Fuminori Taniguchi

Apoptosis and endometriosis.

Apoptosis is a distinctive form of programmed cell death resulting in the efficient elimination of cells without eliciting an inflammatory response. Endometriosis is characterized by the presence of endometrial cells with capacity to avoid apoptosis outside the uterus. Apoptosis plays a fundamental role for the pathogenesis of endometriosis. Eutopic endometrium from women with endometriosis has increased expression of anti-apoptotic factor and decreased expression of pro-apoptotic factors compared with endometrium from healthy women. These differences could contribute to the survival of regurgitating endometrial cells into the peritoneal cavity and development of endometriosis. Increased apoptosis of Fas-bearing immune cells in the peritoneal cavity may leads to their decreased scavenger activity that eventually results in prolonged survival of ectopic endometrial cells in women with endometriosis. This study is a current review of the literatures focused on the physiological role of apoptosis in normal endometrium and alterations in regulation of apoptosis in eutopic and ectopic endometrium from women with endometriosis. The role of apoptosis in the treatment of endometriosis is also reviewed.

Demethylation of a nonpromoter cytosine-phosphate-guanine island in the aromatase gene may cause the aberrant up-regulation in endometriotic tissues

OBJECTIVEnTo search for the demethylated cytosine-phosphate-guanine (CpG) islands within the aromatase gene in stromal cells derived from endometriotic chocolate cysts.nnnDESIGNnProspective study.nnnSETTINGnDepartment of Obstetrics and Gynecology and Department of Biosignaling, Tottori University, Yonago, Japan.nnnPATIENT(S)nTwenty-eight women who underwent laparoscopy (n=14) and laparotomy (n=14).nnnINTERVENTION(S)nEndometrial and endometriotic stromal cells were obtained from the uterus and chocolate cyst lining of the ovary.nnnMAIN OUTCOME MEASURE(S)nWe searched for the CpG island and examined methylation profile and the association of methyl-binding proteins with the CpG island.nnnRESULT(S)nUp-regulation of aromatase messenger RNA (mRNA) expression was demonstrated in endometriotic cells. Three proximal promoters drove the mRNA expression. In endometrial cells, a marginal level of aromatase mRNA expression was observed. Treating endometrial cells with the demethylating agent 5-aza-2-deoxycytidine markedly enhanced aromatase mRNA expression. The same promoters as in the endometriotic cells were used. To identify the unmethylated CpGs in endometriotic cells, we searched for CpG islands within the aromatase gene and subsequently examined the methylation profiles. Sequence analysis of bisulfite-treated genomic DNA demonstrated a stretch of CpG demethylation within a nonpromoter CpG island of the aromatase gene in endometriotic cells. In endometrial cells, the CpG sequences were heavily methylated and associated with methyl-CpG-binding proteins.nnnCONCLUSION(S)nThe up-regulation of the aromatase gene in endometriosis may be ascribed to the epigenetic disorder associated with aberrant DNA demethylation in a nonpromoter CpG island.

The role of survivin in the resistance of endometriotic stromal cells to drug-induced apoptosis.

BACKGROUNDnDecreased susceptibility of endometrial tissue to apoptosis may contribute to the pathogenesis of endometriosis. We investigate the role of survivin in the pathophysiology of endometriosis through the ability of ectopic and eutopic endometrial stromal cells (ESCs) to resist apoptosis.nnnMETHODSnEctopic ESCs were obtained from ovarian chocolate cysts in patients undergoing laparoscopic surgery (n = 22). Eutopic ESCs were isolated from endometrial tissue of cyclic premenopausal women undergoing hysterectomy for fibroids (n = 22). Purified stromal cells were studied in vitro. The number of surviving cells and activation of caspases were assessed by WST-8 assay and immunoblotting. Expression of inhibitor of apoptosis proteins (IAP) family members: cIAP1 (birc2), cIAP2 (birc3), XIAP (birc4), survivin (birc5) were examined using cDNA array and real-time RT-PCR. Effects of gene silencing by small inhibitor RNAs (siRNA) were examined by WST-8-assay, Annexin-V staining and immunoblotting.nnnRESULTSnAfter staurosporine (SS) treatment, 55% of eutopic ESCs survived versus 70% of ectopic ESCs. Procaspase-3 or -7 was more intensely activated by SS treatment in eutopic than in ectopic ESCs (P < 0.01). mRNAs for IAP-family genes, such as cIAP-1, XIAP and survivin, were highly expressed in ectopic ESCs before SS treatment. The fold induction of survivin expression after SS treatment was higher in ectopic than eutopic ESCs (2.8 +/- 0.27 versus 0.69 +/- 0.07, respectively). Survivin gene silencing in SS-treated ectopic ESCs led to an increase of apoptotic cells (P < 0.05, versus control siRNA).nnnCONCLUSIONSnWe demonstrated that survivin plays a critical role in susceptibility of ESCs to apoptosis. Our results indicate that a survivin inhibitor may be effective as a novel treatment for endometriosis.

Epigenetic aberration of gene expression in endometriosis.

