Matrix metalloproteinases in pathophysiology and treatment of heart failure.
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Animals↗
Biomedical subjects
Y Y Li
Publications and source records attributed to Y Y Li.
Myocardial extracellular matrix remodeling in transgenic mice overexpressing tumor necrosis factor alpha can be modulated by anti-tumor necrosis factor alpha therapy.
Myocardial fibrosis caused by maladaptive extracellular matrix (ECM) remodeling is implicated in the dysfunction of the failing heart. Matrix metalloproteinases (MMPs) regulate ECM remodeling, and are regulated by cytokines. Transgenic mice with cardiac-specific overexpression of tumor necrosis factor alpha (TNF-alpha) (TNF1.6) develop heart failure. We hypothesized that modulation of TNF-alpha and/or MMP activity might alter the myocardial ECM remodeling process and the development of heart failure. To test this hypothesis, we took advantage of the TNF1.6 mice and studied soluble and total collagens and collagen type profiling by using hydroxyproline quantification, Sircol collagen assay, Northern blot analysis, and immunohistochemistry and studied myocardial function by using echocardiography. Progressive ventricular hypertrophy and dilation in the TNF1.6 mice were accompanied by a significant increase in MMP-2 and MMP-9 activity, an increase in collagen synthesis, deposition, and denaturation, and a decrease in undenatured collagens. In young TNF1.6 mice, these changes in the ECM were associated with marked diastolic dysfunction as demonstrated by significantly reduced transmitral Doppler echocardiographic E/A wave ratio. Anti-TNF-alpha treatment with adenoviral vector expressing soluble TNF-alpha receptor type I attenuated both MMP-2 and MMP-9 activity, prevented further collagen synthesis, deposition and denaturation, and preserved myocardial diastolic function in young, but not old, TNF1.6 mice. The results suggest a critical role of TNF-alpha and MMPs in myocardial matrix remodeling and functional regulation and support the hypothesis that both TNF-alpha and MMPs may serve as potential therapeutic targets in the treatment of heart failure.
Animals↗
Protein disulphide isomerase genes of Kluyveromyces lactis.
Two genes of Kluyveromyces lactis, KlPDI1 and KlMPD1, were studied. They code for a protein disulphide isomerase and its structural and functional homologue, respectively. The KlPDI1 product was 52.6% identical to Pdi1p and the KlMPD1 product 47% identical to Mpd1p of S. cerevisiae. Both genes contained the thioredoxin-active site-related signature. Their C-termini showed a new variant of the endoplasmic reticulum-retention signal, QDEL. A single copy of KlPDI1 was able to complement the growth defect of a pdi1 mutation. KlMPD1 on a multicopy vector partially suppressed the klpdi1 and pdi1 mutations. The Klpdi1 null mutation was lethal. The klmpd1 disruptant was viable, but showed an increased sensitivity to high temperature. Several stress response motifs were present in the upstream sequence of KlMPD1, but not of KlPDI1, whilst the opposite is known for the S. cerevisiae homologues. The viability of the klmpd1 mutant under starvation for nitrogen or carbon source was not different from that of the wild-type. The syntenic relationship is discussed for the KlPDI1 gene regions with respect to the duplicated segments PDI1/EUG1 in S. cerevisiae.
Amino Acid Sequence↗
The role of tumor necrosis factor in the pathophysiology of heart failure.
Recent studies have focused their attention on the role of the proinflammatory cytokine tumor necrosis factor (TNF) in the development of heart failure. First recognized as an endotoxin-induced serum factor that caused necrosis of tumors and cachexia, it is now recognized that TNF participates in the pathophysiology of a group of inflammatory diseases including rheumatoid arthritis and Crohn's disease. The normal heart does not express TNF; however, the failing heart produces robust quantities. Furthermore, there is a direct relationship between the level of TNF expression and the severity of disease. In addition, both in vivo and in vitro studies demonstrate that TNF effects cellular and biochemical changes that mirror those seen in patients with congestive heart failure. Furthermore, in animal models, the development of the heart failure phenotype can be abrogated at least in part by anticytokine therapy. Based on information from experimental studies, investigators are now evaluating the clinical efficacy of novel anticytokine and anti-TNF strategies in patients with heart failure; one such strategy is the use of a recombinantly produced chimeric TNF alpha soluble receptor. Thus, in view of the emerging importance of proinflammatory cytokines in the pathogenesis of heart disease, we review the biology of TNF, its role in inflammatory diseases, the effects of TNF on the physiology of the heart and the development of clinical strategies that target the cytokine pathways.
