Extracellular Lactate Dehydrogenase A Release From Damaged Neurons Drives Central Nervous System Angiogenesis.

Angiogenesis, a prominent feature of pathology, is known to be guided by factors secreted by living cells around a lesion. Although many cells are disrupted in a response to injury, the relevance of degenerating cells in pathological angiogenesis is unclear. Here, we show that the release of lactate dehydrogenase A (LDHA) from degenerating neurons drives central nervous system (CNS) angiogenesis. Silencing neuronal LDHA expression suppressed angiogenesis around experimental autoimmune encephalomyelitis (EAE)- and controlled cortical impact-induced lesions. Extracellular LDHA-mediated angiogenesis was dependent on surface vimentin expression and vascular endothelial growth factor receptor (VEGFR) phosphorylation in vascular endothelial cells. Silencing vimentin expression in vascular endothelial cells prevented angiogenesis around EAE lesions and improved survival in a mouse model of glioblastoma. These results elucidate novel mechanisms that may mediate pathologic angiogenesis and identify a potential molecular target for the treatment of CNS diseases involving angiogenesis.

Immunocytochemistry and fluorescence imaging efficiently identify individual neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures.

BACKGROUND: CRISPR/Cas9 system is a powerful method to investigate the role of genes by introducing a mutation selectively and efficiently to specific genome positions in cell and animal lines. However, in primary neuron cultures, this method is affected by the issue that the effectiveness of CRISPR/Cas9 is different in each neuron. Here, we report an easy, quick and reliable method to identify mutants induced by the CRISPR/Cas9 system at a single neuron level, using immunocytochemistry (ICC) and fluorescence imaging. RESULTS: Dissociated cortical cells were transfected with CRISPR/Cas9 plasmids targeting the transcription factor cAMP-response element binding protein (CREB). Fluorescence ICC with CREB antibody and quantitative analysis of fluorescence intensity demonstrated that CREB expression disappeared in a fraction of the transfected neurons. The downstream FOS expression was also decreased in accordance with suppressed CREB expression. Moreover, dendritic arborization was decreased in the transfected neurons which lacked CREB immunoreactivity. CONCLUSIONS: Detection of protein expression is efficient to identify individual postmitotic neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures. The present method composed of CRISPR/Cas9 system, ICC and fluorescence imaging is applicable to study the function of various genes at a single-neuron level.