Preparation and characterization of anti-hBLyS monoclonal antibody by DNA immunization

AIM:To establish the monoclonal antibody against human B lymphocyte stimulator (hBLyS) by DNA immunization and analyse its characterization. METHODS:The 858 bp DNA fragment of hBLyS was cloned into pcDNA3 plasmids. The cloned insert was identified by both sequence analysis and double digestion of the recombinant plasmid with restriction enzymesXho Iand EcoR I. After the splenocytes from BALB/c mice immunized with the recombinant plasmid of pcDNA3/hBLyS were fused with myeloma cells SP2/0,the hybridoma which can produce monoclonal antibodies against hBLyS were obtained. The specificity of anti-BLyS monoclonal antibody from hybridoma was verified by ELISA, Western blot and flow cytometry. RESULTS:The recombinant mammalian cell expression vector of pcDNA3/hBLyS was constructed,the sequence of the insert gene was identified to be the sequence encoding hBLy S antigen. The culture supernatants of hybridoma 9c10 were tested to be the monoclonal antibody with specificity against hBLyS on human peripheral blood CD3⁺T cell activated by hIFN-γ by ELISA,Western blot and flow cytometry.CONCLUSION:The monoclonal antibodies against hBLyS with high activity and specificity have been established successfully, and will be an useful tool in the studies of relationship between hBLyS and human autoimmunity diseases.     

Preparation and identification of anti- angiostatin monoclonal antibodies

AIM:To further study the anti-tumor effect of angiostatin, an anti-human angiostatin monoclonal antibody was prepared and identified.METHODS:The hybrodoma techniques were used. The BALB/C mice were immunized with angiostatin. The supernatant of cell culture were collected and screened by ELISA and double immunodiffusion.RESULTS:There cell lines which steadily secreted the anti-angiostatin monoclonal antibody were identified by ELISA and double immunodiffusion. The antibody was IgG1 and specifically recognized angiostatin without crossing reactions to rhIL-2, rhTNF-α, rhIFN-α and serum proteins.CONCLUSION:The antibodies secreted by three hybridoma cell lines identified by several methods were specific antibodies of angiostatin.     

Regulation by reactive oxygen species of matrix metalloproteinase-1, 3 and tissue inhibitor of matrix metalloproteinase-1 in smooth muscle cells

AIM: To understand whether reactive oxygen species promote the rupture of atherosclerotic plaques by regulating the balance of matrix metalloproteinase-1, 3 (MMP-1, 3) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in smooth muscle cells. METHODS: Aortic smooth muscle cells from 4-6months-healthy abortive fetuses were incubated for 24 hours with xanthine (100 μmol/L) and xanthine oxidase (5 U/L) in vitro . MMP-1, 3 and TIMP-1 in the concentrated culture media were measured by Western blotting ( n =3 independent experiments). RESULTS: Incubation with xanthine/xanthine oxdiase decreased the amount of MMP-1 in the aortic smooth muscle cells (21.2%±5.5% of the control group), and pro-MMP-1 was activated completely. Reactive oxygen species (ROS) also activated pro-MMP-3, and increased the production of MMP-3 in the aortic smooth muscle cells. On the other hand, ROS inhibited the production of TIMP-1 in the aortic smooth muscle cells. CONCLUSION: It is complicated that ROS regulates the balance of MMPs and TIMPs. ROS may contribute to matrix degradation and the rupture in the atherosclerotic plaques.     

The clinical application of fluorescently-labeled monoclonal antibody against P-selectin

AIM: To investigate the clinical significance in determination of the P-selectin levels in subjects with prethrombotic state or thrombosis by flow cytometry (FCM). METHODS: The P-selectin expression on platelet membrane in 42 patients with diabetes mellitus, 33 with hyperlipidemia, 23 with cerebral infarction and 20 healthy individuals, were analyzed using fluorescently-labeled SZ-51 by direct FCM comparing with indirect FCM and enzyme-linked immunosorbent assay (ELISA). RESULTS: The level of P-selectin on platelet membrane is higher in DM (23.92%±15.83%), in hyperlipidemia (18.34%±9.46%) and in cerebral infarction (19.32%±10.38%) than normal subjects (3.38%±1.11%) (P<0.01). In addition, similar results on P-selectin were obtained by indirect FCM and ELISA in patients with DM and cerebral infarction. CONCLUSION: FITC-labeled SZ-51-IgG can be used in FCM, and it would be a new and sensitive method in detecting platelet activation.     

