OBJECTIVETo study the relationship between atrial structural remodeling and the expressions of matrix metalloproteinase (MMPs) and their tissue inhibitors (TIMPs) in atrial fibrillation (AF).

METHODSBiopsy samples of the right atrial appendages were collected from 20 patients with sinus rhythm and 30 with AF undergoing heart valve replacement surgery for rheumatic heart diseases. All the patients received echocardiographic examination preoperatively. MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 protein expressions were detected by immunohistochemistry and RT-PCR.

RESULTSCompared with those in patients with sinus rhythm, the AF patients had significantly increased left and right atrial diameters and mRNA levels of MMP-3, -7, -9 and TIMP-1, -2, -3, -4 (P<0.01). MMP-1 expression also showed an increase in AF patients, but the difference was no statistically significant from that in patients with sinus rhythm.

CONCLUSIONThe expressions of MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 increase in fibrillating atrial tissue, which may contribute to atrial structural remodeling and atrial dilatation in AF patients.

Adult ; Aged ; Atrial Fibrillation ; enzymology ; pathology ; physiopathology ; Female ; Humans ; Male ; Matrix Metalloproteinases ; genetics ; metabolism ; Middle Aged ; Tissue Inhibitor of Metalloproteinases ; genetics ; metabolism

AIMThe changes of tissue inhibitor of metalloproteinase-4 (TIMP-4) expression in mouse ovary during pregnant and postpartum period were studied to investigate the role of TIMP-4 in corpus luteum (CL).

METHODSRT-PCR was used to deter mine the change of TIMP-4 mRNA and indirect immunofluorescence was used to observe the change of TIMP-4 protein. The expression of TIMP-4 mRNA was observed in various periods throughout the stage of pregnancy and postpartum day 1.

RESULTSThe expression of TIMP-4 was gradually enhanced from day 1 to day 8, reached a maximal expression at day 8, while decreased at day 11 and to the lowest level at postpartum day 1. Indirect immunofluorescence results further indicated that TIMP-4 protein was localized to CL and theca-intera cells in various periods throughout the pregnancy and postpartum day 1. In addition, the change pattern of TIMP-4 protein agreed with that of the TIMP-4 mRNA in pregnancy CL.

CONCLUSIONThe expression of TIMP-4 in mouse ovary during pregnancy and postpartum is in spatio-temporal pattern and it may be involved in the formation and function maintain of CL during pregnancy in mice.

Animals ; Female ; Mice ; Mice, Inbred Strains ; Ovary ; metabolism ; Postpartum Period ; Pregnancy ; RNA, Messenger ; genetics ; Tissue Inhibitor of Metalloproteinases ; metabolism

Hepatic fibrogenesis, a complex process that involves a marked accumulation of extracellular matrix components, activation of cells capable of producing matrix materials, cytokine release, and tissue remodeling, is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The MMP-TIMP balance can regulate liver fibrogenesis. The aim of this study was to evaluate the expression patterns of MMPs and TIMPs during thioacetamide (TAA)-induced liver fibrogenesis. Chronic liver injury was induced with TAA (200 mg/kg i.p.) for 4 or 7 weeks in male Sprague-Dawley rats. Hepatic injury and fibrosis were assessed by hematoxylin-eosin (H&E) staining, and collagen deposition was confirmed by Sirius Red staining. The level of hepatic injury was quantified by serological analysis. The transcriptional and translational levels of alpha-smooth muscle actin (alpha-SMA), MMPs, and TIMPs in the liver were measured by Western blotting, RT-PCR, and immunohistochemistry. MMP, TIMP, and alpha-SMA were observed along fibrotic septa and portal spaces around the lobules. TAA treatment increased transcription of both MMPs and TIMPs, but only TIMPs showed increased translation. The dominant expression of TIMPs may regulate the function of MMPs to maintain liver fibrosis induced by TAA.
Animals ; Collagen/metabolism ; Extracellular Matrix/chemistry/metabolism ; *Liver Cirrhosis/chemically induced/metabolism/pathology ; Male ; Matrix Metalloproteinases/genetics/*metabolism ; Rats ; Rats, Sprague-Dawley ; Thioacetamide/*toxicity ; Tissue Inhibitor of Metalloproteinases/genetics/*metabolism

OBJECTIVETo determine the molecular mechanisms involved in atrial fibrosis which occurs in patients with atrial fibrillation (AF) and to investigate their effects on the initiation and maintenance of AF.

