Peroxisome proliferator-activated receptor-gamma and retinoid X receptor agonists synergistically suppress proliferation of immortalized endometrial stromal cells

Hypermethylation of Klotho and Peroxisome Proliferator-Activated Receptor γ Concomitant with Overexpression of DNA Methyltransferase 1 in Adenomyosis

Cellular senescence is known to be involved in tissue repair, but its role in adenomyosis remains unclear. This study was tasked to evaluate the expression of Klotho, a well-known aging-suppressing protein, as well as PPARγ and DNMT1 in adenomyotic lesions (AD) in comparison with that of control endometrium (CT). We performed immunohistochemistry analysis of markers of cellular senescence p16 and p21, along with Klotho, PPARγ and DNMT1 in CT and AD samples, followed by the quantification of gene expression of Klotho, PPARγ and DNMT1 in epithelial organoids derived from AD and CT samples and methylation-specific PCR to evaluate promoter methylation status. The effect of forced expression and knockdown of DNMT1 on Klotho and PPARγ expression in ectopic endometrial epithelial cells was evaluated. We found that both p16 and p21 immunoreactivity in AD was significantly higher while that of Klotho and PPARγ was significantly lower than CT samples, which was concomitant with elevated immunoexpression of DNMT1. The results were confirmed by transcriptional analysis using epithelial organoids derived from AD and CT samples. In addition, the promoter regions of both Klotho and PPARγ genes were hypermethylated in AD as compared with CT, and treatment with HDAC and DNMT inhibitors reactivated the expression of both Klotho and PPARγ. Forced expression of DNMT1 resulted in downregulation of both Klotho and PPARγ but its knockdown increased their expression. Thus, overexpression of DNMT1 seems to facilitate the promoter hypermethylation of both Klotho and PPARγ in AD, resulting in their reduced expression that is suggestive of the role of senescence in adenomyosis.

The role of peroxisome proliferator-activated receptors in endometriosis

Endometriosis constitutes the most common cause of chronic pelvic pain in female patients and is associated with infertility. Although there is no known cause for the disease, it is a heritable condition that is determined by numerous genetic, epigenetic, and environmental aspects. Peroxisome proliferator-activated receptors (PPARs) represent nuclear receptor proteins that control gene expression. By using the MEDLINE and LIVIVO databases we conducted a literature review in order to look into the role of PPARs in the endometriosis pathophysiology and succeeded in revealing 36 pertinent publications between 2001 and 2022. In regards to PPAR expression in endometriosis, PPARγ seems to represent the most studied PPAR isoform in endometriosis and to influence various pathways involved in the disease onset and progression. It's interesting to note that diverse treatment agents targeting the PPAR system have been identified as innovative, effective therapeutic alternatives in the context of endometriosis treatment. In conclusion, PPARs appear to contribute an important role in both endometriosis pathophysiology and therapy.

The Impact of Histone Modifications in Endometriosis Highlights New Therapeutic Opportunities

Endometriosis is a chronic disorder of the female reproductive system which afflicts a great number of women worldwide. Histone deacetylases (HDACs) prevent the relaxation of chromatin, thereby positively or negatively modulating gene transcription. The current review aims at studying the impact of histone modifications and their therapeutic targeting in endometriosis. In order to identify relevant studies, a literature review was conducted using the MEDLINE and LIVIVO databases. The current manuscript represents the most comprehensive, up-to-date review of the literature focusing on the particular role of HDACs and their inhibitors in the context of endometriosis. HDAC1, HDAC2, HDAC3, Sirtuin 1, and Sirtuin 3, are the five most studied HDAC enzymes which seem to, at least partly, influence the pathophysiology of endometriosis. Both well-established and novel HDACIs could possibly represent modern, efficacious anti-endometriotic drug agents. Altogether, histone modifications and their therapeutic targeting have been proven to have a strong impact on endometriosis.

