Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA encoding a putative tissue inhibitor of metalloprotease was cloned from an Ancylostoma caninum adult hookworm cDNA library by immunoscreening with anti-hookworm secretory products antiserum. Ac-TMP (A. caninum tissue inhibitor of metalloproteinase) is encoded by a 480-bp mRNA with a predicted open reading frame of 140 amino acids (molecular weight, 16,100 Da) that contains one potential N-linked glycosylation site and an N-terminal Cys-X-Cys consensus sequence. The open reading frame corresponds to a putative hookworm tissue inhibitor of metalloproteases (TIMP) with 33% identity and 50% similarity to the N-terminal domain of human TIMP-2. Analysis by reverse transcriptase-polymerase chain reaction indicates that transcription of Ac-tmp is restricted to the adult stage. The protein was isolated from A. caninum adult secretory products by reverse-phase high-performance liquid chromatography and identified as one of the most abundant proteins released by the parasite. To our knowledge, this is the first description of a TIMP from a parasitic invertebrate.
...
PMID:Molecular cloning and purification of Ac-TMP, a developmentally regulated putative tissue inhibitor of metalloprotease released in relative abundance by adult Ancylostoma hookworms. 1213 14

Matrix metalloproteinase-2 (MMP-2) is overexpressed in human cancers and facilitates tumor growth and metastasis. It is synthesized as an inactive proenzyme that is activated by membrane-type matrix metalloproteinase-1 (MT1-MMP) and inhibited by tissue inhibitor of metalloproteinase-2 (TIMP-2). We hypothesized that there is an imbalance between the expression of TIMP-2 and the expression of MMP-2 and MT1-MMP that favors activation of MMP-2 in malignant colon tumors compared to normal colonic tissue. Specimens of colon tumors and of adjacent normal mucosa were obtained from 22 patients at the time of surgical resection. MMP-2, MT1-MMP, and TIMP-2 RNA transcripts were measured in each sample using a quantitative reverse transcriptase polymerase chain reaction assay. We observed that MMP-2 RNA levels were significantly elevated in tumors compared to normal tissue (P = 0.039). In addition, the TIMP-2:MMP-2 ratio was twofold lower (P = 0.001) and the TIMP-2:MT1-MMP ratio was 1.5-fold lower (P = 0.003) in tumors compared to normal mucosa. These results suggest that the balance between genes that activate and inhibit MMP-2 is shifted toward activation in colon tumors. The abnormal expression of gene products that regulate MMP-2 activity may be an important early step in the malignant transformation of colon cancer and may provide a useful target for new chemoprevention and adjuvant treatment strategies.
...
PMID:Balance between activation and inhibition of matrix metalloproteinase-2 (MMP-2) is altered in colorectal tumors compared to normal colonic epithelium. 1218 36

The detection of epithelial cells in dried bloodstains by reverse transcriptase-polymerase chain reaction is based on cell- and tissue-specific gene expression. In this paper mRNA markers suitable for the identification of menstrual blood were evaluated. RNA isolated from autopsy tissue samples including endometrium, vaginal mucosa, and blood were screened for tissue-specific expression patterns using RT-PCR with primers for hormone receptors, intermediate filaments, matrix metalloproteinases, heat shock proteins, cytokines, and growth factors. Matrix metalloproteinase (MMP) mRNA could be detected in endometrium but not in blood and other epithelia. This was confirmed in further studies with artificial menstrual bloodstains, indicating that the detection of MMP expression in bloodstains may serve as a forensic marker for menstrual blood.
...
PMID:Evaluation of mRNA markers for the identification of menstrual blood. 1245 49