METHODSThe right atrial tissue samples were taken from 73 patients with rheumatic heart disease who underwent heart valve replacement surgery. 34 patients had no history of AF (sinus rhythm group), 9 patients had paroxysmal AF and 30 patients had persistent AF. The mRNA content of collagen type I, collagen type III, MMP-2, TIMP-1, TIMP-2, TIMP-3 and TIMP-4 was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and normalized to beta-actin or GAPDH.

RESULTSCompared to sinus rhythm group, the mRNA of collagen type I and MMP-2 increased significantly in the persistent AF group (all, P < 0.01), followed by the paroxysmal AF group (all, P < 0.05). The mRNA of collagen type III was slightly higher in both AF groups than in the sinus rhythm group, but the differences were not statistically significant (P > 0.05). The mRNA of TIMP-1, TIMP-2 and TIMP-3 was down-regulated in the persistent AF group (all, P < 0.01, respectively), however, the trends of reduction did not reach statistical significance in the paroxysmal AF group (P > 0.05). The mRNA of TIMP-4 remained compatible in each group. The mRNA of collagen type I was significantly correlated with left atrial dimension (r = 0.336, P = 0.004) and AF duration (r = 0.339, P = 0.003). The mRNA of MMP-2 was significantly correlated with the mRNA of TIMP-2 (r = -0.326, P = 0.006), the mRNA of collagen type I (r = 0.322, P = 0.006), left atrial dimension (r = 0.300, P = 0.011) and AF duration (r = 0.300, P = 0.010).

CONCLUSIONThe increased level of collagen type I associated with selective downregulation of TIMP-2 and upregulation of MMP-2 gene expression in atrium could be one of the molecular mechanisms of atrial fibrosis during atrial fibrillation, which correlates with the initiation and maintenance of AF.

Adolescent ; Adult ; Atrial Fibrillation ; metabolism ; pathology ; Collagen Type I ; genetics ; Female ; Fibrosis ; Humans ; Male ; Matrix Metalloproteinase 2 ; genetics ; Middle Aged ; Myocardium ; pathology ; RNA, Messenger ; analysis ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; Tissue Inhibitor of Metalloproteinases ; genetics

OBJECTIVETo study the relationship between activation of pro-MMP-2 and expression of matrix metalloproteinases (MMP)-2, MT1-MMP and tissue inhibitor of metalloproteinases (TIMP)-2 mRNA in thymoma and thymic carcinoma; and to study the molecular mechanism of invasion and metastasis of thymic epithelial tumors.

METHODSFresh tissue specimens of thymoma, thymic carcinoma and normal thymus were included. The mRNA expression of MMP-2, MT1-MMP and TIMP-2 were analyzed by real-time reverse transcription polymerase chain reaction. The pro-MMP-2 activation ratio and its localization were determined by gelatin zymography and film in-situ gelatin-Zymography, respectively. Correlation of mRNA expression of MMP-2, MT1-MMP and TIMP-2 was investigated in tumors with different histological subtypes and clinical stages.

RESULTSThere were no significant differences in the expressions of MMP-2, MT1-MMP and TIMP-2 mRNA between I and II stage or III and IV stage thymomas (P > 0.05). However, significant differences of the expressions were observed between three tumor groups: I-II stage, III-IV stage and thymic carcinomas (P < 0.005), and between three histological subtypes: AB-B1 (lymphocyte-rich and mixed types), B2-B3 (cortical and predominantly polygonal cells types) and thymic carcinomas (P < 0.05). Expression levels of MT1-MMP and TIMP-2 mRNA were correlated with pro-MMP-2 activation ratio (Spearman rank correlation: r = 0.7235, r = 0.7647, P < 0.005). The expression of MMP-9 did not show significant differences between thymomas and thymic carcinomas.

CONCLUSIONSMMP-2, MT1-MMP and TIMP-2 mRNA expression levels are correlated with the histologic subtypes and clinical stages of thymoma. The mRNA expressions of MT1-MMP and TIMP-2 are correlated with the activation ratio of pro-MMP-2. It is speculated that upregulation of MT1-MMP gene expression may induce an activation of pro-MMP-2 through TIMP-2.

