anandamide and Endometriosis

The endocannabinoid system consists of an array of endogenously produced bioactive lipids that activate cannabinoid 1 (CB1) and 2 (CB2) receptors. Alterations of this system have been described in almost every category of disease. These changes can be protective or maladaptive, making the endocannabinoid network an attractive therapeutic target. Little is known about the potential role of endocannabinoids in endometriosis development although this is a topic worthy of further investigation since endocannabinoid modulators have recently been shown to affect specific mechanisms critical to endometriosis establishment and maintenance. A literature review was herein performed with the aim of defining the regulation and function of the endocannabinoid signaling in in vitro and animal models of endometriosis. The components of the endocannabinoid system, CB1 and CB2 receptors and the enzymes N-acylphosphatidylethanolamine-phospholipase D and fatty acid amide hydrolase are differentially regulated throughout the menstrual cycle in the endometrium and are expressed in deep endometriotic nodules and in sensory and sympathetic neurons innervating the lesions. Selective cannabinoid receptor agonists, such as WIN 55212-2, appear to have a favorable action in limiting cell proliferation and in controlling pain symptoms. Conversely, endometrial cell migration tends to be stimulated by receptor agonists. The phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase 1/2 pathways seem to be involved in these processes. However, the underlying mechanisms of action are only just beginning to unfold. Given the complexity of the system, further studies are needed to clarify whether the endocannabinoid system might represent a promising target for endometriosis.

Topics: Arachidonic Acids; Cannabinoids; Endocannabinoids; Endometriosis; Endometrium; Female; Humans; Polyunsaturated Alkamides

Although N-arachidonoylethanolamine (AEA; also known as anandamide) is present in human follicular fluid (FF), its regulation remains unknown. Therefore, the aims of the present study were to: (1) investigate the relationships between FF AEA concentrations in women undergoing assisted reproductive technology and their age, body mass index, ART characteristics and fertility treatment outcomes; and (2) assess how different inflammatory patterns may trigger AEA production by human granulosa cells (hGCs). FF AEA concentrations were higher in women undergoing IVF than in those undergoing intracytoplasmic sperm injection group. FF AEA median concentrations were lower in women undergoing ART because of male factor infertility than in women with endometriosis (1.6 vs 2.5nM respectively), but not women with tubal, hormonal or unexplained infertility (1.6, 2.4 and 1.9nM respectively). To evaluate the effects of macrophages on AEA production by hGCs, hGCs were cocultured with monocyte-derived macrophages. The conditioned medium from M1 polarised macrophages increased AEA production by hGCs. This was accompanied by an increase in AEA-metabolising enzymes, particularly N-acyl phosphatidylethanolamine-specific phospholipase D. The results of the present study show that high FF AEA concentrations in patients with endometriosis may be associated with the recruitment of inflammatory chemokines within the ovary, which together may contribute to the decreased reproductive potential of women with endometriosis. Collectively, these findings add a new player to the hormone and cytokine networks that regulate fertility in women.

Topics: Adolescent; Adult; Amidohydrolases; Arachidonic Acids; Case-Control Studies; Coculture Techniques; Cross-Sectional Studies; Endocannabinoids; Endometriosis; Female; Follicular Fluid; Granulosa Cells; Humans; Infertility, Female; Macrophages; Paracrine Communication; Phenotype; Phospholipase D; Polyunsaturated Alkamides; Prospective Studies; Reproductive Techniques, Assisted; THP-1 Cells; Young Adult

Cannabinoids and modulators of the endocannabinoid system affect specific mechanisms that are critical to the establishment and development of endometriosis. The aim of this study was to measure the systemic levels of endocannabinoids and related mediators in women with and without endometriosis and to investigate whether such levels correlated with endometriosis-associated pain. Plasma and endometrial biopsies were obtained from women with a laparoscopic diagnosis of endometriosis (n = 27) and no endometrial pathology (n = 29). Plasma levels of endocannabinoids (N-arachidonoylethanolamine [AEA] and 2-arachidonoylglycerol [2-AG]) and related mediators (N-oleoylethanolamine [OEA] and N-palmitoylethanolamine [PEA]), messenger RNA expression of some of their receptors (cannabinoid receptor type 1 [CB1], CB2, transient receptor potential vanilloid type [TRPV1]), and the enzymes involved in the synthesis (N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D [NAPE-PLD]) and degradation (fatty acid amide hydrolase 1 [FAAH]) of AEA, OEA, and PEA were evaluated in endometrial stromal cells. The systemic levels of AEA, 2-AG, and OEA were elevated in endometriosis in the secretory phase compared to controls. The expression of CB1 was higher in secretory phase endometrial stromal cells of controls versus endometriosis. Similar expression levels of CB2, TRPV1, NAPE-PLD, and FAAH were detected in controls and endometriosis. Patients with moderate-to-severe dysmenorrhea and dyspareunia showed higher AEA and PEA levels than those with low-to-moderate pain symptoms, respectively. The association of increased circulating AEA and 2-AG with decreased local CB1 expression in endometriosis suggests a negative feedback loop regulation, which may impair the capability of these mediators to control pain. These preliminary data suggest that the pharmacological manipulation of the action or levels of these mediators may offer an alternative option for the management of endometriosis-associated pain.

Topics: Adult; Amides; Amidohydrolases; Arachidonic Acids; Endocannabinoids; Endometriosis; Ethanolamines; Female; Glycerides; Humans; Menstrual Cycle; Middle Aged; Oleic Acids; Palmitic Acids; Phospholipase D; Polyunsaturated Alkamides; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; RNA, Messenger; Stromal Cells; TRPV Cation Channels; Young Adult