Tatsuya Nomoto

Interleukin-10 Expression Mediated by an Adeno-Associated Virus Vector Prevents Monocrotaline-Induced Pulmonary Arterial Hypertension in Rats

Pulmonary arterial hypertension (PAH) is a fatal disease associated with inflammation and pathological remodeling of the pulmonary artery (PA). Interleukin (IL)-10 is a pleiotropic antiinflammatory cytokine with vasculoprotective properties. Here, we report the preventive effects of IL-10 on monocrotaline-induced PAH. Three-week-old Wistar rats were intramuscularly injected with an adeno-associated virus serotype 1 vector expressing IL-10, followed by monocrotaline injection at 7 weeks old. IL-10 transduction significantly improved survival rates of the PAH rats 8 weeks after monocrotaline administration compared with control gene transduction (75% versus 0%, P<0.01). IL-10 also significantly reduced mean PA pressure (22.8±1.5 versus 29.7±2.8 mm Hg, P<0.05), a weight ratio of right ventricle to left ventricle plus septum (0.35±0.04 versus 0.42±0.05, P<0.05), and percent medial thickness of the PA (12.9±0.3% versus 21.4±0.4%, P<0.01) compared with controls. IL-10 significantly reduced macrophage infiltration and vascular cell proliferation in the remodeled PA in vivo. It also significantly decreased the lung levels of transforming growth factor-β1 and IL-6, which are indicative of PA remodeling. In addition, IL-10 increased the lung level of heme oxygenase-1, which strongly prevents PA remodeling. In vitro analysis revealed that IL-10 significantly inhibited excessive proliferation of cultured human PA smooth muscle cells treated with transforming growth factor-β1 or the heme oxygenase inhibitor tin protoporphyrin IX. Thus, IL-10 prevented the development of monocrotaline-induced PAH, and these results provide new insights into the molecular mechanisms of human PAH.

Adeno-associated virus vector-mediated interleukin-10 gene transfer inhibits atherosclerosis in apolipoprotein E-deficient mice

Inflammation is a major contributor to atherosclerosis by its effects on arterial wall biology and lipoprotein metabolism. Interleukin-10 (IL-10) is an anti-inflammatory cytokine that may modulate the atherosclerotic disease process. We investigated the effects of adeno-associated virus (AAV) vector-mediated gene transfer of IL-10 on atherogenesis in apolipoprotein E (ApoE)-deficient mice. A murine myoblast cell line, C2C12, transduced with AAV encoding murine IL-10 (AAV2-mIL10) secreted substantial amounts of IL-10 into conditioned medium. The production of monocyte chemoattractant protein-1 (MCP-1) by the murine macrophage cell line, J774, was significantly inhibited by conditioned medium from AAV2-mIL10-transduced C2C12 cells. ApoE-deficient mice were injected with AAV5-mIL10 into their anterior tibial muscle at 8 weeks of age. The expression of MCP-1 in the vascular wall of the ascending aorta and serum MCP-1 concentration were decreased in AAV5-mIL10-transduced mice compared with AAV5-LacZ-transduced mice. Oil red-O staining of the ascending aorta revealed that IL-10 gene transfer resulted in a 31% reduction in plaque surface area. Serum cholesterol concentrations were also significantly reduced in AAV5-mIL10-transduced mice. To understand the cholesterol-lowering mechanism of IL-10, we measured the cellular cholesterol level in HepG2 cells, resulting in its significant decrease by the addition of IL-10 in a dose-dependent manner. Furthermore, IL-10 suppressed HMG-CoA reductase expression in the HepG2 cells. These observations suggest that intramuscular injection of AAV5-mIL10 into ApoE-deficient mice inhibits atherogenesis through anti-inflammatory and cholesterol-lowering effects.

Adeno‐associated virus vector‐mediated systemic interleukin‐10 expression ameliorates hypertensive organ damage in Dahl salt‐sensitive rats

Inflammation plays an important role in the pathogenesis of hypertension and hypertensive organ damage. Interleukin (IL)‐10, a pleiotropic anti‐inflammatory cytokine, exerts vasculoprotective effects in many animal models. In the present study, we examined the preventive effects of adeno‐associated virus (AAV) vector‐mediated sustained IL‐10 expression against hypertensive heart disease and renal dysfunction in Dahl salt‐sensitive rats.