Bone marrow mesenchymal stem cell-derived extracellular vesicles facilitate endometrial injury repair by carrying the E3 ubiquitin ligase WWP1

Bone marrow mesenchymal stem cells-derived extracellular vesicles (BMSC-EVs) relieve endometrial injury. This study aimed to elucidate the BMSC-EV mechanism in alleviating endometrial injury. Endometrial injury model in vivo was induced using 95% ethanol, and endometrial epithelial cells (EECs) treated with mifepristone were applied as an endometrial injury model in vitro. After BMSCs and BMSC-EVs were isolated and identified, the BMSC-EV function was evaluated by hematoxylin-eosin and Masson staining, immunohistochemistry, quantitative real-time PCR, Cell Counting Kit-8 assay, flow cytometry, enzyme-linked immunosorbent assay, and Transwell and tubule formation assays. The BMSC-EV mechanism was assessed using Western blot, ubiquitination, and cycloheximide-chase assays. After isolation and identification, BMSC-EVs were effective in endometrial injury repair in vivo and facilitated EEC proliferation and repressed cell apoptosis in vitro; the EEC supernatants accelerated human umbilical vein endothelial cell proliferation, migration, and invasion and facilitated angiogenesis after endometrial injury in vitro. For the BMSC-EV mechanism, E3 ubiquitin ligase WWP1 in BMSC-EVs mediated the ubiquitination of peroxisome proliferator-activated receptor gamma (PPARγ), thus relieving the PPARγ inhibition on vascular endothelial growth factor expression. Furthermore, the WWP1 in BMSC-EVs alleviated endometrial injury in vitro and in vivo. BMSC-EVs facilitated endometrial injury repair by carrying WWP1.

Comprehensive Analysis of Copy Number Variation, Nucleotide Mutation, and Transcription Level of PPAR Pathway-Related Genes in Endometrial Cancer

Endometrial cancer is a common malignant tumor in gynecology, and the prognosis of advanced patients is dismal. Recently, many studies on the peroxisome proliferator-activated receptor pathway have elucidated its crucial involvement in endometrial cancer. Copy number variation (CNA) and nucleotide mutations often occur in tumor tissues, leading to abnormal protein expression and changes in protein structure. We analyzed the exon sequencing data of endometrial cancer patients in the TCGA database and found that somatic changes in PPAR pathway-related genes (PPAR-related-gene) often occur in UCEC patients. Patients with CNA or mutation changes in the exon region of the PPAR-related-gene usually have different prognostic outcomes. Furthermore, we found that the mRNA transcription and protein translation levels of PPAR-related-gene in UCEC are significantly different from that of adjacent tissues/normal uterus. The transcription level of some PPAR-related-gene (DBI, CPT1A, CYP27A1, and ME1) is significantly linked to the prognosis of UCEC patients. We further constructed a prognostic predicting tool called PPAR Risk score, a prognostic prediction tool that is a strong independent risk factor for the overall survival rate of UCEC patients. Comparing to the typical TNM classification system, this tool has higher prediction accuracy. We created a nomogram by combining PPAR Risk score with clinical characteristics of patients in order to increase prediction accuracy and promote clinical use. In summary, our study demonstrated that PPAR-related-gene in UCEC had significant alterations in CNA, nucleotide mutations, and mRNA transcription levels. These findings can provide a fresh perspective for postoperative survival prediction and individualized therapy of UCEC patients.

Regulation of Epigenetic Modifications in the Placenta during Preeclampsia: PPARγ Influences H3K4me3 and H3K9ac in Extravillous Trophoblast Cells

The aim of this study was to analyze the expression of peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RxRα), a binding heterodimer playing a pivotal role in the successful trophoblast invasion, in the placental tissue of preeclamptic patients. Furthermore, we aimed to characterize a possible interaction between PPARγ and H3K4me3 (trimethylated lysine 4 of the histone H3), respectively H3K9ac (acetylated lysine 9 of the histone H3), to illuminate the role of histone modifications in a defective trophoblast invasion in preeclampsia (PE). Therefore, the expression of PPARγ and RxRα was analyzed in 26 PE and 25 control placentas by immunohistochemical peroxidase staining, as well as the co-expression with H3K4me3 and H3K9ac by double immunofluorescence staining. Further, the effect of a specific PPARγ-agonist (Ciglitazone) and PPARγ-antagonist (T0070907) on the histone modifications H3K9ac and H3K4me3 was analyzed in vitro. In PE placentas, we found a reduced expression of PPARγ and RxRα and a reduced co-expression with H3K4me3 and H3K9ac in the extravillous trophoblast (EVT). Furthermore, with the PPARγ-antagonist treated human villous trophoblast (HVT) cells and primary isolated EVT cells showed higher levels of the histone modification proteins whereas treatment with the PPARγ-agonist reduced respective histone modifications. Our results show that the stimulation of PPARγ-activity leads to a reduction of H3K4me3 and H3K9ac in trophoblast cells, but paradoxically decreases the nuclear PPARγ expression. As the importance of PPARγ, being involved in a successful trophoblast invasion has already been investigated, our results reveal a pathophysiologic connection between PPARγ and the epigenetic modulation via H3K4me3 and H3K9ac in PE.

