The role of NLRP3/GATA-4/VEGF signal pathway in neovascular age-related macular degeneration / 中国医师杂志

Objective:To explore the potential role of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)/GATA-binding protein 4 (GATA-4)/vascular endothelial growth factor (VEGF) signal pathway in neovascular age-related macular degeneration (nAMD).Methods:We applied the TRANSFAC Public database to search the human and mouse VEGF promoters and upstream transcription factors, analyzed the transcription factors that may influence the transcriptional activity of VEGF. The RAW264.7 cells were divided into control group and lipopolysaccharide (LPS) stimulated group (LPS group). Real time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the activation of NLRP3 inflammasome, and the mRNA levels of GATA-4 and VEGFA. Thus, we applied the specific small molecular NLRP3 inhibitor MCC950 pretreated RAW264.7 cells (LPS+ MCC950 group), and detected the gene expression of NLRP3, Caspase-1, interleukin 1β( IL-1β), GATA-4 and VEGFA.Results:There were multiple GATA transcription factor binding sites upstream of human and mouse VEGF promoters. Compared with the control group, mRNA expression of NLRP3, Caspase-1, IL-1β, GATA-4 and VEGFA in LPS group were increased (all P<0.05). Compared with LPS group, mRNA expression of NLRP3, Caspase-1, IL-1β, GATA-4 and VEGFA in LPS+ MCC950 group were significantly decreased (all P<0.05). Conclusions:NLRP3/GATA-4/VEGF signal pathway may play a significant role in the pathologic processes of nAMD.

Salidroside alleviates retinopathy in diabetes rats by inhibiting oxidative stress and immune inflammation through activating PI3K/AKT pathway / 细胞与分子免疫学杂志

Objective To investigate the ameliorative effect of salidroside on diabetes retinopathy (DR) rats and its mechanism. Methods Male SD rats were randomly divided into blank group, model group, low-dose and high-dose salidroside treatment groups. Except for the blank group, other groups were modeled by intraperitoneal injection of streptozotocin. After successful modeling, treatment groups were injected intraperitoneally with [50 mg/(kg.d)] and [100 mg/(kg.d)] salidroside respectively, for 4 weeks; the blank group and model group were injected with corresponding doses of saline. ELISA was used to measure the expression levels of antioxidant-related enzyme activity and inflammatory factors in blood glucose and serum of rats in each group. Retinal tissue lesions were detected by HE staining, and the expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule 1 (ICAM-1) in retinal tissues were detected by immunohistochemical staining. Western blot analysis was used to detect the expression of phosphatidylinositol 3 kinase (PI3K) , nuclear factor κB p65 (NF-κB p65), phosphorylated p38 MAPK (p-p38 MAPK), and phosphorylated protein kinase B (p-AKT) proteins. Results Compared with model group, salidroside could significantly reduce blood glucose level and increase body mass in DR rats. The serum levels of superoxide dismutase (SOD) and catalase (CAT) were significantly increased, while the levels of malondialdehyde (MDA), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and IL-1β were reduced. The protein expression of VEGF, ICAM-1, NF-κB p65 and p-p38 MAPK was significantly decreased, while the protein expression of PI3K and p-AKT was increased. Conclusion Salidroside can reduce DR in rats by inhibiting oxidative stress and immune inflammatory response, which may be related to the reduction of abnormal expression of VEGF and ICAM-1 and the activation of PI3K/AKT signaling pathway.

Effect of GYY4137 on cytosolic lipid decomposition in mouse primary hepatocytes / 中国病理生理杂志

AIM: To evaluate the effect of GYY4137, a novel hydrogen sulfide (H2S) donor, on cytosolic lipid decomposition in mouse primary steatosis hepatocytes.METHODS: Oleic acid (OA) was used to induce hepatic steatosis model in vitro.The C57BL/6 mouse primary hepatocytes isolated and cultured by 2-step in situ perfusion were divided into 4 groups: the cells in control group were incubated with normal medium for 54 h;the cells in model group were incubated with OA at 1.2 mmol/L for 48 h followed by serum-free phenol red-free RPMI-1640 for 6 h;the cells in H2S group or DL-propar-gylglycine (PAG;an inhibitor of cystathione γ-lysase, inhibiting H2S synthesis) group were incubated with OA at 1.2 mmol/L for 48 h followed by serum-free phenol red-free RPMI-1640 which contained 1 mmol/L GYY4137 or 200 μmol/L PAG for 6 h.The glycerin release and the protein expression of hormone-sensitive lipase (HSL) in the cells were mea-sured.RESULTS: Compared with model group, the glycerin release and the protein expression of phosphorylated HSL (p-HSL) in H2S group decreased significantly, while those increased significantly in PAG group.CONCLUSION: In steatosis hepatocytes, exogenous H2S possibly decreases cytosolic lipid decomposition by decreasing the protein level of p-HSL.

Effect of hydrogen sulfide on hepatic lipid accumulation in obese mice / 中国药理学通报

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.

Sodium nitrite reduces lipid accumulation in steatotic cells by enhancing autophagy / 药学学报

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.