MicroRNA changes of bone marrow-derived mesenchymal stem cells differentiated into neuronal-like cells by Schwann cell-conditioned medium

Bone marrow-derived mesenchymal stem cells differentiate into neurons under the induction of Schwann cells. However, key microRNAs and related pathways for differentiation remain unclear. This study screened and identified differentially expressed microRNAs in bone marrow- derived mesenchymal stem cells induced by Schwann cell-conditioned medium, and explored targets and related pathways involved in their differentiation into neuronal-like cells. Primary bone marrow-derived mesenchymal stem cells were isolated from femoral and tibial bones, while primary Schwann cells were isolated from bilateral saphenous nerves. Bone marrow-derived mesenchymal stem cells were cultured in unconditioned (control group) and Schwann cell-conditioned medium (bone marrow-derived mesenchymal stem cell + Schwann cell group). Neuronal differentiation of bone marrow-derived mesenchymal stem cells induced by Schwann cell-conditioned medium was observed by time-lapse imaging. Upon induction, the morphology of bone marrow-derived mesencaymal stem cells changed into a neural shape with neurites. Results of quantitative reverse transcription-polymerase chain reaction revealed that nestin mRNA expression was upregulated from 1 to 3 days and downregulated from 3 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. Compared with the control group, microtubule-associated protein 2 mRNA expression gradually increased from 1 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. After 7 days of induction, microRNA analysis iden:ified 83 significantly differentially expressed microRNAs between the two groups. Gene Ontology analysis indicated enrichment of microRNA target genes for neuronal projection development, regulation of axonogenesis, and positive regulation of cell proliferation. Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that Hippo, Wnt, transforming growth factor-beta, and Hedgehog signaling pathv/ays were potentially associated with neural differentiation of bone marrow-derived mesenchymal stem cells. This study, which carried out successful microRNA analysis of neuronal-like cells differentiated from bone marrow-derived mesenchymal stem cells by Schwann cell induction, revealed key microRNAs and pathways involved in neural differentiation of bone marrow-derived mesenchymal stem cells. All protocols were approved by the Animal Ethics Committee of Institute of Radiation Medicine, Chinese Academy of Medical Sciences on March 12, 2017 (approval number: DWLI-20170311).

Neuronal-like cell differentiation of non-adherent bone marrow cell-derived mesenchymal stem cells

Non-adherent bone marrow cell-derived mesenchymal stem cells from C57BL/6J mice were sepa- rated and cultured using the ＂pour-off＂ method. Non-adherent bone marrow cell-derived mesen- chymal stem ceils developed colony-forming unit-fibroblasts, and could be expanded by supple- mentation with epidermal growth factor. Immunocytochemistry showed that the non-adherent bone marrow cell-derived mesenchymal stem cells exposed to basic fibroblast growth factor/epidermal growth factor/nerve growth factor expressed the neuron specific markers, neurofilament-200 and NeuN, in vitro. Non-adherent bone marrow cell-derived mesenchymal stem cells from 13-galactosidase transgenic mice were also transplanted into focal ischemic brain （right corpus striatum） of C57BL/6J mice. At 8 weeks, cells positive for LacZ and 13-galactosidase staining were observed in the ischemic tissues, and cells co-labeled with both 13-galactosidase and NeuN were seen by double immunohistochemical staining. These findings suggest that the non-adherent bone marrow cell-derived mesenchymal stem cells could differentiate into neuronal-like cells in vitro and in vivo.

In vivo tracking of neuronal-like cells by magnetic resonance in rabbit models of spinal cord injury

In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesen- chymal stem cells can survive, migrate, integrate and help to restore the function and behaviors of spinal cord injury models, and that they may serve as a suitable approach to treating spinal cord injury. However, it is very difficult to track transplanted cells in vivo. In this study, we injected su- perparamagnetic iron oxide-labeled neuronal-like cells into the subarachnoid space in a rabbit model of spinal cord injury. At 7 days after cell transplantation, a small number of dot-shaped low signal intensity shadows were observed in the spinal cord injury region, and at 14 days, the number of these shadows increased on T2-weighted imaging. Perl＇s Prussian blue staining detected dot-shaped low signal intensity shadows in the spinal cord injury region, indicative of superpara- magnetic iron oxide nanoparticle-labeled cells. These findings suggest that transplanted neu- ronal-like cells derived from bone marrow mesenchymal stem cells can migrate to the spinal cord injury region and can be tracked by magnetic resonance in vivo. Magnetic resonance imaging represents an efficient noninvasive technique for visually tracking transplanted cells in vivo.

