Project description:Environmental enteric dysfunction (EED), a chronic diffuse inflammation of the small intestine, is associated with stunting in children in the developing world. The pathobiology of EED is poorly understood because of the lack of a method to elucidate the host response. This study utilized a novel microarray method to interrogate the host transcriptome in feces in Malawian children with EED. Our data showed that the children studied had a range of %L values, consistent a spectrum of EED from normal to severe. We identified 12 transcripts associated with the severity of EED, including chemokines that stimulate T-cell proliferation, Fc fragments of multiple immunoglobulin families, interferon-induced proteins, activators of neutrophils and B-cells, and mediators that dampen cellular responses to hormones. EED associated transcripts mapped to pathways related to cell adhesion, and responses to a broad spectrum of viral, bacterial and parasitic microbes and enhanced phagocytosis. Several mucins, regulatory factors and protein kinases associated with the maintenance of the mucous layer were expressed less in children with EED than normal children. In conclusion, EED represents the focused activation of elements of the immune system and is associated with widespread intestinal barrier disruption. The differentially expressed transcripts may be explored as potential biomarkers. In 259 children, EED was measured by lactulose permeability (%L) in the small intestine. After isolating low copy numbers of mRNA, the transcriptome was reliably and reproducibly profiled. mRNA copy number was correlated with %L using analyses of covariance. The transcripts identified were mapped to biological pathways and processes.
Project description:Tissue maintenance and repair depend on the integrated activity of multiple cell types. Whereas the contributions of epithelial, immune and stromal cells in intestinal tissue integrity are well understood, the role of intrinsic neuroglia networks remains largely unknown. Here, we uncover pivotal roles of enteric glial cells (EGCs) in intestinal homeostasis, immunity and tissue repair. We demonstrate that infection of mice with Heligmosomoides polygyrus (H. poly) leads to enteric gliosis and upregulation of the interferon gamma (IFN-γ) gene signature. Single-cell transcriptomics of tunica muscularis (TM) showed that glia-specific abrogation of IFN-γ signaling leads to tissue-wide activation of pro-inflammatory transcriptional programs. In addition, disruption of the IFN-γ-EGC signaling axis enhanced the inflammatory and granulomatous response of TM to helminths. Mechanistically, we show that upregulation of Cxcl10 is an early immediate response of EGCs to IFN-γ signaling and provide evidence that this chemokine and the downstream amplification of IFN-γ signaling in the TM are required for a measured inflammatory response to helminths and resolution of granulomatous pathology. Our study demonstrates that IFN-γ signaling in enteric glia is central to intestinal homeostasis and reveals critical roles of the IFN-γ-EGC-Cxcl10 axis in immune response and tissue repair following infectious challenge. To characterize the response of enteric glia to helminth infection, we performed bulk RNAseq of tdT+ cells (=EGCs) and tdT- cells (=non-glia cells) from the TM of naïve and H. poly-infected Sox10CreERT2;Rosa26tdTomato mice.
Project description:Tissue maintenance and repair depend on the integrated activity of multiple cell types. Whereas the contributions of epithelial, immune and stromal cells in intestinal tissue integrity are well understood, the role of intrinsic neuroglia networks remains largely unknown. Here, we uncover pivotal roles of enteric glial cells (EGCs) in intestinal homeostasis, immunity and tissue repair. We demonstrate that infection of mice with Heligmosomoides polygyrus (H. poly) leads to enteric gliosis and upregulation of the interferon gamma (IFN-γ) gene signature. Single-cell transcriptomics of tunica muscularis (TM) showed that glia-specific abrogation of IFN-γ signaling leads to tissue-wide activation of pro-inflammatory transcriptional programs. In addition, disruption of the IFN-γ-EGC signaling axis enhanced the inflammatory and granulomatous response of TM to helminths. Mechanistically, we show that upregulation of Cxcl10 is an early immediate response of EGCs to IFN-γ signaling and provide evidence that this chemokine and the downstream amplification of IFN-γ signaling in the TM are required for a measured inflammatory response to helminths and resolution of granulomatous pathology. Our study demonstrates that IFN-γ signaling in enteric glia is central to intestinal homeostasis and reveals critical roles of the IFN-γ-EGC-Cxcl10 axis in immune response and tissue repair following infectious challenge. To characterize the response of enteric glia to helminth infection at single cell resolution, we next performed scRNAseq (C1 Fluidigm platform) of tdT+ cells from the TM of naïve and H. poly-infected mice.
Project description:Environmental Enteric Dysfunction (EED) is a chronic inflammatory condition of the intestine characterized by villus blunting, compromised intestinal barrier function, and reduced nutrient absorption. Here, we show that key genotypic and phenotypic features of EED-associated intestinal injury can be reconstituted in a human intestine-on-a-chip (Intestine Chip) microfluidic culture device lined by organoid-derived intestinal epithelial cells from EED patients and cultured in nutrient deficient medium lacking niacinamide and tryptophan (-N/-T). Exposure of EED Intestine Chips to -N/-T deficiencies resulted in transcriptional changes similar to those seen in clinical EED patient samples including congruent changes in six of the top ten upregulated genes. Exposure of EED Intestine Chips or chips lined by healthy intestinal epithelium (healthy Intestine Chips) to -N/-T medium resulted in severe villus blunting and barrier dysfunction, as well as impairment of fatty acid uptake and amino acid transport.
Project description:Circadian clock is a highly conserved regulatory system which could coordinate many physiological processes with external stimuli, displaying oscillation with a periodicity of ~24 hour. Dysfunction of circadian clock has been involved in the pathogenesis of a broad spectrum of diseases such as metabolic diseases and chronic kidney disease. However the role of circadian clock in diabetic nephropathy remains largely unknown.