166 results on '"John P. Lynch"'
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2. Cox2 and β-Catenin/T-cell Factor Signaling Intestinalize Human Esophageal Keratinocytes When Cultured under Organotypic Conditions
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Jianping Kong, Mary Ann S. Crissey, Douglas B. Stairs, Antonia R. Sepulveda, and John P. Lynch
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
The incidence of esophageal adenocarcinoma (EAC) is rising in the United States. An important risk factor for EAC is the presence of Barrett esophagus (BE). BE is the replacement of normal squamous esophageal epithelium with a specialized columnar epithelium in response to chronic acid and bile reflux. However, the emergence of BE from squamous keratinocytes has not yet been demonstrated. Our research has focused on this. Wnt and cyclooxygenase 2 (Cox2) are two pathways whose activation has been associated with BE and progression to EAC, but their role has not been tested experimentally. To explore their contribution, we engineered a human esophageal keratinocyte cell line to express either a dominant-active Wnt effector CatCLef or a Cox2 complementary DNA. In a two-dimensional culture environment, Cox2 expression increases cell proliferation and migration, but neither transgene induces known BE markers. In contrast, when these cells were placed into three-dimensional organotypic culture conditions, we observed more profound effects. CatCLef-expressing cells were more proliferative, developed a thicker epithelium, and upregulated Notch signaling and several BE markers including NHE2. Cox2 expression also increased cell proliferation and induced a thicker epithelium. More importantly, we observed cysts form within the epithelium, filled with intestinal mucins including Muc5B and Muc17. This suggests that Cox2 expression in a three-dimensional culture environment induces a lineage of mucin-secreting cells and supports an important causal role for Cox2 in BE pathogenesis. We conclude that in vitro modeling of BE pathogenesis can be improved by enhancing Wnt signaling and Cox2 activity and using three-dimensional organotypic culture conditions.
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- 2011
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3. The Homeodomain Transcription Factor Cdx1 Does Not Behave as an Oncogene in Normal Mouse Intestine
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Mary Ann S. Crissey, Rong-Jun Guo, Franz Fogt, Hong Li, Jonathan P. Katz, Debra G. Silberg, Eun Ran Suh, and John P. Lynch
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
The Caudal-related homeobox genes Cdx1 and Cdx2 are intestine-specific transcription factors that regulate differentiation of intestinal cell types. Previously, we have shown Cdx1 to be antiproliferative and to promote cell differentiation. However, other studies have suggested that Cdx1 may be an oncogene. To test for oncogenic behavior, we used the murine villin promoter to ectopically express Cdx1 in the small intestinal villi and colonic surface epithelium. No changes in intestinal architecture, cell differentiation, or lineage selection were observed with expression of the transgene. Classic oncogenes enhance proliferation and induce tumors when ectopically expressed. However, the Cdx1 transgene neither altered intestinal proliferation nor induced spontaneous intestinal tumors. In a murine model for colitis-associated cancer, the Cdx1 transgene decreased, rather than increased, the number of adenomas that developed. In the polyps, the expression of the endogenous and the transgenic Cdx1 proteins was largely absent, whereas endogenous Villin expression was retained. This suggests that transgene silencing was specific and not due to a general Villin inactivation. In conclusion, neither the ectopic expression of Cdx1 was associated with changes in intestinal cell proliferation or differentiation nor was there increased intestinal cancer susceptibility. Our results therefore suggest that Cdx1 is not an oncogene in normal intestinal epithelium.
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- 2008
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4. Unintended consequences of changes to lung allocation policy
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Margaret S. Harrison, Bryan F. Meyers, William C. Chapman, Daniel Kreisel, Diane Brockmeier, Gene Ridolfi, Varun Puri, Gary Marklin, G.A. Patterson, Ruben G. Nava, John P. Lynch, Ramsey R. Hachem, Stuart C. Sweet, Benjamin D. Kozower, Michael K. Pasque, Tara R. Semenkovich, Christian Corbin Frye, and Casey Rowe
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Adult ,Male ,Tissue and Organ Procurement ,Waiting Lists ,medicine.medical_treatment ,030230 surgery ,Regional Health Planning ,Resource Allocation ,Unit (housing) ,03 medical and health sciences ,0302 clinical medicine ,Procurement ,Humans ,Immunology and Allergy ,Medicine ,Lung transplantation ,Pharmacology (medical) ,Operations management ,Justice (ethics) ,Human services ,Transplantation ,business.industry ,Unintended consequences ,Middle Aged ,Tissue Donors ,Lawsuit ,Female ,business ,Lung Transplantation - Abstract
Organ allocation for transplantation aims to balance the principles of justice and medical utility to optimally utilize a scarce resource. To address practical considerations, the United States is divided into 58 donor service areas (DSA), each constituting the first unit of allocation. In November 2017, in response to a lawsuit in New York, an emergency action change to lung allocation policy replaced the DSA level of allocation for donor lungs with a 250 nautical mile circle around the donor hospital. Similar policy changes are being implemented for other organs including heart and liver. Findings from a recent US Department of Health and Human Services report, supplemented with data from our institution, suggest that the emergency policy has not resulted in a change in the type of patients undergoing lung transplantation (LT) or early postoperative outcomes. However, there has been a significant decline in local LT, where donor and recipient are in the same DSA. With procurement teams having to travel greater distances, organ ischemic time has increased and median organ cost has more than doubled. We propose potential solutions for consideration at this critical juncture in the field of transplantation. Policymakers should choose equitable and sustainable access for this lifesaving discipline.
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- 2019
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5. Maintenance Golimumab Treatment in Pediatric UC Patients With Moderately to Severely Active UC: PURSUIT PEDS PK Long-Term Study Results
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Joel R. Rosh, Anne M. Griffiths, Jeffrey S. Hyams, Geneviève Veereman, Melvin B. Heyman, Omoniyi J. Adedokun, Daphne Chan, Christopher D. O'Brien, Richard Strauss, Ghassan Wahbeh, Dan Turner, John P. Lynch, Lakshmi Padgett, Pediatrics, Clinical sciences, and Growth and Development
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medicine.medical_specialty ,Tuberculosis ,clinical response ,Autoimmune Disease ,030226 pharmacology & pharmacy ,Gastroenterology ,03 medical and health sciences ,Rare Diseases ,0302 clinical medicine ,Pharmacokinetics ,Clinical Research ,Internal medicine ,Internal Medicine ,medicine ,Pediatrics, Perinatology, and Child Health ,ulcerative colitis ,Pediatric ,clinical remission ,business.industry ,Inflammatory Bowel Disease ,SERUM SICKNESS-LIKE REACTION ,Cancer ,medicine.disease ,Ulcerative colitis ,Golimumab ,Good Health and Well Being ,Long term learning ,Disease remission ,030211 gastroenterology & hepatology ,Digestive Diseases ,business ,medicine.drug - Abstract
Background Long-term safety, pharmacokinetics, and efficacy of open-label golimumab therapy in children with moderate–severe ulcerative colitis were evaluated. Methods Week-6 golimumab responders (Mayo score decrease of ≥30% and ≥3 points from baseline, rectal bleeding subscore of 0/1 or ≥1 decrease from baseline) entered the long-term extension at week 14 and received maintenance therapy (subcutaneous, q4w). Patients ≥45 kg could receive at-home treatments at week 18. Pharmacokinetic, safety, and efficacy results were summarized through week 126 (2 years). Results Among 35 enrolled children, 21 (60%) responded at week 6 and 20 entered the long-term extension (median age of 14.5 years and median weight of 46.1 kg). Eleven of 20 patients (55%) completed 2 years of treatment. No anaphylactic or serum sickness-like reactions, opportunistic infections, malignancies, tuberculosis, or deaths occurred. The safety profile of golimumab from weeks 14 through 126 and that observed through week 14 was generally consistent. Median trough golimumab concentrations in evaluable patients were consistent from weeks 14 (1.39, interquartile range 0.67–3.60) through 102 (1.18, 0.78–2.16), but higher at week 110 (4.10, 1.30–4.81). The incidence of antigolimumab antibodies increased from 10% (2/20) at week 30 to 25.0% (5/20) at week 126; 1 patient had neutralizing antibodies. At week 110, 50% (10/20) of patients were in remission (ie, Pediatric Ulcerative Colitis Activity Index Conclusions Among children with ulcerative colitis who initially responded to golimumab induction and received q4w maintenance treatment in the long-term extension, 50% showed continued clinical benefit through 2 years. No new safety signals were observed.
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- 2020
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6. Five-Year Efficacy and Safety of Ustekinumab Treatment in Crohn’s Disease: The IM-UNITI Trial
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Christopher Gasink, Subrata Ghosh, Rory Rebuck, Bruce E. Sands, Omoniyi J. Adedokun, John P. Lynch, Jean-Frederic Colombel, William J. Sandborn, Bin Zou, Stephen B. Hanauer, Willem J.S. de Villiers, Brian G. Feagan, Stephan R. Targan, and Yuhua Wang
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medicine.medical_specialty ,Placebo ,Inflammatory bowel disease ,Article ,Maintenance Chemotherapy ,03 medical and health sciences ,0302 clinical medicine ,Crohn Disease ,Maintenance therapy ,Internal medicine ,Ustekinumab ,medicine ,Humans ,Dosing ,Adverse effect ,Crohn's disease ,Hepatology ,business.industry ,Remission Induction ,Gastroenterology ,Induction Chemotherapy ,medicine.disease ,Crohn's Disease Activity Index ,Treatment Outcome ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,business ,medicine.drug - Abstract
Background & Aims The IM-UNITI study and long-term extension (LTE) evaluated the long-term efficacy, safety, and immunogenicity of subcutaneous ustekinumab maintenance therapy in patients with Crohn’s disease. Here, we report the final results of IM-UNITI LTE through 5 years. Methods Patients completing safety and efficacy evaluations at week 44 of the maintenance study were eligible to participate in the LTE and continue the treatment they were receiving. Unblinding occurred after completion of maintenance study analyses (August 2015), and patients receiving placebo were discontinued from the study after unblinding. No dose adjustment occurred in the LTE. Efficacy assessments were conducted every 12 weeks until unblinding and at dosing visits thereafter through week 252. Serum ustekinumab concentrations and antidrug antibodies were evaluated through weeks 252 and 272, respectively. Results Using an intent-to-treat analysis of all patients randomized to ustekinumab at maintenance baseline, 34.4% of patients in the every-8-weeks group and 28.7% in the every-12-weeks group were in clinical remission at week 252. Corresponding remission rates among patients who entered the LTE were 54.9% and 45.2%. Overall, adverse event rates (per 100 patient-years) from maintenance week 0 through the final visit generally were similar in the placebo and combined ustekinumab groups for all adverse events (440.3 vs 327.6), serious adverse events (19.3 vs 17.5), infections (99.8 vs 93.8), and serious infections (3.9 vs 3.4). Serum ustekinumab concentrations were maintained throughout the LTE. Antidrug antibodies occurred in 5.8% of patients who received ustekinumab during induction and maintenance and continued in the LTE. Conclusions Patients receiving subcutaneous ustekinumab maintained clinical remission through 5 years. No new safety signals were observed. ClinicalTrials.gov number NCT01369355.
