ABSTRACT
Objective: To investigate the effects of Gastrodiae rhizoma, a dried root of Gastrodia elata Blume, on proliferation and differentiation of human NSCs derived from embryonic stem cells. Methods: A 70% ethanol extract of Gastrodiae rhizoma (EEGR) was estimated with 4-hydroxybenzyl alcohol as a representative constituent by HPLC. Results: MTT assay showed that the treatment with EEGR increased the viability of NSCs in growth media. Compared to control, EEGR increased the number of dendrites and denritic spines extended from a differentiated NSC. Whereas EEGR decreased the mRNA expression of Nestin, it increased that of Tuj1 and MAP2 in NSCs grown in differentiation media. Immunocytochemical analysis using confocal microscopy also revealed the increased expression of MAP2 in dendrites of EEGR-treated NSCs. Furthermore, EEGR decreased mRNA expression of Sox2 in NSCs grown even in growth media. Conclusions: In conclusion, our study demonstrates for the first time that EEGR induced proliferation and neuronal differentiation of NSCs, suggesting its potential benefits on NSC-based therapies and neuroregeneration in various neurodegenerative diseases and brain injuries.
ABSTRACT
OBJECTIVE@#To investigate the effects of Gastrodiae rhizoma, a dried root of Gastrodia elata Blume, on proliferation and differentiation of human NSCs derived from embryonic stem cells.@*METHODS@#A 70% ethanol extract of Gastrodiae rhizoma (EEGR) was estimated with 4-hydroxybenzyl alcohol as a representative constituent by HPLC.@*RESULTS@#MTT assay showed that the treatment with EEGR increased the viability of NSCs in growth media. Compared to control, EEGR increased the number of dendrites and denritic spines extended from a differentiated NSC. Whereas EEGR decreased the mRNA expression of Nestin, it increased that of Tuj1 and MAP2 in NSCs grown in differentiation media. Immunocytochemical analysis using confocal microscopy also revealed the increased expression of MAP2 in dendrites of EEGR-treated NSCs. Furthermore, EEGR decreased mRNA expression of Sox2 in NSCs grown even in growth media.@*CONCLUSIONS@#In conclusion, our study demonstrates for the first time that EEGR induced proliferation and neuronal differentiation of NSCs, suggesting its potential benefits on NSC-based therapies and neuroregeneration in various neurodegenerative diseases and brain injuries.
ABSTRACT
Chronic (>24 h) exposure of arsenite, an environmental toxicant, has shown the decreased nitric oxide (NO) production in endothelial cells (EC) by decreasing endothelial NO synthase (eNOS) expression and/or its phosphorylation at serine 1179 (eNOS-Ser1179 in bovine sequence), which is associated with increased risk of vascular diseases. Here, we investigated the acute (<24 h) effect of arsenite on NO production using bovine aortic EC (BAEC). Arsenite acutely increased the phosphorylation of eNOS-Thr497, but not of eNOS-Ser116 or eNOS-Ser1179, which was accompanied by decreased NO production. The level of eNOS expression was unaltered under this condition. Treatment with arsenite also induced reactive oxygen species (ROS) production, and pretreatment with a ROS scavenger N-acetyl-L-cysteine (NAC) completely reversed the observed effect of arsenite on eNOS-Thr497 phosphorylation. Although protein kinase C (PKC) and protein phosphatase 1 (PP1) were reported to be involved in eNOS-Thr497 phosphorylation, treatment with PKC inhibitor, Ro318425, and overexpression of various PKC isoforms did not affect the arsenite-stimulated eNOS-Thr497 phosphorylation. In contrast, treatment with PP1 inhibitor, calyculin A, mimicked the observed effect of arsenite on eNOS-Thr497 phosphorylation. Lastly, we found decreased cellular PP1 activity in arsenite-treated cells, which was reversed by NAC. Overall, our study demonstrates firstly that arsenite acutely decreases NO production at least in part by increasing eNOS-Thr497 phosphorylation via ROS-PP1 signaling pathway, which provide the molecular mechanism underlying arsenite-induced increase in vascular disease.