BACKGROUND AND OBJECTIVES: Adenosine diphosphate (ADP), which is usually secreted from activated platelets, may activate integrins on vascular smooth muscle cells, resulting in adhesion and proliferation. Integrins, mediating the ADP-stimulated adhesion and proliferation of vascular smooth muscle cells, was investigated in this study. MATERIALS AND METHODS: Prothrombin (PT) and bone sialoprotein (BSP) were used as activation-dependent ligands in an adhesion assay. The adhesion of human aortic smooth muscle cells (HASMC) were measured after ADP stimulation, using ligand-coated 24-well plates. The 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the ADP-stimulated proliferation of the HASMC.RESULTS: ADP activated the HASMC to increase their adhesion to the PT or BSP, and their proliferation in a dose-dependent manner. The adhesion of the ADP-stimulated HASMC to the PT was completely blocked by P5H9, a blocking monoclonal Ab (mAb) to integrin alphavbeta5 (92% inhibition), but was only slightly inhibited by LM609, a blocking mAb to integrin alphavbeta3 (30% inhibition). The adhesion of the ADP-stimulated HASMC to the BSP was partially inhibited by both P5H9 (46% inhibition) and JBS5, a blocking mAb to integrin alpha5beta1 (75% inhibition), but was not affected by c7E3, a blocking mAb to integrin beta3. The ADP-stimulated proliferation of the HASMC was inhibited by both c7E3 and LM609 (98% and 93% inhibition, respectively), but not by either P1F5, a blocking mAb to integrin alphavbeta5 or JBS5. CONCLUSION: These results indicate the different roles of integrins on vascular smooth muscle cells after ADP stimulation; the integrins alphavbeta5 and alpha5beta1 for adhesion, and the integrin alphavbeta3 for proliferation.
Adenosine Diphosphate ; Humans ; Integrin alpha5beta1 ; Integrin alphaVbeta3 ; Integrin beta3 ; Integrin-Binding Sialoprotein ; Integrins* ; Ligands ; Muscle, Smooth, Vascular* ; Myocytes, Smooth Muscle ; Negotiating* ; Prothrombin

OBJECTIVETo study the expression of alpha5beta1 integrin in the abnormal scars and its role and significance in the formation and development of abnormal scars.

METHODSThe expression of alpha5beta1 integrin was observed in hypertrophic scar (15 samples), keloid (15 samples) and normal skin (10 samples) with SP immunohistochemical method and colloidal gold immuno-electron microscopic technique. The data were semi-quantitatively analyzed.

RESULTSThe expression levels of alpha5beta1 integrin in the fibroblasts of keloids and hypertrophic scars were higher than normal skin; the expression of alpha5beta1 integrin in the fibroblasts of keloids was higher than hypertrophic scars (P < 0.01).

CONCLUSIONThe alpha5beta1 integrin appears to have close relation to the formation and development of abnormal scars. To find a way to decrease the expression level of alpha5beta1 integrin in fibroblasts may be a new approach to inhibit scar hypertrophy.

Cicatrix ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Integrin alpha5beta1 ; analysis ; metabolism ; Keloid ; metabolism ; pathology ; Microscopy, Immunoelectron ; Skin ; chemistry ; pathology ; ultrastructure

OBJECTIVE: The adhesion molecule that mediate cell-cell and cell-extracellular matrix adhes.ion provides very important role in growth and differentiation of cells and tissue. VLA integrin is a prototype of adhesion molecule which participate in cell-cell and cell-extracellular matrix interacton, especially for collagen, laminin and fibronectin. The biologic functions of VLA-integrin are very diverse. Cartilage is the target tissue of various arthritides including rheumatoid arthritis and osteoarthritis and the process of homeostasis in cartilage matrix may be very important in preservation of cartilage. Although VLA integrin may participate in the process of cartilage degeneration and repair mechanism, tissue.distribution and exact role of VLA integtin in cartilage was not yet clearly defined. METHODS:Immunohistochemical analysis of VLA-integrin in cryostat section of articular cartilage was conducted using monoclonal antibody and avidin-biotin complex method. Analysis was performed in 10 rheumatoid arthritis specimens, 7 osteoarthritis specimens and 1 normal control. RESULTS: 1) Normal cartilage showed strong and diffuse stain with CD29, CD51 and moderate stain of VLA-5. Staining pattern of VLA-1 and 3 was inconstant and weak in intensity. 2) The intensity of VLA expression in articular cartilage of osteoarthritis was upregulated chiefly in CD29, CD51 and slightly in VLA-5. The positive rate of VLA-1 and 3 was similar to that of normal cartilage though the intensity was increased especially at cluster of chondrocytes. 3) VLA-integrin expression of rheumatoid arthritis cartilage was similar to that of osteoarthritis cartilage. CONCLUSION: VLA integrins functioning as fibronectin receptor such as VLA-5 and alpha, beta1 were upregulated in osteoarthritis and rheumatoid arthritis. Intensity was increased at clusters of chondrocytes. It was able to presume from above findings that VLA molecule has some role in the maintenance and repair of articular cartilage. The regulation of expression by cytokines and growth factors and exact function of VLA molecule in cartilage have to be elucidated.
Arthritis ; Arthritis, Rheumatoid ; Cartilage ; Cartilage, Articular* ; Chondrocytes ; Collagen ; Cytokines ; Fibronectins ; Homeostasis ; Integrin alpha1beta1 ; Integrin alpha5beta1 ; Integrins ; Intercellular Signaling Peptides and Proteins ; Laminin ; Osteoarthritis

