Publications by authors named "Stephanie J King"
Article Synopsis
- - A subset of patients with inflammatory bowel disease (IBD) shows an increase in a harmful gut bacteria known as adherent-invasive E. coli (AIEC), which is connected to mutations in the protein tyrosine phosphatase type 2 (PTPN2) gene that disrupts gut microbiota balance.
- - The study examines how the host protein CEACAM6, which AIEC uses to invade intestinal cells, is regulated in the context of the PTPN2 gene and its variants, finding that patients with specific SNPs have higher CEACAM6 levels.
- - Experimental cell lines with altered PTPN2 expression showed increased adhesion and invasion by AIEC, indicating that the absence of PTP
Background And Aims: Loss-of-function variants in protein tyrosine phosphatase non-receptor type-2 [PTPN2] promote susceptibility to inflammatory bowel diseases [IBD]. PTPN2 regulates Janus-kinase [JAK] and signal transducer and activator of transcription [STAT] signalling, while protecting the intestinal epithelium from inflammation-induced barrier disruption. The pan-JAK inhibitor tofacitinib is approved to treat ulcerative colitis, but its effects on intestinal epithelial cell-macrophage interactions and on barrier properties are unknown.
View Article and Find Full Text PDFAMPK mediates inhibition of electrolyte transport and NKCC1 activity by reactive oxygen species.
Am J Physiol Gastrointest Liver Physiol
August 2019
Reactive oxygen species such as HO are believed to play a prominent role in the injury and loss of transport function that affect the intestinal epithelium in inflammatory conditions such as inflammatory bowel diseases. Defects in intestinal epithelial ion transport regulation contribute to dysbiosis and inflammatory phenotypes. We previously showed that HO inhibits Ca-dependent Cl secretion across intestinal epithelial cells (IECs) via a phosphatidylinositol 3-kinase (PI3K)- and extracellular signal-regulated kinase (ERK)-dependent mechanism that occurs, at least in part, through inhibition of the basolateral Na-K-2Cl cotransporter NKCC1.
View Article and Find Full Text PDFInflammatory bowel diseases (IBD) are chronic conditions of the gastrointestinal tract-the main site of host-microbial interaction in the body. Development of IBD is not due to a single event but rather is a multifactorial process where a patient's genetic background, behavioral habits, and environmental exposures contribute to disease pathogenesis. IBD patients exhibit alterations to gut bacterial populations "dysbiosis" due to the inflammatory microenvironment, however whether this alteration of the gut microbiota precedes inflammation has not been confirmed.
View Article and Find Full Text PDFBackground: AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine protein kinase that is activated by cellular perturbations associated with ATP depletion or stress. While AMPK modulates the activity of a variety of targets containing a specific phosphorylation consensus sequence, the number of AMPK targets and their influence over cellular processes is currently thought to be limited.
Results: We queried the human and the mouse proteomes for proteins containing AMPK phosphorylation consensus sequences.