金属血蛋白的ESR谱及其在病理学诊断学中的应用

利用电子自旋共振（ESR）对金属血蛋白的结构、活性位置及生理机能进行研究，具有重要的病理学诊断学意义．本文对有关的研究现状及应用予以介绍．

捻转血矛线虫锌金属蛋白酶NAS-31的表达特性及功能初步研究

捻转血矛线虫病由捻转血矛线虫(Haemonchus contortus)寄生于反刍动物皱胃之中引起。为探究捻转血矛线虫锌金属蛋白酶NAS-31基因(Hc-nas-31)在虫体自由生活时期(特别是3期幼虫)中发挥的功能,本研究通过实时荧光定量聚合酶链反应(real-time quantitative polymerase chain reaction,qRT-PCR)检测目的基因在捻转血矛线虫各发育阶段的转录水平,利用cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)、基因步移及融合PCR方法扩增并分析其基因结构;构建原核表达载体后转化至BL21感受态细胞中进行诱导表达;将纯化后的蛋白免疫新西兰大白兔以制备多克隆抗体;通过虫体间接免疫荧光分析Hc-NAS-31在捻转血矛线虫体内的表达特性并预测其功能。结果表明:Hc-nas-31在各时期虫体中均有转录,其中在3期幼虫中的转录水平最高;蛋白质印迹结果显示,制备的抗体能特异性结合Hc-NAS-31天然蛋白;间接免疫荧光分析发现,Hc-NAS-31蛋白主要表达于3期幼虫的上皮细胞合胞体内,在成虫中则分布于肠道、生殖腺(性腺)、肌肉组织及早期虫卵中。本实验明确了NAS-31在捻转血矛线虫中的表达特性,为进一步研究Hc-nas-31的生物学功能奠定了基础。

原发性高血压成人尿钠排泄量与颈动脉硬化及血基质金属蛋白酶9的关系

目的探讨原发性高血压成人尿钠排泄量与颈动脉粥样硬化及血基质金属蛋白酶9的关系。方法选择成人原发性高血压117例，通过24h尿钠排泄量测定钠盐摄入量，将人选人群分为低盐组（n=30），低中盐组（n=28），中高盐组（n=27），高盐组（n=32）。测量颈动脉内膜中层厚度（IMT）值，采用酶联免疫吸附法检测血基质金属蛋白酶9（MMP-9）水平。用多元逐步线性回归分析法分析24h尿钠排泄量、年龄、性别、血压、脉率、BMI、胆固醇、三酰甘油、血糖对IMT值的影响。对MMP-9与尿钠排泄量及IMT值进行相关性分析。结果4组患者的收缩压、舒张压、IMT值，随24h尿钠排泄量的增加而增高（P〈0．05）。多元逐步线性回归分析结果显示24h尿钠排泄量增高是IMT增加的独立危险因素（回归系数0．021，P〈0．05）。MMP-9与尿钠排泄量存在正相关性（r=0．33，P〈0．05）。结论高血压患者高钠饮食可能有独立于血压之外的影响，促进动脉粥样硬化的形成。MMP。9的活性可能发挥了作用。

Purification and Characterization of Jerdonitin, a Non-hemorrhagic Metalloproteinase from Trimeresurus jerdonii Venom

Previously, we have purified Jerdonitin from Trimeresurusjerdonii venom. Compared with other P-Ⅱ class snake venom metalloproteinases （SVMPs）, Jerdonitin has a primary structure comprising metalloproteinase and disintegrin domains. However, no hemorrhagic and fibrinogenolytic activities were detected for Jerdonitin. We thought that organic buffer of high performance liquid charamatography （HPLC） might affect its enzymatic activity. In this study, we purified Jerdonitin by another procedure excluding the HPLC. It was homogenous as judged by SDS-PAGE and had an apparent molecular weight of 36 kDa under non-reducing conditions and 38 kDa under reducing conditions, respectively. Like other typical metalloproteinases, Jerdonitin preferentially degraded alpha-chain of human fibrinogen and this fibrinogenolytic activity was completely inhibited by EDTA, but not by PMSF. It was interesting that Jerdonitin did not induce hemorrhage after intradermal injection in mice.

