 95:849-58. [PMID: 15838879 DOI: 10.1002/jcb.20472] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The endothelial cell Ca2+/calmodulin (CaM)-dependent myosin light chain kinase isoform (EC MLCK) is a multifunctional contractile effector involved in vascular barrier regulation, leukocyte diapedesis, apoptosis, and angiogenesis. The EC MLCK isoform and its splice variants contain a unique N-terminal sequence not present in the smooth muscle MLCK isoform (SM MLCK), which allows novel upregulation of MLCK activation by signaling cascades including p60src. The yeast two-hybrid assay system using the entire EC MLCK1 N-terminus (922 aa) as bait, identified additional stable MLCK binding partners including the 12 KDa macrophage migration inhibitory factor (MIF). This finding was confirmed by cross immunoprecipitation assays under non-denaturing conditions and by GST pull down experiments using GST-N-terminal MLCK (#1-923) and MLCK N-terminal deletion mutants in TNFalpha- and thrombin-stimulated endothelium. This EC MLCK-MIF interaction was shown biochemically and by immunofluorescent microscopy to be enhanced in TNFalpha- and thrombin-stimulated endothelium, both of which induce increased MLCK activity. Thrombin induced the colocalization of an epitope-tagged, full-length MIF fusion protein with phosphorylated MLC along peripheral actin stress fibers. Together these studies suggest that the novel interaction between MIF and MLCK may have important implications for the regulation of both non-muscle cytoskeletal dynamics as well as pathobiologic vascular events that involve MLCK.
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Affiliation(s)
- Raj Wadgaonkar
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA
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Kolosova IA, Mirzapoiazova T, Adyshev D, Usatyuk P, Romer LH, Jacobson JR, Natarajan V, Pearse DB, Garcia JGN, Verin AD. Signaling pathways involved in adenosine triphosphate-induced endothelial cell barrier enhancement. Circ Res 2005; 97:115-24. [PMID: 15994434 DOI: 10.1161/01.res.0000175561.55761.69] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Endothelial barrier dysfunction caused by inflammatory agonists is a frequent underlying cause of vascular leak and edema. Novel strategies to preserve barrier integrity could have profound clinical impact. Adenosine triphosphate (ATP) released from endothelial cells by shear stress and injury has been shown to protect the endothelial barrier in some settings. We have demonstrated that ATP and its nonhydrolyzed analogues enhanced barrier properties of cultured endothelial cell monolayers and caused remodeling of cell-cell junctions. Increases in cytosolic Ca2+ and Erk activation caused by ATP were irrelevant to barrier enhancement. Experiments using biochemical inhibitors or siRNA indicated that G proteins (specifically Galphaq and Galphai2), protein kinase A (PKA), and the PKA substrate vasodilator-stimulated phosphoprotein were involved in ATP-induced barrier enhancement. ATP treatment decreased phosphorylation of myosin light chain and specifically activated myosin-associated phosphatase. Depletion of Galphaq with siRNA prevented ATP-induced activation of myosin phosphatase. We conclude that the mechanisms of ATP-induced barrier enhancement are independent of intracellular Ca2+, but involve activation of myosin phosphatase via a novel G-protein-coupled mechanism and PKA.
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Affiliation(s)
- Irina A Kolosova
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Sui XF, Kiser TD, Hyun SW, Angelini DJ, Del Vecchio RL, Young BA, Hasday JD, Romer LH, Passaniti A, Tonks NK, Goldblum SE. Receptor protein tyrosine phosphatase micro regulates the paracellular pathway in human lung microvascular endothelia. Am J Pathol 2005; 166:1247-58. [PMID: 15793303 PMCID: PMC1602370 DOI: 10.1016/s0002-9440(10)62343-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The pulmonary vascular endothelial paracellular pathway and zonula adherens (ZA) integrity are regulated, in part, through protein tyrosine phosphorylation. ZA-associated protein tyrosine phosphatase (PTP)s are thought to counterregulate tyrosine phosphorylation events within the ZA multiprotein complex. One such receptor PTP, PTPmu, is highly expressed in lung tissue and is almost exclusively restricted to the endothelium. We therefore studied whether PTPmu, in pulmonary vascular endothelia, associates with and/or regulates both the tyrosine phosphorylation state of vascular endothelial (VE)-cadherin and the paracellular pathway. PTPmu was expressed in postconfluent human pulmonary artery and lung microvascular endothelial cells (ECs) where it was almost exclusively restricted to EC-EC boundaries. In human lung microvascular ECs, knockdown of PTPmu through RNA interference dramatically impaired barrier function. In immortalized human microvascular ECs, overexpression of wild-type PTPmu enhanced barrier function. PTPmu-VE-cadherin interactions were demonstrated through reciprocal co-immunoprecipitation assays and co-localization with double-label fluorescence microscopy. When glutathione S-transferase-PTPmu was incubated with purified recombinant VE-cadherin, and when glutathione S-transferase-VE-cadherin was incubated with purified recombinant PTPmu, PTPmu directly bound to VE-cadherin. Overexpression of wild-type PTPmu decreased tyrosine phosphorylation of VE-cadherin. Therefore, PTPmu is expressed in human pulmonary vascular endothelia where it directly binds to VE-cadherin and regulates both the tyrosine phosphorylation state of VE-cadherin and barrier integrity.
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Affiliation(s)
- Xiu Fen Sui
- Department of Medicine and Pathology, Division of Infectious Diseases and Pulmonary Medicine, Mucosal Biology Research Center, University of Maryland School of Medicine, 22 Penn St., Baltimore, MD 21201, USA
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Affiliation(s)
- K Burridge
- Department of Cell Biology and Anatomy, University of North Carolina at Chapel hill, Chapel Hill, North Carolina 27599, USA
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Lemmon CA, Sniadecki NJ, Ruiz SA, Tan JL, Romer LH, Chen CS. Shear force at the cell-matrix interface: enhanced analysis for microfabricated post array detectors. Mech Chem Biosyst 2005; 2:1-16. [PMID: 16708468 PMCID: PMC1480360] [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] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The interplay of mechanical forces between the extracellular environment and the cytoskeleton drives development, repair, and senescence in many tissues. Quantitative definition of these forces is a vital step in understanding cellular mechanosensing. Microfabricated post array detectors (mPADs) provide direct measurements of cell-generated forces during cell adhesion to extracellular matrix. A new approach to mPAD post labeling, volumetric imaging, and an analysis of post bending mechanics determined that cells apply shear forces and not point moments at the matrix interface. In addition, these forces could be accurately resolved from post deflections by using images of post tops and bases. Image analysis tools were then developed to increase the precision and throughput of post centroid location. These studies resulted in an improved method of force measurement with broad applicability and concise execution using a fully automated force analysis system. The new method measures cell-generated forces with less than 5% error and less than 90 seconds of computational time. Using this approach, we demonstrated direct and distinct relationships between cellular traction force and spread cell surface area for fibroblasts, endothelial cells, epithelial cells and smooth muscle cells.
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Affiliation(s)
- Christopher A Lemmon
- Dept. of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
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Rhoads JM, Chen W, Gookin J, Wu GY, Fu Q, Blikslager AT, Rippe RA, Argenzio RA, Cance WG, Weaver EM, Romer LH. Arginine stimulates intestinal cell migration through a focal adhesion kinase dependent mechanism. Gut 2004; 53:514-22. [PMID: 15016745 PMCID: PMC1774018 DOI: 10.1136/gut.2003.027540] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND L-Arginine is a nutritional supplement that may be useful for promoting intestinal repair. Arginine is metabolised by the oxidative deiminase pathway to form nitric oxide (NO) and by the arginase pathway to yield ornithine and polyamines. AIMS To determine if arginine stimulates restitution via activation of NO synthesis and/or polyamine synthesis. METHODS We determined the effects of arginine on cultured intestinal cell migration, NO production, polyamine levels, and activation of focal adhesion kinase, a key mediator of cell migration. RESULTS Arginine increased the rate of cell migration in a dose dependent biphasic manner, and was additive with bovine serum concentrate (BSC). Arginine and an NO donor activated focal adhesion kinase (a tyrosine kinase which localises to cell matrix contacts and mediates beta1 integrin signalling) after wounding. Arginine stimulated cell migration was dependent on focal adhesion kinase (FAK) signalling, as demonstrated using adenovirus mediated transfection with a kinase negative mutant of FAK. Arginine stimulated migration was dependent on NO production and was blocked by NO synthase inhibitors. Arginine dependent migration required synthesis of polyamines but elevating extracellular arginine concentration above 0.4 mM did not enhance cellular polyamine levels. CONCLUSIONS These results showed that L-arginine stimulates cell migration through NO and FAK dependent pathways and that combination therapy with arginine and BSC may enhance intestinal restitution via separate and convergent pathways.
