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Jian Cao

Publications and source records attributed to Jian Cao.

35 records · Page 2Linked to original sources
PubMed2005

[Analysis of protamine content in patients with asthenozoospermia].

OBJECTIVE: To study the significance of the change of protamine content in the management of male infertility. METHODS: Sperm nuclear proteins extracted from 199 infertile patients were analyzed by polyacrylamide gel-electrophoresis and scanning microdensitometry. RESULTS: Forty-two (21%) cases of the total number had normal sperm nuclear proteins and 157 (79%) had aberrant ones, which mainly presented the interruption of HPRR and abnormality of P2 protamine. Thirty patients were selected at random from 157 abnormal cases for clinical treatment. After the treatment, the sperm nuclear proteins were extracted and analyzed and the results demonstrated that 11 cases (36.6%) improved markedly, 5 (16.6%) restored to normal and the other 16 (46.6%) remained unchanged. CONCLUSION: There is a reduced level or selective absence or even complete selective absence of protamines in infertile patients. Protamines may act as a parameter for evaluating the treatment effect of infertile males and protamine content can be influenced by a certain or several factors.

Adult↗
PubMed2005

[Reliability of an improved measurement system used in three-dimensional reconstruction of stomatognathic system by cutting and scanning layer-by-layer].

OBJECTIVE: To reconstruct 3D shape of edentulous jaw by using improved measurement system and to analyze the precision of this method. METHODS: Standard edentulous jaw models were measured with a improved measurement system by cutting and scanning layer-by-layer, and the 3D shape of the models was reconstructed by image processing with specialty software. Ten cubic plaster modes were reconstructed by the same way, data of every border before and after reconstruction were measured and analyzed. RESULTS: Data of edentulous jaw models were obtained. The errors in ten cubic before and after reconstruction were not significantly different (P > 0.05), data measured in horizontal plane were not significantly different (P > 0.05), and data measured in altitude direction were significantly different (P < 0.01), data measured after reconstruction were less than before, the error was (0.09 +/- 0.08) mm. CONCLUSION: The improved cutting and scanning measurement system can be fit for the 3D reconstruction of stomatognathic system with high precision.

Humans↗
PubMed2005

[IR study on the thermal decomposition IR of the cationic fenugreek gum].

The title complexes shown as cationic fenugreek gum were prepared. The thermal decomposition process of fenugreek gum and cationic fenugreek gum was studied quantitatively by means of thermogravimetric analysis an dinfrared spectroscopic measurement of samples after heating at different temperatures. Additionally, according to the fact that the absorbance peak changes and theanalysis of TG-IR of cationic fenugreek gum at different temperatures, it can be drawn that the thermal decomposition of the cationic fenugreek gum might lead to a possible thermal-cracking process.

Cations↗
PubMed2004

Intracellular processing and activation of membrane type 1 matrix metalloprotease depends on its partitioning into lipid domains.

The integral membrane type 1 matrix metalloprotease (MT1-MMP) is a pivotal protease in a number of physiological and pathological processes and confers both non-tumorigenic and tumorigenic cell lines with a specific growth advantage in a three-dimensional matrix. Here we show that, in a melanoma cell line, the majority (80%) of MT1-MMP is sorted to detergent-resistant membrane fractions; however, it is only the detergent-soluble fraction (20%) of MT1-MMP that undergoes intracellular processing to the mature form. Also, this processed MT1-MMP is the sole form responsible for ECM degradation in vitro. Finally, furin-dependent processing of MT1-MMP is shown to occur intracellularly after exit from the Golgi apparatus and prior to its arrival at the plasma membrane. It is thus proposed that the association of MT1-MMP with different membrane subdomains might be crucial in the control of its different activities: for instance in cell migration and invasion and other less defined ones such as MT1-MMP-dependent signaling pathways.

Biotinylation↗
PubMed2004

Emmprin promotes anchorage-independent growth in human mammary carcinoma cells by stimulating hyaluronan production.

