Vaginal Aging-What We Know and What We Do Not Know

Aging Is Associated With Decreased Lactobacillus and Increased Cervicovaginal Inflammation in Canadian Women

PROBLEM

Aging is characterized by a general dysregulation of systemic immune responses that increases susceptibility to infections and malignancies. Immune cells in the female genital tract (FGT) are regulated by sex hormones, but little is known about the impact of aging and menopause on immunology in the FGT.

METHOD OF STUDY

This study conducted an age-focused sub-analysis of cervicovaginal samples collected from 47 women enrolled in the Vaginal Mucosal Systems study in Winnipeg, Canada. Paired cervicovaginal lavage and cervical cytobrush were collected and analyzed by Luminex cytokine array, mass spectrometry based metaproteomics, metabolomics, and high dimensional flow cytometry.

RESULTS

The median age of study participants was 38 (range 19-88), with 12 over the age of 50. Increasing age was significantly correlated with increased cervicovaginal inflammation, including inflammatory cytokine MIP-1β (r = 0.335, p = 0.023), and activated T cells (CD4+HLA-DR+ r = 0406, p = 0.009; CD8+HLA-DR+ r = 0.399, p = 0.010; CD8+CD38+HLA-DR+ r = 0.386, p = 0.013). Proteomic analysis of cervicovaginal mucus identified 925 human proteins, with 108 (11.7%) significantly correlated with age. Pathway analysis indicated biofunctions related to immune response, migration, and myeloid cell phagocytosis increased with age. Interestingly, neutrophil related pathways decreased with age, including G-CSF (r = -0.396, p = 0.006) and reactive oxygen species (z-score = -2.607, p = 2.31E-4). Vaginal Lactobacillus crispatus, a species associated with mucosal health, significantly decreased with age (r = -0.340, p = 0.022), with participants over the age of 50 more likely to have non-Lactobacillus dominant microbiomes compared to those under 40.

CONCLUSIONS

Together, our data suggests that there is an increase in cervicovaginal inflammation and a decrease in L. crispatus that occurs with aging.

Vaginal Microbiome: Environmental, Biological, and Racial Influences on Gynecological Health Across the Lifespan

The human vaginal microbiome (VMB) is a complex and unique ecosystem composed of various microorganisms, including bacteria, fungi, archaea, viruses, and candidate phyla radiation. A healthy VMB is often characterized by the presence of Lactobacillus species, which play a crucial role in protecting and maintaining homeostasis within the vaginal environment. When this balance is disrupted, the protection of the vaginal epithelium weakens, leading to a reduction in Lactobacillus species and an increased risk of various gynecological and reproductive health issues. However, this generalized description can lead to misconceptions and an incomplete understanding of vaginal health, as Lactobacillus is not always dominant across all ages and racialized groups. Therefore, this review provides a comprehensive analysis of the environmental, biological, and racial influences on the VMB at each stage of a woman's life, highlighting their implications for gynecological health and offering a holistic understanding of the VMB for all women.

5-Hydroxymethylcytosine: Far Beyond the Intermediate of DNA Demethylation

Epigenetics plays a pivotal role in regulating gene expression and cellular differentiation. DNA methylation, involving the addition of methyl groups to specific cytosine bases, is a well-known epigenetic modification. The recent discovery of 5-hydroxymethylcytosine (5hmC) has provided new insights into cytosine modifications. 5hmC, derived from the oxidation of 5-methylcytosine (5mC), serves as both an intermediate in demethylation and a stable chemical modification in the genome. In this comprehensive review, we summarize the recent research advancements regarding the functions of 5hmC in development and disease. We discuss its implications in gene expression regulation, cellular differentiation, and its potential role as a diagnostic and prognostic marker in various diseases. Additionally, we highlight the challenges associated with accurately detecting and quantifying 5hmC and present the latest methodologies employed for its detection. Understanding the functional role of 5hmC in epigenetic regulation and further advancing our understanding of gene expression dynamics and cellular processes hold immense promise for the development of novel therapeutic strategies and precision medicine approaches.