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- 2022
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7. P388 Agreement between locally and centrally reviewed Mayo endoscopic subscores in the UNIFI study of ustekinumab in patients with Ulcerative Colitis
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A Simi, John P. Lynch, Hongyan Zhang, L Noonan, Bruce E. Sands, Walter Reinisch, D Mishkin, Unifi, and Colleen Marano
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Surrogate endpoint ,Gastroenterology ,General Medicine ,medicine.disease ,Ulcerative colitis ,Endoscopy ,Internal medicine ,Ustekinumab ,Disease remission ,medicine ,In patient ,business ,medicine.drug - Abstract
Background In the UNIFI clinical study of ustekinumab (UST) in ulcerative colitis (UC), an endoscopic subscore (ES) was assigned by a local endoscopist, and the video was reviewed by central readers who provided an independent ES. Here, we determined ES agreement between local and central readers. Methods UNIFI (NCT02407236) was a placebo-controlled double-blind trial consisting of randomized induction and maintenance studies.1 Endoscopies were performed at screening (I-0), induction Wk 8 (I-8), and maintenance Wk 44 (M-44). Mayo ESs (range 0-3) were assigned by local endoscopists and a central reader reviewing the endoscopy video. The local reader was blinded to treatment, and the central reader was blinded to local ESs, treatment, and visit. If local and central readers assigned the same ES, that was the final ES (FES). If local and central reader ESs did not agree, videos were reviewed by an adjudicator who was blinded to the two previous ESs. If the adjudicator assigned the same ES as the local or central reader, that was the FES. If not, the FES was the median of the 3 ESs. Results Agreement between individual local and central reader ESs was fair (κ=0.25-0.33, Figure 1) and was less than the agreement between central reader and adjudicator (κ=0.55–0.56) at all timepoints. However, at I-0, when determining study entry eligibility (ES≥2), local and central reader agreed more than 85% of the time. At I-0, 98.2% of 1051 endoscopies with FES 2/3 were also scored 2/3 by local ES, while for the 104 with FES 0/1, 49% had a local ES 2/3. At I-8 and M-44 (primary endpoint timepoints), the local ES and FES agreed 87% (785/899) and 80% (497/625), respectively. The proportions of subjects with clinical remission and endoscopic improvement were slightly higher when using the local ES compared to the FES (Figure 2), whereas clinical response rates when using the local ES were similar to FES. Despite these findings, treatment differences between UST and placebo were generally similar when local ES and FES were used to calculate clinical remission at I-8 and M-88. Approximately 90% of endoscopies had an image quality considered “optimal” or “readable with certainty but with minor technical difficulties” by central readers. Overall, image adequacy did not impact agreement between readers. Conclusion Even though agreement between local and central readers was fair and less than that between the central reader and adjudicator, the overall impact on primary and secondary study endpoints was minimal. Overall, the use of both local and central ES to determine the FES yielded a robust and reliable measure for study endpoint determination, however, efforts facilitating reproducible endoscopic assessments in UC are warranted.
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- 2021
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8. S885 Safety of Ustekinumab in Older IBD Patients (≥60 Years): Pooled Safety Analysis Through 5 Years in CD and 2 Years in UC and All Approved Indications
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Aline Charabaty, Subrata Ghosh, John P. Lynch, Maria T. Abreu, Christopher Gasink, Colleen Marano, Elyssa Ott, and Ye Miao
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medicine.medical_specialty ,Hepatology ,business.industry ,Internal medicine ,Ustekinumab ,Gastroenterology ,medicine ,business ,medicine.drug - Published
- 2021
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9. GUCY2C maintains intestinal LGR5+ stem cells by opposing ER stress
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John P. Lynch, Adam E. Snook, Amanda M. Pattison, Crystal L. Kraft, Jeffrey A. Rappaport, and Scott A. Waldman
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inorganic chemicals ,0301 basic medicine ,Chemistry ,Regeneration (biology) ,Endoplasmic reticulum ,fungi ,LGR5 ,Context (language use) ,digestive system ,Cell biology ,03 medical and health sciences ,Paracrine signalling ,030104 developmental biology ,0302 clinical medicine ,Oncology ,Multipotent Stem Cell ,030220 oncology & carcinogenesis ,Unfolded protein response ,Stem cell - Abstract
Long-lived multipotent stem cells (ISCs) at the base of intestinal crypts adjust their phenotypes to accommodate normal maintenance and post-injury regeneration of the epithelium. Their long life, lineage plasticity, and proliferative potential underlie the necessity for tight homeostatic regulation of the ISC compartment. In that context, the guanylate cyclase C (GUCY2C) receptor and its paracrine ligands regulate intestinal epithelial homeostasis, including proliferation, lineage commitment, and DNA damage repair. However, a role for this axis in maintaining ISCs remains unknown. Transgenic mice enabling analysis of ISCs (Lgr5-GFP) in the context of GUCY2C elimination (Gucy2c-/- ) were combined with immunodetection techniques and pharmacological treatments to define the role of the GUCY2C signaling axis in supporting ISCs. ISCs were reduced in Gucy2c-/- mice, associated with loss of active Lgr5+ cells but a reciprocal increase in reserve Bmi1+ cells. GUCY2C was expressed in crypt base Lgr5+ cells in which it mediates canonical cyclic (c) GMP-dependent signaling. Endoplasmic reticulum (ER) stress, typically absent from ISCs, was elevated throughout the crypt base in Gucy2c-/- mice. The chemical chaperone tauroursodeoxycholic acid resolved this ER stress and restored the balance of ISCs, an effect mimicked by the GUCY2C effector 8Br-cGMP. Reduced ISCs in Gucy2c-/- mice was associated with greater epithelial injury and impaired regeneration following sub-lethal doses of irradiation. These observations suggest that GUCY2C provides homeostatic signals that modulate ER stress and cell vulnerability as part of the machinery contributing to the integrity of ISCs.
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- 2017
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10. Mutual reinforcement between telomere capping and canonical Wnt signalling in the intestinal stem cell niche
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F. Brad Johnson, Anil K. Rustgi, Jennifer T. Deng, Geetha Jagannathan, Ting-Lin B. Yang, John P. Lynch, Shan Wang, Christopher J. Lengner, David C. Schultz, John W. Tobias, and Qijun Chen
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0301 basic medicine ,Paneth Cells ,Telomerase ,Telomere Capping ,Science ,Down-Regulation ,Gene Expression ,General Physics and Astronomy ,Apoptosis ,Biology ,Dyskeratosis Congenita ,Article ,General Biochemistry, Genetics and Molecular Biology ,Mice ,03 medical and health sciences ,Downregulation and upregulation ,medicine ,Animals ,Intestinal Mucosa ,Stem Cell Niche ,Wnt Signaling Pathway ,Telomere Shortening ,Feedback, Physiological ,Mice, Knockout ,Genetics ,Multidisciplinary ,Stem Cells ,Wnt signaling pathway ,General Chemistry ,Telomere ,medicine.disease ,Intestinal epithelium ,Cell biology ,030104 developmental biology ,RNA ,Stem cell ,Dyskeratosis congenita - Abstract
Critical telomere shortening (for example, secondary to partial telomerase deficiency in the rare disease dyskeratosis congenita) causes tissue pathology, but underlying mechanisms are not fully understood. Mice lacking telomerase (for example, mTR−/− telomerase RNA template mutants) provide a model for investigating pathogenesis. In such mice, after several generations of telomerase deficiency telomeres shorten to the point of uncapping, causing defects most pronounced in high-turnover tissues including intestinal epithelium. Here we show that late-generation mTR−/− mutants experience marked downregulation of Wnt pathway genes in intestinal crypt epithelia, including crypt base columnar stem cells and Paneth cells, and in underlying stroma. The importance of these changes was revealed by rescue of crypt apoptosis and Wnt pathway gene expression upon treatment with Wnt pathway agonists. Rescue was associated with reduced telomere-dysfunction-induced foci and anaphase bridges, indicating improved telomere capping. Thus a mutually reinforcing feedback loop exists between telomere capping and Wnt signalling, and telomere capping can be impacted by extracellular cues in a fashion independent of telomerase., Mice lacking telomerase provide a model to study pathogenesis caused by critical telomere shortening. Here, the authors provide evidence that telomere shortening causes downregulation of Wnt signalling in intestinal crypts and that defects can be partially rescued by treatment with Wnt agonists.
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- 2017
11. S0645 Efficacy and Safety of Ustekinumab for Crohn's Disease Through 5 Years: Final Results From the IM-UNITI Long-Term Extension
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Christopher Gasink, Brian G. Feagan, Omoniyi J. Adedokun, Willem J.S. de Villiers, Bruce E. Sands, Jean-Frederic Colombel, Paul Rutgeerts, Yuhua Wang, Subrata Ghosh, Stephan R. Targan, John P. Lynch, William J. Sandborn, Rory Rebuck, Bin Zou, and Stephen B. Hanauer
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Crohn's disease ,Pediatrics ,medicine.medical_specialty ,Hepatology ,business.industry ,Ustekinumab ,Gastroenterology ,medicine ,medicine.disease ,business ,medicine.drug ,Term (time) - Published
- 2020
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12. A Holistic Analysis of the Intestinal Stem Cell Niche Network
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Kelley S. Yan, Barbara Olack, James C.Y. Dunn, Ariel Paulson, Henning S, Christopher M. Dekaney, Courtney W. Houchen, Linheng Li, Jian Yu, Xi C. He, J. Wang, Joyce C. Niland, Shiyuan Chen, Giles Pim, Darrick M. Hansen, John P. Lynch, John S. Kaddis, Aparna Venkatraman, Calvin J. Kuo, Martin G. Martin, Matthias Stelzner, Timothy C. Wang, Kim W, Hanash Am, Hu D, and Melissa H. Wong
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0303 health sciences ,Cell type ,Stromal cell ,Cell ,Niche ,RNA ,Biology ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Immune system ,Intestinal mucosa ,medicine ,Stem cell ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
SummaryAlthough many studies into the intestinal stem cell (ISC) niche have been carried out, they have focused on the role of a single cell type or molecular signal. However, no holistic comparisons of the predominant cell types and signals present within the intestinal mucosa have been conducted to date. We utilize bulk RNA sequencing to profile 20 different mucosal cell types covering four major cell categories: epithelial, stromal, endothelial and immune. We further examined the stromal signaling environment using scRNAseq to provide a more comprehensive view of the signaling microenvironment within the intestinal mucosa. We identified the primary signals for the major ISC regulatory pathways and their respective cellular sources. Our analysis suggests that a ‘niche network’ exists, with no single cell type being responsible for ISC self-renewal, proliferation, or differentiation; rather, each cell type within the network carries out specific functions in a highly cooperative and coordinated manner.
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- 2019
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13. Determining the Molecular Characteristics of How Ligands Interact with an ABC Transporter
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John D. Schuetz, Yao Wang, Sourav Das, Yu Fukuda, Tomoka Gose, John P. Lynch, and Anang A. Shelat
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Biochemistry ,Chemistry ,Genetics ,ATP-binding cassette transporter ,Molecular Biology ,Biotechnology - Published
- 2019
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14. Organoids and Engineered Organ Systems
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John P. Lynch and Linda C. Samuelson
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Pluripotent Stem Cells ,Hepatology ,Tissue Engineering ,Chemistry ,Gastroenterology ,Cell Culture Techniques ,Computational biology ,Organoids ,Organ Specificity ,Organoid ,Commentary ,Animals ,Humans ,Microtechnology ,Organ system ,Introductory Journal Article - Published
- 2019
15. 129 SAFETY OF USTEKINUMAB IN IBD: POOLED SAFETY ANALYSIS THROUGH 5 YEARS IN CD AND 2 YEARS IN UC
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Christopher Gasink, Silvio Danese, Colleen Marano, Bruce E. Sands, Brian G. Feagan, Elyssa Ott, Ye Miao, Ilia Tikhonov, John P. Lynch, Subrata Ghosh, and William J. Sandborn
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medicine.medical_specialty ,Hepatology ,business.industry ,Internal medicine ,Ustekinumab ,Gastroenterology ,medicine ,business ,medicine.drug - Published
- 2021
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16. Fr540 THE PHARMACOKINETICS AND IMMUNOGENICITY OF 5 YEARS OF TREATMENT WITH USTEKINUMAB: RESULTS FROM THE IM-UNITI LONG-TERM EXTENSION
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Brian G. Feagan, Yuhua Wang, Christopher Gasink, Omoniyi J. Adedokun, Bruce E. Sands, Subrata Ghosh, Willem J.S. de Villiers, John P. Lynch, Bin Zou, and William J. Sandborn
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Oncology ,medicine.medical_specialty ,Hepatology ,Pharmacokinetics ,business.industry ,Internal medicine ,Immunogenicity ,Ustekinumab ,Gastroenterology ,medicine ,business ,medicine.drug ,Term (time) - Published
- 2021
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17. Intestinal Enteroids Model Guanylate Cyclase C-Dependent Secretion Induced by Heat-Stable Enterotoxins
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Fang Wang, Adam E. Snook, Scott A. Waldman, Mary Ann S. Crissey, Amanda M. Pattison, Crystal L. Kraft, John P. Lynch, Dante J. Merlino, Jeffrey A. Rappaport, and Erik S. Blomain
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Diarrhea ,0301 basic medicine ,Receptors, Peptide ,Bacterial Toxins ,Immunology ,Cystic Fibrosis Transmembrane Conductance Regulator ,Receptors, Enterotoxin ,Enzyme-Linked Immunosorbent Assay ,Mice, Transgenic ,medicine.disease_cause ,Microbiology ,Enterotoxins ,Mice ,03 medical and health sciences ,Paracrine signalling ,chemistry.chemical_compound ,Enterotoxigenic Escherichia coli ,medicine ,Animals ,Humans ,Secretion ,Intestinal Mucosa ,Receptor ,Protein kinase A ,Cyclic GMP ,Linaclotide ,Escherichia coli Infections ,Analysis of Variance ,biology ,Escherichia coli Proteins ,Bacterial Infections ,Guanylate cyclase 2C ,Cystic fibrosis transmembrane conductance regulator ,Cell biology ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Infectious Diseases ,Receptors, Guanylate Cyclase-Coupled ,chemistry ,biology.protein ,Parasitology ,Signal Transduction - Abstract
Enterotoxigenic Escherichia coli (ETEC) causes ∼20% of the acute infectious diarrhea (AID) episodes worldwide, often by producing heat-stable enterotoxins (STs), which are peptides structurally homologous to paracrine hormones of the intestinal guanylate cyclase C (GUCY2C) receptor. While molecular mechanisms mediating ST-induced intestinal secretion have been defined, advancements in therapeutics have been hampered for decades by the paucity of disease models that integrate molecular and functional endpoints amenable to high-throughput screening. Here, we reveal that mouse and human intestinal enteroids in three-dimensional ex vivo cultures express the components of the GUCY2C secretory signaling axis. ST and its structural analog, linaclotide, an FDA-approved oral secretagog, induced fluid accumulation quantified simultaneously in scores of enteroid lumens, recapitulating ETEC-induced intestinal secretion. Enteroid secretion depended on canonical molecular signaling events responsible for ETEC-induced diarrhea, including cyclic GMP (cGMP) produced by GUCY2C, activation of cGMP-dependent protein kinase (PKG), and opening of the cystic fibrosis transmembrane conductance regulator (CFTR). Importantly, pharmacological inhibition of CFTR abrogated enteroid fluid secretion, providing proof of concept for the utility of this model to screen antidiarrheal agents. Intestinal enteroids offer a unique model, integrating the GUCY2C signaling axis and luminal fluid secretion, to explore the pathophysiology of, and develop platforms for, high-throughput drug screening to identify novel compounds to prevent and treat ETEC diarrheal disease.
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- 2016
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18. 2001 Flight Mechanics Symposium
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John P Lynch
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Astrodynamics - Abstract
This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on June 19-21, 2001. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to attitude/orbit determination, prediction and control; attitude simulation; attitude sensor calibration; theoretical foundation of attitude computation; dynamics model improvements; autonomous navigation; constellation design and formation flying; estimation theory and computational techniques; Earth environment mission analysis and design; and, spacecraft re-entry mission design and operations. Government, industry, and the academic community participated in the preparation and presentation of these papers.
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- 2001
19. KLF4 activates NFκB signaling and esophageal epithelial inflammation via the Rho-related GTP-binding protein RHOF
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Dorottya Laczkó, Divya Rao, Khvaramze Shaverdashvili, Kelly A. Whelan, Amanda B. Muir, Daniel Weinblatt, Wenpeng Jiang, Jennie Padlo, Jonathan P. Katz, Yang Jia, and John P. Lynch
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0301 basic medicine ,Keratinocytes ,rho GTP-Binding Proteins ,Esophageal Mucosa ,Science ,Kruppel-Like Transcription Factors ,Inflammation ,Mice, Transgenic ,03 medical and health sciences ,Kruppel-Like Factor 4 ,Mice ,0302 clinical medicine ,Downregulation and upregulation ,medicine ,Animals ,Esophagitis ,Esophagus ,Transcription factor ,Multidisciplinary ,business.industry ,Esophageal disease ,NF-kappa B ,Esophageal cancer ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,KLF4 ,030220 oncology & carcinogenesis ,Cancer research ,Medicine ,Signal transduction ,medicine.symptom ,business ,Signal Transduction - Abstract
Understanding the regulatory mechanisms within esophageal epithelia is essential to gain insight into the pathogenesis of esophageal diseases, which are among the leading causes of morbidity and mortality throughout the world. The zinc-finger transcription factor Krüppel-like factor (KLF4) is implicated in a large number of cellular processes, such as proliferation, differentiation, and inflammation in esophageal epithelia. In murine esophageal epithelia, Klf4 overexpression causes chronic inflammation which is mediated by activation of NFκB signaling downstream of KLF4, and this esophageal inflammation produces epithelial hyperplasia and subsequent esophageal squamous cell cancer. Yet, while NFκB activation clearly promotes esophageal inflammation, the mechanisms by which NFκB signaling is activated in esophageal diseases are not well understood. Here, we demonstrate that the Rho-related GTP-binding protein RHOF is activated by KLF4 in esophageal keratinocytes, leading to the induction of NFκB signaling. Moreover, RHOF is required for NFκB activation by KLF4 in esophageal keratinocytes and is also important for esophageal keratinocyte proliferation and migration. Finally, we find that RHOF is upregulated in eosinophilic esophagitis, an important esophageal inflammatory disease in humans. Thus, RHOF activation of NFκB in esophageal keratinocytes provides a potentially important and clinically-relevant mechanism for esophageal inflammation and inflammation-mediated esophageal squamous cell cancer.
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- 2018
20. Is Inhibitor Binding the Sole Requirement in Determining Inhibition of ABCG2 Mediated Transport?
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John P. Lynch, Anang A. Shelat, Yu Fukuda, Alice Allcock, Wenwei Lin, Tomoka Gose, Sourav Das, Taosheng Chen, and John D. Schuetz
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0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Abcg2 ,biology ,Chemistry ,Mediated transport ,Genetics ,biology.protein ,Molecular Biology ,Biochemistry ,Biotechnology ,Cell biology - Published
- 2018
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21. 1999 Flight Mechanics Symposium
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John P. Lynch
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Astrodynamics - Abstract
This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on May 18-20, 1999. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to orbit-attitude prediction, determination, and control; attitude sensor calibration; attitude determination error analysis; attitude dynamics; and orbit decay and maneuver strategy. Government, industry, and the academic community participated in the preparation and presentation of these papers.
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- 1999
22. Quality Indicators for the Management of Barrett’s Esophagus, Dysplasia, and Esophageal Adenocarcinoma: International Consensus Recommendations from the American Gastroenterological Association Symposium
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Douglas A. Corley, David A. Katzka, Nicholas J. Shaheen, Rhonda F. Souza, Hashem B. El-Serag, Navtej S. Buttar, Alessandro Repici, Kenneth K. Wang, Gary W. Falk, Prateek Sharma, David H. Ilson, Pankaj J. Pasricha, John M. Inadomi, Jaffer A. Ajani, David C. Metz, Frank McKeon, Jeffrey H. Peters, John R. Goldblum, Rebecca C. Fitzgerald, Stuart J. Spechler, Prashanth Vennalaganti, E. J. Kuipers, Stefan Seewald, Neil Gupta, Richard M. Peek, John P. Lynch, Amitabh Chak, Frank Gress, Oliver Pech, and Gastroenterology & Hepatology
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medicine.medical_specialty ,Consensus ,Esophageal Neoplasms ,Consensus Development Conferences as Topic ,media_common.quotation_subject ,Endoscopic mucosal resection ,Adenocarcinoma ,Article ,Barrett Esophagus ,Esophagus ,Documentation ,medicine ,Humans ,Quality (business) ,Disease management (health) ,media_common ,Government ,Hepatology ,business.industry ,Gastroenterology ,Disease Management ,medicine.disease ,United States ,digestive system diseases ,Surgery ,medicine.anatomical_structure ,Dysplasia ,Family medicine ,Barrett's esophagus ,Disease Progression ,Esophagoscopy ,business - Abstract
The development of and adherence to quality indicators in gastroenterology, as in all of medicine, is increasing in importance to ensure that patients receive consistent high-quality care. In addition, government-based and private insurers will be expecting documentation of the parameters by which we measure quality, which will likely affect reimbursements. Barrett’s esophagus remains a particularly important disease entity for which we should maintain up-to-date guidelines, given its commonality, potentially lethal outcomes, and controversies regarding screening and surveillance. To achieve this goal, a relatively large group of international experts was assembled and, using the modified Delphi method, evaluated the validity of multiple candidate quality indicators for the diagnosis and management of Barrett’s esophagus. Several candidate quality indicators achieved >80% agreement. These statements are intended to serve as a consensus on candidate quality indicators for those who treat patients with Barrett’s esophagus.
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- 2015
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23. Autophagy levels are elevated in barrett's esophagus and promote cell survival from acid and oxidative stress
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John P. Lynch, Gary W. Falk, Brendan Dang, Angeliz Caro Monroig, Dorottya Laczkó, Anil K. Rustgi, Kelly A. Whelan, John Falcone, Ravi K. Amaravadi, Ali Soroush, Gregory G. Ginsberg, Jianping Kong, and Hiroshi Nakagawa
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,Cancer Research ,Reactive oxygen species ,Programmed cell death ,Autophagy ,Inflammation ,Biology ,medicine.disease_cause ,humanities ,Pathogenesis ,03 medical and health sciences ,030104 developmental biology ,chemistry ,Cell culture ,Immunology ,Cancer research ,medicine ,medicine.symptom ,Molecular Biology ,Oxidative stress ,Intracellular - Abstract
Autophagy is a highly conserved mechanism that is activated during cellular stress. We hypothesized that autophagy may be induced by acid reflux, which causes injury, and inflammation, and therefore, contributes to the pathogenesis of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Currently, the role of autophagy in BE and EAC is poorly studied. We quantitatively define autophagy levels in human BE cell lines, a transgenic mouse model of BE, and human BE, and EAC biopsies. Human non-dysplastic BE had the highest basal number of autophagic vesicles (AVs), while AVs were reduced in normal squamous cells and dysplastic BE cells, and nearly absent in EAC. To demonstrate a functional role for autophagy in BE pathogenesis, normal squamous (STR), non-dysplastic BE (CPA), dysplastic BE (CPD), and EAC (OE19) cell lines were exposed to an acid pulse (pH 3.5) followed by incubation in the presence or absence of chloroquine, an autophagy inhibitor. Acid exposure increased reactive oxygen species (ROS) levels in STR and CPA cells. Chloroquine alone had a small impact on intracellular ROS or cell survival. However, combination of chloroquine with the acid pulse resulted in a significant increase in ROS levels at 6 h in STR and CPA cells, and increased cell death in all cell lines. These findings establish increased numbers of AVs in human BE compared to normal squamous or EAC, and suggest that autophagy functions to improve cell survival after acid reflux injury. Autophagy may thus play a critical role in BE pathogenesis and progression. © 2015 Wiley Periodicals, Inc.
