The Memory Orchestra: Contribution of Astrocytes / 神经科学通报·英文版

For decades, memory research has centered on the role of neurons, which do not function in isolation. However, astrocytes play important roles in regulating neuronal recruitment and function at the local and network levels, forming the basis for information processing as well as memory formation and storage. In this review, we discuss the role of astrocytes in memory functions and their cellular underpinnings at multiple time points. We summarize important breakthroughs and controversies in the field as well as potential avenues to further illuminate the role of astrocytes in memory processes.

Presenilin and Alzheimer's disease: calcium signaling pathway / 中华行为医学与脑科学杂志

Presenilin (PS) is the main pathogenic gene of familial Alzheimer's disease(AD). Mutations of PS gene can promote the processing of amyloid precursor protein (APP) into a toxic form of amyloid beta protein (Aβ), which plays an important role in the pathogenesis of AD.However, the current targeted therapy for Aβ has not yet produced a good effect on AD, suggesting the existence of additional pathogenic mechanisms.In recent years, the abnormal calcium homeostasis and its pathological role in AD have attracted people's attention.The calcium signaling pathway is regulated by presenilin.And the calcium regulation of PS gene mutant neurons is impaired, resulting in reduced ability to deal with oxidative stress, which leads to cell death and promotes the occurrence of AD.In addition, damage to neuronal autophagy induced by PS gene mutations also depends on the ability to partially deplete endoplasmic reticulum calcium content.Recent studies have shown that abnormal Ca 2+ homeostasis caused by PS gene mutations can lead to impaired mitochondrial metabolism and defects in brain network activity.This review will focus on the calcium signaling pathway, and explore the pathogenesis of presenilin in AD through the regulation of calcium signals from the perspectives of impaired autophagy, endoplasmic reticulum stress, mitochondrial dysfunction, apoptosis and defects in brain network activity, so as to provide ideas for the etiology of AD and the discovery of drug targets.

Significance of phosphoinositol metabolism by DNA methylation may contribute in oral leukoplakia carcinogenesis / 口腔疾病防治

Objective @# To study the role of DNA methylation in oral leukoplakia carcinogenesis.@*Methods@# DNA methylation was detected in forty cases of oral squamous cell carcinoma (OSCC), twenty-eight cases of oral leukoplakia (OLK) and forty cases of healthy oral mucosa. Download the expression profile data of OSCC, OLK and healthy oral mucosa from Gene Expression Omnibus (GEO) database. DNA methylation data and expression profile data were compared for repeatability, DNA methylation data for difference analysis and corresponding expression profile data for IPA pathway analysis.@*Results @#The data analysis showed that DNA methylation had greater flexibility and instability. Ingenuity Pathway Analysis (IPA) analysis showed that genes related to OLK differential methylation sites were mainly concentrated in the process of cell movement and differentiation. Genes related to differential methylation sites of OSCC are mainly enriched in cell proliferation, migration, oxidation regulation, and anti-apoptosis processes. The genes associated with OLK and OSCC differential methylation sites are co-enriched in phosphoinositol metabolism and phospholipase C signaling pathway.@* Conclusion@#DNA methylation is involved in the formation of oral squamous cell carcinoma, and the activation of phosphoinositol metabolism may promote oral leukinoma.

Bioinformatic analysis of the structure and function of human TACSTD2 / 医学研究生学报

ObjectiveThe role of human tumor-related calcium signal transductor 2 (TACSTD2) in promoting tumorigenesis has been noticed recently. We predicted the molecular structure and biological function of TACSTD2 by bioinformatic methods, in order to provide reference for further study of TACSTD2.MethodsThe homo sapiens TACSTD2 mRNA and protein amino acid sequences were obtained from the National Center for Biotechnology Information (NCBI) database. The bioinformatic methods were used to analyze the open reading frame(ORF) of TACSTD2, physicochemical properties, signal peptide and protein localization, subcellular localization, and prediction of transmembrane structure and secondary structure, tertiary structure, potential protein modification sites, domains, protein modification sites proteins, protein interacting with TACSTD2, biological functions of TACSTD2, and expression of TACSTD2 in human normal tissues and certain tumor types.ResultsAccording to the mRNA sequence of TACSTD2, there are 12 ORFs, and the longest is ORF1, with a total of 972bp, encoding 323 amino acids. The hydrophilic amino acid of TACSTD2 is more than that of hydrophobic amino acid, indicating that TACSTD2 belongs to hydrophilic protein. TACSTD2 is a highly conserved alkaline secreted protein with a transmembrane region both inside and outside the cytoplasm. The presence of nuclear localization signal(NLS) in the amino acid sequence of TACSTD2 suggests that TACSTD2 can locate in cell nucleus. TACSTD2 mainly distribute in cytoplasmic membrane, extracellular, nucleus and cytoplasm. The secondary structure prediction results showed that the main structure of TACSTD2 was random coil, followed by a α helix. TACSTD2 has 15 serine modification sites, 17 threonine modification sites, and 8 tyrosine modification sites. The TACSTD2 has protein interactions with Claudin(CLDN) protein family; and participating in signaling pathway such as cell surface receptor, cell proliferation, negative regulation of epithelial cell migration, and so on. Comparing with normal human tissues, its mRNA expression is up-regulated in most tumor types such as cervical cancer, lung cancer, thyroid cancer, uterine cancer, liver cancer, colorectal cancer.ConclusionAccording to the analysis of the structure and function of TACSTD2, TACSTD2 is highly-expression in multiple malignancies. It can participate in the process of proliferation, migration and adhesion of malignant tumor cells through cell surface receptor signaling pathways. This study provide reference for the further research about the function of TACSTD2.

Bioinformatic analysis of the structure and function of human TACSTD2 / 医学研究生学报

ObjectiveThe role of human tumor-related calcium signal transductor 2 (TACSTD2) in promoting tumorigenesis has been noticed recently. We predicted the molecular structure and biological function of TACSTD2 by bioinformatic methods, in order to provide reference for further study of TACSTD2.MethodsThe homo sapiens TACSTD2 mRNA and protein amino acid sequences were obtained from the National Center for Biotechnology Information (NCBI) database. The bioinformatic methods were used to analyze the open reading frame(ORF) of TACSTD2, physicochemical properties, signal peptide and protein localization, subcellular localization, and prediction of transmembrane structure and secondary structure, tertiary structure, potential protein modification sites, domains, protein modification sites proteins, protein interacting with TACSTD2, biological functions of TACSTD2, and expression of TACSTD2 in human normal tissues and certain tumor types.ResultsAccording to the mRNA sequence of TACSTD2, there are 12 ORFs, and the longest is ORF1, with a total of 972bp, encoding 323 amino acids. The hydrophilic amino acid of TACSTD2 is more than that of hydrophobic amino acid, indicating that TACSTD2 belongs to hydrophilic protein. TACSTD2 is a highly conserved alkaline secreted protein with a transmembrane region both inside and outside the cytoplasm. The presence of nuclear localization signal(NLS) in the amino acid sequence of TACSTD2 suggests that TACSTD2 can locate in cell nucleus. TACSTD2 mainly distribute in cytoplasmic membrane, extracellular, nucleus and cytoplasm. The secondary structure prediction results showed that the main structure of TACSTD2 was random coil, followed by a α helix. TACSTD2 has 15 serine modification sites, 17 threonine modification sites, and 8 tyrosine modification sites. The TACSTD2 has protein interactions with Claudin(CLDN) protein family; and participating in signaling pathway such as cell surface receptor, cell proliferation, negative regulation of epithelial cell migration, and so on. Comparing with normal human tissues, its mRNA expression is up-regulated in most tumor types such as cervical cancer, lung cancer, thyroid cancer, uterine cancer, liver cancer, colorectal cancer.ConclusionAccording to the analysis of the structure and function of TACSTD2, TACSTD2 is highly-expression in multiple malignancies. It can participate in the process of proliferation, migration and adhesion of malignant tumor cells through cell surface receptor signaling pathways. This study provide reference for the further research about the function of TACSTD2.

Roles of two-photon calcium imaging technology for visual cortex Ⅱ/Ⅲ layer neurons in model animals / 国际眼科杂志(Guoji Yanke Zazhi)

@#Calcium is an important messenger in the mammalian nerve cells which mediates a variety of intracellular signal transduction pathways and plays critical roles in regulating the neuronal functions. Calcium signaling exerts its highly specific function in a defined sub-region of the cell, especially in the visual cortex of the brain. Detection of calcium signals in neurons is particularly important for the studying of neuronal function. The two-photon microscope has a unique advantage in the detection of calcium signal in the superficial cortex. In this paper, the application of two-photon in the <i>in vivo</i> detection of the visual cortical Ⅱ/Ⅲ layer of model animals are reviewed.

Regulatory mechanism underlying mycelium aggregation during filamentous fungi submerged fermentation / 生物工程学报

Filamentous fungi are one of the platforms for producing fermented products. The specific characteristic of their submerged fermentation is the aggregation of mycelia that is affected by environmental conditions, leading to significantly different rheology for fermentation broth. Such a rheological change not only affects the transfer of mass, heat and momentum, but also the biosynthesis of target products and the efficiency of their production. In this article, strategies for morphological regulation of filamentous fungi are reviewed, and the impact of calcium signal transduction and chitin biosynthesis on apical growth of hyphae and branching of mycelia for their aggregation are further commented.

Effect of IVF-ET on mesenteric vascular function in offspring / 中国药理学通报

To study the effect of in vitro fertilization-embryo transfer (IVF-ET) on the contractile function of mesenteric vessels in offspring mouse model and its regulatory mechanism. Methods Offspring mouse model of IVF-ET (20 weeks after birth) was built to compare with natural born descendant in vascular regulation. The bodyweight and BMI of mice were measured. Serum levels of cardiovascular related cytokines were tested by ELISA and colorimetric method. Samples of mesenteric vascular were from IVF-ET mice and normal controls. Given the vital function in regulating vascular contraction which Ca2+signaling pathway exhibited , four representative genes (Calm2, Itprl, RyR2, RyR3) were selectedfor study. And the mRNA expression levels of Calm2, Itpr2, RyR2, RyR3 were tested by qPCR. The protein expression levels of Calm2 and Itprl were tested by Western blot. Results Mice born under IVF-ET showed increased bodyweight and abnormal BMI after 20th week, and the serum levels of NO and Ang II were significantly higher than those of control (P < 0. 0 5) . The expression levels of Calm2, Itprl were up-regulated both in molecular and protein levels (P <0. 0 1) , RyR3 was up-regulated in molecular level (P < 0. 01) , while RyR2 was down-regulated in molecular level (P < 0. 0 1) . Conclusions The changes of serological markers and regulatory gene expression level related to vasoconstriction function may be closely related to the increased risk of cardiovascular diseases in IVF-ET offspring.

Identification and expression analysis of four CIPKs genes from a rare and medicinal plant, Dendrobium officinale / 药学学报

The calcineurin B-like protein (CBL)-interacting protein kinase (CIPK) plays a vital role in the growth, development, and stresses adaptation in plants by interaction with the calcium signaling. In this study, four full length cDNAs of CIPKs genes, namely DoCIPK1, DoCIPK2, DoCIPK3 and DoCIPK4 (GenBank accession No. KT957557, KT957558, KT957559 and KT957560, respectively) were cloned from the rear and medicinal plant, Dendrobium officinale, by rapid amplification of cDNA ends (RACE) for the first time. The corresponding encoded proteins, consisting of 473, 449, 451 and 440 amino acids (aa), respectively, with a molecular weight of 53.50, 50.93, 51.50 and 50.16 kDa, and an isoelectric point (pI) of 7.99, 9.25, 8.81 and 9.11, respectively, shared 70%-90%, 69%-80%, 78%-93%, and 66%-82% identities CIPKs with various plants. Each deduced protein contained a conserved protein kinase domain (respectively at 21 -275, 14-268, 16-271 and 12-266 aa position), a CIPKs family characteristic NAF/FISL domain (respectively at 335-391, 313-370, 310-369 and 305-362 aa position) and some functional motifs. The four DoCIPK proteins, without signal peptide or transmembrane region, were located in the plasma membrane and endoplasmic reticulum at the subcellular level. The three dimensional structure of the proteins were similar to that of Arabidopsis AtCIPK24. DoCIPK1 and DoCIPK3 were respectively clustered in the group E and A of the Arabidopsis and rice CIPK evolutionary tree, while DoCIPK2 and DoCIPK4 belonged to group C. The relative expression of DoCIPK1 showed no significant difference in the leaves and stems, and its transcripts in the roots was 0.35 fold over that in the leaves. The abundance of DoCIPK3 transcripts in the stems and the roots were 3.36 fold and 3.47 fold higher, respectively, than those in the leaves. DoCIPK2 exhibited similar expression pattern to DoCIPK4. Their relative expression in the leaves and the stems had no apparent difference, and the transcript levels were higher in the roots than that in the leaves, with 2.08 fold and 7.86 fold, respectively. Cloning, bioinformatics analyses, and expression patterns of the four DoCIPK genes provide a basis for functional elucidation of these genes further during the physiological responses in D. officinale.

Tau-Induced Ca/Calmodulin-Dependent Protein Kinase-IV Activation Aggravates Nuclear Tau Hyperphosphorylation / 神经科学通报·英文版

Hyperphosphorylated tau is the major protein component of neurofibrillary tangles in the brains of patients with Alzheimer's disease (AD). However, the mechanism underlying tau hyperphosphorylation is not fully understood. Here, we demonstrated that exogenously expressed wild-type human tau40 was detectable in the phosphorylated form at multiple AD-associated sites in cytoplasmic and nuclear fractions from HEK293 cells. Among these sites, tau phosphorylated at Thr205 and Ser214 was almost exclusively found in the nuclear fraction at the conditions used in the present study. With the intracellular tau accumulation, the Ca concentration was significantly increased in both cytoplasmic and nuclear fractions. Further studies using site-specific mutagenesis and pharmacological treatment demonstrated that phosphorylation of tau at Thr205 increased nuclear Ca concentration with a simultaneous increase in the phosphorylation of Ca/calmodulin-dependent protein kinase IV (CaMKIV) at Ser196. On the other hand, phosphorylation of tau at Ser214 did not significantly change the nuclear Ca/CaMKIV signaling. Finally, expressing calmodulin-binding protein-4 that disrupts formation of the Ca/calmodulin complex abolished the okadaic acid-induced tau hyperphosphorylation in the nuclear fraction. We conclude that the intracellular accumulation of phosphorylated tau, as detected in the brains of AD patients, can trigger nuclear Ca/CaMKIV signaling, which in turn aggravates tau hyperphosphorylation. Our findings provide new insights for tauopathies: hyperphosphorylation of intracellular tau and an increased Ca concentration may induce a self-perpetuating harmful loop to promote neurodegeneration.

Neuroprotective effect and mechanism of scutellarin ethyl ester on cerebral ischemia in vitro / 中国药学杂志

OBJECTIVE: To observe the blood-brain barrier permeability of scutellarin ethyl ester, the structural modification product of scutellarin, and to explore the mechanism of nerve protection on cerebral ischemia. METHODS: By co-culturing brain microvascular endothelial cells (BMVEC) and astrocytes cells (AC) in vitro, blood-brain barrier model was established. The active components were analyzed by HPLC. Rat cerebral cortical neurons cells were cultivated in vitro, and the survival rate was determined by MTT assay. The model of rat cortical neurons cell injury was established by glutamate and KCl, and the change of fluorescence intensity was detected by Laser Scanning Confocal Microscopy (LSCM). RESULTS: Compared with control group, scutellarin ethyl ester could penetrate BBB, promote the survival of cortex nerve cells in vitro significantly(P < 0.01), and inhibit intracellular calcium overload induced by 500 μmol · L-1 glutamate (P < 0.01). CONCLUSION: Scutellarin ethyl ester can pass through BBB and has neuroprotective effect by regulation of calcium signal pathway to resist cerebral ischemia. Copyright 2012 by the Chinese Pharmaceutical Association.