Switch-like Gene Expression Modulates Disease Susceptibility

A fundamental challenge in biomedicine is understanding the mechanisms predisposing individuals to disease. While previous research has suggested that switch-like gene expression is crucial in driving biological variation and disease susceptibility, a systematic analysis across multiple tissues is still lacking. By analyzing transcriptomes from 943 individuals across 27 tissues, we identified 1,013 switch-like genes. We found that only 31 (3.1%) of these genes exhibit switch-like behavior across all tissues. These universally switch-like genes appear to be genetically driven, with large exonic genomic structural variants explaining five (~18%) of them. The remaining switch-like genes exhibit tissue-specific expression patterns. Notably, tissue-specific switch-like genes tend to be switched on or off in unison within individuals, likely under the influence of tissue-specific master regulators, including hormonal signals. Among our most significant findings, we identified hundreds of concordantly switched-off genes in the stomach and vagina that are linked to gastric cancer (41-fold, p<10-4) and vaginal atrophy (44-fold, p<10-4), respectively. Experimental analysis of vaginal tissues revealed that low systemic levels of estrogen lead to a significant reduction in both the epithelial thickness and the expression of the switch-like gene ALOX12. We propose a model wherein the switching off of driver genes in basal and parabasal epithelium suppresses cell proliferation therein, leading to epithelial thinning and, therefore, vaginal atrophy. Our findings underscore the significant biomedical implications of switch-like gene expression and lay the groundwork for potential diagnostic and therapeutic applications.

Switch-like Gene Expression Modulates Disease Susceptibility

A fundamental challenge in biomedicine is understanding the mechanisms predisposing individuals to disease. While previous research has suggested that switch-like gene expression is crucial in driving biological variation and disease susceptibility, a systematic analysis across multiple tissues is still lacking. By analyzing transcriptomes from 943 individuals across 27 tissues, we identified 1,013 switch-like genes. We found that only 31 (3.1%) of these genes exhibit switch-like behavior across all tissues. These universally switch-like genes appear to be genetically driven, with large exonic genomic structural variants explaining five (~18%) of them. The remaining switch-like genes exhibit tissue-specific expression patterns. Notably, tissue-specific switch-like genes tend to be switched on or off in unison within individuals, likely under the influence of tissue-specific master regulators, including hormonal signals. Among our most significant findings, we identified hundreds of concordantly switched-off genes in the stomach and vagina that are linked to gastric cancer (41-fold, p<10-4) and vaginal atrophy (44-fold, p<10-4), respectively. Experimental analysis of vaginal tissues revealed that low systemic levels of estrogen lead to a significant reduction in both the epithelial thickness and the expression of the switch-like gene ALOX12. We propose a model wherein the switching off of driver genes in basal and parabasal epithelium suppresses cell proliferation therein, leading to epithelial thinning and, therefore, vaginal atrophy. Our findings underscore the significant biomedical implications of switch-like gene expression and lay the groundwork for potential diagnostic and therapeutic applications.

The role of microbiota in the management of genitourinary syndrome of menopause

It is estimated that the 25-50% of women who are reaching menopause every year report symptoms related to the genitourinary syndrome of menopause (GSM). The symptoms are not due simply to lack of estrogen. One possible contributing cause of symptoms is the vaginal microbiota. The vaginal microbiota is a dynamic entity and plays a critical role in the pathogenic interplay of postmenopausal changes. Treatment of this syndrome depends on the severity and type of the symptoms and on the preferences and expectations of women. As there are many treatment options, therapy should be individualized. While new evidence on the role of Lactobacilli in premenopause is emerging, the role of Lactobacilli is still unclear in GSM and the impact of microbiota on vaginal health remains conflictual. However, some reports show promising data on the effect of probiotic therapy in menopause. In the literature there are few studies and small population samples on the role of an exclusive therapy with Lactobacilli and further data will be mandatory. Studies involving large numbers of patients and different intervention periods will be necessary to obtain evidence of the preventive and curative role of vaginal probiotics.