HDAC inhibitor Trichostatin A suppresses adipogenesis in 3T3-L1 preadipocytes

Background and purpose: Obesity is becoming a major global health issue and is mainly induced by the accumulation of adipose tissues mediated by adipogenesis, which is reported to be regulated by peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer-binding protein α (C/EBPα). Trichostatin A (TSA) is a novel histone deacetylase inhibitor (HDACI) that was recently reported to exert multiple pharmacological functions. The present study will investigate the inhibitory effect of TSA on adipogenesis, as well as the underlying mechanism.

Methods: The adipogenesis of 3T3-L1 cells was induced by stimulation with a differentiation cocktail (DMI) medium for 8 days. MTT assay was used to measure the cell viability and Oil Red O staining was used to evaluate the adipogenesis of 3T3-L1 cells. The total level of triglyceride and released glycerol were detected to evaluate the lipolysis during 3T3-L1 adipogenesis. The expression levels of Leptin, fatty acid-binding protein 4 (FABP4), and sterol regulatory element-binding protein (SREBP1C) were determined by qRT-PCR. qRT-PCR assay was utilized to detect the expression levels of PPARγ and C/EBPα in 3T3-L1 cells. A high-fat diet (HFD) was used to construct an obese mice model, followed by the treatment with TSA. HE staining was conducted to evaluate the pathological state of adipose tissues. Body weights and the weights of adipose tissues were recorded to evaluate the anti-obesity property of TSA.

Results: Firstly, the promoted lipid accumulation induced by DMI incubation was significantly reversed by the treatment with TSA in a dose-dependent manner. The elevated expression levels of Leptin, FABP4, SREBP1C, PPARγ, and C/EBPα induced by the stimulation with DMI incubation were dramatically inhibited by the introduction of TSA, accompanied by the upregulation of phosphorylated AMP-activated protein kinase (p-AMPK). Secondly, the inhibitory effect of TSA against the expression level of PPARγ and lipid accumulation was greatly abolished by an AMPK inhibitor. Lastly, the increased body weights and visceral adipocyte tissue weight, as well as the enlarged size of adipocytes induced by HFD were pronouncedly reversed by the administration of TSA.

Conclusion: TSA inhibited adipogenesis in 3T3-L1 preadipocytes by activating the AMPK pathway.

Revisiting estrogen-dependent signaling pathways in endometriosis: Potential targets for non-hormonal therapeutics

Endometriosis is an estrogen-dependent gynecologic disease. Endometriotic cells survive in oxidative stress and hypoxic environments. The aim of this review is to reconsider new therapeutic strategies for endometriosis by focusing on estrogen signaling, ROS production and scavenging, and mitochondrial metabolism. Each keyword alone or in combination was used to search from PubMed and Embase by applying the filters of the title and the publication years between January 2000 and May 2020. Abnormal epigenetic marks of estrogen receptors (ERs) in endometriosis cause overexpression of ERβ, progesterone resistance, inflammation, anti-apoptosis, and mitochondrial metabolic modification. In addition to hormonal action, estrogen is involved in various functions such as mitochondrial biosynthesis and energy metabolism. Estrogen works with its downstream target genes to modulate mitochondrial gene expression, regulate ROS production, and affect mitochondrial biology, including ATP production, antioxidant defenses, mitochondrial biosynthesis, quality control, and energy-transducing capacity. Endometriosis can shift mitochondrial metabolism from oxidative phosphorylation to aerobic glycolysis. This metabolic conversion suppresses ROS production and thus activates the survival signal of endometriotic cells. Therefore, molecules associated with aerobic glycolysis and mitochondrial metabolism are considered therapeutic targets for endometriosis. In conclusion, estrogen downstream target genes involved in mitochondrial metabolic biosynthesis may be potential targets for non-hormonal treatment of endometriosis.

