Project description:The gastrointestinal (GI) epithelium is a highly regenerative tissue with the potential to provide a renewable source of insulin+ cells using cellular reprogramming. Here, we describe the antral stomach as a previously unrecognized source highly amenable to conversion into functional insulin-secreting cells. Native antral endocrine cells share a surprising degree of transcriptional similarity with pancreatic beta-cells. Expression of beta-cell reprogramming factors in vivo converts antral cells efficiently into insulin+ cells with close molecular and functional resemblance to beta-cells. Our data further indicate that the intestine-expressed Cdx2 acts as a molecular barrier for beta-cell conversion. Induced GI insulin+ cells can suppress hyperglycemia over at least 6 months and they regenerate rapidly after ablation from the native stem-cell compartment. Transplantation of bioengineered stomach mini-organs also produced insulin+ cells and suppressed hyperglycemia. These studies demonstrate the potential of developing engineered stomach tissue as a renewable source of functional beta-cells for glycemic control. Total RNA extracted from primary mouse tissues: Stomach (3 replicates), Duodenum (3 replicates) and Colon (2 replicates)
Project description:The gastrointestinal (GI) epithelium is a highly regenerative tissue with the potential to provide a renewable source of insulin+ cells using cellular reprogramming. Here, we describe the antral stomach as a previously unrecognized source highly amenable to conversion into functional insulin-secreting cells. Native antral endocrine cells share a surprising degree of transcriptional similarity with pancreatic beta-cells. Expression of beta-cell reprogramming factors in vivo converts antral cells efficiently into insulin+ cells with close molecular and functional resemblance to beta-cells. Our data further indicate that the intestine-expressed Cdx2 acts as a molecular barrier for beta-cell conversion. Induced GI insulin+ cells can suppress hyperglycemia over at least 6 months and they regenerate rapidly after ablation from the native stem-cell compartment. Transplantation of bioengineered stomach mini-organs also produced insulin+ cells and suppressed hyperglycemia. These studies demonstrate the potential of developing engineered stomach tissue as a renewable source of functional beta-cells for glycemic control.
Project description:Saccharomyces cerevisiae cannot metabolize non-glucose sugars including cellobiose, xylose, xylodextrins in nature, which are prevalent in plant cell wall. Here, one engineered S. cerevisiae strain, which expresses a cellodextrin transporter gene (cdt-1) and an intracellular β-glucosidase gene (codon-optimized gh1-1) from Neurospora crassa; XYL1 (xylose reductase gene), XYL2 (xylitol dehydrogenase gene), and XKS1 (xylulose kinase gene) from Scheffersomyces stipitis, as well as cdt-2 (coding for cellodextrin transporter 2), gh43-2 (coding for β-xylosidase) and gh43-7 (coding for a xylosyl-xylitol-specific β-xylosidase) from N. crassa, can utilize the above non-glucose sugars. We sequenced mRNA from exponential cultures of the engineered S. cerevisiae grown on glucose, cellobiose, xylose or xylodextrins as a single carbon source in both aerobic and anaerobic conditions in biological triplicate. Differences in gene expression between non-glucose sugar and glucose metabolism revealed by RNA deep sequencing indicated that non-glucose sugar metabolism induced mitochondrial activation and reduced amino acid and protein biosynthesis under fermentation conditions.
Project description:Saccharomyces cerevisiae cannot metabolize cellobiose in nature. Here, S. cerevisiae was engineered to achieve cellobiose utilization by introducing both a cellodextrin transporter gene (cdt-1) and an intracellular β-glucosidase gene (gh1-1) from Neurospora crassa. We sequenced mRNA from anaerobic exponential cultures of engineered S. cerevisiae grown on cellobiose or glucose as a single carbon source in biological triplicate. Differences in gene expression between cellobiose and glucose metabolism revealed by RNA deep sequencing indicated that cellobiose metabolism induced mitochondrial activation and reduced amino acid biosynthesis under fermentation conditions. mRNA levels in cellobiose-grown and glucose-grown cells of engineered cellobiose-utilizing Saccharomyces cerevisiae were examined by deep sequencing, in triplicate, using Illumina Genome Analyzer-II. We sequenced 3 samples from cellobiose-grown cells and 3 samples from glucose-grown cells and identified differential expressions in the cellobiose versus glucose fermentations by using mRNA levels of glucose-grown cells as a reference.
Project description:Saccharomyces cerevisiae cannot metabolize cellobiose in nature. Here, S. cerevisiae was engineered to achieve cellobiose utilization by introducing both a cellodextrin transporter gene (cdt-1) and an intracellular β-glucosidase gene (gh1-1) from Neurospora crassa. We sequenced mRNA from anaerobic exponential cultures of engineered S. cerevisiae grown on cellobiose or glucose as a single carbon source in biological triplicate. Differences in gene expression between cellobiose and glucose metabolism revealed by RNA deep sequencing indicated that cellobiose metabolism induced mitochondrial activation and reduced amino acid biosynthesis under fermentation conditions.
