The improved efficient method for introducing macromolecules into cells using HVJ (Sendai virus) liposomes with gangliosides

The effects of myocilin expression on functionally relevant trabecular meshwork genes: a mini-review

Myocilin is a secreted glaucoma-associated protein, specifically induced by dexamethasone in human trabecular meshwork cells, where it was discovered. Myocilin is expressed in several tissues of the body, but it causes disease only in the eye. The protein contains two domains: an N-terminal region with significant homologies to nonmuscle myosin, and a C-terminal region, which is similar to the olfactomedin proteins. Forty percent of myocilin undergoes an intracellular endoproteolytic cleavage by calpain II, a calcium-dependent cysteine protease, which releases the 2 domains. The protein is known to interact with intracellular and extracellular matrix proteins, and some is released into the extracellular space associated with exosomes. Myocilin mutations are linked to glaucoma and induce elevated intraocular pressure. Most of the glaucoma-causative mutations map to the olfactomedin domain, which appears to be a critical domain for the function of the protein. Myocilin mutants are misfolded, aggregate in the endoplasmic reticulum, and are not secreted. Overexpression of myocilin and of its mutants in primary human trabecular meshwork cells triggers changes in the expression of numerous genes, many of which have been known to be involved in mechanisms important for the physiology and pathology of the tissue. Here we review recent studies from our laboratory and those of others that deal with trabecular meshwork genes, which are altered by the overexpression of wild-type and glaucoma-causative mutant myocilin genes.

Efficient in vivo delivery of plasmids and oligonucleotides using hemagglutinating virus of Japan envelope (HVJ-E) vector in immunological disease models

This unit describes a method for in vivo delivery of oligonucleotides or plasmids using the hemagglutinating virus of Japan envelope (HVJ-E), an inactivated Sendai virus particle, as a delivery system. Viral transfection methods generally show a higher transfection efficiency than nonviral methods for the delivery of genes to cells. However, in using these methods one must bear in mind that the introduction of a virus particle into a host carries a risk for leukemia induction and for creation of disturbances in immune function due to cytotoxicity.

Bio-nanocapsule conjugated with liposomes for in vivo pinpoint delivery of various materials

Bio-nanocapsules (BNCs) consisting of hepatitis B virus (HBV) surface antigen (HBsAg) are approximately 50-nm hollow particles displaying a human hepatocyte-recognizing molecule (pre-S1 peptide). They have been used as an HB vaccine for the last two decades. Original BNC can incorporate various payloads (e.g., drugs, genes) by electroporation and deliver them to human hepatocytes specifically by utilizing the HBV infection mechanism. Here, we developed a new BNC conjugated with liposomes and succeeded in incorporating large materials (100-nm fluorescence-labeled polystyrene beads and >30 kbp plasmids) into the BNC-liposome complex. The complex delivered these large materials to human hepatocytes specifically ex vivo and in vivo. The transfection efficiency of the BNC-liposome complex was significantly higher than that of the original BNC. These results indicated that BNC confers the tissue- and cell-specificity on the conventional liposomes and raises new possibilities for drug delivery systems, gene delivery systems, and bio-imaging systems in vivo.

Functional implication of nucleolin in the mouse first molar development

We examined the functional implication of nucleolin in the mouse first molar development. Both the nucleolin mRNA and protein expressions were demonstrated in the odontogenic epithelial cells in the early stage and in the inner enamel epithelial layer in the late stage. The expression pattern of nucleolin corresponded to the proliferating cells in the tooth germ, thus showing that nucleolin could possibly be related to cell proliferation. No in situ signal of nucleolin was found in the primary enamel knot (PEK). Furthermore, nucleolin protein was demonstrated in the PEK by immunohistochemistry. The existence of nucleolin protein in the PEK may possibly be related to the apoptosis in the PEK cells. An inhibition assay using the hemagglutinating virus of Japan-liposome containing nucleolin antisense phosphorothioated oligonucleotide (AS S-ODN) in cultured mouse mandibles at embryonic day (E) 11.0 showed a marked growth inhibition of tooth germ. Moreover, no developmental arrest was found in the cultured tooth germ at E15.0 treated with nucleolin AS S-ODN. Real time PCR was performed to examine the mRNA expression of nucleolin-related genes, and a significant reduction in the midkine mRNA expression was thus observed in the mouse mandible after being treated with nucleolin AS S-ODN. This inhibition assay indicated that nucleolin could thus be involved in the early stage of tooth germ initiation and morphogenesis, possibly by regulating the midkine expression.

Effect of AP-1 decoy using hemagglutinating virus of Japan-liposome on the intimal hyperplasia of the autogenous vein graft in mongrel dogs

Intimal hyperplasia is the leading cause of late vein graft failure. Smooth muscle cell proliferation and migration is the underlying mechanism. Pharmacological approaches to prolong vein graft patency have produced limited results. AP-1 proteins play a role in the expression of many genes involved in cellular proliferation and cell cycle progression. Previously we reported inhibition of vascular smooth muscle cell migration, proliferation, and intimal hyperplasia in the balloon-injured rat carotid artery using an AP-1 decoy with HVJ-liposomes. In this report, we evaluated the effect of the AP-1 decoy on intimal hyperplasia in a large animal model. The jugular vein was transfected with hemagglutinating virus of Japan-liposomes containing the AP-1 decoy or scrambled oligonucleotides. An interposition graft was performed with the pretreated jugular vein between the transected femoral arteries. The graft was harvested at 16 weeks after the procedure. The intimal area was compared: the intimal area of the AP-1 decoy-treated versus control group was 47.3 +/- 15.2 versus 102.3 +/- 15.9 (P < .05), respectively. In conclusion, AP-1 decoy using HVJ-liposomes effectively prevented intimal hyperplasia of an autogenous vein graft in mongrel dogs.

Nigral injection of antisense oligonucleotides to synaptotagmin I using HVJ-liposome vectors causes disruption of dopamine release in the striatum and impaired skill learning

To produce an animal model of a dopa-responsive motor disorder with depletion of dopamine (DA) release in the striatum by dysfunction of the transmitter release machinery of the nigrostriatal DA system, we performed an intra-nigral injection of an HVJ-liposome gene transfer vector containing antisense oligodeoxynucleotides (ODNs) against synaptotagmin I (SytI), a key regulator of Ca(2+)-dependent exocytosis and endocytosis in adult rats. A unilateral intra-nigral injection of HVJ-liposome vectors containing antisense ODNs against SytI (syt-AS) caused a moderate disruption of methamphetamine-induced release of DA in the treated side of the striatum, while the syt-AS treatment did not affect physiological release of DA in the treated striatum. A bilateral intra-nigral injection of HVJ-liposome vectors containing syt-AS induced an impairment of the striatal DA-mediated acquisition of skilled behavior in a rotarod task without any deficits in general motor functions, such as spontaneous locomotor activity, motor adjusting steps, equilibrium function, or muscle strength. These findings suggest that an intra-nigral treatment with HVJ-liposome vectors containing syt-AS may cause a long-lasting nigral knockdown of SytI which, in turn, leads to a moderate dysfunction of the DA release machinery in the terminals of the nigrostriatal DA system and a subsequent mild depletion of DA release in the striatum.