Feeding hempseed cake alters the bovine gut, respiratory and reproductive microbiota

A growing number of studies have investigated the feasibility of utilizing hemp by-products as livestock feedstuffs; however, their impact on livestock microbiomes remains unexplored. Here, we evaluated the effects of feeding hempseed cake on the gastrointestinal, respiratory, and reproductive microbiota in beef heifers. Angus-crossbred heifers (19-months old, initial body weight = 494 ± 10 kg [SE]) were fed a corn-based finishing diet containing 20% hempseed cake as a substitute for 20% corn dried distillers' grains with solubles (DM basis; Control; n = 16/group) for 111 days until slaughter. Ruminal fluid and deep nasopharyngeal swabs (days 0, 7, 42, 70 and 98), and vaginal and uterine swabs (at slaughter) were collected, and the microbiota assessed using 16S rRNA gene sequencing. Diet affected the community structure of the ruminal (d 7-98; 0.06 ≤ R² ≤ 0.12; P < 0.05), nasopharyngeal (d 98; R² = 0.18; P < 0.001), and vaginal (R² = 0.06; P < 0.01) microbiota. Heifers fed hempseed cake had increased microbial diversity in the rumen, reduced microbial richness in the vagina, and greater microbial diversity and richness in the uterus. In addition to the distinct microbial communities in the rumen, nasopharynx, vagina and uterus, we identified 28 core taxa that were shared (≥ 60% of all samples) across these sampling locations. Feeding hempseed cake appeared to alter the bovine gut, respiratory and reproductive microbiota. Our results suggest that future research aiming to evaluate the use of hemp by-products in livestock diet should consider their impact on animal microbiome and microbiome mediated animal health and reproductive efficiency. Our findings also highlight the need for research evaluating the impact of hemp-associated food and personal care products on the human microbiome.

A Novel Technique Combining Human Acellular Dermal Matrix (HADM) and Enriched Platelet Therapy (EPT) for the Treatment of Vaginal Laxity: A Single-Arm, Observational Study

BACKGROUND

There is a paucity of knowledge about cosmetic vaginal tightening procedures; therefore, the present study aimed to describe the clinical effects of a novel combination technique of human acellular dermal matrix (HADM) and enriched platelet therapy (EPT) for the treatment of vaginal laxity.

METHODS

This single-arm, observational study was conducted on 52 patients with grade II to III vaginal relaxation. HADM biological band (U-shaped) was implanted in these patients by submucosal puncture in vagina under anesthesia. This was followed by thrice administration of EPT injection, once at the time surgery followed by each dose at a time interval of one month. Patients were followed up for a period of 6 months based on Female Sexual Function Index (FSFI) and Vaginal Health Index (VHI) scores. Patient satisfaction was measured using Visual Analogue Score (VAS).

RESULTS

About 52 women with median age of 39 years were included in the study. The average time reported to complete HADM surgery was reported as 27 minutes. Following implantation, it was found that labia minora was significantly closed and perineal length was increased from 1.5 to 2.2 cm. Moreover, there was improvement in elasticity, contractility and lubricity of vaginal mucosa. The sexual function scores from pre- to post-surgery were significantly increased (7.95 vs. 30.09; p value: <0.001). The mean VHI score also increased significantly after 6 months of treatment (mean ± S.D. before vs after treatment: 11.2 ± 3.3 vs. 19.6 ± 4.1, P < 0.0001). The mean VAS after surgery was 1.61 ± 0.31. About 96% of the patients did not feel any pain after treatment at 6-month follow-up. No adverse effects were reported in this study.

CONCLUSIONS

These findings supported that combination treatment with HADM and EPT was safe and associated with both improved vaginal laxity and sexual function. These results may provide a novel surgical technique for this prevalent and undertreated condition.

LEVEL OF EVIDENCE IV

Therapeutic Study This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .