50 research outputs found
Study of the cytological features of bone marrow mesenchymal stem cells from patients with neuromyelitis optica.
Neuromyelitis optica (NMO) is a refractory autoimmune inflammatory disease of the central nervous system without an effective cure. Autologous bone marrowâderived mesenchymal stem cells (BMâMSCs) are considered to be promising therapeutic agents for this disease due to their potential regenerative, immune regulatory and neurotrophic effects. However, little is known about the cytological features of BMâMSCs from patients with NMO, which may influence any therapeutic effects. The present study aimed to compare the proliferation, differentiation and senescence of BMâMSCs from patients with NMO with that of ageâ and sexâmatched healthy subjects. It was revealed that there were no significant differences in terms of cell morphology or differentiation capacities in the BMâMSCs from the patients with NMO. However, in comparison with healthy controls, BMâMSCs derived from the Patients with NMO exhibited a decreased proliferation rate, in addition to a decreased expression of several cell cycleâpromoting and proliferationâassociated genes. Furthermore, the cell death rate increased in BMâMSCs from patients under normal culture conditions and an assessment of the gene expression profile further confirmed that the BMâMSCs from patients with NMO were more vulnerable to senescence. Plateletâderived growth factor (PDGF), as a major mitotic stimulatory factor for MSCs and a potent therapeutic cytokine in demyelinating disease, was able to overcome the decreased proliferation rate and increased senescence defects in BMâMSCs from the patients with NMO. Taken together, the results from the present study have enabled the proposition of the possibility of combining the application of autologous BMâMSCs and PDGF for refractory and severe patients with NMO in order to elicit improved therapeutic effects, or, at the least, to include PDGF as a necessary and standard growth factor in the current in vitro formula for the culture of NMO patientâderived BMâMSCs
Neural Stem Cells Engineered to Express Three Therapeutic Factors Mediate Recovery from Chronic Stage CNS Autoimmunity
© The American Society of Gene and Cell Therapy. Treatment of chronic neurodegenerative diseases such as multiple sclerosis (MS) remains a major challenge. Here we genetically engineer neural stem cells (NSCs) to produce a triply therapeutic cocktail comprising IL-10, NT-3, and LINGO-1-Fc, thus simultaneously targeting all mechanisms underlie chronicity of MS in the central nervous system (CNS): persistent inflammation, loss of trophic support for oligodendrocytes and neurons, and accumulation of neuroregeneration inhibitors. After transplantation, NSCs migrated into the CNS inflamed foci and delivered these therapeutic molecules in situ. NSCs transduced with one, two, or none of these molecules had no or limited effect when injected at the chronic stage of experimental autoimmune encephalomyelitis; cocktail-producing NSCs, in contrast, mediated the most effective recovery through inducing M2 macrophages/microglia, reducing astrogliosis, and promoting axonal integrity and endogenous oligodendrocyte/neuron differentiation. These engineered NSCs simultaneously target major mechanisms underlying chronicity of multiple sclerosis (MS) and encephalomyelitis (EAE), thus representing a novel and potentially effective therapy for the chronic stage of MS, for which there is currently no treatment available
A Classification Method Based on Principal Components of SELDI Spectra to Diagnose of Lung Adenocarcinoma
Lung cancer is the leading cause of cancer death worldwide, but techniques for effective early diagnosis are still lacking. Proteomics technology has been applied extensively to the study of the proteins involved in carcinogenesis. In this paper, a classification method was developed based on principal components of surface-enhanced laser desorption/ionization (SELDI) spectral data. This method was applied to SELDI spectral data from 71 lung adenocarcinoma patients and 24 healthy individuals. Unlike other peak-selection-based methods, this method takes each spectrum as a unity. The aim of this paper was to demonstrate that this unity-based classification method is more robust and powerful as a method of diagnosis than peak-selection-based methods.The results showed that this classification method, which is based on principal components, has outstanding performance with respect to distinguishing lung adenocarcinoma patients from normal individuals. Through leaving-one-out, 19-fold, 5-fold and 2-fold cross-validation studies, we found that this classification method based on principal components completely outperforms peak-selection-based methods, such as decision tree, classification and regression tree, support vector machine, and linear discriminant analysis.The classification method based on principal components of SELDI spectral data is a robust and powerful means of diagnosing lung adenocarcinoma. We assert that the high efficiency of this classification method renders it feasible for large-scale clinical use
