The Effects of Hormones and Vaginal Microflora on the Glycome of the Female Genital Tract: Cervical-Vaginal Fluid

Abstract

In this study, we characterized the glycome of cervical-vaginal fluid, collected with a Catamenial cup. We quantified: glycosidase levels; sialic acid and high mannose specific lectin binding; mucins, MUC1, MUC4, MUC5AC, MUC7; and albumin in the samples collected. These data were analyzed in the context of hormonal status (day of menstrual cycle, hormonal contraception use) and role, if any, of the type of the vaginal microflora present. When the Nugent score was used to stratify the subjects by microflora as normal, intermediate, or bacterial vaginosis, several important differences were observed. The activities of four of six glycosidases in the samples from women with bacterial vaginosis were significantly increased when compared to normal or intermediate women: sialidase, P = <0.001; α-galactosidase, P = 0.006; β-galactosidase, P = 0.005; α-glucosidase, P = 0.056. Sialic acid binding sites as measured by two lectins, Maackia amurensis and Sambucus nigra binding, were significantly lower in women with BV compared to women with normal and intermediate scores (P = <0.0001 and 0.008 respectively). High mannose binding sites, a measure of innate immunity were also significantly lower in women with BV (P = <0.001). Additionally, we observed significant increases in MUC1, MUC4, MUC5AC, and MUC7 concentrations in women with BV (P = <0.001, 0.001, <0.001, 0.02 respectively). Among normal women we found that the membrane bound mucin MUC4 and the secreted MUC5AC were decreased in postmenopausal women (P = 0.02 and 0.07 respectively), while MUC7 (secreted) was decreased in women using levonorgestrel-containing IUDs (P = 0.02). The number of sialic acid binding sites was lower in the postmenopausal group (P = 0.04), but the number of high mannose binding sites, measured with Griffithsin, was not significantly different among the 6 hormonal groups. The glycosidase levels in the cervical-vaginal mucus were rather low in the groups, with exception of α-glucosidase activity that was much lower in the postmenopausal group (P<0.001). These studies present compelling evidence that the vaginal ecosystem responds to the presence of different vaginal microorganisms. These effects were so influential that it required us to remove subjects with BV for data interpretation of the impact of hormones. We also suggest that certain changes occurring in vaginal/cervical proteins are due to bacteria or their products. Therefore, the quantitation of vaginal mucins and lectin binding offers a new method to monitor bacteria-host interactions in the female reproductive tract. The data suggest that some of the changes in these components are the result of host processing, such as the increases in mucin content, while the microflora is responsible for the increases in glycosidases and the decreases in lectin binding. The methods should be considered a valid marker for insult to the female genital tract.

Medroxyprogesterone acetate mediated alteration in the vaginal microbiota and microenvironment in a Kenyan sex worker cohort

“…As DMPA is potently anti-estrogenic (4), we examined whether DMPA was associated with lower levels of free glycogen and α-amylase in the vaginal microenvironment as compared to NH women (with endogenous hormones), or those on estrogen-containing OCPs. As others have demonstrated the diverse vaginal microflora can overshadow the effect of hormones on vaginal glycosidases and lectins (22, 23), we restricted this analysis to women with Nugent scores ≤3. Vaginal glycogen (Figure 4A; N=16, 18; P=0.043) and α-amylase (Figure 4B; N=16, 16; P=0.0095) were significantly less abundant in the CVLs of sex workers on DMPA compared to NH women (2.04±0.42 vs. 5.98±1.72mg/mL; and 3.91±1.32 vs. 16.90±3.78mU/mL respectively).…”

“…As the diverse vaginal microflora can strongly influence vaginal carbohydrates in CVLs and overshadow the effect of hormones on these types of parameters (22, 23), we restricted our analysis in (A) of vaginal glycogen and α-amylase to sex workers with Nugent scores ≤ 3. (A) Vaginal glycogen, a glucose polymer associated with vaginal colonization by Lactobacillus species, was significantly lower in the vaginal lavage of sex workers on DMPA (N=16) as compared to those not on hormonal contraceptives (proliferative phase of the menstrual cycle, N=18; Unpaired t test; P=0.043).…”

“…This study was designed to examine the effect of hormonal contraceptives on the VMB of healthy, asymptomatic Kenyan sex workers to determine if DMPA is associated with changes in the VMB and vaginal microenvironment that might impact their susceptibility to HIV-1. Importantly, we chose to exclude women with BV because BV is a clinical condition reported to profoundly overshadow the effect of hormones on vaginal biomarkers of microbial health (glycosidases, lectins) in cervico-vaginal lavage (CVL) (22, 23). Furthermore, we (21) and others (19, 20) have demonstrated by 16S ribosomal RNA (rRNA) gene sequencing that women diagnosed with BV by Nugent scoring have inherently diverse VMBs, but women with high diversity VMBs do not always have Nugent scores indicative of BV.…”

Etiological and pathogenetic aspects of non-specific bacterial vaginosis

“…Equilibrium can be impaired by incorrect prescription or incorrect use of contraceptives as well as may develop in the post-menopausal period [6].…”

“…Bacterial vaginosis enhance the risk of infection with viruses, HIV infection and other sexually transmitted infections [6].…”