1
|
Sorber R, Bowen CJ, Radomski SN, Shalhub S. Prevalence and outcomes of select rare vascular conditions in females: A descriptive review. Semin Vasc Surg 2023; 36:571-578. [PMID: 38030331 DOI: 10.1053/j.semvascsurg.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/19/2023] [Accepted: 10/04/2023] [Indexed: 12/01/2023]
Abstract
Rare vascular conditions frequently pose a diagnostic and therapeutic dilemma for health care providers. Several of these conditions have distinct relevance to females populations but, due to their infrequency, there has been little reported on the outcomes of rare vascular conditions specifically in females populations. We performed a literature review of a selection of three rare vascular conditions known to either disproportionately affect females (median arcuate ligament syndrome and fibromuscular dysplasia) or have unique manifestations in females populations (vascular Ehlers-Danlos syndrome). We performed a descriptive review of the literature focused on these three vascular conditions and identified aspects of the current available research describing sex-based differences in prevalence, any pathophysiology explaining the observed sex-based differences, and the contribution of sex to outcomes for each disease process. In addition, considerations for pregnant females with respect to each rare vascular disease process are discussed.
Collapse
Affiliation(s)
- Rebecca Sorber
- Division of Vascular Surgery and Endovascular Therapy, The Johns Hopkins Medical Institutions, Halsted 668, 600 N Wolfe Street, Baltimore, MD, 21287.
| | - Caitlin J Bowen
- Division of Pediatrics, Boston Children's Hospital, Boston, MA
| | - Shannon N Radomski
- Division of Vascular Surgery and Endovascular Therapy, The Johns Hopkins Medical Institutions, Halsted 668, 600 N Wolfe Street, Baltimore, MD, 21287
| | - Sherene Shalhub
- Division of Vascular Surgery, University of Oregon Health Sciences University, Portland, OR
| |
Collapse
|
2
|
Arnold JB, Bowen CJ, Chapman LS, Gates LS, Golightly YM, Halstead J, Hannan MT, Menz HB, Munteanu SE, Paterson KL, Roddy E, Siddle HJ, Thomas MJ. International Foot and Ankle Osteoarthritis Consortium review and research agenda for diagnosis, epidemiology, burden, outcome assessment and treatment. Osteoarthritis Cartilage 2022; 30:945-955. [PMID: 35176480 PMCID: PMC10464637 DOI: 10.1016/j.joca.2022.02.603] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [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] [Received: 11/25/2021] [Revised: 01/25/2022] [Accepted: 02/03/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To summarise the available evidence relating to the diagnosis, epidemiology, burden, outcome assessment and treatment of foot and ankle osteoarthritis (OA) and to develop an agenda to guide future research. METHOD Members of the International Foot and Ankle Osteoarthritis Consortium compiled a narrative summary of the literature which formed the basis of an interactive discussion at the Osteoarthritis Research Society International World Congress in 2021, during which a list of 24 research agenda items were generated. Following the meeting, delegates were asked to rank the research agenda items on a 0 to 100 visual analogue rating scale (0 = not at all important to 100 = extremely important). Items scoring a mean of 70 or above were selected for inclusion. RESULTS Of the 45 delegates who attended the meeting, 31 contributed to the agenda item scoring. Nineteen research agenda items met the required threshold: three related to diagnosis, four to epidemiology, four to burden, three to outcome assessment and five to treatment. CONCLUSIONS Key knowledge gaps related to foot and ankle OA were identified, and a comprehensive agenda to guide future research planning was developed. Implementation of this agenda will assist in improving the understanding and clinical management of this common and disabling, yet relatively overlooked condition.
Collapse
Affiliation(s)
- J B Arnold
- IIMPACT in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - C J Bowen
- School of Health Sciences, University of Southampton, Building 67, University Road, Southampton, SO17 1BJ, UK; Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, University of Southampton, Southampton, SO17 1BJ, UK
| | - L S Chapman
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - L S Gates
- School of Health Sciences, University of Southampton, Building 67, University Road, Southampton, SO17 1BJ, UK; Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, University of Southampton, Southampton, SO17 1BJ, UK
| | - Y M Golightly
- Department of Epidemiology, Gillings School of Global Public Health, Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, 3330 Thurston Building, CB 7280, Chapel Hill, NC 27599, USA
| | - J Halstead
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, LS2 9JT, UK; Podiatry Services, Leeds Community Healthcare NHS Trust, Leeds, LS6 1PF, UK
| | - M T Hannan
- Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Beth Israel Deaconess Medical Center, And Harvard Medical School, Boston, MA, 02108, USA
| | - H B Menz
- School of Allied Health, Human Services and Sport, La Trobe University, Melbourne, Victoria, 3086, Australia; Primary Care Centre Versus Arthritis, School of Medicine, Keele University, Keele, Staffordshire, ST5 5BG, UK.
