Intramuscular injection of adenoviral hepatocyte growth factor at a distal site ameliorates dextran sodium sulfate-induced colitis in mice.

Inflammatory bowel disease (IBD) severely affects the quality of life of patients. At present, there is no clinical solution for this condition; therefore, there is a need for innovative therapies for IBD. Hepatocyte growth factor (HGF) exerts various biological activities in various organs. However, a clinically applicable and effective HGF-based therapy for IBD has yet to be developed. In this study, we examined the therapeutic effect of injecting an adenoviral vector encoding the human HGF gene (Ad.HGF) into the hindlimbs of mice with dextran sodium sulfate (DSS)-induced colitis. Plasma levels of circulating human HGF (hHGF) were measured in injected mice. The results showed that weight loss and colon shortening were significantly lower in Ad.HGF-infected mice as compared to control (Ad.LacZ-infected) colitic mice. Additionally, inflammation and crypt scores were significantly reduced in the entire length of the colon, particularly in the distal section. This therapeutic effect was associated with increased cell proliferation and an antiapoptotic effect, as well as a reduction in the number of CD4+ cells and a decreased CD4/CD8 ratio. The levels of inflammatory, as well as Th1 and Th2 cytokines were higher in Ad.HGF-infected mice as compared to the control colitic mice. Thus, systemically circulating hHGF protein, produced by an adenovirally transduced hHGF gene introduced at distal sites in the limbs, significantly ameliorated DSS-induced colitis by promoting cell proliferation (i.e., regeneration), preventing apoptosis, and immunomodulation. Owing to its clinical feasibility and potent therapeutic effects, this method may be developed into a clinical therapy for treating IBD.

Successful treatment of rectal ulcers in a patient with systemic lupus erythematosus using corticosteroids and tacrolimus.

Systemic lupus erythematosus (SLE) is frequently accompanied by gastrointestinal symptoms. Although all parts of the gastrointestinal tract may be affected, colonic involvement is quite rare. Colonic ulceration, particularly in the rectum, is associated with a high mortality rate in patients with SLE, despite immunosuppressive therapy. While a standard regimen for treating rectal ulcers as a complication of SLE has not been established, combination therapy with steroids and immunosuppressive agents is necessary because of the associated high mortality rate. In this report, we describe a patient with SLE whose condition was complicated with ulcerative lesions in the rectum and sigmoid colon; the lesions were successfully treated with a combination of corticosteroids and tacrolimus therapy. Tacrolimus could be a useful additional or alternative modality for treating rectal involvement in SLE.

In vivo hepatocyte growth factor gene transfer reduces myocardial ischemia-reperfusion injury through its multiple actions.

BACKGROUND: Hepatocyte growth factor (HGF) is reported to protect the heart against ischemia-reperfusion injury. However, whether in vivo adenovirus-mediated HGF gene transfer before ischemia is protective against ischemia-reperfusion and its precise mechanisms are still unknown. METHODS AND RESULTS: By using a rabbit model of ischemia-reperfusion injury, we demonstrate that HGF gene transfer is cardioprotective through its multiple beneficial actions, such as angiogenesis, Bcl-2 overexpression, and decreasing hydroxyl radicals, deoxyuride-5'-triphosphate biotin nick end labeling (TUNEL)-positive myocytes, and fibrotic area. After HGF gene transfer, the rabbits underwent 30 minutes of coronary occlusion and 30 minutes, 4 hours, 48 hours, and 14 days of reperfusion. The infarct size at 48 hours of reperfusion was significantly reduced in the HGF group (13.4% +/- 2.3%) compared with that in the LacZ group (36.5% +/- 2.0%) and saline group (40.3% +/- 3.2%). At 14 days of reperfusion, HGF gene transfer improved left ventricular ejection fraction and fractional shortening, reduced the fibrotic area, and increased the capillary density in the risk area. At 4 hours of reperfusion, Bcl-2 protein was overexpressed and the incidence of TUNEL-positive myocytes was significantly decreased in the risk area in the HGF group compared with the LacZ and saline groups. The myocardial interstitial 2,5-dihydroxybenzoic acid level, an indicator of hydroxyl radical, increased during 30 minutes of ischemia and 30 minutes of reperfusion in the LacZ and saline groups, and was significantly inhibited in the HGF group. CONCLUSION: HGF gene therapy may be a novel therapeutic strategy against unstable angina pectoris or severe angina pectoris, which may progress to acute myocardial infarction.

Increased splenic fluorodeoxyglucose uptake in a patient with granulomatous angitis.

