Whole-genome methylation analysis reveals epigenetic variation between wild-type and nontransgenic cloned,ASMT transgenic cloned dairy goats generated by the somatic cell nuclear transfer

Background:SCNT(somatic cell nuclear transfer)is of great significance to biological research and also to the livestock breeding.However,the survival rate of the SCNT cloned animals is relatively low compared to other transgenic methods.This indicates the potential epigenetic variations between them.DNA methylation is a key marker of mammalian epigenetics and its alterations will lead to phenotypic differences.In this study,ASMT(acetylserotonin-Omethyltransferase)ovarian overexpression transgenic goat was produced by using SCNT.To investigate whether there are epigenetic differences between cloned and WT(wild type)goats,WGBS(whole-genome bisulfite sequencing)was used to measure the whole-genome methylation of these animals.Results:It is observed that the different m Cp G sites are mainly present in the intergenic and intronic regions between cloned and WT animals,and their CG-type methylation sites are strongly correlated.DMR(differentially methylated region)lengths are located around 1000 bp,mainly distributed in the exonic,intergenic and intronic functional domains.A total of 56 and 36 DMGs(differentially methylated genes)were identified by GO and KEGG databases,respectively.Functional annotation showed that DMGs were enriched in biological-process,cellularcomponent,molecular-function and other signaling pathways.A total of 10 identical genes related to growth and development were identified in GO and KEGG databases.Conclusion:The differences in methylation genes among the tested animals have been identified.A total of 10 DMGs associated with growth and development were identified between cloned and WT animals.The results indicate that the differential patterns of DNA methylation between the cloned and WT goats are probably caused by the SCNT.These novel observations will help us to further identify the unveiled mechanisms of somatic cell cloning technology,particularly in goats.

Construction and Identification of a Goat Pox Virus Transfer Vector to Express Peste des Petits Ruminants H gene

[Objective] This study was to develop a live vector vaccine of goat pox virus of Peste des petits ruminants(PPR). [Method] Using PCR amplification technique, PPR H gene was obtained, then ligated into pGEM-T easy vector; the recombinants were digested by Nhe Ⅰ and Hind Ⅲ, and ligated into pEGFP-N1-P7.5, yielding the recombinant vector pEGFP-N1-P7.5-H; next the expression cassette EGFP-N1-P7.5-H was first released from recombinant vector pEGFP-N1-P7.5-H by double digestion of Hind Ⅲ and Nhe Ⅰ and ligated into pUC119-TK that was digested by Kpn Ⅰ, yielding the transfer vector pUC119-TK-EGFP-P7.5-H. [Result] Identification and double enzyme digestion showed that the transfer vector pUC119-TK-EGFP-P7.5-H was correctly constructed. From the transfer vector transfected BHK-21 cells which infected GTPV AV41, specific fluorescence was observed at 48th h of transfection. [Conclusion] The construction of goat poxvirus live vector laid a foundation for the live vector vaccine of PPR vaccine.

cGH Gene Transfer and PCR Detection in Crucian Carp

By inserting the CMV with HSV TK promoter into the plasmid pBlue-cGH which contained cGH gene, a chimeric expression vector was constructed for transgenic fish. After the vector was transferred into fertilized eggs of crucian carp by means of microinjection, the transgenic crucian carp was obtained. The result of PCR detection showed that the growth hormone gene of the exogenous carp was integrated into the genome of crucian carp, and the transgenic crucian carp displayed enhancement of its growth.

Gene therapy for human colorectal carcinoma using human CEA promoter controlled bacterial ADP-ribosylating toxin genes:PEA and DTA gene transfer

AIM To establish a tissue-specific gene therapy for colorectal carcinoma using bacterial ADP-ribosylating toxin genes.METHODS Pseudomonas exotoxin A domain Ⅱ+Ⅲ (PEA) was cloned from genomic DNA of Pseudomonas aeruginosa. PEA and diphtheria toxin A chain gene (DTA) were modified to express eukaryotically. After sequencing, the toxin genes under the control of human carcinoembryonic antigen (CEA) promoter were cloned into retroviral vectors to construct CEAPEA and CEADTA respectively. In vitro cotransfection of the constructs with luciferase vectors and in vivo gene transfer in nude mice were subsequently carried out.RESULTS Both CEAPEA and CEADTA specifically inhibited the reporter gene expression in the CEA positive human colorectal carcinoma (CRC) cells in vitro. Direct injection of CEAPEA and CEADTA constructs into the established human tumors in BALB/c nude mice led to significant and selective reductions in CRC tumor size as compared with that in control groups.CONCLUSION The toxin genes, working as therapeutic genes, are suitable for the tissue-specific gene therapy for colorectal carcinoma.

RETROVIRAL MEDIATED EFFICIENT TRANSFER ANDEXPRESSION OF MULTIPLE DRUG RESISTANCE GENE TO HUMAN LEUKEMIC CELLS

Objective: To investigate retroviral-mediated transfer and expression of human multidrug resistance (MDR) gene MDR1 in leukemic cells. Methods: Human myeloid cells, K562 and NB4, were infected by MDR retrovirus from the producer PA317/HaMDR, and the resistant cells were selected with cytotoxic drug. The transfer and expression of MDR1 gene was analyzed by using polymerase chain reaction (PCR), flow cytometry (FCM) and semisolid colonies cultivation. Results: The resistant cells, K562/MDR and NB4/MDR, in which integration of the exogenous MDR1 gene was confirmed by PCR analysis, displayed a typical MDR phenotype. The expression of MDR1 transgene was detected on truncated as well as full-length transcripts. Moreover, the resistant cells were P-glycoprotein postiive at 78.0% to 98.7% analyzed with FCM. The transduction efficieny in K562 cells was studied on suspension cultures and single-cell colonies. The transduction was more efficient in coculture system (67.9%-72.5%) than in supernatant system (33.1%~46.8%), while growth factors may improve the efficiency. Conclusion: Retrovirus could allow a functional transfer and expression of MDR1 gene in human leukemia cells, and MDR1 might act as a dominant selectable gene for coexpression with the genes of interest in gene therapy.

Progress in gene transfer by germ cells in mammals

Use of germ cells as vectors for transgenesis in mammals has been well developed and offers exciting prospects for experimental and applied biology, agricultural and medical sciences. Such approach is referred to as either male germ cell mediated gene transfer （MGCMGT） or female germ cell mediated gene transfer （FGCMGT） technique. Sperm-mediated gene transfer （SMGT）, including its alternative method, testis-mediated gene transfer （TMGT）, becomes an established and reliable method for transgenesis. They have been extensively used for producing transgenic animals. The newly developed approach of FGCMGT, ovary-mediated gene transfer （OMGT） is also a novel and useful tool for efficient transgenesis. This review highlights an overview of the recent progress in germ cell mediated gene transfer techniques, methods developed and mechanisms of nucleic acid uptake by germ cells.

Adenoviral-mediated Hath1-EGFP gene transfer into guinea pig cochlea through intact round window membrane

Objective To study expression of adenoviral-mediated Hath1-EGFP gene in the guinea pig cochlea after transfer through intact round window membrane(RWM), and to assess its effects on hearing. Methods Twenty adult guinea pigs were used, of which: 12 were surgically inoculated with Ad-Hath1-EGFP in the bony groove of round window niche, and 8 with artificial perilymph. Auditory brainstem response(ABR) thresholds were determined in all animals before and 5 days after surgery. On post-surgery day 5 and day 14, animals were sacrificed and whole mounts of cochlea and frozen sections were examined. Results ABR tests showed no significant change of hearing after the surgery. Strong fluorescence staining in the cochleae was seen in Ad-Hath1-EGFP groups. The highest levels of gene expression were seen in the post-surgery day 5 group with little decrease on post-surgery day 14.The contralateral cochlea and those in the control groups were free of fluorescence staining. Conclusion The transgenic Hath1-EGFP can be effectively delivered into the inner ear through intact RWM, in an atraumatic manner.

