Unknown,Transcriptomics,Genomics,Proteomics

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Expression data from Dmp1-GFP sorted osteocytes

ABSTRACT: Estrogens are well known steroid hormones necessary to maintain bone health. In addition, mechanical loading, which estrogen signaling may intersect with the Wnt/Î²-catenin pathway, is also essential for bone health. As osteocytes are known as the major mechanosensory cells embedded in mineralized bone matrix, osteocyte ERÎ± deletion mice (ERÎ±ÎOcy/ÎOcy) were generated by mating ERÎ± floxed mice with Dmp1-Cre mice to determine functions of ERÎ± in osteocytes. Trabecular bone mineral density of female, but not male ERÎ±ÎOcy/ÎOcy mice was significantly decreased. Bone formation parameters in ERÎ±ÎOcy/ÎOcy were significantly decreased while osteoclast parameters were unchanged. This suggests that ERÎ± in osteocytes exerts osteoprotective function by positively controlling bone formation. To identify potential targets of ERÎ±, gene array analysis of Dmp1-GFP osteocytes FACS sorted from ERÎ±ÎOcy/ÎOcy and control mice was performed. Expression of Mdk and Sostdc1, both known inhibitors of Wnt, were significantly increased without alteration of the mature osteocyte marker Sost or Î²-catenin. Hindlimb unloading exacerbated the trabecular bone loss, but surprisingly cortical bone was resistant. These studies show that ERÎ± in osteocytes has osteoprotective effects in trabecular bone through regulating expression of Wnt antagonists, but conversely plays a negative role in cortical bone loss due to unloading. Wild type and osteocyte-specific Estrogen Receptor alpha knock-out mice were generated. The number of both genotypes of mice was three. Calvarial osteocytes of both genotypes harboring Dmp1-GFP were extracted by sequential enzymatic digestion, followed by FACS Aria sorting and total RNAs were purified for Affymetix GeneChip microarray analysis without pooling.

ORGANISM(S): Mus musculus

SUBMITTER: Yuuki Imai

PROVIDER: E-GEOD-41997 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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