[Expression of tissue inhibitor of metalloproteinase-2 in nasopharyngeal carcinoma]

OBJECTIVE

To study the expression of tissue inhibitor of matrix metalloproteinase 2 (TIMP2)in the nasopharyngeal carcinoma and to evaluate the relationships between the expression of TIMP2 and biological behavior of NPC.

METHOD

The expression of TIMP2 was observed by immunohistochemical technique in 50 cases with nasopharyngeal carcinoma and 15 cases of Inflammation nasopharyngeal tissues.

RESULT

The positive rates of TIMP2 are significantly higher in NPC than in Inflammation tissues (P < 0.05). The expression of TIMP2 increase significantly with lymph node metastasis (P < 0.01), but had no relevant to the rise clinical invasion stage (P > 0.05).

CONCLUSION

The results indicate that TIMP2 may play a critical role in assisting carcinoma cell to degrade basement membrane to invade surrounding tissues and to form metastatic colonies in lymph node. Especially the unbalance in MMP2/TIMP2 has probably a prognostic value in nasopharyngeal carcinoma.

Estrogen improves TIMP-MMP balance and collagen distribution in volume-overloaded hearts of ovariectomized females

Our previous studies demonstrate that 17beta-estradiol limits chronic volume overload-induced hypertrophy and improves heart function in ovariectomized rats. One possible cardioprotective mechanism involves the interaction between estrogen, estrogen receptors, and proteins of the extracellular matrix (ECM). The impact of estrogen deficiency and replacement on left ventricular (LV) hypertrophy and ECM protein expression was studied using five female rat groups: intact sham-operated, ovariectomized sham-operated, intact with volume overload, ovariectomized with volume overload, and ovariectomized with volume overload treated with estrogen. After 8 wk, LV protein extracts were evaluated by Western blot analysis for matrix metalloproteinase-2 (MMP-2) and MMP-9, MT1-MMP, tissue inhibitors of MMPs (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4, collagens type I and III, and estrogen receptor alpha and beta expression. MMP proteolytic activity was assessed by zymography. All volume-overloaded groups exhibited LV hypertrophy, which was associated with a loss of interstitial collagen and perivascular fibrosis. After 8 wk of volume overload, 70% of ovariectomized rats developed heart failure, in contrast to only one intact rat. A downregulation of MMP-2, estrogen receptor-alpha (ERalpha), and ERbeta, and upregulation of MMP-9 and MT1-MMP were found in the volume-overloaded hearts of ovariectomized rats. Estrogen treatment improved TIMP-2/MMP-2 and TIMP-1/MMP-9 protein balance, restored ERalpha expression, and prevented MMP-9 activation, perivascular collagen accumulation and development of heart failure. However, estrogen did not fully restore ERbeta expression and did not prevent the increase of MMP-9 expression or loss of interstitial collagen. These results support that estrogen limits undesirable ECM remodeling and LV dilation, in part, through modulation of ECM protein expression in volume-overloaded hearts of ovariectomized rats.

[Observation of the antitumor effect of endostar combined with docetaxel under different administration sequences]

OBJECTIVE

To observe and analyze the antitumor effect of endostar combined with docetaxel under different administration sequences.

METHODS

Nude mice with xenograft tumor (A549 cell line) were randomized into 3 groups, 8 mice/group: (1) Concurrent administration group (each mouse: endostar 400 µg/d, d1-d35, docetaxel 10 mg/kg, every 3 days, d1-d19); (2) Endo-first group (each mouse: endostar 400 µg/d, d1-d35, docetaxel 10 mg/kg, every 3 days, d16-d34); (3) Model group (positive control, tumor-bearing mice without treatment, each mouse: physiological saline, 100 µl/d, d1-d35, water for injection, 200 µl/d, d1-d35, every 3 days), and blank control group (negative control, normal mice without treatment, 8 mice), the administration method was the same to the model group. The volume of tumor and the weight of mouse were measured during treatment. Circulating endothelial cells (CECs) were detected by flowcytometry, and the expression of matrix metalloproteinase (MMP-2, MMP-9), the tissue inhibitor of MMP (TIMP-1, TIMP-2), the extracellular MMP inducer (EMMPRIN), CD34, α-smooth muscle actin (α-SMA) were determined by immunohistochemistry.