Microbubble-enhanced ultrasound exposure improves gene transfer in vascular endothelial cells

AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein （pEGFP） transfer into human umbilical vein endothelial cells （HUVECs）. METHODS： HUVECs with fluorescein isothiocyanatedextran （FD500） and HUVECs with pEGFP were exposed to continuous wave （1.9 MHz, 80.0 mW/cm^2） for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS： The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone （24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001）. Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue （16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001）. No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue （94.1% ± 2.3% vs 91.1% ± 4.1% ）. CONCLUSION： The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.

Adenovirus-mediated FasL gene transfer into human gastric carcinoma

AIM: To evaluate the possible value of FasL in gastric cancer gene therapy by investigating the effects of FasL expression on human gastric cancer cell line. METHODS: An adenoviral vector encoding the full-length human FasL cDNA was constructed and used to infect a human gastric cancer (SGC-7901) cell line. FasL expression was confirmed by X-gal staining, flow cytometric analysis and RT-PCR. The effect of FasL on cell proliferation was determined by clonogenic assay, cytotoxicity was detected by MTT assay, and cell viability was measured by trypan blue exclusion. The therapeutic efficiency of Ad-FasL in vivo was investigated with a xenograft tumor model in nude mice. RESULTS: SGC-7901 cells infected with Ad-FasL showed increased expression of FasL, resulting in significantly decreased cell growth and colony-forming activity when compared with control adenovirus-infected cells. The cytotoxicity of anti-Fas antibody (CH-11) in gastric cancer cells was stronger than that of ActD (91±8 vs60±5,P<0.01), and the cytotoxicity of Ad-FasL was stronger than that of CH-11 (60±5 vs50±2, P<0.05). In addition, G1-phase arrest (67.75±0.39 vs 58.03±2.16, P<0.05) and apoptosis were observed in Ad-FasL-infected SGC-7901 cells, and the growth of SGC-7901 xenografts in nude mice was retarded after intra-tumoral injection with Ad-FasL (54% vs 0%,P<0.0001). CONCLUSION: Infection of human gastric carcinoma cells with Ad-FasL induces apoptosis, indicating that this target gene might be of potential value in gene therapy for gastric cancer.

Erythropoietin gene transfer into rat testes by in vivo electropo-ration may reduce the risk of germ cell loss caused by cryptorchidism

Aim： To investigate the effects of rat Erythropoietin （Epo） on spermatogenesis by transferring rat Epo gene into cryptorchid testes by means of in vivo electroporation. Methods： Sprague-Dawley rats with surgically-induced unilateral cryptorchidism were divided into three groups： the first group was given intratesticular injections of pCAGGS-Epo （pCAGGS-Epo group）, the second group was given intratesticular injections of pCAGGS （pCAGGS group）, and the third group were given intratesticular injections of phosphate-buffered saline （PBS group）. At the same time, square electric pulses of 30 V were applied six times with a time constant of 100 ms. One or two weeks after injection, each testis was weighed and the ratio of the total number of germ cells to that of Sertoli cells （G/S ratio） was calculated to evaluate the impairment of spermatogenesis. Ten testes taken from each of the three groups were examined at each time point. Results： The testicular weight after the injection of pCAGGS-Epo or pCAGGS control plasmid was （0.85 ± 0.08） g and （0.83 ± 0.03） g, respectively, at week 1 （P = 0.788） and （0.62 ± 0.06） g and （0.52 ± 0.02） g, respectively, at week 2 （P = 0.047）. At week 1, spermatids and sperm were more abundant in testes with pCAGGS-Epo than those in the control testes. At week 2, spermatids and sperm were hardly detected in either group. The G/S ratio was 23.27 ± 6.80 vs. 18.63 ± 5.30 at week 1 （P = 0.0078） and 7.16 ± 3.06 vs. 6.05 ± 1.58 at week 2 （P = 0.1471）, respectively. Conclusion： The transfer of Epo to rat testes by in vivo electroporation may reduce the risk of the germ cell loss caused by cryptorchidism.

