Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2019 Jun 2.
Published in final edited form as: Fertil Steril. 2018 Jun 2;109(6):1072–1078. doi: 10.1016/j.fertnstert.2018.02.004

Elevated levels of adrenomedullin in eutopic endometrium and plasma from women with endometriosis

Brooke C Matson a, Kelsey E Quinn a, Bruce A Lessey b, Steven L Young a,c, Kathleen M Caron a
PMCID: PMC6015786  NIHMSID: NIHMS972616  PMID: 29871794

Abstract

Objective

To test adrenomedullin (Adm, AM) as a downstream target of STAT3 in endometrial cells and to test mid-regional pro-adrenomedullin (MR-proADM) as a biomarker of endometriosis.

Design

Cross-sectional analysis of adrenomedullin (Adm, AM) expression in eutopic endometrium and of MR-proADM in plasma from women with and without endometriosis. Prospective study of MR-proADM levels in women with endometriosis undergoing surgical resection of ectopic lesions.

Setting

Academic medical centers in the United States.

Patients

15 patients with endometriosis and 11 healthy controls who donated eutopic endometrial biopsies; 28 patients with endometriosis and 19 healthy controls who donated plasma for MR-proADM analysis.

Intervention(s)

None.

Main Outcome Measure(s)

Adm mRNA levels by qRT-PCR after activation of STAT3 by IL-6 in Ishikawa cells. Immunohistochemistry for AM in eutopic endometrial biopsies from women with endometriosis compared to healthy donors. MR-proADM levels measured by commercial immunoassay in plasma from healthy women and women with endometriosis who subsequently underwent surgical resection of ectopic lesions.

Result(s)

Activation of STAT3 by IL-6 upregulated Adm mRNA expression in Ishikawa cells. AM protein levels were elevated in the eutopic endometrium of women with endometriosis. MR-proADM concentrations were higher in women with endometriosis but were not correlated with disease stage, corrected by surgery, or predictive of fertility outcome.

Conclusion

MR-proADM may be able to serve as a biomarker of endometriosis, but it is unknown whether elevated MR-proADM levels are secondary to the estrogenic and inflammatory properties of endometriosis or an inciting pathogenic factor.

Keywords: adrenomedullin, endometriosis, mid-regional pro-adrenomedullin

Introduction

Endometriosis is a common gynecological disease characterized by the presence of endometrial tissue outside of the eutopic endometrium, commonly in the peritoneum of the pelvis and in pelvic organs, often causing scarring and pain (1, 2). Although endometriosis is also strongly associated with subfertility and infertility, the mechanisms underlying fertility problems in women with stage 1 to 2 disease is a subject of debate in the field (3, 4). The non-specific nature of endometriosis symptoms makes the disease difficult to diagnose, and confident diagnosis usually requires visualization of ectopic lesions at surgical exploration. Endometriosis is equally difficult to treat; hormonal therapies and surgical excision of ectopic lesions are the mainstays of treatment but are not always effective (5, 6). These diagnostic and therapeutic challenges have fueled interest in identifying biomarkers and signaling pathways associated with endometriosis (7).

Recently, Kim et al. demonstrated aberrant activation of signal transducer and activator of transcription 3 (STAT3) in the eutopic endometrium of women with endometriosis (8). Other studies consistently point to endometriosis-associated factors that affect STAT3 activation: the cytokine interleukin 6 (IL-6), which activates STAT3 through the IL-6 receptor, is elevated in the peritoneal fluid of women with endometriosis (9–11); miR120, which targets STAT3, is elevated in endometriotic cyst stromal cells (12); and protein inhibitor of activated STAT3 (PIAS3) and dual-specificity phosphatase-2 (DUSP2), negative regulators of STAT3, are downregulated in endometriosis (13, 14). Kim et al. also found hypoxia inducible factor 1A (HIF1A), which is stabilized by STAT3, to be elevated in the eutopic endometrium of women with endometriosis. Taken together, these data strongly implicate the IL-6-STAT3-HIF1A pathway in the pathophysiology of endometriosis (8).

