AIM: Transforming .growth factor (TGF)-β related signaling may play an important role in the
pathogenesis of refractory ulcerative colitis (UC). We examined the expression levels of TGF-β receptor (R) I and
TGF-β R II, that is in the downstream pathway of TGF-β signaling.
METHODS: Colonic tissue samples were obtained
from refractory cases and responsive cases with UC, and controls. RNA and protein were extracted from mucosal
samples, and real time-PCR and western blot analysis were performed.
RESULTS: Both of TGF-β R I and TGF-β R II
transcripts were significantly suppressed in refractory cases with UC (0.106±0.0335, 0.185±0.0465) compared with
responsive cases (1.12±0.352, p<0.01, 1.82±0.877, p<0.05). Western blot analysis showed that TGF-β R I and R II
were significantly suppressed in refractory cases with UC (0.587±0.105, 1.02±0.318) compared with responsive cases
(1.89±0,670, p<0.05, 5.02±1.66, p<0.05).
CONCLUSION: From these findings, we conclude that one of the mechanisms
of refractoriness of UC is due to the downregulation of TGF-β receptor at the transcriptional levels and the protein
levels that leads to the loss of TGF-β related signaling.
View full abstract