Emmprin (CD147; basigin) is a plasma membrane glycoprotein, enriched on the surface of many cancer cells, which induces matrix metalloproteinase synthesis via cell-cell interactions. Elevated emmprin production causes increased growth in vivo of human mammary carcinoma cells. In this study, we show that elevation of emmprin expression in less aggressive human carcinoma cells, which normally express low emmprin levels, induces the ability to grow under anchorage-independent conditions. We also found that elevated emmprin expression stimulates hyaluronan production and that the effect of emmprin on anchorage-independent growth is dependent on hyaluronan. Furthermore, emmprin stimulates cell survival pathway signaling in a hyaluronan-dependent manner. From these and other studies we conclude that emmprin enhances several malignant properties of cancer cells, including anchorage-independent growth, invasiveness, and chemoresistance.

Antigens, CD↗
PubMed2004

TIMP-2 is released as an intact molecule following binding to MT1-MMP on the cell surface.

Binding of tissue inhibitor of metalloproteinase-2 (TIMP-2) to pro-MMP-2 and mature membrane type-1 MMP (MT1-MMP) on the cell surface is required for activation of MMP-2. It has been reported that following binding to cell surface receptors, TIMP-2 undergoes endocytosis and extensive degradation in lysosomes. The purpose of this study was to reexamine the fate of TIMP-2 following binding to transfected HT1080 cell surface MT1-MMP at 4 degrees C. Following 37 degrees C incubation, 125I-TIMP-2 release, endocytosis, and degradation were characterized under varying conditions. More than 85% of the total 125I-TIMP-2 bound to cells was released as intact functional molecules; <15% was degraded. Transfection of HT1080 cells with dominant negative mutant dynamin cDNA resulted in delayed endocytosis and release of 125I-TIMP-2 from cells. Pharmacologic agents that induce clustering of cell surface receptors (concanavalin A) and interfere with endosomal/lysosomal function (bafilomycin A(1)) resulted in enhanced binding of 125I-TIMP-2 to cell surface receptors. Abrogation of activation of proMT1-MMP with a furin inhibitor prevented binding and endocytosis of 125I-TIMP-2. Biotinylation of cell surface MT1-MMP followed by Western blotting confirmed the presence of mature MT1-MMP on the cell surface and degraded MT1-MMP in the intracellular compartment. In conclusion, these studies demonstrate that TIMP-2 is released from cells primarily as an intact functional molecule following binding to MT1-MMP on the cell surface.

Animals↗
PubMed2004

Distinct roles for the catalytic and hemopexin domains of membrane type 1-matrix metalloproteinase in substrate degradation and cell migration.

Substrate degradation and cell migration are key steps in cancer metastasis. Membrane-type 1-matrix metalloproteinase (MT1-MMP) has been linked with these processes. Using the fluorescein isothiocyanate (FITC)-labeled fibronectin degradation assay combined with the phagokinetic cell migration assay, structure-function relationships of MT1-MMP were studied. Our data indicate that MT1-MMP initiates substrate degradation and enhances cell migration; cell migration occurs as a concurrent but independent event. Using recombinant DNA approaches, we demonstrated that the hemopexin-like domain and a nonenzymatic component of the catalytic domain of MT1-MMP are essential for MT1-MMP-mediated cell migration. Because the cytoplasmic domain of MT1-MMP was not required for MT1-MMP-mediated fibronectin degradation and cell migration, it is proposed that cross-talk between the hemopexin domain of MT1-MMP and adjacent cell surface molecules is responsible for outside-in signaling. Employing cDNAs encoding dominant negative mutations, we demonstrated that Rac1 participates in the MT1-MMP signal transduction pathway. These data demonstrated that each domain of MT1-MMP plays a distinct role in substrate degradation and cell migration.

Animals↗
PubMed2004

[Synthesis and luminescence spectrum of trinuclear copper(I) complex].

The novel luminescent trinuclear copper( I ) complex [Cu3 (dppm)3 (NO3) (OH)] (NO3) has been obtained by treating binuclear copper(I) [Cu(dppm) (NO3)]2 with sodium tetraphenyl boron (dppm = Ph2 PCH2 PPh2). The complex was characterized by physico-chemical and spectroscopic methods. The title complex exhibits photoluminescence behavior at room temperature.

