Transcription profiling of estrogen target genes in young and old mouse uterus

Mitochondrial Oxidative Stress Regulates FOXP3+ T-Cell Activity and CD4-Mediated Inflammation in Older Adults with Frailty

In healthy older adults, the immune system generally preserves its response and contributes to a long, healthy lifespan. However, rapid deterioration in immune regulation can lead to chronic inflammation, termed inflammaging, which accelerates pathological aging and diminishes the quality of life in older adults with frailty. A significant limitation in current aging research is the predominant focus on comparisons between young and older populations, often overlooking the differences between healthy older adults and those experiencing pathological aging. Our study elucidates the intricate immunological dynamics of the CD4/Treg axis in frail older adults compared to comparable age-matched healthy older adults. By utilizing publicly available RNA sequencing and single-cell RNA sequencing (scRNAseq) data from peripheral blood mononuclear cells (PBMCs), we identified a specific Treg cell subset and transcriptional landscape contributing to the dysregulation of CD4+ T-cell responses. We explored the molecular mechanisms underpinning Treg dysfunction, revealing that Tregs from frail older adults exhibit reduced mitochondrial protein levels, impairing mitochondrial oxidative phosphorylation. This impairment is driven by the TNF/NF-kappa B pathway, leading to cumulative inflammation. Further, we gained a deeper understanding of the CD4/Treg axis by predicting the effects of gene perturbations on cellular signaling networks. Collectively, these findings highlight the age-related relationship between mitochondrial dysfunction in the CD4/Treg axis and its role in accelerating aging and frailty in older adults. Targeting Treg dysfunction offers a critical basis for developing tailored therapeutic strategies aimed at improving the quality of life in older adults.

Multiomics insights into the female reproductive aging

The human female reproductive lifespan significantly diminishes with age, leading to decreased fertility, reduced fertility quality and endocrine function disorders. While many aspects of aging in general have been extensively documented, the precise mechanisms governing programmed aging in the female reproductive system remain elusive. Recent advancements in omics technologies and computational capabilities have facilitated the emergence of multiomics deep phenotyping. Through the application and refinement of various high-throughput omics methods, a substantial volume of omics data has been generated, deepening our comprehension of the pathogenesis and molecular underpinnings of reproductive aging. This review highlights current and emerging multiomics approaches for investigating female reproductive aging, encompassing genomics, epigenomics, transcriptomics, proteomics, metabolomics, and microbiomics. We elucidate their influence on fundamental cell biology and translational research in the context of reproductive aging, address the limitations and current challenges associated with multiomics studies, and offer a glimpse into future prospects.

Protective Role of Kelulut Honey against Toxicity Effects of Polystyrene Microplastics on Morphology, Hormones, and Sex Steroid Receptor Expression in the Uterus of Rats

BACKGROUND

Microplastics (MPs) are an emerging global pollutant. Previous studies have revealed that chronic exposure to MPs can affect animal and human reproductive health, particularly by impairing the reproductive system's normal functions, which may increase the risk of infertility in both males and females. Kelulut honey (KH), an excellent source of antioxidants, has been used to counteract the disruptive effects of Polystyrene microplastics (PS-MPs) in the rat uterus. Thus, this study aimed to investigate the potential protective effects of Kelulut honey against PS-MPs-induced uterine toxicity in pubertal rats.

METHODS

Prepubertal female Sprague Dawley rats were divided into four groups (n = 8): (i) normal control group (NC: treated with deionized water), MPs-exposed group (M: exposed to PS-MPs at 2.5 mg/kg), (iii) Kelulut honey group (DM: pretreated with 1200 mg/kg of KH 30 minutes before they were administered with PS-MPs at 2.5 mg/kg), and (iv) Kelulut honey control group (DC: only treated with KH at 2.5 mg/kg). The rats were treated orally once daily for six consecutive weeks.

RESULTS

Uterine abnormalities in PS-MPs-exposed rats were significantly improved after concurrent treatment with Kelulut honey. Morphology improvement was observed and luminal epithelial cells seemed thicker with more goblet cells, glandular cells had a more regular and circular shape, stromal cell increased in size, interstitial gaps between stromal cells expanded, and the myometrium layer was thicker. Kelulut honey treatment also effectively normalized the suppressive effect of PS-MPs on the expression and distribution of sex steroid receptors (ERα and ERβ), as well as the level of serum gonadotropin (LH and FSH) and sex steroid (estradiol and progesterone) hormones.

