Polycondensed Peptide-Based Polymers for Targeted Delivery of Anti-Angiogenic siRNA to Treat Endometriosis

Endometriosis (EM) is a prevalent gynecological disease characterized by the abnormal growth of tissue similar to the endometrium outside of the uterus. This condition is accompanied by the development of new blood vessels in endometriotic lesions. While surgical intervention is effective in removing endometriotic lesions, some patients require multiple surgeries. Therefore, finding non-surgical treatments for EM is of great interest. One of the promising approaches is anti-angiogenic therapy using siRNA-therapeutics to target the expression of the VEGFA gene. Peptide-based polymers have shown promise as siRNA delivery systems due to their biocompatibility and ease of modification. We conducted a study to evaluate the effectiveness of the R6p-cRGD peptide carrier as a non-viral vehicle for delivering siRNA to endothelial cells in vitro and endometrial implants in vivo. We investigated the physicochemical properties of the siRNA-complexes, assessed cellular toxicity, and examined the efficiency of GFP and VEGFA genes silencing. Furthermore, we tested the anti-angiogenic effects of these complexes in cellular and animal models. The transfection with siRNA complexes led to a significant increase in VEGFA gene knockdown efficiency and a decrease in the migration of endothelial cells. For the animal model, we induced endometriosis in rats by transplanting endometrial tissue subcutaneously. We evaluated the efficiency of anti-angiogenic therapy for EM in vivo using anti-VEGF siRNA/R6p-RGD complexes. During this assessment, we measured the volume of the implants, analyzed VEGFA gene expression, and conducted CD34 immunohistochemical staining. The results showed a significant decrease in the growth of endometriotic implants and in VEGFA gene expression. Overall, our findings demonstrate the potential of the R6p-cRGD peptide carrier as a delivery system for anti-angiogenic therapy of EM.

Regeneration and anti-inflammatory effects of stem cells and their extracellular vesicles in gynecological diseases

There are many gynecological diseases, among which breast cancer (BC), cervical cancer (CC), endometriosis (EMs), and polycystic ovary syndrome (PCOS) are common and difficult to cure. Stem cells (SCs) are a focus of regenerative medicine. They are commonly used to treat organ damage and difficult diseases because of their potential for self-renewal and multidirectional differentiation. SCs are also commonly used for difficult-to-treat gynecological diseases because of their strong directional differentiation ability with unlimited possibilities, their tendency to adhere to the diseased tissue site, and their use as carriers for drug delivery. SCs can produce exosomes in a paracrine manner. Exosomes can be produced in large quantities and have the advantage of easy storage. Their safety and efficacy are superior to those of SCs, which have considerable potential in gynecological treatment, such as inhibiting endometrial senescence, promoting vascular reconstruction, and improving anti-inflammatory and immune functions. In this paper, we review the mechanisms of the regenerative and anti-inflammatory capacity of SCs and exosomes in incurable gynecological diseases and the current progress in their application in genetic engineering to provide a foundation for further research.

iRGD-Targeted Peptide Nanoparticles for Anti-Angiogenic RNAi-Based Therapy of Endometriosis

Anti-angiogenic RNAi-based therapy can be considered as a possible strategy for the treatment of endometriosis (EM), which is the most common gynecological disease. Targeted delivery of siRNA therapeutics is a prerequisite for successful treatment without adverse effects. Here we evaluated the RGD1-R6 peptide carrier as a non-viral vehicle for targeted siRNA delivery to endothelial cells in vitro and endometrial implants in vivo. The physicochemical properties of the siRNA complexes, cellular toxicity, and GFP and VEGFA gene silencing efficiency were studied, and anti-angiogenic effects were proved in cellular and animal models. The modification of siRNA complexes with iRGD ligand resulted in a two-fold increase in gene knockdown efficiency and three-fold decrease in endothelial cells' migration in vitro. Modeling of EM in rats with the autotransplantation of endometrial tissue subcutaneously was carried out. Efficiency of anti-angiogenic EM therapy in vivo by anti-VEGF siRNA/RGD1-R6 complexes was evaluated by the implants' volume measurement, CD34 immunohistochemical staining, and VEGFA gene expression analysis. We observed a two-fold decrease in endometriotic implants growth and a two-fold decrease in VEGFA gene expression in comparison with saline-treated implants. RNAi-mediated therapeutic effects were comparable with Dienogest treatment efficiency in a rat EM model. Taken together, these findings demonstrate the advantages of RGD1-R6 peptide carrier as a delivery system for RNAi-based therapy of EM.