RESULTS

The tumor growth of concurrent administration group (39.94 mm(3)) was lower than that of the endo-first group [(99.57 ± 74.48) mm(3)] during treatment, both of them were smaller than that of the model group [(217.67 ± 95.44) mm(3), P < 0.05]. The amount of CECs in the endo-first group [(77.25 ± 24.02) cells/10(4) cells] was more than that of the concurrent administration group [(25.86 ± 11.77) cells/10(4) cells], the model group [(14.71 ± 11.07) cells/10(4) cells], and the blank control group [(12.90 ± 11.20) cells/10(4) cells, P < 0.01]. The expression of MMPs in the treatment groups was obviously downregulated. The expressions of TIMP-1 in the endo-first group and TIMP-2 in the concurrent administration group were upregulated (P < 0.05). The expression of EMMPRIN was significantly down-regulated in the concurrent administration group (P < 0.05). The MVD and α-SMA expressions of the treatment groups were less than that of the model group (P < 0.05).

CONCLUSION

In comparison with the endo-first group, the anti-tumor effect and survival quality of the concurrent administration group are better. Both of the administration groups may have "vascular normalization effect" by down-regulating MMPs expression through different points, and inhibit the cancer-induced stromal reaction, restraining the cancer progress to a certain extent. The changes of CECs should be a dynamic process with an initial rise in the early-stage suggesting the decrease of vascular bed and subsequent decline ascribed to apoptosis of CECs and the tumor-regression after combined therapy. Investigation of its dynamic changes may be helpful to know the change of tumor burden and vascular bed and predict the antitumor effect.

A comparison of vascular effects from complex and individual air pollutants indicates a role for monoxide gases and volatile hydrocarbons

BACKGROUND

Emerging evidence suggests that the systemic vasculature may be a target of inhaled pollutants of vehicular origin. We have identified several murine markers of vascular toxicity that appear sensitive to inhalation exposures to combustion emissions.

OBJECTIVE

We sought to examine the relative impact of various pollutant atmospheres and specific individual components on these markers of altered vascular transcription and lipid peroxidation.

METHODS

Apolipoprotein E knockout (ApoE(-/-)) mice were exposed to whole combustion emissions (gasoline, diesel, coal, hardwood), biogenically derived secondary organic aerosols (SOAs), or prominent combustion-source gases [nitric oxide (NO), NO(2), carbon monoxide (CO)] for 6 hr/day for 7 days. Aortas were assayed for transcriptional alterations of endothelin-1 (ET-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2), and heme oxygenase-1 (HO-1), along with measures of vascular lipid peroxides (LPOs) and gelatinase activity.

RESULTS

We noted transcriptional alterations with exposures to gasoline and diesel emissions. Interestingly, ET-1 and MMP-9 transcriptional effects could be recreated by exposure to CO and NO, but not NO(2) or SOAs. Gelatinase activity aligned with levels of volatile hydrocarbons and also monoxide gases. Neither gases nor particles induced vascular LPO despite potent effects from whole vehicular emissions.

CONCLUSIONS

In this head-to-head comparison of the effects of several pollutants and pollutant mixtures, we found an important contribution to vascular toxicity from readily bioavailable monoxide gases and possibly from volatile hydrocarbons. These data support a role for traffic-related pollutants in driving cardiopulmonary morbidity and mortality.

[Inhibitory effect on estrogen production and its influence on invasive ability of human endometrial cells of endometriosis by medicated serum of SLW]

OBJECTIVE

To study the inhibitory effect of medicated serum of SLW on estrogen production and to approach on the key mechanism of SLW in inhibiting the invasion ability of endometrial cells of endometriosis.