Overexpression of myocilin in cultured human trabecular meshwork cells

The trabecular meshwork, a specialized eye tissue, is a major site for regulation of the aqueous humor outflow. Malfunctioning of the trabecular meshwork is believed to be responsible for development of glaucoma, a blinding disease. Myocilin is a gene linked to the most common form of glaucoma. Its expression is known to be upregulated by glucocorticoids in trabecular meshwork cells and the altered myocilin level may be the culprit for glaucomatous conditions such as corticosteroid-induced glaucoma. In this study, we examined the influence of myocilin overexpression on the adhesion, spreading, migration, phagocytosis, and apoptosis of human trabecular meshwork cells in culture. When the myocilin expression was increased by 3- to 4-fold, the transfectants showed a dramatic loss of actin stress fibers and focal adhesions. Cell adhesion to fibronectin and spreading were also compromised. Myocilin thus appeared to have a de-adhesive activity, similar to that reported extensively with matricellular proteins. The transfected cells in addition displayed an increased sensitivity to apoptosis. These results demonstrate that overexpression of myocilin renders trabecular meshwork cells in a de-adhesive and vulnerable state. This vulnerability may be the basis for pathologic consequences in subtypes of glaucoma.

Antisense knockdown of spinal-mGluR1 reduces the sustained phase of formalin-induced nociceptive responses

To examine the role of mGluR1 (a subunit of the group I metabotropic glutamate receptor) in the nociceptive responses of rats following a subcutaneous injection of formalin into the plantar surface of the hind paw, we delivered antisense oligonucleotides (ODNs) against mGluR1 into the rat lumbar spinal cord (L3-L5) intrathecally using an HVJ-liposome-mediated gene transfer method. Rats treated with a single injection of mGluR1 antisense ODNs into the intrathecal space of the lumbar spinal cord showed a marked reduction of the early-sustained phase of formalin-induced nociceptive responses, but not of their acute phase. The reduction of nociceptive behavioral responses became apparent at day 2 after the antisense treatment and lasted for 2 days. This corresponded to a long-lasting down-regulation (46%) of mGluR1 expression in the lumbar cord. This down-regulated mGluR1 was observed at day 2 and persisted until day 4 after the intrathecal infusion of mGluR1 antisense ODN. In contrast, rats treated with mGluR1 sense or mismatch ODNs showed none of these changes. These results suggest that mGluR1 may play a crucial role in the sustained nociception of formalin-induced behavioral responses.

TNF combined with IFN-alpha accelerates NF-kappaB-mediated apoptosis through enhancement of Fas expression in colon cancer cells

Immunostaining and EMSA revealed that NF-kappaB was activated strongly by TNF/IFN-alpha compared to TNF alone in a human colon adenocarcinoma cell line, RPMI4788. Although inhibition of activated NF-kappaB, by using an NF-kappaB decoy, reduced cell viability after treatment with TNF only, NF-kappaB decoy resulted in recovery of cell viability after TNF/IFN-alpha treatment. Caspase-3 activity was increased in cells induced by TNF/IFN-alpha, while suppression of caspase-3 activity was observed in cells transfected with NF-kappaB decoy and then treated by TNF/IFN-alpha. On the other hand, Fas expression was strongly enhanced by TNF/IFN-alpha, and inhibition of TNF/IFN-alpha-induced NF-kappaB activation, by using NF-kappaB decoy, decreased Fas expression. Cell viability and caspase-3 activity decreased in cells treated with TNF/IFN-alpha and anti-FasL antibody. Taken together, our findings suggest that activated NF-kappaB induced by the crosstalk between TNF and IFN-alpha is a novel pro-apoptotic signal acting via enhancement of Fas expression.

Antisense hippocampal knockdown of NMDA-NR1 by HVJ-liposome vector induces deficit of prepulse inhibition but not of spatial memory

Considerable evidence suggests that an N-methyl-D-aspartate (NMDA) receptor plays a crucial role in memory and cognitive function. To identify the role of this receptor in higher functions of the brain, we delivered antisense oligonucleotides against an NMDA-NR1 subunit (NR1) to the hippocampus in rats using the HVJ-liposome-mediated gene-transfer method. NR1 hippocampal knockdown was performed by the focal injection of the NR1 antisense-HVJ-liposome complex into the bilateral hippocampus. The blocking effect of NR1-antisense on the expression of NR1 was confirmed by Western blot analysis. Spatial memory was tested by a water maze task, and sensorimotor gating was examined by prepulse inhibition (PPI). Western blot analysis demonstrated that the NR1-antisense treatment specifically provided the down-regulation (about 30%) of NR1 protein levels in the hippocampus. The water maze task showed that the antisense treatment did not affect spatial memory, while the PPI test revealed that NR1 hippocampal knockdown caused a deficit in sensorimotor gating. We conclude that mild dysfunction of hippocampal NMDA receptor causes sensorimotor gating deficit and relatively intact in spatial memory.

Synaptotagmin I hypothalamic knockdown prevents amygdaloid seizure-induced damage of hippocampal neurons but not of entorhinal neurons

We have previously demonstrated that an acute pharmacological interruption of the afferent inputs from the hypothalamus to the hippocampus resulted in the blockade of the genesis and spread of intra-amygdala kainate-induced seizure activity in the hippocampus. This finding suggests that a sustained interruption of the hypothalamic stimulative influences may completely prevent amygdaloid seizure-induced hippocampal neuron damage. To test this assumption, we delivered antisense oligodeoxynucleotides (ODNs) against synaptotagmin I, a regulatory protein of the transmitter release machinery, into the hypothalamus by using a Hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer technique. Four days prior to the induction of status epilepticus by intra-amygdala injection of kainate, the synaptotagmin I antisense was injected into the supramammillary nucleus (SuM) of the hypothalamus to chronically suppress the stimulative influences to the hippocampus via the reduction of transmitter release. The synaptotagmin I hypothalamic knockdown resulted in the almost complete prevention of seizure-induced damage of hippocampal neurons but not of entorhinal neurons following the kainate-induced amygdaloid seizures. This result suggests that the hypothalamic stimulative influences to the hippocampus have a major contribution to the amygdaloid seizure-induced hippocampal sclerosis, probably via disinhibition mechanism.

Designing of 'intelligent' liposomes for efficient delivery of drugs

The liposome- vesicles made by a double phospholipid layers which may encapsulate aqueous solutions- have been introduced as drug delivery vehicles due to their structural flexibility in size, composition and bilayer fluidity as well as their ability to incorporate a large variety of both hydrophilic and hydrophobic compounds. With time the liposome formulations have been perfected so as to serve certain purposes and this lead to the design of "intelligent" liposomes which can stand specifically induced modifications of the bilayers or can be surfaced with different ligands that guide them to the specific target sites. We present here a brief overview of the current strategies in the design of liposomes as drug delivery carriers and the medical applications of liposomes in humans.