Both STAT3 and HIF1A have been previously identified as regulators of the versatile peptide hormone adrenomedullin (Adm, AM) (15–18). AM is expressed in the female reproductive system and has been associated with female reproductive physiology, including embryo implantation and placentation, and in pathophysiology, including subfertility and complications of pregnancy like preeclampsia (19, 20). In endometriosis, AM is higher in intrafollicular fluid and negatively associated with oocyte maturity and embryo quality in women with endometriosis, underscoring a potential link between AM, endometriosis, and fertility (21). Collectively, these data imply that AM may be able to serve as a biomarker of endometriosis.

Mid-regional pro-adrenomedullin (MR-proADM) is a byproduct of post-translational processing of preproAM peptide and is a stabler analyte than the mature AM peptide (22). In the past decade, many groups have found prognostic value for MR-proADM plasma concentrations as a biomarker of heart failure (23), community-acquired pneumonia (24), and sepsis (25), among other diseases. In reproduction, MR-proADM has been tested as a biomarker of gestational diabetes and preeclampsia (26, 27). Here, we test the hypothesis that MR-proADM, as a surrogate for AM potentially downstream of the IL-6-STAT3 axis, can serve as a biomarker of endometriosis.

Materials and Methods

Study Design and Human Subjects

The study was approved by the Institutional Review Boards of Greenville Health System and the University of North Carolina at Chapel Hill. Informed consent was obtained from all study participants, who were between the ages of 18 and 45 and had not used hormonal therapies or an intrauterine device in the three months preceding biopsy or plasma collection. Eutopic endometrial biopsies were collected from healthy donor women and women with endometriosis in both proliferative and secretory phases at the time of surgery at Greenville Health System and the University of North Carolina. Plasma samples for analysis of MR-proADM concentrations were collected from healthy women and from women with endometriosis in both proliferative and secretory phases at Greenville Health System and the University of North Carolina. Patients who wished to conceive were followed expectantly after surgery for up to 6 months and pregnancies recorded. Pregnancy was defined as a visible gestational sac on ultrasound with cardiac activity and referral for obstetrical care. The clinical characteristics of women from whom plasma was collected is displayed in Table 1. MR-proADM concentrations were measured in undiluted plasma using a commercial assay (BRAHMS MR-proADM KRYPTOR) by Phadia Immunology Reference Laboratory.

Table 1.

Clinical characteristics of study participants.

Control (n=19) Endometriosis (n=28)
Age (years) 26.2 ± 4.4 (20–33) 32.9 ± 4.9 (23–41)
BMI 22.4 ± 2.9 (18.3–28.2) 23.7 ± 4.7 (18.7–42.5)
Gravidity at biopsy 0 (0–3) 0 (0–4)
Race
 Caucasian 9 26
 African-American 7 0
 Asian 3 1
 Multiple 0 1
Open in a new tab

Age and BMI are presented as mean ± standard deviation (range). Gravidity is presented as median (range).

Immunohistochemistry

Five micron sections of paraffin-embedded endometrial biopsies were deparaffinized and hydrated. Following antigen retrieval in 10 mM citric acid/0.05% Tween 20, pH 6.0, endogenous peroxidase activity was quenched with 3% hydrogen peroxide in phosphate buffered saline (PBS). Tissues were permeabilized with PBS/0.1% Triton X-100 (PBST) and then blocked in 10% normal goat serum/1% bovine serum albumin in PBST. Tissues were incubated in anti-adrenomedullin primary antibody (1:200, Abcam ab69117) in block overnight at room temperature. The following day, slides were washed and incubated in biotinylated goat anti-rabbit (1:250, Jackson ImmunoResearch) for one hour. Avidin-biotin complexes (VECTASTAIN Elite ABC Kit, Vector Laboratories) were added to tissues for 30 minutes, and then diaminobenzidine (DAB Peroxidase (HRP) Substrate Kit, Vector Laboratories) was added for two minutes. Slides were rinsed with tap water, counterstained with hematoxylin (Vector Laboratories) for 20 seconds, and then rinsed with tap water again. Tissues were dehydrated and then coverslipped using DPX mountant (VWR). Slides were imaged on a Zeiss AxioImager with ProgRes CapturePro software (Jenoptik). Staining intensity was determined by a blinded observer (KEQ) and graded on a scale of 0 (no staining) to 4 (strong staining).

Cell Culture, Western Blot, and qRT-PCR

Ishikawa cells were cultured in DMEM/F12 (Gibco) + 10% fetal bovine serum (FBS) + 1x penicillin/streptomycin (Gibco) in a 37°C incubator containing 5% CO2. For western blot analysis, Ishikawa cells were grown to confluency in 10 cm dishes and were treated with a vehicle control or 1, 10, or 100 ng/mL human IL-6 (R&D Systems) for 15 minutes. Cells were lysed in PBS + 10 nM NaF + 2 mM Na3(VO4) + 2mM PMSF + protease inhibitor cocktail, and protein concentration in the lysates was determined using a BCA Protein Assay Kit (Pierce). Twenty micrograms of protein per sample were loaded on a SDS-PAGE gel (Bio-Rad) and then transferred to a nitrocellulose membrane (GE Healthcare Life Sciences). Membranes were blocked in either 5% bovine serum albumin (Fisher Scientific) or 5% nonfat dry milk for one hour at room temperature and then incubated overnight at 4° in primary antibodies: phospho-STAT3 (1:2,000 in 5% BSA, Cell Signaling) or STAT3 (1:2,000 in 5% milk, Cell Signaling). Blots were washed three times in tris-buffered saline/0.1% Tween 20 and then incubated for two hours at room temperature in secondary antibodies: DyLight 680 goat anti-mouse (1:15,000, Thermo Scientific) and DyLight 680 goat anti-rabbit (1:15,000 Thermo Scientific). Membranes were then imaged on an Odyssey CLx (LI-COR).

For gene expression analysis, Ishikawa cells were grown to near confluency in 10 cm dishes and then serum starved overnight in serum-free media. Cells were treated with 100 ng/mL IL-6 (R&D Systems) for 1 hour. RNA was collected and isolated using TRIzol (Thermo Fisher Scientific) according to the manufacturer’s protocol. Complementary DNA was synthesized from 2000 ng of DNase-treated RNA using M-MLV reverse transcriptase (Invitrogen). Quantitative real-time PCR was performed using a human Adm Assay on Demand (Applied Biosystems, Hs00969450_g1) and human GAPDH primers and probe (Applied Biosystems, 4310884E) on a StepOne Plus (Applied Biosystems). qRT-PCR data was analyzed using the 2−ΔΔCt method.

Statistical Analyses

All statistical analyses were performed in Prism 5 (GraphPad Software, Inc.). Adm gene expression in vehicle- and IL-6 treated Ishikawa cells; AM staining intensity in endometrial biopsies from healthy women and women with endometriosis; and MR-proADM concentrations in plasma from healthy women and women with endometriosis were compared by unpaired t-test. MR-proADM concentrations by menstrual cycle phase; stage of disease; surgical status; and fertility outcome were compared by one-way ANOVA. Data was considered statistically significant if p<0.05.

Results

Activation of STAT3 by IL-6 induces Adm expression

Given elevated levels of IL-6 and phosphorylated STAT3 (pSTAT3) in peritoneal fluid and eutopic endometrium, respectively, of women with endometriosis (9–11), and prior evidence for STAT3 regulation of Adm expression (17, 18), we tested whether IL-6 could induce Adm expression in an endometrial cell line, Ishikawa cells. First, we treated Ishikawa cells with increasing doses of IL-6 to confirm that IL-6 induced phosphorylation of STAT3 in Ishikawa cells. Indeed, we observed an IL-6 dose-dependent increase in pSTAT3 by western blot (Fig. 1A). We then assessed whether IL-6-mediated phosphorylation of STAT3 induced Adm expression, finding that treating Ishikawa cells with 100 ng/mL IL-6 for 15 minutes upregulated Adm gene expression approximately 1.4-fold by qRT-PCR (Fig. 1B).

Figure 1.

Figure 1

Open in a new tab

IL-6 activation of STAT3 upregulates Adm expression in Ishikawa cells. A, Western blot analysis of pSTAT3 expression in Isihawa cells following a 15 minute treatment of varying doses of IL-6. B, qRT-PCR analysis of Adm expression in Ishikawa cells after a 15 minute treatment of 100 ng/mL IL-6. ***p<0.001, unpaired t-test.

AM staining is enhanced in eutopic endometrium of women with endometriosis

Considering the elevation of pSTAT3 in endometriotic endometrium coupled with our in vitro evidence for STAT3-mediated upregulation of Adm expression in endometrial cells, we asked whether AM is also upregulated in the endometrium of women with endometriosis. Indeed, we found that AM staining was significantly greater in luminal epithelium, glandular epithelium, and stroma of eutopic endometrium from women with endometriosis compared to healthy controls (Fig. 2).

Figure 2.

Figure 2

Open in a new tab

Immunohistochemistry for AM in endometrial biopsies reveals elevated levels of AM in women with endometriosis. A, Representative images of immunohistochemistry for AM in eutopic endometrial biopsies from women with endometriosis and from healthy controls. GE, glandular epithelium; LE, luminal epithelium; S, stroma. B–D, Semi-quantitative analysis of AM staining in luminal epithelium (B), glandular epithelium (C), and stroma (D) of endometrial biopsies. DAB score reflects no (0), weak (1), moderate (2), or strong (3) staining. E, Composite DAB score calculated as the sum of the compartmental DAB scores depicted in B–D. Luminal epithelium was not present in all endometrial biopsies from women with endometriosis, therefore LE DAB score and composite DAB score were unable to be calculated in all biopsies. Each dot represents an individual patient. **p<0.01, unpaired t-test.

MR-proADM plasma levels are elevated in women with endometriosis

We then asked whether circulating plasma levels of MR-proADM, a stable precursor to the mature AM peptide, are elevated in women with endometriosis. The clinical characteristics of healthy controls and women with endometriosis who donated plasma for MR-proADM analysis are displayed in Table 1. First, we confirmed that MR-proADM levels are stable across all phases of the menstrual cycle in healthy women (Fig. 3A). MR-proADM levels averaged approximately 0.35 nmol/L, which is nearly equivalent to the mean MR-proADM concentration of 0.33 nmol/L across the general population (22). Subsequently, and consistent with higher levels of AM in eutopic endometrium of women with endometriosis, we found that circulating plasma levels of MR-proADM were higher in women with endometriosis compared to healthy controls (Fig. 3B). However, MR-proADM levels did not vary by stage of disease (Fig. 3C).

Figure 3.

Figure 3

Open in a new tab

MR-proADM plasma concentrations are elevated in women with endometriosis but not correlated with disease stage, surgical status, or pregnancy outcome. A, MR-proADM concentrations in plasma from healthy women across all stages of the menstrual cycle. ns, not significant, one-way ANOVA. B, MR-proADM concentrations in healthy controls and women with endometriosis. C, MR-proADM concentrations in women with endometriosis binned by disease stage and severity. D, MR-proADM concentrations in women with endometriosis before, immediately after, and three months after surgery. E, MR-proADM concentrations in women with endometriosis pre-, post-, and three months post-surgery, binned by those who became pregnant and those who did not. F, Individual, patient-level MR-proADM concentrations over time spanning the surgical period.

We then asked whether the elevated levels of MR-proADM were corrected by surgical resection of ectopic endometrial lesions. Analyzing MR-proADM concentrations immediately after surgery and three months after surgery, we determined that elevated MR-proADM levels persisted through the post-surgical period (Fig. 3D). Finally, we assessed whether MR-proADM concentrations before, after, and three months after surgery correlated with whether participants were able to become pregnant. We did not find any difference in MR-proADM levels between women with endometriosis who became pregnant and those who did not (Fig. 3E and F).

Discussion

In this study, we have presented evidence for Adm as a STAT3 target in the uterus and investigated MR-proADM as a potential biomarker of endometriosis. Prior evidence for a STAT3-Adm axis is two-fold: first, pSTAT3 and Adm levels are positively correlated in breast cancer (18); and second, activation of STAT3 by oncostatin M promotes Adm transcription in astroglioma cells (17). However, to our knowledge, this is the first direct evidence for a STAT3-Adm axis in the uterus. This finding is not surprising, as pSTAT3 and AM are co-localized in the uterus during early pregnancy (28, 29). Furthermore, reduction of STAT3 or AM in the mouse uterus leads to problems with implantation, potentially due to problems with endometrial receptivity (28–31). It will be the subject of future studies to determine whether STAT3 is directly binding active sites in the Adm promoter in uterine cells or whether the STAT3-mediated stabilization of HIF1A induces Adm transcription. Furthermore, it will be pertinent to determine if this interaction is critical for reproductive physiology and pathophysiology, specifically in humans and in the context of endometriosis.

