ABSTRACT
Objective To explore protein extraction efficiency from formaldehyde-fixed paraffin embedded (FFPE) esophageal squamous cell carcinoma (ESCC) tissue samples with different protocols. Methods Six different lysis buffers with 100 °C or 105 °C. treatments were used for protein extraction, followed by evaluation of protein quantity and quality with Bradford, sodium dodecyl sulfate Polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis, Western blotting and immunohistochemistry (IHC), using 8 FFPE samples of ESCC. Results The optimal method for protein extraction from FFPE ESCC tissue was Laemmli lysis buffer (Buffer 4) treated with 100 °C incubation, evidenced by highest amount of protein recovery. Western blotting and IHC method measured consistent 14-3-3σ expression in FFPE ESCC tissue samples. Protein precipitated by two volumes of acetonitrite acetonitrile(ACN) (0.1% trifluoroacetic acid) relative to protein amount reduced background staining on SDS-PAGE gels by commassie staining. Conclusion Laemmli lysis buffer combined with 100 °C incubation has the highest protein extraction efficiency from FFPE ESCC tissue samples for Western blotting measurement of protein biomarkers, and ACN protein precipitation can further eliminate residual cross- linked protein by FFPE.
ABSTRACT
This study aimed to investigate the effect and possible mechanism of Bidens pilosa decoction on non-alcoholic fatty liver disease(NAFLD) induced by high fat and high glucose in mice. Bald/c mice were randomly divided into normal group, model group, metformin(200 mg·kg~(-1)) treatment group, Bidens pilosa decoction(10 g·kg~(-1)) treatment group, metformin and B. pilosa decoction(100 mg·kg~(-1)+5 g·kg~(-1)) treatment group. Except for the normal group, mice in the other four groups were fed with high-fat and high-glucose diet for 8 weeks to establish the non-alcoholic fatty liver model. After 4 weeks of treatment, blood was collected from the eyeballs, the mice were sacrificed, and relevant indicators were detected. The results showed that compared with the model group, blood lipid and blood glucose levels of each treatment group were significantly lower(P<0.05); HE staining results showed that liver pathological damage in each treatment group was significantly improved; oil red O staining results showed fat distribution in each treatment group significantly reduced(P<0.01); immunohistochemical staining showed that glucose regulated the protein expression of protein 78(GRP78) in liver tissues of each treatment group was also significantly reduced(P<0.01); Western blot results showed that endoplasmic reticulum stress signal pathway-related factors GRP78, phosphorylated-protein kinase R-like ER kinase(p-PERK), eukaryotic translation-initiation factor 2α(eIF2α), activating transcription factor 4(ATF4), C/EBP homologous protein(Chop), inositol requiring 1α(IRE1α), and cleaved-cysteinyl aspartate specific proteinase 12(cleaved-caspase-12) were significantly reduced(P<0.01). The results of the combined drug treatment group were better than those of the single drug treatment group. These results showed that B. pilosa decoction had the effect in improving non-alcoholic fatty liver, and its mechanism may be related to the down-regulation of the expression of endoplasmic reticulum stress(ERS)-related factors, and the reduction of the apoptosis of hepatocytes caused by ERS and the down-regulation of blood lipid and blood glucose levels.