Adeno-associated virus vectors for gene transfer to the brain

Gene therapy is a novel method under investigation for the treatment of neurological disorders. Considerable interest has focused on the possibility of using viral vectors to deliver genes to the central nervous system. Adeno-associated virus (AAV) is a potentially useful gene transfer vehicle for neurologic gene therapies. The advantages of AAV vector include the lack of any associated disease with a wild-type virus, the ability to transduce nondividing cells, the possible integration of the gene into the host genome, and the long-term expression of transgenes. The development of novel therapeutic strategies for neurological disorder by using AAV vector has an increasing impact on gene therapy research. This article describes methods that can be used to generate rodent and nonhuman primate models for testing treatment strategies linked to pathophysiological events in the ischemic brain and neurodegenerative disorders such as Parkinsons disease.

Promoter effects of adeno-associated viral vector for transgene expression in the cochlea in vivo

The aims of this study were to evaluate the expression of enhanced green fluorescent protein (EGFP) driven by 6 different promoters, including cytomegalovirus IE enhancer and chicken β-actin promoter (CAG), cytomegalovirus promoter (CMV), neuron-specific enolase promoter (NSE), myosin 7A promoter (Myo), elongation factor 1α promoter (EF-1α), and Rous sarcoma virus promoter (RSV), and assess the dose response of CAG promoter to transgene expression in the cochlea. Serotype 1 adeno-associated virus (AAV1) vectors with various constructs were transduced into the cochleae, and the level of EGFP expression was examined. We found the highest EGFP expression in the inner hair cells and other cochlear cells when CAG promoter was used. The CMV and NSE promoter drove the higher EGFP expression, but only a marginal activity was observed in EF-1α promoter driven constructs. RSV promoter failed to driven the EGFP expression. Myo promoter driven EGFP was exclusively expressed in the inner hair cells of the cochlea. When driven by CAG promoter, reporter gene expression was detected in inner hair cells at a dose as low as 3 x 10(7) genome copies, and continued to increase in a dose- dependent manner. Our data showed that individual promoter has different ability to drive reporter gene expression in the cochlear cells. Our results might provide important information with regard to the role of promoters in regulating transgene expression and for the proper design of vectors for gene expression and gene therapy.

Protection Against Aminoglycoside-induced Ototoxicity by Regulated AAV Vector–mediated GDNF Gene Transfer Into the Cochlea

Since standard aminoglycoside treatment progressively causes hearing disturbance with hair cell degeneration, systemic use of the drugs is limited. Adeno-associated virus (AAV)-based vectors have been of great interest because they mediate stable transgene expression in a variety of postmitotic cells with minimal toxicity. In this study, we investigated the effects of regulated AAV1-mediated glial cell line-derived neurotrophic factor (GDNF) expression in the cochlea on aminoglycoside-induced damage. AAV1-based vectors encoding GDNF or vectors encoding GDNF with an rtTA2s-S2 Tet-on regulation system were directly microinjected into the rat cochleae through the round window at 5 × 1010 genome copies/body. Seven days after the virus injection, a dose of 333 mg/kg of kanamycin was subcutaneously given twice daily for 12 consecutive days. GDNF expression in the cochlea was confirmed and successfully modulated by the Tet-on system. Monitoring of the auditory brain stem response revealed an improvement of cochlear function after GDNF transduction over the frequencies tested. Damaged spiral ganglion cells and hair cells were significantly reduced by GDNF expression. Our results suggest that AAV1-mediated expression of GDNF using a regulated expression system in the cochlea is a promising strategy to protect the cochlea from aminoglycoside-induced damage.Since standard aminoglycoside treatment progressively causes hearing disturbance with hair cell degeneration, systemic use of the drugs is limited. Adeno-associated virus (AAV)-based vectors have been of great interest because they mediate stable transgene expression in a variety of postmitotic cells with minimal toxicity. In this study, we investigated the effects of regulated AAV1-mediated glial cell line-derived neurotrophic factor (GDNF) expression in the cochlea on aminoglycoside-induced damage. AAV1-based vectors encoding GDNF or vectors encoding GDNF with an rtTA2s-S2 Tet-on regulation system were directly microinjected into the rat cochleae through the round window at 5 x 10(10) genome copies/body. Seven days after the virus injection, a dose of 333 mg/kg of kanamycin was subcutaneously given twice daily for 12 consecutive days. GDNF expression in the cochlea was confirmed and successfully modulated by the Tet-on system. Monitoring of the auditory brain stem response revealed an improvement of cochlear function after GDNF transduction over the frequencies tested. Damaged spiral ganglion cells and hair cells were significantly reduced by GDNF expression. Our results suggest that AAV1-mediated expression of GDNF using a regulated expression system in the cochlea is a promising strategy to protect the cochlea from aminoglycoside-induced damage.

