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Uridine from Pleurotus giganteus and Its Neurite Outgrowth Stimulatory Effects with Underlying Mechanism.

Phan CW, David P, Wong KH, Naidu M, Sabaratnam V - PLoS ONE (2015)

Bottom Line: An edible mushroom, Pleurotus giganteus was found to stimulate neurite outgrowth in vitro but the chemical constituents and the underlying mechanism is yet to be elucidated.Uridine (100 μM) was found to increase the percentage of neurite-bearing cells of differentiating neuroblastoma (N2a) cells by 43.1 ± 0.5%, which was 1.8-fold higher than NGF (50 ng/mL)-treated cells.MEK/ERK and PI3K-Akt-mTOR further induced phosphorylation of cAMP-response element binding protein (CREB) and expression of growth associated protein 43 (GAP43); all of which promoted neurite outgrowth of N2a cells.

View Article: PubMed Central - PubMed

Affiliation: Mushroom Research Centre, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
Neurodegenerative diseases are linked to neuronal cell death and impairment of neurite outgrowth. An edible mushroom, Pleurotus giganteus was found to stimulate neurite outgrowth in vitro but the chemical constituents and the underlying mechanism is yet to be elucidated. The chemical constituents of P. giganteus (linoleic acid, oleic acid, cinnamic acid, caffeic acid, p-coumaric acid, succinic acid, benzoic acid, and uridine) were tested for neurite outgrowth activity. Uridine (100 μM) was found to increase the percentage of neurite-bearing cells of differentiating neuroblastoma (N2a) cells by 43.1 ± 0.5%, which was 1.8-fold higher than NGF (50 ng/mL)-treated cells. Uridine which was present in P. giganteus (1.80 ± 0.03 g/100g mushroom extract) increased the phosphorylation of extracellular-signal regulated kinases (ERKs) and protein kinase B (Akt). Further, phosphorylation of the mammalian target of rapamycin (mTOR) was also increased. MEK/ERK and PI3K-Akt-mTOR further induced phosphorylation of cAMP-response element binding protein (CREB) and expression of growth associated protein 43 (GAP43); all of which promoted neurite outgrowth of N2a cells. This study demonstrated that P. giganteus may enhance neurite outgrowth and one of the key bioactive molecules responsible for neurite outgrowth is uridine.

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(a) The effects of two specific inhibitors of P2Y receptors (suramin and PPADS) on neurite outgrowth of differentiating N2a cells. (b) The effects of specific inhibitors of MEK/ERK and PI3K/Akt pathways (U0126 & PD98059; and LY294002, respectively) on neurite outgrowth of differentiating N2a cells. NGF (50 ng/mL) was used as positive control and medium only with no treatment was used as control. Aqueous (AE) and ethanol extracts (AE; 20 μg/mL) were tested to compare with uridine. Values are mean ± SD from three independent experiments. Different alphabets represent significant differences between samples. *p < 0.05 significantly lower relative to group without inhibitor treatment.
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pone.0143004.g005: (a) The effects of two specific inhibitors of P2Y receptors (suramin and PPADS) on neurite outgrowth of differentiating N2a cells. (b) The effects of specific inhibitors of MEK/ERK and PI3K/Akt pathways (U0126 & PD98059; and LY294002, respectively) on neurite outgrowth of differentiating N2a cells. NGF (50 ng/mL) was used as positive control and medium only with no treatment was used as control. Aqueous (AE) and ethanol extracts (AE; 20 μg/mL) were tested to compare with uridine. Values are mean ± SD from three independent experiments. Different alphabets represent significant differences between samples. *p < 0.05 significantly lower relative to group without inhibitor treatment.

Mentions: Specific inhibitors of key intermediates involved in neurite outgrowth signaling pathways were used to explore the mechanism of neuritogenesis in differentiating N2a cells potentiated by uridine and mushroom extracts. It was shown that neurite outgrowth induced by uridine was markedly inhibited (p < 0.05) by P2Y inhibitors, suramin (30 μM) and PPADS (30 μM) (Fig 5A). There is a significant decrease in the number of neuritic processes (p < 0.05) in the N2a cells treated with aqueous and ethanol extracts combined with either suramin or PPADS, On the contrary, both the inhibitors did not inhibit NGF-induced neurite outgrowth (Fig 5A). This could be due to a different receptor, for example the Trk family that is responsible for binding of NGF, but not P2Y receptor. MAPK/ERK1/2 inhibitors U0126 and PD98059 at the concentrations of 10 μM and 40 μM, respectively, caused inhibition effects on N2a cells. The number of differentiating N2a cells with neurite lengths double the cell diameter decreased significantly for NGF-, extracts-, and uridine-treated cells (Fig 5B). Cells pre-treated with the PI3K/Akt inhibitor, LY294002 showed no difference (p > 0.05) to the negative controls, with differentiated cells bearing neurites ranging only from 8.9–10.3% (Fig 5B). From these results, it is proposed that the P. giganteus extract and uridine induced neurite outgrowth on N2a cells via the activation of P2Y receptor. Activation of the P2Y receptor then triggered the activation of ERK1/2 and PI3K/AKt phosphorylation cascade.