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Affiliation(s)
- J M Rhoads
- Department of Pediatrics, and Center in Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, North Carolina, USA.
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Young BA, Sui X, Kiser TD, Hyun SW, Wang P, Sakarya S, Angelini DJ, Schaphorst KL, Hasday JD, Cross AS, Romer LH, Passaniti A, Goldblum SE. Protein tyrosine phosphatase activity regulates endothelial cell-cell interactions, the paracellular pathway, and capillary tube stability. Am J Physiol Lung Cell Mol Physiol 2003; 285:L63-75. [PMID: 12626337 DOI: 10.1152/ajplung.00423.2002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Protein tyrosine phosphorylation is tightly regulated through the actions of both protein tyrosine kinases and protein tyrosine phosphatases. In this study, we demonstrate that protein tyrosine phosphatase inhibition promotes tyrosine phosphorylation of endothelial cell-cell adherens junction proteins, opens an endothelial paracellular pathway, and increases both transendothelial albumin flux and neutrophil migration. Tyrosine phosphatase inhibition with sodium orthovanadate or phenylarsine oxide induced dose- and time-dependent increases in [14C]bovine serum albumin flux across postconfluent bovine pulmonary artery endothelial cell monolayers. These increases in albumin flux were coincident with actin reorganization and intercellular gap formation in both postconfluent monolayers and preformed endothelial cell capillary tubes. Vanadate (25 microM) increased tyrosine phosphorylation of endothelial cell proteins 12-fold within 1 h. Tyrosine phosphorylated proteins were immunolocalized to the intercellular boundaries, and several were identified as the endothelial cell-cell adherens junction proteins, vascular-endothelial cadherin, and beta-, gamma-, and p120-catenin as well as platelet endothelial cell adhesion molecule-1. Of note, these tyrosine phosphorylation events were not associated with disassembly of the adherens junction complex or its uncoupling from the actin cytoskeleton. The dose and time requirements for vanadate-induced increases in phosphorylation were comparable with those defined for increments in transendothelial [14C]albumin flux and neutrophil migration, and pretreatment with the tyrosine kinase inhibitor herbimycin A protected against these effects. These data suggest that protein tyrosine phosphatases and their substrates, which localize to the endothelial cell-cell boundaries, regulate adherens junctional integrity, the movement of macromolecules and cells through the endothelial paracellular pathway, and capillary tube stability.
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Affiliation(s)
- Bradford A Young
- Division of Infectious Diseases, Department of Veterans Affairs Medical Center, Baltimore 21201, USA
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Petrache I, Birukov K, Zaiman AL, Crow MT, Deng H, Wadgaonkar R, Romer LH, Garcia JGN. Caspase-dependent cleavage of myosin light chain kinase (MLCK) is involved in TNF-alpha-mediated bovine pulmonary endothelial cell apoptosis. FASEB J 2003; 17:407-16. [PMID: 12631580 DOI: 10.1096/fj.02-0672com] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cytoskeletal proteins are key participants in the cellular progression to apoptosis. Our previous work demonstrated the critical dependence of actomyosin rearrangement and MLC phosphorylation in TNF-alpha-induced endothelial cell apoptosis. As these events reflect the activation of the multifunctional endothelial cell (EC) MLCK isoform, we assessed the direct role of EC MLCK in the regulation of TNF-alpha-induced apoptosis. Bovine pulmonary artery endothelial cells expressing either an adenovirus encoding antisense MLCK cDNA (Ad.GFP-AS MLCK) or a dominant/negative EC MLCK construct (EC MLCK-ATPdel) resulted in marked reductions in MLCK activity and TNF-alpha-mediated apoptosis. In contrast, a constitutively active EC MLCK lacking the carboxyl-terminal autoinhibitory domains (EC MLCK-1745) markedly enhanced the apoptotic response to TNF-alpha. Immunostaining in GFP-EC MLCK-expressing cells revealed colocalization of caspase 8 and EC MLCK along actin stress fibers after TNF-alpha. TNF-alpha induced the caspase-dependent cleavage of EC MLCK-1745 in transfected endothelial cells, which was confirmed by mass spectroscopy with in vitro cleavage by caspase 3 at LKKD (D1703). The resulting MLCK fragments displayed significant calmodulin-independent kinase activity. These studies convincingly demonstrate that novel interactions between the apoptotic machinery and EC MLCK exist that regulate the endothelial contractile apparatus in TNF-alpha-induced apoptosis.
