Project description:Trophoblasts, as the main part of placenta, undergo cell differentiation including invasion, migration, and fusion. Abnormalities in these processes can lead to a series of gestational diseases whose underlying mechanisms are still unclear. The peroxisome proliferator-activated receptor γ (PPARγ), expressed in the nuclei of extravillous trophoblasts (EVCTs) at the first trimester and villous cytotrophoblasts (VCTs) throughout the pregnancy, is proved to be essential in placentation. We aimed to explore the genome-wide effects of PPARγ on EVCTs and VCTs by the treatment of PPARγ agonist rosiglitazone. EVCTs and CTs were purified from human chorionic villi, followed by primary culture and rosiglitazone treatment. Transcriptomes of EVCTs and VCTs were performed by microarray experiments (Affymetrix and Axon). Owing to the different platforms, threshold for differentially expressed genes (DEGs) detection was performed based on 1.5-fold change and 5% FDR for EVCTs gene expression while 1% FDR was set for VCTs gene expression. Gene ontology (GO) annotation and pathways analysis of DEGs were conducted with ClueGO. PPARγ and DEGs protein interactions predicted by online tool STRING, while PPARγ and DEGs promoters binding sites prediction was conducted by iRegulon. GO and pathway terms were compared between EVCTs and VCTs through ClusterProfiler. Visualization was achieved and modified by Cytoscape. Our microarray data showed that 139 DEGs were detected in rosiglitazone-treated EVCTs (RT-EVCTs) and 197 DEGs in rosiglitazone-treated VCTs (RT-VCTs). Downstream annotation analysis showed the commons and differences between RT-EVCTs and RT-VCTs, including biological process, molecular function, cellular component, KEGG pathway and protein-protein-interaction and transcription factor – target gene binding site prediction. To sum up, our results provide a sight of view to PPARγ-activated trophoblasts performances by giving transcriptomic signatures of the RT-EVCTs and RT-VCTs and make it feasible to acquire more information for further research and find out possible drug-targeted genes or pathways in human placenta.
Project description:Human cytotrophoblast organoid cultures were established from the villous trophoblast of first trimester placentas. We analyzed the global expression profile of the cytotrophoblast organoids (CTB-ORG) and compared to the profile of the tissue of origin i.e. villous cytotrophoblast (vCTB) as well as to differentiated syncytiotrophoblast (STB) and placental fibroblasts (FIB).
Project description:During pregnancy, the placenta ensures multiple functions, which are directly involved in the initiation, fetal growth and outcome of gestation. The placental tissue involved in maternal-fetal exchanges and in synthesis of pregnancy hormones is the mononucleated villous cytotrophoblast (VCT) which aggregates and fuses to form and renew the syncytiotrophoblast (ST). Knowledge of the gene expression pattern specific to this endocrine and exchanges tissue of human placenta is of major importance to understand functions of this heterogeneous and complex tissue. Therefore, we undertook a global analysis of the gene expression profiles of primary cultured-VCT (n=6) and in vitro-differentiated-ST (n=5) in comparison with whole term placental tissue from which mononucleated VCT were isolated. A total of 880 differentially expressed genes (DEG) were observed between VCT/ST compared to whole placenta, and a total of 37 and 137 genes were significantly up and down-regulated, respectively, in VCT compared to ST. The 37 VCT-genes were involved in cellular processes (assembly, organization, and maintenance), whereas the 137 ST-genes were associated with lipid metabolism and cell morphology. In silico, all networks were linked to 3 transcriptional regulators (PPARγ, RARα and NR2F1) which are known to be essential for trophoblast differentiation. Furthermore, a subset of DEG were validated by RT-qPCR or by immunohistochemistry. To conclude, recognition of these pathways is fundamental to increase our understanding of the molecular basis of human trophoblast differentiation. The present study provides for the first time a gene expression signature of the VCT and ST compared to their originated term human placental tissue.
Project description:We showed that hypoxia directs first trimester primary villous cytotrophoblast (vCTB) differentiation preferentially towards HLAG+ extravillous trophoblast (EVT). Infection of primary vCTB with ARNT-specific shRNA attenuates this effect, suggesting a role of the intact HIF-complex in hypoxia-directed CTB differentiation into EVT.
