OBJECTIVETo study the integrin beta1 mRNA changes after orthodontic tooth movement in normal teeth and periodontitis teeth of rats.

METHODSThe OD of positively stained osteoclasts for integrin beta1 mRNA using in situ hybridzation was detected after orthodontic tooth movement in normal teeth and periodontitis teeth groups.

RESULTSIntegrin beta1 mRNA expression were detected on all osteoclasts in tooth movement samples of normal and periodontitis teeth. There were stronger positive signals after given orthodontic force in both of the two groups. But no differences were found after 0.5, 1, 2, 3, 5, 7, 10 days since orthodontic tooth movement. The integrin beta1 mRNA signals in normal tooth movement group were not different from that in periodontitis group.

CONCLUSIONThe integrin beta1 of osteoclasts may play a role in the stability and remodeling of periodontal ligament in orthodontic tooth movement. There were no difference in the OD of integrin beta1 mRNA staining in orthodontic tooth movement between normal teeth group and periodontitis teeth group.

Animals ; Integrin beta1 ; metabolism ; Osteoclasts ; Periodontal Ligament ; Periodontitis ; physiopathology ; RNA, Messenger ; metabolism ; Rats ; Tooth Movement Techniques

Objective To study the characteristics of positive expression of integrin β1 in the rat brain tissue of two kinds of traumatic brain injury models and to explore the feasibility of inferring the mode of traumatic brain injury using the positive expression of integrin β1. Methods The occipital region of rats was hit by hydraulic impact method and pendulum striking method to produce two closed brain injury models of linear and rotation acceleration respectively, then 120 SD rats were randomly divided into linear acceleration injury group, rotation acceleration injury group, sham operation group and normal control group. Immunohistochemistry staining and Western blotting method were used to detect the positive expression of integrin β1 in different parts of the brain tissue at 30 min, 3 h, 6 h, 12 h, 3 d and 7 d after rat injury. The data was processed statistically by SPSS 18.0 software. Results The positive expression of integrin β1 was detected 30 min after brain injury and reached the peak 6 h after brain injury. With the extension of injury time, the expression tended to enhance. At the same time points after injury, the differences in the positive expression of integrin β1 between the linear acceleration injury group and the rotation acceleration injury group in the occipital strike point and thalamus had no statistical significance （ P>0.05）, but the differences in the expression of integrin β1 in the frontal lobe and brain stem had statistical significance （P<0.05）. Conclusion The characteristics of positive expression of integrin β1 in brain tissue can be used to infer the strike point and the manner of injury and has application value for the reconstruction of craniocerebral injury process.
Animals ; Brain/metabolism* ; Brain Injuries ; Brain Injuries, Traumatic ; Integrin beta1/metabolism* ; Rats ; Rats, Sprague-Dawley

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

OBJECTIVETo observe the effects of WWOX on cell attachment in ovarian cancer, and to explore its mechanisms of action.

METHODSAttachment assay was used to assess the adhesion of wwox-transfected PEO1 cells and vector-transfected PEO1 cells that were constructed, as well as PEO1 parent cells. Alpha/beta integrin-mediated cell adhesion assays were designed to identify cells surface integrins in PEO1 clone cells. Integrin function blocking experiments were designed to further determine integrins in PEO1 clone cells according to the integrin that was selected in integrin expression profiling. FACS analysis was used to further detect the level of integrin alpha3 on the cell membrane.

RESULTSAttachment assay showed that adhesion of WWOX-transfected PEO1 cells to fibronectin was significantly slower than that in vector-transfected controls or PEO1 parent cells, cultured on the pre-coated fibronectin for 2 hours (P<0.01). The level of membranous integrins alpha2 and alpha3 in the WWOX-transfected PEO1 cells was significantly decreased, as compared with that in vector-transfected controls (P<0.05), but there was no association with the level of functioning integrins betal or beta2 in clone cells (P>0.05). The attachment assays were repeated after pre-incubating the cells with integrin alpha2 or alpha3 function-blocking antibodies. These results showed that blocking integrin alpha3 significantly reduced the binding to fibronectin of all the PEO1 clonal lines, as compared with cells pre-incubated with a non-specific IgG antibody (P<0.05). In contrast, preincubation with alpha2 blocking antibody had very little effect on fibronectin binding in these cells (P>0.05). FACS analysis showed that membranous integrin alpha3 expression revealed a marked reduction in WWOX-transfected cells than that in vector-transfected cells.