Adult ; Aged ; Aged, 80 and over ; Carcinoma, Squamous Cell ; enzymology ; metabolism ; pathology ; Enzyme Activation ; Female ; Humans ; Male ; Matrix Metalloproteinase 2 ; biosynthesis ; genetics ; Matrix Metalloproteinases ; biosynthesis ; genetics ; Matrix Metalloproteinases, Membrane-Associated ; Middle Aged ; Neoplasm Staging ; RNA, Messenger ; biosynthesis ; genetics ; Thymoma ; classification ; enzymology ; metabolism ; pathology ; Thymus Gland ; enzymology ; metabolism ; Thymus Neoplasms ; classification ; enzymology ; metabolism ; pathology ; Tissue Inhibitor of Metalloproteinase-2 ; biosynthesis ; genetics

OBJECTIVETo observe P38 mitogen-activated protein kinase (P38 MAPK) and matrix metalloproteinase-2 (MMP-2) mRNA expression level changes in neonatal rats with hyperoxia-induced lung injury,and to investigate the influence of P38 MAPK activation on MMP-2 mRNA expression.

METHODSThirty-six Sprague-Dawley (SD) rats were randomly divided into three groups: air control, hyperoxia and SB203580-treated hyperoxia (n=12). The rats were sacrificed on the 3rd and 7th days and the lungs were removed. Hematoxylin-eosine staining was used to observe the pathological changes in lung tissues.

RESULTSCompared with the air and SB203580-treated groups, levels of P38 MAPK and MMP-2 mRNA significantly increased in the hyperoxia group (P<0.01).

CONCLUSIONSExpression of P38 MAPK increases in neonatal rats with hyperoxia-induced acute lung injury and this may play a role in control of the expression of MMP-2 mRNA.

Animals ; Animals, Newborn ; Female ; Hyperoxia ; complications ; Lung ; pathology ; Lung Injury ; metabolism ; Male ; Matrix Metalloproteinase 2 ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Tissue Inhibitor of Metalloproteinases ; genetics ; p38 Mitogen-Activated Protein Kinases ; metabolism

We investigated the expression of membrane type-1 (MT1)-MMP, MMP2, MMP9 and TIMP2 mRNAs and their roles in ductal carcinoma in situ (DCIS) and T1 and T2 invasive ductal carcinoma of the breast. We further compared these two types of carcinomas for differences in microvessel density, and expression of angiogenic factors and CD44std. MT1-MMP, MMP2, MMP9 and TIMP2 mRNA were expressed in both DCIS and invasive ductal carcinomas. Expression rates of MT1-MMP, MMP2, MMP9 and TIMP2 mRNAs were not statistically different between DCIS and invasive ductal carcinomas, nor did they differ statistically when grouped by tumor size, histologic grade or nuclear grade of invasive ductal carcinoma. Microvessel density and expression of VEGF and TGF-beta were not statistically different between DCIS and invasive ductal carcinoma. CD44std expression was significantly increased in DCIS compared to invasive ductal carcinoma (p < 0.05) and it was also significantly increased in lower clinical stage, histologic grade and nuclear grade of invasive ductal carcinoma (p < 0.05). Axillary node metastasis was significantly correlated with MT1-MMP mRNA, VEGF and TGF-beta expression (p < 0.05) and MT1-MMP mRNA was positively correlated with VEGF expression and TIMP2 mRNA (p < 0.05). In summary, patterns of MMP mRNA expression in DCIS and invasive ductal carcinoma suggest that the invasive potential of breast carcinoma is already achieved before morphologically overt invasive growth is observed. As MT1-MMP mRNA expression is significantly correlated with axillary nodal metastasis, it may be useful as a prognostic indicator of invasive ductal carcinoma. Considering the positive correlation of MT1-MMP mRNA and TIMP2mRNA expression, our finding supports a role for TIMP2 in tumor growth, as well as the utility of CD44std as a prognostic indicator of breast cancer.
Tissue Inhibitor of Metalloproteinase-2/genetics ; RNA, Messenger/metabolism ; Matrix Metalloproteinases, Membrane-Associated ; Matrix Metalloproteinases/*genetics ; Matrix Metalloproteinase 9/genetics ; Matrix Metalloproteinase 2/genetics ; Matrix Metalloproteinase 1/genetics ; Humans ; Gene Expression Regulation, Neoplastic ; Gene Expression Regulation, Enzymologic ; Female ; Carcinoma, Ductal, Breast/genetics/*physiopathology ; Carcinoma in Situ/genetics/*physiopathology ; Breast Neoplasms/genetics/*physiopathology

