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1.
J Exp Med ; 191(9): 1535-44, 2000 May 01.
Article in English | MEDLINE | ID: mdl-10790428

ABSTRACT

Interleukin-1beta-converting enzyme (ICE, caspase-1) regulates key steps in inflammation and immunity, by activating the proinflammatory cytokines interleukin (IL-)1beta and IL-18, or mediating apoptotic processes. We recently provided evidence for the regulation of caspase-1 activity via an endogenous inhibitor expressed by human vascular smooth muscle cells (SMCs) (Schönbeck, U., M. Herzberg, A. Petersen, C. Wohlenberg, J. Gerdes, H.-D. Flad, and H. Loppnow. 1997. J. Exp. Med. 185:1287-1294). However, the molecular identity of this endogenous inhibitor remained undefined. We report here that the serine proteinase inhibitor (serpin) PI-9 accounts for the endogenous caspase-1 inhibitory activity in human SMCs and prevents processing of the enzyme's natural substrates, IL-1beta and IL-18 precursor. Treatment of SMC lysates with anti-PI-9 antibody abrogated the caspase-1 inhibitory activity and coprecipitated the enzyme, demonstrating protein-protein interaction. Furthermore, PI-9 antisense oligonucleotides coordinately reduced PI-9 expression and promoted IL-1beta release. Since SMCs comprise the majority of cells in the vascular wall, and because IL-1 is implicated in atherogenesis, we tested the biological validity of our in vitro findings within human atheroma in situ. The unaffected arterial wall contains abundant and homogeneously distributed PI-9. In human atherosclerotic lesions, however, PI-9 expression correlated inversely with immunoreactive IL-1beta, supporting a potential role of the endogenous caspase-1 inhibitor in this chronic inflammatory disease. Thus, our results provide new insights into the regulation of this enzyme involved in immune and inflammatory processes of chronic inflammatory diseases, and point to an endogenous antiinflammatory action of PI-9, dysregulated in a prevalent human disease.


Subject(s)
Caspase Inhibitors , Interleukins/biosynthesis , Muscle, Smooth, Vascular/enzymology , Protein Processing, Post-Translational , Serpins/isolation & purification , Arteries/chemistry , Arteries/pathology , Arteriosclerosis/pathology , Gene Expression Regulation , Humans , Interleukin-1/biosynthesis , Interleukin-18/biosynthesis , Protein Precursors/metabolism
2.
J Exp Med ; 189(5): 843-53, 1999 Mar 01.
Article in English | MEDLINE | ID: mdl-10049948

ABSTRACT

Stromelysin-3 is an unusual matrix metalloproteinase, being released in the active rather than zymogen form and having a distinct substrate specificity, targeting serine proteinase inhibitors (serpins), which regulate cellular functions involved in atherosclerosis. We report here that human atherosclerotic plaques (n = 7) express stromelysin-3 in situ, whereas fatty streaks (n = 5) and normal arterial specimens (n = 5) contain little or no stromelysin-3. Stromelysin-3 mRNA and protein colocalized with endothelial cells, smooth muscle cells, and macrophages within the lesion. In vitro, usual inducers of matrix metalloproteinases such as interleukin-1, interferon-gamma, or tumor necrosis factor alpha did not augment stromelysin-3 in vascular wall cells. However, T cell-derived as well as recombinant CD40 ligand (CD40L, CD154), an inflammatory mediator recently localized in atheroma, induced de novo synthesis of stromelysin-3. In addition, stromelysin-3 mRNA and protein colocalized with CD40L and CD40 within atheroma. In accordance with the in situ and in vitro data obtained with human material, interruption of the CD40-CD40L signaling pathway in low density lipoprotein receptor-deficient hyperlipidemic mice substantially decreased expression of the enzyme within atherosclerotic plaques. These observations establish the expression of the unusual matrix metalloproteinase stromelysin-3 in human atherosclerotic lesions and implicate CD40-CD40L signaling in its regulation, thus providing a possible new pathway that triggers complications within atherosclerotic lesions.


Subject(s)
Arteriosclerosis/metabolism , CD40 Antigens/metabolism , Membrane Glycoproteins/metabolism , Metalloendopeptidases/biosynthesis , Animals , Aorta/pathology , Arteriosclerosis/pathology , CD40 Ligand , Carotid Arteries/pathology , Endothelium, Vascular/metabolism , Humans , Hyperlipidemias/metabolism , Macrophages/metabolism , Matrix Metalloproteinase 11 , Metalloendopeptidases/isolation & purification , Mice , Mice, Mutant Strains , Muscle, Smooth, Vascular/metabolism , Receptors, LDL/genetics , Signal Transduction
3.
Zh Evol Biokhim Fiziol ; 45(2): 202-7, 2009.
Article in Russian | MEDLINE | ID: mdl-19435263

