The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier...The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.展开更多
BACKGROUND: Chemotaxis is an important step durin the invasion of carcinoma cells. And integrins are most im portant receptors mediating interaction between cells an extracellular matrix ( ECM). This study was designe...BACKGROUND: Chemotaxis is an important step durin the invasion of carcinoma cells. And integrins are most im portant receptors mediating interaction between cells an extracellular matrix ( ECM). This study was designed t study integrin betal mediating chemotaxis of hepatocellula carcinoma (HCC) cells to laminin (LN). METHODS: A micropipette technique was adopted to in vestigate the effect of blockade of integrin betal on pseudo pod protrusion of HCC cells in response to LN stimulation Chemotactic pseudopod protrusion of a HCC cell was eva luated using a dual-pipette set-up, in which two pipette filled with LN solution were positioned in close contact wit the same cell, and pseudopod protrusion into each pipett was viewed dynamically and recorded with a tape recorder The lengths of pseudopods were measured and plotte against time to obtain a pseudopod growth curve. The in tegrin betal subunit on the surfaces of HCC cells were ana lyzed by flow cytometry. RESULTS: In dual pipette chemotaxis experiment, whe the two pipettes were filled with LN(50 μg/ml, 200 μg/ml) pseudopods extended from the HCC cell into each of th pipettes nearly symmetrically, ie, with nearly identica maximum pseudopod length and similar pseudopod growth curves. Upon addition of anti-CD29 (20 μg/ml) to one o the pipettes, pseudopod protrusion was blocked nearly completely while protrusion into the opposite pipette be came more evidently, with a larger maximum length. Ex pression of integrin betal was up to 95.78% to cells chosen in the experiment. CONCLUSION: Integrin betal subunit was an importan constituent receptor subunit for mediating chemotactic pseudopod protrusion of HCC cell to LN.展开更多
The 67KD laminin receptor (LN-R ) that binds laminin (LN) is involved in the metastasis cascade. Using immunohistochemical technique, in situ hybridization and reverse transcription polymerase chain reaction(RT-PCR), ...The 67KD laminin receptor (LN-R ) that binds laminin (LN) is involved in the metastasis cascade. Using immunohistochemical technique, in situ hybridization and reverse transcription polymerase chain reaction(RT-PCR), we studied LN-R protein and RNA levels in 30 cases of human hepatocellular carcinoma (HCC) to further understand its role in the metastasis of HCC. In our 14 cases of HCC with metastasis, its positive rates were 71. 4 %, 57. 1%, 85.7% respectively, whereas its positive expression in 16 cases without metastasis were 31.3 %, 18. 8 %, 50. 0 % respectively. The significant difference was found between these two groups. The results suggest that the 67KD LN-R expression plays a very important role in the metastasis of HCC.展开更多
The change in serum laminin (LN) level and its clinical significance in epithelial ovarian tumor were investigated. The LN levels in serum and ascites samples from 69 patients with epithelial ovarian tumor and 42 case...The change in serum laminin (LN) level and its clinical significance in epithelial ovarian tumor were investigated. The LN levels in serum and ascites samples from 69 patients with epithelial ovarian tumor and 42 cases as control group before and after operation were analyzed by radioimmunoassay. The results showed that the serum LN levels in the patients with malignant tumors (157.85 ±14.37 ng/ml) were significantly higher than that in the control group (125.14 ±7.03 ng/ml) and in the patients with benign tumors (128.36±8.75 ng/ml)(both P <0.01) before operation. The serum LN levels in the malignant group were decreased significantly after operation as compared with those before operation ( P <0.05). The serum LN levels in low differentiated tumors was higher than those in moderate differentiated tumors and high differentiated tumors ( P <0.05). The LN levels in ascites (172.94±15.26 ng/ml) was significantly higher than in serum (161.34±6.59 ng/ml)( P <0.05) in malignant tumors. The serum LN levels in the patients with lymph node metastasis (165.41±19.91 ng/ml) was obviously higher than those without lymph node metastasis (152.35±10.34 ng/ml)( P <0.05). It was concluded that LN levels in serum and acistes were remarkably increased in malignant epithelial ovarian tumors, suggesting that LN might be one of important diameters reflecting tumor biological characteristics.展开更多
Objective: To prepare monoclonal antibody (McAb) against the Integrin a6 extracellular domain and identify its biological activities. Methods: Fusion-protein of integrin a6 extracellular domain (GST-IAGED) was express...Objective: To prepare monoclonal antibody (McAb) against the Integrin a6 extracellular domain and identify its biological activities. Methods: Fusion-protein of integrin a6 extracellular domain (GST-IAGED) was expressed in E.coli. JM109 and used for immunizing BALB/C mice. The spleen cells from immunized mice were fused with SP2/0 cells and selectively cultured with HAT medium. ELISA and immunocytochemistry staining were used to select hybridomas. Results: One strain of hybridoma cells that secreted specific monoclonal antibody against integrin a6 extracellular domain was indentified. The immunoglobulin subclass of the McAb was IgG1. Conclusion: The McAb against the extracellular domain of integrin a6 was successfully prepared by using GST-IA6ED fusion protein expressed by E.Coli. And the McAb had positive reaction with human hepatocarcinoma cells-BEL-7402.展开更多
Our previous reports have shown that lamininglycopeptides (LN-GPs), the total glycopeptides prepared from laminin (LN), can prevent the experimental lung metastasis and liver metastasis of mouse cancer cells. In order...Our previous reports have shown that lamininglycopeptides (LN-GPs), the total glycopeptides prepared from laminin (LN), can prevent the experimental lung metastasis and liver metastasis of mouse cancer cells. In order to explore the anti-metastatic mechanism of LNGPs, we studied the effects of LN-GPs on metastasisrelated behaviors of cancer cells in vitro. LN-GPs did not affect cell survival. However, LN-GPs inhibited cell attachment and spreading Of 5180 cells on LN- and Matrigelsubstrate in dose-dependent and time-dependent manners. Moreover, inhibition of cen attachment and spreading on Matrigel substrates were much greater on Matrigel substrate than on LN substrate. In the presence of LN-GPs, 5180 cells on LN substrate changed from a flattened polygonal shape to a round one, the migration of 5180 cells on LN substrate decreased, and the number of a highly invasive human pulmonary giant caxcinoma PG cells invading Matrigel filter in a Boyden chamber was reduced. LN-GPs thus have multiple inhibitory effects on cancer motastasisrelated behaviors.展开更多
AIM:To clarify the clinicopathological significance of laminin-5 γ2 (LNγ2) and β3 (LNβ3) chains and MMP7 expression in biliary tract cancer.METHODS: We analyzed the association between immunohistochemically detect...AIM:To clarify the clinicopathological significance of laminin-5 γ2 (LNγ2) and β3 (LNβ3) chains and MMP7 expression in biliary tract cancer.METHODS: We analyzed the association between immunohistochemically detected LNγ2, LNβ3, and MMP7 expression in biliary tract cancer and clinicopathological characteristics. Activity of MMP7 was analyzed by casein zymography. An in vitro invasion assay after treatment with MMP7-specific siRNA was performed.RESULTS: LNγ2 expression was predominantly observed in carcinoma cells at the invasive front. LNγ2 expression was seen in 57% of patients with biliary tract cancer, and was associated with depth of invasion, histologic type, and advanced stage. The expression pattern of LNβ3 was classified into two types: invasive front dominant type (38%) and diffuse type (28%).The invasive front dominant type was associated with histologic type and advanced stage. MMP7 positivity was correlated with LNγ2 or LNβ3 expression but not with clinicopathological characteristics. Active MMP7 detected by casein zymography was correlated with depth of invasion and advanced stage. Downregulation of MMP7 expression by siRNA resulted in a significant decrease in biliary tract cancer cell invasion in vitro.CONCLUSION: Our results suggest that LNγ2 and LNβ3, in conjunction with MMP7, play a key role in the progression of biliary tract cancer.展开更多
Objective To explore the role of serum fibrotic indices including hyaluronic acid (HA), procollagen type III NH_ 2-terminal peptide (PCIIIP), and laminin (LN) in assessing the severity of myocardial fibrosis in chroni...Objective To explore the role of serum fibrotic indices including hyaluronic acid (HA), procollagen type III NH_ 2-terminal peptide (PCIIIP), and laminin (LN) in assessing the severity of myocardial fibrosis in chronic congestive heart failure (CHF).Methods Serum levels of HA, PCIIIP, and LN in 39 patients with CHF[14 with New York Heart Association (NYHA) functional class II, 21 with class III, 4 with class IV]and in 46 patients with NYHA functional class I were assessed by radioimmunoassay.Results The serum concentrations of HA, PCIIIP, and LN were 359.75±84.59 μg/L, 77.88±24.67 μg/L, 86.73±23.90 μg/L in CHF group, and 211.60±54.80 μg/L, 64.82±23.99 μg/L, 82.26±23.98 μg/L in NYHA functional class I group, respectively. The HA level was significantly higher in CHF patients as compared with NYHA functional class I group (P<0.05). However, no difference was found in the levels of PCIIIP and LN between CHF group and NYHA functional class I group. The serum HA concentration was negatively correlated with left ventricular ejection fraction (r=-0.71, P<0.05).Conclusion Serum HA level may act as an indicator for myocardial fibrosis.展开更多
Laminin is a glycoprotein which has an important role in the mechanism of fibrogenesis and is,thus,related to hepatic fibrosis in addition to presenting increased levels in several types of neoplasias. However,its det...Laminin is a glycoprotein which has an important role in the mechanism of fibrogenesis and is,thus,related to hepatic fibrosis in addition to presenting increased levels in several types of neoplasias. However,its determination is not routinely considered in the study of hepatic fibrosis. In this review,the authors critically comment on the role of this glycoprotein compared to other markers of fibrosis through non-invasive procedures(Fibroscan). They also consider its clinical investigational potential and believe that the continuation of these investigations might contribute to a better understanding of the fibrogenic mechanism,which could in turn either lead to the identification of patients at risk of developing fibrosis non-alcoholic fatty liver disease(NAFLD) and non-alcoholic steatohepatitis(NASH) or at least be used as an indicator for hepatic biopsy in such patients. Finally,the authors believe that serum laminin determination might contribute to the diagnosis of epithelial tumor metastasis and peritoneal carcinomatosis.展开更多