Changes of matrix metalloproteinase-3 and urokinase-type plasminogen activator receptor in type 2 diabetes mellitus with macroangiopathy

AIM: To investigate the function of matrix metalloproteinase-3 (MMP-3) and urokinase-type plasminogen activator receptor (uPAR) to macroangiopathy in type 2 diabetes mellitus. METHODS: The levels of MMP-3 and uPAR in plasma were determined by ELISA sandwich method in 26 healthy controls and 39 patients with type 2 diabetes mellitus including 15 complication-free cases and 24 with macroangiopathy. RESULTS: The plasma level of uPAR but not MMP-3 was higher in patients without macroangiopathy than that in normal controls (P<0.05). In patients with macroangiopathy, the plasma levels of MMP-3 and uPAR were higher than those in normal controls (P<0.01) and patients without angiopathy. There was positive relationship between MMP-3 and uPAR in type 2 diabetes mellitus (r=0.405, P<0.05), and LDL-C was the important affecting factor of uPAR. CONCLUSION: MMP-3 and uPAR are associated with the development of macroangiopathy in type 2 diabetes mellitus. MMP-3 can be regarded as the circulatory markers in type 2 diabetes mellitus with macroangiopathy.     

Matrix metalloproteinase-9 and inflammatory reaction

MMP-9 is one of the family of matrix metalloproteinases, which degrades extracellular matrix.MMP-9 is induced by many inflammatory factors, including IL-1β, IL-8 and TNF-α.Mean-while, MMP-9 potentiates inflammatory factors by aminoterminal processing.The signal transduction by which inflammatory factors induce MMP-9 is also an important part in recent research.This review will give a summary in all these fields.     

The effect of intercellular adhesion molecule-1 monoclonal antibody on microcirculation of burn shock in rats

AIM: To detect the effect of intercellular adhesion molecule-1(ICAM-1) monoclonal antibody on microcirculation disorder in burn shock of Wistar rats. METHODS: The blood flow velocity and diameter of venule were measured with RBC tracking correlator and IV550 model video microscaler in burn shock models of rats. The number of leukocytes adhered on venule wall was calculated under microscope. The animal survival time was observed. RESULTS: ICAM-1monoclonal antibody could attenuate the falling of mean arterial pressure, significantly reduce the number of leukocytes adhered on venule wall, and obviously prolong the animal mean survival time, but less than 24h.CONCLUSION: ICAM-1 monoclonal antibody can decrease the number of adhered leukocytes to endothelial cells, attenuate the tether of leukocytes to venule and improve microcirculation and protect tissue cells in burn shock of rats. However, a comprehensive therapy should be taken in severe shock.     

Antiproliferation effects of 188Re labeled monoclonal antibody on prostate cancer cells in vitro

AIM: To investigate the effect of 188Re labeled monoclonal antibody on prostatic specific membrane antigen 7E11C5.3,radioimmunotherapy for the treatment of human prostate cancer cell line LNCaP in vitro.METHODS: 188Re-7E11C5.3 was prepared by direct 2-mercaptoethanol reduction method.Labeling efficiency and radiochemical purity was measured by paper chromatography.Immunoreactive fraction was determined by linear extrapolation.Cytotoxicity to LNCaP cells was determined by MTT assay.RESULTS: The labeling yield of 188Re-7E11C5.3 was (93.16±2.18)%,the radiochemical purity was (95.62±0.48)%,and the immunoreactive fraction was (74.86±1.86)%.The inhibitory effect of 188Re-7E11C5.3 on cell proliferation of LNCaP cells was significantly higher than that of 188Re-mIgG or 188ReO-4.The 50% inhibitory doses (IC50) of 188Re-7E11C5.3,188Re-mIgG,and 188ReO-4 were (23.38±3.73)×107 Bq/L,(59.21±8.02)×107 Bq/L and (68.89±10.91)×107 Bq/L,respectively.CONCLUSION: 188Re-7E11C5.3 can effectively inhibit the growth of in vitro cultured prostate cancer cells and shows much potential for prostate cancer radioimmunotherapy.     