Animals↗
Microvascular effects of oral interleukin-6 on ischemia/reperfusion in the murine small intestine.
Oral administration of interleukin-6 (IL-6) has been shown to reduce hemorrhage-induced bacterial translocation from the gut in mice and rats. To examine the intestinal microvasculature, mice were given the electron-dense tracer horseradish peroxidase (HRP) after hemorrhage and IL-6 or vehicle administration. In normal mice and in those hemorrhaged and given IL-6, the electron-dense marker, administered intravenously, could be found in intestinal capillaries and between mucosal epithelial cells, suggesting that the microvasculature was patent. In mice given saline after shock, however, no marker was present in the gut, suggesting that the intestinal microvasculature was unable to deliver the marker to the epithelia. When mice were given HRP intralumenally (il) the tracer was able to penetrate between intestinal epithelial cells only in mice given vehicle after hemorrhage. This finding suggests that hemorrhaged mice were susceptible to sepsis and endotoxic shock from the leaky gut. In normal and IL-6-treated mice, the tracer was unable to pass from the lumen between mucosal epithelial cells, because the presence of an intact zonula occludens prevented passage. Functional studies supported the electron microscopy findings. Bacteria were cultured from the livers of mice fed vehicle after hemorrhage, but not from those fed IL-6. These data support the conclusions that parts of the intestinal microvasculature remain diminished after hemorrhage and resuscitation and that oral IL-6 restores this circulation.
Administration, Oral↗
Interplay of matrix metalloproteinases, tissue inhibitors of metalloproteinases and their regulators in cardiac matrix remodeling.
Myocardial fibrosis due to maladaptive extracellular matrix remodeling contributes to dysfunction of the failing heart. Further elucidation of the mechanism by which myocardial fibrosis and dilatation can be prevented or even reversed remains of great interest as a potential means to limit myocardial remodeling and dysfunction. Matrix metalloproteinases (MMPs) are the driving force behind extracellular matrix degradation during remodeling and are increased in the failing human heart. MMPs are regulated by a variety of growth factors, cytokines, and matrix fragments such as matrikines. In the present report, we discuss the regulation of MMPs, the role of MMPs in the development of cardiac fibrosis, and the modulation of MMP activity using gene transfer and knockout technologies. We also present recent findings from our laboratory on the regulation of the extracellular MMP inducer (EMMPRIN), MMPs, and transforming growth factor-beta(1) in the failing human heart before and after left ventricular assist device support, as well as the possibility of preventing ventricular fibrosis using different anti-MMP strategies. Several studies suggest that such modulation of MMP activity can alter ventricular remodeling, myocardial dysfunction, and the progression of heart failure. It is therefore suggested that the interplay of MMPs and their regulators is important in the development of the heart failure phenotype, and myocardial fibrosis in heart failure may be modified by modulating MMP activity.
Animals↗
Resurfacing deep wound of upper extremities with pedicled groin flaps.
A total of 29 axial pedicled groin skin flaps were applied clinically with satisfactory result excepting for one flap which tailed on transplantation. These cases included severe scar contracture of the dorsum of hands in 20 patients, deeply burned wounds with infection and exposure of deep structure in upper extremities in nine patients, such as electrical burns and hot-crushing injuries. The flap is supplied by two groups of nutrient vessels with abundant vascularization and located in a hidden area. Therefore, the pedicled groin skin flap is still valuable due to its advantages as safe, easy operation and strong antiinfective ability although the free groin flap is more widely used today.
Adult↗
Comparison of lansoprazole-based triple and dual therapy for treatment of Helicobacter pylori-related duodenal ulcer: an Asian multicentre double-blind randomized placebo controlled study.