CONCLUSIONWWOX acts as an ovarian tumor suppressor by modulating the interaction between tumor cells and the extracellular matrix, decreasing integrin activity and adhesion of tumor cells to fibronectin. This suggests an important role for loss of WWOX tumor suppressor in promoting attachment and adhesion of ovarian cancer cells on locoregional peritoneum, and further resulting in enhancing locoregional peritoneal tumor spread.

CD18 Antigens ; metabolism ; Cell Adhesion ; Female ; Fibronectins ; metabolism ; Humans ; Integrin alpha2 ; metabolism ; Integrin alpha3 ; metabolism ; Integrin beta1 ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; Oxidoreductases ; genetics ; metabolism ; Protein Binding ; Transfection ; Tumor Suppressor Proteins ; genetics ; metabolism ; WW Domain-Containing Oxidoreductase

OBJECTIVETo explore the association between renal transforming growth factor-β1 (TGF-β1) and the expressions of α3 and β1 integrins and observe the effect of irbesartan on their expressions in diabetic rats.

METHODSThirty 8-week-old male Wistar rats were randomly divided into normal control group (n=7), diabetic control group (n=14) and irbesartan group (n=9). Rat models of diabetes were established by a single peritoneal injection of streptozotocin (STZ), and 4 weeks later the rats received irbesartan treatment for 8 weeks. Enzyme-linked immunosorbent assay (ELISA) was used to measure the urinary albumin excretion rate, and PAS staining was utilized to observe the renal pathologies. Immunohistochemistry was performed for semi-quantitative determination of podocyte density, and real-time RT-PCR was used to detect the renal TGF-β1 and α3/β1 integrin mRNA expressions.

RESULTSIn diabetic rats, the expression of renal TGF-β1 mRNA was significantly increased, while α3 and β1 integrin mRNA expressions and podocyte density significantly decreased with increased proteinuria. Irbesartan obviously improved such changes.

CONCLUSIONIn diabetic rats renal TGF-β1 can regulate α3 and β1 integrin mRNA expressions to reduce the number of podocytes, and inhibition of this pathway may be one of the mechanisms of the renal protective effect of irbesartan.

Animals ; Biphenyl Compounds ; pharmacology ; Diabetes Mellitus ; metabolism ; Diabetic Nephropathies ; metabolism ; Integrin alpha3 ; metabolism ; Integrin beta1 ; metabolism ; Kidney ; drug effects ; metabolism ; Male ; Rats ; Rats, Wistar ; Tetrazoles ; pharmacology ; Transforming Growth Factor beta1 ; metabolism

Liver fibrosis is a pathological process of the excessive accumulation of extracellular matrix, especially collagen al (I) in liver. Ultimately, hepatic fibrosis leads to cirrhosis or hepatic failure. Liver fibrosis and early cirrhosis can be reversed, thus control of the development of liver fibrosis is very important for preventive treatment of cirrhosis and hepatic failure. This is a review of potential targets for anti-hepatic fibrosis based on plenty of publications, including TGF-β1 and integrin α(v) and so on, aimed at providing novel therapeutic targets in liver fibrosis.
Collagen ; metabolism ; Humans ; Integrin alphaV ; metabolism ; Liver ; pathology ; Liver Cirrhosis ; drug therapy ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo study the effects of integrin beta1 on the chemotaxis of hepatocellular carcinoma (HCC) cells to laminin (LN).

METHODSA micropipette technique was adopted to investigate the effect of integrin beta1 blockade on pseudopod protrusion of HCC cells in response to LN stimulation. Chemotactic pseudopod protrusion of a HCC cell was evaluated using a dual-pipette set-up, in which two pipettes filled with LN solution were positional in close contact with the same cell, and pseudopod protrusion into each pipette was viewed dynamically and recorded with a tape recorder. The lengths of pseudopods were measured, then plotted against time to obtain a pseudopod growth curve. The integrin beta1 subunit on the surfaces of HCC cells was analyzed by flow cytometry.

