The Role Of TLR4 Signaling Pathway On The Growth Of Neurons

Objective: To clarify the key role of TLR4,an important signal molecule in Toll signaling pathway,in the growth of neurons;and to elucidate the relationship between TLR4 and TLR4 TLR4 extracellular signaling molecules MD-2.Methods: 1.Observing the expression of TLR4 in PC12 cells by immunofluorescence histochemistry.2.According to the birth date,rats are divided into seven groups,that is P1,P2,P4,P6,P8,P14 and adult rat,then tested the expression of TLR4 in frozen section of brain tissue by immunofluorescence histochemistry.3.At the cellular level,(1)the primary cultured neurons were observed its growth condition at the 2nd,4th,6th,8th,10 th and 12 th day;(2)the 2nd,4th,6th,8th,10 th and 12 th of primary cultured neurons were tested by immunofluorescence histochemistry assay,identified its purity and proved the expression of TLR4 in different growth period;(3)extracting the different periods of primary neuron's RNA,amplified by RT-PCR,try to confirm that TLR4's expression is changeable in different growth period of neurons.4.Primary neurons were cultured with TLR4 / MD2 inhibitors,which are used for inhibiting the activation of signaling pathway,observed the growth condition of different periods of primary neurons,and try to prove the effect of TLR4 extracellular signaling molecules MD-2 on growth of neurons.Results: 1.TLR4 has been highly expressed in PC12 cells,and mainly distributed in the cytoplasm and axon.2.The immunofluorescence histochemistry staining test of frozen section of brain tissue showed that there existed the expression of neurons in the brain tissue,and the TLR4 has been also highly expressed in neurons of the P1,P2 and P14 rats' brain tissue;it was also have a certain expression in the neurons of the adult rats' brain tissue.3.In the culture of primary neurons,there was a certain growth cycle,which included the emergence of axon,growth of axon and formation of complex networks,degradation of axon and cell body;in this growth cycle,the TLR4 content has been increased and then decreased.4.TLR4/MD2 inhibitors could inhibit the growth of neurons.Conclusion: 1.TLR4 is essential for the growth of neurons.2.TLR4 plays role in the growth of neurons by TLR4 signaling pathway which is actived by the combined action of TLR4 and MD-2.