Anticancer peptides mechanisms, simple and complex

Peptide therapy has started since 1920s with the advent of insulin application, and now it has emerged as a new approach in treatment of diseases including cancer. Using anti-cancer peptides (ACPs) is a promising way of cancer therapy as ACPs are continuing to be approved and arrived at major pharmaceutical markets. Traditional cancer treatments face different problems like intensive adverse effects to patient's body, cell resistance to conventional chemical drugs and in some worse cases the occurrence of cell multidrug resistance (MDR) of cancerous tissues against chemotherapy. On the other hand, there are some benefits conceived for peptides usage in treatment of diseases specifically cancer, as these compounds present favorable characteristics such as smaller size, high activity, low immunogenicity, good biocompatibility in vivo, convenient and rapid way of synthesis, amenable to sequence modification and revision and there is no limitation for the type of cargo they carry. It is possible to achieve an optimum molecular and functional structure of peptides based on previous experience and bank of peptide motif data which may result in novel peptide design. Bioactive peptides are able to form pores in cell membrane and induce necrosis or apoptosis of abnormal cells. Moreover, recent researches have focused on the tumor recognizing peptide motifs with the ability to permeate to cancerous cells with the aim of cancer treatment at earlier stages. In this strategy the most important factors for addressing cancer are choosing peptides with easy accessibility to tumor cell without cytotoxicity effect towards normal cells. The peptides must also meet acceptable pharmacokinetic requirements. In this review, the characteristics of peptides and cancer cells are discussed. The various mechanisms of peptides' action proposed against cancer cells make the next part of discussion. It will be followed by giving information on peptides application, various methods of peptide designing along with introducing various databases. Future aspects of peptides for employing in area of cancer treatment come as conclusion at the end.

A Reassessment of the Therapeutic Potential of a Dopamine Receptor 2 Agonist (D2-AG) in Endometriosis by Comparison against a Standardized Antiangiogenic Treatment

Dopamine receptor 2 agonists (D2-ags) have been shown to reduce the size of tumors by targeting aberrant angiogenesis in pathological tissue. Because of this, the use of a D2-ag was inferred for endometriosis treatment. When assayed in mouse models however, D2-ags have been shown to cause a shift of the immature vessels towards a more mature phenotype but not a significant reduction in the amount of vascularization and size of lesions. These has raised concerns on whether the antiangiogenic effects of these compounds confer a therapeutic value for endometriosis. In the belief that antiangiogenic effects of D2-ags in endometriosis were masked due to non-optimal timing of pharmacological interventions, herein we aimed to reassess the antiangiogenic therapeutic potential of D2-ags in vivo by administering compounds at a timeframe in which vessels in the lesions are expected to be more sensitive to antiangiogenic stimuli. To prove our point, immunodeficient (NU/NU) mice were given a D2-ag (cabergoline), anti-VEGF (CBO-P11) or vehicle (saline) compounds (n = 8 per group) starting 5 days after implantation of a fluorescently labeled human lesion. The effects on the size of the implants was estimated by monitoring the extent of fluorescence emitted by the lesion during the three-week treatment period. Subsequently mice were sacrificed and lesions excised and fixed for quantitative immunohistochemical/immunofluorescent analysis of angiogenic parameters. Lesion size, vascular density and innervation were comparable in D2-ag and anti-VEGF groups and significantly decreased when compared to control. These data suggest that D2-ags are as powerful as standard antiangiogenic compounds in interfering with angiogenesis and lesion size. Our preliminary study opens the way to further exploration of the mechanisms beneath the antiangiogenic effects of D2-ags for endometriosis treatment in humans.

The Pathogenesis of Endometriosis: Molecular and Cell Biology Insights

The etiopathogenesis of endometriosis is a multifactorial process resulting in a heterogeneous disease. Considering that endometriosis etiology and pathogenesis are still far from being fully elucidated, the current review aims to offer a comprehensive summary of the available evidence. We performed a narrative review synthesizing the findings of the English literature retrieved from computerized databases from inception to June 2019, using the Medical Subject Headings (MeSH) unique ID term "Endometriosis" (ID:D004715) with "Etiology" (ID:Q000209), "Immunology" (ID:Q000276), "Genetics" (ID:D005823) and "Epigenesis, Genetic" (ID:D044127). Endometriosis may origin from Müllerian or non-Müllerian stem cells including those from the endometrial basal layer, Müllerian remnants, bone marrow, or the peritoneum. The innate ability of endometrial stem cells to regenerate cyclically seems to play a key role, as well as the dysregulated hormonal pathways. The presence of such cells in the peritoneal cavity and what leads to the development of endometriosis is a complex process with a large number of interconnected factors, potentially both inherited and acquired. Genetic predisposition is complex and related to the combined action of several genes with limited influence. The epigenetic mechanisms control many of the processes involved in the immunologic, immunohistochemical, histological, and biological aberrations that characterize the eutopic and ectopic endometrium in affected patients. However, what triggers such alterations is not clear and may be both genetically and epigenetically inherited, or it may be acquired by the particular combination of several elements such as the persistent peritoneal menstrual reflux as well as exogenous factors. The heterogeneity of endometriosis and the different contexts in which it develops suggest that a single etiopathogenetic model is not sufficient to explain its complex pathobiology.

Evaluation of Oxidative Stress and Severity of Endometriosis

Aims

The aim was to evaluate the association between oxidative stress with the severity of endometriosis in blood and peritoneal fluid.

Settings and Design

This study was a prospective observational study conducted in the department of obstetrics and gynecology in a tertiary center over 2 years in patients with endometriosis requiring laparoscopy.

Methodology

Patients diagnosed with endometriosis and undergoing laparoscopy for infertility and/or chronic pelvic pain were included in the study. Out of the 64 patients recruited, only 55 patients formed the part of our study. Blood and peritoneal fluid was evaluated for oxidative stress parameters such as glutathione peroxidase, superoxide dismutase (SOD), and lipid peroxides.

