Evidence of biomechanical and collagen heterogeneity in uterine fibroids

Coenzyme Q-10 reduced the aberrant production of extracellular matrix proteins in uterine leiomyomas through transforming growth factor beta 3

OBJECTIVE

To evaluate the impact of coenzyme Q-10 (CoQ-10) on the dysregulated synthesis of extracellular matrix proteins mediated by transforming growth factor beta 3 (TGF-β3) in uterine leiomyomas.

DESIGN

Laboratory study.

SETTING

University.

PATIENTS

None.

INTERVENTIONS

Treatment of immortalized uterine myometrial and leiomyoma cells to TGF-β3 and CoQ-10.

MAIN OUTCOME MEASURES

The protein concentrations of collagen 1A1 (COL1A1), collagen 3A1 (COL3A1), collagen 11A1 (COL11A1), and fibronectin (FN1) were assessed through western blot analysis after treatment of immortalized uterine myometrial and leiomyoma cells with both transforming growth factor beta (TGF-β) 3 and concentrations of CoQ-10 at 10, 50, and 100 μM concurrently for 24 hours.

RESULTS

Immortalized uterine leiomyoma and myometrial cells exposed to TGF-β3 for 24 hours demonstrated a significant up-regulation of COL1A1, COL3A1, COL11A1, and FN1 compared with untreated cells. In leiomyoma cells, concurrent treatment with CoQ-10 over the same timeframe revealed a dose-dependent decrease in these protein concentrations compared with those in cells treated with TGF-β3 alone. At the highest concentration of 100 μM of CoQ-10, significant decreases in the amounts of COL1A1 (0.59 ± 0.10-fold), COL3A1 (0.46 ± 0.09-fold), COL11A1 (0.53 ± 0.09-fold), and FN1 (0.56 ± 0.09-fold) were observed. Similarly, myometrial cells exposed to both TGF-β3 and CoQ-10 demonstrated a dose-responsive decline in the amount of extracellular matrix protein compared with cells exposed to TGF-β3 alone. Significant reductions in the amounts of COL1A1 (0.75 ± 0.03-fold), COL3A1 (0.48 ± 0.06-fold), COL11A1 (0.38 ± 0.06), and FN1 (0.69 ± 0.04-fold) were appreciated at 100-μM CoQ-10.

CONCLUSION

Coenzyme Q-10 mitigated the aberrant production of key biomarkers of the extracellular matrix mediated by TGF-β3 in uterine leiomyomas. Our findings highlight a promising nonhormonal compound that can counteract the fibroproliferative process inherent to leiomyomas.

Material properties of nonpregnant and pregnant human uterine layers

The uterus has critical biomechanical functions in pregnancy and undergoes dramatic material growth and remodeling from implantation to parturition. The intrinsic material properties of the human uterus and how they evolve in pregnancy are poorly understood. To address this knowledge gap and assess the heterogeneity of these tissues, the time-dependent material properties of all human uterine layers were measured with nanoindentation. The endometrium-decidua layer was found to be the least stiff, most viscous, and least permeable layer of the human uterus in nonpregnant and third-trimester pregnant tissues. In pregnancy, the endometrium-decidua becomes stiffer and less viscous with no material property changes observed in the myometrium or perimetrium. Additionally, uterine material properties did not significantly differ between third-trimester pregnant tissues with and without placenta accreta. The foundational data generated by this study will facilitate the development of physiologically accurate models of the human uterus to investigate gynecologic and obstetric disorders.

Racial disparity in uterine leiomyoma: new insights of genetic and environmental burden in myometrial cells

Uterine leiomyoma (LM), also known as uterine fibroids, are common gynecological tumors and can reach a prevalence of 70% among women by the age of 50 years. Notably, the LM burden is much higher in Black women with earlier onset, a greater tumor number, size, and severity compared to White women. Published knowledge shows that there are genetic, environmental, and lifestyle-based risk factors associated with racial disparity for LM. Significant strides have been made on genomic, epigenomic, and transcriptomic data levels in Black and White women to elucidate the underlying pathomolecular reasons of racial disparity in LM development. However, racial disparity of LM remains a major area of concern in gynecological research. This review highlights risk factors of LM and their role in different races. Furthermore, we discuss the genetics and uterine myometrial microenvironment in LM development. Comparative findings revealed that a major racial difference in the disease is linked to myometrial oxidative burden and altered ROS pathways which is relevant to the oxidized guanine in genomic DNA and MED12 mutations that drive the LM genesis. Considering the burden and morbidity of LM, we anticipate that this review on genetic risk and myometrial microenvironment will strengthen understanding and propel the growth of research to address the racial disparity of LM burden.

Variants in exon 2 of MED12 gene causes uterine leiomyoma's through over-expression of MMP-9 of ECM pathway

AIMS

To study the impact of Mediator complex subunit 12 (MED12) gene variants on the encoded protein's function and pathogenic relevance for genesis of uterine leiomyoma's (ULs).

METHODS

Mutational analysis in exon-2 of MED12 gene was performed by PCR amplification and DNA sequencing in 89 clinically diagnosed ULs tissues. Pathogenicity prediction of variation was performed by computational analysis. The functional effects of missense variation were done by quantity RT-PCR and western blot analysis.

RESULT(S)

Out of 89 samples, 40 (44.94%) had missense variation in 14 different CDS position of exon-2 of MED12 gene. Out of 40 missense variation, codon 44 had 25 (62.5%) looking as a hotspot region for mutation for ULs, because CDS position c130 and c131present at codon 44 that have necleotide change G>A, T, C at c130 and c131 have necleotide change G>A and C. We also find somenovel somatic mutations oncodon 36 (T > C), 38 (G>T) of exon-2 and 88 (G>C) of intron-2. No mutations were detected in uterine myometrium samples. Our computational analysis suggests that change in Med12c .131 G>A leads to single substitution of amino acid [Glycine (G) to Aspartate (D)] which has a pathogenic and lethal impact and may cause instability of MED12 protein. Further, analysis of extracellular matrix (ECM) component (MMP-2 & 9, COL4A2 and α-SMA) mRNA and protein expression levels in the set of ULs having MED12 mutation showed significantly higher expression of MMP-9 and α-SMA.