The Pathogenesis of Endometriosis: Molecular and Cell Biology Insights

The etiopathogenesis of endometriosis is a multifactorial process resulting in a heterogeneous disease. Considering that endometriosis etiology and pathogenesis are still far from being fully elucidated, the current review aims to offer a comprehensive summary of the available evidence. We performed a narrative review synthesizing the findings of the English literature retrieved from computerized databases from inception to June 2019, using the Medical Subject Headings (MeSH) unique ID term "Endometriosis" (ID:D004715) with "Etiology" (ID:Q000209), "Immunology" (ID:Q000276), "Genetics" (ID:D005823) and "Epigenesis, Genetic" (ID:D044127). Endometriosis may origin from Müllerian or non-Müllerian stem cells including those from the endometrial basal layer, Müllerian remnants, bone marrow, or the peritoneum. The innate ability of endometrial stem cells to regenerate cyclically seems to play a key role, as well as the dysregulated hormonal pathways. The presence of such cells in the peritoneal cavity and what leads to the development of endometriosis is a complex process with a large number of interconnected factors, potentially both inherited and acquired. Genetic predisposition is complex and related to the combined action of several genes with limited influence. The epigenetic mechanisms control many of the processes involved in the immunologic, immunohistochemical, histological, and biological aberrations that characterize the eutopic and ectopic endometrium in affected patients. However, what triggers such alterations is not clear and may be both genetically and epigenetically inherited, or it may be acquired by the particular combination of several elements such as the persistent peritoneal menstrual reflux as well as exogenous factors. The heterogeneity of endometriosis and the different contexts in which it develops suggest that a single etiopathogenetic model is not sufficient to explain its complex pathobiology.

Molecular Actions of PPARα in Lipid Metabolism and Inflammation

Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor of clinical interest as a drug target in various metabolic disorders. PPARα also exhibits marked anti-inflammatory capacities. The first-generation PPARα agonists, the fibrates, have however been hampered by drug-drug interaction issues, statin drop-in, and ill-designed cardiovascular intervention trials. Notwithstanding, understanding the molecular mechanisms by which PPARα works will enable control of its activities as a drug target for metabolic diseases with an underlying inflammatory component. Given its role in reshaping the immune system, the full potential of this nuclear receptor subtype as a versatile drug target with high plasticity becomes increasingly clear, and a novel generation of agonists may pave the way for novel fields of applications.

Activation of RXR/PPARγ underlies neuroprotection by bexarotene in ischemic stroke

The identification of novel drug targets for the treatment of ischemic stroke is currently an urgent challenge. Recent experimental findings have highlighted the neuroprotective potential of immunomodulatory strategies, based on polarization of myeloid cells toward non-inflammatory, beneficial phenotypes. Given the role of retinoid X receptors (RXR) in myeloid cells differentiation and polarization, here we have explored the neuroprotective potential of the RXR agonist bexarotene in mice subjected to focal cerebral ischemia. Acute administration of bexarotene significantly reduced blood brain barrier leakage, brain infarct damage and neurological deficit produced by transient middle cerebral artery occlusion in mice, without affecting cerebral blood flow. The rexinoid exerted neuroprotection with a wide time-window, being effective when administered up to 4.5h after the insult. The amelioration of histological outcome, as well as the ability of bexarotene to revert middle cerebral artery occlusion (MCAo)-induced spleen atrophy, was antagonised by BR1211, a pan-RXR antagonist, or by the selective peroxisome proliferator-activated receptor (PPAR)γ antagonist bisphenol A diglycidyl ether (BADGE), highlighting the involvement of the RXR/PPARγ heterodimer in the beneficial effects exerted by the drug. Immunofluorescence analysis revealed that bexarotene elevates Ym1-immunopositive N2 neutrophils both in the ipsilateral hemisphere and in the spleen of mice subjected to transient middle cerebral artery occlusion, pointing to a major role for peripheral neutrophil polarization in neuroprotection. Thus, our findings suggest that the RXR agonist bexarotene exerts peripheral immunomodulatory effects under ischemic conditions to be effectively repurposed for the acute therapy of ischemic stroke.