Novel biomarkers for cardiovascular risk prediction

Cardiovascular disease （CVD） is the leading cause of death and disability worldwide. The primary prevention of CVD is dependent upon the ability to identify high-risk individuals long before the development of overt events. This highlights the need for accurate risk strati- fication. An increasing number of novel biomarkers have been identified to predict cardiovascular events. Biomarkers play a critical role in the definition, prognostication, and decision-making regarding the management of cardiovascular events. This review focuses on a variety of promising biomarkers that provide diagnostic and prognostic information. The myocardial tissue-specific biomarker cardiac troponin, high- sensitivity assays for cardiac troponin, and heart-type fatty acid binding proteinall help diagnose myocardial infarction （MI） in the early hours following symptoms. Inflammatory markers such as growth differentiation factor-15, high-sensitivity C-reactive protein, fibrinogen, and uric acid predict MI and death. Pregnancy-associated plasma protein A, myeloperoxidase, and matrix metalloproteinases predict the risk of acute cor- onary syndrome. Lipoprotein-associated phospholipase A2 and secretory phospholipase A2 predict incident and recurrent cardiovascular events. Finally, elevated natriuretic peptides, ST2, endothelin-1, mid-regional-pro-adrenomedullin, copeptin, and galectin-3 have all been well validated to predict death and heart failure following a MI and provide risk stratification information for heart failure. Rapidly develop- ing new areas, such as assessment ofmicro-RNA, are also explored. All the biomarkers reflect different aspects of the development ofather- osclerosis.

Plasma matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 as biomarkers of ulcerative colitis activity

AIM:Overexpression of mucosal metalloproteinases(MMP) has been demonstrated recently in inflammatory bowel disease.Their activity can be counterbalanced by the tissue inhibitor of metalloproteinases(TIMP).The aim of this study was to evaluate the effect of ulcerative colitis(UC)on MMP- 1 and TIMP-1 plasma concentrations,as two possible biomarkers of the disease activity. METHODS:MMP-1 and TIMP-1 plasma concentrations were measured with an enzyme immunoassay in 16 patients with endoscopically confirmed active UC. RESULTS:Plasma concentrations of both MMP-1(13.7±0.2 ng/ml)and TIMP-1(799±140 ng/ml)were significantly elevated in UC patients in comparison to healthy controls (11.9±0.9 ng/ml and 220±7 ng/ml respectively).There was no correlation between TIMP-1 and MMP-1 concentrations (r=0.02).TIMP-1 levels revealed significant positive correlations with scored endoscopic degree of mucosal injury, disease activity index and clinical activity index values as well as C-reactive protein concentration.There was no correlation between MMP-1 and laboratory,clinical or endoscopic indices of the disease activity.CONCLUSION: These results confirm the role of both MMP- 1 and TIMP-1 in the pathogenesis of ulcerative colitis. However only TIMP-1 can be useful as a biomarker of the disease activity, demonstrating association with clinical and endoscopic pictures.

Complex role of matrix metalloproteinases in angiogenesis

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play a significant role in regulating angiogenesis, the process of new blood vessel formation. Interstitial collagenase (MMP-1), 72 kDa gelatinase A/type IV collagenase (MMP-2), and 92 kDa gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and Promote angiogenesis. TIMP-1, TIMP-2, TIMP-3, and possibly,TIMP-4 inhibit neovascularisation. A new paradigm is emerging that matrilysin (MMP-7), MMP-9, and metalloelastase (MMP-12) may block angiogehesis by converting plasndnogen to angiostatin, which is one of the most potent angiogenesis antagonists. MMPs and TIMPs play a complex role in regulating angiogenesis. An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide importal information to allow the control of angiogenesis, e.g. the stimulation of angiogenesis for coronary collateral circulation formation; while the inhibition for treating arthritis and cancer.

