Experimental Study of Plasmid TGF-β1 DNA Gene Transfer with Lipofectamine into Rabbit Corneal Epithelial Cells In Vitro

To investigate whether the TGF-β1 plasmid DNA carried by lipofectamine could be introduced into cultured rabbit corneal epithelial cells, specific expression of the plasmid pMAM TGF-β1in the cultured corneal epithelial cells was studied. Two days after 12 h of transfection of pMAMTGF-β1 mediated by lipofectamine into the cultured corneal epithelial cells, the TGF-β1 protein expression specific for pMAMTGF-β1 in the cells was detected by means of immunohistochemical staining and the positive rate was 23. 37 %. The results suggested that foreign plasmid DNA could be effectively delivered into cultured rabbit corneal epithelial cells by means of lipofectamine, and this will provide a promising method of studying TGF-β1 on the mechanism of physiology and pathology concerned with corneal epithelial cells.     

Comparative study of catheter-mediated gene transfer into heart

ObjectiveTo investigate the feasibility and features of 3 catheter-mediated approaches of gene transfer into heart, including direct myocardial injection (DMI), coronary artery perfusion (CAP), and intrapericardial cavity injection (ICI).MethodsFifteen dogs were used, and 03ml (1×10［9］ pfu) of an adenovirus (Adex1SR LacZ) was injected into the heart by 3 methods.The dogs were killed 5 days following injection, and gene expressions in heart and liver were evaluated by histochemical analysis.ResultsThe results showed that ① the CAP method was relatively less damaging and induced sparse LacZ expression in the myocardium, and the gene expression was also foundin both vessels within the myocardium and liver; ② gene transfer by DMI resulted in intense LacZ expression around the injection accompanied by a local inflammatory response; ③ LacZ expression elicited by ICI was detected in either the inner surface of the parietal pericardium or epicardial surface of the heart,and also in the myocardium underlying the visceral pericardium.ConclusionThree catheter-mediated methods of gene transfer into the heart may be used and a reasonable approach should be chosen according to purpose     

Effect of intramuscular injection of hepatocyte growth factor plasmid DNA with electroporation on bleomycin-induced lung fibrosis in rats

Background So far, there is no efficient treatment for pulmonary fibrosis. The objective of this study was to determine whether intramuscular injection of the hepatocyte growth factor (HGF) plasmid DNA by in vivo electroporation could prevent bleomycin-induced pulmonary fibrosis in rats, and to investigate the possible mechanisms. Methods Twenty male Wistar rats were randomly divided into four groups: control group (group C),model group (group M), early intervention group (groupⅠ) and late intervention group (groupⅡ). Groups M, Ⅰ and Ⅱ were intratracheally infused with bleomycin, then injected the plasmid pcDNA3.1-hHGF to group Ⅰon day 7, 14 and 21. GroupⅡ received the same treatment like Group Ⅰ on day 14 and 21. All the rats were killed on day 28 after bleomycin injection. We detected Homo HGF expression in the rats with ELISA method and estimated the pathological fibrosis score of lung tissue using hematoxylin eosin (HE) and Massion staining. The mRNA expression of transforming growth factor-β1 (TGF-β1), cycloxygenase-2 (COX-2), and rat HGF in rat pulmonary parenchyma were evaluated by RT-PCR. Immunohistochemistry and Western blotting were performed to determine the protein expression of transforming TGF-β1 and COX-2 in lung parenchyma. Results The plasmid pcDNA3.1-hHGF could express hHGF in NIH3T3 cells and the hHGF protein is secreted into the culture medium. The expression of hHGF protein could be monitored in quadriceps muscle, plasma and lung in Groups Ⅰ and Ⅱ. Pulmonary fibrosis levels of Groups Ⅰ and Ⅱ were obviously lower than that of group M (P<0.05). Expression of TGF-β1 protein and mRNA in lung tissue was markedly decreased in Groups Ⅰ and Ⅱ compared with Group M (P<0.05). The level of expression of HGF and COX-2 mRNA was higher in Groups Ⅰ and Ⅱ than in Group M (P<0.05). Conclusions Injection of the plasmid pcDNA3.1-hHGF into skeletal muscle with electroporation has a potential role in the treatment of bleomycin-induced lung fibrosis. Exogenous HGF may inhibit the expression of TGF-β1 and regulate the crosstalk between AECs and mesenchymal fibroblasts.     

