title: An in vitro tissue model to study the effect of age on nucleus pulposus cells.
abstract: Differentiation between age (physiological) and disease-induced changes in the nucleus pulposus will facilitate our understanding of the mechanism(s) leading to the development of degenerative disc disease. The aim of this study was to develop an in vitro model that would allow the study of age-induced alterations of cell function in nucleus pulposus. Nucleus pulposus (NP) cells were isolated from intervertebral discs obtained from either calves (<9 months) or cows (>18 months). The cells were placed in culture and grown for 19 days. Although nucleus pulposus tissue was formed by the cells of the two different ages the more mature (older) cells formed less tissue as determined histologically by light microscopy. This was confirmed biochemically as the wet weight and proteoglycan content of the tissue formed by the older cells were significantly less than that of the younger tissue. The older cells accumulated less proteoglycans as determined by quantifying radioisotope incorporation. The older cells showed lower constitutive gene expression of collagen type II and aggrecan whereas collagen type I and link protein levels were similar to those of the younger cells. Metalloprotease (MMP) 13 gene and protein expression increased with age. There was no change in the levels of gene expression of MMP 2 and TIMP 1, 2, or 3 with age. Cells obtained from NP tissue harvested from younger or mature animals showed both genotypic and phenotypic differences in vitro that resulted in the inability of the older cells to reconstitute their extracellular matrix to the same extent as the younger cells. This suggests that this in vitro NP tissue model will be suitable to determine the mechanism(s) regulating age-induced changes.
authors: CIHR-BioEngineering of Skeletal Tissues Team, Department of Laboratory Medicine and Pathobiology, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Suite 6-500, M5X 1G5, Toronto, ON, Canada. rkandel@mtsinai.on.ca
authors: R A
authors: RA
authors: Kandel
authors: D
authors: D
authors: Hamilton
authors: C
authors: C
authors: Séguin
authors: S-Q
authors: SQ
authors: Li
authors: C
authors: C
authors: Arana
authors: R
authors: R
authors: Pilliar
mesh_terms: D053674:Aggrecans / Q000235:genetics / Q000378:metabolism; D000375:Aging; D000818:Animals; D002417:Cattle; D002454:Cell Differentiation; D002478:Cells, Cultured; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D051445:Fibrocartilage / Q000473:pathology / Q000503:physiopathology*; D007403:Intervertebral Disc / Q000473:pathology / Q000503:physiopathology*; D007405:Intervertebral Disc Displacement / Q000473:pathology / Q000503:physiopathology*; D023421:Models, Animal; D011509:Proteoglycans / Q000378:metabolism; D012038:Regeneration
chemical_list: D053674:Aggrecans; D024043:Collagen Type II; D011509:Proteoglycans
references: Am J Hypertens. 2005 Apr;18(4 Pt 1):504-9
references: 15831360
references: Spine (Phila Pa 1976). 1998 Sep 1;23(17):1821-7; discussion 1828
references: 9762737
references: Spine (Phila Pa 1976). 2004 Jun 1;29(11):1187-95
references: 15167656
references: Spine (Phila Pa 1976). 1999 Sep 1;24(17):1765-71
references: 10488504
references: J Bone Joint Surg Am. 2006 Apr;88 Suppl 2:25-9
references: 16595439
references: Biorheology. 2004;41(5):613-28
references: 15477668
references: Am J Clin Pathol. 2006 Feb;125(2):193-202
references: 16393686
references: Arch Gerontol Geriatr. 2001 Sep-Oct;33(2):151-61
references: 15374031
references: J Orthop Res. 2006 Jun;24(6):1292-8
references: 16649177
references: Spine (Phila Pa 1976). 2001 Nov 15;26(22):2421-6
references: 11707703
references: Spine (Phila Pa 1976). 2000 Dec 1;25(23):3005-13
references: 11145811
references: Spine (Phila Pa 1976). 2006 Jul 15;31(16):1770-4
references: 16845348
references: J Bone Joint Surg Am. 2006 Apr;88 Suppl 2:30-5
references: 16595440
references: J Pathol. 2004 Sep;204(1):47-54
references: 15307137
references: J Biol Chem. 1999 Aug 6;274(32):22679-85
references: 10428849
references: J Anat. 1995 Feb;186 ( Pt 1):43-53
references: 7544335
references: Biogerontology. 2002;3(5):257-64
references: 12237562
references: Biochem J. 1996 Oct 15;319 ( Pt 2):489-98
references: 8912686
references: J Bone Joint Surg Am. 2006 Apr;88 Suppl 2:76-82
references: 16595449
references: J Clin Invest. 1996 Aug 15;98(4):996-1003
references: 8770872
references: Arthritis Res Ther. 2003;5(3):120-30
references: 12723977
references: Spine (Phila Pa 1976). 2004 Jun 15;29(12):1299-306; discussion 1306-7
references: 15187628
references: Biomaterials. 2001 May;22(9):963-72
references: 11311015
references: Spine (Phila Pa 1976). 2007 Apr 15;32(8):849-56
references: 17426628
references: Spine (Phila Pa 1976). 2000 Jan 15;25(2):166-9
references: 10685479
references: Cardiovasc Res. 2005 May 1;66(2):410-9
references: 15820210
references: Eur Spine J. 2002 Aug;11(4):308-20
references: 12193991
references: Spine (Phila Pa 1976). 2001 Dec 1;26(23):2550-7
references: 11725235
references: Ann Rheum Dis. 2002 Dec;61(12):1095-8
references: 12429542
references: Biochem J. 1997 Aug 15;326 ( Pt 1):235-41
references: 9337874
references: Spine (Phila Pa 1976). 2005 Sep 1;30(17):1940-8
references: 16135983
references: Biochem Soc Trans. 2002 Nov;30(Pt 6):869-74
references: 12440935