Micro Rna-499C Induces the Differentiation of Mouse Embryonic Stem Cells (mESCs) into Cardiomyocytes

Background: A microRNA, miR499c, has been discovered in human fetal heart which rescues mutant hearts in cardiac nonfunction mutant axolotl (salamander) embryos and also induces the differentiation of mouse embryonic stem cells (mESCs) to form into definitive cardiomyocytes. Results: Eight days after transfection with MiR499c, approximately 75-80% of the stem cells develop typical cardiomyocyte morphologies and express the cardiac specific marker, Troponin T, as well as the muscle proteins, tropomyosin and α-actinin, as shown by immunohistochemical staining. qRT-PCR confirms that transfection with MiR499c increases expression of troponin T and tropomyosin and further shows an increased expression of myosin as well as Wnt11 and Sox17. Untreated controls do not show significant expression of these proteins. Conclusion: It is evident that the miR499c induces the development of contractile myofibrils characteristic of striated cardiac muscle indicating that the miR499c microRNA plays an important role in the differentiation of cardiomyocytes

Cardiac myofibiril induction

Methods and products for altering or promoting the development of heart tissue are disclosed. The methods include the use of nucleic acids of cardiogenic inducing factor for treating a subject having heart disease.U

Cardiac myofibiril induction

Methods and products for altering or promoting the development of heart tissue are disclosed. The methods include the use of nucleic acids of cardiogenic inducing factor for treating a subject having heart disease.U

Differentiation of Human Pluripotent Cell-derived Neural Rosettes to Dopaminergic Neurons by Small Molecules

A major challenge for regenerative medicine is differentiation of pluripotent cells to one of the hundreds of specialized cell types in the human body, without the introduction of animal traits or pathogens that would make them useless for transplantation. One approach to this problem is differentiation promoted by small molecules. In this work, a chemical library was prepared based on compounds that are neurotrophic for rat dopaminergic neurons and mimic some effects of glial-cell derived neurotrophic factor (GDNF). Members of a library of a N-(heteroarylsulfamoyl)-phenyl cinnamides were studied in a low-throughput phenotypic screen for their ability to promote differentiation of human pluripotent stem cell-derived neural rosettes to dopaminergic neurons, with morphological scoring. A hit series was identified and the cells resulting from compound treatments were shown by phenotypic assays to exhibit traits of the A9 dopaminergic neuron subtype. The method is effective with both hES cell- and hiPS cell-derived rosettes

Identification of a truncated form of methionine sulfoxide reductase a expressed in mouse embryonic stem cells

BACKGROUND: Methionine Sulfoxide Reductase A (MsrA), an enzyme in the Msr gene family, is important in the cellular anti-oxidative stress defense mechanism. It acts by reducing the oxidized methionine sulfoxide in proteins back to sulfide and by reducing the cellular level of reactive oxygen species. MsrA, the only enzyme in the Msr gene family that can reduce the S-form epimers of methionine sulfoxide, has been located in different cellular compartments including mitochondria, cytosol and nuclei of various cell lines. METHODS: In the present study, we have isolated a truncated form of the MsrA transcript from cultured mouse embryonic stem cells and performed eGFP fusion protein expression, confocal microscopy and real time RT-PCR studies. RESULTS: Results show a different expression response of this truncated transcript to oxygen deprivation and reoxygenation treatments in stem cells, compared to the longer full length form. In addition, a different subcellular localization pattern was noted with most of the eGFP fusion protein detected in the cytosol. CONCLUSION: One possibility for the existence of a truncated form of the MsrA transcripts could be that with a smaller protein size, yet retaining a GCWFG action site, this protein might have easier access to oxidize methionine residues on proteins than the longer form of the MsrA protein, thus having an evolutionary selection advantage. This research opens the door for further study on the role and function of the truncated MsrA embryonic mouse stem cells