Endostatin promotes the anabolic program of rabbit chondrocyte

Endostatin is a natural occurred angiogenesis inhibitor derived from collagenXVIII. So far its function during the angiogenesis process of bone formation and arthropathy has not been well studied yet. The present study addresses the function of endostatin in rabbit articular chondrocytes (RAC). We found that endostatin can promote RAC adhesion and spreading as well as its proliferation. In monolayer cultured RAC, CollagenII, TIMP1 and collagenXVIII transcription were up regulated by endostatin while collagenI and MMP9 were down regulated. Moreover collagenXVIII and endostatin antigens are present at synovial fluid. These findings indicate new function of endostatin as a homeostatic factor in cartilage metabolism.

Thrombotic microangiopathy-like disorder after living-donor liver transplantation:A single-center experience in Japan

AIM:To investigate thrombotic microangiopathy (TMA)in liver transplantion,because TMA is an infrequent but life-threatening complication in the transplantation field. METHODS:A total of 206 patients who underwent living-donor liver transplantation (LDLT) were evaluated,and the TMA-like disorder (TMALD) occurred in seven recipients. RESULTS:These TMALD recipients showed poor outcomes in comparison with other 199 recipients. Although two TMALD recipients successfully recovered,the other five recipients finally died despite intensive treatments including repeated plasma exchange (PE) and re-transplantation. Histopathological analysis of liver biopsies after LDLT revealed obvious differences according to the outcomes. Qualitative analysis of antibodies against a disintegrin-like domain and metalloproteinase with thrombospondin type 1 motifs (ADAMTS-13) were negative in all patients. The fragmentation of red cells,the microhemorrhagic macules and the platelet counts were early markers for the suspicion of TMALD after LDLT. Although the absolute values of von Willebrand factor (vWF) and ADAMTS-13 did not necessarily reflect TMALD,the vWF/ADAMTS-13 ratio had a clear diagnostic value in all cases. The establishment of adequate treatments for TMALD,such as PE for ADAMTS-13 replenishment or treatments against inhibitory antibodies,must be decided according to each case. CONCLUSION:The optimal induction of adequate therapies based on early recognition of TMALD by the reliable markers may confer a large advantage for TMALD after LDLT.

EXPRESSION OF MATRIX METALLOPROTEINASE-7 INVOLVING IN GROWTH, INVASION, METASTASIS AND ANGIOGENESIS OF GASTRIC CANCER

Objective. To investigate the role of matrix metalloproteinase-7 (MMP-7) expression in caricinogenesisand progression of gastric cancer.Methods. We studied MMP-7 expression and microvessel density (MVD) in adjacent mucosa and pri-mary foci of 113 cases of gastric cancer by streptavidin-biotin-immunoperoxidase method using anti-MMP-7 and anti-CD34 antibodies. MMP-7 expression and mean MVD were compared with clinicopatholog-ical features of gastric cancer, with the relationship between MMP-7 expression and MVD concerned in gastric cancer.Results. MMP-7 showed positive expression in adjacent mucosa of gastric cancer (29.20%, 33/113),less than that in gastric cancer (69.03%, 78/113). MMP-7 expression in primary foci of gastric cancerwas positively correlated with tumor size, invasive depth, metastasis and TNM staging (P＜0.05), but notwith differentiation or growth pattern of gastric cancer (P＞0.05). Positive correlation of mean MVD withtumor size, invasive depth, metastasis and TNM staging was found (P＜0.05), despite no relationshipbetween mean MVD and differentiation of gastric cancer (P＞0.05). Mean MVD was dependent on MMP-7expression in gastric cancer (P＜0.05).Conclusion. Up-regulated expression of MMP-7 played an important role in carcinogenesis and pro-gression by participating in growth, invasion, metastasis and angiogenesis of gastric cancer. MMP-7 ex-pression could be regarded as an effective and objective marker to reflect the biological behaviors of gas-tric cancer.

Matrix metalloproteinase-9:A deleterious link between hepatic ischemia-reperfusion and colorectal cancer

Despite the advent of improved surgical techniques and the development of cytotoxic chemotherapeutic agents useful for the treatment of colorectal cancer,the primary clinical challenge remains that of preventing and combating metastatic spread.Surgical resection is the best treatment for colorectal metastases isolated to the liver.However,in rodent models,the hepatic ischemia-reperfusion(I/R) applied during the surgery accelerates the outgrowth of implanted tumors.Among the adverse effects of I/R on cellular function,several studies have demonstrated an over expression of the matrix metalloproteinase-9(MMP-9) in the ischemic liver.Since several studies showed high local levels of expression and activity of this proteolytic enzyme in the primary colorectal adenocarcinoma,the role of MMP-9 might be considered as a potential common mediator,favoring both growth of local tumor and the dissemination of colorectal carcinoma metastases.

The relationship between matrix metalloproteinases-9 and CD15s antigen in angiogenesis of gastric carcinoma

Objective： To investigate the relationship between matrix metalloproteinases-9 （MMP-9） and sialyl Lewis X （CD15s） antigen in invasion and metastasis of gastric carcinoma. Methods： Expression of CD105, MMP-9 and CD15s in 47 cases of gastric carcinoma undergone radical surgery were evaluated by SP immunohistochemical staining using the respective monoclonal antibody. The microvessel density （MVD） marked with CD105 was detected. Correlation between MVD and MMP-9, CD15s was also statistically analyzed. Results： The MVD in both MMP-9 and CD15s positive expression group was higher significantly than that in MMP-9 or CD15s positive expression alone group, and it was also significantly higher than that in both MMP-9 and CD15s negative expression group. Conclusion： MMP-9 is a marker of invasion and CD15s is a marker of metastasis in gastric carcinoma. Combining detection of MMP-9 and CD15s has certain clinical significance for diagnosis, treatment and assessing the prognosis for gastric caner.

Expression and correlation of CD44v6, vascular endothelial growth factor, matrix metalloproteinase-2, and matrix metalloproteinase-9 in Krukenberg tumor

AIM： To explore the expression and correlation of CD44v6, vascular endothelial growth factor （VEGF）, matrix metalloproteinase （MMP）-2 and matrix metalloproteinase （MMP）-9 in Krukenberg and primary epithelial ovarian carcinoma. METHODS： The expressions of CD44v6, VEGF, MMP-2 and MMP-9 were detected by immunohistochemical method in 20 cases of normal ovarian tissues, 38 cases of Krukenberg tumor and 45 cases of primary epithelial ovarian carcinoma. RESULTS： The expression of CD44v6 （primary epithelial ovarian carcinoma tissue vs normal ovarian tissue： χ^2= 4.516, P= 0.034; Krukenberg tumor tissue vsnormal ovarian tissue： χ^2 = 19.537, P = 0.001） and VEGF （primary epithelial ovarian carcinoma tissue vs normal ovarian tissue： P = 0.026; Krukenberg tumor tissue vs normal ovarian tissue： χ^2 = 22.895, P = 0.001） was significantly higher in primary epithelial ovarian carcinoma tissue and Krukenberg tumor tissue than in normal ovarian tissue. The positive expression rate of MMP-2 and MMP-9 was 0% in the normal ovarian tissue. The positive expression rate of CD44v6 （ χ^2= 10.398, P= 0.001）, VEGF （ χ^2= 13.149, P = 0.001）, MMP-2 （ χ^2 = 33.668, P = 0.001） and MMP-9 （ χ^2= 38.839, P = 0.001） was remarkably higher in Krukenberg tumor than in primary epithelial ovarian carcinoma. The correlation of CD44v6, VEGF, MMP-2, and MMP-9 was observed in primary epithelial ovarian carcinoma and Krukenberg tumor. CONCLUSION： CD44v6, VEGF, MMP-2, and MMP-9 are involved in ovarian carcinoma, gastric cancer and Krukenberg tumor. Detection of CD44v6, VEGF, MMP-2 and MMP-9 may contribute to the diagnosis of ovarian carcinoma, gastric cancer, and Krukenberg tumor.

