OBJECTIVETo investigate the effect of chemically synthetic small interfering RNA (siRNA) targeting connective tissue growth factor (CTGF) on the synthesis and secretion of extracellular matrix (ECM) in hepatic stellate cells (HSC).

METHODSChemically synthetic siRNA targeting CTGF was transfected into HSC T6 (an active HSC line in rats) by oligofectamine package, and untreated HSC T6 were used as control. Total RNA and protein of the cells, after their incubation with siRNA for 24, 48 and 72 hours, were extracted, and the supernatants were collected. The expressions of CTGF and type I and III collagen genes were detected by means of reverse transcription-polymerase chain reaction (RT-PCR) and/or Western blot. Contents of hyaluronic acid and type III pro-collagen in the supernatants were determined by radioimmunoassay.

RESULTSThe expression of CTGF at mRNA and protein level and type I and III collagen at mRNA levels were markedly down-regulated in siRNA-transfected HSCs. The contents of hyaluronic acid and type III pro-collagen in the supernatants decreased by 46%+/-7%, 52%+/-7%, 53%+/-7% and 29%+/-18%, 29%+/-7%, 27%+/-5%, compared with those of the blank control at 24, 48 and 72 hours.

CONCLUSIONSChemically synthetic anti-CTGF siRNA can significantly inhibit CTGF gene expression in HSC, and markedly reduce the synthesis and secretion of ECM including type I and III collagen and hyaluronic acid. The siRNA-directed suppression of CTGF gene in HSC was maintained for 72 hours. This suggests that chemically synthetic siRNA may be a potential in preventing and treating liver fibrosis and may have a promising future for development

Cell Line ; Connective Tissue Growth Factor ; Extracellular Matrix ; metabolism ; Gene Targeting ; Humans ; Immediate-Early Proteins ; genetics ; Intercellular Signaling Peptides and Proteins ; genetics ; Liver ; cytology ; metabolism ; RNA, Small Interfering ; genetics

OBJECTIVETo investigate the effect of cytomegalovirus (CMV) infection on actin and microfilament in human embryo fibroblast cells (HF) and its relationship with CMV replication.

METHODSCell morphology was observed after the infection of CMV. Western-blot was used to measure the expression levels of beta-actin, G-actin and F-actin proteins. CMV immediately early antigen (CMV IE) in HF cells was analyzed by indirect immunofluorescence assay. Microfilament alteration was determined by cytoskeleton fluorescence probe.

RESULTCMV IE was demonstrated in more than 95% of HF cells after infection, which was primarily located in nucleus. The shape of HF cells changed from thin shuttle like to round and thick ball like, even escaping from wall after infection by CMV. Compared with control group, the expression of G-actin protein increased at 24 h of CMV infection (0.941 +/-0.061 compared with 0.714 +/-0.119, P <0.05), then decreased at 72 h, 96 h respectively(0.218 +/-.035, 0.230 +/-0.055 compared with 0.714 +/-0.119, P <0.05). The levels of F-actin in infected cells gradually decreased at 24 h, 72 h and 96 h compared with control HF cells (0.256 +/-0.021, 0.127 +/-0.032, 0.026 +/-0.008 compared with 0.373 +/-0.050, P<0.05). In infected HF cells, microfilaments were found ruptured, arranged turbulently. Cells fused and fluorescence density of microfilament markedly reduced.

CONCLUSIONCytomegalovirus can induce alteration of actins and microfilament, which may be associated with its infection, replication and reactivity in host cells.

Actin Cytoskeleton ; metabolism ; Actins ; biosynthesis ; genetics ; Antigens, Viral ; analysis ; Cells, Cultured ; Cytomegalovirus ; Cytoskeleton ; metabolism ; Embryo, Mammalian ; Fibroblasts ; metabolism ; ultrastructure ; virology ; Humans ; Immediate-Early Proteins ; analysis

OBJECTIVETo investigate the effect of EBV immediate-early protein Zta on cell cycle of Daudi cells and the involved mechanisms.

