Obesity linked to the expression of genes that code for enzymes involved in sex steroid biosynthesis
Yousefi, M., Karmaus, W., Mudd, L. M., Landgraf, J., Mikucki, D., Haan, P., ... Osuch, J. (2008). Obesity linked to the expression of genes that code for enzymes involved in sex steroid biosynthesis. In ISEE 20th Annual Conference, Pasadena, California, October 12-16, 2008, , p. S162. .
Objectives: 1) Providing groundwork for future studies relating PCB and DDE exposure to changes in gene expression and the consequent influences on obesity and other health outcomes. 2) Testing for an association between a change in the gene expressions of aromatase (CYP19, 17? dehydroxylase (CYP17), and estrogen receptors ? and ? (ER ?+?) and anthropometric measurements in the offspring of participants in the Michigan Fish Eater Cohort Study.
Methods and Procedures: Data was analyzed from the Michigan Fish Eater Cohort Study, a two generational cohort where fish-eaters were enrolled and followed between 1973 and 1991, and the offspring of the original participants were followed up in 2001/02 and 2006/07. Information on education, gynecologic and reproductive history, and smoking was gathered via interviews. Information on the birth weight and breastfeeding of the offspring was confirmed against birth registry data. Anthropometric measurements and venous blood were collected and analyzed for gene expression in SSAM (sex steroid activity and metabolism) from the offspring. Gene expression was standardized against 18s ribosomal RNA and RNA Polymerase II expression. Spearman's Correlation was used to assess associations between the anthropometric outcomes as well as between the target gene expressions. Mixed models were used to account for multiple offspring from one mother.
Results: Of 149 women in the study, anthropometric measurements were obtained from 140 women and gene expression was tested in 139. Maternal height and birth weight was available for 138 and 134 women respectively. The three height measurements (standing height, leg length, and trunk length) were strongly correlated (>0.75, P-value 0.60, P-value Conclusion: The results suggest that CYP19 (aromatase) and CYP17 (17? dehydroxylase) expression influence certain anthropometric measurements that are established during an individual's development. These findings are sound intermediate for our investigation of a link between exposure to environmental contaminants and changes in gene expression in SSAM. Future studies that examine the effects PCB and DDE exposure on BMI, early age of menarche, and other health outcomes are well underway.