BACKGROUND: [corrected] In Asian countries with limited resources, clarithromycin-based triple therapy may not be readily available. There are also few direct comparisons of different regimens in Asia. AIM: To compare two lansoprazole-based non-clarithromycin triple therapies and one dual therapy in a prospective double-blind placebo-controlled study of Helicobacter pylori eradication and duodenal ulcer healing. METHODS: Fourteen centres in Asia participated in this study. Patients with acute duodenal ulcer who were H. pylori-positive were recruited. They were randomized to receive: (a) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and metronidazole 500 mg b.d. for 2 weeks (LAM-2 W), or (b) LAM for 1 week and placebo (LAM-1 W), or (c) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and placebo for 2 weeks (LA-2 W). Upper endoscopy was repeated at week 6 to check for duodenal ulcer healing. Symptoms and side-effects were recorded. RESULTS: A total of 228 patients were recruited, and two patients took less than 50% of the drugs. H. pylori eradication rates (intention-to-treat) were 68 out of 82 (83%) with LAM-2 W, 55 out of 71 (78%) with LAM-1 W and 43 out of 75 (57%) with LA-2 W. There were significant differences (P=0. 001) in eradication rates when comparing either LAM-2 W or LAM-1 W with LA-2 W. The eradication rate in patients with metronidazole resistant H. pylori strains were significantly lower than those with metronidazole sensitive strains (P=0.0001). The duodenal ulcer healing rates at week 6 were 85%, 85% and 72% in LAM-2 W, LAM-1 W and LA-2 W, respectively (P=0.065). Side-effects occurred in 13%, 11% and 9% in LAM-2 W, LAM-1 W and LA-2 W, respectively. H. pylori eradication and initial ulcer size were factors affecting duodenal ulcer healing. CONCLUSIONS: This Asian multicentre study showed that 1-week lansoprazole-based triple therapy without clarithromycin has similar efficacy in H. pylori eradication and ulcer healing compared with a 2-week regimen. Both triple therapies were significantly better than dual therapy in H. pylori eradication. Therefore, 1-week lansoprazole-based triple therapy is as safe and effective as 2-week therapy in eradication of H. pylori infection and healing of duodenal ulcer in these Asian centres.
2-Pyridinylmethylsulfinylbenzimidazoles↗
In vitro activity of a cellulose acetate phthalate topical cream against organisms associated with bacterial vaginosis.
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Anti-Bacterial Agents↗
[The diploid of genetically engineered yeast for expression of hybrid HBsAg gene SA-28].
By mating a yeast haploid expressing hybrid HBsAg gene SA-28, Y19/YFD158, with another hapolid Y95, the diploid Y95xY19/YFD158 was constructed. The experiments showed that the cell density of the diploid in fermentation was three time higher than that of the haploid, the stability of expression vector in the diploid was much higher than in the haploid, the xpression level of hybrid HBsAg gene of the diploid was more than three time higher than that of the haploid and the average cope number in diploid cell was a little lower than that in the haploid.
Diploidy↗
[Effects of gene copy number and chromosomal position on the expression of a modified HBsAg gene SA-28 in yeast].
The effect of gene copy number and chromosomal position on heterologous gene expression in Saccharomyces cerevisae has been tentatively investigated using a modified hepatitis B virus surface antigen SA-28 gene. The plasmids containing different copies of SA-28 gene expression cassette were integrated into different chromosomal loci via FLP recombinase mediated targeted integration. The expression of SA-28 gene in the resultant transformants was then measured. The result indicated that the expression of SA-28 gene was positively related to the gene dosage at HIS3 locus and had chromosomal polarity at several chromosomal loci.
Chromosome Mapping↗
Mutational analysis and clinical correlation in Leber congenital amaurosis.
UNLABELLED: Leber congenital amaurosis (LCA, MIM 204001) is a clinically and genetically heterogeneous retinal disorder characterized by severe visual loss from birth, nystagmus, poor pupillary reflexes, retinal pigmentary or atrophic changes, and a markedly diminished electroretinogram (ERG). PURPOSE: To examine 100 consecutive patients with LCA in order to assess the relative burden of the three known genes involved in LCA, namely retinal guanylyl cyclase (GUCY2D), retinal pigment epithelium protein ( RPE65), and the cone-rod homeobox (CRX), and to define their clinical correlates. METHODS: Mutational analysis and detailed clinical examinations were performed in patients diagnosed with LCA at the Johns Hopkins Center for Hereditary Eye Diseases and the Montreal Children's Hospital. RESULTS: Mutations were identified in 11% of our patients: GUCY2D mutations accounted for 6%, while RPE65 and CRX gene mutations accounted for 3% and 2%, respectively. The clinical presentation was variable; however, the visual evolution in patients with mutations in GUCY2D and CRX remained stable, while individuals with mutations in the RPE65 gene showed progressive visual loss. CONCLUSIONS: This study suggests that molecular diagnosis of Leber congenital amaurosis could provide important information concerning prognosis and course of treatment.
