ObjectiveTo observe the morphological and functional changes of retinal degeneration in mice with CLN7 neuronal ceroid-lipofuscinosis, and the therapeutic effects of glial cell derived neurotrophic factor (GDNF) and/or ciliary neurotrophic factor (CNTF) based on neural stem cells (NSC) on mouse photoreceptor cells. MethodsA total of 100 CLN7 mice aged 14 days were randomly divided into the experimental group and the control group, with 80 and 20 mice respectively. Twenty C57BL/6J mice aged 14 days were assigned as wild-type group (WT group). Mice in control group and WT group did not receive any interventions. At 2, 4, and 6 months of age, immunohistochemical staining was conducted to examine alterations in the distribution and quantity of cones, rod-bipolar cells, and cone-bipolar cells within the retinal of mice while electroretinography (ERG) examination was utilized to record scotopic a and b-waves and photopic b-wave amplitudes. At 14 days of age, the mice in the experimental group were intravitreally injected with 2 μl of CNTF-NSC, GDNF-NSC, and a 1:1 cell mixture of CNTF-NSC and GDNF-NSC (GDNF/CNTF-NSC). Those mice were then subdivided into the CNTF-NSC group, the GDNF-NSC group, and the GDNF/CNTF-NSC group accordingly. The contralateral eyes of the mice were injected with 2 μl of control NSC without neurotrophic factor (NTF) as their own control group. At 2 and 4 months of age, the rows of photoreceptor cells in mice was observed by immunohistochemical staining while ERG was performed to record amplitudes. At 4 months of age, the differentiation of grafted NSC and the expression of NTF were observed. Statistical comparisons between the groups were performed using a two-way ANOVA. ResultsCompared with WT group, the density of cones in the peripheral region of the control group at 2, 4 and 6 months of age (F=285.10), rod-bipolar cell density in central and peripheral retina (F=823.20, 346.20), cone-bipolar cell density (F=356.30, 210.60) and the scotopic amplitude of a and b waves (F=1 911.00, 387.10) in central and peripheral retina were significantly decreased, with statistical significance (P＜0.05). At the age of 4 and 6 months, the density of retinal cone cells (F=127.30) and b-wave photopic amplitude (F=51.13) in the control group were significantly decreased, and the difference was statistically significant (P＜0.05). Immunofluorescence microscopy showed that the NSC transplanted in the experimental group preferentially differentiated into astrocytes, and stably expressed CNTF and GDNF at high levels. Comparison of retinal photoreceptor nucleus lines in different treatment subgroups of the experimental group at different ages: CNTF-NSC group, at 2 months of age: the whole, central and peripheral regions were significantly different (F=31.73, 75.06, 75.06; P＜0.05); 4 months of age: The difference between the whole area and the peripheral region was statistically significant (F=12.27, 12.27; P＜0.05). GDNF/CNTF-NSC group, 2 and 4 months of age: the whole (F=27.26, 27.26) and the peripheral area (F=16.01, 13.55) were significantly different (P＜0.05). In GDNF-NSC group, there was no statistical significance at all in the whole, central and peripheral areas at different months of age (F=0.00, 0.01, 0.02; P＞0.05). ConclusionsCLN7 neuronal ceroid-lipofuscinosis mice exhibit progressively increasing degenerative alterations in photoreceptor cells and bipolar cells with age growing, aligning with both morphological and functional observations. Intravitreal administration of stem cell-based CNTF as well as GDNF/CNTF show therapeutic potential in rescuing photoreceptor cells. Nevertheless, the combined application of GDNF/CNTF-NSC do not demonstrate the anticipated synergistic protective effect. GDNF has no therapeutic effect on the retinal morphology and function in CLN7 neuronal ceroid-lipofuscinosis mice.
ObjectiveTo construct a lentiviral vector carrying rat sirt1 gene and observe the expression of sirt1 in retinal ganglion cell (RGC) of rat. MethodsRat sirt1 cDNA was inserted into pLV5 vector. After identification by sequencing analysis and PCR, the recombinant sirt1expressinglentivirus vector was packaged by cotransfecting 293T cells with packaged plasmid.Then pLV5-sirt1 was used to infect the cultured Sprague-Dawley rat RGC cell in vitro.The expressions of sirt1 protein and mRNA in infected rat RGC were detected by quantitative real-time PCR and Western blot. ResultsThe sirt1 expression vector pLV5 was successful constructed and sequence was proved to be correct. The expression of sirt1 protein and mRNA in RGC was significantly increased than that in cells infected with control lentiviruses(P < 0.05). ConclusionWe have successful constructed a sirt1 expression lentivirus vector pLV5-sirt1 and it can increase the expression of sirt1 protein and mRNA in the rat retinal ganglion cells.