MS4a4B, a CD20 Homologue in T Cells, Inhibits T Cell Propagation by Modulation of Cell Cycle
MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcΔRIÎČ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, FcΔRIÎČ and HTm4 have been found to function in B cells, mast cells and hematopoietic cells respectively. However, little is known about the function of MS4a4B in T cell regulation. We demonstrate here that MS4a4B negatively regulates mouse T cell proliferation. MS4a4B is highly expressed in primary T cells, natural killer cells (NK) and some T cell lines. But its expression in all malignant T cells, including thymoma and T hybridoma tested, was silenced. Interestingly, its expression was regulated during T cell activation. Viral vector-driven overexpression of MS4a4B in primary T cells and EL4 thymoma cells reduced cell proliferation. In contrast, knockdown of MS4a4B accelerated T cell proliferation. Cell cycle analysis showed that MS4a4B regulated T cell proliferation by inhibiting entry of the cells into S-G2/M phase. MS4a4B-mediated inhibition of cell cycle was correlated with upregulation of Cdk inhibitory proteins and decreased levels of Cdk2 activity, subsequently leading to inhibition of cell cycle progression. Our data indicate that MS4a4B negatively regulates T cell proliferation. MS4a4B, therefore, may serve as a modulator in the negative-feedback regulatory loop of activated T cell
Drought-induced proline is mainly synthesized in leaves and transported to roots in watermelon under water deficit
Proline accumulation has been shown to occur in plants in response to various environmental stresses. Although proline metabolism-related genes have been functionally characterized, the inter-organ transport of proline in stressed plants remains unclear. In this study, free proline was detected with significant accumulations in the roots, stems, and leaves of watermelon drought-tolerant germplasm M08 and drought-susceptible line Y34 under drought stress. Expression profiling and enzyme activity measurements revealed that ClP5CS1 gene, rather than its paralog ClP5CS2, mainly contributes to the proline synthesis in leaves via the Glu pathway. Additionally, over-expression of the ClP5CS genes significantly enhanced the drought tolerance of transgenic Arabidopsis lines. Furthermore, we confirmed that proline is mainly synthesized in leaves and transported to roots in watermelon under drought stress. Transcriptome and expression analyses revealed that the genes involved in proline metabolism exhibited different expression levels. Specifically, ClP5CS1 was upregulated in leaves and roots, while ClP5CS2 was downregulated under drought stress. Also, 415 and 362 differently expressed TFs were identified in roots and leaves, respectively, with the majority upregulated in the former. Ultimately, a model for proline metabolism was proposed. The findings of this study provided new insights into the biosynthesis, transport, and regulatory mechanism of drought-induced proline in plants
Protective effect of vitamin C against tetrachlorobenzoquinone-induced 5-hydroxymethylation-dependent apoptosis in HepG2 cells mainly via the mitochondrial apoptosis pathway
Tetrachlorobenzoquinone (TCBQ) is an active metabolite of pentachlorophenol, and stimulates the accumulation of ROS to trigger apoptosis. The preventive effect of vitamin C (Vc) against TCBQ-induced apoptosis in HepG2 cells is unknown. And there is little known about TCBQ-triggered 5-hydromethylcytosine (5hmC)-dependent apoptosis. Here, we confirmed that Vc alleviated TCBQ-induced apoptosis. Through investigating the underlying mechanism, we found TCBQ downregulated 5hmC levels of genomic DNA in a Tet-dependent manner, with a particularly pronounced decrease in the promoter region, using UHPLC-MS-MS analysis and hydroxymethylated DNA immunoprecipitation sequencing. Notably, TCBQ exposure resulted in alterations of 5hmC abundance to âŒ91% of key genes at promoters in the mitochondrial apoptosis pathway, along with changes of mRNA expression in 87% of genes. By contrast, 5hmC abundance of genes only exhibited slight changes in the death receptor/ligand pathway. Interestingly, the pretreatment with Vc, a positive stimulator of 5hmC generation, restored 5hmC in the genomic DNA to near-normal levels. More notably, Vc pretreatment further counter-regulated TCBQ-induced alteration of 5hmC abundance in the promoter with 100% of genes, accompanying the reverse modulation of mRNA expressions in 89% of genes. These data from Vc pretreatment supported the relationship between TCBQ-induced apoptosis and the altered 5hmC abundance. Additionally, Vc also suppressed TCBQ-stimulated generation of ROS, and further increased the stability of mitochondria. Our study illuminates a new mechanism of TCBQ-induced 5hmC-dependent apoptosis, and the dual mechanisms of Vc against TCBQ-stimulated apoptosis via reversely regulating 5hmC levels and scavenging ROS. The work also provided a possible strategy for the detoxification of TCBQ
