The role of the endocannabinoid system in aetiopathogenesis of endometriosis: A potential therapeutic target

Placental Cannabinoid Receptor Expression in Preterm Birth

Background: The cannabinoid receptor (CBR) plays a significant role in oogenesis, pregnancy, and childbirth. It might also play a significant role in preterm birth (PTB). The aim of the study was to investigate the association between the expression of the CBR in the placenta and the incidence of PTB. Methods: This prospective, observational, multicentre preliminary study was conducted on placental samples obtained from 109 women. The study included 95 patients hospitalized due to the high risk of PTB. They were divided into two groups: Group 1, where the expression of the CBR1 and CBR1a was analyzed, and Group 2, in which we examined CBR2 expression. The control group, that is, Group 3, consisted of 14 women who delivered at term, and their placentas were tested for the presence of all three receptor types (CBR1, CBR1a, and CBR2). Results: The study used reverse transcription and real-time PCR methods to assess the expression of CBRs in the placental tissues. The expression of the CBR2, CBR1, and CBR1a receptors was significantly lower in the placentas of women after PTB compared to those after term births, p = 0.038, 0.033, and 0.034, respectively. Conclusions: The presence of CBR mRNA in the human placental tissue was confirmed. The decreased expression of CBRs could serve as an indicator in predicting PTB.

Therapeutic applicability of cannabidiol and other phytocannabinoids in epilepsy, multiple sclerosis and Parkinson's disease and in comorbidity with psychiatric disorders

Studies have demonstrated the neuroprotective effect of cannabidiol (CBD) and other Cannabis sativa L. derivatives on diseases of the central nervous system caused by their direct or indirect interaction with endocannabinoid system-related receptors and other molecular targets, such as the 5-HT1A receptor, which is a potential pharmacological target of CBD. Interestingly, CBD binding with the 5-HT1A receptor may be suitable for the treatment of epilepsies, parkinsonian syndromes and amyotrophic lateral sclerosis, in which the 5-HT1A serotonergic receptor plays a key role. The aim of this review was to provide an overview of cannabinoid effects on neurological disorders, such as epilepsy, multiple sclerosis and Parkinson's diseases, and discuss their possible mechanism of action, highlighting interactions with molecular targets and the potential neuroprotective effects of phytocannabinoids. CBD has been shown to have significant therapeutic effects on epilepsy and Parkinson's disease, while nabiximols contribute to a reduction in spasticity and are a frequent option for the treatment of multiple sclerosis. Although there are multiple theories on the therapeutic potential of cannabinoids for neurological disorders, substantially greater progress in the search for strong scientific evidence of their pharmacological effectiveness is needed.

Cannabis and Endometriosis: The Roles of the Gut Microbiota and the Endocannabinoid System

Endometriosis, a chronic condition affecting around 10-14% of women, is challenging to manage, due to its complex pathogenesis and limited treatment options. Research has suggested a potential role of the gut microbiota and the endocannabinoid system in the development and progression of endometriosis. This narrative review aims to explore the role of, and any potential interactions between, the endocannabinoid system (ECS) and the gut microbiota in endometriosis. This review found that both the ECS and microbiota influence endometriosis, with the former regulating inflammation and pain perception and the latter influencing immune responses and hormonal balance. There is evidence that a dysregulation of the endocannabinoid system and the gut microbiota influence endometriosis symptoms and progression via changes in CB1 receptor expression and increased circulating levels of endocannabinoids. Microbial imbalances in the gut, such as increases in Prevotella, have been directly correlated to increased bloating, a common endometriosis symptom, while increases in E. coli have supported the bacterial contamination hypothesis as a potential pathway for endometriosis pathogenesis. These microbial imbalances have been correlated with increases in inflammatory markers such as TNF-α and IL-6, both often raised in those with endometriosis. Protective effects of the ECS on the gut were observed by increases in endocannabinoids, including 2-AG, resulting in decreased inflammation and improved gut permeability. Given these findings, both the ECS and the gut microbiota may be targets for therapeutic interventions for endometriosis; however, clinical studies are required to determine effectiveness.