Results

The severity of endometriosis was assessed intraoperatively by the revised American Society for Reproductive Medicine scoring in all 55 patients who underwent laparoscopy into minimal (n = 3), mild (n = 7), moderate (n = 32), and severe (n = 17). Median activity of SOD and glutathione peroxidase was lowest in the severe stage of endometriosis, whereas the median activity of lipid peroxide was highest in the severe stage of endometriosis in both blood and peritoneal fluid samples. There was a statistically significant increase in oxidative stress with the severity of endometriosis.

Conclusions

Oxidative stress might play a role in the disease process of endometriosis. Control of oxidative stress can be used as the latest treatment option for the management of endometriosis.

Pathogenesis of endometriosis: the genetic/epigenetic theory

OBJECTIVE

To study the pathophysiology of endometriosis.

DESIGN

Overview of observations on endometriosis.

SETTING

Not applicable.

PATIENT(S)

None.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The hypothesis is compatible with all observations.

RESULT(S)

Endometriosis, endometrium-like tissue outside the uterus, has a variable macroscopic appearance and a poorly understood natural history. It is a hereditary and heterogeneous disease with many biochemical changes in the lesions, which are clonal in origin. It is associated with pain, infertility, adenomyosis, and changes in the junctional zone, placentation, immunology, plasma, peritoneal fluid, and chronic inflammation of the peritoneal cavity. The Sampson hypothesis of implanted endometrial cells following retrograde menstruation, angiogenic spread, lymphogenic spread, or the metaplasia theory cannot explain all observations if metaplasia is defined as cells with reversible changes and an abnormal behavior/morphology due to the abnormal environment. We propose a polygenetic/polyepigenetic mechanism. The set of genetic and epigenetic incidents transmitted at birth could explain the hereditary aspects, the predisposition, and the endometriosis-associated changes in the endometrium, immunology, and placentation. To develop typical, cystic ovarian or deep endometriosis lesions, a variable series of additional transmissible genetic and epigenetic incidents are required to occur in a cell which may vary from endometrial to stem cells. Subtle lesions are viewed as endometrium in a different environment until additional incidents occur. Typical cystic ovarian or deep endometriosis lesions are heterogeneous and represent three different diseases.

CONCLUSION(S)

The genetic epigenetic theory is compatible with all observations on endometriosis. Implications for treatment and prevention are discussed.

Shaofu Zhuyu Decoction Regresses Endometriotic Lesions in a Rat Model

The current therapies for endometriosis are restricted by various side effects and treatment outcome has been less than satisfactory. Shaofu Zhuyu Decoction (SZD), a classic traditional Chinese medicinal (TCM) prescription for dysmenorrhea, has been widely used in clinical practice by TCM doctors to relieve symptoms of endometriosis. The present study aimed to investigate the effects of SZD on a rat model of endometriosis. Forty-eight female Sprague-Dawley rats with regular estrous cycles went through autotransplantation operation to establish endometriosis model. Then 38 rats with successful ectopic implants were randomized into two groups: vehicle- and SZD-treated groups. The latter were administered SZD through oral gavage for 4 weeks. By the end of the treatment period, the volume of the endometriotic lesions was measured, the histopathological properties of the ectopic endometrium were evaluated, and levels of proliferating cell nuclear antigen (PCNA), CD34, and hypoxia inducible factor- (HIF-) 1α in the ectopic endometrium were detected with immunohistochemistry. Furthermore, apoptosis was assessed using the terminal deoxynucleotidyl transferase (TdT) deoxyuridine 5′-triphosphate (dUTP) nick-end labeling (TUNEL) assay. In this study, SZD significantly reduced the size of ectopic lesions in rats with endometriosis, inhibited cell proliferation, increased cell apoptosis, and reduced microvessel density and HIF-1α expression. It suggested that SZD could be an effective therapy for the treatment and prevention of endometriosis recurrence.

Basic mechanisms of vascularization in endometriosis and their clinical implications

BACKGROUND

Vascularization is a major hallmark in the pathogenesis of endometriosis. An increasing number of studies suggests that multiple mechanisms contribute to the vascularization of endometriotic lesions, including angiogenesis, vasculogenesis and inosculation.

OBJECTIVE AND RATIONALE

In this review, we provide an overview of the basic mechanisms of vascularization in endometriosis and give special emphasis on their future clinical implications in the diagnosis and therapy of the disease.

SEARCH METHODS

Literature searches were performed in PubMed for English articles with the key words 'endometriosis', 'endometriotic lesions', 'angiogenesis', 'vascularization', 'vasculogenesis', 'endothelial progenitor cells' and 'inosculation'. The searches included both animal and human studies. No restriction was set for the publication date.

OUTCOMES

The engraftment of endometriotic lesions is typically associated with angiogenesis, i.e. the formation of new blood vessels from pre-existing ones. This angiogenic process underlies the complex regulation by angiogenic growth factors and hormones, which activate intracellular pathways and associated signaling molecules. In addition, circulating endothelial progenitor cells (EPCs) are mobilized from the bone marrow and recruited into endometriotic lesions, where they are incorporated into the endothelium of newly developing microvessels, referred to as vasculogenesis. Finally, preformed microvessels in shed endometrial fragments inosculate with the surrounding host microvasculature, resulting in a rapid blood supply to the ectopic tissue. These vascularization modes offer different possibilities for the establishment of novel diagnostic and therapeutic approaches. Angiogenic growth factors and EPCs may serve as biomarkers for the diagnosis and classification of endometriosis. Blood vessel formation and mature microvessels in endometriotic lesions may be targeted by means of anti-angiogenic compounds and vascular-disrupting agents.

