Abstract
Adenosine in the normal kidney significantly elevates in response to cellular damage. The renal A3 adenosine receptor (A3AR) is up-regulated under stress, but the therapeutic effects of A3AR antagonists on chronic kidney disease are not fully understood. The present study examined the effect of LJ-1888 [(2R,3R,4S)-2-[2-chloro-6-(3- iodobenzylamino)-9H-purine-9-yl]-tetrahydrothiophene-3,4-diol], a newly developed potent, selective, species-independent, and orally active A 3AR antagonist, on unilateral ureteral obstruction (UUO)-induced renal fibrosis. Pretreatment with LJ-1888 inhibited UUO-induced fibronectin and collagen I up-regulation in a dose-dependent manner. Masson's trichrome staining confirmed that LJ-1888 treatment effectively reduced UUO-induced interstitial collagen accumulation. Furthermore, delayed administration of LJ-1888 showed an equivalent therapeutic effect on tubulointerstitial fibrosis to that of losartan. Small-interfering A3AR transfection effectively inhibited transforming growth factor-β1 (TGF-β1)-induced fibronectin and collagen I up-regulation in proximal tubular cells similar to LJ-1888, confirming that the renoprotective effect of LJ-1888 resulted from A 3AR blockade. UUO- or TGF-β1-induced c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation decreased significantly after LJ-1888 administration. A3AR blockade reduced UUO- or TGF-β1-induced up-regulation of lysyl oxidase, which induces cross-linking of extracellular matrix, suggesting that LJ-1888 may also regulate extracellular matrix accumulation via post-translational regulation. In conclusion, the present data demonstrate that the A3AR antagonist, LJ-1888, blocked the development and attenuated the progression of renal fibrosis, and they suggest that LJ-1888 may become a new therapeutic modality for renal interstitial fibrosis.
Original language | English |
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Pages (from-to) | 1488-1497 |
Number of pages | 10 |
Journal | American Journal of Pathology |
Volume | 183 |
Issue number | 5 |
DOIs | |
State | Published - Nov 2013 |
Bibliographical note
Funding Information:Supported by the Basic Science Research Program through the National Research Foundation of Korea , funded by the Ministry of Education, Science and Technology , grant 2010-0005740 .