CONCLUSION

Kelulut honey can protect the female reproductive system against the disruptive effects of PS-MPs. The phytochemical properties of Kelulut honey might be responsible for these beneficial benefits. However, future studies are warranted to identify the mechanisms involved.

Protective role of Mas Cotek (Ficus deltoidea) against the toxic effects of bisphenol A on morphology and sex steroid receptor expression in the rat uterus

BACKGROUND

Numerous scientific studies have found that young women are at a high risk of reproductive infertility due to their routine exposure to numerous bisphenol A (BPA) products. This risk is highly associated with the production of reactive oxygen species from BPA products. Ficus deltoidea, which has strong antioxidant properties, was selected as a potential protective agent to counter the detrimental effects of BPA in the rat uterus.

METHODS

Female Sprague-Dawley rats were allocated into four groups (n = 8) as follows: (i) the Normal Control group (NC), (ii) the BPA-exposed group (PC), (iii) the group concurrently treated with BPA and F. deltoidea (FC) and (iv) the group treated with F. deltoidea alone (F).

RESULTS

After 6 weeks of concurrent treatment with F. deltoidea, uterine abnormalities in the BPA-exposed rats showed a significant improvement. Specifically, the size of stromal cells increased; interstitial spaces between stromal cells expanded; the histology of the glandular epithelium and the myometrium appeared normal and mitotic figures were present. The suppressive effects of BPA on the expression levels of sex steroid receptors (ERα and ERβ) and the immunity gene C3 were significantly normalised by F. deltoidea treatment. The role of F. deltoidea as an antioxidant agent was proven by the significant reduction in malondialdehyde level in BPA-exposed rats. Moreover, in BPA-exposed rats, concurrent treatment with F. deltoidea could normalise the level of the gonadotropin hormone, which could be associated with an increase in the percentage of rats with a normal oestrous cycle.

CONCLUSION

F. deltoidea has the potential to counter the toxic effects of BPA on the female reproductive system. These protective effects might be due to the phytochemical properties of F. deltoidea. Therefore, future study is warranted to identify the bioactive components that contribute to the protective effects of F. deltoidea.

Age-specific changes in genome-wide methylation enrich for Foxa2 and estrogen receptor alpha binding sites

The role of DNA methylation patterns in complex phenotypes remains unclear. To explore this question, we adapted our methods for rare variant analysis to characterize genome-wide murine DNA hybridization array to investigate methylation at CpG islands, shores, and regulatory elements. We have applied this platform to compare age and tissue- specific methylation differences in the brain and spleen of young and aged mice. As expected from prior studies, there are clear global differences in organ-specific, but not age-specific, methylation due mostly to changes at repetitive elements. Surprisingly, out of 200,000 loci there were only 946 differentially methylated cytosines (DMCs) between young and old samples (529 hypermethylated, 417 hypomethylated in aged mice) compared to thousands of tissue-specific DMCs. Hypermethylated loci were clustered around the promoter region of Sfi1, exon 2 of Slc11a2, Drg1, Esr1 and Foxa2 transcription factor binding sites. In particular, there were 75 hypermethylated Foxa2 binding sites across a 2.7 Mb region of chromosome 11. Hypomethylated loci were clustered around Mid1, Isoc2b and genome-wide loci with binding sites for Foxa2 and Esr1, which are known to play important roles in development and aging. These data suggest discreet tissue-independent methylation changes associated with aging processes such as cell division (Sfi1, Mid1), energy production (Drg1, Isoc2b) and cell death (Foxa2, Esr1).

Developmental exposure to bisphenol A alters the differentiation and functional response of the adult rat uterus to estrogen treatment

We assessed the long-term effect of perinatal exposure to bisphenol A (BPA) on the rat uterus and the uterine response to estrogen (E2) replacement therapy. BPA (0.5 or 50μg/kg/day) was administered in the drinking water from gestational day 9 until weaning. We studied the uterus of female offspring on postnatal day (PND) 90 and 360, and the uterine E2 response on PND460 (PND460-E2). On PND90, BPA-exposed rats showed altered glandular proliferation and α-actin expression. On PND360, BPA exposure increased the incidence of abnormalities in the luminal and glandular epithelium. On PND460-E2, the multiplicity of glands with squamous metaplasia increased in BPA50 while the incidence of glands with daughter glands increased in BPA0.5. The expression of steroid receptors, p63 and IGF-I was modified in BPA-exposed rats on PND460-E2. The long-lasting effects of perinatal exposure to BPA included induction of abnormalities in uterine tissue and altered response to E2 replacement therapy.

