PPAR-gamma signaling pathway in placental development and function: a potential therapeutic target in the treatment of gestational diseases

Proteomics analysis of plasm exosomes in early pregnancy among normal pregnant women and those with antiphospholipid syndrome

Introduction

Antiphospholipid syndrome (APS) is an autoimmune disorder associated with thrombosis and adverse obstetric outcomes. Early diagnosis and intervention can improve pregnancy outcomes to some extent, but current results are unsatisfactory. Exosomes, containing biomacromolecules relevant to reproduction, play essential roles in pregnancy. However, research progress on their involvement in APS remains limited.

Objectives

This study aims to investigate protein profile changes in plasma exosomes and identify potential biomarkers for obstetric APS.

Methods

We employed tandem mass tag (TMT) markers to analyze exosome protein profiles from 6 healthy early pregnant women and 6 early-stage APS patients. Quantitative proteomics analysis was conducted using the Maxquant search engine.

Results

Differential expression analysis identified 51 upregulated and 22 downregulated proteins in plasma exosomes from early pregnant women with APS, such as serpin peptidase inhibitor C1/A1/A7, apolipoprotein 1/2, orosomucoid 1/2 and apolipoprotein H. Kyoto Encyclopedia of Genes and Genomes analysis shows that differentially expressed proteins are enriched in the PPAR signaling pathway and staphylococcus aureus infection pathway. Enrichment analysis indicated associations with glycerolipid biosynthesis, vitamin transport, and negative regulation of very-low-density lipoprotein particle remodeling.

Conclusion

Our study highlights alterations in the protein profiles of plasma exosomes in APS pregnant patients and proposes potential biomarkers, offering insights for early diagnosis and treatment and improving reproductive outcomes.

f25, a novel synthetic quinoline derivative, inhibits tongue cancer cell invasion and survival by the PPAR pathway in vitro and vivo

Tongue cancer has a very high incidence in China, and there is a need to develop new anti-tumour drugs against it. We synthesised 31 novel quinoline derivatives to test their anti-tumour activity. A compound referred to as "f25" was identified through screening for its high in vitro toxicity against an oral squamous carcinoma cell line (CAL-27). f25 exhibited significant cytotoxicity against CAL-27 cells (IC50 = 7.70 ± 0.58 μΜ). f25 also inhibited the migration and invasion of CAL-27 cells to a level comparable with that of the chemotherapy agent cisplatin. Moreover, f25 promoted the apoptosis of CAL-27 cells. Transcriptome sequencing and western blotting showed that the mechanism of action of f25 against CAL-27 cells involved the peroxisome proliferator-activated receptor (PPAR) signalling pathway. Specifically, f25 could bind to PPAR-α, PPAR-β, and PPAR-γ and increase their expression. In vivo experiments showed that treatment with f25 led to a reduction in tumour volume in nude mice without significant toxicity. Overall, this study highlights the potential of quinoline compounds (particularly f25) for the design and synthesis of anti-tumour drugs. It also underscores the importance of the PPAR signalling pathway as a target for potential cancer therapies.

The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism

Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. Late miscarriages are mostly caused by factors such as cervical insufficiency. However, the causes of 50% of miscarriages remain unknown. Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidation‒reduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. Depending on aetiology, the current treatments for miscarriage include hormonal and immunological drugs, as well as surgery, while there are few therapies for metabolism. Therefore, we also summarize the drugs for metabolism-related targets. The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies.

DHA supplementation and pregnancy complications

Docosahexaenoic acid (DHA) supplementation is recommended for women during pregnancy because of its neurological, visual, and cognitive effects. Previous studies have suggested that DHA supplementation during pregnancy may prevent and treat certain pregnancy complications. However, there are contradictions in the current related studies, and the specific mechanism by which DHA acts remains unclear. This review summarizes the research on the relationship between DHA intake during pregnancy and preeclampsia, gestational diabetes mellitus, preterm birth, intrauterine growth restriction, and postpartum depression. Furthermore, we explore the impact of DHA intake during pregnancy on the prediction, prevention, and treatment of pregnancy complications as well as its impact on offspring neurodevelopment. Our results suggest that there is limited and controversial evidence for the protective effect of DHA intake on pregnancy complications, with the exception of preterm birth and gestational diabetes mellitus. However, additional DHA supplementation may improve long-term neurodevelopmental outcomes in the offspring of women with pregnancy complications.

