Biomedical subjects

W Bian

Publications and source records attributed to W Bian.

14 recordsLinked to original sources

PubMed2001

Mouse nestin cDNA cloning and protein expression in the cytoskeleton of transfected cells.

Complementary DNA (cDNA) corresponding to mouse nestin intermediate filament protein, a specific marker for neural stem cells, was isolated and characterized. The complete sequence comprised 5983 base pairs encoding 1821 amino acids, and the deduced polypeptide was similar to rat (84%), hamster (73%), and human (62%) nestin. Southern blots showed that mouse nestin was a single-copy gene, and Northern blots detected a 6.0 kilobase mRNA transcript. When the cDNA was overexpressed as an enhanced green fluorescent fusion protein in COS7 cells, nestin immunoreactivity appeared in the filamentous cytoskeletal network. Accordingly, biologically active mouse nestin cDNA may offer an important new tool for stem cell research.

Amino Acid Sequence↗

PubMed2001

A role of N-cadherin in neuronal differentiation of embryonic carcinoma P19 cells.

N-cadherin is one of the important molecules for cell to cell interaction in the development of the central nervous system (CNS). In this report, we have shown that N-cadherin mRNA and protein were increased rapidly in retinoic acid (RA)-induced neuronal differentiation of embryonic carcinoma P19 cells. To explore possible roles for N-cadherin during this process, N-cadherin-overexpressing P19 cell lines were established. These transfected cells could differentiate into neurofilament-expressing neurons in the absence of RA. RT-PCR revealed that the expression patterns of development-related genes, such as Oct-3/4, nestin, Notch-1, and Mash-1 were similar between the transfected P19 cells and the RA-induced wild-type P19 cells during their neuronal differentiation. On the contrary, the Wnt-1 gene was up-regulated in the N-cadherin-overexpressing P19 cells, but could not be detected in the wild-type P19 cells. These results suggest N-cadherin may play a role in neuronal differentiation of P19 cells, possibly through the Wnt-1 signaling pathway.

Animals↗

PubMed2001

Mouse nestin protein localizes in growth cones of P19 neurons and cerebellar granule cells.

The neuronal growth cone, a highly motile structure at the distal tip of growing axons, contains filamentous actin and microtubules as its main cytoskeletal components. Using immunocytochemistry, we observed that nestin, which is the predominant intermediate filament protein in neuroepithelial cells and young neurons of the developing brain, appears to be strongly expressed in neurites and growth cones of neurons differentiating from P19 embryonic carcinoma cells in vitro. Double-staining of nestin and microtubule-associated protein-2 as well as nestin and growth-associated protein-43 revealed that nestin protein localizes in neurites and the central regions of growth cones of primary cultures of cerebellar granule cells from postnatal day 6 mice. These results suggest a role for nestin in growth cone guidance during axon elongation.

Age Factors↗

PubMed2001

Maternal zinc deficiency impairs brain nestin expression in prenatal and postnatal mice.

Effects of maternal dietary zinc deficiency on prenatal and postnatal brain development were investigated in ICR strain mice. From d 1 of pregnancy (E0) until postnatal d 20 (P20), maternal mice were fed experimental diets that contained 1 mg Zn/kg/day (severe zinc deficient, SZD), 5 mg Zn/kg/day (marginal zinc deficient, MZD), 30 mg Zn/kg/day (zinc adequately supplied, ZA) or 100 mg Zn/kg/day (zinc supplemented, ZS and pair-fed, PF). Brains of offspring from these dietary groups were examined at various developmental stages for expression of nestin, an intermediate filament protein found in neural stem cells and young neurons. Immunocytochemistry showed nestin expression in neural tube 10.5 d post citrus (dpc) as well as in the cerebral cortex and neural tube from 10.5 dpc to postnatal d 10 (P10). Nestin immunoreactivities in both brain and neural tube of those zinc-supplemented control groups (ZA, ZS, PF) were stronger than those in zinc-deficient groups (SZD and MZD). Western blot analysis confirmed that nestin levels in pooled brain extracts from each of the zinc-supplemented groups (ZA, ZS, PF) were much higher than those from the zinc-deficient groups (SZD and MZD) from 10.5 dpc to P10. Immunostaining and Western blots showed no detectable nestin in any of the experimental and control group brains after P20. These observations of an association between maternal zinc deficiency and decreased nestin protein levels in brains of offspring suggest that zinc deficiency suppresses development of neural stem cells, an effect which may lead to neuroanatomical and behavioral abnormalities in adults.

