Project description:Histone deacetylases (Hdac) remove acetyl groups from proteins, influencing global and specific gene expression. Hdacs control inflammation, as shown by Hdac inhibitor-dependent protection from DSS-induced murine colitis. While tissue-specific Hdac knockouts show redundant and specific functions, little is known of their intestinal epithelial cell (IEC) role. We have shown previously that dual Hdac1/Hdac2 IEC-specific loss disrupts cell proliferation and determination, with decreased secretory cell numbers and altered barrier function. We thus investigated how compound Hdac1/Hdac2 or Hdac2 IEC-specific deficiency alters the inflammatory response. Floxed Hdac1 and Hdac2 and villin-Cre mice were interbred. Compound Hdac1/Hdac2 IEC-deficient mice showed chronic basal inflammation, with increased basal Disease Activity Index (DAI) and deregulated Reg gene colonic expression. DSS-treated dual Hdac1/Hdac2 IEC-deficient mice displayed increased DAI, histological score, intestinal permeability and inflammatory gene expression. In contrast to double knockouts, Hdac2 IEC-specific loss did not affect IEC determination and growth, nor result in chronic inflammation. However, Hdac2 disruption protected against DSS colitis, as shown by decreased DAI, intestinal permeability and caspase-3 cleavage. Hdac2 IEC-specific deficient mice displayed increased expression of IEC gene subsets, such as colonic antimicrobial Reg3b and Reg3g mRNAs, and decreased expression of immune cell function-related genes. Our data show that Hdac1 and Hdac2 are essential IEC homeostasis regulators. IEC-specific Hdac1 and Hdac2 may act as epigenetic sensors and transmitters of environmental cues and regulate IEC-mediated mucosal homeostatic and inflammatory responses. Different levels of IEC Hdac activity may lead to positive or negative outcomes on intestinal homeostasis during inflammation Total RNAs from the colon of three control and three Hdac2 IEC-specific knockout mice were isolated with the Rneasy kit (Qiagen, Mississauga, ON, Canada).
Project description:Histone deacetylases (Hdac) remove acetyl groups from proteins, influencing global and specific gene expression. Hdacs control inflammation, as shown by Hdac inhibitor-dependent protection from DSS-induced murine colitis. While tissue-specific Hdac knockouts show redundant and specific functions, little is known of their intestinal epithelial cell (IEC) role. We have shown previously that dual Hdac1/Hdac2 IEC-specific loss disrupts cell proliferation and determination, with decreased secretory cell numbers and altered barrier function. We thus investigated how compound Hdac1/Hdac2 or Hdac2 IEC-specific deficiency alters the inflammatory response. Floxed Hdac1 and Hdac2 and villin-Cre mice were interbred. Compound Hdac1/Hdac2 IEC-deficient mice showed chronic basal inflammation, with increased basal Disease Activity Index (DAI) and deregulated Reg gene colonic expression. DSS-treated dual Hdac1/Hdac2 IEC-deficient mice displayed increased DAI, histological score, intestinal permeability and inflammatory gene expression. In contrast to double knockouts, Hdac2 IEC-specific loss did not affect IEC determination and growth, nor result in chronic inflammation. However, Hdac2 disruption protected against DSS colitis, as shown by decreased DAI, intestinal permeability and caspase-3 cleavage. Hdac2 IEC-specific deficient mice displayed increased expression of IEC gene subsets, such as colonic antimicrobial Reg3b and Reg3g mRNAs, and decreased expression of immune cell function-related genes. Our data show that Hdac1 and Hdac2 are essential IEC homeostasis regulators. IEC-specific Hdac1 and Hdac2 may act as epigenetic sensors and transmitters of environmental cues and regulate IEC-mediated mucosal homeostatic and inflammatory responses. Different levels of IEC Hdac activity may lead to positive or negative outcomes on intestinal homeostasis during inflammation
Project description:We have performed quantitative proteomic TandemMassTag to investigate proteomic changes after deletion of epigenetic eraser genes Hdac1 and Hdac2 in intestinal epithelial cells. Both HDAC1 and HDAC2 are epigenetic erasers that drive specific and redundant gene expression patterns, in part by removing acetyl groups on histones. Deletion of these Hdac in intestinal epithelial cell (IEC) in vivo alters intestinal homeostasis, dependent on the Hdac deleted and the level of expression of both. To determine the specific IEC function of HDAC1 and HDAC2, we have performed transcriptomic and quantitative proteomic approaches on IEC deficient in Hdac1 and Hdac2. We have defined changes in both mRNA and protein expression patterns affecting IEC differentiation. We have identified IEC Hdac1- and Hdac2-dependent common as well as specific pathways and biological processes. These findings uncover unrecognized similarities and differences between Hdac1 and Hdac2 in IEC.