A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly(ethylene terephthal...A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly(ethylene terephthalate) (PET) and polyethylene (PE) as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with laminin (LCP solution). The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin-apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite composite coating.展开更多
Objective To study the serum laminin(LN)and fibronectin(FN)changes in acute coronary syndromes(ACS),and explore the role of them in assessing the severity of ACS.Methods This study included 46 ACS patients [25 with ac...Objective To study the serum laminin(LN)and fibronectin(FN)changes in acute coronary syndromes(ACS),and explore the role of them in assessing the severity of ACS.Methods This study included 46 ACS patients [25 with acute myocardial infarction(AMI)and 21 with unstable angina(UA)],51 stable angina(SA)patients and 47 people without CHD as controls.Serum levels of LN,FN,fibrinogen and blood fat were assessed.Coronary angiography were performed on 49 of them.Results The serum concentration of LN was lower in ACS patients [(85.20±27.57)ng/mL],higher in SA patients [(116.80±28.80)ng/mL] as compared to that in the control group [(100.06±29.96)ng/mL],with significant difference among the groups(P<0.05).No difference was found in FN among the three groups.However,the subgroup analysis in the group with ACS showed that the serum concentration of FN was significantly higher in UA patients [(229.60±121.39)μg/mL],and lower in AMI patients [(108.31±47.12)μg/mL].The serum LN and FN concentration could respectively enter the logistic regression equations of ACS patients and US patients.Neither LN nor FN concentration was correlated with narrowing of coronary artery of angiography.Conclusion Serum LN and FN level may be a useful indicator for stability of atherosclerosis plaque in coronary arterial disease patients,but could not predict the extent of narrowing in coronary angiography.展开更多
Previous studies have shown that the expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess t...Previous studies have shown that the expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess the expressions of laminin-5 γ2 chain and SPARC in esophageal squamous cell carcinoma (SCC), and to clarify the prognostic significance of the expressions of laminin-5 γ2 chain and SPARC in esophageal SCC, we detected the expressions of laminin-5 γ2 chain and SPARC in cancer tissue and corresponding normal mucosa from 116 patients with advanced (stages II-IV) esophageal SCC using the tissue microarray-based immunohistochemistry and analyzed the correlation of the expressions with clinicopathologic characteristics and survival. We found that in normal esophageal tissues, laminin-5 γ2 chain was expressed in the basement membrane, whereas in esophageal SCC tissues, laminin-5 γ2 chain was expressed in the cytoplasm of carcinoma cells, with a positive rate of 72.4%. SPARC was not detected in normal esophageal mucosa, but was expressed in stromal fibroblasts in 84.6% of esophageal SCC cases and in cancer cells in 7.8% of esophageal SCC cases. There was a significant correlation between laminin-5 γ2 chain and stromal SPARC expression in esophageal SCC (Spearman's rho = 0.423, P < 0.001). The expressions of both laminin-5 γ2 chain and stromal SPARC were correlated with survival (P = 0.032 and P = 0.034, respectively). In stage-II esophageal SCC, the expression of laminin-5 γ2 chain was significantly correlated with survival (P = 0.023), while the expression of SPARC was not significantly correlated with survival (P = 0.154). Patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis than did those lacking elevated levels of laminin-5 γ2 chain expression and/or elevated levels of SPARC expression (P = 0.001). In stage-II esophageal SCC, patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis (P < 0.001). These results suggest that laminin-5 γ2 chain and SPARC may play roles in the progression of esophageal SCC and their simultaneous expression is correlated with poorer prognosis, especially in patients with stage-II SCC.展开更多
The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. ...The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. However like other MMPs, the molecular basis of ST3 function in vivo remains unclear due to the lack of information on its physiological substrates. Furthermore, ST3 has only weak activities toward all tested ECM proteins. Using thyroid hormone-dependent Xenopus laevis metamorphosis as a model, we demonstrated previously that ST3 is important for apoptosis and tissue morphogenesis during intestinal remodeling. Here, we used yeast two-hybrid screen with mRNAs from metamorphosing tadpoles to identify potential substrate of ST3 during development. We thus isolated the 37 kd laminin receptor precursor (LR). We showed that LR binds to ST3 in vitro and can be cleaved by ST3 at two sites distinct from where other MMPs cleave. Through peptide sequencing, we determined that the two cleavage sites are in the extracellular domain between the transmembrane domain and laminin binding sequence. Furthermore, we demon strated that these cleavage sites are conserved in human LR. These results together with high levels of human LR and ST3 expression in carcinomas suggest that LR is a likely in vivo substrate of ST3 and that its cleavage by ST3 may alter cell-extracellular matrix interaction, thus, playing a role in mediating the effects of ST3 on cell fate and behavior ob- served during development and pathogenesis.展开更多