Novel agents for the medical treatment of endometriosis

PURPOSE OF REVIEW

Current medical treatments for endometriosis-associated pain, including oral contraceptives, progestins and GnRH agonists, are partially effective and have significant side-effects. The purpose of this review is to present new hormonal and nonhormonal treatment for endometriosis.

RECENT FINDINGS

At present, the ideal drug that can prevent, inhibit or stop development of endometriosis, reduce associated pain or infertility and allow conception does not exist. New drugs in development for endometriosis modulate GnRH, estrogen and/or progesterone receptors, or target endometriosis-associated inflammation, angiogenesis, adhesion and/or tissue invasion. Most have been tested in rodents, and have been evaluated in more relevant animal models like nonhuman primates (baboons), but only a few, that is GnRH antagonists, have been tested in human randomized controlled trials. Important safety and efficacy issues remain a concern, as steroid receptors, inflammation, adhesion, angiogenesis and tissue invasion are key factors in physiological events like ovulation, menstruation and embryo implantation.

SUMMARY

New drugs for the medical treatment of endometriosis targeting both hormonal (GnRH, estrogen and progesterone receptors) and nonhormonal pathways (inflammation, angiogenesis, adhesions, tissue invasion) are promising, but their efficacy and safety need to be established in randomized human trials before they can be used in clinical practice.

PPARγ upregulation induced by vagus nerve stimulation exerts anti-inflammatory effect in cerebral ischemia/reperfusion rats

Background

It is well known that peroxisome proliferator-activated receptor gamma (PPARγ), a ligand-activated transcription factor, plays a protective role in anti-inflammatory responses in both acute and chronic central nerve system (CNS) insults. Emerging evidence in rats suggests that vagus nerve stimulation (VNS), while restraining inflammatory cytokine production in the peripheral nervous system, also exerts a significant CNS neuroprotective function against ischemic stroke injury. The aim of this study was to explore the role of PPARγ in VNS-mediated anti-inflammatory protection against ischemic stroke damage.

Material/Methods

Adult male Sprague-Dawley rats (total n=160) preconditioned through transfection with either PPARγ small interfering RNA (siRNA) or lentiviral vector without siRNA and surgically subjected to middle cerebral artery occlusion and reperfusion subsequently received VNS treatment at 30 min post-occlusion. The expression of PPARγ after VNS treatment was measured by real-time PCR and Western blotting, also supported by immunofluorescence staining. Subsequently, the neurological deficits scores, the infarct volume, and the brain histopathology were all evaluated. Additionally, the influence on the pro-inflammatory cytokines expression and neuro-immune cells activation was determined by ELISA and immunofluorescence staining.

Results

We found that VNS upregulated expression of PPARγ in ischemia penumbra, diminished the extent of ischemic infarct, alleviated neuronal injury, and suppressed pro-inflammatory cytokine expression and immune cell activation (P<0.05). However, rats with PPARγ silencing failed to manifest significant neuroprotection and anti-inflammatory effect induced by VNS treatment (p>0.05).

Conclusions

PPARγ may participate in the process by which VNS modulates the neuro-inflammatory response following ischemia/reperfusion in rats.

Medical treatments for endometriosis-associated pelvic pain

The main sequelae of endometriosis are represented by infertility and chronic pelvic pain. Chronic pelvic pain causes disability and distress with a very high economic impact. In the last decades, an impressive amount of pharmacological agents have been tested for the treatment of endometriosis-associated pelvic pain. However, only a few of these have been introduced into clinical practice. Following the results of the controlled studies available, to date, the first-line treatment for endometriosis associated pain is still represented by oral contraceptives used continuously. Progestins represent an acceptable alternative. In women with rectovaginal lesions or colorectal endometriosis, norethisterone acetate at low dosage should be preferred. GnRH analogues may be used as second-line treatment, but significant side effects should be taken into account. Nonsteroidal anti-inflammatory drugs are widely used, but there is inconclusive evidence for their efficacy in relieving endometriosis-associated pelvic pain. Other agents such as GnRH antagonist, aromatase inhibitors, immunomodulators, selective progesterone receptor modulators, and histone deacetylase inhibitors seem to be very promising, but there is not enough evidence to support their introduction into routine clinical practice. Some other agents, such as peroxisome proliferator activated receptors-γ ligands, antiangiogenic agents, and melatonin have been proven to be efficacious in animal studies, but they have not yet been tested in clinical studies.