WIDER IMPLICATIONS

The establishment of vascularization-based approaches in the management of endometriosis still represents a major challenge. For diagnostic purposes, reliable angiogenic and vasculogenic biomarker panels exhibiting a high sensitivity and specificity must be identified. For therapeutic purposes, novel compounds selectively targeting the vascularization of endometriotic lesions without inducing severe side effects are required. Recent progress in the field of endometriosis research indicates that these goals may be achieved in the near future.

Three-Dimensional Power Doppler Vascularization in Women With Ovarian Endometriomas and Relationship With Associated Painful Symptoms

OBJECTIVES

The objective of the study was to evaluate the correlation between endometrioma-associated pain and lesion vascularization as measured with 3-dimensional power Doppler transvaginal sonography.

METHODS

Endometriomas were examined, and 4 indices were obtained: mean grayness, flow index, vascularization index, and vascularization-flow index. Dysmenorrhea, chronic pelvic pain, and dyspareunia were analyzed in terms of severity, presence/absence, and duration.

RESULTS

Twenty-nine women were selected. The univariable association of painful symptoms in terms of presence/absence and duration was low with the exception of mean grayness with the presence of chronic pelvic pain (β = -0.106; P = .047; 95% confidence interval, 0.810 to 0.998). The R² value increased to 0.226 for dysmenorrhea (β = -0.475; P = .029) when analyzing the association between the vascularization index and the severity of painful symptoms. The visual analog scale scores for chronic pelvic pain and dyspareunia were higher (R²  = 0.300; β = -0.547 and -0.548, respectively; P = .028 and .053).

CONCLUSIONS

We observed an inverse association between the severity of pain and endometrioma vascularization. Further larger studies are required to confirm our findings.

Differential Impact of Plasma Proteins on the Adhesion Efficiency of Vascular-Targeted Carriers (VTCs) in Blood of Common Laboratory Animals

Vascular-targeted carrier (VTC) interaction with human plasma is known to reduce targeted adhesion efficiency in vitro. However, the role of plasma proteins on the adhesion efficiency of VTCs in laboratory animals remains unknown. Here, in vitro blood flow assays are used to explore the effects of plasma from mouse, rabbit, and porcine on VTC adhesion. Porcine blood exhibited a strong negative plasma effect on VTC adhesion while no significant plasma effect was found with rabbit and mouse blood. A brush density poly(ethylene glycol) (PEG) on VTCs was effective at improving adhesion of microsized, but not nanosized, VTCs in porcine blood. Overall, the results suggest that porcine models, as opposed to mouse, can serve as better models in preclinical research for predicting the in vivo functionality of VTCs for use in humans. These considerations hold great importance for the design of various pharmaceutical products and development of reliable drug delivery systems.

Plasma protein corona modulates the vascular wall interaction of drug carriers in a material and donor specific manner

The nanoscale plasma protein interaction with intravenously injected particulate carrier systems is known to modulate their organ distribution and clearance from the bloodstream. However, the role of this plasma protein interaction in prescribing the adhesion of carriers to the vascular wall remains relatively unknown. Here, we show that the adhesion of vascular-targeted poly(lactide-co-glycolic-acid) (PLGA) spheres to endothelial cells is significantly inhibited in human blood flow, with up to 90% reduction in adhesion observed relative to adhesion in simple buffer flow, depending on the particle size and the magnitude and pattern of blood flow. This reduced PLGA adhesion in blood flow is linked to the adsorption of certain high molecular weight plasma proteins on PLGA and is donor specific, where large reductions in particle adhesion in blood flow (>80% relative to buffer) is seen with ∼60% of unique donor bloods while others exhibit moderate to no reductions. The depletion of high molecular weight immunoglobulins from plasma is shown to successfully restore PLGA vascular wall adhesion. The observed plasma protein effect on PLGA is likely due to material characteristics since the effect is not replicated with polystyrene or silica spheres. These particles effectively adhere to the endothelium at a higher level in blood over buffer flow. Overall, understanding how distinct plasma proteins modulate the vascular wall interaction of vascular-targeted carriers of different material characteristics would allow for the design of highly functional delivery vehicles for the treatment of many serious human diseases.

Impact of surgical excision of lesions on pain in a rat model of endometriosis

BACKGROUND

Chronic pain is the most common and disabling feature of endometriosis. Surgical excision of endometriosis lesions provides relief but pain relapse is common. Studies in a preclinical model of endometriosis might help to unravel the role of the ectopic lesions as the source of pain. Thus, we evaluated the impact of lesion excision on mechanical hyperalgesia in a preclinical model of endometriosis pain.

METHODS

Endometriosis was induced by implanting autologous uterine tissue onto the gastrocnemius muscle. Surgical excision or aspiration drainage of the cystic lesion was performed at different times post-implant and mechanical nociceptive thresholds were assessed at the site of the lesion.