Perinatal exposure to diethylstilbestrol alters the functional differentiation of the adult rat uterus

The exposure to endocrine disrupters and female reproductive tract disorders has not been totally clarified. The present study assessed the long-term effect of perinatal (gestation+lactation) exposure to diethylstilbestrol (DES) on the rat uterus and the effect of estrogen replacement therapy. DES (5μg/kg bw/day) was administered in the drinking water from gestational day 9 until weaning and we studied the uterus of young adult (PND90) and adult (PND360) females. To investigate whether perinatal exposure to DES modified the uterine response to a long-lasting estrogen treatment, 12-month-old rats exposed to DES were ovariectomized and treated with 17β-estradiol for 3 months (PND460). In young adult rats (PND90), the DES treatment decreased both the proliferation of glandular epithelial cells and the percentage of glandular perimeter occupied by α-smooth muscle actin-positive cells. The other tissue compartments remained unchanged. Cell apoptosis was not altered in DES-exposed females. In control adult rats (PND360), there were some morphologically abnormal uterine glands. In adult rats exposed to DES, the incidence of glands with cellular anomalies increased. In response to estrogens (PND460), the incidence of cystic glands increased in the DES group. We observed glands with daughter glands and conglomerates of glands only on PND460 and in response to estrogen replacement therapy, independently of DES exposure. The p63 isoforms were expressed without changes on PND460. Estrogen receptors α and β showed no changes, while the progesterone receptor decreased in the subepithelial stroma of DES-exposed animals with estrogen treatment. The long-lasting effects of perinatal exposure to DES included the induction of abnormalities in uterine tissues of aged female rats and an altered response of the adult uterus to estradiol.

Estradiol induces type 8 17beta-hydroxysteroid dehydrogenase expression: crosstalk between estrogen receptor alpha and C/EBPbeta

Hydroxysteroid (17-beta) dehydrogenase (HSD17B) are the enzymes responsible for the reversible interconversion of 17-hydroxy and 17-keto steroids. The human and mouse type 8 17beta-HSD (HSD17B8) selectively catalyze the conversion of estradiol (E2) to estrone (E1). We previously described thatHSD17B8 is transcriptionally regulated by C/EBPbeta, and that C/EBPbeta is bound to CCAAT boxes located at -5 and -46 of the transcription start site in basal conditions in HepG2 cells. Furthermore, ectopic expression of C/EBPbeta transactivated the HSD17B8 promoter activity. Here, we show that HSD17B8 expression is up-regulated in response to E2 in the estrogen receptor alpha (ERalpha) positive MCF-7 cells. Results showed that this induction is mediated by ERalpha because i) E2 did not induce HSD17B8 expression in ERalphanegative HepG2 cells, ii) ectopic expression of ERalpha restored E2-induced HSD17B8 expression, and iii) this induction was blocked by the anti-ER ICI 182,780. Additional experiments showed that no estrogen response element was necessary for this regulation. However, the CCAAT boxes located at the HSD17B8 proximal promoter were required for E2-induced transcription. Furthermore, co-immunoprecipitation studies revealed tethering of ERalphatoC/EBPbeta in response to E2 in cells expressing ERalpha. Additionally, chromatin immunoprecipitation assays demonstrated that, in response to E2, ERalpha is recruited to the CCAAT boxes in which C/EBPbeta is already bound. Taken together, our results reveal that ERalpha is involved in the transcriptional regulation of HSD17B8 gene in response to E2 through its interaction with C/EBPbeta.

