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Zhen Wang

Publications and source records attributed to Zhen Wang.

At least 37 records · Page 2Linked to original sources

hSef co-localizes and interacts with Ras in the inhibition of Ras/MAPK signaling pathway.

To study the mechanism of the inhibitory effects of Sef (similar expression to fgf genes) on Ras/mitogen-activated protein kinase (MAPK) signaling pathway, we observed cellular localization of this protein. Immunofluorescent staining results show that Sef locates in the vesicles of the cytoplasm without bFGF treatment but co-localizes with Ras on the plasma membrane (PM) in response to bFGF stimulation. The coimmunoprecipitation assay demonstrates that Sef interacts with Ras or RasG12V, respectively. We observed that Sef inhibited FGF induced, but not RasG12V mediated, signal transduction. We propose that Sef interacted with Ras in the inhibition of Ras/MAPK signaling pathway.

Animals↗

Cochlear function after selective spiral ganglion cells degeneration induced by ouabain.

BACKGROUND: Ouabain, a cardiac glycoside that specifically binds to Na/K-ATPase and inhibits its activity, was applied to gerbils to develop a method for studying auditory neuropathy. METHODS: Ouabain was applied to the round window of the cochlea in each gerbil by using a piece of gelfoam with 3 microl or 24 microl (1 mmol/L) ouabain solution. The changes of the threshold of auditory brainstem response, cochlear function round window electrocochleography, as well as the morphological changes of the spiral ganglion cells of the cochlea were observed after application of ouabain for 24 hours or 96 hours. RESULTS: In ouabain treated gerbils, auditory brainstem response and compound action potential thresholds showed either elevation or no response at all. However, the thresholds of cochlear microphonic and distortion product otoacoustic emissions were not affected. Degeneration and necrosis of some spiral ganglion cells in ears with applications of ouabain (24 hours, 3 microl, 1 mmol/L; 96 hours, 24 microl, 1 mmol/L ouabain). The number of spiral ganglion cells was decreased (24 hours, 3 microl, 1 mmol/L ouabain) or near to a total loss (96 hours, 24 microl, 1 mmol/L ouabain). CONCLUSIONS: These results indicate a high degree of independence between the spiral ganglion cells and the outer hair cell systems in the cochlear transduction mechanism. The method used in this study would provide a valuable tool for studying auditory neuropathy.

Action Potentials↗

New luminescent europium(III) chelates for DNA labeling.

The new europium(III) chelate [2,2',2'',2'''-[[4'-(aminobiphenyl-4-yl)-2,2':6',2''-terpyridine- 6,6''-diyl]bis(methylenenitrilo)]tetrakis(acetato)] europium(III) (ATBTA-Eu3+) and its 4,6-dichloro-1,3,5-triazinyl and succinimidyl derivatives (DTBTA and NHS-ATBTA, respectively) were synthesized and characterized. Both labeling complexes DTBTA-Eu3+ and NHS-ATBTA-Eu3+ are luminescent. Especially DTBTA-Eu3+ is strongly luminescent, with a luminescence quantum yield of 9.1%, molar extinction coefficient of 3.1 x 10(4) cm(-1) M(-1) (335 nm), and luminescence lifetime of 1.02 ms. The excitation and emission maximum wavelengths of DTBTA-Eu3+ are 335 and 616 nm, respectively. The complex is very stable in aqueous buffers, with a conditional formation constant log K(DTBTA-Eu) of 25.0 at pH 8, and can be conjugated to DNA and proteins. The chelates are also highly resistant to thermal decomposition, photodegradation, and ozone oxidation. These properties prove that DTBTA-Eu3+ is suitable as a luminescence label in DNA assays.

Chelating Agents↗

Iterative one-pot syntheses of chitotetroses.

Rapid syntheses of chitotetrose derivatives were achieved in good yields using the newly developed reactivity independent iterative one-pot strategy. The protective groups on donors and acceptors were independently evaluated allowing matching of the two partners in glycosylation. No anomeric reactivity adjustments or intermediate purification were necessary thus significantly improving the overall synthetic efficiency. Only near stoichiometric amounts of building blocks were required for the assembly of target molecules further highlighting the potential of the iterative one-pot method in complex oligosaccharide synthesis.