Amelioration of carbon tetrachloride-induced cirrhosis and portal hypertension in rat using adenoviral gene transfer of Akt

AIM:To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride(CCl4).METHODS:Using cre-loxp technique,we created an Ad-myr-HA-Akt virus,in which Akt is labeled by a HA tag and its expression is driven by myr promoter.Further,through measuring enzyme levels and histological structure,we determined the efficacy of this Ad-myrHA-Akt virus in inhibiting the development of cirrhosis induced by CCl4in rats.Lastly,using western blotting,we examined the expression levels and/or phosphorylation status of Akt,apoptotic mediators,endothelial nitric oxide synthase(eNOS),and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus.RESULTS:The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment,which was consistent with the sequence reported in the GenBank.The concentrations of Admyr-HA-Akt and adenoviral enhanced green fluorescent protein(Ad-EGFP)virus used in the current study were5.5×1011vp/mL.The portal vein diameter,peak velocity of blood flow,portal blood flow and congestion index were significantly increased in untreated,saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection.In contrast,these parameters in the Akt cirrhosis group were comparable to normal control group.Compared to the normal control,the liver function(Alanine aminotransferase,Aspartate aminotransferase and Albumin)was significantly impaired in the untreated,saline and Ad-EGFP cirrhosis groups.The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated,saline and Ad-EGFP cirrhosis groups.The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups.The results of HE and Van Gieson staining indicated that Akt group has better preservation of histological structure and less fibrosis than other cirrhosis groups.The percentage of apoptotic cell was greatly less in Akt cirrhosis group than in other cirrhosis groups.Akt group showed positive HA tag and an increased level of phosphorylated Akt as well as decreased levels of Fas.In contrast,Caspase-3 and Caspase-9 levels in Akt group were significantly lower than other cirrhosis groups.Noticeable decrease of DR5 andα-SMA and increase of phosphorylated eNOS were observed in the Akt group when compared to other cirrhosis groups.The NO level in liver was significantly higher in Akt group than other cirrhosis groups,which was consistent with the level of phosphorylated eNOS in these groups.CONCLUSION:This study suggest that Ad-myr-HA-Akt virus is a useful tool to prevent CCl4-induced cirrhosis in rat model and Akt pathway may be a therapeutic target for human cirrhosis.

Genome-wide analysis of the barley non-specific lipid transfer protein gene family

Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and biotic or abiotic stress response. With the completion of the barley genome sequence, a genome-wide analysis of nsLTPs in barley(Hordeum vulgare L.)(HvLTPs) will be helpful for understanding the function of nsLTPs in plants. We performed a genome-wide analysis of the nsLTP gene family in barley and identified 70 nsLTP genes,which can be divided into five types(1, 2, C, D, and G). Each type of nsLTPs shares similar exon and intron gene structures. Expression analysis showed that barley nsLTPs have diverse expression patterns, revealing their various roles. Our results shed light on the phylogenetic relationships and potential functions of barley nsLTPs and will be useful for future studies of barley development and molecular breeding.

Intrastriatal Gene Transfer of Vascular Endothelial Growth Factor Rescues Dopaminergic Neurons in a Rat Parkinson's Disease Model

To examine the ability of intrastriatal gene transfer of vascular endothelial growth factor 165 mediated by adenoviral vector to rescue dopaminergic neurons in a rat model of Parkinson＇s disease （PD）, we constructed recombinant replication-deficent adenoviral vectors carrying the gene of VEGF165 （Ad-VEGF）, and injected Ad-VEGF （or Ad-LacZ and PBS as controls） into the striatum of rats 7 days after the lesion by 6-hydroxydopamine. The rat rotational behavior analysis and tyrosine hydroxylase （TH） immunohistochemistry were performed to assess the change of dopaminergic neurons. Our results showed that the rats receiving Ad-VEGF injection displayed a significant improvement in apomorphine-induced rotational behavior and a significant preservation of TH-positive neurons and fibers compared with control animals, It is concluded that intrastriatal gene transfer by Ad-VEGF may rescue the dopaminergic neurons from degeneration in a rat model of PD.

