Purification and Trypsin Inhibitor Activity of a Sporamin B from Sweet Potato (Ipomoea batatas Lam. 55-2)

Sporamin is a soluble protein in sweet potato, and falls into two distinct homology groups, subfamilies A and B. In this research, a sporamin B was purified and its amino acid sequences, trypsin inhibitor activity （Ti activity） were analyzed. This sporamin B was isolated from sweet potato tubers [Ipomoea batatas （L.） Lam cv. 55-2] through extraction of the water-soluble fraction, dialysis, ultrafiltration and ion-exchange chromatography. Homology determined by polyacrylamide gel electrophoresis showed that mainly one bond appeared in gel after being reduced by SDS （sodium dodecyl sulfate）, or by SDS and 2-mercaptoethanol, or in native situation. By comparing the data of the polypeptide mass Matrix-assisted laser desorption/ionization time-of-flight （MALDI-TOF） mass spectrometry with those of the mass of the theoretical amino acid sequences from NCBI protein database, it was revealed that it was Q40091｜Q40091_IPOBA, sweet potato sporamin B - Ipomoea Batatas （sweet potato） （Batate）. The sequence coverage was 70.6%. N-terminal sequence was SETPV （Ser-Glu-Thr-Pro-Val）. There is a linear relationship between trypsin inhibitor activity （Ti activity） and amounts of this sporamin B （3-18 μg mL-1）. The equation of linear regression was y = 2.5809x ＋ 17.049 （r2 = 0.9966）. There was a curvilinear relationship between Ti activity and amounts of this sporamin B （21-150 μg mL-1）. The equation of curvilinear regression is y = 14.417ln（x） ＋ 23.26 （r2 = 0.9924）. The concentration of sporamin B with Ti activity after heating at 40°C may induce part denature of this sporamin B, and there was no statistic difference after heating at 40, 50, 60°C for 20 min. Heat treatment at more than 90°C leads to a dramatic decrease of trypsin inhibitor efficiency. The results suggested that Q40091｜Q40091_IPOBA was the major sporamin B in sweet potato tubers [Ipomoea Batatas （L.） Lam cv. 55-2], which had strong Ti activity, and was stable to both thermal and DTT （DL-dithiothreitol） relatively.

同源Activator－Inhibitor模型的整体解

本文证明了同源Ａｃｔｉｖａｔｏｒ—Ｉｎｈｉｂｉｔｏｒ模型：ｕｔ＝ｄ△ｕ─μμ＋μｐ／ｖｑ＋σ整体解的存在性．

Expression of serine protease SNC19/matriptase and its inhibitor hepatocyte growth factor activator inhibitor type 1 in normal and malignant tissues of gastrointestinal tract

AIM： To provide the expression profile of serine protease SNC19/matriptase and its inhibitor hepatocyte growth factor activator inhibitor type 1 （HAI-1） in normal and malignant tissues of gastrointestinal tract at mRNA level for further study on their correlations with tumor progression and metastasis. METHODS： Total RNAs were prepared from 37 samples of colorectal cancer tissues, 40 samples of gastric cancer tissues, and their adjacent normal tissues. The expression of SNC19/matriptase and HAI-1 in these samples was detected by real-time fluorescent quantitative PCR using glyceraldehyde-3-phosphate dehydrogenase as internal standard, and the clinical significance for the correlation with clinicopathological parameters was evaluated. RESULTS： In gastric cancer tissues the expression of HAI-1 and SNC19/matriptase was significantly lower than that in the corresponding adjacent normal tissues （Z = -3.280, P= 0.006; Z= -4.651, P= 0.000）. HAI-1：SNC19/matriptase ratio showed no difference between normal and malignant tissues （P〉0.05）. Analysis of clinicopathological parameters showed decreased expression of HAI-1 and HAI-1：SNC19/ matriptase ratio associated with stage Ⅲ/Ⅳ gastric tumors as compared to stage Ⅰ/Ⅱ ones （Z= -2.140, P= 0.031; Z = -2.155, P = 0.031）, and with lymph node-positive gastric cancer tissues as compared to lymph node-negative ones （Z = -2.081, P = 0.036; Z= -2.686, P = 0.006）. The expression of SNC19/matriptase had no relationship with stages and lymph node metastasis （P〉0.05）. The expression of HAI-1 and HAI-1：SNC19/matriptase ratio increased in well-differentiated gastric cancer tissues, but there was no statistical significance （P〉0.05）. The difference of SNC19/matriptase expression was not significant in gastric cancer tissues of different histological differentiation status （P〉0.05）. In colorectal cancer tissues, the expression of HAI-1 and SNC19/matriptase was also markedly lower than that in their adjacent normal tissues （Z= -3.100, P = 0.002; Z= -2.731, P = 0.006）, whereas HAI-1：SNC19/matriptase ratio showed no difference. Decreased expression of HAI-1 was associated with increased invasive depth and lymph node metastasis, but there was no statistical significance （P〉0.05）. The difference of SNC19/matriptase expression and HAI-1： SNC19/matriptase ratio was not significant in different stages and different lymph node metastasis status （P〉0.05）. The expression of SNC19/matriptase, HAI-1 or HAI-1： SNC19/matriptase ratio showed no difference in colorectal cancer tissues of different histological differentiation status （P〉0.05）. CONCLUSION： The expressions of SNC19/matriptase and its inhibitor HAI-1 are decreased in gastrointestinal cancer tissues compared to their normal counterparts, and the decreased expression of HAI-1 may correlate with invasion and lymph node metastasis. The possible mechanisms involved need to be further investigated.