Chitin↗

Increased transcriptional response to mechanical strain in keloid fibroblasts due to increased focal adhesion complex formation.

Clinicians have observed that keloids preferentially form in body areas subject to increased skin tension. We hypothesized a difference exists in the transcriptional response of keloid fibroblasts to mechanical strain compared with normal fibroblasts. Normal and keloid fibroblasts were seeded in a device calibrated to deliver a known level of equibiaxial strain. We examined the transcriptional response of TGF-beta isoforms and collagen Ialpha, genes differentially expressed in keloids. Keloid fibroblasts produced more mRNA for TGF-beta1, TGF-beta2, and collagen Ialpha after mechanical strain compared to normals, and this was correlated with protein production. Inhibiting the major mechanical signal transduction pathway with the ERK inhibitor, U0126, blocked upregulation of gene expression. In addition, keloid fibroblasts formed more focal adhesion complexes as measured by immunofluorescence for focal adhesion kinase, integrin beta1, and vinculin. Finally, there is increased activation of focal adhesion kinase when we detected the phosphorylated form of focal adhesion kinase with immunofluorescence and immunoblotting. In summary, keloid fibroblasts have an exaggerated response to mechanical strain compared to normal fibroblasts leading to increased production of pro-fibrotic growth factors. This may be one molecular mechanism for the development of keloids.

Adolescent↗

Beneficial effects of alkaline phosphatase in septic shock.

OBJECTIVE: Alkaline phosphatase may decrease the harmful effects of lipopolysaccharide by detoxifying lipid A. The aim of this study was to investigate whether administration of alkaline phosphatase is beneficial in a clinically relevant septic shock model. DESIGN: Interventional laboratory study. SETTING: University hospital animal research laboratory. SUBJECTS: Fourteen fasted, anesthetized, invasively monitored, mechanically ventilated, female sheep (27.6 +/- 3.9 kg). INTERVENTIONS: Each animal received 1.5 g/kg body weight of feces intraperitoneally to induce sepsis. Ringer's lactate and a 6% hydroxyethyl starch solution were infused throughout the experiment to prevent hypovolemia. Two hours after feces injection, animals were randomized to alkaline phosphatase (60 units/kg intravenous bolus followed by a continuous infusion of 20 units/kg/hr for a total of 15 hrs) or no alkaline phosphatase (control group). MEASUREMENTS AND MAIN RESULTS: All animals were studied until their spontaneous death or for a maximum of 30 hrs. Plasma alkaline phosphatase concentrations decreased in the control group but increased in the treatment group following alkaline phosphatase administration. In the treatment group, the Pao2/Fio2 ratio was higher (p < .05), blood interleukin-6 concentrations were lower (p < .05), and the survival time was longer (median time 23.8 vs. 17 .0 hrs, p < 0.05) than in the control group. There were no significant differences in systemic hemodynamics or diuresis. CONCLUSIONS: In this clinically relevant septic shock model, alkaline phosphatase administration improved gas exchange, decreased interleukin-6 concentrations, and prolonged survival time.

Alkaline Phosphatase↗

Prognostic analysis in chronic hepatitis B patients: a retrospective study of 216 cases about Scheuer scores, in situ expression of viral antigens and tissue hepatitis B virus DNA levels.

BACKGROUND: Most of the previous studies of patients with chronic hepatitis B virus (HBV) infection concentrated on serum samples. Liver biopsy specimens for HBV have not been systematically analyzed. This study was performed to analyze some histopathological indicators (Scheuer scores, the expression of HBV antigens in situ, HBV DNA quantification) in the biopsy samples and showed the relationship among them and the prognosis of chronic hepatitis. METHODS: A total of 216 consecutive chronic HBV-infected patients were followed up by clinical and laboratory data and classified into two groups at first: carcinogenesis and non-carcinogenesis. The non-carcinogenesis also included two groups: cirrhosis and non-cirrhosis. The non-cirrhosis was still divided into fluctuation and normalization at last. Histological activity index was described by Scheuer scores. Two-step immunohistochemical staining showed the expression of viral antigens in situ. Tissue HBV DNA levels were determined by fluorescence quantitative real-time PCR. RESULTS: Regression analysis revealed significant positive correlations between the expression of hepatitis B e antigen (HBeAg) and grading, as well as between hepatitis Bx (HBx) protein and grading or staging of Scheuer scores. Positive correlations between grading or staging and prognosis were statistically significant. The expressions of HBeAg and HBx protein were higher in patients with cirrhosis than those without cirrhosis. Scheuer score was the most important indicator of prognosis. CONCLUSIONS: HBeAg and HBx protein can be used as indicators of hepatitis activity and their positive expressions increase the risk for cirrhosis remarkably. In addition to be a marker of liver damage, Scheuer score is the most reliable indicator of the prognosis.