Effects of carbon dioxide pneumoperitoneum on metastasis of ovarian carcinoma cell line SKOV_3

The long suspicion of the potential harm of carbon dioxide （CO2） pneumoperitoneum exists in laparoscopic cancer surgery. For better understanding of this problem, we targeted this study at the effects of CO2 pneumoperitoneum on the invasive ability of ovarian carcinoma cell line and the possible mechanism within it. To study the effects of CO2 pneumoperitoneum on carcinoma cell, SKOV3 cells were divided into 2 groups, respectively exposed to pneumoperitoneal CO2-insuffiation and normal conditions. To study the possible mechanism, SKOV3 cells were divided into 3 groups, one was exposed to CO2 pneumoperitoneum, one to N2 and the other to normal conditions served as control. The in vitro adhesive and invasive ability of the cells was analyzed through 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay and Boyden filters metastasis model; the expressions of vascular endothelial growth factor C （VEGF-C） and matrix metalloproteinase 9 （MMP9） were determined by reverse transcription polymerase chain reaction（RT-PCR）, and Western blot. We found that the adhesive ratio of SKOV3 cells exposed to CO2 was significantly higher than that of the control group; cells exposed to CO2 invaded the matrigel with a greater number （P〈0.01）; the expression of VEGF-C exposed to both CO2 and N2 was significantly increased compared with control group （P〈0.05）; the MMP9 expression level of CO2 group was higher than that of N2 group, P〈0.05. We concluded that carbon dioxide pneumoperitoneum may improve the adhesive and invasive ability of ovarian carcinoma cell line in vitro and CO2 can also be an independent factor to stimulate the expression of MMP9.

Effect of Metallothionein on Cell Cycle,Apoptosis Rate and Subsets Distribution of Lymphocytes in Peripheral Blood of Dairy Cattle under Heat Stress

[Objective] This study aimed to research the effect of metallothionein on cell cycle, apoptosis rate and subsets distribution of lymphocytes in peripheral blood of dairy cows under heat stress, so as to perfect the regulative mechanism re- searches of MT to anti-heat stress. [Method] Twenty lactating Chinese Holstein cows were randomly divided into four groups （A, B, C and D）, and injected with 0, 4.0, 8.0 and 12.0 mg Zn-metallothionein, respectively by intravenous route. Blood sam- ples were collected at 1＂, 16~, 31~, 46~ and 61~ day, and the dynamic changes of cell cycle, apoptosis rate and subsets distribution of lymphocytes were determined. [Result] The apoptosis rate of cells in group B and C was lower than those in group A by 26.63% （P〉0.05） and 24.84% （P〉0.05） respectively. The number of cells in the Gc/G1 phage in trial groups was increased and the number of cells in the S and GJM phages tended to decrease, but there were no significant differences （P〉 0.05）. The number of CD3~ T cell in three trial groups was greater than those in group A by 7.02% （P〉0.05）, 5.45% （P〉0.05） and 3.85% （P〉0.05） respectively, while the number of CD4~ T cell in trial groups was higher than those in control group by 31.04% （P〈0.05）, 35.68% （P〈0.05） and 39.34% （P〈0.05） respectively. The number of CD8＇ T cell and the levels of CD4＊/CD8~ in trial groups were increased observ- ably, but significant difference （P〈0.05） was observed in the levels of CD4~/CD8~ between groups A and C only. It demonstrated that exogenous Zn-metallothionein can decrease apoptosis rate, improve cell cycle and regulate subsets distribution of lymphocytes in dairy cattle in a dose-dependent manner. [Conclusion] This study will provide scientific basis for safe utilization of MT in dairy industry.