Anodic spark deposition method(ASD) surface treated titanium implant possesses a considerable osteoconductive potential that promoting a high level of implant osseointegration in normal bone. The purpose of this study was to observe the ASD implant's osseointegration in the osteoporosis-induced animal model. Twenty four rats, 10 weeks of age, were ovarectomized and 5 weeks later divided into two groups : ASD implant group and control implant group. Titanium screw implants (diameter; 2.0 mm, length, 3.5 mm; pitch-height, 0.4 mm) were designed for this study. Experimental implants were ASD treated and no treatment on control implants. ASD implants and control implants were placed in to left tibiae of rats. The rats were sacrificed at different time interval(1, 2, 4 and 8 weeks after implantation) for histopathologic observation and immunohisto -chemistrical observation, with collagen type I, fibronectin, integrin alpha2beta1 and integrin alpha5beta1 antibodies. The results obtained from this study were as follow: 1. Histopathologic findings, overall tissue response and the pattern of bone formation in both groups were similar. In ASD group, more newly formed bone was seen at 1 week and 2weeks than control group. 2. The levels of type I collagen and fibronectin expression were the most abundant at 2weeks and decreased gradually in both groups. Fibronectin and type I collagen expression in ASD group were stronger than control group but no significance. 3. The levels of integrin alpha2beta1 and Integrin alpha5beta1 expression were most abundant at 2 weeks and decreased gradually in both groups. No significant difference was observed in both groups. From this results, anodic oxidized titanium implants were more advantages in early stage of bone formation than control group, but have no significance in tissue responses and late bone formations. It could be stated that although anodic oxidized titanium implant possesses considerable osteoconductive potential but in osteoporotic bone condition dental implant procedure should performed after improving or treating the osteoporotic bone condition.
Animals ; Antibodies ; Collagen Type I ; Dental Implants ; Fibronectins ; Implants, Experimental ; Integrin alpha2beta1 ; Integrin alpha5beta1 ; Models, Animal ; Osseointegration ; Osteogenesis ; Osteoporosis ; Rats ; Tibia ; Titanium

OBJECTIVETo explore the correlation between the expression of integrin subunits alpha5 and beta1 in prostate cancer (PCa) and its clinicopathological data including tumor grade and clinical stage.

METHODSExpressions of integrin subunits alpha5 and beta1 were examined in 30 cases of PCa and 30 cases of normal prostatic tissues by immunohistochemical assay.

RESULTSExpressions of integrin subunits alpha5 and beta1 in PCa were lower than those in normal prostatic tissues (P <0.05) respectively.

CONCLUSIONCompared with normal prostatic tissues, expressions of integrin subunits alpha5 and beta1 in PCa were rather weaker or even faded. Expressions of integrin subunits alpha5 and beta1 revealed an positive correlation with tumor's Gleason grade and negative with clinical TNM stage. The results indicate that integrin subunits alpha5 and beta1 have potential values in the diagnosis and are predictable indices in the proliferation of PCa.