The present study was conducted to investigate if the mechanism of human heme oxygenase-1 (HO-1) mediated angiogenesis was through the induction of vascular endothelial growth factor (VEGF). Also, the effect of HO-1 on the expression of transforming growth factor beta (TGF-beta),was studied in the presence and absence of HO-1 inducers. Rat lung microvessel endothelial cell line transduced with human HO-1 gene was subjected to cell culture (six separate experiments). mRNA extraction and reverse transcriptase polymerase chain reaction (RT-PCR) experiments, were performed to evaluate the expression of HO-1, VEGF, and TGF-beta in the presence and absence of HO inducers including H(2)O(2), endotoxin and snake venom metalloproteinase with disintegrin like activity(SnMP). ELISA technique was performed to evaluate the levels of the studied growth factors. The results of the study showed over expression of VEGF in endothelial cells transduced with HO-1 compared to control non-transduced endothelial cells. On the other hand, the expression of TGF-beta and its protein level were markedly inhibited in HO-1 transduced endothelial cells compared to control non-transduced cells. Endotoxin and SnMP showed more prominent effect on the expression of VEGF and suppression of TGF-beta in HO-1 transduced endothelial cells, suggesting that their effect is most probably mediated through induction of HO-1.
...
PMID:Retrovirus-mediated human heme oxygenase-1 (HO-1) gene transfer into rat endothelial cells: the effect of HO-1 inducers on the expression of cytokines. 1253 Dec 45

Pulmonary lymphangioleiomyomatosis (LAM) is characterized by abnormal smooth muscle-like cell proliferation leading to tissue destruction and cyst formation. We demonstrate that serum response factor (SRF), a critical smooth muscle transcription factor, is overexpressed in LAM cells. To determine whether abnormal SRF levels might have a pathogenic role in LAM, we transfected SRF into mouse lung fibroblasts and performed a cDNA array analysis. High SRF level upregulated the expression of matrix metalloproteinase (MMP)-2 and MMP-14, two MMPs previously shown to be increased in LAM. In addition, SRF down-regulated tissue inhibitor of metalloproteinase (TIMP)-3, one of their inhibitors. TIMP-3 inhibition was further confirmed by reverse transcriptase/polymerase chain reaction, immunoblotting, and immunostaining of human lung fibroblasts transfected with SRF fused to DsRed2 (a red variant of green fluorescent protein). To determine the in vivo significance of our findings, we immunostained 12 LAM cases for TIMP-3. In eight of them, TIMP-3 was ubiquitously present in normal lung parenchyma, but it was absent in LAM lesions. In the remaining cases, including two out of five normal control lungs, the antibody immunoreacted exclusively with elastin, probably due to suboptimal tissue processing. Because timp-3-null mice develop spontaneous emphysema, our findings suggest that SRF-mediated TIMP-3 inhibition might contribute to the tissue damage seen in LAM.
...
PMID:Tissue inhibitor of metalloproteinase-3 downregulation in lymphangioleiomyomatosis: potential consequence of abnormal serum response factor expression. 1270 9

The aim of this study was to evaluate the effect of estrogen on matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, and tissue inhibitor of metalloproteinase (TIMP)-1 in osteoarthritic chondrocytes. Chondrocytes from the knee cartilage of 25 postmenopausal osteoarthritic (OA) patients were cultured under various conditions: 0 pg/mL, 50 pg/mL, 500 pg/mL, and 5,000 pg/mL of 17beta-estradiol, with or without 10-1,000 pg/mL of either interleukin (IL)-1beta or tumor necrosis factor alpha (TNFalpha). MMP-1, MMP-3, MMP-13, and TIMP-1 in the conditioned media were analyzed with immunoblot or enzyme-linked immunosorbent assay (ELISA). Type II collagenolytic activity was measured by fluorogenic type II collagenolytic activity assay. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) using SYBR Green I dye was performed for the quantification of mRNA. Without cytokine stimulation, the secretion of MMP-1 was significantly reduced by 50 pg/mL of 17beta-estradiol (in immunoblot by a median of 12.3%, P=0.007; in ELISA by a median of 18.4%, P=0.001), and 500 pg/mL (in immunoblot by a median of 23.1%, P=0.001; in ELISA by a median of 21.0%, P=0.001). Additionally, under 10 pg/mL TNFalpha, 17beta-estradiol also significantly suppressed the secretion of MMP-1 (in immunoblot by a median of 39.0%, P=0.016; in ELISA by a median of 38.4%, P=0.041). Estrogen did not exert any significant effect on MMP-3, MMP-13, or TIMP-1 expression. With IL-1beta or TNFalpha above 10 pg/mL stimulation, 17beta-estradiol demonstrated no effect on MMP-1, MMP-3, MMP-13, or TIMP-1 secretion. Type II collagenolytic activity in the 50 pg/mL estradiol group decreased by 9.6% (-51.5-5.5%, P>0.05). 17beta-estradiol showed a tendency to decrease in MMP-1 mRNA. Estrogen may improve the imbalance between the amounts of MMPs and TIMP in chondrocytes, and these results suggest that hormone replacement therapy may provide some chondroprotective effect.
...
PMID:Effect of estrogen on the expression of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 and tissue inhibitor of metalloproternase-1 in osteoarthritis chondrocytes. 1268 36

Abdominal aortic aneurysm (AAA) is characterized by chronic aortic wall inflammation and loss of matrix components. Proinflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) are thought to be involved in this inflammatory process and, therefore, to play an important role in the pathogenesis of human AAA. TNF-alpha-converting enzyme (TACE) has recently been purified and cloned as a disintegrin and metalloproteinase that converts TNF-alpha precursor into its mature form. The aim of the present study was to determine whether TNF-alpha and TACE were expressed and localized in aortic tissues in human AAA. Infrarenal aortic tissues were obtained from AAA patients (n=19) undergoing elective aneurysm reconstruction and from autopsy cases without cardiovascular disorders as normal controls (n=5). Internal thoracic artery samples were also obtained from patients with coronary artery disease undergoing coronary artery bypass grafting to represent biopsied conduit vessels (n=5). The AAA specimens were taken from the mid-portion of the aneurysm and from the longitudinal transition zone between the non-dilated aorta and the proximal aspect of the aneurysm. TNF-alpha and TACE mRNA levels were determined by real-time quantitative reverse transcriptase-PCR. Expression levels of both TNF-alpha mRNA and TACE mRNA were significantly greater in the transition zone than in the mid-portion (both P<0.05). Expression levels of both forms of mRNA were significantly higher in AAA samples than in control aortas or atherosclerotic arteries. There was a significant correlation between the expression of TNF-alpha mRNA with that of TACE mRNA in AAA (r=0.54, P<0.005). Immunostaining was positive for both TNF-alpha and TACE in CD68-positive macrophages in the media and adventitia obtained from the transition zone in AAA, whereas neither TNF-alpha nor TACE was expressed in control vessels. In conclusion, the concomitant activation and localization of TNF-alpha and TACE in the media and adventitia of the transition zone in human AAA underlines the importance of this system in the pathogenesis of this disorder.
...
PMID:Expression and localization of tumour necrosis factor-alpha and its converting enzyme in human abdominal aortic aneurysm. 1458 Feb 34

The expression and activation of matrix metalloproteinases (MMPs) by tumor cells is correlated with progression to invasive and metastatic status. The purpose of this study was to examine the role of increased MMP-2 (gelatinase A) expression in prostate cancer progression utilizing human prostate PC-3 cancer cells that overexpress MMP-2 using gene transfection. PC-3 cells were transfected with pCR-3 vector only and pCR-3 MMP-2 plasmids employing the LipofectAMINE method, and stable transfectants were selected with G418. The expression of MMP-2, tissue inhibitor of metalloproteinase-2 (TIMP-2), and membrane-type MMP 1 (MT1-MMP) in PC-3 parental and transfected cells under serum-free conditions was determined by zymography, immunoblotting, immunofluorescent microscopy, Northern blotting, and/or reverse transcriptase-polymerase chain reaction (RT-PCR). MMP-2 transfected cells produced primarily the proenzyme form of MMP-2; the parental and vector control transfected PC-3 cells did not express any MMP-2 that was detectable by the methods we employed. Treatment of PC-3 MMP-2 transfected cells with Concanavalin A (Con A), in contrast to HT-1080 cells, processed only a small amount of the secreted 72-kd proenzyme to a 62-kd intermediate and a cell-associated 59-kd active form. The low level of secreted pro-MMP-2 processing induced by Con A was inhibited by serine protease inhibitors and was unaffected by cyclic adenosine monophosphate (cAMP). Immunoblotting showed that these cells produced abundant TIMP-2 and lower amounts of MT1-MMP in comparison with Con A-responding HT-1080 cells. HT-1080 cells respond to Con A by translocating MT1-MMP from intracellular localization sites to the plasma membrane, an effect not observed in PC-3 cells. The molecular basis for the low level of processing of pro-MMP-2 by PC-3 cells may be due to an overabundance of TIMP-2 and/or a low level of cell surface active MT1-MMP.
...
PMID:Limited processing of pro-matrix metalloprotease-2 (gelatinase A) overexpressed by transfection in PC-3 human prostate tumor cells: association with restricted cell surface localization of membrane-type matrix metalloproteinase-1. 1476 14

