Treatment of MPS I mice with microencapsulated cells overexpressing IDUA: effect of the prednisolone administration

Clinical Development of Cell Therapies to Halt Lysosomal Storage Diseases: Results and Lessons Learned

Although cross-correction was discovered more than 50 years ago, and held the promise of drastically improving disease management, still no cure exists for lysosomal storage diseases (LSDs). Cell therapies hold the potential to halt disease progression: either a subset of autologous cells can be ex vivo/ in vivo transfected with the functional gene or allogenic wild type stem cells can be transplanted. However, majority of cell-based attempts have been ineffective, due to the difficulties in reversing neuronal symptomatology, in finding appropriate gene transfection approaches, in inducing immune tolerance, reducing the risk of graft versus host disease (GVHD) when allogenic cells are used and that of immune response when engineered viruses are administered, coupled with a limited secretion and uptake of some enzymes. In the last decade, due to advances in our understanding of lysosomal biology and mechanisms of cross-correction, coupled with progresses in gene therapy, ongoing pre-clinical and clinical investigations have remarkably increased. Even gene editing approaches are currently under clinical experimentation. This review proposes to critically discuss and compare trends and advances in cell-based and gene therapy for LSDs. Systemic gene delivery and transplantation of allogenic stem cells will be initially discussed, whereas proposed brain targeting methods will be then critically outlined.

Current and Emerging Therapies for Mucopolysaccharidoses

Mucopolysaccharidoses (MPSs) are caused by deficiencies of specific lysosomal enzymes that affect the degradation of mucopolysaccharides or glycosaminoglycans (GAGs). Enzyme replacement therapies are available for an increasing number of MPSs since more than 15 years. Together with hematopoietic stem cell transplantation, these enzyme therapies are currently the gold standard of causal treatment in MPS. Both treatments can improve symptoms and prognosis, but they do not cure these severe conditions. The limitations of intravenous enzyme replacement and cell therapy can be summarized as the development of immune reactions against the therapeutic molecules/cells and failure to restore enduring and sufficient drug exposures in all relevant tissues. Thus innovative approaches include small molecules and encapsulated cells that do not induce immune reactions, gene therapy approaches that aim for sustained enzyme expression, and new enzymes that are able to penetrate barriers to drug distribution like the blood-brain barrier. This chapter provides an update on the state of development of these new therapies and highlights current challenges.

Subcutaneous implantation of microencapsulated cells overexpressing α-L-iduronidase for mucopolysaccharidosis type I treatment

Mucopolysaccharidosis type I (MPS I) is caused by a deficiency of α-L-iduronidase (IDUA), resulting in accumulation of glycosaminoglycans (GAG) in lysosomes. Microencapsulation of recombinant cells is a promising gene/cell therapy approach that could overcome the limitations of the current available treatments. In the present study we produced alginate-poly-L-lysine-alginate (APA) microcapsules containing recombinant cells overexpressing IDUA, which were implanted in the subcutaneous space of MPS I mice in order to evaluate their potential effect as a treatment for this disease. APA microcapsules enclosing genetically modified Baby Hamster Kidney cells overexpressing IDUA were produced and implanted in the subcutaneous space of 4-month-old MPS I mice (Idua ^-/-). Treatment was performed using two cell concentrations: 8.3 × 10⁷ and 8.3 × 10⁶ cells/mL. Untreated MPS I and normal mice were used as controls. Microcapsules were retrieved and analyzed after treatment. Increased IDUA in the liver, kidney and heart was detected 24 h postimplantation. After 120 days, higher IDUA activity was detected in the liver, kidney and heart, in both groups, whereas GAG accumulation was reduced only in the high cell concentration group. Microcapsules analysis showed blood vessels around them, as well as inflammatory cells and a fibrotic layer. Microencapsulated cells were able to ameliorate some aspects of the disease, indicating their potential as a treatment. To achieve better performance of the microcapsules, improvements such as the modulation of inflammatory response are suggested.

Alginate-embedded HuH-7 cells increase MMP-9 and reduce OCLN expression in vitro

BACKGROUND

Hepatocellular carcinoma is a common cancer, ranking third in cancer-associated deaths. An important cause of cancer patients' mortality is metastasis. At the start of metastasis progression, there is an epithelial-mesenchymal transition, characterized by matrix degradation, junction reductions and vessels formation. HuH-7 is a cell line used in research as an in vitro model for hepatocellular carcinoma. It is known that two-dimensional growth reflects tumor characteristics poorly. In contrast, three-dimensional cultures provide a better approach to the study of tumorigenic potential. The purpose of this work was to mimic a three-dimensional environment in order to assess gene expression of some epithelial-mesenchymal transition and metastasis progression markers in HuH-7 cells and compare them with traditional two-dimensional culture model.