Adult↗
[Synonymous codon usage in Pichia pastoris].
According to the synonymous codons used in 28 open reading frames from Pichia pastoris, the codon usage in this species was calculated and 19 codons have been inferred to be its optimal codons. The results show that pattern of the codon usage in P. pastoris is similar to that in S. cerevisiae and in K. lactis except for the synonymous codon of glutamic acid, which may be the special bias of P. pastoris.
Codon↗
Dimethylamiloride-induced differentiation of HL-60 cells.
AIM: To study the effect of 5-(N,N-dimethyl) amiloride (DMA) on the proliferation and differentiation of HL-60 cells in vitro. METHODS: MTT assay to test cytotoxicity; cell staining and NBT reduction to test cell differentiation. RESULTS: DMA inhibited HL-60 cells growth in a concentration-dependent manner, and IC50 value for 96 h was 31.7 (95% confidence limits: 6.3-57.1) mumol.L-1. DMA also induced granulocytic differentiation in HL-60 cells. The percentage of differentiating cells increased from 6.5% to 70% after DMA 100 mumol.L-1 treatment for 3 d. The differentiating effect of DMA was distinguishable from amiloride, 5-(N-ethyl-N-isopropyl)amiloride (EIPA), and (5-(N-ethyl-N-isopropyl)amiloride (MIA). None among the amiloride, EIPA, and MIA were capable of triggering the differentiation of HL-60 cells. CONCLUSION: DMA inhibited the proliferation of HL-60 cells and induced differentiation of HL-60 cells.
Amiloride↗
Alpha 2 beta 1 integrin mediates dermal fibroblast attachment to type VII collagen via a 158-amino-acid segment of the NC1 domain.
Dermal fibroblasts are in apposition to type VII (anchoring fibril) collagen in both unwounded and wounded skin. The NC1 domain of type VII collagen contains multiple submodules with homology to known adhesive molecules, including fibronectin type III-like repeats and a potential RGD cell attachment site. We previously reported the structure and matrix binding properties of authentic and recombinant NC1. In this study, we examined the interaction between dermal fibroblasts and the NC1 domain of type VII collagen. We found that both recombinant and authentic NC1 vigorously promoted human fibroblast attachment. Adhesion of fibroblasts to NC1 was dose dependent, saturable, and abolished by both polyclonal and monoclonal antibodies to NC1. Cell adhesion to NC1 was divalent cation dependent and specifically inhibited by a monoclonal antibody directed against the alpha2 or beta1 integrin subunits, but not by the presence of RGD peptides. Furthermore, the cell-binding activity of NC1 was not conformation dependent, since heat-denatured NC1 still promoted cell adhesion. Using a series of recombinant NC1 deletion mutant proteins, the cell binding site of NC1 was mapped to a 158-aa (residues 202-360) subdomain. We conclude that human dermal fibroblasts interact with the NC1 domain of type VII collagen and this cell-matrix interaction is mediated by the alpha2beta1 integrin and is RGD independent.
Binding Sites↗
Design of a "microbicide" for prevention of sexually transmitted diseases using "inactive" pharmaceutical excipients.