CONCLUSION(S)

The findings of present study suggest that missense variation in codon 44 of MED12 gene lead to the genesis of leiomyoma's through over-expression of MMP-9 of ECM pathway which could be therapeutically targeted for non-surgical management of ULs.

Material Properties of Nonpregnant and Pregnant Human Uterine Layers

The uterus has critical biomechanical functions in pregnancy and undergoes dramatic material growth and remodeling from implantation to parturition. The intrinsic material properties of the human uterus and how they evolve in pregnancy are poorly understood. To address this knowledge gap and assess the heterogeneity of these tissues, the time-dependent material properties of all human uterine layers were measured with nanoindentation. The endometrium-decidua layer was found to be the least stiff, most viscous, and least permeable layer of the human uterus in nonpregnant and third-trimester pregnant tissues. In pregnancy, endometrium-decidua becomes stiffer and less viscous with no material property changes observed in the myometrium or perimetrium. Additionally, uterine material properties did not significantly differ between third-trimester pregnant tissues with and without placenta accreta. The foundational data generated by this study will facilitate the development of physiologically accurate models of the human uterus to investigate gynecologic and obstetric disorders.

Uterine fibroid cell cytoskeletal organization is affected by altered G protein-coupled estrogen receptor-1 and phosphatidylinositol 3-kinase signaling

OBJECTIVE

To determine whether cyclic strain affects fibroid cell cytoskeletal organization, proliferation, and collagen synthesis differently than myometrial cells.

DESIGN

A basic science study using primary cultures of patient-matched myometrial and fibroid cells.

SETTING

Academic laboratory.

PATIENT(S)

Premenopausal women undergoing myomectomy or hysterectomy for the treatment of symptomatic uterine fibroids.

INTERVENTION(S)

Application of uniaxial strain patterns mimicking periovulation, menses, or dysmenorrhea using the Flexcell tension system or static control. Secondarily, inhibition of G protein-coupled estrogen receptor-1 and phosphatidylinositol 3-kinase.

MAIN OUTCOME MEASURE(S)

Cell alignment, cell number, and collagen content.

RESULT(S)

Menses-strained cells demonstrated the most variation in cell alignment, cell proliferation, and procollagen content between myometrial and fibroid cells. Procollagen content decreased in myometrial cells with increasing strain amplitude and decreasing frequency. G protein-coupled estrogen receptor-1 inhibition decreases cellular alignment in the presence of strain.

CONCLUSION(S)

Mechanotransduction affecting cytoskeletal arrangement through the G protein-coupled estrogen receptor-1-phosphatidylinositol 3-kinase pathway is altered in fibroid cells. These results highlight the importance of incorporating mechanical stimulation into the in vitro study of fibroid pathology.

Upregulated TIMP1 facilitates and coordinates myometrial contraction by decreasing collagens and cell adhesive capacity during human labor

Myometrial contraction is one of the key events involved in parturition. Increasing evidence suggests the importance of the extracellular matrix (ECM) in this process, in addition to the functional role of myometrial smooth muscle cells, and our previous study identified an upregulated tissue inhibitor of metalloproteinase 1 (TIMP1) in human laboring myometrium compared to nonlabor samples. This study aimed to further explore the potential role of TIMP1 in myometrial contraction. First, we confirmed increased myometrial TIMP1 levels in labor and during labor with cervical dilation using transcriptomic and proteomic analyses, followed by real-time PCR, western blotting, and immunohistochemistry. Then, a cell contraction assay was performed to verify the decreased contractility after TIMP1 knockdown in vitro. To further understand the underlying mechanism, we used RNA-sequencing analysis to reveal the upregulated genes after TIMP1 knockdown; these genes were enriched in collagen fibril organization, cell adhesion, and ECM organization. Subsequently, a human matrix metalloproteinase (MMP) array and collagen staining were performed to determine the TIMPs, MMPs and collagens in laboring and nonlabor myometrium. A real-time cell adhesion assay was used to detect cell adhesive capacity. The results showed upregulated MMP8 and MMP9, downregulated collagens, and attenuated cell adhesive capacity in laboring myometrium, while lower MMP levels and higher collagen levels and cell adhesive capacity were observed in nonlabor. Moreover, TIMP1 knockdown led to restoration of cell adhesive capacity. Together, these results indicate that upregulated TIMP1 during labor facilitates and coordinates myometrial contraction by decreasing collagen and cell adhesive capacity, which may provide effective strategies for the regulation of myometrial contraction.

Regulation of oxytocin-induced calcium transients and gene expression in engineered myometrial tissues by tissue architecture and matrix rigidity

The uterus is susceptible to benign tumors known as fibroids, which have been associated with many pregnancy complications, including preterm labor. However, the impact of fibrotic tissue remodeling on the physiology of the myometrium, the smooth muscle layer of the uterus, is poorly understood, in large part due to a lack of model systems. In this study, we engineered healthy-like and fibrotic-like myometrium by culturing human myometrial smooth muscle cells on polyacrylamide hydrogels micropatterned with fibronectin to independently tune matrix rigidity and tissue alignment, respectively. We then evaluated calcium transients in response to oxytocin stimulation. Isotropic myometrial tissues on stiff substrates (representing fibrotic myometrium) had shorter calcium transients due to shorter decay time compared to aligned myometrial tissues on soft substrates (representing healthy myometrium). Calcium transients in aligned tissues had longer response times and longer decay times than isotropic tissues, irrespective of substrate stiffness. The amplitude of calcium transients was also higher on soft substrates compared to stiff substrates, irrespective of tissue alignment. We also performed RNA sequencing to detect differentially expressed genes between healthy- and fibrotic-like tissues, which revealed that a bitter taste receptor shown to induce smooth muscle relaxation, TAS2R31, was down-regulated in fibrotic-like tissues. Finally, we measured oxytocin-induced calcium transients in response to pre-treatment with progesterone, caffeine, thrombin, and nifedipine to demonstrate applications for our model system in drug screening. Both progesterone and caffeine caused a decrease in calcium transient duration, as expected, while thrombin and nifedipine had less impact. Collectively, our engineered model of the myometrium enables new insights into myometrial mechanobiology and can be extended to identify or screen novel drug targets.

