Methotrexate-induced accumulation of fluorescent annexin V in collagen-induced arthritis.
We examined the accumulation of Cy5.5-labeled annexin V in the paws of mice with and without collagen-induced arthritis, with and without methotrexate (MTX) treatment, by near-infrared fluorescence imaging. Fluorescence reflectance imaging (FRI) of paws was performed 48 hr after MTX injection and at 10 min and 3 hr after the injection of Cy5.5-annexin V (1 nmol dye per mouse). With arthritic paws, MTX treatment caused a 7-fold increase in fluorescence intensity compared with the paws of untreated mice and a 4-fold increase compared to nonarthritic paws of MTX-treated mice (p < .001 each). Tissue samples of paws were examined histologically for Cy5.5 fluorescence and by TUNEL staining for apoptosis. Cy5.5-annexin V was seen in the hyperplastic synovia of MTX-treated mice, and TUNEL staining for apoptosis showed apoptotic cells in the hyperplastic synovia. Monitoring the uptake of Cy5.5-annexin V in arthritic paws by FRI provided a method of assessing a response to MTX, a response that was readily quantitated with simple instrumentation and that occurred before conventional measurements of treatment response.
Wunder
Andreas
A
German Cancer Research Center (DKFZ).
Schellenberger
Eyk
E
Mahmood
Umar
U
Bogdanov
Alexei
A
Müller-Ladner
Ulf
U
Weissleder
Ralph
R
Josephson
Lee
L
D000818:Animals; D017304:Annexin A5 / Q000187:drug effects / Q000378:metabolism*; D018501:Antirheumatic Agents / Q000494:pharmacology*; D001169:Arthritis, Experimental / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D002232:Carbocyanines / Q000378:metabolism; D003094:Collagen / Q000633:toxicity; D005456:Fluorescent Dyes / Q000378:metabolism; D007596:Joints / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008727:Methotrexate / Q000494:pharmacology*; D051379:Mice; D008811:Mice, Inbred DBA; D008967:Molecular Biology / Q000379:methods; D013582:Synovial Fluid / Q000378:metabolism
D017304:Annexin A5; D018501:Antirheumatic Agents; C098793:CY5.5 cyanine dye; D002232:Carbocyanines; D005456:Fluorescent Dyes; D003094:Collagen; D008727:Methotrexate