Overexpression of hepatic plasminogen activator inhibitor type 1 mRNA in rabbits with fatty liver

INTRODUCTIONPlasminogen activator inhibitor type 1 ( PAI-I ), an approximately Mr 50000 glycoprotein, is the major physiological inhibitor of plasminogen activators. It is not only the priming factor for atherosclerosis and coronary thrombosis[1-3] , but also participates in the genesis of chronic hepatitis and liver fibrosis[4-11] . However, there has been no available report yet about the research of hepatic PAl-1 gene expression in hyperlipidemia and fatty liver. The present study aimed to explore the change of hepatic PAl-1 mRNA and its plasma activity by means of animal model.

INVESTIGATION OF THROMBOMODULIN AND PLASMINOGEN ACTIVATOR INHIBITOR TYPE-I IN PREGNANCY INDUCED HYPERTENSION AND ITS CLINICAL SIGNIFICANCE

Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH,26 moderate PIH,22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA,PAI- I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method. Results. Circulating levels of TM, PAI- I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups. Conclusion. TM and PAI- I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.

THE INCREASE IN PLASMINOGEN ACTIVATOR INHIBITOR TYPE-1 EXPRESSION BY STIMULATION OF ACTIVATORS FOR PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS IN HUMAN ENDOTHELIAL CELLS

Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the possi-ble mechanism.Methods.Human umbilical vein endothelial ce lls(HUVECs )were obtained from normal fetus,and cul-tured conventionally.Then the HUVECs were exposed to test agents(linolenic acid,linoleic acid,oleic acid,stearic acid and prostaglandin J 2 respectively)in varying concentrations with fresh media.RT -PCR and ELISA were applied to determine the expression of PPARs and PAI-1in HUVECs.Results.PPARα,PPARδand PPARγmRNA were detected by using RT-PCR in HUVECs.Treatment of HUVECs with PPARαand PPARγactivators---linolenic acid,linoleic acid,oleic acid and prostaglandin J 2 respectively,but not with stearic a cid could augment PAI-I mRNA expression and protein secretion in a concentration-dependent manner.However,the mRNA expressions of 3subclasses of PPAR with their activators in HUVECs were not changed compared w ith controls.Conclusion.HUVECs express PPARs.PPARs activators may increase PAI-1expression in ECs,but the underlying mechanism remains uncle ar.Although PPARs expression was not enhanced after stimulated by their activators in ECs,the role of functionally active PPARs in regulating PA I-1expression in ECs needs to be further investigated by using transient gen e transfection assay.

Roles of tissue plasminogen activator and its inhibitor in proliferative diabetic retinopathy

AIMTo investigate the role of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in proliferative diabetic retinopathy (PDR) and to discuss the correlations among t-PA, PAI and vascular endothelial growth factor (VEGF) expressions.

Expression and prognostic value of plasminogen activator inhibitor type 1 in node-negative breast cancer

