It is under a complex control by substrates such as hormones, nutrients, and neuronal impulses. Insulin promotes glycogen synthesis, lipogenesis, and lipoprotein synthesis and inhibits gluconeogenesis, glycogenolysis, and VLDL secretion by modifying the expression and enzymatic activity of specific molecules. To understand the pathophysiological mechanisms leading to metabolic liver disease, we analyzed liver protein patterns expressed in a mouse model of diabetes by proteomic approaches. We used insulin receptor-knockout (IR Ϫ/Ϫ ) and heterozygous (IR ϩ/Ϫ ) mice as a murine model of liver metabolic dysfunction associated with diabetic ketoacidosis and insulin resistance. We evaluated liver fatty acid levels by microscopic examination and protein expression profiles by orthogonal experimental strategies using protein 2-DE MALDI-TOF/TOF and peptic nLC-MS/MS shotgun profiling. Identified proteins were then loaded into Ingenuity Pathways Analysis to find possible molecular networks. Twenty-eight proteins identified by 2-DE analysis and 24 identified by nLC-MS/MS shotgun were differentially expressed among the three genotypes. Bioinformatic analysis revealed a central role of high-mobility group box 1/2 and huntigtin never reported before in association with metabolic and related liver disease. A different modulation of these proteins in both blood and hepatic tissue further suggests their role in these processes. These results provide new insight into pathophysiology of insulin resistance and hepatic steatosis and could be useful in identifying novel biomarkers to predict risk for diabetes and its complications. insulin resistance; huntigtin; high-mobility group-B1; proteomics TYPE 2 DIABETES (T2D) is a complex metabolic disorder characterized by increased levels of insulin resistance and impaired -cell function with reduced insulin secretion (35). In T2D, modification of hepatic metabolism is associated with glucose and lipid overproduction, leading to overt hyperglycemia and diabetic dyslipidemia. Glucose overproduction is a physiological response in T2D, whereas the overproduction of lipids linked with insulin resistance remains a phenomenon to clarify since insulin increases abundance of lipogenic enzymes and insulin resistance diminishes lipogenesis (31, 41). Furthermore, insulin resistance and T2D are linked with hepatic steatosis, which is an exacerbation of liver dysfunction generated by accumulation of lipids, mainly triglycerides (23).Several etiological mechanisms have been proposed to explain the pathological link between insulin resistance, T2D, and liver disease, including inflammation and oxidative stress (36). Recently, novel anti-inflammatory proteins called chaperones and Toll-like receptors (TLRs) have been suggested to play a significant role in this pathological process (27). However, to date, the molecular mechanisms linking the impairment in glucose homeostasis with liver disease are not fully understood.Therefore, elucidation of molecular alterations, which regulate metabolic liver dysfunct...