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- 2015
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24. Mechanisms of Gastrointestinal Malignancies
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Bryson W. Katona and John P. Lynch
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Gastrointestinal malignancy ,business.industry ,Normal tissue ,Medicine ,Context (language use) ,Gastrointestinal cancer ,business ,medicine.disease ,Bioinformatics ,Malignancy ,Carcinogenesis ,medicine.disease_cause - Abstract
Gastrointestinal cancers represent a heterogeneous complex array of disorders and diseases. They may be divided into rare inherited forms and more frequent sporadic forms. There is a critical interplay of genetic and environmental factors that foster the conversion of normal tissue to precursor, premalignant lesions, and eventually to frank malignancy. While it is apparent that certain genetic mechanisms are better appreciated in a cell-type and tissue-type specific context, there are nevertheless overarching shared features between gastrointestinal cancers of different origin. To that end, this chapter will approach gastrointestinal cancers by focusing upon a dissection of the genetic basis of gastrointestinal cancers and underlying molecular mechanisms. Thus, it is not the intention of this chapter to elaborate upon the etiologic mechanisms of each gastrointestinal cancer due to space constraints, but rather to provide the reader with an understanding of the pivotal principles of oncogenesis and use this as a platform for elucidation of the molecular steps involved in initiation, evolution, and progression of gastrointestinal cancers. Finally, this chapter will emphasize the underpinnings of epithelial-based gastrointestinal cancers given they represent the preponderant form of gastrointestinal malignancy, but certainly, gastrointestinal malignancies can emanate from different cell types and these in aggregate constitute lymphomas, sarcomas or stromal tumors, and other rare forms of gastrointestinal neoplasms.
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- 2018
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25. Contributors
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Yasutada Akiba, Denise Al Alam, Rana Al-Sadi, Qasim Aziz, Eric J. Battaglioli, Adil E. Bharucha, Richard S. Blumberg, Natacha Bohin, Joel C. Bornstein, Stuart M. Brierley, Simon J.H. Brookes, Joel Castro, Eugene B. Chang, Benoit Chassaing, Mary Cheung, Matthew A. Ciorba, Sheila E. Crowe, Michael Czerwinski, Soula Danopoulos, Soumita Das, Peter J. Dempsey, Gerco den Hartog, Hideki Enomoto, Andelain Erickson, Peter B. Ernst, Adam D. Farmer, Jaime P.P. Foong, Mark R. Frey, Andrew T. Gewirtz, Fayez K. Ghishan, Fiona M. Gribble, Luke Grundy, Marlene M. Hao, Andrea M. Harrington, Grant W. Hennig, Hongzhen Hu, Jan D. Huizinga, Shankar S. Iyer, Izumi Kaji, Purna C. Kashyap, Jonathan D. Kaunitz, Jennifer S. Labus, Brigitte Lavoie, Cambrian Y. Liu, Thomas Y. Ma, Xiaoya Ma, Gary M. Mawe, Juanita L. Merchant, Jeannette S. Messer, Larry Miller, Bruce D. Naliboff, Mark T. Nelson, Donald F. Newgreen, Prashant Nighot, Monica Passi, D. Brent Polk, Maria J. Pozo, Frank Reimann, Geoffrey P. Roberts, Bani C. Roland, James K. Ruffle, Hyder Said, Linda C. Samuelson, Michael A. Schumacher, Yatrik M. Shah, Terez Shea-Donohue, Noah F. Shroyer, Jason R. Spence, Nick J. Spencer, Stephanie N. Spohn, Lincon A. Stamp, William F. Stenson, Miyako Takaki, Kirsten Tillisch, Toshihiro Uesaka, Gijs R. van den Brink, Willemijn A. van Dop, Anil Vegesna, Jakob von Moltke, Arnold Wald, B. Florien Westendorp, Mathew Whitson, Jackie D. Wood, Hua Xu, Vincent W. Yang, Heather M. Young, Vincent B. Young, Nada A. Abumrad, Waddah A. Alrefai, Rana Ammoury, Gregory J. Anderson, Shinji Asano, Giorgos Bamias, Yangzom D. Bhutia, Niviann M. Blondet, Patrick Borel, Vincenza Cifarelli, James F. Collins, Robert J. Cousins, Nicholas O. Davidson, Paul A. Dawson, Guillaume de Lartigue, Charles Desmarchelier, Pradeep K. Dudeja, Shireen R.L. Flores, Vadivel Ganapathy, Chiara Ghezzi, Ravinder K. Gill, Fred S. Gorelick, Matthew B. Grisham, Earl H. Harrison, Gail A. Hecht, Dawn A. Israel, James D. Jamieson, Bryson W. Katona, Pawel R. Kiela, Rachel E. Kopec, Kris V. Kowdley, Nicholas F. LaRusso, Seong M. Lee, Rodger A. Liddle, Juan P. Liuzzi, Donald D.F. Loo, John P. Lynch, Anatoliy I. Masyuk, Tatyana V. Masyuk, Donald J. Messner, Mark B. Meyer, Karen F. Murray, Ebba Nexo, Curtis T. Okamoto, Bernardo Ortega, Stephen Pandol, Richard M. Peek, J. Wesley Pike, Shubha Priyamvada, Gordon B. Proctor, Vazhaikkurichi M. Rajendran, Helen E. Raybould, Jesus Rivera-Nieves, Hamid M. Said, Hideki Sakai, Seema Saksena, Monica Sala-Rabanal, Jörg-Dieter Schulzke, Ursula E. Seidler, Abeer K. Shaalan, Irshad A. Sheikh, Jay R. Thiagarajah, Alan S. Verkman, Xiaoyu Wang, Paul A. Welling, Allan W. Wolkoff, and Ernest M. Wright
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- 2018
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26. Mito-protective autophagy is impaired in erythroid cells of aged mtDNA-mutator mice
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John D. Schuetz, John P. Lynch, Tomas A. Prolla, Rekha Iyengar, Xiujie Li-Harms, Mondira Kundu, Yong-Dong Wang, Christopher M. Wright, Geoffrey Neale, Aashish Joshi, Joseph T. Opferman, Xi Wang, James E. Thompson, Sandra Milasta, and Douglas R. Green
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Aging ,Heterozygote ,Proteasome Endopeptidase Complex ,Mitochondrial DNA ,Erythrocytes ,Somatic cell ,Immunology ,Cell Separation ,DNA-Directed DNA Polymerase ,Biology ,Mitochondrion ,medicine.disease_cause ,DNA, Mitochondrial ,Biochemistry ,Mice ,Oxygen Consumption ,Red Cells, Iron, and Erythropoiesis ,Erythroid Cells ,hemic and lymphatic diseases ,Autophagy ,medicine ,Animals ,Phosphorylation ,Mechanistic target of rapamycin ,Mutation ,TOR Serine-Threonine Kinases ,Anemia ,Cell Biology ,Hematology ,Flow Cytometry ,medicine.disease ,DNA Polymerase gamma ,Mitochondria ,Haematopoiesis ,Phenotype ,Myelodysplastic Syndromes ,biology.protein ,Cancer research ,Macrocytic anemia ,Ribosomes - Abstract
Somatic mitochondrial DNA (mtDNA) mutations contribute to the pathogenesis of age-related disorders, including myelodysplastic syndromes (MDS). The accumulation of mitochondria harboring mtDNA mutations in patients with these disorders suggests a failure of normal mitochondrial quality-control systems. The mtDNA-mutator mice acquire somatic mtDNA mutations via a targeted defect in the proofreading function of the mtDNA polymerase, PolgA, and develop macrocytic anemia similar to that of patients with MDS. We observed an unexpected defect in clearance of dysfunctional mitochondria at specific stages during erythroid maturation in hematopoietic cells from aged mtDNA-mutator mice. Mechanistically, aberrant activation of mechanistic target of rapamycin signaling and phosphorylation of uncoordinated 51-like kinase (ULK) 1 in mtDNA-mutator mice resulted in proteasome-mediated degradation of ULK1 and inhibition of autophagy in erythroid cells. To directly evaluate the consequence of inhibiting autophagy on mitochondrial function in erythroid cells harboring mtDNA mutations in vivo, we deleted Atg7 from erythroid progenitors of wild-type and mtDNA-mutator mice. Genetic disruption of autophagy did not cause anemia in wild-type mice but accelerated the decline in mitochondrial respiration and development of macrocytic anemia in mtDNA-mutator mice. These findings highlight a pathological feedback loop that explains how dysfunctional mitochondria can escape autophagy-mediated degradation and propagate in cells predisposed to somatic mtDNA mutations, leading to disease.
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- 2015
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27. Modeling Esophagitis Using Human Three-Dimensional Organotypic Culture System
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F. Bradley Johnson, Anil K. Rustgi, Dorottya Laczkó, Gregory G. Ginsberg, Gary W. Falk, John P. Lynch, Nirag Jhala, András Rosztóczy, and Fang Wang
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0301 basic medicine ,Population ,Cell Culture Techniques ,Inflammation ,Biology ,medicine.disease_cause ,Article ,Pathology and Forensic Medicine ,Cell Line ,03 medical and health sciences ,Immune system ,Esophagus ,medicine ,Esophagitis ,Humans ,education ,education.field_of_study ,medicine.disease ,Epithelium ,Oxidative Stress ,030104 developmental biology ,medicine.anatomical_structure ,Cell culture ,Immunology ,medicine.symptom ,Oxidative stress - Abstract
Esophagitis, whether caused by acid reflux, allergic responses, graft-versus-host disease, drugs, or infections, is a common condition of the gastrointestinal tract affecting nearly 20% of the US population. The instigating agent typically triggers an inflammatory response. The resulting inflammation is a risk factor for the development of esophageal strictures, Barrett esophagus, and esophageal adenocarcinoma. Research into the pathophysiology of these conditions has been limited by the availability of animal and human model systems. Three-dimensional organotypic tissue culture (OTC) is an innovative three-dimensional multicellular in vitro platform that recapitulates normal esophageal epithelial stratification and differentiation. We hypothesized that this platform can be used to model esophagitis to better understand the interactions between immune cells and the esophageal epithelium. We found that human immune cells remain viable and respond to cytokines when cultured under OTC conditions. The acute inflammatory environment induced in the OTC significantly affected the overlying epithelium, inducing a regenerative response marked by increased cell proliferation and epithelial hyperplasia. Moreover, oxidative stress from the acute inflammation induced DNA damage and strand breaks in epithelial cells, which could be reversed by antioxidant treatment. These findings support the importance of immune cell–mediated esophageal injury in esophagitis and confirms the utility of the OTC platform to characterize the underlying molecular events in esophagitis.
