IRE1signaling in Osx1-cre expressing cells

The Unfolded Protein Response (UPR) fine tunes the protein folding capacity of the endoplasmic reticulum (ER) in eukaryotic cells via the actions of PERK, IRE1 and ATF6 proteins. However, the specific contributions of these proteins to bone health have not been investigated. These studies evaluated the role of IRE1 signlaing in preosteoblasts by condcting studies in osteoprogenitors lacking IRE1 (generated via Osx1-cre). The studies invovled isolation and culture of IRE1KO and flox control osteoprogenitor cells that gene expression analysis. Our studies reveal a novel regulatory role in stimulating osteoprogenitor proliferation by stimulating ß-catenin/TCF mediated transcription and subsequent bone formation Overall design: Osx1-Cre cells were flow sorted from neonatal calvarial cells cultured in alpha-MEM medium containing 10% FBS and plated in a 6-well plate. RNA was isolated after cells attained 90% confluence. Osx1-Cre cells isolated from 3-5 neonatal pups (2-4 d old) as described constituted 1 biological replicate. Total of 9 libraries (n=5 IRE1 KO and n=4 WT) were generated.