ABSTRACT

Obstructive apnea during sleep is accompanied by intermittent hypoxia (IH) leading to hypertension and other cardiovascular disturbances. A comparative evaluation of long-term effects of the neonatal IH on the cardiovascular function was performed in normotensive Sprague-Dawley and spontaneously hypertensive rats (SHR). The newborn rats were placed for 30 days to conditions of IH (8 and 21% O2, alternating every 90 s for 12 h/day). Control groups of rats were constantly kept in normoxia. By 6 months, in the spontaneously hypertensive rats submitted to IH at the period of wakefulness there was a statistically significant increase (as compared with control) of the systolic (correspondingly 185.8 +/- 1.7 and 169.9 +/- 1.4 mm Hg, p < 0.01) and diastolic pressure (correspondingly 96.2 +/- 4.9 and 86.0 +/- 2.6 mm Hg, p < 0.01). During sleep, the systolic and diastolic pressure in these rats was higher than in control animals by 10 mm Hg (p < 0.01) and 12 mm Hg (p < 0.01), its decrease during sleep being absent. SHR submitted to IH had an increase in low- to the high-frequency power ratio of the heart rate variability from 0.9 +/- 0.15 to 1.5 +/- 0.17, which indicates a shift of the sympatho-parasympathetic balance in this group towards predominance of the sympathetic component. In the Sprague-Dawley rats submitted to neonatal hypoxia, the above changes were not pronounced. These peculiarities of the hypertensive rats allow establishing connection of the genetic factor with the sympathetic mechanism providing long-term consequences of the neonatal IH for the cardiovascular control in these rats.


Subject(s)
Hypertension/etiology , Hypertension/physiopathology , Hypoxia/complications , Hypoxia/physiopathology , Animals , Animals, Newborn , Blood Pressure/physiology , Hypertension/genetics , Hypoxia/genetics , Rats , Rats, Inbred SHR , Rats, Sprague-Dawley , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/genetics , Sleep Apnea, Obstructive/physiopathology
4.
J Clin Invest ; 94(6): 2493-503, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7989608

ABSTRACT

Dysregulated extracellular matrix (ECM) metabolism may contribute to vascular remodeling during the development and complication of human atherosclerotic lesions. We investigated the expression of matrix metalloproteinases (MMPs), a family of enzymes that degrade ECM components in human atherosclerotic plaques (n = 30) and in uninvolved arterial specimens (n = 11). We studied members of all three MMP classes (interstitial collagenase, MMP-1; gelatinases, MMP-2 and MMP-9; and stromelysin, MMP-3) and their endogenous inhibitors (TIMPs 1 and 2) by immunocytochemistry, zymography, and immunoprecipitation. Normal arteries stained uniformly for 72-kD gelatinase and TIMPs. In contrast, plaques' shoulders and regions of foam cell accumulation displayed locally increased expression of 92-kD gelatinase, stromelysin, and interstitial collagenase. However, the mere presence of MMP does not establish their catalytic capacity, as the zymogens lack activity, and TIMPs may block activated MMPs. All plaque extracts contained activated forms of gelatinases determined zymographically and by degradation of 3H-collagen type IV. To test directly whether atheromata actually contain active matrix-degrading enzymes in situ, we devised a method which allows the detection and microscopic localization of MMP enzymatic activity directly in tissue sections. In situ zymography revealed gelatinolytic and caseinolytic activity in frozen sections of atherosclerotic but not of uninvolved arterial tissues. The MMP inhibitors, EDTA and 1,10-phenanthroline, as well as recombinant TIMP-1, reduced these activities which colocalized with regions of increased immunoreactive MMP expression, i.e., the shoulders, core, and microvasculature of the plaques. Focal overexpression of activated MMP may promote destabilization and complication of atherosclerotic plaques and provide novel targets for therapeutic intervention.


Subject(s)
Arteries/enzymology , Arteriosclerosis/enzymology , Extracellular Matrix/enzymology , Metalloendopeptidases/antagonists & inhibitors , Metalloendopeptidases/isolation & purification , Arteries/pathology , Carotid Arteries/enzymology , Carotid Arteries/pathology , Collagenases/isolation & purification , Collagenases/metabolism , Elastin/isolation & purification , Extracellular Matrix/pathology , Frozen Sections , Glycoproteins/isolation & purification , Humans , Immunohistochemistry , Leukocyte Common Antigens/isolation & purification , Matrix Metalloproteinase 1 , Matrix Metalloproteinase 3 , Matrix Metalloproteinase 9 , Proteins/isolation & purification , Tissue Distribution , Tissue Inhibitor of Metalloproteinase-2 , Tissue Inhibitor of Metalloproteinases
5.
J Clin Invest ; 104(8): 1041-50, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10525042