Objective： To investigate the expressions of plasminogen activator inhibitor type 1 （PAl-1）, C-erbB-2, VEGF and Ki-67 by immunohistostaining and then to evaluate the prognostic value of PAl-1 in node-negative breast cancer. Methods： The study included a retrospective series of 62 female patients with axillary lymph node-negative breast cancer. Expressions of PAl-1, C-erbB-2, VEGF and Ki-67 were determined by immunohistostaining on formalin-fixed paraffin-embedded tissue sections from these patients after a median follow-up of 69 months （range 22-117 months）. Correlations with well known clinicopathologic factors were assessed and multivariate survival analyses were performed. Results： High PAl-1 level was positively associated with high histologic grade of the tumors. Disease-free survival （DFS） was significantly shorter for the patients with moderate to intensive expression of PAl-1 than for those with negative （χ^2 = 25.46, P 〈 0.001; χ^2 = 23.07, P 〈 0.001） to mild expression （χ^2 = 19.75, P 〈 0.001; χ^2 = 17.40, P 〈 0.001）. Although on univariate analysis of the prognostic factors, tumor size, location of primary tumor and age as well as expressions of PAl-1, VEGF and Ki-67 were all significantly prognostic factors for DFS （P 〈 0.05）, PAl-1 was the only independent prognostic factor on multivariate analysis （P 〈 0.0001; hazard ratio [HR], 4.041; 95% confidence interval [CI], 1.928-8.468）. Conclusion： These results of the current study indicate that intermediate or high expression of PAl-1 represents a strong and independent unfavorable prognostic factor for the development of recurrence or metastases in axillary node-negative breast cancer.

Performance of water-based foams affected by chemical inhibitors to retard spontaneous combustion of coal

The micelle generating process of the sodium dodecyl sulfate(SDS) solution with the addition of chemical inhibitors was elucidated using phase separation model, and the descending order of the capacity for the selected chemical inhibitors to reduce the critical micelle concentrations of the solution are Mg Cl_2, Ca Cl_2,NH_4HCO_3 and NH_4Cl. The data to quantitatively describe the foam decay process, including foaming ratio,foam life and decay behaviors, was obtained by pressure measuring system. The results indicate that chemical inhibitors can improve the solution foamability. The capacity of the inhibitors to enhance the solution foamability is sorted as NH_4 Cl, NH_4HCO_3, Mg Cl2 and Ca Cl_2 which can distinctly improve the foam stability as well. The capacity of the inhibitors to enhance the SDS foam stability can be arranged as Mg Cl_2, NH_4 Cl, NH_4HCO_3 and Ca Cl_2. It is observed that the gravity drainage plays a leading role in the increase of proportion of diffusion drainage. The oxidation dynamic parameters of the coal samples treated by inhibition foams were investigated using thermal analysis technique, and their synergistic effects on inhibiting coal oxidation were explored.

CRYSTAL STRUCTURE OF THE COMPLEX OF MUNG BEAN TRYPSIN INHIBITOR LYSINE ACTIVE FRAGMENT WITH BOVINE TRYPSIN AT 1.8 A RESOLUTION

The structure of the complex of mung bean trypsin inhibitor lysine active fragment with bovine trypsin has been determined at a resolution of 1.8 A by A-ray crystallographic analysis and the complex model refined by restrained least-squares minimization with the data between 10 and 1.8 resolution.The current conventional R factor is 17.3%,and the model con- tains 1648 protein atoms,219 inhibitor atoms and 126 water molecules.The most prominent feature of the inhibitor fragment is that it does not contain any alpha-helices.Most of the chain fold in an irregular fashion.The seven residues of the binding segment of the inhibitor lysine active frag- ment are in specific contact with bovine trypsin.The binding interaction and geometry around the reactive site are similar to that observed in other studies of trypsin-inhibitor complexes.

Comment on roles of tissue plasminogen activator and its inhibitor in proliferative diabetic retinopathy

Dear Sir,We congratulate Wu et al for their study entitled＂Roles of tissue plasminogen activator and its inhibitor in proliferative diabetic retinopathy＂.The authors investigated the effects of tissue plasminogen activator（t-PA）and plasminogen activator inhibitor（PAI）in the pathogenesis of proliferative diabetic retinopathy（PDR）.The authors reported that t-PA and PAI are involved in the pathogenesis of PDR.

EFFECTS OF TGF-β_1 ON THE EXPRESSION OF PLASMINOGEN ACTIVATOR INHIBITOR TYPE 1 IN CULTURED HUMAN RENAL INTERSTITIAL FIBROBLASTS

Objective To investigate the effects of transforming growth factor-β1 (TGF-β1 ) on the expression of plasminogen activator inhibitor type 1 (PAI-1 ) mRNA in renal interstitial fibrosis in vitro. Methods Human renal interstitial fibroblasts were isolated and cultured in vitro. The cells wers stimulated by TGF-β1 with different concentration (0 to 10ng/ml ) at different time (0 to 48h). The expression of PAI-1 mRNA was assayed by RT-PCR. Results TGF-β1, had dose-dependent and time-dependent effects on the expression of PAI-1 mRNA in renal interstitial fibroblasts. Conclusion TGF-β1 may partic- ipate in renal fibrosis with inducing the expression of PAI-1 mRNA in renal fibroblasts and affecting the synthesis and degradation of extracellular matrix (ECM).

Cardiac-targeted PIASy gene silencing mediates deSUMOylation of caveolin-3 and prevents ischemia/reperfusion-induced Na_(v)1.5 downregulation and ventricular arrhythmias

Background:Abnormal myocardial voltage-gated sodium channel 1.5(Nav1.5)expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion(I/R).Protein inhibitor of activated STAT Y(PIASy)-mediated caveolin-3(Cav-3)small ubiquitin-related modifier(SUMO)modification affects Cav-3 binding to the Nav1.5.PIASy activity is increased after myocardial I/R,but it is unclear whether this is attributable to plasma membrane Nav1.5 downregulation and ventricular arrhythmias.Methods:Using recombinant adeno-associated virus subtype 9(AAV9),rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA(shRNA).After two weeks,rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias.Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements.Results:PIASy was upregulated by I/R(P<0.01),with increased SUMO2/3 modification of Cav-3 and reduced membrane Nav1.5 density(P<0.01).AAV9-PIASy shRNA intraventricular injection into the rat heart down-regulated PIASy after I/R,at both mRNA and protein levels(P<0.05 vs.Scramble-shRNA+I/R group),decreased SUMO-modified Cav-3 levels,enhanced Cav-3 binding to Nav1.5,and prevented I/R-induced decrease of Nav1.5 and Cav-3co-localization in the intercalated disc and lateral membrane.PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias,which was reflected by a modest decrease in the duration of ventricular fibrillation(VF;P<0.05 vs.Scramble-shRNA+I/R group)and a significantly reduced arrhythmia score(P<0.01 vs.Scramble-shRNA+I/R group).The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia(VT),sustained VT and VF,especially at the time 5–10 min after ischemia(P<0.05 vs.Scramble-shRNA+IR group).Using in vitro human embryonic kidney 293 T(HEK293T)cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation(H/R),we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Nav1.5/Cav-3 dissociation after H/R.Mutation of SUMO consensus lysine sites in Cav-3(K38R or K144R)altered the membrane expression levels of Nav1.5 and Cav-3 before and after H/R in HEK293T cells.Conclusions:I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Nav1.5-related ventricular arrhythmias.Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Nav1.5 downregulation in the plasma membrane of cardiomyocytes,and subsequent ventricular arrhythmias in rats.PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.

An Experimental Study of Pathogenesis of Steroid-induced Avascular Necrosis of Femoral Head

Objective: To explore the pathogenesis of avascular necrosis of femoral head(ANFH) and search an effective method for clinical practice. Methods: Twenty-four Japanese rabbitswere divided into 2 groups of models and controls. ANFH models were produced byintramuscular-injection of large dosage of steroid to rabbits for 8 weeks. From the 4th, 8th and12th week after production of models, 2 rabbits of each group were sacrificed to observe thestructure of femoral head through light microscope and scanning electron microscope. The contents ofNitric Oxide (NO), tissue-type plasminogen activator (t-PA) and -plasminogen activator inhibitor(PAI) in plasma of the 4 rabbits in each group were estimated at the same time. Results: Comparedwith control group, the rabbits of model group exhibited many differences: such as osteoporosis offemoral head, the presence of more bone lacuna and fat cell through light microscope observing; thebroken and sunk bone trabecula, the loosen and broken collagen fibers on the surface of bone matrixthrough scanning electron microscope observing. Compared with control group, the Concentration ofNO and t-PA in plasma of the model rabbits decreased obviously, but the Concentration of the PAIincreased obviously. Conclusion: The steroid-induced ANFH might be related to the lower level of NOand the descent of fibrinolytic activity.

The involvement of p38 MAPK in transforming growth factor β1-induced apoptosis in murine hepatocytes

We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.

Crystal Structure of PAI-1 in Complex with Gallate

PAI-1 is the primary physiologic inhibitor of urokinase-type plasminogen activator （uPA） and tissue-type plasminogen activator （tPA） and plays important roles in a number of physiologic processes including fibrinolysis, angiogenesis, wound healing, and cell migration. PAI-1 has been proposed as a potential target for inhibitor development and many inhibitors have been reported. However, little was known about the inhibitory mechanism of these inhibitors. Here we determine the crystal structure of PAI-1 in complex with a reported inhibitor, sodium gallate. The PAI-1 ：gallate structure shows that gallate inserts into the cavity formed by helix D, helix E, helix F and t-strand 2A. This work provides insights into the inhibitory mechanism of gallate and lays out structural basis for further PAI-I inhibitor design.

