Proteoglycans of uterine fibroids and keloid scars: similarity in their proteoglycan composition

Periostin's role in uterine leiomyoma development: a mini-review on the potential periostin poses as a pharmacological intervention for uterine leiomyoma

Uterine leiomyomas, also known as fibroids or myomas, occur in an estimated 70-80% of reproductive aged women. Many experience debilitating symptoms including pelvic pain, abnormal uterine bleeding (AUB), dyspareunia, dysmenorrhea, and infertility. Current treatment options are limited in preserving fertility, with many opting for sterilizing hysterectomy as a form of treatment. Currently, surgical interventions include hysterectomy, myomectomy, and uterine artery embolization in addition to endometrial ablation to control AUB. Non-surgical hormonal interventions, including GnRH agonists, are connotated with negative side effects and are unacceptable for women desiring fertility. Periostin, a regulatory extra cellular matrix (ECM) protein, has been found to be expressed in various gynecological diseases including leiomyomas. We previously determined that periostin over-expression in immortalized myometrial cells led to the development of a leiomyoma-like cellular phenotype. Periostin is induced by TGF-β, signals through the PI3K/AKT pathway, induces collagen production, and mediates wound repair and fibrosis, all of which are implicated in leiomyoma pathology. Periostin has been linked to other gynecological diseases including ovarian cancer and endometriosis and is being investigated as pharmacological target for treating ovarian cancer, post-surgical scarring, and numerous other fibrotic conditions. In this review, we provide discussion linking pathological inflammation and wound repair, with a TGF-β-periostin-collagen signaling in the pathogenesis of leiomyomas, and ultimately the potential of periostin as a druggable target to treat leiomyomas.

Uterine leiomyomata and keloids fibrosis origins: a mini-review of fibroproliferative diseases

Diseases such as uterine leiomyomata (fibroids and benign tumors of the uterus) and keloids (raised scars) may share common etiology. Fibroids and keloids can co-occur in individuals, and both are highly heritable, suggesting they may share common genetic risk factors. Fibroproliferative diseases are common and characterized by scarring and overgrowth of connective tissue, impacting multiple organ systems. These conditions both have racial disparities in prevalence, with the highest prevalence observed among individuals of African ancestry. Several fibroproliferative diseases are more severe and common in populations of sub-Saharan Africa. This mini-review aims to provide a broad overview of the current knowledge of the evolutionary origins and causes of fibroproliferative diseases. We also discuss current hypotheses proposing that the increased prevalence of these diseases in African-derived populations is due to the selection for profibrotic alleles that are protective against helminth infections and provide examples from knowledge of uterine fibroid and keloid research.

Serum versican as a potential biomarker in patients with uterine fibroids: A study from Eastern India

Objective

Versican is a chondroitin sulphate proteoglycan with raised expression at site of inflammation, and uterine fibroids are associated with local inflammation. Hence, this study aimed to estimate serum Versican levels in pre-menopausal women with uterine fibroids to evaluate its diagnostic efficiency.

Materials and Methods

This case-control study included forty uterine fibroid cases and 40 healthy controls. Cases clinically evaluated with USG findings, that is number, location of fibroid and volume calculated by prolate ellipse formula a × b × c × 0.523 (a - height, b - width, c - depth). Biochemical investigations, that is serum Versican levels, were estimated by ELISA with total cholesterol, HDLc and LDLc. Triglycerides by fully automated chemistry analysers. Serum biochemical parameters were compared and correlated with volume of fibroid. Area under receiver operating characteristic curve was calculated along with cut-off value to determine diagnostic potential of Versican, differentiating women with fibroids.

Results

In the present study, patients with fibroids had decreased levels of serum Versican (79.43 ± 18.60) as compared to healthy controls (101.81 ± 28.24, P < 0.001). There was a statistically significant negative correlation (r = - 0. 307, P = 0.04) between serum Versican level and volume of fibroid. Area under ROC was 0.726 (95% CI: 0.616-0.836; P = 0.001). The best cut-off value for serum Versican level was 96.90 ng/ml with 90% sensitivity and 48% specificity.

Conclusion

Serum Versican levels were found significantly lower in women with fibroid with a negative correlation with volume of fibroid uterus. Furthermore, extensive study would help in substantiating diagnostic potential of serum Versican in fibroid uterus patients.

Keloids, hypertrophic scars, and uterine fibroid development: a prospective ultrasound study of Black and African American women

OBJECTIVE

To examine the association between keloids, hypertrophic scars, and uterine fibroid incidence as well as growth. Both keloids and fibroids are fibroproliferative conditions that have been reported to be more prevalent among Blacks than Whites, and they share similar fibrotic tissue structures, including extracellular matrix composition, gene expression, and protein profiles. We hypothesized that women with a history of keloids would have greater uterine fibroid development.