ObjectiveTo explore the effects of PKD1 gene on mouse aortic smooth muscle (MOVAS) cells autophagy.MethodsThe shRNA and over-expression lentiviral vectors for the target gene of PKD1 were constructed. MOVAS cells were infected by a number of successful packaging shRNA (PKD1 knockdown) or ETS-1 (PKD1 over-expressing) lentiviral vectors, and qPCR was used to test interference and over-expressing effects. Then qPCR and Western blotting were used to detect the expression levels of autophagy markers including Atg5, Beclin1 and LC3 in control group, shPKD1 group and ETS-1 group.ResultsCompared with the control group, PKD1 mRNA level was decreased in the shPKD1 group (P<0.05); ETS-1 and PKD1 mRNA levels were increased in the ETS-1 group (P<0.05). In contrast with the control group, the mRNA levels of autophagy markers including Atg5 (P<0.05) and Beclin1 (P<0.01) were obviously decreased in the shPKD1 group, but they were obviously increased in the ETS-1 group (P<0.001). Protein levels of Atg5, Beclin1 and LC3 were significantly decreased in the shPKD1 group (P<0.05), but they were increased obviously in the ETS-1 group (P<0.05) in contrast with the control group.ConclusionPKD1 gene is involved in MOVAS cells autophagy, low expression of PKD1 gene can inhibit autophagy and high expression of PKD1 promotes autophagy in vascular smooth muscle cells.
Objective To study the interferencing and anti-tumor effects of lentiviral vector of siRNA targeting IGF1R and EGFR gene of the liver cancer cell. Methods The complementary DNA containing both sense and antisense Oligo DNA of the targeting sequence was designed, synthesized and connected to the pLVTHM vector, named pLVTHM-IGF1R, into whom the EGFR-siRNA expression frame containing H1 promotor synthesized by RT-PCR was cloned to generate pLVTHM-IGF1R-EGFR-siRNA. The 293T cells were cotransfected by 3 plasmids of pLVTHM-IGF1R-EGFR-siRNA, psPAX2 and pMD2G to enclose LVTHM-IGF1R-EGFR-siRNA, which was amplified in large amount and purified by caesium chloride density gradient centrifugation for measurement of virus titer. SMMC7721 cells infected by LVTHM-IGF1R-EGFR-siRNA were infection group, the untreated SMMC7721 cells and blank vector plasmid LVTHM were two control groups (SMMC7721 cell group and blank vector group). The effect of LVTHM-IGF1R-EGFR-siRNA on IGF1R and EGFR expressions of SMMC7721 cells were detected by RT-PCR and Western blot. The antitumor potential of LVTHM-IGF1R-EGFR-siRNA to SMMC7721 cells was evaluated by Cell Counting Kit-8 assay for cell growth and TUNEL for apoptosis respectively. Results LVTHM-IGF1R-EGFR-siRNA was constructed successfully. Functional pfu titers of LVTHM-IGF1R-EGFR-siRNA was 4.58×109 pfu/ml. Protein and mRNA expression of IGF1R and EGFR of infection group were less than those of blank vector group and SMMC7721 cell group （P＜0.05）, LVTHM-IGF1R-EGFR-siRNA was more effective to inhibit the proliferation and promote apoptosis of SMMC7721 cells （P＜0.05）. Conclusion LVTHM-IGF1R-EGFR-siRNA expressing IGF1R-EGFR-siRNA can inhibit the expression of IGF1R and EGFR, and may be used for further investigation of gene therapy of liver cancer.
Objective To construct inducible lentiviral vector containing human bone morphogenetic protein 2 (hBMP-2) gene and to study its expression in human umbil ical cord blood mesenchymal stem cells (HUMSCs). Methods hBMP-2 gene was ampl ified by PCR from a plasmid and was cloned into pDown by BP reaction. pLV/EXPN2-Neo-TRE-hBMP-2 and pLV/EXPN2-Puro-EF1A-reverse transactivator (rtTA) were obtained with GATEWAY technology, and then were sequenced and analyzed by PCR. The recombinant vectors were transfected into 293FT cells respectively through l ipofectamine, and the lentiviral viruses were harvested from 293FT cells, then the titer was determined. Viruses were used to infect HUMSCs in tandem. In order to research the influence of induction time and concentration, one group of HUMSCs was induced by different doxycl ine concentrations (0, 10, 100 ng/mL, and 1, 10, 100 μg/mL) in the same induction time (48 hours), and the other by the same concentration (10 μg/mL) in different time points (12, 24, 48, and 72 hours). The expression of target gene hBMP-2 was indentified by ELISA method. After 2-week osteogenic induction of transfected HUMSCs, the mineral ization nodes were detected with Al izarin bordeaux staining method. Results Therecombinant inducible lentiviral vectors (pLV/EXPN2-Neo-TRE-hBMP-2 and pLV/EXPN2-Puro-EF1A-rtTA) were successfully constructed. The lentiviruses were also obtained and mediated by 293FT cells, and the virus titers were 3.5 × 108 TU/mL and 9.5 × 107 TU/mL respectively. HUMSCs could expression hBMP-2 by induction of doxycycl ine. The expression of hBMP-2 reached the peak at 10 μg/mL doxycl ine at 48 hours of induction. After 2-week osteogenic induction, a lot of mineral ization nodes were observed. Conclusion The recombinant inducible lentiviral vectors containing hBMP-2 gene can be successfully constructed, which provide an effective and simple method for the further study of stem cells and animal experiment in vivo.
