Characterization of the integrin receptor subunit profile in themammalian sclera

[摘要] Purpose: During the increased eye growth that results in myopia, thesclera undergoes biochemical and biomechanical remodeling. The cellsurface integrin receptor family has important roles during tissueremodeling, regulating the extracellular matrix environment and cellularbiomechanical properties. As integrin receptors may have a role inremodeling during myopia, this study detailed subunit gene expression inthe mammalian sclera.Methods: Several tissues, including sclera, were isolated from thetree shrew, a mammalian model used in eye growth studies. Total RNA waspurified, reverse transcribed and primers for the α- andβ-integrin subunits were designed to the published human sequence inareas of high inter-species homology. PCR was used to amplify productsof predetermined size and all tree shrew integrin subunits weresequenced to confirm their identity. Multiple PCR conditions were usedto identify the scleral integrin subunits, and positive control tissueswere included to reduce the possibility of false negative results.Results: Integrin PCR products corresponding to the β1-, β4-, β5-, and β8-integrin subunits and the α-integrinsubunits, α1-6-, α9-11- and αv-integrin wereidentified in the sclera and in scleral fibroblast cultures. Therespective sequences showed a high identity (>81%) to their humancounterparts. The β2-, β3-, β6-, β7-, α7-, andα8-integrin subunits were not detected in tree shrew scleralsamples, despite being present in the respective positive controls.Association of the 4 β-integrin subunits with the 10 α-integrinsubunits suggests that the mammalian sclera is capable of expressing 13of the 24 identified integrin receptors.Conclusions: This is the first systematic description of theintegrin subunit expression profile in the sclera. Due to the multipleroles of integrin receptors during tissue remodeling, the identificationof these scleral integrins is an important preliminary step indetermining the role of these receptors during normal eye growth andmyopia development.

[学科分类] 生物化学/生物物理