title: Modulation of Nuclear Shape by Substrate Rigidity.
abstract: The nucleus is mechanically coupled to the three cytoskeletal elements in the cell via linkages maintained by the LINC complex (for Linker of Nucleoskeleton to Cyto-skeleton). It has been shown that mechanical forces from the extracellular matrix (ECM) can be transmitted through the cytoskeleton to the nuclear surface. Here we quantified nuclear shape in NIH 3T3 fibroblasts on polyacrylamide gels with a controlled degree of cross-linking. On soft substrates with a Young's modulus of 0.4 kPa, the nucleus appeared rounded in its vertical cross-section, while on stiff substrates (308 kPa), the nucleus appears more flattened. Over-expression of dominant negative Klarsicht ANC-1 Syne Homology (KASH) domains, which disrupts the LINC complex, eliminated the sensitivity of nuclear shape to substrate rigidity; myosin inhibition had similar effects. GFP-KASH4 over-expression altered the rigidity dependence of cell motility and cell spreading. Taken together, our results suggest that nuclear shape is modulated by substrate rigidity-induced changes in actomyosin tension, and that a mechanically integrated nucleus-cytoskeleton is required for rigidity sensing. These results are significant because they suggest that substrate rigidity can potentially control nuclear function and hence cell function.
authors.affiliation: Department of Chemical Engineering, University of Florida, Bldg. 723, Gainesville, FL 32611, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Lovett
authors.forename: Nandini
authors.initials: N
authors.lastname: Shekhar
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Nickerson
authors.forename: Kyle J
authors.initials: KJ
authors.lastname: Roux
authors.forename: Tanmay P
authors.initials: TP
authors.lastname: Lele
keywords: LINC complex; Mechanosensing; Nucleus; Polyacrylamide gels; Substrate rigidity
references.citation: Science. 1997 May 30;276(5317):1425-8
references.pmid: 9162012
references.citation: J Biol Chem. 2012 Feb 17;287(8):5317-26
references.pmid: 22170055
references.citation: Proc Natl Acad Sci U S A. 2002 Feb 19;99(4):1972-7
references.pmid: 11842191
references.citation: J Biol Chem. 2011 Jul 29;286(30):26743-53
references.pmid: 21652697
references.citation: J Cell Biol. 2004 Sep 13;166(6):877-87
references.pmid: 15364962
references.citation: Tissue Eng. 2003 Aug;9(4):657-66
references.pmid: 13678444
references.citation: Science. 2002 Oct 11;298(5592):406-9
references.pmid: 12169658
references.citation: Curr Opin Genet Dev. 2009 Apr;19(2):180-6
references.pmid: 19303765
references.citation: Science. 2005 Nov 18;310(5751):1139-43
references.pmid: 16293750
references.citation: Prog Clin Biol Res. 1987;249:251-62
references.pmid: 3671428
references.citation: Development. 1999 Jun;126(14):3171-81
references.pmid: 10375507
references.citation: Annu Rev Cell Dev Biol. 2010;26:421-44
references.pmid: 20507227
references.citation: J Cell Biol. 2006 Jan 2;172(1):41-53
references.pmid: 16380439
references.citation: FEBS Lett. 2011 Dec 15;585(24):3992-7
references.pmid: 22094165
references.citation: J Cell Sci. 1992 Dec;103 ( Pt 4):1215-22
references.pmid: 1487498
references.citation: Cell Mol Bioeng. 2009 Mar 1;2(1):39-48
references.pmid: 20582230
references.citation: J Cell Physiol. 2006 Apr;207(1):187-94
references.pmid: 16288479
references.citation: Biophys J. 2009 Mar 4;96(5):2009-22
references.pmid: 19254561
references.citation: J Cell Biol. 2005 Dec 5;171(5):799-810
references.pmid: 16330710
references.citation: J Theor Biol. 1982 Nov 7;99(1):31-68
references.pmid: 6892044
references.citation: Science. 2010 Aug 20;329(5994):956-9
references.pmid: 20724637
references.citation: J Cell Sci. 2003 Apr 1;116(Pt 7):1157-73
references.pmid: 12615960
references.citation: Nat Phys. 2010 Jun 1;6(6):468-473
references.pmid: 20563235
references.citation: Cell. 1980 Sep;21(2):365-72
references.pmid: 6157481
references.citation: Proc Natl Acad Sci U S A. 2003 Apr 29;100(9):5181-6
references.pmid: 12702768
references.citation: J Cell Sci Suppl. 1987;8:327-43
references.pmid: 3332665
references.citation: Cancer Res. 2009 May 15;69(10):4167-74
references.pmid: 19435897
references.citation: Exp Cell Res. 2008 May 1;314(8):1892-905
references.pmid: 18396275
references.citation: Biophys J. 2000 Jul;79(1):144-52
references.pmid: 10866943
references.citation: J Cell Physiol. 2005 Jul;204(1):198-209
references.pmid: 15669099
references.citation: Cell Adh Migr. 2011 Jan-Feb;5(1):16-9
references.pmid: 20818154
references.citation: Proc Natl Acad Sci U S A. 1997 Feb 4;94(3):849-54
references.pmid: 9023345
references.citation: J Biol Chem. 2004 Aug 20;279(34):35557-63
references.pmid: 15205456
references.citation: J Appl Physiol (1985). 2005 Apr;98(4):1547-53
references.pmid: 15772065
references.citation: J Phys Condens Matter. 2010 May 19;22(19):194116
references.pmid: 20454525
references.citation: Proc Natl Acad Sci U S A. 2009 Nov 10;106(45):19017-22
references.pmid: 19850871
references.citation: J Microsc. 2005 Apr;218(Pt 1):68-78
references.pmid: 15817065
references.citation: J Cell Sci. 2010 Feb 1;123(Pt 3):297-308
references.pmid: 20130138
references.citation: Dev Cell. 2009 Nov;17(5):587-97
references.pmid: 19922864
references.citation: Nat Rev Mol Cell Biol. 2006 Oct;7(10):782-8
references.pmid: 16926857
references.citation: Biomaterials. 2011 Dec;32(36):9584-93
references.pmid: 21955687
references.citation: Biophys J. 2010 Jul 7;99(1):115-23
references.pmid: 20655839
references.citation: Ann Med. 2009;41(1):19-28
references.pmid: 18608132
references.citation: Int J Biochem Cell Biol. 2010 Oct;42(10):1717-28
references.pmid: 20621196
references.citation: Science. 1979 Jun 22;204(4399):1315-7
references.pmid: 451539
references.citation: Cell. 2006 Aug 25;126(4):677-89
references.pmid: 16923388
references.citation: Mol Cell Biol. 2006 May;26(10):3738-51
references.pmid: 16648470
references.citation: Mol Cell Biol. 1983 Feb;3(2):182-9
references.pmid: 6835208
references.citation: Biophys J. 2005 Dec;89(6):L52-4
references.pmid: 16214867
references.citation: Curr Biol. 1999 Nov 4;9(21):1211-20
references.pmid: 10556085
references.citation: Biochem Soc Trans. 2011 Dec;39(6):1719-24
references.pmid: 22103514
references.citation: Development. 1994 Sep;120(9):2609-18
references.pmid: 7956836
references.citation: Cell Motil Cytoskeleton. 2005 Jan;60(1):24-34
references.pmid: 15573414
references.citation: Invest Ophthalmol Vis Sci. 2008 Jan;49(1):262-9
references.pmid: 18172101
references.citation: Biorheology. 2006;43(6):721-8
references.pmid: 17148855
references.citation: Hum Mol Genet. 2010 Jan 15;19(2):329-41
references.pmid: 19864491
references.citation: Nat Rev Mol Cell Biol. 2011 Oct 05;12(11):695-708
references.pmid: 21971041
references.citation: Cell. 1981 Jun;24(3):859-66
references.pmid: 6166390
references.citation: Biophys J. 2007 Dec 15;93(12):4453-61
references.pmid: 18045965
references.citation: J Cell Sci. 1985 Jun;76:17-33
references.pmid: 4066786
references.citation: Proc Natl Acad Sci U S A. 1997 Dec 9;94(25):13661-5
references.pmid: 9391082
references.citation: Am J Physiol Cell Physiol. 2008 Oct;295(4):C994-1006
references.pmid: 18701651
references.citation: Nat Mater. 2012 May 27;11(7):642-9
references.pmid: 22635042
references.citation: Ann Biomed Eng. 2011 Apr;39(4):1201-14
references.pmid: 21424849
references.citation: Proc Natl Acad Sci U S A. 2009 Feb 17;106(7):2194-9
references.pmid: 19164528
references.citation: Biomaterials. 2010 Jul;31(19):5143-50
references.pmid: 20382423