Molecular Tissue Engineering: Applications for Modulation of Mesenchymal Stem Cells Proliferation by Transforming Growth Factor β_1 Gene Transfer

The effect of transforming growth factor β 1 (TGF β 1 ) gene transfection on the proliferation of bone marrow derived mesenchymal stem cells (MSC S ) and the mechanism was investigated to provide basis for accelerating articular cartilage repairing using molecular tissue engineering technology. TGF β 1 gene at different doses was transduced into the rat bone marrow derived MSCs to examine the effects of TGF β 1 gene transfection on MSCs DNA synthesis, cell cycle kinetics and the expression of proliferating cell nuclear antigen (PCNA). The results showed that 3 μl lipofectamine mediated 1 μg TGF β 1 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 the 3 H incorporation, DNA content in S phase and the expression of PCNA. Transfection of gene encoding TGF β 1 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.

Influence of heme oxygenase-1 gene transfer on the viability and function of rat islets in in vitro culture

AIM. To investigate the influence of heme oxygenase-1 （HO-1） gene transfer on the viability and function of cultured rat islets in vitro. METHODS： Islets were isolated from the pancreata of Sprague-Dawley rats by intraductal collagenase digestion, and purified by discontinuous Ficoll density gradient centrifugation. Purified rat islets were transfected with adenoviral vectors containing human HO-1 gene （Ad- HO-1） or enhanced green fluorescent protein gene （Ad- EGFP）, and then cultured for seven days. Transfection was confirmed by fluorescence microscopy and Western blot. Islet viability was evaluated by acridine orange/ propidium iodide fluorescent staining. Glucose-stimulated insulin release was detected using insulin radioimmunoassay kits and was used to assess the function of islets. Stimulation index （SI） was calculated by dividing the insulin release upon high glucose stimulation by the insulin release upon low glucose stimulation. RESULTS： After seven days culture, the viability of cultured rat islets decreased significantly （92% ± 6% vs 52% ± 13%, P 〈 0.05）, and glucose-stimulated insulin release also decreased significantly （6.47 ± 0.55 mIU/ L/30IEO vs 4.57 ± 0.40 mIU/L/3OIEO., 14.93 ± 1.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P 〈 0.05）. Transfection of rat islets with adenoviral vectors at an 1±10 of 20 was efficient, and did not impair islet function. At 7 d post-transfection, the viability of Ad-HO-1 transfected islets was higher than that of control islets（71% ± 15% vs 52% ± 13%, P 〈 0.05）. There was no significant difference in insulin release upon low glucose stimulation （2.8 mmol/L） among Ad-HO-1 transfected group, Ad-EGFP transfected group, and control group （P 〉 0.05）, while when stimulated by high glucose （16.7 mmol/L） solution, insulin release in Ad-HO-1 transfected group was significantly higher than that in Ad-EGFP transfected group and control group, respectively （12.50 ±2.17 mIU/L/30IEQ vs 8.87 ± 0.65 mIU/L/30IEQ, 12.50 ± 2.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P 〈 0.05）. The SI of Ad-HO-1 transfected group was also significantly higher than that of Ad-EGFP transfected group and control group, respectively （2.21 ± 0.02 vs 2.08 ± 0.05; 2.21 ± 0.02 vs 2.11 ± 0.03, P 〈 0.05）. CONCLUSION： The viability and function of rat islets decrease over time in in vitro culture, and heine oxygenase-1 gene transfer could improve the viability and function of cultured rat islets.

