Gastroenterology Commons^™

Systematic-Narrative Hybrid Literature Review: Crosstalk Between Gastrointestinal Renin-Angiotensin And Dopaminergic Systems In The Regulation Of Intestinal Permeability By Tight Junctions, Nadia Khan, Magdalena Kurnik-Łucka, Gniewomir Latacz, Krzysztof Gil

Journal Articles

In the first part of this article, the role of intestinal epithelial tight junctions (TJs), together with gastrointestinal dopaminergic and renin-angiotensin systems, are narratively reviewed to provide sufficient background. In the second part, the current experimental data on the interplay between gastrointestinal (GI) dopaminergic and renin-angiotensin systems in the regulation of intestinal epithelial permeability are reviewed in a systematic manner using the PRISMA methodology. Experimental data confirmed the copresence of DOPA decarboxylase (DDC) and angiotensin converting enzyme 2 (ACE2) in human and rodent enterocytes. The intestinal barrier structure and integrity can be altered by angiotensin (1-7) and dopamine (DA). Both …

Intestinal Neuropod Cell Gucy2c Regulates Visceral Pain, Joshua R. Barton, Annie K. Londregran, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP(cGMP), which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we revealed that intestinal GUCY2C was selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2Chi neuropod cells associated with cocultured dorsal root ganglia neurons and induced hyperexcitability, reducing the rheobase and increasing the resulting …

The Gastrointestinal-Brain-Microbiota Axis: A Promising Therapeutic Target For Ischemic Stroke, Yan-Hao Wei, Ren-Tang Bi, Yan-Mei Qiu, Chun-Lin Zhang, Jian-Zhuang Li, Ya-Nan Li, Bo Hu

Journal Articles

Ischemic stroke is a highly complex systemic disease characterized by intricate interactions between the brain and gastrointestinal tract. While our current understanding of these interactions primarily stems from experimental models, their relevance to human stroke outcomes is of considerable interest. After stroke, bidirectional communication between the brain and gastrointestinal tract initiates changes in the gastrointestinal microenvironment. These changes involve the activation of gastrointestinal immunity, disruption of the gastrointestinal barrier, and alterations in gastrointestinal microbiota. Importantly, experimental evidence suggests that these alterations facilitate the migration of gastrointestinal immune cells and cytokines across the damaged blood-brain barrier, ultimately infiltrating the ischemic brain. …

Natural Killer Cells In Liver Transplantation: Can We Harness The Power Of The Immune Checkpoint To Promote Tolerance?, Jennifer Halma, Stephen Pierce, Rebecca Mclennan, Todd Bradley, Ryan T. Fischer

Manuscripts, Articles, Book Chapters and Other Papers

The roles that natural killer (NK) cells play in liver disease and transplantation remain ill-defined. Reports on the matter are often contradictory, and the mechanisms elucidated are complex and dependent on the context of the model tested. Moreover, NK cell attributes, such as receptor protein expression and function differ among species, make study of primate or rodent transplant models challenging. Recent insights into NK function and NK-mediated therapy in the context of cancer therapy may prove applicable to transplantation. Of specific interest are immune checkpoint molecules and the mechanisms by which they modulate NK cells in the tumor micro-environment. In …

Genomic Characterization Of Malignant Progression In Neoplastic Pancreatic Cysts, Michaël Noë, Noushin Niknafs, Catherine G Fischer, Wenzel M Hackeng, Violeta Beleva Guthrie, Waki Hosoda, Marija Debeljak, Eniko Papp, Vilmos Adleff, James R White, Claudio Luchini, Antonio Pea, Aldo Scarpa, Giovanni Butturini, Giuseppe Zamboni, Paola Castelli, Seung-Mo Hong, Shinichi Yachida, Nobuyoshi Hiraoka, Anthony J Gill, Jaswinder S Samra, G Johan A Offerhaus, Anne Hoorens, Joanne Verheij, Casper Jansen, N Volkan Adsay, Wei Jiang, Jordan Winter, Jorge Albores-Saavedra, Benoit Terris, Elizabeth D Thompson, Nicholas J Roberts, Ralph H Hruban, Rachel Karchin, Robert B Scharpf, Lodewijk A A Brosens, Victor E Velculescu, Laura D Wood

