ABSTRACT
<p><b>OBJECTIVE</b>To investigate whether Notch signaling is activated in hepatic stellate cells (HSCs), and to determine whether manipulation of the Notch signaling pathway can effect the activation of HSCs.</p><p><b>METHODS</b>The expression of Notch signaling components in unactivated or TGF-b1-activated HSC-T6 cells was detected by Taqman Probe-based gene expression analysis. Differential expression of Notch3 and Jagged1 was detected by immunofluorescence analysis. Notch3-mediated expression of the myofibroblastic markers, a-SMA and collagen I, was detected in HSC-T6 cells transfected with pcDNA3.1-N3ICD or Notch3 siRNA by Western blotting.</p><p><b>RESULTS</b>Notch signaling components were expressed in both unactivated and activated HSC-T6 cells, but the TGF-b1-treated cells showed significantly higher expression levels of Jagged1 (3.9-fold, F = 2543.482), Notch3 (4.2-fold, F = 287.982), and HES1 (3.2-fold, F = 1719.851). Transfection-mediated over-expression of Notch3 led to significantly increased expression of a-SMA (6.8-fold, t = 13.157) and collagen I (5.5-fold, t = 9.810) (both P less than 0.01). Transient knock-down of Notch3 expression by siRNA decreased expression of the myofibroblastic markers (a-SMA by approximately 90%, t = 19.863 and collagen I by 84%, t = 10.376; both, P less than 0.01). Moreover, knock-down of Notch3 antagonized the TGF-b1-induced expression of a-SMA and collagen I.</p><p><b>CONCLUSION</b>Notch signaling may participate in liver fibrogenesis by regulating HSC activation. Selective interruption of Notch3 may represent a new anti-fibrotic strategy to treat liver fibrosis.</p>
Subject(s)
Animals , Rats , Calcium-Binding Proteins , Genetics , Metabolism , Cell Line , Hepatic Stellate Cells , Metabolism , Intercellular Signaling Peptides and Proteins , Genetics , Metabolism , Jagged-1 Protein , Membrane Proteins , Genetics , Metabolism , RNA, Messenger , Genetics , RNA, Small Interfering , Receptor, Notch3 , Receptors, Notch , Genetics , Metabolism , Serrate-Jagged Proteins , Signal TransductionABSTRACT
<p><b>OBJECTIVE</b>To develop an simple and sensitive method for detecting anti-coronavirus IgG antibodies in bat sera based on enzyme-linked immunosorbent assay (ELISA).</p><p><b>METHODS</b>A commercial ELISA kit for detecting SARS-CoV antibody was modified for detecting coronavirus antibodies in bat serum samples. The second antibody in the kit was replaced with horseradish peroxidase-conjugated protein-A (HRP-SPA) based on the characteristics of binding between Staphylococcus aureus protein A (SPA) and mammal IgG Fc fragment. The sera of 55 fulvous fruit bats (Rousettus dasymallus) were tested using the SPA-ELISA.</p><p><b>RESULTS</b>The test results of the positive and negative controls in the kit and the serum samples from convalescent ;patient were consistent with expectation. Coronavirus antibody was detected in 2 out of the 55 bat serum samples. Serum neutralization test confirmed the validity of the SPA-ELISA method.</p><p><b>CONCLUSION</b>This SPA-ELISA method is applicable for detecting coronavirus antibody in bat sera.</p>