Influence of TROP-2 gene on the ability of human breast cancer cell metastasis / 中国基层医药

ObjectiveTo study the effects of tumor-associated calcium signal transducer-2 (TROP-2) gene small interfering RNA(siRNA) on adhesion and invasion of human breast cancer cell. MethodsReal time PCR was used to evaluate the TROP-2 mRNA of seven human breast cancer cell lines Bcap-37 ,LCC1 ,MCF-7 ,MDA-MB-231,MDA-MB-435, MDA-MB-468 ,and ZR75-1. The cell line of TROP-2 highest expression was transfected with different dose of TROP-2 siRNA. The expression of TROP-2 mRNA and protein were determined by Real-time quantitative PCR and immumoflurescence method. The cell adhesion was evaluated by MTT assay,and invasion was exmined by hoyden chamber,respectively. Results Cell line MCF-7 showed the highest elevation of TROP-2 mRNA in seven breast cancer cell lines. The results from real-time quantitative PCR and immumoflurescence method showed that TROP-2 mRNA and protein reduced in time-and dose-dependent manners( P ＜ 0.01 ;P ＜ 0.01 ). The adhesive rate of siRNA groups(5 nM,10 nM,and 20 nM)was(52.9 +2.5)％ ,(25.6 ±2.3)％, ( 12.8 +2.2)％ (P ＜0.01 ) ,respectively.The transwell results showed that the invasion cells was(78 ± 17), (39 ± 15), ( 19 ± 16), ( 136 +25 ) and( 139 ±21 )in different groups(5,10,20 nM siRNA,and controls) ,respectively(P ＜0.01). ConclusionTROP-2 gene might play an important role in adhesion and invasion of human breast cancer cell. siRNA targeted TROP-2 could effectively inhibit adhesion and invasion of human breast cancer cell.

Effects of Nicotinamide on Melanin Transportation in Human Skin Melanocytes / 环境与健康杂志

Objective To study the effects of nicotinamide on the human skin melanocytes and try to explore the potential mechanism of nicotinamide on the calcium signal transduction,cytoskeleton.Methods The primary cultured human skin melanocytes from foreskin were selected as the target cells in the present study.0.00,0.05,0.25,1.25 and 6.25 mg/ml nicotinamide were applied respectively.Western blot,fluorescent probes(Flu-3AM),flow cytometry analysis and time-lampse microscope digital skill were used to evaluate the effects of nicotinamide on melanosome motility and the melanosome distribution in melanocytes.Results The results showed that nicotinamide had a potential effect on regulating free calcium concentration in a dose-dependent manner(y=76.461 2-5.435x,r=0.97);The activity of Na+-K+-Ca2+-ATPase was down regulated with the increasing concentration of nicotinamide.The expression of cellular dynein was also altered by nicotinamide;Na +-K+-Ca2+-ATPase activity was kept normal when given 0.05,0.25 mg/ml nicotinamide,while the dynein protein expression was inhibited(P

Signaling Role of Exogenous Arachidonic Acid in the Invasion of Macrophages by Toxoplasma gondii / 中国寄生虫学与寄生虫病杂志

Objective To investigate the signaling role of arachidonic acid in the invasion of RAW264.7 macrophage by Toxoplasma gondii . Methods Rate of infection was calculated by both light microscope and flow cytometer. Fluorescent emission spectra were recorded using a microspectrofluometer for the concentration of cytoplasmic free calcium. Results Calcium concentration in macrophages and rate of infection increased with a higher concentration of exogenous arachidonic acid in a dose-dependent manner. The invasion was dependent on the mobilization of calcium from the extracellular medium and from intracellular stores and followed the influx of calcium into the parasitized cell. Conclusion Arachidonic acid may enhance the rate of infection via calcium transduction pathway.