Negative effects of Notch1 on the differentiation of muscle-derived stem cells into neuronal-like cells

We cultured rat muscle-derived stem cells in medium containing nerve growth factor and basic fi-broblast growth factor to induce neuronal-like cell differentiation.Immunocytochemical staining and reverse transcription-PCR showed that the differentiated muscle-derived stem cells exhibited processes similar to those of neuronal-like cells and neuron-specific enolase expression,but Notch1 mRNA and protein expression was decreased.Down-regulation of Notch1 expression may facilitate neuronal-like cell differentiation from muscle-derived stem cells.

Static and 50 Hz Electromagnetic Fields Effects on Human Neuronal-Like Cells Vibration Bands in the Mid-Infrared Region

Human neuronal-like cells were exposed to static and 50 Hz electromagnetic fields at the intensities of 2 mT and 1 mT, respectively. The effects of exposure were investigated in the mid-infrared region by means of Fourier self deconvolu-tion spectroscopic analysis. After exposure of 3 hours to static and 50 Hz electromagnetic fields, the vibration bands of CH2 methilene group increased significantly after both exposures, suggesting a relative increase of lipid related to conformational changes in the cell membrane due to electromagnetic fields. In addition, PO2- stretching phosphate bands decreased after both exposures, suggesting that alteration in DNA/RNA can be occurred. In particular, exposure of 3 hours to 50 Hz electromagnetic fields produced significant increases in β-sheet contents in amide I, and around the 1740 cm?1 band assigned to non-hydrogen-bonded ester carbonyl stretching mode, that can be related to unfolding processes of proteins structure and cells death. Further exposure up to 18 hours to static magnetic field produced an increase in β-sheet contents as to α-helix components of amide I region, as well.

Xuefuzhuyu injection induces neuronal differentiation of rat bone morrow mesenchymal stem cells

The primary effective components of Xuefuzhuyu, including Rhizoma Chqanxiong, Radix Salviae Miltiorrhiae, and Radix Angelicae Sinensis, have been shown to induce the differentiation of bone marrow mesenchymal stem cells （BMMSCs） into neuronal-like cells. However, there is little available evidence on the effects of the Chinese herbal compound Xuefuzhuyu on BMMSC differentiation. The present study investigated the effects of Xuefuzhuyu on differentiation of rat BMMSCs into neuronal-like cells, and evaluated the optimal concentration for inducing differentiation. Inverted microscopy was used to observe BMMSCs induced by Xuefuzhuyu; immunocytochemistry revealed expression of the neuronal marker neuron-specific enolase surface antigen in the majority of BMMSCs following treatment with Xuefuzhuyu at concentrations of 1,3, 5 and 10 g/L. A concentration of 3 g/L resulted in highest neuron-specific enolase expression. These results suggest that BMMSCs can be induced to differentiate into neuronal-like cells with Xuefuzhuyu, and 3 g/L is the optimal inductive concentration for effective differentiation.

Fasudil hydrochloride differentiates bone marrow mesenchymal stem cells into neurons via notch signaling

BACKGROUND： Notch signaling regulates bone marrow mesenchymal stem cell （MSC） proliferation, differentiation, and apoptosis, Notch signaling and Rho kinase signaling exhibit a crosstalk phenomenon with JAK/STAT, and both participate in the neuronal dendritic spine development. Inhibition of RhoA/Rho kinase signaling may regulate MSC differentiation into neuronal-like cells. OBJECTIVE： To investigate the effect of Notch1 signaling on the differentiation of rat MSCs into neurons induced by fasudil hydrochloride （C14H17N3O2S-HCI）, a Rho kinase inhibitor, through a siRNA approach. DESIGN, TIME AND SETTING： An in vitro cytological experiment was performed in the Cell Laboratory of Henan Academy of Medical and Pharmaceutical Sciences between December 2007 and May 2009. MATERIALS： MSCs were obtained from Wistar rat femoral bone, fasudil hydrochloride was provided by -Tianjin Chase Sun Pharmaceutical Co., Ltd. Rn-notchl-siRNa, negative control siRNA （Cy3 label） and Rn-MAPK1 control siRNA were provided by QIAGEN, Coloqne, German. METHODS： The cultured MSCs were divided into non-transfected, transfected group （transfected with Rn-Notchl-siRNA）, positive control （transfected with Rn-MAPK-1 control siRNA）, and negative control （transfected with negative control siRNA） groups. Fasudil hydrochloride was applied to induce MSCs to differentiate into neurons. MAIN OUTCOME MEASURES： The fluorescence expression by the transfected MSCs was observed under an inverted fluorescence microscope; the expression of Notch1 mRNA, Hesl mRNA, and MAPK1 mRNA in MSCs was detected by reverse transcription polymerase chain reaction; the expression of Notch1 protein, nestin, neurofilament M, and glial fibrillary acidic protein was detected by immunocytochemistry. The viability of MSCs was detected by tetrazolium bromide assay. RESULTS： MSC fluorescence increased following a 72-hour siRNA transfection, with transfection efficiencies of up to （0.91 ± 0.04）; the Notch1 mRNA and Hesl mRNA expressed by transfected MSCs was significantly decreased （P 〈 0.05） compared with non-transfected cells. Fasudil hydrochloride induced MSCs to differentiate into neurons with greater efficiency in the transfected group （P 〈 0.05）. CONCLUSION： Fasudil hydrochloride induces rat MSCs to differentiate into neurons; inhibition of Notch1 signaling and Hesl expression may jointly promote the differentiation of MSCs into neurons.

Autophagy activator promotes neuronal differentiation of adult adipose-derived stromal cells

Preliminary research from our group found altered autophagy intensity during adipose-derived stromal cell differentiation into neuronal-like cells, and that this change was associated with morphological changes in differentiated cells. This study aimed to verify the role of rapamycin, an autophagy activator, in the process of adipose-derived stromal cell differentiation into neuronal-like cells. Immunohistochemical staining showed that expression of neuron-specific enolase and neurofilament-200 were gradually upregulated in adipose-derived stromal cells after 5 mM 13-mercaptoethanol induction, and the differentiation rate gradually increased with induction time. Using transmission electron microscopy, induced cells were shown to exhibit cytoplasmic autophagosomes, with bilayer membranes, and autolysosomes. After rapamycin （200 IJg/L） induction for 1 hour, adipose-derived stromal cells began to extend long processes, similar to the morphology of neuronal-like cells, while untreated cells did not exhibit similar morphologies until 3 hours after induction. Moreover, the differentiation rate was significantly increased after rapamycin treatment. Compared with untreated cells, expression of LC3, an autophagy protein, was also significantly upregulated. Positive LC3 expression tended to concentrate at cell nuclei with increasing induction times. Our experimental findings indicate that autophagy can significantly increase the speed of adipose-derived stromal cell differentiation into neuronal-like cells.

Neuronal differentiation effects of vascular endothelial factor on bone marrow stromal cells

