Phytoestrogen Agathisflavone Ameliorates Neuroinflammation-Induced by LPS and IL-1 beta and Protects Neurons in Cocultures of Glia/Neurons
BIOMOLECULES
Authors: Alves de Almeida, Monique Marylin; Souza, Cleide dos Santos; Dourado, Naiara Silva; da Silva, Alessandra Bispo; Ferreira, Rafael Short; David, Jorge Mauricio; David, Juceni Pereira; Dias Costa, Maria de Fatima; Amaral da Silva, Victor Diogenes; Butt, Arthur Morgan; Costa, Silvia Lima
Abstract
Inflammation and oxidative stress are common aspects of most neurodegenerative diseases in the central nervous system. In this context, microglia and astrocytes are central to mediating the balance between neuroprotective and neurodestructive mechanisms. Flavonoids have potent anti-inflammatory and antioxidant properties. Here, we have examined the anti-inflammatory and neuroprotective potential of the flavonoid agathisflavone (FAB), which is derived from the Brazilian plant Poincianella pyramidalis, in in vitro models of neuroinflammation. Cocultures of neurons/glial cells were exposed to lipopolysaccharide (LPS, 1 mu g/mL) or interleukin (IL)-1 beta (10 ng/mL) for 24 h and treated with FAB (0.1 and 1 mu M, 24 h). FAB displayed a significant neuroprotective effect, as measured by nitric oxide (NO) production, Fluoro-Jade B (FJ-B) staining, and immunocytochemistry (ICC) for the neuronal marker beta-tubulin and the cell death marker caspase-3, preserving neuronal soma and increasing neurite outgrowth. FAB significantly decreased the LPS-induced microglial proliferation, identified by ICC for Iba-1/bromodeoxyuridine (BrdU) and CD68 (microglia M1 profile marker). In contrast, FAB had no apparent effect on astrocytes, as determined by ICC for glial fibrillary acidic protein (GFAP). Furthermore, FAB protected against the cytodestructive and proinflammatory effects of IL-1 beta, a key cytokine that is released by activated microglia and astrocytes, and ICC showed that combined treatment of FAB with alpha and beta estrogen receptor antagonists did not affect NF-kappa B expression. In addition, qPCR analysis demonstrated that FAB decreased the expression of proinflammatory molecules TNF-alpha, IL-1 beta, and connexins CCL5 and CCL2, as well as increased the expression of the regulatory molecule IL-10. Together, these findings indicate that FAB has a significant neuroprotective and anti-inflammatory effect in vitro, which may be considered as an adjuvant for the treatment of neurodegenerative diseases.
Genetic and genomic alterations differentially dictate low-grade glioma growth through cancer stem cell-specific chemokine recruitment of T cells and microglia
NEURO-ONCOLOGY
Authors: Guo, Xiaofan; Pan, Yuan; Gutmann, David H.
Abstract
Background. One of the clinical hallmarks of low-grade gliomas (LGGs) arising in children with the neurofibromatosis type 1 (NF1) cancer predisposition syndrome is significant clinical variability with respect to tumor growth, associated neurologic deficits, and response to therapy. Numerous factors could contribute to this clinical heterogeneity, including the tumor cell of origin, the specific germline NF1 gene mutation, and the coexistence of additional genomic alterations. Since human specimens are rarely acquired, and have proven difficult to maintain in vitro or as xenografts in vivo, we have developed a series of Nf1 mutant optic glioma mouse strains representing each of these contributing factors. Methods. Optic glioma stem cells (o-GSCs) were generated from this collection of Nf1 genetically engineered mice, and analyzed for their intrinsic growth properties, as well as the production of chemokines that could differentially attract T cells and microglia. Results. The observed differences in Nf1 optic glioma growth are not the result of cell autonomous growth properties of o-GSCs, but rather the unique patterns of o-GSC chemokine expression, which differentially attract T cells and microglia. This immune profile collectively dictates the levels of chemokine C-C ligand 5 (Ccl5) expression, the key stromal factor that drives murine Nf1 optic glioma growth. Conclusions. These findings reveal that genetic and genomic alterations create murine LGG biological heterogeneity through the differential recruitment of T cells and microglia by o-GSC-produced chemokines, which ultimately determine the expression of stromal factors that drive tumor growth.