HIGH EFFICIENCY RETROVIRUS-MEDIATED GENE TRANSFERTO LEUKEMIA CELLS

Objective: To establish an efficient and safe gene transfer system mediated by retrovirus for gene marking and gene therapy of human leukemia. Method: The retroviral vector LXSN, containing the neomycin resistance (NeoR) gene, was transferred into amphotropic packaging cells GP+envAm12 by liposome transfection or by ecotropic retrovirus transduction. Amphotropic retrovirus in supernatants with higher titer was used to infect human leukemic cell lines NB4, U937, and THP-1. The efficiency of gene transfer was assayed on colonies formed by transduced K562 cells. Results: The titer of DOSPER directly transfected GP+envAm12 cells determined on NIH3T3 cells was 8.0×105 CFU/ml, while that of producer infected with retrovirus was 1.6×107 CFU/ml. Integration of NeoR gene into all leukemia cells was confirmed by polymerase chain reaction (PCR). Absence of replication-competent virus was proved by both nested PCR for env gene and marker gene rescue assay. Gene transfer with the efficiency as high as 93.3 to 100% in K562 cells was verified by seminested PCR for integrated NeoR gene on colonies after 7 days’ culture. Conclusion: The efficiency and safety of retrovirus mediated gene transfer system might provide an optimal system in gene therapy for leukemia or genetic diseases.

Differentiation of embryonic stem cells into insulin-producing cells promoted by Nkx2.2 gene transfer

AIM： To investigate the ability of a genetically altered embryonic stem （ES） cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS： Hamster Nkx2.2 genes were transferred into mouse ES cells. Parental and Nkx2.2-transfected ES cells were initiated toward differentiation in embryoid body （EB） culture for 5 d and the resulting EBs were transferred to an attached culture system. Dithizone （DTZ）, a zincchelating agent known to selectively stain pancreatic beta cells, was used to detect insulin-producing cells.The outgrowths were incubated in DTZ solution （final concentration, 100μg/mL） for 15 rain before being examined microscopically. Gene expression of the endocrine pancreatic markers was also analyzed by RT-PCR. In addition, insulin production was determined immunohistochemically and its secretion was examined using an ELISA.RESULTS： DTZ-stained cellular clusters appeared after approximately 14 d in the culture of Nkx2.2-transfected ES cells （Nkx-ES cells）, which was as much as 2 wk earlier, than those in the culture of parental ES cells （wt-ES）. The frequency of DTZ-positive cells among total cultured cells on day 28 accounted for approximately 1.0% and 0.1% of the Nkx-ES- and wt-ES-derived EB outgrowths, respectively. The DTZ-positive cellular clusters were found to be immunoreactive to insulin, while the gene expressions of pancreatic-duodenal homeobox 1 （PDX1）, proinsulin 1 and proinsulin 2 were observed in the cultures that contained DTZ-positive cellular clusters.Insulin secretion was also confirmed by ELISA, whereas glucose-dependent secretion was not demonstrated.CONCLUSION： Nkx2.2-transfected ES cells showed an ability to differentiate into insulin-producing cells.

Ameliorated stress related proteins are associated with improved cardiac function by sarcoplasmic reticulum calcium ATPase gene transfer in heart failure

Background Previous studies showed that overexpression of sarco-endoplasmic retieulum calcium ATPase （SERCA2a） in a variety of heart failure （HF） models was associated with greatly enhanced cardiac performance. However, it still undefined the effect of SERCA2a overexpression on the systemic inflammatory response and neuro-hormonal factors. Methods A rapid right ventricular pacing model of experimental HF was used in beagles. Then the animals underwent recombinant adeno-associated vires 1 （rAAV1） mediated gene trans- fection by direct intra-myocardium injection. HF animals were randomized to receive the SERCA2a gene, enhanced green fluorescent protein （control） gene, or equivalent phosphate buffered saline. Thirty days after gene delivery, the cardiac function was evaluated by echocardiographic testing. The protein level of SERCA2a was measured by western blotting. The proteomic analysis of left ventricular （LV） sample was determined using two-dimensional （2-D） gel el^ctrophoresis and MALDI-TOF-MS. The serum levels of the systemic inflammatory and neuro-hormonal factors were assayed using radioimmunoassay kits. Results The cardiac function improved after SERCA- 2a gene transfer due to the significantly increased SERCA2a protein level. Beagles treated with SERCA2a had significantly decreased serum levels of the inflammatory markers （interleukin-6 and tumor necrosis factor-a） and neuro-hormonal factors （brain natriuretic peptide, endothelin-1 and angiotensin II） compared with HF animals. The myocardial proteomic analysis showed that haptoglobin heavy chain, heat shock protein （alpha-crystallin-related, B6） were down-regulated, and galectin-1 was up-regulated in SERCA2a group compared with HF group, companied by up-regulated contractile proteins and NADH dehydrogenase. Conclusions These findings demonstrate that regional intramyocardial injections of rAAV 1-SERCA2a vectors may improve global LV function, correlating with reverse activation of the systemic inflammatory, excessive neuroendocrine factors and the stress-associated myocardial proteins, suggesting that the beneficial effects of SERCA2a gene transfer may involve the attenuation of stress-associated reaction.

