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Dopamine D1 receptor activation regulates the expression of the estrogen synthesis gene aromatase B in radial glial cells.

Xing L, McDonald H, Da Fonte DF, Gutierrez-Villagomez JM, Trudeau VL - Front Neurosci (2015)

Bottom Line: The estrogen synthesis enzyme aromatase B is exclusively found in RGCs, but this is lost as cells differentiate to neurons and other glial types in adult teleost brain.Pharmacological experiments using the cultured RGCs established that specific activation of dopamine D1 receptors up-regulates aromatase B mRNA through a cyclic adenosine monophosphate-dependent molecular mechanism.These data indicate that dopamine enhances the steroidogenic function of this neuronal progenitor cell.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa Ottawa, ON, Canada.

ABSTRACT
Radial glial cells (RGCs) are abundant stem-like non-neuronal progenitors that are important for adult neurogenesis and brain repair, yet little is known about their regulation by neurotransmitters. Here we provide evidence for neuronal-glial interactions via a novel role for dopamine to stimulate RGC function. Goldfish were chosen as the model organism due to the abundance of RGCs and regenerative abilities of the adult central nervous system. A close anatomical relationship was observed between tyrosine hydroxylase-positive catecholaminergic cell bodies and axons and dopamine-D1 receptor expressing RGCs along the ventricular surface of telencephalon, a site of active neurogenesis. A primary cell culture model was established and immunofluorescence analysis indicates that in vitro RGCs from female goldfish retain their major characteristics in vivo, including expression of glial fibrillary acidic protein and brain lipid binding protein. The estrogen synthesis enzyme aromatase B is exclusively found in RGCs, but this is lost as cells differentiate to neurons and other glial types in adult teleost brain. Pharmacological experiments using the cultured RGCs established that specific activation of dopamine D1 receptors up-regulates aromatase B mRNA through a cyclic adenosine monophosphate-dependent molecular mechanism. These data indicate that dopamine enhances the steroidogenic function of this neuronal progenitor cell.

No MeSH data available.


Related in: MedlinePlus

Involvement of D1R/cAMP/PKA/p-CREB signaling pathway in dopaminergic regulation of cyp19a1b mRNA in RGC culture. Total cAMP production rapidly increased by 10 μM SKF 38393 (30 min). Data were normalized to control value and defined as % of control, bars represent the mean + SEM (n = 3), and values for each sample were determined in duplicate. (A) Regulation of cyp19a1b mRNA in primary RGC culture after 24 h exposure of 8-Br-cAMP (B), SKF 38393 and/or H89 (C). Data were defined as fold change relative to control, bars represent the mean + SEM of cyp19a1b (n = 4), and values for each sample were determined in duplicate. Western blot image showing the effects of SKF 38393 on p-CREB immunoreactivity, where actin served as internal control (D). The densitometric analysis of western blot is reported as an arbitrary value relative to the average of all bands on the same blot. Data were normalized and defined as fold change relative to control, and bars represent the mean + SEM (n = 6) (E). a,b-Groups marked by different letters are significantly different (P < 0.05), *Groups marked by asterisks are significantly different to control (P < 0.05).
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Figure 6: Involvement of D1R/cAMP/PKA/p-CREB signaling pathway in dopaminergic regulation of cyp19a1b mRNA in RGC culture. Total cAMP production rapidly increased by 10 μM SKF 38393 (30 min). Data were normalized to control value and defined as % of control, bars represent the mean + SEM (n = 3), and values for each sample were determined in duplicate. (A) Regulation of cyp19a1b mRNA in primary RGC culture after 24 h exposure of 8-Br-cAMP (B), SKF 38393 and/or H89 (C). Data were defined as fold change relative to control, bars represent the mean + SEM of cyp19a1b (n = 4), and values for each sample were determined in duplicate. Western blot image showing the effects of SKF 38393 on p-CREB immunoreactivity, where actin served as internal control (D). The densitometric analysis of western blot is reported as an arbitrary value relative to the average of all bands on the same blot. Data were normalized and defined as fold change relative to control, and bars represent the mean + SEM (n = 6) (E). a,b-Groups marked by different letters are significantly different (P < 0.05), *Groups marked by asterisks are significantly different to control (P < 0.05).

Mentions: Activation of D1R by SKF 38393 increased total cyclic adenosine monophosphate (cAMP) production by 25% (P = 0.03, Figure 6A). Furthermore, 10 μM 8-Br-cAMP increased cyp19a1b mRNA by 1.8-fold, similar to the 2-fold increases following 10 μM SKF 38393 (P = 0.02, Figure 6B). Therefore, we focused on the classic cAMP-dependent signaling pathway. The protein kinase A (PKA) inhibitor H89 blocked (P = 0.67) the D1R-dependent increase in cyp19a1b mRNA induced by SKF 38393 (P = 0.02) in cultured RGCs (Figure 6C). It is known that PKA activation leads to phosphorylation of cAMP response element binding protein (CREB). Exposure to SKF 38393 increased p-CREB protein levels by 1.8-fold (P = 0.0051, Figures 6D,E).