Role of the endocannabinoid system in the pathophysiology of endometriosis and therapeutic implications

Endometriosis patients experience debilitating chronic pain, and the first-line treatment is ineffective at managing symptoms. Although surgical removal of the lesions provides temporary relief, more than 50% of the patients experience disease recurrence. Despite being a leading cause of hysterectomy, endometriosis lacks satisfactory treatments and a cure. Another challenge is the poor understanding of disease pathophysiology which adds to the delays in diagnosis and overall compromised quality of life. Endometriosis patients are in dire need of an effective therapeutic strategy that is both economical and effective in managing symptoms, while fertility is unaffected. Endocannabinoids and phytocannabinoids possess anti-inflammatory, anti-nociceptive, and anti-proliferative properties that may prove beneficial for endometriosis management, given that inflammation, vascularization, and pain are hallmark features of endometriosis. Endocannabinoids are a complex network of molecules that play a central role in physiological processes including homeostasis and tissue repair, but endocannabinoids have also been associated in the pathophysiology of several chronic inflammatory diseases including endometriosis and cancers. The lack of satisfactory treatment options combined with the recent legalization of recreational cannabinoids in some parts of the world has led to a rise in self-management strategies including the use of cannabinoids for endometriosis-related pain and other symptoms. In this review, we provide a comprehensive overview of endocannabinoids with a focus on their potential roles in the pathophysiology of endometriosis. We further provide evidence-driven perspectives on the current state of knowledge on endometriosis-associated pain, inflammation, and therapeutic avenues exploiting the endocannabinoid system for its management.

Gene expression of the endocannabinoid system in endometrium through menstrual cycle

Endocannabinoids mediate cellular functions and their activity is controlled by a complex system of enzymes, membrane receptors and transport molecules. Endocannabinoids are present in endometrium, a cyclical regenerative tissue requiring tightly regulated cellular mechanisms for maturation. The objective of this study was to investigate the gene expression of key elements involved in the endocannabinoid system across the menstrual cycle. RNA was isolated from endometrial tissue and genome-wide gene expression datasets were generated using RNA-sequencing. An a priori set of 70 genes associated with endocannabinoid system were selected from published literature. Gene expression across the menstrual cycle was analyzed using a moderated t test, corrected for multiple testing with Bonferroni’s method. A total of 40 of the 70 genes were present in > 90% of the samples, and significant differential gene expression identified for 29 genes. We identified 4 distinct regulation patterns for synthesizing enzymes, as well as a distinct regulation pattern for degradations and transporting enzymes. This study charts the expression of endometrial endocannabinoid system genes across the menstrual cycle. Altered expression of genes that control endocannabinoid may allow fine control over endocannabinoid concentrations and their influence on cellular function, maturation and differentiation as the endometrium matures through the menstrual cycle.

Directive clinique no 425a : Le cannabis aux différentes périodes de la vie des femmes - Partie 1 : Fertilité, contraception, ménopause et douleur pelvienne

OBJECTIF

Fournir aux fournisseurs de soins de santé les meilleures données probantes sur l'utilisation de cannabis et la santé des femmes. Les domaines d'intérêt sont : les profils généraux d'utilisation du cannabis ainsi que la sécurité de la consommation; les soins aux femmes qui utilisent le cannabis; la stigmatisation; le dépistage, l'intervention brève et l'orientation vers le traitement; les effets sur la régulation hormonale; la santé reproductive, y compris la contraception et la fertilité; la fonction sexuelle; les effets sur les symptômes périménopausiques et postménopausiques; et l'utilisation dans le traitement des syndromes de douleur pelvienne chronique.

