IMMUNOHISTOCHEMICAL DEMONSTRATION OF CCAAT/ENHANCER BINDING PROTEIN (C/EBP) IN HUMAN LIVER TISSUES OF VARIOUS ORIGIN

C / EBP is a sequence-specific DNA-binding protein. In order to indentify its distribution and localization, immunohistochemical technique (ABC method) was done using anti-C / EBP polypeptide antibodies 1103#, 425# in liver specimens from 20 normal adults, 5 neonates, 6 patients with hepatitis, 25 with liver cirrhosis, 80 with hepatocellular carcinoma (40 cases were associated with surrounding nontumorous tissues) and 26 patients with cholangiocarcinoma (15 cases were associated with surrounding nontumorous tissues). The results showed that C / EBP was diffusely distributed in nuclei and cytoplasm of differentiated liver cells and very low or undetectable in liver cancer cells. The manifestation of C / EBP correlated with degree of differentiation of tumour cells, and was obviously weaker than that in surrounding nontumorous tussues. C / EBP positive staining has also been found in regenerating epithelial cells of bile ductules. The results suggested that C / EBP should play an important role in establishing and maintaining the differentiation of liver cells.

Construction and characterization of a cDNA library from human liver tissue with chronic hepatitis B

Objective: To construct a cDNA library from human liver tissue with chronic hepatitis B and check its quality for investigating the expression level of liver tissue infected by hepatitis B virus. This will then be used to find the relevant genes and interesting proteins associated with the development of hepatitis B. Methods: The total RNA from liver tissue with chronic hepa- titis B was extracted and the mRNA was purified using TRIZOL method. Switching mechanism at 5′ end of the RNA transcript (SMART) technique and CDS III/3′ primer were used for first-strand cDNA synthesis. Long distance polymerase chain reaction (LD PCR) was then used to synthesize the double-strand cDNA that was then digested by Sfi I and fractionated by CHROMA SPIN-400 column. The longer than 0.4 kb cDNAs were collected and ligated to λTriplEx2 vector. Then λ phage packaging reaction and library amplification were performed. The qualities of both unamplified and amplified cDNA libraries were strictly checked by conventional titer determination. Fourteen plaques were randomly picked and tested using PCR with universal primers derived from the sequence flanking the vector. Results: The titers of unamplifed and amplified libraries were 1.94×106 pfu/ml and 1.49×109 pfu/ml respectively. The percentages of recombinants from both libraries were 98.15% in unamplified library and 98.76% in amplified library. The lengths of the inserts were 1.23 kb in average, 1?2 kb in 64.29%, and 0.5?1.0 kb in 35.71%. Conclusion: A high quality cDNA library from human liver tissue with chronic hepatitis B was successfully constructed.

Con A affinity glycoproteomics of normal human liver tissue

In order to establish the novel high throughput, high efficiency and low cost technological platform for the research of N-glycoproteomics, to resolve the significance of characteristic expression profile of glycoprotein and to find the proteins with biological functional importance, the glycoproteins with high-mannose core and the two antennary types were purified and enriched by the Con A affinity chromatography. Con A affinity protein expression profiles of normal human liver tissue were gener- ated by using SDS-PAGE, two-dimensional electrophoresis (2-DE) followed by fast fluorescence stain- ing based on multiplexed proteomics (MP) technology. 301 visible protein spots on the gel were de- tected and 85 of glycoproteins were further successfully identified via peptide mass fingerprinting (PMF) by a matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF- MS/MS) and annotated to IPI databases. Identified glycoproteins definitely take part in the regulation of cell cycle and metabolic processes. The glycosylation sites were predicted with NetNGlyc 1.0 and NetOGlyc 3.1 software, meanwhile they were classified according to the geneontology methods. The construction of Con A affinity glycoprotein database of normal human liver tissue would contribute to the subsequent research.