Although utility of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) has been rehearsed in large vessel vasculitides, it is not known if small vessel vasculitides are also associated with increased FDG uptake. Hereby described is a 64-year-old female patient with prolonged fever and splenomegaly, which was depicted as a hot area in FDG-PET. Splenectomy disclosed microaneurysms, giant cell granuloma, perivascular leukocytic infiltration with fibrinoid necrosis, consistent with granulomatous angitis. Serum myeloperoxidase-antineutrophil cytoplasmic antibody was positive. The present case illustrates that vasculitides affecting small vessels present increased FDG uptake as do those affecting large vessels.

In vivo hepatic HB-EGF gene transduction inhibits Fas-induced liver injury and induces liver regeneration in mice: a comparative study to HGF.

BACKGROUND/AIMS: It is unknown whether heparin-binding EGF-like growth factor (HB-EGF) can be a therapeutic agent, although previous studies suggested that HB-EGF might be a hepatotrophic factor. This study explores the potential of hepatic HB-EGF gene therapy in comparison with HGF. METHODS: Mice received an intraperitoneal injection of the agonistic anti-Fas antibody 72 h after an intravenous injection of either adenoviral vector (1x10(11) particles) expressing human HB-EGF (Ad.HB-EGF), human HGF (Ad.HGF) or no gene (Ad.dE1.3), and were sacrificed 24 or 36 h later to assess liver injury and regeneration. RESULTS: Exogenous HB-EGF was predominantly localized on the membrane, suggesting the initial synthesis of proHB-EGF in hepatocytes. The control Ad.dE1.3-treated mice represented remarkable increases in serum ALT and AST levels and histopathologically severe liver injuries with numerous apoptosis, but a limited number of mitogenic hepatocytes. In contrast, the liver injuries and apoptotic changes were significantly inhibited, but the mitogenic hepatocytes remarkably increased, in both the Ad.HB-EGF- and Ad.HGF-treated mice. More mitogenic hepatocytes and milder injuries were observed in the Ad.HB-EGF-treated mice. CONCLUSIONS: HB-EGF has more potent protective and mitogenic effects for hepatocytes than HGF, at least for the present conditions. In vivo hepatic HB-EGF gene transduction is therapeutic for Fas-induced liver injury.

Adenoviral gene transduction of hepatocyte growth factor elicits inhibitory effects for hepatoma.

Hepatocyte growth factor (HGF) gene therapy may have potential for treating chronic hepatitis (CH) and liver cirrhosis (LC). However, the lack of an HGF gene therapy study on hepatomas that are often associated with CH or LC, together with the stimulatory effects of HGF on many types of cancer, may hamper its application. This study explored the effects of adenoviral HGF gene transduction and their mechanisms on two types of hepatoma cells (hepatoblastoma and hepatocellular carcinoma) in in vitro experiments. Both types of hepatomas were revealed to have higher adenoviral gene transduction efficiencies and more efficient expressions of the HGF transgene, which successfully activated the HGF receptor/c-Met in an autocrine fashion, than those of other types of cancer. Notably, not only HGF, but also adenoviral infection, inhibited DNA synthesis, whereas only HGF but not adenoviral infection exerted a potent apoptotic effect. Moreover, adenoviral HGF gene transduction additively exerted inhibitory effects on cisplatin-treated hepatomas. In conclusion, inhibitory and apoptotic effects of adenoviral HGF gene transduction in hepatomas in contrast to potent mitogenic and antiapoptotic effects of HGF for hepatocytes are not only of biological interest, but also pose clinical benefits for adenoviral HGF gene therapy for CH and LC.

Postinfarction gene therapy against transforming growth factor-beta signal modulates infarct tissue dynamics and attenuates left ventricular remodeling and heart failure.

BACKGROUND: Fibrosis and progressive failure are prominent pathophysiological features of hearts after myocardial infarction (MI). We examined the effects of inhibiting transforming growth factor-beta (TGF-beta) signaling on post-MI cardiac fibrosis and ventricular remodeling and function. METHODS AND RESULTS: MI was induced in mice by left coronary artery ligation. An adenovirus harboring soluble TGF-beta type II receptor (Ad.CAG-sTbetaRII), a competitive inhibitor of TGF-beta, was then injected into the hindlimb muscles on day 3 after MI (control, Ad.CAG-LacZ). Post-MI survival was significantly improved among sTbetaRII-treated mice (96% versus control at 71%), which also showed a significant attenuation of ventricular dilatation and improved function 4 weeks after MI. At the same time, histological analysis showed reduced fibrous tissue formation. Although MI size did not differ in the 2 groups, MI thickness was greater and circumference was smaller in the sTbetaRII-treated group; within the infarcted area, alpha-smooth muscle actin-positive cells were abundant, which might have contributed to infarct contraction. Apoptosis among myofibroblasts in granulation tissue during the subacute stage (10 days after MI) was less frequent in the sTbetaRII-treated group, and sTbetaRII directly inhibited Fas-induced apoptosis in cultured myofibroblasts. Finally, treatment of MI-bearing mice with sTbetaRII was ineffective if started during the chronic stage (4 weeks after MI). CONCLUSIONS: Postinfarction gene therapy aimed at suppressing TGF-beta signaling mitigates cardiac remodeling by affecting cardiac fibrosis and infarct tissue dynamics (apoptosis inhibition and infarct contraction). This suggests that such therapy may represent a new approach to the treatment of post-MI heart failure, applicable during the subacute stage.

