Fluorescence Tracking of Exogenous DNA in Genetic Transformation of the Chinese Oak Silkmoth Antheraea Pernyi via Sperm-Mediated Gene Transfer

Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.

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.

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.

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

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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.

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.

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.

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.

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.

Gene Transfer into Hematopoietic Cells of Mouse and Its in vivo Expression after Transplantation

We have shown previously that high-efficient gene transfer can be attained in primary hematopoietic cells using liposome-mediated gene transfer strategy. In order to examine the stability of gene expression mediated by this gene transduction protocol, we observed the expression of marker gene in vivo by using bone marrow transplantation (BMT) to engraft lethally irradiated mouse with the genetically modified hematopoietic cells. The results showed that the mouse transplanted with appropriated number of transduced cells remained alive andhealthy. The PCR analysis and G418 selection of the spleen colonies and bone marrow cells isolated from lethally irradiated animals 15 days and 30 days after injection of genetically modified bone marrow cells showed that the progeny cells of the transduced hematopoietic stem cells still contained and expressed the transduced genes, suggesting that the hematopoietic system is at least partially re-constructed by the stem cells with marker gene and that the stable expression of foreign genes in vivo can be attained by using this easy and harmless transduction protocol. These findings provide experimental basis for clinician to further investigate the biology of marrow reconstruction and the mechanism of leukemia relapse after BMT.

INCREASED EXPRESSION OF DIRECT GENE TRANSFER INISCHEMIC SKELETAL MUSCLES OF RABBITS

Objective The gene expression of skeletal muscle under ischemic condition by direct gene injectionwas observed in order to find a new gene delivery method to treat chronic arterial occlusion disease. Methods Weestablished the rabbit hindlimb ischemic model and used plasmid PSV-β-gal as a reporter gene. We transferedgene intramuscularly and detected the activity of β-galactosidase by histochemistry method. Results Weobserved that the gene expression of skeletal muscle under ischemic condition was higher than normalmuscle. Conclusion The result demonstrated that the direct gene injection was suitable for the chronic peripheralarterial occlusion disease, and might be a novel gene delivery method for this disease.

Retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells

Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells.Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP_2 vector by the optimized retroviral transduction protocol.Fluorescent microscopy's examination was to evaluate the results of the transduction,flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells.Bioactivity test from C_2C_12K_4 cells was to show the expression and bio-activity of the fusion gene.Results Fluorescent microscopy showed the success of the transduction.By flow cytometer's analysis,the mean efficiency of the transduction with EGFP was(42.8±6.1)% SD.Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting,almost of those showed the expression of BMP_2.Fluorescently and strongly bioactivity test for C_2C_12K_4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control.Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting.Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2,the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique,the expressed chimeric protein embraced the double bioactivity of EGFP and BMP_2,and moreover,the expression had not attenuated over time.

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 donogenic 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 vs 50±2, P＜0.05). In addition, G1-phase arrest (67.75±0.39 vs58.03±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.

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.

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 plasmid DNA encoding enhanced green fluorescent protein (pEGFP) transfer into human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs with fluorescein isothiocyanate- dextran (FD500) and HUVECs with pEGFP were exposed to continuous wave (1.9 MHz, 80.0 mW/cm2) 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 cytometry, respectively. RESULTS: The percentage of FD500-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 withoutobvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.

S2B-4 Hijacking Dorsal Raphe to Improve Moods and Metabolism via BDNF Gene Transfer in Mice

Background:Mood disorders such as depression and metabolic diseases like obesity and diabetes have significant comorbidities;furthermore,each disease increases the risk of the other one.Continuing use of antidepressant medication is associated with an elevated risk of type 2 diabetes and weight gain.On the other hand,antiobesity drugs are found to have varying neuropsychiatric adverse event profiles.Therefore,there is an urgent need to develop more effective and safer therapies for mood disorders and metabolic diseases with minimal side effects.Both brain derived neurotrophic factor(BDNF)and serotonin(5-HT)can regulate moods in the limbic system and metabolism in the hypothalamus,respectively.The dorsal raphe nucleus(DR)in the midbrain contains the largest number of serotonin-expressing neurons as well as other neurons expressing various neurotransmitters.Both serotonergic and nonserotonergic DR neurons send projections widely to the forebrain including the limbic system and the hypothalamus.This study aimed to investigate whether BDNF gene transfer in DR neurons can improve moods and metabolism.Methods:Recombinant adeno-associated virus(AAV)was microinjected into DR to achieve BDNF gene transfer.Chronic unpredictable mild stress(CUMS)model of depression in C57 BL/6 mice was established to investigate the role of DR BDNF gene transfer in depression.Forced swimming test(FST)and sucrose consumption test(SCT)were used to examine the depressive-like behaviors.Open field test(OPT)and elevated zero maze(EZM)were used to examine the anxiety-like behaviors.Diet-induced obesity(DIO)and leptin receptor mutant db/db mice were employed to investigate the role of DR BDNF gene transfer in regulating metabolism.Metabolic profiling included body weight,food intake,fat mass,serum factors,energy expenditure,glucose tolerance and insulin sensitivity.Quantitative RT-PCR was performed to determine expression changes of several key genes in DR,hypothalamus,liver and fat tissues.Tph2 conditional knockout mice were used to examine whether 5-HT is essential for BDNF in improving metabolism.In addition,chemogenetic activation of DR neurons via AAVmediated hM3Dq expression was also performed to examine whether there is a similar effect as BDNF.Results:FST and SCT showed significant anti-depressant effects of DR BDNF gene transfer in the CUMS model,meanwhile,OPT and EZM showed significant anxiolytic effects.BDNF gene transfer in DR also markedly ameliorated obesity and hyperglycemia in DIO and db/db mice,which was revealed by lightened body weight,decreased food intake,increased energy expenditure,improved glucose tolerance and insulin sensitivity,reduced levels of serum factors like insulin and leptin.The mRNA expression of genes related to 5-HT signaling such as tph2 and vmat2 was significantly increased in DR after BDNF gene transfer.Expression levels of multiple genes regulating energy balance in the hypothalamus,liver,and fat tissues also changed.Conditional knockout of tph2,encoding the rate-limiting enzyme of 5-HT synthesis,did not block the effects of DR BDNF gene transfer in improving metabolism.Chemogenetic activation of DR neurons also had the effects of improving metabolism in DIO mice.Conclusion:BDNF gene transfer in DR of mice improves moods and metabolism.This study surmounts the“hypothalamocentric”paradigm dominating in metabolism research by connecting metabolism and moods via dorsal raphe.