Laminin receptor(LN-R, Mr=70,000) isolated from murine Lewis lung carcinoma was shown to be a single band on SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide gel electrophoresis) after reduction. The present study Indi...Laminin receptor(LN-R, Mr=70,000) isolated from murine Lewis lung carcinoma was shown to be a single band on SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide gel electrophoresis) after reduction. The present study Indicates that LN-R was a kind of glycoproteins by periodic add Schiff staining. It’s pI was 4. 93. LN-R preperation was associated with phospholipid and neutral glycolipid by TLC (thin layer chromatography) or HPTLC (high performance thin layer chromtography) of chloroform-methanol extracts of LN-R, respectively, but without acidic glycolipid. Binding of LN-R with its ligand, Lamlnin, depended on the presence of Ca+ + , Mg++. LN-R may bind to actin.展开更多
The variation of membrane surface and lateral diffusion of membrane protein was studied after the interaction of laminin with its membrane receptor in mouse macrophages. A pattern of membrane surface which showed smal...The variation of membrane surface and lateral diffusion of membrane protein was studied after the interaction of laminin with its membrane receptor in mouse macrophages. A pattern of membrane surface which showed smaller and bigger peaks was obtained by scanning tunneling microscope(STM), looking like the domains of lipid groups and proteins in the model of fluid mosaic biomembraoe. Some even more higher and wider peaks projected out from the membrane surface in STM im-age after the interacting of laminin with membrane receptor were probably, tile complexes of laminin and membraue receptor. Furthermore. the deeceasad lateral diffusion coofficeent value(D^_) was obtained by Huorescence recovery after photobleaching (FRAP) after the laminin was reacted with membrane receptor. This phenomenon provides an evidence that the complexes of laminin and its membrane receptor were located on the membrane of macrophages. So we could consider that the laminin is combined with membrane receptor leading to the variation in the properties of membrane surface.展开更多
The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindr...The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindrical hydroxyapatite scaffolds with a hollow center were immersed in 100 mg/ml laminin solution and air-dried. Rat bone marrow cells in 200 ml culture medium at 1 × 106 cells/ml were seeded in the scaffolds. The scaffolds were implanted into the dorsal subcutis of 7-week-old male Fischer 344 rats for 6 weeks. The scaffolds were then removed and examined histologically. For in vitro examinations, 1 × 105 rat bone marrow cells in 2 ml culture medium were then cultured with the addition of dexamethasone and laminin. Rat bone marrow cells were also cultured in laminin-coated culture plates. In vitro examinations showed the effectiveness of laminin for hard tissue formation from the results of biochemical and immunochemical analysis. From the in vivo examination, laminin coating of the scaffolds induced hard tissue in the pores with the cells. It is concluded that laminin is useful for bone formation, as in an in vitro culture study using bone marrow cells, in hydroxyapatite scaffolds in vivo.展开更多
Microenvironmental biophysical factors play a fundamental role in controlling cell behaviors including cell morphology,proliferation,adhesion and differentiation,and even determining the cell fate.Cells are able to ac...Microenvironmental biophysical factors play a fundamental role in controlling cell behaviors including cell morphology,proliferation,adhesion and differentiation,and even determining the cell fate.Cells are able to actively sense the surrounding mechanical microenvironment and change their cellular morphology to adapt to it.Although cell morphological changes have been considered to be the first and most important step in the interaction between cells and their mechanical microenvironment,their regulatory network is not completely clear.In the current study,we generated silicon-based elastomer polydimethylsiloxane(PDMS)substrates with stiff(15:1,PDMS elastomer vs.curing agent)and soft(45:1)stiffnesses,which showed the Young’s moduli of~450 k Pa and 46 kPa,respectively,and elucidated a new path in cytoskeleton re-organization in chondrocytes in response to changed substrate stiffnesses by characterizing the axis shift from the secreted extracellular protein lamininβ1,focal adhesion complex protein FAK to microfilament bundling.We first showed the cellular cytoskeleton changes in chondrocytes by characterizing the cell spreading area and cellular synapses.We then found the changes of secreted extracellular linkage protein,lamininβ1,and focal adhesion complex protein,FAK,in chondrocytes in response to different substrate stiffnesses.These two proteins were shown to be directly interacted by Co-IP and colocalization.We next showed that impact of FAK on the cytoskeleton organization by showing the changes of microfilament bundles and found the potential intermediate regulators.Taking together,this modulation axis of lamininβ1-FAK-microfilament could enlarge our understanding about the interdependence among mechanosensing,mechanotransduction,and cytoskeleton re-organization.展开更多
文摘The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.