We investigated the expression of membrane type-1 (MT1)-MMP, MMP2, MMP9 and TIMP2 mRNAs and their roles in ductal carcinoma in situ (DCIS) and T1 and T2 invasive ductal carcinoma of the breast. We further compared these two types of carcinomas for differences in microvessel density, and expression of angiogenic factors and CD44std. MT1-MMP, MMP2, MMP9 and TIMP2 mRNA were expressed in both DCIS and invasive ductal carcinomas. Expression rates of MT1-MMP, MMP2, MMP9 and TIMP2 mRNAs were not statistically different between DCIS and invasive ductal carcinomas, nor did they differ statistically when grouped by tumor size, histologic grade or nuclear grade of invasive ductal carcinoma. Microvessel density and expression of VEGF and TGF-beta were not statistically different between DCIS and invasive ductal carcinoma. CD44std expression was significantly increased in DCIS compared to invasive ductal carcinoma (p < 0.05) and it was also significantly increased in lower clinical stage, histologic grade and nuclear grade of invasive ductal carcinoma (p < 0.05). Axillary node metastasis was significantly correlated with MT1-MMP mRNA, VEGF and TGF-beta expression (p < 0.05) and MT1-MMP mRNA was positively correlated with VEGF expression and TIMP2 mRNA (p < 0.05). In summary, patterns of MMP mRNA expression in DCIS and invasive ductal carcinoma suggest that the invasive potential of breast carcinoma is already achieved before morphologically overt invasive growth is observed. As MT1-MMP mRNA expression is significantly correlated with axillary nodal metastasis, it may be useful as a prognostic indicator of invasive ductal carcinoma. Considering the positive correlation of MT1-MMP mRNA and TIMP2mRNA expression, our finding supports a role for TIMP2 in tumor growth, as well as the utility of CD44std as a prognostic indicator of breast cancer.
Tissue Inhibitor of Metalloproteinase-2/genetics ; RNA, Messenger/metabolism ; Matrix Metalloproteinases, Membrane-Associated ; Matrix Metalloproteinases/*genetics ; Matrix Metalloproteinase 9/genetics ; Matrix Metalloproteinase 2/genetics ; Matrix Metalloproteinase 1/genetics ; Humans ; Gene Expression Regulation, Neoplastic ; Gene Expression Regulation, Enzymologic ; Female ; Carcinoma, Ductal, Breast/genetics/*physiopathology ; Carcinoma in Situ/genetics/*physiopathology ; Breast Neoplasms/genetics/*physiopathology

OBJECTIVETo compare the effects of matrix metalloproteinase (MMP) inhibitor doxycycline, losartan, and their combination on the expression of MMP-8, 13, tissue inhibitor of MMP-1, 2 (TIMP-1, 2), and collagen remodeling in the noninfarcted myocardium after acute myocardial infarction (AMI) in rats.

METHODSTwo hundred and fifty-four AMI rats, induced by left coronary ligation, were randomly assigned to the following groups: (1) AMI controls group (n = 64); (2) doxycycline group (30 mg x kg(-1) x d(-1), n = 63); (3) losartan group (10 mg x kg(-1) x d(-1), n = 62); (4) concomitant doxycycline and losartan group (30 and 10 mg x kg(-1) x d(-1) respectively, n = 65); and (5) Sham-operated rats (n = 30), which were randomly selected to serve as noninfarction controls. Each group was further divided into three subgroups of 1, 2, and 4 weeks that received treatment. After the completion of treatment, the rats were killed. The mRNA and protein expression of MMPs and TIMPs in the noninfarcted myocardium were quantified by RT-PCR and Western blot, respectively. The type I and type III collagen volume fraction (CVF) of the noninfarced myocardium were assessed immunohistochemically.