RESULTS

Lesions at 2, 8 and 16 weeks post-implant produced mechanical hyperalgesia of similar magnitude (n = 6/group). Excision of lesions (n = 6/group) produced a longer inhibition, with a magnitude and time course depending upon the timing of excision. Excision at 2 and 8 weeks produced a rapid onset marked attenuation of hyperalgesia, which returned to pre-excision values by post-surgical week 3. In contrast, excision of the lesion at 16 weeks produced a peak of inhibition of hyperalgesia 2 weeks post-excision, but then the inhibition was sustained. Aspiration of fluid from cysts in the lesions briefly attenuated mechanical hyperalgesia (n = 6/group).

CONCLUSIONS

In this preclinical model, we demonstrate that endometriosis pain is alleviated by surgical excision of the ectopic lesion or drainage of its cysts, providing support for the clinical observation that endometriosis pain is dependent upon the ongoing presence of the lesions.

Pigment epithelial-derived factor expression in endometriotic lesions in a rat model of endometriosis

Angiogenesis is a prerequisite for endometriotic lesion formation and development. Pigment epithelium-derived factor (PEDF) is a potential inhibitor of angiogenesis. The objective of this study was to detect PEDF immunolocalization in endometriotic lesions and the correlation with vascular endothelial growth factor (VEGF) and microvascular density (MVD) in a rat model of endometriosis. A subcutaneous endometriosis rat model was established by using auto-transplantation. Expression of PEDF, VEGF and MVD labeled by von Willebrand factor (v-WF) in endometriotic lesions and endometrial tissues was evaluated using immunohistochemical staining. We detected lower PEDF immunostaining and higher VEGF and MVD immunostaining in active lesions in a rat model of endometriosis than that in endometriosis endometrium or control endometrium (P<0.05), but no differences between endometriosis and control endometrium were found (P>0.05). In lesions, PEDF expression was negatively correlated with VEGF expression, MVD or sizes of cysts (P<0.01). On the contrary, both VEGF expression and MVD were positively correlated with lesion sizes (P<0.05). In addition, VEGF expression was positively correlated with MVD (P<0.01). Our results suggest that PEDF might be involved in the pathogenesis of endometriosis and may lead to novel treatment for this disease.

Vascular endothelial cells mediate mechanical stimulation-induced enhancement of endothelin hyperalgesia via activation of P2X2/3 receptors on nociceptors

Endothelin-1 (ET-1) is unique among a broad range of hyperalgesic agents in that it induces hyperalgesia in rats that is markedly enhanced by repeated mechanical stimulation at the site of administration. Antagonists to the ET-1 receptors, ET(A) and ET(B), attenuated both initial as well as stimulation-induced enhancement of hyperalgesia (SIEH) by endothelin. However, administering antisense oligodeoxynucleotide to attenuate ET(A) receptor expression on nociceptors attenuated ET-1 hyperalgesia but had no effect on SIEH, suggesting that this is mediated via a non-neuronal cell. Because vascular endothelial cells are both stretch sensitive and express ET(A) and ET(B) receptors, we tested the hypothesis that SIEH is dependent on endothelial cells by impairing vascular endothelial function with octoxynol-9 administration; this procedure eliminated SIEH without attenuating ET-1 hyperalgesia. A role for protein kinase Cε (PKCε), a second messenger implicated in the induction and maintenance of chronic pain, was explored. Intrathecal antisense for PKCε did not inhibit either ET-1 hyperalgesia or SIEH, suggesting no role for neuronal PKCε; however, administration of a PKCε inhibitor at the site of testing selectively attenuated SIEH. Compatible with endothelial cells releasing ATP in response to mechanical stimulation, P2X(2/3) receptor antagonists eliminated SIEH. The endothelium also appears to contribute to hyperalgesia in two ergonomic pain models (eccentric exercise and hindlimb vibration) and in a model of endometriosis. We propose that SIEH is produced by an effect of ET-1 on vascular endothelial cells, sensitizing its release of ATP in response to mechanical stimulation; ATP in turn acts at the nociceptor P2X(2/3) receptor.

The relation of pelvic pain and dense adhesions to Doppler ultrasound findings in patients with ovarian endometriomas

PURPOSE

To study the relation of pelvic pain symptoms and pelvic adhesions to Doppler ultrasound findings in patients with ovarian endometriomas.

METHODS

62 patients who underwent laparoscopic surgery for endometrioma were divided into two groups according to their pelvic pain symptoms. Group 1 (n = 27) included patients with pelvic pain, group 2 (n = 35) asymptomatic patients. Patients were evaluated for the vascularization of endometrioma by transvaginal color and power Doppler ultrasonography before the surgery. The presence and amount of blood flow reported in terms of a color scale, pulsed Doppler indices, and dense pelvic adhesions were compared between the groups. The relation of Doppler ultrasound findings to the dense pelvic adhesions was also analyzed.

RESULTS

Blood flow was present in 74.1 % (n = 20) of patients in group 1 and 68.6 % (n = 24) in group 2 (p = 0.63). The volume and vascularization of the endometriomas, pulsed Doppler indices, stage of endometriosis, and the presence of dense pelvic adhesions were also similar. Patients with dense pelvic adhesions had significantly higher amount of blood flow compared to patients without adhesions (p = 0.006), but the mean pulsatility index and resistance index were not different between the groups (p = 0.55 and 0.59, respectively).