| | - S E Munteanu
- School of Allied Health, Human Services and Sport, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - K L Paterson
- Centre for Health, Exercise and Sports Medicine, School of Health Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - E Roddy
- Primary Care Centre Versus Arthritis, School of Medicine, Keele University, Keele, Staffordshire, ST5 5BG, UK; Haywood Academic Rheumatology Centre, Midlands Partnership NHS Foundation Trust, Haywood Hospital, Burslem, Staffordshire, ST6 7AG, UK
| | - H J Siddle
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - M J Thomas
- Primary Care Centre Versus Arthritis, School of Medicine, Keele University, Keele, Staffordshire, ST5 5BG, UK; Haywood Academic Rheumatology Centre, Midlands Partnership NHS Foundation Trust, Haywood Hospital, Burslem, Staffordshire, ST6 7AG, UK
| |
Collapse
|
3
|
Cottrill EJ, Bowen CJ, Pennington ZA, Murray JA, Rajkovic CJ, Dietz HC, Sponseller PD. Tendon Healing in a Mouse Model of Loeys-Dietz Syndrome: Controlled Study Using a Patellar Tendon Transection Model. J Pediatr Orthop 2022; 42:e590-e595. [PMID: 35442932 DOI: 10.1097/bpo.0000000000002131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Loeys-Dietz syndrome (LDS) is a rare autosomal-dominant connective tissue disorder caused by genetic mutations in the transforming growth factor-β (TGFβ) signaling pathway. In addition to vascular malformations, patients with LDS commonly present with bone and tendon abnormalities, including joint laxity. While TGFβ signaling dysregulation has been implicated in many of these clinical manifestations, the degree to which it influences the tendinopathy and tendon healing issues in LDS has not been determined. METHODS Wound healing after patellar tendon transection was compared between wild-type (WT) and Tgfbr2-mutant (LDS) mice (7 mice per group). In all mice, the right patellar tendon was transected at midsubstance, while the left was untouched to serve as a control. Mice were euthanized 6 weeks after surgery. Tendon specimens were harvested for histopathologic grading according to a previously validated scoring metric, and gene expression levels of Mmp2, Tgfb2, and other TGFβ-signaling genes were assayed. Between-group comparisons were made using 1-way analysis of variance with post hoc Tukey honestly significant difference testing. RESULTS Expression levels of assayed genes were similar between LDS and WT tendons at baseline; however, at 6 weeks after patellar tendon transection, LDS tendons showed sustained elevations in Mmp2 and Tgfb2 compared with baseline values; these elevations were not seen in normal tendons undergoing the same treatments. Histologically, untreated LDS tendons had significantly greater cellularity and cell rounding compared with untreated WT tendons, and both WT and LDS tendons had significantly worse histologic scores after surgery. CONCLUSION We present the first mechanistic insight into the effect of LDS on tendons and tendon healing. The morphologic differences between LDS and WT tendons at baseline may help explain the increased risk of tendon/ligament dysfunction in patients with LDS, and the differential healing response to injury in LDS may account for the delayed healing and weaker repair tissue. LEVEL OF EVIDENCE Level V.
Collapse
Affiliation(s)
| | - Caitlin J Bowen
- Genetic Medicine
- Howard Hughes Medical Institute, Bethesda, MD
| | | | - Jason A Murray
- Pathology, The Johns Hopkins University School of Medicine
| | | | - Harry C Dietz
- Genetic Medicine
- Howard Hughes Medical Institute, Bethesda, MD
| | | |
Collapse
|
4
|
Sorber R, Bowen CJ, Hicks CW, Black JH. Connective tissue disease type mediates branch patency of grafts in open thoracoabdominal aortic reconstruction. J Vasc Surg 2022; 75:90-98. [PMID: 34186165 PMCID: PMC8710179 DOI: 10.1016/j.jvs.2021.05.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 05/24/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Despite a shared degenerative vascular phenotype, Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and other genetically distinct connective tissue diseases (CTDs) have unique extravascular pathologies that impact the outcomes of aortic replacement. The aim of our study was to investigate the association of CTD genotype with postoperative outcomes and branch patency following open thoracoabdominal aortic replacement in a large institutional cohort. METHODS All patients undergoing open branched thoracoabdominal aortic replacement at a single academic center from 2006 to 2020 were included and classified as CTD or non-CTD based on the presence of genotypic documentation. Outcomes were compared using analysis of variance and χ2 testing for continuous and discrete variables, respectively. Kaplan-Meier curves were utilized to examine patency of graft branches over time. RESULTS Overall, 172 patients were included, with a mean follow-up of 30.5 ± 34.9 months. CTD was present in 45 patients (26%); specifically, 32 had MFS, five had LDS, and eight had another CTD. Patients with CTDs had more extent II thoracoabdominal aneurysms (40% vs 15%), more reconstructed branches (3.5 vs 1.8), more frequently reconstructed visceral branches (86.7% vs 22.7%), and higher intraoperative blood loss (13.3 vs 6.8 L; all P < .05) compared with non-CTD patients. Patients with MFS were more frequently systemically anticoagulated preoperatively (50% vs 5%) and demonstrated higher rates of postoperative deep vein thrombosis/pulmonary embolism compared with non-CTD patients (9% vs 2%; both P < .05). Five-year renal branch patency was decreased among all patients compared with visceral branches (87.3% vs 95.6%; P = .05), but there were no individual branch patency differences between patients with and without CTDs (P = .086). Overall branch patency at 1 and 5 years was significantly higher in patients with MFS than in non-CTD patients (98.9% vs 89.1% at 5 years); there were no significant patency differences between non-CTD patients and any other CTD subgroup, mostly due to early patency loss. CONCLUSIONS Open thoracoabdominal reconstruction in patients with CTD is technically challenging and associated with increased transfusion and postoperative thromboembolic events when compared with non-CTD patients. Technical outcomes of the procedure are excellent and are differentially associated with genotype, with patients with MFS experiencing significantly improved branch patency over both non-CTD patients and patients with other CTDs, a finding which has multifactorial drivers.
