title: The masticatory contractile load induced expression and activation of Akt1/PKBalpha in muscle fibers at the myotendinous junction within muscle-tendon-bone unit.
abstract: The cell specific detection of enzyme activation in response to the physiological contractile load within muscle-tendon-bone unit is essential for understanding of the mechanical forces transmission from muscle cells via tendon to the bone. The hypothesis that the physiological mechanical loading regulates activation of Akt1/PKBalpha at Thr308 and at Ser473 in muscle fibers within muscle-tendon-bone unit was tested using quantitative immunohistochemistry, confocal double fluorescence analysis, and immunoblot analysis. In comparison to the staining intensities in peripheral regions of the muscle fibers, Akt1/PKBalpha was detected with a higher staining intensity in muscle fibers at the myotendinous junction (MTJ) areas. In muscle fibers at the MTJ areas, Akt1/PKBalpha is dually phosphorylated at Thr308 and Ser473. The immunohistochemical results were confirmed by immunoblot analysis. We conclude that contractile load generated by masticatory muscles induces local domain-dependent expression of Akt1/PKBalpha as well as activation by dually phosphorylation at Thr308 and Ser473 in muscle fibers at the MTJ areas within muscle-tendon-bone unit.
authors.affiliation: Department of Operative Dentistry, Periodontics and Endodontics, Heinrich-Heine-University, 40225 Düsseldorf, Germany.
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Korkmaz
authors.forename: Franz J
authors.initials: FJ
authors.lastname: Klinz
authors.forename: Mehrnoush
authors.initials: M
authors.lastname: Moghbeli
authors.forename: Klaus
authors.initials: K
authors.lastname: Addicks
authors.forename: Wolfgang H-M
authors.initials: WH
authors.lastname: Raab
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Bloch
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000201:enzymology* / Q000502:physiology; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D008410:Masticatory Muscles / Q000201:enzymology* / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000201:enzymology* / Q000502:physiology; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D021381:Protein Transport; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013710:Tendons / Q000201:enzymology* / Q000502:physiology; D016474:Weight-Bearing
chemical_list: D010769:Phosphothreonine; D010768:Phosphoserine; D051057:Proto-Oncogene Proteins c-akt
references.citation: Trends Biochem Sci. 2001 Nov;26(11):657-64
references.pmid: 11701324
references.citation: Science. 1998 Jan 30;279(5351):710-4
references.pmid: 9445477
references.citation: Nat Cell Biol. 2003 Feb;5(2):87-90
references.pmid: 12563267
references.citation: Mol Cell Biol. 2004 Nov;24(21):9295-304
references.pmid: 15485899
references.citation: J Physiol. 2003 Sep 1;551(Pt 2):467-78
references.pmid: 12813146
references.citation: J Biol Chem. 2002 Apr 5;277(14):11910-7
references.pmid: 11809761
references.citation: J Cell Biol. 2008 Mar 10;180(5):1037-49
references.pmid: 18332223
references.citation: J Biomech. 1991;24 Suppl 1:43-52
references.pmid: 1791181
references.citation: J Cell Physiol. 2009 May;219(2):503-11
references.pmid: 19142853
references.citation: Curr Biol. 1997 Oct 1;7(10):776-89
references.pmid: 9368760
references.citation: Cell. 2006 Oct 6;127(1):125-37
references.pmid: 16962653
references.citation: Am J Physiol Endocrinol Metab. 2003 Nov;285(5):E1081-8
references.pmid: 12837666
references.citation: Mol Cell Biol. 2002 Jul;22(13):4803-14
references.pmid: 12052887
references.citation: J Biol Chem. 2000 Mar 24;275(12):8271-4
references.pmid: 10722653
references.citation: Genes Dev. 2001 Sep 1;15(17):2203-8
references.pmid: 11544177
references.citation: Trends Biochem Sci. 2004 May;29(5):233-42
references.pmid: 15130559
references.citation: FEBS Lett. 2003 Jul 3;546(1):108-12
references.pmid: 12829245
references.citation: Mol Cell. 2004 May 7;14(3):395-403
references.pmid: 15125842
references.citation: J Dent Res. 2005 Sep;84(9):774-83
references.pmid: 16109984
references.citation: Arch Oral Biol. 2008 Dec;53(12):1129-37
references.pmid: 18675952
references.citation: Nat Cell Biol. 2001 Nov;3(11):1014-9
references.pmid: 11715023
references.citation: Mol Cell Biol. 2002 Sep;22(17):6247-60
references.pmid: 12167717
references.citation: Genes Dev. 2003 Jun 1;17(11):1352-65
references.pmid: 12782654
references.citation: J Biol Chem. 2007 Feb 23;282(8):5106-10
references.pmid: 17218321
references.citation: Cell. 2004 Apr 30;117(3):399-412
references.pmid: 15109499
references.citation: J Periodontol. 2009 May;80(5):850-9
references.pmid: 19405839
references.citation: Nat Cell Biol. 2000 Mar;2(3):142-7
references.pmid: 10707084
references.citation: J Physiol. 2008 Jun 1;586(11):2675-81
references.pmid: 18440990
references.citation: J Histochem Cytochem. 2000 Feb;48(2):163-6
references.pmid: 10639482
references.citation: J Anat. 2007 Oct;211(4):464-70
references.pmid: 17692082
references.citation: J Dent Res. 2005 Sep;84(9):784-93
references.pmid: 16109985
references.citation: Annu Rev Cell Dev Biol. 1995;11:379-416
references.pmid: 8689563
references.citation: Cell. 1989 Dec 1;59(5):771-2
references.pmid: 2686838
references.citation: J Cell Sci. 2005 Dec 15;118(Pt 24):5675-8
references.pmid: 16339964
references.citation: Science. 2005 Feb 18;307(5712):1098-101
references.pmid: 15718470
references.citation: Physiol Rev. 2004 Apr;84(2):649-98
references.pmid: 15044685
references.citation: Genes Dev. 1999 Nov 15;13(22):2905-27
references.pmid: 10579998
references.citation: J Biol Chem. 2004 Sep 24;279(39):41189-96
references.pmid: 15262962
references.citation: Proc Natl Acad Sci U S A. 2002 Jul 9;99(14):9213-8
references.pmid: 12084817
references.citation: J Orthop Res. 2005 Sep;23(5):1219-25
references.pmid: 16140203
references.citation: Proc Natl Acad Sci U S A. 2001 Nov 6;98(23):13108-13
references.pmid: 11606756