From bench to bedside: The promise of sotatercept in hematologic disorders

Sotatercept (ACE-011) is an activin receptor IIA-Fc (ActRIIA-Fc) fusion protein currently under investigation for its potential in the treatment of hematologic diseases. By impeding the activities of the overexpressed growth and differentiation factor 11 (GDF11), activin A, and other members of the transforming growth factor-β (TGF-β) superfamily, commonly found in hematologic disorders, sotatercept aims to restore the normal functioning of red blood cell maturation and osteoblast differentiation. This action is anticipated to enhance anemia management and hinder the progression of myeloma. Simultaneously, comprehensive research is ongoing to investigate sotatercept's pharmacokinetics and potential adverse reactions, thus laying a robust foundation for its prospective clinical use. In this review, we provide a detailed overview of TGF-β pathways in physiological and hematologic disorder contexts, outline the potential mechanism of sotatercept, and delve into its pharmacokinetics and clinical research advancements in various hematologic diseases. A particular emphasis is given to the relationship between sotatercept dosage and its efficacy or associated adverse reactions.

Sphingosine 1-phosphate receptors are dysregulated in endometriosis: possible implication in transforming growth factor β-induced fibrosis

OBJECTIVE

To study the molecular mechanisms involved in the appearance of the fibrotic trait in endometriosis by investigating whether the signaling pathway of the bioactive sphingolipid sphingosine 1-phosphate (S1P) was altered in endometriotic lesions.

DESIGN

Case-control laboratory study.

SETTING

University research institute and university hospital.

PATIENT(S)

A total of 75 women, with and without endometriosis, were included in the study.

INTERVENTIONS(S)

Endometrial samples were obtained from women affected (n = 15 endometrioma [OMA]; n = 30 deep infiltrating endometriosis [DIE]) and not (n = 30) by endometriosis by means of laparoscopic surgery, followed by clinical and imaging investigation and checking for the expression of fibrosis markers and genes implicated in S1P metabolism and signaling by means of real-time polymerase chain reaction.

MAIN OUTCOME MEASURE(S)

The role of the S1P signaling axis in endometriosis-associated fibrosis was studied in vitro, where RNA interference approaches were used to investigate if S1P synthesis by sphingosine kinases (SKs) and specific S1P receptors (S1PRs) are implicated in the profibrotic effect of the cytokine transforming growth factor (TGF) β1.

RESULT(S)

mRNA expression analysis of S1PR demonstrated a deep dysregulation of S1P signaling in endometriosis, characterized by increased expression of fibrosis markers: S1P₁ was transcriptionally more expressed in OMA, and S1P₃ and S1P₅ mRNA levels were significantly augmented in both OMA and DIE. SK1 and its activating protein calcium- and integrin-binding protein 1 (CIB1) were significantly up-regulated in OMA and DIE. A crucial role for the SK/S1PR axis in the profibrotic effect elicited by TGFβ1 was highlighted in vitro.

CONCLUSION(S)

The S1P signaling axis may represent a useful biomarker or innovative pharmacologic target for endometriosis.

Computational analysis for identification of the extracellular matrix molecules involved in endometrial cancer progression