Adult↗

Sugar and alcohol molecules provide a therapeutic strategy for the serpinopathies that cause dementia and cirrhosis.

Mutations in neuroserpin and alpha1-antitrypsin cause these proteins to form ordered polymers that are retained within the endoplasmic reticulum of neurones and hepatocytes, respectively. The resulting inclusions underlie the dementia familial encephalopathy with neuroserpin inclusion bodies (FENIB) and Z alpha1-antitrypsin-associated cirrhosis. Polymers form by a sequential linkage between the reactive centre loop of one molecule and beta-sheet A of another, and strategies that block polymer formation are likely to be successful in treating the associated disease. We show here that glycerol, the sugar alcohol erythritol, the disaccharide trehalose and its breakdown product glucose reduce the rate of polymerization of wild-type neuroserpin and the Ser49Pro mutant that causes dementia. They also attenuate the polymerization of the Z variant of alpha1-antitrypsin. The effect on polymerization was apparent even when these agents had been removed from the buffer. None of these agents had any detectable effect on the structure or inhibitory activity of neuroserpin or alpha1-antitrypsin. These data demonstrate that sugar and alcohol molecules can reduce the polymerization of serpin mutants that cause disease, possibly by binding to and stabilizing beta-sheet A.

Carbohydrates↗

Increased expressions of vascular endothelial growth factor (VEGF), VEGF-C and VEGF receptor-3 in prostate cancer tissue are associated with tumor progression.

AIM: To investigate the differences in microvessel densities (MVD) and the expressions of vascular endothelial growth factor (VEGF), VEGF-C and VEGF receptor-3 (VEGFR-3) between prostate cancer (PCa) tissues and adjacent benign tissues, and to explore the correlations among MVD, Jewett-Whitmore staging, Gleason scores and expressions of VEGF, VEGF-C and VEGFR-3 in the progression of PCa. METHODS: An immunohistochemical approach was adopted to detect the expressions of CD34, VEGF, VEGF-C and VEGFR-3 in both cancer areas and peripheral benign areas of 71 primary prostatic adenocarcinoma specimens. A statistic analysis was then performed according to the experimental and clinic data. RESULTS: Significantly upregulated expressions of VEGF, VEGF-C and VEGFR-3 were all found in malignant epithelium/cancer cells compared with adjacent benign epithelium (P<0.01). Patients in stage D had a significantly higher score than patients in stage A, B or C when comparing the expression of VEGF-C or VEGFR-3 in the tumor area (P<0.01). In addition, significant correlations were observed between Jewett-Whitmore staging and VEGF-C (r(s)=0.738, P<0.01), clinical staging and VEGFR-3 (r(s)=0.410, P<0.01), VEGF-C and Gleason scores (r(s)=0.401, P<0.01), VEGFR-3 and Gleason scores (r(s)=0.581, P<0.001) and MVD and VEGF (r(s)=0.492, P<0.001). CONCLUSION: Increased expressions of VEGF and VEGF-C were closely associated with progression of PCa. The main contribution of increased VEGF expression for PCa progression was to upregulate MVD, which maintained the growth advantage of tumor tissue. However, the chief role of increased expressions of VEGF-C and VEGFR-3 was to enhance lymphangiogenesis and provide a main pathway for cancer cells to disseminate.

Aged↗

Trauma and dissociation in China.