Dopamine D1 receptor activation regulates the expression of the estrogen synthesis gene aromatase B in radial glial cells.

Xing L, McDonald H, Da Fonte DF, Gutierrez-Villagomez JM, Trudeau VL - Front Neurosci (2015)

Involvement of D1R/cAMP/PKA/p-CREB signaling pathway in dopaminergic regulation of cyp19a1b mRNA in RGC culture. Total cAMP production rapidly increased by 10 μM SKF 38393 (30 min). Data were normalized to control value and defined as % of control, bars represent the mean + SEM (n = 3), and values for each sample were determined in duplicate. (A) Regulation of cyp19a1b mRNA in primary RGC culture after 24 h exposure of 8-Br-cAMP (B), SKF 38393 and/or H89 (C). Data were defined as fold change relative to control, bars represent the mean + SEM of cyp19a1b (n = 4), and values for each sample were determined in duplicate. Western blot image showing the effects of SKF 38393 on p-CREB immunoreactivity, where actin served as internal control (D). The densitometric analysis of western blot is reported as an arbitrary value relative to the average of all bands on the same blot. Data were normalized and defined as fold change relative to control, and bars represent the mean + SEM (n = 6) (E). a,b-Groups marked by different letters are significantly different (P < 0.05), *Groups marked by asterisks are significantly different to control (P < 0.05).
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Figure 6: Involvement of D1R/cAMP/PKA/p-CREB signaling pathway in dopaminergic regulation of cyp19a1b mRNA in RGC culture. Total cAMP production rapidly increased by 10 μM SKF 38393 (30 min). Data were normalized to control value and defined as % of control, bars represent the mean + SEM (n = 3), and values for each sample were determined in duplicate. (A) Regulation of cyp19a1b mRNA in primary RGC culture after 24 h exposure of 8-Br-cAMP (B), SKF 38393 and/or H89 (C). Data were defined as fold change relative to control, bars represent the mean + SEM of cyp19a1b (n = 4), and values for each sample were determined in duplicate. Western blot image showing the effects of SKF 38393 on p-CREB immunoreactivity, where actin served as internal control (D). The densitometric analysis of western blot is reported as an arbitrary value relative to the average of all bands on the same blot. Data were normalized and defined as fold change relative to control, and bars represent the mean + SEM (n = 6) (E). a,b-Groups marked by different letters are significantly different (P < 0.05), *Groups marked by asterisks are significantly different to control (P < 0.05).
Mentions: Activation of D1R by SKF 38393 increased total cyclic adenosine monophosphate (cAMP) production by 25% (P = 0.03, Figure 6A). Furthermore, 10 μM 8-Br-cAMP increased cyp19a1b mRNA by 1.8-fold, similar to the 2-fold increases following 10 μM SKF 38393 (P = 0.02, Figure 6B). Therefore, we focused on the classic cAMP-dependent signaling pathway. The protein kinase A (PKA) inhibitor H89 blocked (P = 0.67) the D1R-dependent increase in cyp19a1b mRNA induced by SKF 38393 (P = 0.02) in cultured RGCs (Figure 6C). It is known that PKA activation leads to phosphorylation of cAMP response element binding protein (CREB). Exposure to SKF 38393 increased p-CREB protein levels by 1.8-fold (P = 0.0051, Figures 6D,E).

Bottom Line: The estrogen synthesis enzyme aromatase B is exclusively found in RGCs, but this is lost as cells differentiate to neurons and other glial types in adult teleost brain.Pharmacological experiments using the cultured RGCs established that specific activation of dopamine D1 receptors up-regulates aromatase B mRNA through a cyclic adenosine monophosphate-dependent molecular mechanism.These data indicate that dopamine enhances the steroidogenic function of this neuronal progenitor cell.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa Ottawa, ON, Canada.

ABSTRACT
Radial glial cells (RGCs) are abundant stem-like non-neuronal progenitors that are important for adult neurogenesis and brain repair, yet little is known about their regulation by neurotransmitters. Here we provide evidence for neuronal-glial interactions via a novel role for dopamine to stimulate RGC function. Goldfish were chosen as the model organism due to the abundance of RGCs and regenerative abilities of the adult central nervous system. A close anatomical relationship was observed between tyrosine hydroxylase-positive catecholaminergic cell bodies and axons and dopamine-D1 receptor expressing RGCs along the ventricular surface of telencephalon, a site of active neurogenesis. A primary cell culture model was established and immunofluorescence analysis indicates that in vitro RGCs from female goldfish retain their major characteristics in vivo, including expression of glial fibrillary acidic protein and brain lipid binding protein. The estrogen synthesis enzyme aromatase B is exclusively found in RGCs, but this is lost as cells differentiate to neurons and other glial types in adult teleost brain. Pharmacological experiments using the cultured RGCs established that specific activation of dopamine D1 receptors up-regulates aromatase B mRNA through a cyclic adenosine monophosphate-dependent molecular mechanism. These data indicate that dopamine enhances the steroidogenic function of this neuronal progenitor cell.

No MeSH data available.


Related in: MedlinePlus