基金This study was supported by grants from the Natural Science Foundation of China (39970198) and Visiting Scholar Foundation of Education Ministry,China ([2002]4).
文摘BACKGROUND: Chemotaxis is an important step durin the invasion of carcinoma cells. And integrins are most im portant receptors mediating interaction between cells an extracellular matrix ( ECM). This study was designed t study integrin betal mediating chemotaxis of hepatocellula carcinoma (HCC) cells to laminin (LN). METHODS: A micropipette technique was adopted to in vestigate the effect of blockade of integrin betal on pseudo pod protrusion of HCC cells in response to LN stimulation Chemotactic pseudopod protrusion of a HCC cell was eva luated using a dual-pipette set-up, in which two pipette filled with LN solution were positioned in close contact wit the same cell, and pseudopod protrusion into each pipett was viewed dynamically and recorded with a tape recorder The lengths of pseudopods were measured and plotte against time to obtain a pseudopod growth curve. The in tegrin betal subunit on the surfaces of HCC cells were ana lyzed by flow cytometry. RESULTS: In dual pipette chemotaxis experiment, whe the two pipettes were filled with LN(50 μg/ml, 200 μg/ml) pseudopods extended from the HCC cell into each of th pipettes nearly symmetrically, ie, with nearly identica maximum pseudopod length and similar pseudopod growth curves. Upon addition of anti-CD29 (20 μg/ml) to one o the pipettes, pseudopod protrusion was blocked nearly completely while protrusion into the opposite pipette be came more evidently, with a larger maximum length. Ex pression of integrin betal was up to 95.78% to cells chosen in the experiment. CONCLUSION: Integrin betal subunit was an importan constituent receptor subunit for mediating chemotactic pseudopod protrusion of HCC cell to LN.
文摘The 67KD laminin receptor (LN-R ) that binds laminin (LN) is involved in the metastasis cascade. Using immunohistochemical technique, in situ hybridization and reverse transcription polymerase chain reaction(RT-PCR), we studied LN-R protein and RNA levels in 30 cases of human hepatocellular carcinoma (HCC) to further understand its role in the metastasis of HCC. In our 14 cases of HCC with metastasis, its positive rates were 71. 4 %, 57. 1%, 85.7% respectively, whereas its positive expression in 16 cases without metastasis were 31.3 %, 18. 8 %, 50. 0 % respectively. The significant difference was found between these two groups. The results suggest that the 67KD LN-R expression plays a very important role in the metastasis of HCC.
基金This project was supported by a grant from the NationalNatural Sciences Foundation of China (No.30 0 70 786 ) andHubei Science and Technology Department Foundation(No.0 1P15 0 5 )
文摘The change in serum laminin (LN) level and its clinical significance in epithelial ovarian tumor were investigated. The LN levels in serum and ascites samples from 69 patients with epithelial ovarian tumor and 42 cases as control group before and after operation were analyzed by radioimmunoassay. The results showed that the serum LN levels in the patients with malignant tumors (157.85 ±14.37 ng/ml) were significantly higher than that in the control group (125.14 ±7.03 ng/ml) and in the patients with benign tumors (128.36±8.75 ng/ml)(both P <0.01) before operation. The serum LN levels in the malignant group were decreased significantly after operation as compared with those before operation ( P <0.05). The serum LN levels in low differentiated tumors was higher than those in moderate differentiated tumors and high differentiated tumors ( P <0.05). The LN levels in ascites (172.94±15.26 ng/ml) was significantly higher than in serum (161.34±6.59 ng/ml)( P <0.05) in malignant tumors. The serum LN levels in the patients with lymph node metastasis (165.41±19.91 ng/ml) was obviously higher than those without lymph node metastasis (152.35±10.34 ng/ml)( P <0.05). It was concluded that LN levels in serum and acistes were remarkably increased in malignant epithelial ovarian tumors, suggesting that LN might be one of important diameters reflecting tumor biological characteristics.
基金This work was supported by a grand from the Natural Science Foundation of Beijing (No. 7022006).
