Send to:

Choose Destination
See comment in PubMed Commons below
Invest Ophthalmol Vis Sci. 2004 Apr;45(4):1117-24.

Roles of thrombospondin-1 and -2 in regulating corneal and iris angiogenesis.

Author information

  • 1Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston Massachusetts 02114, USA.



Thrombospondin (TSP)-1 and -2 are important antiangiogenic factors thought to be involved in maintaining corneal avascularity (angiogenic privilege). This study was undertaken to investigate whether deficiencies of these factors altered developmental and inflammation-induced angiogenesis in the cornea and developmental angiogenesis of the iris of mice.


Expression of TSP-1 and -2 mRNA and protein was assayed in cornea and iris stroma by RT-PCR and Western blot. Corneas and irides of TSP-1(-/-), TSP-2(-/-), and TSP-1,2(-/-) mice aged 2, 3, and 6 months, and wild-type control mice, were analyzed for spontaneous angiogenesis biomicroscopically, histologically, and with CD31 immunohistochemistry. The mouse model of suture-induced, inflammatory corneal neovascularization was used to evaluate the lack of TSP-1,2 and both TSPs on induced-corneal angiogenesis. Seven days after intrastromal placement of three 11-0 sutures, vascularized areas were analyzed morphometrically on CD31-stained corneal flatmounts.


Corneas and irises from normal mouse eyes constitutively expressed TSP-1 and -2 mRNAs and proteins. Corneas of TSP-1(-/-), -2(-/-), and -1,2(-/-) mice displayed no evidence of spontaneous developmental-postnatal angiogenesis, although irises of these mice contained significantly increased iris vessel density compared with wild-type animals (P < 0.01). One week after suturing, corneas of all TSP(-/-) mice had significantly greater corneal angiogenesis than those of control mice (P < 0.05). TSP-1(-/-) had a significantly greater effect on induced corneal neovascularization than did TSP-2(-/-), with the opposite being the case in developmental iris angiogenesis (P < 0.01).


Corneal avascularity during development is redundantly regulated, shown by the fact that lack of the antiangiogenic factors TSP-1 and/or -2 resulted in no spontaneous corneal angiogenesis. By contrast, TSP-1, more than TSP-2, helps to suppress inflammation-induced corneal angiogenesis postnatally, implying that angiogenic privilege in the cornea is actively maintained.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk