Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0162871 (abdominal aortic aneurysm)
 8,664 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One of the most consistent observations in abdominal aortic aneurysm (AAA) disease is the disorganization and disruption of elastin and other matrix components of the aortic wall. The enzymatic basis for the biochemical features of AAA has been investigated beginning with the demonstration on substrate gel enzymography of a typical "profile" of proteinase activities in AAA tissue extracts which degrade gelatin, casein and elastin. A recombinant TIMP-1 affinity column was developed and three of the elastolytic/caseinolytic activities with approximate molecular weights of approximately 80 kDa, approximately 50 kDa and approximately 32 kDa were partially purified from these extracts. Affinity for rTIMP-1 suggests that these enzymes are members of the matrix metalloproteinase (MMP) family. High molecular weight forms of two MMPs, collagenase (MMP-1) and stromelysin-1 (MMP-3), were also isolated from the AAA tissue on this column; active forms of MMP-1 could be demonstrated by immunoblotting techniques in this preparation under reducing conditions. Infiltrating inflammatory cells are known sources of these proteolytic activities; analysis of these cell populations in the aneurysmal aortic wall using fluorescence-activated cell counting revealed a fifty-fold increase in macrophages (a well-known source of matrix-degrading enzymes) as well as a significant increase in lymphocytes.
 ...
PMID:Matrix metalloproteinases in abdominal aortic aneurysm: characterization, purification, and their possible sources. 795 5

Changes in extracellular matrix composition induced by abnormal collagen metabolism in the aortic wall may be an important factor in the progression of aortic structural changes. The authors have measured several types of biochemical marker for collagen metabolism in plasma: carboxyterminal propeptide of type Icollagen (PICP) for a pure collagen synthesis marker, matrix metalloproteinase-1 (MMP-1) for a degradation marker of collagen matrix, and tissue inhibitors of metalloproteinase-1 (TIMP-1) as a native inhibitor of MMP-1. Subjects of this study were 17 patients with abdominal aortic aneurysm (AAA), 14 patients with atherosclerosis obliterans (ASO), and 22 age/sex-matched healthy controls (HC). Blood samples were drawn from a forearm vein and measured by radioimmunoassay or enzyme-linked immunosorbent assay. Plasma concentrations of PICP in patients with AAA were significantly decreased compared to those in HC patients (82.0 +/- 16.4 vs 111.3 +/- 40.3 ng/mL; p < 0.01), but those in patients with ASO (105.4 +/- 55.4 ng/mL) were comparable to control concentrations. Although no differences in plasma concentrations of MMP-1 were observed among the three subject groups (HC, 20.0 +/- 5.6 ng/mL; ASO, 21.4 +/- 13.8 ng/mL; AAA, 24.5 +/- 11.7 ng/mL; NS), MMP-1/PICP ratio as an index of collagen degradation to collagen neosynthesis in AAA was significantly elevated compared to HC (0.32 +/- 0.18 vs 0.20 +/- 0.08; p < 0.01). Plasma concentrations of TIMP-1 in patients with AAA (293.8 +/- 61.2 ng/mL) or ASO (327.6 +/- 54.9 ng/mL) were significantly higher than in HC (227.3 +/- 60.2 ng/mL; both p < 0.01). In conclusion, these data suggest that although a compensatory mechanism such as increased TIMP-1 may be activated, collagen neosynthesis may decrease with relatively increased collagen degradation in patients with AAA.
 ...
PMID:Circulating biochemical marker levels of collagen metabolism are abnormal in patients with abdominal aortic aneurysm. 1082 55

