-
[show abstract]
[hide abstract]
ABSTRACT: Cold/menthol-activated TRPM8 (transient receptor potential channel melastatin member 8) is primarily expressed in sensory neurons, where it constitutes the principal receptor of environmental innocuous cold.
TRPM8 has been shown to be regulated by multiple influences such as phosphorylation, pH, Ca2+, and lipid messengers. One such messenger is arachidonic acid (AA), which has been shown to inhibit TRPM8 channel activity.
However, the physiological pathways mediating the inhibitory effect of AA on TRPM8 still remain unknown. Here, we demonstrate
that TRPM8 is regulated via M3 muscarinic acetylcholine receptor-coupled signaling cascade based on the activation of cytosolic
phospholipase A2 (cPLA2) and cPLA2-catalyzed derivation of AA. Stimulation of M3 receptors heterologously co-expressed with
TRPM8 in HEK-293 cells by nonselective muscarinic agonist, oxotremorine methiodide (Oxo-M), caused inhibition of TRPM8-mediated
membrane current, which could be mimicked by AA and antagonized by pharmacological or siRNA-mediated cPLA2 silencing. Our
results demonstrate the intracellular functional link between M3 receptor and TRPM8 channel via cPLA2/AA and suggest a novel
physiological mechanism of arachidonate-mediated regulation of TRPM8 channel activity through muscarinic receptors. We also
summarize the existing TRPM8 regulations and discuss their physiological and pathological significance.
Journal of Biological Chemistry 03/2011; 286(11):9849-9855. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cold/menthol-activated TRPM8 (transient receptor potential channel melastatin member 8) is primarily expressed in sensory neurons, where it constitutes the principal receptor of environmental innocuous cold. TRPM8 has been shown to be regulated by multiple influences such as phosphorylation, pH, Ca(2+), and lipid messengers. One such messenger is arachidonic acid (AA), which has been shown to inhibit TRPM8 channel activity. However, the physiological pathways mediating the inhibitory effect of AA on TRPM8 still remain unknown. Here, we demonstrate that TRPM8 is regulated via M3 muscarinic acetylcholine receptor-coupled signaling cascade based on the activation of cytosolic phospholipase A2 (cPLA2) and cPLA2-catalyzed derivation of AA. Stimulation of M3 receptors heterologously co-expressed with TRPM8 in HEK-293 cells by nonselective muscarinic agonist, oxotremorine methiodide (Oxo-M), caused inhibition of TRPM8-mediated membrane current, which could be mimicked by AA and antagonized by pharmacological or siRNA-mediated cPLA2 silencing. Our results demonstrate the intracellular functional link between M3 receptor and TRPM8 channel via cPLA2/AA and suggest a novel physiological mechanism of arachidonate-mediated regulation of TRPM8 channel activity through muscarinic receptors. We also summarize the existing TRPM8 regulations and discuss their physiological and pathological significance.
Journal of Biological Chemistry 01/2011; 286(11):9849-55. · 4.77 Impact Factor
-
V'yacheslav Lehen'kyi,
Maylis Raphaël,
Agathe Oulidi,
Matthieu Flourakis,
Sergii Khalimonchyk, Artem Kondratskyi,
Dmitri V Gordienko,
Brigitte Mauroy,
Jean-Lois Bonnal,
Roman Skryma,
Natalia Prevarskaya
[show abstract]
[hide abstract]
ABSTRACT: Despite remarkable advances in the therapy and prevention of prostate cancer it is still the second cause of death from cancer in industrialized countries. Many therapies initially shown to be beneficial for the patients were abandoned due to the high drug resistance and the evolution rate of the tumors. One of the prospective therapeutical agents even used in the first stage clinical trials, 1,25-dihydroxyvitamin D3, was shown to be either unpredictable or inefficient in many cases. We have already shown that TRPV6 calcium channel, which is the direct target of 1,25-dihydroxyvitamin D3 receptor, positively controls prostate cancer proliferation and apoptosis resistance (Lehen'kyi et al., Oncogene, 2007). However, how the known 1,25-dihydroxyvitamin D3 antiproliferative effects may be compatible with the upregulation of pro-oncogenic TRPV6 channel remains a mystery. Here we demonstrate that in low steroid conditions 1,25-dihydroxyvitamin D3 upregulates the expression of TRPV6, enhances the proliferation by increasing the number of cells entering into S-phase. We show that these pro-proliferative effects of 1,25-dihydroxyvitamin D3 are directly mediated via the overexpression of TRPV6 channel which increases calcium uptake into LNCaP cells. The apoptosis resistance of androgen-dependent LNCaP cells conferred by TRPV6 channel is drastically inversed when 1,25-dihydroxyvitamin D3 effects were combined with the successful TRPV6 knockdown. In addition, the use of androgen-deficient DU-145 and androgen-insensitive LNCaP C4-2 cell lines allowed to suggest that the ability of 1,25-dihydroxyvitamin D3 to induce the expression of TRPV6 channel is a crucial determinant of the success or failure of 1,25-dihydroxyvitamin D3-based therapies.
PLoS ONE 01/2011; 6(2):e16856. · 4.09 Impact Factor
-
Alexis Bavencoffe,
Dimitra Gkika, Artem Kondratskyi,
Benjamin Beck,
Anne-Sophie Borowiec,
Gabriel Bidaux,
Jérôme Busserolles,
Alain Eschalier,
Yaroslav Shuba,
Roman Skryma,
Natalia Prevarskaya
[show abstract]
[hide abstract]
ABSTRACT: The transient receptor potential channel melastatin member 8 (TRPM8) is expressed in sensory neurons, where it constitutes the main receptor of environmental innocuous cold (10-25 degrees C). Among several types of G protein-coupled receptors expressed in sensory neurons, G(i)-coupled alpha 2A-adrenoreceptor (alpha 2A-AR), is known to be involved in thermoregulation; however, the underlying molecular mechanisms remain poorly understood. Here we demonstrated that stimulation of alpha 2A-AR inhibited TRPM8 in sensory neurons from rat dorsal root ganglia (DRG). In addition, using specific pharmacological and molecular tools combined with patch-clamp current recordings, we found that in heterologously expressed HEK-293 (human embryonic kidney) cells, TRPM8 channel is inhibited by the G(i) protein/adenylate cyclase (AC)/cAMP/protein kinase A (PKA) signaling cascade. We further identified the TRPM8 S9 and T17 as two key PKA phosphorylation sites regulating TRPM8 channel activity. We therefore propose that inhibition of TRPM8 through the alpha 2A-AR signaling cascade could constitute a new mechanism of modulation of thermosensation in both physiological and pathological conditions.
Journal of Biological Chemistry 03/2010; 285(13):9410-9. · 4.77 Impact Factor