Serum metrix metalloproteinase-9 combined with homocysteine, IL-6, TNF-α, CRP, HbA11c and lipid profile in the incipient diabetic nephropathy with or without macrovascular diseases

Objective ： To evaluate the changes of serum matrix metalloproteinase-9 （romp-9） in patients of incipient diabetic nephropathy with or without macrovascular disease and to analyze the factors associated with homocysteine（hcy）, interleukin-6（IL-6）, tumor necrosis factor-alpha （TNF-α）, highly sensitive C-reactive protein （hsCRP）, HbAlc and lipid profile in those patients in order to know whether this marker or other factors are more important to induce diabetic macrovascular disease. Methods： Type 2 diabetes mellitus（T2DM） subjects with incipient diabetic nephropathy with or without macrovascular disease were selected for participation and divided into 2 groups. The patients in group 1 （n= 38） used insulin, and patients in group 2 （n=34） were treated with an oral antidiabetic drug. Then serum mmp-9, hey, IL-6 and TNF-α in these patients were measured, and compared to the healthy subjects as control （n= 16）. The results were analyzed by SPSS13. Results： Serum romp-9 and hcy of the patients having incipient diabetic nephropathy with macrovascular disease were higher than that of patients without macrovascular disease （P〈0.01）. For insulin-injected patients, whether they accompanied with macrovascular diseases or not, the serum levels of romp-9, hcy, IL-6 and TNF-α were all lower, but no significant statistics compared with non-insulin used patients or the healthy subjects. The serum level of romp-9 was more correlated with the serum hcy in antidiabetic drug used patients. （P〈0. 000） Conclusion： The serum level of romp-9 plays an important role of pathogenesis in the macrovascular disease in the incipient diabetic patients, and the serum level of hcy also can reflect the severely degree of macrovascular disease in these patients, insulin can reduce these markers.

Octreotide inhibits proliferation and invasion of MHCC97-H cells in vitro and in vivo

Objective: To figure out the effect of somatostatin analogue Octreotide on proliferation and invasion of human hepatocellular carcinoma cell MHCC97-H and the underlying mechanism in vitro and in vivo. Methods: MHCC97-H cells were treated with Octreotide at the concentration of 0.2 ug/mL in vitro, proliferation related to time was evaluated. After treated with Octreotide at the concentration of 0.2 ug/mL for 48 h, MHCC97-H cells were observed by transmission electron microscope. Cell proliferation was detected by MTT assay after MHCC97-H cells were treated with Octreotide at different concentrations including 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 ug/mL for 36 h in vitro. 27 nude mice, in which MHCC97-H tumor mass was planted orthotopically, were divided into 3 groups randomly including control group (intraperitoneal injection with equal volume normal saline; n=8), low dose treated group (intraperitoneal injection with Octreotide at 50 ug/kg?d; n=9) and large dose treated group (intraperitoneal injection with Octreotide at 200 ug/kg?d; n=10). All mice were raised for 35 d and sacrificed. The information about survival time, the weight at death point and the pathology change of liver and lung was collected. The expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases-2 (MMP-2) in mouse HCC tissues were detected by immunohistochemistry finally. Results: MTT assays showed that Octreotide inhibited the proliferation of MHCC97-H cells significantly. Apoptosis cells were found by transmission electron microscope after treatment with Octreotide at 0.2 ug/mL for 48 h in vitro. The proliferation was inhibited significantly by Octreotide in a dose-dependant manner (r=0.86, P<0.01). Compared with control group, the treated group had the heavier weight at death point and lower intrahepatic metastasis ratio (P<0.05), meanwhile, there was not significant difference in treated groups (P>0.05). The positive expression ratios of VEGF and MMP-2 in treated groups were lower than those in control group (P<0.05), while there was no apparent difference in treated groups (P>0.05). Conclusion: Octreotide could inhibit the proliferation of MHCC97-H cells in vitro via inducing apoptosis and the inhibitory function acts in a dose-dependant manner. Octreotide could improve survival of mice with MHCC97-H cells and inhibit the metastasis of MHCC97-H cells in vivo. Regulation of VEGF and MMP-2 expression by Octreotide would be involved in its inhibition in vivo.

