Zuze Wu

HEPATOCYTE GROWTH FACTOR PLAYS A CRITICAL ROLE IN THE REGULATION OF CYTOKINE PRODUCTION AND INDUCTION OF ENDOTHELIAL PROGENITOR CELL MOBILIZATION: A PILOT GENE THERAPY STUDY IN PATIENTS WITH CORONARY HEART DISEASE

1 There is growing evidence of the beneficial effects of hepatocyte growth factor (HGF) in myocardial infarction, heart failure and occlusive peripheral arterial disease. The aim of the present study was to evaluate the effects of intracoronary administration of an adenovirus vector encoding the human HGF gene (Ad‐HGF) on serum levels of cytokines and mobilization of CD34+ and CD117+ cells in patients with coronary heart disease. 2 Twenty‐one patients with severe coronary artery disease were recruited to the study: 11 patients received both a stent and administration of Ad‐HGF; the remaining 10 patients received a stent alone and served as the control group. Blood samples were obtained from the femoral vein before and then 6 and 24 h, 3 and 6 days and 2 weeks after treatment for the isolation of serum and peripheral blood mononuclear cells. Intracoronary administration of Ad‐HGF in patients with coronary heart disease resulted in high levels of HGF gene expression, as well as its receptor c‐met, compared with the control group, as demonstrated by real‐time reverse transcription–polymerase chain reaction. In addition, serum levels of HGF, vascular endothelial growth factor, monocyte chemoattractant protein‐1 and interleukin (IL)‐10 were increased and serum levels of IL‐8 were decreased in patients administered Ad‐HGF compared with the control group. The percentage of CD34+ and CD117+ cells in the peripheral blood increased in patients administered Ad‐HGF. 3 In conclusion, HGF gene therapy may play an important role in the regulation of cytokines and the induction of endothelial progenitor cell mobilization in patients with coronary heart disease.

Notch signaling stimulates osteogenic differentiation of human bone marrow-derived mesenchymal stem cells

Notch signaling is one of the most important pathways mediating cell determination and differentiation. In this study, the roles of Notch signal in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) were investigated. The expression of Notchl, Jaggedl and DTX1 detected by reverse transcription polymerase chain reaction (RT-PCR) suggested that Notch signal might exhibit a physiological regulatory role in the differentiation of MSCs. Constitutive expression of the intracellular domain of Notchl (ICN), the active form of Notchl protein, can activate Notch signal in cells without ligands’ binding. hMSCs were isolated, expanded, and infected with retrovirus carrying green fluorescent protein (GFP) gene orICN. Overexpression of ICN in hMSCs resulted in enhanced osteogenic differentiation induced by dexamethasone (Dex), which was characterized by an increase of cellular alkaline phosphatase (ALP) activity and calcium deposition. These results indicate that Notch stimulates differentiation of MSCs into osteoblasts.

Catheter-Based Intramyocardial Delivery (NavX) of Adenovirus Achieves Safe and Accurate Gene Transfer in Pigs

Background Hepatocyte growth factor (HGF) is one of the major angiogenic factors being studied for the treatment of ischemic heart diseases. Our previous study demonstrated adenovirus-HGF was effective in myocardial ischemia models. The first clinical safety study showed a positive effect in patients with severe and diffused triple coronary disease. Methods 12 Pigs were randomized (1∶1) to receive HGF, which was administered as five injections into the infarcted myocardium, or saline (control group). The injections were guided by EnSite NavX left ventricular electroanatomical mapping. Results The catheter-based injections caused no pericardial effusion, malignant arrhythmia or death. During mapping and injection, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, serum creatinine and creatine kinase-MB levels have no significant increase as compared to those before and after the injection in HGF group(P>0.05). HGF group has high HGF expression with Western blot, less myocardial infarct sizes by electroanatomical mapping (HGF group versus after saline group, 5.28±0.55 cm2 versus 9.06±1.06 cm2, P<0.01), better cardiac function with Gated-Single Photon Emission Computed Tomography compared with those in saline group. Histological, strongly increased lectin–positive microvessels and microvessel density were found in the myocardial ischemic regions in HGF group. Conclusion Intramyocardial injection guided by NavX system provides a method of feasible and safe percutaneous gene transfer to myocardial infarct regions.

HGF percutaneous endocardial injection induces cardiomyocyte proliferation and rescues cardiac function in pigs.