文摘Objective: To prepare monoclonal antibody (McAb) against the Integrin a6 extracellular domain and identify its biological activities. Methods: Fusion-protein of integrin a6 extracellular domain (GST-IAGED) was expressed in E.coli. JM109 and used for immunizing BALB/C mice. The spleen cells from immunized mice were fused with SP2/0 cells and selectively cultured with HAT medium. ELISA and immunocytochemistry staining were used to select hybridomas. Results: One strain of hybridoma cells that secreted specific monoclonal antibody against integrin a6 extracellular domain was indentified. The immunoglobulin subclass of the McAb was IgG1. Conclusion: The McAb against the extracellular domain of integrin a6 was successfully prepared by using GST-IA6ED fusion protein expressed by E.Coli. And the McAb had positive reaction with human hepatocarcinoma cells-BEL-7402.
文摘Our previous reports have shown that lamininglycopeptides (LN-GPs), the total glycopeptides prepared from laminin (LN), can prevent the experimental lung metastasis and liver metastasis of mouse cancer cells. In order to explore the anti-metastatic mechanism of LNGPs, we studied the effects of LN-GPs on metastasisrelated behaviors of cancer cells in vitro. LN-GPs did not affect cell survival. However, LN-GPs inhibited cell attachment and spreading Of 5180 cells on LN- and Matrigelsubstrate in dose-dependent and time-dependent manners. Moreover, inhibition of cen attachment and spreading on Matrigel substrates were much greater on Matrigel substrate than on LN substrate. In the presence of LN-GPs, 5180 cells on LN substrate changed from a flattened polygonal shape to a round one, the migration of 5180 cells on LN substrate decreased, and the number of a highly invasive human pulmonary giant caxcinoma PG cells invading Matrigel filter in a Boyden chamber was reduced. LN-GPs thus have multiple inhibitory effects on cancer motastasisrelated behaviors.
基金Supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture,Sports,Science and Technology of Japan (H.Y. and K.I.)Grants-in-Aid for Cancer Research and for the Third Term Comprehensive 10-Year Strategy for Cancer Control from the Ministry of Health,Labor and Welfare of Japan (H.Y. and K.I.)
文摘AIM:To clarify the clinicopathological significance of laminin-5 γ2 (LNγ2) and β3 (LNβ3) chains and MMP7 expression in biliary tract cancer.METHODS: We analyzed the association between immunohistochemically detected LNγ2, LNβ3, and MMP7 expression in biliary tract cancer and clinicopathological characteristics. Activity of MMP7 was analyzed by casein zymography. An in vitro invasion assay after treatment with MMP7-specific siRNA was performed.RESULTS: LNγ2 expression was predominantly observed in carcinoma cells at the invasive front. LNγ2 expression was seen in 57% of patients with biliary tract cancer, and was associated with depth of invasion, histologic type, and advanced stage. The expression pattern of LNβ3 was classified into two types: invasive front dominant type (38%) and diffuse type (28%).The invasive front dominant type was associated with histologic type and advanced stage. MMP7 positivity was correlated with LNγ2 or LNβ3 expression but not with clinicopathological characteristics. Active MMP7 detected by casein zymography was correlated with depth of invasion and advanced stage. Downregulation of MMP7 expression by siRNA resulted in a significant decrease in biliary tract cancer cell invasion in vitro.CONCLUSION: Our results suggest that LNγ2 and LNβ3, in conjunction with MMP7, play a key role in the progression of biliary tract cancer.
文摘Objective To explore the role of serum fibrotic indices including hyaluronic acid (HA), procollagen type III NH_ 2-terminal peptide (PCIIIP), and laminin (LN) in assessing the severity of myocardial fibrosis in chronic congestive heart failure (CHF).Methods Serum levels of HA, PCIIIP, and LN in 39 patients with CHF[14 with New York Heart Association (NYHA) functional class II, 21 with class III, 4 with class IV]and in 46 patients with NYHA functional class I were assessed by radioimmunoassay.Results The serum concentrations of HA, PCIIIP, and LN were 359.75±84.59 μg/L, 77.88±24.67 μg/L, 86.73±23.90 μg/L in CHF group, and 211.60±54.80 μg/L, 64.82±23.99 μg/L, 82.26±23.98 μg/L in NYHA functional class I group, respectively. The HA level was significantly higher in CHF patients as compared with NYHA functional class I group (P<0.05). However, no difference was found in the levels of PCIIIP and LN between CHF group and NYHA functional class I group. The serum HA concentration was negatively correlated with left ventricular ejection fraction (r=-0.71, P<0.05).Conclusion Serum HA level may act as an indicator for myocardial fibrosis.