Understanding PPARγ and Its Agonists on Trophoblast Differentiation and Invasion: Potential Therapeutic Targets for Gestational Diabetes Mellitus and Preeclampsia

The increasing incidence of pregnancy complications, particularly gestational diabetes mellitus (GDM) and preeclampsia (PE), is a cause for concern, as they can result in serious health consequences for both mothers and infants. The pathogenesis of these complications is still not fully understood, although it is known that the pathologic placenta plays a crucial role. Studies have shown that PPARγ, a transcription factor involved in glucose and lipid metabolism, may have a critical role in the etiology of these complications. While PPARγ agonists are FDA-approved drugs for Type 2 Diabetes Mellitus, their safety during pregnancy is not yet established. Nevertheless, there is growing evidence for the therapeutic potential of PPARγ in the treatment of PE using mouse models and in cell cultures. This review aims to summarize the current understanding of the mechanism of PPARγ in placental pathophysiology and to explore the possibility of using PPARγ ligands as a treatment option for pregnancy complications. Overall, this topic is of great significance for improving maternal and fetal health outcomes and warrants further investigation.

The Role of Peroxisome Proliferator-Activated Receptors in Preeclampsia

Preeclampsia is a common pregnancy-related hypertensive disorder. Often presenting as preexisting or new-onset hypertension complicated by proteinuria and/or end-organ dysfunction, preeclampsia significantly correlates with maternal and perinatal morbidity and mortality. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptor proteins that regulate gene expression. In order to investigate the role of PPARs in the pathophysiology of preeclampsia, we conducted a literature review using the MEDLINE and LIVIVO databases. The search terms "peroxisome proliferator-activated receptor", "PPAR", and "preeclampsia" were employed and we were able to identify 35 relevant studies published between 2002 and 2022. Different study groups reached contradictory conclusions in terms of PPAR expression in preeclamptic placentae. Interestingly, PPARγ agonists alone, or in combination with well-established pharmaceutical agents, were determined to represent novel, potent anti-preeclamptic treatment alternatives. In conclusion, PPARs seem to play a significant role in preeclampsia.

Protective effect of nimbolide against streptozotocin induced gestational diabetes mellitus in rats via alteration of inflammatory reaction, oxidative stress, and gut microbiota

BACKGROUND

Gestational diabetes mellitus (GDM) is a significant pregnancy-related condition, which showed effect on the development of fetal. Anti-inflammatory and antioxidant therapy commonly used for the treatment of GDM. Nimbolide already confirmed their anti-inflammatory and anti-oxidant effect against various animal disease model. Our objective in this research is to investigate the protective effect of nimbolide against STZ induced GDM and elucidate the mechanism.

METHODS

In this experimental study, pregnant female Wistar rats were used and STZ (40 mg/kg) was used to induce the GDM. Blood glucose level (BGL), body weight and plasma insulin were assessed at regular time (gestational day 0, 9, and 18). Water intake, food intake, fecal and urine output were also estimated. In the female rats, hemoglobin (Hb), glycalated hemoglobin (HbA1c), hepatic glycogen, fructosamine, adiponectin, leptin, lipid, antioxidant and inflammatory cytokines parameters were estimated. In the fetuses, the fetues weight, implementation loss, and fetal weight were estimated. At the completion of the protocol, biochemical parameters were calculated. Gut microbiota was estimated in end of the study.

RESULTS

Nimbolide treatment significantly (p < .001) improved the fetuses level and suppressed the fetal weight and implantation loss. Nimbolide treatment significantly (p < .001) suppressed the BGL and enhanced the body weight, insulin level. Nimbolide treatment suppressed the water intake, food intake, urinary and fecal output. Nimbolide significantly (p < .001) suppressed the fructosamine, leptin and enhanced the adiponectin level. Nimbolide treatment significantly (p < .001) decreased the malonaldehyde (MDA) level and boosted the total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and catalase (CAT); suppressed the level of TNF-α, IL-1β, IL-6, and boosted the level of IL-10. Furthermore, nimbolide treatment reversed the gut microbiota alteration induced via STZ in female rats. At the phylum level, the Firmicutes and Bacteroidetes relative abundance was altered via nimbolide treatment. The ratio of F/B boosted in GDM group and nimbolide treatment significantly (p < .001) suppressed. Nimbolide considerably suppressed the firmicutes and enhanced the Bacteroidetes, CAG-352, Lacnospirace.

