By: Jami Myong Reece, Michael W. Greene
Although obesity is not an infectious disease, one could describe the state of obesity in the U.S. as an epidemic due to its relatively high prevalence that transcends age, gender, and socioeconomic groups. Subsequent conditions linked to obesity include but are not limi ted to type II diabetes, non-alcoholic fatty liver disease, heart disease, stroke, and even some types of cancer. Although obesity is most closely associated with elevated body mass, it is more accurately diagnosed by excess adipose tissue, which can result from diets high in fat and sugar like those common in the US.
To understand better the role of sugar in adipose gene expression, we performed transcriptional profiling using RNA sequencing (RNAseq) in adipose tissues of mice fed a control chow diet, a high-fat Western diet (HFWD), or a HFWD with 4% sugary water (HFWDS) over 12 weeks. We observed 548 epididymal white adipose tissue (eWAT) genes that were differentially expressed greater than two-fold in mice fed the HFWDS compared to those fed the HFWD. Samples were also co llected from two other major white adipose tissue depots: retroperitoneal and inguinal; time did not allow complete analysis of gene expression in these depots in this project. We conducted quantitat ive reverse transcription polymerase chain reactions (qRT-PCR) on retroperitoneal white adipose tissue and inguinal white adipose tissue in addition to eWAT to verify the RNAseq results.
Our results confirm differences in gene regulation among the differing diets. Statistical analysis revealed that the expression of two key genes correlated with obesity-associated parameters. The expression of Cyp1a1 was demonstrated to be down-regulated in association with HFWDS. The expression of Glt6d1, which was demonstrated to be up-regulated in mice with a HFWDS, exhibited positive correlation with blood glucose levels. Additional studies of these genes and their expressi on in adipocytes will further elucidate their role in adipose tissues. Our findings may pave the way to uncovering novel mechanisms for pathogenesis within adipose tissue and potential targets for therapeutics to treat obesity-linked conditions. Further research to elucidate the mechanisms by which these genes and corresponding proteins operate in relation to sugary water consumption would also shed light on how our favorite soft drinks and juices are affecting our overall health.
Statement of Research Advisor
Jami’s research focused on validating results from a gene expression discovery experiment to examine the role of sugary water consumption. Our objective was to identify genes that may regulate adipose tissue dysfunction, which is commonly associated with obesity. Jami’s results indicate that consumption of sugary water in an animal model of obesity results in differential regulation of specific genes within the adipose tissue. Her results have contributed to our understanding of the role of adipose tissue in the pathophysiology of obesity.
—Michael Green, Nutrition
Last Modified: