Effects of α-asarone on Proliferation and Differentiation of Neural Progenitor Cells / 체질인류학회지

This study investigated whether α-asarone could promote proliferation and differentiation of neural progenitor cells into the neuronal cell types in in vitro and ex vivo studies. For in vitro assay, neural progenitor cells were isolated from fetal cerebral cortex (E15) and checked cell proliferation rate and neural progenitor cell marker in neurospheres. Treatment of α-asarone, particularly at a concentration of 3 µM, promoted the proliferation of neural progenitor cells and effectively differentiated neural progenitor cells into neurons. For ex vivo assay, a hippocampi slice culture system from 7 day postnatal rat fetuses was used. Although slight tissue damage was observed in the hippocampus after the high concentration (100 µM) of α-asarone, however, α-asarone enhanced the proliferation of neural progenitor cells in dentate gyrus region and also effectively differentiated into neuroblast at concentration of 30 µM. Consequently, α-asarone promotes the proliferation of neural progenitor cells and effectively differentiates neural progenitor cells into neurons. Therefore, our results support the therapeutic benefits of α-asarone for treating neurodegenerative diseases.

Role of Notch Signaling Pathway in Neurogenesis in Central Nervous System (review) / 中国康复理论与实践

@#The Notch signaling pathway plays a pivotal role in the process of neurogenesis in central nervous system. It not only maintains the appropriate number and proportion of neurons and glial cells in the growth and development of embryo, but also regulates the injured neural stem/progenitor cells to differentiate into neurons/glial cells of the adult nervous system, promoting the repair of the nervous system.

Dendritic cells differentiated from 129/svj ES-D3 embryonic stem cells prolong syngeneic neural progenitor cells survival in ischemic rat brain / 中国免疫学杂志

Objective:To study if embryonic stem cell derived dendritic cells(esDCs) could induce transplant tolerance to syngeneic neural progenitor cells ( NPCs) in ischemic rat brain.Methods:Neural progenitor cells ( NPCs) were differentiated from 129/svj pCX-eGFP ES-D3 embryonic stem cells and dendritic cells were directly differentiated from 129/svj ES-D3 respectively.All of SD rats were accepted MCAo surgery and subdivided in two groups based on pretreatment with or without esDCs through tail vein injection 1 week after MCAo.pCX-eGFP NPCs were then injected into the lateral ventricle of animals 2 weeks after MCAo.A proliferation assay of lymphocytes dissociated from cervical lymph nodes by MTT method,counting of the survival of the grafted cells, histological evaluation of CD4,CD8 and ED1 positive cells in brain and detection of mRNA level of IL-10 and IFN-γin ischemic lesions by reverse transcriptase-polymerase chain reaction(RT-PCR) were performed 2 weeks after graft (4 weeks after MCAo).Results:Pre-treatment with esDCs decreased CD4 positive cells infiltration (134.7 ±36.2 vs.198.8 ±59.6,P0.05).There was also no difference in lymphocytes proliferation (PI,1.245 ±0.211 vs.1.331 ±0.235) or mRNA expression level of IL-10 ( 1.147 ±0.260 vs.1.264 ±0.119 ) and IFN-γ( 1.697 ±0.273 vs.1.829 ±0.250 ) between two groups ( P>0.05).Conclusion:The results indicate that pretreatment with esDCs may prolong syngeneic NPCs survival though reducing CD4 positive cells reaction in ischemic striatum,which provides some evidence for the tolerogenic function of esDCs.However,there was lack of evidence for cytokine-dependent routine involving in this mode and further investigation was needed to make certain the cardinal principle.

Curcumin Stimulates Proliferation of Spinal Cord Neural Progenitor Cells via a Mitogen-Activated Protein Kinase Signaling Pathway

OBJECTIVE: The aims of our study are to evaluate the effect of curcumin on spinal cord neural progenitor cell (SC-NPC) proliferation and to clarify the mechanisms of mitogen-activated protein (MAP) kinase signaling pathways in SC-NPCs. METHODS: We established cultures of SC-NPCs, extracted from the spinal cord of Sprague-Dawley rats weighing 250 g to 350 g. We measured proliferation rates of SC-NPCs after curcumin treatment at different dosage. The immuno-blotting method was used to evaluate the MAP kinase signaling protein that contains extracellular signal-regulated kinases (ERKs), p38, c-Jun NH2-terminal kinases (JNKs) and beta-actin as the control group. RESULTS: Curcumin has a biphasic effect on SC-NPC proliferation. Lower dosage (0.1, 0.5, 1 microM) of curcumin increased SC-NPC proliferation. However, higher dosage decreased SC-NPC proliferation. Also, curcumin stimulates proliferation of SC-NPCs via the MAP kinase signaling pathway, especially involving the p-ERK and p-38 protein. The p-ERK protein and p38 protein levels varied depending on curcumin dosage (0.5 and 1 microM, p<0.05). CONCLUSION: Curcumin can stimulate proliferation of SC-NPCs via ERKs and the p38 signaling pathway in low concentrations.

The Effect of Agmatine on Expression of IL-1beta and TLX Which Promotes Neuronal Differentiation in Lipopolysaccharide-Treated Neural Progenitors

Differentiation of neural progenitor cells (NPCs) is important for protecting neural cells and brain tissue during inflammation. Interleukin-1 beta (IL-1beta) is the most common pro- inflammatory cytokine in brain inflammation, and increased IL-1beta levels can decrease the proliferation of NPCs. We aimed to investigate whether agmatine (Agm), a primary polyamine that protects neural cells, could trigger differentiation of NPCs by activating IL-1beta in vitro. The cortex of ICR mouse embryos (E14) was dissociated to culture NPCs. NPCs were stimulated by lipopolysaccharide (LPS). After 6 days, protein expression of stem cell markers and differentiation signal factors was confirmed by using western blot analysis. Also, immunocytochemistry was used to confirm the cell fate. Agm treatment activated NPC differentiation significantly more than in the control group, which was evident by the increased expression of a neuronal marker, MAP2, in the LPS-induced, Agm-treated group. Differentiation of LPS-induced, Agm-treated NPCs was regulated by the MAPK pathway and is thought to be related to IL-1beta activation and decreased expression of TLX, a transcription factor that regulates NPC differentiation. Our results reveal that Agm can promote NPC differentiation to neural stem cells by modulating IL-1beta expression under inflammatory condition, and they suggest that Agm may be a novel therapeutic strategy for neuroinflammatory diseases.

Mechanism of cyclin-dependent inhibitor p27~(Kip1) in regulating the differentiation of immortalized human neural progenitor cells / 解剖学报

Objective To investigate whether there is any functional link between p27~(Kip1) function and all-trans retinoic acid (RA) in the control of neuronal differentiation of immortalized human neural progenitor cells (hSN12W-TERT cells). To investigate the mechanism by which p27~(Kip1) regulates the differentiation of immortalized human neural progenitor cells. Methods hSN12W-TERT cells were derived from the striatums of human embryos at 12 weeks gestation and cultured with serum-free medium in presence of EGF and bFGF. At the appropriated time, hSN12W-TERT cells were exposed to 1μmol/L RA for 3, 5, 7 days respectively. The experiment was repeated there times. Cell cycle analysis was performed by flow cytometry analysis (FACS). The expression of p27~(Kip1), p21~(cip1), cyclin-dependent kinase 2 (cdk2), p-cdk2 and S-phase kinase-associated protein 2 (skp2) in hSN12W-TERT cells before and after RA treatment cells were determined by using Western blotting analysis. Results FACS result showed that 77.25% of proliferating hSN12W-TERT cells were in the G1/G0-phase while 9.38% of cells in the S-phase. Following RA treatment, cell growth was arrested, and 85.68% of cells accumulated in G1/G0-phase while 8.57% of cells in the S-phase. Western blotting analysis demonstrated that the levels of p27~(Kip1) in the hSN12W-TERT cells increased following 3 days' treatment with RA compared with those of normal untreated cells, with a peak at 5 days (P<0.05). The similar results were acquired both in nuclear proteins and in cytoplasm proteins of hSN12W-TERT cells. The expression level of p21~(cip1) decreased in response to RA treatment. RA did not affect the expression of cdk2, but the expression of p-cdk2, which represented the activity of cdk2, was markedly decreased in response to RA treatment. Skp2, which was required for the ubiquitin-mediated degradation of p27~(Kip1), was detected in proliferating hSN12W-TERT cells. The expression of skp2 reduced dramatically in response to RA treatment in a time-dependent manner.Conclusion There is a functional link between RA and p27~(Kip1) function in the control of neuronal differentiation in hSN12W-TERT cells. P27~(Kip1) plays a key role during neuronal differentiation. Moreover, high levels of p27~(Kip1) are associated with its degradation inhibiting through reducing proteasome-dependent proteolysis.