CONCLUSION

Based on the findings, we may conclude that nimbolide protects the pregnant rats from GDM via alteration of inflammation, oxidative stress, and gut microbiota.

PFOS Inhibited Normal Functional Development of Placenta Cells via PPARγ Signaling

Perfluorooctane sulfonic acid (PFOS), a persistent environmental pollutant, has adverse effects on gestation pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) is involved in angiogenesis, metabolic processes, anti-inflammatory, and reproductive development. However, the function of PPARγ in PFOS evoked disadvantageous effects on the placenta remain uncertain. Here, we explored the role of PPARγ in PFOS-induced placental toxicity. Cell viability, cell migration, angiogenesis, and mRNA expression were monitored by CCK-8 assay, wound healing assay, tube formation assay, and real-time PCR, respectively. Activation and overexpression of PPARγ were conducted by rosiglitazone or pcDNA-PPARγ, and inhibition and knockdown of PPARγ were performed by GW9662 or si-PPARγ. Results revealed that PFOS decreased cell growth, migration, angiogenesis, and increased inflammation in human HTR-8/SVneo and JEG-3 cells. Placenta diameter and fetal weight decreased in mice treated with PFOS (12.5 mg/kg). In addition, rosiglitazone or pcDNA-PPARγ rescued cell proliferation, migration, angiogenesis, and decreased inflammation induced by PFOS in HTR8/SVneo and JEG-3 cells. Furthermore, GW9662 or si-PPARγ exacerbated the inhibition of cell viability, migration, angiogenesis, and aggravated inflammation induced by PFOS in HTR-8/SVneo and JEG-3 cells. Meanwhile, the results of mRNA expression level were consistent with the cell representation. In conclusion, our findings revealed that PFOS induced placenta cell toxicity and functional damage through PPARγ pathway.

Enhancer RNA lnc-CES1-1 inhibits decidual cell migration by interacting with RNA-binding protein FUS and activating PPARγ in URPL

Unexplained recurrent pregnancy loss (URPL) is a significant reproductive health issue, affecting approximately 5% of pregnancies. Enhancer RNAs (eRNAs) have been reported to play important roles during embryo development and may be related to URPL. To investigate whether and how eRNAs are involved in URPL, we performed RNA sequencing in decidual tissue. Through comprehensive screening and validation, we identified a decidua-enriched eRNA long noncoding-CES1-1 (lnc-CES1-1) enriched in URPL patients and studied its function in decidua-associated cell lines (DACs). Higher expression of lnc-CES1-1 increased the level of inflammatory factors tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) and impaired the cell migration ability, which was attenuated by downregulating peroxisome proliferators-activated receptor γ (PPARγ). Upon activation by signal transduction and activation of transcription 4 (STAT4), lnc-CES1-1 interacted with the transcription factor fused in sarcoma (FUS) to upregulate the expression of PPARγ and affected cell migration. Taken together, these findings provide novel insights into the biological functions of decidua-associated lnc-CES1-1 and the molecular mechanisms underlying URPL. Our findings indicated that lnc-CES1-1 might be a potential candidate biomarker for URPL diagnosis and treatment.

Differences in expression of Peroxisome Proliferator-activated Receptor-γ in early-onset preeclampsia and late-onset preeclampsia

OBJECTIVE

PPARγ is a ligand-binding transcription factor that has been reported to be implicated in lipid metabolism, immune function, and cellular growth and differentiation. It has been suspected to play a role in the pathophysiology of preeclampsia, although the mechanism is yet to be elaborated. This study aims to investigate the expression of PPARγ in early onset preeclampsia (EOPE), late onset preeclampsia (LOPE), and normal pregnancy. We conducted this study using primary trophoblastic cell culture incubated with serum from EOPE, LOPE, and normal pregnancy. The expression of PPARγ in these cells was analyzed using Western Blot. Statistical analysis was performed using one-way ANOVA and Bonferroni's post hoc test. p < 0.05 is considered significant.