Comparative effects of estradiol, methyl-piperidino-pyrazole, raloxifene, and ICI 182 780 on gene expression in the murine uterus

Selective estrogen receptor modulators (SERMs) are potentially useful in treating various endometrial disorders, including endometrial cancer, as they block some of the detrimental effects of estrogen. It remains unclear whether each SERM regulates a unique subset of genes and, if so, whether the combination of a SERM and 17beta-estradiol has an additive or synergistic effect on gene expression. We performed microarray analysis with Affymetrix Mouse Genome 430 2.0 short oligomer arrays to determine gene expression changes in uteri of ovariectomized mice treated with estradiol (low and high dose), methyl-piperidino-pyrazole (MPP), ICI 182 780, raloxifene, and combinations of high dose of estradiol with one of the SERM and dimethyl sulfoxide (DMSO) vehicle control. The nine treatments clustered into two groups, with MPP, raloxifene, and high dose of estradiol in one, and low dose of estradiol, ICI + estradiol, ICI, MPP + estradiol, and raloxifene + estradiol in the second group. Surprisingly, combining a high dose of estradiol with a SERM markedly increased (P<0.02) the number of regulated genes compared with each individual treatment. Analysis of expression for selected genes in uteri of estradiol and SERM-treated mice by quantitative (Q)RT-PCR generally supported the microarray results. For some cancer-associated genes, including Klk1, Ihh, Cdc45l, and Cdca8, administration of MPP or raloxifene with estradiol resulted in greater expression than estradiol alone (P<0.05). By contrast, ICI 182 780 suppressed more genes governing DNA replication compared with MPP and raloxifene treatments. Therefore, ICI 182 780 might be superior to MPP and raloxifene to treat estrogen-induced endometrial cancer in women.

Expression analysis of androgen-responsive genes in the prostate of veal calves treated with anabolic hormones

In order to identify indirect molecular biomarkers of anabolic treatments in veal calves, an animal experiment was performed using two combinations of growth promoters (consisting of boldenone undecylenate and estradiol benzoate, and of testosterone enantate and estradiol benzoate). We selected a set of 12 genes that are known to be androgen responsive in other mammalian species. The expression profile of this set of genes was analysed on prostate samples of veal calves using a real-time RT-PCR approach. For each selected gene the corresponding bovine sequence was obtained and a gene specific real-time assay was optimised and validated. The amplification was shown to be highly specific, linear and efficient. High reproducibility (<1%) and low-test variability (<2.5%) were also been achieved. Messenger RNA levels were quantified in prostate samples, non-parametric analysis of variance showed significant up-regulation of three genes (MAF, ESR1 and AR) and significant down-regulation of four genes (HMGCS1, HPGD, DBI, and LIM) in treated samples when compared with untreated controls. To assess the possibility of identifying hormone-treated animals by molecular means we performed a discriminant analysis that was effective in classifying treated and non-treated samples with an accuracy of 93%. Our results indicate that identification of treatment with steroid hormones in veal calves by means of gene expression analysis is a feasible approach and could be improved increasing both the number of genes and the number of controls analysed.

Molecular responses to xenoestrogens: mechanistic insights from toxicogenomics

The xenoestrogen group of endocrine disruptors has the potential to cause reproductive and developmental effects through stimulation or disruption of sex steroid nuclear receptor signalling pathways. A more detailed understanding of the ways in which xenoestrogens interact with biological systems at the molecular level will provide a mechanistic basis for improved safety assessment. The recent sequencing of mammalian genomes has driven the development of toxicogenomic technologies, including microarray based gene expression profiling, which allow the expression levels of thousands of genes to be measured simultaneously. Since the cellular responses to xenoestrogens are predominantly mediated by estrogen receptors, which function as ligand-activated transcription factors to regulate gene expression, the application of toxicogenomics has great potential for providing insights into the molecular mechanisms of xenoestrogen action. A major challenge in applying toxicogenomics to the field of endocrine disruption is the need to define how xenoestrogen-induced changes in gene expression relate to conventional physiological and toxicological endpoints. Gene Ontology Mapping, Pathway Mapping and Phenotypic Anchoring of xenoestrogen-induced gene expression changes to cellular pathways and processes represent key steps in defining these relationships. Mechanistic insights into how xenoestrogens target specific genes and into the functional significance of xenoestrogen-induced alterations in gene expression can be further enhanced by combining transcript profiling with transgenic animal models or cell-based systems in which the estrogen receptor signalling pathways have been modified experimentally. This review illustrates how these toxicogenomic approaches are providing an unprecedented amount of mechanistic information on the molecular responses to xenoestrogens and how they are likely to impact on hazard and risk assessment.