Microarray analysis of the failure of filtering blebs in a rat model of glaucoma filtering surgery.
OBJECTIVE
To generate data concerning changes in levels of protein expression associated with wound healing and bleb failure in a rat model of glaucoma filtration surgery (GFS), and to identify factors that may play a role in this process.


METHODS
Of 36 Sprague-Dawley rats, GFS was performed on 27 by introducing a silicone cannula through a scleral tunnel under a conjunctival flap, resulting in aqueous-filtering blebs that failed over 8 to 13 days. The additional nine rats were used as the nonsurgical control. Nine blebs were harvested at each of days 0, 2, 5, and 12 and pooled, yielding three replicates of three blebs per time point. RNA was extracted, labeled, and hybridized to 230A rat GeneChip arrays (Affymetrix, Santa Clara, CA).


RESULTS
Of the 15,924 probe sets/genes present on the array, 923 genes were indicated to have a significant treatment effect at P < 0.005. Eight gene expression clusters were identified that could be broadly classified into three basic patterns. These were an increase on day 2, a decrease on day 2, or an increase on either day 5 or 12. The greatest change occurred between days 0 and 2. The most heavily populated functional categories included growth factors, structural proteins, and matrix metalloproteinases.


CONCLUSIONS
This study represents the first large-scale gene expression analysis after GFS. Expression patterns for known mediators of the bleb scarring process, including transforming growth factor-beta, connective tissue growth factor, and matrix metalloproteinases, were confirmed, and a number of mediators not previously associated with this process were identified.
Esson
Douglas W
DW
Department of Ophthalmology, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610-0284, USA.
Popp
Michael P
MP
Liu
Li
L
Schultz
Gregory S
GS
Sherwood
Mark B
MB
D000818:Animals; D018463:Filtering Surgery; D015870:Gene Expression; D020869:Gene Expression Profiling; D005901:Glaucoma / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017211:Treatment Failure