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Lu Wang

Publications and source records attributed to Lu Wang.

At least 109 records · Page 6Linked to original sources
PubMed2004

Visceral hyperalgesia and intestinal dysmotility in a mouse model of postinfective gut dysfunction.

BACKGROUND & AIMS: We established the concept that transient enteric infection may lead to persistent gut dysfunction, evident in vitro, in nematode-infected mice. The present study determined whether gut dysfunction in this model involves motor and sensory changes reminiscent of changes found in patients with postinfective irritable bowel syndrome (PI-IBS) and investigated underlying mechanisms. METHODS: Mice infected up to 70 days previously with Trichinella spiralis (Tsp) underwent videofluoroscopy with image analysis to assess upper gastrointestinal motility. Pseudoaffective responses to colorectal distention (CRD) were assessed using a barostat and validated by single fiber recordings from spinal nerves during CRD. Tissues were examined at different time points for histology, immunohistochemistry, and cytokine analysis. Some mice received dexamethasone intraperitoneally on days 23-25 PI or Tsp antigen orally on days 29, 43, and 57 PI. RESULTS: From day 28 PI, no discernible inflammation was present in the gut. Frequency and propagation velocity of intestinal contractions decreased, and retroperistalsis increased at days 28 to 42 PI. CRD induced an allodynic and hyperalgesic response in PI mice, which was accompanied by increased single unit discharge. Gavage of Tsp antigen induced T-cell responses and sustained gut dysfunction for 70 days PI. Administration of dexamethasone postinfection normalized dysmotility and visceral hyperalgesia. CONCLUSIONS: Long-lasting gut dysmotility and hyperalgesia develop in mice after transient intestinal inflammation. These changes are maintained by luminal exposure to antigen and reversed by corticosteroid treatment. The findings prompt consideration of this as a model of PI-IBS.

Animals↗
PubMed2004

Patensin-induced apoptosis is accompanied by decreased bcl-2 expression and telomerase activity in HL-60 cells.

The present study aimed to investigate the effect of telomerase activity in patensin-induced apoptosis and the regulation of B cell leukemia/lymphoma 2 (bcl-2) gene expression in human leukemia HL-60 cells. Apoptosis of HL-60 cells was induced by patensin (100 micromol L(-1)) for 3, 6, 12 and 24 h. Apoptosis and bcl-2 were determined by flow cytometry analysis. A polymerase-chain-reaction-based telomeric repeat amplification protocol assay was used to detect the telomerase activity. Patensin induced growth arrest and apoptotic cell death in HL-60 cells. The telomerase activity was inhibited in a time-dependent manner during the patensin-induced apoptosis of HL-60 cells, and the expression of bcl-2 was progressively down-regulated by patensin. Inhibition of the telomerase activity of HL-60 cells was closely related to the patensin-induced apoptosis. The present results indicate that inhibition in telomerase and reduced bcl-2 gene expression may play a role in the patensin-induced apoptosis of HL-60 cells.

Apoptosis↗
PubMed2004

Mechanisms of arsenic-induced prolongation of cardiac repolarization.

Arsenic trioxide (As(2)O(3)) produces dramatic remissions in patients with relapsed or refractory acute promyelocytic leukemia. Its clinical use is burdened by QT prolongation, torsade de pointes, and sudden cardiac death. In the present study, we analyzed the molecular mechanisms leading to As(2)O(3)-induced abnormalities of cardiac electrophysiology. Using biochemical and electrophysiological methods, we show that long-term exposure to As(2)O(3) increases cardiac calcium currents and reduces surface expression of the cardiac potassium channel human ether-a-go-go-related gene (HERG) at clinically relevant concentrations of 0.1 to 1.5 microM. In ventricular myocytes, As(2)O(3) increases action potential duration measured at 30 and 90% of repolarization. As(2)O(3) interferes with hERG trafficking by inhibition of hERG-chaperone complexes and increases calcium currents by a faster cellular process. We propose that an increase in cardiac calcium current and reduced trafficking of hERG channels to the cell surface cause QT prolongation and torsade de pointes in patients treated with As(2)O(3). Our results suggest that calcium-channel antagonists will be useful in normalizing QT prolongation during As(2)O(3) therapy. As(2)O(3) is the first example of a drug that produces hERG liability by inhibition of ion-channel trafficking. Other drugs that interfere with proteins in the processing pathway of cardiac ion channels may be proarrhythmic for similar reasons.

Animals↗
PubMed2004

On the terminology for describing the length-force relationship and its changes in airway smooth muscle.

The observation that the length-force relationship in airway smooth muscle can be shifted along the length axis by accommodating the muscle at different lengths has stimulated great interest. In light of the recent understanding of the dynamic nature of length-force relationship, many of our concepts regarding smooth muscle mechanical properties, including the notion that the muscle possesses a unique optimal length that correlates to maximal force generation, are likely to be incorrect. To facilitate accurate and efficient communication among scientists interested in the function of airway smooth muscle, a revised and collectively accepted nomenclature describing the adaptive and dynamic nature of the length-force relationship will be invaluable. Setting aside the issue of underlying mechanism, the purpose of this article is to define terminology that will aid investigators in describing observed phenomena. In particular, we recommend that the term "optimal length" (or any other term implying a unique length that correlates with maximal force generation) for airway smooth muscle be avoided. Instead, the in situ length or an arbitrary but clearly defined reference length should be used. We propose the usage of "length adaptation" to describe the phenomenon whereby the length-force curve of a muscle shifts along the length axis due to accommodation of the muscle at different lengths. We also discuss frequently used terms that do not have commonly accepted definitions that should be used cautiously.

Animals↗
PubMed2004

Reduction in p48-ISGFgamma levels confers resistance to interferon-alpha2a in MHCC97 cells.

OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies in China and, due to the limited efficacy of currently available therapies, is responsible for a large number of deaths. IFN-alpha therapy has shown promise in the treatment of various forms of human cancer and is considered in the treatment of HCC. Previous results from our group showed that high doses of IFN-alpha exert a significant antiproliferative effect on MHCC97 human xenografts in nude mice, but not on MHCC97 cells when tested in vitro. Here we present experiments designed to characterize the molecular mechanism underlying the defective response of MHCC97 cells to IFN-alpha. Elucidation of the mechanism underlying the defective response of MHCC97 to IFN-alpha may help to explain and possibly to overcome clinical failures of this form of tumor therapy. METHODS: IFN-alpha(2a) was administered between 3,000 and 10,000 IU/ml, a range strongly inhibiting proliferation in other cell lines. Gene expression profiles of MHCC97 cells were obtained before and after treatment with IFN-alpha(2a) using cDNA microarray analysis. The transcriptional activity of relevant genes responding to IFN-alpha(2a) in the cDNA microarray experiments was confirmed by RT-PCR and Northern blot analysis. Transient transfection with an expression vector was used to restore p48-ISGFgamma (IRF9) protein levels. Cell proliferation was evaluated using the MTT assay. RESULTS: Although IFN-alpha treatment caused the activation of several signal transduction pathways in MHCC97 cells, the lack of an antiproliferative effect was found to mainly derive from a defect in the activation of the transcription factor ISGF3 required for Jak/STATS signaling. We show that the defect in ISGF3 activation is mainly caused by the absence of one of its essential components, the protein p48-ISGFgamma from MHCC97 cells. Indeed, transient expression of p48-ISGFgamma restores sensitivity to IFN-alpha(2a). Although the mRNA levels of p48-ISGFgamma were normal in MHCC97 cells, mutations could be detected in the gene coding for the protein. We hypothesize, therefore, that these mutations alter the message or protein stability, leading to the reduced protein levels observed. CONCLUSION: Our results confirm the important role of Jak/STATS signaling in the antiproliferative effects of IFN-alpha in tumor cells and indicate that defects in ISGF3 can cause resistance to IFN-alpha(2a) treatment.

Antineoplastic Agents↗
PubMed2004

[Study on the relationship between polymorphism of insulin-receptor gene EXON2-2257 and insulin resistance in Chinese people].

