Overexpression of transcripts containing LINE-1 in the synovia of patients with rheumatoid arthritis.
OBJECTIVE
To identify novel diagnostic markers by comparing gene expression in rheumatoid (RA) and reactive arthritis (ReA) synovium.


METHODS
Synovial biopsy specimens were obtained by needle arthroscopy from the knees of 10 patients with either RA or ReA. RNA was isolated from the biopsy specimens and cDNA synthesised for analysis using a customised cDNA macroarray. Confirmatory analysis was performed using in situ hybridisation on a second set of synovial samples.


RESULTS
Two unique transcripts (ReXS1 and fibronectin) were consistently more abundant in ReA and three homologous transcripts were more abundant in RA. The latter all mapped within long interspersed nucleotide elements (LINE-1), that form one of the families of repetitive sequences in the human genome.


CONCLUSIONS
The abundance of transcripts containing LINE-1 in the RA synovium may be an epiphenomenon or may have pathogenic significance. Further work is required to determine the identity of the full length transcript(s) before its use as a diagnostic marker in RA can be assessed.
Ali
M
M
Rheumatology and Rehabilitation Research and Molecular Medicine Units, University of Leeds, UK. medma@leeds.ac.uk
Veale
D J
DJ
Reece
R J
RJ
Quinn
M
M
Henshaw
K
K
Zanders
E D
ED
Markham
A F
AF
Emery
P
P
Isaacs
J D
JD
D000293:Adolescent; D000328:Adult; D000368:Aged; D016918:Arthritis, Reactive / Q000235:genetics; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology; D001182:Arthroscopy; D005260:Female; D015870:Gene Expression; D005819:Genetic Markers; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D000091402:Prohibitins; D013583:Synovial Membrane / Q000378:metabolism*
D005819:Genetic Markers; C000717331:PHB2 protein, human; D000091402:Prohibitins