Contemporary approaches in the management of uterine leiomyomas

BACKGROUND

Leiomyomas (fibroids), the most common benign solid tumours in females, originate from the myometrium and are associated with poor quality of life for patients. The current management of uterine leiomyomas mainly includes surgical interventions such as hysterectomy and myomectomy, either by laparoscopy or laparotomy, which have several complications and are not ideal for preserving fertility. Therefore, there is a need to develop or repurpose medical treatments that do not require surgical intervention.

OBJECTIVE

Many drugs are used to treat the symptoms associated with uterine fibroids. The main objective of this systematic review is to give an up-to-date account of potential pharmacological agents (non-surgical methods) for the management of uterine leiomyomas.

SEARCH STRATEGY

PubMed was searched for scientific and clinical literature using the keyword 'uterine fibroids' along with the drug names described in each section. For example, 'uterine fibroids' and 'ulipristal acetate' were the keywords used to search for literature on ulipristal acetate (UPA).

RESULTS

Various preclinical and clinical studies have shown that some drugs and herbal formulations exhibit activity in the management of uterine leiomyomas. Recent studies found that drugs such as UPA, elagolix, EC313, asoprisnol, nutritional supplements and herbal preparations were helpful in treating the symptoms associated with uterine leiomyomas.

CONCLUSION

Many drugs show efficacy in patients with symptomatic uterine fibroids. UPA is one of the most studied and prescribed medicines for uterine fibroids; however, its usage has been restricted due to a few recent incidences of hepatic toxicity. Herbal drugs and natural supplements have also shown promising effects on uterine fibroids. The synergistic effects of nutritional and herbal supplements have been reported in certain cases, and should be studied in detail. Further research is warranted to identify the mode of action of the drugs, and to determine the precise conditions that would explain the causes of toxicity in some patients.

Update on the Role and Regulatory Mechanism of Extracellular Matrix in the Pathogenesis of Uterine Fibroids

Uterine fibroids (UFs), also known as leiomyomas, are benign tumors of the myometrium affecting over 70% of women worldwide, particularly women of color. Although benign, UFs are associated with significant morbidity; they are the primary indication for hysterectomy and a major source of gynecologic and reproductive dysfunction, ranging from menorrhagia and pelvic pain to infertility, recurrent miscarriage, and preterm labor. So far, the molecular mechanisms underlying the pathogenesis of UFs are still quite limited. A knowledge gap needs to be filled to help develop novel strategies that will ultimately facilitate the development of therapies and improve UF patient outcomes. Excessive ECM accumulation and aberrant remodeling are crucial for fibrotic diseases and excessive ECM deposition is the central characteristics of UFs. This review summarizes the recent progress of ascertaining the biological functions and regulatory mechanisms in UFs, from the perspective of factors regulating ECM production, ECM-mediated signaling, and pharmacological drugs targeting ECM accumulation. In addition, we provide the current state of knowledge by discussing the molecular mechanisms underlying the regulation and emerging role of the extracellular matrix in the pathogenesis of UFs and in applications. Comprehensive and deeper insights into ECM-mediated alterations and interactions in cellular events will help develop novel strategies to treat patients with this common tumor.

Prevention of Uterine Fibroids: molecular mechanisms and potential clinical application

Uterine fibroids (UFs; leiomyoma) are the most common benign neoplastic threat to women worldwide, exacting an immense personal burden on female health and a monetary expense to the healthcare system estimated in the hundreds of billions of dollars every year globally. With no long-term non-invasive treatment option currently available to treat UFs, deeper insights regarding tumor etiology are the key for developing newer therapies. Accordingly, in this review, we discuss new mechanistic paradigm to explain UF tumor development through an exquisite model involving developmental reprogramming of myometrial stem cells due to early life endocrine disruptors exposure, inflammation, fibrosis, DNA damage, and eventually tissue stiffness. Further, we propose to utilize shear wave elastography as a potential screening tool for the early identification of women at risk for developing UFs who can benefit from several simple preventive strategies, including the consumption of natural compounds such as vitamin D and green tea as a safe fertility friendly non-hormonal modality to delay or even arrest or reverse UF progression.

Uterine fibroids - Causes, impact, treatment, and lens to the African perspective

Leiomyomas, or uterine fibroids as they are commonly known, are mostly seen in women of reproductive age. However, they can go undetected in most women, and approximately 25% of women show clinical symptoms. Although fibroids are a global burden impacting 80% of premenopausal women, they are more prevalent among Black women than among women of other races. Based on clinical diagnosis, the estimated cumulative incidence of fibroids in women ≤50 years old is significantly higher for black (>80%) versus white women (∼70%). The cause of leiomyomas is not clearly known, but studies have shown evidence of factors that drive the development or exacerbation of the disease. Evidence has linked risk factors such as lifestyle, age, environment, family history of uterine fibroids, and vitamin D deficiencies to an increased risk of uterine fibroids, which impact women of African descent at higher rates. Treatments may be invasive, such as hysterectomy and myomectomy, or non-invasive, such as hormonal or non-hormonal therapies. These treatments are costly and tend to burden women who have the disease. Sub-Saharan Africa is known to have the largest population of black women, yet the majority of uterine fibroid studies do not include populations from the continent. Furthermore, the prevalence of the disease on the continent is not well determined. To effectively treat the disease, its drivers need to be understood, especially with regard to racial preferences. This paper aims to review the existing literature and build a case for conducting future research on African women.