Objective To construct the lentiviral vector containing homo sapiens forkhead box C2 (Foxc2) gene and to detect its expression in bone marrow mesenchymal stem cells (BMSCs) of rabbits. Methods Human Foxc2 gene coding region fragment was obtained by RT-PCR and then cloned into the plasmid of LV-green fluorescent protein (GFP) to prepare Foxc2 lentiviral plasmid. Foxc2 lentiviral plasmid, pGC-LV, pHelper1.0, and pHelper2.0 were co-transfected into 293T cells to obtain recombinant virus containing Foxc2 gene. The lentiviral titer was detected. BMSCs were isolated from bone marrow of rabbit and infected with Foxc2 recombined lentiviral, then the optimum multiplicity of infection (MOI) was determined by detecting the intensity of fluorescence expression. The expression of Foxc2 in the infected BMSCs was determined at 1, 3, and 7 days after transfection by inverted fluorescence microscope and Western blot. After osteogenic induction, Alizarin red staining was done to observe the formation of mineralized nodule. Results The Foxc2 recombinant lentiviral vector was constructed and was confirmed by restriction enzyme digestion and sequencing analysis. It could efficiently transfect 293T cells and express in 293T cells. The lentiviral titer was 2 × 108 TU/mL. The optimum MOI was 200. The inverted fluorescence microscope observation showed that the Foxc2 gene expressed in 84.5% ± 4.8% of infected BMSCs at 3 days after transfection. The expression of Foxc2 in infected BMSCs was stable and high, and increased gradually within 7 days after transfection by Western blot. At 2 weeks after osteogenic induction, Alizarin red staining showed that there were a large number of red calcified matrix deposition in the cytoplasm. Conclusion Foxc2 recombined lentivirus with high viral titer is successfully constructed and packaged, and the Foxc2 gene can be transfected into BMSCs with stable and high expression of Foxc2 in infected cells, and these cells may be applied for gene therapy of avascular necrosis of the femoral head.
Objective To observe the effect of shRNA interference lentivirus vector targeting rat Sirt1 gene on the expression of Sirt1 in retinal ganglion cell (RGC). Methods Four short hairpin (sh) RNA interference sequences targeting rat Sirt1 gene were designed. The target sequences of Oligo DNA were synthesized and annealed to double strand DNA, which was subsequently connected with pGLV3 lentivirus vector to build the lentiviral vector. The positive clones were identified by polymerase chain reaction (PCR) and DNA sequencing. The lentiviral vector construct and lentiviral packaging plasmids were co-transfected into 293T cells, then the titer of lentivirus were determined. The RGC were divided into 6 groups including blank group, negative control group and si-Sirt1-1, si-Sirt1-2, si-Sirt1-3, si-Sirt1-4 groups. Real-time PCR and Western blotting were used to detect the expression of Sirt1 mRNA and protein in the RGC cells. Results PCR and DNA sequencing analysis confirmed that the shRNA sequence was successfully inserted into the lentivirus vector. The concentrated titer of virus suspension was 8×108 TU/ml after the recombinant lentiviral vector successfully transfected and harvested in 293T cells. Comparing with NC group, the expression of Sirt1 mRNA and protein were significantly decreased in the si-Sirt1-1, si-Sirt1-2, si-Sirt1-3 and si-Sirt1-4 groups (F=27.682, 1 185.206; P=0.000, 0.000). The si-Sirt1-2 group had the strongest effect in reducing the expression of Sirt1 mRNA and protein. Conclusion The 4 lentiviral vectors harboring RNAi targeting rat Sirt1 gene can effectively down regulate the expression of Sirt1 mRNA and protein in RGC cells.
