Appraising cervical mucus: a new approach to evaluating contraceptives

Phase 1 randomized trials to assess safety, pharmacokinetics, and vaginal bleeding associated with use of extended duration dapivirine and levonorgestrel vaginal rings

BACKGROUND

Vaginal rings formulated to deliver two drugs simultaneously have potential as user-controlled, long-acting methods for dual prevention of HIV and pregnancy.

METHODS

Two phase 1 randomized trials (MTN-030/IPM 041 and MTN-044/IPM 053/CCN019) respectively enrolled 24 and 25 healthy, HIV-negative participants to evaluate safety, pharmacokinetics, and vaginal bleeding associated with use of a vaginal ring containing 200mg dapivirine (DPV) and 320mg levonorgestrel (LNG) designed for 90-day use. MTN-030/IPM 041 compared the DPV/LNG ring to a DPV-only ring (200mg) over 14 days of use. MTN-044/IPM 053/CCN019 compared continuous or cyclic use of the DPV/LNG ring over 90 days of use. Safety was assessed by recording adverse events (AEs). DPV and LNG concentrations were quantified in plasma, cervicovaginal fluid, and cervical tissue. Vaginal bleeding was self-reported.

RESULTS

There were no differences in the proportion of participants with grade ≥2 genitourinary AEs or grade ≥3 AEs with DPV/LNG ring vs. DPV ring use (p = .22), or with DPV/LNG ring continuous vs. cyclic use (p = .67). Higher plasma DPV concentrations were observed in users of DPV/LNG compared to DPV-only rings (Cmax p = 0.049; AUC p = 0.091). Plasma DPV and LNG concentrations were comparable with continuous and cyclic use (Cmax p = 0.74; AUC p = 0.25). With cyclic use, median nadir plasma DPV concentration was approximately 300 pg/mL two days after removal and median t1/2 for cervicovaginal fluid DPV concentration was 5.76 hours (n = 3). Overall bleeding experiences did not differ between continuous and cyclic users (p = 0.12).

CONCLUSIONS

The extended duration DPV/ LNG rings were well tolerated and the observed DPV concentrations in plasma and cervicovaginal fluid when used continuously exceeded concentrations observed in previous DPV ring efficacy studies. LNG concentrations in plasma were comparable with other efficacious LNG-based contraceptives. Genital DPV concentrations had a short half-life and were thus not well sustained following ring removal.

Transcriptional profiling of mucus production and modification in rhesus macaque endocervical cells under hormonal regulation

Objective

Endocervical mucus production is a key regulator of fertility throughout the menstrual cycle. With cycle-dependent variability in mucus quality and quantity, cervical mucus can either facilitate or block sperm ascension into the upper female reproductive tract. This study seeks to identify genes involved in the hormonal regulation of mucus production, modification, and regulation through profiling the transcriptome of endocervical cells from the non-human primate, the Rhesus Macaque (Macaca mulatta).

Design

Experimental.

Setting

Translational science laboratory.

Intervention

We treated differentiated primary endocervical cultures with estradiol (E2) and progesterone (P4) to mimic peri-ovulatory and luteal-phase hormonal changes. Using RNA-sequencing, we identified differential expression of gene pathways and mucus producing and modifying genes in cells treated with E2 compared to hormone-free conditions and E2 compared to E2-primed cells treated with P4.

Main Outcome Measures

We pursued differential gene expression analysis on RNA-sequenced cells. Sequence validation was done using qPCR.

Results

Our study identified 158 genes that show significant differential expression in E2-only conditions compared to hormone-free control, and 250 genes that show significant differential expression in P4-treated conditions compared to E2-only conditions. From this list, we found hormone-induced changes in transcriptional profiles for genes across several classes of mucus production, including ion channels and enzymes involved in post-translational mucin modification that have not previously been described as hormonally regulated.

Conclusion

Our study is the first to use an in vitro culture system to create an epithelial-cell specific transcriptome of the endocervix. As a result, our study identifies new genes and pathways that are altered by sex-steroids in cervical mucus production.

