TY - JOUR
T1 - Hydroxylases regulate intestinal fibrosis through the suppression of ERK mediated TGF-β1 signaling
AU - Manresa, Mario Cabrero
AU - Tambuwala, Murtaza M.
AU - Rhadakrishnan, Praveen
AU - Harnoss, Jonathan M.
AU - Brown, Eric
AU - Cavadas, Miguel A.
AU - Keogh, Ciara E.
AU - Cheong, Alex
AU - Barrett, Kim E.
AU - Cummins, Eoin P.
AU - Schneider, Martin
AU - Taylor, Cormac T.
N1 - © APS
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Fibrosis is a complication of chronic inflammatory disorders such as inflammatory bowel disease (IBD), a condition which has limited therapeutic options and often requires surgical intervention. Pharmacologic inhibition of oxygen-sensing prolyl hydroxylases (PHD), which confer oxygen-sensitivity upon the hypoxia inducible factor (HIF) pathway, has recently been shown to have therapeutic potential in colitis, although the mechanisms involved remain unclear. Here, we investigated the impact of hydroxylase inhibition on inflammation-driven fibrosis in a murine colitis model. Mice exposed to dextran sodium sulfate followed by period of recovery developed intestinal fibrosis characterized by alterations in the pattern of collagen deposition and infiltration of activated fibroblasts. Treatment with the hydroxylase inhibitor dimethyloxalylglycine (DMOG) ameliorated fibrosis. TGF-β1 is a key regulator of fibrosis which acts through the activation of fibroblasts. Hydroxylase inhibition reduced TGF-β1-induced expression of fibrotic markers in cultured fibroblasts suggesting a direct role for hydroxylases in TGF-β1 signalling. This was at least in part due to inhibition of non-canonical activation of extracellular signal-regulated kinase (ERK) signalling. In summary, pharmacologic hydroxylase inhibition ameliorates intestinal fibrosis, through suppression of TGF-β1-dependent ERK activation in fibroblasts. We hypothesize that in addition to previously reported immunosupressive effects, hydroxylase inhibitors independently suppress pro-fibrotic pathways
AB - Fibrosis is a complication of chronic inflammatory disorders such as inflammatory bowel disease (IBD), a condition which has limited therapeutic options and often requires surgical intervention. Pharmacologic inhibition of oxygen-sensing prolyl hydroxylases (PHD), which confer oxygen-sensitivity upon the hypoxia inducible factor (HIF) pathway, has recently been shown to have therapeutic potential in colitis, although the mechanisms involved remain unclear. Here, we investigated the impact of hydroxylase inhibition on inflammation-driven fibrosis in a murine colitis model. Mice exposed to dextran sodium sulfate followed by period of recovery developed intestinal fibrosis characterized by alterations in the pattern of collagen deposition and infiltration of activated fibroblasts. Treatment with the hydroxylase inhibitor dimethyloxalylglycine (DMOG) ameliorated fibrosis. TGF-β1 is a key regulator of fibrosis which acts through the activation of fibroblasts. Hydroxylase inhibition reduced TGF-β1-induced expression of fibrotic markers in cultured fibroblasts suggesting a direct role for hydroxylases in TGF-β1 signalling. This was at least in part due to inhibition of non-canonical activation of extracellular signal-regulated kinase (ERK) signalling. In summary, pharmacologic hydroxylase inhibition ameliorates intestinal fibrosis, through suppression of TGF-β1-dependent ERK activation in fibroblasts. We hypothesize that in addition to previously reported immunosupressive effects, hydroxylase inhibitors independently suppress pro-fibrotic pathways
KW - hypoxia
KW - inflammatory bowel disease
KW - intestinal fibrosis
KW - hydroxylase inhibition
KW - transforming growth factor-b1 signaling
UR - http://ajpgi.physiology.org/content/early/2016/10/21/ajpgi.00229.2016
U2 - 10.1152/ajpgi.00229.2016
DO - 10.1152/ajpgi.00229.2016
M3 - Article
SN - 0193-1857
VL - 311
SP - G1076-G1090
JO - Gastrointestinal and Liver Physiology
JF - Gastrointestinal and Liver Physiology
IS - 6
ER -