Hemagglutinating virus of Japan (HVJ) envelope vector as a versatile gene delivery system

We have developed a simple method for converting the lipid envelope of an inactivated virus to a gene transfer vector. Hemagglutinating virus of Japan (HVJ; Sendai virus) envelope vector was constructed by incorporating plasmid DNA into inactivated HVJ particles. This HVJ envelope vector introduced plasmid DNA efficiently and rapidly into various cell lines, including cancer cells and several types of primary cell culture. Efficiency of gene transfer was greatly enhanced by protamine sulfate and centrifugation. Fluorescein isothiocyanate-labeled oligodeoxynucleotides (FITC-ODN) were also delivered to cells at > 95% efficiency. When HVJ envelope vector was injected into organs directly, reporter gene expression was observed in organs including liver, brain, skin, uterus, tumor masses, lung, and eye. When HVJ envelope vector containing luciferase gene was injected into mouse tail vein, luciferase gene expression was detected primarily in spleen. FITC-ODN were also delivered to spleen cells by intravenous injection of HVJ envelope. These results suggest that HVJ envelope vector will be useful for both ex vivo and in vivo gene therapy experiments.

Novel immunotherapy for peritoneal dissemination of murine colon cancer with macrophage inflammatory protein-1beta mediated by a tumor-specific vector, HVJ cationic liposomes

A critical issue for cancer treatment is control of metastatic or disseminated tumors. Although immune gene therapy has been considered as a possible strategy for treatment of such tumors, successful results have not yet been obtained. To evoke antitumor immunity more efficiently, macrophage inflammatory protein-1beta (MIP-1beta) was used for gene therapy of colon cancer in mice. Injection of hemagglutinating virus of Japan (HVJ) cationic liposomes-MIP-1beta into subcutaneous tumor masses resulted in local expression of MIP-1beta and local accumulation of CD4(+) T lymphocytes. Few studies of cancer gene therapies have targeted peritoneal dissemination. In a mouse model of peritoneal dissemination of colon tumor, we used a luciferase-based assay to demonstrate that HVJ cationic liposomes had high tumor specificity and were effective vectors for transfer of genes in peritoneal dissemination. When mice were treated by intraperitoneal injection of HVJ cationic liposomes containing the MIP-1beta gene, the survival periods of the MIP-1beta-treated mice were significantly longer than those of control mice. Therefore, this HVJ cationic liposome strategy may serve as a powerful tool against peritoneal disseminated cancer.

Cationic polymer-mediated genetic transduction into cultured human chondrosarcoma-derived HCS-2/8 cells

The usefulness of three types of cationic polymer, i.e., degraded polyamidoamine (PAMAM) dendrimer (SuperFect Transfection Reagent; Oiagen), linear polyethylenimine (PEI; ExGen 500; Euromedex), and branched PEI in gene delivery into chondrocytes was examined comparatively. A plasmid vector containing the Escherichia coli LacZ (pSES.beta) was combined with one of the three cationic polymers at various molar ratios and the resultant complex (polyplex) was used to transduce a human chondrocyte-like cell line, HCS-2/8. Gene expression was evaluated by an O-nitrophenyl beta-D-galactopyranoside (ONPG) assay and by staining with 0.05% 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal; Nacalai Tesque). The ONPG assay showed that the highest delivery rate was achieved when 2microg of pSES.beta was combined with either 21 microg of dendrimer, 1.7microg of linear PEI, or 2.0microg of branched PEI. At the same DNA/polymer ratios, the proportions of X-gal-stained cells were also the highest (31.3 +/- 7.5%, 30.3 +/- 9.0%, and 8.3 +/- 3.1%, respectively). LacZ expression reached the highest level 3 days after the dendrimer-mediated transduction, and gradually declined, returning to the background level on day 14. Possible cytotoxicity was examined by trypan blue staining and phase contrast microscopic observations. Neither cytotoxicity nor morphological change was induced at the optimal dose of each polymer. The cationic polymers, particularly the degraded dendrimer and linear PEI, would be a useful nonviral vector for gene delivery to cells of chondrocytes.

Preclinical and therapeutic utility of HVJ liposomes as a gene transfer vector for hepatocellular carcinoma using herpes simplex virus thymidine kinase

Although gene therapy has been suggested to be a novel strategy to treat hepatocellular carcinoma (HCC), no study showing the clinical feasibility of vectors to treat HCC has been reported. In this preclinical study, we show evidence indicating that hemagglutinating virus of Japan (HVJ) liposomes are a feasible vector to treat HCC in a clinical setting using ganciclovir (GCV) and herpes simplex virus thymidine kinase (HSV-tk), which is driven by the cytomegalovirus immediate early enhancer/promoter (plasmid pcDNA3/HSV-tk). In in vitro experiments, almost complete tumor cell regression was achieved with the optimal GCV concentration (100 microg/mL) and more than 1/3 regression was seen even with a 20% transduction ratio using HuH7 HCC cells stably transformed by HSV-tk. HVJ liposomes showed a 19.7% (mean) transduction rate of the lacZ gene in a relatively large mass of more than 300 mm3 in vivo, which is a clinically detectable size, implanted into SCID mice. Moreover, a single HSV-tk injection of HVJ liposomes followed by GCV treatment inhibited tumor growth at least within a week, and repeat administration was more effective. Furthermore, subcutaneous injection of an HVJ liposomes vehicle induced no apparent inflammatory response in C3H/HeN mice, whereas lacZ gene transfection resulted in inflammatory pathology, suggesting a lower immunogenicity of the HVJ envelope protein than those of bacteria-derived plasmid DNA or the beta-galactosidase gene product. From these findings, we conclude that HVJ liposomes are a clinically safe and effective gene transfer vector to treat HCC.

Non-viral vectors in cancer gene therapy: principles and progress

This review focuses on the use of synthetic (non-viral) delivery systems for cancer gene therapy. Therapeutic strategies such as gene replacement/mutation correction, immune modulation and molecular therapy/'suicide' gene therapy type approaches potentially offer unique and novel ways of fighting cancer, some of which have already shown promise in early clinical trials. However, the specific and efficient delivery of the genetic material to remote tumors/metastases remains a challenge, which is being addressed using a variety of viral and non-viral systems. Each of these disparate systems has distinct advantages and disadvantages, which need to be taken into account when a specific therapeutic gene is being used. The review concentrates on particulate gene delivery systems, which are formed through non-covalent complexation of cationic carrier molecules (e.g. lipids or polymers) and the negatively charged plasmid DNA. Such systems tend to be comparatively less efficient than viral systems, but have the inherent advantage of flexibility and safety. The DNA-carrier complex acts as a protective package, and needs to be inert and stable while in circulation. Once the remote site has been reached the complex needs to efficiently transfect the targeted (tumor) cells. In order to improve overall transfection specificity and efficiency it is necessary to optimize intracellular trafficking of the DNA complex as well as the performance after systemic administration. Common principles and specific advantages or disadvantages of the individual synthetic gene delivery systems are discussed, and their interaction with tumor-specific and generic biological barriers are examined in order to identify potential strategies to overcome them.

