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

BACKGROUND: It has been known that integrins are not only simple glue which mediate cell-to-cell or cell to extra-cellular matrix but also function as signaling molecules at the surface of cell by conformational change. Because of the diversity of subunits and versatility of ligand recognition, integrins have been recognized as important molecules in kidney and the expression of integrin in normal human kidney has already been reported. METHODS: To know the significance of integrin expression in the pathogenesis of various renal diseases, we stained kidney specimens from the patients with membrano- proliferative glomerulonephritis(MPGN), minimal change nephrotic syndrome(MCNS) and membraneous nephropathy(MN) of lupus nephritis with 13 monoclonal antibodies of integrins. RESULTS: There was a significant change in the distribution of integrin subunits according to the types of glomerular diseases. Integrin subunit alpha2 was helpful in confirming the mesangial interposition as there was intense staining of subendotherial area in MPGN, while only the mesangium was stained with this unit in normal. In addition, an abundant staining of alpha4 and beta2 was observed and this finding indicated non-glomerular resident cell is participating in the MPGN, while in MN type of lupus nephritis, alpha2 staining was restricted to mesangium and alpha4 or beta2 integrin staining was negative. In the MN type of lupus nephritis, the remarkable finding was a ragged appearance in the subepithelial area, just below the glomerular basement membrane, which was visible in alpha3 and alphaV integrin staining. In MCNS, there was no difference in the staining pattern of integrin. CONCLUSION: Integrin subunits can be useful in evaluating the specific cell types which is actively involved in pathogenesis and these results suggest that alteration of integrin distribution can play an important role in the pathogenesis of glomerular diseases.
Adhesives ; Antibodies, Monoclonal ; Antigens, CD18 ; Glomerular Basement Membrane ; Glomerulonephritis ; Glomerulonephritis, Membranoproliferative ; Humans ; Integrin alphaV ; Integrins ; Kidney ; Lupus Nephritis

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

Introduction: Epidermolysis Bullosa (EB) is a rare genodermatosis characterized by fragility of the skin and mucous membranes, manifested by blistering with little or no trauma. There are three subtypes: EB Simplex, Junctional EB, and Dystrophic EB. Each type of EB has its own specific genetic defect. We report a case of a 13-year-old girl who presented with multiple tense blisters and eroded plaques since birth on the entire body. Case summary: This is a 13-year-old-girl who presented with solitary tense blister on her right thigh three days after birth, which gradually affected the scalp, trunk, and upper and lower extremities, particularly on the trauma prone areas. There was nail dystrophy and multiple brownish dental pits at three years of age. A 4 mm lesional skin punch biopsy showed subepidermal blisters containing fibrin, lymphocytes and few red blood cells. PAS showed basement membrane zone beneath the blister, compatible with EB. Immunofluorescence mapping showed decreased immunofluorescence (+1) on keratin 5/6, (+2) on keratin 14, and absence of immunofluorescence on alpha 6 / beta 4 integrins. Final diagnosis is EB Simplex. Conclusion Early detection is important in managing this case, to detect systemic involvement and provide palliative care. Genetic counseling is recommended for prospective parents who have a family history of any form of epidermolysis bullosa. The prognosis of Inherited EB is very variable and the mortality is usually due to complications of systemic involvement. A multidisciplinary approach in the supportive management of this case is necessary as there is still no cure for this condition.
Fluorescent Antibody Technique ; Integrins

Recent studies have showed that thrombosis is closely related to leucocytes involved in immunity. Interfering with the binding of leukocyte integrin Mac-1 and platelet GPIbα can inhibit thrombosis without affecting physiological coagulation. Mac-1-GPIbα is proposed as a potential safety target for antithrombotic agents. Guanxinning tablet (GXNT) is an oral Chinese patent medicine used for the treatment of angina pectoris, which contains phenolic acid active ingredients, such as salvianolic acids, ferulic acid, chlorogenic acid, caffeic acid, rosmarinic acid, tanshinol, and protocatechualdehyde. Our previous studies demonstrated that GXN exhibited significant antithrombotic effects, and clinical studies suggested that it did not increase bleeding risk. In addition, GXN exerted a significantly regulatory effect on immune inflammation. In the current study, we intended to evaluate the effects of GXN on bleeding events and explore the safety antithrombotic mechanism of GXN based on leukocyte-platelet interaction. First, we established a gastric ulcer model induced by acetic acid in rats and found that GXN not only did not increase the degree of gastrointestinal bleeding when gastric ulcer occurred, but also had a certain promoting effect on the healing of gastric ulcer. Second, in vitroexperiments showed that after pretreatment with GXN and activation by phorbol 12-myristate-13-acetate (PMA), the adhesion and aggregation of leukocytes with human platelets were reduced. It was also found that GXN reduced the expression and activation of Mac-1 in leucocytes, and inhibited platelet activation due to leukocyte engagement via Mac-1. Overall, the results suggest that GXN may be a safe antithrombotic agent, and its low bleeding risk mechanism is probably related to inhibited leukocyte-platelet aggregation and its interaction target Mac-1-GPIbα.
Animals ; Fibrinolytic Agents ; Humans ; Integrins ; Leukocytes ; Macrophage-1 Antigen ; Rats ; Stomach Ulcer ; Tablets ; Thrombosis