Biomechanical Forces Determine Fibroid Stem Cell Transformation and the Receptivity Status of the Endometrium: A Critical Appraisal

Myometrium cells are an important reproductive niche in which cyclic mechanical forces of a pico-newton range are produced continuously at millisecond and second intervals. Overproduction and/or underproduction of micro-forces, due to point or epigenetic mutation, aberrant methylation, and abnormal response to hypoxia, may lead to the transformation of fibroid stem cells into fibroid-initiating stem cells. Fibroids are tumors with a high modulus of stiffness disturbing the critical homeostasis of the myometrium and they may cause unfavorable and strong mechanical forces. Micro-mechanical forces and soluble-chemical signals play a critical role in transcriptional and translational processes' maintenance, by regulating communication between the cell nucleus and its organelles. Signals coming from the external environment can stimulate cells in the format of both soluble biochemical signals and mechanical ones. The shape of the cell and the plasma membrane have a significant character in sensing electro-chemical signals, through specialized receptors and generating responses, accordingly. In order for mechanical signals to be perceived by the cell, they must be converted into biological stimuli, through a process called mechanotransduction. Transmission of fibroid-derived mechanical signals to the endometrium and their effects on receptivity modulators are mediated through a pathway known as solid-state signaling. It is not sufficiently clear which type of receptors and mechanical signals impair endometrial receptivity. However, it is known that biomechanical signals reaching the endometrium affect epithelial sodium channels, lysophosphatidic acid receptors or Rho GTPases, leading to conformational changes in endometrial proteins. Translational changes in receptivity modulators may disrupt the selectivity and receptivity functions of the endometrium, resulting in failed implantation or early pregnancy loss. By hypermethylation of the receptivity genes, micro-forces can also negatively affect decidualization and implantation. The purpose of this narrative review is to summarize the state of the art of the biomechanical forces which can determine fibroid stem cell transformation and, thus, affect the receptivity status of the endometrium with regard to fertilization and pregnancy.

Importance of Fibrosis in the Pathogenesis of Uterine Leiomyoma and the Promising Anti-fibrotic Effects of Dipeptidyl Peptidase-4 and Fibroblast Activation Protein Inhibitors in the Treatment of Uterine Leiomyoma

Uterine fibroid or leiomyoma is the most common benign uterus tumor. The tumor is primarily composed of smooth muscle (fibroid) cells, myofibroblast, and a significant amount of extracellular matrix components. It mainly affects women of reproductive age. They are uncommon before menarche and usually disappear after menopause. The fibroids have excessive extracellular matrix components secreted by activated fibroblast cells (myofibroblast). Myofibroblast has the characteristics of fibroblast and smooth muscle cells. These cells possess contractile capability due to the expression of contractile proteins which are normally found only in muscle tissues. The rigid nature of the tumor is responsible for many side effects associated with uterine fibroids. The current drug treatment strategies are primarily hormone-driven and not anti-fibrotic. This paper emphasizes the fibrotic background of uterine fibroids and the mechanisms behind the deposition of excessive extracellular matrix components. The transforming growth factor-β, hippo, and focal adhesion kinase-mediated signaling pathways activate the fibroblast cells and deposit excessive extracellular matrix materials. We also exemplify how dipeptidyl peptidase-4 and fibroblast activation protein inhibitors could be beneficial in reducing the fibrotic process in leiomyoma. Dipeptidyl peptidase-4 and fibroblast activation protein inhibitors prevent the fibrotic process in organs such as the kidneys, lungs, liver, and heart. These inhibitors are proven to inhibit the signaling pathways mentioned above at various stages of their activation. Based on literature evidence, we constructed a narrative review on the mechanisms that support the beneficial effects of dipeptidyl peptidase-4 and fibroblast activation protein inhibitors for treating uterine fibroids.

Uterine leiomyoma as useful model to unveil morphometric and macromolecular collagen state and impairment in fibrotic diseases: An ex-vivo human study

Collagen is one of the main components of the extracellular matrix (ECM), involved, among all, in the maintenance of the structural support of tissues. In fibrotic diseases, collagen is overexpressed, and its production determines the formation of a significantly stiffer ECM. The cross-linking of high-resolution analytical tools, able to investigate both the tridimensional organization and the secondary structure of collagen in fibrotic diseases, could be useful to identify defined markers correlating the status of this protein with specific pathological conditions. To this purpose, an innovative multidisciplinary approach based on Phase-Contrast MicroComputed Tomography, Transmission Electron Microscopy, and Fourier Transform Infrared Imaging Spectroscopy was exploited on leiomyoma samples and adjacent myometrium to characterize microstructural collagen features. Uterine leiomyoma is a common gynecological disorder affecting women in fertile age. It is characterized by a massive collagen production due to the repairing processes occurring at myometrium level, and, hence, it represents a valuable model to investigate collagen self-organization in a pathological condition. Moreover, to evaluate the sensitivity of this multidisciplinary approach, the effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) omega-3 fatty acids in collagen reduction were also investigated.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Uterine fibroids increase the risk of preterm birth and other adverse birth events: a systematic review and meta-analysis

BACKGROUND

Uterine fibroids may cause preterm birth. This meta-analysis evaluates the effect of uterine fibroids on the risk of preterm birth and other obstetric outcomes.

METHODS

Using the literature review method, the databases PubMed, Medline, Embase and Central were retrieved to obtain relevant research literature. The selected studies were analyzed and evaluated. The literature was a cohort study or a case-control study of pregnant women as the research object and uterine fibroids as the exposure factor to observe adverse events during pregnancy. The chi-square test was used to test for heterogeneity. Subgroup analyses were used to explore sources of heterogeneity. Publication bias was assessed using Egger's test. Enumeration data were described by odds ratio (OR). Measurement data were described by mean difference (MD). Calculate the confidence interval (CI).

