Vitamin E isomer δ-tocopherol enhances the efficiency of neural stem cell differentiation via L-type calcium channel.
Deng Sihao,Hou Guoqiang,Xue Zhiqin,Zhang Longmei,Zhou Yuye,Liu Chao,Liu Yanqing,Li Zhiyuan
The effects of the vitamin E isomer δ-tocopherol on neural stem cell (NSC) differentiation have not been investigated until now. Here we investigated the effects of δ-tocopherol on NSC neural differentiation, maturation and its possible mechanisms. Neonatal rat NSCs were grown in suspended neurosphere cultures, and were identified by their expression of nestin protein and their capacity for self-renewal. Treatment with a low concentration of δ-tocopherol induced a significant increase in the percentage of β-III-tubulin-positive cells. δ-Tocopherol also stimulated morphological maturation of neurons in culture. We further observed that δ-tocopherol stimulation increased the expression of voltage-dependent Ca(2+) channels. Moreover, a L-type specific Ca(2+) channel blocker verapamil reduced the percentage of differentiated neurons after δ-tocopherol treatment, and blocked the effects of δ-tocopherol on NSC differentiation into neurons. Together, our study demonstrates that δ-tocopherol may act through elevation of L-type calcium channel activity to increase neuronal differentiation.
Stem cells and calcium signaling.
Tonelli Fernanda M P,Santos Anderson K,Gomes Dawidson A,da Silva Saulo L,Gomes Katia N,Ladeira Luiz O,Resende Rodrigo R
Advances in experimental medicine and biology
The increasing interest in stem cell research is linked to the promise of developing treatments for many lifethreatening, debilitating diseases, and for cell replacement therapies. However, performing these therapeutic innovations with safety will only be possible when an accurate knowledge about the molecular signals that promote the desired cell fate is reached. Among these signals are transient changes in intracellular Ca(2+) concentration [Ca(2+)](i). Acting as an intracellular messenger, Ca(2+) has a key role in cell signaling pathways in various differentiation stages of stem cells. The aim of this chapter is to present a broad overview of various moments in which Ca(2+)-mediated signaling is essential for the maintenance of stem cells and for promoting their development and differentiation, also focusing on their therapeutic potential.
Potential of resveratrol in enrichment of neural progenitor-like cell induction of human stem cells from apical papilla.
Songsaad Anupong,Gonmanee Thanasup,Ruangsawasdi Nisarat,Phruksaniyom Chareerut,Thonabulsombat Charoensri
Stem cell research & therapy
INTRODUCTION:Stem cell transplantation of exogenous neural progenitor cells (NPCs) derived from mesenchymal stem cells (MSCs) has emerged as a promising approach for neurodegenerative disease. Human stem cells from apical papilla (hSCAPs) are derived from migratory neural crest stem cells and exhibit a potential of neuronal differentiation. However, their neuronal differentiation is low and unpredictable. Resveratrol has been described as a sirtuin 1 (SIRT1) activator which plays an important role in enhancing neuronal differentiation. In this study, we investigate the potential of resveratrol as an enhancer on neuronal differentiation through NPCs induction of hSCAPs. METHODS:Stem cells were isolated from human apical papilla and characterized as MSCs. The cellular toxicity of resveratrol treatment to the characterized hSCAPs was investigated by MTT assay. The non-cellular toxicity concentrations of resveratrol were assessed with various pre-treatment times to select the optimal condition that highly expressed the neural progenitor gene, NES. Consequently, the optimal condition of resveratrol pre-treatment was synergistically performed with a neuronal induction medium to trigger neuronal differentiation. The differentiated cells were visualized, the genes profiling was quantified, and the percentage of neuronal differentiation was calculated. Moreover, the intracellular calcium oscillation was demonstrated. RESULTS:The cellular toxicity of resveratrol was not observed for up to 50 μM for 12 h. Interestingly, hSCAPs pre-treated with 10 μM resveratrol for 12 h (RSV-hSCAPs) significantly expressed NES, which is determined as the optimal condition. Under neuronal induction, both of hSCAPs and RSV-hSCAPs were differentiated (d-hSCAPs and RSV-d-hSCAPs) as they exhibited neuronal-like appearances with Nissl substance staining. The highest expression of NES and SOX1 was observed in RSV-d-hSCAPs. Additionally, the percentage of neuronal differentiation of RSV-d-hSCAPs was significantly higher than d-hSCAPs for 4 times. Importantly, the neuronal-like cells exhibited slightly increasing pattern of calcium intensity. CONCLUSION:This study demonstrated that pre-treatment of resveratrol strongly induces neural progenitor marker gene expression which synergistically enhances neural progenitor-like cells' induction with neuronal induction medium.