We then asked whether AM, like pSTAT3, was upregulated in the eutopic endometrium of women with endometriosis, finding more AM in both epithelial and stromal compartments of the uterus. The increased expression is consistent with previously demonstrated elevated pSTAT3 and HIF1A abundance in the eutopic endometrium of women with endometriosis, echoing the possibility of an indirect relationship between STAT3 and Adm via HIF1A (8). However, the expression of AM in ectopic lesions remains unknown.

Because MR-proADM is a stable surrogate for AM peptide in circulating plasma, we compared levels of MR-proADM in women with and without endometriosis. This is the first study, to our knowledge, to examine levels of MR-proADM across the menstrual cycle. As the MR-proADM assay was developed just over a decade ago, reference intervals in different physiological conditions and disease states are just emerging (32). Here, we contribute evidence for stable levels of MR-proADM across all stages of the menstrual cycle in healthy women.

Comparison of MR-proADM concentrations in women with and without endometriosis led to our primary finding of elevated MR-proADM in women with endometriosis. We posit several explanations for the finding: First, endometriosis is well-understood to be an estrogenic disease, and Adm is transcriptionally regulated by estrogen (33, 34). Second, endometriosis is an inflammatory condition with consequences for fertility, and AM is an anti-inflammatory peptide commonly upregulated in response to inflammation (35, 36). Endometriosis is also associated with an elevated risk of epithelial ovarian cancer, and AM has been shown to promoter angiogenesis in this subtype of ovarian cancer (37–39). Therefore, our finding of elevated MR-proADM in women with endometriosis is consistent with associations common to both endometriosis and AM.

However, MR-proADM levels were not correlated with disease stage or corrected by surgical resection of ectopic lesions. Endometriosis staging determined primarily by the location and extent of ectopic lesions, and surgical resection aims to remove these lesions. Therefore, if ectopic lesions were the primary source of circulating MR-proADM, we would expect MR-proADM levels to be positively correlated with disease stage and to be corrected by surgery. While the expression of AM in ectopic lesions is not examined in this study, together, these data suggest that ectopic lesions are not the primary source of circulating MR-proADM.

MR-proADM levels were not predictive of fertility outcome in women with endometriosis, which is associated with subfertility or infertility, in women who underwent surgery. In our study, therefore, MR-proADM may not demonstrate a prognostic value in endometriosis that is equivalent to that observed by other groups in cardiovascular and pulmonary diseases. However, studies by our group and others demonstrate that levels of both maternal- and fetal-derived AM are important for fertility and pregnancy (19, 20). It appears that AM levels are carefully titrated in normal physiology; for example, while Adm−/−mice are embryonic lethal, Admhi/hi mice, which overexpress AM, develop hyperplastic hearts during development (40, 41). Therefore, it is becoming clear that concentrations of AM at either extreme can be detrimental to normal physiology.

In summary, we present evidence for a STAT3-Adm interaction in vivo; for upregulation of AM in the eutopic endometrium of women with endometriosis; and for higher circulating levels of MR-proADM in endometriosis. Whether elevated MR-proADM in endometriosis is secondary to the estrogenic and inflammatory properties of endometriosis or an inciting pathogenic factor will be the subject of future study.

Acknowledgments

This work was supported by U.S. National Institutes of Health Grants HD060860 (to KMC), HD067721 (to SLY and BAL), and HD085652 (to BCM).

We thank Angela Houwing of Greenville Health and Jana Phillips of the University of North Carolina at Chapel Hill for clinical research support and for acquisition of clinical characteristics of study participants. We also acknowledge Imani Sweatt for experimental efforts toward identifying a link between STAT3 and Adm.

Footnotes

Conflict of Interest: BCM and KMC have a pending patent application, Adrenomedullin Therapy to Improve Fetal Implantation. BAL and SLY have intellectual property licensed to CiceroDx. BAL advises and consults for AbbVie and Exeltis and has received grant funding from Pfizer, Inc. KEQ has nothing to disclose.

