Background Cataracts is considered be formed because of an abnormal glucose metabolic pathway or oxidative stress. We explored the damaging role of ONOO^- and antagonism of cholecystokinin octapeptide-8 （CCK-8） in d...Background Cataracts is considered be formed because of an abnormal glucose metabolic pathway or oxidative stress. We explored the damaging role of ONOO^- and antagonism of cholecystokinin octapeptide-8 （CCK-8） in diabetic cataractal rat lenses. Methods A diabetic cataractal animal model was established by peritoneal injection of streptozotocine （STZ）. Thirty-six normal SD rats were taken as control group; seventy-two were given STZ （45 mg/kg） and then divided into STZ group and CCK-8 group （peritoneal injection CCK-8）. STZ induced diabetic rats were treated with CCK-8 for 60 days. Lenses were examined with slit lamp at 20, 40 and 60 days. Immunofluorescent staining and Western blot analysis were used for determining nitrotyrosine （NT, a marker for ONOO-）. RT-PCR and gene array analysis were used for determining the expression of inducible nitric oxide synthetase mRNA （iNOS mRNA） in lens epithelium （LEC）. Results STZ group rats developed lens opacity by 20 days that reached a high level by 60 days after STZ injection. CCK-8 group rats delayed the cataract formation. There was no distinct expression of NT and iNOS mRNA in control group. In STZ group, there were distinct expression of NT and upregulation of iNOS mRNA; however, CCK-8 group showed weak expression of NT and downregulation of iNOS mRNA. Conclusions NT, which may be a new form of oxidative stress, was expressed in diabetic rat LEC although CCK-8 could reverse NT damage in LEC. The results suggested that CCK-8 might be a useful therapeutic agent against diabetic cataract. The antagonizing mechanism of CCK-8 may be related to direct antagonism of ONOO^- as well as its inhibition of the expression of iNOS mRNA for production of NO and therefore decrease in the formation of ONOO^-.展开更多
AIM: To explore that if peroxynitrite induced the expression of inducible nitric oxide synthase (iNOS)via nuclear factor-kappa B (NF-kappa B)pathway in retinal pigment epithelial (RPE) cells and the antagonism of chol...AIM: To explore that if peroxynitrite induced the expression of inducible nitric oxide synthase (iNOS)via nuclear factor-kappa B (NF-kappa B)pathway in retinal pigment epithelial (RPE) cells and the antagonism of cholecystokinin octapeptide-8 (Melatonin, CCK-8) in vitro. METHODS: RPE cells were obtained from eyes of C57BL/6 mouse and divided into control, peroxynitrite and CCK-8 groups. Control group was treated with saline, peroxynitrite group was treated with peroxynitrite, and CCK-8 group was treated with CCK-8 after added with peroxynitrite. All changes were observered at 6, 12 and 24 hours after treatment. Gene array analysis, Reverse Transcription Polymerase Chain Reaction (RT-PCR) were used to determine the expression of inducible nitric oxide synthase ( iNOS)mRNA in RPE cells. Western blotting was used to test the apoptosis of RPE cells. Immunofluorescent staining was used to determine the NF-kappa B pathway signal transduction. RESULTS: Compared to the control group, the expression of iNOS mRNA was up-regulated in peroxynitrite group and down-regulated in CCK-8 group with gene array analysis. Apoptosis was increased in peroxynitrite group and decreased in CCK-8 group with western blotting. The NF-kappa B pathway signal transduction was more and more stronger in the peroxynitrite group. But in CCK-8 group, little stronger could be observed at 12 hours, then weak at 24 hours with immunofluorescent staining (P<0.001). CONCLUSION: This study suggested that apoptosis of RPE cells was partly induced by peroxynitrite, which may be the new way of oxidative damage to the RPE cells. The NF-kappa B signal transduction may affect and reinforce apoptosis mediated by peroxynitrite. CCK-8 decreased apoptosis of RPE cells induced by peroxynitrite and is a potential agent for therapy of retinopathy. The mechanism of CCK-8 dealing with RPE cells may be related to its direct inhibition of the formation of iNOS to produce peroxynitrite and antagnism of damage of peroxynitrite to the RPE cells.展开更多