DESIGN

A prospective community cohort study (enrollment 2010-2012) with 4 study visits over 5 years to conduct standardized ultrasounds to detect and measure fibroids ≥0.5 cm in diameter, assess the history of keloid and hypertrophic scars, and update covariates.

SETTING

Detroit, Michigan area.

PATIENTS

A total of 1,610 self-identified Black and/or African American women aged 23-35 years at enrollment without a previous clinical diagnosis of fibroids.

EXPOSURE(S)

Keloids (raised scars that grow beyond the margins of the original injury) and hypertrophic scars (raised scars that stay within the bounds of the original injury). Because of the difficulties in distinguishing keloids and hypertrophic scars, we separately examined the history of keloids and the history of either keloids or hypertrophic scars (any abnormal scarring) and their associations with fibroid incidence and growth.

MAIN OUTCOME MEASURE(S)

Fibroid incidence (new fibroid after a fibroid-free ultrasound at enrollment) was assessed using Cox proportional-hazards regression. Fibroid growth was assessed using linear mixed models. The estimates for the change in log volume per 18 months were converted to the estimated percentage difference in volume for scarring vs. no-scarring. Both incidence and growth models were adjusted for time-varying demographic, reproductive, and anthropometric factors.

RESULT(S)

Of the 1,230 fibroid-free participants, 199 (16%) reported ever having keloids, 578 (47%) reported keloids or hypertrophic scars, and 293 (24%) developed incident fibroids. Neither keloids (adjusted hazard ratio = 1.04; 95% confidence interval: 0.77, 1.40) nor any abnormal scarring (adjusted hazard ratio = 1.10; 95% confidence interval: 0.88, 1.38) were associated with fibroid incidence. Fibroid growth differed little by scarring status.

CONCLUSION(S)

Despite molecular similarities, self-reported keloid and hypertrophic scars did not show an association with fibroid development. Future research may benefit from the examination of dermatologist-confirmed keloids or hypertrophic scars; however, our data suggest little shared susceptibility for these 2 types of fibrotic conditions.

The Effects of Periostin Expression on Fibroid-Like Transition of Myometrial Cells

Fibroids, benign tumors of the myometrium, are the most common tumors in women and are associated with spontaneous abortion, preterm birth, placenta abruption, and infertility, among others. The incidence of fibroids in reproductive aged women is 20-89%. Fibroids are characterized by high production of extracellular matrix (ECM), particularly collagens, which play a role in their growth. However, their pathogenesis is poorly understood. Recently, we and others have found periostin (POSTN), a regulatory ECM protein, to be overexpressed in the majority of fibroids analyzed. Periostin is an ECM protein that is a critical regulator and well-established biomarker for fibrosis in tissues such as the lung, skin, and kidney. Our hypothesis was that periostin plays a role in the fibrotic transition of myometrial cells to fibroid cells. To test this, we evaluated the effects of POSTN overexpression in myometrial cells. Telomerase-immortalized myometrial cells were transduced with control or POSTN-overexpression lentivirus particles, generating one control (dCas9-Mock) and two overexpression (dCas9-POSTN-01, dCas9-POSTN-02) cell lines. Overexpression of POSTN in immortalized myometrial cells resulted in a change in phenotype consistent with fibroid cells. They upregulated expression of key fibroid genes and had increased proliferation, adhesion, and migration in vitro. Here, we show a potential role for periostin in the transition of myometrial cells to fibroid cells, giving rationale for future investigation into the role of periostin in fibroid pathogenesis and its potential as a therapeutic target.

Impaired collagen fibril assembly in keloids with enhanced expression of lumican and collagen V

Keloids are characterized by fibroblast activation and altered architecture of extracellular matrix (ECM). Excessive deposition of ECM molecules and irregular organization of collagen fibers have been observed in keloids. However, the ultrastructural alteration of collagen has not been fully investigated. In this study, the differences in tissue structure, collagen ultrastructure, matrix components, mechanical properties and collagen assembling molecules between keloids and their extra-lesional skins (ELSs) were explored using histology, transmission electron microscope (TEM), qPCR, Western blot, immunohistochemistry and bioinformatics. Histological evaluation showed thinner fibers in keloids with increased contents of collagen III and proteoglycans, which were supported by TEM findings of thinner collagen fibrils and less developed D-band periodicity in keloids than in ELSs (p < 0.05). In addition, total collagen and water contents were significantly increased (p < 0.05) along with richer proteoglycan production in keloids vs ELSs, which also led to increased stiffness and decreased maximal load in keloids compared with ELSs. Mechanism study showed that multiple molecules related to matrix assembly were significantly upregulated in keloids (p < 0.05). In particular, lumican and collagen V showed high degrees in co-expression analysis and their upregulation levels were revealed from microarray data, which were also verified in keloids at both gene and protein levels (p < 0.05). Nevertheless, siRNA knockdown of lumican failed to affect in vitro collagen assembly, but caused upregulated collagen V expression along with the upregulation of focal adhesion kinase, TGF-β1, TGF-β3 and PDGF, among which some are known for capable of enhancing collagen V expression. In conclusion, this study demonstrates impaired collagen assembly along with enhanced expression of lumican and collagen V, both are known for interfering with collagen fibril assembly.

