Widespread biochemical correction of murine mucopolysaccharidosis type VII pathology by liver hydrodynamic plasmid delivery

Hydrodynamic Delivery: Characteristics, Applications, and Technological Advances

The principle of hydrodynamic delivery was initially used to develop a method for the delivery of plasmids into mouse hepatocytes through tail vein injection and has been expanded for use in the delivery of various biologically active materials to cells in various organs in a variety of animal species through systemic or local injection, resulting in significant advances in new applications and technological development. The development of regional hydrodynamic delivery directly supports successful gene delivery in large animals, including humans. This review summarizes the fundamentals of hydrodynamic delivery and the progress that has been made in its application. Recent progress in this field offers tantalizing prospects for the development of a new generation of technologies for broader application of hydrodynamic delivery.

Diagnosis and Emerging Treatment Strategies for Mucopolysaccharidosis VII (Sly Syndrome)

Mucopolysaccharidosis VII (MPS VII, Sly syndrome) is an ultra-rare lysosomal disease caused by a deficiency of the enzyme β-glucuronidase (GUS). The diagnosis is suspected based on a range of symptoms that are common to many other MPS types, and it is confirmed through biochemical and molecular studies. Besides supportive treatment, current and emerging treatments include enzyme replacement therapy, hematopoietic stem cell transplantation, and gene therapy. This review summarizes the clinical manifestations, diagnosis, and emerging treatments for MPS VII.

C-Type Natriuretic Peptide Restores Growth Impairment Under Enzyme Replacement in Mice With Mucopolysaccharidosis VII

Growth impairment in mucopolysaccharidoses (MPSs) is an unresolved issue as it is resistant to enzyme replacement therapy (ERT) and growth hormone therapy. C-type natriuretic peptide (CNP) is a promising agent that has growth-promoting effects. Here we investigate the effects of CNP on growth impairment of MPSs using Gusbmps-2J mice, a model for MPS type VII, with combination therapy of CNP and ERT by hydrodynamic gene delivery. Although monotherapies were not sufficient to restore short statures of treated mice, combination therapy resulted in successful restoration. The synergistic effects of CNP and ERT were not only observed in skeletal growth but also in growth plates. ERT reduced cell swelling in the resting zone and increased cell number by accelerating proliferation or inhibiting apoptosis. CNP thickened the proliferative and hypertrophic zones. Regarding changes in the bone, ERT restored bone sclerosis through decreased bone formation and increased bone resorption, and CNP did not adversely affect this process. In addition, improvement of joint deformation by ERT was suggested by analyses of joint spaces and articular cartilage. CNP additively provided restoration of the short stature of MPS VII mice in combination with ERT, which improved abnormalities of growth plates and bone metabolism.

Improved molecular platform for the gene therapy of rare diseases by liver protein secretion

Many rare monogenic diseases are treated by protein replacement therapy, in which the missing protein is repetitively administered to the patient. However, in several cases, the missing protein is required at a high and sustained level, which renders protein therapy far from being adequate. As an alternative, a gene therapy treatment ensuring a sustained effectiveness would be particularly valuable. Liver is an optimal organ for the secretion and systemic distribution of a therapeutic transgene product. Cutting edge non-viral gene therapy tools were tested in order to produce a high and sustained level of therapeutic protein secretion by the liver using the hydrodynamic delivery technique. The use of S/MAR matrix attachment region provided a slight, however not statistically significant, increase in the expression of a reporter gene in the liver. We have selected the von Willebrand Factor (vWF) gene as a particularly challenging large gene (8.4 kb) for liver delivery and expression, and also because a high vWF blood concentration is required for disease correction. By using the optimized miniplasmid pFAR free of antibiotic resistance gene together with the Sleeping Beauty transposon and the hyperactive SB100X transposase, we have obtained a sustainable level of vWFblood secretion by the liver, at 65% of physiological level. Our results point to the general use of this plasmid platform using the liver as a protein factory to treat numerous rare disorders by gene therapy.