Project description:Human intestinal macrophages contribute to tissue homeostasis in noninflamed mucosa through profound down-regulation of pro-inflammatory cytokine release. Here, we show that this down-regulation extends to Toll-like receptor (TLR)-induced cytokine release, as intestinal macrophages expressed TLR3-TLR9 but did not release cytokines in response to TLR-specific ligands. Likely contributing to this unique functional profile, intestinal macrophages expressed markedly down-regulated adapter proteins MyD88 and Toll interleukin receptor 1 domain-containing adapter-inducing interferon beta, which together mediate all TLR MyD88-dependent and -independent NF-kappaB signaling, did not phosphorylate NF-kappaB p65 or Smad-induced IkappaBalpha, and did not translocate NF-kappaB into the nucleus. Importantly, transforming growth factor-beta released from intestinal extracellular matrix (stroma) induced identical down-regulation in the NF-kappaB signaling and function of blood monocytes, the exclusive source of intestinal macrophages. Our findings implicate stromal transforming growth factor-beta-induced dysregulation of NF-kappaB proteins and Smad signaling in the differentiation of pro-inflammatory blood monocytes into noninflammatory intestinal macrophages. Comparison of unstimulated monocytes and macrophages, and flagellin stimulated monocytes and macrophages.
Project description:Yeast sugar transporters are highly evolved for optimized glucose transport, a major roadblock when it comes to utilizing non-glucose sugars in renewable feedstocks such as lignocellulosic biomass. The AtSWEET7p transporter has been identified for simultaneous transport of glucose and xylose, prevalent in plant cell wall hydrolysates. Here, we replaced endogenous hexose transporters with AtSWEET7 to construct an engineered Saccharomyces cerevisiae capable of multiple sugars with no glucose repression. The resulting strain (NKSW7-1) gained the capacity to simultaneously co-ferment glucose, xylose, mannose, and fructose in a synthetic medium, as well as the sugars in mixtures of bagasse hydrolysate and cane juice. Notably, the replacement of native sugar transporters by AtSWEET7 led to reprogramming of central carbon metabolism, activating glucose-repressed genes even in the presence of substantial amounts of glucose. Continuous culture experiments with the NKSW7-1 strain demonstrated feasibility of AtSWEET7 to disable glucose repression on other hexose or/and pentose sugar uptake. The broad transport capacity of AtSWEET7p can be utilized for achieving co-consumption of all sugars, especially in the case of emerging, underutilized, and renewable substrates.
Project description:Gastric ulcer, which affect many of patients and is deeply related with gastric cancer, is caused by chronic gastric acid stimulation. Stomach fundus, the main body of stomach, is a major source of gastric acid and peptidase for food digestion. Recapturing the main body of stomach requires mainly 3 functionally differentiated cells; parietal (oxyntic) cells, chief (zymogenic) cells, and surface mucous foveolar (pit) cells. We have previously shown the induction of stomach tissue with functional secreting activities by directed differentiation of mouse embryonic stem cells (ES cells) to stomach primordium with both gut epithelium and splanchnic mesoderm. However, generating human stomach with fundus and such functions has been elucidated and a long-desired goal. Here, we describe the method for establishing human embryonic stem cell-derived stomach organoids with fundus gland structure. Along with mouse stomach development and de novo stomach generation from mouse ES cells in vitro, we observed gut-like structure formation from human embryonic stem cells by induction of both endoderm and mesoderm. These human embryonic gut could differentiate into stomach primordium by growth factor stimulation as well as stomach development, and form stomach tissue in three-dimensional organoid culture. Furthermore, these stomach organoids contain fundus-like gland with parietal cells and chief cells, some of secreting activities, and is transcriptionally close to human stomach. Human functional stomach derived from embryonic stem cells represent powerful tools for analying human stomach development, and gastric ulcer related disease including gastric tumorgenesis.
Project description:Beta cells are the sole source of insulin in our body, yet we do not understand how they mature into fully functional, glucose-responsive beta cells. We generated transcriptomes of FACS-purified beta cells using the Ins1-H2b-mCherry reporter line (Jax # 028589) at different peri- and postnatal maturation stages. This enables a systematic comparison across thousands of genes as beta cells mature.
Project description:Human intestinal macrophages contribute to tissue homeostasis in noninflamed mucosa through profound down-regulation of pro-inflammatory cytokine release. Here, we show that this down-regulation extends to Toll-like receptor (TLR)-induced cytokine release, as intestinal macrophages expressed TLR3-TLR9 but did not release cytokines in response to TLR-specific ligands. Likely contributing to this unique functional profile, intestinal macrophages expressed markedly down-regulated adapter proteins MyD88 and Toll interleukin receptor 1 domain-containing adapter-inducing interferon beta, which together mediate all TLR MyD88-dependent and -independent NF-kappaB signaling, did not phosphorylate NF-kappaB p65 or Smad-induced IkappaBalpha, and did not translocate NF-kappaB into the nucleus. Importantly, transforming growth factor-beta released from intestinal extracellular matrix (stroma) induced identical down-regulation in the NF-kappaB signaling and function of blood monocytes, the exclusive source of intestinal macrophages. Our findings implicate stromal transforming growth factor-beta-induced dysregulation of NF-kappaB proteins and Smad signaling in the differentiation of pro-inflammatory blood monocytes into noninflammatory intestinal macrophages.