Integrated hepatic transcriptome and proteome analysis of mice with high-fat diet-induced nonalcoholic fatty liver disease

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease in the US and refers to a wide spectrum of liver damage, including simple steatosis, steatohepatitis, fibrosis and cirrhosis. The goal of the present study was to achieve a more detailed understanding of the molecular changes in response to high fat-induced liver steatosis through the identification of a differentially expressed liver transcriptome and proteome. Male C57/BL6 mice fed a high-fat lard diet for 8 weeks developed visceral obesity and hepatic steatosis characterized by significantly increased liver and plasma free fatty acid and triglyceride levels and plasma alanine aminotransferase activities. Transcriptome analysis demonstrated that, compared to the control diet (CD), high-fat diet changed the expression of 309 genes (132 up- and 177 down-regulated; by a twofold change and more, P<.05). Multiple genes encoding proteins involved in lipogenesis were down-regulated, whereas genes involved in fatty acid oxidation were up-regulated. Proteomic analysis revealed 12 proteins which were differentially expressed. Of these, glutathione S-transferases mu1 and pi1 and selenium-binding protein 2 were decreased at both the gene and protein levels. This is the first study to perform a parallel transcriptomic and proteomic analysis of diet-induced hepatic steatosis. Several key pathways involving xenobiotic and lipid metabolism, the inflammatory response and cell-cycle control were identified. These pathways provide targets for future mechanistic and therapeutic studies as related to the development and prevention of NAFLD.

Glutathione s-transferase p in glucose homeostasis in mice.

“…Kirpich et al reported a decrease in hepatic GSTP and GSTM protein in high-fat lard diet-fed C57Bl/6J mice [49]. In a separate study, investigators fed male…”

“…For example, GSTP specifically catalyzes GSH conjugation to acrolein facilitating its detoxification [95]. Similarly, diet-induced obesity in mice downregulates hepatic GSTP [49], increases levels of tissue and plasma protein-acrolein adducts [100], and urinary acrolein level correlates with glycated hemoglobin in T2D subjects [101]. Distinct from its catalytic function, GSTP binds and inhibits c-Jun NH 2 -terminal kinase (JNK)…”

“…isozymes [40,49,135]. The GSTs are a multigene family of abundant and ubiquitous phase II enzymes [36] that primarily catalyze glutathione (GSH) conjugation of toxic, unsaturated aldehydes such as acrolein and 4-hydroxynonenal (4HNE).…”

Human skeletal muscle perilipin 2 and 3 expression varies with insulin sensitivity

“…Furthermore, perilipin 2 [18], LPL [19,20], and ATGL [4] have been used in other publications. However, additional testing was done for ATGL, HSL, perilipin 2, and LPL, see Figure 1.…”

Advanced Glycation Endproduct Changes to Bruch's Membrane Promotes Lipoprotein Retention by Lipoprotein Lipase

“…It does not cross-react with other lipases and is suitable for use in human and mouse tissues. [37][38][39] Sections were incubated with primary antibody overnight at 4°C, washed with PBS, and incubated with goat antirabbit and donkey anti-goat secondary antibodies, respectively (1:400; Santa Cruz Biotechnologies). Appropriate mouse, rabbit, and goat IgGs (Santa Cruz Biotechnologies) were used as isotype controls.…”