No abstract

Progressive fibrosis is recalcitrant to conventional therapy and commonly complicates chronic diseases and surgical healing. We evaluate here a novel mechanism that regulates scar-tissue collagen (COL1A1/Col1a1) expression and characterizes its translational relevance as a targeted therapy for fibrosis in an endometriosis disease model. Endometriosis is caused by displacement and implantation of uterine endometrium onto abdominal organs and spreads with progressive scarring. Transcription factor KLF11 is specifically diminished in endometriosis lesions. Loss of KLF11-mediated repression of COL1A1/Col1a1 expression resulted in increased fibrosis. To determine the biological significance of COL1A1/Col1a1 expression on fibrosis, we modulated its expression. In human endometrial-stromal fibroblasts, KLF11 recruited SIN3A/HDAC (histone deacetylase), resulting in COL1A1-promoter deacetylation and repression. This role of KLF11 was pharmacologically replicated by a histone acetyl transferase inhibitor (garcinol). In contrast, opposite effects were obtained with a HDAC inhibitor (suberoyl anilide hydroxamic acid), confirming regulatory specificity for these reciprocally active epigenetic mechanisms. Fibrosis was concordantly reversed in Klf11(-/-)animals by histone acetyl transferase inhibitor and in wild-type animals by HDAC inhibitor treatments. Aberrant lesional COL1A1 regulation is significant because fibrosis depended on lesion rather than host genotype. This is the first report demonstrating feasibility for targeted pharmacological reversal of fibrosis, an intractable phenotype of diverse chronic diseases.

Fertility-sparing management and close follow-up of low-grade endometrial stromal sarcoma may be a viable option for those desiring future fertility.

Recent studies suggest that chemokines may mediate the luteolytic action of PGF2α (PGF). Our objective was to identify chemokines induced by PGF in vivo and to determine the effects of IL8 on specific luteal cell types in vitro. Midcycle cows were injected with saline or PGF, ovaries were removed after 0.5 – 4 h and chemokine expression was analyzed by qPCR. In vitro expression of IL8 was analyzed after PGF administration and with cell signaling inhibitors to determine the mechanism of PGF-induced chemokine expression. Purified neutrophils were analyzed for migration and activation in response to IL8 and PGF. Purified luteal cell types (steroidogenic, endothelial and fibroblast cells) were used to identify which cells respond to chemokines. Neutrophils and peripheral blood mononuclear cells (PBMCs) were co-cultured with steroidogenic cells to determine their effect on progesterone production. IL8, CXCL2, CCL2, and CCL8 transcripts were rapidly increased following PGF treatment in vivo and. The stimulatory action of PGF on IL8 mRNA expression in vitro was prevented by inhibition of p38 and JNK signaling. IL8, but not PGF, TNF, or TGFB1, stimulated neutrophil migration. IL8 had no apparent action in purified luteal steroidogenic, endothelial, or fibroblast cells, but IL8 stimulated ERK phosphorylation in neutrophils. In co-culture experiments neither IL8 nor activated neutrophils altered basal or LH-stimulated luteal cell progesterone synthesis. In contrast, activated PBMCs inhibited LH-stimulated progesterone synthesis from cultured luteal cells. These data implicate a complex cascade of events during luteolysis involving chemokine signaling, neutrophil recruitment, and immune cell action within the corpus luteum.