Hepatic stellate cells (HSCs) were changed in their morphology, proliferative activity, and functions by culturing on type I collagen gel, as compared to the culture on polystyrene surface. HSCs have been found to produce extracellular matrix components and matrix metalloproteinases (MMPs). In this study, we have assessed the effects of several types of substrata on the expression of MMPs in HSC culture. MMP-1 expression was detectable in HSC culture on polystyrene surface and on type I collagen gel by immunofluorescence staining and reverse transcriptase-polymerase chain reaction (RT-PCR). The results from in situ zymography revealed the presence of interstitial collagenase activity around HSCs and along their cellular processes. Although proMMP-2 and proMMP-9 were detectable by gelatin zymography in the conditioned medium from both cultures using type I collagen gel and Matrigel as substratum, an active form of MMP-2 but not of MMP-9 was detected only in the culture using type I collagen as a substratum. Tissue inhibitor of metalloproteinase-2 expression was observed by RT-PCR in HSCs cultured on or in type I collagen gel, suggesting the suppression of MMP-2 activity detected in HSC culture using type I collagen. These results indicate a differential expression of MMP activity, hence the remodeling of extracellular matrix components is dependent on the substratum used for HSC culture. The HSC culture using several types of substrata appears to be a useful in vitro model to study the mechanism of extracellular matrix remodeling.
...
PMID:Regulatory role of extracellular matrix components in expression of matrix metalloproteinases in cultured hepatic stellate cells. 1521 80

Carnosol, a constant constituent of Rosmarinus officinalis extracts, is a phenolic diterpene shown to have antioxidant and anticarcinogen properties. In our studies, carnosol inhibited the invasion of highly metastatic mouse melanoma B16/F10 cells in vitro. First, the antimetastatic potentials of carnosol were examined by soft agar colony formation assay. Second, carnosol dose-dependently inhibited B16/F10 cell migration and invasion by in vitro transwell assay. Third, the decreasing activity of metalloproteinase was observed by zymographic assay. The result revealed that the treatment of carnosol could diminish the activity of MMP-9 more than MMP-2. Next, we analyzed the amounts of MMP-9 and MMP-2 proteins in the cells. The data indicated MMP-9 protein was also suppressed by carnosol in the same manner. In accordance with the above data, the results of reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed a reduced level of MMP-9 mRNA. Furthermore, carnosol significantly inhibited the tyrosine phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, AKT, p38, JNK and inhibition of activation of transcription factors NFkappa-B and c-Jun. These results lead us to conclude that carnosol could restrict the invasive ability of B16/F10 mouse melanoma cells by reducing MMP-9 expression and activity through suppressing (ERK) 1/2, AKT, p38, and JNK signaling pathway and inhibition of NF-kappaB and AP-1 binding activity. Taken together, these results indicate that carnosol targets MMP-mediated cellular events in cancer cells and provides a new mechanism for its anticancer activity.
...
PMID:Carnosol inhibits the invasion of B16/F10 mouse melanoma cells by suppressing metalloproteinase-9 through down-regulating nuclear factor-kappa B and c-Jun. 1562 74


<< Previous 1 2 3 4 Next >>

---