Translational Advances of Hydrofection by Hydrodynamic Injection

Hydrodynamic gene delivery has proven to be a safe and efficient procedure for gene transfer, able to mediate, in murine model, therapeutic levels of proteins encoded by the transfected gene. In different disease models and targeting distinct organs, it has been demonstrated to revert the pathologic symptoms and signs. The therapeutic potential of hydrofection led different groups to work on the clinical translation of the procedure. In order to prevent the hemodynamic side effects derived from the rapid injection of a large volume, the conditions had to be moderated to make them compatible with its use in mid-size animal models such as rat, hamster and rabbit and large animals as dog, pig and primates. Despite the different approaches performed to adapt the conditions of gene delivery, the results obtained in any of these mid-size and large animals have been poorer than those obtained in murine model. Among these different strategies to reduce the volume employed, the most effective one has been to exclude the vasculature of the target organ and inject the solution directly. This procedure has permitted, by catheterization and surgical procedures in large animals, achieving protein expression levels in tissue close to those achieved in gold standard models. These promising results and the possibility of employing these strategies to transfer gene constructs able to edit genes, such as CRISPR, have renewed the clinical interest of this procedure of gene transfer. In order to translate the hydrodynamic gene delivery to human use, it is demanding the standardization of the procedure conditions and the molecular parameters of evaluation in order to be able to compare the results and establish a homogeneous manner of expressing the data obtained, as ‘classic’ drugs.

Activity of daily living for Morquio A syndrome

The aim of this study was to evaluate the activity of daily living (ADL) and surgical interventions in patients with mucopolysaccharidosis IVA (MPS IVA). The factor(s) that affect ADL are age, clinical phenotypes, surgical interventions, therapeutic effect, and body mass index. The ADL questionnaire comprises three domains: "Movement," "Movement with cognition," and "Cognition." Each domain has four subcategories rated on a 5-point scale based on the level of assistance. The questionnaire was collected from 145 healthy controls and 82 patients with MPS IVA. The patient cohort consisted of 63 severe and 17 attenuated phenotypes (2 were undefined); 4 patients treated with hematopoietic stem cell transplantation (HSCT), 33 patients treated with enzyme replacement therapy (ERT) for more than a year, and 45 untreated patients. MPS IVA patients show a decline in ADL scores after 10years of age. Patients with a severe phenotype have a lower ADL score than healthy control subjects, and lower scores than patients with an attenuated phenotype in domains of "Movement" and "Movement with cognition." Patients, who underwent HSCT and were followed up for over 10years, had higher ADL scores and fewer surgical interventions than untreated patients. ADL scores for ERT patients (2.5years follow-up on average) were similar with the-age-matched controls below 10years of age, but declined in older patients. Surgical frequency was higher for severe phenotypic patients than attenuated ones. Surgical frequency for patients treated with ERT was not decreased compared to untreated patients. In conclusion, we have shown the utility of the proposed ADL questionnaire and frequency of surgical interventions in patients with MPS IVA to evaluate the clinical severity and therapeutic efficacy compared with age-matched controls.

Image-Guided Hydrodynamic Gene Delivery: Current Status and Future Directions

Hydrodynamics-based delivery has been used as an experimental tool to express transgene in small animals. This in vivo gene transfer method is useful for functional analysis of genetic elements, therapeutic effect of oligonucleotides, and cancer cells to establish the metastatic cancer animal model for experimental research. Recent progress in the development of image-guided procedure for hydrodynamics-based gene delivery in large animals directly supports the clinical applicability of this technique. This review summarizes the current status and recent progress in the development of hydrodynamics-based gene delivery and discusses the future directions for its clinical application.

