KLF11 epigenetically regulates glycodelin-A, a marker of endometrial biology via histone-modifying chromatin mechanisms

Pathways regulating the expression of the immunomodulatory protein glycodelin in non‑small cell lung cancer

Glycodelin [gene name, progesterone associated endometrial protein (PAEP)] was initially described as an immune system modulator in reproduction. Today, it is also known to be expressed in several types of cancer, including non‑small cell lung cancer (NSCLC). In this cancer type, the feasibility of its usage as a follow‑up biomarker and its potential role as an immune system modulator were described. It is assumed that NSCLC tumours secrete glycodelin to overcome immune surveillance. Therefore, targeting glycodelin might be a future approach with which to weaken the immune system defence of NSCLC tumours. In this context, it is important to understand the regulatory pathways of PAEP/glycodelin expression, as these are mostly unknown so far. In this study, we analysed the influence of several inducers and of their downstream pathways on PAEP/glycodelin expression in a human lung adenocarcinoma carcinoma (ADC; H1975) and a human lung squamous cell carcinoma (SQCC) cell line (2106T). PAEP/glycodelin expression was notably stimulated by the canonical transforming growth factor (TGF)‑β pathway in SQCC cells and the PKC signalling cascade in both cell lines. The PI3K/AKT pathway inhibited PAEP/glycodelin expression in the ADC cells and an antagonizing role towards the other investigated signalling cascades is suggested herein. Furthermore, the mitogen‑activated protein kinase kinase (MEK)/extracellular‑signal regulated kinases (ERK) pathway was, to a lesser extent, found to be associated with increased PAEP/glycodelin amounts. The phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT), MEK/ERK pathway and TGF‑β are targets of NSCLC drugs that are already approved or are currently under investigation. On the whole, the findings of this study provide evidence that inhibiting these targets affects the expression of glycodelin and its immunosuppressive effect in NSCLC tumours. Moreover, understanding the regulation of glycodelin expression may lead to the development of novel therapeutic approaches with which to weaken the immune system defence of NSCLC tumours in the future.

Epigenetic Therapy: Novel Translational Implications for Arrest of Environmental Dioxin-Induced Disease in Females

Increased toxicant exposure and resultant environmentally induced diseases are a tradeoff of industrial productivity. Dioxin [2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)], a ubiquitous byproduct, is associated with a spectrum of diseases including endometriosis, a common, chronic disease in women. TCDD activates cytochrome (CYP) p450 metabolic enzymes that alter organ function to cause disease. In contrast, the transcription factor, Krüppel-like factor (KLF) 11, represses these enzymes via epigenetic mechanisms. In this study, we characterized these opposing mechanisms in vitro and in vivo as well as determining potential translational implications of epigenetic inhibitor therapy. KLF11 antagonized TCDD-mediated activation of CYP3A4 gene expression and function in endometrial cells. The repression was pharmacologically replicated by selective use of an epigenetic histone acetyltransferase inhibitor (HATI). We further showed phenotypic relevance of this mechanism using an animal model for endometriosis. Fibrotic extent in TCDD-exposed wild-type animals was similar to that previously observed in Klf11-/- animals. When TCDD-exposed animals were treated with a HATI, Cyp3 messenger RNA levels and protein expression decreased along with disease progression. Fibrotic progression is ubiquitous in environmentally induced chronic, untreatable diseases; this report shows that relentless disease progression can be arrested through targeted epigenetic modulation of protective mechanisms.

Emerging role for dysregulated decidualization in the genesis of preeclampsia

In normal human placentation, uterine invasion by trophoblast cells and subsequent spiral artery remodeling depend on cooperation among fetal trophoblasts and maternal decidual, myometrial, immune and vascular cells in the uterine wall. Therefore, aberrant function of anyone or several of these cell-types could theoretically impair placentation leading to the development of preeclampsia. Because trophoblast invasion and spiral artery remodeling occur during the first half of pregnancy, the molecular pathology of fetal placental and maternal decidual tissues following delivery may not be informative about the genesis of impaired placentation, which transpired months earlier. Therefore, in this review, we focus on the emerging prospective evidence supporting the concept that deficient or defective endometrial maturation in the late secretory phase and during early pregnancy, i.e., pre-decidualization and decidualization, respectively, may contribute to the genesis of preeclampsia. The first prospectively-acquired data directly supporting this concept were unexpectedly revealed in transcriptomic analyses of chorionic villous samples (CVS) obtained during the first trimester of women who developed preeclampsia 5 months later. Additional supportive evidence arose from investigations of Natural Killer cells in first trimester decidua from elective terminations of women with high resistance uterine artery indices, a surrogate for deficient trophoblast invasion. Last, circulating insulin growth factor binding protein-1, which is secreted by decidual stromal cells was decreased during early pregnancy in women who developed preeclampsia. We conclude this review by making recommendations for further prospectively-designed studies to corroborate the concept of endometrial antecedents of preeclampsia. These studies could also enable identification of women at increased risk for developing preeclampsia, unveil the molecular mechanisms of deficient or defective (pre)decidualization, and lead to preventative strategies designed to improve (pre)decidualization, thereby reducing risk for preeclampsia development.

Investigation on the ability of first trimester glycodelin and angiopoietin-2 to predict small-for-gestational age pregnancies at delivery

BACKGROUND

The aim was to investigate whether first trimester glycodelin and angiopoietin-2 can predict small-for-gestational age (SGA) at delivery, individually or in combination.

METHODS

In this case-control study we measured glycodelin and angiopoietin-2 on serum from 170 singleton pregnant women delivering SGA neonates and 985 singleton pregnant women delivering normal-weighted neonates. All values were converted to multiples of the medians (MoM).

RESULTS

Pregnant women delivering SGA neonates had lower first trimester glycodelin and angiopoietin-2 MoM values [median (interquartile range)] compared with pregnant women delivering normal-weighted neonates for glycodelin: 0.86 (0.58-1.24) vs. 1.03 (0.74-1.45), p<0.001, and for angiopoietin-2: 0.89 (0.69-1.19) vs. 1.01 (0.78-1.31), p<0.001. The prediction performances of the biomarkers showed that the areas under the curve (AUC) were 0.59 (glycodelin), 0.58 (angiopoietin-2), and 0.60 (glycodelin and angiopoietin-2).

CONCLUSIONS

We demonstrated that first trimester glycodelin and angiopoietin-2 were associated with SGA, but they were, individually and in combination, poor predictors of SGA at delivery. The AUCs were low which indicate low detection rates and high false positive rates.

TGF-β Induces Endometriotic Progression via a Noncanonical, KLF11-Mediated Mechanism

Endometriosis, a chronic disease of heterogeneous etiopathology affects 10% of young women and is characterized by ectopic implantation of endometrial cells. Growth and spread of endometriosis lesions involves biological interplay between intrinsic lesion-driven and extrinsic host-responsive mechanisms. We propose a role for TGFβ and its target transcription factor Krüppel-like factor 11 (KLF11) in mediating such mechanisms. Although TGFβ, a pleiotropic cytokine implicated in endometriosis potentially, mediates its pathological phenotypes, KLF11 is associated with endocrine and reproductive tract diseases, specifically progression of endometriosis. In Ishikawa cells, TGFβ1 treatment resulted in noncanonical SMAD-mediated transient up-regulation and sustained repression of KLF11. KLF11 recruits histone deacetylases to epigenetically repress multiple synthetic and metabolic cytochrome P450 (CYP) enzymes such as CYP3A4, which affects endometrial metabolism and pathophysiology. In contrast to KLF11, TGFβ1 treatment caused transient repression and sustained activation of CYP3A4 expression. CYP3A4 increased endometrial cell proliferation and was also increased in human endometriosis lesions compared with eutopic endometrium. To determine whether dysregulation of TGFβ/Klf11/Cyp3a signaling affected endometriotic progression, we treated wild-type control and Klf11-/- mice with a Tgfβ type 1 receptor inhibitor (TGFβR1I) that inhibits Tgfβ signaling upstream of the canonical Smad proteins or a combination of TGFβR1I and a histone acetyltransferase inhibitor that additionally inhibits Klf11 signaling. Disease progression and lesional Cyp3a expression was diminished in TGFβR1I-treated animals and more so in animals treated synergistically with TGFβR1I and histone acetyltransferase inhibitor. TGFβ and KLF11 thus mediate critical, translationally relevant host and lesion-driven responses that enable establishment and progression of endometriosis.