ABSTRACT

Activated T lymphocytes accumulate early in atheroma formation and persist at sites of lesion growth and rupture, suggesting that they may play an important role in the pathogenesis of atherosclerosis. Moreover, atherosclerotic lesions contain the Th1-type cytokine IFN-gamma, a potentiator of atherosclerosis. The present study demonstrates the differential expression of the 3 IFN-gamma-inducible CXC chemokines--IFN-inducible protein 10 (IP-10), monokine induced by IFN-gamma (Mig), and IFN-inducible T-cell alpha chemoattractant (I-TAC)--by atheroma-associated cells, as well as the expression of their receptor, CXCR3, by all T lymphocytes within human atherosclerotic lesions in situ. Atheroma-associated endothelial cells (ECs), smooth muscle cells (SMCs), and macrophages (MO) all expressed IP-10, whereas Mig and I-TAC were mainly expressed in ECs and MO, as detected by double immunofluorescence staining. ECs of microvessels within lesions also expressed abundant I-TAC. In vitro experiments supported these results and showed that IL-1beta, TNF-alpha, and CD40 ligand potentiated IP-10 expression from IFN-gamma-stimulated ECs. In addition, nitric oxide (NO) treatment decreased IFN-gamma induction of IP-10. Our findings suggest that the differential expression of IP-10, Mig, and I-TAC by atheroma-associated cells plays a role in the recruitment and retention of activated T lymphocytes observed within vascular wall lesions during atherogenesis.


Subject(s)
Arteriosclerosis/immunology , Chemokines, CXC/analysis , Intercellular Signaling Peptides and Proteins , Animals , Cells, Cultured , Chemokine CXCL10 , Chemokine CXCL11 , Chemokine CXCL9 , Chemokines, CXC/genetics , Humans , Immunohistochemistry , Nitric Oxide/physiology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , RNA, Messenger/analysis , Rabbits , Receptors, CXCR3 , Receptors, Chemokine/analysis
6.
J Clin Invest ; 102(3): 576-83, 1998 Aug 01.
Article in English | MEDLINE | ID: mdl-9691094

ABSTRACT

Formation of the atherosclerotic intima must involve altered metabolism of the elastin-rich arterial extracellular matrix. Proteases potentially involved in these processes remain unclear. This study examined the expression of the potent elastases cathepsins S and K in human atheroma. Normal arteries contained little or no cathepsin K or S. In contrast, macrophages in atheroma contained abundant immunoreactive cathepsins K and S. Intimal smooth muscle cells (SMC), especially cells appearing to traverse the internal elastic laminae, also contained these enzymes. Extracts of atheromatous tissues had approximately twofold greater elastase-specific activity than extracts of uninvolved arteries, mostly due to cysteine proteases. Cultured human SMC displayed no immunoreactive cathepsins K and S and exhibited little or no elastolytic activity when incubated with insoluble elastin. SMC stimulated with the atheroma-associated cytokines IL-1beta or IFN-gamma secreted active cathepsin S and degraded substantial insoluble elastin (15-20 microg/10(6) cells/24 h). A selective inhibitor of cathepsin S blocked > 80% of this elastolytic activity. The presence of cathepsins K and S at sites of vascular matrix remodeling and the ability of SMC and macrophages to use these enzymes to degrade elastin supports a role for elastolytic cathepsins in vessel wall remodeling and identifies novel therapeutic targets in regulating plaque stability.


Subject(s)
Arteriosclerosis/enzymology , Cathepsins/biosynthesis , Elastin/metabolism , Muscle, Smooth, Vascular/enzymology , Arteriosclerosis/genetics , Carotid Stenosis/enzymology , Carotid Stenosis/genetics , Cathepsin K , Cathepsins/genetics , Cells, Cultured , Coronary Disease/enzymology , Coronary Disease/genetics , Enzyme Induction , Humans , Interferon-gamma/pharmacology , Muscle, Smooth, Vascular/drug effects , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Tunica Intima/cytology , Tunica Intima/metabolism
7.
J Clin Invest ; 107(9): 1117-26, 2001 May.
Article in English | MEDLINE | ID: mdl-11342575

ABSTRACT

Degradation of ECM, particularly interstitial collagen, promotes plaque instability, rendering atheroma prone to rupture. Previous studies implicated matrix metalloproteinases (MMPs) in these processes, suggesting that dysregulated MMP activity, probably due to imbalance with endogenous inhibitors, promotes complications of atherosclerosis. We report here that the serine proteinase inhibitor tissue factor pathway inhibitor-2 (TFPI-2) can function as an MMP inhibitor. TFPI-2 diminished the ability of the interstitial collagenases MMP-1 and MMP-13 to degrade triple-helical collagen, the primary load-bearing molecule of the ECM within human atheroma. In addition, TFPI-2 also reduced the activity of the gelatinases MMP-2 and MMP-9. In contrast to the "classical" tissue inhibitors of MMPs (TIMPs), TFPI-2 expression in situ correlated inversely with MMP levels in human atheroma. TFPI-2 colocalized primarily with smooth muscle cells in the normal media as well as the plaque's fibrous cap. Conversely, the macrophage-enriched shoulder region, the prototypical site of matrix degradation and plaque rupture, stained only weakly for TFPI-2 but intensely for gelatinases and interstitial collagenases. Evidently, human mononuclear phagocytes, an abundant source of MMPs within human atheroma, lost their ability to express this inhibitor during differentiation in vitro. These findings establish a new, anti-inflammatory function of TFPI-2 of potential pathophysiological significance for human diseases, including atherosclerosis.