Pre-activation of retinoid signaling facilitates neuronal differentiation of mesenchymal stem cells.
Bi Yang,Gong Min,Zhang Xiaojuan,Zhang Xuan,Jiang Wei,Zhang Yun,Chen Jie,Liu Youxue,He Tong-Chuan,Li Tingyu
Development, growth & differentiation
Mesenchymal stem cells (MSCs) can differentiate into neurons in an appropriate cellular environment. Retinoid signaling pathway is required in neural development. However, the effect and mechanism through retinoid signaling regulates neuronal differentiation of MSCs are still poorly understood. Here, we report that all-trans-retinoic acid (ATRA) pre-induction improved neuronal differentiation of rat MSCs. We found that, when MSCs were exposed to different concentrations of ATRA (0.01-100 micromol/L) for 24 h and then cultured with modified neuronal induction medium (MNM), 1 micromol/L ATRA pre-induction significantly improved neuronal differentiation efficiency and neural-cell survival. Compared with MNM alone induced neural-like cells, ATRA/MNM induced cells expressed higher levels of Nestin, neuron specific enolase (NSE), microtubule-associated protein-2 (MAP-2), but lower levels of CD68, glial fibrillary acidic protein (GFAP), and glial cell line-derived neurotrophic factor(GDNF), also exhibited higher resting membrane potential and intracellular calcium concentration, supporting that ATRA pre-induction promotes maturation and function of derived neurons but not neuroglia cells from MSCs. Endogenous retinoid X receptors (RXR) RXRalpha and RXRgamma (and to a lesser extent, RXRbeta) were weakly expressed in MSCs. But the expression of RARalpha and RARgamma was readily detectable, whereas RARbeta was undetectable. However, at 24 h after ATRA treatment, the expression of RARbeta, not RARalpha or RARgamma, increased significantly. We further found the subnuclear redistribution of RARbeta in differentiated neurons, suggesting that RARbeta may function as a major mediator of retinoid signaling during neuronal differentiation from MSCs. ATRA treatment upregulated the expression of Vimentin and Stra13, while it downregulated the expression of Brachyury in MSCs. Thus, our results demonstrate that pre-activation of retinoid signaling by ATRA facilitates neuronal differentiation of MSCs.
DHA promotes the neuronal differentiation of rat neural stem cells transfected with GPR40 gene.
Ma Dexuan,Zhang Minmin,Larsen Christian P,Xu Feng,Hua Wei,Yamashima Tetsumori,Mao Ying,Zhou Liangfu
G-protein coupled receptor 40 (GPR40), which is expressed ubiquitously in the human brain and pancreas, is a member of the large family of seven-transmembrane receptors and can be activated by polyunsaturated fatty acid (PUFA), in particular docosahexaenoic acid (DHA). Recent studies have shown that the DHA/GPR40 signaling pathway may be closely related with adult neurogenesis in the hippocampus. Here, reconstructing pEGFP-N1 vector-expressing GPR40 gene in cultured rat neural stem cells, we demonstrated that DHA-induced neuronal differentiation, neurite growth and branching of adult rat stem cells is mediated at least in part through GPR40 and it remains effective even at low concentrations of DHA. Furthermore, we also revealed that DHA/GPR40 induced the PLC/IP3 signaling pathway and therefore modulated intracellular Ca(2+) mobilization independent of extracellular Ca(2+) concentration. This may be involved in neuronal differentiation and neurite growth in rat neural stem cells transfected with GPR40 gene. These data provide a new sight in the future utilization of neural stem cells transplantation.