Construction of Eukaryotic Expression Plasmid of bFGF Gene in Rats and Its Expression in Tenocytes

The bFGF plays an important role in embryonic development of tendons and ligaments and in the healing of injuried tendons and ligaments. The eukaryotic expression plasmid of rat basic fibroblast growth factor (bFGF) gene was constructed in order to further investigate the bFGF func-tion in molecular regulatory mechanism in the repair of tendons and ligaments and to provide the foundation for the clinical application. The cDNA fragments of bFGF were cloned from the skin of rats by RT-PCR, and recombinated to the pMD18-T vector. The cDNA encoding bFGF was cloned from the pMD18-T vector by RT-PCR, digested with restriction enzyme EcoRⅠ, PstⅠ and bound to eukaryotic expression plasmid pIRES2-EGFP to construct eukaryotic expression plasmid pIRES2-EGFP-bFGF. The pIRES2-EGFP-bFGF was transfected into the tenocytes by lipid-mediated ransfection technique. MTT test was used to detect the biological activity of bFGF in supernatants after the transfection. The expression of type Ⅰ and Ⅲ collagen genes was detected by using RT-PCR. It was verified that the pIRES2-EGFP-bFGF was successfully constructed, and its transfec-tion into tenocytes could significantly enhance the biological activity of bFGF, and increase the ex-pression of type Ⅰ and Ⅲ collagen mRNA, suggesting that pIRES2-EGFP-mediated bFGF gene therapy was beneficial to the repair of tendons and ligaments.     

Gene transfer of a β2-adrenergic receptor kinase inhibitor up-regulates the level of β2-adrenergic receptor and cAMP in the asthmatic murine lung

Objective: To investigate the effects of gene transfer of a β-adrenergic receptor(β-AR) kinase inhibitor(β ARKct)on pulmonary β2-adrenergic receptor and cAMP following β2-AR agonist treatment in asthmatic mice, and to analyze the relationship between the routes of gene delivery and the changes of β2AR and cAMP. Methods: BALB/c mice were sensitized and challenged by ovalbumin to establish the asthmatic model treated with βAR agonist ( salbutamol injected intramuscularly). The plasmid with the expression of βARKct was constructed and βARKct gene transfer was performed through intravenous injection or intratracheal instillation in asthmatic mice.The gene expression was measured with Western blot analysis, and the changes of pulmonary β-AR and cAMP evaluated by Radioimmunoassay. Results: The expression of tranfered βARKct gene was detectable in lungs and it was expressed more in the lungs of the mice receiving intratracheally plasmid than those receiving intravenously. The levels of βAR and cAMP were upregulated after using plasmid-βARKct to the asthmatic mice treated with β AR agonist. Conclusion: Our results indicated that there were down-regulation of βAR and cAMP in asthmatic mice treated with βAR agonist. Gene transfer of βARKct could inhibit the extent of the down-regulation of βAR and cAMP. The route of gene delivery could also affect the degree of up-regulation of βAR and cAMP. Gene transfer βARKct may provide a novel approach to the therapeutic strategy for asthma.     

Gene transfer of a β2-adrenergic receptor kinase inhibitor up-regulates the level of β2-adrenergic receptor and cAMP in the asthmatic murine lung

Objective： To investigate the effects of gene transfer of a β-adrenergic receptor（β-AR） kinase inhibitor（β ARIct） on pulmonary β2-adrenergic receptor and cAMP following β2-AR agonist treatment in asthmatic mice, and to analyze the relationship between the routes of gene delivery and the changes of β2AR and cAMP. Methods： BALB/c mice were sensitized and challenged by ovalbumin to establish the asthmatic model treated with βAR agonist （salbutamol injected intramuscularly）. The plasmid with the expression of βARKct was constructed and βARKct gene transfer was performed through intravenous injection or intratracheal instillation in asthmatic mice. The gene expression was measured with Western blot analysis, and the changes of pulmonary β-AR and cAMP evaluated by Radioimmunoassay. Results： The expression of tranfered βARKct gene was detectable in lungs and it was expressed more in the lungs of the mice receiving intratracheally plasmid than those receiving intravenously. The levels of βAR and cAMP were upregulated after using plasmid-βARKct to the asthmatic mice treated with βAR agonist. Conclusion： Our results indicated that there were down-regulation of βAR and cAMP in asthmatic mice treated with βAR agonist. Gene transfer of βARKct could inhibit the extent of the down-regulation of βAR and cAMP. The route of gene delivery could also affect the degree of up-regulation of βAR and cAMP. Gene transfer βARKct may provide a novel approach to the therapeutic strategy for asthma.     

Construction of Porcine CCK pDNA and Its Expression in COS-7 Cells

CCK correlates with the generation and progression of pancreatic cancer. The research aims to construct eukaryotic expression plasmid pIRES2-EGFP/CCK (CCK pDNA) and transiently express it in COS-7 cells. Total RNA was extracted from porcine intestinal mucosa. RT-PCR was used to amplify the aimed segments CCKcDNA which was then digested with EcoR1 and BamH1 and inserted into a eukaryotic expression plasmid pIRES2-EGFP to construct CCK pDNA. The con- structed plasmid was transfected into COS-7 cells by lepofectamineTM2000-mediated transfer method. The expression of CCK in transfected COS-7 cells was detected 24, 48 and 72 h post-transfection with fluorescence microscopy and the expression level of CCK mRNA in transfected COS-7 cells was assayed by using RT-PCR. The results showed CCK pDNA was successfully constructed and expressed transiently in COS-7 cells. Green fluorescent protein could be detected in the COS-7 cells transfected with porcine CCK pDNA 24 h post-transfection. At 48th h post-transfection, the number of positive cells was increased significantly and much brighter green fluorescence could be detected. And 72 h post-transfection, the green fluorescence of positive cells became even stronger, while no green fluorescence was detected in the control group. The expression of CCK mRNA in the cells was detectable by using RT-PCR. In COS-7 cells transfected with CCK pDNA a high level of porcine CCK mRNA was detected while no expression of porcine CCKmRNA was found in the cells trans- fected with null plasmid. It was concluded CCK pDNA was expressed successfully in COS-7 cells, which lays a foundation for further research on the relationship between CCK and tumor.     

Ultrasound-mediated microbubble delivery of pigment epithelium-derived factor gene into retina inhibits choroidal neovascularization