Advanced Glycation End Products Enhance Murine Monocyte Proliferation in Bone Marrow and Prime Them into an Inflammatory Phenotype through MAPK Signaling
Objective. Increased monocytes, particularly the inflammatory subset, are associated with accelerated atherosclerosis in diabetes through thus far incompletely defined mechanisms. The present study tested the hypothesis that advanced glycation end products (AGEs) promote bone marrow monocytes to proliferate and drive them into an inflammatory phenotype. Methods and Results. In vivo, AGEs (25âmg/kg i.p. for 7 days) increased proportions of CD115+ monocytes and the inflammatory subset, the CD115+Ly6Chigh cells, in murine bone marrow (flow cytometry analysis (FCM)), and enhanced gene expression of proinflammatory cytokines (IL-1ÎČ and TNF-α) but only slightly upregulated mRNA expression of anti-inflammatory cytokine (IL-10) (real-time PCR) in monocytes. In vitro, when the monocytes were treated with different dosages of AGEs (50, 150, and 300âÎŒg/mL), we found that proliferation (CCK8) but not apoptosis (FCM) of the monocytes was induced; the mRNA expressions of proinflammatory cytokines (IL-1ÎČ and TNF-α) and GM-CSF were upregulated in a dose-dependent manner while mRNA levels of IL-10 and M-CSF were changed much less in monocytes (real-time PCR). Furthermore, AGEs (300âÎŒg/mL) significantly enhanced the expression of Ki67 in monocytes (immunofluorescence staining (IF)), and this dose of AGEs markedly increased secretion of GM-CSF but not that of M-CSF (ELISA). For a pathway study, the monocytes were stimulated by 300âÎŒg/mL AGEs for different periods of time (0, 15, 30, and 120âmin) and the activation of the MAPK pathway was tested (FCM); the results showed the p38 and ERK pathways were activated but not JNK signaling. Pretreatment with an inhibitor of p38 (SB203580) or ERK (U0126) attenuated AGE-induced gene expression of proinflammatory cytokines and GM-CSF (real-time PCR), as well as reversing AGE-induced Ki67 expression (IF). Conclusions. AGEs promote bone marrow monocytes to proliferate and drive them into an inflammatory phenotype through p38 and ERK activation
A simple route to fabricate high sensibility gas sensors based on erbium doped ZnO nanocrystals
ZnO based nanostructures including ZnO and erbium (Er) doped ZnO nanocrystals (NCs) were synthesized by a one-step solvothermal method. Compared with the pure ZnO NCs, photoluminescence (PL) of the Er-doped ZnO NCs made an improvement in the visible emissions, which was attributed to the defects or vacancies resulted from Er-dopants. The enhanced defects or vacancies resulted in high activity surfaces, which benefit sensing properties. Furthermore, sensing experiments confirmed that the sensing performance of Er-doped ZnO NCs was improved almost doubled than the pure ZnO NCs. Therefore, the high sensibility gas sensors based on Er-doped ZnO NCs were successfully fabricated. (C) 2011 Elsevier B.V. All rights reserved.National Basic Research Program of China ("973 Program")[2011CB925600]; National Natural Science Foundation of China[60827004, 90921002]; Science and Technology Program of Xiamen of China; Science and Technology Program of Fujian of China; China Postdoctoral Science Foundation[20080430786
Inhibitory effect of IL-17 on neural stem cell proliferation and neural cell differentiation.
BACKGROUND: IL-17, a Th17 cell-derived proinflammatory molecule, has been found to play an important role in the pathogenesis of autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). While IL-17 receptor (IL-17R) is expressed in many immune-related cells, microglia, and astrocytes, it is not known whether IL-17 exerts a direct effect on neural stem cells (NSCs) and oligodendrocytes, thus inducing inflammatory demyelination in the central nervous system.
METHODS: We first detected IL-17 receptor expression in NSCs with immunostaining and real time PCR. We then cultured NSCs with IL-17 and determined NSC proliferation by neurosphere formation capability and cell number count, differentiation by immunostaining neural specific markers, and apoptosis of NSCs by flow cytometry.
RESULTS: NSCs constitutively express IL-17R, and when the IL-17R signal pathway was activated by adding IL-17 to NSC culture medium, the number of NSCs was significantly reduced and their ability to form neurospheres was greatly diminished. IL-17 inhibited NSC proliferation, but did not induce cytotoxicity or apoptosis. IL-17 hampered the differentiation of NSCs into astrocytes and oligodendrocyte precursor cells (OPCs). The effects of IL-17 on NSCs can be partially blocked by p38 MAPK inhibitor.
CONCLUSIONS: IL-17 blocks proliferation of NSCs, resulting in significantly reduced numbers of astrocytes and OPCs. Thus, in addition to its proinflammatory role in the immune system, IL-17 may also play a direct role in blocking remyelination and neural repair in the CNS