Project description:We obtained a spatial measurement of RNA and Proteins in the small intestinal epithelium along the crypt-villus axis. We found that both were spatially heterogeneous, yet often spatially anti-correlated. We developed a Bayesian approach to infer protein translation and degradation rates from the combined spatial profiles, and demonstrate that space-independent protein-synthesis delays can explain the mRNA-protein discordances. Our work provides a proteomic spatial blueprint of the Intestinal epithelium and highlights the importance of protein measurements for inferring states of tissue cells that operate outside of steady state
Project description:Receptor guanylyl cyclase C (GC-C) is expressed in the intestinal epithelia and plays a key role in intestinal physiology. Activation of GC-C by its ligands has been shown to regulate proliferation and differentiation of enterocytes along the crypt-villus axis. This study aims to identify genes regulated by GC-C activation and elevation of cGMP in colorectal carcinoma cells. This will help understand the molecular targets and biological pathways regulated by GC-C to bring about cancer cell cytostasis. ST (Cy5) Vs. Control (Cy3), ST (Cy5) Vs. Control (Cy3)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:The small intestinal epithelium mediates vital functions of nutrient absorption and host defense. The spatial organization of the epithelial cells along the crypt-villus axis segregates them into regions of specialized function. However, many of the mechanisms governing intestinal epithelial cell migration and the coordination of interactions with adjacent cells and the extracellular matrix are not fully understood. We have evaluated in vivo gene expression patterns of ileal epithelial cells in healthy human subjects, isolated by laser capture microdissection from either the villus epithelial or crypt cell regions of the small intestinal mucosa. Expression profiles in villus epithelium and Paneth cell lineages were determined by quantitative real-time PCR, DNA microarray, and immunohistochemistry based methods. Relative expression levels of selected epithelial biomarkers were compared between the ileum, jejunum, duodenum, colon, stomach, and esophagus. Previously established biomarkers as well as a novel and distinct set of genes believed to be linked to epithelial cell motility, adhesion, and differentiation were found to be enriched in each of the two corresponding cell populations. Additionally, high baseline expression levels of innate antimicrobials, alpha defensin 5 (HD5) and regenerating islet-derived 3 alpha (Reg3A), were detected exclusively within the small bowel, most notably in the ileum, in comparison to other sites along the gastrointestinal tract. Our findings provide new and important insights regarding the molecular machinery employed by small intestinal epithelial cells to mediate their function and spatial organization in vivo. Experiment Overall Design: Surgical specimens of human intestinal mucosa were obtained from 4 individuals undergoing surgery for colon cancer, bowel obstruction, or other non-inflammatory conditions. The samples were fixed overnight in 4% (w/v) paraformaldehyde, dehydrated in a graded alcohol series and paraffin-embedded. At least 500 epithelial cells from the crypt or upper villus regions were then captured by LCMD from unstained 6µm thick sections using a PALM MicroLaser System Total RNA was extracted for microarray-based gene expression analysis.
