A model of mucopolysaccharidosis type IIIB in pigs

Mucopolysaccharidosis type IIIB (MPS IIIB) is a rare genetic disorder caused by loss-of-function mutations in the NAGLU gene. Pigs are an ideal large animal model for human diseases; however, a porcine model of MPS IIIB has not been reported. We have previously generated a heterozygous NAGLU-deficient (NAGLU ^+/-) Large White boar via a transgenic approach. Here we characterized phenotypes of the F₁ offspring of this founder to establish a pig model for MPS IIIB. qRT-PCR revealed that the NAGLU expression level was significantly decreased in a variety of tissues in NAGLU ^+/- pigs. ELISA assays showed obvious deficiency of NAGLU and higher (P<0.05) glycosaminoglycan levels in multiple tissues from NAGLU ^+/- pigs. NAGLU ^+/- pigs grew at a significantly (P<0.05) slower rate than control animals (NAGLU ^+/+). Death, mostly sudden death, occurred at all ages in NAGLU ^+/- pigs, most of which died within two years. Necropsy findings included pleural adhesions, lung shrinkage and abnormalities in the pericardium and mild hepatomegaly in NAGLU ^+/- pigs. Notable pathological changes were observed in the sections of brain, liver, spleen and kidney from NAGLU ^+/- pigs. Brain atrophy, ventriculomegaly, cerebellar atrophy and abnormalities in the intracerebral capsule, parietal lobes and the thalamus were also evident in NAGLU ^+/- pigs. Together, NAGLU ^+/- pigs show typical symptoms of human MPS IIIB patients and thus represent a novel large animal model for the disease.This article has an associated First Person interview with the first author of the paper.

Neonatal umbilical cord blood transplantation halts skeletal disease progression in the murine model of MPS-I

Umbilical cord blood (UCB) is a promising source of stem cells to use in early haematopoietic stem cell transplantation (HSCT) approaches for several genetic diseases that can be diagnosed at birth. Mucopolysaccharidosis type I (MPS-I) is a progressive multi-system disorder caused by deficiency of lysosomal enzyme α-L-iduronidase, and patients treated with allogeneic HSCT at the onset have improved outcome, suggesting to administer such therapy as early as possible. Given that the best characterized MPS-I murine model is an immunocompetent mouse, we here developed a transplantation system based on murine UCB. With the final aim of testing the therapeutic efficacy of UCB in MPS-I mice transplanted at birth, we first defined the features of murine UCB cells and demonstrated that they are capable of multi-lineage haematopoietic repopulation of myeloablated adult mice similarly to bone marrow cells. We then assessed the effectiveness of murine UCB cells transplantation in busulfan-conditioned newborn MPS-I mice. Twenty weeks after treatment, iduronidase activity was increased in visceral organs of MPS-I animals, glycosaminoglycans storage was reduced, and skeletal phenotype was ameliorated. This study explores a potential therapy for MPS-I at a very early stage in life and represents a novel model to test UCB-based transplantation approaches for various diseases.

Endothelial and Astrocytic Support by Human Bone Marrow Stem Cell Grafts into Symptomatic ALS Mice towards Blood-Spinal Cord Barrier Repair

Vascular pathology, including blood-CNS barrier (B-CNS-B) damage via endothelial cell (EC) degeneration, is a recently recognized hallmark of Amyotrophic Lateral Sclerosis (ALS) pathogenesis. B-CNS-B repair may be a new therapeutic approach for ALS. This study aimed to determine effects of transplanted unmodified human bone marrow CD34+ (hBM34+) cells into symptomatic G93A mice towards blood-spinal cord barrier (BSCB) repair. Thirteen weeks old G93A mice intravenously received one of three different doses of hBM34+ cells. Cell-treated, media-treated, and control mice were euthanized at 17 weeks of age. Immunohistochemical (anti-human vWF, CD45, GFAP, and Iba-1) and motor neuron histological analyses were performed in cervical and lumbar spinal cords. EB levels in spinal cord parenchyma determined capillary permeability. Transplanted hBM34+ cells improved behavioral disease outcomes and enhanced motor neuron survival, mainly in high-cell-dose mice. Transplanted cells differentiated into ECs and engrafted within numerous capillaries. Reduced astrogliosis, microgliosis, and enhanced perivascular end-feet astrocytes were also determined in spinal cords, mostly in high-cell-dose mice. These mice also showed significantly decreased parenchymal EB levels. EC differentiation, capillary engraftment, reduced capillary permeability, and re-established perivascular end-feet astrocytes in symptomatic ALS mice may represent BSCB repair processes, supporting hBM34+ cell transplantation as a future therapeutic strategy for ALS patients.

Repeated Administrations of Human Umbilical Cord Blood Cells Improve Disease Outcomes in a Mouse Model of Sanfilippo Syndrome Type III B

Sanfilippo syndrome type III B (MPS III B) is an inherited disorder characterized by a deficiency of α- N-acetylglucosaminidase (Naglu) enzyme leading to accumulation of heparan sulfate in lysosomes and severe neurological deficits. We have previously shown that a single administration of human umbilical cord mononuclear cells (hUCB MNCs) into Naglu knockout mice decreased behavioral abnormalities and tissue pathology. In this study, we tested whether repeated doses of hUCB MNCs would be more beneficial than a single dose of cells. Naglu mice at 3 months of age were randomly assigned to either a Media-only group or one of three hUCB MNC treatment groups-single low dose (3 × 106 cells), single high dose (1.8 × 107 cells), or multiple doses (3 × 106 cells monthly for 6 months) delivered intravenously; cyclosporine was injected intraperitoneally to immune suppress the mice for the duration of the study. An additional control group of wild-type mice was also used. We measured anxiety in an open field test and cognition in an active avoidance test prior to treatment and then at monthly intervals for 6 months. hUCB MNCs restored normal anxiety-like behavior in these mice ( p< 0.001). The repeated cell administrations also restored hippocampal cytoarchitecture, protected the dendritic tree, decreased GM3 ganglioside accumulation, and decreased microglial activation, particularly in the hippocampus and cortex. These data suggest that the neuroprotective effect of hUCB MNCs can be enhanced by repeated cell administrations.

