Osteoporosis is a common disease mainly characterized by low bone mineral density (BMD) and increased risk of fractures. Peripheral blood monocytes (PBMs) may not only act as precursors of osteoclasts, the bone resorption cells, but also produce cytokines important for osteoclast differentiation, activation, and apoptosis, and thus represent major systemic cells for bone metabolism. Alterations in DNA methylation as an important epigenetic regulator of gene expression, is significant in the etiology of human complex diseases. In vitro studies have shown that DNA methylation is involved in osteoclastogenesis;however, the in vivo significance of global DNA methylation profiles (methylome) in humans underlying osteoporosis risk is unknown. Our Hypothesis is that altered DNA methylation profiles in PBMs and the associated changes in gene expression and osteoclastogenesis contribute to peak BMD variation in humans. Our Goal/Expectation is to i) identify differentially methylated regions (DMRs) in PBMs at the whole methylome level between premenopausal women with extremely high peak BMD and those with extremely low peak BMD;ii) study potential epigenetic mechanisms of osteoporosis, namely, how the DMRs identified may influence the peak BMD variation through affecting the expression of the relevant genes and subsequent osteoclastogenesis. Methods: 1) PBMs and their DNAs and total RNAs will be extracted from 160 premenopausal Caucasian females aged 25-40 years, including 80 with extremely high peak BMD and 80 with extremely low peak BMD (but otherwise matched). 2) DMRs will be identified by performing state-of-the-art methylome profiling studies with the cutting-edge technology MeDIP-seq (methylated DNA immunoprecipitation assays followed by next-generation sequencing) in a discovery sample of 80 subjects (including 40 with high and 40 with low BMD). 3) The identified DMRs will be subject to confirmation by bisulfite sequencing in an independent replication sample (including 40 with high and 40 with low BMD), and their target genes will be identified by correlating the DNA methylation data with the mRNA expression levels of the potential candidate target genes in PBMs of the total 160 subjects. 4) The roles of the identified most significant DMR-affiliated target genes on osteoclastogenesis will be further investigated by cell based in vitro assays. This highly novel R01 project holds great promise of award to generate breakthroughs in the osteoporosis research field. The results may lead to a major paradigm shift by expanding current genetic epidemiology studies of osteoporosis, from classical DNA variants to novel epigenetics/epigenomics mechanisms of DNA modification. Therefore, the results will be highly important for understanding the underlying molecular mechanisms, and thus help prevention and treatment, of osteoporosis.

Public Health Relevance

Osteoporosis is a serious public health problem leading to severe bone loss and increased risk of fractures in elderly subjects, especially women. The proposed study will identify differentially methylated regions (DMRs) between subjects with discordant BMD phenotypes and reveal some epigenetic mechanisms of BMD variation and osteoporosis risk. The findings will contribute to a better and more comprehensive understanding of molecular mechanisms, and thus help prevention and treatment, of osteoporosis.

National Institute of Health (NIH)
Research Project (R01)
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Neurological, Aging and Musculoskeletal Epidemiology Study Section (NAME)
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Sharrock, William J
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Tulane University
Biostatistics & Other Math Sci
Schools of Public Health
New Orleans
United States
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Huang, Hua-Lin; Lv, Chao; Zhao, Ying-Chun et al. (2014) Mutant ZP1 in familial infertility. N Engl J Med 370:1220-6
Zhang, Lei; Pei, Yu-Fang; Fu, Xiaoying et al. (2014) FISH: fast and accurate diploid genotype imputation via segmental hidden Markov model. Bioinformatics 30:1876-83
Yang, Tao; Deng, Hong-Wen; Niu, Tianhua (2014) Critical assessment of coalescent simulators in modeling recombination hotspots in genomic sequences. BMC Bioinformatics 15:3
Deng, Fei-Yan; Zhu, Wei; Zeng, Yong et al. (2014) Is GSN significant for hip BMD in female Caucasians? Bone 63:69-75
Duan, Junbo; Deng, Hong-Wen; Wang, Yu-Ping (2014) Common copy number variation detection from multiple sequenced samples. IEEE Trans Biomed Eng 61:928-37
Zhang, Lei; Choi, Hyung Jin; Estrada, Karol et al. (2014) Multistage genome-wide association meta-analyses identified two new loci for bone mineral density. Hum Mol Genet 23:1923-33
Ran, Shu; Liu, Yong-Jun; Zhang, Lei et al. (2014) Genome-wide association study identified copy number variants important for appendicular lean mass. PLoS One 9:e89776
Tan, Li-Jun; Zhu, Hu; He, Hao et al. (2014) Replication of 6 obesity genes in a meta-analysis of genome-wide association studies from diverse ancestries. PLoS One 9:e96149
Shen, Hui; Li, Jian; Zhang, Jigang et al. (2013) Comprehensive characterization of human genome variation by high coverage whole-genome sequencing of forty four Caucasians. PLoS One 8:e59494
Yang, T-L; Guo, Y; Li, S M et al. (2013) Ethnic differentiation of copy number variation on chromosome 16p12.3 for association with obesity phenotypes in European and Chinese populations. Int J Obes (Lond) 37:188-90

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