Aging↗

PubMed2000

Nestin expression during mouse eye and lens development.

Nestin is an intermediate filament protein, which is expressed predominantly in the developing central nervous system and skeletal muscles. In situ hybridization revealed that mouse nestin mRNA is in the optic stalk at 9.0 days post coitus (dpc) and in the lens vesicle at 10.0 dpc. From 14.5 dpc onward, nestin transcripts appear in lens fibers and neuroretina. Immunohistochemistry showed that nestin protein appears in the optic stalk at 9.5 dpc and in the posterior lens epithelium at 10.5 dpc. By 12.5 dpc, it is found in the lens, neuroretina, and optic stalk as well as in developing extrinsic ocular muscle, and it localizes in lens epithelium, optic disc, and optic nerve from 14.5 dpc to postnatal day 1. In adult eye, nestin protein appears in the optic nerve.

Animals↗

PubMed2000

Mood state changes of students enrolled in physical activity classes.

74 students enrolled in physical activity classes completed the happiness and sadness scales of the Emotional Assessment Scale each week for the 7-week course. A repeated measures analysis of variance indicated no significant change in mean mood state scores. Subjects' scores remained fairly happy throughout the length of the course, women having significantly happier scores than men.

Adolescent↗

PubMed2000

[Study on thermal unfolding process of trichosanthin by FTIR spectroscopy].

Fourier-transform infared spectroscopy, combined with resolution-enhancement techniques including second-derivative spectroscopy, Fourier self-deconvolution and curvefitting technique, was used to investigate the thermally induced unfolding process of anti-HIV-I toxin protein trichosanthin. During heating from 25 degrees C to 85 degrees C, the peak of Amide I shifted to 1618 cm-1 while the secondary structural contents change with the temperature. Upon cooling the protein from 85 degrees C to 25 degrees C, the contour of the Amide I do not change. All these show that the thermal unfolding of trichosanthin is an irreversible intermolecular aggregation process between 25 degrees C and 85 degrees C. The changes of secondary structures with temperature suggest the presence of folding intermediates.

Hot Temperature↗

PubMed2000

[Study on unfolding process of neo-trichosanthin in the presence of GdnHCl].

Fluorescence spectroscopy and circular dichroism are effective instruments to determine the chemical unfolding process of protein solution. In this paper, both of them were selected to investigate the unfolding processes of neo-trichosanthin in the presence of GdnHCl. One GdnHCl is added, both spectra of fluorescence and circular dichroism changed remarkedly. The denaturation curve of CD ellipticity meets that of fluorescence intensive excitation at 295 nm very well. The result shows that, in the presence of GdnHCl, the unfolding of neo-trichosantin matches the two-state process well. The model is different from the model of trichosanthin that others reported previously. The mechanism will be further probed later.

Circular Dichroism↗

PubMed1999

van der waals interactions in the Cl + HD reaction

The van der Waals forces in the entrance valley of the Cl + HD reaction are shown here to play a decisive role in the reaction's dynamics. Exact quantum mechanical calculations of reactive scattering on a potential energy surface without Cl-HD van der Waals forces predict that the HCl and DCl products will be produced almost equally, whereas the same calculations on a new ab initio potential energy surface with van der Waals forces show a strong preference for the production of DCl. This preference is also seen in crossed molecular beam experiments on the reaction. The study of chemical reaction dynamics has now advanced to the stage where even comparatively weak van der Waals interactions can no longer be neglected in calculations of the potential energy surfaces of chemical reactions.