OBJECTIVE: In order to determine whether pathological dissociation occurs in China, the authors conducted a survey among psychiatric inpatients, outpatients, and the general population in Shanghai, China. There is virtually no popular or professional knowledge of dissociative identity disorder in China, and therefore professional and popular contamination cannot exist. METHOD: Chinese versions of the Dissociative Experiences Scale and the Dissociative Disorders Interview Schedule were administered to 423 inpatients, 304 outpatients, and 618 factory workers in Shanghai by Chinese psychiatrists working at the Shanghai Mental Health Center. RESULTS: Dissociative disorders were diagnosed in 24 respondents by structured interview, and 15 respondents fell into the dissociative taxon on the Dissociative Experiences Scale. The outpatients reported the highest rates of childhood physical and/or sexual abuse and of pathological dissociation. CONCLUSIONS: Pathological dissociation can be detected readily among psychiatric outpatients in China but is much less common in the general population. Pathological dissociation is more frequent in more traumatized subsamples of the Chinese population. The findings are not consistent with the sociocognitive, contamination, or iatrogenic models of dissociative identity disorder.

Adult↗

Dissociative experiences in China.

The Dissociative Experiences Scale was administered to a non-clinical sample in Shanghai, China (N = 618) and the results were compared with a previous sample of the general population from Winnipeg, Canada (N = 1055). The Dissociative Disorders Interview Schedule was administered to the 618 Chinese participants and results were compared with those of the Canadian participants (N = 502). In addition, both measures were administered to a sample of Chinese psychiatric inpatients (N = 423) and outpatients (N = 304). Rates of childhood trauma and dissociation were far lower in the Chinese non-clinical sample than in the two Chinese psychiatric patient groups, and far lower than in the Canadian general population. Among the 618 respondents in the Chinese non-clinical sample, no childhood sexual abuse was reported and only one person reported childhood physical abuse. These rates of childhood abuse were far lower than in other non-clinical samples from China; for example, rates were 16.7% for sexual abuse of girls and 10.5% for sexual abuse of boys in a previous study. Among the more traumatized Chinese psychiatric patients, and among the Canadian respondents, dissociative experiences were much more common than in the Chinese general population. The data provide a base frequency for dissociation in non-clinical samples reporting little or no childhood physical and sexual abuse.

Adult↗

Gene expression programs in response to hypoxia: cell type specificity and prognostic significance in human cancers.

BACKGROUND: Inadequate oxygen (hypoxia) triggers a multifaceted cellular response that has important roles in normal physiology and in many human diseases. A transcription factor, hypoxia-inducible factor (HIF), plays a central role in the hypoxia response; its activity is regulated by the oxygen-dependent degradation of the HIF-1alpha protein. Despite the ubiquity and importance of hypoxia responses, little is known about the variation in the global transcriptional response to hypoxia among different cell types or how this variation might relate to tissue- and cell-specific diseases. METHODS AND FINDINGS: We analyzed the temporal changes in global transcript levels in response to hypoxia in primary renal proximal tubule epithelial cells, breast epithelial cells, smooth muscle cells, and endothelial cells with DNA microarrays. The extent of the transcriptional response to hypoxia was greatest in the renal tubule cells. This heightened response was associated with a uniquely high level of HIF-1alpha RNA in renal cells, and it could be diminished by reducing HIF-1alpha expression via RNA interference. A gene-expression signature of the hypoxia response, derived from our studies of cultured mammary and renal tubular epithelial cells, showed coordinated variation in several human cancers, and was a strong predictor of clinical outcomes in breast and ovarian cancers. In an analysis of a large, published gene-expression dataset from breast cancers, we found that the prognostic information in the hypoxia signature was virtually independent of that provided by the previously reported wound signature and more predictive of outcomes than any of the clinical parameters in current use. CONCLUSIONS: The transcriptional response to hypoxia varies among human cells. Some of this variation is traceable to variation in expression of the HIF1A gene. A gene-expression signature of the cellular response to hypoxia is associated with a significantly poorer prognosis in breast and ovarian cancer.

Adult↗

[Gene's construction, expression and activity analysis of humanized single-domain antibody against human lung cancer].

AIM: To construct the gene of humanized single-domain antibody hu3D3V(H) against human lung cancer, to express it in E.coli and analyze its activity. METHODS: The mAb3D3V(H) was humanized by using CDRs grafting technique. The hu3D3V(H) gene was assembled by overlapping PCR. The expression vector pET22(b+)/hu3D3V(H) was constructed and transformed into E.coli BL21(DE3) and the hu3D3V(H) protein was expressed under IPTG induction. After purification by Ni(2+)-affinity chromatographic column, the activity of hu3D3V(H) protein was analyzed by indirect ELISA and competitive inhibition ELISA. RESULTS: The target gene with correct sequence was obtained by overlapping PCR. The hu3D3V(H) protein was expressed as inclusion bodies with the yield of more than 30% of total bacterial proteins. After purification, the purity of hu3D3V(H) was more than 95%. The reactivity of purified protein was the same as parent antibody, and could inhibit the binding of mAb3D3 to L342 cells. CONCLUSION: The hu3D3V(H) still retains the reactivity and specificity of mAb3D3, which lays the foundation for its further clinical application.

