No abstract available.
Blood Platelets* ; Diagnosis* ; Flow Cytometry* ; Integrin beta3* ; Thrombasthenia*

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

OBJECTIVE: To investigate new signal transduction cascade through integrin, FAK and ERK in the suppressed cell proliferation by GnRH-I and -II. METHOD: Human endometrial cancer cells (HEC1A) were cultured under the following condition: DMEM/F12 (10% FBS). GnRH-I and -II were treated time (0, 5, 10, 15, 20, 30 min; 100 nM) and dose (10 nM or 100 nM; 20 min) dependent manner according to experimental purposes. Cell proliferation was measured using [3H] thymidine incorporation assay. Immunoblotting was utilized to detect proteins. RESULTS: GnRH-I and -II inhibited proliferation of HEC1A cells and induced expression of integrin beta3. Phosphorylation of FAK and ERK were induced by GnRH-I and -II. CONCLUSION: GnRH inhibited cell proliferation via the expression of integrin and FAK, ERK phosphorylation.
Cell Proliferation* ; Endometrial Neoplasms* ; Female ; Gonadotropin-Releasing Hormone* ; Humans ; Immunoblotting ; Integrin beta3 ; Phosphorylation ; Signal Transduction ; Thymidine

OBJECTIVETo study the effect of interaction of the talin rod domain integrin binding site 2 with integrin β3 on platelet signal transduction.

METHODSA peptide that mimics the membrane proximal α helix 6 residues R724 KEFAK729 of the integrin β3 cytoplasmic tails was designed and synthesized, to which the myristoylation was covalently linked to the N-terminal of the peptide enabling membrane penetration. The effects of myr-RKEFAK peptide on the typical platelet outside-in signaling ovent (stable adhesion and spreading on immobilized fibrinogen, aggregation, fibrin clot retraction) and inside-out signaling events (soluble fibrinogen binding) were tested.

RESULTSmyr-RKEFAK peptide dose-dependently inhibited platelet stable adhesion and spreading on immobilized fibrinogen, irreversible aggregation, as well as fibrin clot retraction, but not soluble fibrinogen binding and reversible phase of platelet aggregation.

CONCLUSIONThe cell-penetrating peptide myr-RKEFAK causes an inhibitory effect on integrin β3 outside-in signaling-regulated platelets functions, but did not affect inside-out signaling-regulated platelets functions.

Blood Platelets ; Fibrinogen ; Humans ; Integrin beta3 ; Peptides ; Platelet Adhesiveness ; Platelet Aggregation ; Signal Transduction

OBJECTIVE: To investigate the damaging of human umbilical vein endothelial cells (HUVEC) induced by antiplatelet integrin β3 antibodies in vitro. METHODS: The serum from 36 chronic ITP patients were collected, flow cytometry and monoclonal antibody specific immobilization of platelet antigen (MAIPA) assay were used to collect antiplatelet integrin β3 antibodies from the serum of the patients. After HUVEC were treated by ITP patient serum (PS) containing anti-integrin β3 antibodies, the cell damage was detected by Lactate dehydrogenase (LDH) assay, cell apoptosis was detected by flow cytometry, the expression of apoptosis-related gene Bax was detected by Reverse transcription-Quantitative real-time PCR (RT-qPCR), and expression of Apoptosis-related signaling pathway protein Akt and related protein Bax were detected by Western blot. HUVEC were treated by PS combined with Akt activator SC79, the cells damage were detected by LDH assay, apoptosis of the cells were detected by flow cytometry, the expression of apoptosis-related gene Bax was detected by RT-qPCR. RESULTS: Among 36 cases of serum from the chronic ITP patients, 5 patients' serum containing anti-integrin β3 antibodies were collected. After HUVEC was treated by PS, the viability of LDH was significant increased（P<0.05）, so as for the apoptosis of the cells（P<0.05）, the expression of gene and protein of Bax was increased up-regulated（P<0.05）, the protein expression of pAkt was down-regulated（P<0.05）. Comparing with HUVEC cultured with PS alone, the viability of LDH of HUVEC treated by PS combined with SC79 was significantly reduced（P<0.05）, so as for the apoptosis of the cells（P<0.05）, and gene expression of Bax was significantly decreased（P<0.05）. CONCLUSION Anti-integrin β3 serum can cause the damage and apoptosis of HUVEC through Akt signaling pathway，the apoptotic effects of anti-integrin β3 antibodies to HUVEC was effectively reversed by SC79.
Apoptosis ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; Humans ; Integrin beta3 ; Signal Transduction