The Keloid Disorder: Heterogeneity, Histopathology, Mechanisms and Models

Keloids constitute an abnormal fibroproliferative wound healing response in which raised scar tissue grows excessively and invasively beyond the original wound borders. This review provides a comprehensive overview of several important themes in keloid research: namely keloid histopathology, heterogeneity, pathogenesis, and model systems. Although keloidal collagen versus nodules and α-SMA-immunoreactivity have been considered pathognomonic for keloids versus hypertrophic scars, conflicting results have been reported which will be discussed together with other histopathological keloid characteristics. Importantly, histopathological keloid abnormalities are also present in the keloid epidermis. Heterogeneity between and within keloids exists which is often not considered when interpreting results and may explain discrepancies between studies. At least two distinct keloid phenotypes exist, the superficial-spreading/flat keloids and the bulging/raised keloids. Within keloids, the periphery is often seen as the actively growing margin compared to the more quiescent center, although the opposite has also been reported. Interestingly, the normal skin directly surrounding keloids also shows partial keloid characteristics. Keloids are most likely to occur after an inciting stimulus such as (minor and disproportionate) dermal injury or an inflammatory process (environmental factors) at a keloid-prone anatomical site (topological factors) in a genetically predisposed individual (patient-related factors). The specific cellular abnormalities these various patient, topological and environmental factors generate to ultimately result in keloid scar formation are discussed. Existing keloid models can largely be divided into in vivo and in vitro systems including a number of subdivisions: human/animal, explant/culture, homotypic/heterotypic culture, direct/indirect co-culture, and 3D/monolayer culture. As skin physiology, immunology and wound healing is markedly different in animals and since keloids are exclusive to humans, there is a need for relevant human in vitro models. Of these, the direct co-culture systems that generate full thickness keloid equivalents appear the most promising and will be key to further advance keloid research on its pathogenesis and thereby ultimately advance keloid treatment. Finally, the recent change in keloid nomenclature will be discussed, which has moved away from identifying keloids solely as abnormal scars with a purely cosmetic association toward understanding keloids for the fibroproliferative disorder that they are.

Novel contribution to clubfoot pathogenesis: The possible role of extracellular matrix proteins

Idiopathic pes equinovarus (clubfoot) is a congenital deformity of the feet and lower legs. Clubfoot belongs to a group of fibro-proliferative disorders but its origin remains unknown. Our study aimed to achieve the first complex proteomic comparison of clubfoot contracted tissue of the foot (medial side; n = 16), with non-contracted tissue (lateral side; n = 13). We used label-free mass spectrometry quantification and immunohistochemistry. Seven proteins were observed to be significantly upregulated in the medial side (asporin, collagen type III, V, and VI, versican, tenascin-C, and transforming growth factor beta induced protein) and four in the lateral side (collagen types XII and XIV, fibromodulin, and cartilage intermediate layer protein 2) of the clubfoot. Comparison of control samples from cadavers brought only two different protein concentrations (collagen types I and VI). We also revealed pathological calcification and intracellular positivity of transforming growth factor beta only in the contracted tissue of clubfoot. Most of the 11 differently expressed proteins are strongly related to the extracellular matrix architecture and we assume that they may play specific roles in the pathogenesis of this deformity. These proteins seem to be promising targets for future investigations and treatment of this disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Molecular targets of dietary phytochemicals for possible prevention and therapy of uterine fibroids: Focus on fibrosis

Uterine fibroids (myomas or leiomyomas) are common benign tumors of reproductive aged women. Fibroids are clinically apparent in 20-50% of women, and cause abnormal uterine bleeding, abdominal pain and discomfort, pregnancy complications and infertility. Unfortunately, limited numbers of medical treatment are available but no effective preventive strategies exist. Moreover, the benefits of medical treatments are tempered by lack of efficacy or serious adverse side effects. Fibrosis has recently been recognized as a key pathological event in leiomyoma development and growth. It is defined by the excessive deposition of extracellular matrix (ECM). ECM plays important role in making bulk structure of leiomyoma, and ECM-rich rigid structure is believed to be a cause of abnormal bleeding and pelvic pain/pressure. Dietary phytochemicals are known to regulate fibrotic process in different biological systems, and being considered as potential tool to manage human health. At present, very few dietary phytochemicals have been studied in uterine leiomyoma, and they are mostly known for their antiproliferative effects. Therefore, in this review, our aim was to introduce some dietary phytochemicals that could target fibrotic processes in leiomyoma. Thus, this review could serve as useful resource to develop antifibrotic drugs for possible prevention and treatment of uterine fibroids.

Versican Proteolysis by ADAMTS Proteases and Its Influence on Sex Steroid Receptor Expression in Uterine Leiomyoma

CONTEXT

Leiomyomas have abundant extracellular matrix (ECM), with upregulation of versican, a large proteoglycan.

OBJECTIVE

We investigated ADAMTS (a disintegrin-like and metalloprotease with thrombospondin type 1 motifs) protease-mediated versican cleavage in myometrium and leiomyoma and the effect of versican knockdown in leiomyoma cells.

DESIGN

We used quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, immunohistochemistry, and RNA in situ hybridization for analysis of myometrium, leiomyoma and immortalized myometrium and leiomyoma cells. Short interfering RNA (siRNA) was used to knockdown versican in leiomyoma cells.

SETTING

This study was performed in an academic laboratory.

PATIENTS

Study subjects were women with symptomatic or asymptomatic leiomyoma.

MAIN OUTCOME MEASURES

We quantified messenger RNAs (mRNAs) for versican splice variants. We identified ADAMTS-cleaved versican in myometrium and leiomyoma and ADAMTS messenger RNAs and examined the effect of VCAN siRNA on smooth muscle differentiation and expression of estrogen and progesterone receptors.

RESULTS

The women in the symptomatic group (n = 7) had larger leiomyoma (P = 0.01), heavy menstrual bleeding (P < 0.01), and lower hemoglobin levels (P = 0.02) compared with the asymptomatic group (n = 7), but were similar in age and menopausal status. Versican V0 and V1 isoforms were upregulated in the leiomyomas of symptomatic versus asymptomatic women (P = 0.03 and P = 0.04, respectively). Abundant cleaved versican was detected in leiomyoma and myometrium, as well as in myometrial and leiomyoma cell lines. ADAMTS4 (P = 0.03) and ADAMTS15 (P = 0.04) were upregulated in symptomatic leiomyomas. VCAN siRNA did not effect cell proliferation, apoptosis, or smooth muscle markers, but reduced ESR1 and PR-A expression (P = 0.001 and P = 0.002, respectively).

CONCLUSIONS

Versican in myometrium, leiomyomas and in the corresponding immortalized cells is cleaved by ADAMTS proteases. VCAN siRNA suppresses production of estrogen receptor 1 and progesterone receptor-A. These findings have implications for leiomyoma growth.

Soybean-fragmented proteoglycans against skin aging

OBJECTIVE

The majority of age-dependent skin changes happen in the dermis layer inducing changes in skin collagen and in the proteoglycans. The main aim of this work is to study the efficacy of a Proteum serum, containing soybean-fragmented proteoglycans, against skin aging.

MATERIALS AND METHODS

In vitro tests were performed to evaluate the Proteum serum ability on activating the production of collagen and proteoglycans. An in vivo long-term study was performed to determine the efficacy of the Proteum serum when applied on skin. Protection of healthy skin against detergent-induced dermatitis and the antioxidant properties of the applied Proteum serum were also studied.

RESULTS AND DISCUSSION

The in vitro tests demonstrated that the Proteum serum was able to elevate the production of molecules which are essential for supporting the dermal extracellular matrix organization. These results were correlated by the in vivo measurements where a clear trend on improving the measured skin parameters due to the Proteum serum application was found.

CONCLUSIONS

A beneficial effect of the Proteum serum was demonstrated with an improvement in the skin roughness and a reinforcement of the skin barrier function. Moreover, a significant protector effect on human stratum corneum against lipids peroxides (LPO) was demonstrated.

Loss of stiffness in collagen-rich uterine fibroids after digestion with purified collagenase Clostridium histolyticum

BACKGROUND

Uterine fibroids are a significant health problem. These common benign tumors occur in 70-80% of women before age 50 years and often cause bleeding and pain and can interfere considerably with daily life. Current treatment options are limited. Fibroids contain substantial amounts of altered and disordered collagens, which contribute to their bulk. Targeting these collagens directly presents a novel treatment approach.

OBJECTIVES

We sought to test the hypothesis that a highly purified collagenase Clostridium histolyticum will digest interstitial collagen in uterine fibroids and reduce their stiffness and thereby evaluate the feasibility that this collagenase C histolyticum can be developed into an alternative treatment for fibroids. A secondary objective was to describe the collagen content of the fibroid tissue.

STUDY DESIGN

Fibroid tissue cubes (1 cm³; n = 154) were cut from 17 uterine fibroids that were obtained from 7 consented subjects undergoing scheduled hysterectomies. Tissue cubes were injected with diluent, placebo, or highly purified collagenase C histolyticum (0.05, 0.1, or 0.2 mg/cube) and incubated at 37°C for 24, 48, 72, or 96 hours. At each time point, 6 noninjected control cubes were also evaluated. Tissue cubes were photographed before and after incubation. Myometrial samples (n = 21) were also evaluated. Stiffness was quantified through rheometry by measuring complex shear moduli of the tissues. Percent fibrosis was determined by computerized analysis of Masson-trichrome-stained slides. Digestion of collagen fibrils was confirmed by transmission electron microscopy.

