RNAi-mediated knockdown of HMG CoA reductase enhances gene expression from physiologically regulated low-density lipoprotein receptor therapeutic vectors in vivo

The development of novel strategies to enhance gene expression from therapeutic vectors may prove advantageous for complementation gene therapy. This applies to therapeutic expression of the low-density lipoprotein receptor (LDLR) gene to treat familial hypercholesterolaemia (FH), where appropriate gene regulation could enhance therapeutic effect. We have previously reported that LDLR genomic DNA expression vectors can be regulated in vivo by pravastatin. In the current study, we investigated whether targeted knockdown of the mevalonate pathway in conjunction with LDLR delivery would lead to enhanced LDLR transgene expression and improved phenotype recovery. We demonstrated here that knockdown of HMG CoA reductase (HMGCR) by up to 70% using small interfering RNAs (siRNAs) led to a significant increase in binding and internalisation of LDL particles in vitro in mouse and human cells. In vivo co-injection of LDLR promoter luciferase expression plasmids with siRNAs or microRNA (miRNA) expression vectors targeting mouse Hmgcr led to at least a 10-fold increase in luciferase expression. Injection of Ldlr(-/-) mice with pLDLR-LDLR expression plasmids led to a significant reduction in plasmid LDL cholesterol, which was further enhanced by co-injection with miRNA expression vectors targeted to mouse Hmgcr. Our data suggest that targeted knockdown of HMGCR may enhance gene therapy outcomes for FH.     

Strategy of surgical treatment for ischemic heart disease

The efficacy of regenerative cell therapy as strategy of cardiac functional recovery in patients with end-stage heart failure has been recently reported, and clinical applications of autologous skeletal myoblast cell transplantation has been already started in Europe and U.S. We developed cell-sheet technology with a temperature-responsive culture dish, which enabled cell-to-cell junction to retain, and started a clinical study of cardiac regenerative therapy using autologous skeletal myoblast cell sheet implantation.     

Herpes simplex virus-based vectors for the treatment of cancer and neurodegenerative disease

Vectors based on herpes simplex virus (HSV) are being developed for use in human neurodegenerative diseases and cancer. In neurodegenerative disease, this involves the use of highly disabled, non-replicating HSV vectors engineered to carry a therapeutic gene. In contrast, the use of HSV vectors in cancer involves partially disabled viruses that can replicate in dividing cells but not in non-dividing cells and therefore have an oncolytic effect. Both these approaches have produced promising results in cell culture and animal models. Moreover, phase I clinical trials have demonstrated the safety of HSV vectors and their possible efficacy in otherwise untreatable cancers.     

缺血性脑血管病治疗的点滴体会

缺血性脑血管病是当今侵袭中、老年人群的常见病、多发病,呈现愈来愈多的趋势。该病的反复性、致残性相当高,探讨它的预防和治疗势在必行。本人在临床工作中积累了点滴体会。现总结如下:病例1.李某,女,62岁,农民。以“言语不清,右侧肢体瘫痪1小时余”入院,既往有2型糖尿病史。PE:T:36.4℃;P:75次/min;R:16次/min;BP:160/90mmHg。意识清楚,精神差,形体肥胖,言语不清,抬入病房,双瞳孔等大等圆,直径3.0mm,对光反应灵敏,右侧鼻唇沟变浅,伸舌右偏。心肺(-),腹部膨隆、柔软,肝脾(-)。左侧肢体无功能障碍,右侧上肢肌力和右手握力均为零级,右下…     

Potential of AAV vectors in the treatment of metabolic disease

Inborn errors of metabolism are collectively common, frequently severe and in many instances difficult or impossible to treat. Accordingly, there is a compelling need to explore novel therapeutic modalities, including gene therapy, and examine multiple phenotypes where the risks of experimental therapy are outweighed by potential benefits to trial participants. Among available gene delivery systems recombinant AAV shows special promise for the treatment of metabolic disease given the unprecedented efficiencies achieved in transducing key target tissues, such as liver and muscle, in small animal models. To date over 30 metabolic disease phenotypes have been investigated in small animal studies with complete phenotype correction being achieved in a substantial proportion. Achieving adequately widespread transduction within the central nervous system, however, remains a major challenge, and will be critical to realization of the therapeutic potential of gene therapy for many of the most clinically troubling metabolic disease phenotypes. Despite the relatively low immunogenicity of AAV vectors, immune responses are also emerging as a factor requiring special attention as efforts accelerate toward human clinical translation. Four metabolic disease phenotypes have reached phase I or I/II trials with one, targeting lipoprotein lipase deficiency, showing exciting early evidence of efficacy.     

Antiarrhythmic drugs for ischemic heart disease.

Therapy with antiarrhythmic drugs may offer the best immediate hope for reducing the large number of deaths due to arrhythmias among patients with ischemic heart disease (IHD). For the prevention of sudden death from ventricular fibrillation, chronic use of these drugs is reasonable in high-risk ambulatory IHD patients, in any patient in whom acute myocardial infarction (MI) is suspected, and in some patients hospitalized for acute MI. However, the effectiveness and possible risks of administering antiarrhythmic drugs in these settings remain essentially unknown. The selection of IHD patients who will benefit most from prophylactic antiarrhythmic drug therapy, the best times for starting and stopping this therapy, and the choice of drug cannot yet be guided by controlled clinical experience. Carefully controlled prospective studies of the beneficial and untoward effects of different drugs in IHD patients are urgently required to provide better guidelines for the clinical use of these potentially life-saving drugs.     

