Beta ig-h3 is synthesized by corneal epithelium and perhaps endotheliumin Fuchs' dystrophic corneas.
OBJECTIVE
Deposition of abnormal sub-epithelial matrix and posterior collagenous layer by epithelium and endothelium, respectively, in Fuchs' dystrophy gives us the opportunity to determine if these tissues synthesize beta ig-h3.


METHODS
Immunohisto-/immunocytochemistry of corneas were conducted with rabbit anti-human beta ig-h3 and monoclonal anti-human type VI collagen. Labeled sense and anti-sense beta ig-h3 oligonucleotide probes were used for in situ hybridization.


RESULTS
beta ig-h3-specific fluorescence was found just beneath detached epithelium in the sub-epithelial matrix, abnormal Descemet's membrane and posterior collagenous layer. Type VI collagen co-localized with beta ig-h3 within abnormal sub-epithelial matrix and corneal stroma adjacent to Descemet's membrane. beta ig-h3 mRNA was detected in corneal epithelium of dystrophic corneas.


CONCLUSIONS
Expression of beta ig-h3 in sub-epithelial matrix and posterior collagenous layer of Fuchs' dystrophy is consistent with the synthesis of new extracellular matrices by epithelial and endothelial tissues. beta ig-h3 mRNA in corneal epithelium further supports an epithelial source of this protein. Endothelial synthesis of beta ig-h3 is based on circumstantial evidence due to cell loss during surgical and histological procedures. Co-localization of beta ig-h3 with type VI collagen in abnormal sub-epithelial matrix and at the stromal/Descemet's membrane interface suggest this collagen in association with beta ig-h3 interacts with these tissues and anchors them to the adjacent stroma.
Hirano
K
K
Schepens Eye Research Institute/Harvard Medical School, Boston, MA 02114, USA.
Klintworth
G K
GK
Zhan
Q
Q
Bennett
K
K
Cintron
C
C
D000818:Animals; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000378:metabolism*; D004728:Endothelium, Corneal / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000235:genetics; D005136:Eye Proteins / Q000096:biosynthesis* / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D005642:Fuchs' Endothelial Dystrophy / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D016253:Microscopy, Immunoelectron; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics
D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D003094:Collagen