RESULTS

Fibrosis in untreated fibroids ranged from 37% to 77%, reflecting the collagen-rich nature of these tumors. After treatment with collagenase for 96 hours, fibrosis ranged from 5.3% to 2.4%. Transmission electron microscopy confirmed complete digestion of collagen fibrils. Tissue stiffness was reduced with all 3 doses of collagenase treatment and at all 4 time points. Longer incubation times with collagenase caused greater reduction in stiffness, and treated cubes lost their cuboidal shape and had gelatinous/liquefied centers. At 96 hours the stiffness in tissues treated with the lowest dose was reduced to 966 ± 106 Pascal compared with the diluent-treated control at the same time (5323 ± 903 Pascal; P < .0001; by analysis of variance with Tukey-Kramer).

CONCLUSION

Uterine fibroids have a high content of collagen that can be effectively digested by highly purified collagenase C histolyticum, resulting in reduced tissue stiffness. Loss of stiffness may decrease bulk symptoms in vivo and possibly lead to shrinkage of fibroids through changed mechanotransduction, leading ultimately to reduced fibroid symptoms of pain and bleeding. Clinical trials are necessary to evaluate the safety and efficacy of collagenase C histolyticum including the rate of regrowth of fibroids. The data of this study provide a strong rationale for using this purified collagenase in clinical trials as a local treatment for women with fibroids.

Epidemiology of Uterine Fibroids: From Menarche to Menopause

Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses.

Mifepristone inhibits extracellular matrix formation in uterine leiomyoma

OBJECTIVE

To characterize the efficacy of mifepristone treatment on extracellular matrix (ECM) production in leiomyomas.

DESIGN

Laboratory study.

SETTING

University research laboratory.

PATIENT(S)

None.

INTERVENTION(S)

Treatment of human immortalized two-dimensional (2D) and three-dimensional (3D) leiomyoma and myometrial cells with mifepristone and the progestin promegestone (R5020).

MAIN OUTCOME MEASURE(S)

Expression of COL1A1, fibronectin, versican variant V0, and dermatopontin in treated leiomyoma cells by Western blot analysis and confirmatory immunohistochemistry staining of treated 3D cultures.

RESULT(S)

Treatment with progestin stimulated production of COL1A1, fibronectin, versican, and dermatopontin. Mifepristone treatment inhibited protein production of these genes, most notably with versican expression. Combination treatment with both the agonist and antagonist further inhibited protein expression of these genes. Immunohistochemistry performed on 3D cultures demonstrated generalized inhibition of ECM protein concentration.

CONCLUSION(S)

Our study demonstrated that the progesterone agonist R5020 directly stimulated extracellular matrix components COL1A1, fibronectin, versican, and dermatopontin production in human leiomyoma cells. Progesterone antagonist mifepristone decreased protein production of these genes to levels comparable with untreated leiomyoma cells.

Decorin: A Growth Factor Antagonist for Tumor Growth Inhibition

Decorin (DCN) is the best characterized member of the extracellular small leucine-rich proteoglycan family present in connective tissues, typically in association with or “decorating” collagen fibrils. It has substantial interest to clinical medicine owing to its antifibrotic, anti-inflammatory, and anticancer effects. Studies on DCN knockout mice have established that a lack of DCN is permissive for tumor development and it is regarded as a tumor suppressor gene. A reduced expression or a total disappearance of DCN has been reported to take place in various forms of human cancers during tumor progression. Furthermore, when used as a therapeutic molecule, DCN has been shown to inhibit tumor progression and metastases in experimental cancer models. DCN affects the biology of various types of cancer by targeting a number of crucial signaling molecules involved in cell growth, survival, metastasis, and angiogenesis. The active sites for the neutralization of different growth factors all reside in different parts of the DCN molecule. An emerging concept that multiple proteases, especially those produced by inflammatory cells, are capable of cleaving DCN suggests that native DCN could be inactivated in a number of pathological inflammatory conditions. In this paper, we review the role of DCN in cancer.