Safety evaluation of hemagglutinating virus of Japan--artificial viral envelope liposomes in nonhuman primates

We tested, in cynomolgus monkeys, the safety and effectiveness of a hybrid liposome vector, hemagglutinating virus of Japan (HVJ)--artificial viral envelope (AVE) liposomes, for human therapeutic gene transfer in a series of experiments. In a repetitive intramuscular administration study, vehicle control macaques (n = 2), which were treated with HVJ--AVE liposome suspension, received repetitive intramuscular injections of 2 ml of test substance. Human hepatocyte growth factor (HGF) cDNA-inserted expression vector (pUC-SR alpha/HGF) injection animals (n = 2), which were treated with HVJ--AVE liposome suspension containing pUC-SR alpha/HGF, received repetitive intramuscular injection of 2 ml of test substance. General body condition, hematology, blood chemistry, and serum HGF were determined sequentially before treatment and 7, 21, 28, and 29 days after treatment. Elevations in HGF were detected in monkeys injected with pUC-SR alpha/HGF. After this observation period, macaques were killed for autopsy and histological examination. pUC-SR alpha/HGF was detected by polymerase chain reaction (PCR) analysis in the liver, spleen, and at the injection site. In single intravenous administration study, control macaques (n = 4) received a single intravenous injection of 10 ml of physiological saline. Vehicle control animals (n = 5) received a single intravenous injection of 10 ml of HVJ--AVE liposome suspension. DNA-treated animals (n = 7) received a single intravenous injection of 10 ml of HVJ--AVE liposome suspension containing plasmid DNA [pcDNA 3.1(+)]. General body condition, body weight, hematology, blood chemistry, and urine composition were determined sequentially before treatment and 1, 14, 21, and 28 days after treatment. After this observation period, macaques were killed for autopsy and histological examination. pcDNA 3.1(+) was detected by PCR analysis on day 1 in lung, liver, and spleen of all monkeys, in kidney of one of two monkeys, and in heart of one of two monkeys. However, no DNA was detected in any of the tissues examined on days 14, 21, and 28. No virus genomic RNA was detected by reverse transcription (RT)-PCR analysis with HVJ-specific primers. In this series of safety evaluations, the animals tolerated the safety study with no change in body weight or general condition. No hematological changes or alterations in blood chemistry or urine composition was detected. Moreover, no histological changes were observed. This safety evaluation study demonstrates the safety, feasibility, and therapeutic potential of the novel transfection vehicle, HVJ--AVE liposomes, in humans.

Efficient introduction of macromolecules and oligonucleotides into brain capillary endothelial cells using HVJ-liposomes

In this study, we examined the feasibility of introducing macromolecules into cultured mouse brain capillary endothelial cells (MBEC4 cells) by utilizing the hemagglutating virus of Japan (HVJ)-liposomes with fusogenic activity. We used fluorescein isothiocyanate dextran (FITC-Dextran) and FITC-labeled oligodeoxynucleotide (FITC-ODN) as models of a macromolecule and an ODN, respectively. Intracellular fluorescence appeared rapidly after the exposure of MBEC4 cells to FITC-Dextran-containing HVJ-liposomes, and remained detectable for at least 3 days. Only a control level of intracellular fluorescence was seen after treatment with FITC-Dextran alone, FITC-Dextran with empty HVJ-liposomes or FITC-Dextran-containing liposomes without fusogenic activity. In the early phase after administration (0-30 min), the introduction of FITC-Dextran into MBEC4 cells by the HVJ-liposome method resulted in a rapid and time-dependent increase of intracellular fluorescence intensity. Moreover, FITC-ODN was also introduced into MBEC4 cells by the HVJ-liposome method, although FITC-ODN alone was not introduced. These results indicate that the HVJ-liposome method is useful for the efficient introduction of macromolecules, including ODN, into brain capillary endothelial cells.

Gene transfer of human prostacyclin synthase ameliorates monocrotaline-induced pulmonary hypertension in rats

BACKGROUND

Prostacyclin is a potent vasodilator that also inhibits platelet adhesion and cell growth. We investigated whether in vivo gene transfer of human prostacyclin synthase (PGIS) ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats.

METHODS AND RESULTS

The cDNA encoding PGIS was intratracheally transfected into the lungs of rats by the hemagglutinating virus of Japan-liposome method. Rats transfected with control vector lacking the PGIS gene served as controls. Three weeks after MCT injection, mean pulmonary arterial pressure and total pulmonary resistance had increased significantly; the increases were significantly attenuated in PGIS gene-transfected rats compared with controls [mean pulmonary arterial pressure, 31+/-1 versus 35+/-1 mm Hg (-12%); total pulmonary resistance, 0.087+/-0.01 versus 0.113+/-0.01 mm Hg x mL x min(-1) x kg(-1) (-23%), both P:<0.05]. Systemic arterial pressure and heart rate were unaffected. Histologically, PGIS gene transfer inhibited the increase in medial wall thickness of peripheral pulmonary arteries that resulted from MCT injection. PGIS immunoreactivity was intense predominantly in the bronchial epithelium and alveolar cells. Lung tissue levels of 6-keto-PGF(1alpha), a stable metabolite of prostacyclin, were significantly increased for >/=1 week after transfer of PGIS gene. The Kaplan-Meier survival curves demonstrated that repeated transfer of PGIS gene every 2 weeks increased survival rate in MCT rats (log-rank test, P:<0.01).

CONCLUSIONS

Intratracheal transfer of the human PGIS gene augmented pulmonary prostacyclin synthesis, ameliorated MCT-induced pulmonary hypertension, and thereby improved survival in MCT rats.

Soluble Flt-1 gene therapy for peritoneal metastases using HVJ-cationic liposomes

Many studies have reported a close association between VEGF and tumor angiogenesis. The aim of the present study was to evaluate the effectiveness of gene therapy against cancer, including peritoneal metastasis, using a cDNA encoding a soluble type of Flt-1, one of the VEGF receptors. In a peritoneal metastasis model of MKN45 human gastric cancer cells, mice repetitively treated with intraperitoneal injections of HVJ-Fex, a type of HVJ-cationic liposome encapsulating a plasmid expressing soluble mFlt-1, exhibited smaller disseminated foci with fewer microvessels, thus resulting in a significantly longer survival period than the control mice. In another peritoneal metastasis model using HT1080S cells, a clone of HT1080 human fibrosarcoma cells stably transfected with hVEGF, treatments with HVJ-Fex also reduced the growth of disseminated foci without ascites formation. In conclusion, this study demonstrated that the peritoneal metastases of some cancers were largely dependent on VEGF, and that the repeated intraperitoneal transduction of a soluble flt-1 gene using HVJ-cationic liposomes suppressed peritoneal metastases, thereby contributing to a longer survival period.

