Objective： To investigate the possible mechanism of San-Cao Granule（SCG, 三草颗粒） mediating antiliver fibrosis. Methods： A total of 60 male Sprague-Dawley rats were randomly divided into the normal control group,...Objective： To investigate the possible mechanism of San-Cao Granule（SCG, 三草颗粒） mediating antiliver fibrosis. Methods： A total of 60 male Sprague-Dawley rats were randomly divided into the normal control group, porcine serum-treated group, ursodesoxycholic acid（UDCA, 60 mg/kg）, SCG（3.6 g/kg） group, SCG（1.8 g/kg） group and SCG（0.9 g/kg） group, with 10 rats in each group. Liver fibrosis was induced with porcine serum by intraperitoneal injection for 8 weeks, except for the normal control group. Then, the rats in the three SCG-treated groups and UDCA group were administered SCG and UDCA respectively for 4 weeks. The serum levels of alanine transaminase（ALT）, aspartate transaminase（AST）, albumin（ALB）, total bilirubin（TBIL）, hyaluronic acid（HA）, laminin（LN）, and type Ⅳcollagen（ⅣC） were examined using commercial kits and hepatic histopathology was examined with hematoxylin and eosin and Masson staining. Moreover, the protein expression levels of high mobility group box-1 protein（HMGB1）, transforming growth factor β1（TGF-β1）, phosphorylated mothers against decapentaplegic homolog 3（p-Smad3）, Smad7, toll-like receptor 4（TLR4）, myeloid differentiation factor 88（My D88）, nuclear factor-kappa B（NF-κB） and α-smooth muscle actin（α-SMA） were determined by western blot, immunohistochemistry and real time quantitativereverse transcription polymerase. Results： Both SCG（3.6 and 1.8 g/kg） and UDCA significantly ameliorated the liver fibrosis induced by porcine serum as indicated by retarding the serum levels increasing of ALT, AST, TBIL, HA, LN and ⅣC and preventing the serum level reducing of ALB compared with the model group（all P〈0.01）. Meanwhile, the collagen deposition was attenuated by SCG and UDCA treatment. Furthermore, SCG markedly reduced the expressions of HMGB1, TGF-β1, p-Smad3, TLR4, My D88, NF-κB and α-SMA, and enhanced the expression of the Smad7 compared with the model group（all P〈0.01）. Conclusion： SCG ameliorates hepatic fibrosis possibly through inhibiting HMGB1, TLR4/NF-κB and TGF-β1/Smad signaling pathway.展开更多
Chloroplast-located proteins which are encoded by the nuclear genome have to be imported from the cytosol into the organelle in a posttranslational manner. Among these nuclear-encoded chloroplast proteins are the ligh...Chloroplast-located proteins which are encoded by the nuclear genome have to be imported from the cytosol into the organelle in a posttranslational manner. Among these nuclear-encoded chloroplast proteins are the light- harvesting chlorophyll a/b-binding proteins （LHCPs）. After translation in the cytosol, precursor proteins of LHCPs are imported via the TOC/TIC translocase, processed to their mature size to insert into thylakoid membranes where they recruit chlorophylls a and b to form pigment-protein complexes. The translocation of proteins is a highly regulated process which employs several regulators. To analyze whether CAO （chlorophyll a oxigenase） which converts chlorophyll a to chlorophyll b at the inner chloroplast membrane, is one of these regulators, we performed import reactions utilizing a homozygous loss-of-function mutant （cao-1）. We imported in vitro translated and 35S-labeled precursor proteins of light- harvesting proteins of photosystem II LHCB1, LHCB4, and LHCB5 into chloroplasts isolated from cao-1 and show that import of precursor proteins and their processing to mature forms are not impaired in the mutant. Therefore, regulation of the import machinery cannot be responsible for the decreased steady-state levels of light-harvesting complex （LHC） proteins. Regulation does not take place at the transcriptional level either, because Lhcb mRNAs are not down-regulated. Additionally, reduced steady-state levels of LHCPs also do not occur due to posttranslational turnover of non-functional LHCPs in chloroplasts. Taken together, our data show that plants in the absence of CAO and therefore devoid of chlorophyll b are not influenced in their import behavior of LHC proteins.展开更多
