OBJECTIVETo investigate the expression of PDGF receptor-beta and its correlation with extracellular matrix in hepatic tissue during hepatic fibrosis.

METHODSThe model of hepatic fibrosis in rats was induced by carbon tetrachloride. PDGF receptor-beta subunit, collagen I, collagen III and a-SMA in hepatic tissues of these rats were examined using immunohistochemistry. The correlation between PDGF receptor-beta subunit and collagen I, III was analyzed using SAS software after the results of immunohistochemistry were semi-quantified.

RESULTSPDGF receptor-beta subunit and a-SMA were not detected in normal controls. Collagen I and III were distributed in the portal tracts and beneath the endothelia of the central veins and of the Disse spaces. Two weeks after CCl4 injection, the PDGF receptor-beta and a-SMA were detected, and the expression of collagen I and III increased. At the end of 4 and 6 weeks, the above four proteins were further increased. Two weeks after CCl4 injection, PDGF receptor-beta had no apparent correlation with collagen I and III. However, PDGF receptor-beta had a significant correlation with collagen I and III 2 weeks later, and the correlation coefficient was 0.74 and 0.60 respectively at 4 weeks, and 0.83 and 0.67 respectively at 6 weeks. PDGF receptor-beta had a significant correlation with a-SMA during the whole process of hepatic fibrosis and the correlation coefficient was 0.62, 0.69 and 0.81, respectively at the time of 2, 4 and 6 weeks after CCl4 injection.

CONCLUSIONThe PDGF receptor-beta was overexpressed during the process of hepatic fibrosis development, and it significantly correlated with collagen I and collagen III.

Animals ; Carbon Tetrachloride ; Carbon Tetrachloride Poisoning ; Collagen Type I ; biosynthesis ; genetics ; Collagen Type III ; biosynthesis ; genetics ; Extracellular Matrix ; metabolism ; Liver ; metabolism ; Liver Cirrhosis, Experimental ; chemically induced ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, Platelet-Derived Growth Factor beta ; biosynthesis ; genetics

OBJECTIVETo explore the proliferation of primary cultured rats hepatocytes after delivery of exogenous hepatocyte growth factor (HGF) gene which was inserted into the genome of replication-deficient recombinant adenovirus vector.

METHODSThe recombinant adenovirus-AdHGF which could express HGF was generated by homologous recombination. After the HGF gene was delivered into the hepatocytes, the expression of both HGF and c-met/HGF receptor mRNA in the cells was detected by RT-PCR and the level of HGF in the culture supernatant was also assayed by ELISA. On the other hand, cell proliferation was compared between before and after delivery of the HGF gene by MTS assay and the percentages of cell cycles were analyzed by flow cytometry. In addition, the expression of proliferating cell nuclear antigen (PCNA) was determined by immunocytofluorescent stain.

RESULTS4 x 10(10) efu/ml titer of AdHGF was obtained after recombination, RT-PCR indicated that the expression of HGF mRNA in hepatocytes increased on the third day after infected by the viruses and c-met/HGF receptor mRNA was also up-regulated. The HGF level in the culture supernatant assayed by ELISA was (5,939.0+/-414.39) pg/ml, which was much higher than that in the control (208.1pg/ml+/-37.20pg/ml, F=13.661, P<0.01). In addition, the proliferation of hepatocytes infected with AdHGF increased significantly according to MTS method (F>or=15.158, P<0.01) and more hepatocytes in G0/G1 stages changed into S stage (chi2=41.616, P<0.01), accordingly, PCNA index increased from 6.42+/- 1.88 to 14.56+/-2.85 (F=42.122, P<0.01).

CONCLUSION

THE RESULTSshow that HGF gene delivered into hepatocytes by AdHGF can be expressed with high efficiency in the cells, which can stimulate hepatocytes proliferation. It may be an effective tool for hepatocyte transplantation by gene modified donor hepatocytes.

Adenoviridae ; genetics ; metabolism ; Animals ; Cell Division ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Genetic Vectors ; Hepatocyte Growth Factor ; biosynthesis ; genetics ; pharmacology ; Hepatocytes ; cytology ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology

BACKGROUNDActivation and proliferation of hepatic stellate cells (HSC) is essentially involved in the development and progression of hepatic fibrosis. The most potent growth factor for HSC is platelet-derived growth factor receptor (PDGF) and PDGF receptor beta subunit (PDGFR-beta) is the predominant signal transduction pathway of PDGF which is overexpressed in activated HSC. This study investigated the cleavage activity of hammerhead ribozyme targeting PDGFR-beta mRNA in HSC and the effect on biological characteristics of HSC.