The purpose of this paper is to investigate the probable molecular mechanism in mechano-transduction of the regulation of integrins and the effects of cyclic biaxial mechanical strain on proliferation and synthetic function in the osteoblasts isolated from 3-month-old female Sprague-Dawley (SD) rats. The osteoblasts were cultured in F-12 medium contained with 10% fetal bovine serum(FBS) and grown to subconfluency in Flexercell type I dishes in a humidified incubator with 5% CO2 and 95% air at 37 degrees C. Mechanical strains were applied to the cells for periods of 30 min, 2, 4 and 8 hours every day, lasting 2 days. The amplitude of mechanical strain applied to the cells were 400, 1,000 and 4,000 mu strain respectively, at a frequency of one hertz(1 Hz). Unstrained cells were used as control. The expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts and proliferation activity of osteoblasts were studied with Flow Cytometry(FCM). The content of osteocalcin, carboxyterminal propeptide of type-I procollage(PICP), total protein secreted by osteoblastes were detected with the isotope labelling method. The results showed that there are actual expressions of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts without mechanical strain and that the expression of integrins beta 1 is highest. The mechanical strain increased the expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts, but the strain-related up-regulation of expression of integrins alpha 2, beta 1, beta 3 are different in various amplitude and different duration of mechanical stains. The up-regulation of expression of integrins beta 3 is most sensitive to mechanical strain. The up-regulation of expression of integrins alpha 2, beta 1, beta 3 is higher at 4,000 mu strain than at 400, 1,000 mu strain. The mechanical strain can elevate the proliferation activity and the synthetic function of osteoblast at 400, 1,000 mu strain. However, the mechanical strain increased significant the proliferation in the osteoblasts and suppressed obviously the synthetic function in the osteoblasts. In the present study, the reaction of the osteoblasts in 3 month-old rat to the mechanical stimulation suggested that 1) expressions of integrins alpha 2, beta 1, beta 3 were increased in a amplitude of strain-dependent manner; 2) the changes of expression of integrins alpha 2, beta 1, beta 3 relate close to the changes of the proliferation and synthetic function of the osteoblasts. Low amplitude of strain can increase the proliferation and the synthetic function of the osteoblasts along with up-regulation of expression of integrins alpha 2, beta 1, beta 3; while higher amplitude of strain elevated significantly the proliferation of osteoblasts and suppressed obviously the synthetic function of the osteoblasts along with up-regulation of expression of integrins alpha 2, beta 1, beta 3. The amplitude of 4,000 mu strain is an optimal amplitude as stimulus for up-regulation of expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts and increase the proliferation activity, but decrease the synthetic function of osteoblasts in the present study. Accordingly it indicates that integrins have a important role in regulation of signal transduction pathway in osteoblasts as a result of mechanical strain.
Animals ; Cell Division ; Cells, Cultured ; Female ; Integrin alpha2 ; biosynthesis ; Integrin beta1 ; biosynthesis ; Integrin beta3 ; biosynthesis ; Mechanics ; Osteoblasts ; metabolism ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVES: To develop a new immunohistochemical marker system for supplementation of the Noyes histological classification of the endometrium in women of child bearing age with regular menstrual cycles, and to employ this system to evaluate pathologic factors involved in endometriosis, and thus to ascertain if it is useful in diagnosis. MATERIALS AND METHODS: Endometrial biopsies were sampled from the posterior fundus of 41 (24 proliferative phases, 17 secretory phases) women with regular menstrual cycles (28-32 days), and each sample was immunhistochemically stained according to Noyes et al (1975) for determination of expression for extrogen receptor (ER), progesterone receter(PR), integrin alpha1, alpha4, beta3, COX-1 and COX-2. Then, the PR, the integrin beta3, and COX-2 which were clearly expressed in the luteal phase was with endometrial samples were obtained from 20 cases of normal patients (group 1) and 25 cases with endometriosis (group 2) after confirming the day of ovulation by sex steroid level measurements 7-8 days after ovulation. RESULTS: In the regular menstruation group the expression of ER showed a tendency to be increased in the proliferative phase and decreased in the secretory phase, and was the highest in the proliferative phase. However, PR in the stromal cells showed no change in the entire menstrual cycle while in the epithelial cells, PR reached a peak in the late proliferative phase and was almost absent in the secretory phase. Integrin alpha 1, alpha4, and beta3 expression in the epithelial cells was absent in the proliferative phase but alpha1 was expressed strongly in the early and mid secretory phases and disappeared in the late proliferative phase, while beta3, appeared after the mid secretory phase and continued to be expressed until the late secretory phase. Expression in the stromal cells was weak overall and did not show any cyclic pattern. COX-1 expression was shown as a cyclic pattern in the stromal and epithelial cells and was partcularly strongly expressed in the mid secretory phase of epithelial cells, and in the mid secretory and menstruation phase of stromal cells. In the endometrial epithelial cells there was strong expression during the entire cycle with stronger expression in the secretory phase compared to the prolferative phase. COX-2 was clearly expressed in the late proliferative, early and mid secretory phased in the stromal cells. No expression was observed in the proliferative phase of the epithelial cells, but which began to appear in the early secretory phase reaching a significant pattern from the mid secretory phase onwards. There was almost no expression in the stromal cells. In the cases with endometriosis showing normal endometrial maturation according to the Noyes classification, PR expression was increased while Integrin-beta3 expression was significantly decreased compared to the normal group. Also, COX-2 expression was slightly decreased in the stromal cells of patients with endometriosis while it was significantly increased in the stromal cells. CONCLUSION: Immunohistochemical markers can supplement the original Noyes classification of histological endometrial dating and therefore ascertain existing pathologic conditions. Particularly for patients with endometriosis with normally mature endometrial cells, changes in COX-2 and integrin expression patterns may assist in elucidating pathophysiologic mechanisms and therefore aid in the diagnosis of abnormal implantation conditions, and consequently determine a treatment modality.
Biopsy ; Child ; Classification ; Diagnosis ; Endometriosis* ; Endometrium* ; Epithelial Cells ; Female ; Humans* ; Integrin alpha1 ; Integrin beta3 ; Luteal Phase ; Menstrual Cycle ; Menstruation ; Ovulation ; Progesterone* ; Prostaglandin-Endoperoxide Synthases* ; Receptors, Progesterone* ; Stromal Cells

