The role of glucagon-like peptide-1 in reproduction: from physiology to therapeutic perspective.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs) have become firmly established in the treatment of type 2 diabetes and obesity, disorders frequently associated with diminished reproductive health. Understanding of the role of GLP-1 and GLP-1 RAs in reproduction is currently limited and largely unaddressed in clinical studies. OBJECTIVE AND RATIONALE: The purpose of this narrative review is to provide a comprehensive overview of the role of GLP-1 in reproduction and to address a therapeutic perspective that can be derived from these findings. SEARCH METHODS: We performed a series of PubMed database systemic searches, last updated on 1 February 2019, supplemented by the authors' knowledge and research experience in the field. A search algorithm was developed incorporating the terms glucagon-like peptide-1, GLP-1, glucagon-like peptide-1 receptor, GLP-1R, or incretins, and this was combined with terms related to reproductive health. The PICO (Population, Intervention, Comparison, Outcome) framework was used to identify interventional studies including GLP-1 RAs and dipeptidyl peptidase-4 (DPP-4) inhibitors, which prevent the degradation of endogenously released GLP-1. We identified 983 potentially relevant references. At the end of the screening process, we included 6 observational (3 preclinical and 3 human) studies, 24 interventional (9 preclinical and 15 human) studies, 4 case reports, and 1 systematic and 2 narrative reviews. OUTCOMES: The anatomical distribution of GLP-1 receptor throughout the reproductive system and observed effects of GLP-1 in preclinical models and in a few clinical studies indicate that GLP-1 might be one of the important modulating signals connecting the reproductive and metabolic system. The outcomes show that there is mostly stimulating role of GLP-1 and its mimetics in mammalian reproduction that goes beyond mere weight reduction. In addition, GLP-1 seems to have anti-inflammatory and anti-fibrotic effects in the gonads and the endometrium affected by obesity, diabetes, and polycystic ovary syndrome (PCOS). It also seems that GLP-1 RAs and DPP-4 inhibitors can reverse polycystic ovary morphology in preclinical models and decrease serum concentrations of androgens and their bioavailability in women with PCOS. Preliminary data from interventional clinical studies suggest improved menstrual regularity as well as increased fertility rates in overweight and/or obese women with PCOS treated with GLP-1 RAs in the preconception period. WIDER IMPLICATIONS: GLP-1 RAs and DPP-4 inhibitors show promise in the treatment of diabetes and obesity-related subfertility. Larger interventional studies are needed to establish the role of preconception intervention with GLP-1 based therapies, assessing fertility outcomes in obesity, PCOS, and diabetes-related fertility problems. The potential impact of the dose- and exposure time-response of different GLP-1 RAs need further exploration. Future research should also investigate sex-specific variability of GLP-1 on reproductive outcomes, in particular on the gonads where the observations in males are most conflicting.

Kisspeptins and the control of gonadotrophin secretion.

Kisspeptins, the peptide products of the KiSS-1 gene, bind to the G protein coupled receptor 54 (GPR54). Since 2003, research has revealed the important role of kisspeptins in initiating puberty, timing puberty and regulating fertility in adulthood. Specific mutations in GPR54 gene cause either delayed/absent puberty or precocious puberty. The KiSS-1/GPR54 system stimulates the gonadotrophin releasing hormone (GnRH) neurons and is involved in the feedback regulation of the HPG axis by gonadal steroids. Different hypothalamic nuclei are involved in negative (arcuate nucleus; ARC) and positive (anteroventral periventricular nucleus; AVPV) feedback in mice. Continuous administration of kisspeptins down-regulates the HPG axis. During pregnancy, kisspeptins are secreted from the placenta in large amounts and are responsible for the physiological invasion of primary human trophoblast. Kisspeptins have been administered to normal male and female individuals as well as to women with hypothalamic secondary amenorrhoea. In all cases, gonadotrophin secretion was potently stimulated. Kisspeptin antagonists have been synthesized to successfully suppress GnRH and gonadotrophin release. These agonists and antagonists appear as valuable new tools for manipulating the HPG axis and are promising drugs for future treatment. The scope of this review highlights the role of kisspeptins in regulating gonadotrophin secretion and explores their possible therapeutic use.