RESULTS

A total of 11 studies were included in this study, including 7 cohort studies and 4 case-control studies, with a total of 313,913 women. The probability of uterine fibroids among women was 3.99%. The results of meta-analysis showed that women with uterine fibroids experienced preterm birth <37 weeks (OR =1.43, 95% CI: 1.25 to 1.64, P<0.00001), preterm birth <34 weeks (OR =1.73, 95% CI: 1.34 to 2.25, P<0.0001), premature rupture of membranes (OR =1.38, 95% CI: 1.08 to 1.75, P=0.009), placental abruption (OR =1.60, 95% CI: 1.20 to 2.14, P=0.001), cesarean section (OR =2.09, 95% CI: 1.69 to 2.58, P<0.00001), and postpartum hemorrhage (OR =2.95, 95% CI: 1.86 to 4.66, P<0.00001) were all at higher risk, and the mean gestational age at delivery [mean difference (MD) =-0.58, 95% CI: -0.66 to -0.51, P<0.00001] and birth weight (MD =-117.82, 95% CI: -155.19 to -80.45, P<0.00001) were lower. Egger's test indicated that there was no publication bias among the included studies (P>0.05).

CONCLUSIONS

Pregnant women with uterine fibroids are at higher risk for preterm birth and other adverse obstetric outcomes and require closer monitoring.

A Retractable Six-Prong Laparoscopic Grasper for Laparoscopic Myomectomy

The fixation and manipulation of fibroids during laparoscopic myomectomy is a persistent issue for gynecologic surgeons. In this paper, we present a laparoscopic grasper that, through a sheath-based deployment mechanism, opens into a larger multi-toothed grasper within the patient and collapses back for removal. Due to the increased number of contact points with the tumor, the expanded grasper allows for reliable fixation, aiding in manipulation during excision. We describe the nature-inspired design of the grasper from a physical foundation, establish the design theory and practical issues, and present manufacturing and testing of a full-scale 5 mm grasper. The unit was tested on synthetic fibroid models and was able to sustain a 50% higher load before tearing than a common single-tooth tenaculum. This development not only promises to improve fibroid fixation in myomectomy, but its design could be adapted to aid in the fixation of other difficult tissues in laparoscopic surgery.

A Comparison of Shear Wave Elastography between Normal Myometrium, Uterine Fibroids, and Adenomyosis: A Cross-Sectional Study

Background

The differential diagnosis between uterine fibroid and adenomyosis is sometimes difficult; a precise diagnosis is required in women with infertility because of the different choice of treatments. Ultrasound elastography (UE) is a novel technique to evaluate the elasticity or the stiffness of the tissue of interest. The present study aims to compare UE shear wave velocity (SWV) among normal uterine myometrium, uterine fibroid, and adenomyosis, and assess the accuracy of shear wave elastography in the diagnosis of adenomyosis.

Materials and Methods

This cross-sectional study recruited 25 subjects for each group (control, adenomyosis, and fibroid) from April 2019 to April 2020. Transvaginal UE using an Aplio 500 (Toshiba Medical Systems, Japan) with ultrasound mapping for point of tissue biopsy was performed for all subjects. The diagnosis was confirmed by histology. Masson’s trichrome staining for collagen was performed and quantified

Results

The mean ± standard deviation (SD) for SWV was 3.44 ± 0.95 m/seconds (control group), 4.63 ± 1.45 m/seconds (adenomyosis group), and 4.53 ± 1.07 m/seconds (fibroid group). The mean SWV differed when comparing normal myometrium and adenomyosis after adjustments for age and endometrial pathology (P=0.019). The cut-off point of SWV at 3.465 m/seconds could differentiate adenomyosis from the normal uterus with an 80% sensitivity, 80% specificity, and an area under the curve (AUC) of 0.80 (95% confidence interval [CI]: 0.68-0.93) (P<0.001). No significant difference in SWV between the adenomyosis and fibroid groups was detected.

Conclusion

Shear wave elastography could be an alternative tool to distinguish between normal myometrium and adenomyosis; however, it could not differentiate adenomyosis from uterine fibroid or uterine fibroid from normal myometrium.

Using rheology to quantify the effects of localized collagenase treatments on uterine fibroid digestion

Uterine fibroids are stiff, benign tumors containing excessive, disordered collagens that occur in 70-80% of women before age 50 and cause bleeding and pain. Collagenase Clostridium histolyticum (CCH) is a bacterial enzyme capable of digesting the collagens present in fibroids. By combining CCH with injectable drug delivery systems to enhance effectiveness, a new class of treatments could be developed to reduce the stiffness of fibroids, preventing the need for surgical removal and preserving fertility. In this work, we achieved localization of CCH via physical entrapment by co-injecting a thermoresponsive pNIPAM-based polymeric delivery system called LiquoGel (LQG), which undergoes a sol-gel transition upon heating. Toxicity study results for LQG injected subcutaneously into mice demonstrate that LQG does not induce lesions or other adverse effects. We then used rheology to quantify the effects of localized CCH injections on the modulus and viscoelasticity of uterine fibroids, which exhibit gel-like behavior, through ex vivo and in vivo digestion studies. Ex vivo CCH injections reduce the tissue modulus by over two orders of magnitude and co-injection of LQG enhances this effect. Rheological results from an in vivo digestion study in mice show a significant reduction in tissue modulus and increase in tissue viscoelasticity 7 days after a single injection of LQG+CCH. Parallel histological staining validates that the observed rheological changes correspond to an increase in collagen lysis after treatment by LQG+CCH. These results show promise for development of injectable and localized enzymatic therapies for uterine fibroids and other dense tumors. STATEMENT OF SIGNIFICANCE: Uterine fibroids are stiff, benign tumors containing high collagen levels that cause bleeding and pain in women. Fertility-preserving and minimally-invasive treatments to soften fibroids are needed as an alternative to surgical removal via hysterectomy. We demonstrate through ex vivo and in vivo studies that co-injecting a thermoresponsive polymer delivery system (LQG) alongside a bacterial collagenase (CCH) enzyme significantly increases treatment effectiveness at softening fibroids through CCH localization. We use rheology to measure the modulus and viscoelasticity of fibroids and histology to show that fibroid softening corresponds to a decrease in collagen after treatment with LQG+CCH. These results highlight the utility of rheology at quantifying tissue properties and present a promising injectable therapy for fibroids and other dense tumors.