METHODS

HuH-7 cells were encapsulated in sodium alginate (three-dimensional model) to be compared with cells grown in two-dimensional flasks. After 4 days in culture, gene expression of Matrix metallopeptidase 9, Occludin, p65, Intercellular adhesion molecule 1 and Vascular endothelial growth factor A was analyzed by qPCR and cytoskeleton assessment was performed by rhodamine-phalloidin staining.

RESULTS

Differences were found in gene expression, with a high increment of Matrix metallopeptidase 9 and Occludin reduction. The cytoskeleton morphology also showed differences, with a cytoplasm restricted only near the nuclei in the three-dimensional model.

CONCLUSIONS

This work shows the effects of using sodium alginate capsules as a three-dimensional model to the study of HuH-7. Cells in this 3D system show key markers of epithelial-mesenchymal transition, such as Matrix metallopeptidase 9 overexpression and Occludin down-regulation.

Emerging drugs for the treatment of mucopolysaccharidoses

INTRODUCTION

Despite being reported for the first time almost one century ago, only in the last few decades effective have treatments become available for the mucopolysaccharidoses (MPSs), a group of 11 inherited metabolic diseases that affect lysosomal function. These diseases are progressive, usually severe, and, in a significant number of cases, involve cognitive impairment.

AREAS COVERED

This review will not cover established treatments such as bone marrow/hematopoietic stem cell transplantation and classic intravenous enzyme replacement therapy (ERT), whose long-term outcomes have already been published (MPS I, MPS II, and MPS VI), but it instead focuses on emerging therapies for MPSs. That includes intravenous ERT for MPS IVA and VII, intrathecal ERT, ERT with fusion proteins, substrate reduction therapy, gene therapy, and other novel approaches.

EXPERT OPINION

The available treatments have resulted in improvements for several disease manifestations, but they still do not represent a cure for these diseases; thus, it is important to develop alternative methods to approach the unmet needs (i.e. bone disease, heart valve disease, corneal opacity, and central nervous system (CNS) involvement). The work in progress with novel approaches makes us confident that in 2017, when MPS will commemorate 100 years of its first report, we will be much closer to an effective cure for these challenging conditions.

The relationship between the inflammatory response and cell adhesion on alginate-chitosan-alginate microcapsules after transplantation

Cell microencapsulation technology is a potential alternative therapy, but cell overgrowth and adhesion on the microcapsules after transplantation shortens their time of therapeutic efficacy. Inflammatory cells were the main cells that adhered to the microcapsules, so understanding the body's inflammatory processes would help to better identify the mechanisms of cell adhesion to the outer surface of the microcapsules. Our study measured the inflammatory cells and the cytokines and characterized the associated changes in the alginate-chitosan-alginate (ACA) microcapsules 1, 7, 14, and 28 days after implantation in the peritoneal cavity. Then the relationship between the inflammatory response and cell adhesion on the microcapsules was evaluated by multiple regression analysis. The results showed that the microcapsules did not evoke a systemic inflammatory response, but initiated a local inflammatory response in the peritoneal cavity. Furthermore, the correlation analysis showed that the level of cell adhesion on the microcapsules was related to the number of lymphocytes and macrophages, and the amount of IL-6, IL-10, and MCP-1 in the peritoneal cavity. Our results may provide a foundation for reducing the immune response to these microcapsules, prolonging graft survival and improving the efficacy of these treatments.

Multifunctional hydrogel-based scaffold for improving the functionality of encapsulated therapeutic cells and reducing inflammatory response

Since the introduction of cell immunoisolation as an alternative to protect transplanted cells from host immune attack, much effort has been made to develop this technology into a realistic clinical proposal. Several promising approaches have been investigated to resolve the biotechnological and biosafety challenges related to cell microencapsulation. Here, a multifunctional hydrogel-based scaffold consisting of cell-loaded alginate-poly-l-lysine-alginate (APA) microcapsules and dexamethasone (DXM)-loaded poly(lactic-co-glycolic) acid (PLGA) microspheres embedded in alginate hydrogel is developed and evaluated. Initially, the feasibility of using an alginate hydrogel for enclosing APA microcapsules was studied in a xenogeneic approach. In addition, the performance of the local release of DXM was addressed. The in vitro studies confirmed the correct adaptation of the enclosed cells to the scaffolds in terms of metabolic activity and viability. The posterior implantation of the hydrogel-based scaffolds containing cell-loaded microcapsules revealed that the hematocrit levels were maintained high and constant, and the pericapsular overgrowth was reduced in the DXM-treated rats for at least 2months. This multifunctional scaffold might have a synergistic effect: (1) providing a physical support for APA microcapsules, facilitating administration, ensuring retention and recuperation and preventing dissemination; and (2) reducing post-transplantation inflammation and foreign body reaction, thus prolonging the lifetime of the implant by the continuous and localized release of DXM.