RESULTS

Serum from normal pregnant women and EOPE did not induce any difference in the expression of PPAR-γ (p > 0.05). In contrast, expression of PPAR-γ was increased in those cells induced by serum from LOPE (p < 0.001). Therefore, we conclude that hypothetically PPAR-γ might play role in the pathophysiology of LOPE but not in EOPE. Other possibility is the activity of PPAR-γ in EOPE is inversely correlated with its expression, therefore the high enzymatic activity of PPAR-γ is tightly regulated by attenuating its expression.

Treating diabetes during pregnancy

INTRODUCTION

Gestational diabetes mellitus (GDM), defined as glucose intolerance with first recognition or onset during pregnancy, is steadily rising in prevalence. GDM affects ∼ 3 - 5% of pregnancies in the US and is associated with significant adverse perinatal and maternal outcomes. Diagnosing and treating GDM early in pregnancy is of utmost importance as it can prevent poor outcomes such as macrosomia, shoulder dystocia and obstetric complications.

AREAS COVERED

This review describes the importance of treating GDM and the various available interventions for glycemic control in women with GDM, including the latest evidence regarding pharmacological treatments and specifically anti-hyperglycemic agents. It deals with timing of pharmacological treatments, recommended doses and what pharmacological agent should be used.

EXPERT OPINION

Unless diagnosed late during pregnancy, a stepwise approach is the best way to treat GDM, beginning with diet and exercise and proceeding to pharmacological interventions if failure occurred. Although insulin is the dominant treatment, the use of anti-hyperglycemic agents such as glyburide and metformin in treating GDM has gained popularity and consideration should be made using these agents as first-line pharmacological treatment. Anti-hyperglycemic agents do not require frequent monitoring or injections and may therefore appeal more to patients. Further studies are needed regarding long-acting insulin and other anti-hyperglycemic agents such as thiazolidinediones, as well as identifying treatment options more specific to an individual based on risk factors and other variables predicting treatment outcomes in GDM.

Gestational diabetes mellitus alters apoptotic and inflammatory gene expression of trophobasts from human term placenta

AIM

Increased placental growth secondary to reduced apoptosis may contribute to the development of macrosomia in GDM pregnancies. We hypothesize that reduced apoptosis in GDM placentas is caused by dysregulation of apoptosis related genes from death receptors or mitochondrial pathway or both to enhance placental growth in GDM pregnancies.

METHODS

Newborn and placental weights from women with no pregnancy complications (controls; N=5), or with GDM (N=5) were recorded. Placental villi from both groups were either fixed for TUNEL assay, or snap frozen for gene expression analysis by apoptosis PCR microarrays and qPCR.

RESULTS

Maternal, placental and newborn weights were significantly higher in the GDM group vs. Controls. Apoptotic index of placentas from the GDM group was markedly lower than the Controls. At a significant threshold of 1.5, seven genes (BCL10, BIRC6, BIRC7, CASP5, CASP8P2, CFLAR, and FAS) were down regulated, and 13 genes (BCL2, BCL2L1, BCL2L11, CASP4, DAPK1, IκBκE, MCL1, NFκBIZ, NOD1, PEA15, TNF, TNFRSF25, and XIAP) were unregulated in the GDM placentas. qPCR confirmed the consistency of the PCR microarray. Using Western blotting we found significantly decreased placental pro-apoptotic FAS receptor and FAS ligand (FASL), and increased mitochondrial anti-apoptotic BCL2 post GDM insult. Notably, caspase-3, which plays a central role in the execution-phase of apoptosis, and its substrate poly (ADP-ribose) polymerase (PARP) were significantly down regulated in GDM placentas, as compared to non-diabetic Control placentas.

CONCLUSION

Maternal GDM results in heavier placentas with aberrant placental apoptotic and inflammatory gene expression that may account, at least partially, for macrosomia in newborns.

Inhibition of PPARγ during rat pregnancy causes intrauterine growth restriction and attenuation of uterine vasodilation

Decreased peroxisome proliferator-activated receptor gamma (PPARγ) activity is thought to have a major role in preeclampsia through abnormal placental development. However, the role of PPARγ in adaptation of the uteroplacental vasculature that may lead to placental hypoperfusion and fetal growth restriction during pregnancy is not known. Here, pregnant Sprague-Dawley rats (n = 11/group) were treated during the second half of pregnancy with the PPARγ inhibitor GW9662 (10 mg/kg/day in food) or vehicle. Pregnancy outcome and PPARγ mRNA, vasodilation and structural remodeling were determined in maternal uterine and mesenteric arteries. PPARγ was expressed in uterine vascular tissue of both non-pregnant and pregnant rats with ~2-fold greater expression in radial vs. main uterine arteries. PPARγ mRNA levels were significantly higher in uterine compared to mesenteric arteries. GW9662 treatment during pregnancy did not affect maternal physiology (body weight, glucose, blood pressure), mesenteric artery vasodilation or structural remodeling of uterine and mesenteric vessels. Inhibition of PPARγ for the last 10 days of gestation caused decreased fetal weights on both day 20 and 21 of gestation that was associated with impaired vasodilation of radial uterine arteries in response to acetylcholine and sodium nitroprusside. These results define an essential role of PPARγ in the control of uteroplacental vasodilatory function during pregnancy, an important determinant of blood flow to the placenta and fetus. Strategies that target PPARγ activation in the uterine circulation could have important therapeutic potential in treatment of pregnancies complicated by hypertension, diabetes or preeclampsia.

Homeobox genes and down-stream transcription factor PPARγ in normal and pathological human placental development

The placenta provides critical transport functions between the maternal and fetal circulations during intrauterine development. Formation of this interface is controlled by nuclear transcription factors including homeobox genes. Here we summarize current knowledge regarding the expression and function of homeobox genes in the placenta. We also describe the identification of target transcription factors including PPARγ, biological pathways regulated by homeobox genes and their role in placental development. The role of the nuclear receptor PPARγ, ligands and target genes in human placental development is also discussed. A better understanding of these pathways will improve our knowledge of placental cell biology and has the potential to reveal new molecular targets for the early detection and diagnosis of pregnancy complications including human fetal growth restriction.

Expression of peroxisome proliferator activated receptor-gamma (PPAR-γ) in human non-small cell lung carcinoma: correlation with clinicopathological parameters, proliferation and apoptosis related molecules and patients' survival

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has currently been considered as molecular target for the treatment of human metabolic disorders. PPAR-γ has also been implicated in the pathogenesis and progression of several types of cancer, being associated with cell differentiation, growth and apoptosis. The present study aimed to evaluate the clinical significance of PPAR-γ expression in non-small cell lung carcinoma (NSCLC). PPAR-γ protein expression was assessed immunohistochemically in tumoral samples of 67 NSCLC patients and was statistically analyzed in relation to clinicopathological parameters, proliferation and apoptosis related molecules and patients' survival. Positive PPAR-γ expression was prominent in 30 (45 %) out of 67 NSCLC cases. PPAR-γ positivity was more frequently observed in squamous cell lung carcinoma cases compared to lung adenocarcinoma ones (p = 0.048). PPAR-γ positivity was significantly associated with bcl-2 positivity (p = 0.016) and borderline with c-myc positivity (p = 0.052), whereas non associations with grade of differentiation, TNM stage, Ki-67, p53, bax proteins' expression and patients' survival were noted. In the subgroup of squamous cell lung carcinoma cases, PPAR-γ positivity was significantly associated with tumor size (p = 0.038), while in lung adenocarcinoma ones with histopathological grade of differentiation (p = 0.026). The present study supported evidence for possible participation of PPAR-γ in the biological mechanisms underlying the carcinogenic evolution of the lung. Although the survival prediction using PPAR-γ expression as a marker seems uncertain, the observed correlation with apoptosis related proteins reinforces the potential utility of PPAR-γ ligands as cell cycle modulators in future therapeutic approaches in lung cancer.

Correlation of Peroxisome Proliferator-Activated Receptor-gamma (PPAR-gamma) and Retinoid X Receptor-alpha (RXR-alpha) expression with clinical risk factors in patients with advanced carotid atherosclerosis

Background

Peroxisome proliferator-activated Receptor-γ (PPAR-γ) and its nuclear partners, the Retinoid X Receptors (RXRs), have been recognized as crucial players in the pathogenesis of atherosclerosis. The present study aimed to assess the clinical significance of PPAR-γ and RXR-α expression in different cellular populations localized within advanced carotid atherosclerosis lesions.

Material/Methods

PPAR-γ and RXR-α expression was assessed by immunohistochemistry ïn 134 carotid atherosclerotic plaques obtained from an equal number of patients that underwent endarterectomy procedure for vascular repair, and was correlated with patients’ medical history, risk factors and medication intake.

Results

Increased incidence of low PPAR-γ expression in both macrophages and smooth muscle cells was noted in patients presenting coronary artery disease (p=0.032 and p=0.046, respectively). PPAR-γ expression in smooth muscle cells was borderline down-regulated in symptomatic compared to asymptomatic patients (p=0.061), reaching statistical significance when analyzing groups of patients with specific cerebrovascular events; amaurosis fugax (p=0.008), amaurosis fugax/stroke (p=0.020) or amaurosis fugax/transient ischemic attack patients (p=0.028) compared to asymptomatic patients. Low RXR-α expression in macrophages was more frequently observed in hypertensive (p=0.048) and hyperlipidemic patients (p=0.049). Increased incidence of low RXR-α expression in smooth muscle cells was also noted in patients presenting advanced carotid stenosis grade (p=0.015).

Conclusions

PPAR-γ and RXR-α expression down-regulation in macrophages and smooth muscle cells was associated with a more pronounced disease progression in patients with advanced carotid atherosclerotic lesions.

PPARγ and human trophoblast differentiation

The peroxisome proliferator-activated receptor-γ (PPARγ) is a member of the nuclear receptor superfamily that controls in a ligand-dependent manner the expression of a large array of genes involved in the control of energy homeostasis and in cell differentiation, proliferation, apoptosis, and the inflammatory process. Unexpectedly, genetic studies performed in mice established that PPARγ is essential for placental development. In the human placenta, PPARγ is specifically expressed in the trophoblast, both endocrine villous and invasive extravillous cytotrophoblasts (EVCT). Activation of PPARγ induces accumulation of lipids, villous trophoblast differentiation and inhibits trophoblast invasiveness. Oxidized LDLs that contain potential PPARγ ligands, but not native LDL, induce PPARγ transcriptional activity and inhibit trophoblast invasion in vitro. Recently, human cytomegalovirus (HCMV) was shown to activate trophoblastic PPARγ for its own replication and consequently inhibits invasiveness of infected cytotrophoblasts. Analysis of PPARγ target genes revealed trophoblastic factors described to control trophoblast invasiveness and surprisingly chorionic gonadotropin hormone (hCG), known to be mainly produced by the endocrine villous trophoblast. Analysis of hCG gene expression revealed opposite regulation by PPARγ in the two trophoblast subtypes. Finally, a hyperglycosylated form of hCG (hCG-H) only produced by invasive EVCT was shown to promote trophoblast invasion. Together, these data underscore the major role of PPARγ and its target genes, such as hCG, in the control of human trophoblast differentiation and invasion, and suggest that over-activation of this nuclear receptor following HCMV infection or by excess of ligands at the maternal-fetal interface could impair implantation and placentation and therefore embryonic development.

The possible role of epigenetics in gestational diabetes: cause, consequence, or both

Gestational diabetes mellitus (GDM) is defined as the glucose intolerance that is not present or recognized prior to pregnancy. Several risk factors of GDM depend on environmental factors that are thought to regulate the genome through epigenetic mechanisms. Thus, epigenetic regulation could be involved in the development of GDM. In addition, the adverse intrauterine environment in patients with GDM could also have a negative impact on the establishment of the epigenomes of the offspring.

SIRT1 is a novel regulator of key pathways of human labor

Human sirtuin (SIRT) 1 and SIRT2, which possess nicotinamide adenosine dinucleotide (NAD(+))-dependent deacetylase activity, exhibit anti-inflammatory actions. However, there are no data available on SIRT1 and SIRT2 expression and regulation in human intrauterine tissues. Thus, the aim of this study was to characterize the localization and expression of SIRT1 and SIRT2 in 1) placenta and fetal membranes before and after term spontaneous labor onset, 2) prelabor fetal membranes from the supracervical site (SCS) and a distal site (DS), and 3) in response to proinflammatory stimuli. Further, the effect of SIRT activation using resveratrol and SRT1720 on prolabor mediators was also assessed. SIRT1 and SIRT2 were localized in the syncytiotrophoblast layer and the cytotrophoblasts of the placenta, amnion epithelium, trophoblast layer of the chorion, and decidual cells. Additionally, SIRT2 was found within the endothelial walls of placental vessels. SIRT2, but not SIRT1, staining was significantly lower in amnion and chorion obtained from the SCS compared to a DS. On the other hand, SIRT1, but not SIRT2, gene and/or protein expression was significantly lower in placenta, amnion, and chorion obtained after labor compared to prelabor. SIRT1 expression, but not SIRT2, was down-regulated by lipopolysaccharide (LPS) and proinflammatory cytokines TNF and IL1B. The SIRT1 activators resveratrol and SRT1720 significantly decreased LPS-induced TNF, IL6, and IL8 gene expression and release and PTGS2 mRNA expression and resultant prostaglandin (PG) E(2) and PGF(2α) release from human gestational tissues. In conclusion, SIRT1 possesses anti-inflammatory actions and thus may play a role in regulating pregnancy and parturition.

Nuclear receptors of the peroxisome proliferator-activated receptor (PPAR) family in gestational diabetes: from animal models to clinical trials

Gestational diabetes mellitus (GDM) is defined as impaired glucose tolerance and affects 2%-8% of all pregnancies. Among other complications, GDM can lead to the development of type 2 diabetes mellitus (DM 2) in both mother and child. Peroxisome proliferator-activated receptors (PPARs) are major regulators of glucose and lipid metabolism. Furthermore, PPARs are mediators of inflammation and angiogenesis and are involved in the maternal adaptational dynamics during pregnancy to serve the requirements of the growing fetus. PPARs were originally named for their ability to induce hepatic peroxisome proliferation in mice in response to xenobiotic stimuli. The expression of three PPAR isoforms, alpha, beta/delta, and gamma, have been described. Each of them is encoded by different genes; however, they share 60%-80% homology in their ligand-binding and DNA-binding domains. PPARs are involved in trophoblast differentiation, invasion, metabolism, and parturition and are expressed in invasive extravillous trophoblast and villous trophoblast cells. Nuclear receptors, to which PPARs belong, are promising targets for disease-specific treatment strategies because they act as transcription factors controlling cellular processes at the level of gene expression and may produce selective alterations in downstream gene expression. To date, PPAR agonists are therapeutically used in patients with DM 2 and in patients with reproductive disorders such as polycystic ovary syndrome. Because of safety concerns and limited data, PPAR agonists are not yet included in GDM-related treatment strategies. Our objective herein is to review newly emerging generations of selective PPAR modulators and panagonists, which may have potent therapeutic implications in the context of GDM.

Transcriptional regulation of the processes of human labour and delivery

Preterm birth is the most important complication contributing to poor pregnancy and neonatal outcome. A critical issue that must be resolved is how spontaneous onset labour is initiated both at term and preterm. Over the past decade, we and others have provided evidence in support of the hypothesis that labour onset is regulated by specific nuclear regulatory factor (NR) pathways, involving an interplay between transcription factors (TFs) and nuclear hormone receptors, that control the expression of many of the effector pathways requisite for labour and delivery. There is now compelling evidence implicating NRs, including the nuclear factor-kappaB (NF-kappaB) family of nuclear TFs, the nuclear hormone receptor superfamily of peroxisome proliferator activated receptors (PPARs), and the steroid receptors for progesterone (PRA, PRB and PRC), as candidate upstream regulators of labour-associated processes. Based on these studies and recent data obtained in our laboratory, we provide a new model of how the multiple pathways involved in spontaneous onset labour and delivery are coordinated at a nuclear level. We propose that spontaneous onset labour and delivery are consequent upon withdrawal of the repressive effect of nuclear receptors (PPAR and PR) on pro-labour TF pathways (NF-kappaB). The withdrawal of NR-mediated repression is affected by competition between TFs and NRs for a limited pool of nuclear cofactors. We also propose that coordination of these different pathways is achieved by competition for common cofactors that control the activity of NRs in human gestational tissues.