Background Many studies have suggested that the imbalance of angiogenic factor and anti-angiogenic factor expression contributes significantly to the development of choroidal neovascularization （CNV）, and ultrasound microbubble combination system can increase the gene transfection efficiency successfully. This study was designed to investigate whether ultrasound-mediated microbubble destruction could effectively deliver therapeutic plasmid into the retina of rat, and whether gene transfer of pigment epithelium-derived factor （PEDF） could inhibit CNV.
Methods Human retinal pigment epithelial cells were isolated and treated either with ultrasound or plasmid alone, or with a combination of plasmid, ultrasound and microbubbles to approach feasibility of microbubble-enhanced ultrasound enhance PEDFgene expression; For in vivo animal studies, CNV was induced by argon lasgon laser in rats. These rats were randomly assigned to five groups and were treated by infusing microbubbles attached with the naked plasmid DNA of PEDF into the vitreous of rats followed by immediate ultrasound exposure （intravitreal injection）; infusing liposomes with the naked plasmid DNA of PEDF into the vitreous （lipofectamine ＋ PEDF）; infusing microbubbles attached with PEDF into the orbit of rats with ultrasound irradiation immediately （retrobular injection）; infusing microbubbles attached with PEDF into the femoral vein of rats with exposed to ultrasound immediately （vein injection）. The CNV rats without any treatment served as control. Rats were sacrificed and eyes were enucleated at 7, 14, and 28 days after treatment. Gene and protein expression of PEDF was detected by quantitative real-time RT-PCR, Western blotting and immunofluorescence staining, respectively. The effect of PEDF gene transfer on CNV was examined by fluorescein fundus angiography.
Results In vitro cell experiments showed that microbubbles with ultrasound irradiation could significantly enhance PEDF delivery as compared with microbubbles or ultrasound alone. In the rat CNV model, transfection efficiency mediated by ultrasound/microbubbles was significantly higher than that by lipofectamine-mediated gene transfer at 28 days after treatment. The study also showed that with the administration of ultrasound-mediated microbubbles destruction, the CNV of rats was inhibited effectively.
Conclusions Ultrasound-microbubble technique could increase PEDF gene transfer into rats＇ retina and chorioid, in association with a significant inhibition of the development of CNV, suggesting that this noninvasive gene transfer method may provide a useful tool for clinical gene therapy.     

Effects of heparin on transforming growth factor-β1 and extracellular matrix components in the glomeruli of diabetic rats

Summary The effects of heparin on the expression of transforming growth factor-β₁ (TGF-β₁) and two extracellular matrix components laminin (LN) and fibronectin (FN) in diabetic rat glomeruli were investigated. Twenty-six rats were randomly divided into control group (C,n=8), diabetic group (D,n=9), and diabetes+heparin group (DH,n=9). After 8-week therapy of heparin (200 U once daily by abdominal injection), TGF-β₁, LN and FN expression in glomeruli was detected by immunohistochemical method. The results showed that the expression levels of TGF-β₁, LN and FN were higher in group D than in group C. It was found that heparin could reduce 24-h urinary albumin excretion and inhibit overexpression of TGF-β₁, LN and FN in glomeruli of diabetic rats. It suggested that the inhibitory effect of heparin on diabetic glomerular sclerosis was at least partly related with the inhibition of TGF-β₁ expression. LI Yuanhong, female, born in 1973, Resident     

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β1 in Cultured Human RPE Cells

Matrix metalloproteinases(MMPs)are a familyof zinc binding,calcium-dependent endopeptidases thatfunction by degrading extracellular matrix(ECM)components.The functional effects of these enzymesare in part controlled byinteractions withtissueinhibi-tors of metalloproteinases(TI MPs)acting as naturalMMPinhibitors.Aprecise balance between MMPandTI MPactivities may be i mportant for the integrity ofECMcomponents[1].It shows that the expression andactivity of MMPs could be regulated by va…     

Molecular tissue engineering: Applications for modulation of mesenchymal stem cells proliferation by transforming growth factor β1 gene transfer

Summary The effect of transforming growth factor β₁ (TGF-β₁) gene transfection on the proliferation of bone marrow-derived mesenchymal stem cells (MSCs) and the mechanism was investigated to provide basis for accelerating articular cartilage repairing using molecular tissue engineering technology. TGF-β₁ gene at different doses was transduced into the rat bone marrow-derived MSCs to examine the effects of TGF-β₁ gene transfection on MSCs DNA synthesis, cell cycle kinetics and the expression of proliferating cell nuclear antigen (PCNA). The results showed that 3 μl lipofectaminemediated 1 μg TGF-β₁ gene transfection could effectively promote the proliferation of MSCs best; Under this condition (DNA/Lipofectamine= 1μg/3μl) flow cytometry and immunohistochemical analyses revealed a significant increase in the³H incorporation, DNA content in S phase and the expression of PCNA. Transfection of gene encoding TGF-β₁ could induce the cells at G0/G1 phase to S1 phase, modulate the replication of DNA through the enhancement of the PCNA expression, increase the content of DNA at S1 phase and promote the proliferation of MSCs. This new molecular tissue engineering approach could be of potential benefit to enhance the repair of damaged articular cartilage, especially those caused by degenerative joint diseases. This project was supported by a grant from National Natural Science Foundation of China (No. 30170270).     

Osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β1 genein vitro

Summary To study the osteogenic potential of cultured bone marrow stromal cells (BMSCs) transfected with transforming growth factor β₁ (TGF-β₁) genein vitro, cultured BMSCs were transfected with the complexes of pcDNA₃-TGF-β₁ and Lipofectamine Reagentin vitro. The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type I propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type I expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF-β₁ gene could promote the osteogenic potential of cultured BMSCs.     

Effect of Coiquhoumia Root on the Expression of Transforming Growth Factor-β in Mesangiai Proliferation Giomerulonephritis Model

Summary： To study the efficacy and the mechanism of Colquhoumia root （ Tripterygium hypoglaucure （Le,vL） Hutch） in the treatment of mesangial proliferation glomerulonephritis （MsPGN）, SD rats were injected with anti-thymoeyte serum （ATS） to make MsPGN model （anti-Thyl model）. The rats were then divided into 3 groups： normal control group, anti-Thyl model group and treatment group. Histopathologieal （HE, PAS）, immunohistoehemieal, RT-PCR technique and computer imaging analysis system were used to evaluate mesangial matrix production, the expression of TGF-β protein and mRNA in the tissues of kidney. Our result showed that proteinuria and the ratio of extraeellular matrix/glomerular capillaries area （ECM/CA） were increased significantly in model group. The expression of both TGF-β protein and mRNA in glomeruli was much higher in model group than in control group （P〈0.01）. After the treatment with Colquhoumia root, proteinuria, ECM/CA and the expression of both TGF-β1 protein and mRNA in glomeruli were significantly decreased in treatment group as compared with those in model group. It is concluded that Colquhoumia root is effective in reducing proteinuria and mesangial matrix proliferation in MsPGN and it may achieve these effects by inhibiting the expressions of TGF-β1 protein and mRNA of mesangial cells.     

Expression of transforming growth factor β<Subscript>1</Subscript> in mesenchymal stem cells: Potential utility in molecular tissue engineering for osteochondral repair

Summary The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor (TGF)-β₁ genes in bone marrow-derived mesenchymal stem cells (MSCs)in vitro. The full-length rat TGF-β₁ cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418, a synthetic neomycin analog. The transient and stable expression of TGF-β₁ by MSCs was detected by using immunohistochemical staining. The lipofectamine-mediated gene therapy efficiently transfected MSCsin vitro with the TGF-β₁ gene causing a marked up-regulation in TGF-β₁ expression as compared with the vector-transfected control groups, and the increased expression persisted for at least 4 weeks after selected with G418. It was suggested that bone marrow-derived MSCs were susceptible toin vitro lipofectamine mediated TGF-β₁ gene transfer and that transgene expression persisted for at least 4 weeks. Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology, an innovative concept, i.e. molecular tissue engineering, are put forward for the first time. As a new branch of tissue engineering, it represents both a new area and an important trend in research. Using this technique, we have a new powerful tool with which: (1) to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and (2) to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis. GUO Xiaodong, male, born in 1970, Doctor in Charge     

Expression of TGF-β2 mRNA and PCNA, FN Protein in Lens Epithelial Cells in Age-related Nuclear and Cortex Cataract

Summary： By using RT PCR and immunohistochemistry, the expressions of transforming growth factor 132 （TGF-β2） mRNA, proliferating cell nuclear antigen （PCNA） and fibronection （FN） protein in lens epithelial cells （LECs） of age-related nuclear and cortex cataract were detected and compared. The results of RT-PCR revealed that the expression of TGF-β2 mRNA was higher in cortex cataract than in nuclear cataract. Immunohistochemistry demonstrated that the expression of PCNA protein was lower and the expression of FN protein was higher in cortex cataract than in nuclear cataract. It was suggested that TGF-β2 , PCNA and FN might take important parts in the process of age-related cataract. Cortex cataract was related to the transdifferentiation of LECs, and nuclear cataract to the proliferation of LECs.     

