Search

Abstract Machado-Joseph disease (MJD) is a neurodegenerative disorder characterized by widespread neuronal death affecting the cerebellum. Cell therapy can trigger neuronal replacement and neuroprotection through bystander effects providing a therapeutic option for neurodegenerative diseases. Here, human control (CNT) and MJD iPSC-derived neuroepithelial stem cells (NESC) were established and tested for their therapeutic potential. Cells’ neuroectodermal phenotype was demonstrated. Brain organoids obtained from the Control NESC showed higher mRNA levels of genes related to stem cells' bystander effects, such as BDNF, NEUROD1, and NOTCH1, as compared with organoids produced from MJD NESC, suggesting that Control NESC have a higher therapeutic potential. Graft-derived glia and neurons, such as cells positive for markers of cerebellar neurons, were detected six months after NESC transplantation in mice cerebella. The graft-derived neurons established excitatory and inhibitory synapses in the host cerebella, although CNT neurons exhibited higher excitatory synapse numbers compared with MJD neurons. Cell grafts, mainly CNT NESC, sustained the bystander effects through modulation of inflammatory interleukins (IL1B and IL10), neurotrophic factors (NGF), and neurogenesis-related proteins (Msi1 and NeuroD1), for six months in the mice cerebella. Altogether this study demonstrates the long-lasting therapeutic potential of human iPSC-derived NESC in the cerebellum.

Abstract The establishment of robust human brain organoids to model cerebellar diseases is essential to study new therapeutic strategies for cerebellum-associated disorders. Machado-Joseph disease (MJD) is a cerebellar hereditary neurodegenerative disease, without therapeutic options able to prevent the disease progression. In the present work, control and MJD induced-pluripotent stem cells were used to establish human brain organoids. These organoids were characterized regarding brain development, cell type composition, and MJD-associated neuropathology markers, to evaluate their value for cerebellar diseases modeling. Our data indicate that the organoids recapitulated, to some extent, aspects of brain development, such as astroglia emerging after neurons and the presence of ventricular-like zones surrounded by glia and neurons that are found only in primate brains. Moreover, the brain organoids presented markers of neural progenitors proliferation, neuronal differentiation, inhibitory and excitatory synapses, and firing neurons. The established brain organoids also exhibited markers of cerebellar neurons progenitors and mature cerebellar neurons. Finally, MJD brain organoids showed higher ventricular-like zone numbers, an indication of lower maturation, and an increased number of ataxin-3-positive aggregates, compared with control organoids. Altogether, our data indicate that the established organoids recapitulate important characteristics of human brain development and exhibit cerebellar features, constituting a resourceful tool for testing therapeutic approaches for cerebellar diseases.

Brain regenerative strategies through the transplantation of stem cells hold the potential to promote functional rescue of brain lesions caused either by trauma or neurodegenerative diseases. Most of the positive modulations fostered by stem cells are fueled by bystander effects, namely increase of neurotrophic factors levels and reduction of neuroinflammation. Nevertheless, the ultimate goal of cell therapies is to promote cell replacement. Therefore, the ability of stem cells to migrate and differentiate into neurons that later become integrated into the host neuronal network replacing the lost neurons has also been largely explored. However, as most of the preclinical studies demonstrate, there is a small functional integration of graft-derived neurons into host neuronal circuits. Thus, it is mandatory to better study the whole brain cell therapy approach in order to understand what should be better comprehended concerning graft-derived neuronal and glial cells migration and integration before we can expect these therapies to be ready as a viable solution for brain disorder treatment. Therefore, this review discusses the positive mechanisms triggered by cell transplantation into the brain, the limitations of adult brain plasticity that might interfere with the neuroregeneration process, as well as some strategies tested to overcome some of these limitations. It also considers the efforts that have been made by the regulatory authorities to lead to better standardization of preclinical and clinical studies in this field in order to reduce the heterogeneity of the obtained results.

The present work aimed at the development and application of a lipid-based nanocarrier for targeted delivery of nucleic acids to glioblastoma (GBM). For this purpose, chlorotoxin (CTX), a peptide reported to bind selectively to glioma cells while showing no affinity for non-neoplastic cells, was covalently coupled to liposomes encapsulating antisense oligonucleotides (asOs) or small interfering RNAs (siRNAs). The resulting targeted nanoparticles, designated CTX-coupled stable nucleic acid lipid particles (SNALPs), exhibited excellent features for in vivo application, namely small size (