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

Intexcellular adhesion molecule-10CAM- 1) is an important moleade in aehating immune and inflammatory responses. It is found on the surface of hematopoietic and nonhematopoietic cells. It can act as an adhesive ligand for integrins such as LFA-1 (CD1&/CD11a) and MAC-1 (CD18/ CD11b). ICAM-1 is basally expressed in sigaificant amount on a limited number of cell types, including monocytes and endothelial ceRs. But it is inducible or upregulated by INF-r, IL-1p and TNF-a on many cell types. IL-4, a pleiotropic cytokine and mast cell differentiation factor, is upregulated in human allergic disease and stimulates expression of vascular adhesion molecule-1 (VCAM-1) in endothelial cells. IL-4 also promotes expression of surhce ICAM-1 in human mast cells and dermal fidroblasts. So in allergic rhinitis and asthma, IL-4 may be an important cytokine implicated in the pathogenesis of inflammation. We studied the effect of INF-r and IL-4 on expression of ICAM-1 in human nasal epithelial cells (HNEC). HNEC were prepared by primary culture method of monolayer culture of dissociated cells hom human inferior nasal turbinate mucosa. Nasal mucosa were obtained by partial turbinectomy of septal deviation patients. Primary cultured cells were charaterized as an epithelial cell type by indirect immuno-fluorescence assay using antilmdies against cytokeratin-pan, cytokeratin No. 8, vimentin and von Willebrand factor. Using fluorescence activated cell sorter (Coulter EI1TE), we analyzed the quantitative expression of ICAM-1 on HNEC. Treatment of HNEC with IFN-r (1ng/ml) for 24 hours caused about 8 fold increase of the surface ICAM-1 compared with constitutive expression by mean fluorescence intensity (MIF) but IL-4 had little effect. Theses foundings suggest that IFN-r is a potent ICAM-1 inducer in HNEC and further studies are necessary for the role of IL-4 on HNEC.
Adhesives ; Asthma ; Cells, Cultured ; Cytokines* ; Endothelial Cells ; Epithelial Cells* ; Fluorescence ; Humans ; Inflammation ; Integrins ; Intercellular Adhesion Molecule-1 ; Interleukin-4 ; Keratins ; Lymphocyte Function-Associated Antigen-1 ; Mast Cells ; Monocytes ; Mucous Membrane ; Nasal Mucosa ; Rhinitis ; Turbinates ; Vimentin ; von Willebrand Factor

Breast Neoplasms ; etiology ; Female ; Humans ; Integrins ; physiology

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 has focal hemorrhage, tubular necrosis and interstitial mononuclear infiltrates. Hantavirus pulmonary syndrome(HPS) caused by Sin Nombre virus which is known as a member of Hantavirus genus, characterized by rapidly progressive pulmonary edema, hypotension and interstitial pulmonary infiltrate with lymphocytes. The predominant cell type in the renal and pulmonary interstitium is a fibroblast and it participates in the healing process at injury site by secreting a large amount of extracellular matrix proteins. Cultured human lung fibroblasts and Mongolian gerbil fibroblasts were known as the good host cells to the hantaan virus. It is possible that not only endothelial cell but also fibroblast is a target of Hantaan virus and the fibroblast might be involved in the pathogenesis and the healing process in HFRS. Integrins are an adhesion molecule, and act as the 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 on the infection of Hantaan virus was examined by using an anti-alpha5beta1 integrin antibody in chicken embryo fibroblasts(CEF) and Mongolian gerbil fibroblasts(MGF). CEF and MGF were treated with anti-alpha5beta1, integrin antibody during 30 minutes before viral infection and the culture supernatants were harvested 5 days after virus infection. The treatment of anti-alpha5beta1 integrin antibody on CEF reduced the viral titers about 30% when compared with the non-antibody treatment control CEF. In MGF, these viral titers were reduced by 36% and 68% according to the assay methods by FFU and ELISA, respectively. These results suggested that alpha5beta1 integrin might be act as a receptor for the Hantaan virus or blocking of alpha5beta1 integrin influence on the viral replication in CEF and MGF. To find out which suggestion is related with, further studies are going on.
Acute Kidney Injury ; Autopsy ; Chickens ; Embryonic Structures ; Endothelial Cells ; Enzyme-Linked Immunosorbent Assay ; Extracellular Matrix ; Extracellular Matrix Proteins ; Fever ; Fibroblasts* ; Fibronectins ; Gerbillinae ; Hantaan virus* ; Hantavirus ; Hemorrhage ; Hemorrhagic Fever with Renal Syndrome ; Humans ; Hypotension ; Inflammation ; Integrin alpha5beta1 ; Integrins ; Lung ; Lymphocytes ; Necrosis ; Pulmonary Edema ; Shock ; Sin Nombre virus ; Vascular System Injuries

Recent years have seen an explosion of new knowledge defining the molecular events that are critical for development and activation of immune cells. Much of this new information has come from a careful molecular dissection of key signal transduction pathways that are initiated when immune cell receptors are engaged. In addition to the receptors themselves and critical effector molecules, these signaling pathways depend on adapters, proteins that have no intrinsic effector function but serve instead as scaffolds to nucleate multimolecular complexes. This review summarizes some of what has been learned about one such adapter protein, SH2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76), and how it regulates and integrates signals after engagement of immunoreceptors and integrins on various immune cell lineages.
Explosions ; Integrins ; Leukocytes ; Proteins ; Signal Transduction ; T-Lymphocytes