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- 2017
28. Increasing the Complexity of Organoid Cultures: Current Status and Future Challenges
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John P. Lynch
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Hepatology ,Gastroenterology ,Organoid ,Coculture Technique ,Computational biology ,Biology ,Current (fluid) - Published
- 2019
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29. Barrett's Esophagus Translational Research Network (BETRNet): The Pivotal Role of Multi-institutional Collaboration in Esophageal Adenocarcinoma Research
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Sanford D. Markowitz, Julian A. Abrams, Rihab Yassin, Eric J. Seibel, Henry D. Appelman, Kenneth K. Wang, Gary W. Falk, John P. Lynch, Yu Shyr, David G. Beer, Anil K. Rustgi, Ellen Richmond, Amitabh Chak, Thomas D. Wang, William M. Grady, Rebecca C. Fitzgerald, Nicholas J. Shaheen, Gregory G. Ginsberg, Timothy C. Wang, Asad Umar, Bishnu P. Joshi, and Lynne D. Berry
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Pathology ,medicine.medical_specialty ,Databases, Factual ,Esophageal Neoplasms ,Translational research ,Tissue Banks ,Disease ,Adenocarcinoma ,Article ,Translational Research, Biomedical ,Barrett Esophagus ,Risk Factors ,medicine ,Animals ,Humans ,Organizational Objectives ,Cooperative Behavior ,Medical education ,Cancer prevention ,Hepatology ,business.industry ,Gastroenterology ,Cancer ,Prognosis ,medicine.disease ,Interinstitutional Relations ,Biorepository ,Tissue bank ,Barrett's esophagus ,business - Abstract
The incidence of esophageal adenocarcinoma (EAC) has been increasing steadily over the past few decades,1 despite widespread recognition of the problem and a vast body of research. This disease is believed to originate in the broadest sense from Barrett’s Esophagus (BE), the recognized precursor of EAC, but current methods for surveillance have not been found to be effective in defining patients at risk. While a number of molecular and cellular mechanisms that underlie the transformation of BE to EAC have been outlined, their utility in understanding and preventing the progression of this cancer or in managing the intervention-resistant clones has not been demonstrated in a number of proposed models. As the rate of progression of BE to EAC is very low, estimated at
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- 2014
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30. A multicenter study to standardize reporting and analyses of fluorescence-activated cell-sorted murine intestinal epithelial cells
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John S. Kaddis, Calvin J. Kuo, Courtney W. Houchen, Jiafang Wang, Susan J. Henning, James C.Y. Dunn, John P. Lynch, Martin G. Martin, Matthias Stelzner, Jian Yu, Brent J. Puthoff, Kelley S. Yan, Linheng Li, Dajun Qian, Mary Ann S. Crissey, Xinwei Wang, Joyce C. Niland, Scott T. Magness, Melissa H. Wong, Barbara Olack, Randal May, Fengchao Wang, and John R. Swain
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Male ,Cell Survival ,Physiology ,Cellular differentiation ,Cell ,Population ,Cell Culture Techniques ,Biology ,Flow cytometry ,Mice ,Intestinal mucosa ,Physiology (medical) ,medicine ,Animals ,Intestinal Mucosa ,education ,Observer Variation ,education.field_of_study ,Staining and Labeling ,Hepatology ,medicine.diagnostic_test ,CD44 ,Gastroenterology ,LGR5 ,Epithelial Cells ,Cell sorting ,Flow Cytometry ,Mice, Inbred C57BL ,Hyaluronan Receptors ,medicine.anatomical_structure ,Gene Expression Regulation ,Immunology ,Call for Papers ,biology.protein - Abstract
Fluorescence-activated cell sorting (FACS) is an essential tool for studies requiring isolation of distinct intestinal epithelial cell populations. Inconsistent or lack of reporting of the critical parameters associated with FACS methodologies has complicated interpretation, comparison, and reproduction of important findings. To address this problem a comprehensive multicenter study was designed to develop guidelines that limit experimental and data reporting variability and provide a foundation for accurate comparison of data between studies. Common methodologies and data reporting protocols for tissue dissociation, cell yield, cell viability, FACS, and postsort purity were established. Seven centers tested the standardized methods by FACS-isolating a specific crypt-based epithelial population (EpCAM+/CD44+) from murine small intestine. Genetic biomarkers for stem/progenitor (Lgr5 and Atoh 1) and differentiated cell lineages (lysozyme, mucin2, chromogranin A, and sucrase isomaltase) were interrogated in target and control populations to assess intra- and intercenter variability. Wilcoxon's rank sum test on gene expression levels showed limited intracenter variability between biological replicates. Principal component analysis demonstrated significant intercenter reproducibility among four centers. Analysis of data collected by standardized cell isolation methods and data reporting requirements readily identified methodological problems, indicating that standard reporting parameters facilitate post hoc error identification. These results indicate that the complexity of FACS isolation of target intestinal epithelial populations can be highly reproducible between biological replicates and different institutions by adherence to common cell isolation methods and FACS gating strategies. This study can be considered a foundation for continued method development and a starting point for investigators that are developing cell isolation expertise to study physiology and pathophysiology of the intestinal epithelium.
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- 2013
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31. Upregulated heme biosynthesis, an exploitable vulnerability in MYCN-driven leukemogenesis
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Yiping Fan, Shinjiro Nagai, Yu Fukuda, Ayten Kandilci, Geoffrey Neale, Yao Wang, John D. Schuetz, Martine F. Roussel, John P. Lynch, Laura J. Janke, Brian P. Sorrentino, Shangli Lian, Bruce Fanshawe, and Gerard Grosveld
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0301 basic medicine ,Abcg2 ,biology ,General Medicine ,medicine.disease ,Porphyrin ,Molecular biology ,In vitro ,Cell biology ,03 medical and health sciences ,Leukemia ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Downregulation and upregulation ,embryonic structures ,medicine ,biology.protein ,Progenitor cell ,Heme ,neoplasms ,Homeostasis ,Research Article - Abstract
The increased heme biosynthesis long observed in leukemia was previously of unknown significance. Heme, synthesized from porphyrin precursors, plays a central role in oxygen metabolism and mitochondrial function, yet little is known about its role in leukemogenesis. Here, we show increased expression of heme biosynthetic genes, including UROD, only in pediatric AML samples that have high MYCN expression. High expression of both UROD and MYCN predicts poor overall survival and unfavorable outcomes in adult AML. Murine leukemic progenitors derived from hematopoietic progenitor cells (HPCs) overexpressing a MYCN cDNA (MYCN-HPCs) require heme/porphyrin biosynthesis, accompanied by increased oxygen consumption, to fully engage in self-renewal and oncogenic transformation. Blocking heme biosynthesis reduced mitochondrial oxygen consumption and markedly suppressed self-renewal. Leukemic progenitors rely on balanced production of heme and heme intermediates, the porphyrins. Porphyrin homeostasis is required because absence of the porphyrin exporter, ABCG2, increased death of leukemic progenitors in vitro and prolonged the survival of mice transplanted with Abcg2-KO MYCN-HPCs. Pediatric AML patients with elevated MYCN mRNA display strong activation of TP53 target genes. Abcg2-KO MYCN-HPCs were rescued from porphyrin toxicity by p53 loss. This vulnerability was exploited to show that treatment with a porphyrin precursor, coupled with the absence of ABCG2, blocked MYCN-driven leukemogenesis in vivo, thereby demonstrating that porphyrin homeostasis is a pathway crucial to MYCN leukemogenesis.
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- 2016
32. P396 Pharmacokinetics, immunogenicity and clinical outcomes of golimumab from the PURSUIT PEDS ulcerative colitis study long-term (through week 126) extension
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R. Strauss, Dan Turner, Daphne Chan, J Adedokun, Gigi Veereman, Joel R. Rosh, Anne M. Griffiths, John P. Lynch, Lakshmi Padgett, Ghassan Wahbeh, J. Hyams, Melvin B. Heyman, and Christopher D. O'Brien
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Oncology ,medicine.medical_specialty ,business.industry ,Immunogenicity ,Gastroenterology ,Cancer ,General Medicine ,medicine.disease ,Ulcerative colitis ,Golimumab ,Term (time) ,Pharmacokinetics ,Internal medicine ,medicine ,business ,medicine.drug - Published
- 2018
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33. H. pylori Infection Is Associated with DNA Damage of Lgr5-Positive Epithelial Stem Cells in the Stomach of Patients with Gastric Cancer
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John P. Lynch, Amy Ziober, Michael Feldman, Deqin Ma, Hiroyoshi Ota, Knashawn H. Morales, Yuan Yao, Antonia R. Sepulveda, and Takeshi Uehara
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Pathology ,medicine.medical_specialty ,biology ,Physiology ,DNA damage ,business.industry ,Stomach ,Gastroenterology ,Helicobacter pylori ,biology.organism_classification ,Molecular biology ,medicine.anatomical_structure ,medicine ,Gastric mucosa ,Gastritis ,medicine.symptom ,Enterochromaffin-like cell ,Stem cell ,business ,Antrum - Abstract
H. pylori (Hp) infection is a major risk factor in gastric carcinogenesis leading to epithelial mutagenesis, and may affect gastric epithelial stem cells. To characterize the expression of Lgr5, a marker of epithelial stem cells in human gastric mucosa, to determine whether Hp infection affects Lgr5-positive epithelial cells (LPECs) and whether LPECs are susceptible to DNA damage associated with Hp infection. Lgr5 expression was characterized in non-neoplastic gastric mucosa from 52 patients (34 with and 18 without gastric cancer (GC); 21 Hp-positive (Hp+) and 31 Hp-negative (Hp−)) by immunohistochemical and immunofluorescence staining. To determine the extent of DNA damage in LPECs, nuclear 8-hydroxydeoxyguanosine (8OHdG), a marker of DNA damage associated with oxidative stress, was measured by quantitative spectral image analysis. LPECs were primarily present in gastric antrum. Higher numbers of LPECs were seen in Hp+ than in Hp− non-neoplastic mucosa of GC patients, P = .006, but not in patients without GC. 8OHdG levels in LPECs were significantly higher than in Lgr5-negative epithelial cells in Hp+ GC patients (P = .012) but not in Hp− cases (P = .414), whereas no difference was seen between Hp+ and Hp− mucosa of patients without GC. The Lgr5-positive epithelial stem cell pool is expanded in Hp-associated gastritis in the antrum of patients with GC. In GC patients with active Hp infection, LPECs may be more susceptible to DNA damage than Lgr5-negative epithelial cells, suggesting that Hp infection may contribute to GC risk by affecting epithelial stem cells in the human stomach.
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- 2012
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34. A nomenclature for intestinal in vitro cultures
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Jian Yu, Calvin J. Kuo, Matthias Stelzner, Martin G. Martin, Michael A. Helmrath, Scott T. Magness, Courtney W. Houchen, Susan J. Henning, John P. Lynch, James C.Y. Dunn, Linheng Li, and Melissa H. Wong
- Subjects
Pathology ,medicine.medical_specialty ,Colon ,Physiology ,Mesenchyme ,Cell ,Cell Culture Techniques ,Reviews ,Biology ,Intestinal mucosa ,Terminology as Topic ,Physiology (medical) ,Intestine, Small ,medicine ,Organoid ,Humans ,Intestinal Mucosa ,Hepatology ,Stem Cells ,Gastroenterology ,Small intestine ,In vitro ,Cell biology ,medicine.anatomical_structure ,Cell culture ,Stem cell - Abstract
Many advances have been reported in the long-term culture of intestinal mucosal cells in recent years. A significant number of publications have described new culture media, cell formations, and growth patterns. Furthermore, it is now possible to study, e.g., the capabilities of isolated stem cells or the interactions between stem cells and mesenchyme. However, at the moment there is significant variation in the way these structures are described and named. A standardized nomenclature would benefit the ability to communicate and compare findings from different laboratories using the different culture systems. To address this issue, members of the NIH Intestinal Stem Cell Consortium herein propose a systematic nomenclature for in vitro cultures of the small and large intestine. We begin by describing the structures that are generated by preparative steps. We then define and describe structures produced in vitro, specifically: enterosphere, enteroid, reconstituted intestinal organoid, induced intestinal organoid, colonosphere, colonoid, and colonic organoid.