Proteoglycans in Leiomyoma and Normal Myometrium: Abundance, Steroid Hormone Control, and Implications for Pathophysiology

Uterine leiomyoma are a common benign pelvic tumors composed of modified smooth muscle cells and a large amount of extracellular matrix (ECM). The proteoglycan composition of the leiomyoma ECM is thought to affect pathophysiology of the disease. To test this hypothesis, we examined the abundance (by immunoblotting) and expression (by quantitative real-time polymerase chain reaction) of the proteoglycans biglycan, decorin, and versican in leiomyoma and normal myometrium and determined whether expression is affected by steroid hormones and menstrual phase. Leiomyoma and normal myometrium were collected from women (n = 17) undergoing hysterectomy or myomectomy. In vitro studies were performed on immortalized leiomyoma (UtLM) and normal myometrial (hTERT-HM) cells with and without exposure to estradiol and progesterone. In leiomyoma tissue, abundance of decorin messenger RNA (mRNA) and protein were 2.6-fold and 1.4-fold lower, respectively, compared with normal myometrium. Abundance of versican mRNA was not different between matched samples, whereas versican protein was increased 1.8-fold in leiomyoma compared with myometrium. Decorin mRNA was 2.4-fold lower in secretory phase leiomyoma compared with proliferative phase tissue. In UtLM cells, progesterone decreased the abundance of decorin mRNA by 1.3-fold. Lower decorin expression in leiomyoma compared with myometrium may contribute to disease growth and progression. As decorin inhibits the activity of specific growth factors, its reduced level in the leiomyoma cell microenvironment may promote cell proliferation and ECM deposition. Our data suggest that decorin expression in leiomyoma is inhibited by progesterone, which may be a mechanism by which the ovarian steroids affect leiomyoma growth and disease progression.

Recent scientific advances in leiomyoma (uterine fibroids) research facilitates better understanding and management

Uterine leiomyomas (fibroids) are the most prevalent medical problem of the female reproductive tract, but there are few non-surgical treatment options. Although many advances in the understanding of the molecular components of these tumors have occurred over the past five years, an effective pharmaceutical approach remains elusive. Further, there is currently no clinical method to distinguish a benign uterine leiomyoma from a malignant leiomyosarcoma prior to treatment, a pressing need given concerns about the use of the power morcellator for minimally invasive surgery. This paper reviews current studies regarding the molecular biology of uterine fibroids, discusses non-surgical approaches and suggests new cutting-edge therapeutic and diagnostic approaches.

Proteomic analysis of the extracellular matrix in idiopathic pes equinovarus

Idiopathic pes equinovarus is a congenital deformity of the foot and lower leg defined as a fixation of the foot in adduction, supination, and varus. Although the pathogenesis of clubfoot remains unclear, it has been suggested that fibroblasts and growth factors are involved. To directly analyze the protein composition of the extracellular matrix in contracted tissue of patients with clubfoot. A total of 13 infants with idiopathic clubfoot treated with the Ponseti method were included in the present study. Tissue samples were obtained from patients undergoing surgery for relapsed clubfeet. Contracted tissues were obtained from the medial aspect of the talonavicular joint. Protein was extracted after digestion and delipidation using zip-tip C18. Individual collagenous fractions were detected using a chemiluminescent assay. Amino acid analysis of tissue samples revealed a predominance of collagens, namely collagen types I, III, and VI. The high content of glycine and h-proline suggests a predominance of collagens I and III. A total of 19 extracellular matrix proteins were identified. The major result of the present study was the observation that the extracellular matrix in clubfoot is composed of an additional 16 proteins, including collagens V, VI, and XII, as well as the previously described collagen types I and III and transforming growth factor β. The characterization of the general protein composition of the extracellular matrix in various regions of clubfoot may help in understanding the pathogenesis of this anomaly and, thus, contribute to the development of more efficacious therapeutic approaches.

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

BACKGROUND

Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function.

METHODS

Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed.

RESULTS

Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain.

CONCLUSIONS

PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies.

Keloid incidence in Asian people and its comorbidity with other fibrosis-related diseases: a nationwide population-based study

Keloids is a fibroproliferative disease. The incidence of keloids among Asians has not been thoroughly studied. The objective of this study is to determine the incidence of keloids in Taiwan, which mainly consists of ethnic Chinese. Furthermore, we want to determine the comorbidity rate of other fibrosis-related diseases among keloid patients. This study was based on the National Health Insurance Research Database, which contains the data of 1 million randomly selected patients. Multivariate logistic regression analyses were employed to estimate the relative odds of keloids as a function of fibrosis-related diseases. The annual keloid incidence rate in Taiwan was 0.15 % for the general population. With a 1.33 ratio, women outnumbered men. Women with uterine leiomyoma have a 2.25-fold greater risk of keloids, compared with women without leiomyoma. We concluded that keloid incidence in Taiwan is approximately 0.15 %. Women with leiomyoma have a greater risk of keloids, this implicates that both diseases share a common etiopathological pathway.

