2.Efficient Secretion of Recombinant PEX in COS7 Cells Directed by MMP-9 Signal Peptide
China Biotechnology 2006;0(05):-
With the rapidly development of the biotechnology industry,large quantities of recombinant proteins are needed for specific therapeutic and diagnostic applications.Bacterial cells are most often used for the production of recombinant proteins.However,recombinant proteins expressed in the cytoplasm of bacteria are often misfolded as insoluble inclusion bodies and therefore inactive.To circumvent this problem,several eukaryotic expression systems have also been developed over the years,ranging from yeast to mammalian cell-based technologies.For many mammalian proteins,especially those secreted and modified posttranslationally,a more compatible expression system is highly desirable because proper folding or modification can only be provided with closely related cells,i.e.,mammalian cells.Large scale transient transfection of mammalian cells is a recent and powerful technology for the fast production of milligram amounts of recombinant proteins.Transient expression by means of extrachromosomal replication in COS cells is frequently used to check the functional integrity of genes/plasmids and to produce small quantities of cell supernatants containing the protein of interest.As it is allowed for easy and efficient purification,many recombinant proteins used for therapeutic and structural studies are naturally secreted or engineered to be secreted.The use of a proper signal peptide is one of the major determinants for the efficient secretion of heterologous proteins from mammalian cells.The noncatalytic C-terminal hemopexin-like domain of MMP-2,PEX,can block angiogenesis and tumor growth in vivo.Large quantities of biochemically active recombinant PEX are required for the study of their functions and biochemical properties,as well as for their industrial applications.For this purpose,the rat growth hormone,mouse IgG? chain and MMP-9 signal peptides were used for expression of PEX in COS7 cells,and their secretion efficiencies were compared by Western blotting and ELISA.Western-blotting of PEX protein from culture media,resulted in detection of proteins with the predicted molecular mass,which indicate that all of the signal sequences could direct PEX secretion successfully.The MMP-9 signal peptide seems to be superior to the signal peptides from IgG and rGH both in terms of extracellular yield and in terms of secretion efficiency.Thus,expression of pM9PEX construct resulted in higher yields of extracellular PEX and the majority of the produced PEX was secreted and not trapped intracellularly.To examine whether the observed difference in secretion yields is promoted at the transcriptional level,a RT-PCR analysis was performed at 6 h after transfection.The presence of mRNA transcripts of PEX was observed in all the DNA constructs.Moreover,semiquantitative reverse transcription(RT-PCR)results show that there were no significant differences in the expression levels of PEX among the constructs at 6 h after transfection.Though there was no difference in the expression levels of PEX at an early time point after transfection,the presence of an ER-targeting signal peptide sequence in the expression vector affected the trafficking of expressed proteins in the cells.Hence,the described difference in exported yields is probably promoted at the secretion level,rather than at the transcriptional level.Chick chorioallantoic membrane(CAM)bioassay show that the PEX protein purified from cell culture had biological activity to inhibit the angiogenesis.The MMP-9's signal peptide is used for the first time as leader sequence for secretion of foreign proteins.The results revealed that higher amounts of secreted PEX were obtained when vectors containing MMP-9 signal peptide were used and it is also indicated that MMP-9 signal sequence could be effective on promoting the secretion of other heterologous proteins in eukaryotic cells.
4.Evaluation of the application effect of evidence- based nursing model in hemostasis by compression in patients after renal biopsy
Zhi LIN ; Chaohui ZHANG ; Yanyan ZHAO ; Lian LIN ; Bining LIANG
Chinese Journal of Practical Nursing 2012;28(19):13-15
Objective To evaluate the application effect of evidence-based care model in hemostasis by compression in patients after renal biopsy.Methods 80 patients undergoing renal biopey from December 2006 to December 2009 in our hospital were chosen as the research object.They were randomly divided into the control group and the observation group with 40 patients in each group.The control group was given routine nursing,and the observation group was treated with evidence-based care model for nusing.The re-bleeding rates,satisfaction degree and the SAS,SDS score,mastering degree of related knowledge,treatment compliance for the two groups before and after nursing were compared.Results The ineidence rate of bleeding in the observation group was higher than the control group,satisfaction degree was higher,and the SAS,SDS score,related knowledge,treatment compliance were all better than the control group,there were significant differences.Conclusions The effect of evidence-based care model in hemostasis by compression after renal biopsy is better.It can significantly reduce the incidence of adverse circumstances and improve the negative emotional state of patients.
5.Effect of telmisartan on the levels of serum adiponectin and C-reactive protein in elderly hypertensive patients with unstable angina pectoris
Ze-Peng LIN ; Guang-Lin JIN ; Zhi-Wei ZHANG ;
Chinese Journal of Geriatrics 2003;0(08):-
ObjectiveTo determine the effect of telmisartan on the levels of serum adiponectin and C-reactive protein(hs-CRP)in elderly hypertensive patients with unstable angina pectoris. MethodsOne hundred and twenty elderly hypertensive patients with unstable angina pectoris were randomized into two groups, telmisartan(n=60) and perindopril(n=60) groups.The levels of hs-CRP,adiponectin, lipid factors, fasting plasma glucose (FPG), insulin and insulin sensitivity index (ISI) were measured before and 6 months after telmisartan and perindopril treatments.ResultsAt the end of 6 months, the telmisartan group showed more reduction in plasma levels of hs-CRP and more increment in serum adiponectin concentrations and ISI significantly. The frequency of cardiovascular events was significantly lower in the patients of the telmisartan group than that of the perindopril group.ConclusionsCompared with perindopril, telmisartan significantly decreases plasma levels of hs-CRP and increases serum adiponectin concentrations in elderly hypertensive patients with unstable angina pectoris. It also significantly decreases the frequency of cardiovascular events in these patients.
7.One case report of systemic onset juvenile idiopathic arthritis with atlantoaxial subluxation as the initial manifesta-tion
Zhi LIN ; Zhihui LI ; Yi ZHANG ; Liang ZHANG ; Mai XUN
Journal of Clinical Pediatrics 2016;(2):139-141
Objective To explore the clinical features of systemic onset of juvenile idiopathic arthritis (SoJIA) with atlantoaxial subluxation as the initial manifestation. Methods The clinical data from one SoJIA patient with atlantoaxial subluxation as the initial manifestation were retrospectively analyzed. Results A 9-year-old boy presented the head and neck movement disorder as the ifrst symptom, developed fever on the third day, then rapidly progressed on 23rd day, with a sharp decline in red blood cell, platelet, and hemoglobin, blood coagulation dysfunction, and a large number of bilateral pulmonary exudation. Ultrasonography showed excess lfuid in abdomen, chest, and pericardium. According to the 2001 version of the revised International College of Rheumatology standard, the diagnosis of SoJIA combined macrophage activation syndrome was conifrmed. Then treated with hemoperfusion, ifltration, and methylprednisolone combined with cyclosporine A, the disease was in remission. Conclusion For children with spontaneous atlantoaxial subluxation accompanied by the systemic symptoms, with no obvious skeletal deformity or acute inlfammation etc., should be alerted to the consideration of systemic juvenile idiopathic arthritis.
8.Role of JAK/STAT signaling pathway in high glucose-induced damage in human umbilical vein endothelial cells
Jingqiu LIAO ; Jiaqiong LIN ; Weijie ZHANG ; Lin XU ; Ximei ZHI ; Kai LIN ; Wen WU
Chinese Journal of Pathophysiology 2016;32(3):392-397
AIM: To investigate whether Janus kinase/signal transducer and activator of transcription ( JAK/STAT) signaling pathway mediates high glucose-induced damage in human umbilical vein endothelial cells ( HUVECs ) . METHODS:The cell viability was examined by CCK-8 assay.The expression levels of JAK2, STAT3, caspase-9 and en-dothelial nitric oxide synthase ( eNOS) were detected by Western blot .The intracellular levels of reactive oxygen species ( ROS) were tested by DCFH-DA staining followed by photofluorography .Mitochondrial membrane potential ( MMP) was measured by rhodamine 123 staining followed by photofluorography .RESULTS:Treatment of HUVECs with high glucose (40 mmol/L glucose) for 6~12 h enhanced the protein level of phosphorylated JAK 2, peaking at 9 h.Treatment of the cells with high glucose for 6~12 h also increased the protein level of p-STAT3 with the peak value at 12 h.Pretreatment with the inhibitor of JAK/STAT pathway AG490 for 1 h before exposure of the HUVECs to high glucose significantly inhibi-ted the high glucose -induced injury , as evidenced by an increase in the cell viability , decreases in the expression of caspase-9 and the intracellular ROS production , and increases in MMP and the expression of eNOS .CONCLUSION:JAK/STAT signaling pathway is involved in the high glucose-induced damage in HUVECs .
9.Progress of plasma exchange in treatment of nervous system diseases
Lin YUAN ; Zhi CHEN ; Guiju ZHANG ; Ying SHEN
International Journal of Pediatrics 2010;37(1):95-97
Plasma exchange is a commonly used blood purification method, h includes plasma exchange,double filtration plasmapheresis and immunoadsorption.Many nervous system diseases have the antibody. Guillian-Barre syndrome is caused by antibodies of the nervous system demyelinafing disease; Myasthenia grads is caused by the acetylcholinc receptor antibodies. CIDP also has autoimmune-mediated mechanism. Plasma exchange can be apphed effectively to remove antibodies, and to quickly improve the patient' s clinical symptoms and shorten the course of disease.