Recurrence and poorly differentiated (grade 3 and above) and atypical cell type endometrial cancer (EC) have poor prognosis outcome. The mechanisms and characteristics of recurrence and distal metastasis of EC remain unclear. The extracellular matrix (ECM) of the reproductive tract in women undergoes extensive structural remodelling changes every month. Altered ECMs surrounding cells were believed to play crucial roles in a cancer progression. To decipher the associations between ECM and EC development, we generated a PAN-ECM Data list of 1516 genes including ECM molecules (ECMs), synthetic and degradation enzymes for ECMs, ECM receptors, and soluble molecules that regulate ECM and used RNA-Seq data from The Cancer Genome Atlas (TCGA) for the studies. The alterations of PAN-ECM genes by comparing the RNA-Seq expressions profiles of EC samples which have been grouped as tumorigenesis and metastasis group based on their pathological grading were identified. Differential analyses including functional enrichment, co-expression network, and molecular network analysis were carried out to identify the specific PAN-ECM genes that may involve in the progression of EC. Eight hundred and thirty-one and 241 PAN-ECM genes were significantly involved in tumorigenesis (p-value <1.571e-15) and metastasis (p-value <2.2e-16), respectively, whereas 140 genes were in the intersection of tumorigenesis and metastasis. Interestingly, 92 of the 140 intersecting PAN-ECM genes showed contrasting fold changes between the tumorigenesis and metastasis datasets. Enrichment analysis for the contrast PAN-ECM genes indicated pathways such as GP6 signaling, ILK signaling, and interleukin (IL)-8 signaling pathways were activated in metastasis but inhibited in tumorigenesis. The significantly activated ECM and ECM associated genes in GP6 signaling, ILK signaling, and interleukin (IL)-8 signaling pathways may play crucial roles in metastasis of EC. Our study provides a better understanding of the etiology and the progression of EC.

Expression and Role of Peptides, Proteins and Growth Factors in the Pathogenesis of Endometriosis

Growing evidence is demonstrating that several peptides (corticotrophin-releasing factor, urocortins, ghrelin), proteins (leptin, adiponectin) and growth factors (vascular endothelial growth factor; epidermal growth factor family of growth factors and receptors, fibroblast growth factor, insulin like growth factor and insulin like growth factor-binding proteins, transforming growth factor-β and, activin A and related proteins) are expressed in endometriotic implants, and locally play a relevant role in affecting the biological mechanisms leading to endometriosis. They establish a complex network of interactions by which they are therefore able to stimulate angiogenesis, inflammatory cell recruitment and reaction, the growth of endometriotic tissue and its survival through the modulation of the narrow immune system. This review will evaluate the role played by several regulatory peptides, proteins and growth factors in affecting endometrial physiology and the putative mechanisms advocated to explain endometriosis (angiogenesis, cellular and humoral immunity, inflammatory response, endometrial cell proliferation, activation, motility, adhesion and invasion).

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

Serum markers for the noninvasive diagnosis of endometriosis

Endometriosis is a disease that affects millions of women worldwide and its diagnosis is still challenging. Medical history, symptoms together with imaging data may address the correct diagnosis, but the gold standard remains laparoscopic assessment with histological confirmation. The development of serum markers as diagnostic tools for endometriosis may allow a prompt and noninvasive diagnosis. Several serum biomarkers have been investigated over the years, but none of these have shown a clinical utility and nowadays the more realistic diagnostic biomarker consists in a panel of biomarkers. The recent introduction of new technologies such as genomics and proteomics may represent the future perspective of endometriosis diagnosis.

The role of TGFβ superfamily members in the pathophysiology of endometriosis

The transforming growth factor-beta (TGFβ) superfamily comprises over 30 dimeric proteins with conserved structures, which play important roles in the control of cellular proliferation, differentiation and apoptosis. These proteins are expressed and finely regulated in human endometrium during the menstrual cycle, which is consistent with their effects on endometrial cell proliferation and tissue remodeling. This review is focused on summarizing the role of key members of the TGFβ superfamily in the pathophysiology of endometriosis. Evidence suggests that TGFβ, activins, inhibins, nodal, bone morphogenetic proteins, growth differentiation factors, and anti-Müllerian hormone are produced by endometriotic lesions and could be involved in the establishment and progression of the disease. Their receptors and signaling pathways may also be altered in the presence of endometriosis and may be potential targets to the development of therapeutic agents.

