Yeast surface display (YSD) is a technology that fuses the exogenous target protein gene sequence with a specific vector gene sequence, followed by introduction into yeast cells. Subsequently, the target protein is expressed and localized on the yeast cell surface by using the intracellular protein transport mechanism of yeast cells, whereas the most widely used YSD system is the α-agglutinin expression system. Yeast cells possess the eukaryotic post-translational modification mechanism, which helps the target protein fold correctly. This mechanism could be used to display various eukaryotic proteins, including antibodies, receptors, enzymes, and antigenic peptides. YSD has become a powerful protein engineering tool in biotechnology and biomedicine, and has been used to improve a broad range of protein properties including affinity, specificity, enzymatic function, and stability. This review summarized recent advances in the application of YSD technology from the aspects of library construction and screening, antibody engineering, protein engineering, enzyme engineering and vaccine development.
Saccharomyces cerevisiae/metabolism* ; Protein Engineering ; Biotechnology ; Antibodies/metabolism* ; Amino Acid Sequence

Mechanically sensitive ion channels play an important role in the cells' perception of external pressure and the growth of tissues and organs, and participate in the regulation of various cell functions. Among them, Piezo1 is a non-selective mechanically sensitive ion channel, which mainly exists in endothelial cells and vascular smooth muscle cells. The regulation of vascular function affects the progression of cardiovascular diseases such as atherosclerosis and hypertension. This article mainly reviews the role of Piezo1 in cardiovascular diseases, and provides new directions for the clinical intervention research of cardiovascular diseases.

Objective To study the effect of tissue plasminogen activator (t-PA) on p57NTR ,inflammatory reaction ,immune regulation and oxidative stress and its effect on intimal hyperplasia .Methods The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of ace-tylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxi-dative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the athero-sclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neu-ron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Results The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of acetylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxidative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the ath-erosclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neuron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Conclusion t-PA activates MMPs and feedback in-hibits p75NTR-NF-kappa B signaling pathway to increase vascular adventitia autonomic nerve reconstruction and delay the occur-rence and development of atherosclerosis disease .

A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly (155 m). Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46%and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk dis-tance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient’s heart functions.

Objective To investigate the correlation between the CD40 gene( - 1 C/T)single nucleotide polymorphism(SNP) and acute coronary syndromes(ACS), and the expression of CD40 on platelets. Method A total of 562 patients with ACS canfirmed by coronary angiography were divided into 3 groups according to the clinical characteristics, namely ACS patients( n = 210), stable angina(SA) patients( n = 189) and control group( n = 163).ACS was defined as ischemic chest pain at rest resulting in admission to hospital and > 50% stenosis in a major coronary artery with or without a rise in troponin Ⅰ. SA was defined as stable effort-related angina without change in angina pattern in 3 months. Patients with infection, tumor, or liver or kidney disease were excluded The gene polymorphism was measured by the polymerase chain reaction and restriction fragment length polymorphism(PCR-RFIP) and identiffed by sequencing. The expression of CD40 on platelets was detected by flow cytometry. The frequency, distribution of genotypes was compared using cross-tabulation and standard X~2 test. Result The CC genotype(31% ) and C allele of frequency(57.9%)of CD40 gene in ACS patients were significantly higher than those in SA(15.9%, 43.1% ) and control groups( 16.1%, 42.6% ). No significant difference of the genotypes or allele frequencies was found between SA and control group(X~2 = 0.053, P = 0.974;X~2 = 0.017, P = 0.897). 1he expression of CD40 on platelets in patients with C alleles carries was significandy higher than that of T allele carries in each group( P <0.0001). Conclusions CD40- 1C/T polymorphism was associated with ACS in Chinese Han nationallity.

Objective:To observe the effect of percutaneous tr ansluminal coronary angioplasty (PTCA) on coronary circulating tumor necrosis fa ctor-α (TNF-α) activity. Methods: Plasma TNF-α levls were measured with radioimmunoassay and bioactive assay respectively. Result s: Plasma TNF-α activity in femoral artery (AO) was significantly incr eased immediately after PTCA ［(15.86±3.75) U/ml vs （41.32±4.36） U/ml， P<0.01］, and plasma TNF-α activity in coronary sinus was remarkably incre ased immediately after PTCA　［(16.72±4.14） U/ml vs （65.61±6.25） U/ml, P<0.01］. There was no change in plasma TNF-α activity in AO 24 h after PT CA ［(18.32±5.12） U/ml vs （15.86±3.75） U/ml, P>0.05］. Conclu sion: The increase in plasma TNF-α activity after PTCA may be associat ed with the injury of coronary artery caused by PTCA, suggesting that TNF-α ma y be involved in the coronary occlusion and the development of coronary restenos is after PTCA.

