Effects of LNG-IUS on nerve growth factor and its receptors expression in patients with adenomyosis

Impact of Adenomyosis on Infertile Patients-Therapy Options and Reproductive Outcomes

Adenomyosis is associated with a negative impact on reproductive outcomes. Although adenomyosis is detected more frequently in women of late reproductive age, its impact on pregnancy rates is important because, in today's world, family planning has shifted towards the late reproductive phase of life for many women. Although the diagnostic indications for imaging studies are well-known, we lack strict diagnostic criteria and classification systems concerning the extent of the disease. Selecting the optimal evidence-based treatment option for adenomyosis is difficult because of the paucity of evidence concerning the association between fertility and the degree and composition of adenomyosis. Furthermore, the treatment of infertility might interfere with the treatment of adenomyosis due to the presence of pain. The aim of this review is to analyze the association between adenomyosis and infertility, and describe treatment options to enhance reproductive outcomes. The following aspects will be addressed in detail: (a) prevalence and causes of adenomyosis, (b) diagnostic tools with imaging techniques, (c) clinical symptoms, (d) proposed pathomechanism of adenomyosis and infertility, and (e) different treatment approaches (pharmacological, surgical, others) and their impact on reproductive outcomes.

Cracking the enigma of adenomyosis: an update on its pathogenesis and pathophysiology

In brief

Traditionally viewed as enigmatic and elusive, adenomyosis is a fairly common gynecological disease but is under-recognized and under-researched. This review summarizes the latest development on the pathogenesis and pathophysiology of adenomyosis, which have important implications for imaging diagnosis of the disease and for the development of non-hormonal therapeutics.

Abstract

Traditionally considered as an enigmatic disease, adenomyosis is a uterine disease that affects many women of reproductive age and is a contributing factor for pelvic pain, heavy menstrual bleeding (HMB), and subfertility. In this review, the new development in the pathogenesis and pathophysiology of adenomyosis has been summarized, along with their clinical implications. After reviewing the progress in our understanding of the pathogenesis and describing the prevailing theories, in conjunction with their deficiencies, a new hypothesis, called endometrial-myometrial interface disruption (EMID), which is backed by extensive epidemiologic data and demonstrated by a mouse model, is reviewed, along with recent data implicating the role of Schwann cells in the EMI area in the genesis of adenomyosis. Additionally, the natural history of adenomyotic lesions is elaborated and underscores that, in essence, adenomyotic lesions are fundamentally wounds undergoing repeated tissue injury and repair (ReTIAR), which progress to fibrosis through epithelial-mesenchymal transition, fibroblast-to-myofibroblast transdifferentiation, and smooth muscle metaplasia. Increasing lesional fibrosis propagates into the neighboring EMI and endometrium. The increased endometrial fibrosis, with ensuing greater tissue stiffness, results in attenuated prostaglandin E2, hypoxia signaling and glycolysis, impairing endometrial repair and causing HMB. Compared with adenomyosis-associated HMB, the mechanisms underlying adenomyosis-associated pain are less understood but presumably involve increased uterine contractility, hyperinnervation, increased lesional production of pain mediators, and central sensitization. Viewed through the prism of ReTIAR, a new imaging technique can be used to diagnose adenomyosis more accurately and informatively and possibly help to choose the best treatment modality.

Conservative surgical and drug therapies for adenomyosis Medicine

Adenomyosis is a benign invasion/infiltration of endometrial glands and stroma in the uterine myometrium. The optimal choice of adenomyosis treatment remains a subject of discussion. For patients with adenomyosis without fertility requirements, hysterectomy can be performed by laparotomy or laparoscopic surgery to eliminate symptoms. However, this is an inadequate option for women who want to preserve fertility or avoid more extensive surgery. To summarize the medicine and conservative surgery treatment for adenomyosis. An extensive literature search was performed using PubMed, Web of Science, Embase, Ovid Medline, Cochrane Central Register of Controlled Trials, Google Scholar and China National Knowledge Infrastructure (CNKI) without language restriction. The search terms were as follows: adenomyomas, adenomyosis, conservative therapy; combined therapy; medicine; surgery. The search included all titles and abstracts assessing conservative treatment for adenomyosis including medical and surgical therapy. All published papers were analyzed if considered relevant. Increasing current conservative treatments will not only improve the quality of life of the patients but also preserve fertility. Therefore, conservative treatment is extremely important for patients with fertility requirements or a strong desire to retain the uterus. Conservative treatment for adenomyosis may become a future trend in the field of gynecology.