METHODSExpression vector of anti-PDGFR-beta ribozyme was constructed and transfected into rat activated HSC with lipofectamin. The positive cell clones were gained by G418 selection. The expression of PDGFR-beta, alpha-smooth muscle actin, and typeI and type III collagen were detected by using Northern blot, Western blot and immunocytochemical staining, respectively. The cell proliferation was determined with MTT colorimetric assay. The cell apoptosis was analyzed by using flow cytometry, acridine orange fluorescence vital staining and transmission electron microscopy.

RESULTSThe expression of PDGFR-beta at mRNA and protein level was markedly reduced in ribozyme-transfected HSC by 49% - 57% (P < 0.05 - 0.01). The proliferation and alpha-smooth muscle actin expression of ribozyme-transfected HSC were significantly decreased (P < 0.05 - 0.01), and the type I and type III collagen synthesis were also reduced (P < 0.01). In addition, the proliferative response of ribozyme-transfected HSC to PDGF BB was significantly inhibited. Otherwise, the apoptotic cells were significantly increased in ribozyme-transfected HSC (P < 0.01), and typical apoptotic cells could be found under transmission electron microscopy.

CONCLUSIONSThe anti-PDGFR-beta ribozyme effectively cleaved the target RNA and significantly inhibited its expression, which blocked the signal transduction of PDGF at receptor level, inhibited HSC proliferation and collagen synthesis, and induced HSC apoptosis. These results suggest that inhibiting PDGFR-beta expression of HSC may be a new target for the therapy of liver fibrogenesis, and ribozyme may be a useful tool for inhibiting PDGFR-beta expression.

Actins ; biosynthesis ; Animals ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Collagen ; biosynthesis ; Liver ; cytology ; Liver Cirrhosis ; drug therapy ; pathology ; RNA, Catalytic ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Receptor, Platelet-Derived Growth Factor beta ; genetics

OBJECTIVETo study the cleavage activity of hammerhead ribozyme targeting at platelet-derived growth factor receptor beta subunit (PDGFR- beta) mRNA in hepatic stellate cells (HSCs) and its effect on the biological characters of HSCs.

METHODSExpression vector of anti-PDGFR- beta ribozyme was constructed and transfected into rat-derived HSC-T6 cells with lipofectin. The positive cell clones were gained by G418 selection. The expression of PDGFR- beta, alpha-smooth muscle actin (alpha-SMA), and type I and type III collagen was detected by means of northern blot, Western blot and immunocytochemical staining respectively. The cell proliferation was determined with MTT colorimetric assay. The cell apoptosis was demonstrated with flow cytometry, acridine orange fluorescence vital staining and transmission electron microscopy.

RESULTSThe expression of PDGFR- beta at mRNA and protein level was markedly reduced in ribozyme-transfected HSCs only 43% to 51% of that in control cells (t > or = 3.957, P < 0.05), and alpha-SMA expression level, type I and type III collagen synthesis ability were also reduced (t > or = 6.790, P < 0.01). The proliferation of ribozyme-transfected HSCs was significantly decreased (t > or = 3.858, P < 0.05), and the proliferation response to PDGF BB was markedly inhibited. However the apoptotic rate was significantly increased in ribozyme-transfected HSCs (chi2 > or = 14.157, P < 0.01), and typical apoptotic cells could be found under transmission electron microscopy.

CONCLUSIONSThe anti-PDGFR- beta ribozyme can be expressed stably in HSCs, cleave the target RNA effectively, inhibit HSCs proliferation and collagen synthesis, and induce HSC apoptosis. The results suggest that inhibiting PDGFR- beta expression in HSCs may be a new therapy for liver fibrosis.

Apoptosis ; drug effects ; Cell Division ; Cells, Cultured ; Hepatocytes ; drug effects ; physiology ; Humans ; Liver ; pathology ; RNA, Catalytic ; pharmacology ; RNA, Messenger ; biosynthesis ; Receptor, Platelet-Derived Growth Factor beta ; antagonists & inhibitors ; metabolism

AIMTo investigate apoptosis induced by 3,3'-diethyl-9-methylthia-carbocyanine iodide (DMTCCI), an inhibitor of DNA primase found in our previous study, and the mechanism of DMTCCI in human myelogenous leukemia HL-60 cells.