METHOD

First, the model of eutopic primary cultured endometrial cells of endometriosis and hysteromyoma in vitro was successfully established. Taking that of endometrial cells of hysteromyoma as control, the secretion level of E2 of endometrial cells in the culture media supernatant at different time point with the treatment of high, middle and low dose of SLW serum was detected by electrochemiluminescence immunoassay, the activities of matrix metalloproteinase-2, 9 (MMP-2, 9) were detected by gelatinase zymography assay, and the expression of tissue inhibitor of metalloproteinase-1, 2 (TIMP-1, 2) protein was observed by immunofluorescence. After the optimal time for SLW to inhibit invasion ability of endometrial cells was identified based on time-effect relationship, another endometrial cells were divided into six groups: hysteromyoma endometrium group, eutopic endometrium of endometriosis group, eutopic endometrium of endometriosis + middle dose of SLW serum group, eutopic endometrium of endometriosis + middle dose of SLW serum + E2 group, eutopic endometrium of endometriosis + anastrozole serum group , and eutopic endometrium of endometriosis + E2 group. The activities of MMP-2, 9 and the expression of TIMP-1, 2 protein were detected according to the optimal time point.

RESULT

The secretion level of E2 of eutopic endometrium in endometriosis could be decreased by SLW, which showed the dependence of time and concentration. The result of gelatinase zymography assay and immunofluorescence respectively showed that along with the time the activities of MMP-2, 9 of eutopic endometrial cells of endometriosis were significantly higher than those of hysteromyoma at the same time point (P < 0.01). After 48 hours, with the treatment of middle dose of SLW serum, the activities of MMP-2, 9 of eutopic endometrial cells of endometriosis could be decreased (P < 0.01) while the expression of TIMP-1, 2 protein could be increased obviously (P < 0.01). The malignant invasion ability improved by SLW of eutopic endometrial cells of endometriosis was partly recruited by add-back E2 treatment. There was no significant difference in the activity of MMP-2 and the expression of TIMP-1, 2 protein between eutopic endometrium of endometriosis + middle dose of SLW serum + E2group and untreated group. The behavior of invasion of endometrial cells of endometriosis could be deteriorated treated by E2 as contrast to anastrozole, a specific aromatase inhibitor.

CONCLUSION

SLW could decrease the secretion of E2 so as to inhibit the invasion of the eutopic endometrial cells of endometriosis.

Matrix metalloproteinases 2 and 9 and their tissue inhibitors in the follicular fluid of patients with polycystic ovaries undergoing in vitro fertilisation

The present study was undertaken to investigate the levels of matrix metalloproteinase (MMP)-2, MMP-9 and their tissue inhibitors (TIMP-2 and TIMP-1, respectively) in the follicular fluid of 39 patients with polycystic ovary syndrome (PCOS) and compare them with the levels found in 56 age- and weight-matched normally ovulating women, all undergoing in vitro fertilisation (IVF) treatment. Significantly higher levels of MMP-2 and MMP-9 (p=0.02 and p<0.001, respectively) as well as TIMP-2 and TIMP-1 (p=0.006 and p<0.001, respectively) were found in the PCOS group compared to controls. Women who achieved pregnancy had higher TIMP-1 levels compared to the non-pregnant ones in the control group (p=0.01). In conclusion, women with PCOS exhibited significantly increased gelatinolytic activity compared with controls of similar age and body mass index, thus indicating a more intense extracellular matrix remodelling in this group of patients during IVF treatment due to multiple follicular development and cyst formation.

In vitro reoxygenation following hypoxia increases MMP-2 and TIMP-2 secretion by human umbilical vein endothelial cells

Endothelial cells lining the inner blood vessel walls play a key role in the response to hypoxia, which is frequently encountered in clinical conditions such as myocardial infarction, renal ischemia and cerebral ischemia. In the present study we investigated the effects of hypoxia and hypoxia/reoxygenation on gelatinases (matrix metalloproteinase-2 and -9), their inhibitor (TIMP-2) and activator (MT1-MMP), in human umbilical vein endothelial (HUVE) cells. HUVE cells were subjected to 4 h of hypoxia or hypoxia followed by 4 and 24 h of reoxygenation. The pro- and active forms of MMP-2 and MMP-9 were analyzed by gelatin zymography; TIMP-2 protein level was assayed using ELISA, while MT1-MMP activity was measured using an activity assay. The secretion of MMP-2 proform increased significantly in cells subjected to 4 h of hypoxia followed by 4 or 24 h of reoxygenation, compared with the normoxic group. TIMP-2 protein level also increased significantly in the hypoxia/reoxygenation groups, compared with the normoxic group. There were no statistically significant differences in the levels of active MT1-MMP in all groups. This study indicates that MMP-2 and TIMP-2 could be regarded as important components of a mechanism in the pathophysiology of ischemic injury following reperfusion.