A controlled clinical trial comparing potent progestins, LNG-IUS and dienogest, for the treatment of women with adenomyosis

PURPOSE

To evaluate the efficacy of two progestins, levonorgestrel intrauterine system (LNG-IUS) and dienogest (DNG), for adenomyosis.

METHODS

This study enrolled 157 women with adenomyosis, randomized to either LNG-IUS (n = 76) or DNG (n = 81) groups as a controlled clinical trial for 72 months. Participants were classified by three different localizations of adenomyosis: diffuse, focal, and extrinsic. VAS (Visual analog scale) score, days, and amount of uterine bleeding were assessed. Uterine volume or bone mineral density (BMD) were measured by three-dimensional ultrasonography or dual-energy X-ray absorptiometry.

RESULTS

LNG-IUS and DNG comparably reduced pain scores in patients with adenomyosis. With regard to pain control, DNG offered greater efficacy than LNG-IUS in 3 months of treatment. In all types of adenomyosis, the days of bleeding after 12 months with DNG were significantly decreased compared to those with LNG-IUS. The decrease of whole uterine body was transient in any subtypes. A comparable decrease in BMD due to age-related changes in both groups was observed.

CONCLUSIONS

LNG-IUS and DNG could be useful for long-term management of adenomyosis. In terms of durations of uterine bleeding, DNG was superior to LNG-IUS for 6 years.

[Efficacy and adverse effects of levonorgestrel-releasing intrauterine system in treatment of adenomyosis]

OBJECTIVE

To evaluate the efficacy and adverse effects of levonorgestrel-releasing intrauterine system (Mirena) in the treatment of adenomyosis.

METHODS

The clinical data of 75 patients with adenomyosis who had Mirena insertion in Women's Hospital,Zhejiang University School of Medicine from September 2013 to December 2013 were retrospectively analyzed. The patients were followed up to 39 months. The efficacy and adverse effects were assessed.

RESULTS

Pictorial Blood Loss Assessment Chart (PBAC) scores were decreased significantly after Mirena insertion both in patients with menorrhea (118±13 vs. 29±33, P<0.01) and normal menstruation (82±15 vs. 14±13, P<0.01); the patients with menorrhea showed a more significant decrease in PBAC score than those with normal menstruation (90±35 vs. 69±19,P<0.01). The visual analogue scale (VAS) score decreased significantly after Mirena insertion compared with pre-treatment[7(6,7) vs. 1(0,2), P<0.01]. The expulsion of Mirena occurred in 18 cases (24.0%); 9 cases (12.0%) had no effect and 28 cases (37.3%) had changes of menstruation patterns. Multivariate Cox regression analysis showed that the expulsion of Mirena was not associated with post-treatment VAS score, PBAC score before and after treatment or menstrual stabilization time (all P>0.05).

CONCLUSIONS

Mirena is effective and safe in the long term management of adenomyosis, but about one third patients may require further treatment because of the expulsion or ineffectiveness of Mirena.

Partners in Crime: NGF and BDNF in Visceral Dysfunction

Neurotrophins (NTs), particularly Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF), have attracted increasing attention in the context of visceral function for some years. Here, we examined the current literature and presented a thorough review of the subject. After initial studies linking of NGF to cystitis, it is now well-established that this neurotrophin (NT) is a key modulator of bladder pathologies, including Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) and Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS. NGF is upregulated in bladder tissue and its blockade results in major improvements on urodynamic parameters and pain. Further studies expanded showed that NGF is also an intervenient in other visceral dysfunctions such as endometriosis and Irritable Bowel Syndrome (IBS). More recently, BDNF was also shown to play an important role in the same visceral dysfunctions, suggesting that both NTs are determinant factors in visceral pathophysiological mechanisms. Manipulation of NGF and BDNF improves visceral function and reduce pain, suggesting that clinical modulation of these NTs may be important; however, much is still to be investigated before this step is taken. Another active area of research is centered on urinary NGF and BDNF. Several studies show that both NTs can be found in the urine of patients with visceral dysfunction in much higher concentration than in healthy individuals, suggesting that they could be used as potential biomarkers. However, there are still technical difficulties to be overcome, including the lack of a large multicentre placebo-controlled studies to prove the relevance of urinary NTs as clinical biomarkers.