The human immunodeficiency virus (HIV-1) pandemic has been driven primarily by the sexual transmission of the virus, and facilitated by prior infections with other sexually transmitted disease (STD) pathogens. Although treatment of these STDs has been proposed as a means to decrease the rate of HIV-1 sexual transmission, preventive measures effective against both HIV-1 and other STD pathogens are expected to have a larger impact. These measures include topically applied mechanical and chemical (i.e. microbicidal) barriers. Microbicides of preference should have a broad specificity against diverse STD pathogens and a well established safety record, considering their repeated use over decades. Here, we report that cellulose acetate phthalate (CAP), an "inactive" pharmaceutical excipient, commonly used in the production of enteric tablets and capsules: (1) has antiviral activity against HIV-1 and several herpesviruses (HSV); and (2) when appropriately formulated, in micronized form, inactivates HIV-1, HSV-1, HSV-2, cytomegalovirus, Neisseria gonorrhoeae, Trichomonas vaginalis, Haemophilus ducreyi and Chlamydia trachomatis but does not affect Lactobacilli, components of the natural vaginal flora contributing to resistance against STDs. Thus, the CAP formulations meet the criteria for preferred microbicides and warrant further evaluation in vivo in humans.
Animals↗
Proinflammatory cytokines regulate tissue inhibitors of metalloproteinases and disintegrin metalloproteinase in cardiac cells.
OBJECTIVE: Tissue inhibitors of metalloproteinases (TIMPs) are downregulated in the failing human heart. The objective of the present study was to test the hypothesis that cytokines might be involved in the regulation of TIMPs in cardiac cells. METHODS: Neonatal Sprague-Dawley rat ventricular cells were exposed to 100 units/ml tumor necrosis factor-alpha and/or 5 ng/ml interleukin-1 beta. The mRNA and protein expression of TIMPs-1-4 and disintegrin metalloproteinase was analyzed using Northern blot, ELISA and/or Western blot, respectively. Proteolytic activity and extracellular matrix degradation and turnover were determined using gelatin zymography and pulse-chase experiments. RESULTS: The TIMP-1 mRNA was upregulated in cardiac cells, while TIMP-1 protein levels were unchanged in myocytes but downregulated in non-myocytes. The TIMP-2 expression did not change with the cytokine treatment. TIMP-3 was downregulated at both the mRNA and protein levels in cardiac cells. TIMP-4 protein was transiently increased and then returned to control level. In contrast, disintegrin metalloproteinase mRNA and protein were significantly upregulated in those cells. The gelatinolytic activity and extracellular matrix protein degradation were significantly increased. CONCLUSIONS: Tumor necrosis factor-alpha and interleukin-1 beta regulate the expression of TIMPs and disintegrin metalloproteinase, which may in turn contribute to the increased matrix degradation in cardiac cells. Since heart failure in humans is characterized by both re-expression of myocardial cytokines and remodeling of the extracellular matrix, those in vitro results suggest a potential role for those cytokines in the regulation of extracellular matrix remodeling and therefore in the transition to the end-stage heart failure phenotype.
Animals↗
NC1 domain of type VII collagen binds to the beta3 chain of laminin 5 via a unique subdomain within the fibronectin-like repeats.
Type VII collagen, the major component of anchoring fibrils, consists of a central collagenous triple-helical domain flanked by two noncollagenous, globular domains, NC1 and NC2. Approximately 50% of the molecular mass of the molecule is consumed by the NC1 domain. We previously demonstrated that NC1 binds to various extracellular matrix components including a complex of laminin 5 and laminin 6 (Chen et al, 1997a). In this study, we examined the interaction of NC1 with laminin 5 (a component of anchoring filaments). Both authentic and purified recombinant NC1 bound to human and rat laminin 5 as measured by enzyme-linked immunosorbant assay and by binding of 125I-radiolabeled NC1 to laminin 5-coated wells, but not to laminin 1 or albumin. NC1 bound predominantly to the beta3 chain of laminin 5, but also to the gamma2 chain when examined by a protein overlay assay. The binding of 125I-NC1 to laminin 5 was inhibited by a 50-fold excess of unlabeled NC1 or de-glycosylated NC1, as well as a polyclonal antibody to laminin 5 or a monoclonal antibody to the beta3 chain. In contrast, the NC1-laminin 5 interaction was not affected by a monoclonal antibody to the alpha3 chain. Using NC1 deletion mutant recombinant proteins, a 285 AA (residues 760-1045) subdomain of NC1 was identified as the binding site for laminin 5. IgG from an epidermolysis bullosa acquisita serum containing autoantibodies to epitopes within NC1 that colocalized with the laminin 5 binding site inhibited the binding of NC1 to laminin 5. Thus, perturbation of the NC1-laminin 5 interaction may contribute to the pathogenesis of epidermolysis bullosa acquisita.
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