MMP inhibition blocks fibroblast-dependent skin cancer invasion, reduces vascularization and alters VEGF-A and PDGF-BB expression

Tumor invasion requires intense interactions with stromal cells and a profound extracellular matrix remodelling by matrix metalloproteinases (MMPs). Here, we assessed the specific contribution of fibroblasts to tumor invasion, MMPs, tissue inhibitors of MMPs and angiogenesis-related cytokine expression in organotypic cultures of highly malignant HaCaT-ras A-5RT3 cells, with and without MMP inhibition. Collagen degradation, the hallmark of tumor invasion, was dependent on fibroblasts and active MMP-2. Additionally, MMP blockade down-regulated VEGF-A and up-regulated PDGF-BB. These results were paralleled in xenotransplants in vivo, demonstrating strong inhibitory effects of MMP blockade on tumor invasion and vascularization, as shown by the almost complete absence of VEGF-A and MMP-14 and by the decrease in relative blood volume. MMP blockade also increased the fraction of mature vessels, as demonstrated by an increased mean tumor vessel diameter and a higher ratio of Ng2-positive vessels. Thus, this study highlights the importance of targeting the tumor stroma to defeat cancer.

Changes in plasma levels of MMP-9, MMP-7 and their inhibitors in patients with coronary artery disease

To describe the enzymatic profile of plasma matrix metalloproteinases (MMP-7 and -9) and tissue inhibitors of metalloproteinases (TIMP-1 and -2) in different categories of patients (pts.) with coronary artery disease (CAD), and their relationship with clinical status, left ventricular (LV) function and remodelling.

METHODS

Total plasma MMP7, active fraction of MMP9, TIMP1 and TIMP2 were determined in 68 consecutive pts with confirmed CAD (Group A, 56.6 +/- 9 y, 75% men, LVEF 56.4 +/- 11%) and compared with a control group of 23 pts. without cardiovascular disease and normal coronary arteries (Group B, 58.1 +/- 10 y, 56.5% men, LVEF 58.7 +/- 5%). LVEF and wall motion index (WMI) were computed. Diastolic function parameters were evaluated: mitral E/A ratio, E/E'septal ratio. We calculated global longitudinal (L), circumferential (C) and radial (R) strain (S) and strain rate (SR) values as the average of segmental values, by 2D strain analysis.

RESULTS

The active form of MMP9 differed significantly between group A and B, as did the MMP9/TIMP1 and MMP9/TIMP2 ratios (8.78 +/- 10.0 ng/ml vs 3.33 +/- 4.0 ng/ml; 5.43 +/- 3.4 vs 0.85 +/- 0.9, and 11.60 +/- 5.2 vs 3.71 +/- 1.0, respectively, p < 0.04 for all). Group A included 35 pts. with acute coronary syndromes (ACS) and 33 pts. with stable angina (SA), with similar profile of LVEF and number of coronary arteries involved. There were no significant differences in plasma MMP9, MMP9/TIMP1 and MMP/TIMP2 ratio between normal and SA group, but only between normal and ACS group (p = 0.02 for MMP9). In group A, only MMP7, TIMP1/MMP7 and TIMP2/MMP7 ratio correlated with markers of systolic function: LVEF, WMI and global LS.

CONCLUSION

There were no significant changes in extracellular matrix markers in pts. with chronic stable ischemia vs normals. Only active form of MMP9 and its ratio with TIMP differed significantly in ACS. Total MMP7 and its ratio with TIMP correlated with parameters of LV systolic function even in pts. with normal LVEF.