Subject(s)
Arteriosclerosis/etiology , Glycoproteins/pharmacology , Matrix Metalloproteinase Inhibitors , Serpins/pharmacology , Aorta/pathology , Carotid Arteries/pathology , Dose-Response Relationship, Drug , Glycoproteins/genetics , Humans , Macrophages/metabolism , Muscle, Smooth, Vascular/metabolism , Procollagen/metabolism , Protein Binding , Protein Processing, Post-Translational/drug effects , Recombinant Proteins/pharmacology
8.
J Clin Invest ; 104(9): 1191-7, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10545518

ABSTRACT

The pathogenesis of atherosclerosis and abdominal aortic aneurysm involves breakdown of the elastic laminae. Elastolytic cysteine proteases, including cathepsins S and K, are overexpressed at sites of arterial elastin damage, but whether endogenous local inhibitors counterbalance these proteases is unknown. We show here that, whereas cystatin C is normally expressed in vascular wall smooth muscle cells (SMCs), this cysteine protease inhibitor is severely reduced in both atherosclerotic and aneurysmal aortic lesions. Furthermore, increased abdominal aortic diameter among 122 patients screened by ultrasonography correlated inversely with serum cystatin C levels. In vitro, cytokine-stimulated vascular SMCs secrete cathepsins, whose elastolytic activity could be blocked when cystatin C secretion was induced by treatment with TGF-beta(1). The findings highlight a potentially important role for imbalance between cysteine proteases and cystatin C in arterial wall remodeling and establish that cystatin C deficiency occurs in vascular disease.


Subject(s)
Aortic Aneurysm, Abdominal/metabolism , Arteriosclerosis/metabolism , Cystatins/deficiency , Cysteine Proteinase Inhibitors/deficiency , Aorta/pathology , Aortic Aneurysm, Abdominal/pathology , Arteries/metabolism , Arteries/pathology , Arteriosclerosis/pathology , Cells, Cultured , Cystatin C , Cystatins/blood , Cysteine Proteinase Inhibitors/blood , Dose-Response Relationship, Drug , Humans , Immunoblotting , Immunohistochemistry , Interferon-gamma/metabolism , Muscle, Smooth/metabolism , Transforming Growth Factor beta/metabolism
9.
Circ Res ; 86(2): 131-8, 2000 Feb 04.
Article in English | MEDLINE | ID: mdl-10666407

ABSTRACT

Chemokines are chemotactic cytokines that activate and direct the migration of leukocytes. However, their role in modulating platelet function has not been shown. We studied the direct effect of chemokines on human platelets and found that of the 16 tested only stromal cell-derived factor (SDF)-1 induced platelet aggregation, accompanied by a rise in intracellular calcium. Platelets expressed the SDF-1 receptor, CXCR4, and an antibody to CXCR4 and pertussis toxin inhibited SDF-1-induced platelet aggregation, confirming that this effect is mediated through CXCR4, a Galphai-coupled receptor. SDF-1-induced platelet aggregation was also inhibited by wortmannin, LY294002, and genistein, suggesting that phosphatidylinositol 3-kinase and tyrosine kinase are likely involved in SDF-1-induced platelet aggregation. Because chemokines are produced from multiple vascular cells and atherosclerotic vessels are prone to develop platelet-rich thrombi, we examined the expression of SDF-1 in human atheroma. SDF-1 protein was highly expressed in smooth muscle cells, endothelial cells, and macrophages in human atherosclerotic plaques but not in normal vessels. Our studies demonstrate a direct effect of a chemokine in inducing platelet activation and suggest a role for SDF-1 in the pathogenesis of atherosclerosis and thrombo-occlusive diseases.


Subject(s)
Carotid Artery Diseases/metabolism , Carotid Artery Diseases/pathology , Chemokines, CXC/pharmacology , Platelet Aggregation/drug effects , Antibodies, Monoclonal , Aortic Diseases/metabolism , Aortic Diseases/pathology , Biological Transport/drug effects , Blotting, Western , Calcium/metabolism , Chemokine CXCL12 , Chemokines, CXC/analysis , Chemokines, CXC/immunology , Chemokines, CXC/metabolism , Female , Flow Cytometry , Humans , Immunoenzyme Techniques , Male , Receptors, CXCR4/immunology , Receptors, CXCR4/metabolism , Signal Transduction/drug effects
10.
Circ Res ; 92(5): 493-500, 2003 Mar 21.
Article in English | MEDLINE | ID: mdl-12600886

ABSTRACT

During angiogenesis, microvascular endothelial cells (ECs) secrete proteinases that permit penetration of the vascular basement membrane as well as the interstitial extracellular matrix. This study tested the hypothesis that cathepsin S (Cat S) contributes to angiogenesis. Treatment of cultured ECs with inflammatory cytokines or angiogenic factors stimulated the expression of Cat S, whereas inhibition of Cat S activity reduced microtubule formation by impairing cell invasion. ECs from Cat S-deficient mice showed reduced collagenolytic activity and impaired invasion of collagens type I and IV. Cat S-deficient mice displayed defective microvessel development during wound repair. This abnormal angiogenesis occurred despite normal vascular endothelial growth factor and basic fibroblast growth factor levels, implying an essential role for extracellular matrix degradation by Cat S during microvessel formation. These results demonstrate a novel function of endothelium-derived Cat S in angiogenesis.


Subject(s)
Cathepsins/physiology , Endothelium, Vascular/enzymology , Endothelium, Vascular/growth & development , Animals , Capillaries/cytology , Cathepsins/genetics , Cell Adhesion , Cell Movement , Cells, Cultured , Collagen/metabolism , Elastin/metabolism , Endothelium, Vascular/cytology , Endothelium, Vascular/physiology , Humans , Mice , Mice, Knockout , Wound Healing
11.
Circulation ; 99(24): 3125-31, 1999 Jun 22.
Article in English | MEDLINE | ID: mdl-10377075

ABSTRACT

BACKGROUND: Adhesion molecule expression on the endothelial cell (EC) surface is critical for leukocyte recruitment to atherosclerotic lesions. Better understanding of transcriptional regulation of adhesion molecules in ECs may provide important insight into plaque formation. Peroxisome proliferator-activated receptor-alpha (PPARalpha), a member of the nuclear receptor family, regulates gene expression in response to certain fatty acids and fibric acid derivatives. The present study investigated PPARalpha expression in human ECs and their regulation of vascular cell adhesion molecule-1 (VCAM-1). METHODS AND RESULTS: Immunohistochemistry revealed that human carotid artery ECs express PPARalpha. Pretreatment of cultured human ECs with the PPARalpha activators fenofibrate or WY14643 inhibited TNF-alpha-induced VCAM-1 in a time- and concentration-dependent manner, an effect not seen with PPARgamma activators. Both PPARalpha activators decreased cytokine-induced VCAM-1 mRNA expression without altering its mRNA half-life. Transient transfection of deletional VCAM-1 promoter constructs and electrophoretic mobility shift assays suggest that fenofibrate inhibits VCAM-1 transcription in part by inhibiting NF-kappaB. Finally, PPARalpha activators significantly reduced adhesion of U937 cells to cultured human ECs. CONCLUSIONS: Human ECs express PPARalpha, a potentially important regulator of atherogenesis through its transcriptional control of VCAM-1 gene expression. Such findings also have implications regarding the clinical use of lipid-lowering agents, like fibric acids, which can activate PPARalpha.


Subject(s)
Endothelium, Vascular/chemistry , Receptors, Cytoplasmic and Nuclear/genetics , Transcription Factors/genetics , Tumor Necrosis Factor-alpha/pharmacology , Vascular Cell Adhesion Molecule-1/genetics , Anticholesteremic Agents/pharmacology , Arteriosclerosis/genetics , Arteriosclerosis/metabolism , Carotid Arteries/chemistry , Carotid Arteries/cytology , Cell Adhesion/drug effects , Cell Adhesion/physiology , Dose-Response Relationship, Drug , Endothelium, Vascular/cytology , Endothelium, Vascular/physiology , Fenofibrate/pharmacology , Gene Expression/drug effects , Gene Expression/physiology , Humans , Hypolipidemic Agents/pharmacology , Monocytes/cytology , Monocytes/physiology , NF-kappa B/metabolism , Promoter Regions, Genetic/physiology , Pyrimidines/pharmacology , RNA, Messenger/analysis , Receptors, Cytoplasmic and Nuclear/metabolism , Saphenous Vein/cytology , Transcription Factors/metabolism , Transfection , U937 Cells
12.
Circulation ; 104(16): 1899-904, 2001 Oct 16.
Article in English | MEDLINE | ID: mdl-11602491

ABSTRACT

BACKGROUND: Loss of interstitial collagen, particularly type I collagen, the major load-bearing molecule of atherosclerotic plaques, renders atheroma prone to rupture. Initiation of collagen breakdown requires interstitial collagenases, a matrix metalloproteinase (MMP) subfamily consisting of MMP-1, MMP-8, and MMP-13. Previous work demonstrated the overexpression of MMP-1 and MMP-13 in human atheroma. However, no study has yet evaluated the expression of MMP-8, known as "neutrophil collagenase," the enzyme that preferentially degrades type I collagen, because granulocytes do not localize in plaques. METHODS AND RESULTS: Transcriptional profiling and reverse transcription-polymerase chain reaction analysis revealed inducible expression of MMP-8 transcripts in CD40 ligand-stimulated mononuclear phagocytes. Western blot analysis demonstrated that 3 atheroma-associated cell types, namely, endothelial cells, smooth muscle cells, and mononuclear phagocytes, expressed MMP-8 in vitro upon stimulation with proinflammatory cytokines such as interleukin-1beta, tumor necrosis factor-alpha, or CD40 ligand. MMP-8 protein elaborated from these atheroma-associated cell types migrated as 2 immunoreactive bands, corresponding to the molecular weights of the zymogen and the active molecule. Extracts from atherosclerotic, but not nondiseased arterial tissue, contained similar immunoreactive bands. Moreover, all 3 cell types expressed MMP-8 mRNA and protein in human atheroma in situ. Notably, MMP-8 colocalized with cleaved but not intact type I collagen within the shoulder region of the plaque, a frequent site of rupture. CONCLUSIONS: These data point to MMP-8 as a previously unsuspected participant in collagen breakdown, an important determinant of the vulnerability of human atheroma.