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- 2012
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35. How Changes In Washington University’s Medicare Coordinated Care Demonstration Pilot Ultimately Achieved Savings
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Randall Brown, Deborah Peikes, Sandy Graff, Greg Peterson, and John P. Lynch
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Aged, 80 and over ,Gerontology ,Chronic care ,Missouri ,Universities ,business.industry ,Health Policy ,MEDLINE ,Pilot Projects ,Medicare ,medicine.disease ,United States ,Patient Care Management ,Medication Reconciliation ,Cost Savings ,Phone ,Humans ,Medicine ,Medical emergency ,business ,Aged - Abstract
As one of the initial fifteen participants in the Medicare Coordinated Care Demonstration, the Washington University School of Medicine in St. Louis was not able to demonstrate any reduction in hospitalizations or Medicare spending for the patients it served. In fact, the Washington University program increased total Medicare spending by 12 percent. But after a redesign, the results changed. The program stopped conducting care management of most of its patients via telephone from a remote site in California and, instead, served all patients through frequent phone and occasional in-person contact from local care managers in St. Louis. Care management efforts were focused especially on patients deemed at greatest risk of hospitalization, and stronger hospital transition planning and medication reconciliation were provided, among other changes. After that point, the program reduced hospitalizations by 12 percent and monthly Medicare spending by $217 per enrollee-more than offsetting the program's monthly $151 care management fee. The results underscore findings from the overall Medicare Coordinated Care Demonstration that suggest that programs with more in-person contacts were more likely than others to build trusting relationships with patients and providers, improve patient adherence to care plans, and address additional needs and barriers that entirely telephonic contacts had been unable to identify. The results also indicate that programs can be more effective by focusing on the highest-risk patients, for whom the largest savings resulted.
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- 2012
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36. Autophagy inhibitor Lys05 has single-agent antitumor activity and reproduces the phenotype of a genetic autophagy deficiency
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Arabinda Samanta, Antonia R. Sepulveda, Zhihui Zhang, Xiao Hong Ma, Lisa E. Davis, Jeffrey D. Winkler, Ravi K. Amaravadi, John P. Lynch, Samuel M. Levi, Quentin McAfee, Takeshi Uehara, and Shengfu Piao
- Subjects
Programmed cell death ,Autophagy-Related Proteins ,Mice, Nude ,Antineoplastic Agents ,Adenocarcinoma ,Pharmacology ,Biology ,Antimalarials ,Mice ,Chloroquine ,In vivo ,Lysosome ,Autophagy ,Polyamines ,medicine ,Animals ,Humans ,ATG16L1 ,Multidisciplinary ,Cell Death ,Brain Neoplasms ,Biological Sciences ,Xenograft Model Antitumor Assays ,medicine.anatomical_structure ,Drug Resistance, Neoplasm ,Colonic Neoplasms ,Paneth cell ,Cancer cell ,Aminoquinolines ,Carrier Proteins ,Glioblastoma ,Lysosomes ,HT29 Cells ,Intestinal Obstruction ,Hydroxychloroquine ,medicine.drug - Abstract
Autophagy is a lysosome-dependent degradative process that protects cancer cells from multiple stresses. In preclinical models, autophagy inhibition with chloroquine (CQ) derivatives augments the efficacy of many anticancer therapies, but CQ has limited activity as a single agent. Clinical trials are underway combining anticancer agents with hydroxychloroquine (HCQ), but concentrations of HCQ required to inhibit autophagy are not consistently achievable in the clinic. We report the synthesis and characterization of bisaminoquinoline autophagy inhibitors that potently inhibit autophagy and impair tumor growth in vivo. The structural motifs that are necessary for improved autophagy inhibition compared with CQ include the presence of two aminoquinoline rings and a triamine linker and C-7 chlorine. The lead compound, Lys01, is a 10-fold more potent autophagy inhibitor than HCQ. Compared with HCQ, Lys05, a water-soluble salt of Lys01, more potently accumulates within and deacidifies the lysosome, resulting in impaired autophagy and tumor growth. At the highest dose administered, some mice develop Paneth cell dysfunction that resembles the intestinal phenotype of mice and humans with genetic defects in the autophagy gene ATG16L1 , providing in vivo evidence that Lys05 targets autophagy. Unlike HCQ, significant single-agent antitumor activity is observed without toxicity in mice treated with lower doses of Lys05, establishing the therapeutic potential of this compound in cancer.
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- 2012
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37. Prognostic Risk Score From a Multicenter Cohort of Patients With T1b Esophageal Adenocarcinoma: 2017 Presidential Poster Award
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Prasad G. Iyer, Julian A. Abrams, Lori S. Lutzke, Cadman L. Leggett, Fouad Otaki, Gregory G. Ginsberg, Anna Krigel, Michele L. Johnson, Timothy C. Wang, Charles J. Lightdale, Gary W. Falk, Kenneth K. Wang, Anil K. Rustgi, Christopher H. Blevins, John P. Lynch, and Gene K. Ma
- Subjects
medicine.medical_specialty ,Framingham Risk Score ,Hepatology ,business.industry ,Internal medicine ,Cohort ,Gastroenterology ,Medicine ,Esophageal adenocarcinoma ,business - Published
- 2017
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38. Math1/Atoh1 Contributes to Intestinalization of Esophageal Keratinocytes by Inducing the Expression of Muc2 and Keratin-20
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Mary Ann S. Crissey, Jianping Kong, John P. Lynch, and Antonia R. Sepulveda
- Subjects
Keratinocytes ,Pathology ,medicine.medical_specialty ,Physiology ,Gene Expression ,Keratin-20 ,Mucin 2 ,Biology ,Cell morphology ,digestive system ,Article ,Cell Line ,Barrett Esophagus ,Esophagus ,Culture Techniques ,Metaplasia ,Basic Helix-Loop-Helix Transcription Factors ,medicine ,Humans ,RNA, Messenger ,Cells, Cultured ,Cell Proliferation ,Mucin-2 ,Keratin 20 ,Gastroenterology ,Intestinal metaplasia ,Cell Differentiation ,medicine.disease ,digestive system diseases ,medicine.anatomical_structure ,Barrett's esophagus ,Cancer research ,Ectopic expression ,Goblet Cells ,medicine.symptom - Abstract
Esophageal intestinal metaplasia, also known as Barrett’s esophagus, is the replacement of the normal epithelium with one that resembles the intestine morphologically. Generally, this includes intestinal mucin-secreting goblet cells. Barrett’s esophagus is an important risk factor for adenocarcinoma development. In-vitro models for Barrett’s esophagus have not, to date, focused on the induction of goblet cells in Barrett’s epithelium. To explore the contribution of Math1/Atoh1 to induction of Barrett’s esophagus and intestinal mucin-secreting goblet cells from normal human esophageal epithelium. We explored the level and pattern of Math1/Atoh1 mRNA and protein expression in human Barrett’s esophagus. Then, using retroviral-mediated gene expression, we induced Math1 mRNA and protein expression in a human esophageal keratinocyte cell line. We evaluated the effects of this ectopic Math1 expression on cell proliferation and gene expression patterns in cells cultured under two-dimensional and three-dimensional tissue-engineering conditions. Math1/Atoh1 mRNA and protein are detected in human Barrett’s esophagus specimens, but the mRNA levels vary substantially. In the keratinocyte expression studies, we observed that Math1/Atoh1 ectopic expression significantly reduced cell proliferation and altered cell morphology. Moreover, Math1/Atoh1 expression is associated with a more intestinalized gene expression pattern that is distinct from that reported in after studies using other intestinal transcription factors. Most significantly, we observe the induction of the Barrett’s esophagus markers Mucin-2 and Keratin-20 with Math1/Atoh1 expression. We conclude that ectopic Math1/Atoh1 expression makes unique contributions to intestinalization of the esophageal epithelium in Barrett’s esophagus.
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- 2011
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39. Molecular mechanisms of Barrett's esophagus and adenocarcinoma
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Katerina Dvorak, John P. Lynch, JeanMarie Houghton, Kausilia K. Krishnadath, Hao Chen, Aaron Goldman, Lloyd Hutchinson, Jianping Kong, Xiaoxin Chen, and Wytske Westra
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medicine.medical_specialty ,business.industry ,General Neuroscience ,Intestinal metaplasia ,medicine.disease ,digestive system ,Gastroenterology ,digestive system diseases ,General Biochemistry, Genetics and Molecular Biology ,surgical procedures, operative ,medicine.anatomical_structure ,History and Philosophy of Science ,Barrett's esophagus ,Metaplasia ,Internal medicine ,medicine ,Cancer research ,Adenocarcinoma ,Bone marrow ,medicine.symptom ,Esophagus ,CDX2 ,business ,Transcription factor - Abstract
The following on molecular mechanisms of Barrett's esophagus and adenocarcinoma contains commentaries on the mechanism of bile and gastric acid induced damage; the roles of BMP-4 and CDX-2 in the development of intestinal metaplasia; the transcription factors driving intestinalization in Barrett's esophagus; the contribution of bone marrow to metaplasia and adenocarcinoma; activation and inactivation of transcription factors; and a novel study design targeting molecular pathways in Barrett's esophagus.
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- 2011
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40. Barrett's esophagus: genetic and cell changes
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Jean S. Wang, Andrew C. Chang, Giancarlo Freschi, John P. Lynch, Kiron M. Das, Paolo Bechi, Manisha Bajpai, Rhonda F. Souza, Maria Novella Ringressi, Usha Malhotra, George Triadafilopoulos, Paul M. Schneider, Antonio Taddei, Hugh Barr, Kausilia K. Krishnadath, Francesca Castiglione, and Duccio Rossi Degl'Innocenti
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Pathology ,medicine.medical_specialty ,Stromal cell ,General Neuroscience ,Intestinal metaplasia ,Biology ,medicine.disease ,medicine.disease_cause ,digestive system diseases ,General Biochemistry, Genetics and Molecular Biology ,medicine.anatomical_structure ,History and Philosophy of Science ,CDKN2A ,Barrett's esophagus ,Metaplasia ,medicine ,Adenocarcinoma ,medicine.symptom ,Esophagus ,Carcinogenesis - Abstract
The following includes commentaries on how genetic code of Barrett's esophagus (BE) patients, the mechanisms for GERD-induced esophageal expression of caudal homeobox, and the development of Barrett's metaplasia are increasingly better known, including the role of stromal genes in oncogenesis. Additional lessons have been learned in vitro models in nonneoplastic cell lines, yet there are limitations to what can be expected from BE-derived cell lines. Other topics discussed include clonal diversity in Barrett's esophagus; the application of peptide arrays to clinical samples of metaplastic mucosa; proliferation and apoptosis of Barrett's cell lines; tissue biomarkers for neoplasia; and transcription factors associated with BE.