The cytokine gene CXCL14 restricts human trophoblast cell invasion by suppressing gelatinase activity

Well-controlled trophoblast invasion into uterine decidua is a critical process for the normal development of placenta, which is tightly regulated by various factors produced within the trophoblast-endometrial microenvironment. CXCL14 is involved in tumor growth and metastasis, and its expression in placenta is temporally regulated during pregnancy. However, the role of CXCL14 in trophoblast function during human pregnancy is not clear. In this study, by using RT-PCR through human pregnancy, we found that CXCL14 was selectively expressed at early but not late pregnancy. Immunostaining revealed that CXCL14 proteins were strongly expressed in villous cytotrophoblasts and moderately in decidualized stromal cells but very weakly in syncytiotrophoblasts and extravillous trophoblasts. The effect of CXCL14 on trophoblast invasion were examined by using human villous explants cultured on Matrigel and further proved by invasion and migration assay of primary trophoblast cells and trophoblast cell line HTR-8/SVneo. Our data showed that CXCL14 significantly inhibited outgrowth of villous explant in vitro; this effect is due to suppression of trophoblast invasion and migration through regulating matrix metalloproteinases activities, whereas the trophoblast proliferation was not affected. Moreover, because a receptor for CXCL14 has not been identified, we performed further cell-specific CXCL14 binding activities with regard to different cell types within the maternal-fetal interface. Our data revealed that CXCL14 could specifically bind to trophoblast cells but not decidual cells from the maternal-fetal interface. These results suggest that CXCL14 plays an important role in regulating trophoblast invasion through an autocrine/paracrine manner during early pregnancy.

Antitumor and antimetastatic activities of Rhizoma Paridis saponins

Rhizoma Paridis saponins (RPS) have been found to show strong antitumor activity. However, few studies have yet investigated its role on pulmonary metastasis treated with this herb. To investigate the molecular mechanisms related to metastasis, we studied RPS-treated T739 mice using histopathology, immunohistochemistry and reverse transcription polymerase chain reaction. Apoptosis was measured by TUNEL assay. As a result, RPS inhibited tumor growth by inducing apoptosis and upregulated the expression of TIMP-2 and down-regulated the level of MMP-2 and MMP-9. In conclusion, RPS is a potent anticancer agent that elicits programmed cell death and inhibits metastases in murine lung adenocarcinoma in vivo.

[Effects of losartan and simvastatin on collagen content, myocardial expression of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in pressure overload rat hearts]

OBJECTIVE

To investigate the effects of simvastatin(Sim) and losartan(Los) on cardiac fibrosis and myocardial expression of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in pressure overloaded rat hearts.

METHODS

The pressure overload model was induced by descending aortic constriction (DAC) in rats. SD rats were randomized into 6 groups (n = 20 each): normol control group, control sham group, DAC group, Los group (DAC + Los, 5 mg/kg), Sim group (DAC + Sim, 2 mg/kg), Los + Sim group (DAC + Los + Sim, Los 5 mg/kg, Sim 2 mg/kg). Water, Los or Sim drug was administrated by gavage daily beginning from day 5 after operation for 30 days. Collagen was measured on Masson stained myocardial sections, and the level of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in left ventricle were detected by RT-PCR.

RESULTS

Collagen volume fraction (CVF) in DAC group was significantly higher than the normal control and sham groups (P < 0.01) which could be significantly reduced by Los and Sim (P < 0.05), especially in DAC + Los + Sim group (P < 0.01). The levels of myocardial MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA were also significantly higher in DAC group than in normal control and sham groups (P < 0.01). Treatment Sim and Los alone and especially in combination significantly decreased the TIMP-1 mRNA, TIMP-2 mRNA expressions (P < 0.01) while MMP-2 mRNA, MMP-9 mRNA levels remained unchanged (P > 0.05).

CONCLUSION

Upregulation of myocardial MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA expressions might contribute to myocardial fibrosis in this model, Sim and Los significantly inhibited myocardial fibrosis possibly by downregulating myocardial TIMP-1 mRNA, TIMP-2 mRNA expressions in this model.

[Expression of TGF-beta1 and the mechanism of invasiveness and metastasis induced by TGF-beta1 in breast cancer]

OBJECTIVE

To investigate the expression of MMP-2, TIMP-2, TGF-beta1 and TGF-betaRI and the relationship among them in breast cancer.

METHODS

The protein expression of MMP-2, TIMP-2, TGF-beta1 and TGF-betaRI was detected on tissue chips by S-P immunohistochemical staining in 160 cases of breast carcinoma.