Subject(s)
Arteriosclerosis/enzymology , Collagen/metabolism , Gene Expression Profiling , Matrix Metalloproteinase 8/biosynthesis , Matrix Metalloproteinase 8/genetics , Aorta/enzymology , Aorta/pathology , Arteriosclerosis/pathology , CD40 Ligand , Carotid Arteries/enzymology , Carotid Arteries/pathology , Cells, Cultured , Cytokines/pharmacology , Endothelium, Vascular/enzymology , Endothelium, Vascular/pathology , Humans , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/enzymology , Muscle, Smooth, Vascular/enzymology , Muscle, Smooth, Vascular/pathology , Phagocytes/enzymology , Phagocytes/pathology , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction
13.
J Am Coll Cardiol ; 31(3): 684-91, 1998 Mar 01.
Article in English | MEDLINE | ID: mdl-9502654

ABSTRACT

OBJECTIVES: This study examined the direct effects of pravastatin on the artery wall of atherosclerotic monkeys after dietary lipid lowering. BACKGROUND: Clinical trials suggest that hepatic hydroxymethylglutaryl coenzyme A reductase inhibitors may reduce the risk of coronary heart disease out of proportion to their effect on angiographically assessed lumen stenosis. METHODS: Thirty-two cynomolgus monkeys were fed an atherogenic diet for 2 years (progression phase) and then fed a lipid-lowering diet either containing (n = 14) or not containing (n = 18) pravastatin in the diet for an additional 2 years (treatment phase). As designed, total plasma cholesterol and high density lipoprotein concentrations did not differ between groups at the beginning of or during the treatment phase of the experiment (p > 0.05). RESULTS: Quantitative angiography revealed that coronary arteries of the pravastatin-treated monkeys dilated 10 +/- 3%, whereas those from untreated control monkeys constricted -2 +/- 2% in response to acetylcholine (p < 0.05). There were no treatment effects on plaque size of coronary arteries measured at the end of the treatment phase of the study (0.110 +/- 0.048 mm2 [untreated] vs. 0.125 +/- 0.051 mm2 [pravastatin]; p > 0.05) or on the amount of reduction in plaque size in common iliac arteries during the treatment phase of the study (48 +/- 5% [untreated] vs. 45 +/- 6% [pravastatin]; p > 0.05). However, histochemical analysis of the atherosclerotic lesions indicated that the arteries from pravastatin-treated monkeys had significantly fewer macrophages in the intima and media, less calcification and less neovascularization in the intima (p < 0.05). CONCLUSIONS: We conclude that compared with control monkeys, the arteries of pravastatin-treated monkeys had better dilator function and plaque characteristics more consistent with plaque stability than those of monkeys not receiving pravastatin. These beneficial arterial effects of pravastatin occurred independently of plasma lipoprotein concentrations and despite similar changes in plaque size between the groups.


Subject(s)
Anticholesteremic Agents/pharmacology , Coronary Artery Disease/drug therapy , Coronary Artery Disease/physiopathology , Coronary Vessels/drug effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Pravastatin/pharmacology , Vasodilation/drug effects , Acetylcholine/antagonists & inhibitors , Animals , Arteriosclerosis/drug therapy , Arteriosclerosis/physiopathology , Confounding Factors, Epidemiologic , Coronary Artery Disease/blood , Coronary Vessels/pathology , Coronary Vessels/physiopathology , Lipids/blood , Macaca fascicularis , Time Factors , Vasoconstriction/drug effects
14.
Atherosclerosis ; 100(2): 237-48, 1993 May.
Article in English | MEDLINE | ID: mdl-8357356

ABSTRACT

In a search for early atherosclerotic lesions, we have investigated grossly normal areas of human thoracic aortas taken at autopsy from 40 trauma victims aged from 3 to 40 years. Two areas of aorta were compared: lesion predisposed to atherosclerosis (LP) area localized on the dorsal aspect of the vessel along the row of intercostal branching sites, and lesion resistant (LR) area located on the ventral aspect of the vessel. Accumulation of apolipoprotein B (apo B) was found in LP aortic area of each child older than 6 years. Similar retention of apo B in LR area appeared only in aortas of teenagers. The apo B staining increased with age in both areas tested but was usually of a greater extent in LP area than in LR area. Typical smooth muscle cells (SMCs) and a few monocytes/macrophages (Mn/Mph) were revealed in the intimal layer of all aortas examined. The number of Mn/Mph dramatically increased in LP areas of individuals over 17 years. Quantitative study of double stained sections has shown a 2- to 6-fold enhanced number of Mn/Mph in LP area compared with LR aortic area of 10 men over 21 years. Focal infiltration of Mn/Mph in aortas of young adults occurred without endothelial denudation. In addition, some intimal SMCs in LP area of 12 aortas out of 29 expressed desmin and contained well-developed endoplasmic reticulum, while such cells were seldom detected in LP area of the vessels. Thus, focal accumulation of apo B with subsequent Mn/Mph infiltration and SMC phenotypic modulation in LP aortic area of young adults may be causally involved in fatty streak and atherosclerotic plaque formation.