文摘Laminin is a glycoprotein which has an important role in the mechanism of fibrogenesis and is,thus,related to hepatic fibrosis in addition to presenting increased levels in several types of neoplasias. However,its determination is not routinely considered in the study of hepatic fibrosis. In this review,the authors critically comment on the role of this glycoprotein compared to other markers of fibrosis through non-invasive procedures(Fibroscan). They also consider its clinical investigational potential and believe that the continuation of these investigations might contribute to a better understanding of the fibrogenic mechanism,which could in turn either lead to the identification of patients at risk of developing fibrosis non-alcoholic fatty liver disease(NAFLD) and non-alcoholic steatohepatitis(NASH) or at least be used as an indicator for hepatic biopsy in such patients. Finally,the authors believe that serum laminin determination might contribute to the diagnosis of epithelial tumor metastasis and peritoneal carcinomatosis.
文摘A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly(ethylene terephthalate) (PET) and polyethylene (PE) as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with laminin (LCP solution). The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin-apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite composite coating.
文摘Objective To study the serum laminin(LN)and fibronectin(FN)changes in acute coronary syndromes(ACS),and explore the role of them in assessing the severity of ACS.Methods This study included 46 ACS patients [25 with acute myocardial infarction(AMI)and 21 with unstable angina(UA)],51 stable angina(SA)patients and 47 people without CHD as controls.Serum levels of LN,FN,fibrinogen and blood fat were assessed.Coronary angiography were performed on 49 of them.Results The serum concentration of LN was lower in ACS patients [(85.20±27.57)ng/mL],higher in SA patients [(116.80±28.80)ng/mL] as compared to that in the control group [(100.06±29.96)ng/mL],with significant difference among the groups(P<0.05).No difference was found in FN among the three groups.However,the subgroup analysis in the group with ACS showed that the serum concentration of FN was significantly higher in UA patients [(229.60±121.39)μg/mL],and lower in AMI patients [(108.31±47.12)μg/mL].The serum LN and FN concentration could respectively enter the logistic regression equations of ACS patients and US patients.Neither LN nor FN concentration was correlated with narrowing of coronary artery of angiography.Conclusion Serum LN and FN level may be a useful indicator for stability of atherosclerosis plaque in coronary arterial disease patients,but could not predict the extent of narrowing in coronary angiography.
基金supported by National Natural Science Foundation of the People's Republic of China(No.30670964,30770973)Beijing Hope Run Special Fund(No.LC2007B51)
文摘Previous studies have shown that the expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess the expressions of laminin-5 γ2 chain and SPARC in esophageal squamous cell carcinoma (SCC), and to clarify the prognostic significance of the expressions of laminin-5 γ2 chain and SPARC in esophageal SCC, we detected the expressions of laminin-5 γ2 chain and SPARC in cancer tissue and corresponding normal mucosa from 116 patients with advanced (stages II-IV) esophageal SCC using the tissue microarray-based immunohistochemistry and analyzed the correlation of the expressions with clinicopathologic characteristics and survival. We found that in normal esophageal tissues, laminin-5 γ2 chain was expressed in the basement membrane, whereas in esophageal SCC tissues, laminin-5 γ2 chain was expressed in the cytoplasm of carcinoma cells, with a positive rate of 72.4%. SPARC was not detected in normal esophageal mucosa, but was expressed in stromal fibroblasts in 84.6% of esophageal SCC cases and in cancer cells in 7.8% of esophageal SCC cases. There was a significant correlation between laminin-5 γ2 chain and stromal SPARC expression in esophageal SCC (Spearman's rho = 0.423, P < 0.001). The expressions of both laminin-5 γ2 chain and stromal SPARC were correlated with survival (P = 0.032 and P = 0.034, respectively). In stage-II esophageal SCC, the expression of laminin-5 γ2 chain was significantly correlated with survival (P = 0.023), while the expression of SPARC was not significantly correlated with survival (P = 0.154). Patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis than did those lacking elevated levels of laminin-5 γ2 chain expression and/or elevated levels of SPARC expression (P = 0.001). In stage-II esophageal SCC, patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis (P < 0.001). These results suggest that laminin-5 γ2 chain and SPARC may play roles in the progression of esophageal SCC and their simultaneous expression is correlated with poorer prognosis, especially in patients with stage-II SCC.
文摘The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. However like other MMPs, the molecular basis of ST3 function in vivo remains unclear due to the lack of information on its physiological substrates. Furthermore, ST3 has only weak activities toward all tested ECM proteins. Using thyroid hormone-dependent Xenopus laevis metamorphosis as a model, we demonstrated previously that ST3 is important for apoptosis and tissue morphogenesis during intestinal remodeling. Here, we used yeast two-hybrid screen with mRNAs from metamorphosing tadpoles to identify potential substrate of ST3 during development. We thus isolated the 37 kd laminin receptor precursor (LR). We showed that LR binds to ST3 in vitro and can be cleaved by ST3 at two sites distinct from where other MMPs cleave. Through peptide sequencing, we determined that the two cleavage sites are in the extracellular domain between the transmembrane domain and laminin binding sequence. Furthermore, we demon strated that these cleavage sites are conserved in human LR. These results together with high levels of human LR and ST3 expression in carcinomas suggest that LR is a likely in vivo substrate of ST3 and that its cleavage by ST3 may alter cell-extracellular matrix interaction, thus, playing a role in mediating the effects of ST3 on cell fate and behavior ob- served during development and pathogenesis.