Widespread gene transfection into the central nervous system of primates

We attempted in vivo gene transfection into the central nervous system (CNS) of non-human primates using the hemagglutinating virus of Japan (HVJ)-AVE liposome, a newly constructed anionic type liposome with a lipid composition similar to that of HIV envelopes and coated by the fusogenic envelope proteins of inactivated HVJ. HVJ-AVE liposomes containing the lacZ gene were applied intrathecally through the cisterna magna of Japanese macaques. Widespread transgene expression was observed mainly in the neurons. The lacZ gene was highly expressed in the medial temporal lobe, brainstem, Purkinje cells of cerebellar vermis and upper cervical cord (29.0 to 59.4% of neurons). Intrastriatal injection of an HVJ-AVE liposome-lacZ complex made a focal transfection around the injection sites up to 15 mm. We conclude that the infusion of HVJ-AVE liposomes into the cerebrospinal fluid (CSF) space is applicable for widespread gene delivery into the CNS of large animals. Gene Therapy (2000) 7, 759-763.

Sendai virosomes revisited: reconstitution with exogenous lipids leads to potent vehicles for gene transfer

A reliable new procedure is described for the reconstitution of Sendai viral envelopes suitable for gene transfer. Both fusion and hemagglutinin-neuraminidase glycoproteins were extracted from purified Sendai virus and reconstituted together with DNA in the presence of cholesterol:sphingomyelin:phosphatidylcholine:phosphatidylethanolamin e (Chol:SM:PC:PE) in a molar ratio of 3.5:3.5:2:1. Before reconstitution, the DNA to be transferred was condensed by pretreatment with polylysine. Exogenous lipid addition and the DNA-condensation step were essential for maximal size as well as for fusogenic activity of the resulting virosomes, the analysis of which revealed (1) the absence of any genomic material originating from Sendai virus, (2) the presence of fusogenic spikes in a functional orientation, (3) the encapsulation of reporter genes, and (4) high-transfer activity for plasmids carrying the green fluorescent protein (GFP) gene and double-stranded nucleotides into different mammalian cells. Transfer rates were up to 10-fold higher than those obtained with different cationic lipids. Gene delivery by means of our lipid-enriched Sendai virosomes extends the known gene transfer strategies, including those based on Sendai virus previously published.

Antisense oligodeoxynucleotide inhibition of vascular angiotensin-converting enzyme expression attenuates neointimal formation: evidence for tissue angiotensin-converting enzyme function

It has been proposed that vascular angiotensin-converting enzyme (ACE) plays an important role in regulating vascular growth. Indeed, ACE inhibitors have been reported to prevent neointimal formation after vascular injury in a rat carotid artery model. However, classic pharmacological experiments cannot exclude the potential contributions of hemodynamics and the circulating renin-angiotensin system (RAS). In this study, we used antisense oligodeoxynucleotide (ODN) to obtain local blockade of vascular ACE expression without effects on systemic hemodynamics and circulating RAS. To increase the effectiveness of antisense action, we modified the hemagglutinating virus of Japan-liposome ODN delivery method by cotransfection with nuclear protein (high mobility group 1 [HMG-1]) and RNase H. In vitro experiments showed the enhanced efficacy of antisense ODN by cotransfection of HMG-1 and RNase H compared with ODN alone. In vivo transfection of antisense ACE ODNs into intact uninjured rat carotid artery resulted in a significant reduction of vascular ACE activity, and cotransfection of HMG-1 and RNase H showed further reduction. We examined the effects of local blockade of vascular ACE expression on neointimal formation after vascular injury. Transfection of antisense ACE ODNs resulted in the attenuation of neointimal formation, whereas sense and scrambled ODNs did not. Blood pressure, heart rate, and serum ACE activity were not affected by antisense treatment. The magnitude of vascular ACE inhibition correlated with the suppression of the neointimal size. Overall, this study demonstrates that local antisense ODN inhibition of vascular ACE expression attenuates neointimal formation independent of hemodynamics and circulating RAS. The results support the existence of a functional tissue angiotensin system in the rat vessel wall.

Protective immunization against melanoma by gp100 DNA-HVJ-liposome vaccine

DNA-based vaccine immunization effectively induces both humoral and cell-mediated immunity to antigens and can confer protection against numerous infectious diseases as well as some cancers. Human and mouse melanomas consistently express the tumor-associated antigen interacted with the melanogenesis pathway. Gp100 is immunogenic and has been shown to induce both antibody and cytotoxic T cell (CTL) responses in humans. To explore the potential use of DNA immunization to induce melanoma-specific immune responses, we assessed HVJ-AVE liposome incorporated with plasmid DNA encoding human gp100. The gp100 DNA vaccine was used in a mouse melanoma model to assess immunity against the B16 melanoma of C57BL/6 mice. Intramuscular injection of the DNA-HVJ-AVE liposomes induced both anti-gp100 antibody and CTL responses. Gp100 DNA-HVJ-AVE liposome immunization significantly delayed tumor development in mice challenged with B16 melanoma cells. Mice immunized with gp100 DNA-HVJ-AVE liposomes survived longer compared with control mice immunized with HVJ-AVE liposome alone. These results indicate that immunization with human gp100 DNA by HVJ-AVE liposomes can induce protective immunity against melanoma in this pre-clinical mouse model. This strategy may provide an effective approach for vaccine therapy with tumor-associated antigens against human melanoma.

Oxidation-dependent changes in the stability and permeability of lipid bilayers

Peroxidation-dependent change in the permeability of lipid bilayers was mesaured by using artificial membrane systems, that is, planar lipid bilayers and liposomes. The unsaturated fatty acyl chains of phospholipids in small unilamellar vesicles were peroxidized time-dependently by the hydroxyl radical chemically generated by the reaction of H2O2 and Cu(en)2. In contrast, at the same hydroxyl radical concentration and time ranges, no ionic current through the planar lipid bilayers and no release of K+ from the liposomes were observed. These findings indicate that accumulation of lipid peroxide within lipid bilayers is not responsible for the permeability increase that is often observed in biomembranes exposed to oxidative stresses. Higher concentration of the hydroxyl radical caused break-down of the planar lipid bilayers composed of the mixture (7:3) of phosphatidylethanolamine (PE) and phosphatidylcholine (PC). The bilayer containing 100% PE at least at one leaflet of the bilayer (facing the hydroxyl radical-generating solution) was not broken-down by the application of the hydroxyl radical, suggesting that PE stabilizes the planar lipid bilayer against the attack of the hydroxyl radical.

Antisense oligodesoxynucleotide strategies in renal and cardiovascular disease

Antisense oligodesoxynucleotides (ODN) provide a novel strategy to inhibit RNA transcription and thereby the synthesis of the gene product. Because antisense ODN hybridize with the mRNA strand, they are highly specific. Their backbone structure has been modified to phosphorothioates or phosphoamidates so that they can better withstand degradation after delivery. We have shown that antisense ODN are a useful research tool to elucidate intracellular processes. The example we provide involves the inhibition of PKC signaling. Furthermore, we have shown the potential clinical utility of antisense treatment. We successfully inhibited the expression of the surface adhesion molecule ICAM-1 with antisense ODN in a model of reperfusion injury. This model is highly applicable to the problem of delayed graft function in humans. However, "getting there" is a major problem and clearly less than half the fun. Cationic substances such as lipofectin have worked sufficiently well in the experimental setting. Viral gene transfer offers a possibility; however, viruses produce an additional series of problems. Liposomes may not provide sufficient transfer efficiency. Coating liposomes with viral fusion proteins may offer an ideal way with which to deliver the goods into the cytoplasm of the target cell.

Transfer of wild-type p53 gene effectively inhibits vascular smooth muscle cell proliferation in vitro and in vivo

Wild-type p53 (wt-p53), a key protein in cell cycle regulation, inactivates the G1 cyclins through direct activation of p21Waf-1/Cip-1/Sdi-1. Persistent vascular smooth muscle cell (VSMC) proliferation following vascular interventions hinders the benefits of these therapeutics. Using the hemagglutinating virus of Japan/liposome-mediated gene transfer method, we examined the inhibitory effect of overexpression of exogenous wt-p53 on VSMC proliferation in vitro and in vivo. We assessed the proliferative activity of human p53 cDNA-transduced bovine VSMCs by DNA synthesis assay, flow cytometry, and cell proliferation assay. p53 gene transfer reduced thymidine incorporation of VSMCs stimulated by platelet-derived growth factor-BB (P<.001). The p53-transduced VSMCs underwent synthetic phase depletion (mean, 8.02% versus 33.7% of control; P<.001) and transient G2/M accumulation 2 days after gene transfection, and in almost all cells, G1 arrest occurred (mean, 92.6% versus 79.3% of control; P<.001) 5 days later. The wt-p53 gene transfection also inhibited the VSMC proliferation (P<.001) with no detectable induction of apoptosis. Cell death of p53-transduced VSMCs was induced only by additional treatment with an apoptosis-stimulating reagent, doxorubicin. The verification of apoptosis was made by DNA ladder, flow cytometry, and electron microscopy. In vivo transfection of p53 cDNA inhibited neointimal formation after balloon injury in rabbit carotid arteries, without apoptotic stimuli (P<.01). Thus, overexpression of the p53 gene in the injured arterial wall inhibits the proliferation of VSMCs in vitro and in vivo. This novel concept, including not only exogenous but also endogenous p53 overexpression in the vessel wall, may be one approach worth exploring in the treatment of patients with restenosis occurring after vascular interventions.

Use of EBV-based Vector/HVJ-liposome complex vector for targeted gene therapy of EBV-associated neoplasms

Targeted suicide gene therapy for Epstein-Barr virus (EBV)-associated neoplasms was attempted by using EBV-based plasmid vectors coupled with hemagglutinating virus of Japan (HVJ)-liposome in vitro. Expression of EBV nuclear antigen (EBNA)1 is a common feature of the neoplasms associated with EBV. When various leukemic cell lines were transduced with a vector carrying a marker gene and EBV replication origin of plasmid (oriP), the marker gene product was exclusively detected in cells expressing EBNA1. Transduction of herpes simplex virus (HSV)-1 thymidine kinase (Tk) gene resulted in a marked reduction in viable cell number by ganciclovir (GCV) specifically in EBNA1 positive cells. The results demonstrate that this virus-free system may be applicable to gene therapy of EBV-associated neoplasms.

Ribozyme-based gene cleavage approach to chronic arthritis associated with human T cell leukemia virus type I: induction of apoptosis in synoviocytes by ablation of HTLV-I tax protein

OBJECTIVE

To develop gene therapy for patients with human T cell leukemia virus type I (HTLV-I)-associated arthropathy (HAAP), we investigated the effects of ribozyme-mediated cleavage of HTLV-I tax/rex messenger RNA (mRNA) on synovial overgrowth.

METHODS

We introduced 2 hammerhead ribozymes targeted against HTLV-I tax/rex mRNA into synovial cells obtained from patients with HAAP and from patients with HTLV-I-negative rheumatoid arthritis (RA) and examined the ribozyme-mediated ablation of Tax expression. Using standard methods, we also determined the cells' ability to stop proliferating and to undergo apoptosis.

RESULTS

The ribozymes successfully cleaved tax/rex mRNA in HAAP patient synoviocytes. Both tax mRNA expression and Tax protein synthesis were inhibited significantly, resulting in inhibition of synovial cell growth and induction of apoptosis. In contrast, synovial cells from RA patients were not affected.

CONCLUSION

In vitro results suggest that ribozyme-mediated gene therapy can inhibit the growth of HTLV-I-infected synovial cells, which is maintained by Tax protein, in HTLV-I-related diseases including HAAP.

Development and characterization of cationic liposomes conjugated with HVJ (Sendai virus): reciprocal effect of cationic lipid for in vitro and in vivo gene transfer

Today, nonviral gene transfer vectors attract more attention as a therapeutic strategy for human diseases, because viral vectors such as adenoviral and herpes viral vectors have been proven to have problems, especially in immunogenicity and cytotoxicity. However, the main limitation of nonviral vectors has been low efficiency of gene expression. To overcome this defect, we have developed a new class of transfection vehicles, HVJ-cationic liposomes. The use of the cationic lipid DC-cholesterol facilitates efficient entrapment of negatively charged macromolecules (plasmid DNA, oligodeoxynucleotides, and proteins) and efficient interaction with negatively charged plasma membranes of cultured cells in vitro. Moreover, the fusogenic envelope proteins of hemagglutinating virus of Japan (HVJ) enhance delivery of the enclosed materials into cells. Using firefly luciferase as a marker, we optimized the liposome formula. As a result, we have succeeded in obtaining 100-800 times higher gene expression in vitro than with the conventional HVJ-anionic liposomes. However, in vivo gene transfer experiments have revealed that the use of cationic lipid instead of anionic lipid reduced the transgene expression dramatically in organs such as muscle and liver. We further discovered that the use of anionic liposomes with a viral-mimic king lipid composition increased transfection efficiency by several times in vivo. We conclude that the alternative usage of transfer vectors, for example, HVJ-anionic liposomes for in vivo delivery to extended areas of organs and HVJ-cationic liposomes for in vitro delivery (and possibly for in vivo delivery to a restricted area of organs), is of significance.