P21-Activated Kinase 1 Overactivates in Eutopic Endometrium of Adenomyosis

Adenomyosis is a common gynecological disease, characterized by the existence of endometrium in the myometrium. The pathogenesis of adenomyosis is not fully understood. P21-activated kinase 1 (PAK1) is an effector of small Rho GTPases including CDC42 and RAC1 and plays various roles in cellular biology, especially cytoskeletal remodeling. This study aimed to evaluate whether the expression and activation of PAK1 in adenomyosis were different from normal. Immunohistochemistry was performed to evaluate the expression of PAK1 and its active form phosphorylated-PAK1 (pPAK1) semi-quantitatively in women with and without adenomyosis. Immunofluorescence was performed to locate the distribution of pPAK1. This study found that PAK1 in eutopic endometrium of adenomyosis was overactivated compared to normal. Phosphorylated-PAK1 assembled along the apical surface of glandular cell membrane. In ectopic lesions, PAK1 expression decreased and its activation returned to the baseline. The expression of pPAK1 correlated with the frequency of reproduction. These findings suggest that PAK1 overactivation in the endometrium may be an important event during the development of adenomyosis, meanwhile, decreased phosphorylation may assist to form lesions.

Expression of Nerve Injury-Induced Protein1 (Ninj1) in Endometriosis

OBJECTIVE

The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

BACKGROUND

Nerve injury-induced protein 1 (Ninj1) is a molecule originally identified in dorsal root ganglion neurons and Schwann cells after nerve injury and promotes neurite outgrowth. The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

MATERIALS AND METHODS

Tissues were obtained with consent from patients diagnosed with ovarian endometrioma (n = 15 in total), peritoneal endometriosis (n = 5), adenomyosis (n = 5), and other gynecological disorders (n = 5, control) during surgery. Immunohistochemistry was conducted in order to detect Ninj1 protein expression in the lesion of endometriosis, adenomyosis, and eutopic endometrium. Nerve fibers in the ovarian endometrioma were detected by positive staining of PGP-9.5. To evaluate the effects of IL-1β on Ninj1 gene expression in endometriosis, ESCs isolated from ovarian endometrioma (n = 5) were treated with IL-1β (5 ng/mL) for 3 or 6 hours. Messenger RNA (mRNA) expression for Ninj1 was examined using quantitative RT-PCR.

RESULTS

The Ninj1 protein was expressed by ovarian endometrioma, peritoneal endometriotic, and adenomyotic tissue. Nerve fibers were found in the areas of positive staining for Ninj1 in ovarian endometrioma. IL-1β, an indicator of inflammation in endometriosis, significantly increased Ninj1 mRNA expression by ESC.

CONCLUSION

Our study demonstrates that Ninj1 is expressed in endometriosis and adenomyosis and is induced by the inflammatory stimuli. Given the neurogenetic property of Ninj1, our results imply that Ninj1, induced by inflammation in endometriosis lesion, may contribute to the pathogenesis of pain symptoms characteristic of endometriosis.

Drug therapy for adenomyosis: a prospective, nonrandomized, parallel-controlled study

Objective To provide novel insights into the clinical treatment of adenomyosis. Methods Two hundred patients with adenomyosis were enrolled in this prospective, nonrandomized, parallel-controlled study with a 1-year follow-up in our hospital. Group 1 was treated with 3.75 mg leuprorelin acetate (LA) (n = 40), Group 2 was treated with 1.88 mg LA (n = 40), Group 3 underwent Mirena implantation (n = 40), Group 4 underwent Mirena implantation after treatment with 3.75 mg LA (n = 40), Group 5 underwent Mirena implantation after treatment with 1.88 mg LA (n = 20), and Group 6 received San-Jie-Zhen-Tong capsules alone (n = 20). Uterine volume, pain, cancer antigen 125 level, ovary function, adverse effects, and Mirena expulsion were evaluated. Results The uterine volume and pain scores were lower in the groups treated with 1.88 than 3.75 mg LA, but the lower dose was associated with significantly fewer hot flashes and sweating. The 1-year Mirena expulsion rate was higher in Group 3 than in Groups 4 and 5 (10.00% vs. 3.33%, respectively). Costs were significantly higher in Groups 1 and 4 than in Groups 2 and 5. Conclusion Administration of 1.88 mg LA may be an alternative therapy for Asian patients with adenomyosis. The combination of LA and Mirena could enhance the therapeutic effect. Registration number: ChiCTR-IPR-15005971.

