Progesterone Up-Regulates Anandamide Hydrolase in Human Lymphocytes: Role of Cytokines and Implications for Fertility

Abstract

Physiological concentrations of progesterone stimulate the activity of the endocannabinoid-degrading enzyme anandamide hydrolase (fatty acid amide hydrolase, FAAH) in human lymphocytes. At the same concentrations, the membrane-impermeant conjugate of progesterone with BSA was ineffective, suggesting that binding to an intracellular receptor was needed for progesterone activity. Stimulation of FAAH occurred through up-regulation of gene expression at transcriptional and translational level, and was partly mediated by the Th2 cytokines. In fact, lymphocyte treatment with IL-4 or with IL-10 had a stimulating effect on FAAH, whereas the Th1 cytokines IL-12 and IFN-γ reduced the activity and the protein expression of FAAH. Human chorionic gonadotropin or cortisol had no effect on FAAH activity. At variance with FAAH, the lymphocyte anandamide transporter and cannabinoid receptors were not affected by treatment with progesterone or cytokines. Good FAAH substrates such as anandamide and 2-arachidonoylglycerol inhibited the release of leukemia-inhibitory factor from human lymphocytes, but N-palmitoylethanolamine, a poor substrate, did not. A clinical study performed on 100 healthy women showed that a low FAAH activity in lymphocytes correlates with spontaneous abortion, whereas anandamide transporter and cannabinoid receptors in these cells remain unchanged. These results add the endocannabinoids to the hormone-cytokine array involved in the control of human pregnancy.

Progesterone Activates Fatty Acid Amide Hydrolase (FAAH) Promoter in Human T Lymphocytes through the Transcription Factor Ikaros

“…Incubation of T lymphocytes with P, alone or in the presence of different compounds, was performed at 37°C in humidified 5% CO 2 atmosphere, at the indicated concentrations and for the indicated periods of time. Cells were treated for 1 h in serum-free medium, and then heat-inactivated fetal bovine serum was added at a final concentration of 10% (12). Controls were incubated with vehicles alone.…”

“…Peripheral lymphocytes were purified by gradient centrifugation, using the density separation medium Lymphoprep (Nycomed Pharma, Oslo, Norway), and then T-cells were isolated from the whole lymphocyte population by means of the Dynal CD2 CELLection kit (Dynal, Olso, Norway), as reported previously (12). Purified T lymphocytes were resuspended in RPMI 1640 medium (Invitrogen, Paisley, UK), supplemented with 25 mM Hepes, 2.5 mM sodium pyruvate, 100 units/ml penicillin, 100 g/ml streptomycin, and 10% heat-inactivated fetal bovine serum (Invitrogen), at a density of 1.5 ϫ 10 6 cells/ml in ventilated 25-ml flasks (12). Incubation of T lymphocytes with P, alone or in the presence of different compounds, was performed at 37°C in humidified 5% CO 2 atmosphere, at the indicated concentrations and for the indicated periods of time.…”

“…Indeed, P has been shown to favor the development of human T lymphocytes producing type 2 T-helper (Th2) cytokines (interleukins 4 and 10), which inhibit Th1-type cytokines (interleukin-12 and interferon-␥), thus allowing the survival of fetal allograft and therefore a successful pregnancy (10,11). In this context, the activity of FAAH in maternal peripheral lymphocytes is under control of progesterone, which binds to its intracellular receptor and activates FAAH expression (12). As a consequence, the release of cytokines critical for fertility, such as the leukemia inhibitory factor, is favored (12).…”

“…In this context, the activity of FAAH in maternal peripheral lymphocytes is under control of progesterone, which binds to its intracellular receptor and activates FAAH expression (12). As a consequence, the release of cytokines critical for fertility, such as the leukemia inhibitory factor, is favored (12). Moreover, lymphocyte FAAH has been shown to control the levels of blood AEA in pregnant women, where low FAAH activity implies high AEA levels, leading to spontaneous abortion (7,12,13).…”

“…As a consequence, the release of cytokines critical for fertility, such as the leukemia inhibitory factor, is favored (12). Moreover, lymphocyte FAAH has been shown to control the levels of blood AEA in pregnant women, where low FAAH activity implies high AEA levels, leading to spontaneous abortion (7,12,13). Taken together, these data have suggested a cross-talk between steroid hormones, cytokines, and the peripheral endocannabinoid system in lymphocytes, which is implicated in regulating immunity and fertility in humans (14).…”