CONCLUSIONS

Pelvic pain symptoms were not found to be related to endometrioma vascularization. On the other hand, we observed an association between higher vascularized endometrioma and the presence of dense pelvic adhesions.

Sorafenib inhibits growth, migration, and angiogenic potential of ectopic endometrial mesenchymal stem cells derived from patients with endometriosis

OBJECTIVE

To characterize the proliferation, migration, and angiogenic properties of mesenchymal stem cells (MSC) from ectopic and eutopic endometrial tissue and to investigate the effect of the tyrosine kinase inhibitor sorafenib.

DESIGN

In vitro studies.

SETTING

University hospital and research center.

PATIENT(S)

Patients receiving surgical treatment of endometriosis (n = 4) and control patients without endometriosis (n = 2) undergoing surgery for benign gynecologic diseases.

INTERVENTION(S)

Mesenchymal stem cell lines were isolated from ectopic and eutopic endometrial tissue, and sorafenib was administered to them.

MAIN OUTCOME MEASURE(S)

Proliferation, migration, invasion of endometrial MSC, and expression of ezrin, vascular endothelial growth factor, and hypoxia-inducible factor-1α (HIF-1α) were measured.

RESULT(S)

Ectopic endometrial MSC from patients with endometriosis showed a higher proliferation, migration, and angiogenic ability than eutopic MSC from the same patient or control MSC from patients without endometriosis. Sorafenib reduced the proliferation, motility, ezrin phosphorylation, vascular endothelial growth factor release, and HIF-1α expression of ectopic MSC.

CONCLUSION(S)

The increased proliferative, migratory, and angiogenic phenotype of ectopic MSC may be reverted by treatment with sorafenib. Targeting of the MSC population involved in sustaining the ectopic lesions might be useful in eradicating endometriotic implants.

Slit2 overexpression results in increased microvessel density and lesion size in mice with induced endometriosis

We recently reported that Slit/Roundabout (ROBO) 1 pathway may be a constituent biomarker for recurrence of endometriosis, likely through promoting angiogenesis. In this study, we sought to determine as whether Slit2 overexpression can facilitate angiogenesis, increase lesion size, and induce hyperalgesia in mice with induced endometriosis. We used 30 Slit2 transgenic (S) and 29 wild-type (W) mice and cross-transplanted endometrial fragments from S to W (group SW) and vice versa (group WS), and also within the S and W (groups SS and WW, respectively), into the peritoneal cavity, inducing endometriosis. We also performed a sham surgery within both S and W mice (groups Sm and Wm, respectively). The size of the ectopic implants, microvessel density (MVD) and immunoreactivity to ROBO1, and vascular endothelial cell growth factor (VEGF) in ectopic and eutopic endometrium, along with hotplate and tail-flick tests in all mice, were then evaluated. We found that the induction of endometriosis resulted in generalized hyperalgesia, which was unaffected by Slit2 overexpression. Slit2 overexpression did increase the lesion size significantly and correlated positively with the MVD in ectopic and eutopic endometrium. Slit2 expression levels appear to correlate with the MVD, but not with VEGF immunoreactivity, in ectopic endometrium. Consequently, we conclude that Slit2 may play an important role in angiogenesis in endometriosis. The increased angiogenesis, as measured by MVD, but not VEGF immunoreactivity, likely resulted in increased lesion size in induced endometriosis. Thus, SLIT2/ROBO1 pathway may be a potential therapeutic target for treating endometriosis.

New trends for the medical treatment of endometriosis

INTRODUCTION

Endometriosis is a benign sex hormone-dependent gynecological disease, characterized by the presence and growth of endometrial tissue outside the uterus; it affects 10% of women of reproductive age and is associated with infertility and pain. Treatment of endometriosis involves conservative or radical surgery, or medical therapies. The goals for endometriosis treatment may be the relief of pain and/or a successful pregnancy achievement in infertile patients. Treatment must be individualized with a multidisciplinary approach. The classical treatments carry adverse side effects and in some cases a negative impact on quality of life. New agents promise a distinct perspective in endometriosis treatment.

AREAS COVERED

The aim of this paper is to systematically review the literature evidence of new medical treatments for endometriosis, defined as pharmacological treatments not yet commonly available and currently under investigation.

EXPERT OPINION

These new medical therapies would be used associated with surgical treatment and, in the future, will render possible the association of hormone therapy with non-hormonal treatment for endometriosis.

A proteome comparison between physiological angiogenesis and angiogenesis in glioblastoma

The molecular pathways involved in neovascularization of regenerating tissues and tumor angiogenesis resemble each other. However, the regulatory mechanisms of neovascularization under neoplastic circumstances are unbalanced leading to abnormal protein expression patterns resulting in the formation of defective and often abortive tumor vessels. Because gliomas are among the most vascularized tumors, we compared the protein expression profiles of proliferating vessels in glioblastoma with those in tissues in which physiological angiogenesis takes place. By using a combination of laser microdissection and LTQ Orbitrap mass spectrometry comparisons of protein profiles were made. The approach yielded 29 and 12 differentially expressed proteins for glioblastoma and endometrium blood vessels, respectively. The aberrant expression of five proteins, i.e. periostin, tenascin-C, TGF-beta induced protein, integrin alpha-V, and laminin subunit beta-2 were validated by immunohistochemistry. In addition, pathway analysis of the differentially expressed proteins was performed and significant differences in the usage of angiogenic pathways were found. We conclude that there are essential differences in protein expression profiles between tumor and normal physiological angiogenesis.

