K L A Souza1,2, M Elsner1, P C F Mathias2, S Lenzen1, M Tiedge3. 1. Institute of Clinical Biochemistry, Hanover Medical School, 30623, Hanover, Germany. 2. Department of Cell Biology and Genetics, University of Maringá, Maringá, Brazil. 3. Institute of Clinical Biochemistry, Hanover Medical School, 30623, Hanover, Germany. tiedge.markus@mh-hannover.de.
Abstract
AIMS/HYPOTHESIS: Cytokines are important humoral mediators of beta cell destruction in autoimmune diabetes. The aim of this study was to identify novel cytokine-induced genes in insulin-producing RINm5F cells, which may contribute to beta cell death or survival. METHODS: A global gene expression profile in cytokine-exposed insulin-producing RINm5F cells was achieved by automated restriction fragment differential display PCR. The expression of selected candidate genes was confirmed by real-time RT-PCR analysis. RESULTS: Exposure of RINm5F cells to IL-1beta or to a cytokine mixture (IL-1beta, TNF-alpha, IFN-gamma) for 6 h resulted in the differential expression of a functional gene cluster. Apart from the well-known up-regulation of the cytokine-responsive genes iNOS, NF-kappaB, MnSOD and Hsp70, several genes that belong to the functional cluster of the endocytotic pathway were identified. These endocytotic genes comprised: clathrin, megalin, synaptotagmin and calcineurin, which were up-regulated by IL-1beta or the cytokine mixture. In contrast, the expression of the calcineurin inhibitor CAIN and of the GDP/GTP exchange protein Rab3 was down-regulated by cytokines. Other up-regulated cytokine-responsive genes were: agrin, murine adherent macrophage protein mRNA ( MAMA) and transport-associated protein ( TAP1/MTP), whereas the plasma membrane calcium ATPase ( PMCA) 2 and PMCA 3 genes were down-regulated by cytokines. CONCLUSIONS/ INTERPRETATION: Our results indicate that genes of the endocytotic pathway are regulated by pro-inflammatory cytokines. This might affect the density of cytokine receptors at the beta cell surface and concomitantly the sensitivity of the cells to cytokine toxicity. A better understanding of the functional cross-talk between endocytotic and cytokine signalling pathways could further the development of novel strategies to protect pancreatic beta cells against toxic effects of pro-inflammatory cytokines.
AIMS/HYPOTHESIS: Cytokines are important humoral mediators of beta cell destruction in autoimmune diabetes. The aim of this study was to identify novel cytokine-induced genes in insulin-producing RINm5F cells, which may contribute to beta cell death or survival. METHODS: A global gene expression profile in cytokine-exposed insulin-producing RINm5F cells was achieved by automated restriction fragment differential display PCR. The expression of selected candidate genes was confirmed by real-time RT-PCR analysis. RESULTS: Exposure of RINm5F cells to IL-1beta or to a cytokine mixture (IL-1beta, TNF-alpha, IFN-gamma) for 6 h resulted in the differential expression of a functional gene cluster. Apart from the well-known up-regulation of the cytokine-responsive genes iNOS, NF-kappaB, MnSOD and Hsp70, several genes that belong to the functional cluster of the endocytotic pathway were identified. These endocytotic genes comprised: clathrin, megalin, synaptotagmin and calcineurin, which were up-regulated by IL-1beta or the cytokine mixture. In contrast, the expression of the calcineurin inhibitor CAIN and of the GDP/GTP exchange protein Rab3 was down-regulated by cytokines. Other up-regulated cytokine-responsive genes were: agrin, murine adherent macrophage protein mRNA ( MAMA) and transport-associated protein ( TAP1/MTP), whereas the plasma membrane calcium ATPase ( PMCA) 2 and PMCA 3 genes were down-regulated by cytokines. CONCLUSIONS/ INTERPRETATION: Our results indicate that genes of the endocytotic pathway are regulated by pro-inflammatory cytokines. This might affect the density of cytokine receptors at the beta cell surface and concomitantly the sensitivity of the cells to cytokine toxicity. A better understanding of the functional cross-talk between endocytotic and cytokine signalling pathways could further the development of novel strategies to protect pancreatic beta cells against toxic effects of pro-inflammatory cytokines.
Authors: I Martinez; B Sveinbjørnsson; F Vidal-Vanaclocha; A Asumendi; B Smedsrød Journal: Biochem Biophys Res Commun Date: 1995-07-06 Impact factor: 3.575
Authors: B Frantz; E C Nordby; G Bren; N Steffan; C V Paya; R L Kincaid; M J Tocci; S J O'Keefe; E A O'Neill Journal: EMBO J Date: 1994-02-15 Impact factor: 11.598
Authors: Letícia P Roma; Camila A M Oliveira; Everardo M Carneiro; Gabriela G Albuquerque; Antonio C Boschero; Kleber L A Souza Journal: Redox Rep Date: 2011 Impact factor: 4.412
Authors: Ren Song; Orkide O Koyuncu; Todd M Greco; Benjamin A Diner; Ileana M Cristea; Lynn W Enquist Journal: MBio Date: 2016-02-02 Impact factor: 7.867