Abdominal aortic aneurysms (AAAs) are characterized by structural alterations of the aortic wall resulting from degradation of collagen and elastin. Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, show strong elastinolytic activity. We examined the levels of mRNA for MMP-2, MMP-9, membrane type (MT)-MMP-1, tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-2 in AAAs (n = 8), atherosclerotic occlusive diseases (AOD) (n = 8), and normal subjects (n = 8) using the reverse transcription-polymerase chain reaction (RT-PCR). We also analyzed the gelatinolytic activity of these metalloproteinases using gelatin zymography. The levels of MMP-2 and MMP-9 mRNA were increased in the AAA group compared with those in the AOD group and normal subjects. The levels for TIMP-1 and TIMP-2 mRNA in the AAA group were also higher than those in the AOD and normal groups. Only in the case of MT-MMP-1 was the difference between AAA and AOD not statistically significant. By gelatin zymography with the same samples used for RT-PCR, gelatinolytic activity of MMP-9 was elevated in all AAA tissues. The 62-kDa form of MMP-2 was elevated in both the AAA and AOD groups and did not differ significantly between them. Linear regression analysis demonstrated a significant positive correlation between mRNA levels of MMPs and those of TIMPs. These observations suggest that aneurysm formation in patients with atherosclerosis is related to the degree of MMP-9 expression.
 ...
PMID:Enhanced expression of matrix metalloproteinase-9 in abdominal aortic aneurysms. 1134 73

Serine-, cysteine-, and metalloproteases are widely spread in many pathogenic bacteria, where they play critical functions related to colonization and evasion of host immune defenses, acquisition of nutrients for growth and proliferation, facilitation of dissemination, or tissue damage during infection. Since all the antibiotics used clinically at the moment share a common mechanism of action, acting as inhibitors of the bacterial cell wall biosynthesis or affecting protein synthesis on ribosomes, resistance to these pharmacological agents represents a serious medical problem, which might be resolved by using new generation of antibiotics, possessing a different mechanism of action. Bacterial protease inhibitors constitute an interesting such possibility, due to the fact that many specific as well as ubiquitous proteases have recently been characterized in some detail in both gram-positive as well as gram-negative pathogens. Few potent, specific inhibitors for such bacterial proteases have been reported at this moment except for some signal peptidase, clostripain, Clostridium histolyticum collagenase, botulinum neurotoxin, and tetanus neurotoxin inhibitors. No inhibitors of the critically important and ubiquitous AAA proteases, degP or sortase have been reported, although such compounds would presumably constitute a new class of highly effective antibiotics. This review presents the state of the art in the design of such enzyme inhibitors with potential therapeutic applications, as well as recent advances in the use of some of these proteases in therapy.
 ...
PMID:Bacterial protease inhibitors. 1211 49

The effect of active absorbable algal calcium (AAA Ca) with collagen and other matrix components on aging-associated skin changes and backache and joint pain was tested in a case-controlled study of 40 test subjects and 40 age-matched control subjects (mean age, 65 years) complaining of backache and knee joint pain due to osteoarthritis, spondylosis deformans, and/or osteoporosis. Supplementation with 900 mg calcium (given as AAA Ca) and 3.5 g collagen and other matrix components, including glucosamine, daily for 4 months resulted in a marked alleviation of subjective pain, assessed by the face scale. A fall of skin impedance in response to exercise loads, such as standing up, walking, squatting, and climbing up and down stairs, reported as an objective manifestion of pain, was also alleviated. The basal skin impedance, which increases with age, was significantly reduced in response to the Ca-collagen-matrix supplementation, suggesting a change of skin properties similar to rejuvenation, along with subjective smoothening and moistening of the skin. Urinary excretion of N-terminal crosslinking telopeptide of type I collagen (NTx) was decreased in the Ca-collagen-matrix supplementation group, but not in the control group. In addition to calcium suppression of parathyroid hormone, preventing bone resorption, collagen, acting on the intestinal lymphatic system, may protect collagen from degradation through the inhibition of cytokine-induced release of metalloproteinases, including collagenase.
 ...
PMID:The effect of active absorbable algal calcium (AAA Ca) with collagen and other matrix components on back and joint pain and skin impedance. 1220 36