Objective To construct gene-modified hepatic stem cells (WB-F344 cells), which have rat IL-13 gene and can secrete the recombinant rat IL-13 cytokine in the cells. Methods Firstly, the rat IL-13 sequences were synthesized. Then the sequences were amplificated in bacterium coli after recombinated with pWPXL-MOD plasmid. After PCR and sequence identification, the positive clones were packaged into lentivirus. After detecting the virus titer, the WB-F344 cells with constructed lentivirus vector with rat IL-13 gene were cultured, then the valid targets (expression level of the IL-13) were detected by real time-PCR and Western blot in cultured WB-F344 cells on 5 days. Results The valid DNA of rat IL-13 was recombinated and packaged in lentivirus vector. The recombinant gene sequence was correct by checking with gene sequence test. Then the recombinant was introducted into the WB-F344 cells cultures. The best multiplicity of infection (MOI) value for effective transfection was 5. IL-13 had been detected on day 5 after transfection by checking with real-time PCR and Western blot. Conclusion The recombinant rat IL-13 gene with lentivirus vector is constructed and gene-modified WB-F344 cells are cultured successfully, which can be used in next animal experiment.
ObjectiveTo establish 16HBE cell lines stably expressing glutathione S-transferase mu 5 (GSTM5) gene, and explore the mechanism of GSTM5 nuclear translocation. MethodsRecombinant lentiviral expression vector containing GSTM5 gene was constructed and lentivirus was produced. After lentivirus infection of 16HBE cells, 16HBE-GSTM5 cell lines were obtained by screening with puromycin. Expression of GSTM5 in different cells was examined by RT-qPCR and Western blot. The nuclear translocation of GSTM5 was observed by confocal laser scanning microscope, after the 16HBE-GSTM5 cell lines were treated with tumor necrosis factor-α (TNF-α; 10 ng/ml) for 0.5 hour. ResultsLentiviral expression plasmids, PLVX-puro-3*flag-SBP-GSTM5-C and PLVX-puro-GSTM5-SBP-3*flag-N, were constructed and lentiviral particles were successfully packed. After infected with lentivirus and screened by puromycin, two cell lines, 16HBE-GSTM5-SBP-3*flag-N and 16HBE-3*flag-SBP-GSTM5-C, were obtained. GSTM5 expression in these two cell lines was significantly higher compared with the control group and parental cells. After treated with TNF-α for 0.5 hour, the nuclear translocation of GSTM5 in 16HBE-GSTM5-SBP-3*flag-N was much more obviously than that in 16HBE-3*flag-SBP-GSTM5-C. ConclusionThe N-terminal region of GSTM5 is critical for nuclear translocation induced by TNF-α, which is mediated by a novel and non-classical nuclear localization signal.
ObjectiveTo build a lentiviral expression vector regulated by two targets 5 copies of HREs and hTERTp, express the target gene CDX2, and to test the activity of hTERT promoter by using LoVo cells for transfection. MethodsAfter the primer sets were designed, the hTERT promoter was cloned by PCR amplification from the genome of colon cancer. The CEA promoter was removed from the original vector pLEGFP-5HRE-CEAp by double digestion and PCR method, and then the hTERTp was introduced into the vector to construct the recombinant plasmid pLEGFP-5HRE-hTERTp. 5HRE-hTERTp was obtained by PCR, while the CMV promoter was removed from the original vector pLVX-EGFP-3FLAG by double digestion and PCR method, and then the 5HRE-hTERTp was introduced into the vector to construct the recombinant plasmid pLVX-5HRE-hTERTp-EGFP-3FLAG. The CDX2 was cloned by PCR amplification from GV230-CDX2-EGFP, and the EGFP was removed from the vector pLVX-5HRE-hTERTp-EGFP-3FLAG by double digestion, and then the CDX2 was introduced into the vector to construct the recombinant plasmid pLVX-5HRE-hTERTp-CDX2-3FLAG. LoVo cells ex vivo was transiently transfected by pLVX-5HRE-hTERTp-EGFP-3FLAG to evaluate the activity of hTERTp by detecting the expression of green fluorescence protein EGFP. ResultsPCR and sequencing analyzing showed that pLEGFP-5HRE-hTERTp, pLVX-5HRE-hTERTp-EGFP-3FLAG, and pLVX-5HRE-hTERTp-CDX2-3FLAG were sequenced correctly and the same as our designed. pLVX-5HRE-hTERTp-EGFP-3FLAG was successfully transfected into LoVo cells ex vivo and expressed green fluorescence protein EGFP, which showed that hTERTp was activated and promoted the expression of downstream gene. ConclusionThe lentiviral expression vector, pLVX-5HREhTERTp-EGFP-3FLAG and pLVX-5HRE-hTERTp-CDX2-3FLAG are successfully constructed, which lays the foundation of further research. But the function of dual-target regulation needs further proof.