RESULTSIn dual pipette chemotaxis experiment, when the two pipettes were filled with LN (50microg/ml, 200microg/ml), pseudopods extended from the HCC cells into each of the pipettes nearly symmetrically. Upon addition of anti-CD29 (20microg/ml) to one of the pipettes, the pseudopod protrusion was blocked almost completely, while the pseudopod protrusion into the opposite pipette became more evidently, with larger maximum length. The expression rate of integrin beta1 on the cells was up to 95.78%.

CONCLUSIONIntegrin beta1 subunit is the important receptor for mediating HCC cells chemotaxis to laminin.

Carcinoma, Hepatocellular ; pathology ; Cell Adhesion ; Cell Line, Tumor ; Chemotaxis ; Humans ; Integrin beta1 ; immunology ; metabolism ; physiology ; Laminin ; metabolism ; Liver Neoplasms ; pathology

OBJECTIVETo study the effect of substrate stiffness on proliferation, migration of fibroblast and integrin β(1) expression in fibroblast.

METHODSFibroblasts were inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa. After being cultured for 5 days or 6 days, cells were counted and cell proliferative activities (recorded as absorbance value) were assessed with methyl thiazolyl blue (MTT). After being cultured for 3 days, cell cycle was detected and proliferation index (PI) was calculated. The cell scratch test was used for determination of cell migration rate on post scratch day (PSD) 0 (the day of scratch), 1, 2, and 3. After being cultured for 2 days, the expression of integrin β(1) was determined by flow cytometry with fluorescence. Data were processed with one-way analysis of variance.

RESULTS(1) The proliferative speed and proliferative activity of fibroblasts were all increased along with the increase in substrate stiffness. PI of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa was respectively 24.8%, 27.4%, 32.4%. On PSD 2, migration rate of fibroblasts inoculated on silicon substrate with stiffness of (19.8 ± 1.1) and (200.1 ± 2.6) kPa was respectively (91.4 ± 5.1)%, (100.0 ± 1.3)%, which were higher than that of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa [(55.8 ± 6.8)%, with F value respectively 3.5, 4.0, P values all below 0.01]. (3) The expression rate of integrin β(1) in fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa was the lowest (43.22%), and that in fibroblast inoculated on silicon substrate with stiffness of (200.1 ± 2.6) kPa was the highest (81.26%).

CONCLUSIONSSubstrate stiffness may have a great effect on proliferation and migration of fibroblast during the process of wound healing and scar formation, which can be related to regulation of integrin β(1) expression.

Cell Movement ; Cell Proliferation ; Cells, Cultured ; Fibroblasts ; cytology ; metabolism ; pathology ; Humans ; Integrin beta1 ; metabolism ; Mechanical Phenomena ; Silicon

OBJECTIVETo study the effect of calcium on the activity and protein expression of integrin beta1 promoter in human immortal keratinocyte colony HaCaT cell and cell migration.

METHODS(1) HaCaT cells were cultured in vitro (12-slot plate) and divided into 5 groups according to the random number table, with 18 slots in each group: reporter plasmid pGL3 promoter (positive control group, PC), pGL3 empty vector (negative control group, NC), pGL3-1756 bp (total length promoter group, TL), pGL3-1442 bp (distal promoter group, D), and pGL3-261 bp (proximal promoter group, P) was respectively used to transfect HaCaT cells in non-serum RPMI 1640 culture medium with 0.00, 0.03, 0.09, 0.30, 0.80, or 1.20 mmol/L calcium (3 slots in each group with each concentration). Luciferase activity was detected with dual-luciferase reporter assay system 24 hours after transfection. (2) HaCaT cells steadily transfected with small interfering RNA-integrin beta1 vector (steadily transfected in brief) constructed in our laboratory were normally cultured and divided into 6 parts according to the random number table. And then they were treated with former 6 different concentrations of calcium, with 3 samples for each concentration. Expression level of integrin beta1 protein was determined with Western blot. (3) Normal and steadily transfected HaCaT cells were cultured in 6-slot plate, 18 slots for each kind of cells. They were cultured with former 6 kinds of calcium culture media (divided according to the random number table, with 3 slots of cells for each concentration) for 12 hours after scratch test. Cell migration rate was observed and determined. (4) Data were processed with one-way analysis of variance and independent samples t test.