METHODSHL-60 cells were cultured in RPMI-1640 medium and treated with different concentrations of DMTCCI. MTT assay was used to detect growth inhibition. Flow cytometry and DNA ladders were used to detect apoptosis. Western blotting was used to observe the expression of survivin, Bcl-xL, Bad, Bax, Bcl-2, caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity was measured by ApoAlert Caspase-3 Assay Kit.

RESULTSDMTCCI inhibited proliferation of human leukemia HL-60 cells with IC50 value of 0.24 micromol x L(-1). The results of flow cytometry and DNA ladders showed that DMTCCI could induce apoptosis of HL-60 cells. The expression levels of protein survivin and Bcl-xL were down-regulated, Bad and Bax were up-regulated, while Bcl-2 protein had no change in response to DMTCCI treatment in HL-60 cells. Treatment of HL-60 cells with DMTCCI induced the proteolytic cleavage of caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity apparently increased at 3 h and reached a peak at 12 h after exposure to 1 micromol x L(-1) of DMTCCI in HL-60 cells.

CONCLUSIONDMTCCI inhibited proliferation and induced apoptosis of human leukemia HL-60 cells. Bcl-2 family proteins, survivin and caspases family proteins might play a role in the apoptosis process induced by DMTCCI.

Apoptosis ; drug effects ; Carbocyanines ; pharmacology ; Caspase 3 ; metabolism ; Cell Proliferation ; drug effects ; DNA Damage ; DNA Fragmentation ; drug effects ; DNA Primase ; antagonists & inhibitors ; Flow Cytometry ; HL-60 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; Leukemia, Myeloid ; metabolism ; pathology ; Microtubule-Associated Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; bcl-2-Associated X Protein ; metabolism ; bcl-Associated Death Protein ; metabolism ; bcl-X Protein ; metabolism

Objective:To evaluate the feasibility of using a visual positioning system for both motion phantom and clinical quality control.Methods:A phantom experiment was conducted using the Dynamic Thorax Phantom from CIRS. Different ranges of motion were simulated to assess the discrepancies between camera-recorded positions and actual movements. Visual markers were also attached to the treatment bed and the collimator head, and their movements were simulated as part of the experiment. The experiment was repeated for three times. Discrepancies between system measurements and manual measurements were recorded and analyzed to assess the accuracy and reliability of the system.Results:In the motion phantom test, the deviation between the actual motion distance of the phantom and the system's recorded measurement was (0.18±0.07) mm. For linear motion analysis along the X, Y, and Z axes on the treatment table, the measurement errors were (0.14±0.08) mm, (0.15±0.09) mm, and (0.16±0.08) mm, respectively. Additionally, the measurement error in the rotational direction of the treatment couch was 0.18°±0.09°. For the rotational direction of the collimator head, the measurement error was 0.11°±0.02°. Conclusion:The system demonstrates good accuracy and stability, and has potential clinical application value.

This study was designed to investigate the effect of dihydromyricetin (DHM) on inducing apoptosis of ovarian cancer cells A2780 through endoplasmic reticulum stress (ERS) pathway and the mechanisms involved in vitro and in vivo. A2780 cells were treated with different concentrations of DHM, and the protein expression levels of glucose-regulated protein 78 (GRP78) which is related to ERS increased, apoptotic proteins C/EBP-homologous protein (CHOP), and cysteinyl aspartate specific proteinase-12 (caspase-12) elevated. After pretreatment with ERS inhibitor, 4-phenyl butyric acid (4-PBA), following the intervention with DHM, the A2780 cell viability decreased and apoptotic rate increased. All animal welfare and experimental procedures were approved by the Animal Ethics Committee of Chongqing Medical University. Intraperitoneal injection of DHM suspension into nude mice with ovarian cancer could significantly inhibit the growth of transplanted tumor in vivo, increase the protein expression levels of GRP78, CHOP, and caspase-3. Moreover, swollen and broken endoplasmic reticulum could be observed in tumor tissues, suggesting that DHM intervention induces apoptosis mediated by ERS. The results indicated that DHM could induce apoptosis of ovarian cancer cells and inhibit the growth of transplanted tumors in nude mice, which might be related to the activation of ERS pathway.

Cerebral Hemorrhage ; pathology ; physiopathology ; Child ; Child, Preschool ; Female ; Heart Defects, Congenital ; pathology ; physiopathology ; Hemodynamics ; physiology ; Humans ; Infant ; Male ; Risk Factors ; Stroke ; pathology ; physiopathology ; Vascular Malformations ; pathology ; physiopathology

China ; Health Care Costs ; Hospitalization ; Humans ; Idiopathic Pulmonary Fibrosis ; Retrospective Studies ; Tertiary Care Centers