BACKGROUND：Studies have demonstrated that bone marrow stromal cells （BMSCs） undergo neuronal differentiation under certain in vitro conditions.However,very few inducers of BMSC differentiation have been used in clinical application.The effects of vascular endothelial growth factor （VEGF） on in vitro neuronal differentiation of BMSCs remain poorly understood.OBJECTIVE：To investigate the effect of VEGF on neuronal differentiation of BMSCs in vitro,and to determine the best VEGF concentration for experimental induction.DESIGN,TIME AND SETTING：In vitro comparative study was performed at the Central Laboratory and Laboratory of Male Reproductive Medicine,Shenzhen Hospital of Peking University from October 2008 to August 2009.MATERIALS：Recombinant human VEGF165 was purchased from Peprotech Asia,Rehovot,Israel.Neuron-specific enolase （NSE） was purchased from Beijing Biosynthesis Biotechnology,China.METHODS：BMSCs were harvested from adult Sprague Dawley rats.The passaged cells were pre-induced with 10 ng/mL basic fibroblast growth factor for 24 hours,followed by differentiation induction with 0,5,10,and 20 ng/mL VEGF,respectively.MAIN OUTCOME MEASURES：Morphological changes in BMSCs prior to and following VEGF induction.Expression of NSE following induction was determined by immunocytochemistry.RESULTS：Shrunken,round cells,with a strong refraction and thin bipolar or multipolar primary and secondary branches were observed 3 days after induction with 5,10,and 20 ng/mL VEGF.However,these changes were not observed in the control group.At 10 days after induction,the number of NSE-positive cells was greatest in the 10 ng/mL VEGF-treated group （P〈 0.05）.The number of NSE-positive cells was least in the control group at 3 and 10 days post-induction （P〈 0.05）.Moreover,the number of NSE-positive cells was greater at 10 days compared with at 3 days after induction （P〈 0.05）.CONCLUSION：Of the VEGF concentrations tested,10 ng/mL induced the greatest number of neuronal-like cells in vitro from BMSCs.

Natural cerebrolysin induces neuronal differentiation in bone marrow mesenchymal stem cells

BACKGROUND： Bone marrow mesenchymal stem cells （MSCs） have been shown to differentiate into neuronal-like cells through the use of several factors, such as 2-mercaptoethanol, dimethyl sulfoxide, or monothioglycero However, these factors are not suitable for human use due to toxicity. Theoretically speaking, traditional Chinese medicine could be used as potential and safe factors. OBJECTIVE： To investigate the effect of natural cerebrolysin on neuronal-like differentiation of MSCs, based on protein and mRNA analyses. DESIGN, TIME AND SETTING： A parallel controlled, in vitro experiment was performed at the Institute of Integrated Chinese and Western Medicine, Shenzhen Hospital, Southern Medical University, between June 2006 and April 2008. MATERIALS： Natural cerebrolysin was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. It primarily consisted of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae）, and Yinxingye （Ginkgo Leaf） at a proportion of 1：2：2. Natural cerebrolysin extract （1：20） was prepared using conventional water extraction methodology. Each gram of extract equaled 20 grams of the crude drug. Twelve adult, male, New Zealand rabbits were included, six of which underwent intragastric administration of natural cerebrolysin extract （0.976 g/kg per day） for 1 month for natural cerebrolysin-containing serum. The remaining six rabbits received intragastric administration of equal volumes of physiological saline for normal blank serum. METHODS： Sprague Dawley male rats, 6-8 weeks old, were used to harvest tibial and femoral bone marrow. Isolation and purification of MSCs were established from the whole bone marrow by removing the non-adherent cells in primary and passage cultures. For cellular identification, MSCs from four to five passages were co-cultured with LG-DMEM media containing 10% natural cerebrolysin. Simultaneously, MSCs cultured in/G-DMEM media containing 10% blank rabbit serum served as the control group. MAIN OUTCOME MEASURES： Morphology of MSCs and neurite outgrowth during differentiation was observed under inverted phase contrast microscope. Neurite-positive cells were classified by neurite length that was longer than 1.5x the cell body diameter. Immunocytochemistry was used to identify purity of MSCs following passage, as well as expression of nidogen, neuron-specific enolase, glial fibrillary acidic protein, and microtubule-associated protein 2 following treatment with natural cerebrolysin, mRNA expression of neuron-specific enolase and glial fibrillary acidic protein was detected using semi-quantitative RT-PCR. RESULTS： After MSCs were treated with natural cerebrolysin for 3-5 hours, the cell bodies were larger, and small neurites - similar to neuronal neurites - were observed. The number of neurite-positive cells significantly increased compared with the control group （P 〈 0.05）. After MSCs were treated with natural cerebrolysin for 12 hours, most expressed nidogen, neuron-specific enolase, and microtubule-associated protein 2 at higher levels than the control group （P 〈 0.01）. No evident expression of glial fibrillary acidic protein was found （P 〉 0.05）. CONCLUSION： Natural cerebrolysin promoted neurite outgrowth and induced neuronal-like differentiation of MSCs.