ABSTRACT
Recent data have revealed that inhibiting autophagy exacerbates lipid accumulation in hepatocytes and nitrite treatment reduces total triglyceride levels in the high-fat diet mice. Therefore, the present study aimed to determine the effects of nitrite on simple hepatic steatosis and the possible role of autophagy. Firstly, steatotic L-02 cells were induced by incubating L-02 cells with 1.2 mmol · L(-1) oleic acid (OA) for 24 h. Secondly, steatotic L-02 cells were treated with 0.2 mmol · L(-1) sodium nitrite (SN) plus 3-methyladenine (3-MA), or chloroquine (CQ) for 24 h, and then lipid accumulation was measured with oil red O staining and triglyceride quantification. The notable steatosis could be observed in L-02 cells following exposure to 1.2 mmol · L(-1) OA for 24 h. Treatment with 0.2 mmol · L(-1) sodium nitrite reduced lipid accumulation in steatotic L-02 cells. 3-MA weakened the ability of sodium nitrite to ameliorate hepatic steatosis. Additionally, the sodium nitrite increased number of LC3-II immunostaining puncta and LC3-II protein expression was confirmed by immunofluorescence or Western blot analysis, and the effects were enhanced by CQ treatment. The number of increased cytoplasm vacuoles and lysosomes increased was confirmed by phase contrast and fluorescence microscope respectively. The increased autolysosome was detected by electron microscopy, this phenomenon could be reversed by CQ treatment. These data demonstrated that sodium nitrite enhanced the autophagic flux and decomposition of triglycerides in steatotic L-02 cells.
ABSTRACT
Aim To investigate the effect of hydrogen sulfide on hepatic lipid accumulation in obese mice. Methods C57 BL/6 J mice were randomly divided into control group, model group, and NaHS group. The mice of the control group were fed with normal diet. The mice of the model group and the NaHS group were fed with high-fat diet. From the thirteenth week, the mice of NaHS group were injected intraperitoneally with NaHS (H2S donor) in a dose of 50 μmol·kg-1 per day for 4 weeks and the mice of the model group were injected with the same volume of saline. All mice were sacrificed at the end of the 16th week. The tis-sues of liver were homogenized and centrifugated. The supernatants were used for the determination of triglyc-eride and cholesterol in liver. The morphology of liver was tested by H&E staining. Liver lipid accumulation was determined by oil red staining. Total RNA was ex-tracted from frozen tissue of liver. PCR was used to de-tect CPT-1 , FAS gene expression and ELISA method was used to detect CPT-1,FAS activity in mice liver. Results The body weight of the mice from NaHS group and model group was bigger than that of the mice from control group. Compared with the model group, the body weight of the mice from NaHS group was less;the content of triglyceride and cholesterol in liver was lower; the degree of liver tissue pathological changes and lipid accumulation were alleviated; CPT-1 expres-sion and activity were increased; FAS expression and activity were decreased. Conclusions These data in-dicate that hydrogen sulfide can reduce the lipid con-tent of liver tissue in obese mice and alleviate fatty liv-er. The mechanism may be associated with the in-creased expression of CPT-1 and the decreased expres-sion of FAS in liver.