| Mitochondria play a very important role in eukaryotic cell.It is best known for its critical function in energy production via oxidative phosphorylation and can also participate in many other types of metabolism,such as regulating intracellular calcium concentration,in apoptosis and in innate immunity.It can also participate in the growth and differentiated of neurons and synaptic transmission.The morphology and distribution of mitochondria are dynamic and regulated by mitochondrial fission and fusion in neurons.Mitochondria form a functionally interconnected network in the cell by continuous fission and fusion,which can lead to the change of mitochondria morphology.The fusion machinery is composed of three large GTPase,the mitofusins(Mfn1、Mfn2)and the dynamin-related protein OPA1,while fission depends on the GTPase protein Drpl and Mff.Mitochondria morphology become variety along with the change of protein contents during the program of mitochondria dynamic.Mitochondria can be transported to the part of the high energy demand which depend on the increased number of mitochondrial by division.On opposite side,the damaged mitochondrial can be eliminated by mitochondrial fusion which also ensure the integrity of the mitochondrial genome.Disruption of the balance of mitochondria fusion-fisson,leads to developmental neurodegenerative diseases in human,such as Alzheimer’s,Huntington’s and Parkinson’s and mitochondrial morphology and function will change.Of late years,Brain-derived neurotrophic factor(BDNF)has been paid great attention among scientific researchers.It benefits the growth and development of neurons and synaptic plasticity.It is a coincident that neuronal activity are correlation with mitochondria dynamic.Therefore,in this study we investigated the relationship between BDNF and mitochondria dynamic.The results are as follows:1.BDNF induces mitochondria morphology change.The process that BDNF stimulate mitochondrial morphology change is regulated by the BDNF-TrkB signal pathway which activing the PLCy-IP3 and PI3K signaling.2.The change of mitochondria morphology under BDNF treatment was related to the distribution of Drp1 on mitochondria.We detect that BDNF can increase the content of Myosin Ⅱ protein.And BDNF may can activate Myosin Ⅱ,and then recruit more cytoplasm DRP1 to the mitochondria Membrane.In order to prove this conclusion further,we also use liposome transfection and immunofluorescence method,through the covariant intuition to further prove this conclusion.3.BDNF promotes more mitochondria to localization at synapse.In addition to the above findings,we use mitochondria and PDS95 common positioning method found that under the stimulation of BDNF,the co-localization of mitochondria and PDS95 was significantly increased.This suggests that BDNF can promote more mitochondria distributed to the synapse to play more important roles. |