Plasma replacement in the treatment of ischemic heart disease

AIM: To investigate whether plasma replacement (PR) can raise efficiency of drug therapy of ischemic heart disease (IHD). MATERIAL AND METHODS: A 30-60% replacement of circulating plasma for salt or dextran using PF-05 unit has been performed in 324 patients 35-79 years of age with recurrent myocardial infarction and angina pectoris. A total of 520 PR procedures were performed. Biochemical, acid-base, coagulative, viscosity, microcirculatory blood parameters were taken, ECG and stress tests were made. RESULTS: PR resulted in a significant reduction in packed cell volume, total protein, fibrinogen, low density lipoproteins, total cholesterol and led to diminution of blood viscosity, acceleration of capillary blood flow, improvement of O2/CO2. Lowering of fibrinogen levels, number of platelets and their aggregation, enhancement of fibrinolytic blood activity created conditions for moderate controlled hypocoagulation. As shown by stress tests, two weeks after PR 60% of anginal patients of functional class IV can be transferred to class III. CONCLUSION: Because PR is beneficial by many parameters, it lessens the requirement in pharmacological support of patients with complicated IHD.     

Metabolic therapy for the treatment of ischemic heart disease: reality and expectations

Ischemic heart disease is a major cause of morbidity and mortality in the world. Most of the existing therapeutic strategies used to treat ischemic heart disease aim at either increasing the oxygen supply to the heart (thrombolysis, revascularization, angiotensin converting enzyme inhibition and antiplatelet therapy) or decreasing the oxygen demand of the heart (beta-blockers and nitrates). Despite the fact that a compromised energy supply to the heart muscle is central to the pathology of ischemic heart disease, therapeutic approaches that focus on altering cardiac energy metabolism have not seen major clinical use. Therapeutic strategies in which the efficiency of oxygen utilization by the heart is enhanced could theoretically benefit the ischemic heart, and could have an additive benefit to existing therapeutic strategies. The energy supply for the heart (in the form of ATP) is normally provided by the balanced metabolism of both fatty acids (major part) and carbohydrates (minor part) oxidation. During reperfusion, this balance is broken by the dramatic enhancement of fatty acid oxidation and attenuation of carbohydrate oxidation, which results in intracellular H(+) accumulation and Ca(2+) overload. This article reviews the alterations in cardiac energy metabolism that occur in the ischemic heart, and discusses the existing and proposed pharmacologic therapies to optimize the balance of fatty acids and carbohydrate oxidation for the treatment of ischemic heart diseases.     

Metabolic therapy for the treatment of ischemic heart disease: reality and expectations

Ischemic heart disease is a major cause of morbidity and mortality in the world. Most of the existing therapeutic strategies used to treat ischemic heart disease aim at either increasing the oxygen supply to the heart (thrombolysis, revascularization, angiotensin converting enzyme inhibition and antiplatelet therapy) or decreasing the oxygen demand of the heart (β-blockers and nitrates). Despite the fact that a compromised energy supply to the heart muscle is central to the pathology of ischemic heart disease, therapeutic approaches that focus on altering cardiac energy metabolism have not seen major clinical use. Therapeutic strategies in which the efficiency of oxygen utilization by the heart is enhanced could theoretically benefit the ischemic heart, and could have an additive benefit to existing therapeutic strategies. The energy supply for the heart (in the form of ATP) is normally provided by the balanced metabolism of both fatty acids (major part) and carbohydrates (minor part) oxidation. During reperfusion, this balance is broken by the dramatic enhancement of fatty acid oxidation and attenuation of carbohydrate oxidation, which results in intracellular H⁺ accumulation and Ca²⁺ overload. This article reviews the alterations in cardiac energy metabolism that occur in the ischemic heart, and discusses the existing and proposed pharmacologic therapies to optimize the balance of fatty acids and carbohydrate oxidation for the treatment of ischemic heart diseases.     

Novel application of lentiviral vectors towards treatment of graft-versus-host disease

Allogeneic transplantation of hematopoietic stem cells and lymphocytes is a curative treatment for malignant and non-malignant disease. However, the primary complication limiting the safety of transplantation is graft-versus-host disease (GvHD), which is mediated by donor T cells. Strategies for pre- and post-transplant manipulation of graft cells are not yet optimal for balancing GvHD severity with beneficial Graft-versus-Leukemia (GvL) effects. Emerging cell fate control gene therapy (CFCGT)-based strategies, such as ‘suicide’ gene therapy for donor T cell regulation, can supplement existing transplantation approaches by providing a safety element to reduce GvHD. Past uses of CFCGT in the clinic have provided proof-of-principle that GvHD can be controlled by such a strategy. However, there exists a need for improved transgene delivery and suicide control systems. Recently, lentiviral vectors (LVs) have emerged as effective gene delivery vehicles for the clinic. Combining lentiviral gene delivery with newer generations of ‘suicide’ systems that possess improved enzyme/prodrug specificities, activities, and reduced immunogenicity, could provide the necessary degree of control required to more successfully manage GvHD. Improving the safety of transplantation through successful CFCGT will serve to expand the potential donor pool and the spectrum of disorders that can be treated by this therapeutic schema.