Host immunity and KLF 11 deficiency together promote fibrosis in a mouse model of endometriosis.

BACKGROUND: Endometriosis is a debilitating disease typically characterized by prolific fibrotic scarring. Earlier we reported downregulation of two transcription factors belonging TGF-ßR signaling pathway Sp/Krüppel-like factor 11 (KLF11) and 10 (KLF10) in human endometriosis lesions. Here we investigated the role of these nuclear factors and immunity in the scaring fibrosis associated with endometriosis. METHODS: We used a well characterized experimental mouse model of endometriosis. WT, KLF10 or KLF11 deficient mice were compared. The lesions were evaluated histologically, fibrosis was quantified with Masons' Trichome staining, immune-infiltrates were quantified by immunohistochemistry, peritoneal adhesions were score, gene expression was evaluated by bulk RNA sequencing. RESULTS: Intense fibrotic reactions and large changes in gene expression were detected in KLF11 deficient implants associated with squamous metaplasia of the ectopic endometrium, as compared to KLF10 deficient or WT implants. Fibrosis was mitigated with pharmacologic agents that blocked histone acetylation or TGF-ßR signaling or with genetic deficiency for SMAD3. The lesions were richly infiltrated with T-cells, regulatory T-cells, and innate immune cells. Fibrosis was exacerbated when implants expressed ectopic genes implicating autoimmunity as a major factor contributing to the scaring fibrosis. CONCLUSIONS: Our findings identify KLF11 and TGF-ßR signaling as cell intrinsic mechanisms and autoimmune responses as cell extrinsic mechanisms of scaring fibrosis in ectopic endometrium lesions. GENERAL SIGNIFICANCE: Immunological factors associated with inflammation and tissue repair drive scaring fibrosis in experimental endometriosis, providing the rationale for immune therapy of endometriosis.

Is there still a role for a cleavage-stage embryo transfer?

OBJECTIVE: To determine whether pregnancy outcomes are poor or futile when an intended day 5 transfer is converted to a cleavage-stage transfer because of poor embryo development or a lower number of embryos. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENTS: Women with a limited number of embryos, defined as ≤6 two pronuclear embryos, after in vitro fertilization. INTERVENTIONS: Patients who had a cleavage-stage transfer were age matched with patients who had a day 5 transfer. MAIN OUTCOME MEASURES: Live birth rate. RESULTS: A total of 146 women were included in the study with 73 women in each group. Cleavage-stage transfer was associated with significantly lower implantation and clinical pregnancy rates compared with those of day 5 transfer. Although the live birth rate of the cleavage-stage transfer group was lower than that of the day 5 transfer group (25% vs. 40%, respectively), the cleavage-stage transfer still resulted in a live birth rate of 25%. A subanalysis comparing women who did and did not achieve live birth after cleavage-stage transfer demonstrated a live birth rate of 27% when at least one grade A embryo was transferred vs. 17% when a lesser quality embryo (grade B or C) was transferred. CONCLUSIONS: As expected, the live birth rate after cleavage-stage transfer was lower than that after day 5 transfer. However, the live birth rate of cleavage-stage transfer still fell into acceptable practice, >5%, for patients who were otherwise at very high risk of having no day 5 embryo transfer. Extended culture may not be necessary for all patients.

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.

Progressive Fibrosis: A Progesterone- and KLF11-Mediated Sexually Dimorphic Female Response.

Progressive scarring is ubiquitous postoperatively and in an array of chronic systemic diseases. Recent studies indicate that such scarring has a high female propensity; females are also almost exclusively affected by endometriosis, a common sex steroid-dependent fibrotic disease. Endometriosis-related fibrosis is regulated epigenetically through transcription factor Krüppel-like factor 11 (KLF11). In response to surgical induction of endometriosis, Klf11-/- female mice develop significant fibrosis in contrast to wild-type mice. We therefore hypothesized that female fibrotic predilection was mediated by differential sex steroid regulation of KLF11/collagen 1a1 signaling and investigated the fibrotic response in wild-type and Klf11-/- male and female animals using a sterile peritonitis model. Fibrosis selectively developed in Klf11-/- females. Fibrosis in these animals was almost completely abrogated by ovariectomy. Ovariectomized animals were selectively supplemented with estradiol, medroxyprogesterone acetate (MPA), or dihydrotestosterone; fibrosis was only observed in mice exposed to MPA. Fibrosis therefore selectively developed in Klf11-/- female mice in response to physiological or pharmacological progesterone. The fibrotic response in these animals was also mitigated in response to antiprogestin therapy. Profibrotic gene expression was activated in a primary human peritoneal cell line in response to KLF11 short hairpin RNA and MPA but not estradiol. KLF11/collagen 1a1 signaling previously shown to be linked to fibrosis was thus selectively dysregulated in MPA-treated cells. Our in vivo and in vitro findings in an animal model and human cells, respectively, suggest that progressive fibrotic scarring is a sexually dimorphic response irrespective of etiology; moreover, it is responsive to novel, individualized therapeutic intervention.

KLF11 is an Epigenetic Mediator of DRD2/Dopaminergic Signaling in Endometriosis.

Endometriosis is a heterogeneous, recalcitrant disease that affects 10% of reproductive-age women. Resistance to conventional therapy critically raises the need for novel treatment options that target specific, dysregulated underlying molecular mechanisms. Dopamine receptor 2 (DRD2) has been shown to be associated with vascularity and fibrosis in endometriosis. Transcription factor KLF11 has been implicated in the pathogenesis of several human endocrine and reproductive tract diseases including endometriosis. KLF11 recruits epigenetic cofactors for regulation of target genes; dysregulation of critical target genes and associated signaling pathways results in diverse disease phenotypes. KLF11 regulates the expression of DRD2 in neurons. We investigated the regulation of DRD2 by KLF11 in the established eutopic and ectopic endometrial cell lines as well as in an animal model of endometriosis. KLF11 binding and activation of the DRD2 promoter was conserved across species. Promoter activation was reflected in correspondingly increased gene expression in an endometrial cell line and in primary endometriotic cells. In vivo, disease relevance was further evaluated in a surgically induced murine endometriotic model using Klf11-/- and wild-type mice. Consistent with loss of Klf11-mediated activation, lesions in Klf11-/- animals were associated with progressive fibrosis and decreased Drd2 expression. KLF11 binds specific epigenetic corepressors to repress several target genes. Activation of DRD2 by KLF11 could not be explained simply by loss of corepressor binding and is thus likely due to selective coactivator recruitment; identification of the precise pathway is the focus of ongoing investigation. Characterization of pharmacologically reversible epigenetic regulatory mechanisms has translational relevance in health and disease.