Soy glycinin derived octapeptide(SGP8)is a peptide obtained from degradation of the soy glycinin,whose amino acid sequence is IAVPGEVA.To determine the effect of SGP8 on non-alcoholic fatty liver disease(NAFLD),steato...Soy glycinin derived octapeptide(SGP8)is a peptide obtained from degradation of the soy glycinin,whose amino acid sequence is IAVPGEVA.To determine the effect of SGP8 on non-alcoholic fatty liver disease(NAFLD),steatosis Hep G2 cells were induced by 1 mmol/L free fatty acid(FFA)and C57 BL/6 J mice were fed with methionine-choline defi cient(MCD)diet for 3 weeks to establish NAFLD model.The results of oil red O staining and total cholesterol(TC)/triglyceride(TG)contents showed that SGP8 could signifi cantly reduce the lipid content of steatosis Hep G2 cells.In vivo,SGP8 lowered plasma alanine aminotransferase(ALT)and low density lipoprotein(LDL)content,normalized hepatic superoxide dismutase(SOD)and malondialdehyde(MDA)production,and reduced the severity of liver infl ammation.The results of Western blotting showed that SGP8 increased expression of Sirtuin-1(SIRT1)and phosphorylation level of AMP activated protein kinase(AMPK)in hepatocytes.Through activation of SIRT1/AMPK pathway,SGP8 downregulated the expression of sterol regulatory element binding protein 1 c(SREBP-1 c)and its target genes ACC and FAS expression levels,and increased the phosphorylation level of acetyl Co A carboxylase(ACC).Furthermore,SGP8 also upregulated the expression of transcription factor peroxisome proliferator activated receptorα(PPARα),which was regulated by SIRT1/AMPK pathway,and its target gene CPT1 level.In conclusion,SGP8 might improve NAFLD by activating the SIRT1/AMPK pathway.Our data suggest that SGP8 may act as a novel and potent therapeutic agent against NAFLD.展开更多
文摘Background Cataracts is considered be formed because of an abnormal glucose metabolic pathway or oxidative stress. We explored the damaging role of ONOO^- and antagonism of cholecystokinin octapeptide-8 （CCK-8） in diabetic cataractal rat lenses. Methods A diabetic cataractal animal model was established by peritoneal injection of streptozotocine （STZ）. Thirty-six normal SD rats were taken as control group; seventy-two were given STZ （45 mg/kg） and then divided into STZ group and CCK-8 group （peritoneal injection CCK-8）. STZ induced diabetic rats were treated with CCK-8 for 60 days. Lenses were examined with slit lamp at 20, 40 and 60 days. Immunofluorescent staining and Western blot analysis were used for determining nitrotyrosine （NT, a marker for ONOO-）. RT-PCR and gene array analysis were used for determining the expression of inducible nitric oxide synthetase mRNA （iNOS mRNA） in lens epithelium （LEC）. Results STZ group rats developed lens opacity by 20 days that reached a high level by 60 days after STZ injection. CCK-8 group rats delayed the cataract formation. There was no distinct expression of NT and iNOS mRNA in control group. In STZ group, there were distinct expression of NT and upregulation of iNOS mRNA; however, CCK-8 group showed weak expression of NT and downregulation of iNOS mRNA. Conclusions NT, which may be a new form of oxidative stress, was expressed in diabetic rat LEC although CCK-8 could reverse NT damage in LEC. The results suggested that CCK-8 might be a useful therapeutic agent against diabetic cataract. The antagonizing mechanism of CCK-8 may be related to direct antagonism of ONOO^- as well as its inhibition of the expression of iNOS mRNA for production of NO and therefore decrease in the formation of ONOO^-.