Collapse
Affiliation(s)
- Rebecca Sorber
- Department of Vascular Surgery and Endovascular Therapy, The Johns Hopkins Hospital,Department of Genetic Medicine, Johns Hopkins University School of Medicine
| | - Caitlin J. Bowen
- Department of Genetic Medicine, Johns Hopkins University School of Medicine
| | - Caitlin W. Hicks
- Department of Vascular Surgery and Endovascular Therapy, The Johns Hopkins Hospital,Johns Hopkins Surgery Center For Outcomes Research (JSCOR),Johns Hopkins University School of Medicine
| | - James H. Black
- Department of Vascular Surgery and Endovascular Therapy, The Johns Hopkins Hospital
| |
Collapse
|
5
|
Cherry L, Gates L, Arden NK, Bowen CJ. Lifetime occupation is not associated with radiographic osteoarthritis of the first metatarsophalangeal joint in a cohort study of UK women. J Foot Ankle Res 2020; 13:61. [PMID: 33004072 PMCID: PMC7528246 DOI: 10.1186/s13047-020-00429-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE The study aim was to determine whether lifetime occupation was associated with the presence of radiographic osteoarthritis (ROA) of the first metatarsophalangeal joint (MTPJ) in women. METHOD Data were collected from the prospective, population-based Chingford 1000 Women study. This cohort of women, aged 45-64 years at inception, was established in 1989 from a single general practice in Chingford, UK. Data has subsequently been collected repeatedly. Data from baseline, year six and year ten was used for the purposes of this cross-sectional study. The primary outcome was the presence of dorsal view ROA of the first MTPJ. The main exposure was lifetime occupation, categorised according to levels of occupation previously defined via international consensus: 1. Sedentary, 2. Light, 3. Light manual, 4. Heavy manual. Logistic regression analyses were conducted to quantify the relationship between lifetime occupation type and the presence of ROA of the first MTPJ, adjusting for age, body mass index and lifetime high-heeled footwear use as potential interactive variables for each decade. RESULTS Data for 209 women were included within this study. The mean (SD) age was 57 (±5.2) years. Predominant lifetime occupation was reported as sedentary by 51.7%, as light by 0%, as light manual by 33.5% and as heavy manual by 14.8% of participants. There were no statistical associations between lifetime occupation type and the presence of ROA of the first MTPJ in either the unadjusted (OR = 0.99, CI = 0.78-1.26,P = 0.96) partially adjusted (for age and BMI; OR = 1.00, CI = 0.78-1.29, P = 0.99) or fully adjusted models (for age, BMI and lifetime high heel footwear use for each decade of working life (OR = 1.02, CI = 0.79-1.31, P = 0.91); high-heel footwear use up to 20s (OR = 0.83, CI = 0.71-1.31, P = 0.83); high-heel footwear use in 20-30s (OR = 1.00, CI = 0.75-1.3, P = 0.98); high-heel footwear use in 30-40s (OR = 1.00, CI = 0.70-1.42, P = 0.99); high-heel footwear use in 40-50s (OR = 0.90, CI = 0.58-1.40, P = 0.65); high-heel footwear use in 50s (OR = 0.63,CI = 0.36-1.09, P = 0.10). CONCLUSIONS The findings suggest that lifetime occupation is not associated with the presence of ROA of the fist metatarsophalangeal joint. There does not appear to be any interactive effect between lifetime occupation, lifetime high-heel footwear use, age or BMI and ROA of the first MTPJ. In later life a positive trend towards increased ROA in those who reported lifetime high-heel footwear use was noted and this may be worthy of further research.
Collapse
Affiliation(s)
- L Cherry
- School of Health Sciences, University of Southampton, Building 67, University Road, Southampton, SO17 1BJ, UK. .,Department of Podiatry, Solent NHS Trust, Southampton, UK.
| | - L Gates
- School of Health Sciences, University of Southampton, Building 67, University Road, Southampton, SO17 1BJ, UK.,Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.,Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, Southampton, UK
| | - N K Arden
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.,Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, Southampton, UK
| | - C J Bowen
- School of Health Sciences, University of Southampton, Building 67, University Road, Southampton, SO17 1BJ, UK.,Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, Southampton, UK
| |
Collapse
|
6
|
DeDreu J, Bowen CJ, Logan CM, Pal-Ghosh S, Parlanti P, Stepp MA, Menko AS. An immune response to the avascular lens following wounding of the cornea involves ciliary zonule fibrils. FASEB J 2020; 34:9316-9336. [PMID: 32452112 PMCID: PMC7384020 DOI: 10.1096/fj.202000289r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [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: 02/07/2020] [Revised: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022]
Abstract
The lens and central cornea are avascular. It was assumed that the adult lens had no source of immune cells and that the basement membrane capsule surrounding the lens was a barrier to immune cell migration. Yet, microfibril‐associated protein‐1 (MAGP1)‐rich ciliary zonules that originate from the vasculature‐rich ciliary body and extend along the surface of the lens capsule, form a potential conduit for immune cells to the lens. In response to cornea debridement wounding, we find increased expression of MAGP1 throughout the central corneal stroma. The immune cells that populate this typically avascular region after wounding closely associate with this MAGP1‐rich matrix. These results suggest that MAGP1‐rich microfibrils support immune cell migration post‐injury. Using this cornea wound model, we investigated whether there is an immune response to the lens following cornea injury involving the lens‐associated MAGP1‐rich ciliary zonules. Our results provide the first evidence that following corneal wounding immune cells are activated to travel along zonule fibers that extend anteriorly along the equatorial surface of the lens, from where they migrate across the anterior lens capsule. These results demonstrate that lens‐associated ciliary zonules are directly involved in the lens immune response and suggest the ciliary body as a source of immune cells to the avascular lens.
