Ghrelin misbalance affects mice embryo implantation and pregnancy success by uterine immune dysregulation and nitrosative stress.

Introduction: In a previous study we found that ghrelin (Ghrl) misbalance during the peri-implantation period significantly impaired fetus development. In this study we aimed to evaluate the putative mechanisms underlying these effects, including embryo implantation success, uterine nitric oxide synthase (NOS) activity, nitric oxide synthesis and the inflammatory/immune uterine profile. Methods: Ghrelin misbalance was induced by injecting 4nmol/animal/day of Ghrl (hyperghrelinemia) or 6nmol/animal/day of a Ghrl antagonist (Ant: (D-Lys3)GHRP-6) from day 3 to 8 of pregnancy. Control animals (C) were injected with de vehicle. Females were euthanized at pregnancy day 8 and their uteri excised in order to evaluate: the percentage of reabsorbed embryos (microscopically), eNOS, iNOS and nytrotirosine expression (by immunohistochemistry), nitrite synthesis (by Griess technique), VEGF, IL-10, IL-17, IL-6, MMP9 and GM-CSF expression (by qPCR) and leukocyte infiltration by flow cytometry (evaluating T cells, NK cells, granulocytes, dendritic cells and macrophages). Results: Ant-treatment significantly increased the percentage of reabsorbed embryos and the uterine expression of eNOS, iNOS and nytrotirosine. (D-Lys3)GHRP-6-treatment increased also the expression of the inflammatory cytokines IL-6, IL-17 and MMP9, and decreased that of IL-10 (anti-inflammatory). Moreover, Ant-treatment increased also the NK cells population and that of CD11b+ dendritic cells; and decreased T cells percentages. Similarly, hyperghrelinemia showed a significant increase vs. C on eNOS, iNOS and nytrotirosineuterine expression and a decrease in T cells percentages. Conclusion: Ghrl misbalance during the peri-implantation period induces pro-inflammatory changes and nitrosative stress in the gravid uterus, impairing significantly embryo implantation and/or development.

Evolution of Risk Behaviors, Sexually Transmitted Infections and PrEP Care Continuum in a Hospital-Based PrEP Program in Barcelona, Spain: A Descriptive Study of the First 2 Years' Experience.

INTRODUCTION: Pre-exposure prophylaxis (PrEP) is effective for HIV prevention, but the PrEP care continuum also involves improving PrEP awareness, uptake, adherence, and retention in care. Users' awareness is often compromised because of vulnerability factors and risk behaviors, such as chemsex practice or specific substance use, which could lead to risk compensation. Correct adherence and retention in care are essential to achieve the full effectiveness of PrEP. This study describes changes in users' risk behaviors and sexually transmitted infections (STIs), as well also PrEP care continuum details. METHODS: This was a descriptive single-center retrospective study including adults at high HIV risk screened between November 2019 and June 2021 in the PrEP program of our hospital. Demographic, behavioral, STI, adherence, and retention in care variables were assessed. Data were collected from medical records and self-report questionnaires. RESULTS: A total of 295 people were included, 94% men and 5% transgender women, with a mean age of 34 years (SD 10) and 10% sex workers. At baseline, 55% disclosed chemsex practice and 3% slamming. During follow-up, condom use for anal intercourse decreased from 41% to 13% (p ≤ 0.0001) and one HIV infection was detected; other risk behaviors and STIs remained stable. Chemsex, group sex, fluid exchange, and condomless anal intercourse were related to STI risk. Adherence was correct in 80% of users, and retention in care was 57%. Discontinuations and loss to follow-up were high, mainly affecting transgender women, sex workers, and people practicing fisting. CONCLUSION: PrEP program implementation in our hospital was adequate, since it allowed, in a population at high HIV risk, overall users' risk behaviors and STIs to remain stable, with only one HIV diagnosis during the follow-up. We should target specific strategies to improve adherence and retention in care, as vulnerable subgroups at higher risk of loss to follow-up are identified.