Systemic delivery of IL-10 by an AAV vector prevents vascular remodeling and end-organ damage in stroke-prone spontaneously hypertensive rat

Interleukin-10 (IL-10) ameliorates various T-helper type 1 cell-mediated chronic inflammatory diseases. Although the therapeutic benefits of IL-10 include antiatherosclerotic effects, pathophysiological effects of IL-10 on vascular remodeling in hypertension have not yet been elucidated. These studies were designed to determine whether sustained IL-10 expression, mediated by an adeno-associated virus (AAV) vector, prevents vascular remodeling and target-organ damage in the stroke-prone spontaneously hypertensive rat (SHR-SP)—an animal model of malignant hypertension. A single intramuscular injection of an AAV1 vector encoding rat IL-10 introduced long-term IL-10 expression. These IL-10-transduced rats had decreased stroke episodes and proteinuria, resulting in improved survival. Histological examination revealed a reduced level of deleterious vascular remodeling of resistance vessels in the brain and kidney of these rats. Immunohistochemical analysis indicated that IL-10 inhibited the enhanced renal transforming growth factor-β expression and perivascular infiltration of monocytes/macrophages and nuclear factor-κB-positive cells normally observed in the SHR-SP. Four weeks after IL-10 vector injection, systolic blood pressure significantly decreased and this effect persisted for several months. Overall, AAV vector-mediated systemic IL-10 expression prevented vascular remodeling and inflammatory lesions of target organs in the SHR-SP. This approach provides significant insights into the prevention strategy of disease onset with unknown genetic predisposition or intractable polygenic disorders.

Distinct patterns of gene transfer to gerbil hippocampus with recombinant adeno-associated virus type 2 and 5.

Genetic modification of the gerbil hippocampal neuronal cells in vivo helps us understand the mechanisms of neuronal function under various circumstances such as ischemic insult. In this study, we examined the distinct distribution of the recombinant adeno-associated virus type 2 (rAAV2) and rAAV5 vectors for gene delivery to primary cultured cells and the gerbil hippocampus. Mixed cortical cultures containing both neurons and astrocytes from E17 rat embryos were infected with rAAVs containing the Cytomegalovirus virus (CMV) promoter. rAAV2 was preferably transduced to neurons, whereas rAAV5 was inclined to be transduced to astrocytes in vitro. rAAV2 and rAAV5 vectors, each with the CMV or Rous sarcoma virus (RSV) promoter, were injected into the gerbil hippocampus using a stereotaxic apparatus. Five days after injection, transgene expression was analyzed with X-gal staining. In the gerbil hippocampus, rAAV5 with the CMV promoter achieved a higher overall transgene expression than rAAV2 with the CMV promoter. The transgene expression of rAAV2 with the RSV promoter was found in the pyramidal and granular cells, while the transgene expression of rAAV5 with the RSV promoter was preferentially found in the granular cells. These findings would be valuable in optimizing rAAV-mediated gene transfer to the gerbil hippocampus.

In situ generation of pseudotyped retroviral progeny by adenovirus‐mediated transduction of tumor cells enhances the killing effect of HSV‐tk suicide gene therapy in vitro and in vivo

Hybrid adeno‐retroviral vector systems utilize the high efficiency of adenovirus transduction to direct the in situ production of retroviral progeny. In this study, we show that a single‐step transduction of glioma cells with trans‐complementing hybrid adeno‐retroviral vectors effectively turns these cells into retrovirus vector‐producing cells, which in turn facilitates the transduction of adjacent cells.

Cerebral arteriopathy with extracranial artery involvement in a patient with ulcerative colitis

Arteriopathy of the central nervous system (CNS) complicated with ulcerative colitis is a rare condition, moreover the involvement of extracranial arteries has not been documented. An 18-year-old female complained of a severe pulsatile headache and nausea. She had been diagnosed and treated for ulcerative colitis for four years. Magnetic resonance imaging of the brain showed normal results; however, magnetic resonance angiography (MRA) revealed severe irregularity of the intracerebral arteries. After treatment with prednisolone, the patient fully recovered and the irregularity of the intracerebral arteries was dramatically improved. Vasculitis was strongly suggested as the cause of arteriopathy of the CNS in the present case. Involvement of extracranial arteries such as the carotid artery was also incidentally discovered by duplex ultrasonography and the HLA typing suggested genetic susceptibility to Takayasus arteritis. Findings from our patient suggest that extracranial arterial involvement should be considered in the case of arteriopathy of the CNS associated with ulcerative colitis.