Minimally invasive treatment of adenomyosis

The aim of the present review is to give a comprehensive overview of minimal invasive treatment options and suggest a minimally invasive approach in women with adenomyosis (AD). A review of relevant literature on medical and surgical treatment options is performed. Surgical options include endometrial ablation, hysteroscopic endometrial and adenomyoma resection, laparoscopic resection of AD, high-intensity focused ultrasonography (HIFU), and uterine artery embolization (UAE). This review summarizes treatment strategies for the management of AD and highlights the present lack of knowledge, which makes suggestions of evidence-based treatment difficult.

Ginsenoside Rg3 Decreases Fibrotic and Invasive Nature of Endometriosis by Modulating miRNA-27b: In Vitro and In Vivo Studies

This research aimed to evaluate the potential therapeutic effects of Rg3 on endometriosis and identify target miRNAs. We designed an in vitro study using human endometrial stromal cells (HESCs) obtained from patients with endometriosis and an in vivo study using mouse models. HESCs were treated with Rg3-enhanced red ginseng extract (Rg3E); real-time PCR and microarray profiling, transfection, and western blot were performed. Mouse endometriosis models were developed and supplemented with Rg3E for 8 weeks. Gross lesion size and fibrotic character were analyzed in the mouse models. RNA levels of Ki-67, col-1, CTGF, fibronectin, TGF-β1, MMP2 and MMP9 significantly decreased in HESCs after Rg3E treatment. Microarray analysis revealed downregulation of miR-27b-3p, which is related to fibrosis modulation. Expression of miR-27b-3p was significantly higher in HESCs from patients with endometriosis than that of controls, and Rg3E treatment significantly decreased its expression; the contraction and migration assay revealed significant reductions in both fibrosis and migration potential in Rg3E-treated HESCs from endometriosis patients. A decrease in size and fibrotic character of endometrial lesions from the Rg3E groups was observed in vivo. In conclusion, Rg3 effectively altered fibrotic properties of HESCs from patients with endometriosis, which is likely associated with miR-27b-3p modulation.

The Impact of Adenomyosis on Women's Fertility

Until recently, adenomyosis has been associated with multiparity, not impaired fertility. Currently, adenomyosis is diagnosed with increasing frequency in infertile patients since women delay their first pregnancy until their late 30s or early 40s. Although an association between adenomyosis and infertility has not been fully established, based on the available information, recent studies suggested that adenomyosis has a negative impact on female fertility. Several uncontrolled studies with limited data also suggested that treatment of adenomyosis may improve fertility. This article discusses (i) the hypothesis and epidemiology of adenomyosis, (ii) diagnostic techniques, (iii) clinical evidence of correlation between adenomyosis and infertility, (iv) proposed mechanism of infertility in women with adenomyosis, (v) different treatment strategies and reproductive outcomes, and (vi) assisted reproductive technology outcome in women with adenomyosis.

Nerve fibers and endometriotic lesions: partners in crime in inflicting pains in women with endometriosis

One of major objectives in treating endometriosis is to alleviate pain since dysmenorrhea and other types of pain top the list of complaints from women with endometriosis who seek medical attention. Indeed, endometriosis-associated pain (EAP) is the most debilitating of the disease that negatively impacts on the quality of life in affected women, contributing significantly to the burden of disease and adding to the substantial personal and societal costs. Unfortunately, the mechanisms underlying the EAP are still poorly understood. In the last two decades, one active research field in endometriosis is the investigation on the distribution and genesis of nerve fibers in eutopic and ectopic endometrium, and the attempt to use endometrial nerve fiber density for diagnostic purpose. Since EAP presumably starts with the terminal sensory nerves, in or around endometriotic lesions, that transduce noxious mediators to the central nervous system (CNS) which ultimately perceives pain, this field of research holds the promise to elucidate the molecular mechanisms underlying the EAP, thus opening new avenues for novel diagnostics and therapeutics. In this review, we shall first briefly provide some basic facts on nerve fibers, and then provide an overview of some major findings in this filed while also note some conflicting results and expose areas in need of further research. We point out that since recently accumulated evidence suggests that endometriotic lesions are wounds undergoing repeated tissue injury and repair, the relationship between endometriotic lesions and nerve fibers is not simply unidirectional, i.e. lesions promote hyperinnervations. Rather, it is bidirectional, i.e. endometriotic lesions and nerve fibers engage active cross-talks, resulting in the development of endometriosis and pain. That is, nerve fibers and endometriotic lesions are actually partners in crime in inflicting pains in women with endometriosis, aided and abetted possibly by other culprits, some yet to be identified. We provide a list of possible perpetrators likely to be involved in this crime. Finally, we discuss possible implications when viewing the relationship from this vista.