OBJECTIVE: To understand the role of insulin-receptor gene in the development of insulin resistance on a population-based study in China. METHODS: Polymerase chain reaction (PCR) was used to amplify the EXON2 of the insulin-receptor gene and all amplified products were analyzed by direct sequencing. RESULTS: Three genotypes of single nucleotide at the site of 2257 in EXON2 of the insulin-receptor gene were identified. In 237 of the 345 cases (68.7%), homozygote genotype of CC phenotype was found with a gene frequency of 0.825; 13 cases (3.77%) showed homozygote genotype of TT phenotype with a gene frequency of 0.175 and the rest 95 cases (27.54%) showed heterozygote genotype of CT phenotype. Data were in agreement with the test of Hardy-Weinberg balance (chi(2) = 0.2898, upsilon = 3 - 2 = 1, 0.5 < P < 0.75). The serum level of triglyceride and the HOMA-IR index, the status of insulin resistance assessed by homeostasis model assessment (HOMA), were lower in the TT or CT genotype group than that in the CC genotype group (P < 0.05). Comparing with CC genotype, the proportion of CT genotype (18.4%) in the insulin resistance group (large than 75th percentile of HOMA-IR) was significantly lower than that in the control group (30.6%) (P = 0.022, OR = 0.493). The proportion of TT genotype (2.3%) in insulin resistance group was lower than that in the control group (4.3%, P = 0.297). logistic analysis revealed that after adjusting possible confounding factors such as taking anti-hypertensive and anti-diabetic medications, serum triglyceride and high density lipoprotein cholesterol (HDL-C), hypertension, BMI, smoking history, the OR value of people in the insulin resistance group with CT genotype was 0.448 (95% CI: 0.214 to 0.940) compared to the group with CC genotype. CONCLUSION: The hybridization CT genotype at the site of 2257 in EXON2 of insulin-receptor gene might have a candidate gene to serve as a protective factor for insulin resistance.

Adult↗
PubMed2004

Polymorphisms of exon 17 of insulin-receptor gene in pathogenesis of human disorders with insulin resistance.

OBJECTIVE: To investigate the relationship between polymorphisms of insulin-receptor (INSR) gene and insulin resistance in a population-based study in China. METHODS: Polymerase Chain Reaction (PCR) was used to the amplify Exon 17 of INSR gene and all amplified products were analyzed by direct sequencing. RESULTS: Six single-nucleotide polymorphisms (SNPs) were found at the following loci: T to TC at the locus of 10699 (Tyr(984)), G to GC at the locus of 10731 (Glu(994)), Deletion G at the locus of 10798 (Asp(1017)), C to T/TC at the locus of 10923 (His(1058)), C to CA at the locus of 10954 (Leu(1069)), and T to TA at the locus of 10961 (Phe(1071)), which might not change the amino acid sequence. The data were in agreement with the test of Hardy-Weinberg balance (P > 0.05). Among the 345 cases, all clinical indices were higher in males than in females except for HDL cholesterol (P < 0.05). The proportion of insulin resistance in males (64.4%) was higher than that in females (35.6%, OR = 1.83). It implied that the relative risk of developing insulin resistance in males was 1.83 times as high as that in females. The biochemical indices in different loci on Exon 17 showed that the individuals with deletion G on the locus of 10798 had lower TG (P = 0.052) and higher HDL (P = 0.027) than those without deletion G on the same site. Homa-Index was lower in those with deletion G than in those without deletion G (P > 0.05). After sex stratification in analysis, all allele frequencies on the six loci of SNPs of Exon 17 had different distributions between the insulin resistant group and the control group, but P > 0.05. CONCLUSION: SNPs of Exon 17 of INSR gene are unlikely to play a direct role in the pathogenesis of human disorders with insulin resistance.

Amino Acid Sequence↗
PubMed2004

[Synthesis and spectral characterization of boron complexes of bis-schiff base from acylpyrazolone].

Three novel bis-schiff base complexes [B(PMaFP)2en]Ac, [B(PMaFP)2pen]Ac and [B(PMTHP)2en]Ac have been synthesized, where (HPMalphaFP)2 en = N,N'-bis [(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine, (HPMalphaFP)2pen = N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne]-o-phenylenediimine and (HPMTHP)2en = N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl)-2-thenoylmethylidyne] ethylenediimine. They were characterized by elemental analysis, IR, UV-Vis, 1H NMR, 13C NMR, and molar conductance measurements. The results show that the bis-schiff base is a quadridentate ligand and boron is four-coordinated in the complexes.

