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Series GSE13153 Query DataSets for GSE13153
Status Public on Oct 11, 2008
Title Stimulation of Human and Rat Islet β-Cell Proliferation with Retention of Function by Nkx6.1
Organism Rattus norvegicus
Experiment type Expression profiling by array
Summary The homeodomain transcription factor Nkx6.1 plays an important role in pancreatic islet β-cell development, but its effects on adult β-cell function, survival, and proliferation are not well understood. In the present study, we demonstrated that treatment of primary rat pancreatic islets with a cytomegalovirus promoter-driven recombinant adenovirus containing the Nkx6.1 cDNA (AdCMV-Nkx6.1) causes dramatic increases in [methyl-3H] thymidine and 5-bromo-2'-deoxyuridine (BrdU) incorporation and in the number of cells per islet relative to islets treated with a control adenovirus (AdCMV-βGAL), whereas suppression of Nkx6.1 expression reduces thymidine incorporation. Immunocytochemical studies reveal that >80% of BrdU-positive cells in AdCMV-Nkx6.1-treated islets are β cells. Microarray, real-time PCR, and immunoblot analyses reveal that overexpression of Nkx6.1 in rat islets causes concerted upregulation of a cadre of cell cycle control genes, including those encoding cyclins A, B, and E, and several regulatory kinases. Cyclin E is upregulated earlier than the other cyclins, and adenovirus-mediated overexpression of cyclin E is shown to be sufficient to activate islet cell proliferation. Moreover, chromatin immunoprecipitation assays demonstrate direct interaction of Nkx6.1 with the cyclin A2 and B1 genes. Overexpression of Nkx6.1 in rat islets caused a clear enhancement of glucose-stimulated insulin secretion (GSIS), whereas overexpression of Nkx6.1 in human islets caused an increase in the level of [3H]thymidine incorporation that was twice the control level, along with complete retention of GSIS. We conclude that Nkx6.1 is among the very rare factors capable of stimulating β-cell replication with retention or enhancement of function, properties that may be exploitable for expansion of β-cell mass in treatment of both major forms of diabetes.

Keywords: Insulin secretion, islet biology, transcription factor, cell cycle regulation, diabetes
Overall design We utilized a “sample x reference” experimental design strategy in which RNA extracted from rat pancreatic islets was hybridized to the microarray slide in the presence of labeled rat reference RNA (RRR, Stratagene, LaJolla, CA). Cultures were treated with adenoviruses expressing either the hamster form of Nkx6.1 or the beta-galactosidase enzyme. 5 biological replicates each representing independent islet isolations were used for microarray analysis. Briefly, five hundred nanograms of total RNA were used for gene expression profiling following reverse transcription and T-7 polymerase-mediated amplification/labeling with Cyanine-5. Labeled subject cRNA was co-hybridized to Operon rat 27K oligonucleotide arrays with equimolar amounts of Cyanine-3 labeled RRR. Slides were hybridized, washed, and scanned on a Gene Pix 5000 microarray scanner.
Contributor(s) Schisler JC, Fueger PT, Babu DA, Hohmeier HE, Tessem JS, Lu D, Becker TC, Naziruddin B, Levy M, Mirmira RG, Newgard CB
Citation(s) 18347054
Submission date Oct 10, 2008
Last update date Jul 24, 2013
Contact name Jonathan C Schisler
Phone 919-843-8708
Organization name The University of North Carolina at Chapel Hill
Department McAllister Heart Institute
Lab Schisler Lab
Street address MBRB, Rm 2340C
City Chapel Hill
State/province NC
ZIP/Postal code 27599-7126
Country USA
Platforms (1)
GPL7471 Operon Rat V3.0 printed oligonucleotide array
Samples (10)
GSM329300 bGAL01
GSM329301 bGAL02
GSM329302 bGAL03
BioProject PRJNA109735

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Supplementary file Size Download File type/resource
GSE13153_RAW.tar 21.7 Mb (http)(custom) TAR (of GPR)
Raw data provided as supplementary file
Processed data included within Sample table

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