Journal Article↗

PubMed1999

[Nestin expression during P19 neuron differentiation].

Mouse nestin, an intermediate filament gene, is transiently expressed during the development of the central nervous system. In order to find the clue of its function during neural development, we tried to find out the gene expression pattern during the neuronal differentiation of P19 EC cells induced RA. RT-PCR showed that nestin was transiently expressed during P19 neuron differentiation, with a peak at day 4 of this process. However, BMP4, a neural precursor cell marker, was transiently expressed with its highest level at day 6, while NF160 kD a terminal differentiated neuronal marker, was increasingly expressed during the whole process. These results implied that nestin might play some roles during the process of neural progenitor cells differentiating into neural precursor cells. Moreover, immunostaining showed that nestin was located in the neurite and the growth cone of the P19 neuron, suggesting that nestin might be also involved in the process of the establishment of neural connection.

Animals↗

PubMed1998

[Neural differentiation of Wnt-1 overexpression P19 cells].

Wnt-1 gene plays important roles during the development of the mouse central neural system. and shown a transient expression during neuronal differentiation of P19 EC cells. We transfected Wnt-1 gene into P19 cells and found the Wnt-1 transfected cells could differentiate into neurons without the induction of RA. However, MASH-1, a crucial gene for the early neural differentiation, was expressed later than P19 cells induced by RA.

Animals↗

PubMed1998

[The sub-cellular distribution of beta-catenin in the neural differentiation of RA induced P19 EC cells].

Wnt signals have been shown to play an important role in the development of the central nervous system (CNS) of mouse. In our previous work, it was demonstrated that Wnt signal could initiate differentiation of P19 EC cells. In the present investigation, it was examined with RT-PCR whether expression of beta-catenin, a downstream gene of Wnt in its signal transduction pathway, is regulated. It was found that the level of protein or transcript beta-catenin during P19 neuronal differentiation was not changed. However, immunostaining data showed that beta-catenin was translocalized into nuclei after retinoic acid induced P19 cell aggregates were trypsinized and cultured in serum free N2 medium for 2 and 4 d. In this period, transcription of En-2, a downstream target gene of Wnt signal, increased evidently. The above data suggest that Wnt signals are involved in the early stage of neuronal differentiation process of P19 cell. Meanwhile, the distribution of beta-catenin on the neurites indicates that this protein may also be involved in neuritis outgrowth process.

Animals↗

PubMed1997

[Study on the tribochemistry of antiwear additive BA1 by FTIRM].

This paper studied the tribochemistry of antiwear additive BA1 by FTIR microscope technique. We observed the changes of physical properties, interpreted the infrared spectra of the products in the track and concluded the chemical mechanism through the change of BA1 concentration, load and rubbing time. The results shows that the BA1 was decomposed, oxided and a thin film was produced when rubbed. This film makes the rubbing efficiency less.

English Abstract↗

PubMed1997

[Nestin mRNA expression during the development of mouse central nervous system].

Intermediate filament Nestin is a marker of neural precursor cells. Its expression pattern during mouse brain development was studied in the present investigation. A pair of primers based on the sequence of mouse Nestin were found best to be suit for the reverse transcriptional PCR (RT-PCR) with this pair of Nestin Primer. Using RT-PCR, Nestin transcripts were detected during the development of the central nervous system (CNS) of mouse, from embryonic day 10 to adult brain. We found that the Nestin showed a transient expression in the development of cerebrum. At the embryonic day 14, the expression of Nestin mRNA reached the highest peak, and was then down-regulated. In the postnatal cerebellum, Nestin gene was also expressed in a transient pattern. The highest peak of Nestin mRNA expression emerged at postnatal day 5, and was then down-regulated. Nestin mRNA expression in 10 kinds of adult mouse tissues did not yield any positive results.

Animals↗