Collapse
Affiliation(s)
- JodiRae DeDreu
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Caitlin J Bowen
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Caitlin M Logan
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Paola Parlanti
- George Washington University Nanofabrication and Imaging Center, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.,Department of Ophthalmology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| |
Collapse
|
7
|
Bowen CJ, Calderón Giadrosic JF, Burger Z, Rykiel G, Davis EC, Helmers MR, Benke K, Gallo MacFarlane E, Dietz HC. Targetable cellular signaling events mediate vascular pathology in vascular Ehlers-Danlos syndrome. J Clin Invest 2020; 130:686-698. [PMID: 31639107 PMCID: PMC6994142 DOI: 10.1172/jci130730] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [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: 06/04/2019] [Accepted: 10/15/2019] [Indexed: 12/21/2022] Open
Abstract
Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal-dominant connective tissue disorder caused by heterozygous mutations in the COL3A1 gene, which encodes the pro-α 1 chain of collagen III. Loss of structural integrity of the extracellular matrix is believed to drive the signs and symptoms of this condition, including spontaneous arterial dissection and/or rupture, the major cause of mortality. We created 2 mouse models of vEDS that carry heterozygous mutations in Col3a1 that encode glycine substitutions analogous to those found in patients, and we showed that signaling abnormalities in the PLC/IP3/PKC/ERK pathway (phospholipase C/inositol 1,4,5-triphosphate/protein kinase C/extracellular signal-regulated kinase) are major mediators of vascular pathology. Treatment with pharmacologic inhibitors of ERK1/2 or PKCβ prevented death due to spontaneous aortic rupture. Additionally, we found that pregnancy- and puberty-associated accentuation of vascular risk, also seen in vEDS patients, was rescued by attenuation of oxytocin and androgen signaling, respectively. Taken together, our results provide evidence that targetable signaling abnormalities contribute to the pathogenesis of vEDS, highlighting unanticipated therapeutic opportunities.
Collapse
Affiliation(s)
- Caitlin J. Bowen
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | | | - Zachary Burger
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Graham Rykiel
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Elaine C. Davis
- Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Mark R. Helmers
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kelly Benke
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Elena Gallo MacFarlane
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Harry C. Dietz
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| |
Collapse
|
8
|
Kersbergen CJ, Bowen CJ, Dykema AG, Koretzky MO, Tang O, Beach MC. Student Perceptions of M.D.-Ph.D. Programs: A Qualitative Identification of Barriers Facing Prospective M.D.-Ph.D. Applicants. Teach Learn Med 2020; 32:1-10. [PMID: 30983420 PMCID: PMC6995689 DOI: 10.1080/10401334.2019.1598414] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Phenomenon: Despite a high degree of interest in research among matriculating M.D. students, very few apply to combined M.D.-Ph.D. training programs. Even fewer of those applicants are female, leading to a gender disparity among M.D.-Ph.D. trainees. We used a qualitative approach to understand why students choose not to apply or matriculate to M.D.-Ph.D. programs. Approach: We recruited recently matriculated medical students at a private research university with a self-reported interest in academic medicine and biomedical research to participate in focus groups, in which students discussed their career and life goals, general knowledge and sources of information for M.D.-Ph.D. programs, perceived benefits and downsides, and barriers to applying to such programs. Findings: Twenty-two students participated in focus groups. Participants desired careers combining clinical work, research, and teaching. Students had knowledge of the structure and goals of M.D.-Ph.D. training and received information about dual-degree programs from research mentors, the Internet, and peers. Tuition remission and increased grant access were cited as benefits of M.D.-Ph.D. programs, whereas duration, perceived excessive research training, and early commitment were downsides. Perceived competitiveness, misconceptions about training, a lack of M.D.-Ph.D. program-specific advising, discouragement from applying, and duration of training all served as barriers preventing students from pursuing dual-degree training. Insights: Through this qualitative study, we identified perceptions and misconceptions that recent medical school applicants have about M.D.-Ph.D. programs. These findings suggest targetable barriers to increase applications from interested students, such as improving awareness of programs, increased accessibility of advising and resources, and addressing concerns over training length, with the goal of improving training access for aspiring physician-scientists.
Collapse
Affiliation(s)
- Calvin J. Kersbergen
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Caitlin J. Bowen
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Arbor G. Dykema
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Maya Overby Koretzky
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Olive Tang
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mary Catherine Beach
- General Internal Medicine and Berman Bioethics Institute, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
9
|
Cooper SL, Young DJ, Bowen CJ, Arwood NM, Poggi SG, Brown PA. Universal premedication and therapeutic drug monitoring for asparaginase-based therapy prevents infusion-associated acute adverse events and drug substitutions. Pediatr Blood Cancer 2019; 66:e27797. [PMID: 31099154 PMCID: PMC8294186 DOI: 10.1002/pbc.27797] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [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: 10/18/2018] [Revised: 03/28/2019] [Accepted: 04/09/2019] [Indexed: 11/10/2022]
Abstract
BACKGROUND Asparaginase is a critical component of lymphoblastic leukemia therapy, with intravenous pegaspargase (PEG) as the current standard product. Acute adverse events (aAEs) during PEG infusion are difficult to interpret, representing a mix of drug-inactivating hypersensitivity and noninactivating reactions. Asparaginase Erwinia chrysanthemi (ERW) is approved for PEG hypersensitivity, but is less convenient, more expensive, and yields lower serum asparaginase activity (SAA). We began a policy of universal premedication and SAA testing for PEG, hypothesizing this would reduce aAEs and unnecessary drug substitutions. PROCEDURE Retrospective chart review of patients receiving asparaginase before and after universal premedication before PEG was conducted, with SAA performed 1 week later. We excluded patients who had nonallergic asparaginase AEs. Primary end point was substitution to ERW. Secondary end points included aAEs, SAA testing, and cost. RESULTS We substituted to ERW in 21 of 122 (17.2%) patients pre-policy, and 5 of 68 (7.4%) post-policy (RR, 0.427; 95% CI, 0.27-0.69, P = 0.028). All completed doses of PEG yielded excellent SAA (mean, 0.90 units/mL), compared with ERW (mean, 0.15 units/mL). PEG inactivation post-policy was seen in 2 of 68 (2.9%), one silent and one with breakthrough aAE. The rate of aAEs pre/post-policy was 17.2% versus 5.9% (RR, 0.342; 95% CI, 0.20-0.58, P = 0.017). Grade 4 aAE rate pre/post-policy was 15% versus 0%. Cost analysis predicts $125 779 drug savings alone per substitution prevented ($12 402/premedicated patient). CONCLUSIONS Universal premedication reduced substitutions to ERW and aAE rate. SAA testing demonstrated low rates of silent inactivation, and higher SAA for PEG. A substantial savings was achieved. We propose universal premedication for PEG be standard of care.