Analysis of Plasma Fibrinolysis in the Patients with Acute Cerebral Infarction

In the present study, the plasma fibrinolytic activity in 30 cases of cortical artery territory cerebral infarction (CACI) and 32 cases of perforating artery territory cerebral infarction (PACI) within 3 days after ictus, and 30 sexand age-matched controls without cardio-cerebrovascular diseases were evaluated by a comprehensive panel of assay, including the plasma tPA activity, PAI activity, endothelial capacity of tPA release and PAI/tPA ratio. The results showed that the plasma fibrinolysis and the endothelial potential to release tPA responding to stimulation in boch subtypes of the patients were significantly lower than those in the controls, which provide. the theoretical basis for carrying out the thrombolytic therapy in the ischemic stroke. And the study also suggested that increased Plasma PAI activity could increase the risk of AS chrombotic events with increased serum triglyceride level.

Evaluate the Expression of uPA,PAI-1 in Human Gastric Cancer and its Correlation with the Angiogenesis by the Application of Tissue Microarray

OBJECTIVE To investigate the expression of urokinase-type plasminogen （uPA）, its inhibitor-1 （PAI-1） mRNA and its protein in human gastric cancer and to find out the relationship among the tumor differentiation, angiogenesis, and other clinical pathologic factors. METHODS In situ hybridization （ISH） was used to get the uPA, PAI-lmRNA in 110 cases with human gastric cancer in 2-tissue microarray （TMA）. Immunohistochemical staining （S-P method） for uPA, PAI-1 protein and CD34 were performed in the 110 cases in 2 TMA. RESULTS The expression of the uPA, PAI-lmRNA and their protein happened in the cytoplasm of gastric cancer cells were induced by the poor differentiation of the GC, and the expression of uPA had an increasing trend while the expression of the PAI-1 had a decreasing trend. The microvessel density （MVD） had a positive correlation with the clinical stages and the significant relationship with the lymph node metastasis （P 〈 0.05）. The MVD in uPA positive group was significantly higher than those in uPA negative group （P 〈 0.05）. The expression of PAI-1 has no correlation neither with the clinical stages nor the lymph node metastasis. CONCLUSION The uPA play an important role in invasion and metastasis of GC through promoting angiogenesis. Interdicting the secretion and function of the uPA may allow the target therapy against the tumor invasion. As a new high-throughput technology, the tissue microarray is a valuable way to be used in clinical treatment.

The Physiopathological Crossroads of Aging

Stress, inflammation and Plasminogen activator inhibitor 1 (PAI-1) are key mechanisms throughout the development of aging, constituting a crossroad in the most frequent pathologies that accompany it. Among metabolic processes, obesity, metabolic syndrome and type 2 diabetes mellitus are included and Alzheimer’s disease among the neurodegenerative processes. Stress is a mechanism of defense of the organism against exogenous and endogenous actions called stressors. In the case of low intensity stimuli, the organism responds with actions aimed at a physiological adaptation (Homeostasis). On the other hand, when a high intensity (experimental level) or chronic stimulus (oxidative stress) is repeated, structural and functional changes are observed in different organs with activation of the hypothalamus-pituitary-adrenal axis, the renin angiotensin system and the sympathetic nervous system, stimulating the production of hormones that release cytokines with proin-flammatory/antiinflammatory properties that play an important role in the previously mentioned pathologies, as well as a marked increase in PAI-1, a gene regulated by stress and by cytokines, with manifest action at the origin of thromboembolic disease, so frequent in aging. The objective of this review is to highlight the importance of the binomial stress and PAI-1 in aging and in the pathologies that accompany it. Because PAI-1 is part of the pathology and complications in aging, some authors suggest the study of PAI-1 inhibitors to achieve its physiological levels, as part of the treatment of these diseases.

tPA Involvement in Ovulation──Studies on Mechanism of Ovulation：Role of Tissue Type Plasminogen Activator

This review summarized our recent studies on involvement of tissue type plasminogen activator(tPA)and plasminogen activator inhibitor type 1(PAI-1) in process of ovulation.We have demonstrated that 1)hCG induces ovulation and coordinated tPA and PAI-1 gene expression in both rat and monkey ovaries;(2) GnRH and FSH are also capable of inducing ovulation by increasing ovarian tPA and PAI-1 gene expression in the same manner as hCG does;(3)Compounds which increase tPA production can induce oviation while compounds which decrease tPA and/or increase PAI-1 expression inhibit ovulation. Based on the data provided,a working model on the involvement of tPA in ovulation is presented.