Efficient expression of stabilized mRNA PEG-peptide polyplexes in liver

The expression efficiency in liver following hydrodynamic delivery of in vitro transcribed mRNA was improved 2000-fold using a codon-optimized mRNA luciferase construct with flanking 3' and 5' human β-globin untranslated regions (UTR mRNA) over an un-optimized mRNA without β-globin UTRs. Nanoparticle UTR mRNA polyplexes were formed using a novel polyacridine PEG-peptide, resulting in an additional 15-fold increase in expression efficiency in the liver. The combined increase in expression for UTR mRNA PEG-peptide polyplexes was 3500-fold over mRNA lacking UTRs and PEG-peptide. The expression efficiency of UTR mRNA polyplex was 10-fold greater than the expression from an equivalent 1 µg dose of pGL3. Maximal expression was maintained from 4 to 24 hours. Serum incubation established the unique ability of the polyacridine PEG-peptide to protect UTR mRNA polyplexes from RNase metabolism by binding to double stranded regions. UTR mRNA PEG-peptide polyplexes are efficient non-viral vectors that circumvent the need for nuclear uptake, representing an advancement toward the development of a targeted gene delivery system to transfect liver hepatocytes.

Activities of daily living in patients with Hunter syndrome: impact of enzyme replacement therapy and hematopoietic stem cell transplantation

The aim of this study was to assess the activities of daily living (ADL) in patients with Hunter syndrome (mucopolysaccharidosis II; MPS II) using a newly designed ADL questionnaire. We applied the questionnaire to evaluate clinical phenotypes and therapeutic efficacies of enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT). We also explored early signs and symptoms to make early diagnosis feasible. We devised a new ADL questionnaire with three domains: "movement," "movement with cognition," and "cognition." Each domain has four subcategories rated on a 5-point scale based on level of assistance. We also scored signs and symptoms unique to MPS by 12 subcategories (five points per category), providing 60 points in total. The questionnaire was first administered to 138 healthy Japanese controls (0.33-50 years), and successively, to 74 Japanese patients with Hunter syndrome (4-49 years). The patient cohort consisted of 51 severe and 23 attenuated phenotypes; 20 patients treated with HSCT, 23 patients treated early with ERT (≤8 years), 25 patients treated late with ERT (>8 years), and 4 untreated patients. Among 18 severe phenotypic patients treated by HSCT, 10 were designated as early HSCT (≤5years), while 8 were designated as late HSCT (>5years). Scores from patients with severe phenotypes were lower than controls and attenuated phenotypes in all categories. Among patients with severe phenotypes, there was a trend that HSCT provides a higher ADL score than early ERT, and there was a significant difference in ADL scores between late ERT and HSCT groups. Early ERT and early HSCT provided a higher score than late ERT and late HSCT, respectively. In conclusion, we have evaluated the feasibility of a new questionnaire in control population and patients with Hunter syndrome, leading to a novel evaluation method for clinical phenotypes and therapeutic efficacy. Early treatment with HSCT provides a better consequence in ADL of patients.

Hydrodynamic delivery

Hydrodynamic delivery (HD) is a broadly used procedure for DNA and RNA delivery in rodents, serving as a powerful tool for gene/protein drug discovery, gene function analysis, target validation, and identification of elements in regulating gene expression in vivo. HD involves a pressurized injection of a large volume of solution into a vasculature. New procedures are being developed to satisfy the need for a safe and efficient gene delivery in clinic. Here, we summarize the fundamentals of HD, its applications, and future perspectives for clinical use.

Current and potential therapeutic strategies for mucopolysaccharidoses

WHAT IS KNOWN AND OBJECTIVE

Mucopolysaccharidoses (MPSs) are a group of rare inherited metabolic diseases caused by genetic defects in the production of lysosomal enzymes. MPSs are clinically heterogeneous and are characterized by progressive deterioration in visceral, skeletal and neurological functions. This article aims to review the classification and pathophysiology of MPSs and discuss current therapies and new targeted agents under development.

METHODS

A Medline search through PubMed was performed for relevant articles and treatment guidelines on MPSs published in English for years 1970 to September of 2013 inclusive. The references listed in the identified articles, prescribing information of the drugs approved for the treatment of MPSs, as well as recent clinical trial information posted on Clinicaltrials.gov website, were reviewed.

