Multipotential differentiation and potential applications of adipose-derived stem cells / 生物工程学报

Adipose tissue contains a population of multipotent cells called adipose-derived stem cells (ADSCs). With the similar properties of marrow-derived mesenchymal stem cells, ADSCs have the ability to differentiate differentiate towards adipogenic, osteogenic, chondrogenic, myogenic, endothelial, hematopoietic, hepatic, islet, and neurogenic cell lineages. As adipose tissue in harvested in large amounts with minimal morbidity, it can be widely used in tissue engineering, organ repair and gene therapy. This paper focused on the plasticity of ADSCs and reviewed the new advances of this field. Finally, the problems and prospect for application was also discussed.

The targeting study of human serum albumin gene / 生物工程学报

To generate transgenic porcine which expresses human serum albumin (HSA), the HSA gene targeting vector was constructed with HSA cDNA as the gene of interestand partial porcine serum albumin (PSA) gene as homologous arms which respectively were 7.2 kb 5' regulation sequence and 2.8 kb genomic sequence from the first intron to the fourth intron. The resistant gene neo was inserted into intron 1 and tk was ligated to the 3' end of the construct. Linearized targeting construct DNA was introduced into the fibroblast cells obtained from porcine fetus by electroporation. The positive-negative selection was performed and survival clones were screened by PCR and Southern blot. Three colonies with correct homologous recombination were obtained. Our results set a good basis for the establishment of transgenic porcine by gene target and nuclear transfer methods.

The synthesis and function analysis of omega-3 fatty acid desaturase gene from Caenorhabditis briggssae / 生物工程学报

Omega-3 polyunsaturated fatty acids (PUFAs) have been broadly investigated and shown to exert many preventive and therapeutic actions besides their important role in maintenances human health and normal development. In mammals, the level of omega-3 PUFAs is relatively too low compared with omega-6 PUFAs, which metabolically and functionally distinct from omega-3 PUFAs and often have important opposing physiological functions. Either the inefficiency of omega-3 PUFAs or the excess of omega-6 PUFAs will cause many healthy problems. So methods have been sought to increase the amount of omega-3 PUFAs and to improve the omega-6/omega-3 ratio in body. In this study, the sFat-1 gene, which putatively encodes a omega-3 fatty acid desaturase, was chemically synthesized according to the sequence from Caenorhabditis briggssae (with codon usage modified), and constructed into a mammal expression vector pcDNA3. 1-sFat1-EGFP. This vector was introduced into CHO cells by lipid-mediated transfection, and it's expression quickly and effectively elevated the cellular omega-3 PUFAs (from 18-carbon to 22-carbon) contents and dramatically improved the ratio of omega-6/omega-3 PUFAs. Cellular lipids extracts from stably selected cells were analyzed with GC-MS and the results showed that amount of total omega-6 PUFAs dropped from 48.97% (in GFP cells)to 35.29% (in sFat-1 cells), whereas the amount of total omega-3 PUFAs increased from 7.86% to 24.02%, respectively. The omega-6/omega-3 ratio also dropped from 6.23 to 1.47. These data demonstrates the Caenorhabditis briggssae omega-3 Fatty Acid Desaturase gene, sFat-1, was synthesized successfully and can produce omega-3 PUFAs by using the corresponding omega-6 PUFAs as substrates, which shows its potential for use in the production of omega-3 PUFAs in transgenic animals.

Advance of Ser/Thr Kinase Pololike Kinase 1 (Plk1) Research / 中国生物工程杂志

Pololike kinase 1(Plk1)contain an Nterminal Ser/Thr kinase catalytic domain and a Cterminal region that contains two poloboxes.As a key regulator of multiple steps during cell cycle across eukaryotic species,many proteins interact with Plk1.Plk1 is highly expressed in malignant cells and serves as a negative prognostic marker in specific human cancer types.Plk1 is a potential target for cancer therapy.Some novel smallmolecule inhibitors of pololike kinase 1 provide novel opportunities for cancerdrug discovery,such as BI 2536,ON01910.

The progress of expressing vector for mammary gland bioreactor / 生物工程学报

The mammary gland bioreactor has great commercial value, but the examples for high level expression of foreign gene were so few that the most examples were not suitable for commercial program. The key resolution for improving the expression level of foreign gene is the construction of expression vector for mammary gland bioreactor. Nearly, many new ideas and new methods about the construction of expression vector were presented, the article summarized them.