POPULATION CIBLE

La population cible comprend toutes les femmes qui consomment ou utilisent du cannabis ou qui envisagent de le faire. RéSULTATS: Un dialogue ouvert et fondé sur des données probantes relativement à l'utilisation et la consommation de cannabis, dialogue qui mènera à l'amélioration des soins aux patientes. BéNéFICES, RISQUES ET COûTS: L'exploration de l'utilisation et de la consommation de cannabis par une approche basée sur la connaissance des traumatismes donne l'occasion au fournisseur de soins et à la patiente de créer une solide alliance thérapeutique collaborative. Cette alliance permet aux femmes de faire des choix éclairés sur leurs propres soins. Elle facilite également le diagnostic et le traitement possible des troubles de l'usage du cannabis. Il ne faut pas stigmatiser la consommation, car la stigmatisation nuit à l'alliance thérapeutique (c'est-à-dire le partenariat entre la patiente et le fournisseur de soins). Plusieurs effets indésirables de la consommation de cannabis peuvent être confondus avec d'autres problèmes de santé. À l'heure actuelle, l'utilisation du cannabis pour traiter les problèmes de santé féminine n'est pas financée par le secteur public; par conséquent, les utilisatrices doivent assumer les coûts directs. Les coûts indirects de l'utilisation de cannabis sont inconnus. Ainsi, les fournisseurs de soins et les patientes doivent comprendre le rôle du cannabis dans les problèmes de santé féminine de sorte que les femmes puissent prendre des décisions éclairées. DONNéES PROBANTES: Des recherches ont été effectuées dans PubMed, Embase et la littérature grise pour recenser des études publiées entre le 1^er janvier 2018 et le 18 février 2021 concernant l'utilisation du cannabis et ses effets sur l'infertilité, la contraception, les symptômes périménopausiques et postménopausiques et la douleur pelvienne. Toutes les publications des types suivants ont été incluses : essais cliniques, études observationnelles, revues (y compris les revues systématiques et les méta-analyses), directives cliniques et déclarations de conférences de consensus. Un survol des publications a été effectué pour en confirmer la pertinence. Les termes de recherche ont été définis à l'aide des termes MeSH (Medical Subject Headings) et mots clés (et variantes) suivants : cannabis, cannabinoids, marijuana, dexanabinol, dronabinol et tetrahydrocannabinol. À ces termes ont été combinés les termes suivants afin de cerner la santé des femmes : estrogen, estradiol, medroxyprogesterone acetate, vaginal contraception, oral contraceptives, fertilization, amenorrhea, oligomenorrhea, pelvic pain, dysmenorrhea, endometriosis, interstitial cystitis, vulvodynia et menopause. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant l'approche d'évaluation, de développement et d'évaluation (GRADE). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins de santé qui prodiguent des soins aux femmes. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Guideline No. 425a: Cannabis Use Throughout Women's Lifespans - Part 1: Fertility, Contraception, Menopause, and Pelvic Pain

OBJECTIVE

To provide health care providers with the best evidence on cannabis use with respect to women's health. Areas of focus include general patterns of cannabis use as well as safety of use; care for women who use cannabis; stigma; screening, brief intervention, and referral to treatment; impact on hormonal regulation; reproductive health, including contraception and fertility; sexual function; effects on perimenopausal and menopausal symptoms; and use in chronic pelvic pain syndromes.

TARGET POPULATION

The target population includes all women currently using or contemplating using cannabis.

OUTCOMES

Open, evidence-informed dialogue about cannabis use, which will lead to improvement in patient care.

BENEFITS, HARMS, AND COSTS

Exploring cannabis use through a trauma-informed approach provides the health care provider and patient with an opportunity to build a strong, collaborative, therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of cannabis use disorders. Use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Multiple side effects of cannabis use may be mistaken for other disorders. Currently, use of cannabis to treat women's health issues is not covered by public funding; as a result, individual users must pay the direct cost. The indirect costs of cannabis use are unknown. Thus, health care providers and patients must understand the role of cannabis in women's health issues, so that women can make knowledgeable decisions.

EVIDENCE

PubMed, EMBASE, and grey literature were searched to identify studies of "cannabis use and effect on infertility, contraception, perimenopause and menopausal symptoms, and pelvic pain" published between January 1, 2018 and February 18, 2021. All clinical trials, observational studies, reviews (including systematic reviews and meta-analyses), guidelines, and conference consensus statements were included. Publications were screened for relevance. The search terms were developed using the Medical Subject Headings (MeSH) terms and keywords (and variants), including cannabis, cannabinoids, marijuana, dexanabinol, dronabinol, tetrahydrocannabinol; the specific terms to capture women's health were estrogen, estradiol, medroxyprogesterone acetate, vaginal contraception, oral contraceptives, fertilization, amenorrhea, oligomenorrhea, pelvic pain, dysmenorrhea, endometriosis, interstitial cystitis, vulvodynia, and menopause.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All heath care providers who care for women.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Neurogenic Inflammation in the Context of Endometriosis-What Do We Know?

