Alteration of apoptosis-related genes in postmenopausal women with uterine prolapse

The alteration of apoptosis-related genes in female pelvic supportive tissues with regard to menopausal status

PURPOSE

We aimed to compare the expression levels of anti-apoptotic and proapoptotic genes in the parametrium, sacrouterine and round ligaments with respect to menopausal status in women presenting without any indication of pelvic organ prolapse (POP). We hypothesized that apoptosis related gene expressions in female pelvic tissues may be altered during menopause.

METHODS

The study groups consisted of pre-menopausal (n = 10) and menopausal (n = 10) females who did not have POP symptoms. Three different types of tissue samples (Parametrium, Round Ligament and Sacrouterine Ligament) were obtained and RNA was isolated from these tissues. After purifying and quantifying RNA samples, qPCR was used to determine the expression levels of anti-apoptotic and pro-apoptotic genes.

RESULTS

BCL-2 gene expression levels were significantly lower in all the tissues of menopausal patients compared to those of premenopausal patients. In comparison to premenopausal patients, the sacrouterine ligament tissue BAD expression level was significantly high (p = 0.035), and the BCL-2/BAD ratio was significantly lower in menopausal patients (p = 0.006).

CONCLUSION

Apoptosis-related protein levels change during menopause; pro-apoptotic gene expressions decrease and anti-apoptotic gene expressions increase. The significant alteration of BCL-2 and BAD expression in sacrouterine ligament with respect to menopausal status was observed and this suggested that when compared to other pelvic tissues, the sacrouterine ligament, which plays a crucial role for genital organs in restoring normal pelvic anatomy and providing support, could be affected more by menopause.

Exosomes derived from mesenchymal stromal cells: a promising treatment for pelvic floor dysfunction

Pelvic floor dysfunction (PFDs), which include pelvic organ prolapse (POP), stress urinary incontinence (SUI) and anal incontinence (AI), are common degenerative diseases in women that have dramatic effects on quality of life. The pathology of PFDs is based on impaired pelvic connective tissue supportive strength due to an imbalance in extracellular matrix (ECM) metabolism, the loss of a variety of cell types, such as fibroblasts, muscle cells, peripheral nerve cells, and oxidative stress and inflammation in the pelvic environment. Fortunately, exosomes, which are one of the major secretions of mesenchymal stromal cells (MSCs), are involved in intercellular communication and the modulation of molecular activities in recipient cells via their contents, which are bioactive proteins and genetic factors such as mRNAs and miRNAs. These components modify fibroblast activation and secretion, facilitate ECM modelling, and promote cell proliferation to enhance pelvic tissue regeneration. In this review, we focus on the molecular mechanisms and future directions of exosomes derived from MSCs that are of great value in the treatment of PFD.

Mechanical stress influences the morphology and function of human uterosacral ligament fibroblasts and activates the p38 MAPK pathway

Introduction and hypothesis

Pelvic organ prolapse (POP) is a common condition in older women that affects quality of life. Mechanical injury of the pelvic floor support system contributes to POP development. In our study, we aimed to examine the mechanical damage to human uterosacral ligament fibroblasts (hUSLFs) to preliminarily explore the mechanism of mechanical transduction in POP.

Methods

hUSLFs were derived from POP and non-POP patients. Mechanical stress was induced by the FX-5000 T-cell stress loading system. Student’s t-test was used for comparisons between different groups.

Results

We found that hUSLFs from POP patients were larger and longer than those from non-POP patients and exhibited cytoskeleton F-actin rearrangement. Collagen I and III expression levels were lower and matrix metalloproteinase 1 (MMP1) levels were higher in POP patients than in non-POP patients. Additionally, the apoptosis rate was significantly increased in POP patients compared to non-POP patients. After mechanical stretching, hUSLFs underwent a POP-like transformation. Cells became longer, and the cytoskeleton became thicker and rearranged. The extracellular matrix (ECM) was remodelled because of the upregulation of collagen I and III expression and downregulation of MMP1 expression. Mechanical stress also induced hUSLF apoptosis. Notably, we found that the p38 MAPK pathway was activated by mechanical stretching.

Conclusions

Mechanical stress induced morphological changes in ligament fibroblasts, leading to cytoskeleton and ECM remodelling and cell apoptosis. p38 MAPK might be involved in this process, providing novel insights into the mechanical biology of and possible therapies for this disease.

Dilemmas in Management of the Geriatric Bladder

Purpose of review

In this article, we will review current dilemmas regarding evaluation and management of the geriatric bladder incorporating concepts of normal changes of aging as well as common lower urinary tract dysfunction.

Recent findings

Increasing age leads to functional changes in essentially all organ systems including the genitourinary system. Understanding the natural changes with age of the bladder as well as the signs and symptoms of pathologic conditions is paramount to diagnosis and treatment of urologic conditions in the geriatric population.

Summary

There are several conundrums in the diagnosis and evaluation of the geriatric bladder including the ability of the bladder to store, empty, as well as sensitivity disturbances. Diagnostic testing and goals of treatment should be individualized for each patient and personalized to consider patient comorbidities, limitations, and expectations.