English Abstract↗
PubMed2003

A decade's studies on metastasis of hepatocellular carcinoma.

Metastasis remains one of the major challenges before hepatocellular carcinoma (HCC) is finally conquered. This paper summarized a decade's studies on HCC metastasis at the Liver Cancer Institute of Fudan University. We have established a stepwise metastatic human HCC model system, which included a metastatic HCC model in nude mice (LCI-D20), a HCC cell line with high metastatic potential (MHCC97), a relatively low metastatic potential cell clone (MHCC97L) and several stepwise high metastatic potential cell clones (MHCC97H, HCCLM3, and HCCLM6) from their parent MHCC97 cell. Endeavors have been made for searching human HCC metastasis-related chromosomes/proteins/genes. Monogene-based studies revealed that HCC invasion/metastasis was similar to that of other solid tumors, and the biological characteristics of small HCC were only slightly better than that of large HCC. Using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), genotyping, cDNA microarray, and 2-dimensional gel electrophoresis, we obtained some interesting results. In particular, in collaboration with the National Institute of Health (NIH) in the United States, we generated a molecular signature that can classify metastatic HCC patients, identified osteopontin as a lead gene in the signature, and found that genes favoring metastasis progression were initiated in the primary tumors. We also found that chromosome 8p deletion, particularly in the region of 8p23, was associated with HCC metastasis. Cytokeratin 19 was identified as one of the proteins, which was found in MHCC97H, but not in MHCC97L cells. Experimental interventions using the high metastatic nude mice model have provided clues for the prevention of HCC metastasis. Translation from workbench to bedside demonstrated that serum VEGF, microvessel density, and p53 scoring may be of value for the prediction of postoperative metastatic recurrence. Interferon alpha proved effective for the prevention of recurrence both experimentally and clinically. In conclusion, HCC metastasis that probably initiated in the primary tumor is a multigene-involved, multistep, and changing process. The further elucidation of the mechanism underlying HCC metastasis will provide a more solid basis for the prediction and prevention of the metastatic recurrence of HCC.

Animals↗
PubMed2003

Pyrosequencing trade mark : A one-step method for high resolution HLA typing.

While the use of high-resolution molecular typing in routine matching of human leukocyte antigens (HLA) is expected to improve unrelated donor selection and transplant outcome, the genetic complexity of HLA still makes the current methodology limited and laborious. Pyrosequencing trade mark is a gel-free, sequencing-by-synthesis method. In a Pyrosequencing reaction, nucleotide incorporation proceeds sequentially along each DNA template at a given nucleotide dispensation order (NDO) that is programmed into a pyrosequencer. Here we describe the design of a NDO that generates a pyrogram unique for any given allele or combination of alleles. We present examples of unique pyrograms generated from each of two heterozygous HLA templates, which would otherwise remain cis/trans ambiguous using standard sequencing based typing (SBT) method. In addition, we display representative data that demonstrate long read and linear signal generation. These features are prerequisite of high-resolution typing and automated data analysis. In conclusion Pyrosequencing is a one-step method for high resolution DNA typing.

Journal Article↗
PubMed2003

Expression and effects of cardiotrophin-1 (CT-1) in human airway smooth muscle cells.

1. Cellular hypertrophy and/or a reduced rate of apoptosis could increase airway smooth muscle mass. As cardiotrophin-1 (CT-1) induces hypertrophy and inhibits apoptosis in cardiomyocytes, we tested for the expression and effects of CT-1 in human bronchial smooth muscle cells (HBSMC). 2. CT-1 was detected in abundance in normal adult human lung and was expressed in both fetal and adult HBSMC. 3. Following serum deprivation, CT-1 was released by reintroduction of serum and by TGF-beta 2/IL-4 in fetal but not adult cells. TGF-beta 2/IL-4 triggered the release of CT-1 in serum-fed adult cells. Hypoxia and strain had no effect on the release of CT-1. 4. CT-1 reduced the apoptosis induced both by serum deprivation and by Fas antibody/TNF-alpha treatment in adult cells, with greater efficacy than other members of the IL-6 superfamily. The MAPK/ERK kinase inhibitor PD98059 (1-10 microM) reduced the effect of CT-1. Fetal cells were more resistant to apoptosis. 5. CT-1 (10 ng ml-1) induced a significant increase in cell size as judged by protein/DNA ratios and flow cytometry. No effects on smooth muscle alpha-actin or vimentin proteins were noted, although CT-1 qualitatively alters the cytostructural distribution of SM22, an actin filament-associated protein, and increased SM22 protein abundance. No effect on proliferation or migration was evident. 6. These data suggest CT-1 expression primarily in fetal and synthetic HBSMC phenotypes. By reducing the rates of apoptosis and inducing hypertrophy, CT-1 may contribute to increased smooth muscle mass in airway disease.

Adolescent↗
PubMed2003

Kinetics and mechanisms of the reactions of hypochlorous acid, chlorine, and chlorine monoxide with bromite ion.

The reaction between BrO2(-) and excess HOCl (p[H+] 6-7, 25.0 degrees C) proceeds through several pathways. The primary path is a multistep oxidation of HOCl by BrO(2)(-) to form ClO(3)(-) and HOBr (85% of the initial 0.15 mM BrO(2)(-)). Another pathway produces ClO(2) and HOBr (8%), and a third pathway produces BrO(3)(-) and Cl(-) (7%). With excess HOCl concentrations, Cl(2)O also is a reactive species. In the proposed mechanism, HOCl and Cl(2)O react with BrO(2)(-) to form steady-state species, HOClOBrO(-) and ClOClOBrO(-). Acid facilitates the conversion of HOClOBrO(-) and ClOClOBrO(-) to HOBrOClO(-). These reactions require a chainlike connectivity of the intermediates with alternating halogen-oxygen bonding (i.e. HOBrOClO(-)) as opposed to Y-shaped intermediates with a direct halogen-halogen bond (i.e. HOBrCl(O)O(-)). The HOBrOClO(-) species dissociates into HOBr and ClO(2)(-) or reacts with general acids to form BrOClO. The distribution of products suggests that BrOClO exists as a BrOClO.HOCl adduct in the presence of excess HOCl. The primary products, ClO(3)(-) and HOBr, are formed from the hydrolysis of BrOClO.HOCl. A minor hydrolysis path for BrOClO.HOCl gives BrO(3)(-) and Cl(-). An induction period in the formation of ClO(2) is observed due to the buildup of ClO(2)(-), which reacts with BrOClO.HOCl to give 2 ClO(2) and Br(-). Second-order rate constants for the reactions of HOCl and Cl(2)O with BrO(2)(-) are k(1)(HOCl) = 1.6 x 10(2) M(-1) s(-1) and k(1)(Cl)()2(O) = 1.8 x 10(5) M(-)(1) s(-)(1). When Cl(-) is added in large excess, a Cl(2) pathway exists in competition with the HOCl and Cl(2)O pathways for the loss of BrO(2)(-). The proposed Cl(2) pathway proceeds by Cl(+) transfer to form a steady-state ClOBrO species with a rate constant of k(1)(Cl2) = 8.7 x 10(5) M(-1) s(-1).

Journal Article↗
PubMed2003

Deep inspiration and airway smooth muscle adaptation to length change.

In normal subjects a deep inspiration (DI) taken during bronchoconstriction substantially reduces airway narrowing (bronchodilation) and a DI taken prior to bronchoconstriction attenuates subsequent airway narrowing (bronchoprotection). Although the exact mechanism(s) for these phenomena are unclear the time course of these effects supports the hypothesis that they are mediated through actions of airway smooth muscle (ASM). There is convincing evidence that both the bronchodilation and bronchoprotection actions of DI are deficient or absent in asthmatic subjects. Various theories have been proposed such as a failure of transmission of stress and strain to the ASM in asthma, stretch-induced contraction of smooth muscle in asthmatics, a failure to release bronchodilating substances and differential effects on cross-bridge dynamics or contractile element rearrangement. In this brief review we focus on the mechanical consequences of DI on the ASM. We suggest that a failure of plastic rearrangement of the contractile apparatus following DI is at the basis of the abnormal response to DI in asthma.

Adaptation, Physiological↗
PubMed2003

Octreotide acts as an antitumor angiogenesis compound and suppresses tumor growth in nude mice bearing human hepatocellular carcinoma xenografts.

PURPOSE: To investigate the effect of octreotide on angiogenesis induced by human hepatocellular carcinoma (HCC) and to evaluate whether octreotide can suppress tumor growth in nude mice bearing human HCC xenografts through inhibition of angiogenesis. METHODS: Using MTT assay, invasion assay, migration assay, and Matrigel assay, the effects of octreotide on endothelial cells stimulated by vascular endothelial growth factor (VEGF) were evaluated in vitro. MTT assay was also used to investigate the effects of octreotide on human HCC cells with high (MHCC97-H) and low (MHCC97-L) metastatic potential that were established from the animal model of human HCC LCI-D20 in nude mice. The expression of somatostatin receptor (SSTR) subtypes in human umbilical vein endothelial cells (HUVECs), MHCC97-H, and MHCC97-L cells was detected by RT-PCR analysis. An LCI-D20 corneal micropocket model in nude mice was used to evaluate the effect of octreotide on angiogenesis induced by human HCC in vivo. Male nude mice were subcutaneously implanted with LCI-D20 tumor tissues for the tumor xenograft studies. Microvessel density was analyzed in CD34-stained tumor sections by the immunohistochemical SP method. RESULTS: In vitro, octreotide inhibited the proliferation, invasion, and differentiation of HUVECs elicited by VEGF. RT-PCR analysis demonstrated that HUVECs expressed the somatostatin receptor subtype SSTR3. In vivo, octreotide was sufficiently potent to suppress nude mice corneal neovascularization induced by tumor tissues from LCI-D20. Systemic administrations of octreotide produced a significant suppression of the growth of LCI-D20. In cell culture, MHCC97-H and MHCC97-L cells were insensitive to octreotide at concentrations that significantly inhibited endothelial cells proliferation. The HCC cells used did not express any known SSTRs. Immunohistochemical studies of tumor tissues revealed decreased microvessel density in octreotide-treated animals as compared with controls. CONCLUSIONS: The present study demonstrates that the somatostatin analogue octreotide is a potent antitumor angiogenesis compound and the antiproliferative effect of octreotide on tumor growth in nude mice bearing HCC xenografts may be mediated, at least in part, by its suppressive effect on blood vessel supply. The somatostatin analogue octreotide might provide a useful and relatively nontoxic adjuvant therapy in the treatment of HCC.

Animals↗
PubMed2003

Role of the cytosolic chaperones Hsp70 and Hsp90 in maturation of the cardiac potassium channel HERG.

The human ether-a-gogo-related gene (hERG) encodes the alpha subunit of the cardiac potassium current IKr. Several mutations in hERG produce trafficking-deficient channels that may cause hereditary long-QT syndrome and sudden cardiac death. Although hERG currents have been studied extensively, little is known about the proteins involved in maturation and trafficking of hERG. Using immunoprecipitations, we show that the cytosolic chaperones heat shock protein (Hsp) 70 and Hsp90, but not Grp94, interact with hERG wild type (WT) during maturation. The specific Hsp90 inhibitor geldanamycin prevents maturation and increases proteasomal degradation of hERG WT, while reducing hERG currents in heterologous expression systems. In ventricular myocytes, inhibition of Hsp90 also decreases IKr, whereas geldanamycin had no effect on IKs or heterologously expressed Kv2.1 and Kv1.5 currents. Both Hsp90 and Hsp70 interact directly with the core-glycosylated form of hERG WT present in the endoplasmic reticulum but not the fully glycosylated, cell-surface form. For the trafficking-deficient LQT2 mutants, hERG R752W and hERG G601S, interactions with Hsp90 and Hsp70 are increased as both mutants remained tightly associated with Hsp90 and Hsp70 in the endoplasmic reticulum. Incubation at lower temperature for R752W or with the hERG blocker astemizole for G601S dissociates channel-chaperone complexes and restores trafficking. In contrast, nonfunctional but trafficking-competent hERG G628S is released from chaperone complexes during maturation comparable to WT. We conclude that Hsp90 and Hsp70 are crucial for the maturation of hERG WT as well as the retention of trafficking-deficient LQT2 mutants. The full text of this article is available online at http://www.circresaha.org.

Analysis of Variance↗
PubMed2003

[Expression of MMP-9 and MMP-9 mRNA in gastric carcinoma and its correlation with angiogenesis].

OBJECTIVE: To investigate the expression of MMP-9 and MMP-9 mRNA in the tissue and cell line of the gastric carcinoma and its correlation with invasion, metastasis and angiogenesis of the cancer. METHODS: Seventy-four specimens of resected human gastric carcinoma were collected. Human lowly differentiated gastric carcinoma cells of BGC823 line were cultured. Hematoxylin and eosin staining, immunohistochemistry, in situ hybridization, and zymography were used to examine the expression of MMP-9, MMP-9 mRNA, CD34, alpha-SMA, VEGFR-1, VEGFR-2. Invasion test was made to observe the number of cells penetrating the Matrigel. The relationship between the expression of MMP-9 and MMP-9 mRNA and the clinical parameters was analyzed. RESULTS: The positive rate of MMP-9 expression was 77.03% in gastric carcinoma tissues (57/74). Most of the MMP-9 positive cells were located at the invasive areas. The average microvascular density (MVD) of the 74 cases of gastric carcinoma was 73.76 +/- 11.50/200 x visual field. MVD was 75.46 +/- 10.98 in the MMP-9 positive group and was 68.08 +/- 11.71 in the MMP-9 negative group (P < 0.05). The positive rate of MMP-9 mRNA expression was 72.97% in the gastric carcinoma tissues (54/74). The expressions of MMP-9 and its mRNA were closely related to invasion, differentiation and lymph nodes status of the gastric carcinoma; MVD was closely related to the invasion and lymph nodes status of the gastric carcinoma. All BGC823 cells were MMP-9, MMP-9 mRNA, VEGFR-2 positive and VEGFR-1 negative. The number of invasive BGC823 cells was (18 +/- 4)/400 x in the MMP-9 antibody group and was (69 +/- 5)/400 x in the control group. BGC823 cells cultivated in culture dishes expressed the proenzyme of MMP-2 and MMP-9 stably. BGC823 cells cultivated on the surface of type I collagen expressed more MMP-2 proenzyme and active MMP-2. When BGC823 cells were incubated with VEGF, the content of MMP-9 proenzyme was increased by VEGF dose-dependently. CONCLUSION: Gastric cancer cells have the ability to produce and secret MMP-9 which can promote the invasion and metastasis of the neoplasm.

Adenocarcinoma↗
PubMed2003

Structure-function correlation in airway smooth muscle adapted to different lengths.

Airway smooth muscle is able to adapt and maintain a nearly constant maximal force generation over a large length range. This implies that a fixed filament lattice such as that found in striated muscle may not exist in this tissue and that plastic remodeling of its contractile and cytoskeletal filaments may be involved in the process of length adaptation that optimizes contractile filament overlap. Here, we show that isometric force produced by airway smooth muscle is independent of muscle length over a twofold length change; cell cross-sectional area was inversely proportional to cell length, implying that the cell volume was conserved at different lengths; shortening velocity and myosin filament density varied similarly to length change: increased by 69.4% +/- 5.7 (SE) and 76.0% +/- 9.8, respectively, for a 100% increase in cell length. Muscle power output, ATPase rate, and myosin filament density also have the same dependence on muscle cell length: increased by 35.4% +/- 6.7, 34.6% +/- 3.4, and 35.6% +/- 10.6, respectively, for a 50% increase in cell length. The data can be explained by a model in which additional contractile units containing myosin filaments are formed and placed in series with existing contractile units when the muscle is adapted at a longer length.

Adaptation, Physiological↗