The role of TGF-β1 in mice hepatic fibrosis bySchistosomiasis Japonica

Summary To investigate the role of transforming growth factor-β₁ (TGF-β₁) in mice with hepatic fibrosis caused bySchistosomiasis Japonica, ELISA, VG staining and multimedia color hieroglyph quantitative analysis were used to study the change of the serum TGF-β₁, liver collagen fiber and reticular fiber in mice. The level of serum TGF-β₁ in experimental group was significantly higher than that in control group (P < 0. 01 orP < 0. 05) 8, 10, 12 weeks after infected by schistosomiasis. After infection, the level of liver collagen fiber and reticular fiber, and that of TGF -β₁ increased over time (P < 0. 01 orP < 0. 05). In mice infected bySchistosomiasis Japonica, the level of TGF-β₁ increased with prolongation of infection time, and with the increase of liver collagen fiber and reticular fiber. TGFβ₁ plays an important role of immunomodulation in hepatic fibrosis formation caused bySchistosomiasis Japonica.     

Effect of huan-shuai recipe on expression of extracellular matrix in 5/6 nephrectomized rats

Objective: To investigate the effect of Huan-shuai Recipe on the expression level of fibronectin (FN) and transforming growth factor-β₂ (TGF-β₂) in the remnant kidney of rats.Methods : Male Wistar rats, after 4 weeks of 5/6 nephrectomy, were divided into two groups at random, and treated with water and Huanshuai Recipe (HSR) respectively. Serum creatinine (SCr) and urinary protein of 24-hours were observed at beginning, 6th week and 12th week of the experiment, and FN and TGF-β2 were assayed by immunohistochemical technique and computer assisted image analysis as well.Results : Serum SCr and urinary protein of 24-hours were increased significantly in the animals after 5/6 nephrectomy. The increased parameters decreased in the HSR group after treatment, as compared with those in the control group, and the difference was significant (P < 0.05); Immunohistochemical measurement and computer assisted image analysis showed a marked suppression of FN and TGF-β₂ in animals of the HSR group with significant difference from those in the control group (P<0.05).Conclusion : HSR not only plays the role of renal function protection, but could also alleviate the glomerular pathological injury. The effect on TGF-β2 and FN may be the mechanism of HSR in slowing down the progression of chronic renal failure.     

Effects of <Emphasis Type="Italic">Panax notoginoside</Emphasis> on the expression of TGF-β1 and Smad-7 in renal tissues of diabetic rats

In order to explore the effects of Panax notoginoside (PNS) on the expression of transforming growth factor β1 (TGF-β1) and Smad-7 in renal tissues of diabetes, a rat model of diabetic nephropathy was set up by intravenous injection of streptozotocin (STZ). Wistar rats were randomly divided into normal group, diabetic control group, group treated by PNS at low-dosage (PL), group treated by PNS at high-dosage (PH) and group treated by catopril (C), respectively. Fasting blood glucose (FBG), renal index, endogenous creatinine clearance rate (CCr) and urinary albumin (UAlb) in 24 h were examined after 6 weeks. Meanwhile, the expressions of TGF-β1 and Smad7 in renal tissues were immunohistochemically dectected. At the end of the sixth week, FBG, renal index, Ccr, UAlb were all elevated significantly in control group (P<0.01). The expression of TGF-β1 protein was increased while Smad7 protein decreased in renal tissue (P<0.01). However, the treatment with PNS reversed the aforementioned changes in renal tissues of diabetic rats. These results indicate that PNS possess a protective effect on the kidney of diabetic rats and it might protect kidney by inhibiting the expression of TGF-β1 protein and enhancing the expression of Smad7 protein.