Bystander effect on brain tissue of mesoangioblasts producing neurotrophins.

Neurotrophic factors (NTFs) are involved in the regulation of neuronal survival and function and, thus, may be used to treat neurological diseases associated with neuronal death. A major hurdle for their clinical application is the delivery mode. We describe here a new strategy based on the use of progenitor cells called mesoangioblasts (MABs). MABs can be isolated from postnatal mesoderm tissues and, because of a high adhesin-dependent migratory capacity, can reach perivascular targets especially in damaged areas. We generated genetically modified MABs producing nerve growth factor (MABs-NGF) or brain-derived neurotrophic factor (MABs-BDNF) and assessed their bystander effects in vitro using PC12 cells, primary cultures, and organotypic cultures of adult hippocampal slices. MABs-NGF-conditioned medium induced differentiation of PC12 cells, while MABs-BDNF-conditioned medium increased viability of cultured neurons and slices. Slices cultured with MABs-BDNF medium also better retained their morphology and functional connections, and all these effects were abolished by the TrkB kinase blocker K252a or the BDNF scavenger TrkB-IgG. Interestingly, the amount of BDNF released by MABs-BDNF produced greater effects than an identical amount of recombinant BDNF, suggesting that other NTFs produced by MABs synergize with BDNF. Thus, MABs can be an effective vehicle for NTF delivery, promoting differentiation, survival, and functionality of neurons. In summary, MABs hold distinct advantages over other currently evaluated approaches for NTF delivery in the CNS, including synergy of MAB-produced NTF with the neurotrophins. Since MABs may be capable of homing into damaged brain areas, they represent a conceptually novel, promising therapeutic approach to treat neurodegenerative diseases.

Localized overexpression of FGF-2 and BDNF in hippocampus reduces mossy fiber sprouting and spontaneous seizures up to 4 weeks after pilocarpine-induced status epilepticus.

PURPOSE: We have recently reported that viral vector-mediated supplementation of fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF) in a lesioned, epileptogenic rat hippocampus limits neuronal damage, favors neurogenesis, and reduces spontaneous recurrent seizures. To test if this treatment can also prevent hippocampal circuit reorganization, we examined here its effect on mossy fiber sprouting, the best studied form of axonal plasticity in epilepsy. METHODS: A herpes-based vector expressing FGF-2 and BDNF was injected into the rat hippocampus 3 days after an epileptogenic insult (pilocarpine-induced status epilepticus). Continuous video-electroencephalography (EEG) monitoring was initiated 7 days after status epilepticus, and animals were sacrificed at 28 days for analysis of cell loss (measured using NeuN immunofluorescence) and mossy fiber sprouting (measured using dynorphin A immunohistochemistry). KEY FINDINGS: The vector expressing FGF-2 and BDNF decreased both mossy fiber sprouting and the frequency and severity of spontaneous seizures. The effect on sprouting correlated strictly with the cell loss in the terminal fields of physiologic mossy fiber innervation (mossy cells in the dentate gyrus hilus and CA3 pyramidal neurons). SIGNIFICANCE: These data suggest that the supplementation of FGF-2 and BDNF in an epileptogenic hippocampus may prevent epileptogenesis by decreasing neuronal loss and mossy fiber sprouting, that is, reducing some forms of circuit reorganization.

Hippocampal FGF-2 and BDNF overexpression attenuates epileptogenesis-associated neuroinflammation and reduces spontaneous recurrent seizures.

Under certain experimental conditions, neurotrophic factors may reduce epileptogenesis. We have previously reported that local, intrahippocampal supplementation of fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF) increases neurogenesis, reduces neuronal loss, and reduces the occurrence of spontaneous seizures in a model of damage-associated epilepsy. Here, we asked if these possibly anti-epileptogenic effects might involve anti-inflammatory mechanisms. Thus, we used a Herpes-based vector to supplement FGF-2 and BDNF in rat hippocampus after pilocarpine-induced status epilepticus that established an epileptogenic lesion. This model causes intense neuroinflammation, especially in the phase that precedes the occurrence of spontaneous seizures. The supplementation of FGF-2 and BDNF attenuated various parameters of inflammation, including astrocytosis, microcytosis and IL-1ß expression. The effect appeared to be most prominent on IL-1ß, whose expression was almost completely prevented. Further studies will be needed to elucidate the molecular mechanism(s) for these effects, and for that on IL-1ß in particular. Nonetheless, the concept that neurotrophic factors affect neuroinflammation in vivo may be highly relevant for the understanding of the epileptogenic process.

The biocompatibility of materials used in printed circuit board technologies with respect to primary neuronal and K562 cells.

Printed circuit board (PCB) technology can be used for producing lab-on-a-chip (LOAC) devices. PCBs are characterized by low production costs and large-scale development, both essential elements in the frame of disposable applications. LOAC platforms have been employed not only for diagnostic and/or analytical purposes, but also for identification and isolation of eukaryotic cells, including cancer and stem cells. Accordingly, the compatibility of the employed materials with the biological system under analysis is critical for the development of LOAC devices to be proposed for efficient and safe cell isolation. In this study, we analyzed the in-vitro compatibility of a large set of materials and surface treatments used for LOAC development and evaluation with quasi-standard PCB processes. Biocompatibility was analyzed on hippocampal primary cells (a model of attached cell cultures), in comparison with the reference K562 cell line (a model of cells growing in suspension). We demonstrate here that some of the materials under study alter survival, organization, morphology and adhesion capacity of hippocampal cells, and inhibit growth and differentiation of K562 cells. Nonetheless, a subset of the materials tested did not negatively affect these functions, thus demonstrating that PCB technology, with some limitations, is suitable for the realization of LOAC devices well compatible at least with these preparations.