Examination of diet of harbor porpoise (Phocoena phocoena) from central California using stomach content and stable isotope analysis from multiple tissues

by Amanda K. Toperoff."Thesis (M.S.) -- San Jose State University, 2002."A thesis presented to the faculty of Moss Landing Marine Laboratories.""A thesis presented to the faculty of Moss Landing Marine Laboratories.

Altered DNA methylation of glycolytic and lipogenic genes in liver from obese and type 2 diabetic patients

OBJECTIVE: Epigenetic modifications contribute to the etiology of type 2 diabetes.  METHOD: We performed genome-wide methylome and transcriptome analysis in liver from severely obese men with or without type 2 diabetes and non-obese men to discover aberrant pathways underlying the development of insulin resistance. Results were validated by pyrosequencing.  RESULT: We identified hypomethylation of genes involved in hepatic glycolysis and insulin resistance, concomitant with increased mRNA expression and protein levels. Pyrosequencing revealed the CpG-site within ATF-motifs was hypomethylated in four of these genes in liver of severely obese non-diabetic and type 2 diabetic patients, suggesting epigenetic regulation of transcription by altered ATF-DNA binding.  CONCLUSION: Severely obese non-diabetic and type 2 diabetic patients have distinct alterations in the hepatic methylome and transcriptome, with hypomethylation of several genes controlling glucose metabolism within the ATF-motif regulatory site. Obesity appears to shift the epigenetic program of the liver towards increased glycolysis and lipogenesis, which may exacerbate the development of insulin resistance