Expression of Nodal, Cripto, SMAD3, phosphorylated SMAD3, and SMAD4 in the proliferative endometrium of women with endometriosis

BACKGROUND

Nodal is a growth factor of the transforming growth factor β superfamily that is expressed in high turnover tissues, such as the human endometrium, and in several malignancies. The effects of Nodal are modulated by the coreceptor Cripto and mediated by SMAD proteins. This study evaluated the gene and protein expression of Nodal, Cripto, total and phosphorylated (p) SMAD3, and SMAD4 in the proliferative endometrium of women with and without endometriosis.

METHOD

Total RNA was isolated and complementary DNA synthesized from eutopic endometrium of women with (n = 15) and without (n = 12) endometriosis, followed by quantitative real-time polymerase chain reaction (PCR) to evaluate the gene expression of Nodal, Cripto, SMAD3, and SMAD4. Western blot was used to evaluate the protein levels of Nodal and Cripto, and immunohistochemistry was performed to localize SMAD3, pSMAD3, and SMAD4.

RESULTS

Although Nodal expression was unchanged in women with endometriosis, real-time PCR indicated lower gene expression of Cripto (fold change 0.27, P < .05) in the endometriosis group. This difference, however, was not maintained at protein expression level as assessed by Western blot. The immunostaining of total SMAD3 was reduced in the endometriosis group (P < .01), but the localization of pSMAD3 and the nuclear staining of SMAD4 were unchanged.

CONCLUSION

These findings suggest that the Nodal signaling pathway has subtle changes in the endometrium of women with endometriosis, but this imbalance may not cause functional damage as it seems not to affect the nuclear expression of SMAD4.

Endogenous protection derived from activin A/Smads transduction loop stimulated via ischemic injury in PC12 cells

Activin A (ActA), a member of transforming growth factor-beta (TGF-b) super- family, affects many cellular processes, including ischemic stroke. Though the neuroprotective effects of exogenous ActA on oxygen-glucose deprivation (OGD) injury have already been reported by us, the endogenous role of ActA remains poorly understood. To further define the role and mechanism of endogenous ActA and its signaling in response to acute ischemic damage, we used an OGD model in PC12 cells to simulate ischemic injury on neurons in vitro. Cells were pre-treated by monoclonal antibody against activin receptor type IIA (ActRII-Ab). We found that ActRII-Ab augments ischemic injury in PC12 cells. Further, the extracellular secretion of ActA as well as phosphorylation of smad3 in PC12 cells was also up-regulated by OGD, but suppressed by ActRII-Ab. Taken together, our results show that ActRII-Ab may augment ischemic injury via blocking of transmembrane signal transduction of ActA, which confirmed the existence of endogenous neuroprotective effects derived from the ActA/Smads pathway. ActRIIA plays an important role in transferring neuronal protective signals inside. It is highly possible that ActA transmembrance signaling is a part of the positive feed-back loop for extracellular ActA secretion.

NODAL signaling components regulate essential events in the establishment of pregnancy

Successful mammalian reproduction is dependent on a receptive and nurturing uterine environment. In order to establish pregnancy in humans, the uterus must i) be adequately prepared to receive the blastocyst, ii) engage in a coordinated molecular dialog with the embryo to facilitate implantation, and iii) undergo endometrial decidualization. Although numerous factors have been implicated in these essential processes, the precise network of molecular interactions that govern receptivity, embryo implantation, and decidualization remain unclear. NODAL, a morphogen in the transforming growth factor β superfamily, is well known for its critical functions during embryogenesis; however, recent studies have demonstrated an emerging role for NODAL signaling during early mammalian reproduction. Here, we review the established data and a recent wave of new studies implicating NODAL signaling components in uterine cycling, embryo implantation, and endometrial decidualization in humans and mice.