METHODSThe expression vector encoding Zta was constructed and electroporated into Daudi cells. Flow cytometric analysis was used to detect the cell cycle, Western blot to the protein levels of p21, Rb and E2F-1.

RESULTSThe vector was constructed successfully, the expression of Zta protein inhibited the proliferation of Daudi cells and promoted cell cycle from G(0)/G(1) phase \[(30.0 ± 3.4)%\] to S phase \[(47.7 ± 1.1)%\]. Meanwhile, Rb expression was significantly downregulated, E2F-1 and p21 expression upregulated by Zta.

CONCLUSIONZta could promote G(0)/G(1) phase to S phase transition in Daudi cells, which might be associated with the reduced expression of Rb and increased expression of E2F-1 and p21 protein.

Cell Cycle ; genetics ; Cell Division ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; E2F1 Transcription Factor ; metabolism ; Genetic Vectors ; Herpesvirus 4, Human ; genetics ; Humans ; Immediate-Early Proteins ; genetics ; Retinoblastoma Protein ; metabolism ; Trans-Activators ; genetics ; Transcriptional Activation ; Viral Proteins ; genetics

OBJECTIVETo explore the effect of connective tissue growth factor on the pathogenesis of human hypertrophic scar.

METHODSNormal skin and hypertrophic scar fibroblasts were cultured in vitro. The collagen synthesis of fibroblasts were measured by H3-proline incorporation method. The expression of connective tissue growth factor protein and mRNA of fibroblasts were detected with immunocytochemistry staining and reverse transcription polymerase chain reaction methods.

RESULTSCompared with normal skin fibroblast, the collagen synthesis and the expression of connective tissue growth factor protein and mRNA in the hypertrophic scar fibroblast was higher (P < 0.01).

CONCLUSIONConnective tissue growth factor may play an important role in promoting the fibrotic process of hypertrophic scar.

Cells, Cultured ; Cicatrix, Hypertrophic ; genetics ; metabolism ; pathology ; Collagen ; biosynthesis ; Connective Tissue Growth Factor ; Fibroblasts ; metabolism ; pathology ; Gene Expression ; Humans ; Immediate-Early Proteins ; genetics ; Immunohistochemistry ; Intercellular Signaling Peptides and Proteins ; genetics ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

During the infection of host cells, IE2 protein is one of the first and most abundantly expressed products of HCMV genome, which plays an important role in the controlling of cell cycle and apoptosis. But the correlation between expression level and anti-apoptotic activity of IE2 protein is still not clear. In this study, we successfully established a HCMV IE2 protein expression cell line that was controlled by Tet-On system. The effect of IE2 protein on cell apoptosis and the expression of p53 was detected under different condition of induction. Our results showed that the IE2 protein could inhibit cell apoptosis induced by TNF-alpha. Additionally, the anti-apoptotic activity of IE2 protein seemed to be relevant to its expression level. However, we failed to detect any difference of p53 expression between the IE2 protein expression and non-expression cells. These data indicated that the IE2 protein might inhibit cell apoptosis through regulating different signal pathways.
Anti-Bacterial Agents ; pharmacology ; Apoptosis ; drug effects ; genetics ; Doxycycline ; pharmacology ; Gene Expression Regulation ; drug effects ; genetics ; HeLa Cells ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Plasmids ; genetics ; Trans-Activators ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo study influence of lanthanum chloride (LaCl(3)) on the expression of immediate early genes (IEGs) including c-jun, early growth response gene 1 (Egr1) and activity-regulated cytoskeletal gene (Arc) in the hippocampus of rats, and discuss the mechanism of LaCl(3) undermining learning and memory capability.

