Expression of Junctophilin 1 during cardiogenesis of mouse embryonic stem cells and rat embryos / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the expression of Junctophilin 1 (JP1) in cardiogenesis of mammalian.</p><p><b>METHODS</b>Cardiac differentiation of embryonic stem cells (ESCs) was generated by hanging drop method. Fetal heart was obtained from the rats aged d 14-20 of gestation. The expression of JP1 and JP2 during cardiogenesis of ESCs and rat embryos was analyzed by RT-PCR or Western blotting. Immunofluorescence staining was employed to reveal the distribution of JP1 and JP2 in embryoid body (EB), probing for merging of JP1 and JP2 and cardiac sarcomeric α-Actinin or Troponin-T. Percentage of JP1 and JP2-positive staining cells was analyzed quantitatively by FCS on d17.</p><p><b>RESULTS</b>JP1 mRNA was up-regulated at the early stage (d 5-11) and then decreased. The expression of JP1 protein was up-regulated at the early stage (d 7-9), then decreased gradually and disappeared after d 15. While JP2 gene and protein expression increased in a time-dependent manner during cardiogenesis of rat embryos. The results of immunofluorescence staining showed that there was a parallel co-localization of JP2 with Troponin-T or α-Actinin on d17, while JP1 failed to express in the sarcomeric positive area at the same time point. Furthermore, FCS analysis showed that about 16.59% of cells were JP2-positive, while no cells were stained positively for JP1 in d17 EBs.</p><p><b>CONCLUSION</b>JP1 gene is expressed during the whole process of cardiogenesis, while JP1 protein only appears on the early stage. The expression of JP1 in cardiogenesis of ESCs is consistent with that of rat embryos.</p>

Establishment of optimized neuronal differentiation-promoting model derived from P19 embryonic carcinoma cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish an optimized primary drug screen model of neuronal differentiation using P19 embryonal carcinoma cells.</p><p><b>METHODS</b>The final concentration of retinoid acid (RA), days of suspension culture, manner of adherent culture, suitable cell density and adherent culture medium were tested, respectively. Two stages of neuronal differentiation were examined based on morphological changes and immunocytochemistry analysis of neuronal specific protein β-tubulin III.</p><p><b>RESULTS</b>On d 8 of differentiation culture, neuron-like cells were observed with final concentration of 1 μmol/L RA. Neuron-like network was formed on d 16 of neuronal differentiation. β-tubulin III was positively stained on both stages, indicating P19 cells were differentiated into neurons.</p><p><b>CONCLUSION</b>The model using RA to induce P19 embryonic carcinoma cells to differentiate into neuron-like cells has been successfully established, which may provide a rapid, phenotypic cell-based platform for primary screening of neurogenesis-promoting drugs.</p>