Project description:During human pregnancy, placental cytotrophoblasts invade the uterus and its blood vessels, anchoring the progeny and rerouting maternal blood to the embryo/fetus. In preeclampsia, cytotrophoblast invasion is restricted and blood flow to the placenta is reduced. The causes of restricted cytotrophoblast invasion are unknown. Here, preeclampsia and control cytotrophoblasts were cultured for 48 h to allow differentiation/invasion. In various severe forms of preeclampsia ± intrauterine growth restriction, global transcriptional profiling revealed common aberrations in cytotrophoblast gene expression that resolved with culture. Villous cytotrophoblasts were isolated from preeclampsia placentas (PRE, n=5) and placentas of preterm labor patients without signs of infection (PTL, n=5), which served as gestation-matched controls. To better understand the CTB phenotype in the context of PE variants, we included patients with the most clinically significant forms of this condition that necessitated preterm delivery: women with severe PE ± intrauterine growth restrictions, PE with superimposed hypertension and HELLP syndrome (hemolysis, elevated liver enzymes; low platelet count). RNA was purified immediately after the cells were isolated (0 h) and after 12, 24 and 48 h in culture. The relative gene expression across the whole genome was profiled using the Affymetrix HG-U133Plus 2.0 GeneChip platform. Array quality was assesed using RMAExpress. One sample of preterm labor collected at 48h was omitted (39 arrays total). We used both LIMMA and maSigPro (R/Bioconductor) to determine differentially expressed genes.
Project description:Objective : This work aimed at characterizing PPARα involvement in metabolism regulation and at comparing PPARα and PPARγ roles in human white adipocytes. Research Design and Methods : Profiling of gene expression alterations was assessed with microarrays and RT-qPCR. Primary cultures of human adipocytes were treated with PPARα agonist GW7647 or PPARγ agonist Rosiglitazone. Western blot were used to determine protein level modifications. Metabolic changes were evaluated with palmitate and glucose oxidation studies and with metabolite measurements. Results : GW7647 induces an upregulation of β-oxidation gene expression and increases palmitate oxidation. Unexpectedly glycolysis was strongly reduced at transcriptional and functional levels by GW7647 while the overall glucose oxidation remains unaltered, leading to a decrease in pyruvate and lactate production. Moreover lipogenesis was downregulated by GW7647 inhibiting triglyceride esterification and de novo lipogenesis. GW7647 induced alterations were abolished by a PPARα antagonist treatment and were clearly different from Rosiglitazone effects. Rosiglitazone had no major impact on glycolysis and β-oxidation but increased glucose incorporation into glycerol backbone of triglycerides. Conclusions : Altogether these results show that PPARα can upregulate β-oxidation in human white adipocytes. Its pharmacological activation may be used to oxidize fatty acids in situ when lipolysis is activated thus preventing their release into systemic circulation.
Project description:Objective : This work aimed at characterizing PPARα involvement in metabolism regulation and at comparing PPARα and PPARγ roles in human white adipocytes. Research Design and Methods : Profiling of gene expression alterations was assessed with microarrays and RT-qPCR. Primary cultures of human adipocytes were treated with PPARα agonist GW7647 or PPARγ agonist Rosiglitazone. Western blot were used to determine protein level modifications. Metabolic changes were evaluated with palmitate and glucose oxidation studies and with metabolite measurements. Results : GW7647 induces an upregulation of β-oxidation gene expression and increases palmitate oxidation. Unexpectedly glycolysis was strongly reduced at transcriptional and functional levels by GW7647 while the overall glucose oxidation remains unaltered, leading to a decrease in pyruvate and lactate production. Moreover lipogenesis was downregulated by GW7647 inhibiting triglyceride esterification and de novo lipogenesis. GW7647 induced alterations were abolished by a PPARα antagonist treatment and were clearly different from Rosiglitazone effects. Rosiglitazone had no major impact on glycolysis and β-oxidation but increased glucose incorporation into glycerol backbone of triglycerides. Conclusions : Altogether these results show that PPARα can upregulate β-oxidation in human white adipocytes. Its pharmacological activation may be used to oxidize fatty acids in situ when lipolysis is activated thus preventing their release into systemic circulation. We treated four adipocyte cultures, each one coming from different subjects, with GW7647, Rosiglitazone (ROSI) or DMSO. DMSO treated cells are control samples. Thus we have four paired sample groups for each treatment (GW7647 and ROSI).
Project description:Insulin resistance and islet failure are the two etiological roots of type 2 diabetes mellitus, and understanding global islet gene expression may provide insight into the mechanisms that regulate islet function. In this study we systematically investigated the gene expression profile and proliferative response of islets to insulin sensitization, insulin resistance, and islet failure. Five-week old male Zucker Diabetic Fatty rats (n=24) were randomized into one of three groups: four-week rosiglitazone treated, rosiglitazone withdrawal, or untreated controls. Affymetrix GeneChip Rat Genome 230 2.0 gene arrays were performed on isolated islets to measure the gene expression profile of islets at 9, 11, and 13 weeks of age.