Hormonal regulation of non-cystic fibrosis transmembrane conductance regulator ion channels in the endocervix

OBJECTIVE

To characterize ion channel expression and localization in the endocervix under different hormonal conditions using a nonhuman primate primary endocervical epithelial cell model.

DESIGN

Experimental.

SETTING

University-based, translational science laboratory.

INTERVENTIONS

We cultured and treated conditionally reprogrammed primary rhesus macaque endocervix cells with estradiol and progesterone and measured gene expression changes for several known ion channel and ion channel regulators of mucus secreting epithelia. Using both rhesus macaque endocervical samples and human samples, we localized channels in the endocervix using immunohistochemistry.

MAIN OUTCOME MEASURES

The relative abundance of transcripts was evaluated using real-time polymerase chain reaction. Immunostaining results were evaluated qualitatively.

RESULTS

Compared with controls, we found that estradiol increased gene expression for ANO6, NKCC1, CLCA1, and PDE4D. Progesterone down-regulated gene expression for ANO6, SCNN1A, SCNN1B, NKCC1, and PDE4D (P≤.05). Immunohistochemistry confirmed endocervical cell membrane localization of ANO1, ANO6, KCNN4, LRR8CA, and NKCC1.

CONCLUSIONS

We found several ion channels and ion channel regulators that are hormonally sensitive in the endocervix. These channels, therefore, may play a role in the cyclic fertility changes in the endocervix and could be further investigated as targets for future fertility and contraceptive studies.

Evaluation of the impact of humor used in contraception education on the attitudes of university students towards contraceptive methods

OBJECTIVE

This study has been performed as a parallel randomised controlled study to evaluate the impact of humour benefitted in contraception education of university students on the attitudes of students towards contraception methods.

METHODS

The study sample was composed of 88 students (44 experiments, 44 controls) studying at a public university in Turkey. The study data were collected using the Questionnaire Form and the Family Planning Attitude Scale. The students were divided into experimental and control groups as per the pre-test score of the Family Planning Attitude Scale and gender using stratified block randomisation. The students were divided into groups of 10 people, and each group received a one-time education of 45-60 min. The content of the education was the same for the experimental and control groups, but additionally, the humour method was used during the education of the experimental group. The Family Planning Attitude Scale was re-applied to the students one month after the education. Number, percentage, mean value, Student t-test Mann Whitney-U test, and Chi-square test were used to evaluate the data.

RESULTS

While there was no statistically significant difference between the pre-test mean scores of the students in the experimental and control groups (p > 0.05); the post-test showed a significantly higher mean score in the experimental group (p < 0.05) (1-β: 0.921, Cohen's d: 0.658). While there was no significant difference between the pre-test and post-test total mean scores of the students in the control group (p > 0.05); the post-test mean score of the students in the experimental group was significantly higher than the pre-test mean (p < 0.05) (1-β: 1.000, Cohen's d: 1.556).

CONCLUSIONS

The method of contraception education with humour given to university students is more effective than the education given ordinarily in developing attitudes towards contraceptives.

Comparing endocervical mucus proteome of humans and rhesus macaques

PURPOSE

Endocervical mucus changes play a key role in regulating fertility throughout the menstrual cycle and in response to hormonal contraceptives. Non-human primates (NHP) provide the most translational animal model for reproductive tract studies, as they have hormonally-regulated menstrual cycles and mucus changes, similar to women.

EXPERIMENTAL DESIGN

We used TMT labelling and LC-LC/MS to compare the proteins found in the mucus of the rhesus macaque to the mucus of the human endocervix. Data are available via ProteomeXchange with identifier PXD021710.

RESULTS

We found 3048 total proteins present in both rhesus mucus and human mucus, and of these, 57% showed a similar expression pattern. An even higher similarity occurred in the top 500 most prevalent proteins, with overlap in 341 (68%) proteins. Mucin MUC5B was the most highly expressed mucin protein (top 10 expressed proteins in both) but other key proteins related to mucus structure were present in both samples.