METHODSForty female Wistar adult rats were divided into control group, low LaCl(3)-contaminated group (0.25%), medium LaCl(3)-contaminated group (0.50%), and high LaCl(3)-contaminated group (1.00%) by randomized design. Each group had ten female rats along with five male rats and mated by the ratio of 2:1. The amounts of pups in the above four groups were 80, 83, 78 and 75 separately. The pups in respective group were La-dyed by lactation, and then the pups in LaCl(3)-contaminated groups drank 0.25%, 0.50% and 1.00% LaCl(3) separately for one month. Learning and memory capability of pups were measured in jumping stairs experiment. Hippocampal lanthanum content was determined by inductively coupled plasma mass spectrometry (ICP-MS). Hippocampal c-jun, Egr1 and Arc mRNA expression was detected by RT-PCR, and corresponding protein expression was measured by Western blotting method.

RESULTSIn the jumping stairs experiment, pups in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups respectively made (1.75 ± 0.71), (2.38 ± 0.92) and (3.00 ± 0.76) mistakes; significantly higher than control group (1.25 ± 0.46) (q values were 4.386, 6.793, P < 0.05). However, the incubation period of 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups were (174.13 ± 33.72), (139.25 ± 45.83) and (75.50 ± 18.56) respectively, which were all significantly lower than that of control group (206.75 ± 20.47) (q values were 2.958, 6.121, 11.902, P < 0.05). Hippocampal c-jun mRNA expression were (0.89 ± 0.08), (0.77 ± 0.12), (0.58 ± 0.14) and (0.29 ± 0.10); while the c-jun protein expression were (0.72 ± 0.13), (0.64 ± 0.11), (0.43 ± 0.11) and (0.31 ± 0.14), and the Egr1 mRNA expression were (0.78 ± 0.09), (0.61 ± 0.13), (0.53 ± 0.10) and (0.22 ± 0.08), Egr1 protein expression were (0.65 ± 0.18), (0.40 ± 0.15), (0.32 ± 0.13) and (0.14 ± 0.09) in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups; and all of which presented a dose-effect relationship that the correlation coefficients of these parameters with dose were -0.900 (t = 11.309, P = 0.000), -0.969 (t = 7.058, P = 0.000), -0.898 (t = 11.179, P = 0.000) and -0.962 (t = 6.739, P = 0.000).

CONCLUSIONLaCl(3) undermines the learning and memory capability of rats, which is possibly related to lower expression of c-jun and Egr1 gene and protein induced by lanthanum in hippocampus.

Animals ; Early Growth Response Protein 1 ; metabolism ; Female ; Gene Expression ; Genes, Immediate-Early ; drug effects ; genetics ; Hippocampus ; drug effects ; metabolism ; Lanthanum ; pharmacology ; Learning ; drug effects ; Male ; Memory ; drug effects ; Proto-Oncogene Proteins c-jun ; metabolism ; Rats ; Rats, Wistar

Animals ; Cells, Cultured ; Connective Tissue Growth Factor ; Hepatocytes ; cytology ; metabolism ; Immediate-Early Proteins ; biosynthesis ; genetics ; Intercellular Signaling Peptides and Proteins ; biosynthesis ; genetics ; Male ; Plasmids ; genetics ; RNA Interference ; RNA, Small Interfering ; genetics ; Rats ; Transfection

The role of serum and glucocorticoid-induced kinase 1 (SGK1) pathway in the connective tissue growth factor (CTGF) expression was investigated in cultured human mesangial cells (HMCs) under high glucose. By using RT-PCR and Western blot, the effect of SGK1 on the CTGF expression in HMCs under high glucose was examined. Overexpression of active SGK1 in HMCs transfected with pIRES2-EGFP-S422D hSGK1 (SD) could increase the expression of phosphorylated SGK1 and CTGF as compared with HMCs groups transfected with pIRES2-EGFP (FP) under high glucose or normal glucose. Overexpression of inactive SGK1 in HMCs transfected with pIRES2-EGFP-K127N hSGK1 (KN) could decrease phosphorylated SGK1 and CTGF expression as compared with HMCs groups transfected with FP under high glucose. In conclusion, these results suggest that high glucose-induced CTGF expression is mediated through the active SGK1 in HMCs.
Cells, Cultured ; Connective Tissue Growth Factor/genetics ; Connective Tissue Growth Factor/*metabolism ; Glucose/*pharmacology ; Immediate-Early Proteins/metabolism ; Immediate-Early Proteins/*physiology ; Mesangial Cells/cytology ; Mesangial Cells/*metabolism ; Protein-Serine-Threonine Kinases/metabolism ; Protein-Serine-Threonine Kinases/*physiology ; Signal Transduction/drug effects