Circulating endothelial progenitor cells are up-regulated in a mouse model of endometriosis

Endometriosis is a debilitating disease characterized by the growth of ectopic endometrial tissue. It is widely accepted that angiogenesis plays an integral part in the establishment and growth of endometriotic lesions. Recent data from a variety of angiogenesis-dependent diseases suggest a critical role of bone marrow–derived endothelial progenitor cells (EPCs) in neovascularization. In this study we examined the blood levels of EPCs and mature circulating endothelial cells in a mouse model of surgically induced endometriosis. Fluorescence-activated cell sorting analysis revealed elevated levels of EPCs in the blood of mice with endometriosis compared with control subject that underwent a sham operation. EPC concentrations positively correlated with the amount of endometriotic tissue and peaked 1 to 4 days after induction of disease. In a green fluorescent protein bone marrow transplant experiment we found green fluorescent protein–positive endothelial cells incorporated into endometriotic lesions but not eutopic endometrium, as revealed by flow cytometry and immunohistochemistry. Finally, treatment of endometriosis-bearing mice with the angiogenesis inhibitor Lodamin, an oral nontoxic formulation of TNP-470, significantly decreased EPC levels while suppressing lesion growth. Taken together, our data indicate an important role for bone marrow–derived endothelial cells in the pathogenesis of endometriosis and support the potential clinical use of anti-angiogenic therapy as a novel treatment modality for this disease.

Midterm outcome of ultrasound-guided alcohol gel sclerotherapy for symptomatic leiomyoma

OBJECTIVE

The purpose of this study was to describe the outcome of ultrasound-guided ethanol gel sclerotherapy of myomatous nodules 1 to 18 months after treatment.

METHODS

A total of 118 consecutive patients with a diagnosis of symptomatic leiomyomas referred for ethanol gel sclerotherapy were studied between November 2005 and July 2007. Clinical (self-administered symptom questionnaire) and ultrasound follow-ups were done 1 to 2, 6 to 8, and 12 to 18 months after the procedure.

RESULTS

The mean baseline volumes +/- SD were 223.3 +/- 158.3 cm(3) for the uterus and 68.4 +/- 110.5 cm(3) for the dominant fibroid. The most common adverse reaction in the immediate postoperative period was pelvic pain in 27.1% of the patients, but 58.4% had no reactions. After 12 months, a 29.5% reduction in uterine volume was observed in 64.7% of the patients. A 55.5% reduction in dominant fibroid volume was observed in 82.8% of the patients. Pelvic pain improved in 29.8% of the sample, dysmenorrhea in 51.7%, and menstrual flow in 39%. Most patients (77%) reported being satisfied or very satisfied with the treatment.

CONCLUSIONS

The results suggest that ethanol gel sclerotherapy is a safe, conservative alternative for treating symptomatic uterine leiomyomas. Further randomized studies are necessary to determine the suitability and indications of this procedure in comparison to other minimally invasive techniques.

Involvement of the nuclear factor-κB pathway in the pathogenesis of endometriosis

OBJECTIVE

To evaluate the role of nuclear factor-κB (NF-κB) in the pathogenesis of endometriosis.

DESIGN

A literature search was conducted in PubMed to identify all relevant citations.

RESULT(S)

Our findings highlight the important role of NF-κB in the pathophysiology of endometriosis. In vitro and in vivo studies show that NF-κB-mediated gene transcription promotes inflammation, invasion, angiogenesis, and cell proliferation and inhibits apoptosis of endometriotic cells. Constitutive activation of NF-κB has been demonstrated in endometriotic lesions and peritoneal macrophages of endometriosis patients. Agents blocking NF-κB are effective inhibitors of endometriosis development and some drugs with known NF-κB inhibitory properties have proved efficient at reducing endometriosis-associated symptoms in women. Iron overload activates NF-κB in macrophages. NF-κB activation in macrophages and ectopic endometrial cells stimulates synthesis of proinflammatory cytokines, generating a positive feedback loop in the NF-κB pathway and promoting endometriotic lesion establishment, maintenance and development.

CONCLUSION(S)

NF-κB transcriptional activity modulates key cell processes contributing to the initiation and progression of endometriosis. Because endometriosis is a multifactorial disease, inhibiting NF-κB appears to be a promising strategy for future therapies targeting different cell functions involved in endometriosis development, such as cell adhesion, invasion, angiogenesis, inflammation, proliferation, and apoptosis. Upcoming research will elucidate these hypotheses.