Falling from grace: HPRT is not suitable as an endogenous control for cancer-related studies

HPRT is a housekeeping enzyme involved in recycling guanine and inosine in the purine salvage pathway. As a housekeeping gene, HPRT has been widely used as an endogenous control for molecular studies evaluating changes in gene expression. Yet, recent evidence has shown that HPRT exhibits high variability within malignant samples. We designed this study to determine whether this observed upregulation is consistently found, therefore rendering hprt an unsuitable normalization control in cancer. Utilizing protein and RNA-seq expression, we found that malignant and normal patient samples vary significantly both within the same tissue type and across organ sites. Upon staining for HPRT via immunohistochemistry, we found that expression is highly variable in malignant samples (Lung; 89.2-111.8, Breast; 66.7-98.3, Colon; 85.3-129.7, Prostate; 90.8-155.4, Pancreas; 74.1-132.1). Similarly, we observed high variability across cell lines via western blotting (p < 0.0001) which was further confirmed using RNA sequencing. Comparing normal and malignant patient samples, we observed consistent upregulation of HPRT expression within malignant samples relative to normal samples (p = 0.0001). These data indicate that HPRT is unsuitable as an endogenous control for cancer-related studies because its expression is highly variable and exceeds that of an appropriate control; therefore, we recommend its discontinued use as a normalization gene.

Hypoxia-Inducible Factor 1-α (HIF-1α) Induces Apoptosis of Human Uterosacral Ligament Fibroblasts Through the Death Receptor and Mitochondrial Pathways

Background

Hypoxia induces cell apoptosis in the uterosacral ligaments of patients with pelvic organ prolapse by upregulation of hypoxia-inducible factor-1α (HIF-1α). This study aimed to investigate the effects of HIF-1α on human uterosacral ligament fibroblasts (hUSLFs) following treatment with the chemical inducer of hypoxia, cobalt chloride (CoCl₂), and to explore the underlying mechanisms.

Material/Methods

Ten women who underwent hysterectomy for benign disease provided uterosacral ligament tissue for cell extraction. Following CoCl₂ treatment, cell viability of isolated and cultured hUSLFs was evaluated by the MTT assay. JC-1 fluorescence mitochondrial imaging was used to study the change in mitochondrial membrane potential. Cell apoptosis and expression of apoptosis-associated proteins and collagen type I alpha 1 (COL1A1) were measured by flow cytometry, TUNEL and Western blot, respectively.

Results

Hypoxia increased the expression of HIF-1α and increased cell apoptosis, decreased cell viability and expression levels of COL1A1. The JC-1 assay showed that the mitochondrial membrane potential was reduced and caspase-8, and -9 inhibitors partly reduced hUSLF apoptosis. HIF-1α treatment downregulated the expression of cellular FLICE inhibitory protein (c-FLIP), decoy receptor 2 (DcR2), and the ratio of Bcl-2 to Bax, and upregulated the expression tumor necrosis factor related apoptosis-inducing ligand (TRAIL), death receptor 5 (DR5) or TRAIL-R2, Fas, Bcl-2 interacting protein 3 (BNIP3), and cytochrome C, and increased the activation of caspase-3, caspase-8, and caspase-9, all of which were reversed by knockdown of HIF-1α.

Conclusions

HIF-1α significantly induced apoptosis of hUSLFs through both the cell death receptor and the mitochondrial-associated apoptosis pathways.

Hypoxia Induces Apoptosis through HIF-1α Signaling Pathway in Human Uterosacral Ligaments of Pelvic Organ Prolapse

The purpose of this study is to evaluate the expression of hypoxia-inducible factor-1α (HIF-1α) in women uterosacral ligament tissues with pelvic organ prolapse and women with normal uterine support structures and illuminate its relationship with apoptosis. Samples were collected from 38 women with pelvic organ prolapse and 31 age matched controls. The expression levels of HIF-1α and BNIP3 in the uterosacral ligaments were measured using immunohistochemistry, qRT-PCR, and Western blot. To assess apoptosis we performed TUNEL assay and Western blot analyses. Lastly, the short form of the Pelvic Floor Impact Questionnaire-7 (PFIQ-7) was used to evaluate prognosis of surgical patients and twenty patients finished the follow-up. The expressions of HIF-1α and BNIP3 in the uterosacral ligaments were significantly higher in patients with pelvic organ prolapse than in control group. Pearson's correlation test revealed significant positive correlations between HIF-1α and apoptosis index. Similarly, Western blot analysis showed the expression of proapoptosis proteins (Bax and Bad), Cytochrome-c, cleaved caspase-3, and caspase-9 in patients with pelvic organ prolapse was upregulated. The PFIQ-7 scores were higher in HIF-1α positive group than in the negative group. Hypoxia may contribute to the pathological process of pelvic organ prolapse by increasing apoptosis via activating HIF-1α signaling pathway.

The regulation of thermal stress induced apoptosis in corals reveals high similarities in gene expression and function to higher animals

Recent studies suggest that controlled apoptotic response provides an essential mechanism, enabling corals to respond to global warming and ocean acidification. However, the molecules involved and their functions are still unclear. To better characterize the apoptotic response in basal metazoans, we studied the expression profiles of selected genes that encode for putative pro- and anti-apoptotic mediators in the coral Stylophora pistillata under thermal stress and bleaching conditions. Upon thermal stress, as attested by the elevation of the heat-shock protein gene HSP70’s mRNA levels, the expression of all studied genes, including caspase, Bcl-2, Bax, APAF-1 and BI-1, peaked at 6–24 h of thermal stress (hts) and declined at 72 hts. Adversely, the expression levels of the survivin gene showed a shifted pattern, with elevation at 48–72 hts and a return to basal levels at 168 hts. Overall, we show the quantitative anti-apoptotic traits of the coral Bcl-2 protein, which resemble those of its mammalian counterpart. Altogether, our results highlight the similarities between apoptotic networks operating in simple metazoans and in higher animals and clearly demonstrate the activation of pro-cell survival regulators at early stages of the apoptotic response, contributing to the decline of apoptosis and the acclimation to chronic stress.