Objective: To assess the effect of balloon angiopl asty on circulating endothelin (ET) and TNF-α levels and tissue endothelin in experimental atherosclerosis in rabbits. Methods: After 20 New Z ealand rabbits had a high cholesterol diet for at least 8 weeks, successful ball oon angioplasty was performed in rihgt iliac arteries in 18 rabbits. Circulatin g levels of ET and TNF-α were measured before as well as immediately and 24 h after balloon angioplasty. Tissue endothelin immunoreactivity in atherosclerotic iliac artery wall after balloon angioplasty was assessed by immunohistochemica l technique. Results: Plasma levels of ET and TNF-α were signi ficantly increased immediately after ballon angioplasty (76.40±13.58)pg/ml vs (92.67±11.38) pg/ml and (31.35±6.23) U/ml vs (56.26±7.37) U/ml, resp ectively (P<0.05) .There was no change in plasma ET and TNF-α levels 24 h after balloon angioplasty (77.13±12.87) pg/ml vs (76.40±13.58) pg/ml and (33.41±6.79) U/ml vs (31.35±6.23) U/ml， respectively (P>0.05). T issue endothelin immunoreactiuvity was markedly increased in right iliac artery wall after balloon angioplasty than that in opposite iliac artery wall. Conclusion: The increase of plasma ET, TNF-α levels and tissue ET-IR in iliac artery wall after balloon angioplasty may be associated with the injury of l ocal vascular intima, suggesting that ET and TNF-α may take part in the corona ry constriction and the development of coronary restenosis after percutaneous tr ansluminal coronary angioplasty.

Objective: To investigate the efficacy and safety of naftopidil on patients with mild-to-moderate essential hypertension. Methods: A prospective, open study was performed in patients with hyp ertension. Forty patients were administered naftopidil for 8 weeks. Results:BP decreased significantly 2 weeks after administration an d reached to its trough at week 4. The magnitudes were 2.28 kPa (17.1 mmHg) and 1.43 kPa (10.7 mmHg) for SBP and DBP, respectively. The effect lasted to the end of experiment. HR had no change.The total effective rate was 82.05%.There was n o significant change in liver and renal function and electrocardiograph. Conclusion: Naftopidil has a stable hypotensive effect and the complia nce is good.

AIM: To investigate the effects of platelet-derived growth factor BB (PDGF-BB) on vasoconstriction of the vascular vessels. METHODS: The contractile effects of PDGF-BB at different concentrations on the rat thoracic aortic rings and the effects of verapimil, indomerthacin, phentolamine and propranolol on the response of the thoracic aortic rings were observed by using the technique of vascular perfusion in vitro, and norepinephrine was used to severe as control. RESULTS: PDGF-BB showed a remarkable contractile effect on the thoracic aorta rings of rats in a dose-dependent manner, more potent than norepinephrine at the same molar concentration. Verapimil and propranolol inhibited the contractile effect of PDGF-BB on the rat thoracic rings, but the effect of indomerthacin and phentolamine on the vasoconstriction of PDGF-BB was not observed. CONCLUSION: PDGF-BB significantly contracts the thoracic aorta rings of rats in dose-dependent and non-endothelium-dependent manners. Verapimil and propranolol inhibits the contractile effect of PDGF-BB on the rat thoracic rings.

Objective: To investigate the effect of doxazosin on mild to moderate essential hypertension. Methods: A prospective, randomized, double blind study was carried out in 80 patients with hypertension. Forty patients were randomly given doxazosin (doxazosin group) or terazosin (control group) for 8 weeks. The others 40 were given doxazosin (open group), 10 of them for 6 months. Results: BP decreased significantly after administration of both doxazosin and terazosin, and reached its peak at week 4. The effect continued at the end of experiment. HR was slightly increased. In open group, the results was similar and the total effective rate was 90.0%. There were no significant changes in liver and renal functions and electrocardiography. The incidence of adverse effects like dizziness, palpitation and somnolence in doxazosin group was 30.0% . No significant difference between doxazosin and control group was found. Conclusion: Doxazosin has stable hypotensive effect and the patients compliance is good.