The hallmark feature of abdominal aortic aneurysm (AAA) is the progressive degeneration of aortic wall. Matrix proteoglycans (PGs) play important roles in the development of vascular diseases and the function of the tissue. In this study, we examined the concentration, expression and localization of the small extracellular matrix PG biglycan and decorin. The concentration of small PGs present in normal and aneurysmal aortas was determined by biochemical methods following extraction of the tissues with guanidine hydrochloride and treatment with collagenase/elastase, isolation by ion-exchange and gel chromatographies and identification by Western blotting. The levels of mRNA encoding for biglycan and decorin were evaluated in corresponding tissue samples by reverse transcriptase polymerase chain reaction (RT-PCR). Distribution of extracellular matrix macromolecules was examined using Movat's pentachrome staining and localization of biglycan and decorin by immunohistochemistry. Both normal and aneurysmal aortas contained almost equal amounts of decorin (1.13+/-0.08 and 1.22+/-0.10 mg uronic acid per g of dry defatted (dd) tissue, respectively). Furthermore, the expression of decorin was almost constant in both tissues. In normal specimens decorin accounts for 22% of total PGs, whereas in AAA ones for 60%, due to the significant loss of other matrix PGs. In contrast, the concentration of biglycan was markedly decreased in aneurysmal aortas (57%, 0.478+/-0.04 mg uronic acid per g of dd tissue) in comparison to normal ones (1.12+/-0.10 mg uronic acid per g of dd tissue). Biglycan accounts for 22% of total PGs in normal aortas and 25% of total in aneurysmal tissue. A similar decrease (60%) in the amounts of mRNA encoding for biglycan was observed in the AAA. Immunohistochemical study showed that all aortic layers of AAA were characterized by a significant loss of elastin, biglycan and other PGs/GAGs and replacement of these molecules with collagen fibrils and decorin. The obtained data suggest that the altered matrix architecture of aorta, i.e. the differential expression of biglycan and localization of decorin may well be crucial parameters accounting for the functional degeneration of the tissue and the development of aneurysmal dilatation.
 ...
PMID:Decreased biglycan expression and differential decorin localization in human abdominal aortic aneurysms. 1241 72

Medial degeneration of extracellular matrix (ECM) proteins in the wall of abdominal aortas results in smooth muscle cell destruction, a loss of architectural integrity, and abdominal aortic aneurysm (AAA) formation. It has been theorized that an imbalance between proteinases and their naturally occurring inhibitors is the cause of these observed histologic abnormalities. Therefore, the purpose of this investigation was to determine if differences in the matrix metalloproteinase (MMP) -2 and -9, tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA) protein and activity levels existed between infrarenal AAA and normal abdominal aortic tissue specimens. Between November 1995 and January 1997, 10 patients undergoing elective infrarenal AAA repair had a portion of their aneurysm walls snap frozen in liquid nitrogen and processed for subsequent western blot or zymographic analysis. Tissue specimens from 6 normal abdominal aortas obtained from fresh cadaver specimens were similarly processed and served as controls. Protein levels for MMP-2, MMP-9, TIMP-1, uPA, and tPA were analyzed by western blotting. The degree of MMP-2 and MMP-9 gelatinolytic activity was analyzed by zymography. Detection and immunolocalization for MMP-2, MMP-9 and CD68 was performed on tissue sections of AAA and normal infrarenal abdominal aortas fixed in 10% formalin. MMP-9 and tPA protein levels were increased in AAAs compared to controls by western blotting. However, uPA levels were slightly increased in controls. No differences in TIMP-1 protein levels were identified. Similarly, zymography demonstrated increased MMP-2 and MMP-9 gelatinolytic activity in AAAs compared to controls (p < or = 0.05). CD68-positive cells (macrophages) in the adventitia and media demonstrated immunoreactivity to MMP-9. This investigation demonstrated increased MMP-9 proteinase activity and tPA protein levels in the walls of AAAs, as well as inflammatory leukocyte invasion of the adventitia and media compared to controls. These data suggest that leukocyte-derived MMP-9 is associated with aortic wall degeneration and aneurysm formation. Furthermore, activation of MMP-9 may be caused by increased tPA levels in the walls of AAAs.
 ...
PMID:Matrix metalloproteinase expressions in arteriosclerotic aneurysmal disease. 1270 18