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

References

  • 1.Vercellini P, Vigano P, Somigliana E, Fedele L. Endometriosis: pathogenesis and treatment. Nat Rev Endocrinol. 2014;10:261–75. doi: 10.1038/nrendo.2013.255. [DOI] [PubMed] [Google Scholar]
  • 2.Greene AD, Lang SA, Kendziorski JA, Sroga-Rios JM, Herzog TJ, Burns KA. Endometriosis: where are we and where are we going? Reproduction. 2016;152:R63–78. doi: 10.1530/REP-16-0052. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Miravet-Valenciano J, Ruiz-Alonso M, Gomez E, Garcia-Velasco JA. Endometrial receptivity in eutopic endometrium in patients with endometriosis: it is not affected, and let me show you why. Fertil Steril. 2017;108:28–31. doi: 10.1016/j.fertnstert.2017.06.002. [DOI] [PubMed] [Google Scholar]
  • 4.Lessey BA, Kim JJ. Endometrial receptivity in the eutopic endometrium of women with endometriosis: it is affected, and let me show you why. Fertil Steril. 2017;108:19–27. doi: 10.1016/j.fertnstert.2017.05.031. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Singh SS, Suen MW. Surgery for endometriosis: beyond medical therapies. Fertil Steril. 2017;107:549–54. doi: 10.1016/j.fertnstert.2017.01.001. [DOI] [PubMed] [Google Scholar]
  • 6.Bedaiwy MA, Alfaraj S, Yong P, Casper R. New developments in the medical treatment of endometriosis. Fertil Steril. 2017;107:555–65. doi: 10.1016/j.fertnstert.2016.12.025. [DOI] [PubMed] [Google Scholar]
  • 7.Ahn SH, Singh V, Tayade C. Biomarkers in endometriosis: challenges and opportunities. Fertil Steril. 2017;107:523–32. doi: 10.1016/j.fertnstert.2017.01.009. [DOI] [PubMed] [Google Scholar]
  • 8.Kim BG, Yoo JY, Kim TH, Shin JH, Langenheim JF, Ferguson SD, et al. Aberrant activation of signal transducer and activator of transcription-3 (STAT3) signaling in endometriosis. Hum Reprod. 2015;30:1069–78. doi: 10.1093/humrep/dev050. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Moberg C, Bourlev V, Ilyasova N, Olovsson M. Endometrial expression of LIF and its receptor and peritoneal fluid levels of IL-1alpha and IL-6 in women with endometriosis are associated with the probability of pregnancy. Arch Gynecol Obstet. 2015;292:429–37. doi: 10.1007/s00404-015-3626-0. [DOI] [PubMed] [Google Scholar]
  • 10.Kang YJ, Jeung IC, Park A, Park YJ, Jung H, Kim TD, et al. An increased level of IL-6 suppresses NK cell activity in peritoneal fluid of patients with endometriosis via regulation of SHP-2 expression. Hum Reprod. 2014;29:2176–89. doi: 10.1093/humrep/deu172. [DOI] [PubMed] [Google Scholar]
  • 11.Keenan JA, Chen TT, Chadwell NL, Torry DS, Caudle MR. Interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) in peritoneal fluid and macrophage-conditioned media of women with endometriosis. Am J Reprod Immunol. 1994;32:180–3. doi: 10.1111/j.1600-0897.1994.tb01111.x. [DOI] [PubMed] [Google Scholar]
  • 12.Okamoto M, Nasu K, Abe W, Aoyagi Y, Kawano Y, Kai K, et al. Enhanced miR-210 expression promotes the pathogenesis of endometriosis through activation of signal transducer and activator of transcription 3. Hum Reprod. 2015;30:632–41. doi: 10.1093/humrep/deu332. [DOI] [PubMed] [Google Scholar]
  • 13.Hsiao KY, Chang N, Tsai JL, Lin SC, Tsai SJ, Wu MH. Hypoxia-inhibited DUSP2 expression promotes IL-6/STAT3 signaling in endometriosis. Am J Reprod Immunol. 2017 doi: 10.1111/aji.12690. [DOI] [PubMed] [Google Scholar]
