MicroRNA Expression in Alpha and Beta Cells of Human Pancreatic Islets

Dagmar Klein, Ryosuke Misawa, Valia Bravo-Egana, Nancy Vargas, Samuel Rosero, Julieta Piroso, Hirohito Ichii, Oliver Umland, Jiang Zhijie, Nicholas Tsinoremas, Camillo Ricordi, Luca Inverardi, Juan Domínguez-Bendala, Ricardo L. Pastori

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71 Scopus citations

Abstract

microRNAs (miRNAs) play an important role in pancreatic development and adult β-cell physiology. Our hypothesis is based on the assumption that each islet cell type has a specific pattern of miRNA expression. We sought to determine the profile of miRNA expression in α-and β-cells, the main components of pancreatic islets, because this analysis may lead to a better understanding of islet gene regulatory pathways. Highly enriched (>98%) subsets of human α-and β-cells were obtained by flow cytometric sorting after intracellular staining with c-peptide and glucagon antibody. The method of sorting based on intracellular staining is possible because miRNAs are stable after fixation. MiRNA expression levels were determined by quantitative high throughput PCR-based miRNA array platform screening. Most of the miRNAs were preferentially expressed in β-cells. From the total of 667 miRNAs screened, the Significant Analysis of Microarray identified 141 miRNAs, of which only 7 were expressed more in α-cells (α-miRNAs) and 134 were expressed more in β-cells (β-miRNAs). Bioinformatic analysis identified potential targets of β-miRNAs analyzing the Beta Cell Gene Atlas, described in the T1Dbase, the web platform, supporting the type 1 diabetes (T1D) community. cMaf, a transcription factor regulating glucagon expression expressed selectively in α-cells (TFα) is targeted by β-miRNAs; miR-200c, miR-125b and miR-182. Min6 cells treated with inhibitors of these miRNAs show an increased expression of cMaf RNA. Conversely, over expression of miR-200c, miR-125b or miR-182 in the mouse alpha cell line αTC6 decreases the level of cMAF mRNA and protein. MiR-200c also inhibits the expression of Zfpm2, a TFα that inhibits the PI3K signaling pathway, at both RNA and protein levels. In conclusion, we identified miRNAs differentially expressed in pancreatic α- and β-cells and their potential transcription factor targets that could add new insights into different aspects of islet biology and pathophysiology.

Original languageEnglish (US)
Article numbere55064
JournalPloS one
Volume8
Issue number1
DOIs
Publication statusPublished - Jan 29 2013
Externally publishedYes

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ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Cite this

Klein, D., Misawa, R., Bravo-Egana, V., Vargas, N., Rosero, S., Piroso, J., ... Pastori, R. L. (2013). MicroRNA Expression in Alpha and Beta Cells of Human Pancreatic Islets. PloS one, 8(1), [e55064]. https://doi.org/10.1371/journal.pone.0055064