The Potential of the FSP1cre-Pparb/d-/- Mouse Model for Studying Juvenile NAFLD

Oridonin regulates the polarized state of Kupffer cells to alleviate nonalcoholic fatty liver disease through ROS-NF-κB

Oridonin (Ori) is a kind of diterpenoid small molecule, but its role in nonalcoholic fatty liver disease (NAFLD) has not been reported yet. This study aimed to explore the pharmacological function of Ori in liver protection through the reactive oxygen species (ROS)-mediated polarization of Kupffer cells (KCs). In the present work, KCs were adopted for study in vitro. To be specific, LPS and IFN-γ were utilized to induce M1 polarization, then the influence of Ori intervention on the expression of inflammatory factors IL-1β, IL-6 and TNF-α was detected by enzyme-linked immunosorbent assay (ELISA), that of CD86 and P65 was measured through fluorescence staining, that of p-P65 and p-P50 was detected by Western blotting (WB) assay, and ROS expression was measured by using the DCFH-DA probe. The C57BL/6J mice were fed with the high fat diet (HFD) to construct the NAFLD model, and intervened with Ori. The blood glucose (BG), body weight (BW), food intake and water intake of mice were monitored; meanwhile, glucose and insulin tolerance tests were conducted. The liver tissues of mice were subjected to H&E staining and oil red O staining. Moreover, the serum ALT, AST and TG levels in mice were monitored, the CD86 and CD206 levels were measured through histochemical staining, the expression of inflammatory factors was detected by ELISA, and the p-P65 and p-P50 protein levels were detected by WB assay. Ori suppressed the M1 polarization of KCs, reduced the levels of inflammatory factors, and decreased the expression of ROS, p-P65 and p-P50. In animal experiments, Ori improved lipid deposition and liver injury in the liver tissues of NAFLD mice, increased the proportion of M2 cells (up-regulated CD206 expression), reduced that of M1 cells (down-regulated CD86 expression), and decreased the serum ALT, AST and TG levels. This study discovered that Ori suppressed ROS production and regulated the M1 polarization of KCs, thus protecting the liver in NAFLD.

Peroxisome Proliferator-Activated Receptors and Their Novel Ligands as Candidates for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a major health issue worldwide, frequently associated with obesity and type 2 diabetes. Steatosis is the initial stage of the disease, which is characterized by lipid accumulation in hepatocytes, which can progress to non-alcoholic steatohepatitis (NASH) with inflammation and various levels of fibrosis that further increase the risk of developing cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD is influenced by interactions between genetic and environmental factors and involves several biological processes in multiple organs. No effective therapy is currently available for the treatment of NAFLD. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that regulate many functions that are disturbed in NAFLD, including glucose and lipid metabolism, as well as inflammation. Thus, they represent relevant clinical targets for NAFLD. In this review, we describe the determinants and mechanisms underlying the pathogenesis of NAFLD, its progression and complications, as well as the current therapeutic strategies that are employed. We also focus on the complementary and distinct roles of PPAR isotypes in many biological processes and on the effects of first-generation PPAR agonists. Finally, we review novel and safe PPAR agonists with improved efficacy and their potential use in the treatment of NAFLD.