Up-regulation of cyclooxygenase-2 expression and prostaglandin E2 production in human endometriotic cells by macrophage migration inhibitory factor: involvement of novel kinase signaling pathways

Cyclooxygenase (COX) is the rate-limiting enzyme in the metabolic conversion of arachidonic acid to prostaglandins (PGs), including prostaglandin E(2) (PGE(2)), a major mediator of inflammation and angiogenesis. Herein, we report that macrophage migration inhibitory factor (MIF), a potent proinflammatory and growth-promoting factor found at elevated concentrations in the peritoneal fluid of women with endometriosis and active endometriosis lesions, acts directly on ectopic endometrial cells to stimulate the synthesis of COX-2, the inducible form of COX, and the release of PGE(2). MIF treatment strongly activated p38 and ERK MAPK, and specific inhibitors of both pathways completely blocked basal and MIF-induced PGE(2) synthesis. Whereas p38 inhibitors negatively affected the stimulated synthesis of COX-2 and that of PGE(2), ERK inhibitors only decreased the production of PGE(2). These findings show for the first time a direct role for MIF in the up-regulation of COX-2 synthesis and PGE(2) secretion in ectopic endometrial cells. They further indicate that whereas p38 and ERK MAPK signaling pathways both play a significant role in the regulation of basal and MIF-induced synthesis of PGE(2) by ectopic endometrial cells, only p38 kinase is involved in the regulation of COX-2 expression in these cells. This suggests that MIF acts at more than one level to stimulate the synthesis of PGE(2) and triggers the coordinate activation of multiple enzymes in the biosynthesis pathway. Our data provide evidence for a novel mechanism by which MIF can induce a proinflammatory phenotype in ectopic endometrial cells, and favor the establishment of endometriosis and its related clinical symptoms.

Oxytocin stimulates in vitro angiogenesis via a Pyk-2/Src-dependent mechanism

We previously reported that the hypothalamic hormone oxytocin (OT), best known for its uterotonic activity, also stimulates migration and invasion in human umbilical vein endothelial cells (HUVECs), thus suggesting a possible role for the peptide in the regulation of angiogenesis. We identified the Gq coupling of OT receptors (OTRs) and phospholipase C (PLC) as the main effectors of OT's action in HUVECs. Moreover, the pro-migratory effect of OT required the OTR-induced activation of the phosphatidylinositol-3-kinase (PI-3-K)/AKT/endothelial nitric oxide synthase (eNOS) pathway. To better characterize the proposed pro-angiogenic effect of OT in HUVECs, we have now utilized a three-dimensional (3-D) in vitro angiogenesis assay, and demonstrated that OT stimulates the outgrowth of capillary-like structures from HUVEC spheroids to an extent comparable to that of vascular endothelial growth factor (VEGF). This OT effect was abolished by inhibitors of PLC, PI-3-K and Src kinase. It was also found that OT phosphorylates proline-rich tyrosine kinase-2 (Pyk-2) and Src kinase in a PLC- and calcium-dependent manner. Furthermore, knockdown of Pyk-2 expression by RNA interference markedly impaired Src phosphorylation, migration and endothelial cell sprouting induced by OT. In conclusion, by using a pharmacological and genetic approach, the OT pro-angiogenic action and the cascade of intracellular signals responsible for it were defined by showing for the first time that OT, by interacting with its Gq-coupled receptor, induces HUVEC capillary outgrowth via Pyk-2 phosphorylation, which activates Src which in turn activates the PI-3-K/AKT pathway.

SRB Reproduction, Fertility and Development Award Lecture 2008. Regulation and manipulation of angiogenesis in the ovary and endometrium

The marked cyclical physiological angiogenesis in the developing follicle, corpus luteum and endometrium implies a critical role in health and disease. Our approach to understanding its regulation has been to localise and quantify the temporal changes in putative angiogenic factors, and their receptors, in human and non-human primate tissue and to use antagonists to dissect their role by specific inhibition at defined periods during the ovulatory cycle in non-human primates in vivo. The course of angiogenesis throughout the cycle and the cellular and molecular effects of inhibitory treatments have been investigated in the marmoset ovary and uterus, whereas consequences on pituitary-ovarian function have been monitored in macaques. Inhibition of vascular endothelial growth factor (VEGF) at the time of follicle recruitment or selection prevents endothelial cell proliferation, leading to inhibition of follicular development. VEGF inhibition during the early luteal phase prevents angiogenesis and restricts development of the luteal microvasculature. Inhibition of angiogenesis at all stages of the cycle leads to profound suppression of ovarian function. Even during the 'post-angiogenic' period of the luteal phase, inhibition of VEGF precipitates a suppression of progesterone secretion, pointing to additional roles for VEGF in the ovary. In the endometrium, oestrogen drives endometrial angiogenesis through VEGF. Thus, oestrogen can restore angiogenesis after ovariectomy, but not in the presence of VEGF inhibitors. These investigations enhance our understanding of the regulation of angiogenesis in the ovary and uterus and inform studies on conditions with abnormal vascularisation, such as polycystic ovary syndrome, endometriosis, uterine fibroids and menstrual dysfunction.

Proteomics technologies in endometriosis

Endometriosis is a common disorder that is associated with infertility and pelvic pain. Diagnosis is based on the visualization of endometriotic lesions during surgery as no reliable serum marker is currently available. The etiology of endometriosis is largely unknown. Over the last 20 years, several proteomics technologies have been used to research novel proteins with a potential etiological role in endometriosis, and to identify candidate serum markers for this condition. While some molecules identified by proteomics technologies may have a relevant role in the pathogenesis of endometriosis, the research of potential serum markers for this condition is still far from any clinical application. This review summarizes the state of the art and potential applications of proteomics in endometriosis research.