Abdominal aortic aneurysm (AAA) is a localized dilatation of the arterial wall as a result of extensive breakdown of its structural proteins by matrix metalloproteinases (MMPs). AAA continuously expand and may eventually rupture, causing high mortality rates. The molecular processes underlying expansion and rupture of AAA are only poorly understood. In this study, evidence was sought for a direct involvement of macrophage migration inhibitory factor (MIF) in the pathogenesis of AAA through up-regulating MMPs, with particular reference to macrophages. To this end, expression and cellular localization of MIF were analyzed in human aortic wall samples of stable AAA and ruptured AAA, and compared with control aorta and atherosclerotic aorta (AS). MIF expression was up-regulated in stable AAA and further intensified in ruptured AAA. The increased aneurysmal MIF expression was paralleled by an enhanced expression of specific MMPs, viz. MMP-1, MMP-9, and MMP-12, and by a decrease of their inhibitors. Immunohistochemical analysis of AAA and AS showed MIF protein in endothelial cells, smooth muscle cells (SMCs), macrophages, and T cells. MMP-1 (in SMCs and macrophages) and MMP-9 (in macrophages) were colocalized with MIF at the cellular level in ruptured AAA. The up-regulation of aneurysmal MIF/MMP expression was associated with an increased content of cytotoxic T cells.
 ...
PMID:Up-regulation and coexpression of MIF and matrix metalloproteinases in human abdominal aortic aneurysms. 1611 23

Growth and rupture of abdominal aortic aneurysms (AAAs) result from increased collagen turnover. Collagen turnover critically depends on specific collagenases that cleave the triple helical region of fibrillar collagen. As yet, the collagenases responsible for collagen degradation in AAAs have not been identified. Increased type I collagen degradation products confirmed collagen turnover in AAAs (median values: <1, 43, and 108 ng/mg protein in control, growing, and ruptured AAAs, respectively). mRNA and protein analysis identified neutrophil collagenase [matrix metalloproteinase (MMP)-8] and cysteine collagenases cathepsin K, L, and S as the principle collagenases in growing and ruptured AAAs. Except for modestly increased MMP-14 mRNA levels, collagenase expression was similar in growing and ruptured AAAs (anterior-lateral wall). Evaluation of posttranslational regulation of protease activity showed a threefold increase in MMP-8, a fivefold increase in cathepsins K and L, and a 30-fold increase in cathepsin S activation in growing and ruptured AAAs. The presence of the osteoclastic proton pump indicated optimal conditions for extracellular cysteine protease activity. Protease inhibitor mRNA expression was similar in AAAs and controls, but AAA protein levels of cystatin C, the principle cysteine protease inhibitor, were profoundly reduced (>80%). We found indications that this secondary deficiency relates to cystatin C degradation by (neutrophil-derived) proteases.
 ...
PMID:Collagen degradation in the abdominal aneurysm: a conspiracy of matrix metalloproteinase and cysteine collagenases. 1732 67

Because current therapy to treat abdominal aortic aneurysm (AAA), and particularly to manage small AAA, is limited to elective surgical repair, we explored less invasive molecular therapy by simultaneous inhibition of the transcription factors nuclear factor (NF)kappaB and ets using a decoy strategy. Both NFkappaB and ets were shown to be markedly activated in human AAA. In addition, NFkappaB- and ets-positive cells were increased in the aneurysm wall, and a part of the expression of NFkappaB and ets was detected in migrating macrophages. Thus, we used chimeric decoy oligodeoxynucleotides (ODNs) containing consensus sequences of both NFkappaB and ets binding sites to treat AAA. Inhibitory effects of chimeric decoy ODNs on matrix metalloproteinase-1 and -9 expression were confirmed by ex vivo experiments using a human aorta organ culture. To examine the regressive effect in a rabbit already-formed AAA model, transfection by wrapping a delivery sheet containing chimeric decoy ODNs around the aneurysm was performed 1 week after incubation with elastase. Importantly, treatment with chimeric decoy ODNs significantly decreased the size of AAA. Interestingly, significant preservation of elastic fibers was observed with chimeric decoy ODN treatment, accompanied by a reduction of matrix metalloproteinase-2 and -9 and induction of macrophage apoptosis. Regression of AAA was also associated with an increase in elastin and collagen type I and III synthesis in the aneurysm wall. Minimally invasive molecular therapy targeted to the inhibition of NFkappaB and ets is expected to be useful for AAA through the rebalance of matrix synthesis and degradation.
 ...
PMID:Regression of abdominal aortic aneurysms by simultaneous inhibition of nuclear factor kappaB and ets in a rabbit model. 1788 20


1 2 3 Next >>