Project description:In the chorionic villi of placenta, trophoblasts and endothelial cells are present, and moreover mesenchymal cells (stromal cells) can be obtained. We generated cells with the mesenchymal phenotype from the chorionic mesoderm, and showed that: a) physiologically functioning cardiomyocytes were transdifferentiated from human placenta-derived chorionic villi cells, but these cells did not induce to osteoblasts and adipocytes ; b) the cardiomyogenic induction rate obtained using our system was relatively high compared to that obtained using the previously described method ; c) co-cultivation with fetal murine cardiomyocytes alone without transdifferentiation factors such as 5-azaC or oxytocin is sufficient for cardiomyogenesis in our system; d) Chorionic villi cells have the electrophysiological properties of 'working' cardiomyocytes. The chorionic mesoderm contained a large number of cells with a cardiomyogenic potential. Experiment Overall Design: To isolate chorionic villi cells, we used the explant culture method, in which the cells were outgrown from pieces of chorionic villi attached to dishes. Chorionic villi cells were harvested with 0.25% trypsin and 1 mM EDTA, and overlaid onto the cultured fetal cardiomyocytes at 7 x 103/cm2. Every 2 days, the culture medium was replaced with fresh culture medium that was supplemented with 10% FBS and 1 ug/ml Amphotericin B (GIBCO). The morphology of the beating chorionic villi cells was evaluated under a fluorescent microscope.
Project description:In the chorionic villi of placenta, trophoblasts and endothelial cells are present, and moreover mesenchymal cells (stromal cells) can be obtained. We generated cells with the mesenchymal phenotype from the chorionic mesoderm, and showed that: a) physiologically functioning cardiomyocytes were transdifferentiated from human placenta-derived chorionic villi cells, but these cells did not induce to osteoblasts and adipocytes ; b) the cardiomyogenic induction rate obtained using our system was relatively high compared to that obtained using the previously described method ; c) co-cultivation with fetal murine cardiomyocytes alone without transdifferentiation factors such as 5-azaC or oxytocin is sufficient for cardiomyogenesis in our system; d) Chorionic villi cells have the electrophysiological properties of 'working' cardiomyocytes. The chorionic mesoderm contained a large number of cells with a cardiomyogenic potential. Keywords: Cardiomyogenic induction
Project description:The placenta is considered one of the candidate cell sources in cellular therapeutics because of a large number of cells and heterogenous cell population with myogenic potentials. We first analyzed myogenic potential of cells obtained from six parts of the placenta, i.e., umbilical cord, amniotic epithelium, amniotic mesoderm, chorionic plate, villous chorion (chorion frondosum), , and decidua basalis. Implantation of placenta-derived cells into dystrophic muscles of immunodeficient mdx mice restored sarcolemmal expression of human dystrophin. Co-existence of human and murine nuclei in one myotube and presence of human dystrophin in murine myotube suggests that human dystrophin expression is due to cell fusion between host murine myocytes and implanted human cells. In vitro analysis revealed that cells derived from amniotic mesoderm, chorionic plate, ,and villous chorion efficiently transdifferentiate into myotubes. These cells fused to C2C12 murine myoblasts by in vitro co-culturing, and murine myoblasts start to express human dystrophin after fusion. These results demonstrate that placenta-derived cells, especially extraembryonic mesodermal cells, have a myogenic potential and regenerative capacity of skeletal muscle. Determination of cell specification with the gene chip analysis revealed that each placental cell has a distinct expression pattern. Experiment Overall Design: To isolate chorionic villi cells, we used the explant culture method, in which the cells were outgrown from pieces of chorionic villi attached to dishes. Chorionic villi cells were harvested with 0.25% trypsin and 1 mM EDTA, and overlaid onto the cultured fetal cardiomyocytes at 7 x 103/cm2. Every 2 days, the culture medium was replaced with fresh culture medium that was supplemented with 10% FBS and 1 ug/ml Amphotericin B (GIBCO). The morphology of the beating chorionic villi cells was evaluated under a fluorescent microscope.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.