Local overexpression of HB-EGF exacerbates remodeling following myocardial infarction by activating noncardiomyocytes.

Insulin-like growth factor (IGF), hepatocyte growth factor (HGF), and heparin-binding epidermal growth factor-like growth factor (HB-EGF) are cardiogenic and cardiohypertrophic growth factors. Although the therapeutic effects of IGF and HGF have been well demonstrated in injured hearts, it is uncertain whether natural upregulation of HB-EGF after myocardial infarction (MI) plays a beneficial or pathological role in the process of remodeling. To answer this question, we conducted adenoviral HB-EGF gene transduction in in vitro and in vivo injured heart models, allowing us to highlight and explore the HB-EGF-induced phenotypes. Overexpressed HB-EGF had no cytoprotective or additive death-inducible effect on Fas-induced apoptosis or oxidative stress injury in primary cultured mouse cardiomyocytes, although it significantly induced hypertrophy of cardiomyocytes and proliferation of cardiac fibroblasts. Locally overexpressed HB-EGF in the MI border area in rabbit hearts did not improve cardiac function or exhibit an angiogenic effect, and instead exacerbated remodeling at the subacute and chronic stages post-MI. Namely, it elevated the levels of apoptosis, fibrosis, and the accumulation of myofibroblasts and macrophages in the MI area, in addition to inducing left ventricular hypertrophy. Thus, upregulated HB-EGF plays a pathophysiological role in injured hearts in contrast to the therapeutic roles of IGF and HGF. These results imply that regulation of HB-EGF may be a therapeutic target for treating cardiac hypertrophy and fibrosis.

Critical roles for the Fas/Fas ligand system in postinfarction ventricular remodeling and heart failure.

In myocardial infarction (MI), granulation tissue cells disappear via apoptosis to complete a final scarring with scanty cells. Blockade of this apoptosis was reported to improve post-MI ventricular remodeling and heart failure. However, the molecular biological mechanisms for the apoptosis are unknown. Fas and Fas ligand were overexpressed in the granulation tissue at the subacute stage of MI (1 week after MI) in mice, where apoptosis frequently occurred. In mice lacking functioning Fas (lpr strain) and in those lacking Fas ligand (gld strain), apoptotic rate of granulation tissue cells was significantly fewer compared with that of genetically controlled mice, and post-MI ventricular remodeling and dysfunction were greatly attenuated. Mice were transfected with adenovirus encoding soluble Fas (sFas), a competitive inhibitor of Fas ligand, on the third day of MI. The treatment resulted in suppression of granulation tissue cell apoptosis and produced a thick, cell-rich infarct scar containing rich vessels and bundles of smooth muscle cells with a contractile phenotype at the chronic stage (4 weeks after MI). This accompanied not only alleviation of heart failure but also survival improvement. However, the sFas gene delivery during scar tissue phase was ineffective, suggesting that beneficial effects of the sFas gene therapy owes to inhibition of granulation tissue cell apoptosis. The Fas/Fas ligand interaction plays a critical role for granulation tissue cell apoptosis after MI. Blockade of this apoptosis by interfering with the Fas/Fas ligand interaction may become one of the therapeutic strategies against chronic heart failure after large MI.

Gene therapy eradicating distant disseminated micro-metastases by optimal cytokine expression in the primary lesion only: novel concepts for successful cytokine gene therapy.