OBJECTIVE: To comparatively investigate the expression of several integrins in specimens of human bone metastases and degenerative bone tissue. METHODS: Degenerative cancellous tissue was obtained from a sample of human degenerative spine. Thirteen human specimens were obtained from metastatic spine tumors, whose primary cancer was colon cancer (n=3), hepatocellular cancer (n=3), lung cancer (n=4), and breast cancer (n=3). The expression of vimentin and integrins alphav, beta1, and beta3 was assessed in metastatic and degenerative specimens by immunohistochemistry and real-time reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: Immunohistochemical staining showed that vimentin and integrin alphav was broadly expressed in all tissues examined. By contrast, integrin beta1 was weakly expressed only in 38.4% (5/13) of tissues. Integrin beta3 was consistently negative in all cases examined. qRT-PCR analysis showed that vimentin gene expression was higher in all metastatic specimens, as compared to degenerative bone. The gene expression of integrin alphav in breast specimen was significantly higher than others (p=0.045). The gene expression of integrin beta1 was also higher in all metastatic specimens than in degenerative bone tissue. The gene expression of integrin beta3 was variable. CONCLUSION: Spinal metastatic tumors have mesenchymal characteristics such as increased expression of vimentin. The increased expression of integrin alphav and beta1 in spine metastatic tumors suggests that adhesive molecules such as integrin may have implications for the prevention of spine metastasis.
Adhesives ; Antigens, CD29 ; Bone and Bones ; Breast ; Breast Neoplasms ; Colonic Neoplasms ; Gene Expression ; Humans ; Immunohistochemistry ; Integrin alphaV ; Integrin beta3 ; Integrins* ; Liver Neoplasms ; Lung Neoplasms ; Neoplasm Metastasis ; Spine* ; Vimentin*

BACKGROUNDGlanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder characterized by the tendency to hemorrhage and the inability of platelets to aggregate in response to agonists. GT is caused by a defect of the platelet glycoprotein IIb/IIIa complex. The objective of this study was to describe the clinical features and the genetic cause of GT in a 6-year-old girl from south China.

METHODSA three-generation family was studied. The proband patient aged 6 years and her parents undertook examinations of platelet counts, blood film, bleeding time, platelet aggregation, and flow cytometry. All coding exons of the ITGA2B and ITGB3 genes were amplified by polymerase chain reaction (PCR), and direct sequencing was performed for mutational screening on the patient and normal controls consisted of 52 healthy blood donors. Reverse transcription PCR was conducted to test for exon skipping.

RESULTSThe proposita patient showed dispersing platelets, prolonged bleeding time, and severely reduced platelet aggregation in response to the physiological agonists adenosine diphosphate (ADP), epinephrine, collagen, and ristocetin. Flow cytometric measurements showed that the contents of alphaIIb and beta3 were significantly decreased. Sequencing results demonstrated two different types of heterozygous mutations existed in the alphaIIb gene (c.2930delG and IVS15-1delG). The compound mutations were also confirmed in the patient's mother and father separately.

CONCLUSIONSThe alphaIIbbeta3 deficiency of the proband was caused by two compound ITGA2B mutations, which were first reported in Chinese GT patients. The IVS15-1delG was first confirmed to cause an exon skipping.

Asian Continental Ancestry Group ; Child ; Female ; Flow Cytometry ; Heterozygote ; Humans ; Integrin alpha2 ; genetics ; Integrin beta3 ; genetics ; Mutation ; Pedigree ; Reverse Transcriptase Polymerase Chain Reaction ; Thrombasthenia ; genetics ; metabolism ; pathology

UNLABELLEDOBJLECTIVE: To investigate the effect of integrin β3 cytoplasmic NITY motif on αIIbβ3-mediated cell functions.

METHODSStable Chinese hamster ovary (CHO) cell lines that co-express human wild type integrin αIIb and wild type β3 or mutant β3ΔNITY (β3 deleting cytoplasmic NITY motif) were established. Expression of αIIb and β3 were tested by Western blot and flow cytometry in CHO cell lines. Spreading and adhesion of stable cell lines on immobilized fibrinogen were examined. The co-immunoprecipitation was used to detect protein interactions.

RESULTSCHO-αIIbβ3, CHO-αIIbβ3ΔNITY cells were successfully established. The CHO cells transfected with wild type αIIbβ3 had the ability of adhesion and spreading. Compared with CHO-αIIbβ3 cells, CHO-αIIbβ3ΔNITY cells showed an impaired capacity of adhesion but no significant difference was observed in spreading of adhered cells. The co-immunoprecipitation showed that kindlin-2 associated with wild type integrin αIIbβ3. The β3ΔNITY mutation substantially reduced kindlin-2 association.

CONCLUSIONDeletion of NITY motif causes an impaired ability of adhesion. The deletion mutation can suppress kindlin-2 binding to integrin β3, thereby partially inhibit the integrin β3 signaling.

Animals ; CHO Cells ; Cricetinae ; Cricetulus ; Fibrinogen ; Humans ; Integrin alpha2 ; Integrin beta3 ; Platelet Glycoprotein GPIIb-IIIa Complex ; Protein Structure, Tertiary ; Signal Transduction