基金Supported by Hebei Province Science foundation,China(No.07276101D-3)Clinical Science Project Fund of the Ministry of Health in Hebei Province,China(No. 03078)Foreign Studying Project Fund in Hebei Province,China
文摘AIM: To explore that if peroxynitrite induced the expression of inducible nitric oxide synthase (iNOS)via nuclear factor-kappa B (NF-kappa B)pathway in retinal pigment epithelial (RPE) cells and the antagonism of cholecystokinin octapeptide-8 (Melatonin, CCK-8) in vitro. METHODS: RPE cells were obtained from eyes of C57BL/6 mouse and divided into control, peroxynitrite and CCK-8 groups. Control group was treated with saline, peroxynitrite group was treated with peroxynitrite, and CCK-8 group was treated with CCK-8 after added with peroxynitrite. All changes were observered at 6, 12 and 24 hours after treatment. Gene array analysis, Reverse Transcription Polymerase Chain Reaction (RT-PCR) were used to determine the expression of inducible nitric oxide synthase ( iNOS)mRNA in RPE cells. Western blotting was used to test the apoptosis of RPE cells. Immunofluorescent staining was used to determine the NF-kappa B pathway signal transduction. RESULTS: Compared to the control group, the expression of iNOS mRNA was up-regulated in peroxynitrite group and down-regulated in CCK-8 group with gene array analysis. Apoptosis was increased in peroxynitrite group and decreased in CCK-8 group with western blotting. The NF-kappa B pathway signal transduction was more and more stronger in the peroxynitrite group. But in CCK-8 group, little stronger could be observed at 12 hours, then weak at 24 hours with immunofluorescent staining (P<0.001). CONCLUSION: This study suggested that apoptosis of RPE cells was partly induced by peroxynitrite, which may be the new way of oxidative damage to the RPE cells. The NF-kappa B signal transduction may affect and reinforce apoptosis mediated by peroxynitrite. CCK-8 decreased apoptosis of RPE cells induced by peroxynitrite and is a potential agent for therapy of retinopathy. The mechanism of CCK-8 dealing with RPE cells may be related to its direct inhibition of the formation of iNOS to produce peroxynitrite and antagnism of damage of peroxynitrite to the RPE cells.
基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Soy glycinin derived octapeptide(SGP8)is a peptide obtained from degradation of the soy glycinin,whose amino acid sequence is IAVPGEVA.To determine the effect of SGP8 on non-alcoholic fatty liver disease(NAFLD),steatosis Hep G2 cells were induced by 1 mmol/L free fatty acid(FFA)and C57 BL/6 J mice were fed with methionine-choline defi cient(MCD)diet for 3 weeks to establish NAFLD model.The results of oil red O staining and total cholesterol(TC)/triglyceride(TG)contents showed that SGP8 could signifi cantly reduce the lipid content of steatosis Hep G2 cells.In vivo,SGP8 lowered plasma alanine aminotransferase(ALT)and low density lipoprotein(LDL)content,normalized hepatic superoxide dismutase(SOD)and malondialdehyde(MDA)production,and reduced the severity of liver infl ammation.The results of Western blotting showed that SGP8 increased expression of Sirtuin-1(SIRT1)and phosphorylation level of AMP activated protein kinase(AMPK)in hepatocytes.Through activation of SIRT1/AMPK pathway,SGP8 downregulated the expression of sterol regulatory element binding protein 1 c(SREBP-1 c)and its target genes ACC and FAS expression levels,and increased the phosphorylation level of acetyl Co A carboxylase(ACC).Furthermore,SGP8 also upregulated the expression of transcription factor peroxisome proliferator activated receptorα(PPARα),which was regulated by SIRT1/AMPK pathway,and its target gene CPT1 level.In conclusion,SGP8 might improve NAFLD by activating the SIRT1/AMPK pathway.Our data suggest that SGP8 may act as a novel and potent therapeutic agent against NAFLD.