基金Supported by the Major Projects of the National Science and Technology(No.2012ZX10005010-002-002)the National Natural Science Foundation of China(No.81303120 and No.81173571)
文摘Objective： To investigate the possible mechanism of San-Cao Granule（SCG, 三草颗粒） mediating antiliver fibrosis. Methods： A total of 60 male Sprague-Dawley rats were randomly divided into the normal control group, porcine serum-treated group, ursodesoxycholic acid（UDCA, 60 mg/kg）, SCG（3.6 g/kg） group, SCG（1.8 g/kg） group and SCG（0.9 g/kg） group, with 10 rats in each group. Liver fibrosis was induced with porcine serum by intraperitoneal injection for 8 weeks, except for the normal control group. Then, the rats in the three SCG-treated groups and UDCA group were administered SCG and UDCA respectively for 4 weeks. The serum levels of alanine transaminase（ALT）, aspartate transaminase（AST）, albumin（ALB）, total bilirubin（TBIL）, hyaluronic acid（HA）, laminin（LN）, and type Ⅳcollagen（ⅣC） were examined using commercial kits and hepatic histopathology was examined with hematoxylin and eosin and Masson staining. Moreover, the protein expression levels of high mobility group box-1 protein（HMGB1）, transforming growth factor β1（TGF-β1）, phosphorylated mothers against decapentaplegic homolog 3（p-Smad3）, Smad7, toll-like receptor 4（TLR4）, myeloid differentiation factor 88（My D88）, nuclear factor-kappa B（NF-κB） and α-smooth muscle actin（α-SMA） were determined by western blot, immunohistochemistry and real time quantitativereverse transcription polymerase. Results： Both SCG（3.6 and 1.8 g/kg） and UDCA significantly ameliorated the liver fibrosis induced by porcine serum as indicated by retarding the serum levels increasing of ALT, AST, TBIL, HA, LN and ⅣC and preventing the serum level reducing of ALB compared with the model group（all P〈0.01）. Meanwhile, the collagen deposition was attenuated by SCG and UDCA treatment. Furthermore, SCG markedly reduced the expressions of HMGB1, TGF-β1, p-Smad3, TLR4, My D88, NF-κB and α-SMA, and enhanced the expression of the Smad7 compared with the model group（all P〈0.01）. Conclusion： SCG ameliorates hepatic fibrosis possibly through inhibiting HMGB1, TLR4/NF-κB and TGF-β1/Smad signaling pathway.
文摘Chloroplast-located proteins which are encoded by the nuclear genome have to be imported from the cytosol into the organelle in a posttranslational manner. Among these nuclear-encoded chloroplast proteins are the light- harvesting chlorophyll a/b-binding proteins （LHCPs）. After translation in the cytosol, precursor proteins of LHCPs are imported via the TOC/TIC translocase, processed to their mature size to insert into thylakoid membranes where they recruit chlorophylls a and b to form pigment-protein complexes. The translocation of proteins is a highly regulated process which employs several regulators. To analyze whether CAO （chlorophyll a oxigenase） which converts chlorophyll a to chlorophyll b at the inner chloroplast membrane, is one of these regulators, we performed import reactions utilizing a homozygous loss-of-function mutant （cao-1）. We imported in vitro translated and 35S-labeled precursor proteins of light- harvesting proteins of photosystem II LHCB1, LHCB4, and LHCB5 into chloroplasts isolated from cao-1 and show that import of precursor proteins and their processing to mature forms are not impaired in the mutant. Therefore, regulation of the import machinery cannot be responsible for the decreased steady-state levels of light-harvesting complex （LHC） proteins. Regulation does not take place at the transcriptional level either, because Lhcb mRNAs are not down-regulated. Additionally, reduced steady-state levels of LHCPs also do not occur due to posttranslational turnover of non-functional LHCPs in chloroplasts. Taken together, our data show that plants in the absence of CAO and therefore devoid of chlorophyll b are not influenced in their import behavior of LHC proteins.
