title: Burn injury-induced IRS-1 degradation in mouse skeletal muscle.
abstract: Insulin resistance is a major effect of burn injury and insulin receptor substrate-1 (IRS-1) plays an important role in signal transduction. Here, we explored the integrity of IRS-1 in muscle after burn injury. A murine model of severe burn injury was used to explore IRS-1 integrity/degradation in muscle and to map Ser/Thr phosphorylations which represent the trigger sites for degradation. The findings are: three C-terminal IRS-1 cleavage fragments were confirmed with tandem mass spectrometry; MWs 95, 44 and 42 kD. In sham burn animals the level of intact IRS-1 was 51.9 ng/g, whereas, total IRS-1 which includes degradation fragments and post-translationally modified protein was 196.7 ng/g. After burn, intact and total IRS-1 were reduced to 47.8 (92.1 % sham, p<0.05) and 86.9 ng/g (44.2 % sham, p<0.005). In contrast, ubiquitinated IRS-1 increased from 24.5 to 28.4 ng/g (15.9% increment, p< 0.05) in the burned mice. In cytosol, membrane and nuclear fractions, total IRS-1 was reduced by 89.8% (p<0.005), 25.8% (p<0.05) and 87.3% (p<0.005). To further evaluate the IRS-1 degradation pathway, SOCS-3 mRNA levels after burn injury were found to be increased by 35% (p<0.05), 110% (p<0.05) and 140% (p<0.005). However, phosphorylation of Ser473 and Thr308 of Akt1 were reduced to 26.2% (p<0.05) and 49.8% (p<0.005). We conclude: burn injury is associated with IRS-1 degradation via SOCS-3 and ubiquitin-mediated pathways and reduced subcellular levels of IRS-1, serve as molecular basis for burn injury induced alteration in insulin function.
authors: Surgical Service, Massachusetts General Hospital Boston, MA, 02114, USA ; Harvard Medical School Boston, MA, 02114, USA ; The Shriners Hospitals for Children Boston, MA 02114, USA.
authors: X-M
authors: XM
authors: Lu
authors: Rg
authors: R
authors: Tompkins
authors: Aj
authors: A
authors: Fischman
keywords: Insulin receptor substrate-1 degradation; burn injury; tandem mass spectrometry
references: Mol Endocrinol. 2000 Jun;14(6):783-94
references: 10847581
references: Exp Cell Res. 2009 Mar 10;315(5):727-32
references: 18851963
references: Am J Physiol Cell Physiol. 2011 Jun;300(6):C1375-85
references: 21325637
references: Diabetologia. 2003 Nov;46(11):1532-42
references: 14579029
references: Crit Care. 2007;11(4):R90
references: 17716366
references: Biochemistry. 2004 May 18;43(19):5888-901
references: 15134463
references: J Surg Res. 2005 Jan;123(1):144-52
references: 15652963
references: J Am Soc Mass Spectrom. 2006 Apr;17(4):562-567
references: 16503154
references: Trends Cell Biol. 2001 Nov;11(11):437-41
references: 11684411
references: Science. 2002 Dec 6;298(5600):1912-34
references: 12471243
references: Cell Cycle. 2009 Jul 15;8(14):2255-9
references: 19502786
references: J Clin Invest. 2006 Jan;116(1):101-14
references: 16374520
references: J Clin Endocrinol Metab. 2006 Feb;91(2):709-17
references: 16332940
references: Int J Mol Med. 2009 Oct;24(4):531-8
references: 19724894
references: Int J Mol Med. 2004 Oct;14(4):653-8
references: 15375597
references: J Biol Chem. 2005 Feb 11;280(6):4422-8
references: 15574412
references: Mol Cell. 2008 May 23;30(4):403-14
references: 18498745
references: Surgery. 1979 Nov;86(5):742-7
references: 494065
references: Int J Biochem Cell Biol. 2005 Oct;37(10):1948-61
references: 16109499
references: Am J Physiol. 1977 Aug;233(2):E80-5
references: 888949
references: Mol Cell Biol. 1993 Dec;13(12):7418-28
references: 7504175
references: Shock. 2010 Mar;33(3):299-305
references: 22011639
references: Endocrinology. 2010 Jan;151(1):75-84
references: 19887566
references: Shock. 2007 Feb;27(2):205-8
references: 17224797
references: Shock. 2000 Sep;14(3):392-8; discussion 398-9
references: 11028562
references: Crit Care Med. 2007 Sep;35(9 Suppl):S524-30
references: 17713403
references: Biochim Biophys Acta. 2008 Nov;1779(11):697-701
references: 18655850
references: Crit Care Med. 2007 Sep;35(9 Suppl):S519-23
references: 17713402
references: Sci STKE. 2005 Jan 25;2005(268):pe4
references: 15671481
references: J Biol Chem. 2005 Aug 19;280(33):29912-20
references: 15967802
references: J Clin Endocrinol Metab. 2009 May;94(5):1656-64
references: 19240154
references: Exp Dermatol. 2010 Sep;19(9):777-83
references: 20629737
references: J Biol Chem. 2004 Oct 29;279(44):45304-7
references: 15364919
references: J Trauma. 2004 Nov;57(5):1132-8
references: 15580048
references: Ann Surg. 2003 Mar;237(3):422-8
references: 12616128
references: Biochem Biophys Res Commun. 2006 Apr 21;342(4):1183-7
references: 16516141
references: Biochemistry. 1997 Oct 21;36(42):12939-47
references: 9335553
references: Biochimie. 2005 Jan;87(1):99-109
references: 15733744
references: J Cell Physiol. 2007 Dec;213(3):679-89
references: 17657723
references: J Endocrinol. 2001 Oct;171(1):153-62
references: 11572799
references: Crit Care. 2002 Apr;6(2):102-5
references: 11983030
references: Mol Endocrinol. 2001 Nov;15(11):1864-9
references: 11682617
references: Nat Rev Mol Cell Biol. 2006 Feb;7(2):85-96
references: 16493415
references: J Biol Chem. 2002 Nov 1;277(44):42394-8
references: 12228220
references: Science. 2005 Jan 21;307(5708):384-7
references: 15662004
references: Diabetes. 2001 Jan;50(1):24-31
references: 11147790
references: J Biol Chem. 2004 Aug 13;279(33):34733-40
references: 15181014
references: Life Sci. 2005 Oct 28;77(24):3068-77
references: 15982669
references: Biochem Soc Trans. 2003 Dec;31(Pt 6):1152-6
references: 14641015
references: Biochem Biophys Res Commun. 2003 Jul 11;306(4):898-904
references: 12821126
references: Endocrinology. 2002 Nov;143(11):4178-83
references: 12399410
references: Int J Mol Med. 2011 Oct;28(4):589-94
references: 21805045
references: J Biol Chem. 2002 Dec 27;277(52):50230-6
references: 12006582
references: Am J Physiol Endocrinol Metab. 2005 Mar;288(3):E585-91
references: 15536206
references: J Biol Chem. 2004 Aug 20;279(34):35298-305
references: 15199052
references: Science. 2003 Dec 5;302(5651):1710-1
references: 14657487
references: Biochem J. 2002 Dec 15;368(Pt 3):875-84
references: 12220227
references: J Burn Care Res. 2008 Sep-Oct;29(5):683-94
references: 18695610
references: J Biol Chem. 1997 Oct 3;272(40):25289-95
references: 9312146
references: Am J Physiol Endocrinol Metab. 2002 Sep;283(3):E413-22
references: 12169433