Objective To establish and assess a CHO (Chinese Hamster Ovary) cell line that stably expressed the human TSH receptor. Methods The gene of human TSH receptor was amplified by PCR from the recombinant plasmid that had been constructed previously,and then the target gene was linked to linearized vector GV208. Afterwards, with the reconstructed vector and helper vectors, the target gene was packaged into the lentivirus. The recombinant lentivirus infected the CHO cells and integrated the gene into the chromatin. The established CHO cell line was isolated and cultured and its function was assessed.Results The result of gene test identified the correct sequence of DNA of the transformant. The expression of mRNA in CHO cells transfected with the human TSHR was obviously higher than the cells in control or blank group. Within the range of certain density,the more bovine TSH was used to stimulate the established CHO,the more cAMP would be produced. When stimulated with serum of patients of Graves' disease, the cell line also significantly produced more cAMP. Conclusion The established CHO cell line transfected with the human TSHR can stably express the human TSH receptor and response to the stimulation of ligand of TSH receptor.

Objective:Dipeptidyl peptidase 4 (DPP4) is an incretin lyase, while DPP4 inhibitors have been used clinically as hypoglycemic drugs. Serum DPP4 is related to metabolic diseases such as cardiovascular disease and obesity, and lipid metabolic disorder is an important part of metabolic syndrome. This study was designed to explore the relationship between DPP4 and lipid metabolic disorder.Methods:There were 3644 participants from Chengqiao Town, Chongming District, Shanghai. All of the subjects recruited were residents between 40-70 years old, who have not diagnosed as diabetes mellitus (DM) and who have never used any lipid-lowering drugs. Glucose, insulin, lipid level, DPP4 activity and liver enzymes in serum of all participants were tested. In addition, height, weight and blood pressure were also recorded.Results:Participants were divided into four groups (Q1-Q4) according to the quartile value of serum DPP4 activities. Along with the increase of serum DPP4 activity, triglyceride, total cholesterol, and blood glucose levels increased, and triglyceride increased from (1.23 ± 0.70) mmol/L to (2.31 ± 1.89) mmol/L. Compared with cholesterol levels, the triglyceride was more closely related to DPP4 activity [the correlation coefficients of triglyceride, total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) were 0.424, 0.281, 0.142, and 0.027, respectively]. After adjusting for confounding factors (age, gender, BMI), the result was similar. With the increase of DPP4 enzyme activity, the Q4 group had a higher risk of developing hyperglyceridemia ( OR=5.25) than the Q1 group, and the result was almost unchanged after adjusting for confounding factors and blood glucose levels ( OR=4.90). Conclusion:Serum DPP4 activity is independently related to blood lipid levels, and is particularly closely related to blood TG levels.