Cyclosporin A induces myocardial fibrosis and affects expression of matrix metalloproteinases and their inhibitors in rats

AIM: To investigate the changes of matrix metalloproteinases (MMP2 and MMP9) and tissue inhibitor of metalloproteinases (TIMP2 and TIMP1) in the myocardial fibrosis induced by cyclosporin A (CsA), and to explore the underlying mechanism. METHODS: Female Wistar rats (n=64, 6~8 weeks old) weighing (200±25) g were randomly divided into 4 groups[control, low dose of CsA (5 mg·kg^-1·d^-1), medium dose of CsA (12.5 mg·kg^-1·d^-1) and high dose of CsA (25 mg·kg^-1·d^-1)]. The rats were intraperitoneally injected with saline and different doses of CsA, respectively. CsA was continuously administered for 1, 2 and 3 weeks, and then the animals were killed to collect samples. HE staining was used to observe the morphological structure of myocardium. Masson staining was used to observe the deposition of myocardial collagen and the degree of myocardial fibrosis. The protein expression levels of MMP2, MMP9, TIMP2 and TIMP1 were determined by immunohistochemistry and Western blot. RESULTS: HE staining showed that CsA induced cardiomyocyte edema, eosinophilic changes in the cytoplasm, fine granular and vacuolar changes in cardiomyocytes, disappearance of myocardial striae, nuclear condensation, and myocardial focal necrosis and fibrosis. Masson staining showed that the degree of myocardial interstitial fibrosis was getting worse with the increase in the duration and doses of CsA exposure. The results of immunohistochemistry and Western blot showed that the expression of MMP2 in CsA groups was significantly increased in the process of CsA-induced myocardial fibrosis. In each CsA dose group, MMP2 was highly expressed at the first week, and the expression was gradually decreased over time. In contrast, the expression of TIMP2 was increased gradually in a time-and dose-dependent manner (P<0.05). Compared with control group, MMP9 expression level was low at the first week, increased at the second week, and decreased at the third week (P<0.05). Compared with control group, the expression of TIMP1 was dose-dependently increased (P<0.05). CONCLUSION: CsA induces myocardial injury and interstitial fibrosis in rats in a dose-and time-dependent manner. CsA-induced myocardial fibrosis is associated with changes of MMPs and TIMPs, and is affected by the imbalance of MMPs/TIMPs.     

Generation and characterization of a series of monoclonal antibodiesagainst recombinant human augmenter of liver regeneration

AIM:To generate monoclonal antibodies against human augmenter of liver regeneration (rhALR). METHODS:After BALB/C mice were immunized by the purified rhALR, the cells of spleen were fused with the cells of SP2/0; The titer and speciality were respectively fathomed from ascites or foster fluid by ELISA and Western-blot test. RESULTS:2 hybridoma cell lines were successfully obtained. The McAbs titer from ascites and foster fluid are respectively about 10^-3-10^-5 and 10^-2-10^-3. It is evident that the two McAbs were directed at different epitopes. CONCLUSIONS:The McAbs have higher speciality. It is significantly useful of the value that how hALR distribute in tissue organs, how the hALR signals the metabolism in the body and the control distribution of the hALR on cell growth on the translational level and so on is researched.     

Role of vascular remolding induced by nitric oxide and matrix metalloproteinase in aneurysm

Nitric oxide (NO) and matrix metalloproteinases (MMPs) are important in vascular remolding, especially in abdominal aortic aneurysm. NO may be associated with aneurysms by modulating MMPs expression and activity.     