Endometriosis (EM) is an estrogen-dependent disease characterized by the presence of epithelial, stromal, and smooth muscle cells outside the uterine cavity. It is a chronic and debilitating condition affecting ~10% of women. EM is characterized by infertility and pain, such as dysmenorrhea, chronic pelvic pain, dyspareunia, dysuria, and dyschezia. Although EM was first described in 1860, its aetiology and pathogenesis remain uncertain. Recent evidence demonstrates that the peripheral nervous system plays an important role in the pathophysiology of this disease. Sensory nerves, which surround and innervate endometriotic lesions, not only drive the chronic and debilitating pain associated with EM but also contribute to a growth phenotype by secreting neurotrophic factors and interacting with surrounding immune cells. Here we review the role that peripheral nerves play in driving and maintaining endometriotic lesions. A better understanding of the role of this system, as well as its interactions with immune cells, will unearth novel disease-relevant pathways and targets, providing new therapeutics and better-tailored treatment options.

Cannabidiol for the Management of Endometriosis and Chronic Pelvic Pain

OBJECTIVE

To review the available literature on the effect of cannabis-based products on the female reproductive system and establish if there is any evidence that they benefit or harm patients with endometriosis and therefore if there is sufficient evidence to recommend them.

DATA SOURCES

An electronic-based search was performed in PubMed, Embase and the Cochrane Database. Reference lists of articles retrieved were reviewed and a grey literature search was also performed.

METHODS OF STUDY SELECTION

The original database search yielded 264 articles from PubMed, Embase and the Cochrane Database, of which forty-one were included. One hundred and sixty-one studies relating to gynaecological malignancy, conditions unrelated to endometriosis or therapies unrelated to cannabis-based products were excluded. Twelve articles were included from a grey literature search and review of references.

RESULTS

The majority of available evidence is from laboratory studies aiming to simulate the effects of cannabis-based products on preclinical endometriosis models. Some show evidence of benefit with cannabis-based products. However, results are conflicting and the impact in humans cannot necessarily be extrapolated from this data. Few studies exist looking at the effect of cannabis or its derived products in women with endometriosis - the majority are in the form of surveys and are affected by bias. National guidance was also reviewed: at present this dictates that cannabis-based products can only be prescribed for conditions where there is clear published evidence of benefit and only when all other treatment options have been exhausted.

CONCLUSION

Current treatment options for endometriosis often affect fertility and/or have undesirable side effects that impede long-term management. Cannabis-based products have been suggested as a novel therapeutic option that may circumvent these issues. However, there is a paucity of well-designed, robust studies and randomised controlled trials looking at their use in the treatment of endometriosis. In addition, cannabis use has a potential for harm in the long term; with a possible association with 'cannabis use disorder', psychosis and mood disturbances. At present, national guidance cannot recommend cannabis-based products to patients in the UK due to lack of clear evidence of benefit. More comprehensive research into the impact of endocannabinoids in the context of endometriosis is required before their use can be recommended or prescribed.

Cannabis and Cannabinoids in Reproduction and Fertility: Where We Stand

Although cannabis use is increasing in general population, their prevalence among young adults is remarkably high. In recent years, their medical use gained a renewed interest. However, it can underline the reputation of cannabis being a harmless drug. Between cannabinoids, uniquely found on the cannabis plant, Δ⁹-tetrahydrocannabinol (THC) is the well-studied compound. It is responsible for the psychoactive effects via central cannabinoid receptors. Nevertheless, cannabinoids interact with other chemical signalling systems such as the hypothalamic-pituitary-gonadal axis. THC indirectly decreases gonadotropin-releasing hormone (GnRH) secretion by the hypothalamus. The consequences are diverse, and several key hormones are affected. THC disturbs important reproductive events like folliculogenesis, ovulation and sperm maturation and function. Although generally accepted that cannabinoid consumption impacts male and female fertility, prevailing evidence remains largely on pre-clinical studies. Here, we introduce cannabinoids and the endocannabinoid system, and we review the most prominent clinical evidence about cannabis consumption in reproductive potential and teratogenicity.

Concentrations of the endocannabinoid N-arachidonoylethanolamine in the follicular fluid of women with endometriosis: the role of M1 polarised macrophages

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.