Uridine from Pleurotus giganteus and Its Neurite Outgrowth Stimulatory Effects with Underlying Mechanism.

Phan CW, David P, Wong KH, Naidu M, Sabaratnam V - PLoS ONE (2015)

(a) The effects of two specific inhibitors of P2Y receptors (suramin and PPADS) on neurite outgrowth of differentiating N2a cells. (b) The effects of specific inhibitors of MEK/ERK and PI3K/Akt pathways (U0126 & PD98059; and LY294002, respectively) on neurite outgrowth of differentiating N2a cells. NGF (50 ng/mL) was used as positive control and medium only with no treatment was used as control. Aqueous (AE) and ethanol extracts (AE; 20 μg/mL) were tested to compare with uridine. Values are mean ± SD from three independent experiments. Different alphabets represent significant differences between samples. *p < 0.05 significantly lower relative to group without inhibitor treatment.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643974&req=5

pone.0143004.g005: (a) The effects of two specific inhibitors of P2Y receptors (suramin and PPADS) on neurite outgrowth of differentiating N2a cells. (b) The effects of specific inhibitors of MEK/ERK and PI3K/Akt pathways (U0126 & PD98059; and LY294002, respectively) on neurite outgrowth of differentiating N2a cells. NGF (50 ng/mL) was used as positive control and medium only with no treatment was used as control. Aqueous (AE) and ethanol extracts (AE; 20 μg/mL) were tested to compare with uridine. Values are mean ± SD from three independent experiments. Different alphabets represent significant differences between samples. *p < 0.05 significantly lower relative to group without inhibitor treatment.
Mentions: Specific inhibitors of key intermediates involved in neurite outgrowth signaling pathways were used to explore the mechanism of neuritogenesis in differentiating N2a cells potentiated by uridine and mushroom extracts. It was shown that neurite outgrowth induced by uridine was markedly inhibited (p < 0.05) by P2Y inhibitors, suramin (30 μM) and PPADS (30 μM) (Fig 5A). There is a significant decrease in the number of neuritic processes (p < 0.05) in the N2a cells treated with aqueous and ethanol extracts combined with either suramin or PPADS, On the contrary, both the inhibitors did not inhibit NGF-induced neurite outgrowth (Fig 5A). This could be due to a different receptor, for example the Trk family that is responsible for binding of NGF, but not P2Y receptor. MAPK/ERK1/2 inhibitors U0126 and PD98059 at the concentrations of 10 μM and 40 μM, respectively, caused inhibition effects on N2a cells. The number of differentiating N2a cells with neurite lengths double the cell diameter decreased significantly for NGF-, extracts-, and uridine-treated cells (Fig 5B). Cells pre-treated with the PI3K/Akt inhibitor, LY294002 showed no difference (p > 0.05) to the negative controls, with differentiated cells bearing neurites ranging only from 8.9–10.3% (Fig 5B). From these results, it is proposed that the P. giganteus extract and uridine induced neurite outgrowth on N2a cells via the activation of P2Y receptor. Activation of the P2Y receptor then triggered the activation of ERK1/2 and PI3K/AKt phosphorylation cascade.

Bottom Line: An edible mushroom, Pleurotus giganteus was found to stimulate neurite outgrowth in vitro but the chemical constituents and the underlying mechanism is yet to be elucidated.Uridine (100 μM) was found to increase the percentage of neurite-bearing cells of differentiating neuroblastoma (N2a) cells by 43.1 ± 0.5%, which was 1.8-fold higher than NGF (50 ng/mL)-treated cells.MEK/ERK and PI3K-Akt-mTOR further induced phosphorylation of cAMP-response element binding protein (CREB) and expression of growth associated protein 43 (GAP43); all of which promoted neurite outgrowth of N2a cells.

View Article: PubMed Central - PubMed

Affiliation: Mushroom Research Centre, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
Neurodegenerative diseases are linked to neuronal cell death and impairment of neurite outgrowth. An edible mushroom, Pleurotus giganteus was found to stimulate neurite outgrowth in vitro but the chemical constituents and the underlying mechanism is yet to be elucidated. The chemical constituents of P. giganteus (linoleic acid, oleic acid, cinnamic acid, caffeic acid, p-coumaric acid, succinic acid, benzoic acid, and uridine) were tested for neurite outgrowth activity. Uridine (100 μM) was found to increase the percentage of neurite-bearing cells of differentiating neuroblastoma (N2a) cells by 43.1 ± 0.5%, which was 1.8-fold higher than NGF (50 ng/mL)-treated cells. Uridine which was present in P. giganteus (1.80 ± 0.03 g/100g mushroom extract) increased the phosphorylation of extracellular-signal regulated kinases (ERKs) and protein kinase B (Akt). Further, phosphorylation of the mammalian target of rapamycin (mTOR) was also increased. MEK/ERK and PI3K-Akt-mTOR further induced phosphorylation of cAMP-response element binding protein (CREB) and expression of growth associated protein 43 (GAP43); all of which promoted neurite outgrowth of N2a cells. This study demonstrated that P. giganteus may enhance neurite outgrowth and one of the key bioactive molecules responsible for neurite outgrowth is uridine.

Show MeSH
Related in: MedlinePlus