Logo of annrheumdAnnals of the Rheumatic DiseasesVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
Ann Rheum Dis. Mar 2001; 60(3): 262–268.
PMCID: PMC1753566

Inactivation of one allele of the type II collagen gene alters the collagen network in murine articular cartilage and makes cartilage softer


OBJECTIVE—To evaluate the influence of inactivation of one allele ("heterozygous knockout" or "heterozygous inactivation") of the type II procollagen gene (Col2a1) on the biomechanical properties and structure of the articular cartilage and subchondral bone in 15 month old mice.
METHODS—Indentation stiffness of the humerus head articular cartilage was measured by a microindentation method. Cartilage and subchondral bone were prepared for digital densitometry of proteoglycans (PGs), polarised light microscopy (PLM) of collagen, and osteoarthrosis (OA) grading.
RESULTS—Heterozygous inactivation of the Col2a1 gene softened articular cartilage (p=0.002) as measured by indentation stiffness ((mean (SEM) 0.50 (0.07) MPa v 0.94 (0.13) MPa in controls). Fibrillar collagen network exhibited lower birefringence in the intermediate (p=0.04) and deep zones (p=0.01) of cartilage by PLM, indicating either decreased collagen content or a lower degree of fibril parallelism in the knockout mice. The total and zonal thicknesses of articular cartilage were unchanged. Zonal PG contents did not differ significantly. In knockout mice, the prevalence of superficial fibrillation—that is, a sign of OA, was higher than in controls (73% v 21%, p=0.002). The collagen induced birefringence of the superficial zone was not reduced. The subchondral bone volume fraction was lower in knockout mice than in controls, 31% v 43% (p=0.01), and optical retardation values in PLM of bone collagen were slightly but significantly lower (p=0.01).
CONCLUSION—Heterozygous inactivation of the Col2a1 gene made articular cartilage softer, altered the collagenous network, reduced subchondral bone volume, and altered its microstructure. Changes in the cartilage collagen network probably contributed to increased susceptibility to OA.

Full Text

The Full Text of this article is available as a PDF (163K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Mendler M, Eich-Bender SG, Vaughan L, Winterhalter KH, Bruckner P. Cartilage contains mixed fibrils of collagen types II, IX, and XI. J Cell Biol. 1989 Jan;108(1):191–197. [PMC free article] [PubMed]
  • Eyre DR, Wu JJ. Collagen structure and cartilage matrix integrity. J Rheumatol Suppl. 1995 Feb;43:82–85. [PubMed]
  • Prockop DJ, Kivirikko KI. Collagens: molecular biology, diseases, and potentials for therapy. Annu Rev Biochem. 1995;64:403–434. [PubMed]
  • Hardingham TE, Fosang AJ. Proteoglycans: many forms and many functions. FASEB J. 1992 Feb 1;6(3):861–870. [PubMed]
  • Mow VC, Ratcliffe A, Poole AR. Cartilage and diarthrodial joints as paradigms for hierarchical materials and structures. Biomaterials. 1992;13(2):67–97. [PubMed]
  • Bader DL, Kempson GE. The short-term compressive properties of adult human articular cartilage. Biomed Mater Eng. 1994;4(3):245–256. [PubMed]
  • Deák F, Piecha D, Bachrati C, Paulsson M, Kiss I. Primary structure and expression of matrilin-2, the closest relative of cartilage matrix protein within the von Willebrand factor type A-like module superfamily. J Biol Chem. 1997 Apr 4;272(14):9268–9274. [PubMed]
  • Broom ND, Silyn-Roberts H. Collagen-collagen versus collagen-proteoglycan interactions in the determination of cartilage strength. Arthritis Rheum. 1990 Oct;33(10):1512–1517. [PubMed]
  • Kuivaniemi H, Tromp G, Prockop DJ. Mutations in fibrillar collagens (types I, II, III, and XI), fibril-associated collagen (type IX), and network-forming collagen (type X) cause a spectrum of diseases of bone, cartilage, and blood vessels. Hum Mutat. 1997;9(4):300–315. [PubMed]
  • Broom ND, Silyn-Roberts H. The three-dimensional 'knit' of collagen fibrils in articular cartilage. Connect Tissue Res. 1989;23(4):261–277. [PubMed]
  • Speer DP, Dahners L. The collagenous architecture of articular cartilage. Correlation of scanning electron microscopy and polarized light microscopy observations. Clin Orthop Relat Res. 1979 Mar-Apr;(139):267–275. [PubMed]
  • Aspden RM, Hukins DW. Collagen organization in articular cartilage, determined by X-ray diffraction, and its relationship to tissue function. Proc R Soc Lond B Biol Sci. 1981 Jul 14;212(1188):299–304. [PubMed]
  • Jeffery AK, Blunn GW, Archer CW, Bentley G. Three-dimensional collagen architecture in bovine articular cartilage. J Bone Joint Surg Br. 1991 Sep;73(5):795–801. [PubMed]
  • Hwang WS, Li B, Jin LH, Ngo K, Schachar NS, Hughes GN. Collagen fibril structure of normal, aging, and osteoarthritic cartilage. J Pathol. 1992 Aug;167(4):425–433. [PubMed]
  • Käb MJ, Ito K, Clark JM, Nötzli HP. Deformation of articular cartilage collagen structure under static and cyclic loading. J Orthop Res. 1998 Nov;16(6):743–751. [PubMed]
  • Arokoski JP, Hyttinen MM, Lapveteläinen T, Takács P, Kosztáczky B, Módis L, Kovanen V, Helminen H. Decreased birefringence of the superficial zone collagen network in the canine knee (stifle) articular cartilage after long distance running training, detected by quantitative polarised light microscopy. Ann Rheum Dis. 1996 Apr;55(4):253–264. [PMC free article] [PubMed]
  • Arokoski JP, Hyttinen MM, Helminen HJ, Jurvelin JS. Biomechanical and structural characteristics of canine femoral and tibial cartilage. J Biomed Mater Res. 1999;48(2):99–107. [PubMed]
  • Käb MJ, Gwynn IA, Nötzli HP. Collagen fibre arrangement in the tibial plateau articular cartilage of man and other mammalian species. J Anat. 1998 Jul;193(Pt 1):23–34. [PMC free article] [PubMed]
  • Hollander AP, Pidoux I, Reiner A, Rorabeck C, Bourne R, Poole AR. Damage to type II collagen in aging and osteoarthritis starts at the articular surface, originates around chondrocytes, and extends into the cartilage with progressive degeneration. J Clin Invest. 1995 Dec;96(6):2859–2869. [PMC free article] [PubMed]
  • Panula HE, Hyttinen MM, Arokoski JP, Långsjö TK, Pelttari A, Kiviranta I, Helminen HJ. Articular cartilage superficial zone collagen birefringence reduced and cartilage thickness increased before surface fibrillation in experimental osteoarthritis. Ann Rheum Dis. 1998 Apr;57(4):237–245. [PMC free article] [PubMed]
  • Freeman MA. Is collagen fatigue failure a cause of osteoarthrosis and prosthetic component migration? A hypothesis. J Orthop Res. 1999 Jan;17(1):3–8. [PubMed]
  • Vikkula M, Metsäranta M, Ala-Kokko L. Type II collagen mutations in rare and common cartilage diseases. Ann Med. 1994 Apr;26(2):107–114. [PubMed]
  • Metsäranta M, Garofalo S, Decker G, Rintala M, de Crombrugghe B, Vuorio E. Chondrodysplasia in transgenic mice harboring a 15-amino acid deletion in the triple helical domain of pro alpha 1(II) collagen chain. J Cell Biol. 1992 Jul;118(1):203–212. [PMC free article] [PubMed]
  • Helminen HJ, Kiraly K, Pelttari A, Tammi MI, Vandenberg P, Pereira R, Dhulipala R, Khillan JS, Ala-Kokko L, Hume EL, et al. An inbred line of transgenic mice expressing an internally deleted gene for type II procollagen (COL2A1). Young mice have a variable phenotype of a chondrodysplasia and older mice have osteoarthritic changes in joints. J Clin Invest. 1993 Aug;92(2):582–595. [PMC free article] [PubMed]
  • Li SW, Prockop DJ, Helminen H, Fässler R, Lapveteläinen T, Kiraly K, Peltarri A, Arokoski J, Lui H, Arita M, et al. Transgenic mice with targeted inactivation of the Col2 alpha 1 gene for collagen II develop a skeleton with membranous and periosteal bone but no endochondral bone. Genes Dev. 1995 Nov 15;9(22):2821–2830. [PubMed]
  • Busler DE, Li SW. Rapid screening of transgenic type II and type XI collagen knock-out mice with three-primer PCR. Biotechniques. 1996 Dec;21(6):1002–1004. [PubMed]
  • Jurvelin JS, Buschmann MD, Hunziker EB. Optical and mechanical determination of Poisson's ratio of adult bovine humeral articular cartilage. J Biomech. 1997 Mar;30(3):235–241. [PubMed]
  • Hoch DH, Grodzinsky AJ, Koob TJ, Albert ML, Eyre DR. Early changes in material properties of rabbit articular cartilage after meniscectomy. J Orthop Res. 1983;1(1):4–12. [PubMed]
  • Jurvelin JS, Räsänen T, Kolmonen P, Lyyra T. Comparison of optical, needle probe and ultrasonic techniques for the measurement of articular cartilage thickness. J Biomech. 1995 Feb;28(2):231–235. [PubMed]
  • Király K, Hyttinen MM, Lapveteläinen T, Elo M, Kiviranta I, Dobai J, Módis L, Helminen HJ, Arokoski JP. Specimen preparation and quantification of collagen birefringence in unstained sections of articular cartilage using image analysis and polarizing light microscopy. Histochem J. 1997 Apr;29(4):317–327. [PubMed]
  • Kiviranta I, Jurvelin J, Tammi M, Sämänen AM, Helminen HJ. Microspectrophotometric quantitation of glycosaminoglycans in articular cartilage sections stained with Safranin O. Histochemistry. 1985;82(3):249–255. [PubMed]
  • Lapveteläinen T, Nevalainen T, Parkkinen JJ, Arokoski J, Kiraly K, Hyttinen M, Halonen P, Helminen HJ. Lifelong moderate running training increases the incidence and severity of osteoarthritis in the knee joint of C57BL mice. Anat Rec. 1995 Jun;242(2):159–165. [PubMed]
  • Aszódi A, Chan D, Hunziker E, Bateman JF, Fässler R. Collagen II is essential for the removal of the notochord and the formation of intervertebral discs. J Cell Biol. 1998 Nov 30;143(5):1399–1412. [PMC free article] [PubMed]
  • Choi K, Kuhn JL, Ciarelli MJ, Goldstein SA. The elastic moduli of human subchondral, trabecular, and cortical bone tissue and the size-dependency of cortical bone modulus. J Biomech. 1990;23(11):1103–1113. [PubMed]
  • Grynpas MD, Alpert B, Katz I, Lieberman I, Pritzker KP. Subchondral bone in osteoarthritis. Calcif Tissue Int. 1991 Jul;49(1):20–26. [PubMed]
  • Morrison EH, Ferguson MW, Bayliss MT, Archer CW. The development of articular cartilage: I. The spatial and temporal patterns of collagen types. J Anat. 1996 Aug;189(Pt 1):9–22. [PMC free article] [PubMed]
  • Hayes WC, Keer LM, Herrmann G, Mockros LF. A mathematical analysis for indentation tests of articular cartilage. J Biomech. 1972 Sep;5(5):541–551. [PubMed]
  • Mak AF, Lai WM, Mow VC. Biphasic indentation of articular cartilage--I. Theoretical analysis. J Biomech. 1987;20(7):703–714. [PubMed]

