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Epistatic and functional interactions of catechol-o-methyltransferase (COMT) and AKT1 on neuregulin1-ErbB signaling in cell models.

Sei Y, Li Z, Song J, Ren-Patterson R, Tunbridge EM, Iizuka Y, Inoue M, Alfonso BT, Beltaifa S, Nakai Y, Kolachana BS, Chen J, Weinberger DR - PLoS ONE (2010)

Bottom Line: NRG1-induced AKT1 phosphorylation was significantly diminished in Val carriers compared to Met carriers in both normal subjects and in patients.NRG1 induced translocation of AKT1 to the plasma membrane also was impaired in Val carriers, while PIP(3) levels were not decreased.Transfection of SH-SY5Y cells with a COMT Val construct increased COMT activity and significantly decreased PS levels as well as NRG1-induced AKT1 phosphorylation and migration.

View Article: PubMed Central - PubMed

Affiliation: Clinical Brain Disorder Branch, Genes, Cognition, and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA. seiy@mail.nih.gov

ABSTRACT

Background: Neuregulin1 (NRG1)-ErbB signaling has been implicated in the pathogenesis of cancer and schizophrenia. We have previously reported that NRG1-stimulated migration of B lymphoblasts is PI3K-AKT1dependent and impaired in patients with schizophrenia and significantly linked to the catechol-o-methyltransferase (COMT) Val108/158Met functional polymorphism.

Methodology/principal findings: We have now examined AKT1 activation in NRG1-stimulated B lymphoblasts and other cell models and explored a functional relationship between COMT and AKT1. NRG1-induced AKT1 phosphorylation was significantly diminished in Val carriers compared to Met carriers in both normal subjects and in patients. Further, there was a significant epistatic interaction between a putatively functional coding SNP in AKT1 (rs1130233) and COMT Val108/158Met genotype on AKT1 phosphorylation. NRG1 induced translocation of AKT1 to the plasma membrane also was impaired in Val carriers, while PIP(3) levels were not decreased. Interestingly, the level of COMT enzyme activity was inversely correlated with the cells' ability to synthesize phosphatidylserine (PS), a factor that attracts the pleckstrin homology domain (PHD) of AKT1 to the cell membrane. Transfection of SH-SY5Y cells with a COMT Val construct increased COMT activity and significantly decreased PS levels as well as NRG1-induced AKT1 phosphorylation and migration. Administration of S-adenosylmethionine (SAM) rescued all of these deficits. These data suggest that AKT1 function is influenced by COMT enzyme activity through competition with PS synthesis for SAM, which in turn dictates AKT1-dependent cellular responses to NRG1-mediated signaling.

Conclusion/significance: Our findings implicate genetic and functional interactions between COMT and AKT1 and may provide novel insights into pathogenesis of schizophrenia and other ErbB-associated human diseases such as cancer.

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Related in: MedlinePlus

Effects of COMT transfection and SAM treatment on NRG1-stimulated migrataion in SH-SY5Y cells.SH-SY5Y cells were transfected with COMT-GFP or control vectors (empty GFP) and cultured in media containing 2%FBS. After 48 hrs, cells were tested for NRG1-stimulated migration. A graph indicates the chemotaxis index (mean± S.E.) from three transfection experiments (n = 4–5 per group). ANOVA showed a significant a SAM treatment effect (p = 0.0193) and transfection-treatment interaction (P = 0.0144).
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pone-0010789-g008: Effects of COMT transfection and SAM treatment on NRG1-stimulated migrataion in SH-SY5Y cells.SH-SY5Y cells were transfected with COMT-GFP or control vectors (empty GFP) and cultured in media containing 2%FBS. After 48 hrs, cells were tested for NRG1-stimulated migration. A graph indicates the chemotaxis index (mean± S.E.) from three transfection experiments (n = 4–5 per group). ANOVA showed a significant a SAM treatment effect (p = 0.0193) and transfection-treatment interaction (P = 0.0144).

Mentions: Finally, we attempted to determine if high COMT enzyme activity produces a negative effect on cell migration. Since SH-SY5Y cells also migrate in response to NRG1 in a PI3K/AKT1-dependent manner, the SH-SY5Y-COMT transfection system is suited for this experiment. As expected in untransfected SH-SY5Y cells, our migration assay using a transwell chamber showed a positive NRG1-stimulated migration in control-vector transfected cells (Figure 8). In contrast, COMT transfection significantly decreased NRG1-stimulated migration compared to the transfection with a control empty vector (p = 0.0165, unpaired t-test) (Figure 8). Further, SAM treatment significantly rescued the COMT transfection effect on migration (Figure 8). Repeated measures ANOVA revealed a significant main effect of SAM treatment (F1, 12 = 7.30, P = 0.0193) and a significant interaction between COMT transfection and SAM treatment (F1, 12 = 8.18, p = 0.0144). These results are consistent with the effect of COMT Val/Met genotype on NRG1-stimulated migration seen in B lymphoblasts [2] and therefore suggest that the increase in COMT activity reduces migration ability in a SAM-dependent manner.


Epistatic and functional interactions of catechol-o-methyltransferase (COMT) and AKT1 on neuregulin1-ErbB signaling in cell models.

Sei Y, Li Z, Song J, Ren-Patterson R, Tunbridge EM, Iizuka Y, Inoue M, Alfonso BT, Beltaifa S, Nakai Y, Kolachana BS, Chen J, Weinberger DR - PLoS ONE (2010)

Effects of COMT transfection and SAM treatment on NRG1-stimulated migrataion in SH-SY5Y cells.SH-SY5Y cells were transfected with COMT-GFP or control vectors (empty GFP) and cultured in media containing 2%FBS. After 48 hrs, cells were tested for NRG1-stimulated migration. A graph indicates the chemotaxis index (mean± S.E.) from three transfection experiments (n = 4–5 per group). ANOVA showed a significant a SAM treatment effect (p = 0.0193) and transfection-treatment interaction (P = 0.0144).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2875391&req=5

pone-0010789-g008: Effects of COMT transfection and SAM treatment on NRG1-stimulated migrataion in SH-SY5Y cells.SH-SY5Y cells were transfected with COMT-GFP or control vectors (empty GFP) and cultured in media containing 2%FBS. After 48 hrs, cells were tested for NRG1-stimulated migration. A graph indicates the chemotaxis index (mean± S.E.) from three transfection experiments (n = 4–5 per group). ANOVA showed a significant a SAM treatment effect (p = 0.0193) and transfection-treatment interaction (P = 0.0144).
Mentions: Finally, we attempted to determine if high COMT enzyme activity produces a negative effect on cell migration. Since SH-SY5Y cells also migrate in response to NRG1 in a PI3K/AKT1-dependent manner, the SH-SY5Y-COMT transfection system is suited for this experiment. As expected in untransfected SH-SY5Y cells, our migration assay using a transwell chamber showed a positive NRG1-stimulated migration in control-vector transfected cells (Figure 8). In contrast, COMT transfection significantly decreased NRG1-stimulated migration compared to the transfection with a control empty vector (p = 0.0165, unpaired t-test) (Figure 8). Further, SAM treatment significantly rescued the COMT transfection effect on migration (Figure 8). Repeated measures ANOVA revealed a significant main effect of SAM treatment (F1, 12 = 7.30, P = 0.0193) and a significant interaction between COMT transfection and SAM treatment (F1, 12 = 8.18, p = 0.0144). These results are consistent with the effect of COMT Val/Met genotype on NRG1-stimulated migration seen in B lymphoblasts [2] and therefore suggest that the increase in COMT activity reduces migration ability in a SAM-dependent manner.

Bottom Line: NRG1-induced AKT1 phosphorylation was significantly diminished in Val carriers compared to Met carriers in both normal subjects and in patients.NRG1 induced translocation of AKT1 to the plasma membrane also was impaired in Val carriers, while PIP(3) levels were not decreased.Transfection of SH-SY5Y cells with a COMT Val construct increased COMT activity and significantly decreased PS levels as well as NRG1-induced AKT1 phosphorylation and migration.

View Article: PubMed Central - PubMed

Affiliation: Clinical Brain Disorder Branch, Genes, Cognition, and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA. seiy@mail.nih.gov

ABSTRACT

Background: Neuregulin1 (NRG1)-ErbB signaling has been implicated in the pathogenesis of cancer and schizophrenia. We have previously reported that NRG1-stimulated migration of B lymphoblasts is PI3K-AKT1dependent and impaired in patients with schizophrenia and significantly linked to the catechol-o-methyltransferase (COMT) Val108/158Met functional polymorphism.

Methodology/principal findings: We have now examined AKT1 activation in NRG1-stimulated B lymphoblasts and other cell models and explored a functional relationship between COMT and AKT1. NRG1-induced AKT1 phosphorylation was significantly diminished in Val carriers compared to Met carriers in both normal subjects and in patients. Further, there was a significant epistatic interaction between a putatively functional coding SNP in AKT1 (rs1130233) and COMT Val108/158Met genotype on AKT1 phosphorylation. NRG1 induced translocation of AKT1 to the plasma membrane also was impaired in Val carriers, while PIP(3) levels were not decreased. Interestingly, the level of COMT enzyme activity was inversely correlated with the cells' ability to synthesize phosphatidylserine (PS), a factor that attracts the pleckstrin homology domain (PHD) of AKT1 to the cell membrane. Transfection of SH-SY5Y cells with a COMT Val construct increased COMT activity and significantly decreased PS levels as well as NRG1-induced AKT1 phosphorylation and migration. Administration of S-adenosylmethionine (SAM) rescued all of these deficits. These data suggest that AKT1 function is influenced by COMT enzyme activity through competition with PS synthesis for SAM, which in turn dictates AKT1-dependent cellular responses to NRG1-mediated signaling.

Conclusion/significance: Our findings implicate genetic and functional interactions between COMT and AKT1 and may provide novel insights into pathogenesis of schizophrenia and other ErbB-associated human diseases such as cancer.

Show MeSH
Related in: MedlinePlus