Roles of Biomolecules in the Biosynthesis of Silver Nanoparticles: Case of Gardenia jasminoides Extract

Rapid development of biosynthesis of metal nanoparticles using plants has attracted extensive interests to further investigate this novel and eco-friendly method. In the biosynthesis process, the plant may act as reducing agent, capping agent or shape directing agent. However, identifying specific roles of various components in the plant is challenging. In this study, we use biosynthesis of silver nanoparticles with Gardenia jasminoides Ellis extract to address this issue. The formation process of silver nanoparticles is investigated and the nanoparticles are characterized with the ultraviolet-visible spectroscopy, Fourier transform infrared spectra and scanning electron microscopy. The results indicate that the Gardenia jasminoides Ellis extract can reduce silver ions to form silver nanoparticles, stabilize the nanoparticles, and affect the growth of silver nanocrystal to form silver nanowires. Only geniposide in the extract exhibits good shape-directing ability for silver nanowires. It is found that bovine albumin is a potential capping agent, whereas rutin, gallic acid and chlorogenic acid possess reducing and capping ability.

Glucosamine reduces blood-brain barrier disruption by inhibiting the expression of matrix metalloproteinase-9 in experimental autoimmune encephalomyelitis rats

We investigated the effects of glucosamine(GS) on blood-brain barrier(BBB) function and matrix metalloproteinase-9 (MMP-9) expression in rats with experimental autoimmune encephalomyelitis(EAE).Animals were randomly divided into three groups,among which the EAE and GS groups were immunized with complete antigen and pertussis toxin,and the adjuvant group was immunized with complete Freund's adjuvant and pertussis toxin.Rats were treated by peritoneal injection of GS 180 mg/(kg·d) in the GS group and peritoneal injection of phosphate-buffered saline 4.5 mL/(kg·d) in the EAE and adjuvant groups.We proposed to assess the integrity of BBB by calculating cerebrospinal fluid to serum albumin quotient(QA) on days 6,8,10,12,14,16 and 18 post-immunization.At the same time,the brains and spinal cords were removed for MMP-9 immunohistochemical staining. Experiments demonstrated that in the EAE group,QA value and MMP-9 expression were highly elevated and up-regulated and correlated to disease severity.Moreover,there was statistically significantly positive correlation between QA value and MMP-9 expression.In the GS group,we observed that the mean disease onset date was delayed,the incidence and mean score of symptom were suppressed at the peak phase of disease(P<0.05).Furthermore,QA value and MMP-9 expression in the GS group showed stronger inhibition when compared with those of the EAE group(P<0.05).Our study showed that GS would reduce the BBB breakdown and leukocyte trafficking by inhibiting the production of MMP-9 and mitigate EAE.

Functional tuning and expanding of myoglobin by rational protein design

Rational protein design is a powerful strategy,not only for revealing the structure and function relationship of natural metalloproteins,but also for creating artificial metalloproteins with improved properties and functions.Myoglobin(Mb),a small heme protein created by nature with diverse functions,has been shown to be an ideal scaffold for rational protein design.The progress reviewed herein includes fine-tuning its native functions of O2binding and transport,peroxidase activity and nitrite reductase(NIR)activity,and rational expanding its functionalities to peroxygenase,heme-copper oxidase(HCO),nitric oxide reductase(NOR),as well as hydroxylamine reductase.These studies have enhanced our understanding of how metalloproteins work in nature,and provided insights for rational design of functional metalloproteins for practical applications in the future.