RESULTSNo significant difference existed in myocardial infarction sizes among the 12 subgroups of AMI controls and the three treatment groups (42%-48%, all P > 0.05). Compared with sham operated rats, the mRNA and protein expression of MMP-8 and 13 significantly increased by 39%-183% in all three subgroups of AMI controls (all P < 0.05), except both of their mRNA expressions in 2-week subgroups; the mRNA and protein levels of TIMP-1 increased only in 1-week subgroup of AMI controls by 104% and 67%, respectively (both P < 0.05); the mRNA of TIMP-2 increased in all 1, 2, and 4-week subgroups by 144%-232% (all P < 0.05), but its protein expression lagged and only enhanced in 2 and 4-week subgroups of AMI controls by 231% and 332%, respectively (both P < 0.05). Meanwhile, both type I and type III CVF of noninfarcted myocardium significantly increased in all three subgroups of AMI controls (type I CVF: 3.01%-5.64% vs 1.53%-1.67%, P < 0.01-0.001; type III CVF: 2.19%-4.42% vs 1.46%-1.59%, P < 0.05-0.001), with type I CVF being higher in 4-week than in 1 and 2-week subgroups (5.64% vs 3.01% and 3.02% respectively, all P < 0.05). Compared with AMI controls, all three kinds of treatment significantly reduced the increased mRNA and protein expressions of MMP-8, 13 and TIMP-1, 2 after AMI by 14%-60% (all P < 0.05), as well as type I/III CVF in their 2 and 4-week subgroups (type I CVF: 1.56%-2.38% vs 3.02%-5.64%, P < 0.05-0.001; type III CVF: 1.92%-2.65% vs 4.19%-4.42%, P < 0.05-0.01), except for doxycycline's effect on type III CVF in any of its three subgroups (all P > 0.05). Among the three treatment groups, significant differences existed in the above mentioned indicators only at some subgroup levels (all P < 0.05).

CONCLUSIONSLike losartan, doxycycline can also suppress the enhanced mRNA and protein expression of MMP-8, 13 and TIMP-1, 2, and reduce type I collagen deposition in the noninfarcted myocardium after AMI in rats. However, it has no effect on type III collagen deposition.

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Collagen Type I ; biosynthesis ; genetics ; Collagenases ; biosynthesis ; genetics ; Doxycycline ; pharmacology ; Drug Synergism ; Female ; Losartan ; pharmacology ; Matrix Metalloproteinase 13 ; Matrix Metalloproteinase 8 ; biosynthesis ; genetics ; Matrix Metalloproteinase Inhibitors ; Myocardial Infarction ; metabolism ; Myocardium ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tissue Inhibitor of Metalloproteinase-1 ; biosynthesis ; genetics ; Tissue Inhibitor of Metalloproteinase-2 ; biosynthesis ; genetics ; Tissue Inhibitor of Metalloproteinases ; biosynthesis ; genetics

This study evaluated the effects of glucose in human retinal pigment epithelial (RPE) cells to investigate the cause of diabetic retinal complications. Human RPE cells were cultured in media containing 5.5 mM, 11.0 mM, and 16.5 mM D-glucose. The present study performed proliferation and migration assays, and conducted western blotting for the protein expression, as well as RT-PCR for the mRNA expression, of MMP-2 and -9, and TIMP-1 and -2. The results of the western blotting analysis showed that increasing glucose concentration significantly increased the expression of MMP-2 and -9, but significantly decreased the expression of TIMP-1 and -2. Moreover, the RT-PCR results indicated significant increases in the mRNA expression of MMP-2 and -9, as well as of TIMP-1 and -2, by raising glucose concentration. This study provides fundamental data for future research on the mechanism of retinal complication in diabetic patients.
Blotting, Western ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; Comparative Study ; Dose-Response Relationship, Drug ; Glucose/*pharmacology ; Humans ; In Vitro ; Matrix Metalloproteinases/genetics/*metabolism ; Pigment Epithelium of Eye/*drug effects/enzymology ; RNA, Messenger/metabolism ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors ; Tissue Inhibitor of Metalloproteinases/genetics/*metabolism