Increased expression of matrix metalloproteinases in mononuclear blood cells of normal-tension glaucoma patients.
OBJECTIVE
Glaucomatous optic neuropathy involves tissue remodeling by matrix metalloproteinases (MMPs). In this study we investigated MMP gene expression in circulating leukocytes isolated from normal tension glaucoma (NTG) patients in comparison to healthy controls.


METHODS
Blood samples were collected from 6 glaucoma patients and 6 age- and sex-matched healthy controls. Leukocytes were separated using Ficoll-Hypaque gradient. mRNA pools were used for subtractive hybridization to identify genes with altered expression. The subtracted genes were sequenced and individual mRNA pools were quantified using semiquantitative RT-PCRs. Target PCR products were confirmed using sequence-based restriction analysis. In this study we focused on MMPs.


RESULTS
MMP-9 and MT1-MMP (MMP-14) were subtracted as upregulated genes in the group of NTG patients. Upregulation of these genes was confirmed by RT-PCR and Western-blot analysis in all 6 patients. The expression of the tissue inhibitor of matrix metalloproteinases TIMP-1 was slightly enhanced in patients as compared with controls. Expression of MMP-2 was not detected in leukocytes either in glaucoma patients or in healthy subjects.


CONCLUSIONS
A simultaneous upregulation of both MMP-9 and MT1-MMP gene expression and only slightly enhanced expression of TIMP-1 suggest an increased enzymatic matrix metalloproteinase activity delivered by mononuclear blood cells in these patients.
Golubnitschaja
Olga
O
Department of Radiology, University of Bonn, Germany.
Yeghiazaryan
Kristina
K
Liu
Rong
R
Mönkemann
Heike
H
Leppert
David
D
Schild
Hans
H
Haefliger
Ivan O
IO
Flammer
Josef
J
D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D001773:Blood Cells / Q000201:enzymology*; D015153:Blotting, Western; D016022:Case-Control Studies; D005260:Female; D005901:Glaucoma / Q000201:enzymology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood* / Q000235:genetics; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood
D019715:Tissue Inhibitor of Metalloproteinase-1; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020780:Matrix Metalloproteinase 9