Follistatin is induced by IL-1β and TNF-α in stromal cells from endometrioma

The aim of this study is to examine the regulation of follistatin, an activin-binding protein, in endometriosis. Endometrioma stromal cells (EoSCs) were obtained from 9 patients undergoing laparoscopy of the ovarian endometrioma. In cultured EoSCs, interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α), which could induce activin-A, also induced follistatin messenger RNA (mRNA) and protein. The cystic fluid of endometrioma from 8 patients was obtained to measure the concentration of activin-A and follistatin by enzyme-linked immunosorbent assay (ELISA). Also, activin activity in the fluid was examined by erythroid differentiation assay using mouse erythroleukemia F5-5.fl cells. In the cystic fluid of endometrioma, the mean values of activin-A and follistatin concentration were 36.8 ng/mL and 4.0 ng/mL, respectively. In a bioassay, all 8 samples exhibited activin activity, which was equivalent to recombinant activin-A activity of 12.8 ± 1.4 ng/mL. Although follistatin was present in the cystic fluid of endometrioma, the activity of activin, which is an exacerbation factor of endometriosis, was predominant in vivo.

Expression and localization of nodal in bovine oviduct and uterus during different functional stages of oestrus cycle and pregnancy

Members of TGF-β superfamily play a major role in the endometrial changes involved in the establishment and maintenance of pregnancy. Their deregulated expression and action could lead to absolute or partial failure of embryo implantation. Nonetheless, the precise function and mechanism of many of these cytokines remain unclear. Nodal, a transforming growth factor beta (TGF-β) superfamily member, was characterized in the human and rodent uterus and implicated in the tissue remodeling events during menstruation and embryo implantation. In order to study its possible role in the cattle reproductive process, we have analyzed Nodal expression pattern and localization in the oviduct and uterine horn during the oestrus cycle and early pregnancy (day 20). Nodal was detected both in oviduct and uterus during either the oestrus cycle or pregnancy; however, it shows a differential expression profile in the uterine horn at dioestrus and pregnancy, decreasing 1.5 and 1.4 folds in comparison with oestrus. Nodal immunostaining intensity was observed in stromal and in epithelial cells of the surface and the glandular epithelium. The staining pattern correlates with the RT-qPCR expression profile. This work is the first to evidence the presence of Nodal in the bovine reproductive tract; our data suggest that Nodal is a novel cytokine that would be involved in the remodelling occurring in the endometrium of cattle during the oestrus cycle and in the embryo implantation. The identification of new molecules that participate in endometrium cycling and/or pregnancy may be useful for predicting the ability of the uterine tissue to establish and maintain pregnancy or for detecting the infertility processes. These results highlight Nodal as a possible novel marker of the fertility process, nevertheless further studies should be done to determine its role in the reproductive system.

Cripto/GRP78 modulation of the TGF-β pathway in development and oncogenesis

Cripto is a small, GPI-anchored signaling protein that regulates cellular survival, proliferation, differentiation and migration during normal developmental processes and tumorigenesis. Cripto functions as an obligatory co-receptor for the TGF-β ligands Nodal, GDF1 and GDF3 but attenuates signaling of others such as activin-A, activin-B and TGF-β1. Soluble, secreted forms of Cripto also activate Src, ras/raf/MAPK and PI3K/Akt pathways via a mechanism that remains largely obscure. This review describes the biological roles and signaling mechanisms of Cripto, highlighting our identification of the 78 kDa glucose regulated protein (GRP78) as a cell surface receptor/co-factor required for Cripto signaling via both TGF-β and Src/MAPK/PI3K pathways. We discuss emerging evidence indicating that Cripto/GRP78 signaling regulates normal somatic stem cells and their tumorigenic counterparts.

Activin-A is induced by interleukin-1β and tumor necrosis factor-α and enhances the mRNA expression of interleukin-6 and protease-activated receptor-2 and proliferation of stromal cells from endometrioma

OBJECTIVE

To examine the regulation and the function of activin-A in stromal cells derived from endometrioma.

DESIGN

Molecular studies.

SETTING

University research laboratory.

PATIENT(S)

Endometrioma stromal cells (EoSC) were obtained from 28 patients with ovarian endometrioma undergoing laparoscopy.

INTERVENTION(S)

EoSC were cultured with inflammatory stimuli or recombinant activin-A, followed by RNA extraction.

