Regulations Of BMP4 On Expression Of The Key Transcription Factor For Generation Of Cholinergic Neuron

In recent years, nural stem cells have been being hot problems of neuroscience research, and it has broad prospects for clinical use in the nervous system disease treatment. In which cholinergic neurons serve a variety of functions including learning and memory, movement and others, it will lead to various of biology dysfunction, especially can trigger the central nervous system and degenerative diseases such as Alzheimer's diseases, etc. Therefore, determinants of cholinergic neurogenesis are extracellular signal factor and its associated LIM-HD protein. They are the molecular mechanism of cholinergic neurogenesis, development law,and adjustment mechanism; And also exploration central nervous system function and studies related disease treatment. They are the basis of the new target spot in the clinical care. In this sence, studing that key extracellular signal Molecula and LIM-HD which induct the cholinergic neurogenesis has the important theory significance and the great application value.In neural development, gene regulation play a decisive role in the process of model building, and neural differentiation. Which BMP family, FGF family, Wnt, Noggin mobilized to participate in the induction of neural differentiation. BMPs are TGF-βsuperfamily members, and its structure is highly conserved. It has been confirmed plays an important role in the developing nervous system. In which different subtypes of BMP at different time and place is not the same role. BMP9 low concentration in vivo, in vitro can be directly on the E14 mouse brain cells, Increases acetylcholine transferase (ChAT) expression. ChAT is a marker proteins of cholinergic neuron. BMP4 protein expresses along the ventricle in neurogenesis. The distribution of BMP4 expression regions and ChAT positive cells is consistent description BMPs can induce the occurrence of cholinergic neurons. Combination of Noggin and BMP4 inhibit BMP binding to its receptor to promote neuronal differentiation. FGF family also adopted the role of BMP inhibition to induce neuronal differentiation. After the initial induction of neuronal differentiation is still need for further specialization, This process may require specific inducing signals, such as homeobox genes.Cell fate is determined by transcription factors which can stimulate or inhibit the expression of pecific gene. In the nervous developing system, many LIM-HD protein family involved in decisions of,neuronal differentiation of types (cell fate) From the data collect, ISL-1 gene in the LIM homeobox gene family may be involved in the occurrence of development of motor neurons. In ISL-1 gene deficient mice, motor neurons can not be developed. Time there ISL-1 positive cells and development cholinergic in brain is synchronous, and there are many domains where BMP4 and cholinergic neurons co-exist. In addition, homeodomain protein family, another member of the Lhx8 gene deletion induced brain basal ganglia and other regions of the lack of cholinergic neurons, suggesting Lhx8 also decided to cholinergic neurons of the important transcription factors. Our previous work found in the E14 brain cells of rats in vitro culture system,20ng/ml BMP4 can increase acetylcholine transferase (ChAT) immunoreactive cells and promote brain cholinergic terminal differentiation of precursor cells; 40ng/ml BMP4 reduced number of ChAT-positive cells, on the cholinergic inhibition of differentiation of precursor cells. The results show that different concentrations of BMP4 on cholinergic neurons and differentiation. To further confirm that in vitro telencephalon culture system different concentrations of BMP4 on expression of homeodomain protein ISL-1 is consistent with the expression of ChAT. Through the above experimental design to infer that cholinergic neurons works by BMP4 signaling pathway in the homologous domain protein ISL-1.In this study, the discussion group on the basis of previous work, we used terminal brain cells in serum-free culture, immunocytochemical staining method. We further confirmed the in vitro telencephalon culture system, different concentrations of BMP4 on homeodomain protein ISL-1 expression is consistent with the expression of ChAT, To infer whether the cholinergic neurons BMP4 signaling pathway work by acting on the homology domain protein ISL-1.The results showed that the groups were seen homeodomain protein ISL-1 expression mainly in the nucleus. One 10ng/ml BMP4 group ISL-1 immunoreactive cells in the control group showed no significant difference; 20ng/ml BMP4 group ISL-1 positive cells significantly increased compared with other groups, this effect could be blocking BMP inhibitors Noggin break; 40ng/ml BMP4 group ISL-1 positive cells was significantly reduced.This results not only with different concentrations of BMP4 in the preliminary work on the impact of the number of ChAT positive cells in line, but with different concentrations of BMP4 induced the expression of ISL-1mRNA tallied. It suggests that BMP4 signaling pathway is not only involved in the process of cholinergic neurons but also induce homology domain protein ISL-1 expression. The results also suggest BMP4 regulate forebrain cholinergic progenitor cells to differentiate into neurons by induct homologous domain ISL-1 protein In the nervous system development, extracellular signal molecules and expression of transcription factor homology domain which decide to neural progenitor cells differentiated type in the induction, the interaction decide the types of neuron. Among the many LIM transcription factors which is the key transcription factor is the key step to study the development of cholinergic neurons. so we should to select the key factor to Start cholinergic neurons. As extracellular Information molecules, BMP4 induced cholinergic neurons may occur through the ISL-1 and Smad4 proteins act on the cholinergic locus, which starts cholinergic phenotype expression of ChAT. Therefore, ISL-1 may be the key LIM transcription factor which control the middle of the ventral telencephalon cholinergic neurons e need to further explore the interaction of the specific molecular mechanisms of the BMPs and the homeodomain transcription factor on the ChAT locus and the synergistic role of homeobox genes ISL-1 and Lhx8 in the specialized phenotype of cholinergic neurons.