[Ca] fluctuation mediated by T-type Ca channel is required for the differentiation of cortical neural progenitor cells.
The fluctuation of intracellular calcium concentration ([Ca]) is known to be involved in various processes in the development of central nervous system, such as the proliferation of neural progenitor cells (NPCs), migration of intermediate progenitor cells (IPCs) from the ventricular zone (VZ) to the subventricular zone (SVZ), and migration of immature neurons from the SVZ to cortical plate. However, the roles of [Ca] fluctuation in NPC development, especially in the differentiation of the self-renewing NPCs into neuron-generating NPCs and immature neurons have not been elucidated. Using calcium imaging of acute cortical slices and cells isolated from mouse embryonic cortex, we examined temporal changes in the pattern of [Ca] fluctuations in VZ cells from E12 to E16. We observed intracellular Ca levels in Pax6-positive self-renewing NPCs decreased with their neural differentiation. In E11, Pax6-positive NPCs and Tuj1-positive immature neurons exhibited characteristic [Ca] fluctuations; few Pax6-positive NPCs exhibited [Ca] transient, but many Tuj1-positive immature neurons did, suggesting that the change in pattern of [Ca] fluctuation correlate to their differentiation. The [Ca] fluctuation during NPCs development was mostly mediated by the T-type calcium channel and blockage of T-type calcium channel in neurosphere cultures increased the number of spheres and inhibited neuronal differentiation. Consistent with this finding, knockdown of Cav3.1 by RNAi in vivo maintained Pax6-positive cells as self-renewing NPCs, and simultaneously suppressing their neuronal differentiation of NPCs into Tbr1-positive immature neurons. These results reveal that [Ca] fluctuation mediated by Cav3.1 is required for the neural differentiation of Pax6-positive self-renewing NPCs.
Plasticity of calcium signaling cascades in human embryonic stem cell-derived neural precursors.
Forostyak Oksana,Romanyuk Nataliya,Verkhratsky Alexei,Sykova Eva,Dayanithi Govindan
Stem cells and development
Human embryonic stem cell-derived neural precursors (hESC NPs) are considered to be a promising tool for cell-based therapy in central nervous system injuries and neurodegenerative diseases. The Ca(2+) ion is an important intracellular messenger essential for the regulation of various cellular functions. We investigated the role and physiology of Ca(2+) signaling to characterize the functional properties of CCTL14 hESC NPs during long-term maintenance in culture (in vitro). We analyzed changes in cytoplasmic Ca(2+) concentration ([Ca(2+)]i) evoked by high K(+), adenosine-5'-triphosphate (ATP), glutamate, γ-aminobutyric acid (GABA), and caffeine in correlation with the expression of various neuronal markers in different passages (P6 through P10) during the course of hESC differentiation. We found that only differentiated NPs from P7 exhibited significant and specific [Ca(2+)]i responses to various stimuli. About 31% of neuronal-like P7 NPs exhibited spontaneous [Ca(2+)]i oscillations. Pharmacological and immunocytochemical assays revealed that P7 NPs express L- and P/Q-type Ca(2+) channels, P2X2, P2X3, P2X7, and P2Y purinoreceptors, glutamate receptors, and ryanodine (RyR1 and RyR3) receptors. The ATP- and glutamate-induced [Ca(2+)]i responses were concentration-dependent. Higher glutamate concentrations (over 100 μM) caused cell death. Responses to ATP were observed in the presence or in the absence of extracellular Ca(2+). These results emphasize the notion that with time in culture, these cells attain a transient period of operative Ca(2+) signaling that is predictive of their ability to act as stem elements.