  • 14.Yoo JY, Jeong JW, Fazleabas AT, Tayade C, Young SL, Lessey BA. Protein Inhibitor of Activated STAT3 (PIAS3) Is Down-Regulated in Eutopic Endometrium of Women with Endometriosis. Biol Reprod. 2016;95:11. doi: 10.1095/biolreprod.115.137158. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Garayoa M, Martinez A, Lee S, Pio R, An WG, Neckers L, et al. Hypoxia-inducible factor-1 (HIF-1) up-regulates adrenomedullin expression in human tumor cell lines during oxygen deprivation: a possible promotion mechanism of carcinogenesis. Mol Endocrinol. 2000;14:848–62. doi: 10.1210/mend.14.6.0473. [DOI] [PubMed] [Google Scholar]
  • 16.Maybin JA, Battersby S, Hirani N, Nikitenko LL, Critchley HO, Jabbour HN. The expression and regulation of adrenomedullin in the human endometrium: a candidate for endometrial repair. Endocrinology. 2011;152:2845–56. doi: 10.1210/en.2010-1256. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Lim SY, Ahn SH, Park H, Lee J, Choi K, Choi C, et al. Transcriptional regulation of adrenomedullin by oncostatin M in human astroglioma cells: implications for tumor invasion and migration. Sci Rep. 2014;4:6444. doi: 10.1038/srep06444. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Hsieh FC, Cheng G, Lin J. Evaluation of potential Stat3-regulated genes in human breast cancer. Biochem Biophys Res Commun. 2005;335:292–9. doi: 10.1016/j.bbrc.2005.07.075. [DOI] [PubMed] [Google Scholar]
  • 19.Matson BC, Caron KM. Adrenomedullin and endocrine control of immune cells during pregnancy. Cell Mol Immunol. 2014;11:456–9. doi: 10.1038/cmi.2014.71. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20.Lenhart PM, Caron KM. Adrenomedullin and pregnancy: perspectives from animal models to humans. Trends Endocrinol Metab. 2012;23:524–32. doi: 10.1016/j.tem.2012.02.007. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.Singh AK, Dutta M, Chattopadhyay R, Chakravarty B, Chaudhury K. Intrafollicular interleukin-8, interleukin-12, and adrenomedullin are the promising prognostic markers of oocyte and embryo quality in women with endometriosis. J Assist Reprod Genet. 2016;33:1363–72. doi: 10.1007/s10815-016-0782-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22.Morgenthaler NG, Struck J, Alonso C, Bergmann A. Measurement of midregional proadrenomedullin in plasma with an immunoluminometric assay. Clin Chem. 2005;51:1823–9. doi: 10.1373/clinchem.2005.051110. [DOI] [PubMed] [Google Scholar]
  • 23.Potocki M, Ziller R, Mueller C. Mid-regional pro-adrenomedullin in acute heart failure: a better biomarker or just another biomarker? Curr Heart Fail Rep. 2012;9:244–51. doi: 10.1007/s11897-012-0096-6. [DOI] [PubMed] [Google Scholar]
  • 24.Liu D, Xie L, Zhao H, Liu X, Cao J. Prognostic value of mid-regional pro-adrenomedullin (MR-proADM) in patients with community-acquired pneumonia: a systematic review and meta-analysis. BMC Infect Dis. 2016;16:232. doi: 10.1186/s12879-016-1566-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Christ-Crain M, Morgenthaler NG, Struck J, Harbarth S, Bergmann A, Muller B. Mid-regional pro-adrenomedullin as a prognostic marker in sepsis: an observational study. Crit Care. 2005;9:R816–24. doi: 10.1186/cc3885. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Matson BC, Corty RW, Karpinich NO, Murtha AP, Valdar W, Grotegut CA, et al. Midregional pro-adrenomedullin plasma concentrations are blunted in severe preeclampsia. Placenta. 2014;35:780–3. doi: 10.1016/j.placenta.2014.07.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Sugulle M, Herse F, Seiler M, Dechend R, Staff AC. Cardiovascular risk markers in pregnancies complicated by diabetes mellitus or preeclampsia. Pregnancy Hypertens. 2012;2:403–10. doi: 10.1016/j.preghy.2012.03.002. [DOI] [PubMed] [Google Scholar]