Endometriosis is an estrogen-dependent inflammatory disease. In endometriotic tissues, a high-estrogen environment associated with up-regulation of the aromatase gene has been well documented. There is accumulating evidence supporting a concept that endometriosis is a disease associated with an epigenetic disorder. Epigenetics is one of the most expanding fields in the current biomedical research. The word epigenetics refers to the study of mitotically and/or meiotically heritable changes in gene expression that occur without changes in the DNA sequence. The disruption of such changes (epigenetic aberration or disorder) underlies a wide variety of pathologies. Epigenetic regulation includes DNA methylation and histone modifications, and is responsible for a number of gene transcription associated with chromatin modifications that distinguish the states of diseases. In this review, we summarized our studies as well as recent studies from other laboratories using an epigenetic approach focused on DNA methylation. We also summarized studies using advanced technologies including Genome-Wide (GW) methylation profiling analysis and GW Association Study (GWAS). We reviewed recent monozygotic twins studies in relation to environmental factors since they may provide insight into the epigenetic background of endometriosis. Finally, we referred to a new concept of GW DNA methylation.

TAK1 activation for cytokine synthesis and proliferation of endometriotic cells

Endometriosis causes pelvic pain and infertility in women of reproductive age. We explored TNFalpha-induced specific signaling pathways and gene expressions in endometriotic stromal cells (ESCs). Based on the data of the pathway specific cDNA array, we analyzed the role of TAK1, which is believed to work as a common mediator for NF-kappaB and MAPK pathways. Using the NF-kappaB pathway array, we found that TNFalpha upregulated ICAM-3, IL-6, IL-8, TAK1, JNK2, RelA, and TLR4 expressions. TNFalpha augmented the phosphorylation of TAK1. By transfection of TAK1 siRNA, TNFalpha-induced phosphorylation of IkappaBalpha, JNK1/2, and p38MAPK, as well as IL-6 or IL-8 expression, were repressed. TAK1 silencing in TNFalpha-pretreated ESCs caused a decrease in the proportion of cells in S-phase, and reduced TNFalpha-promoted BrdU incorporation. We provide the first evidence that TNFalpha and its downstream TAK1, which are key mediators for NF-kappaB and MAPK pathways, may be involved in the pathogenesis of endometriosis.

Lipopolysaccharide promoted proliferation and invasion of endometriotic stromal cells via induction of cyclooxygenase-2 expression

Lipopolysaccharide-enhanced cyclooxygenase 2 (COX-2) expression and prostaglandin E2 (PGE2) production were compared in endometriotic stromal cells (ESCs) and eutopic endometrial stromal cells. Lipopolysaccharide promotes the proliferation and invasion of ESCs via up-regulation of COX-2 and PGE2 expression, suggesting that pelvic inflammation may promote the progression of endometriosis.

Apigenin inhibits tumor necrosis factor α–induced cell proliferation and prostaglandin E2 synthesis by inactivating NFκB in endometriotic stromal cells

Apigenin suppressed tumor necrosis factor α-induced cell proliferation and prostaglandin E2 expression via the attenuation of nuclear factor κB pathway in endometriotic stromal cells in vitro. Apigenin reduced the mitogenic activity and inflammatory reaction in endometriotic stromal cells.

The Cellular Inhibitor of Apoptosis Protein-2 is a Possible Target of Novel Treatment for Endometriosis

How is the tumor necrosis factor (TNF) α‐induced inhibitor of apoptosis (IAP) protein expression in endometriotic stromal cells (ESCs) involved in cell viability and signaling pathways?

Epigenetics in Endometriosis

There is accumulating evidence supporting the concept that endometriosis is a disease associated with an epigenetic disorder. Epigenetics is one of the most expanding fields in the current biomedical research. The word “epigenetics” refers to the study of mitotically and/or meiotically heritable changes in gene expression that occur without changes in the DNA sequence. The disruption of such changes (epigenetic aberration or disorder) underlies a wide variety of pathologies. Epigenetic regulation includes DNA methylation and histone modifications and is responsible for a number of gene transcriptions associated with chromatin modifications that distinguish the states of diseases. As an introduction, we summarize our findings of epigenetic disorder in endometriotic cells and then overview recent studies focused on DNA methylation in endometriosis. We describe our recent challenge and advanced studies from other laboratories using genome-wide (GW) analysis. Finally, we refer to environmental factors as a potential background of epigenetic disorder in endometriosis.

Apoptosis in Endometriosis

Endometriosis is an inflammatory, estrogen-dependent disease characterized by the growth of endometrial tissues outside the uterus. The eutopic endometrium from women with endometriosis has some fundamental differences compared with the normal endometrium of women without endometriosis. The differences could contribute to the survival of regurgitating endometrial cells into the peritoneal cavity and the development of endometriosis. One mechanism that gained a lot of interests is the finding that apoptosis appeared in eutopic and ectopic endometrium of patients with endometriosis. A common characteristic of endometriotic cells is their ability to evade the apoptotic machinery. Endometriosis could result from increased cellular proliferation or decreased apoptosis in response to appropriate stimuli. This chapter focused on the physiological role of apoptosis in normal endometrium and the alterations in regulation of apoptosis in eutopic and ectopic endometrium from women with endometriosis. Finally, the role of apoptosis in the treatment of endometriosis is reviewed to link the basic research findings into clinical applications.