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are non-invasive neoplasms that are often observed in association with invasive pancreatic cancers, but their origins and evolutionary relationships are poorly understood. In this study, we analyze 148 samples from IPMNs, MCNs, and small associated invasive carcinomas from 18 patients using whole exome or targeted sequencing. Using evolutionary analyses, we establish that both IPMNs and MCNs are direct precursors to pancreatic cancer. Mutations in SMAD4 and TGFBR2 are frequently restricted to invasive carcinoma, while RNF43 alterations are largely in non-invasive lesions. Genomic analyses suggest an average window of over three …

Assessment Of Physical Fitness After Bariatric Surgery And Its Association With Protein Intake And Type Of Cholecalciferol Supplementation, Hendrika J M Smelt, Sjaak Pouwels, Alper Celik, Adarsh Gupta, Johannes F Smulders

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Background: Several studies showed that there is a relationship between vitamin and mineral status and muscle strength. In particular this is the case for handgrip strength (HS) and vitamin D deficiency. In bariatric surgery there is a risk of decrease in muscle strength after surgery and also vitamin and mineral deficiencies are not uncommon. The aim of this study is to assess the effect of low vitamin 25 (OH) cholecalciferol levels, high dose cholecalciferol supplementation regime and protein intake on physical fitness, measured using handgrip strength (HS) and the shuttle walk run test (SWRT). Methods: For this retrospective …

Identification Of Novel Regulatory Genes In Apap Induced Hepatocyte Toxicity By A Genome-Wide Crispr-Cas9 Screen., Katherine Shortt, Daniel P. Heruth, Nini Zhang, Weibin Wu, Shipra Singh, Ding-You Li, Li Qin Zhang, Gerald J. Wyckoff, Lei S Qi, Craig A. Friesen, Shui Qing Ye

Manuscripts, Articles, Book Chapters and Other Papers

Acetaminophen (APAP) is a commonly used analgesic responsible for more than half of acute liver failure cases. Identification of previously unknown genetic risk factors would provide mechanistic insights and novel therapeutic targets for APAP-induced liver injury. This study used a genome-wide CRISPR-Cas9 screen to evaluate genes that are protective against, or cause susceptibility to, APAP-induced liver injury. HuH7 human hepatocellular carcinoma cells containing CRISPR-Cas9 gene knockouts were treated with 15 mM APAP for 30 minutes to 4 days. A gene expression profile was developed based on the 1) top screening hits, 2) overlap of expression data from APAP overdose studies, …

Beta-Catenin Cleavage Enhances Transcriptional Activation, Tatiana Goretsky, Emily M. Bradford, Qing Ye, Olivia F. Lamping, Tomas Vanagunas, Mary Pat Moyer, Patrick C. Keller, Preetika Sinh, Josep M. Llovet, Tianyan Gao, Qing-Bai She, Linheng Li, Terrence A. Barrett

Internal Medicine Faculty Publications

Nuclear activation of Wnt/β-catenin signaling is required for cell proliferation in inflammation and cancer. Studies from our group indicate that β-catenin activation in colitis and colorectal cancer (CRC) correlates with increased nuclear levels of β-catenin phosphorylated at serine 552 (pβ-Cat⁵⁵²). Biochemical analysis of nuclear extracts from cancer biopsies revealed the existence of low molecular weight (LMW) pβ-Cat⁵⁵², increased to the exclusion of full size (FS) forms of β-catenin. LMW β-catenin lacks both termini, leaving residues in the armadillo repeat intact. Further experiments showed that TCF4 predominantly binds LMW pβ-Cat⁵⁵² in the nucleus of inflamed and …