  • 28.Li M, Wu Y, Caron KM. Haploinsufficiency for adrenomedullin reduces pinopodes and diminishes uterine receptivity in mice. Biol Reprod. 2008;79:1169–75. doi: 10.1095/biolreprod.108.069336. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Pawar S, Starosvetsky E, Orvis GD, Behringer RR, Bagchi IC, Bagchi MK. STAT3 regulates uterine epithelial remodeling and epithelial-stromal crosstalk during implantation. Mol Endocrinol. 2013;27:1996–2012. doi: 10.1210/me.2013-1206. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Catalano RD, Johnson MH, Campbell EA, Charnock-Jones DS, Smith SK, Sharkey AM. Inhibition of Stat3 activation in the endometrium prevents implantation: a nonsteroidal approach to contraception. Proc Natl Acad Sci U S A. 2005;102:8585–90. doi: 10.1073/pnas.0502343102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Li M, Yee D, Magnuson TR, Smithies O, Caron KM. Reduced maternal expression of adrenomedullin disrupts fertility, placentation, and fetal growth in mice. J Clin Invest. 2006;116:2653–62. doi: 10.1172/JCI28462. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Joosen A, van der Linden IJM, Schrauwen L, Theeuwes A, de Groot MJM, Ermens AAM. Reference intervals and longitudinal changes in copeptin and MR-proADM concentrations during pregnancy. Clin Chem Lab Med. 2017 doi: 10.1515/cclm-2017-0110. [DOI] [PubMed] [Google Scholar]
  • 33.Kitawaki J, Kado N, Ishihara H, Koshiba H, Kitaoka Y, Honjo H. Endometriosis: the pathophysiology as an estrogen-dependent disease. J Steroid Biochem Mol Biol. 2002;83:149–55. doi: 10.1016/s0960-0760(02)00260-1. [DOI] [PubMed] [Google Scholar]
  • 34.Watanabe H, Takahashi E, Kobayashi M, Goto M, Krust A, Chambon P, et al. The estrogen-responsive adrenomedullin and receptor-modifying protein 3 gene identified by DNA microarray analysis are directly regulated by estrogen receptor. J Mol Endocrinol. 2006;36:81–9. doi: 10.1677/jme.1.01825. [DOI] [PubMed] [Google Scholar]
  • 35.Miller JE, Ahn SH, Monsanto SP, Khalaj K, Koti M, Tayade C. Implications of immune dysfunction on endometriosis associated infertility. Oncotarget. 2017;8:7138–47. doi: 10.18632/oncotarget.12577. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Hofbauer KH, Schoof E, Kurtz A, Sandner P. Inflammatory cytokines stimulate adrenomedullin expression through nitric oxide-dependent and -independent pathways. Hypertension. 2002;39:161–7. doi: 10.1161/hy1201.097201. [DOI] [PubMed] [Google Scholar]
  • 37.Grandi G, Toss A, Cortesi L, Botticelli L, Volpe A, Cagnacci A. The Association between Endometriomas and Ovarian Cancer: Preventive Effect of Inhibiting Ovulation and Menstruation during Reproductive Life. Biomed Res Int. 2015;2015:751571. doi: 10.1155/2015/751571. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Zhang Y, Xu Y, Ma J, Pang X, Dong M. Adrenomedullin promotes angiogenesis in epithelial ovarian cancer through upregulating hypoxia-inducible factor-1alpha and vascular endothelial growth factor. Sci Rep. 2017;7:40524. doi: 10.1038/srep40524. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 39.Chen Q, Chen P, Pang X, Hu Y, Zhang Y. Adrenomedullin Up-regulates the Expression of Vascular Endothelial Growth Factor in Epithelial Ovarian Carcinoma Cells via JNK/AP-1 Pathway. Int J Gynecol Cancer. 2015;25:953–60. doi: 10.1097/IGC.0000000000000465. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 40.Caron KM, Smithies O. Multiple roles of adrenomedullin revealed by animal models. Microsc Res Tech. 2002;57:55–9. doi: 10.1002/jemt.10046. [DOI] [PubMed] [Google Scholar]
  • 41.Wetzel-Strong SE, Li M, Klein KR, Nishikimi T, Caron KM. Epicardial-derived adrenomedullin drives cardiac hyperplasia during embryogenesis. Dev Dyn. 2014;243:243–56. doi: 10.1002/dvdy.24065. [DOI] [PMC free article] [PubMed] [Google Scholar]

RESOURCES