Antibodies↗

[A comparative study on acellular small intestinal submucosa and acellular amnion as dressings for traumatic skin defects].

OBJECTIVE: To compare the reparative effects between the acellular small intestinal submucosa and the acellular amnion as dressings for traumatic skin defects. METHODS: Three full-thickness skin defects, which were close to the vertebral column of the pig, were created on both sides of the dorsum. The skin defects were randomly divided into three groups. In each group, the following different materials were used to cover the skin defects: the acellular amnion in Group A, the acellular small intestinal submucosa (SIS) in Group B, and the physiological saline gauze in Group C (the control group). The specimens from the skin defects were harvested for a histological evaluation and for determination of the hydroxyproline content at 10 (2 pigs), 20 (2 pigs), and 30 days (3 pigs). We observed the healing process of the wound and its healing rate, counted the inflammatory cells, vascular endothelial cells, and proliferating cells, and determined the hydroxyproline content. RESULTS: The acellular amnion in Group A and the acellular SIS in Group B adhered to the wound tightly, but they did not adhere to the dressing; when the dressing was changed, the wound did not bleed. The saline gauze in Group C adhered to the wound tightly, but when the dressing was changed, the wound bled until 22 days after operation. Under the microscope, the collagen in the tissue below the epithelium was arranged more regularly and there were fewer cells concerned with inflammation in Groups A and B than in Group C at 10, 20, and 30 days after operation. At 10, 20, and 30 days after operation, the wound healing rate was greater in Groups A and B than in Group C. The number of the inflammatory cells and the proliferating cells were greater in Group C than in Groups A and B. There was a statistically significant difference (P < 0.05), At 20 and 30 days after operation, the content of hydroxyproline was greater in Group C than in Group A and B. There was a statistically significant difference (P < 0.05). However, there was no statistically significant difference between Group A and Group B in the wound healing rate, the numbers of the inflammatory cells, vascular endothelial cells and proliferating cells, and the content of hydroxyproline (P > 0.05). There was no statistically significant difference among the three groups in the number of the vascular endothelial cells. CONCLUSION: Compared with Group C, the wound healing rate is improved, the collagen in the tissue below the epithelium is arranged more regularly, and the inflammatory cells, bleeding, and effusion are reduced in Groups A and B. The reparative effects of the acellular amnion and the acellular small intestinal submucosa as dressings on the skin defects are almost the same.

Amnion↗

[Experimental study on porcine keratinocytes cultured and purified rapidly and cocultured on acellular amnion in vitro].

OBJECTIVE: To explore an effective method to culture and purify porcine keratinocytes, to observe the morphological characteristics of porcine keratinocytes growing on acellular amnion and to offer the experimental basis for that the amnion is used for tissue engineering. METHODS: The primary porcine keratinocytes were cultivated with DKSFM (Defined keratinocyte-SFM) containing 10% fetal bovine serum (FBS). The second passage porcine keratinocytes were cultivated with the medium of DKSFM containing different concentrations of FBS. Because of the speciality that keratinocytes stick to flask fast, we purified the keratinocytes by 0.02% EDTA and 0.05% trypsin step by step. The second passage keratinocytes were seeded on amnion, the keratinocytes/amnion composites were observed by dye directly, histopathology and immunohistochemical staining. RESULTS: The proliferation of the primary porcine keratinocytes cultured with the medium of DKSFM containing 10% FBS was fast and the morphological characteristics were good. The cultivated porcine keratinocytes expanded to 60%-70% of the total area of the bottle of the flask after 5 days. The proliferation of the second passage porcine keratinocytes cultivated with the medium that DKSFM containing 5% FBS was faster than the second porcine keratinocytes cultured with the medium of DKSFM containing 10% FBS, or DKSFM without FBS. The proliferation of the second passage porcine keratinocytes cultivated with DKSFM without FBS was the slowest one among the 3 medium. The porcine keratinocytes that were purified by 0.02% EDTA and 0.05% trypsin step by step were got with high pure. After the keratinocytes were cultivated on the surface of amnion 12 days, the keratinocytes form a single layer on the surface of amnion and the cells were polygon and arranged like slab- stone. After 14 and 16 days, the cells contacted more closely. But at 16 days after the cells were seeded, some of the cells got aging. CONCLUSION: To culture primary porcine keratinocytes with the medium that DKSFM containing 10% FBS and to cultivate the second passage with the medium containing 5% FBS, the proliferation of porcine keratinocytes are faster. The method that purify the porcine keratinocytes is effective. Acellular amnion offers excellent bioscaffold to support keratinocytes to adhere and grow. After the porcine keratinocytes are cultivated on the surface of the acellular amnion 12 days, the morphologic characteristics are better than that of other groups.

