Nitric oxide signaling inhibits microglia proliferation by activation of protein kinase-G

Maksoud, Matthew J. E.; Tellios, Vasiliki; Yun, Xiang; Lu, Wei‐Yang

doi:10.1016/j.niox.2019.11.005

Cited by 14 publications

(7 citation statements)

References 59 publications

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“…We propose the mechanism for neuroinflammation and microglial activation in gch1deficient larvae is likely mediated via decreased NO-signalling due to limited BH4 availability. A NOdependent mechanism would be consistent with recent findings of increased microglial activation in an iNOS-/-mouse model; proliferation of microglia in the iNOS-/-mouse was repressed by application of a NO-donor, whereas inhibition of iNOS had the opposite effect (Maksoud et al, 2020). Basal NO signalling is sufficient to prevent microglial activation by preventing cell-cycle progression via a protein kinase G (PKG)-dependent mechanism.…”

supporting

confidence: 88%

GCH1 Deficiency Activates Brain Innate Immune Response and Impairs Tyrosine Hydroxylase Homeostasis

et al. 2021

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The Parkinson's disease (PD) risk gene GTP cyclohydrolase 1 (GCH1) catalyzes the ratelimiting step in tetrahydrobiopterin (BH4) synthesis, an essential cofactor in the synthesis of monoaminergic neurotransmitters. To investigate the mechanisms by which GCH1 deficiency may contribute to PD, we generated a loss of function zebrafish gch1 mutant (gch1 -/-), using CRISPR/Cas technology. gch1 -/zebrafish develop marked monoaminergic neurotransmitter deficiencies by 5 dpf, movement deficits by 8 dpf and lethality by 12 dpf.Tyrosine hydroxylase protein levels were markedly reduced without loss of ascending dopaminergic (DAergic) neurons. L-Dopa treatment of gch1 -/larvae improved survival without ameliorating the motor phenotype. RNAseq of gch1 -/larval brain tissue identified highly upregulated transcripts involved in innate immune response. Subsequent experiments provided morphological and functional evidence of microglial activation in gch1 -/-. The results of our study suggest that GCH1 deficiency may unmask early, subclinical parkinsonism and only indirectly contribute to neuronal cell death via immune-mediated mechanisms. Our work highlights the importance of functional validation for GWAS risk factors and further emphasises the important role of inflammation in the pathogenesis of PD.

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confidence: 88%

GCH1 Deficiency Activates Brain Innate Immune Response and Impairs Tyrosine Hydroxylase Homeostasis

et al. 2021

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“…Utilizing this improved method, we efficiently obtained microglia with a purity of up to 92.3%. Moreover, the proliferative potential of iMGs were maintained for 14 d, and the survival time was up to 28 d, both of which were significantly longer than those of the isolated primary microglia (Maksoud et al, 2020). Then, we co-cultured these cells with hROs in Transwell chambers and under mixed conditions to induce the differentiation toward retinal microglia.…”

Section: Discussionmentioning

confidence: 99%

Functional microglia derived from human pluripotent stem cells empower retinal organs

Gao

Zhang

Han

et al. 2022

Sci. China Life Sci.

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Microglia are known to play essential roles in the development, progression and treatment of diverse neurodegenerative diseases in the central nervous system, including the retina, brain and spinal cord. Recently, brain-induced microglia-like cells (iMGs) have been generated from human pluripotent stem cells (hPSCs); however, retinal microglia have yet to be developed in vitro. In this study, by mimicking in vivo microglial development, we established a simplified approach to differentiate hPSCs into high purity (>90%) iMGs. The iMGs express microglia-specific markers, release cytokines upon stimulation, and are capable of phagocytizing bacteria. When co-cultured with three-dimensional human retinal organoids (hROs), iMGs migrated into the hROs, tended to differentiate into resident retinal microglia, and simultaneously induced apoptosis in some neural cells. Notably, the resident iMGs in the hROs formed sparse web-like structures beneath the photoreceptor cell layer, resembling microglia's orientation in human retina. In conclusion, we developed a simplified and efficient method to generate microglia from human pluripotent stem cells, and we report the first derivation of retinaresident microglia in vitro, providing a new source of human retinal microglia for developmental and disease studies and regenerative therapeutics.