Impact of venom nerve growth factor on neural progenitor cell proliferation and migration after cerebral ischemia/reperfusion injury in rats / 中国脑血管病杂志

Objective: To investigate the impact of venom nerve growth factor (vNGF) administered via lateral ventricle on neural progenitor cell proliferation and migration after cerebral ischemia/reperfusion injury in rats. Methods: Ninety healthy and clean male Wistar rats were randomly allocated into 2-day, 7-day, and 14-day groups. Then they were redivided into 5 subgroups at each time point: vNGF 25 U, vNGF 50 U, vNGF 100 U, control, and sham operation. The rat focal cerebral ischemia/reperfusion injury models of the control group and each vNGF subgroup were established. Corresponding dose of vNGF or isotonic saline was administered via the lateral ventricular cannula in all the subgroups according to the specified time points. Immunohistochemical method was used to detect the numbers of DCX positive neural precursor cells around the ischemic cortex and hippocampus CA3/Dentate gyrus in rats of each group. Results: Circled digit oneAfter administering vNGF via the lateral ventricle at each time point, the Longa's scores of the neurological function in all the vNGF subgroups were lower than those in the control group. There were statistical significances (P<0.01). Circled digit twoThe DCX-positive cells in the peri-ischemic cortex and hippocampus CA3/dentate gyrus showed the same change trend. The numbers of DCX positive cells in the 7-d subgroup was higher than those in the 2- and 14-d subgroups when the vNGF dose was the same. There were statistical significances (P < 0.01). Circled digit threeIn comparison of the subgroups with different vNGF doses at the same time points, the numbers of DCX positive cells in the vNGF 50 U subgroup was higher than those of vNGF 25 U and 100 U subgroups. There were statistical significances (P < 0.01). Circled digit fourThe numbers of DCX positive cells at each time point in the vNGF subgroups were significantly higher than those in the control group. There were statistical significances (P < 0.05). Conclusion: After administering vNGF via the lateral ventricle, it may increase the numbers of DCX positive neural precursor cells in the peri-ischemic cortex and hippocampus CA3/dentate gyrus after cerebral ischemia/reperfusion injury in rats.

Neurogenesis in the brain / 西安交通大学学报(医学版)

Neurogenesis is sustained throughout adulthood in the mammalian brain due to the proliferation and differentiation of adult neural progenitor cells found in the subventricular zone of the lateral ventricles and subgranular zone of the dentate gyrus. This review covers recent findings that elucidate different aspects of regulation of neurogenesis, including proliferation, migration and differentiation into mature neurons and functional integration into the existing neural circuits. Furthermore, this review also discusses the effects of pathological conditions on adult neurogenesis in both rodent models and human patients as well as some of the potential problems or limitations in neurogenesis research, which may shed some light on developing novel research strategies for replacement treatment of neurological disorders.

Desert Hedgehog induces the differentiation of neural progenitor cells from embryonic mesencephalon of rat into dopaminergic neurons / 基础医学与临床

Objective To investigate the effect of Desert Hedgehog on direct differentiation of neural progenitor cells(NPCs) cultured from embryonic mesencephalon in the rats.Methods We infected DHH into COS7,NIH/3T3 and 9L cells,and detected the expression of DHH in the cells with immunofluorescence,real-time PCR and Western blot.All of the three cells were co-cultured with NPCs isolated from ventral mesencephalon in embryonic SD rats(E13.5) respectively.Immunoreactivities of tyrosine hydroxylase(TH) was detected by immunocytochemistry after 10 days.Results The expression of DHH in COS7,NIH/3T3 and 9L cells was remarkably detected,but few TH-positive cells were found in the three co-cultral systems at the 10th day.Conclusion The protein derived from DHH itself does not show any inductive effect on the differentiation of NPCs to the dopaminergic neurons in vitro.