Actihaemyl↗

[Profilins in plant cells].

Actin cytoskeleton is one of the major components of cytoskeleton in eukaryotic cells. In response to endogenous cues or external signals, actin filaments undergo quick polymerization and depolymerization with result in rapid reconstruction of actin cytoskeleton. The dynamic rearrangement of actin filaments in cells are regulated by actin-binding proteins. Profilin is a low-molecular-weight, actin-monomer-binding protein ubiquitously presents in organisms ranging from amoebae and fungi up to higher plants and mammals. Besides binding actin, profilin also binds to phosphatidylinositol 4,5-bisphosphate and poly-L-proline. Recent studies suggest that profilin is a multifunctional protein that has positive and negative regulatory effects on actin polymerization and, in certain case, may be involved in signal transduction. We have long been engaged in the studies on characteristic and function of profilin in plant cells, such as the function analysis of Arabidopsis PRF1 and PRF2, and the effects of profilin on the function of forming in modulating actin cytoskeleton. Here, with the combination of our results, we have reviewed the recent progress in profilin research, including its initial finding, biochemical properties, in vivo distribution and functions, as well as its role in signal transduction.

Actin Cytoskeleton↗

[Overexpression of NDRG1: relationship with proliferative activity and invasiveness of breast cancer cell line and breast cancer metastasis].

OBJECTIVE: To investigate the relationship between NDRG1 and metastasis of breast cancer and the effects of NDRG1 overexpression on the proliferation and invasion of breast cancer cells. METHODS: NDRG1 was detected at its protein level by immunohistochemistry (IHC) and its messenger RNA (mRNA) was detected by real-time reverse transcriptase-polymerase chain reaction (real time RT-PCR) in clinical breast cancer specimens. Liposome was used to transiently transfer NDRG1 into MDA-MB-231, a highly invasive human breast cancer cell line. The proliferation of MDA-MB-231 was measured by Bromodeoxy Uridine (BrdU) incorporation assay and the transfection effect on cell cycle distribution was determined by fluorescence assisted cell sorting (FACS). The invasive ability of the transfected cells was investigated by reconstituted matrigel invasion and polycarbonate filters migration experiments. RESULTS: NDRG1 expressions at protein and mRNA levels in tumors of patients with lymph node metastases were significantly lower as compared with those with localized breast cancers (P < 0.01). The amount of NDRG1 mRNA in MCF7, a relatively non-invasive breast cancer cell line, was 10.8 times higher than that in MDA-MB-231 cells (P < 0.01). The BrdU incorporation rate declined significantly (P < 0.05) in NDRG1 overexpressing MDA-MB-231 cells. An increase of the cell population at G(0)/G(1) phase was observed 48 hours post-transfection along with a decrease of cell population at S phase. Overexpression of NDRG1 significantly retarded the invasiveness of MDA-MB-231 cells in matrigel-coated invasion chambers (P < 0.05), when compared to cells transfected with control vectors. However, the migration abilities of cells with or without the transfection were virtually identical. CONCLUSIONS: NDRG1 expression reversely correlates with breast cancer metastasis and progression, and may serve as a prognostic biomarker for predicting early metastasis. The inhibition of proliferation and invasion demonstrated by our MDA-MB-231 transfection experiments implies that NDRG1 is a tumor metastasis suppressor gene and may be a new candidate for gene therapy against human breast cancer.

Breast Neoplasms↗