RESULTS

The positive rates of TGF-beta1, TGF-beta1 mRNA, MMP-2, MMP-9, TIMP-1 and TIMP-2 expression were 73.7%, 56.2%, 96.9%, 95.0%, 87.5% and 89.4%, respectively. Axillary lymph node metastasis and TNM staging (P < 0.01 and P < 0.01, respectively) were positively correlated to the expression of TGF-beta1. Relase-free survival of TGF-beta1 positive group was lower than that of TGF-beta1 negative group (P = 0.023). The expression of MMP-2 or MMP-9 was positively correlated to that of TGF-beta1 (r = 0.170, P < 0.05; r = 0.221, P < 0.01) and was negatively correlated to that of TGF-beta1 mRNA (r = -0.126, P > 0.05;r = 0.019, P > 0.05).

CONCLUSION

The expression of TGF-beta1 may be closely correlated with the invasion and metastasis of breast cancer. TGF-beta1-induced invasiveness and metastasis of breast cancer cells are mediated by MMP-2 and MMP-9.

Matrix metalloproteinase-2 is elevated in midtrimester amniotic fluid prior to the development of preeclampsia

OBJECTIVE

To evaluate levels of matrix metalloproteinases (MMP) and their inhibitors (TIMP) in second trimester amniotic fluid of women with hypertensive disorders compared to normotensive women.

STUDY DESIGN

Amniotic fluid was obtained from 133 women undergoing genetic second trimester amniocentesis. Zymography was performed for MMP characterization and an MMP-2 ELISA kit was used to determine MMP-2 levels. TIMP-2 expression was evaluated using western blot.

RESULTS

Mean amniotic fluid MMP-2 and TIMP-2 levels were significantly higher in women who developed a hypertensive disorder compared to normotensive women (P < 0.0004 and P < 0.01, respectively). When subdivided into subgroups, amniotic fluid from women who eventually developed preeclampsia or superimposed preeclampsia showed significantly higher MMP-2 levels than normotensive women (P < 0.05). However, no statistical difference in MMP-2 levels was found between patients with gestational hypertension and normotensive patients.

CONCLUSION

Higher amniotic fluid MMP-2 and TIMP-2 levels are found in women who eventually develop preeclampsia.

IMMUNOHISTOCHEMICAL STUDY OF TUMOR NECROSIS FACTOR-α, MATRIX METALLOPROTEINASE-12, AND TISSUE INHIBITOR OF METALLOPROTEINASE-2 ON ALVEOLAR MACROPHAGES OF BALB/c MICE EXPOSED TO SHORT-TERM CIGARETTE SMOKE

Alveolar cells were evaluated in BALB/c mice exposed to smoke from 9 cigarettes per day. The mice were sacrificed at 1, 5, and 10 days and examined by lung morphometry and immunohistochemical staining of alveolar macrophages for tumor necrosis factor (TNF)-alpha, matrix metalloproteinase (MMP)-12, and tissue inhibitor of metalloproteinase (TIMP)-2. Cigarette smoke (CS)-exposed mice showed a progressive increase in numbers of alveolar macrophages (AMs) up to 10 days. MMP-12 was increased in AMs compared to the control group. The number of AMs with TNF-alpha and TIMP-2 labeling was higher at 5 days but decreased at 10 days. Short-term CS exposure induced pulmonary inflammation with major participation of MMP-12-positive AMs.

Differential effect of 17-beta-estradiol on smooth muscle cell and aortic explant MMP2

OBJECTIVE

The present investigation tested the hypothesis that intrinsic gender-related differences exist in rat aortic smooth muscle cell matrix metalloproteinase 2 (MMP2).

METHODS

This investigation comprised 3 sets of experiments. Experiment I: Adult male and female rat aortic smooth muscle cells (RASMCs) at passages 4-8 were stimulated in serum-free media for 48 h with interleukin(IL)1beta at doses encountered in human abdominal aortic aneurysms (2 ng/mL). Messenger RNA was extracted from the RASMCs, and gene expression of MMP2 and tissue inhibitor of metalloproteinase 2 (TIMP2), a major MMP2 inhibitor, was measured by real-time polymerase chain reaction. MMP2 protein levels in conditioned media were measured by Western blotting, and MMP2 and TIMP2 activity quantified by standard and reverse gelatin zymography. Experiment II: Male and female RASMCs were incubated for 48 h in Dulbecco's modified Eagler's medium containing IL-1beta and 17-beta-estradiol at doses from 1x10(-10) to 1x10(-6) molar. MMP2 activity in the conditioned media was then determined. Experiment III: Male rats underwent sustained 17-beta-estradiol exposure for 21 d using extended-release, subcutaneously implanted pellets prior to sacrifice and aortic explantation. Aortas from males, females, and estradiol-treated males were stimulated with IL-1beta for 48-h, and MMP2 activity in the conditioned media was determined.