Project description:Purpose: PKM2-mediated metabolic switch to aerobic glycolysis plays a critical role in promoting cell survival and proliferation. However, little is known about the function of intestinal epithelial PKM2 in intestinal homeostasis. Here we investigated whether and how intestinal epithelial PKM2 modulates the morphology and function of the adult intestine in experimental murine colitis. Methods: Colonoscopic biopsies from the Crohn’s disease (CD) and ulcerative colitis (UC) patients (10 each) were analyzed for PKM2 expression. We also generated intestinal epithelial-specific Pkm2 knockout mice and employed them to examine PKM2 function. Mouse intestinal inflammation was induced with dextran sulfate sodium (DSS) in drinking water. Disease phenotypes were investigated by mouse survival, body weight, colon length and analysis of immune cell infiltration in colon, intestinal epithelial cell gene profiling and signal pathway. Results: Intestinal epithelial PKM2 level in UC and CD patients was significantly decreased compared to that from non-inflamed intestinal epithelium. Similar reduction of intestinal epithelial PKM2 was observed in mice with experimental colitis. Supporting the notion that PKM2 serves as a safeguard against colitis, intestinal epithelial-specific Pkm2-deficient (Pkm2-/-) mice displayed a severer intestinal inflammation, companying with shortened colon, disruption of epithelial tight junction, higher permeability, elevation of inflammatory cytokines and immune cell infiltration, compared with wild-type mice. Gene profiling and western blot analysis indicated that cell survival signaling, particularly the Akt/β-catenin pathways, were downregulated in Pkm2-/- mice. Functional assay using mouse primary colonic epithelial cells confirmed that Pkm2 reduction decreased proliferation and migration of epithelial cells, while enhanced expression of Pkm2 was associated with increased transcriptional activity of β-catenin. Moreover, increasing mouse intestinal epithelial Pkm2 expression via delivery of Pkm2-expressing plasmid attenuated DSS-induced experimental colitis. Conclusions: Intestinal epithelial PKM2, through activating Wnt/β-catenin signaling, induces a strong proliferative and migratory response that increases cell survival and wound healing under colitic condition.
Project description:We have exploited organoid SILAC approaches that we have previously developed (A SILAC-Based Method for Quantitative Proteomic Analysis of Intestinal Organoids.- Gonneaud A, Jones C, Turgeon N, Lévesque D, Asselin C, Boudreau F, Boisvert FM. -Sci Rep. 2016 Nov 30;6:38195. doi: 10.1038/srep38195) to investigate proteomic changes after deletion of epigenetic eraser genes Hdac1 and Hdac2 in enteroids. Both HDAC1 and HDAC2 are epigenetic erasers that drive specific and redundant gene expression patterns, in part by removing acetyl groups on histones. Deletion of these Hdac in intestinal epithelial cell (IEC) in vivo alters intestinal homeostasis, dependent on the Hdac deleted and the level of expression of both. To determine the intrinsic specific IEC function of HDAC1 and HDAC2, we have performed transcriptomic and quantitative proteomic approaches on enteroids deficient in Hdac1 or Hdac2. We have defined changes in both mRNA and protein expression patterns affecting IEC differentiation. We have identified IEC Hdac1- and Hdac2-dependent common as well as specific pathways and biological processes. These findings uncover unrecognized similarities and differences between Hdac1 and Hdac2 in IEC.
