RESUMO
Objective To construct a Pnpla3 148M/M Tm6sf2 167K/K double mutant mouse model by crossbreeding Pnpla3 148M/M homozygous mice and Tm6sf2 167K/K homozygous mice. Methods Pnpla3 148I/M Tm6sf2 167E/K heterozygous mice were bred by hybridization of Pnpla3 148M/M Tm6sf2 167E/E and Pnpla3 148I/I Tm6sf2 167K/K homozygous mice, and the Pnpla3 148M/M Tm6sf2 167K/K mice were obtained by the self-crossbreeding of Pnpla3 148I/M Tm6sf2 167E/K mice. Male mice of Pnpla3 148M/M Tm6sf2 167K/K ( n =6), Pnpla3 148M/M Tm6sf2 167E/E ( n =6), and Pnpla3 148I/I Tm6sf2 167K/K ( n =6) genotypes and Wt mice ( n =6) were fed with normal diet for 8 weeks, and then the glucose and lipid metabolism indices were measured. A one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t -test was used for further comparison bewteen two groups. Results Agarose gel electrophoresis and nucleic acid sequencing results showed that the Pnpla3 148M/M Tm6sf2 167K/K double mutant mouse model was successfully constructed. There were no significant difference in body weight between the Pnpla3 148M/M Tm6sf2 167K/K mice and the Pnpla3 148M/M Tm6sf2 167E/E , Pnpla3 148I/I Tm6sf2 167K/K , and Wt mice (all P > 0.05). The Pnpla3 148M/M Tm6sf2 167K/K mice had a significantly higher liver wet weight than the Wt mice ( P 0.05). Also, there were no significant differences in the serum levels of biochemical indices between the Pnpla3 148M/M Tm6sf2 167K/K mice and the Pnpla3 148M/M Tm6sf2 167E/E , Pnpla3 148I/I Tm6sf2 167K/K , and Wt mice (all P > 0.05). Oil red O staining of the liver showed that more lipid accumulation was observed in the Pnpla3 148M/M Tm6sf2 167K/K mice than in the Pnpla3 148M/M Tm6sf2 167E/E and Wt mice. Conclusion The Pnpla3 148M/M Tm6sf2 167K/K double mutant mouse model was successfully constructed. Pnpla3 Ⅰ 148M and Tm6sf2 E 167K double mutations can cause abnormal glucose metabolism in mice.
RESUMO
Objective To establish a mouse model of hepatocyte-specific TM6SF2 knockout, and to investigate the role of TM6SF2 in the development of nonalcoholic fatty liver disease (NAFLD). Methods The CRISPR/Cas9 technique and the Cre/LoxP strategy were used to establish a stable mouse model of hepatocyte-specific TM6SF2 knockout. The mice with hepatocyte-specific TM6SF2 knockout and the control mice were given a normal diet or a high-fat diet (HFD) for 16 weeks, and related indices were measured, including general status (body weight and liver weight), glucose metabolic indices (fasting blood glucose and insulin), and lipid metabolism (plasma triglyceride, cholesterol, and liver triglyceride). The t -test was used for comparison of normally distributed continuous data between two groups. Results Under the condition of HFD, compared with the control mice, the mice with hepatocyte-specific TM6SF2 knockout had significantly higher liver weight (2.235±0.175 g vs 1.258±0.106 g, t =4.789, P 0.05). Under the condition of HFD, there were no significant differences in the levels of plasma triglyceride and cholesterol between the mice with hepatocyte-specific TM6SF2 knockout and the control group ( P > 0.05), while the mice with hepatocyte-specific TM6SF2 knockout had a significant increase in the level of liver triglyceride compared with the control mice (23.969±0.978 mg/g vs 18.229±1.633 mg/g, t =3.015, P =0.024). Conclusion Hepatocyte-specific knockout of TM6SF2 can aggravate liver lipid accumulation and liver injury in mice with NAFLD.