MAIN OUTCOME MEASURE(S)

Activin mRNA expression was evaluated by real-time reverse transcription-polymerase chain reaction (RT-PCR), and activin-A concentration of supernatant of cultured EoSC was evaluated by ELISA. Also, the effect of activin-A on EoSC was evaluated with real-time RT-PCR and cell proliferation assay.

RESULT(S)

Inflammatory stimuli, interleukin (IL) -1β, and tumor necrosis factor (TNF) -α induced inhibin/activin-βA subunit mRNA and activin-A protein expression in EoSC. Additionally, activin-A enhanced EoSC proliferation and increased the expression of IL-6 and protease-activated receptor (PAR)-2 mRNA.

CONCLUSION(S)

An in vitro study revealed that activin-A, which is induced by IL-1β or TNF-α, might promote endometriosis by stimulating IL-6 and PAR-2 mRNA expression and increasing the proliferation of EoSC.

Cytokine array analysis of peritoneal fluid between women with endometriosis of different stages and those without endometriosis

Cytokines are key mediators of intercellular communication and are likely to promote the development and progression of endometriosis. Previous studies provided evidence that endometriosis develops as a result of the pathogenetic factors in the peritoneal environment, especially the peritoneal fluid (PF). We determined different cytokine expression in peritoneal fluid between women with minimal/mild and moderate/severe endometriosis and those without endometriosis using the cytokine array. As a result, 78 cytokines were found to have a threefold change, including 74 increases and four decreases in endometriosis compared with the control group; 96 cytokines had a threefold change including 91 increases and five decreases in minimal and mild endometriosis compared with the control group; 83 cytokines had a threefold change including 14 increases and 69 decreases in moderate and severe endometriosis compared with minimal and mild endometriosis. The cytokine networks were produced by Pathway Studio software and revealed that most cytokines are involved in cell binding, interaction and protein synthesis and transportation regulation. Among them activin A, Smad7 and beta-nerve growth factor are the most interesting as they may be involved in the pathogenesis of endometriosis. These results suggest that cytokines are very important factors in the development of endometriosis. The findings of differentially expressed cytokines improves our knowledge of the pathogenesis and development of endometriosis and these findings warrant further studies to develop potential targets for the diagnosis and treatment of endometriosis.

Expression of nodal signalling components in cycling human endometrium and in endometrial cancer

BACKGROUND

The human endometrium is unique in its capacity to remodel constantly throughout adult reproductive life. Although the processes of tissue damage and breakdown in the endometrium have been well studied, little is known of how endometrial regeneration is achieved after menstruation. Nodal, a member of the transforming growth factor-beta superfamily, regulates the processes of pattern formation and differentiation that occur during early embryo development.

METHODS

In this study, the expression of Nodal, Cripto (co-receptor) and Lefty A (antagonist) was examined by RT-PCR and immunohistochemistry across the menstrual cycle and in endometrial carcinomas.

RESULTS

Nodal and Cripto were found to be expressed at high levels in both stromal and epithelial cells during the proliferative phase of the menstrual cycle. Although immunoreactivity for both proteins in surface and glandular epithelium was maintained at relatively steady-state levels across the cycle, their expression was significantly decreased within the stromal compartment by the mid-secretory phase. Lefty expression, as has previously been reported, was primarily restricted to glandular epithelium and surrounding stroma during the late secretory and menstrual phases. In line with recent studies that have shown that Nodal pathway activity is upregulated in many human cancers, we found that Nodal and Cripto immunoreactivity increased dramatically in the transition from histologic Grade 1 to histologic Grades 2 and 3 endometrial carcinomas. Strikingly, Lefty expression was low or absent in all cancer tissues.

CONCLUSION

The expression of Nodal in normal and malignant endometrial cells that lack Lefty strongly supports an important role for this embryonic morphogen in the tissue remodelling events that occur across the menstrual cycle and in tumourogenesis.