Recent developments in antiandrogens and selective androgen receptor modulators.

The androgens testosterone and dihydrotestosterone play an essential role in the development and maintenance of primary and secondary male characteristics. Androgens bind to a specific androgen receptor (AR), a ligand-dependent transcription factor which controls the expression of a large number of downstream target genes. The AR is an essential player in early and late prostate cancer, and may also be involved in some forms of breast cancer. It also represents a drug target for the treatment of hypogonadism. Recent studies furthermore indicate that targeting the AR in pathologies such as frailty syndrome, cachexia or polycystic ovary syndrome may have clinical benefit. Numerous AR ligands with very different pharmacological properties have been identified in the last 40 years and helped to treat several of these diseases. However, progress still needs to be made in order to find compounds with an improved profile with regard to efficacy, differentiation and side-effects. This will only be achieved through a better understanding of the mechanisms involved in normal and aberrant AR signaling.

Disfunção do eixo gonadotrófico em homens com infecção pelo HIV/Aids: [revisão] / Gonadotrophic axis dysfunction in men with HIV-infection/Aids: [review]

A disfunção do eixo gonadotrófico é frequentemente observada em pacientes infectados pelo HIV. A patogênese é multifatorial e está relacionada à duração da infecção pelo HIV, aos efeitos citopáticos diretos do vírus, ao uso de drogas gonadotóxicas, às infecções oportunistas, às neoplasias, à desnutrição, entre outros fatores. Em homens, a redução dos níveis de testosterona está associada à perda de massa e de força muscular, à redução da densidade mineral óssea, à lipodistrofia, à depressão, à astenia, à fadiga e à disfunção sexual. Em pacientes infectados pelo HIV com hipogonadismo, inúmeros estudos têm comprovado os efeitos benéficos da reposição de testosterona sobre o perfil metabólico e a distribuição da gordura corporal, com aumento da massa corporal magra, além de promover melhora da qualidade de vida, reduzir a perda de massa óssea e reduzir os índices de depressão. Assim, esta revisão teve como objetivo trazer uma breve atualização sobre o presente tema, abordando dados epidemiológicos, mecanismos fisiopatológicos e estratégias terapêuticas para as principais anormalidades do eixo gonadotrófico masculino associadas à infecção pelo HIV e ao seu tratamento.

Gonadotrophic axis dysfunction is commonly observed in HIV-infected patients. The pathogenesis is multifactorial and related to duration of HIV infection, direct cytopathic effects of viruses, use of drugs, opportunistic infections, malignancies, and malnutrition, among other factors. In men, reduced levels of testosterone is associated with loss of muscle mass and strength, decreased bone mineral density, lipodystrophy, depression, asthenia, fatigue and sexual dysfunction. In HIV-infected patients with hypogonadism, numerous studies have shown the beneficial effects of testosterone replacement on the metabolic profile and distribution of body fat, with increased body mass weight, and promote better quality of life, reduce the bone mass loss and the rates of depression. Thus, this review aimed to present a brief update of epidemiologic data, pathophysiology aspects and treatment strategies for the major abnormalities of male gonadotrophic axis associated with HIV infection and its treatment.

[Effect of Tripterygium wilfordii on gonadal injury and progression of its relative Chinese medicine therapy].

The paper reviewed the clinical manifestation and potential mechanism of gonadal injury of Tripterygium wilfordii and the progression of its relative Chinese medicine therapy. The therapeutic effect of T. wilfordii is certain, but its adverse effect is obvious. Therefore, it is very important to investigate the relative therapy for the exploration of rationality and regularity of drug compatibility.

[Gonadotrophic axis dysfunction in men with HIV-infection/aids]. / Disfunção do eixo gonadotrófico em homens com infecção pelo HIV/Aids.

