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Propofol restores TRPV1 sensitivity via a TRPA1-, nitric oxide synthase-dependent activation of PKCε.

Sinharoy P, Zhang H, Sinha S, Prudner BC, Bratz IN, Damron DS - Pharmacol Res Perspect (2015)

Bottom Line: The extent to which the two pathways are directly linked or operating in parallel has not been determined.Intracellular Ca(2+) concentration was measured in individual cells via fluorescence microscopy.Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Kent State University Kent, Ohio, 44242.

ABSTRACT
We previously demonstrated that the intravenous anesthetic, propofol, restores the sensitivity of transient receptor potential vanilloid channel subtype-1 (TRPV1) receptors via a protein kinase C epsilon (PKCε)-dependent and transient receptor potential ankyrin channel subtype-1 (TRPA1)-dependent pathway in sensory neurons. The extent to which the two pathways are directly linked or operating in parallel has not been determined. Using a molecular approach, our objectives of the current study were to confirm that TRPA1 activation directly results in PKCε activation and to elucidate the cellular mechanism by which this occurs. F-11 cells were transfected with complimentary DNA (cDNA) for TRPV1 only or both TRPV1 and TRPA1. Intracellular Ca(2+) concentration was measured in individual cells via fluorescence microscopy. An immunoblot analysis of the total and phosphorylated forms of PKCε, nitric oxide synthase (nNOS), and TRPV1 was also performed. In F-11 cells containing both channels, PKCε inhibition prevented the propofol- and allyl isothiocyanate (AITC)-induced restoration of TRPV1 sensitivity to agonist stimulation as well as increased phosphorylation of PKCε and TRPV1. In cells containing TRPV1 only, neither agonist induced PKCε or TRPV1 phosphorylation. Moreover, NOS inhibition blocked propofol-and AITC-induced restoration of TRPV1 sensitivity and PKCε phosphorylation, and PKCε inhibition prevented the nitric oxide donor, SNAP, from restoring TRPV1 sensitivity. Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031. These data indicate that the AITC- and propofol-induced restoration of TRPV1 sensitivity is mediated by a TRPA1-dependent, nitric oxide synthase-dependent activation of PKCε.

No MeSH data available.


Related in: MedlinePlus

Schematic diagram depicting the proposed signaling pathway for cross talk between TRPA1 and TRPV1 ion channels (depicted by black arrows). Capsaicin (TRPV1 agonist); propofol and allyl isothiocyanate (AITC; TRPA1 agonists); HC-030031 (TRPA1 antagonist; l-NAME (neuronal nitric oxide synthase (nNOS) antagonist); NO (nitric oxide); SNAP (NO donor); protein kinase C epsilon (PKCε); ΨεRACK (PKCε activator peptide); εV1–2 (PKCε inhibitor peptide).
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fig08: Schematic diagram depicting the proposed signaling pathway for cross talk between TRPA1 and TRPV1 ion channels (depicted by black arrows). Capsaicin (TRPV1 agonist); propofol and allyl isothiocyanate (AITC; TRPA1 agonists); HC-030031 (TRPA1 antagonist; l-NAME (neuronal nitric oxide synthase (nNOS) antagonist); NO (nitric oxide); SNAP (NO donor); protein kinase C epsilon (PKCε); ΨεRACK (PKCε activator peptide); εV1–2 (PKCε inhibitor peptide).

Mentions: Overall, our current findings are consistent with previous studies indicating cross talk between TRPV1 and TRPA1 receptors which regulate and modulate nociceptive ion channel function (Brand and Jacquot 2002; Akopian et al. 2007; Salas et al. 2009; Simons et al. 2010). Moreover, our data indicating TRPA1-dependent activation of NOS, leading to PKCε activation and subsequent restoration of TRPV1 sensitivity provides new evidence needed to elucidate the mechanisms by which TRPA1 and TRPV1 regulate each other’s function. A summary of the proposed cellular signaling pathway by which cross talk between TRPA1 and TRPV1 channels occurs is depicted in Figure8. The contribution of TRPV1 and TRPA1 to peripheral nociception supports the idea that one approach to control peripheral nociception is to better understand and manage cross regulation between TRPV1 and TRPA1 channels. A better understanding of these intricate mechanisms could prove vital in the search for therapeutic strategies to treat pathological conditions involving altered nociceptive processes.


