title: High glucose induces mitochondrial p53 phosphorylation by p38 MAPK in pancreatic RINm5F cells.
abstract: Pancreatic β-cell death in type 2 diabetes has been related to p53 subcellular localisation and phosphorylation. However, the mechanisms by which p53 is phosphorylated and its activation in response to oxidative stress remain poorly understood. Therefore, the aim of this study was to investigate mitochondrial p53 phosphorylation, its subcellular localisation and its relationship with apoptotic induction in RINm5F cells cultured under high glucose conditions. Our results show that p53 phosphorylation in the mitochondrial fraction was greater at ser392 than at ser15. This increased phosphorylation correlated with an increase in reactive oxygen species, a decrease in the Bcl-2/Bax ratio, a release of cytochrome c and an increase in the rate of apoptosis. We also observed a decline in ERK 1/2 phosphorylation over time, which is an indicator of cell proliferation. To identify the kinase responsible for phosphorylating p53, p38 mitogen-activated protein kinase (MAPK) activation was analysed. We found that high glucose induced an increase in p38 MAPK phosphorylation in the mitochondria after 24-72 h. Moreover, the phosphorylation of p53 (ser392) by p38 MAPK in mitochondria was confirmed by colocalisation studies with confocal microscopy. The addition of a specific p38 MAPK inhibitor (SB203580) to the culture medium during high glucose treatment blocked p53 mobilisation to the mitochondria and phosphorylation; thus, the release of cytochrome c and the apoptosis rate in RINm5F cells decreased. These results suggest that mitochondrial p53 phosphorylation by p38 MAPK plays an important role in RINm5F cell death under high glucose conditions.
authors: Unidad de Investigación Médica en Bioquímica, HE, Centro Médico Nacional Siglo XXI. IMSS., Av. Cuauhtémoc 330, Col Doctores, Del. Cuauhtémoc, México, DF, Mexico.
authors: Luis A
authors: LA
authors: Flores-López
authors: Margarita
authors: M
authors: Díaz-Flores
authors: Rebeca
authors: R
authors: García-Macedo
authors: Alejandro
authors: A
authors: Ávalos-Rodríguez
authors: Marcela
authors: M
authors: Vergara-Onofre
authors: Miguel
authors: M
authors: Cruz
authors: Alejandra
authors: A
authors: Contreras-Ramos
authors: Mina
authors: M
authors: Konigsberg
authors: Clara
authors: C
authors: Ortega-Camarillo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology*; D047468:Immunoprecipitation; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D048051:p38 Mitogen-Activated Protein Kinases; D005947:Glucose
references: J Biol Chem. 1999 Apr 30;274(18):12229-35
references: 10212189
references: Apoptosis. 2011 Feb;16(2):145-61
references: 21082355
references: Am J Physiol Lung Cell Mol Physiol. 2002 Jun;282(6):L1324-9
references: 12003789
references: Endocrinology. 2007 Jan;148(1):81-91
references: 17053028
references: Trends Biochem Sci. 2006 May;31(5):268-75
references: 16603362
references: Cell Death Differ. 2006 Jun;13(6):941-50
references: 16601750
references: Acta Physiol (Oxf). 2008 Jan;192(1):11-7
references: 18171425
references: FEBS Lett. 2007 Jul 31;581(19):3743-8
references: 17433304
references: PLoS One. 2010 Dec 29;5(12):e15726
references: 21209957
references: Science. 1998 Aug 28;281(5381):1322-6
references: 9735050
references: J Biol Chem. 2000 May 26;275(21):16202-12
references: 10821866
references: Apoptosis. 2005 Jan;10(1):193-200
references: 15711935
references: Mol Cell Biol. 2003 Dec;23(23):8576-85
references: 14612402
references: Mol Cell Biochem. 2006 Jan;281(1-2):163-71
references: 16328969
references: Biochem J. 1981 Nov 1;199(2):393-8
references: 7041886
references: Nature. 2000 Apr 13;404(6779):787-90
references: 10783895
references: Biochem Pharmacol. 2012 May 15;83(10):1349-57
references: 22342995
references: J Biol Chem. 2004 Dec 17;279(51):53015-22
references: 15471885
references: J Biol Chem. 2000 Jul 7;275(27):20444-9
references: 10781582
references: Diabetes. 1992 Jul;41(7):777-81
references: 1612191
references: Nucleic Acids Res. 1994 Dec 11;22(24):5506-7
references: 7816645
references: Toxicol Sci. 2003 Sep;75(1):99-107
references: 12805646
references: Nucleic Acids Res. 1989 Aug 11;17(15):6419
references: 2771659
references: Endocr Rev. 2002 Oct;23(5):599-622
references: 12372842
references: Am J Physiol Heart Circ Physiol. 2009 Feb;296(2):H380-8
references: 19060130
references: J Neurosci Res. 2004 Jan 1;75(1):83-95
references: 14689451
references: Am J Physiol Renal Physiol. 2004 Jan;286(1):F120-6
references: 12952860
references: Diabetes. 2012 Dec;61(12):3181-8
references: 22933112
references: Biochem Biophys Res Commun. 2003 Jan 3;300(1):216-22
references: 12480546
references: PLoS One. 2010 Aug 23;5(8):e12341
references: 20808790
references: Cancer Res. 2005 May 1;65(9):3610-6
references: 15867355
references: Cell Signal. 2005 Dec;17(12):1516-32
references: 15908180
references: Cell Death Differ. 2009 Mar;16(3):368-77
references: 18846109
references: Genes Dev. 2000 Feb 1;14(3):289-300
references: 10673501
references: Mol Pharmacol. 2007 Mar;71(3):736-43
references: 17172466
references: J Biol Chem. 2003 Jun 27;278(26):23432-40
references: 12697749
references: J Biol Chem. 2002 Aug 16;277(33):30010-8
references: 12011047
references: J Biol Chem. 2003 Oct 10;278(41):39527-33
references: 12890678
references: Cancer Res. 2004 Feb 1;64(3):1071-8
references: 14871840
references: Diabetes. 2001 Oct;50(10):2363-75
references: 11574421
references: Mol Med Rep. 2012 Apr;5(4):929-34
references: 22245807
references: Vitam Horm. 2009;80:507-39
references: 19251048
references: Cancer Res. 2004 Jul 15;64(14):4749-54
references: 15256442
references: Diabetes. 2005 Jun;54(6):1615-25
references: 15919781
references: Endocrinology. 2008 Apr;149(4):1654-65
references: 18187551
references: Int J Biol Sci. 2009;5(1):44-51
references: 19159010
references: Endocr Metab Immune Disord Drug Targets. 2009 Mar;9(1):38-46
references: 19275680
references: Cell. 2009 Jan 23;136(2):235-48
references: 19135240
references: Diabetes. 2003 Jan;52(1):102-10
references: 12502499
references: Cell Stress Chaperones. 2011 Sep;16(5):539-48
references: 21472505