Pattern of expression of the CREG gene and CREG protein in the mouse embryo

Background The cellular repressor of ElA-stimulated genes(CREG) is a secreted glycoprotein that inhibits cell proliferation and/or enhances differentiation.CREG is widely expressed in adult tissues such as the brain,heart, lungs,liver,intestines and kidneys in mice.We investigated the level of CREG expression during mouse embryogenesis and its distribution at 18.5 days post coitus(dpc).Methods Immunohistochemical staining with diaminobenzidine,western blotting and reverse transcription-polymerase chain reaction were used.Results CREG expression was rst detected in mouse embryos at 4.5 dpc.It was expressed at almost all stages up to 18.5 dpc.The level of CREG was found to increase gradually and was highest at 18.5 dpc.Western blotting showed that the CREG protein was expressed at higher levels in the brain,heart,intestines and kidneys than in the lungs and liver at 18.5 dpc.In 9.5 dpc embryos,CREG was expressed only in the endothelial cells of blood vessels,after the vascular lumen had formed.With advanced differentiation, vascular smooth muscle cells developed in the embryonic vascular structures;the expression of smooth muscle a-actin protein and CREG were positive and increased gradually in 10.5 dpc embryonic vessels.CREG expression in the embryonic blood vessels peaked at 15.5 dpc and was reduced slightly at 18.5 dpc.Conclusions These results indicate that CREG is expressed during mouse embryogenesis and might participate in the differentiation of these organs during embryogenesis.

Effects of BMP-2 Patterns on Bovine Chondrocytes Adhesion and Alignment

Striped bone morphogenetic protein-2 （BMP-2） patterns are created on polystyrene （PS） surfaces by microcontact printing （μCP） to investigate the influences of the protein patterns on bovine chondrocytes behaviors. Due to the excellent ability of BMP-2 to recruit cells and the limited ability of blank PS areas to bind ceils, bovine chondrocytes preferentially attach on the protein areas, leading to formation of cell patterns and elongated cell morphologies to some degree. The BMP-2 protein stripe can guide bovine chondrocytes adhesion and alignment. The pattern dimensions can significantly affect the cell adhesion and spread. The protein stripe width mainly controls the cell elongation and orientation while the pattern spacing mainly affects the cell spread towards neighboring stripes. Therefore, the cell morphology and distribution direction can be controlled by precisely designing the pattern shapes and sizes. We believe that the present study could fred applications for surface modification of biomaterials＇ surfaces to create the bioactive patterns to control chondrocytes adhesion, spreading and even cell function. It may be helpful for the development of novel biomaterials for cartilage repair.

Cloning, expression profiling and promoter functional analysis of bone morphogenetic protein 2 in the tongue sole(Cynoglossus semilaevis)

BMP2 plays crucial roles in vertebrate developmental process and acts as a bone inducer during osteogenesis. We present here the molecular cloning of bmp2 cDNA from the marine flatfish Cynoglossus semilaevis, and the analysis of bmp2 expression profiling and promoter function. The full length of bmp2 cDNA sequence is 2 048 bp,which encodes a protein of 422 amino acids. Tissue expression distribution of bmp2 was examined in 14 tissues of mature individuals by quantitative real time PCR（qRT-PCR）. The results revealed that bmp2 was expressed ubiquitously, and the highest expression level was detected in the spinal cord. Moreover, bmp2 expression levels were detected at 15 sampling time points of early developmental stages（egg, larva, juvenile and fingerling stages）.The highest expression level of bmp2 was observed at the gastrula stage, which was about ten times higher than those at the other three embryo stages. Whole-mount in situ hybridization showed that the bmp2 signal was strongly detected at the location of the crown-like larval fin, heart and liver, and slightly expressed in the notochord at one day post hatch（dph）; then the expression of bmp2 started to be concentrated in notochord at three dph. Subsequently, we characterized the 5′-flanking region of bmp2 by testing the promoter activity by Luciferase reporter assays. Positive regulatory region was detected at the location of –179 to ＋109. The predicted transcription factor binding sites（E-box binding factors, zinc finger transcription factor, etc.） in this region might participate in the transcriptional regulation of the bmp2 gene.

SDS-PAGE PROTEIN PATTERN AND ITS ANTIGENICITY ANALYSIS OF DIFFERENT ISOLATES OF SCHISTOSOMA JAPONICUM IN CHINA

Homogenates prepared from S. japonicum adult worms ofdifferent isolates from Anhui, Hubei, Guangxi, Yunnan andSichuan Provinces were analyzed by SDS-PAGE and enzymelinked immunoelectrotransfer blot (EITB) tested with rabbitanti-snails antibody. The results of SDS-PAGE indicated thatwith silver staining both male and female worms of Guangxiisolate showed some definite differences in their protein profile,namely, absence of one band between 50-75 kDa in maleworms and marked reduction in quantity of > 110 and 30 kDabands in female worms. There was no obvious differenceamong other isolates both in male and female worms. TheEITB patterns were similar in S. japonicum of Anhui andHubei, and it was also the case with isolates from Yunnan andSichuau, except that Yuunan female worms had a distinct band