The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism, cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase. However, its upstream regulatory pathways as well as whether it has additional function(s) remain largely unknown. We recently reported that Rictor contains a novel ubiquitin E3 ligase activity by forming a novel complex with Cullin-1, but not with other Cullin family members. Furthermore, we identified SGK1 as its downstream target. Interestingly, Rictor, but not Raptor or mTOR, promotes SGK1 ubiquitination. As a result, SGK1 expression is elevated in Rictor(-/-) MEFs. We further defined that as a feedback mechanism, Rictor can be phosphorylated by multiple AGC family kinases including Akt, S6K and SGK1. Phosphorylation of Rictor at the Thr1135 site did not affect its kinase activity towards phosphorylating its conventional substrates including Akt and SGK1. On the other hand, it disrupted the interaction between Rictor and Cullin-1. Consequently, T1135E Rictor was defective in promoting SGK1 ubiquitination and destruction. This finding further expands our knowledge of Rictor's function. Furthermore, our work also illustrates that Rictor E3 ligase activity could be governed by specific signaling kinase cascades, and that misregulation of this process might contribute to SGK overexpression which is frequently observed in various types of cancers.
Animals ; Carrier Proteins ; metabolism ; Cell Proliferation ; Cells, Cultured ; Cullin Proteins ; genetics ; metabolism ; Fibroblasts ; metabolism ; Humans ; Immediate-Early Proteins ; metabolism ; Mice ; Phosphorylation ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Rapamycin-Insensitive Companion of mTOR Protein ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Ubiquitin ; genetics ; metabolism ; Ubiquitination

OBJECTIVETo study the role of connective tissue growth factor (CTGF) in the pathogenesis of human keloid.

METHODSHuman keloid fibroblasts (HKF) were isolated from human keloid and cultured in vitro. The cells were then divided into 3 groups according to different processing, i.e. ASODN treatment (AT), in which phosphorothioate CTGF antisense oligonucleotides (ASODN) labeled by fluorescent isothiocyananate were transfected into the HKFs by liposome; liposome control (LC, with liposome only); control groups (without liposome or ASODN). The distribution of CTGF ASODN in all groups of cells was observed under fluorescent microscope. The CTGF mRNA index (RI) of HKF was assessed by reverse transcription polymerase chain reaction method (RT-PCR). The collagen synthesis of HKF was assessed by (3)H-proline incorporation method.

RESULTSA large amount of fluorescence could be observed in the cytoplasm of HKFs in AT 12 hours after transfection, but not in LC and C groups. The CTGF mRNA index of HKF in AT group 48 hours after transfection was significantly lower than that in LC and C groups (0.12 +/- 0.62 vs 0.51 +/- 0.18 vs 0.54 +/- 0.35, P < 0.01). The (3)H-proline incorporation rate in AT group (108.96 +/- 79.05) was lower than that in LC and C groups (P < 0.01).

CONCLUSIONThe expression of CTGF gene and collagen synthesis of the cultured HKF could be inhibited by CTGF ASODN, implying that CTGF played a role in the development of excessive fibrosis of human keloid.

Collagen ; biosynthesis ; Connective Tissue Growth Factor ; Fibroblasts ; metabolism ; Humans ; Immediate-Early Proteins ; antagonists & inhibitors ; genetics ; physiology ; Intercellular Signaling Peptides and Proteins ; genetics ; physiology ; Keloid ; etiology ; metabolism ; Oligonucleotides, Antisense ; pharmacology ; RNA, Messenger ; analysis ; Transfection