Gonadotrophic axis dysfunction is commonly observed in HIV-infected patients. The pathogenesis is multifactorial and related to duration of HIV infection, direct cytopathic effects of viruses, use of drugs, opportunistic infections, malignancies, and malnutrition, among other factors. In men, reduced levels of testosterone is associated with loss of muscle mass and strength, decreased bone mineral density, lipodystrophy, depression, asthenia, fatigue and sexual dysfunction. In HIV-infected patients with hypogonadism, numerous studies have shown the beneficial effects of testosterone replacement on the metabolic profile and distribution of body fat, with increased body mass weight, and promote better quality of life, reduce the bone mass loss and the rates of depression. Thus, this review aimed to present a brief update of epidemiologic data, pathophysiology aspects and treatment strategies for the major abnormalities of male gonadotrophic axis associated with HIV infection and its treatment.

Structural characterization of the human androgen receptor ligand-binding domain complexed with EM5744, a rationally designed steroidal ligand bearing a bulky chain directed toward helix 12.

Antiandrogens are commonly used to treat androgen-dependent disorders. The currently used drugs unfortunately possess very weak affinity for the human AR (hAR), thus indicating the need to develop new high-affinity steroidal antiandrogens. Our compounds are specially designed to impede repositioning of the mobile carboxyl-terminal helix 12, which blocks the ligand-dependent transactivation function (AF-2) located in the AR ligand-binding domain (ARLBD). Using crystal structures of the hARLBD, we first found that H12 could be directly reached from the ligand-binding pocket (LBP) by a chain positioned on the C18 atom of an androgen steroid nucleus. A set of 5alpha-dihydrotestosterone-derived molecules bearing various C18 chains were thus synthesized and tested for their capacity to bind hAR and act as antagonists. Although most of those having very high affinity for hAR were agonists, several very potent antagonists were obtained, confirming the structural importance of the C18 chain. To understand the role of the C18 chain in their agonistic/antagonistic properties, the structure of the hARLBD complexed with one of these agonists, EM5744, was determined at a 1.65-A resolution. We have identified new interactions involving Gln(738), Met(742), and His(874) that explain both the high affinity of this compound and the inability of its bulky chain to prevent the repositioning of H12. This structural information will be helpful to refine the structure of the chains placed on the C18 atom to obtain efficient H12-directed steroidal antiandrogens.

Probucol therapy overcomes the reproductive defect in CTP: phosphocholine cytidylyltransferase beta2 knockout mice.

The synthesis of phosphatidylcholine (PtdCho), the major phospholipid in mammalian cells, is regulated by the CTP:phosphocholine cytidylyltransferase (CCT). Loss of the CCTbeta2 isoform expression in mice results in gonadal dysfunction. CCTbeta2(-/-) females exhibit ovarian tissue disorganization with progressive loss of follicle formation and oocyte maturation. Ultrastructure revealed a disrupted association between ova and granulosa cells and disorganized Golgi apparati in oocytes of CCTbeta2(-/-) mice. Probucol is a cholesterol-lowering agent that stimulates the uptake and retention of lipids carried by lipoproteins in peripheral tissues. Probucol therapy significantly lowered both serum cholesterol and PtdCho levels. Probucol therapy increased fertility in the CCTbeta2(-/-) females 100%, although it did not completely correct the phenotype, the morphological abnormalities in the knockout ovaries or itself stimulate CCT activity directly. These data indicated that a deficiency in de novo PtdCho synthesis could be complemented by altering the metabolism of serum lipoproteins, an alternative source for cellular phospholipid.

Activity of thalidomide in patients with platinum-refractory germ-cell tumours.