Aged ; Aged, 80 and over ; Animals ; Humans ; Integrin alpha5 ; biosynthesis ; Integrin alpha5beta1 ; biosynthesis ; Male ; Mice ; Middle Aged ; Neoplasm Staging ; Prostatic Hyperplasia ; metabolism ; Prostatic Neoplasms ; metabolism ; pathology

Ullrich's disease is a congenital muscular dystrophy clinically characterized by generalized muscle weakness, multiple contractures of the proximal joints, and hyperextensibility of the distal joints. All the patients develop rigidity of spine, often assoicated with scoliosis, failure to thrive, and early and severe respiratory involvement, irrespective of their levels of motor function. Intellectual development is normal. The biopsied muscles show dystrophies including remarkable variation in the fiber size, notably proliferated endomysial connective tissues, and a lot of degenerated and regenerated fibers. The expression of merosin and dytrophin is normal. Recent studies have demonstrated that collagen VI is deficient in the muscles of the patients with Ullrich's disease, and some result from recessive mutations of the collagen VIalpha 2 gene(COL6A2). And a marked reduction of fibronectin receptors in the extracellular matrix of skin and cultured fibroblasts of these patients is also reported. These results suggest that collagen VI deficiency may lead to the reduction of fibronectin receptors and that any abnormalities of cell adhesion may be involved in the pathogenesis of the disease. A case of Ullrich's disease has not been reported yet in Korea. So, we describe a male patient with Ullrich's disease with a brief review of the literature.
Cell Adhesion ; Collagen ; Connective Tissue ; Contracture ; Extracellular Matrix ; Failure to Thrive ; Fibroblasts ; Humans ; Integrin alpha5beta1 ; Joints ; Korea ; Laminin ; Male ; Muscle Weakness ; Muscles ; Muscular Dystrophies ; Receptors, Fibronectin ; Scoliosis ; Skin ; Spine

PURPOSE: We investigated the effects of recombinant 9-10th type III repeat of fibronectin (rhFNIII9-10) on the adhesion, proliferation, and the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells(hMSCs). MATERIALS AND METHODS: Adhesion and blocking assay for hMSCs were performed on the plates which had been coated with 100 microgram/ml rhFNIII9-10 or fibronectin. hMSCs seeded on the precoated plates were cultured in the osteogenic media for 3 weeks. MTS(Dimethylthiazole carboxymethoxyphenyl sulfophenyl tetrazolium compound) assay for the cell number, [Methyl-3H] thymidine incorporation study, alkaline phosphatase activity assay, calcium content assay and RT-PCR for alkaline phosphatase, osteopontin, cbfa-1, and type I collagen were performed during the osteogenic differentiation. RESULTS: hMSCs showed significantly increased adhesion to rhFNIII9-10-coated plates and fibronectin-coated plates. A monoclonal antibody to the integrin alpha 5 beta 1 inhibited adhesion to rhFNIII9-10-coated plates and fibronectin-coated plates in dose-dependent manner. hMSCs seeded on the rhFNIII9-10-coated plates showed increased proliferation during the osteogenic differentiation. However, there was no significant difference in the alkaline phosphatase activity, calcium content and expression levels of mRNAs for alkaline phosphatase, osteopontin, cbfa-1, and type I collagen of hMSCs seeded on the rhFNIII9-10-coated plates. CONCLUSION: rhFNIII9-10 stimulates hMSCs adhesion and increases hMSCs proliferation during the osteogenic differentiation. Although osteogenic differentiation is not promoted, adsorption of rhFNIII9-10 onto appropriate biomaterials can enhance integrin-mediated hMSCs adhesion and proliferation. This biomolecular engineering strategy represents a robust approach to increase biofunctional activity and integrin specificity of hMSCs.
Adsorption ; Alkaline Phosphatase ; Biocompatible Materials ; Bone Marrow ; Calcium ; Cell Count ; Collagen Type I ; Fibronectins* ; Humans* ; Integrin alpha5beta1 ; Mesenchymal Stromal Cells* ; Osteopontin ; RNA, Messenger ; Sensitivity and Specificity ; Thymidine

To investigate the effect of vascular endothelial growth factor (VEGF) on beta1 integrin (VLA-4 and VLA-5) activation ability in K562 cells transfected with antisense VEGF121 cDNA, K562 cells were transfected with antisense (As), sense (S) and vector (V, pcDNA(3)). Flow cytometry was used to evaluate the expression rate of VLA-4 (CD49d/CD29) and VLA-5 (CD49e/CD29) and beta1 integrin activation ability in the transfected K562 cells. The results showed that the expression rates of VLA-4 and VLA-5 were more than 92% in the transfected K562 cells and there was no difference among the K562/V, K562/S and K562/As cells. However, beta1 integrin activated 9EG7 expression rate in K562/As cells was higher than that in K562/V cells [(75.6 +/- 10.5)% vs (41.2 +/- 2.1)%, P < 0.01)] after activation with beta1 integrin activator 8A2. It is concluded that function of beta1 integrin to be activated is restored in K562 cells transfected with antisense VEGF121 cDNA.
DNA ; genetics ; DNA, Antisense ; genetics ; Endothelial Growth Factors ; genetics ; metabolism ; Flow Cytometry ; Humans ; Integrin alpha4beta1 ; biosynthesis ; Integrin alpha5beta1 ; biosynthesis ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; K562 Cells ; Lymphokines ; genetics ; metabolism ; Transfection ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