Efficient transfer of synthetic ribozymes into cells using hemagglutinating virus of Japan (HVJ)-cationic liposomes. Application for ribozymes that target human t-cell leukemia virus type I tax/rex mRNA

We investigated the usefulness of ribozymes in inhibiting the expression of human T-cell leukemia virus type I (HTLV-I) gene. Two hammerhead ribozymes that were against HTLV-I rex (RR) and tax (TR) mRNA were synthesized. Both ribozymes were sequence-specific in the in vitro cleavage analysis of run-off transcripts from tax/rex cDNA. Intracellular activities of the ribozymes were studied in HTLV-I tax cDNA-transfected rat embryonic fibroblasts (Rat/Tax cells), which expressed the Tax but not Rex. Ribozymes were delivered into cells using anionic or cationic liposomes fused with hemagglutinating virus of Japan (HVJ). Cellular uptake of ribozymes complexed with HVJ-cationic liposomes was 15-20 times higher cellular uptake than naked ribozymes, and 4-5 times higher than that of ribozymes complexed with HVJ-anionic liposomes. HVJ-cationic liposomes promoted accumulation of ribozymes in cytoplasm and accelerated transport to the nucleus. Tax protein levels were decreased about 95% and were five times lower when the same amount of TR was introduced into the cells using HVJ-cationic, rather than HVJ-anionic liposomes. Inactive ribozyme and tax antisense oligodeoxynucleotides reduced Tax expression by about 20%, whereas RR and tax sense oligodeoxynucleotides had no effect. These results suggest that the ribozymes' effect against tax mRNA was sequence-specific, and HVJ-cationic liposomes can be useful for intracellular introduction of ribozymes.

Efficient gene transduction by Epstein-Barr-virus-based vectors coupled with cationic liposome and HVJ-liposome

We show here a novel non-viral strategy to transduce human cells by using an EBV-based vector system. The EBV-based vectors, the plasmid vectors carrying EBV oriP (origin for plasmid replication) and EBNA (EBV nuclear antigen) 1 gene from EBV genome, were combined with 2 gene delivery systems, i.e., cationic liposome and HVJ-liposome. By both methods, EBV-based vectors could be more efficiently transfected into HeLa cells than non-EBV, conventional plasmid vectors. When human primary fibroblasts were transfected, EBV-based vectors coupled with cationic liposome but HVJ-liposome resulted in successful gene transduction, while human bone marrow cells were transduced with both HVJ-liposome- and cationic liposome-EBV vectors. These results suggest the potential applications of the EBV-based vector system for gene therapy.

Experimental bronchiolitis obliterans induced by in vivo HVJ-liposome-mediated endothelin-1 gene transfer

BACKGROUND

Bronchiolitis obliterans (OB) is a lesion that results when injury to small conducting airways is repaired by a proliferation of fibrous granulation tissue. Bronchiolitis obliterans has emerged as a main cause of morbidity and mortality in the setting of lung and heart-lung transplantation. Endothelin-1 (ET-1), initially discovered as a vasoconstrictive peptide, has a mitogenic activity on vascular smooth cells and airway epithelial cells. Overproduction of endothelin has been reported in patients with OB or chronic rejection after lung transplantation. It is still undetermined whether locally overexpressed ET-1 has a potential impact in the pathogenesis of OB.

METHODS

We locally overexpressed ET-1 using ultraviolet irradiation-inactivated hemagglutinating virus of Japan (HVJ)-liposome-mediated in vivo gene transfer. Plasmid DNA of prepro-ET-1 and high mobility group 1 protein were coencapsulated in liposomes, and were introduced into airway epithelial cells by HVJ-mediated membrane fusion. Control animals received instillation of HVJ-liposome with an empty expression cassette. To confirm the efficiency of transfection, HVJ liposome with beta-galactosidase gene was introduced. The expression of ET-1 and beta-galactosidase was assessed by immunohistochemistry.

RESULTS

Bronchial epithelium alveolar cells and alveolar macrophage were stained blue (X-Gal) 1 week after in vivo gene transfer of beta-galactosidase gene, indicating beta-gal activity. In animals 1 to 2 weeks after in vivo transfection of prepro-ET-1 gene, hyperplastic connective tissue plaque was seen in the alveolar duct and small conducting airway, indicating histologically distinctive bronchiolitis obliterans. Strong ET-1-like immunoactivities were seen in the airway epithelial, hyperplastic connective tissue, and alveolar cells. No histopathologic changes were seen in the control animals.

CONCLUSIONS

These results suggested that ET-1 may play an important role in the pathogenesis of OB. The effective pharmacologic antagonist or inhibitor may possibly control the progression of disease in patients of OB.

In vivo direct gene transfer into articular cartilage by intraarticular injection mediated by HVJ (Sendai virus) and liposomes

OBJECTIVE

To establish a system for efficient, direct in vivo gene transfer into joints.

METHODS

A hemagglutinating virus of Japan (HVJ; Sendai virus)-liposome suspension containing SV40 large T antigen (SVT) gene was injected intraarticularly into knee joints of 6-week-old female Lewis rats. Rats were killed at various times for immunohistochemical analysis of the expression of SVT gene.

RESULTS

The expression of SVT gene was detected immunohistochemically in chondrocytes in the superficial and middle zones of articular cartilage in the knee joints. The average percentage of SVT-positive cells was estimated to be approximately 30% on days 3, 7, 14, and 21 after transfection. Moreover, no pathologic change caused by HVJ-liposome injection was observed in the joints.

CONCLUSION

The transfection frequency and stability of expression recognized in this study indicate the possibility of a strategy for treatment of joint disorders, including arthritis, using direct gene transfer.

The immediate early gene of human cytomegalovirus stimulates vascular smooth muscle cell proliferation in vitro and in vivo

Cytomegalovirus (CMV) infection has been carefully studied regarding the relationship with the vascular smooth muscle cell (VSMC) proliferation in either atherosclerosis or post-angioplasty restenosis, but its role in the vessel wall has yet to be elucidated. To clarify the pathogenic ability of CMV in the vessel wall, we transduced the immediate early (IE) gene of CMV into the VSMCs and endothelial cells (ECs) by hemagglutinating virus of Japan-liposome method. The in vitro IE gene transfer demonstrated that the conditioned medium of IE gene transferred ECs enhanced [3H]-thymidine uptake of VSMCs. The enhanced proliferation of the IE gene transferred VSMCs was observed after the stimulation by basic fibroblast growth factor. The in vivo IE gene transfer showed neointimal thickening while the control arteries did not. These findings thus suggest that the expression of CMV-IE gene in the vessel wall may play a role in the fibrocellular neointimal formation or progression of atherosclerosis in vivo.

Fusigenic viral liposome for gene therapy in cardiovascular diseases

To improve the efficiency of liposome-mediated DNA transfer as a tool for gene therapy, we have developed a fusigenic liposome vector based on principles of viral cell fusion. The fusion proteins of hemagglutinating virus of Japan (HVJ; also Sendai virus) are complexed with liposomes that encapsulate oligodeoxynucleotide or plasmid DNA. Subsequent fusion of HVJ-liposomes with plasma membranes introduces the DNA directly into the cytoplasm. In addition, a DNA-binding nuclear protein is incorporated into the HVJ-liposome particle to enhance plasmid transgene expression. The fusigenic viral liposome vector has proven to be efficient for the intracellular introduction of oligodeoxynucleotide, as well as intact genes up to 100 kbp, both in vitro and in vivo. Many animal tissues have been found to be suitable targets for fusigenic viral liposome DNA transfer. In the cardiovascular system, we have documented successful cytostatic gene therapy in models of vascular proliferative disease using antisense oligodeoxynucleotides against cell cycle genes, double-stranded oligodeoxynucleotides as "decoys" to trap the transcription factor E2F, and expression of a transgene encoding the constitutive endothelial cell form of nitric oxide synthase. Similar strategies are also effective for the genetic engineering of vein grafts and for the treatment of a mouse model of immune-mediated glomerular disease.