PRELIMINARY STUDY OF RETROVIRAL MEDIATED TRANSFER OF THE HUMAN mdr-1 GENE INTO MURINE AND HUMAN HEMATOPOIETIC STEM/PROGENITOR CELLS

To investigate the characteristics of multidrugresistance and transplantation of modified stem/ progenitor cells by multidrugresistant gene (mdr1 gene), we established PA317/MDR1 cell line which producing retroviruses by transfecting the retroviral vector PHaMDR1/A into packging cell line PA317 by Lipofectin. The virus titer of the supernatants was 1.2×105 cfu/ml. We transfected the murine hematopietic cells collected from 5FU pretreated mice and they showed the ability to reconstitute the longterm hematopoiesis of preirradiated mice. After 4 months, both of bone marrow cells and peripheral blood cells of transplanted mice still contained mdr1 gene. We also transfered mdr1 gene into human bone marrow CD34+ cells selected by using magnetic cell sorting system. PCR analysis showed that transduced CD34+ cells maintained the mdr1 cDNA. A fraction of CFUGM originated from transfected CD34+ cells had the charactor of resistance to Taxol. It is indicated that mdr1 gene can be transduced into murine and human stem/proginitor cells through retroviral mediated gene transfer and it protects the transfected cells from cytotoxic drugs.

Gene transfer to human trabecular meshwork cells in vitro and ex vivo using HIV-based lentivirus

AIM: To investigate whether the enhanced green fluorescent protein(EGFP) reporter gene could be transferred into human trabecular meshwork(HTM) cells by a HIV-based lentivirus both in vitro and ex vivo.METHODS: The HIV-based lentivirus that contains an EF1-α promoter driving EGFP expression cassette was constructed following the standard molecular cloning methods. The cultured HTM cells were transduced at a range of multiplicity of infection(MOI) with HIV-based lentivirus. EGFP positive cell populations were detected by flow cytometry. Human anterior eye segments were cultured with perfusion culture system and transfected by HIV-based lentivirus with a 1 ×108transducing unit(TU) virus in perfusion liquid. The intraocular pressure was recorded every 8h for 21 d. The expression of EGFP in the anterior segment of the human eye was detected by fluorescence microscopy. Furthermore, the distribution of EGFP expression was confirmed by anti-EGFP immunohistochemical staining.RESULTS: The HIV-based lentivirus which contains an EF1-α promoter driving EGFP expression cassette was constructed successfully. After HTM cells were transduced with HIV-based lentivirus containing EGFP in vitro, the ratio of EGFP positive cells to the total cell number reached 92.3%, with the MOI of 15. After the lentivirus containing EGFP were used to transduce human anterior eye segments, the EGFP could be directly detected by fluorescence microscopy in vivo.Immunohistochemistry staining revealed that 88.19%EGFP-positive trabecular meshwork(TM) cells were observed in the human anterior segment. Nevertheless,the intraocular pressure in the lentivirus-transduced group kept constant when compared with control group(P 】0.05).CONCLUSION: EGFP gene could be efficiently transferred into HTM cells both in vitro and ex vivo by using HIV-based lentivirus.