Project description:STAT3 is a pleiotropic transcription factor with important functions in cytokine signalling in a variety of tissues. However, the role of STAT3 in the intestinal epithelium is not well understood. Here we demonstrate that development of colonic inflammation is associated with the induction of STAT3 activity in intestinal epithelial cells (IEC). Studies in genetically engineered mice showed that epithelial STAT3 activation in DSS colitis is dependent on IL-22 rather than IL-6. IL-22 was secreted by colonic CD11c+ cells in response to Toll-like receptor stimulation. Conditional knockout mice with an IEC specific deletion of STAT3 activity were highly susceptible to experimental colitis, indicating that epithelial STAT3 regulates gut homeostasis. STAT3IEC-KO mice, upon induction of colitis, showed a striking defect of epithelial restitution. Gene chip analysis indicated that STAT3 regulates the cellular stress response, apoptosis and pathways associated with wound healing in IEC. Consistently, both IL-22 and epithelial STAT3 were found to be important in wound-healing experiments in vivo. In summary, our data suggest that intestinal epithelial STAT3 activation regulates immune homeostasis in the gut by promoting IL-22-dependent mucosal wound healing. 4 samples of colon epithelium were analyzed from 4 mice (2 per group Stat3flfl VillinCre- and Stat3flfl VillinCre+, respectively) after they had been treated with DSS (2.5%) for 5 days
Project description:Both HDAC1 and HDAC2 are epigenetic erasers that drive specific and redundant gene expression patterns, in part by removing acetyl groups on histones. Deletion of these Hdac in intestinal epithelial cell (IEC) in vivo alters intestinal homeostasis, dependent on the Hdac deleted and the level of expression of both. To determine the intrinsic specific IEC function of HDAC1 and HDAC2, we have performed transcriptomic and quantitative proteomic approaches on enteroids deficient in Hdac1 or Hdac2. We have defined changes in both mRNA and protein expression patterns affecting IEC differentiation. We have identified IEC Hdac1- and Hdac2-dependent common as well as specific pathways and biological processes. These findings uncover unrecognized similarities and differences between Hdac1 and Hdac2 in IEC.
Project description:STAT3 is a pleiotropic transcription factor with important functions in cytokine signalling in a variety of tissues. However, the role of STAT3 in the intestinal epithelium is not well understood. Here we demonstrate that development of colonic inflammation is associated with the induction of STAT3 activity in intestinal epithelial cells (IEC). Studies in genetically engineered mice showed that epithelial STAT3 activation in DSS colitis is dependent on IL-22 rather than IL-6. IL-22 was secreted by colonic CD11c+ cells in response to Toll-like receptor stimulation. Conditional knockout mice with an IEC specific deletion of STAT3 activity were highly susceptible to experimental colitis, indicating that epithelial STAT3 regulates gut homeostasis. STAT3IEC-KO mice, upon induction of colitis, showed a striking defect of epithelial restitution. Gene chip analysis indicated that STAT3 regulates the cellular stress response, apoptosis and pathways associated with wound healing in IEC. Consistently, both IL-22 and epithelial STAT3 were found to be important in wound-healing experiments in vivo. In summary, our data suggest that intestinal epithelial STAT3 activation regulates immune homeostasis in the gut by promoting IL-22-dependent mucosal wound healing.
Project description:Both HDAC1 and HDAC2 are epigenetic erasers that drive specific and redundant gene expression patterns, in part by removing acetyl groups on histones. Deletion of these Hdac in intestinal epithelial cell (IEC) in vivo alters intestinal homeostasis, dependent on the Hdac deleted and the level of expression of both. To determine the intrinsic specific IEC function of HDAC1 and HDAC2, we have performed transcriptomic and quantitative proteomic approaches on IEC-deficient for Hdac1 and Hdac2. We have defined changes in both mRNA and protein expression patterns affecting IEC differentiation. We have identified IEC Hdac1- and Hdac2-dependent common as well as specific pathways and biological processes. These findings uncover unrecognized similarities and differences between normal IEC and HDAC1/2 deleted jejunum IEC.