RESULTS AND DISCUSSION

Until recently, supportive care was the only option available for the management of MPSs. In the early 2000s, enzyme replacement therapy (ERT) was approved by the United States Food and Drug Administration (FDA) for the treatment of MPS I, II and VI. Clinical trials of ERT showed substantial improvements in patients' somatic symptoms; however, no benefit was found in the neurological symptoms because the enzymes do not readily cross the blood-brain barrier (BBB). Haematopoietic stem cell transplantation (HSCT), another potentially curative treatment, is not routinely advocated in clinical practice due to its high risk profile and lack of evidence for efficacy, except in preserving cognition and prolonging survival in young patients with severe MPS I. In recent years, substrate reduction therapy (SRT) and gene therapy have been rapidly gaining greater recognition as potential therapeutic avenues.

WHAT IS NEW AND CONCLUSION

Enzyme replacement therapy (ERT) is effective for the treatment of many somatic symptoms, particularly walking ability and respiratory function, and remains the mainstay of MPS treatment. The usefulness of HSCT has not been established adequately for most MPSs. Although still under investigation, SRT and gene therapy are promising MPS treatments that may prevent the neurodegeneration not affected by ERT.

Therapies of mucopolysaccharidosis IVA (Morquio A syndrome)

INTRODUCTION

Morquio A syndrome (mucopolysaccharidosis type IVA, MPS IVA) is one of the lysosomal storage diseases and is caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Deficiency of this enzyme leads to accumulation of glycosaminoglycans (GAGs), keratan sulfate (KS) and chondroitin-6-sulfate (C6S). The majority of KS is produced by chondrocytes, and therefore, the undegraded substrates accumulate mainly in cells and extracelluar matrix (ECM) of cartilage. This has a direct impact on cartilage and bone development, leading to systemic skeletal dysplasia. In patients with Morquio A, cartilage cells are vacuolated, and this results in abnormal chondrogenesis and/or endochondral ossification.

AREAS COVERED

This article describes the advanced therapies of Morquio A, focused on enzyme replacement therapy (ERT) and gene therapy to deliver the drug to avascular bone lesions. ERT and gene therapies for other types of MPS are also discussed, which provide therapeutic efficacy to bone lesions.

EXPERT OPINION

ERT, gene therapy and hematopietic stem therapy are clinically and/or experimentally conducted. However, there is no effective curative therapy for bone lesion to date. One of the limitations for Morquio A therapy is that targeting avascular cartilage tissues remains an unmet challenge. ERT or gene therapy with bone-targeting system will improve the bone pathology and skeletal manifestations more efficiently.

TIMP-1 attenuates blood-brain barrier permeability in mice with acute liver failure

Blood-brain barrier (BBB) dysfunction in acute liver failure (ALF) results in increased BBB permeability that often precludes the patients from obtaining a life-saving liver transplantation. It remains controversial whether matrix metalloproteinase-9 (MMP-9) from the injured liver contributes to the deregulation of BBB function in ALF. We selectively upregulated a physiologic inhibitor of MMP-9 (TIMP-1) with a single intracerebroventricular injection of TIMP-1 cDNA plasmids at 48 and 72 hours, or with pegylated-TIMP-1 protein. Acute liver failure was induced with tumor necrosis factor-α and D-(+)-galactosamine in mice. Permeability of BBB was assessed with sodium fluorescein (NaF) extravasation. We found a significant increase in TIMP-1 within the central nervous system (CNS) after the administration of TIMP-1 cDNA plasmids and that increased TIMP-1 within the CNS resulted in an attenuation of BBB permeability, a reduction in activation of epidermal growth factor receptor and p38 mitogen-activated protein kinase signals, and a restoration of the tight junction protein occludin in mice with experimental ALF. Pegylated TIMP-1 provided similar protection against BBB permeability in mice with ALF. Our results provided a proof of principle that MMP-9 contributes to the BBB dysfunction in ALF and suggests a potential therapeutic role of TIMP-1 in ALF.

