Project description:In chronic kidney disease (CKD) and with ageing, individuals lose regenerative capacity after renal injury and are predisposed to progressive fibrosis and cardiovascular disease. With ageing and CKD increased numbers of activated leukocytes are present in the circulation and within the kidney where they correlate with progressive fibrosis. The potential role of activated leukocytes in mediating progressive renal and systemic fibrosis remains incompletely understood. Here, we show that tumour necrosis factor alpha (TNFa) released with injury and aging promotes renal and cardiac fibrosis. We identify a Ubiquitin D expressing population of TNFa induced inflammatory proximal tubular epithelia (iPT) responsible for Indian Hedgehog release in aged and fibrotic kidneys. Indian Hedgehog production by iPT cells activates canonical Hedgehog signalling in Gli1+ stromal cells leading to activation, proliferation and fibrosis deposition. Our data links the immune activation seen in aging and chronic kidney disease to cardio-renal fibrosis. This provides multiple targets for antifibrotic therapies which we validate in murine models of aging and kidney disease.
Project description:The morphogen Indian Hedgehog plays a very important role during intestinal embryogenesis, but also maintains homeostasis of the adult gut. Intestinal Indian Hedgehog is expressed by the intestinal epithelium and signals in paracrine manner to fibroblasts in the stromal compartment. Unresolved deletion of Ihh from the intestinal epithelium leads to a severe enterocolitis. We studied the short term changes in the colon upon deletion of Ihh from the epithelial layer.
Project description:Epithelial Hedgehog (Hh) ligands regulate several aspects of fetal intestinal organogenesis and emerging data implicate the Hh pathway in inflammatory signaling in adult colon. We investigated the effects of chronic Hh inhibition in vivo and profiled molecular pathways acutely modulated by Hh signaling in the intestinal mesenchyme. Experiment Overall Design: E18.5 intestinal mesenchyme was isolated and cultured. Mesenchyme was treated with Sonic (Shh) or Indian (Ihh) hedgehog ligand or Vehicle (control) acutely to identify targets regulated by Hh signaling in intestinal mesenchyme.
Project description:Conditional ablation of Indian hedgehog (Ihh) in the murine uterus results in mice that are sterile due to defects in embryo implantation. We performed microarray analysis on these mice at the time point at which the Ihh target genes are induced by the administration of exogenous hormone to mimic day 3.5 of pregnancy. This analysis identified 863 genes altered by the conditional ablation of Ihh. Of these, genes that regulated the cell cycle were overrepresented. In addition, genes involved in epidermal growth factor (EGF) and estrogen (E2) signaling were found to be deregulated upon Ihh ablation. Furthermore, upon conditional ablation of Ihh, 15 month old mice exhibited hallmarks of estrogenized uteri such as cystically dilated glands and hyalinized stroma. Thus, Ihh regulates embryo implantation by impacting the cell cycle, EGF signaling, and E2 signaling. Keywords: two group comparison We conditionally ablated Indian hedgehog in the mouse uterus using the PRcre mouse model (PRcre/+Ihhf/f; Ihhd/d). High density DNA microarray analysis was performed on Day -1 of the artificial decidual response on Ihhf/f and Ihhd/d uteri.
Project description:Patient-derived intestinal organoids provide an excellent tool to unravel mechanisms underlying ulcerative colitis (UC). Fresh biopsies, to isolate crypts and culture organoids, were obtained from both inflamed and non-inflamed regions from eight patients with active UC (Mayo endoscopic subscore ≥2), and from eight non-IBD controls.To address the inflammatory character of ex vivo organoids, we compared the transcriptome of biopsies, crypts and organoids derived from inflamed, and non-inflamed regions and aimed to (re-)induce inflammation ex vivo.
Project description:Copy number variations (CNVs) including enhancers frequently appear associated with disease, induced by pathomechanisms that are poorly understood. Here we show through transgenic reporter and genome editing studies in mice that Indian hedgehog (Ihh) is regulated by a constellation of enhancers of unusual complexity and we uncover how duplications within this enhancer architecture cause phenotypes reminiscent of those observed in human patients. At least nine enhancers with distinct combinations of activities orchestrate the expression of Ihh in the digit anlagen, growth plates, skull sutures, and digit tips. Consecutive deletions show that they function in an additive manner resulting in growth defects. Duplications, in contrast, cause not only dose-dependent upregulation of Ihh, but also misexpression, leading to phenotypes influenced by the copy number and relative positioning of individual elements. Taken together, our results uncover a complex regulatory landscape at the Ihh locus and exemplify the intricate and precise control of gene expression during morphogenetic processes.
Project description:To investigate the gene expression profile of inflamed and non-inflamed mucosa in patients with Crohn's disease. To investigate TCR repertoires in the intestinal mucosa, the expression profile of the TCR repertoire gene was analyzed.
Project description:Conditional ablation of Indian hedgehog (Ihh) in the murine uterus results in mice that are sterile due to defects in embryo implantation. We performed microarray analysis on these mice at the time point at which the Ihh target genes are induced by the administration of exogenous hormone to mimic day 3.5 of pregnancy. This analysis identified 863 genes altered by the conditional ablation of Ihh. Of these, genes that regulated the cell cycle were overrepresented. In addition, genes involved in epidermal growth factor (EGF) and estrogen (E2) signaling were found to be deregulated upon Ihh ablation. Furthermore, upon conditional ablation of Ihh, 15 month old mice exhibited hallmarks of estrogenized uteri such as cystically dilated glands and hyalinized stroma. Thus, Ihh regulates embryo implantation by impacting the cell cycle, EGF signaling, and E2 signaling. Keywords: two group comparison