Project description:With the increasing common of reduced serum testosterone (T), or hypogonadism, in the male population, there is an urgent require for the approach of obtaining T-producing cells, which could be used to treat hypogonadism based on transplantation and reestablishment of T-producing cell lineage in the body. In human, T is mainly synthesized by the Leydig cells (LCs) that have been proposed to derive from mesenchymal cells of mesonephric origin. Although mesenchymal cells have been successfully induced into LCs, the limited source and possible trauma to donors hinders their wide applications in clinic therapies. Alternatively, human induced pluripotent stem cells (hiPSCs) that are highly expandable in cell culture and have the potential to differentiate into all somatic cell types become the emerging source of autologous cell therapies. In this study, we have successfully induced the differentiation of hiPSCs through mesoderm and early mesenchymal progenitors (EMPs) into either human Leydig cell-like cells (hLLCs) or human adrenal cell-like cells (hALCs) under different chemically defined culture systems. Factors that are critical for the normal development of LCs were added to both culture systems. hLLCs are expressed all steroidogenic genes and proteins that are important for T biosynthesis and are specific for LCs, synthesize T rather than cortisol (F), secret steroid hormones in response to db-cAMP and 22(R)-hydroxycholesterol, and display ultrastructural features resembling LCs. Differentially, hALCs synthesize F rather than T, and secret much less of steroid hormones than hLLCs. Thereafter, we performed microarray analyses to profile the whole gene expression pattern of hiPSCs and thier derivatives hLLCs and hALCs.
Project description:In males, Leydig cells are the main producers of testosterone and insulin-like 3, hormones which are both essential for sex differentiation and reproductive functions. Nuclear receptor chicken ovalbumin upstream promoter-transcription factors II (COUP-TFII) is expressed in the cells committed to give rise to the fully functional steroidogenic adult Leydig cells and has a major role in their function and differentiation. Up to date, only handful of COUP-TFII gene targets have been reported. A transcriptomic approach was used to identify additional genes affected by depletion of COUP-TFII in mouse MA-10 Leydig cell line.
Project description:Testosterone production by Leydig cells is a tightly regulated process requiring synchronized expression of several steroidogenic genes by numerous transcription factors. Myocyte enhancer factor 2 (MEF2) is a transcription factor recently identified in somatic cells of the male gonad. In other tissues, MEF2 is an essential regulator of organogenesis and cell differentiation. So far in the testis, MEF2 was found to regulate Leydig cell steroidogenesis by controlling Nr4a1 and Star gene expression. To expand our understanding of the role of MEF2 in Leydig cells, we performed microarray analyses of MA-10 Leydig cells depleted in MEF2 and results were analyzed using the Partek and IPA softwares. Several genes were differentially expressed in MEF2-depleted Leydig cells and 15 were validated by qPCR. A large number of these genes are known to be involved in fertility, gonad morphology and steroidogenesis and include Pde8a, Por, Ahr, Bmal1, Cyp1a1, Cyp1b1, Map2k1, Tsc22d3, Nr0b2, Smad4, and Star, which were all downregulated in the absence of MEF2. In silico analyses revealed the presence of MEF2 binding sites within the first 2 kb upstream the transcription start site of the Por, Bmal1, and Nr0b2 promoters, which suggests a direct regulation by MEF2. Using transient transfections in MA-10 Leydig cells, siRNA knockdown, and a MEF2-Engrailed dominant negative, we found that MEF2 activates the Por, Bmal1 and Nr0b2 promoters and that this requires an intact MEF2 element. Our results identify novel target genes for MEF2 and define MEF2 as an important regulator of Leydig cell function and male reproduction. MA-10 Leydig cells were treated with siRNA MEF2A/2D (siRNA MEF2) or scrambled siRNA as control (siRNA Ctrl) 48h before total RNA extraction.
Project description:Evidence that persistent environmental pollutants may target the male reproductive system is increasing. The male reproductive system is regulated by secretion of testosterone by testicular Leydig cells, and perturbation of Leydig cells function may have ultimate consequences. 3-methylsulfonyl-DDE (3-MeSO2-DDE) is a potent adrenal toxicants formed from the persistent insecticide DDT. Although studies have revealed endocrine disruptive effect of 3-MeSO2-DDE, the underlying mechanisms at cellular level in steroidogenic Leydig cells remains to be established. The current study addresses the effect of 3-MeSO2-DDE viability, hormone production and proteome response of primary neonatal porcine Leydig cells. The AlamarBlue™ assay was used to evaluate cell viability. Solid phase radioimmunoassay was used to measure concentration of hormones produced by both unstimulated and luteinizing hormone (LH)-stimulated Leydig cells following 48 h exposure. Protein samples from Leydig cells exposed to a non-cytotoxic concentration of 3-MeSO2-DDE (10µM) were subjected to nano-LC-MS/MS and analyzed on a Q Exactive mass spectrometer and quantified using label-free quantitative algorithm. Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA) were carried out for functional annotation and identification of protein interaction networks. 3-MeSO2-DDE regulated Leydig cell steroidogenesis differentially depending on cell culture condition. Whereas its effect on testosterone secretion at basal condition was stimulatory, the effect on LH-stimulated cells was inhibitory. From triplicate experiments, a total of 7540 proteins were identified in which the abundance of 87 proteins in unstimulated Leydig cells and 146 proteins in LH-stimulated Leydig cells were found to be significantly regulated in response to 3-MeSO2-DDE exposure. These proteins not only are the first reported in relation to 3-MeSO2-DDE exposure, but also display small number of proteins shared between culture conditions, suggesting the action of 3-MeSO2-DDE on several targeted pathways, including mitochondrial dysfunction, oxidative phosphorylation, EIF2-signaling, and glutathion-mediated detoxification. Further identification and characterization of these proteins and pathways may build our understanding to the molecular basis of 3-MeSO2-DDE induced endocrine disruption in Leydig cells.
Project description:Tridimensional cardiac differentiation from hiPSCs has been largely described in the literature. However, the exact impact that 3D culture has throughout the entire process of cardiac differentiation remains poorly defined. We developed a robust and efficient 3D platform for cardiomyocyte differentiation from hiPSCs, based on the temporal modulation of WNT signalling using small molecules. 3D aggregates of hiPSCs were generated by forced aggregation in microwells and subsequently differentiated. In order to determine the differences in gene expression profile due to 3D culture throughout the different stages of cardiac differentiation, we compared transcriptional changes between cells in 3D aggregates and standard 2D monolayer cardiac differentiation. Analysis of these data suggests a faster commitment of hiPSCs toward the cardiac lineage and also higher degree of cardiomyocyte functional maturation after 20 days of culture in the 3D aggregates when compared with the 2D monolayer.
Project description:To show the similarity among MAIT-iPSCs, hiPSCs and hESCs and the gradual change of global gene expression of reMAIT cells along with differentiation, this experiment was designed. MAIT cells, MAIT-iPSCs, hiPSCs, hESCs, MAIT cells, and reMAIT cells at the several differerent stages of differentiation were collected. Then, they were applied in this experiment.