A mouse model for Stickler's syndrome: ocular phenotype of mice carrying a targeted heterozygous inactivation of type II (pro)collagen gene (Col2a1).
The influences of targeted heterozygous inactivation of type II (pro)collagen gene (Col2a1) on eye structures in the 15-month-old C57BL/6JOlaHsd mouse was studied. The eyes were collected from C57BL mice heterozygous for a targeted inactivation of one allele of the Col2a1 gene (Col2a1(+/-) mice). The eyes of C57BL mice with normal gene alleles were used as controls (Col2a1(+/+) mice). Ocular histology was analyzed from tissue sections, stained with hematoxylin and eosin, toluidine blue and alcian blue. Type II collagen was localized by immunohistochemistry. Hyaluronan (HA) was stained utilizing the biotinylated complex of the hyaluronan-binding region of aggrecan and link protein (bHABC). The anterior segment of the eye was well-formed in both genotypes, but typical folding of ciliary processes was decreased, while increased stromal extracellular matrix vacuolization was seen in the Col2a1(+/-) mice. In the lens of these mice, subcapsular extracellular matrix changes were observed. Differences in retinal structures or the number of the eyes with retinal detachment were not detected between the genotypes. In Col2a1(+/-) mice, staining for type II collagen was weaker in cornea, ciliary body, iris, lens, vitreous, retina, choroid and sclera than in the control mice. HA staining was detected in the extraocular tissues, ciliary body, iris and the choroid of both genotypes. HA staining was observed only in the vitreous body of the control animals. Heterozygous inactivation of Col2a1 gene causes structural defects in the murine eye. The observed structural changes in the ciliary body, lens and vitreous of the Col2a1(+/-) mice may represent ocular features found in the human Stickler syndrome, where the abnormalities result from COL2A1 gene mutations which lead to functional haploinsufficiency.
Kaarniranta
Kai
K
Department of Ophthalmology, University of Kuopio, P.O. Box 1627, 70211 Kuopio, Finland. kaarnira@messi.uku.fi
Ihanamäki
Tapio
T
Sahlman
Janne
J
Pulkkinen
Hertta
H
Uusitalo
Hannu
H
Arita
Machiko
M
Tammi
Raija
R
Lammi
Mikko J
MJ
Helminen
Heikki J
HJ
D053674:Aggrecans; D000818:Animals; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics; D024043:Collagen Type II / Q000235:genetics*; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005123:Eye / Q000473:pathology; D015785:Eye Diseases, Hereditary / Q000235:genetics* / Q000473:pathology; D005136:Eye Proteins / Q000235:genetics; D020868:Gene Silencing / Q000502:physiology; D005838:Genotype; D006579:Heterozygote; D006820:Hyaluronic Acid / Q000032:analysis; D007150:Immunohistochemistry / Q000379:methods; D037181:Lectins, C-Type / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008854:Microscopy, Electron / Q000379:methods; D009799:Ocular Physiological Phenomena; D010641:Phenotype; D011509:Proteoglycans / Q000235:genetics; D012163:Retinal Detachment / Q000235:genetics; D013577:Syndrome; D000099249:Proteoglycan Link Protein
D053674:Aggrecans; D011508:Chondroitin Sulfate Proteoglycans; D024043:Collagen Type II; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D006820:Hyaluronic Acid; D037181:Lectins, C-Type; D011509:Proteoglycans; D000099249:Proteoglycan Link Protein; C508320:Acan protein, mouse; C447413:Col2a1 protein, mouse