Feasibility of T2 relaxation time in predicting the technical outcome of MR-guided high-intensity focused ultrasound treatment of uterine fibroids

PURPOSE

The aim of this study was to assess the feasibility of T2 relaxation time in predicting the immediate technical outcome i.e., nonperfused volume ratio (NPVr) of magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) treatment of symptomatic uterine fibroids and to compare it with existing T2-weighted imaging methods (Funaki classification and scaled signal intensity, SSI).

MATERIALS AND METHODS

30 patients with 32 uterine fibroids underwent an MRI study including a quantitative T2 relaxation time measurement prior to MRgHIFU treatment. T2 relaxation times were measured with a multi-echo fast imaging-based technique with 16 echoes. The correlation between pretreatment values of the uterine fibroids and treatment outcomes, that is nonperfused volume ratios (NPVr), was assessed with nonparametric statistical measures. T2 relaxation time-based method was compared to existing T2-weighted imaging-based methods using receiver-operating-characteristics (ROC) curve analysis and Chi-square test.

RESULTS

Nonparametric measures of association revealed a statistically significant negative correlation between T2 relaxation time values and NPVr. The T2 relaxation time classification (T2 I, T2 II, and T2 III) resulted in the whole model p-value of 0.0019, whereas the Funaki classification resulted in a p-value of 0.56. The T2 relaxation time classification (T2 I and T2 II) achieved a whole model of a p-value of 0.0024, whereas the SSI classification had a p-value of 0.0749.

CONCLUSIONS

A longer T2 relaxation time of the fibroid prior to treatment correlated with a lower NPVr. Based on our results, the T2 relaxation time classifications seem to outperform the Funaki classification and the SSI method.

Extracellular matrix and Hippo signaling as therapeutic targets of antifibrotic compounds for uterine fibroids

BACKGROUND

Uterine fibroids are highly prevalent, collagen-rich, mechanically stiff, fibrotic tumors for which new therapeutic options are needed. Increased extracellular matrix (ECM) stiffness activates mechanical signaling and Hippo/YAP promoting fibroid growth, but no prior studies have tested either as a therapeutic target. We tested the hypothesis that injection of a purified form of collagenase Clostridium histolyticum (CCH) that selectively digests type I and type III collagens would alter ECM stiffness, Hippo signaling, and selectively reduce fibroid cell growth. We also used two FDA-approved drugs, verteporfin and nintedanib, to elucidate the role of Hippo/YAP signaling in uterine fibroid and myometrial cells.

METHODS

The clinical trial was registered (NCT02889848). Stiffness of samples was measured by rheometry. Protein expression in surgical samples was analyzed via immunofluorescence. Protein and gene expression in uterine fibroid or myometrial cell lines were measured by real time PCR and western blot, and immunofluorescence.

RESULTS

Injection of CCH at high doses (0.1-0.2 mg/cm3 ) into fibroids resulted in a 46% reduction in stiffness in injected fibroids compared to controls after 60 days. Levels of the cell proliferation marker proliferative cell nuclear antigen (PCNA) were decreased in fibroids 60 days after injection at high doses of CCH. Key Hippo signaling factors, specifically the transcriptionally inactive phosphorylated YAP (p-YAP), was increased at high CCH doses, supporting the role of YAP in fibroid growth. Furthermore, inhibition of YAP via verteporfin (YAP inhibitor) decreased cell proliferation, gene and protein expression of key factors promoting fibrosis and mechanotransduction in fibroid cells. Additionally, the anti-fibrotic drug, nintedanib, inhibited YAP and showed anti-fibrotic effects.

CONCLUSIONS

This is the first report that in vivo injection of collagenase into uterine fibroids led to a reduction in Hippo/YAP signaling and crucial genes and pathways involved in fibroid growth. These results indicate that targeting ECM stiffness and Hippo signaling might be an effective strategy for uterine fibroids.

A Phase I Clinical Trial to Assess Safety and Tolerability of Injectable Collagenase in Women with Symptomatic Uterine Fibroids

Uterine fibroids feature excessive deposition of types I and III collagen. Previous ex vivo studies showed an FDA-approved collagenase (EN3835)-digested types I and III collagen fibers in fibroid tissues; however, collagenase had not been evaluated in vivo for effects on uterine fibroids. The objective was to assess the safety and tolerability of collagenase injection directly into uterine fibroids. This was a prospective, open label, dose escalation study. The study participants were fifteen women aged 35-50 years with symptomatic uterine fibroids planning to undergo hysterectomy. Three subjects received saline and methylene blue, three subjects received a fixed dose of EN3835, and 9 subjects received stepped, increasing dosages of EN3835, all by transvaginal, ultrasound-guided injections. Primary outcome measures were safety and tolerability of the injection and change in collagen content between treated and control tissues. There were no significant adverse events following injection of EN3835 into uterine fibroids. Masson's trichrome stains revealed a 39% reduction in collagen content in treated samples compared to controls (p <0.05). Second harmonic generation (SHG) analysis showed treated samples to have a 21% reduction in density of collagen compared to controls. Picrosirius-stained collagenase-treated fibroids showed collagen fibers to be shorter and less dense compared to controls. Subjects reported a decrease in fibroid-related pain on the McGill Pain Questionnaire after study drug injection in Group 2 at both 4-8 days and 60-90 days post-injection. The findings indicated that injection of collagenase was safe and well tolerated. These results support further clinical investigation of collagenase as a minimally invasive treatment of uterine fibroids. NCT0289848.