Subject(s)
Aorta, Thoracic/pathology , Arteriosclerosis/pathology , Macrophages/pathology , Monocytes/pathology , Muscle, Smooth, Vascular/pathology , Adolescent , Adult , Aorta, Thoracic/metabolism , Apolipoproteins B/metabolism , Arteriosclerosis/metabolism , Cell Count , Child , Child, Preschool , Desmin/metabolism , Female , Fluorescent Antibody Technique , Humans , Male , Microscopy, Electron , Muscle, Smooth, Vascular/metabolism , Tunica Intima/pathology
15.
Atherosclerosis ; 79(1): 59-70, 1989 Sep.
Article in English | MEDLINE | ID: mdl-2803347

ABSTRACT

Primary cultures of typical and modified smooth muscle cells isolated from the intima of human aorta were used to study the mechanism whereby low density lipoprotein (LDL) induces accumulation of intracellular cholesterol. Incubation of intimal cells with native LDL obtained from human plasma did not lead to deposition of total cholesterol. LDL added to the cultures simultaneously with hyaluronic acid, heparin, chondroitin sulfate, fibronectin, and mouse monoclonal antibody against LDL also failed to alter the cellular cholesterol. On the other hand, 24-h incubation of the cells with LDL in the presence of dextran sulfate, gelatin, particles of aortic elastin, particles of collagenase-resistant aortic matrix, goat polyclonal antibodies against LDL or latex beads caused a significant (1.5-7-fold) increase in total cholesterol. The compounds which stimulated cholesterol deposition are able to form precipitating complexes with LDL. On the contrary, the agents which failed to induce cholesterol accumulation were unable to insolubilize LDL. A direct correlation (r = 0.927) was found between the cholesterol content of the insoluble complex and the increment of cholesterol in the cultured cells. To find out whether LDL plays a specific role in the deposition of intracellular cholesterol, very low density lipoproteins and high density lipoproteins were used. These lipoproteins stimulated the accumulation of intracellular cholesterol in the presence of agents capable of forming insoluble associates with them. Our data suggest that insolubilization of lipoproteins is a key event in the LDL-mediated accumulation of intracellular cholesterol induced by various agents.


Subject(s)
Aortic Diseases/etiology , Cholesterol, HDL/analysis , Cholesterol, LDL/analysis , Lipoproteins, LDL/analysis , Lipoproteins, VLDL/analysis , Autopsy , Cholesterol, LDL/immunology , Endothelium, Vascular , Fibronectins/pharmacology , Heparin/pharmacology , Humans , Lipoproteins, LDL/immunology , Male , Middle Aged , Solubility
16.
Ann N Y Acad Sci ; 748: 501-7, 1995 Jan 17.
Article in English | MEDLINE | ID: mdl-7695193

ABSTRACT

Dysregulated extracellular matrix (ECM) metabolism may contribute to vascular remodeling during atherogenesis. The ability of vascular cells to synthesize the components of ECM is well characterized, but less is known about their capacity to degrade ECM and the factors that may regulate this process. We therefore studied the expression of matrix metalloproteinases (MMPs), enzymes that degrade various components of ECM, and of tissue inhibitors of MMPs (TIMPs) by untreated or cytokine-stimulated human smooth muscle cells (SMC). Messenger RNA was studied by Northern blotting, and proteins secreted in culture by SMC were identified by immunoprecipitation. Gelatinolytic and caseinolytic activity of MMPs was detected zymographically. SMC constitutively produced a 72 kDa type IV gelatinase (GL), TIMP-1, and TIMP-2. Upon stimulation with IL1 or TNF alpha, SMC synthesized in addition 92 kDa GL, stromelysin, and interstitial collagenase, MMPs that together can degrade all of the ECM components. IL1 or TNF alpha did not alter the level of TIMP mRNA and protein, suggesting that a net excess of MMP production under these conditions may promote breakdown of the vascular ECM. To test the in vivo relevance of these in vitro findings, we analyzed immunohistochemically normal human arteries and carotid atheromas. Normal tissue and the medial layer underlying lesions stained uniformly for 72 kDa GL and TIMPs 1 and 2. Lesions showed regionally increased MMP expression: the shoulders of atherosclerotic plaques contained stromelysin and 92 kDa GL associated with SMC, and clusters of macrophage-derived foam cells associated with the lipid core stained intensely for all MMPs studied. Endothelial cells covering atheroma or of the plaque microvasculature contained interstitial collagenase. In pathological conditions associated with local release of cytokines in the vessel wall, enhanced regional expression of vascular MMPs may contribute to SMC migration and weakening of matrix that would favor plaque rupture, events associated with the development or complication of the atherosclerotic lesions.