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Affiliation(s)
- Irina Petrache
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Cooley MA, Broome JM, Ohngemach C, Romer LH, Schaller MD. Paxillin binding is not the sole determinant of focal adhesion localization or dominant-negative activity of focal adhesion kinase/focal adhesion kinase-related nonkinase. Mol Biol Cell 2000; 11:3247-63. [PMID: 10982414 PMCID: PMC14989 DOI: 10.1091/mbc.11.9.3247] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The carboxy-terminal 150 residues of the focal adhesion kinase (FAK) comprise the focal adhesion-targeting sequence, which is responsible for its subcellular localization. The mechanism of focal adhesion targeting has not been fully elucidated. We describe a mutational analysis of the focal adhesion-targeting sequence of FAK to further examine the mechanism of focal adhesion targeting and explore additional functions encoded by the carboxy-terminus of FAK. The results demonstrate that paxillin binding is dispensable for focal adhesion targeting of FAK. Cell adhesion-dependent tyrosine phosphorylation strictly correlated with the ability of mutants to target to focal adhesions. Focal adhesion targeting was also a requirement for maximal FAK-dependent tyrosine phosphorylation of paxillin and FAK-related nonkinase (FRNK)-dependent inhibition of endogenous FAK function. However, there were additional requirements for these latter functions because we identified mutants that target to focal adhesions, yet are defective for the induction of paxillin phosphorylation or the dominant-negative function of FRNK. Furthermore, the paxillin-binding activity of FRNK mutants did not correlate with their ability to inhibit FAK, suggesting that FRNK has other targets in addition to paxillin.
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Affiliation(s)
- M A Cooley
- Departments of Cell Biology & Anatomy, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Gilmore AP, Metcalfe AD, Romer LH, Streuli CH. Integrin-mediated survival signals regulate the apoptotic function of Bax through its conformation and subcellular localization. J Cell Biol 2000; 149:431-46. [PMID: 10769034 PMCID: PMC2175159 DOI: 10.1083/jcb.149.2.431] [Citation(s) in RCA: 231] [Impact Index Per Article: 9.6] [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: 11/15/1999] [Accepted: 03/08/2000] [Indexed: 01/09/2023] Open
Abstract
Most normal cells require adhesion to extracellular matrix for survival, but the molecular mechanisms that link cell surface adhesion events to the intracellular apoptotic machinery are not understood. Bcl-2 family proteins regulate apoptosis induced by a variety of cellular insults through acting on internal membranes. A pro-apoptotic Bcl-2 family protein, Bax, is largely present in the cytosol of many cells, but redistributes to mitochondria after treatment with apoptosis-inducing drugs. Using mammary epithelial cells as a model for adhesion-regulated survival, we show that detachment from extracellular matrix induced a rapid translocation of Bax to mitochondria concurrent with a conformational change resulting in the exposure of its BH3 domain. Bax translocation and BH3 epitope exposure were reversible and occurred before caspase activation and apoptosis. Pp125FAK regulated the conformation of the Bax BH3 epitope, and PI 3-kinase and pp60src prevented apoptosis induced by defective pp125FAK signaling. Our results provide a mechanistic connection between integrin-mediated adhesion and apoptosis, through the kinase-regulated subcellular distribution of Bax.
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Affiliation(s)
- Andrew P. Gilmore
- School of Biological Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Anthony D. Metcalfe
- School of Biological Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Lewis H. Romer
- Departments of Cell Biology and Anatomy, Pediatrics, and Anesthesiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Charles H. Streuli
- School of Biological Sciences, University of Manchester, Manchester, M13 9PT, UK
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