ABSTRACT
<p><b>OBJECTIVE</b>To study the biological properties of human dental pulp cells (HDPC) by cloning and analysis of genes differentially expressed in HDPC in comparison with human gingival fibroblasts (HGF).</p><p><b>METHODS</b>HDPC and HGF were cultured and identified by immunocytochemistry. HPDC and HGF subtractive cDNA library was established by PCR-based modified subtractive hybridization, genes differentially expressed by HPDC were cloned, sequenced and compared to find homogeneous sequence in GenBank by BLAST.</p><p><b>RESULTS</b>Cloning and sequencing analysis indicate 12 genes differentially expressed were obtained, in which two were unknown genes. Among the 10 known genes, 4 were related to signal transduction, 2 were related to trans-membrane transportation (both cell membrane and nuclear membrane), and 2 were related to RNA splicing mechanisms.</p><p><b>CONCLUSION</b>The biological properties of HPDC are determined by the differential expression of some genes and the growth and differentiation of HPDC are associated to the dynamic protein synthesis and secretion activities of the cell.</p>
Subject(s)
Humans , Cloning, Molecular , Cloning, Organism , Dental Pulp , Fibroblasts , Gene Library , Gingiva , Polymerase Chain ReactionABSTRACT
Optimization of cultivation condition of recombinant E. coli DH5 alpha/pDH-B2m and the condition suitable for expression of recombinant mature peptide of human bone morphogenetic protein-2 was carried out in 500 mL shaking flasks and then transferred to NBS Bioflo IV, a 20 L DO feed-back fed-batch culture system, to obtain rhBMP-2. The results indicate that keeping dissolved oxygen at 40% and controlling nutrient feeding rate with DO feed back strategy can obtain theoretically 3.59 g recombinant mature peptide of hBMP-2 per liter of broth, the final cell density OD600 reaches 57(22.8 g dry cell weight/L), and the expression of rhBMP-2 amounts to 30% of the total protein in E. coli.