Intracerebroventricular transplantation of human bone marrow-derived multipotent progenitor cells in an immunodeficient mouse model of mucopolysaccharidosis type I (MPS-I)

Mucopolysaccharidosis type I (MPS-I; Hurler syndrome) is an inborn error of metabolism caused by lack of the functional lysosomal glycosaminoglycan (GAG)-degrading enzyme α-L-iduronidase (IDUA). Without treatment, the resulting GAG accumulation causes multisystem dysfunction and death within the first decade. Current treatments include allogeneic hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy. HSCT ameliorates clinical features and extends life but is not available to all patients, and inadequately corrects the most devastating features of the disease including mental retardation and skeletal deformities. Recent developments suggest that stem cells can be used to deliver needed enzymes to the central nervous system. To test this concept, we transplanted bone marrow-derived normal adult human MultiStem® cells into the cerebral lateral ventricles of immunodeficient MPS-I neonatal mice. Transplanted cells and human-specific DNA were detected in the hippocampal formation, striatum, and other areas of the central nervous system. Brain tissue assays revealed significant long-term decrease in GAG levels in the hippocampus and striatum. Sensorimotor testing 6 months after transplantation demonstrated significantly improved rotarod performance of transplanted mice in comparison to nontransplanted and sham-transplanted control animals. These results suggest that a single injection of MultiStem cells into the cerebral ventricles of neonatal MPS-I mice induces sustained reduction in GAG accumulation within the brain, and modest long-term improvement in sensorimotor function.

Functional multipotency of stem cells: a conceptual review of neurotrophic factor-based evidence and its role in translational research

We here propose an updated concept of stem cells (SCs), with an emphasis on neural stem cells (NSCs). The conventional view, which has touched principally on the essential property of lineage multipotency (e.g., the ability of NSCs to differentiate into all neural cells), should be broadened to include the emerging recognition of biofunctional multipotency of SCs to mediate systemic homeostasis, evidenced in NSCs in particular by the secretion of neurotrophic factors. Under this new conceptual context and taking the NSC as a leading example, one may begin to appreciate and seek the “logic” behind the wide range of molecular tactics the NSC appears to serve at successive developmental stages as it integrates into and prepares, modifies, and guides the surrounding CNS micro- and macro-environment towards the formation and self-maintenance of a functioning adult nervous system. We suggest that embracing this view of the “multipotency” of the SCs is pivotal for correctly, efficiently, and optimally exploiting stem cell biology for therapeutic applications, including reconstitution of a dysfunctional CNS.

The treatment of neurodegenerative disorders using umbilical cord blood and menstrual blood-derived stem cells

Stem cell transplantation is a potentially important means of treatment for a number of disorders. Two different stem cell populations of interest are mononuclear umbilical cord blood cells and menstrual blood-derived stem cells. These cells are relatively easy to obtain, appear to be pluripotent, and are immunologically immature. These cells, particularly umbilical cord blood cells, have been studied as either single or multiple injections in a number of animal models of neurodegenerative disorders with some degree of success, including stroke, Alzheimer's disease, amyotrophic lateral sclerosis, and Sanfilippo syndrome type B. Evidence of anti-inflammatory effects and secretion of specific cytokines and growth factors that promote cell survival, rather than cell replacement, have been detected in both transplanted cells.

Cell Therapy From Bench to Bedside Translation in CNS Neurorestoratology Era

Recent advances in cell biology, neural injury and repair, and the progress towards development of neurorestorative interventions are the basis for increased optimism. Based on the complexity of the processes of demyelination and remyelination, degeneration and regeneration, damage and repair, functional loss and recovery, it would be expected that effective therapeutic approaches will require a combination of strategies encompassing neuroplasticity, immunomodulation, neuroprotection, neurorepair, neuroreplacement, and neuromodulation. Cell-based restorative treatment has become a new trend, and increasing data worldwide have strongly proven that it has a pivotal therapeutic value in CNS disease. Moreover, functional neurorestoration has been achieved to a certain extent in the CNS clinically. Up to now, the cells successfully used in preclinical experiments and/or clinical trial/treatment include fetal/embryonic brain and spinal cord tissue, stem cells (embryonic stem cells, neural stem/progenitor cells, hematopoietic stem cells, adipose-derived adult stem/precursor cells, skin-derived precursor, induced pluripotent stem cells), glial cells (Schwann cells, oligodendrocyte, olfactory ensheathing cells, astrocytes, microglia, tanycytes), neuronal cells (various phenotypic neurons and Purkinje cells), mesenchymal stromal cells originating from bone marrow, umbilical cord, and umbilical cord blood, epithelial cells derived from the layer of retina and amnion, menstrual blood-derived stem cells, Sertoli cells, and active macrophages, etc. Proof-of-concept indicates that we have now entered a new era in neurorestoratology.