English Abstract↗
PubMed2003

[Infrared spectroscopic investigation on complexes formed from cupric fluoborate and cupric butyrate with Bis (diphenylphosphino) alkane ligands].

The Bis (diphenylphosphino) alkane series ligands and its series of complexes formed from Cu(BF4)2 and Cu(C3H7COO)2 respectively were studied by infrared spectral analysis. This paper discusses the spectral classification and the change regularity of related spectra before and after the Cu(I) complexes were formed. The possible structure model of the formed complexes was discussed, based on the element analysis, powder X-ray diffraction analysis, and thermal gravity analysis.

Borates↗
PubMed2003

[Clinical application of a kind of flexible gingival epithesis material].

OBJECTIVE: The aim of this paper is to introduce the clinical and laboratory procedures of fabricating silicone gingival epithesis and evaluate the long-term effects of the epithesis. METHODS: Flexible gingival epithesises were fabricated by the same way of fabricating partial denture, and their effects were evaluated in 31 patients by following up for 8-20 months. RESULTS: Patients' responses to appearance showed that their esthetic appearance had been much improved in all of the patients and the comfort and retention of their epithesises varied from good to excellent in almost all the patients. Discoloration of the epithesises was noticed by the patients within ten months in average. Doctors' examination confirmed patients' responses, and caries was detected at the necks of teeth covered by epithesises and slight gingivititis was discovered in the area under the epithesises in two cases. CONCLUSION: Flexible gingival epithesis is a simple and effective method for correcting gingival recession, and the fabrication is simple and don't need special equipment. However, discoloration of the epithesis remains a problem.

Adult↗
PubMed2002

EMMPRIN-mediated MMP regulation in tumor and endothelial cells.

Tumor invasion and metastasis are multistep processes which require extracellular matrix remodeling by proteolytic enzymes such as matrix metalloproteinases (MMPs). The production of these enzymes is stimulated by many soluble or cell-bound factors. Among these factors, extracellular matrix metalloproteinase inducer (EMMPRIN) is known to increase in vitro stromal cell production of MMP-1, MMP-2 and MMP-3. In this study, we demonstrated that EMMPRIN-transfected MDA-MB-436 tumor cells displayed a more invasive capacity than vector-transfected cells in a modified Boyden chamber invasion assay. Using gelatin zymography and protein analyses, we showed that EMMPRIN-transfected cancer cells produced significantly more latent and active MMP-2 and MMP-3 than vector-transfected cancer cells. We found that EMMPRIN did not regulate MMP-1, MMP-9, membrane type-1 MMP (MT1-MMP) expression and had also no effect on the production of the specific tissue inhibitors of MMPs (TIMPs), TIMP-1 and TIMP-2. We also demonstrated that tumor-derived EMMPRIN stimulated MMP-1, -2, and -3 without modification of MMP-9, MT1-MMP, TIMP-1 and TIMP-2 production in human umbilical vein endothelial cells (HUVEC). These data provide support for the role of EMMPRIN in tumor invasion, metastasis, and neoangiogenesis by stimulating extracellular matrix remodeling around tumor cell clusters, stroma, and blood vessels.

Antigens, CD↗
PubMed2002

Rapid trafficking of membrane type 1-matrix metalloproteinase to the cell surface regulates progelatinase a activation.

Pericellular matrix degradation during cancer invasion and inflammation is dependent on activation of progelatinase A by membrane type 1-matrix metalloproteinase (MT1-MMP); a stoichiometric concentration of tissue inhibitor of metalloproteinase-2 (TIMP-2) is required. Activation of progelatinase A has generally been considered to be a slow process occurring as a result of enhanced expression of MT1-MMP. We herein report that ConA treatment of HT1080 fibrosarcoma cells is followed by MT1-MMP-induced activation of progelatinase A on the cell surface within 1 hour. Cell surface biotinylation, immunohistochemistry, and (125)I-labeled TIMP-2 binding to cell surface MT1-MMP were used to characterize the appearance and function of MT1-MMP on the plasma membrane. Treatment of HT1080 cells with ConA resulted in increased specific binding of (125)I-labeled TIMP-2 to cell surface receptors within 5 minutes. TIMP-2 binds almost exclusively to activated MT1-MMP on the surface of HT1080 cells. MT1-MMP function at the cell surface was also accelerated by treatment of cells with cytochalasin D, an inhibitor of actin filaments, PMA, a stimulator of protein kinase C, and bafilomycin A(1), an inhibitor of lysosome/endosome function. A functional pool of intracellular MT1-MMP available for trafficking to the cell surface was demonstrated by repetitive ConA stimulation. ConA-induced expression of MT1-MMP mRNA (Northern blot analysis) in HT1080 cells was a delayed event (>6 hours). These data suggest that presynthesized MT1-MMP is sorted to a transient storage compartment (trans-Golgi network/endosomes), where it is available for rapid trafficking to the plasma membrane and cell surface proteolytic activity.