The aim of this study was assess the activity of thalidomide in patients with progressive relapsed or platinum-refractory germ-cell tumours (GCT). Between April 2002 and January 2003, 15 patients with inoperable progressive GCT were treated with escalated daily doses of 200-600 mg thalidomide. All patients had failed first-line and salvage chemotherapy with a median of 6 (range 4-12) cisplatin-based treatment cycles, 13/15 (87%) patients had received high-dose chemotherapy (HDCT) and 8/15 (53%) patients were considered platinum-refractory or absolute refractory; 8/15 (53%) patients had previously received other palliative chemotherapy regimens. No patient achieved a complete remission (CR) or partial remission (PR). However, 5/15 (33%) patients achieved serological PR and 1 additional patient had stable disease for 3 months. The median duration of remissions was 3 months (range 2-12 months) including 2 patients with a progression-free survival of 9 and 12 months. Responses occurred mainly in patients with a low tumour burden, slow disease progression and alpha-foetoprotein (AFP) elevations. Responses to thalidomide were independent from platinum-sensitivity. Toxicity was mild, with lethargy and constipation in the majority of patients. Skin rash grade II developed in 2 patients and peripheral neurotoxicity grade II/III developed in 4 patients. One responding patient died suddenly from an unknown cause. It is concluded that thalidomide shows single-agent activity in patients with heavily pre-treated GCT, AFP elevations and slowly progressive disease.

Drugs and hormones used to treat pediatric and adolescent reproductive endocrine disorders.

Pediatric and adolescent reproductive endocrine disorders represent a myriad of diseases including cryptorchidism, male and female sex steroid deficiencies, precocious puberty, and polycystic ovarian syndrome. While there are many traditional therapeutic interventions, some disorders now benefit from new medications or formulations. In this article, we review the most commonly used pharmacological therapies for these disorders and discuss treatment controversies and toxicities.

A clinician's guide to the use of gonadotropin-releasing hormone analogues in women.

Gonadotropin-releasing hormone (GnRH) and its analogues have been extensively used in clinical medicine since they were identified and synthesized in 1971. Native GnRH stimulates gonadotrophs of the anterior pituitary and has been used for induction of ovulation. The GnRH agonists, which have greater potency and a longer half-life than native GnRH, produce an initial stimulation of pituitary gonadotrophs that results in secretion of follicle-stimulating hormone and luteinizing hormone and the expected gonadal response. This response is followed by downregulation and inhibition of the pituitary-gonadal axis. The GnRH antagonists promptly suppress pituitary gonadotropin by GnRH-receptor competition, thereby avoiding the initial stimulatory phase of the agonists. Discontinuation of GnRH antagonist treatment leads to a rapid and predictable recovery of the pituitary-gonadal axis. The GnRH analogues are potent therapeutic agents that are considerably useful in a variety of clinical indications. These indications include management of endometriosis, uterine leiomyomas, hirsutism, dysfunctional uterine bleeding, premenstrual syndrome, assisted reproduction, and some hormone-dependent tumors.

Autologous bone marrow transplantation for childhood acute lymphoblastic leukaemia in second remission - long-term follow-up.

From 1984 to 1996, 31 consecutive children without sibling donors, aged 5-19 years (median 8) with acute lymphoblastic leukaemia (ALL) in second complete remission (CR), received unpurged autologous bone marrow transplantation (ABMT) after melphalan and single fraction total body irradiation (TBI). ABMT was performed using fresh unmanipulated marrow harvested after standard reinduction and consolidation therapy 2-11 months (median 5) after relapse. With a median survival of 2.9 years the probability of survival for all patients in continuing second CR was 45.1% (95% CI, 24%-62%) after 5 years. Regimen-related and non-leukaemia mortality was 7% (95% CI, 2%-26%). The longest time to second relapse from ABMT was 3.1 years. Pituitary and gonadal dysfunction requiring hormonal replacement therapy occurred in the majority of long-term survivors. Twelve patients developed cataracts. ABMT with melphalan/single fraction TBI has proved an effective anti-leukaemia treatment with low regimen-related mortality but significant long-term morbidity. The current approach of allogeneic BMT from an unrelated donor when no sibling donor is available, following conditioning with cyclophosphamide/ fractionated TBI has resulted in a reduced relapse rate and improved short-term overall survival in the treatment of relapsed childhood ALL. However, long-term results are awaited.