Chemsex Practices in PrEP: Beyond Addiction and Risk Toward a Healthy Sex Life-Baseline Experiences from a Hospital-Based PrEP Program in Barcelona, Spain.

Pre-exposure prophylaxis (PrEP) is a biomedical intervention that has demonstrated efficacy in HIV prevention in individuals at high-risk, among them chemsex users. Out of 190 PrEP users followed at Hospital Clinic of Barcelona until October 2020, 89% reported drug use, and 63% disclosed that they had engaged in chemsex practices, initiated in 64% of cases within the past year. Twenty-one percent used 3 or more drugs simultaneously, being GHB/GBL, nitrites, sildenafil, and methamphetamine the most prevalent combination. Eight percent reported slamming. Forty-one percent described having had negative experiences and 8% did not remember the last time they had sober sex. Methamphetamine, mephedrone, GHB/GBL, and having had open relationships, group sex, double penetration, and fisting were significantly more prevalent. Forty-nine percent admitted being worried about chemsex use, and 18% said they needed help. A comprehensive, interdisciplinary approach is mandatory to enable the attainment of a healthy approach to one's sex life.

RESUMEN: La PrEP es una intervención biomédica eficaz en la prevención del VIH en personas con alto riesgo, entre ellas las personas que practican chemsex. De los 190 usuarios de PrEP seguidos en el Hospital Clínic de Barcelona hasta octubre de 2020, el 89% refirió utilizar drogas y el 63% en contexto de chemsex, iniciando el consumo el 64% durante el último año. El 21% refería policonsumo, siendo GHB/GBL, nitritos, sildenafilo y metanfetamina la combinación más prevalente. El 8% reportó slamming. El 41% describió haber tenido experiencias negativas y el 8% no recordaba la última vez que tuvo sexo sobrio. Metanfetamina, mefedrona, GHB/GBL y haber tenido relaciones abiertas, sexo en grupo, doble penetración y fisting fueron significativamente más frecuentes. El 49% refirió estar preocupado por la práctica de chemsex y el 18% necesitar ayuda. Un abordaje integral e interdisciplinar mejoraría el acompañamiento global de la sexualidad en estas personas.

Role of ghrelin in fertilization, early embryo development, and implantation periods.

In order to clarify the physiological role of ghrelin in gestation, we evaluated the effects of administration of exogenous ghrelin (2 or 4 nmol/animal per day) or its antagonist (6 nmol/animal per day of (d-Lys3)GHRP6) on fertilization, early embryo development, and implantation periods in mice. Three experiments were performed, treating female mice with ghrelin or its antagonist: i) starting from 1 week before copulation to 12 h after copulation, mice were killed at day 18 of gestation; ii) since ovulation induction until 80 h later, when we retrieved the embryos from oviducts/uterus, and iii) starting from days 3 to 7 of gestation (peri-implantation), mice were killed at day 18. In experiments 1 and 3, the antagonist and/or the highest dose of ghrelin significantly increased the percentage of atrophied fetuses and that of females exhibiting this finding or a higher amount of corpora lutea compared with fetuses (nCL/nF) (experiment 3: higher nCL/nF-atrophied fetuses: ghrelin 4, 71.4-71.4% and antagonist, 75.0-62.5% vs ghrelin 2, 46.2-15.4% and control, 10-0.0%; n=7-13 females/group; P<0.01). In experiment 2, the antagonist diminished the fertilization rate, and both, ghrelin and the antagonist, delayed embryo development (blastocysts: ghrelin 2, 62.5%; ghrelin 4, 50.6%; and antagonist, 61.0% vs control 78.4%; n=82-102 embryos/treatment; P<0.0001). In experiment 3, additionally, ghrelin (4 nmol/day) and the antagonist significantly diminished the weight gain of fetuses and dams during pregnancy. Our results indicate that not only hyperghrelinemia but also the inhibition of the endogenous ghrelin effects exerts negative effects on the fertilization, implantation, and embryo/fetal development periods, supporting the hypothesis that ghrelin (in 'adequate' concentrations) has a physiological role in early gestational events.