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“…Thirty minutes before fluorescent imaging, astrocyte cultures were pre‐treated with the following drug preparations— WT : 50 nM 7‐nitroindazole 7(N); for nNOS −/− : 250 μM S‐nitroso‐N‐acetylpenicillamine (SNAP); for both : 10 μM arginyl‐lysyl‐arginyl‐alanyl‐arginyl‐lysyl‐glutamic acid (PKG i ) (Maksoud et al, 2020 ), 1 μM 2‐Amino‐5,6,7,8‐tetrahydro‐4‐(4‐methoxyphenyl)‐7‐(naphthalen‐1‐yl)‐5‐oxo‐4 H ‐chromene‐3‐carbonitrile (UCPH‐101, selective EAAT1 inhibitor) (Liang et al, 2014 ), 1 μM SEA 0400 (NCX inhibitor) (Matsuda et al, 2001 ). Simultaneous Ca 2+ and Na + imaging was then performed using the EVOS FL Auto 2 system under ×20 magnification, with images documented every 10 s. Baseline Ca 2+ and Na + levels were recorded for at least 3 min before application of 100 μM d ‐aspartate to stimulate GLAST activity (Balderas et al, 2014 ).…”

Section: Methodsmentioning

confidence: 99%

“…Thirty minutes before fluorescent imaging, astrocyte cultures were pre-treated with the following drug preparations-WT: 50 nM 7nitroindazole 7(N); for nNOS À/À : 250 μM S-nitroso-N-acetylpenicillamine (SNAP); for both: 10 μM arginyl-lysyl-arginyl-alanyl-arginyl-lysylglutamic acid (PKG i ) (Maksoud et al, 2020), 1 μM 2-Amino-5,-6,7,8-tetrahydro-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-4Hchromene-3-carbonitrile (UCPH-101, selective EAAT1 inhibitor) (Liang et al, 2014), 1 μM SEA 0400 (NCX inhibitor) (Matsuda et al, 2001).…”

Section: Live Cell Calcium and Sodium Imagingmentioning

confidence: 99%

The expression and function of glutamate aspartate transporters in Bergmann glia are decreased in neuronal nitric oxide synthase‐knockout mice during postnatal development

Tellios

Maksoud

2022

Glia

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Bergmann glia (BG) predominantly use glutamate/aspartate transporters (GLAST) for glutamate uptake in the cerebellum. Recently, nitric oxide (NO) treatment has been shown to upregulate GLAST function and increase glutamate uptake in vitro. We previously discovered that neuronal nitric oxide synthase knockout (nNOS À/À ) mice displayed structural and functional neuronal abnormalities in the cerebellum during development, in addition to previously reported motor deficits. Although these developmental deficits have been identified in the nNOS À/À cerebellum, it is unknown whether BG morphology and GLAST expression are also affected in the absence of nNOS in vivo. This study is the first to characterize BG morphology and GLAST expression during development in nNOS À/À mice using immunohistochemistry and western blotting across postnatal development. Results showed that BG in nNOS À/À mice exhibited abnormal morphology and decreased GLAST expression compared with wildtype (WT) mice across postnatal development. Treating ex vivo WT cerebellar slices with the NOS inhibitor L-NAME decreased GLAST expression while treating nNOS À/À slices with the slow-release NO-donor NOC-18 increased GLAST expression when compared with their respective controls. In addition, treating primary BG isolated from WT mice with the selective nNOS inhibitor 7N decreased the membrane expression of GLAST and influx of Ca 2+ /Na + , while treating nNOS À/À BG with SNAP increased the membrane expression of GLAST and Ca 2+ /Na + influx. Moreover, the effects of SNAP on GLAST expression and Ca 2+ /Na + influx in nNOS À/À BG were significantly reduced by a PKG inhibitor. Together, these results reveal a novel role for nNOS/NO signaling in BG development, regulated by a PKG-mediated mechanism.

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Nitric oxide signaling inhibits microglia proliferation by activation of protein kinase-G

Cited by 14 publications

References 59 publications

GCH1 Deficiency Activates Brain Innate Immune Response and Impairs Tyrosine Hydroxylase Homeostasis

GCH1 Deficiency Activates Brain Innate Immune Response and Impairs Tyrosine Hydroxylase Homeostasis

Functional microglia derived from human pluripotent stem cells empower retinal organs

The expression and function of glutamate aspartate transporters in Bergmann glia are decreased in neuronal nitric oxide synthase‐knockout mice during postnatal development

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