Essential genes in thyroid cancers: focus on fascin

Although thyroid cancers are not among common malignancies, they rank as the first prevalent endocrine cancers in human. According to the results of published studies it has been shown the gradual progress from normal to the neoplastic cell in the process of tumor formation is the result of sequential genetic events. Among them we may point the mutations and rearrangements occurred in a group of proto-oncogenes, transcription factors and metastasis elements such as P53, RAS,RET,BRAF, PPARγ and Fascin. In the present article,we reviewed the most important essential genes in thyroid cancers, the role of epithelial mesenchymal transition and Fascin has been highlighted in this paper.

Involvement of the Retinoid X Receptor Ligand in the Anti-Inflammatory Effect Induced by Peroxisome Proliferator-Activated Receptor γ Agonist In Vivo

Peroxisome proliferator-activated receptor γ (PPARγ) forms a heterodimeric DNA-binding complex with retinoid X receptors (RXRs). It has been reported that the effect of the PPAR agonist is reduced in hepatocyte RXR-deficient mice. Therefore, it is suggested that the endogenous RXR ligand is involved in the PPARγ agonist-induced anti-inflammatory effect. However, the participation of the RXR ligand in the PPARγ-induced anti-inflammatory effect is unknown. Here, we investigated the influence of RXR antagonist on the anti-inflammatory effect of PPARγ agonist pioglitazone in carrageenan test. In addition, we also examined the influence of PPAR antagonist on the anti-inflammatory effect induced by RXR agonist NEt-3IP. The RXR antagonist suppressed the antiedema effect of PPARγ agonist. In addition, the anti-inflammatory effect of RXR agonist was suppressed by PPARγ antagonist. PPARγ agonist-induced anti-inflammatory effects were reversed by the RXR antagonist. Thus, we showed that the endogenous RXR ligand might contribute to the PPARγ agonist-induced anti-inflammatory effect.

Molecular determinants of magnolol targeting both RXRα and PPARγ

Nuclear receptors retinoic X receptor α (RXRα) and peroxisome proliferator activated receptor γ (PPARγ) function potently in metabolic diseases, and are both important targets for anti-diabetic drugs. Coactivation of RXRα and PPARγ is believed to synergize their effects on glucose and lipid metabolism. Here we identify the natural product magnolol as a dual agonist targeting both RXRα and PPARγ. Magnolol was previously reported to enhance adipocyte differentiation and glucose uptake, ameliorate blood glucose level and prevent development of diabetic nephropathy. Although magnolol can bind and activate both of these two nuclear receptors, the transactivation assays indicate that magnolol exhibits biased agonism on the transcription of PPAR-response element (PPRE) mediated by RXRα:PPARγ heterodimer, instead of RXR-response element (RXRE) mediated by RXRα:RXRα homodimer. To further elucidate the molecular basis for magnolol agonism, we determine both the co-crystal structures of RXRα and PPARγ ligand-binding domains (LBDs) with magnolol. Structural analyses reveal that magnolol adopts its two 5-allyl-2-hydroxyphenyl moieties occupying the acidic and hydrophobic cavities of RXRα L-shaped ligand-binding pocket, respectively. While, two magnolol molecules cooperatively accommodate into PPARγ Y-shaped ligand-binding pocket. Based on these two complex structures, the key interactions for magnolol activating RXRα and PPARγ are determined. As the first report on the dual agonist targeting RXRα and PPARγ with receptor-ligand complex structures, our results are thus expected to help inspect the potential pharmacological mechanism for magnolol functions, and supply useful hits for nuclear receptor multi-target ligand design.

The inhibitory effect of celecoxib and rosiglitazone on experimental endometriosis

OBJECTIVE

To evaluate the effects of celecoxib and rosiglitazone on the implantation and growth of endometriotic-like lesions in a murine model of endometriosis.