Effects of matrix metalloproteinases on ventricular remodelingfollowing myocardial ischemia in the rat

AIM:To examine the relationship between the activity of matrix metallproteinases(MMPs) and ventricular remodeling following myocardial ischemia in the rat.METHODS:The model of myocardial ischemia(MI) in the rat was established by isoprenaline(ISP). The activity of MMPs was measured by zymography and collagen concentration was assessed by the method of chloramine T, so did I/III collagen ratio by immunohistochemical staining. The microstructure of myocardium was also observed by electron microscope.RESULTS:The activity of MMP-2 in myocardial ischemia group (group M) increased by 5.8 folds at 1 st week(P＜0.01), 2.3 folds at 2 nd week(P＜0.01) and 1.7 flods at 4 th week(P＜0.05) compared with control group (group C) and MMP-9's activity in group M increased by 4.9 folds (P＜0.01), 1.9 flods(P＜0.01) and 1.4 folds(P＜0.05), respectively. Collagen amount and I/III collagen ratio in group M increased compared with that in group C at 2 nd week and 4 th week. It showed that cardiac myocytes in group M were necrosed and collagen grew abundantly in interstitium under electron microscope.CONCLUSION:The activity of MMPs in the myocardial interstitium increased following myocardial ischemia, then collagen amount and I/III collagen ratio increased, which may be the major causes of ventricular remodeling.     

Effects of angiotensionⅡon metalloproteinases and matrix in hypertrophied myocardium from infarcted rats

AIM: To investigate the roles of angiotensionⅡ (AngⅡ) receptors (AT₁, AT₂) antagonists on matrix metalloproteinases (MMPs) and extracellular matrix (ECM) system in septal myocardium from infarcted rats.METHODS: The model of rat myocardium infarction (MI) was established by permanent ligation of the left coronary artery. The treatments of the AT₁ receptor antagonist valsartan (10 mg·kg^-1·d^-1) or AT₂ receptor antagonist PD123319 (30 mg·kg^-1·d^-1) were started 7 days prior to surgery. On day 14 after MI, protein levels of MMP-2, 3, 9, fibronectin (FN), tenascin-C (TN-C) in interventricular septum (IS) were determined. The distributions of FN and TN-C were also determined by immunofluorescence.RESULTS: Pathological changes of IS on day 14 after MI showed typical myocardial hypertrophy. Protein expressions of MMP-2, 3, 9 and TN-C of IS in banding group were higher than those in sham-operation group (P<0.01). The expressions of TIMP-1 and FN were lower than those in sham-operation group (P<0.01). Protein expressions of MMP-2, 3, 9 and TN-C in valsartan group were obviously lower than those in banding and PD123319 groups (P<0.01). TIMP-1 and FN protein expressions in valsartan group were higher than those in banding and PD123319 groups (P<0.01). No difference between banding and PD123319 groups was observed (P>0.05).CONCLUSION: AngⅡis involved in myocardium remodeling in infarcted rats, which is mediated via AT₁ receptor to degrade matrix by MMPs. The heart protection of AT₁ receptor antagonists may relate to inhibition of MMPs.     

Expression and histogenesis of matrix metalloproteinase-9 and transforming growth factor-beta 1 in acute cerebral ischemia model of rats

AIM:To observe the expression and tissue localization of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta 1 (TGF-β1) in the rat acute cerebral ischemia model. METHODS:Male Wistar rats were used to establish acute cerebral ischemia model by a suturing method. The rats were divided into normal control group, sham group and ischemia 6 h, 12 h, 1 d, 2 d, 6 d and 14 d groups. The rat cerebral cortex and hippocampus of the brain were collected at different time points.The mRNA and protein levels of MMP-9 and TGF-β1 in the brain tissues were detected by real-time PCR and in situhistochemistry staining, respectively. The levels of MMP-9 and TGF-β1 in the plasma were also measured by ELISA. RESULTS:The results of real-time PCR showed that the mRNA levels of MMP-9 began to increase 6 h after acute ischemia and reached to a peak 2 d after acute ischemia. Similarly, the mRNA level of TGF-β1began to rise 12 h after acute ischemia and reached to the highest level 6 d after acute ischemia. Compared with the sham rats, the mRNA levels of MMP-9 and TGF-β1 in the rat brains that collected at ischemic time of 12 h, 1 d, 2 d, 6 d and 14 d were significantly increased. Moreover, results of in situhistochemical staining showed that the expression of MMP-9 was detected at cerebral cortex and hippocampus 1 d after acute cerebral ischemia.Further studies showed that MMP-9 dyeing of the rat cerebral cortex was most obvious 2 d after the acute cerebral ischemia. Similarly, the rat cortex and hippocampus began to express TGF-β1 2 d after acute ischemia and TGF-β1 staining at rat cerebral cortex was most obvious 6 d after the acute cerebral ischemia. In addition, ELISA showed that the increase in MMP-9 and TGF-β1 was detected in the plasma 12 h after ischemia. Compared with the sham rats, the level of these 2 factors significantly upregulated since 1 d after ischemia. CONCLUSION: The brain tissue itself contributes to the upregulation of MMP-9 and TGF-β1 post acute cerebral ischemia, which shed light on the related research in the field.     