Subject(s)
Arteriosclerosis/enzymology , Metalloendopeptidases/metabolism , Muscle, Smooth, Vascular/enzymology , Arteries/enzymology , Cells, Cultured , Extracellular Matrix/metabolism , Gelatinases/metabolism , Glycoproteins/metabolism , Humans , In Vitro Techniques , Interleukin-1/pharmacology , Tissue Inhibitor of Metalloproteinases , Tumor Necrosis Factor-alpha/pharmacology
17.
Arkh Patol ; 46(11): 52-8, 1984.
Article in Russian | MEDLINE | ID: mdl-6084502

ABSTRACT

Biopsies of the liver, stomach, pancreas, small salivary glands, lung of patients with chronic alcoholism were studied morphologically including ultrastructural analysis. The formation of fibrillar alcoholic hyalin in hepatocytes is the most characteristic ultrastructural feature of the liver alcoholic damage. Accumulation of intermediate filaments in the epithelial cells of the stomach, pancreas, small salivary glands, stomach macrophages is a characteristic sign of the alcoholic damage to these organs. This disturbance of the structural organization of the cytoskeleton seems to reflect secretory insufficiency of the epithelium and failure of macrophagal function.


Subject(s)
Alcoholism/pathology , Cytoskeleton/ultrastructure , Endoplasmic Reticulum/ultrastructure , Hepatitis, Alcoholic/pathology , Hyalin/analysis , Humans , Liver/ultrastructure , Lung/ultrastructure , Pancreas/ultrastructure , Salivary Glands/ultrastructure , Stomach/ultrastructure
18.
Arkh Patol ; 48(10): 26-33, 1986.
Article in Russian | MEDLINE | ID: mdl-3800679

ABSTRACT

Alcoholic microangiopathy was studied on the biopsy material from kidneys, skin and salivary glands of alcoholic patients by means of histochemical, immunohistochemical and electron-microscopic methods. Its formation is mainly caused by the direct action of ethanol on microcirculatory vessels. Alcohol-induced microangiopathy is morphologically manifested by the accumulation of intermediate filaments in the cytoplasm of endotheliocytes and perivascular infiltrate macrophages. The expression of pathological changes in the cytoskeleton is reduced due to the abstinence from alcohol. Glomerulonephritis in alcoholic patients, that can be considered as a peculiar manifestation of alcoholic microangiopathy, is immunocomplex with predominance in these immune complexes of IgA in combination with IgG and C3 complement fraction. Morphologically it is characterized by the accumulation of intermediate filaments in the cytoplasm of podocytes, mesangiocytes, nephrocytes and some endothelial cells, as well as early and quick formation of fibroplastic transformation and cirrhosis of the kidney.


Subject(s)
Alcoholism/pathology , Microcirculation/pathology , Adult , Atrophy , Humans , Kidney/blood supply , Male , Microcirculation/ultrastructure , Microscopy, Electron , Middle Aged , Salivary Glands, Minor/blood supply , Skin/blood supply
19.
Arkh Patol ; 40(7): 28-34, 1978.
Article in Russian | MEDLINE | ID: mdl-80208

ABSTRACT

Possible ways of alcohol hyalin evolution were studied by repeated electron microscopic examinations of the livers of 2 patients with acute alcoholic hepatitis Four types of ultrastructure of alcoholic hyalin were found: parallely oriented fibrillae, randomly oriented fibrillae, fine granular and large granular (spotlike) substance. Examinations of the material from repeated biopsies showed fibrillar hyalin to be "young" and to turn into "old" hyalin of granular structure. The evolution of alcoholic hyalin from fibrillar to granular is accompanied by hepatocyte necrosis and leukotaxic effect.


Subject(s)
Hepatitis, Alcoholic/pathology , Hyalin/cytology , Inclusion Bodies/ultrastructure , Liver/ultrastructure , Adult , Cell Survival , Female , Humans , Liver/pathology , Male , Microscopy, Electron , Middle Aged , Necrosis
20.
Arkh Patol ; 46(2): 44-50, 1984.
Article in Russian | MEDLINE | ID: mdl-6712511

ABSTRACT

The characteristics of all types of chronic gastritis in patients with chronic alcoholism is given. Alterations of the stomach mucous membrane in alcoholism of different duration are described in detail. The intermediate type filaments in the surface epithelium, cells of glands and macrophages are found which is reported to be a morphological manifestation of alcoholism.


Subject(s)
Alcoholism/pathology , Gastritis, Atrophic/pathology , Gastritis/pathology , Adult , Alcoholism/complications , Chronic Disease , Gastric Mucosa/pathology , Gastric Mucosa/ultrastructure , Gastritis, Atrophic/etiology , Humans , Male , Microscopy, Electron , Middle Aged
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