Axonal transport of mitochondria is critical for neuronal survival and function. Automatically quantifying and analyzing mitochondrial movement in a large quantity remain challenging. Here, we report an efficient meth...Axonal transport of mitochondria is critical for neuronal survival and function. Automatically quantifying and analyzing mitochondrial movement in a large quantity remain challenging. Here, we report an efficient method for imaging and quantifying axonal mitochondrial trans- port using microfluidic-chamber-cultured neurons together with a newly developed analysis package named ＂MitoQuant＂. This tool-kit consists of an automated program for tracking mitochondrial movement inside live neuronal axons and a transient-velocity analysis program for analyzing dynamic movement patterns of mitochondria. Using this method, we examined axonal mitochondrial movement both in cultured mammalian neurons and in motor neuron axons of Drosophila in vivo. In 3 different paradigms （temperature changes, drug treatment and genetic manipulation） that affect mitochondria, we have shown that this new method is highly efficient and sensitive for detecting changes in mitochondrial movement. The method significantly enhanced our ability to quantitatively analyze axonal mitochondrial movement and allowed us to detect dynamic changes in axonal mltochondrial transport that were not detected by traditional kymographic analyses.展开更多
MicroRNAs （miRNAs） are critical for both development and function of the central nervous system. Significant evidence suggests that abnormal expression of miRNAs is associated with neurodevelopmental disorders. MeCP...MicroRNAs （miRNAs） are critical for both development and function of the central nervous system. Significant evidence suggests that abnormal expression of miRNAs is associated with neurodevelopmental disorders. MeCP2 protein is an epigenetic regulator repressing or activating gene transcription by binding to methylated DNA. Both loss-of-function and gain-of-function muta- tions in the MECP2 gene lead to neurodevelopmental disorders such as Rett syndrome, autism and MECP2 duplication syndrome. In this study, we demonstrate that miR-130a inhibits neurite outgrowth and reduces dendritic spine density as well as dendritic complexity. Bioinformatics analyses, cell cultures and biochemical experiments indicate that miR-130a targets MECP2 and down-regulates MeCP2 protein expression. Further- more, expression of the wild-type MeCP2, but not a loss- of-function mutant, rescues the miR-130a-induced phe- notype. Our study uncovers the MECP2 gene as a pre- vious unknown target for miR-130a, supporting that miR-130a may play a role in neurodevelopment by reg- ulating MeCP2. Together with data from other groups,our work suggests that a feedback regulatory mecha- nism involving both miR-130a and MeCP2 may serve to ensure their appropriate expression and function in neural development.展开更多
文摘Axonal transport of mitochondria is critical for neuronal survival and function. Automatically quantifying and analyzing mitochondrial movement in a large quantity remain challenging. Here, we report an efficient method for imaging and quantifying axonal mitochondrial trans- port using microfluidic-chamber-cultured neurons together with a newly developed analysis package named ＂MitoQuant＂. This tool-kit consists of an automated program for tracking mitochondrial movement inside live neuronal axons and a transient-velocity analysis program for analyzing dynamic movement patterns of mitochondria. Using this method, we examined axonal mitochondrial movement both in cultured mammalian neurons and in motor neuron axons of Drosophila in vivo. In 3 different paradigms （temperature changes, drug treatment and genetic manipulation） that affect mitochondria, we have shown that this new method is highly efficient and sensitive for detecting changes in mitochondrial movement. The method significantly enhanced our ability to quantitatively analyze axonal mitochondrial movement and allowed us to detect dynamic changes in axonal mltochondrial transport that were not detected by traditional kymographic analyses.
基金the National Basic Research Program （973 Program） （No. 2013CB917803） and the National Natural Science Foundation of China （Grant No. 91132710）. ZQ is supported by the National Natural Science Foundation of China （Grant Nos. 91432111 and 81527901）. KH is supported by the National Natural Science Foundation of China （Grant Nos. 81070907 and 81271255）. WM is supported by NIH （F30 NS090893）. JYW is supported by NIH （RO1AG033004）.
文摘MicroRNAs （miRNAs） are critical for both development and function of the central nervous system. Significant evidence suggests that abnormal expression of miRNAs is associated with neurodevelopmental disorders. MeCP2 protein is an epigenetic regulator repressing or activating gene transcription by binding to methylated DNA. Both loss-of-function and gain-of-function muta- tions in the MECP2 gene lead to neurodevelopmental disorders such as Rett syndrome, autism and MECP2 duplication syndrome. In this study, we demonstrate that miR-130a inhibits neurite outgrowth and reduces dendritic spine density as well as dendritic complexity. Bioinformatics analyses, cell cultures and biochemical experiments indicate that miR-130a targets MECP2 and down-regulates MeCP2 protein expression. Further- more, expression of the wild-type MeCP2, but not a loss- of-function mutant, rescues the miR-130a-induced phe- notype. Our study uncovers the MECP2 gene as a pre- vious unknown target for miR-130a, supporting that miR-130a may play a role in neurodevelopment by reg- ulating MeCP2. Together with data from other groups,our work suggests that a feedback regulatory mecha- nism involving both miR-130a and MeCP2 may serve to ensure their appropriate expression and function in neural development.
