Engineered stomach tissue as a renewable source of functional beta-cells for blood glucose regulation
Ontology highlight
ABSTRACT: 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:Tbx20 is a transcription factor known to play important roles in embryonic and adult mouse heart function. Our goal in this work was to better understand the function of this gene in embryonic (E11.5) mouse cardiomyocytes that form the developing chambers, expanding our knowledge of its role in heart development. To elucidate the role of Tbx20 in mouse cardiomyocytes, we generated conditional Tbx20 knockout and compared 4 samples with 4 samples of wild-type cardiomyocytes. We found evidence of regulation of cell cycle genes by Tbx20, which are involved in proliferation. In addition, Tbx20 seems to bind and regulate an enhancer of CoupTFII in the atrium, a gene involved in atrial development.
Project description:Doxycycline-inducible YAP1 S127A-driven rhabdomyosarcoma (RMS) tumors, control skeletal muscle and regressed tumors following YAP1 normalization by doxycycline withdrawal were compared to determine the YAP1-regulated gene expression profile relevant to RMS formation. To characterize the role of YAP1 in embryonal RMS at the molecular level and identify a gene signature for YAP1 activity readout, we compared the gene expression profiles of our YAP1-driven ERMS with control donor skeletal muscle (SKM) and doxycycline-withdrawn regressing tumors by microarray (doxycycline withdrawal for 3 or 6 days; OFF3 and OFF6, respectively). We next extracted a list of genes regulated by YAP1 in our YAP1-driven ERMS tumors (TUM) versus the 3 other conditions: skeletal muscle control (SKM), Doxycycline-withdrawn 3 days (OFF3) and 6 days (OFF6). The overlap between the 3 lists identified a subset of 633 common upregulated genes, named the YAP1-ERMS_UP signature, as well as 249 common downregulated genes, termed the YAP1-ERMS_DOWN signature. Proliferative pathways and transcriptional targets of E2F factors were highlighted in the YAP1-ERMS_UP genes, while muscle differentiation and trancriptional targets of myogenic factors Myod1 and Mef2 were highlighted in the YAP1-ERMS_DOWN genes. Tumor regression conditions (OFF3 days; OFF6 days) as well as control muscle (CTL) were compared with tumors at day 0 of doxycycline withdrawal (TUM). 3 samples for each conditions were used.
Project description:Direct lineage conversion of adult cells is a promising approach for regenerative medicine. A major challenge of lineage conversion is to generate specific subtypes of cells, closely related cells with distinct properties. The pancreatic islets contain three major hormone-secreting endocrine subtypes: insulin+ β-cells, glucagon+ α-cells, and somatostatin+ δ-cells. We previously reported that a combination of three transcription factors, Ngn3, Mafa, and Pdx1, directly reprogram pancreatic acinar cells to β-cells. We now show that acinar cells can be converted to δ-like and α-like cells by Ngn3 and Ngn3+Mafa respectively. Thus, three major islet endocrine subtypes can be derived by acinar reprogramming. Ngn3 promotes establishment of a generic endocrine state in acinar cells at the onset of reprogramming in addition to promoting δ-specification. Mafa and Pdx1 suppress δ-specification in α- and β-cell formation. These studies identify a set of defined factors whose combinatorial actions reprogram acinar cells to distinct islet endocrine subtypes in vivo. induced beta cells samples at day 10 collected for the microarray
Project description:Endoderm cells undergo a sequence of fate choices to generate insulin-secreting M-NM-2 cells. Studies of chromatin transitions during this process have been limited to the pancreatic progenitor stage that can be reconstituted from stem cells in vitro, with a gap in understanding the induction of endocrine cells. To address this, we established conditions for isolating endoderm cells, pancreatic progenitors, and endocrine cells from different staged embryos and performed genome wide analysis of the H3K27me3 mark of the repressive Polycomb complex. During the transition from endoderm to pancreas progenitors and during the transition from pancreas progenitors to endocrine cells, genes that lose the H3K27me3 mark typically encode transcriptional regulators, whereas genes that acquire the mark typically are involved in cell biology morphogenesis. Precocious depletion of the EZH2, a H3K27 methylase, at the pancreas progenitor stage enhanced the production of endocrine cells, leading to a later increase in pancreatic beta cells. Similarly, pharmacologic inhibition of EZH2 in embryonic pancreatic tissue explants and human embryonic stem cell cultures led to an increase in endocrine progenitors in vitro. These findings reveal a repeating target gene pattern in H3K27me3 dynamics and provide a means to modulate M-NM-2 cell development from stem cells. Analyzed five FACS-sorted tissues in early mouse embryo; for each tissue we sequenced H3K27me3 and input; no replicates
Project description:Adult pancreatic progenitor cells are a potential source of renewable insulin producing cells that can be used in regenerative medicine and cell replacement therapy for type-1 diabetes. We sought to understand the mechanisms by which adult pancreatic progenitor cells undergo self-renewal. The effects of knockdown of Glis3, CD133 (Prominin-1) and beta-catenin were investigated and we found that Glis3 and CD133 are capable of regulating self-renewal through Wnt gene expression.
Project description:Aims/hypothesis: Duct cells isolated from adult human pancreas can be reprogrammed to express islet beta cell genes by adenoviral transduction of the developmental transcription factor neurogenin3 (Ngn3). In this study we aimed to fully characterize the extent of this reprogramming and intended to improve it. Methods: The extent of the Ngn3-mediated duct-to-endocrine cell reprogramming was measured employing genome wide mRNA profiling. By modulation of the Delta-Notch signaling or addition of pancreatic endocrine transcription factors Myt1, MafA and Pdx1 we intended to improve the reprogramming. Results: Ngn3 stimulates duct cells to express a focused set of genes that are abundant in islet endocrine cells and/or neural tissues. This neuro-endocrine shift, however, covers a minor fraction (5%) of the estimated genome-wide transcriptome difference between duct and islet endocrine cells. Interestingly, transduction of exogenous Ngn3 activates endogenous Ngn3 suggesting auto-activation of this gene. Furthermore, pancreatic endocrine reprogramming of human duct cells can be moderately enhanced by inhibition of Delta-Notch signaling as well as by co-expressing the transcription factor Myt1, but not MafA and Pdx1. Conclusions/interpretation: The results provide further insight into the plasticity of adult human duct cells and suggest measurable routes to enhance Ngn3-mediated in vitro reprogramming protocols for regenerative beta cell therapy in diabetes. We used Affymetrix HG133A and HG133B to get a comprehensive view on the reprogramming potential in vitro of human pancreatic duct cell cultures (n=3-4) at 3 and 14/20 days after ectopic adenoviral expression of murine neurogenin 3 as compared to GFP-expressing control vectors. The microarray analysis was performed on 3 independent samples that each contained RNA extracted from a pool of 3 independent donor pancreata. The total number of non-selected donor organs is 9. Transcripts were considered as differentially regulated by Ngn3 when 1.5 fold (LCB, unpaired P < 0.05) up- or down-regulated in AdGFP-Ngn3 versus AdGFP controls, at 3 and/or 14 dpi. Transcripts that showed differential expression between day 3 and day 14 in AdGFP-Ngn3 duct cells but not in AdGFP control cells, were also considered Ngn3-regulated
Project description:Analysis of global gene expression in the antral portion of the stomach in control and mice with a developing tumor to get further insight into the exact tumor type and the influence of local gene expression.