Objective To investigate the effect of cardiomyocyte proliferation induced by human hepatocyte growth factor (HGF) in pigs with chronic myocardial infarction (CMI). Methods A steerable, deflectable 7F catheter incorporating a 27-guage needle was advanced percutaneously to the left ventricular myocardium of 18 pigs with CMI. Pigs were randomized (1:1:1) to receive adenoviral vector HGF (total dose, 1×1010 genome copies), which was administered as five injections into the infarcted myocardium (total, 1.0 mL), or saline, or Ad-null (control groups). Injections were guided by Ensite NavX left ventricular electroanatomical mapping. HGF and cyclin proteins were detected by western blot and immunoprecipitation analysis. Histological and immunohistochemical analysis determined proliferating cardiomyocytes. Myocardial perfusion and cardiac function were estimated by Gated-Single Photon Emission Computed Tomography (G-SPECT). Results Western blot analyses showed that HGF were predominantly expressed in the infarct core and border in the myocardium of the infarcted heart. G-SPECT analysis indicated that the HGF group had better cardiac function and myocardial perfusion four weeks after the injection of Ad-HGF than before the injection of Ad-HGF. After treatment there were more proliferating cardiomyocytes in the HGF group compared to either of the control groups. Furthermore, the HGF group myocardial samples expressed higher levels of p-Akt, cyclin A, cyclin E, cyclin D1, cdk2, cdk4 than those in the control groups. Conclusion The over-expression of HGF activates pro-survival pathways, induces cardiomyocyte proliferation, and improves the perfusion and function of the porcine CMI heart.

Cardiac-Specific Expression of the Hepatocyte Growth Factor (HGF) Under the Control of a TnIc Promoter Confers a Heart Protective Effect After Myocardial Infarction (MI)

OBJECTIVEnUncontrolled therapeutic gene expression and neovascularization in non-specific tissues has lowered the safety of gene therapy. The aim of the study was to identify a cardiac-specific promoter to control target gene expression in heart tissue in vitro and in vivo.nnnMETHODSnAdenovirus vectors containing the firefly luciferase or hepatocyte growth factor (HGF) genes under control of the Troponin I (TnIc) or Cytomegalievirus (CMV) promoters were transfected into cell lines or injected into the left ventricular wall of Sprague Dawley (SD) rats via thoracotomy. Myocardial infarction (MI) was induced immediately before direct injection. In vivo luciferase expression was assessed using a bioluminescence imaging system. Heart function was monitored via echocardiograph intermittently for eight weeks after injection.nnnRESULTSnThe constitutively active CMV promoter yielded luciferase expression throughout the body while luciferase expression driven by the TnIc promoter was largely restricted to the hypoxic heart. The CMV promoter was more efficient, yielding 100-1000 fold more light output than the TnIc promoter. Four weeks after injection, we observed a significant decline in the ejection fraction (EF) in saline and Ad-Null groups but a 17% increase in the Ad-CMV-HGF group. No change in EF was observed in the Ad-TnIc-HGF group.nnnCONCLUSIONSnThe adenovirus vector combined with the TnIc promoter largely restricts gene-targeted therapy in the hypoxic heart and prevents heart failure after myocardial infarction.

Safety and Efficacy of Adenovirus Carrying Hepatocyte Growth Factor Gene by Percutaneous Endocardial Injection for Treating Post-infarct Heart Failure: A Phase IIa Clinical Trial

OBJECTIVEnOur previous phase I clinical trial has confirmed the safety of Adenovirus carrying Hepatocyte Growth Factor gene (Ad-HGF) by intracoronary administration for treating severe coronary artery disease. This study was performed to evaluate the safety and efficacy of Ad-HGF by percutaneous endocardial injection for treating post-infarct heart failure.nnnMETHODSnA total of 30 patients (15 in the experimental group and 15 in the control group) with postinfarct heart failure who were not indicated to revascularization and had received the optimal standardized medication therapy were included in the study. Percutaneous endocardial Ad-HGF gene transfer was injected with a catheter-based intramyocardial delivery system in the experimental group. Safety parameters were measured and compared between baseline and follow-ups in the experimental group. The Mean Difference (MD) of efficacy parameters from baseline to 6-month follow-up was measured in both groups and compared with each other.nnnRESULTSnNo one suffered from serious adverse events in the experimental group during the 6-month follow-up. The experimental group revealed significant lower left ventricular end-diastolic dimension (LVDd) (68.5 vs. 65.8 MD: -2.69±1.08, P=0.03) and higher LVEF of both echocardiograph (35.2 vs. 39.3, MD: 4.05±0.86, P=0.0005) and single photon emission computed tomography (27.7 vs. 30.6, MD: 2.9±0.8, P=0.003) in the 6-month follow-up than that in the baseline, but the control group did not (P>0.05). Compared to the control group, the experimental group showed significant improvement ranges of lower LVDd (2.6 vs. -2.69, MD: -5.3±1.4, P=0.0009) and higher echocardiographic LVEF (-2 vs. 4.05, MD: 6.1±1.6, P=0.0008) from baseline to 6-month follow-up.nnnCONCLUSIONnPercutaneous endocardial administration of Ad-HGF is safe and potentially efficient in improving LVEF and lowering LVDd of patients with post-infarct heart failure.