文摘Laminin receptor(LN-R, Mr=70,000) isolated from murine Lewis lung carcinoma was shown to be a single band on SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide gel electrophoresis) after reduction. The present study Indicates that LN-R was a kind of glycoproteins by periodic add Schiff staining. It’s pI was 4. 93. LN-R preperation was associated with phospholipid and neutral glycolipid by TLC (thin layer chromatography) or HPTLC (high performance thin layer chromtography) of chloroform-methanol extracts of LN-R, respectively, but without acidic glycolipid. Binding of LN-R with its ligand, Lamlnin, depended on the presence of Ca+ + , Mg++. LN-R may bind to actin.
基金a great from the Nationa Natural Science Foundation,
文摘The variation of membrane surface and lateral diffusion of membrane protein was studied after the interaction of laminin with its membrane receptor in mouse macrophages. A pattern of membrane surface which showed smaller and bigger peaks was obtained by scanning tunneling microscope(STM), looking like the domains of lipid groups and proteins in the model of fluid mosaic biomembraoe. Some even more higher and wider peaks projected out from the membrane surface in STM im-age after the interacting of laminin with membrane receptor were probably, tile complexes of laminin and membraue receptor. Furthermore. the deeceasad lateral diffusion coofficeent value(D^_) was obtained by Huorescence recovery after photobleaching (FRAP) after the laminin was reacted with membrane receptor. This phenomenon provides an evidence that the complexes of laminin and its membrane receptor were located on the membrane of macrophages. So we could consider that the laminin is combined with membrane receptor leading to the variation in the properties of membrane surface.
文摘The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindrical hydroxyapatite scaffolds with a hollow center were immersed in 100 mg/ml laminin solution and air-dried. Rat bone marrow cells in 200 ml culture medium at 1 × 106 cells/ml were seeded in the scaffolds. The scaffolds were implanted into the dorsal subcutis of 7-week-old male Fischer 344 rats for 6 weeks. The scaffolds were then removed and examined histologically. For in vitro examinations, 1 × 105 rat bone marrow cells in 2 ml culture medium were then cultured with the addition of dexamethasone and laminin. Rat bone marrow cells were also cultured in laminin-coated culture plates. In vitro examinations showed the effectiveness of laminin for hard tissue formation from the results of biochemical and immunochemical analysis. From the in vivo examination, laminin coating of the scaffolds induced hard tissue in the pores with the cells. It is concluded that laminin is useful for bone formation, as in an in vitro culture study using bone marrow cells, in hydroxyapatite scaffolds in vivo.
基金supported by the National Natural Science Foundation of China(81771047 to Jing Xie,81901040,82171001 to C.Z.)by the Young Elite Scientist Sponsorship Program by CAST(2020QNR001)。
文摘Microenvironmental biophysical factors play a fundamental role in controlling cell behaviors including cell morphology,proliferation,adhesion and differentiation,and even determining the cell fate.Cells are able to actively sense the surrounding mechanical microenvironment and change their cellular morphology to adapt to it.Although cell morphological changes have been considered to be the first and most important step in the interaction between cells and their mechanical microenvironment,their regulatory network is not completely clear.In the current study,we generated silicon-based elastomer polydimethylsiloxane(PDMS)substrates with stiff(15:1,PDMS elastomer vs.curing agent)and soft(45:1)stiffnesses,which showed the Young’s moduli of~450 k Pa and 46 kPa,respectively,and elucidated a new path in cytoskeleton re-organization in chondrocytes in response to changed substrate stiffnesses by characterizing the axis shift from the secreted extracellular protein lamininβ1,focal adhesion complex protein FAK to microfilament bundling.We first showed the cellular cytoskeleton changes in chondrocytes by characterizing the cell spreading area and cellular synapses.We then found the changes of secreted extracellular linkage protein,lamininβ1,and focal adhesion complex protein,FAK,in chondrocytes in response to different substrate stiffnesses.These two proteins were shown to be directly interacted by Co-IP and colocalization.We next showed that impact of FAK on the cytoskeleton organization by showing the changes of microfilament bundles and found the potential intermediate regulators.Taking together,this modulation axis of lamininβ1-FAK-microfilament could enlarge our understanding about the interdependence among mechanosensing,mechanotransduction,and cytoskeleton re-organization.