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- 2011
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41. TCF4 and CDX2, major transcription factors for intestinal function, converge on the same cis -regulatory regions
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Ellen Freed, Jurian Schuijers, Rita Sulahian, Hyunjin Shin, Michael P. Verzi, Hans Clevers, Pantelis Hatzis, X. Shirley Liu, Juliet Philips, John P. Lynch, Myles Brown, Ramesh A. Shivdasani, Duyen T. Dang, and Hubrecht Institute for Developmental Biology and Stem Cell Research
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Molecular Sequence Data ,Regulatory Sequences, Nucleic Acid ,Biology ,Transcription Factor 4 ,Humans ,CDX2 Transcription Factor ,RNA, Messenger ,RNA, Neoplasm ,Intestinal Mucosa ,Enhancer ,CDX2 ,Transcription factor ,Homeodomain Proteins ,Genetics ,Binding Sites ,Multidisciplinary ,Base Sequence ,Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ,Genetic Complementation Test ,Wnt signaling pathway ,TCF4 ,Biological Sciences ,Intestinal epithelium ,Wnt Proteins ,Regulatory sequence ,Colonic Neoplasms ,Caco-2 Cells ,Chromatin immunoprecipitation ,Signal Transduction ,Transcription Factors - Abstract
Surprisingly few pathways signal between cells, raising questions about mechanisms for tissue-specific responses. In particular, Wnt ligands signal in many mammalian tissues, including the intestinal epithelium, where constitutive signaling causes cancer. Genome-wide analysis of DNA cis -regulatory regions bound by the intestine-restricted transcription factor CDX2 in colonic cells uncovered highly significant overrepresentation of sequences that bind TCF4, a transcriptional effector of intestinal Wnt signaling. Chromatin immunoprecipitation confirmed TCF4 occupancy at most such sites and co-occupancy of CDX2 and TCF4 across short distances. A region spanning the single nucleotide polymorphism rs6983267, which lies within a MYC enhancer and confers colorectal cancer risk in humans, represented one of many co-occupied sites. Co-occupancy correlated with intestine-specific gene expression and CDX2 loss reduced TCF4 binding. These results implicate CDX2 in directing TCF4 binding in intestinal cells. Co-occupancy of regulatory regions by signal-effector and tissue-restricted transcription factors may represent a general mechanism for ubiquitous signaling pathways to achieve tissue-specific outcomes.
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- 2010
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42. The Homeodomain Transcription Factor Cdx1 Does Not Behave as an Oncogene in Normal Mouse Intestine
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Jonathan P. Katz, Rong-Jun Guo, EunRan Suh, Franz Fogt, John P. Lynch, Debra G. Silberg, Hong Li, and Mary Ann S. Crissey
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Cancer Research ,Colon ,Cellular differentiation ,Transgene ,Mice, Transgenic ,lcsh:RC254-282 ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Intestinal mucosa ,Animals ,CDX2 Transcription Factor ,Cell Lineage ,RNA, Messenger ,Intestinal Mucosa ,CDX2 ,030304 developmental biology ,Cell Proliferation ,Homeodomain Proteins ,0303 health sciences ,Oncogene ,biology ,Cell Differentiation ,Oncogenes ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Intestinal epithelium ,Intestines ,Cell Transformation, Neoplastic ,030220 oncology & carcinogenesis ,Colonic Neoplasms ,biology.protein ,Cancer research ,Ectopic expression ,Villin ,Transcription Factors ,Research Article - Abstract
The Caudal-related homeobox genes Cdx1 and Cdx2 are intestine-specific transcription factors that regulate differentiation of intestinal cell types. Previously, we have shown Cdx1 to be antiproliferative and to promote cell differentiation. However, other studies have suggested that Cdx1 may be an oncogene. To test for oncogenic behavior, we used the murine villin promoter to ectopically express Cdx1 in the small intestinal villi and colonic surface epithelium. No changes in intestinal architecture, cell differentiation, or lineage selection were observed with expression of the transgene. Classic oncogenes enhance proliferation and induce tumors when ectopically expressed. However, the Cdx1 transgene neither altered intestinal proliferation nor induced spontaneous intestinal tumors. In a murine model for colitis-associated cancer, the Cdx1 transgene decreased, rather than increased, the number of adenomas that developed. In the polyps, the expression of the endogenous and the transgenic Cdx1 proteins was largely absent, whereas endogenous Villin expression was retained. This suggests that transgene silencing was specific and not due to a general Villin inactivation. In conclusion, neither the ectopic expression of Cdx1 was associated with changes in intestinal cell proliferation or differentiation nor was there increased intestinal cancer susceptibility. Our results therefore suggest that Cdx1 is not an oncogene in normal intestinal epithelium.
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- 2008
43. The homeodomain transcription factors Cdx1 and Cdx2 induce E-cadherin adhesion activity by reducing β- and p120-catenin tyrosine phosphorylation
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Albert B. Reynolds, Hong Li, Rong-Jun Guo, Toshihiko Ezaki, and John P. Lynch
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Delta Catenin ,Physiology ,Protein tyrosine phosphatase ,Biology ,Transfection ,Mice ,chemistry.chemical_compound ,Cell Movement ,Cell Line, Tumor ,Physiology (medical) ,Gene expression ,Cell Adhesion ,Animals ,Humans ,CDX2 Transcription Factor ,Phosphorylation ,Tyrosine ,CDX2 ,Transcription factor ,beta Catenin ,Homeodomain Proteins ,Protein Tyrosine Phosphatase, Non-Receptor Type 1 ,Hepatology ,Cadherin ,Gastroenterology ,Catenins ,Tyrosine phosphorylation ,Cadherins ,Phosphoproteins ,digestive system diseases ,Cell biology ,chemistry ,Colonic Neoplasms ,embryonic structures ,Cancer research ,Protein Tyrosine Phosphatases ,Cell Adhesion Molecules ,Transcription Factors - Abstract
The homeodomain transcription factors Cdx1 and Cdx2 are regulators of intestine-specific gene expression. They also regulate intestinal cell differentiation and proliferation; however, these effects are poorly understood. Previously, we have shown that expression of Cdx1 or Cdx2 in human Colo 205 cells induces a mature colonocyte morphology characterized by the induction of a polarized, columnar shape with apical microvilli and strong cell-cell adhesion. To elucidate the mechanism underlying this phenomenon, we investigated the adherens junction complex. Cdx1 or Cdx2 expression reduced Colo 205 cell migration and invasion in vitro, suggesting a physiologically significant change in cadherin function. However, Cdx expression did not significantly effect E-cadherin, alpha-, beta-, or gamma-catenin, or p120-catenin protein levels. Additionally, no alteration in their intracellular distribution was observed. Cdx expression did not alter the coprecipitation of beta-catenin with E-cadherin; however, it did reduce p120-catenin-E-cadherin coprecipitation. Tyrosine phosphorylation of beta- and p120-catenin is known to disrupt E-cadherin-mediated cell adhesion and is associated with robust p120-catenin/E-cadherin interactions. We specifically investigated beta- and p120-catenin for tyrosine phosphorylation and found that it was significantly diminished by Cdx1 or Cdx2 expression. We restored beta- and p120-catenin tyrosine phosphorylation in Cdx2-expressing cells by knocking down the expression of protein tyrosine phosphatase 1B and noted a significant decline in cell-cell adhesion. We conclude that Cdx expression in Colo 205 cells induces E-cadherin-dependent cell-cell adhesion by reducing beta- and p120-catenin tyrosine phosphorylation. Ascertaining the mechanism for this novel Cdx effect may improve our understanding of the regulation of cell-cell adhesion in the colonic epithelium.
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- 2007
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44. Immature myeloid progenitors promote disease progression in a mouse model of Barrett's-like metaplasia
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Julian A. Abrams, Anil K. Rustgi, Hiroshi Nakagawa, Gary W. Falk, Hong Sai, Jianping Kong, Timothy C. Wang, Mary Ann S. Crissey, Kenneth K. Wang, Nirag Jhala, John P. Lynch, and Gregory G. Ginsberg
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Pathology ,medicine.medical_specialty ,Myeloid ,Esophageal Neoplasms ,T cell ,Population ,Interleukin-1beta ,Apoptosis ,Mice, Transgenic ,Barrett Esophagus ,Mice ,Barrett's esophagus ,Metaplasia ,medicine ,Animals ,Esophagitis ,Humans ,CDX2 Transcription Factor ,Myeloid Cells ,Progenitor cell ,CDX2 ,education ,S100A9 ,Homeodomain Proteins ,education.field_of_study ,business.industry ,medicine.disease ,digestive system diseases ,3. Good health ,Disease Models, Animal ,IL-17 ,medicine.anatomical_structure ,Oncology ,IL-1β ,Cancer research ,Disease Progression ,myeloid-derived suppressor cells (MDSC) ,medicine.symptom ,business ,CD8 ,Transcription Factors ,Research Paper - Abstract
// Jianping Kong 1 , Hong Sai 1 , Mary Ann S. Crissey 1 , Nirag Jhala 2 , Gary W. Falk 1 , Gregory G. Ginsberg 1 , Julian A. Abrams 3 , Hiroshi Nakagawa 1 , Kenneth Wang 4 , Anil K. Rustgi 1 , Timothy C. Wang 3 , John P. Lynch 1 1 Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA 2 Department of Pathology, Temple University, Philadelphia, PA, USA 3 Division of Gastroenterology, Columbia University, New York, NY, USA 4 Division of Gastroenterology, Mayo Clinic, Rochester, MN, USA Correspondence to: John P. Lynch, e-mail: lynchj@mail.med.upenn.edu Keywords: Barrett’s esophagus, myeloid-derived suppressor cells (MDSC), IL-17, S100A9, IL-1β Received: August 14, 2015 Accepted: October 02, 2015 Published: October 12, 2015 ABSTRACT Cdx2, an intestine specific transcription factor, is expressed in Barrett’s esophagus (BE). We sought to determine if esophageal Cdx2 expression would accelerate the onset of metaplasia in the L2-IL-1β transgenic mouse model for Barrett’s-like metaplasia. The K14-Cdx2::L2-IL-1β double transgenic mice had half as many metaplastic nodules as control L2-IL-1β mice. This effect was not due to a reduction in esophageal IL-1 β mRNA levels nor diminished systemic inflammation. The diminished metaplasia was due to an increase in apoptosis in the K14-Cdx2::L2-IL-1β mice. Fluorescence activated cell sorting of immune cells infiltrating the metaplasia identified a population of CD11b + Gr-1 + cells that are significantly reduced in K14-Cdx2::L2-IL-1β mice. These cells have features of immature granulocytes and have immune-suppressing capacity. We demonstrate that the apoptosis in K14-Cdx2::L2-IL-1β mice is CD8 + T cell dependent, which CD11b + Gr-1 + cells are known to inhibit. Lastly, we show that key regulators of CD11b + Gr-1 + cell development, IL-17 and S100A9, are significantly diminished in the esophagus of K14-Cdx2::L2-IL-1β double transgenic mice. We conclude that metaplasia development in this mouse model for Barrett’s-like metaplasia requires suppression of CD8+ cell dependent apoptosis, likely mediated by immune-suppressing CD11b + Gr-1 + immature myeloid cells.
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- 2015
45. A Comparison of Basiliximab and Anti-Thymocyte Globluin as Induction Agents After Lung Transplantation
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Roger D. Yusen, Murali M. Chakinala, John P. Lynch, Ramsey R. Hachem, G. Alexander Patterson, Elbert P. Trulock, and Aviva Aloush
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Adult ,Graft Rejection ,Lung Diseases ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Globulin ,Basiliximab ,Recombinant Fusion Proteins ,medicine.medical_treatment ,Bronchiolitis obliterans ,Gastroenterology ,Internal medicine ,Bronchoscopy ,Humans ,Medicine ,Lung transplantation ,Bronchiolitis Obliterans ,Antilymphocyte Serum ,Retrospective Studies ,Pneumonitis ,First episode ,Transplantation ,biology ,business.industry ,Incidence (epidemiology) ,Graft Survival ,Antibodies, Monoclonal ,Receptors, Interleukin-2 ,Pneumonia ,Middle Aged ,medicine.disease ,Reperfusion Injury ,Cytomegalovirus Infections ,Immunology ,biology.protein ,Surgery ,Cardiology and Cardiovascular Medicine ,business ,Immunosuppressive Agents ,Lung Transplantation ,medicine.drug - Abstract
Background Interleukin-2 receptor antagonists have supplanted polyclonal antibody preparations as the most frequently used induction agents after lung transplantation, but the relative efficacy of these agents has not been firmly established. Methods We retrospectively analyzed the efficacy of basiliximab compared with antithymocyte globulin among 157 adult lung transplant recipients at our center. Results At 3, 6, and 12 months after transplantation, the median cumulative acute rejection A scores for the basiliximab group (2, 2, and 3, respectively) were significantly higher than those for the anti-thymocyte globulin group (1, 1, and 2, respectively; p = 0.003, 0.004, and 0.033, respectively). In addition, basiliximab recipients were more likely to develop acute rejection grade ≥ A2 than anti-thymocyte globulin recipients; in fact, 60% of basiliximab recipients compared with 38% of anti-thymocyte globulin recipients developed their first episode of acute rejection grade ≥ A2 in the first 100 days after transplantation (log-rank p = 0.04). Furthermore, basiliximab recipients were more likely to develop bronchiolitis obliterans syndrome than anti-thymocyte globulin recipients (log-rank p = 0.036). Two years after transplantation, 36% of basiliximab recipients and 26% of anti-thymocyte globulin recipients developed bronchiolitis obliterans syndrome. However, there were no significant differences in the incidences of cytomegalovirus viremia and pneumonitis between the 2 groups ( p = 0.86 and 0.89, respectively). Conclusions Induction with anti-thymocyte globulin is associated with a lower burden of acute rejection and bronchiolitis obliterans syndrome compared with basiliximab, without a significant difference in the incidence of cytomegalovirus infections.
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- 2005
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46. Reliability for Grading Acute Rejection and Airway Inflammation After Lung Transplantation
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Ramsey H. Hachem, Murali M. Chakinala, G. Alexander Patterson, Brian F. Gage, Jon H. Ritter, Aviva Aloush, John P. Lynch, and Elbert P. Trulock
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Adult ,Graft Rejection ,Male ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,medicine.medical_treatment ,Severity of Illness Index ,Cohort Studies ,Cohen's kappa ,Bronchoscopy ,Biopsy ,Humans ,Medicine ,Lung transplantation ,Bronchitis ,Grading (tumors) ,Observer Variation ,Transplantation ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Middle Aged ,Confidence interval ,Surgery ,Acute Disease ,Female ,Cardiology and Cardiovascular Medicine ,Nuclear medicine ,business ,Kappa ,Follow-Up Studies ,Lung Transplantation ,Cohort study - Abstract
Background The Lung Rejection Study Group (LRSG) created a scheme for grading acute allograft rejection in 1990 and then revised it in 1996, but virtually no studies have evaluated the reliability of this formulation. This investigation assessed the reliability of the current LRSG system by determining inter- and intrareader agreement for grading transbronchial biopsy samples from lung transplant recipients. Methods Biopsy samples from a cohort of 204 recipients were reviewed and classified by a single pathologist who was blinded to original interpretations. The "A" and "B" rejection grades from this contemporary review were compared with original grades by the kappa statistic. Results For "A" grading, weighted kappa was 0.65 (95% confidence interval [CI] 0.60–0.70) for interreader agreement ( n = 529 specimens) and 0.65 (95% CI 0.53–0.76) for intrareader agreement ( n = 97 specimens). For "B" grading, weighted kappa was 0.26 (95% CI 0.14–0.39) for interreader agreement ( n = 164 specimens) and 0.33 (95% CI 0.15–0.51) for intrareader agreement ( n = 58 specimens). Conclusions On the basis of the analysis of the LRSG scheme, "A" grades exhibit very good reliability, but "B" grades have only fair reliability, and steps to improve this shortcoming should be taken.
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- 2005
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47. The role of Cdx proteins in intestinal development and cancer
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Rong-Jun Guo, John P. Lynch, and EunRan Suh
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Homeodomain Proteins ,Pharmacology ,Genetics ,Regulation of gene expression ,Cancer Research ,Gene Expression Regulation, Developmental ,Intestinal metaplasia ,Biology ,medicine.disease ,medicine.disease_cause ,Phenotype ,Intestinal epithelium ,Cell biology ,Oncology ,Colonic Neoplasms ,Disease Progression ,medicine ,Humans ,Molecular Medicine ,CDX2 Transcription Factor ,Intestinal Mucosa ,CDX2 ,Carcinogenesis ,Gene ,Function (biology) - Abstract
Since their original identification in Drosophila, the caudal related homologues (Cdx1 and Cdx2) have been known to be evolutionarily conserved both in molecular structure and function. In a great variety of organisms they are recognized to function critically during antero-posterior patterning and the development of the intestinal epithelium. The Cdx homologues, when expressed, modulate a diverse set of processes including proliferation, apoptosis, cell-adhesion, and columnar morphology. They are also necessary for the expression of an increasing number of intestine-specific genes. By targeting these processes and genes, the Cdx homologues promote the appearance of a mature intestinal cell phenotype. In addition to these critical roles during development, accumulating evidence suggests that the Cdx homologues may play significant roles in oncogenesis in the gastrointestinal tract and other tissues. In the colon, several studies suggest the Cdx homologues may act as tumor suppressors. However, ectopic Cdx1 and Cdx2 expression is involved in the development of the precancerous intestinal metaplasia in the stomach and esophagus, and may be a transforming event in one form of acute myelogenous leukemia. This review will explore our current understanding of the roles of the caudal homologues Cdx1 and Cdx2 in intestinal development and carcinogenesis.
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- 2004
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48. Cdx1 or Cdx2 expression activates E-cadherin-mediated cell-cell adhesion and compaction in human COLO 205 cells
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Rong-Jun Guo, Toshihiko Ezaki, Matthew C. Keller, and John P. Lynch
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Transcriptional Activation ,Physiology ,Genetic Vectors ,Cell ,Morphogenesis ,Adenocarcinoma ,Biology ,Cell junction ,Antibodies ,Cell Line, Tumor ,Physiology (medical) ,Gene expression ,Cell Adhesion ,medicine ,Humans ,CDX2 Transcription Factor ,Cell adhesion ,CDX2 ,Homeodomain Proteins ,Hepatology ,Cadherin ,Gastroenterology ,Cell Polarity ,Cell Differentiation ,Cadherins ,Intestinal epithelium ,Cell biology ,Retroviridae ,medicine.anatomical_structure ,Colonic Neoplasms ,Trans-Activators ,Calcium - Abstract
A mature columnar intestinal epithelium develops late in embryogenesis and is maintained throughout the life of the organism. Although the mechanisms driving intestine-specific gene expression have been well studied, those promoting the acquisition of cell-cell junctions, columnar morphogenesis, and polarization have been less studied. The Cdx homeodomain transcription factors (Cdx1 and Cdx2) regulate intestine-specific gene expression and intestinal epithelial differentiation. We report here that Cdx expression induces E-cadherin activity and cell-cell adhesion in human COLO 205 cancer cells. Within days of Cdx1 or Cdx2 expression, a new homotypic cell-cell adhesion phenotype is induced. This is a specific response to Cdx, inasmuch as a Cdx1 mutant failed to elicit the effect. Additionally, Cdx-expressing COLO 205 cells demonstrate a reduced proliferative capacity and an increase in the mRNA expression of differentiation-associated genes. Electron micrographs of these cells demonstrate induction of tight, adherens, and desmosomal junctions, as well as a columnar shape and apical microvilli. Investigations of the adhesion phenotype determined that it was Ca2+dependent and could be blocked by an E-cadherin-blocking antibody. However, E-cadherin protein levels and intracellular distribution were unchanged. Cdx expression restored the ability of the cell membranes to adhere and undergo compaction. We conclude that Cdx1 or Cdx2 expression is sufficient to induce an E-cadherin-dependent adhesion of COLO 205 cells. This adhesion is associated with polarization and cell-cell membrane compaction, as well as induction of a differentiated gene-expression pattern. Ascertaining the mechanism for this novel Cdx effect may yield insight into the development of mature colonic epithelium.
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- 2004
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49. Abdominal-pelvic lymphoproliferative disease after lung transplantation: presentation and outcome
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John P. Lynch, Ramsey R. Hachem, Roger D. Yusen, Murali M. Chakinala, Aviva Aloush, Elbert P. Trulock, and G. Alexander Patterson
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Male ,Epstein-Barr Virus Infections ,medicine.medical_specialty ,Time Factors ,Gastrointestinal Diseases ,medicine.medical_treatment ,Pelvis ,hemic and lymphatic diseases ,Abdomen ,medicine ,Humans ,Lung transplantation ,Retrospective Studies ,Transplantation ,Chemotherapy ,Dose-Response Relationship, Drug ,business.industry ,Lymphoma, Non-Hodgkin ,Respiratory disease ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Burkitt Lymphoma ,Lymphoproliferative Disorders ,Lymphoma ,Surgery ,medicine.anatomical_structure ,Female ,business ,Complication ,Immunosuppressive Agents ,Lung Transplantation - Abstract
Background. Lymphoproliferative disease (LPD) is a well-recognized complication after lung transplantation. However, its presentation in the abdomen and pelvis has not been previously detailed. Methods. We retrospectively identified cases of abdominal-pelvic LPD in lung transplant recipients. The cases were characterized clinically, and the outcomes were analyzed. Results. Abdominal-pelvic LPD was identified in 19 of 603 adult patients who underwent lung or heart-lung transplantation at Barnes-Jewish Hospital between July 1, 1988 and December 31, 2001. The median time from transplantation to the onset of LPD was 5.8 years. Three cases presented early after transplantation (median, 175 days), and 16 cases presented late (median, 2,255 days). The time to diagnosis of LPD was significantly shorter for Epstein-Barr virus (EBV)-seronegative than for EBV-seropositive recipients (median, 175 vs. 2255 days; log-rank, P
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- 2004
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50. Molecular Pathology of Neoplastic Gastrointestinal Diseases
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Antonia R. Sepulveda, John P. Lynch, Antonia R. Sepulveda, and John P. Lynch
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- Pathology, Molecular, Gastrointestinal system--Diseases--Molecular aspects
- Abstract
Molecular Pathology of Neoplastic Gastrointestinal Diseases reviews the molecular aspects that characterize the spectrum of neoplastic conditions that affect the gastrointestinal tract, providing the reader with current up-to-date knowledge. For each disease entity chapters provide reviews on:the molecular basis of the individual diseasemolecular testing approaches currently available or in development for diagnosis or for gene target characterization for selective targeted therapiesrecommended guidelines for clinical application of molecular tests are included whenever availablemolecular testing for hereditary predisposition or disease riskanimal models and cell culture models of disease
- Published
- 2013
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