Transcription of cytoskeleton protein genes in differentiation of neurons from mouse embryonic stem cells induced by small molecules / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the transcription of cytoskeleton protein genes in differentiation of neurons from mouse embryonic stem (ES) cells induced by all-trans retinoic acid (RA), and to explore the possibility of setting up a method to screen small molecules with promoting or inhibiting effect.</p><p><b>METHODS</b>The hanging drop method was employed for embryonic body formation to mimic embryo development in vivo. Reverse transcriptase PCR (RT-PCR) was performed to investigate mRNA expression of the neuron-specific cytoskeleton proteins including Mtap2, Nefm and beta-tubulin III which were regarded as the inducing effect indexes of RA. Morphological evaluation and immunocytochemistry staining were conducted to identify the neural derivatives. Moreover, the inducing effects of six synthetic molecules were further evaluated.</p><p><b>RESULT</b>RA up-regulated the mRNA expression of Mtap2 and Nefm, especially Mtap2 increased by 1.27 times, which was consistent with the morphological alteration. However, there was no significant changes of beta-tubulin III expression. With addition of the six synthetic molecules, the transcription of Mtap2 was inhibited, while the Nefm mRNA expression was up-regulated in some degree, especially for molecule 1 and 3 that was increased by 1.4 and 1.2 times, which, however, was not parallel to the morphological changes.</p><p><b>CONCLUSION</b>The transcriptional levels of Mtap2 and Nefm are both up-regulated in the RA-induced differentiation of ES cells towards neurons. The up-regulation of Mtap2 is consistent with the morphological alteration, which might be the key landmark in the RA-induced differentiation of ES cells into neurons.</p>

Forebrain NMDA receptor 2B subunit over-expression has no influence on anxiety behaviors of mice / 生理学报

It has been known that the glutamate transmission system and N-methyl-D-aspartate receptor (NMDA-R) were possibly related to anxiety processes. Although anxiety symptom can be relieved by NMDA-R antagonists and partial agonists treatment, the functions of NMDA-R and its subunits in anxiety behaviors remain unclear. We used forebrain specific NR2B over-expression mice to examine whether the increase of NR2B subunit level would induce anxiety behaviors. The results indicated that the juvenile (3-5 months old), middle-aged (8-10 months old) and old (19-22 months old ) NR2B transgenic mice showed no significant difference in open field test and elevated plus maze test as compared with the control mice. Capillary electrophoresis of monoamine neurotransmitter in subregions of forebrain revealed no significant difference between transgenic and control mice of 16-18 months age. These results suggest that the increase of NR2B expression and followed NR1 and NR2A expression augmentations in the forebrain have no significant effect on anxiety-related behaviors in mice.