RESULTS(1) The luciferase activity of cells in TL group increased from 0.16+/-0.09 to 0.39+/-0.09 and 0.35+/-0.05 (with t value respectively 3.143, 3.140, P values all below 0.05) as calcium concentration increasing from 0.00 mmol/L to 0.09 and 0.30 mmol/L, and it decreased as calcium concentration increased to 0.80 and 1.20 mmol/L. The change pattern of luciferase activity of cells along with calcium concentration in D group was similar to that in TL group, but its activity (0.56+/-0.32, 0.64+/-0.06) at the concentration of 0.09, 0.30 mmol/L was respectively higher than that in TL group (with t value respectively 0.887, 6.122, P values all below 0.05). There was no obvious influence of calcium in either concentration on the luciferase activity of cells in P group. (2) The expression amount of integrin beta1 of steadily transfected HaCaT cells cultured with 0.03, 0.09, 0.30, 0.80, 1.20 mmol/L calcium (0.58+/-0.09, 1.40+/-0.29, 1.41+/-0.09, 0.99+/-0.10, 1.16+/-0.15) were all increased as compared with that cultured with 0.00 mmol/L calcium (0.53+/-0.10, with t value respectively 0.687, 4.880, 11.210, 5.578, 6.199, P values all below 0.05). (3) Migration speed of normal HaCaT cells cultured with 0.09, 0.30 mmol/L calcium increased obviously as compared with that cultured with 0.00 mmol/L calcium, and it slowed down when cultured with 0.80, 1.20 mmol/L calcium. There was no obvious difference of migration rate among steadily transfected HaCaT cells treated with different concentration of calcium.

CONCLUSIONSDistal promoter region of integrin beta1 plays a vital role in regulating integrin beta1 transcription in human epidermal cells. And calcium regulates activity, protein expression of integrin beta1 promoter and cell migration.

Calcium ; pharmacology ; Cell Line ; Cell Movement ; drug effects ; Epidermis ; cytology ; metabolism ; Humans ; Integrin beta1 ; metabolism ; Promoter Regions, Genetic ; Transfection

OBJECTIVETo investigate the regulatory effect of Jingang Jiangu pill (see text, JGJG) on expression of integrin in ovariectomized rats.

METHODSFifty ovariectomized 10 months old female rats were randomly divided into 5 groups: Fushanmei group (FSM), Jingang Jiangu pill (see text) group (JGJG), Gusongbao granule group (GSB), Model group (OVX), Sham group. After ovariectomized,the rats were raised in the same environment for 13 weeks. The rats in JGJG group took 0.13 g JGJG pill orally each day for each rat; the rats in GSB group took 0.86 g GSB granule orally each day for each rat; the rats in FSM group took 0.28 mg FSM orally each day for each rat; and the rats in OVX and sham groups took sodium. The treatment duration of rats in above 5 groups was 13 weeks. Bone mineral density (BMD) and the expression of integrin beta1 and alphavbeta3 were detected in each group after the treatment. RESYKTS: The BMD and the expression of integrin beta1 in FSM group, JGJG group and GSB group improved obviously than that of OVX group. There were statistical difference between these groups (P<0.05). The expression of integrin alphavbeta3 of the three treating groups significantly depressed.

CONCLUSIONThe JGJG pill improves BMD and express of integrin beta1, in ovariectomized rats and reduces express of integrin alphavbeta3 through the regulation of the coupling of osteoblasts and osteoclasts.

Animals ; Bone Density ; Disease Models, Animal ; Female ; Integrin alphaVbeta3 ; analysis ; Integrin beta1 ; analysis ; Medicine, Chinese Traditional ; Osteoporosis ; drug therapy ; metabolism ; Ovariectomy ; Rats ; Rats, Wistar