Pathophysiological mechanism of hemorrhagic fever with renal syndrome (HFRS) is not fully understood. Major clinical findings of HFRS patients are widespread hemorrhage, acute renal failure and shock. Basic lesion is vascular injury with microvascular hemorrhage and relatively little inflammation. According to autopsy findings, renal medulla shows focal hemorrhage, tubular necrosis and interstitial mononuclear infiltrates. The predominant cell type in the renal and pulmonary interstitium is a fibroblast and it participates in the healing process at the injury site by secreting a large amount of extracellular matrix proteins. Cultured human lung fibroblasts and Mongolian gerbil fibroblasts were known to be good host cells for the hantaan virus. It is possible that not only the endothelial cell but also the fibroblast is a target of Hantaan virus and the fibroblast might be involved in the pathogenesis and the healing process in HFRS. Integrins are adhesion molecules, and act as receptors for many extracellular matrix proteins. Recently, there are many reports that cell surface integrins influence on some viral infections or reversely viruses influence on the expression of integrins. The alpha5beta1 integrin is a major receptor for the fibronectin which is an important extracellular matrix protein secreted by fibroblasts. In this study, the role of alpha5beta1 integrin in the infection of Hantaan virus was examined by using anti-alpha5beta1 integrin, anti-alpha5 integrin and anti-beta1 integrin antibodies in chicken embryo fibroblasts (CEF) and Mongolian gerbil fibroblasts(MGF). The treatment of anti-alpha5beta1 integrin antibody in CEF reduced the virion titers 26.8% and the amount of nucleocapsid N protein 32.6% when compared with control CEF. When MGF were treated with anti-alpha5, anti-beta1 and anti-alpha5beta1 integrin antibodies, virion titers were reduced by 26.5%, 29.4% and 28.7% and the amount of nucleocapsid N protein were reduced by 65.2%, 59.7% and 72.6%. These results suggested that alpha5beta1 integrin might act as a receptor for the Hantaan virus or blocking of alpha5beta1 integrin influences on the viral replication in CEF and MGF. It is also possible that the blocking of only one subunit of integrin represents similar results in that of whole molecule.
Acute Kidney Injury ; Antibodies* ; Autopsy ; Chickens ; Embryonic Structures ; Endothelial Cells ; Extracellular Matrix ; Extracellular Matrix Proteins ; Fibroblasts* ; Fibronectins ; Gerbillinae ; Hantaan virus* ; Hemorrhage ; Hemorrhagic Fever with Renal Syndrome ; Humans ; Inflammation ; Integrin alpha5beta1 ; Integrins ; Lung ; Necrosis ; Nucleocapsid ; Shock ; Vascular System Injuries ; Virion

The clinical symptoms and signs of hemorrhagic fever with renal syndrome (HFRS) are well known, but the pathophysiology caused by Hantaan virus is not fully understood yet. This study was designed to evaluate the effect of Hantaan virus on the regulation of extracellular matrix proteins. The changes of fibronectin, fibronectin receptor (alpha5beta1 integrin), the matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in Vero E6 cell line were observed. Hantaan virus induced the mRNA expression of fibronectin at day 7 after the infection but the surface expression of fibronectin receptor (alpha5beta1 integrin) was reduced. The mRNA expression of MMP-3 was increased at day 5 by 8-fold in the virus infected cells compared with the control cells, and continued to increase until day 9. However, the mRNA expression of TIMP-1 did not show any significant changes. The concentration of plasma fibronectin in the HFRS patients was measured by ELISA. The fibronectin levels were variable and could be divided into three groups: low (14.8%), normal (62.9%) and high (22.2%) groups in comparison with normal range value. These results suggest that Hantaan virus should affect not only the infected cell itself but also the extracelluar matrix, which might play an important role in the pathogenesis.
Cell Line ; Enzyme-Linked Immunosorbent Assay ; Extracellular Matrix Proteins ; Fibronectins* ; Hantaan virus* ; Hemorrhagic Fever with Renal Syndrome ; Humans ; Integrin alpha5beta1 ; Matrix Metalloproteinase 1 ; Plasma ; Reference Values ; RNA, Messenger ; Tissue Inhibitor of Metalloproteinase-1