Anti-Bacterial Agents↗
PubMed2002

Characterization of nicotinic agonist-induced [(3)H]dopamine release from synaptosomes prepared from four mouse brain regions.

The inhibition of uptake of [(3)H]dopamine into synaptosomes prepared from four mouse brain regions was investigated. The inhibition curves demonstrated that in three regions, striatum, nucleus accumbens, and olfactory tubercle, [(3)H]dopamine was taken up exclusively by dopaminergic terminals. In frontal cortex, however, only a portion of the uptake was into dopaminergic terminals, with a larger amount taken up by noradrenergic terminals, and another small portion by serotonergic terminals. Release studies in frontal cortex indicated that in this region only dopaminergic and noradrenergic terminals are capable of packaging [(3)H]dopamine in a form allowing vesicle-mediated release; additionally, only the dopaminergic terminals have functional presynaptic nAChRs that, when stimulated by nicotinic agonists, evoke [(3)H]dopamine release. Agonist-stimulated [(3)H]dopamine release was characterized from synaptosomes prepared from four mouse brain regions. alpha-Conotoxin MII was a partial inhibitor of dopamine release in all of the brain regions, which suggests that a minimum of two nicotinic cholinergic receptors (nAChRs) are expressed in the nerve terminals of all four brain regions. No nicotine-induced [(3)H]dopamine release was detected in any brain region when the synaptosomes were prepared from beta2 null mutant mice, which indicates that the beta2 subunit is required for all nAChRs mediating this release. Dose-response curves were constructed for seven agonists in each of the brain regions. The pharmacological properties of synaptosomal [(3)H]dopamine release appear similar across the four brain regions. The results suggest that all four regions express the same nAChRs, although subtle regional differences may exist.

Animals↗
PubMed2001

A conserved sequence within the propeptide domain of membrane type 1 matrix metalloproteinase is critical for function as an intramolecular chaperone.

The propeptide domain of secreted matrix metalloproteinases (MMPs) is responsible for maintaining the latency of these proteinases. Recently, the propeptide domain of the prototype membrane type matrix metalloproteinase (MT1-MMP) was demonstrated to act as an intramolecular chaperone (Cao, J., Hymowitz, M., Conner, C., Bahou, W. F., and Zucker, S. (2000) J. Biol. Chem. 275, 29648-29653). In the current study, the role of an unique four-amino acid sequence in the propeptide domain of MT1-MMP was examined. The sequence (42)YGYL(45) is conserved in the propeptide domain of all six members of the MT-MMP subfamily, but not in secreted MMPs. Mutant MT1-MMP cDNAs coding for alanine substitutions (single and double amino acid sequences) in this conserved propeptide region were transfected into COS-1 cells deficient in endogenous MT1-MMP. As demonstrated by immunofluorescence, mutant MT1-MMP protein was synthesized and displayed on the plasma membrane of transfected cells. Alanine substitutions within the (42)YGYL(45) sequence proved to be detrimental for enzyme function in terms of activation of proMMP-2 and binding TIMP-2 to the cell surface (MT1-MMP serves as a cell surface receptor for TIMP-2). In contrast to wild-type MT1-MMP-transfected cells, mutant MT1-MMP-transfected cells were incapable of degrading and migrating on a fibronectin substrate. These data indicate that the conserved (42)YGYL(45) sequence within the propeptide domain of MT-MMPs is required for intramolecular chaperone function of these intrinsic membrane proteinases.

Alanine↗