Project description:Changes in gene expression after treatment of E. coli cultures with mitomycin C were assessed using gene array technology. Unexpectedly, a large number of genes (nearly 30% of all genes) displayed significant changes in their expression level. Analysis and classification of expression profiles of the corresponding genes allowed us to assign this large number of genes into a dozen to two dozen small clusters of genes with similar expression profiles. This assignment allowed us to describe systematically the changes in the level of gene expression in response to DNA damage. Among the damage-induced genes more than a hundred are novel. From those genes involved in DNA metabolism that have not been previously shown to be induced by DNA damage, for example, the mutS gene involved in mismatch repair is especially noteworthy. In addition to the SOS response, we observed the induction of other stress response pathways such as those of oxidative stress and osmotic protection. Among the genes that are down-regulated in response to DNA damage are numerous protein biosynthesis genes. Analysis of the gene expression data highlighted the essential involvement of sigmaS regulated genes and the general stress response network in the response to DNA damage. Keywords = DNA damage, recA, SOS
Project description:Changes in human bladder epithelial cell gene expression associated with interstitial cystitis or antiproliferative factor treatment. Explanted bladder epithelial cells from patients with interstitial cystitis (IC) have been shown to differ from explanted control cells in several ways, including production of an antiproliferative factor (APF), altered production of certain epithelial growth factors, and rate of proliferation. To better understand the role of the APF in abnormal bladder epithelial cell proliferation in IC, we studied gene expression patterns in normal bladder epithelial cells treated with APF vs. mock APF and compared them to expression patterns in IC vs. normal cells using microarray analysis. Oligo-dT-primed total cellular RNA was labeled with [33P]dCTP and hybridized to GeneFilter GF211 microarray membranes (Research Genetics) containing cDNA for 3,964 human genes. Thirteen genes that function in epithelial cell proliferation or differentiation were consistently differentially expressed in both IC (compared with control) and APF-treated (compared with mock APF-treated) normal bladder epithelial cells. The general pattern of gene expression in IC and APF-treated cells suggested a less proliferative phenotype, with increased expression of E-cadherin, phosphoribosylpyrophosphate synthetase-associated protein 39, and SWI/SNF complex 170-kDa subunit, and decreased expression of vimentin, {alpha}2-integrin, {alpha}1-catenin, cyclin D1, and jun N-terminal kinase 1; these findings were confirmed for the structural gene products (E-cadherin, vimentin, {alpha}2-integrin, and {alpha}-catenin) by immunohistochemistry. These results are compatible with the previously noted decreased proliferation rate of IC and APF-treated normal cells, and indicate that the mechanism whereby APF inhibits cell proliferation may involve both downregulation of genes that stimulate cell proliferation along with upregulation of genes that inhibit cell growth.
Project description:Taste stem/progenitor cells from the mouse posterior tongue have been recently used to generate taste bud organoids. However, the inaccessible location of the taste receptor cells is observed in conventional organoids. Here, we established a suspension culture method for fine tuning of taste bud organoid by apicobasal polarity alteration to form the accessible localization of taste receptor cells in organoid. Compared to conventional Matrigel-embedded organoids, suspension-cultured organoids showed comparable differentiation and renewal rates to those of taste buds in vivo and exhibited functional taste receptor cells and cycling progenitor cells. Accessible taste receptor cells on the outer region of taste bud organoids enabled the direct application of calcium imaging for evaluating the taste response. Moreover, suspension-cultured organoids could be genetically altered using gene editing methods. Suspension-cultured taste bud organoid harmoniously integrated with the recipient lingual epithelium; maintained the taste receptor cells and gustatory innervation capacity. Thus, we propose that suspension-cultured organoids may provide efficient model for taste research including taste bud development, regeneration and transplantation
Project description:To uncover novel molecules involved in taste detection, we performed a microarray-based screen for genes enriched in taste neurons. Proboscis RNA from flies homozygous for a recessive poxn null mutation was compared to RNA from heterozygous controls. Poxn mutants have a transformation of labellar gustatory chemosensory bristles into mechanosensory bristles and therefore lack most or all taste neurons. Experiment Overall Design: Proboscises of poxn70 homozygous mutant and poxn70 heterozygous mutant males (8-18 days post eclosure) were dissected, and total RNA was harvested in Trizol according to standard trizol protocol. Samples for each microarray were prepared from 164-280 proboscises. We performed 3 biological replicates for each genotype.
Project description:Previously we showed that taste receptor cells in situ in taste buds synthesize insulin. Here we describe a model of pig taste organoid culture in which we have promoted insulin expression by induction of quiescence. The cellular heterogeneity of the lingual epithelium is maintained in the organoids, and stem cell type and organoid architecture can be controlled through changes in media composition and/or use of static versus dynamic culture. Pig taste organoids were maintained long term and organoids cultured in low sheer stress dynamic exhibited an architecture and expression profile akin to the native tissue. Porcine taste organoids also contained insulin, and the insulin critical transcription factors MAFA and PAX4. These results provide a pig model of taste organoid culture that can be used universally and bring us closer to the use of the taste tissue as a new renewable source of beta cells
Project description:To understand the mechanisms that regulate the renewal and maintenance of taste cells we performed RNA-sequencing analysis on isolated taste cells from 2 and 6 month old mice to determine how alterations in the taste cell-transcriptome regulate taste cell maintenance and function in adults. We found that the Activator Protein-1 (AP1) transcription factors (c-Fos, Fosb and c-Jun) and genes associated with this pathway were significantly downregulated in taste cells from 6 month old mice and further declined at 12 months. We generated conditional c-Fos- knockout mice to target K14-expressing cells, including differentiating taste cells. c-Fos deletion caused a severe perturbation in taste bud structure and resulted in a significant reduction in the taste bud size. c-Fos deletion also affected taste cell turnover as evident by, a decrease in proliferative markers, and upregulation of the apoptotic marker cleaved-PARP. Thus, AP1 factors are important regulators of adult taste cell renewal and their downregulation negatively impacts taste maintenance. Comparison of genes responsible for peripheral Taste system maintenance at age, 3 and 6 months. processed_data.txt: List of B vs S gene expression data gene_exp.diff: cuffdiff data for 2 and 6 month taste cells
Project description:Novel taste memories, critical for animal survival, are consolidated to form long term memories which are dependent on translation regulation in the gustatory cortex We used microarray for identification of genes involved in novel taste learning at two time points- 1 and 3 hours following memory formation for novel taste Adult rats were separated into two groups- novel tatse (0.1% sacchain) and water, two time points were used 1, 3 hours following learnin. Rna was extracted and hybridized on Affymetrix microarray
Project description:Efforts to unravel the mechanisms underlying taste sensation (gustation) have largely focused on rodents. The first comprehensive database of gene expression in primate (Macaca fascicularis) taste buds is presented. This database provides a foundation for further studies in diverse aspects of taste biology. A taste bud gene expression database was generated using laser capture microdissection (LCM) of tissue freeze medium OTC embedded macaque tongue tissue blocks. We collected fungiform (FG) taste buds at the front of the tongue, circumvallate (CV) taste buds at the back of the tongue, as well as non-gustatory lingual epithelium (LE). Gene expression was also analyzed in the top and bottom portions of CV taste buds collected using LCM. Samples were collected from 10 animals - 7 female, 3 male.