Gene therapy approaches for lysosomal storage disorders, a good model for the treatment of mendelian diseases

This review describes the different gene therapy technologies applied to approach lysosomal storage disorders, monogenic conditions, with known genetic and biochemical defects, for many of which animal models are available. Both viral and nonviral procedures are described, underlying the specific needs that the treatment of genetic disorders requires.

CONCLUSIONS

Lysosomal storage disorders represent a good model of study of gene therapeutic procedures that are, or could be, relevant to the treatment of several other mendelian diseases.

Liver production of sulfamidase reverses peripheral and ameliorates CNS pathology in mucopolysaccharidosis IIIA mice

Mucopolysaccharidosis type IIIA (MPSIIIA) is an inherited lysosomal storage disease caused by deficiency of sulfamidase, resulting in accumulation of the glycosaminoglycan (GAG) heparan sulfate. It is characterized by severe progressive neurodegeneration, together with somatic alterations, which lead to death during adolescence. Here, we tested the ability of adeno-associated virus (AAV) vector-mediated genetic modification of either skeletal muscle or liver to revert the already established disease phenotype of 2-month-old MPSIIIA males and females. Intramuscular administration of AAV-Sulfamidase failed to achieve significant therapeutic benefit in either gender. In contrast, AAV8-mediated liver-directed gene transfer achieved high and sustained levels of circulating active sulfamidase, which reached normal levels in females and was fourfold higher in males, and completely corrected lysosomal GAG accumulation in most somatic tissues. Remarkably, a 50% reduction of GAG accumulation was achieved throughout the entire brain of males, which correlated with a partial improvement of the pathology of cerebellum and cortex. Liver-directed gene transfer expanded the lifespan of MPSIIIA males, underscoring the importance of reaching supraphysiological plasma levels of enzyme for maximal therapeutic benefit. These results show how liver-directed gene transfer can reverse somatic and ameliorate neurological pathology in MPSIIIA.

Cell microencapsulation: a potential tool for the treatment of neuronopathic lysosomal storage diseases

Lysosomal storage disorders (LSD) are monogenic diseases caused by the deficiency of different lysosomal enzymes that degrade complex substrates such as glycosaminoglycans, sphingolipids, and others. As a consequence there is multisystemic storage of these substrates. Most treatments for these disorders are based in the fact that most of these enzymes are soluble and can be internalized by adjacent cells via mannose-6-phosphate receptor. In that sense, these disorders are good candidates to be treated by somatic gene therapy based on cell microencapsulation. Here, we review the existing data about this approach focused on the LSD treatments, the advantages and limitations faced by these studies.

Storage correction in cells of patients suffering from mucopolysaccharidoses types IIIA and VII after treatment with genistein and other isoflavones

Mucopolysaccharidoses are autosomal and recessive lysosomal storage disorders caused by the deficiency of a lysosomal enzyme involved in glycosaminoglycan catabolism. The Sanfilippo type A disease (MPS III A) results from sulfamidase deficiency, which leads to accumulation of heparan sulfate, whereas Sly disease (MPS VII) results from beta-glucuronidase deficiency, leading to accumulation of heparan, dermatan, and chondroitin sulfates. These syndromes are characterized by severe central nervous system degeneration, resulting in progressive mental retardation, and fatality occurs in severely affected children. To date, no effective treatment is available except for bone marrow transplantation in specific cases. Recently, the use of genistein, an isoflavone that inhibits glycosaminoglycans synthesis, has been tested as substrate reduction therapy for neuronopathic forms of these diseases.We tested five natural analogs to genistein in human fibroblasts from both Sanfilippo A and Sly patients. Four molecules were as efficient as genistein in decreasing glycosaminoglycan accumulation. Moreover, a combination of several isoflavones was more efficient than one single isoflavone, suggesting a synergistic effect. These preliminary data may offer new perspectives for treating Sly and Sanfilippo A diseases and could be relevant to other neurological forms of mucopolysaccharidoses.