Bone marrow mesenchymal stem cell-derived exosome uptake and retrograde transport can occur at peripheral nerve endings.

We investigated the occurrence of mesenchymal stem cell (MSC)-derived exosome uptake and retrograde transport at peripheral nerve endings using bone marrow MSCs (bMSCs) transduced with recombinant CD63-green fluorescent protein (GFP) lentiviral plasmid. GFP was used to track the release of bMSC-derived exosomes and the uptake and transport at peripheral nerve terminals, the dorsal root ganglion (DRG), and the spinal cord. In vitro cell culture and injection of a CD63-GFP exosome suspension into the right gastrocnemius muscle of an in vivo rat model were also performed. Fluorescence microscopy of co-cultured CD63-GFP exosomes and SH-SY5Y or BV2 cell lines and primary cultured DRG cells in a separate experiment demonstrated exosome uptake into DRG neurons and glia. Moreover, we observed both retrograde axoplasmic transport and hematogenous transport of exosomes injected into rat models at the DRG and the ipsilateral side of the anterior horn of the spinal cord using fluorescence microscopy, immunohistochemistry, and Western blot analyses. In conclusion, we showed that exosome uptake at peripheral nerve endings and retrograde transport of exosomes to DRG neurons and spinal cord motor neurons in the anterior horn can occur. In addition, our findings propose a novel drug delivery approach for treating neuronal diseases.

[Effect of electroacupuncture on expression of nestin protein after focal ischemia/reperfusion in rats].

OBJECTIVE: To investigate the effect of electroacupuncturing (EA) Hegu point (LI 4) on proliferation of neural stem cells in the subventricular zone (SVZ) after rat focal ischemia/reperfusion (I/R). METHODS: Animal model was made by ligating external carotid artery and inserting a piece of nylon thread into the internal carotid artery. Eighty-eight Wistar rats were randomly divided into the normal control group (n = 4) ,the sham operated group (n =4),the IR groups (contain 1,7,14,21,28 days' five time points,each point n =8),and the IR + EA group (contain 1,7,14,21,28 days' five time points,each point n = 8). Bilateral Hegu points on rat were consecutively stimulated for 15 min,once daily, and 7 days as one treatment course. The protein expression of Nestin in SVZ was detected by immunochemistry method. RESULTS: Compared with the normal control group, the number of Nestin positive cell in SVZ in the I/R group increased strikingly on the 1st day, peaked on the 7 h day after reperfusion (P <0. 05), began to decrease on the 14th day, and almost reached normal on the 28 h day. A number of Nestin positive cells were present around the ischemic core in the cortex on the 7th day after reperfusion. After performed electroacupuncture, the number of Nestin positive cells in SVZ in the EA group increased on the 1st day, peaked on the 7th day, and increased 1. 5 times as compared with the IR 7 days group, the difference was obvious (P <0. 05) ,and began to decrease on the 14 h day, and almost reached normal on the 28th day. Nestin immunoreactivity around the ischemic core in the cortex was obviously presented in the EA 7 days group. CONCLUSION: The results indicate that cerebral ischemia can stimulate the potent of self-proliferation of neural stem cells and electroacupuncture can obviously increase the proliferation of neural stem cell.