Anisotropic Mechanical Properties of the Human Uterus Measured by Spherical Indentation

The mechanical function of the uterus is critical for a successful pregnancy. During gestation, uterine tissue grows and stretches to many times its size to accommodate the growing fetus, and it is hypothesized the magnitude of uterine tissue stretch triggers the onset of contractions. To establish rigorous mechanical testing protocols for the human uterus in hopes of predicting tissue stretch during pregnancy, this study measures the anisotropic mechanical properties of the human uterus using optical coherence tomography (OCT), instrumented spherical indentation, and video extensometry. In this work, we perform spherical indentation and digital image correlation to obtain the tissue's force and deformation response to a ramp-hold loading regimen. We translate previously reported fiber architecture, measured via optical coherence tomography, into a constitutive fiber composite material model to describe the equilibrium material behavior during indentation. We use an inverse finite element method integrated with a genetic algorithm (GA) to fit the material model to our experimental data. We report the mechanical properties of human uterine specimens taken across different anatomical locations and layers from one non-pregnant (NP) and one pregnant (PG) patient; both patients had pathological uterine tissue. Compared to NP uterine tissue, PG tissue has a more dispersed fiber distribution and equivalent stiffness material parameters. In both PG and NP uterine tissue, the mechanical properties differ significantly between anatomical locations.

Mechanical stiffness augments ligand-dependent progesterone receptor B activation via MEK 1/2 and Rho/ROCK-dependent signaling pathways in uterine fibroid cells

OBJECTIVE

To test whether mechanical substrate stiffness would influence progesterone receptor B (PRB) signaling in fibroid cells. Uterine fibroids feature an excessive extracellular matrix, increased stiffness, and altered mechanical signaling. Fibroid growth is stimulated by progestins and opposed by anti-progestins, but a functional interaction between progesterone action and mechanical signaling has not been evaluated.

DESIGN

Laboratory studies.

SETTING

Translational science laboratory.

PATIENT(S)/ANIMAL(S)

Human fibroid cell lines and patient-matched fibroid and myometrial cell lines.

INTERVENTION(S)

Progesterone receptor B-dependent reporter assays and messenger RNA quantitation in cells cultured on stiff polystyrene plates (3GPa) or soft silicone plates (930KPa). Pharmacologic inhibitors of extracellular signal-related protein kinase (ERK) kinase 1/2 (MEK 1/2; PD98059), p38 mitogen-activated protein kinase (SB202190), receptor tyrosine kinases (RTKs; nintedanib), RhoA (A13), and Rho-associated coiled-coil kinase (ROCK; Y27632).

MAIN OUTCOME MEASURE(S)

Progesterone-responsive reporter activation.

RESULT(S)

Fibroid cells exhibited higher PRB-dependent reporter activity with progesterone (P4) in cells cultured on stiff vs. soft plates. Mechanically induced PRB activation with P4 was decreased 62% by PD98059, 78% by nintedanib, 38% by A13, and 50% by Y27632. Overexpression of the Rho-guanine nucleotide exchange factor (Rho-GEF), AKAP13, significantly increased PRB-dependent reporter activity. Collagen 1 messenger RNA levels were higher in fibroid cells grown on stiff vs. soft plates with P4.

CONCLUSION(S)

Cells cultured on mechanically stiff substrates had enhanced PRB activation via a mechanism that required MEK 1/2 and AKAP13/RhoA/ROCK signaling pathways. These studies provide a framework to explore the mechanisms by which mechanical stiffness affects progesterone receptor activation.

Summary of the Proceedings of the Basic Science of Uterine Fibroids Meeting: New Developments February 28, 2020

Scientists from multiple basic disciplines and an international group of physician-scientists from the field of obstetrics and gynecology presented recent studies and discussed new and evolving theories of uterine fibroid etiology, growth and development at The Basic Science of the Uterine Fibroids meeting, sponsored by the Campion Fund and the National Institute of Environmental Health Sciences. The purpose was to share up-to date knowledge and to stimulate new concepts regarding the basic molecular biology and pathophysiology of uterine fibroids, and to promote future collaborations. The meeting was held at the National Institute of Environmental Health Sciences in North Carolina on February 28, 2020. Speakers reviewed recent advances in cellular and molecular processes that contribute to fibroid growth and new opportunities for treatment. At the conclusion of the conference, attendees identified important new directions for future research.

Cross-talk between Janus kinase-signal transducer and activator of transcription pathway and transforming growth factor beta pathways and increased collagen1A1 production in uterine leiomyoma cells

OBJECTIVE

To characterize the potential interaction between interleukin-6 (IL6), Janus kinase (JAK)-signal transducer and activator of transcription (STAT)-3 (JAK/STAT3) pathway, and Transforming growth factor beta (TGFβ)-3 , and to determine whether such cross-talk was a contributing factor in the dysregulation of type I collagen production in leiomyomas.

DESIGN

Laboratory study.

SETTING

University research laboratory.

PATIENTS

None.

INTERVENTIONS

Exposure of leiomyoma and myometrial cell lines to IL6 and STAT3 activators/inhibitors. Western immunoblot analysis and immunohistochemistry.

MAIN OUTCOME MEASURES

Expression of STAT3, pSTAT3, SOCS3, COL1A1, and TGFb3.

RESULTS

We observed that IL6 increased pSTAT3 as well as collagen1A1 in uterine leiomyoma cells. Direct activation of the JAK/STAT3 pathway increased collagen1A1 production in leiomyoma cells, whereas inhibition of the pathway significantly decreased collagen1A1 production. We further observed that modulation of the JAK/STAT3 pathway also increased the expression of TGFβ3 protein. Leiomyoma cells exposed to TGFβ3 demonstrated a significant decrease in pSTAT3 protein. Myometrial cells demonstrated a less sensitive response to STAT3 modulation and collagen production.

CONCLUSION

Cross-talk between the TGFβ pathway and JAK/STAT3 pathway contributes to the fibrotic nature of uterine leiomyomas.