Collapse
Affiliation(s)
- Stacy L. Cooper
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland,Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - David J. Young
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland,Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Caitlin J. Bowen
- Institute of Human Genetics, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Nicole M. Arwood
- Department of Pharmacy, Johns Hopkins Hospital, Baltimore, Maryland
| | - Sarah G. Poggi
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Patrick A. Brown
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland,Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
| |
Collapse
|
10
|
Bowen CJ, Kersbergen CJ, Tang O, Cox A, Beach MC. Medical school research ranking is associated with gender inequality in MSTP application rates. BMC Med Educ 2018; 18:187. [PMID: 30081928 PMCID: PMC6080404 DOI: 10.1186/s12909-018-1306-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND The number of female trainees in MD and biomedical PhD programs has reached near parity with their male counterparts for several years. However, a gender disparity persists for enrollment in Medical Scientist Research Programs (MSTPs). Several studies suggest women underestimate their abilities compared with male colleagues. If this phenomenon applies, we might expect there to be a gender disparity in applicants to MSTPs, which are typically considered more competitive compared to MD or PhD programs. In this report, we explored this hypothesis by evaluating whether female applicants who do apply to MSTP programs disproportionately apply to lower ranking programs when compared to male applicants. METHODS For each institution, we identified their 2016 U.S. News and World Report "Best Medical Schools: Research" ranking and examined trends across rankings using linear regression models, such as relationships between the percentage of female applicants and other factors that may influence where applicants apply. RESULTS The female applicants who do apply to MSTP programs apply disproportionately to lower ranking programs. Despite this, women seem to have the same success rate for gaining admission to MSTPs, as indicated by matriculation rates across programs, regardless of program rank. CONCLUSIONS Our findings of gender disparity in applications to high-ranking but not low-ranking programs support prior hypotheses that under-confidence or lack of encouragement may drive this inequality. This analysis highlights the need for further systematic studies of gender differences in MSTP applicants and the relationship to career trajectories in order to improve the gender disparity that exists in academic medicine.
Collapse
Affiliation(s)
- Caitlin J. Bowen
- Medical Scientist Training Program, Johns Hopkins University, 1830 East Monument Street, Suite 2-300, Baltimore, MD 21205 USA
| | - Calvin J. Kersbergen
- Medical Scientist Training Program, Johns Hopkins University, 1830 East Monument Street, Suite 2-300, Baltimore, MD 21205 USA
| | - Olive Tang
- Medical Scientist Training Program, Johns Hopkins University, 1830 East Monument Street, Suite 2-300, Baltimore, MD 21205 USA
| | - Andrea Cox
- Oncology, Medicine, and Medical Scientist Training Program, Johns Hopkins University, 1830 East Monument Street, Suite 2-300, Baltimore, MD 21205 USA
| | - Mary Catherine Beach
- General Internal Medicine and Berman Bioethics Institute, Johns Hopkins University, 2024 East Monument Street, Baltimore, MD 21287 USA
| |
Collapse
|
11
|
Logan CM, Bowen CJ, Menko AS. Functional role for stable microtubules in lens fiber cell elongation. Exp Cell Res 2017; 362:477-488. [PMID: 29253534 DOI: 10.1016/j.yexcr.2017.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/17/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023]
Abstract
The process of tissue morphogenesis, especially for tissues reliant on the establishment of a specific cytoarchitecture for their functionality, depends a balanced interplay between cytoskeletal elements and their interactions with cell adhesion molecules. The microtubule cytoskeleton, which has many roles in the cell, is a determinant of directional cell migration, a process that underlies many aspects of development. We investigated the role of microtubules in development of the lens, a tissue where cell elongation underlies morphogenesis. Our studies with the microtubule depolymerizing agent nocodazole revealed an essential function for the acetylated population of stable microtubules in the elongation of lens fiber cells, which was linked to their regulation of the activation state of myosin. Suppressing myosin activation with the inhibitor blebbistatin could attenuate the loss of acetylated microtubules by nocodazole and rescue the effect of this microtubule depolymerization agent on both fiber cell elongation and lens integrity. Our results also suggest that acetylated microtubules impact lens morphogenesis through their interaction with N-cadherin junctions, with which they specifically associate in the region where lens fiber cell elongate. Disruption of the stable microtubule network increased N-cadherin junctional organization along lateral borders of differentiating lens fiber cells, which was prevented by suppression of myosin activity. These results reveal a role for the stable microtubule population in lens fiber cell elongation, acting in tandem with N-cadherin cell-cell junctions and the actomyosin network, giving insight into the cooperative role these systems play in tissue morphogenesis.
Collapse
Affiliation(s)
- Caitlin M Logan
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
| | - Caitlin J Bowen
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
| |
Collapse
|
12
|
Abstract
The lens has been considered to be an immune privileged site not susceptible to the immune processes normally associated with tissue injury and wound repair. However, as greater insight into the immune surveillance process is gained, we have reevaluated the concept of immune privilege. Our studies using an N-cadherin lens-specific conditional knockout mouse, N-cadΔlens, show that loss of this cell-cell junctional protein leads to lens degeneration, necrosis and fibrotic change, postnatally. The degeneration of this tissue induces an immune response resulting in immune cells populating the lens that contribute to the development of fibrosis. Additionally, we demonstrate that the lens is connected to the lymphatic system, with LYVE(+) labeling reaching the lens along the suspensory ligaments that connect the lens to the ciliary body, providing a potential mechanism for the immune circulation. Importantly, we observe that degeneration of the lens activates an immune response throughout the eye, including cornea, vitreous humor, and retina, suggesting a coordinated protective response in the visual system to defects of a component tissue. These studies demonstrate that lens degeneration induces an immune response that can contribute to the fibrosis that often accompanies lens dysgenesis, a consideration for understanding organ system response to injury.
Collapse
Affiliation(s)
- Caitlin M Logan
- Thomas Jefferson University, Department of Pathology, Anatomy and Cell Biology, Philadelphia, Pennsylvania, 19107, United States
| | - Caitlin J Bowen
- Thomas Jefferson University, Department of Pathology, Anatomy and Cell Biology, Philadelphia, Pennsylvania, 19107, United States
| | - A Sue Menko
- Thomas Jefferson University, Department of Pathology, Anatomy and Cell Biology, Philadelphia, Pennsylvania, 19107, United States.
| |
Collapse
|
13
|
Gates LS, Bowen CJ, Sanchez-Santos MT, Delmestri A, Arden NK. Do foot & ankle assessments assist the explanation of 1 year knee arthroplasty outcomes? Osteoarthritis Cartilage 2017; 25:892-898. [PMID: 28043936 DOI: 10.1016/j.joca.2016.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/15/2016] [Accepted: 12/22/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Whilst a number of risk factors for poor patient reported outcome measures (PROMs) following knee arthroplasty (KA) have been identified, unexplained variability still remains. The role of pre-operative foot and ankle status on such outcomes has not been investigated. The aim of this study was therefore to determine the association of clinical foot and ankle assessments with patient reported outcomes 1 year following KA. DESIGN One hundred and fifteen participants from the Clinical Outcomes in Arthroplasty Study (COASt), underwent detailed foot and ankle assessments at baseline, prior to KA (2012-2014) and were followed up for self-reported outcomes 1 year after surgery. RESULTS Thirty nine percent of subjects reported foot pain at baseline. Mean pre-operative Oxford Knee Score (OKS; 0 [worst] to 48 [best outcome]) was 21 and post-operative OKS score was 38. In fully adjusted analysis pre-operative foot pain was significantly associated with 1 year outcome (risk ratio [RR] 0.78 95% confidence interval [95% CI] 0.62, 0.98). No significant association was observed between ankle dorsiflexion or foot posture and outcome. CONCLUSIONS Patients with pre-operative foot pain are more likely to have poorer clinically important outcomes 1 year following KA than patients without foot pain. Static ankle dorsiflexion and foot posture do not further explain post-operative KA outcomes. Consideration should also be given to address pre-operative foot pain when attempting to achieve a good clinical outcome for KA.
Collapse
Affiliation(s)
- L S Gates
- Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, University of Oxford, Oxford, UK; Faculty of Health Sciences, University of Southampton, Southampton, UK.
| | - C J Bowen
- Faculty of Health Sciences, University of Southampton, Southampton, UK
| | - M T Sanchez-Santos
- Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, University of Oxford, Oxford, UK
| | - A Delmestri
- Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, University of Oxford, Oxford, UK
| | - N K Arden
- Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, University of Oxford, Oxford, UK; MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| |
Collapse
|
14
|
Sung DC, Bowen CJ, Vaidya KA, Zhou J, Chapurin N, Recknagel A, Zhou B, Chen J, Kotlikoff M, Butcher JT. Cadherin-11 Overexpression Induces Extracellular Matrix Remodeling and Calcification in Mature Aortic Valves. Arterioscler Thromb Vasc Biol 2016; 36:1627-37. [PMID: 27312222 DOI: 10.1161/atvbaha.116.307812] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 06/06/2016] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Calcific aortic valve (AoV) disease is a significant clinical problem for which the regulatory mechanisms are poorly understood. Enhanced cell-cell adhesion is a common mechanism of cellular aggregation, but its role in calcific lesion formation is not known. Cadherin-11 (Cad-11) has been associated with lesion formation in vitro, but its function during adult valve homeostasis and pathogenesis is not known. This study aims to elucidate the specific functions of Cad-11 and its downstream targets, RhoA and Sox9, in extracellular matrix remodeling and AoV calcification. APPROACH AND RESULTS We conditionally overexpressed Cad-11 in murine heart valves using a novel double-transgenic Nfatc1(Cre);R26-Cad11(TglTg) mouse model. These mice developed hemodynamically significant aortic stenosis with prominent calcific lesions in the AoV leaflets. Cad-11 overexpression upregulated downstream targets, RhoA and Sox9, in the valve interstitial cells, causing calcification and extensive pathogenic extracellular matrix remodeling. AoV interstitial cells overexpressing Cad-11 in an osteogenic environment in vitro rapidly form calcific nodules analogous to in vivo lesions. Molecular analyses revealed upregulation of osteoblastic and myofibroblastic markers. Treatment with a Rho-associated protein kinase inhibitor attenuated nodule formation, further supporting that Cad-11-driven calcification acts through the small GTPase RhoA/Rho-associated protein kinase signaling pathway. CONCLUSIONS This study identifies one of the underlying molecular mechanisms of heart valve calcification and demonstrates that overexpression of Cad-11 upregulates RhoA and Sox9 to induce calcification and extracellular matrix remodeling in adult AoV pathogenesis. The findings provide a potential molecular target for clinical treatment.
Collapse
Affiliation(s)
- Derek C Sung
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Caitlin J Bowen
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Kiran A Vaidya
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Jingjing Zhou
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Nikita Chapurin
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Andrew Recknagel
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Bin Zhou
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Jonathan Chen
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Michael Kotlikoff
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.)
| | - Jonathan T Butcher
- From the Meinig School of Biomedical Engineering (D.C.S., C.J.B., K.A.V., J.Z., N.C., A.R., J.T.B.) and Department of Biomedical Sciences (M.K.), Cornell University, Ithaca, NY; Department of Genetics, Pediatrics, and Medicine (Cardiology), Albert Einstein College of Medicine, Montefiore Medical Center, New York (B.Z.); and Department of Pediatric Cardiovascular Surgery, Seattle Children's Hospital, WA (J.C.).
| |
Collapse
|
15
|
Bowen CJ, Zhou J, Sung DC, Butcher JT. Cadherin-11 coordinates cellular migration and extracellular matrix remodeling during aortic valve maturation. Dev Biol 2015; 407:145-57. [PMID: 26188246 DOI: 10.1016/j.ydbio.2015.07.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 06/15/2015] [Accepted: 07/13/2015] [Indexed: 12/30/2022]
Abstract
Proper remodeling of the endocardial cushions into thin fibrous valves is essential for gestational progression and long-term function. This process involves dynamic interactions between resident cells and their local environment, much of which is not understood. In this study, we show that deficiency of the cell-cell adhesion protein cadherin-11 (Cad-11) results in significant embryonic and perinatal lethality primarily due to valve related cardiac dysfunction. While endocardial to mesenchymal transformation is not abrogated, mesenchymal cells do not homogeneously cellularize the cushions. These cushions remain thickened with disorganized ECM, resulting in pronounced aortic valve insufficiency. Mice that survive to adulthood maintain thickened and stenotic semilunar valves, but interestingly do not develop calcification. Cad-11 (-/-) aortic valve leaflets contained reduced Sox9 activity, β1 integrin expression, and RhoA-GTP activity, suggesting that remodeling defects are due to improper migration and/or cellular contraction. Cad-11 deletion or siRNA knockdown reduced migration, eliminated collective migration, and impaired 3D matrix compaction by aortic valve interstitial cells (VIC). Cad-11 depleted cells in culture contained few filopodia, stress fibers, or contact inhibited locomotion. Transfection of Cad-11 depleted cells with constitutively active RhoA restored cell phenotypes. Together, these results identify cadherin-11 mediated adhesive signaling for proper remodeling of the embryonic semilunar valves.
Collapse
Affiliation(s)
- Caitlin J Bowen
- Department of Biomedical Engineering, Cornell University, United States
| | - Jingjing Zhou
- Department of Biomedical Engineering, Cornell University, United States
| | - Derek C Sung
- Department of Biomedical Engineering, Cornell University, United States
| | - Jonathan T Butcher
- Department of Biomedical Engineering, Cornell University, United States.
| |
Collapse
|
16
|
Wasala NB, Bowen CJ, Jaworski DC. Expression and regulation of macrophage migration inhibitory factor (MIF) in feeding American dog ticks, Dermacentor variabilis. Exp Appl Acarol 2012; 57:179-187. [PMID: 22476444 DOI: 10.1007/s10493-012-9550-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 03/24/2012] [Indexed: 05/31/2023]
Abstract
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine produced by many mammalian tissues. It is also found in ticks and may function to aid the tick in regulating host responses to tick feeding. Our hypothesis is that MIF functions in tick blood meal acquisition and pathogen transmission. This study was performed to understand the expression and regulation of MIF in the American dog tick, Dermacentor variabilis during early stages of blood feeding. We used quantitative reverse transcriptase PCR to study the gene expression during the first 96 h of feeding. Increases in MIF gene expression were observed in salivary gland and midgut tissues during the first 6 days of feeding. RNAi-mediated gene knockdown of D. variabilis MIF was demonstrated but we did not observe measureable phenotypic impact on blood meal acquisition in female ticks. These observations are consistent with previously published data on the lone star tick Amblyomma americanum and suggest that MIF may not have a direct impact on tick blood meal acquisition. Silencing of subolesin, a putative transcription factor, down-regulated MIF expression by 50 %.
Collapse
Affiliation(s)
- Nalinda B Wasala
- Department of Entomology and Plant Pathology, 127 Noble Research Center, Oklahoma State University, Stillwater, OK 74078, USA
| | | | | |
Collapse
|
17
|
Jaworski DC, Zou Z, Bowen CJ, Wasala NB, Madden R, Wang Y, Kocan KM, Jiang H, Dillwith JW. Pyrosequencing and characterization of immune response genes from the American dog tick, Dermacentor variabilis (L.). Insect Mol Biol 2010; 19:617-30. [PMID: 20698900 PMCID: PMC9327058 DOI: 10.1111/j.1365-2583.2010.01037.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [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] [Indexed: 05/22/2023]
Abstract
Ticks continue to be a threat to animal and human health, and new and novel control strategies are needed for ticks and tick-borne pathogens. The characterization of the tick-pathogen interface and the tick immune response to microbial infections is fundamental toward the formulation of new control strategies for ticks and the pathogens they transmit. Our overall hypothesis for this research is that the tick immune system manages the maintenance of pathogens. Therefore, discovery of tick immune response genes may provide targets for novel control strategies directed toward reducing vector competency and pathogen transmission. In these studies, 454 pyrosequencing, a high-throughput genomic sequencing method was used to discover tick genes expressed in response to bacterial and fungal infections. Expressed sequence tags (ESTs) were analysed from Dermacentor variabilis ticks that had been injected with bacteria (Escherichia coli, Bacillus subtilis, Micrococcus luteus) or fungi (Saccharomyces cerevisiae and Candida albicans) and ticks that were naturally infected with the intracellular bacterium, Anaplasma marginale. By this approach, ESTs were assembled into 5995 contigs. Contigs fell into the five main functional categories of metabolism, genetic information processing, environmental information processing, cellular processes and human diseases. We identified more than 30 genes that are likely to encode for proteins involved in tick immune function. We further analysed by reverse transcriptase PCR (RT-PCR) the expression of 22 of these genes in each of our bacterial or fungal treatment groups and found that seven were up-regulated. Up-regulation of these seven genes was confirmed for bacterial, but not fungal treatment by quantitative PCR (qPCR). One of these products was novel, encoding a new tick defensin. Our results clearly demonstrate the complexities of the tick immune system and mark new directions for further study and characterization of proteins that modulate microbial infections in the American dog tick.
Collapse
Affiliation(s)
- D C Jaworski
- Department of Entomology and Plant Pathology, Oklahoma State University, Noble Research Center, Stillwater, OK 74078-8031, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Bowen CJ, Jaworski DC, Wasala NB, Coons LB. Macrophage migration inhibitory factor expression and protein localization in Amblyomma americanum (Ixodidae). Exp Appl Acarol 2010; 50:343-52. [PMID: 19784782 DOI: 10.1007/s10493-009-9324-5] [Citation(s) in RCA: 18] [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] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 09/14/2009] [Indexed: 05/10/2023]
Abstract
Amblyomma americanum (L.) ticks continue to emerge as disease vectors in many areas of the United States. Tick macrophage migration inhibitory factor (MIF) was first identified in A. americanum females and has been demonstrated to inhibit macrophage movement to the same extent as human MIF. This study was conducted to further characterize and elucidate the physiological role for MIF in tick feeding. A relative quantitative PCR assay was developed to determine the level of MIF gene expression during tick feeding. In addition, RNAi techniques were used to silence MIF prior to blood feeding. Physiological parameters of tick engorgement weight, length of feeding interval, and egg masses were observed to check for phenotypic manifestations of RNA silencing. Specific tick MIF antibody was used to localize MIF protein in frozen tick tissue sections. Tissue specific gene expression indicated that the midgut tissues were the most highly enriched for the MIF. Levels of gene expression did not parallel MIF protein pools seen in tissue sections. Of particular importance was the finding that unfed tick salivary glands appear to contain vesicles that are specific for MIF protein. This is the first demonstration of a pool of MIF that could be secreted during the first hours of tick feeding. While MIF silencing was demonstrated at the molecular level, no physiological phenotype was apparent. The MIF protein pools already available in the tissues may be sufficient to accomplish female tick feeding. Our studies show that the most prominent source of MIF during tick feeding is the midgut tissue. Future studies will address the role of MIF in blood feeding and nutrient digestion in the immature life stages of the tick.
Collapse
Affiliation(s)
- C J Bowen
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK 74078-8031, USA
| | | | | | | |
Collapse
|
19
|
Jaworski DC, Bowen CJ, Wasala NB. Amblyomma americanum (L): tick macrophage migration inhibitory factor peptide immunization lengthens lone star tick feeding intervals in vivo. Exp Parasitol 2008; 121:384-7. [PMID: 19111543 DOI: 10.1016/j.exppara.2008.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 10/20/2008] [Accepted: 12/01/2008] [Indexed: 10/21/2022]
Abstract
Immunizations of New Zealand White rabbits with specific macrophage migration inhibitory factor (MIF) tick peptide (PEP) produced circulating anti-tick PEP antibodies in the hosts. Antibody titers of greater than 1:5000 to tick MIF peptide were observed for crude sera from PEP-immunized rabbits. PEP- and BSA-vaccinated rabbits were infested with Amblyomma americanum adults. Feeding intervals, female weights, egg masses and percent egg hatch were measured for ticks feeding on control and immunized hosts. Feeding intervals were significantly lengthened to 13.3 days for PEP-vaccinated hosts compared to BSA-vaccinated controls at 12.4 days, while female engorgement weights and egg masses were unchanged. By immunizing hosts using specific tick PEP, we were able to alter the length of time the ticks fed on their hosts.
Collapse
Affiliation(s)
- D C Jaworski
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK 74078-8031, USA.
| | | | | |
Collapse
|