Figures and Tables

Figure 1
(A) Schematic presentation for the indentation measurement setup. (B) A typical series of four consecutive indentation stress relaxation steps (3 µm for each step with ramping speed of 1 µm/s) causing a total strain of ...
Figure 2
Indentation stiffness of articular cartilage (mean (SEM)) in the head of the humerus of the herterozygous Col2a1 knockout and control mice.
Figure 3
(A) Thickness (mean (SEM)) of superficial, intermediate, and deep zones in control and knockout mice. Absolute cartilage thickness is the sum of these three zones. Mann-Whitney U test. (B) Collagen birefringence expressed as area integrated retardation ...
Figure 4
Safranin O absorbance expressed as area integrated optical density (AIOD) in superficial, intermediate, and deep zones of articular cartilage. Zones are the same as those in figs 3A and B. Mann-Whitney U test.
Figure 5
(A) Volume fraction of subchondral bone (mean (SEM)) in the proximal humerus. Mann-Whitney U test. (B) Collagen birefringence in subchondral bone expressed as area integrated retardation (AIR, mean (SEM)) of semicircularly polarised light. Mann-Whitney ...

Articles from Annals of the Rheumatic Diseases are provided here courtesy of BMJ Group


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Gene
    Gene links
  • GEO Profiles
    GEO Profiles
    Related GEO records
  • HomoloGene
    HomoloGene links
  • Pathways + GO
    Pathways + GO
    Pathways, annotations and biological systems (BioSystems) that cite the current article.
  • PubMed
    PubMed citations for these articles
  • Substance
    PubChem Substance links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...