Role of DNA damage and repair mechanisms in uterine fibroid/leiomyomas: a review

There has been a significant annual increase in the number of cases of uterine leiomyomas or fibroids (UF) among women of all races and ages across the world. A fortune is usually spent by the healthcare sector for fibroid-related treatments and management. Molecular studies have established the higher mutational heterogeneity in UF as compared to normal myometrial cells. The contribution of DNA damage and defects in repair responses further increases the mutational burden on the cells. This in turn leads to genetic instability, associated with cancer risk and other adverse reproductive health outcomes. Such and many more growing bodies of literature have highlighted the genetic/molecular, biochemical and clinical aspects of UF; none the less there appear to be a lacuna bridging the bench to bed gap in addressing and preventing this disease. Presented here is an exhaustive review of not only the molecular mechanisms underlying the predisposition to the disease but also possible strategies to effectively diagnose, prevent, manage, and treat this disease.

Uterine fibroids and preterm birth risk: A systematic review and meta-analysis

AIM

This study explored the association between the presence of uterine fibroids (UF), as determined by ultrasound, and preterm birth (PB) risk.

METHODS

Medline, Embase, Cochrane, Scopus and Web of Science databases. Studies reporting women with and without UF demonstrated by an ultrasound exam. The primary outcome was the risk of PB < 37 weeks of gestation in pregnancies with UF diagnosed by an obstetric ultrasound exam. Effects for dichotomous and continuous outcomes are, respectively, reported as risk ratios (RR) or mean differences and their 95% confidence intervals (CI).

RESULTS

Eighteen studies were included comprising 276 172 pregnancies to whom obstetric ultrasound assessment was performed for the presence/absence of UF. Women with UF were older (mean difference = 2.40 years, 95% CI 0.94-3.85) and were at higher risk of PB before 37 (RR = 1.43, 95% CI 1.27-1.60), 34 (RR = 1.79, 95% CI 1.32-2.42), 32 (RR = 1.94, 95% CI 1.33-2.85) and 28 (RR = 2.17, 95% CI 1.48-3.17) weeks as compared to those without UF (P < 0.01). In addition, women with UF were at higher risk of threatened preterm labor, preterm premature rupture of membranes, fetal malpresentation, placental abruption, lower gestational age and birthweight at delivery and a higher cesarean delivery rate.

CONCLUSION

Pregnant women with UF are at increased risk of PB and other adverse obstetric outcomes.

Putative human myometrial and fibroid stem-like cells have mesenchymal stem cell and endometrial stromal cell properties

STUDY QUESTION

Can endometrial stromal stem/progenitor cell markers, SUSD2 and CD146/CD140b, enrich for human myometrial and fibroid stem/progenitor cells?

SUMMARY ANSWER

SUSD2 enriches for myometrial and fibroid cells that have mesenchymal stem cell (MSC) characteristics and can also be induced to decidualise.

WHAT IS KNOWN ALREADY

Mesenchymal stem-like cells have been separately characterised in the endometrial stroma and myometrium and may contribute to diseases in their respective tissues.

STUDY DESIGN, SIZE, DURATION

Normal myometrium, fibroids and endometrium were collected from hysterectomies with informed consent. Primary cells or tissues were used from at least three patient samples for each experiment.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Flow cytometry, immunohistochemistry and immunofluorescence were used to characterise tissues. In vitro colony formation in normoxic and hypoxic conditions, MSC lineage differentiation (osteogenic and adipogenic) and decidualisation were used to assess stem cell activity. Xenotransplantation into immunocompromised mice was used to determine in vivo stem-like activity. Endpoint measures included quantitative PCR, colony formation, trichrome, Oil Red O and alkaline phosphatase activity staining.

MAIN RESULTS AND THE ROLE OF CHANCE

CD146+CD140b+ and/or SUSD2+ myometrial and fibroid cells were located in the perivascular region and formed more colonies in vitro compared to control cells and differentiated down adipogenic and osteogenic mesenchymal lineages in vitro. SUSD2+ myometrial cells had greater in vitro decidualisation potential, and SUSD2+ fibroid cells formed larger tumours in vivo compared to control cells.

LARGE-SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Markers used in this study enrich for cells with stem/progenitor cell activity; however, they do not distinguish stem from progenitor cells. SUSD2+ myometrial cells express markers of decidualisation when treated in vitro, but in vivo assays are needed to fully demonstration their ability to decidualise.

WIDER IMPLICATIONS OF THE FINDINGS

These results suggest a possible common MSC for the endometrial stroma and myometrium, which could be the tumour-initiating cell for uterine fibroids.

STUDY FUNDING/COMPETING INTEREST(S)

These studies were supported by NIH grants to JMT (R01OD012206) and to ALP (F32HD081856). The authors certify that we have no conflicts of interest to disclose.

Advanced 3D Imaging of Uterine Leiomyoma's Morphology by Propagation-based Phase-Contrast Microtomography

Uterine leiomyoma is the most common benign smooth muscle tumor in women pelvis, originating from the myometrium. It is caused by a disorder of fibrosis, with a large production and disruption of extracellular matrix (ECM). Medical treatments are still very limited and no preventative therapies have been developed. We supposed that synchrotron-based phase-contrast microtomography (PhC-microCT) may be an appropriate tool to assess the 3D morphology of uterine leiomyoma, without the use of any contrast agent. We used this technique to perform the imaging and the quantitative morphometric analysis of healthy myometrium and pathologic leiomyomas. The quantitative morphometric analysis of collagen bundles was coupled to the Roschger approach. This method, previously only used to evaluate mineralized bone density distribution, was applied here to study the fibrosis mass density distribution in healthy and pathologic biopsies from two patients. This protocol was shown to be powerful in studying uterine leiomyomas, detecting also small signs of the ECM alteration. This is of paramount importance not only for the follow-up of the present study, i.e. the investigation of different compounds and their possible therapeutic benefits, but also because it offers new methodologic possibilities for future studies of the ECM in soft tissues of different body districts.