Towards the Replacement Therapy Using Neural Stem/Progenitor cells for Neurological Disorders: Strategies to Enhance Therapeutic Capacity of Transplantation Approaches

Transplantation of neural stem/progenitor cells (NPC) holds potential to improve functional outcomes in various neurological disorders. It seems more difficult than previously envisioned, however, to functionally replace the lost neural cells by grafted NPCs. A lack of appropriate developmental cues in the injured tissue contributes to the failure to guide the NPCs to survive, differentiate, grow axons, and functionally integrate to the host neural circuit. Therefore, we need to design possible strategies to recapitulate the developmental processes for the grafted NPCs to fully mature into functional neural cells. To enhance survival of NPCs following transplantation, pharmacological treatments targeting apoptosis and inflammation can be combined with transplantation. Genetic overexpression of prosurvival genes or growth factors can also improve survival. In vitro predifferentiation not only provides neural cells of a specific lineage in high purity but also greatly reduces chances of a tumor formation. Genetic overexpression of various transcription factors or manipulating molecular microenvironment of the host can also be tried to force differentiation of NPCs to a desired lineage. Pharmacological application to overcome myelin inhibition or enzymatic degradation of the inhibitory extracellular matrix will enhance axonal growth of NPC-derived neurons. Increasing synaptic activity by behavioral training or patterned electrical stimulation may promote proper development of synaptic integration and myelination of the axon. A thorough understanding of cellular and molecular aspects of neural development will help design more sophisticated strategies to enhance therapeutic capacity of NPC transplantation to reconstruct the damaged neural circuit.

Specific proteins of neural stem cell expressed by human amnion cells / 中国康复理论与实践

@#ObjectiveTo characterize the neural progenitor cell in the human amnion mesenchyme and epithelial layer with specific mark proteins of neural stem cell.MethodsExpressions of specific mark proteins of neural stem cell including nestin, glial fibrillary acidic protein (GFAP), musashi-1, vimentin and PSA-NCAM in human amnion tissue and cultured amniotic cells were determined by immunohistochemistry and immunofluorescence staining.ResultsExpressions of pluripotent neural stem cell specific makers (nestin, musashi-1, vimentin and PSA-NCAM) were detected in the human amnion mesenchyme and epithelial layer. In addition, cultured amniotic cells were expressed several neural stem cell specific markers including nestin, GFAP and PSA-NCAM. Nestin+ and GFAP+ double positive cells were identified in the human amnion tissue and cultured amniotic cells by immunohistochemistry and immunofluorescence staining.ConclusionSpecific mark proteins of neural stem cell are expressed in human amnion tissue and cultured amniotic cells.

Increased Viability by Over-Expression of Bcl-XL in a Human Neural Progenitor Cell Line

OBJECTIVE: This study is aimed whether bcl-xl could protect C4 cells from the cell death induced by serum deprivation. METHODS: The transient transfection of the bcl-xl gene was made with a LipofectAMINE reagent. An immunohistocytochemical assay and Western-blotting were performed to examine the bcl-xl transfection into the C4 cells. In order to analyze the effect of the bcl-xl transfection, the number of cells on the well plate were serially counted each day, for 5 days, from the 2nd to the 6th day after transfection. The number of GFP-positive cells in the defined fields, following serum deprivation, was counted using fluorescence microscopy, and the total number of viable cells, including transfected cells, were also assessed. RESULTS: Immunocytochemical staining showed positive cells in 52% of nestin staining, 60% of GFAP and 20% of MAP-2. The number of cells decreased after transfection using the LipofectAMINE in the serum free medium (p<0.001). Western blotting using an anti-human bcl-xl antibodies showed that bcl-xl was expressed in both the non-transfected and bcl-xl transfected C4 cells. Cell death in the C4 cells, and the number of cells, were serially monitored each day for 5 days. In the bcl-xl transfected cells, the cell death induced by serum deprivation was significantly inhibited and delayed compared to that in the control cells (p<0.001). CONCLUSION: It is suggested that the bcl-xl transfected human neural progenitor cells might improve the survival of the grafted cells, and may be an alternative source of cells for neural transplantation in degenerative diseases.