Matrix production and remodeling as therapeutic targets for uterine leiomyoma

Uterine leiomyoma, commonly known as fibroids, is a benign neoplasm of smooth muscle in women. The incidence of clinically symptomatic fibroids in reproductive-age women is approximately 20 %, with nearly 80 % of black women suffering from this condition. Symptoms include severe pain and hemorrhage; fibroids are also a major cause of infertility or sub-fertility in women. Uterine leiomyoma consist of hyperplastic smooth muscle cells and an excess deposition of extracellular matrix, specifically collagen, fibronectin, and sulfated proteoglycans. Extracellular matrix components interact and signal through integrin-β1 on the surface of uterine leiomyoma smooth muscle cells, provide growth factor storage, and act as co-receptors for growth factor-receptor binding. ECM and growth factor signaling through integrin-β1 and growth factor receptors significantly increases cell proliferation and ECM deposition in uterine leiomyoma. Growth factors TGF-β, IGF, PDGF, FGF and EGF are all shown to promote uterine leiomyoma progression and signal through multiple pathways to increase the expression of genes encoding matrix or matrix-modifying proteins. Decreasing integrin expression, reducing growth factor action and inhibiting ECM action on uterine leiomyoma smooth muscle cells are important opportunities to treat uterine leiomyoma without use of the current surgical procedures. Both natural compounds and chemicals are shown to decrease fibrosis and uterine leiomyoma progression, but further analysis is needed to make inroads in treating this common women's health issue.

The extracellular matrix contributes to mechanotransduction in uterine fibroids

The role of the extracellular matrix (ECM) and mechanotransduction as an important signaling factor in the human uterus is just beginning to be appreciated. The ECM is not only the substance that surrounds cells, but ECM stiffness will either compress cells or stretch them resulting in signals converted into chemical changes within the cell, depending on the amount of collagen, cross-linking, and hydration, as well as other ECM components. In this review we present evidence that the stiffness of fibroid tissue has a direct effect on the growth of the tumor through the induction of fibrosis. Fibrosis has two characteristics: (1) resistance to apoptosis leading to the persistence of cells and (2) secretion of collagen and other components of the ECM such a proteoglycans by those cells leading to abundant disposition of highly cross-linked, disoriented, and often widely dispersed collagen fibrils. Fibrosis affects cell growth by mechanotransduction, the dynamic signaling system whereby mechanical forces initiate chemical signaling in cells. Data indicate that the structurally disordered and abnormally formed ECM of uterine fibroids contributes to fibroid formation and growth. An appreciation of the critical role of ECM stiffness to fibroid growth may lead to new strategies for treatment of this common disease.

Role of activin-A and myostatin and their signaling pathway in human myometrial and leiomyoma cell function

CONTEXT

Uterine leiomyomas are highly prevalent benign tumors of premenopausal women and the most common indication for hysterectomy. However, the exact etiology of this tumor is not fully understood.

OBJECTIVE

The objective of the study was to evaluate the role of activin-A and myostatin and their signaling pathways in human myometrial and leiomyoma cells.

DESIGN

This was a laboratory study.

SETTING

Myometrial and leiomyoma cells (primary and cell lines) were cultured in vitro.

PATIENTS

The study included premenopausal women who were admitted to the hospital for myomectomy or hysterectomy.

INTERVENTIONS

Primary myometrial and leiomyoma cells and/or cell lines were treated with activin-A (4 nM) and myostatin (4 nM) for different days of interval (to measure proliferation rate) or 30 minutes (to measure signaling molecules) or 48 hours to measure proliferating markers, extracellular matrix mRNA, and/or protein expression by real-time PCR, Western blot, and/or immunocytochemistry.

RESULTS

We found that activin-A and myostatin significantly reduce cell proliferation in primary myometrial cells but not in leiomyoma cells as measured by a CyQUANT cell proliferation assay kit. Reduced expression of proliferating cell nuclear antigen and Ki-67 were also observed in myometrial cells in response to activin-A and myostatin treatment. Activin-A also significantly increased mRNA expression of fibronectin, collagen1A1, and versican in primary leiomyoma cells. Finally, we found that activin-A and myostatin activate Smad-2/3 signaling but do not affect ERK or p38 signaling in both myometrial and leiomyoma cells.

CONCLUSIONS

This study results suggest that activin-A and myostatin can exert antiproliferative and/or fibrotic effects on these cell types via Smad-2/3 signaling.

Age-dependent alterations of decorin glycosaminoglycans in human skin

Proteoglycans, a family of glycosaminoglycan (GAG) conjugated proteins, are important constituents of human skin connective tissue (dermis) and are essential for maintaining mechanical strength of the skin. Age-related alterations of dermal proteoglycans have not been fully elucidated. We quantified transcripts of 20 known interstitial proteoglycans in human skin and found that decorin was the most highly expressed. Decorin was predominantly produced by dermal fibroblasts. Decorin was localized in dermal extracellular matrix with GAG bound to type I collagen fibrils. Analysis of decorin extracted from young (21–30 years) and aged (>80 years) sun-protected human buttock skin revealed that decorin molecular size in aged skin is significantly smaller than in young skin. The average size of decorin protein did not alter, indicating size of GAG chain is reduced in aged, compared to young skin. This age-dependent alteration of decorin GAG may contribute to skin fragility of elderly people.