CONCLUSIONS AND CLINICAL RELEVANCE

We find that the mucus proteome of the endocervical mucus is highly conserved in NHP and women. This supports use of the NHP model system for studies of the endocervix and trials of novel fertility treatments targeting the cervix.

Molecular and cellular cues governing nanomaterial-mucosae interactions: from nanomedicine to nanotoxicology

Mucosal tissues constitute the largest interface between the body and the surrounding environment and they regulate the access of molecules, supramolecular structures, particulate matter, and pathogens into it. All mucosae are characterized by an outer mucus layer that protects the underlying cells from physicochemical, biological and mechanical insults, a mono-layered or stratified epithelium that forms tight junctions and controls the selective transport of solutes across it and associated lymphoid tissues that play a sentinel role. Mucus is a gel-like material comprised mainly of the glycoprotein mucin and water and it displays both hydrophilic and hydrophobic domains, a net negative charge, and high porosity and pore interconnectivity, providing an efficient barrier for the absorption of therapeutic agents. To prolong the residence time, absorption and bioavailability of a broad spectrum of active compounds upon mucosal administration, mucus-penetrating and mucoadhesive particles have been designed by tuning the chemical composition, the size, the density, and the surface properties. The benefits of utilizing nanomaterials that interact intimately with mucosae by different mechanisms in the nanomedicine field have been extensively reported. To ensure the safety of these nanosystems, their compatibility is evaluated in vitro and in vivo in preclinical and clinical trials. Conversely, there is a growing concern about the toxicity of nanomaterials dispersed in air and water effluents that unintentionally come into contact with the airways and the gastrointestinal tract. Thus, deep understanding of the key nanomaterial properties that govern the interplay with mucus and tissues is crucial for the rational design of more efficient drug delivery nanosystems (nanomedicine) and to anticipate the fate and side-effects of nanoparticulate matter upon acute or chronic exposure (nanotoxicology). This review initially overviews the complex structural features of mucosal tissues, including the structure of mucus, the epithelial barrier, the mucosal-associated lymphatic tissues and microbiota. Then, the most relevant investigations attempting to identify and validate the key particle features that govern nanomaterial-mucosa interactions and that are relevant in both nanomedicine and nanotoxicology are discussed in a holistic manner. Finally, the most popular experimental techniques and the incipient use of mathematical and computational models to characterize these interactions are described.

Comparing cervical mucus changes in response to an oral progestin or oestrogen withdrawal in ovarian-suppressed women: a clinical pilot

Purpose: Prior studies evaluating the effect of administered progestogens on peak cervical mucus have not controlled for the influence of endogenous hormones. To address this, we treated women with a gonadotropin-releasing hormone (GnRH) agonist to suppress the hypothalamus-pituitary-ovarian (HPO) axis and used transdermal oestradiol replacement to stimulate peak cervical mucus and then evaluated the effects of an oral progestin or oestradiol withdrawal. Materials and methods: We used a crossover design to examine cervical mucus changes in women receiving transdermal oestradiol replacement following intramuscular administration of leuprolide acetate. After increasing oestradiol patches to mid-cycle levels, subjects were assigned to either 0.35 mg oral norethindrone with continuation of the patches (NET) or oestradiol withdrawal by patch removal (E2WD). We collected serum and cervical mucus samples at 0, 2, 4, 6, 22 and 24 h following the intervention. Results: We analysed 12 cycles (6 NET, 6 E2WD) from three subjects. Baseline cervical mucus scores were favourable to sperm penetration [NET median 11, interquartile range (9-12), E2WD 13 (12-13)]. Two hours after removal of oestradiol patch or administration of norethindrone, cervical mucus scores declined [NET 8.5 (4-9), E2WD 10.5 (10-12)]. Low cervical mucus scores persisted at 24 h with NET [8.0 (7-8)] but not E2WD [10.5 (8-11)]. Conclusions: We observed a rapid decline in cervical mucus Insler scores following administration of a single dose of oral norethindrone, and scores remained lower and unfavourable through 24 h. Oestradiol withdrawal did not result in similar unfavourable changes.