Propofol restores TRPV1 sensitivity via a TRPA1-, nitric oxide synthase-dependent activation of PKCε.

Sinharoy P, Zhang H, Sinha S, Prudner BC, Bratz IN, Damron DS - Pharmacol Res Perspect (2015)

Schematic diagram depicting the proposed signaling pathway for cross talk between TRPA1 and TRPV1 ion channels (depicted by black arrows). Capsaicin (TRPV1 agonist); propofol and allyl isothiocyanate (AITC; TRPA1 agonists); HC-030031 (TRPA1 antagonist; l-NAME (neuronal nitric oxide synthase (nNOS) antagonist); NO (nitric oxide); SNAP (NO donor); protein kinase C epsilon (PKCε); ΨεRACK (PKCε activator peptide); εV1–2 (PKCε inhibitor peptide).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492729&req=5

fig08: Schematic diagram depicting the proposed signaling pathway for cross talk between TRPA1 and TRPV1 ion channels (depicted by black arrows). Capsaicin (TRPV1 agonist); propofol and allyl isothiocyanate (AITC; TRPA1 agonists); HC-030031 (TRPA1 antagonist; l-NAME (neuronal nitric oxide synthase (nNOS) antagonist); NO (nitric oxide); SNAP (NO donor); protein kinase C epsilon (PKCε); ΨεRACK (PKCε activator peptide); εV1–2 (PKCε inhibitor peptide).
Mentions: Overall, our current findings are consistent with previous studies indicating cross talk between TRPV1 and TRPA1 receptors which regulate and modulate nociceptive ion channel function (Brand and Jacquot 2002; Akopian et al. 2007; Salas et al. 2009; Simons et al. 2010). Moreover, our data indicating TRPA1-dependent activation of NOS, leading to PKCε activation and subsequent restoration of TRPV1 sensitivity provides new evidence needed to elucidate the mechanisms by which TRPA1 and TRPV1 regulate each other’s function. A summary of the proposed cellular signaling pathway by which cross talk between TRPA1 and TRPV1 channels occurs is depicted in Figure8. The contribution of TRPV1 and TRPA1 to peripheral nociception supports the idea that one approach to control peripheral nociception is to better understand and manage cross regulation between TRPV1 and TRPA1 channels. A better understanding of these intricate mechanisms could prove vital in the search for therapeutic strategies to treat pathological conditions involving altered nociceptive processes.

Bottom Line: The extent to which the two pathways are directly linked or operating in parallel has not been determined.Intracellular Ca(2+) concentration was measured in individual cells via fluorescence microscopy.Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Kent State University Kent, Ohio, 44242.

ABSTRACT
We previously demonstrated that the intravenous anesthetic, propofol, restores the sensitivity of transient receptor potential vanilloid channel subtype-1 (TRPV1) receptors via a protein kinase C epsilon (PKCε)-dependent and transient receptor potential ankyrin channel subtype-1 (TRPA1)-dependent pathway in sensory neurons. The extent to which the two pathways are directly linked or operating in parallel has not been determined. Using a molecular approach, our objectives of the current study were to confirm that TRPA1 activation directly results in PKCε activation and to elucidate the cellular mechanism by which this occurs. F-11 cells were transfected with complimentary DNA (cDNA) for TRPV1 only or both TRPV1 and TRPA1. Intracellular Ca(2+) concentration was measured in individual cells via fluorescence microscopy. An immunoblot analysis of the total and phosphorylated forms of PKCε, nitric oxide synthase (nNOS), and TRPV1 was also performed. In F-11 cells containing both channels, PKCε inhibition prevented the propofol- and allyl isothiocyanate (AITC)-induced restoration of TRPV1 sensitivity to agonist stimulation as well as increased phosphorylation of PKCε and TRPV1. In cells containing TRPV1 only, neither agonist induced PKCε or TRPV1 phosphorylation. Moreover, NOS inhibition blocked propofol-and AITC-induced restoration of TRPV1 sensitivity and PKCε phosphorylation, and PKCε inhibition prevented the nitric oxide donor, SNAP, from restoring TRPV1 sensitivity. Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031. These data indicate that the AITC- and propofol-induced restoration of TRPV1 sensitivity is mediated by a TRPA1-dependent, nitric oxide synthase-dependent activation of PKCε.

No MeSH data available.


Related in: MedlinePlus