KLF10 Mediated Epigenetic Dysregulation of Epithelial CD40/CD154 Promotes Endometriosis

Endometriosis is a highly prevalent, chronic, heterogeneous, fibro-inflammatory disease that remains recalcitrant to conventional therapy. We previously showed that loss of KLF11, a transcription factor implicated in uterine disease, results in progression of endometriosis. Despite extensive homology, co-expression, and human disease association, loss of the paralog Klf10 causes a unique inflammatory, cystic endometriosis phenotype in contrast to fibrotic progression seen with loss of Klf11. We identify here for the first time a novel role for KLF10 in endometriosis. In an animal endometriosis model, unlike wild-type controls, Klf10^−/− animals developed cystic lesions with massive immune infiltrate and minimal peri-lesional fibrosis. The Klf10^−/− disease progression phenotype also contrasted with prolific fibrosis and minimal immune cell infiltration seen in Klf11^−/− animals. We further found that lesion genotype rather than that of the host determined each unique disease progression phenotype. Mechanistically, KLF10 regulated CD40/CD154-mediated immune pathways. Both inflammatory as well as fibrotic phenotypes are the commonest clinical manifestations in chronic fibro-inflammatory diseases such as endometriosis. The complementary, paralogous Klf10 and Klf11 models therefore offer novel insights into the mechanisms of inflammation and fibrosis in a disease-relevant context. Our data suggests that divergence in underlying gene dysregulation critically determines disease-phenotype predominance rather than the conventional paradigm of inflammation being precedent to fibrotic scarring. Heterogeneity in clinical progression and treatment response are thus likely from disparate gene regulation profiles. Characterization of disease phenotype-associated gene dysregulation offers novel approaches for developing targeted, individualized therapy for recurrent and recalcitrant chronic disease.

Epigenetic regulation of uterine biology by transcription factor KLF11 via posttranslational histone deacetylation of cytochrome p450 metabolic enzymes

Endocrine regulation of uterine biology is critical for embryo receptivity and human reproduction. Uterine endometrium depends on extrinsic sex steroid input and hence likely has mechanisms that enable adaptation to hormonal variation. Emerging evidence suggests that sex steroid bioavailability in the endometrium is determined by adjusting their metabolic rate and fate via regulation of cytochrome (CYP) p450 enzymes. The CYP enzymes are targeted by ubiquitously expressed Sp/Krüppel-like (Sp/KLF) transcription factors. Specifically, KLF11 is highly expressed in reproductive tissues, regulates an array of endocrine/metabolic pathways via epigenetic histone-based mechanisms and, when aberrantly expressed, is associated with diabetes and reproductive tract diseases, such as leiomyoma and endometriosis. Using KLF11 as a model to investigate epigenetic regulation of endometrial first-pass metabolism, we evaluated the expression of a comprehensive array of metabolic enzymes in Ishikawa cells. KLF11 repressed most endometrial CYP enzymes. To characterize KLF11-recruited epigenetic regulatory mechanisms, we focused on the estrogen-metabolizing enzyme CYP3A4. KLF11 expression declined in secretory phase endometrial epithelium associated with increased CYP3A4 expression. Additionally, KLF11 bound to CYP3A4 promoter GC elements and thereby repressed promoter, message, protein as well as enzymatic function. This repression was epigenetically mediated, because KLF11 colocalized with and recruited the corepressor SIN3A/histone deacetylase resulting in selective deacetylation of the CYP3A4 promoter. Repression was reversed by a mutation in KLF11 that abrogated cofactor recruitment and binding. This repression was also pharmacologically reversible with an histone deacetylase inhibitor. Pharmacological alteration of endometrial metabolism could have long-term translational implications on human reproduction and uterine disease.