Rabbit Anti-Human WDR5 Polyclonal Antibody

Wdr5 a bone morphogenetic protein 2 (BMP 2)-induced protein belonging to the family of the WD repeat proteins is expressed in proliferating and hypertrophic chondrocytes of the growth plate and in osteoblasts Although previous studies have provided insight into the mechanisms by which Wdr5 affects chondrocyte and osteoblast differentiation, whether Wdr5 is required in vivo for endochondral bone development has not been addressed In this study using an avian replication competent retrovirus (RCAS) system delivering Wdr5 short hairpin (sh) RNA to silence Wdr5 in the developing limb we report that reduction of Wdr5 levels delays endochondral bone development and consequently results in shortening of the skeletal elements Shortening of the skeletal elements was due to impaired chondrocyte maturation evidenced by a significant reduction of Runx2, type X collagen, and osteopontin expression A decrease in Runx2 type collagen I and ostepontin expression in osteoblasts and a subsequent defect in mineralized bone was observed as well when Wdr5 levels were reduced Most important retroviral misexpression of Runx2 rescued the phenotype induced by Wdr5 shRNA These findings suggest that during limb development Wdr5 is required for endochondral bone formation and that Wdr5 influences this process at least in part by regulating Runx2 expression (C) 2010 American Society for Bone and Mineral Research

Fibrosis following injury is a common adaptive response in the liver, which can lead to irreparable and life-threatening cirrhosis and hepatocellular carcinoma without effectual intervention. The molecular mechanisms underlying fibrogenic response in the liver remains poorly understood. Here we report that mice with deficiency in myocardin-related transcription factor A (MRTF-A) showed resistance to thioacetamide (TAA)-induced liver fibrosis with significantly reduced expression of pro-fibrogenic genes when compared to wild type littermates. Over-expression of MRTF-A enhanced whereas depletion of MRTF-A alleviated pro-fibrogenic transcription induced by TGF-beta, a major pro-fibrogenic factor in hepatic stellate cells (HSCs). Mechanistically, MRTF-A silencing in HSCs impacted the chromatin structure by reducing the deposition of methylated histone H3K4 on the promoters of pro-fibrogenic genes. Further analyses revealed that MRTF-A interacted with and recruited several key epigenetic factors involved in H3K4 methylation, including ASH2, WDR5, and SET1, to the promoters of pro-fibrogenic genes in response to TGF-beta treatment. Over-expression of ASH2, WDR5, or SET1 enhanced the transactivation of pro-fibrogenic gene promoters by TGF-beta in an MRTF-A-dependent manner. In conclusion, MRTF-A regulates liver fibrosis by epigenetically tuning the TGF-beta signaling pathway in HSCs. (C) 2015 Elsevier Ltd. All rights reserved.