Transient introduction of a foreign gene into healing rat patellar ligament

We investigated the in vivo introduction of a reporter gene into healing rat patellar ligaments using the hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer method. The mid-portion of the medial half of the patellar ligament was cut transversely with a scalpel in 14-wk-old male Wistar rats. A HVJ-liposome suspension containing beta-galactosidase (beta-gal) cDNA was injected directly into the injured site and pooled in the fascial pocket covering the injured site 3 d postoperatively. Thereafter, beta-gal-labeled cells were observed in the wound site accounting for 3% of the wound cells on the first day, 2% on the third, 7% on the seventh, 6% on the 14th, 2% on the 28th, and 0.2% on the 56th day after injection. The beta-gal-labeled cells were initially localized in and adjacent to the wound site, but they were observed spreading into the ligament substance away from the wound on the seventh day after injection. On day 28, beta-gal-labeled cells were observed throughout the length of the ligament substance. With double-labeling for marker antigens for monocyte/macrophage (ED-1) and for collagen I aminopropeptide (pN collagen I), it was revealed that fibroblastic (pN collagen I-positive) cells accounted for 63% and monocyte/macrophage lineage cells for 32% of the beta-gal-labeled cells in the day 7 wound. On day 28, they formed 58 and 35% of the beta-gal-labeled cells in the wound, respectively. Thus, we succeeded in introducing the beta-gal gene into healing rat patellar ligament. Moreover, labeling of the transfected cells made it possible to identify a biological event, namely that the cells in and around the wound site infiltrate into the uninjured ligament substance and come to populate the whole length of the ligament substance as repair progresses. These results suggest that ligament healing may involve not only the repair of the wound site itself but also extensive cellular infiltration of ligament substance adjacent to the wound.

Sendai virosomal infusion of an adeno-associated virus-derived construct containing neuropeptide Y into primary rat brain cultures

A novel neuronal gene-delivery system was investigated in primary neuron-enriched cultures with respect to driving the expression of neuropeptide Y (NPY). This delivery system consists of an adeno-associated virus-derived (AAV) plasmid, pJDT95npy, encapsulated in reconstituted Sendai virosomes. pJDT95npy contains full length rat NPY cDNA inserted downstream from the P40 promoter in a cap-gene deleted AAV-derived construct. The rep-sequences under control of the P5 and P19 promoters are intact. Virosomally encapsulated pJDT95npy drove the expression of NPY mRNAs, predominantly by P40. Total cellular NPY immunoreactivity and release in the presence of depolarization increased following pJDT95npy-transfection. Neither empty virosomes nor virosomes containing pJDT95 affected NPY mRNA expression or immunoreactivity. This study demonstrates that an AAV-derived plasmid can drive exogenous gene expression in intact neurons after infusion by Sendai virosomes.

Pharmacokinetics of antisense oligodeoxyribonucleotides (cyclin B1 and CDC 2 kinase) in the vessel wall in vivo: enhanced therapeutic utility for restenosis by HVJ-liposome delivery

Using a highly efficient viral HVJ (hemagglutinating virus of Japan) liposome-mediated transfer method, we examined the cellular fate of antisense oligodeoxyribonucleotides (oligos) in the vessel wall in vivo. Direct transfer of unmodified FITC (fluorescein isothiocyanate)-labeled oligos into injured rat carotid arteries showed, localized in the medial layer, fluorescence that disappeared within 1 day. In contrast, transfection of unmodified FITC-oligos by the HVJ-liposome method showed, concentrated in the medial layer, high levels of fluorescence that were sustained for at least 1 week. Moreover, we demonstrated nuclear localization and accumulation of fluorescence in the vessel wall using this method. To examine the therapeutic utility of this method, we transferred antisense phosphorothioate oligos against cyclin B1- and CDC2 kinase-encoding genes into balloon-injured rat carotid artery as a potential therapy for experimental restenosis. Two weeks after transfection, antisense oligo treatment directed against either CDC2 kinase or cyclin B1 resulted in a partial, but significant, inhibition in neointima formation. In contrast, transfection of either sense or scrambled control oligos had no effect. Interestingly, co-transfection of antisense oligos against CDC2 kinase and cyclin B resulted in further inhibition of neointima formation, as compared to blockade of either gene target alone. These results demonstrate that: (i) the HVJ-liposome method enhances the half life and nuclear localization of antisense oligos in the vessel wall in vivo; and (ii) HVJ-mediated administration of antisense CDC2 kinase and cyclin B1 oligos produces a sustained inhibition of neointima formation after balloon angioplasty.

Differential adenoassociated virus vector-driven expression of a neuropeptide Y gene in primary rat brain astroglial cultures after transfection with Sendai virosomes versus Lipofectin

The ability of Sendai virosomes or Lipofectin to introduce an AAV vector into primary rat brain astroglial cultures was characterized. The pJDT95npy vector was constructed by inserting rat NPY cDNA downstream from the indigenous AAV p5, p19 and p40 promoters in pJDT95. Lipofectin-mediated transfection with pJDT95npy (10 micrograms) resulted in pronounced expression of several NPY mRNA species: p5-driven (3.3 kb), p19-driven (2.7 kb) and p40-driven (0.6, 0.8, 1.1, and 1.8 kb). Exposure to virosomally encapsulated pJDT95npy (50 or 100 ng) resulted in transient expression of some p40-driven mRNA species (0.8 and 1.8 kb). Neither method produced astroglia cells which synthesized mature NPY immunoreactivity. This demonstrates that an AAV-derived vector can drive gene expression in astroglia, that Sendai virosomes can infuse vectors into astroglia, but that the amount of DNA infused in this manner may limit long term expression.

Efficient transfection of human interferon-beta gene to human glioma cells by means of cationic multilamellar liposomes coupled with a monoclonal antibody [corrected]

We have been devoting our efforts to develop the useful liposomes that have high potentials of gene transfer and we aim human gene therapy for malignant glioma with cytokine genes. In our previous study, we prepared our original reverse-phase evaporation vesicles (REV) by an improved procedure of reverse-phase evaporation method. However, this procedure was very complicate. In this paper, a simple procedure for the preparation of cationic multilamellar vesicles (MLV) was introduced, and efficient expression and growth-inhibitory effect of MLV with entrapped human interferon-beta gene to glioma cells was comparable to that obtained with REV. Considering the present experiments, MLV seem to be more preferable for clinical application.