Peripheral changes in endometriosis-associated pain

BACKGROUND

Pain remains the cardinal symptom of endometriosis. However, to date, the underlying mechanisms are still only poorly understood. Increasing evidence points towards a close interaction between peripheral nerves, the peritoneal environment and the central nervous system in pain generation and processing. Recently, studies demonstrating nerve fibres and neurotrophic and angiogenic factors in endometriotic lesions and their vicinity have led to increased interest in peripheral changes in endometriosis-associated pain. This review focuses on the origin and function of these nerves and factors as well as possible peripheral mechanisms that may contribute to the generation and modulation of pain in women with endometriosis.

METHODS

We conducted a systematic search using several databases (PubMed, MEDLINE, EMBASE and CINAHL) of publications from January 1977 to October 2013 to evaluate the possible roles of the peripheral nervous system in endometriosis pathophysiology and how it can contribute to endometriosis-associated pain.

RESULTS

Endometriotic lesions and peritoneal fluid from women with endometriosis had pronounced neuroangiogenic properties with increased expression of new nerve fibres, a shift in the distribution of sensory and autonomic fibres in some locations, and up-regulation of several neurotrophins. In women suffering from deep infiltrating endometriosis and bowel endometriosis, in which the anatomical distribution of lesions is generally more closely related to pelvic pain symptoms, endometriotic lesions and surrounding tissues present higher nerve fibre densities compared with peritoneal lesions and endometriomas. More data are needed to fully confirm a direct correlation between fibre density in these locations and the amount of perceived pain. A better correlation between the presence of nerve fibres and pain symptoms seems to exist for eutopic endometrium. However, this appears not to be exclusive to endometriosis. No correlation between elevated neurotrophin levels and pain severity appears to exist, suggesting the involvement of other mediators in the modulation of pain.

CONCLUSIONS

The increased expression of neurotrophic factors and nerve fibres in endometriotic lesions, eutopic endometrium and the peritoneum imply a role of such peripheral changes in the pathogenesis of endometriosis-associated pain. However, a clear link between these findings and pain in patients with endometriosis has so far not been demonstrated.

Dienogest inhibits nerve growth factor expression induced by tumor necrosis factor-α or interleukin-1β

OBJECTIVE

Dienogest (DNG), a selective P receptor (PR) agonist, is used to treat endometriosis. To investigate whether DNG affects nerve growth factor (NGF) expression, we stimulated human endometrial epithelial cells (hEECs) with inflammatory cytokines.

DESIGN

Prospective basic research study using immortalized hEEC lines.

SETTING

Development Research, Mochida Pharmaceutical Co., Ltd., Japan.

PATIENT(S)

None.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

In immortalized hEECs, NGF production induced by tumor necrosis factor-α (TNF-α) or interleukin-1β (IL-1β) was evaluated in the presence or absence of the synthetic progestin DNG or endogenous P. The NGF messenger RNA (mRNA) and protein were measured using real-time reverse transcriptase-polymerase chain reaction (PCR) and ELISA, respectively. The NGF bioactivity in the culture medium was measured by assaying neurite outgrowth of PC-12 cells.

RESULT(S)

Tumor necrosis factor-α and IL-1β induced NGF mRNA and protein and increased NGF bioactivity in the culture medium. These activities were inhibited by DNG in a hEEC line that stably expresses PR. In contrast, in an hEEC line that constitutively expresses faint levels of PR, no inhibitory effect of DNG on NGF mRNA was detected. The NGF mRNA was also inhibited in hEEC lines that express only PR-A or only PR-B.

CONCLUSION(S)

Nerve growth factor is one of the key mediators that generates the pain associated with endometriosis. Dienogest inhibits NGF expression through PR-A and PR-B in hEEC, which may contribute to the pharmacological mechanisms of how DNG relieves pain in endometriosis.