Expression of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1 and collagen type IV in lung of rats with multiple organ dysfunction syndrome

AIM: To determine the expression of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of me-talloproteinase-1 (TIMP-1) and collagen type IV (IV-C) in the lung of rats with multiple organ dysfunction syndrome (MODS) and to investigate the mechanism of lung injury in MODS. METHODS: Adult male Sprague-Dawley (SD) rats (n=40) were randomly divided into sham control group and cecal ligation and puncture (CLP) model group. The rats in CLP group were divided into 4 subgroups as different intervals (6 h, 12 h, 24 h and 48 h), and there were 8 rats in each group. The rat model of MODS was established by CLP. All rats were sacrificed at various intervals. The functions of the liver, kidney and lung were determined by blood biochemical and blood gas analysis. The morphological changes of the lung tissues were observed with HE staining. The serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, MMP-9 and TIMP-1 were measured by ELISA. The expression of MMP-9 and TIMP-1 in the lung tissues was detected by RT-PCR and immunohistochemistry, and the expression of IV-C in the lung tissues was detected by immunofluorescence and Western blot. RESULTS: Compared with sham control group, the functions of the liver, kidney and lung were damaged at different degrees in model groups. No histopathological change in the lung tissues of sham control group was found, and the lung injury was serious in model groups. Compared with sham control group, the serum levels of TNF-α, IL-1β, MMP-9 and TIMP-1 in model groups increased significantly (P<0.05) and peaked at the interval of 12~24 h after modeling (P<0.01). The expression of MMP-9 and TIMP-1 in the lung tissues of model groups increased, and peaked at 12 and 24 h, respectively (P<0.01). The protein level of IV-C in MODS 6 h group was not changed as compared with control group, while that at the interval of 12~48 h after modeling was significantly decreased and dropped to the lowest at 24 h (P<0.01). CONCLUSION: MMP-9 and TIMP-1 play important roles in lung injury of MODS rats by regulating the synthesis and decomposition of IV-C which is the main component of extracellular matrix.     

Effect of doxycycline on matrix metalloproteinase activity and vascular remodeling in balloon-injured rat carotid arteries

AIM:To examine the inhibition of matrix metalloproteinase (MMP) activity by doxycycline (Doxy) and its effect on vascular smooth muscle cells (SMCs) proliferation,neointimal hyperplasia and vascular remodeling.METHODS: The model of rat common carotid artery injury was established by balloon-dilatation.Doxy was administered to the animals of treatment group at dose of 30 mg·kg^-1·d^-1.The activity of MMPs in the tissue of injured carotid arteries was measured by gelatin zymography.The thickness and area of neointimal,lumen area and the proliferation of SMCs were measured by histological and morphometric analysis.RESULTS:1.After Doxy treatment,the activity of MMP-9 in the carotid arteries was reduced by 26.3% and 34.5% compared to that in rats without Doxy treatment at 24 hours and 3 days after balloon injury,respectively (P<0.01).The activity of MMP-2 was also reduced by 40.0% at 7 days after injury (P<0.01).2.The thickness of neointimal were significantly decreased by 32.0% and 38.8% (P<0.01) and the lumen area was increased by 58.0% and 90.4 % at 14 and 28 days after injury in the Doxy-treated rats compared to those in control rats,respectively (P<0.01).Doxy treatment significantly reduced intimal SMCs proliferation from 62.76%±1.02 % in the controls to 43.23%±1.06% at 7 days after injury (P<0.01).CONCLUSION: Doxy treatment inhibits the activity of MMPs,the SMCs proliferation of intimal,neointimal hyperplasia and vascular remodeling,suggesting that Doxy treatment is useful in preventing restenosis after PTCA.