DESIGN

Prospective experimental study.

SETTING

Animal research and laboratory facility.

ANIMAL(S)

Two-month-old female BALB/c mice.

INTERVENTION(S)

Surgically induced endometriosis in female BALB/C mice; 28 days of treatment with celecoxib, rosiglitazone, or their combination; counting, measuring, excising, and fixing lesions.

MAIN OUTCOME MEASURE(S)

Immunohistochemical examination for proliferating cell nuclear antigen (PCNA), CD31, and CD34 to assess cell proliferation and vascularization, with the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique for apoptosis evaluation.

RESULT(S)

Celecoxib and the combined treatment (celecoxib and rosiglitazone) statistically significantly reduced the mean number of lesions established per mouse, and all treatments diminished the implant volume. In addition, cell proliferation within the implants was statistically significantly reduced, and apoptosis was statistically significantly enhanced by all treatments. Also, we found that all treatments diminished the vascularized area in the lesion.

CONCLUSION(S)

These results are promising and reveal that celecoxib and rosiglitazone, combined or separately, have a beneficial effect on overall endometriotic growth.

Inhibition of estrogen actions in human gynecological malignancies: new aspects of endocrine therapy for endometrial cancer and ovarian cancer

Endometrial carcinoma and possibly ovarian carcinoma are considered "estrogen-dependent tumors" in human gynecological malignancies. In endometrial carcinoma, the enzymes responsible for intratumoral estrogen metabolism and biosynthesis are different from those in human breast carcinoma, although both of them are considered "estrogen-dependent malignancies". Specific and effective endocrine treatment of endometrial carcinoma should be explored, although progestin agents have been widely used for a long time. Aromatase inhibitors, the most effective endocrine agents of breast carcinoma, retinoids, metabolites of vitamin A, and synthetic peroxisome proliferator-activated receptor (PPAR) gamma ligands, used for the treatment of insulin resistance in type II diabetes mellitus, may be the important candidates for possible endocrine treatment of endometrial carcinoma. In ovarian carcinoma, several clinical studies recently demonstrated that aromatase inhibitors had some therapeutic activity against recurrent ovarian carcinoma. However, at least at this juncture, further studies should be required to establish an aromatase inhibitor treatment as one form of endocrine therapy of ovarian carcinoma in future.

Peroxisome proliferator-activated receptor-(gamma) receptor ligand partially prevents the development of endometrial explants in baboons: a prospective, randomized, placebo-controlled study

A prospective, randomized, placebo-controlled study was conducted in a baboon model to determine if a thiazolidinedione agonist of peroxisome proliferator-activated receptor-gamma, pioglitazone, can impede the development of endometriosis. Endometriosis was induced using laparoscopic, intrapelvic injection of eutopic menstrual endometrium, previously incubated with placebo or pioglitazone for 30 min, in 12 female baboons with a normal pelvis that had undergone at least one menstrual cycle since the time of captivity. At this point, the 12 baboons were randomized into two groups and treated from the day of induction. They received either PBS tablets (n = 6, placebo control, placebo tablets once a day by mouth) or pioglitazone (n = 6, test drug, 7.5 mg by mouth each day). A second and final laparoscopy was performed in the baboons to record the extent of endometriotic lesions between 24 and 42 d after induction (no difference in length of treatment between the two groups, P = 0.38). A videolaparoscopy was performed to document the number and surface area of endometriotic lesions. The surface area and volume of endometriotic lesions were significantly lower in pioglitazone treated baboons than the placebo group (surface area, 48.6 vs. 159.0 mm(2), respectively, P = 0.049; vol, 23.7 vs. 131.8 mm(3), respectively, P = 0.041). The surface area (3.5 vs. 17.8 mm(2), P = 0.017, pioglizatone vs. placebo) and overall number (1.5 vs. 9.5, P = 0.007, pioglizatone vs. placebo) of red lesions were lower in the pioglitazone group. A peroxisome proliferator-activated receptor-gamma ligand, pioglitazone, effectively reduced the initiation of endometriotic disease in the baboon endometriosis model. Using this animal model, we have shown that thiazolidinedione is a promising drug for preventive treatment of endometriosis.