The most serious problem in current gene therapy is that clinical applications have often led to unsatisfactory results. Here we show novel concepts and crucial factors that have been missing for successful cytokine gene therapy. A clinically-relevant mouse model of primary and micro-metastatic osteosarcoma was generated by subcutaneously and intravenously injecting murine osteosarcoma LM8 cells, in which adenoviral gene transduction efficiencies were extremely low; current therapies remain less effective for such disseminated micro-metastases. A single injection of adenoviral vector encoding interleukin-2 gene (Ad.IL-2) was given only into the established primary tumor. Notably, antitumoral immunity was successfully elicited by IL-2 secretion from connective tissues adjacent to the primary tumor, and this immunity not only suppressed primary tumor growth but also eradicated disseminated micro-metastases in distant organs. Most importantly, not only minimal side effects but also maximal therapeutic effects were exerted only in the case of injecting the optimal (i.e., not the highest) dose of Ad.IL-2, because spleen injuries caused by excessive levels of circulating IL-2 might diminish the therapeutic effect. Although the narrow range of the optimal therapeutic expression level of IL-2 may be crucial, it was feasibly determined by serum IL-2 levels. Thus, a crucial factor for successful cytokine gene therapy is not the high gene transduction efficiency in the tumor, which has been generally recommended, but the use of the optimal therapeutic expression level. In conclusion, just a single injection of Ad.IL-2 into a primary tumor lesion, which is feasible, not invasive and cost effective, is potently therapeutic for distant disseminated micro-metastases, as long as the optimal therapeutic level is monitored. These novel concepts, which contradict those of previous studies, warn researches about the possible problems with the ongoing clinical cytokine gene therapy.

Postinfarction treatment with an adenoviral vector expressing hepatocyte growth factor relieves chronic left ventricular remodeling and dysfunction in mice.

BACKGROUND: Hepatocyte growth factor (HGF) is implicated in tissue regeneration, angiogenesis, and antiapoptosis. However, its chronic effects are undetermined on postinfarction left ventricular (LV) remodeling and heart failure. METHODS AND RESULTS: In mice, on day 3 after myocardial infarction (MI), adenovirus encoding human HGF (Ad.CAG-HGF) was injected into the hindlimb muscles (n=13). As a control (n=15), LacZ gene was used. A persistent increase in plasma human HGF was confirmed in the treated mice: 1.0+/-0.2 ng/mL 4 weeks later. At 4 weeks after MI, the HGF-treated mice showed improved LV remodeling and dysfunction compared with controls, as indicated by the smaller LV cavity and heart/body weight ratio, greater % fractional shortening and LV +/-dP/dt, and lower LV end-diastolic pressure. The cardiomyocytes near MI, including the papillary muscles and trabeculae, were greatly hypertrophied in the treated mice. The old infarct size was similar between the groups, but the infarct wall was thicker in the treated mice, where the density of noncardiomyocyte cells, including vessels, was greater. Fibrosis of the ventricular wall was significantly reduced in them. Examination of 10-day-old MI revealed no proliferation or apoptosis but showed augmented expression of c-Met/HGF receptor in cardiomyocytes near MI, whereas a greater proliferating activity and smaller apoptotic rate of granulation tissue cells in the HGF-treated hearts was observed compared with controls. CONCLUSIONS: Postinfarction HGF gene therapy improved LV remodeling and dysfunction through hypertrophy of cardiomyocytes, infarct wall thickening, preservation of vessels, and antifibrosis. These findings imply a novel therapeutic approach against postinfarction heart failure.

An optimal therapeutic expression level is crucial for suicide gene therapy for hepatic metastatic cancer in mice.

The most serious problem in current gene therapy is discrepancies between experimental data and actual clinical outcomes, which may be due to insufficient analyses and/or inappropriate animal models. We have explored suicide gene therapy by using various clinically relevant animal models and doubt the clinical use of maximal suicide gene expression, which has been generally recommended. To explore this subject further, we studied what expression level of suicide gene and what promoter led to the maximal clinical benefit in the case of hepatic metastatic cancer in mice. Therapeutic and adverse side effects of 4 adenoviral vectors that express herpes simplex virus thymidine kinase (HSV-tk) under different promoters were scrupulously investigated in 2 mouse models of hepatic metastasis of gastric cancer that possess clinical characteristics. Surprisingly, increases in HSV-tk expression beyond a certain point, achieved by the Rous sarcoma virus long terminal repeat promoter, not only enhanced the adverse side effects of lethal hepatotoxicity and ganciclovir-independent cytotoxicity but also failed to further increase therapeutic potential. Moreover, the carcinoembryonic antigen (CEA) tumor-specific promoter, the therapeutic potential of which had been underestimated, was much more useful-even in the case of low CEA-producing cancer-than had been previously reported. In conclusion, the optimal therapeutic expression level of a suicide gene is a novel concept and a crucial factor for successful cancer gene therapy. The present results, which contradict those of previous studies, alert researchers about possible problems with ongoing and future clinical trials that lack this concept.