Keloids and ultrasound detected fibroids in young African American women

OBJECTIVE

Keloids and fibroids share a number of biologic and demographic similarities however there are no published reports of the association between them. The objective of this study was to investigate the association between self-reported keloids and ultrasound detected fibroids in a population of young African American women.

STUDY DESIGN

The Study of Environment, Life-style & Fibroids (SELF), is a volunteer cohort of over 1600 African American women aged 23-34 years recruited in Detroit, Michigan. Enrollment occurred between December 2010 and December 2012. Data are available for the first 1196 participants. Participants self-reported a history of raised (hypertrophic) scars or scars extending beyond the limits of the original injury (keloid) and had an enrollment pelvic ultrasound examination to detect prevalent fibroids. Log linear regression was used to model the association between abnormal scars and prevalent fibroids controlling for possible covariates. Among women with fibroids, associations between particular fibroid characteristics (tumor location, size or number) and scarring were assessed using chi-square and Mann Whitney U-tests.

RESULTS

Both abnormal scarring (keloids, 9.0%; hypertrophic scars, 28.3%) and fibroids (23.3%) were common in this cohort. There was no indication [adjusted Risk Ratio (95% Confidence Interval): 0.7 (0.5-1.1)] of an association between self-reported keloids and prevalent fibroids. Nor was there any association with hypertrophic scars. Specific characteristics of the prevalent fibroids were not associated with abnormal scarring.

CONCLUSION

Despite similarly dysregulated extracellular matrices in keloids and fibroids, these conditions did not tend to co-occur in this young African American population.

Racial and ethnic differences in the pathogenesis and clinical manifestations of uterine leiomyoma

Uterine leiomyomas are the most common benign gynecologic condition. The prevalence is three times more common among women of African ethnicity. Disparity in this disease is evidenced by earlier age of onset, greater severity of symptoms, and different response to treatment. Although the pathogenesis of disease development is not completely known, growing evidence focuses on investigating the molecular mechanisms in disease development and the influence of ethnicity. Variation in the expression levels or function of estrogen and progesterone receptors, polymorphism of genes involved in estrogen synthesis and/or metabolism (COMT, CYP17), retinoic acid nuclear receptors (retinoid acid receptor-α, retinoid X receptor-α), and aberrant expression of micro-RNAs (miRNAs) are some of the molecular mechanisms that may be involved. Nutritional factors, such as vitamin D deficiency, might also contribute to the higher incidence in dark skinned populations who are also commonly suffer from hypovitaminosis D. Culture and environmental difference might have a role in disease development. Further analysis and better understanding of these mechanisms will provide insight into the molecular basis of racial disparities in leiomyoma formation and will help to develop new innovations in leiomyoma treatment.

Granzyme B cleaves decorin, biglycan and soluble betaglycan, releasing active transforming growth factor-β1

Objective

Granzyme B (GrB) is a pro-apoptotic serine protease that contributes to immune-mediated target cell apoptosis. However, during inflammation, GrB accumulates in the extracellular space, retains its activity, and is capable of cleaving extracellular matrix (ECM) proteins. Recent studies have implicated a pathogenic extracellular role for GrB in cardiovascular disease, yet the pathophysiological consequences of extracellular GrB activity remain largely unknown. The objective of this study was to identify proteoglycan (PG) substrates of GrB and examine the ability of GrB to release PG-sequestered TGF-β1 into the extracellular milieu.

Methods/Results

Three extracellular GrB PG substrates were identified; decorin, biglycan and betaglycan. As all of these PGs sequester active TGF-β1, cytokine release assays were conducted to establish if GrB-mediated PG cleavage induced TGF-β1 release. Our data confirmed that GrB liberated TGF-β1 from all three substrates as well as from endogenous ECM and this process was inhibited by the GrB inhibitor 3,4-dichloroisocoumarin. The released TGF-β1 retained its activity as indicated by the induction of SMAD-3 phosphorylation in human coronary artery smooth muscle cells.

Conclusion

In addition to contributing to ECM degradation and the loss of tissue structural integrity in vivo, increased extracellular GrB activity is also capable of inducing the release of active TGF-β1 from PGs.

Treatment for Uterine Fibroids: Searching for Effective Drug Therapies

Uterine fibroids are common reproductive-age benign tumors that contribute to severe morbidity and infertility. Cumulative incidence is 4 times higher in Africian-Americans compared to Caucasians and constitutes a major health disparity challenge. Fibroids are the leading indication for hysterectomy and their management averages $21 billion annually in the US. No long term minimally invasive therapies exist. Thus, promising drug therapies, their chemistry, pharmacology, and clinical efficacy, focusing first on innovative drug delivery approaches, are reviewed.