Exome Analysis Of Rare And Common Variants Within The Nod Signaling Pathway., Gaia Andreoletti, Valentina Shakhnovich, Kathy Christenson, Tracy Coelho, Rachel Haggarty, Nadeem A. Afzal, Akshay Batra, Britt-Sabina Petersen, Matthew Mort, R Mark Beattie, Sarah Ennis

Manuscripts, Articles, Book Chapters and Other Papers

Pediatric inflammatory bowel disease (pIBD) is a chronic heterogeneous disorder. This study looks at the burden of common and rare coding mutations within 41 genes comprising the NOD signaling pathway in pIBD patients. 136 pIBD and 106 control samples underwent whole-exome sequencing. We compared the burden of common, rare and private mutation between these two groups using the SKAT-O test. An independent replication cohort of 33 cases and 111 controls was used to validate significant findings. We observed variation in 40 of 41 genes comprising the NOD signaling pathway. Four genes were significantly associated with disease in the discovery cohort …

Novel Genetic Variants Associated With Child Refractory Esophageal Stricture With Food Allergy By Exome Sequencing., Min Yang, Min Xiong, Huan Chen, Lanlan Geng, Peiyu Chen, Jing Xie, Shui Qing Ye, Ding-You Li, Sitang Gong

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Refractory esophageal stricture (RES) may be attributed to food allergy. Its etiology and pathogenesis are not fully understood. Identification of novel genetic variants associated with this disease by exome sequencing (exome-seq) may provide new mechanistic insights and new therapeutic targets.

METHODS: To identify new and novel disease-associating variants, whole-exome sequencing was performed on an Illumina NGS platform in three children with RES as well as food allergy.

RESULTS: A total of 91,024 variants were identified. By filtering out 'normal variants' against those of the 1000 Genomes Project, we identified 12,741 remaining variants which are potentially associated with RES plus …

A Novel Compound-Heterozygous Epithelial Cell Adhesion Molecule Mutation In Tufting Enteropathy., Valentina Shakhnovich, Darrell Dinwiddie, Amber Hildreth, Thomas M. Attard, Stephen Kingsmore

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.

Human And Helicobacter Pylori Coevolution Shapes The Risk Of Gastric Disease, Nuri Kodaman, Alvaro Pazos, Barbara G. Schneider, M. Blanca Piazuelo, Robertino Mera, Rafal S. Sobota

Dartmouth Scholarship

Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster …

Nevirapine Hepatotoxicity: Case Report And Discussion, Matt Baichi

The Medicine Forum

Nevirapine (viramune) is a nonnucleoside reverse transcriptase inhibitor commonly used in combination with other antiretroviral medicines in the treatment of HIV/AIDS. The safety profile of nevirapine, as determined by review of prospective clinical trials, reports rash with an incidence of 16% as the most common side effect. Clinical hepatitis is reported to occur with an incidence of 1%. A review of the literature shows many case reports of nevirapine-induced hepatotoxicity in patients receiving both treatment and prophylaxis for HIV. The purpose of this case report is to stress the importance of early recognition and withdrawal of the offending drug.

A Conserved Tissue-Specific Homeodomain-Less Isoform Of Meis1 Is Downregulated In Colorectal Cancer., Richard C Crist, Jacquelyn J Roth, Scott A Waldman, Arthur M Buchberg

Department of Microbiology and Immunology Faculty Papers

Colorectal cancer is one of the most common cancers in developed nations and is the result of both environmental and genetic factors. Many of the genetic lesions observed in colorectal cancer alter expression of homeobox genes, which encode homeodomain transcription factors. The MEIS1 homeobox gene is known to be involved in several hematological malignancies and solid tumors and recent evidence suggests that expression of the MEIS1 transcript is altered in colorectal cancer. Despite this potential connection, little is known about the role of the gene in the intestines. We probed murine gastrointestinal tissue samples with an N-terminal Meis1 antibody, revealing …