RESULTS

Experiment I: MMP2 gene expression was 3-fold higher in male compared with female IL-1beta stimulated RASMCs (P<0.0001). MMP2:TIMP2 gene expression ratio was 7.5-fold greater in male versus female RASMCs. MMP2 protein levels were 3-fold higher (2.68 versus 0.96 o.d./mg total protein, P=0.003) in male versus female RASMCs. Gelatinolytic activity was more than 6-fold higher (15,010 versus 2,472 o.d./mg total protein, P=0.002) in male versus female RASMCs. Experiment II: MMP2 activity in male and female RASMCs was not altered by a wide range of 17-beta-estradiol concentrations. Experiment III: When pretreated with 17-beta-estradiol, MMP2 activity in the media of male rat whole-aortic explants decreased 2-fold (P=0.002). This post-17-beta-estradiol treatment male level was not different than baseline female aortic explant MMP2 levels.

CONCLUSIONS

MMP2 is higher in male RASMCs compared to female RASMCs. Exogenous 17-beta-estradiol did not alter MMP2 activity in vitro, but in vivo 17-beta-estradiol exposure greatly decreased male aortic MMP2 production to levels seen in the female aorta. Gender differences in MMP2 are speculated to be associated with phenotypic differences in human abdominal aortic aneurysm formation.

Angiotensin II-induced hypertension regulates AT1 receptor subtypes and extracellular matrix turnover in mouse retinal pigment epithelium

Accumulation of specific deposits and extracellular molecules under the retinal pigment epithelium (RPE) has been previously observed in eyes with age-related macular degeneration (AMD) and may play a role in the pathogenesis of AMD. Even though age is the major determinant for developing AMD, clinical studies have revealed hypertension (HTN) as another systemic risk factor. Angiotensin II (Ang II) is considered the most important hormone associated with HTN. To evaluate the relationship of Ang II to AMD, we studied whether mouse RPE expresses functional Ang II receptor subtypes and whether HTN-induced Ang II regulates expression of these receptors as well as critical ECM molecules (MMP-2 and type IV collagen) involved in ECM turnover in RPE. We used 9-month-old C57BL/6 male mice infused with Ang II alone or Ang II in combination with the AT1 receptor antagonist candesartan or the AT2 receptor antagonist PD123319 for 4 weeks to determine whether HTN-associated Ang II was important for ECM regulation in RPE. We found that mouse RPE expressed both Ang II receptor subtypes at the mRNA and protein levels. Infusion with Ang II induced HTN and elevated plasma and ocular Ang II levels. Ang II also regulated AT1a and AT1b receptor mRNA expression, the intracellular concentration of calcium [Ca(2+)](i), MMP-2 activity, and type IV collagen accumulation. Concurrent administration of Ang II with the AT1 receptor blocker prevented the increase in blood pressure and rise in ocular Ang II levels, as well as the calcium and MMP-2 responses. In contrast, the type IV collagen response to Ang II was prevented by blockade of AT2 receptors, but not AT1 receptors. Plasma Ang II levels were not modified by the AT1 or AT2 receptor blockade. Since the effects of Ang II on MMP-2 and type IV collagen require inhibition of both Ang II receptor subtypes, these receptors may play a role as a potential therapeutic targets to prevent ECM turnover dysregulation in the RPE basement membrane, suggesting a pathogenic mechanism to explain the link between HTN and AMD.

[Effects of allicin on invasion and metastasis of colon cancer LoVo cell line in vitro]

OBJECTIVE

To study the effect of allicin on invasion and metastasis of human colon cancer cell line LoVo in vitro and furthermore elucidate its anticancer mechanisms.

METHODS

MTT assay was used to test dynamically the effect of cell growth inhibition. The inhibitory effects of allicin on movement, adhesiveness and invasiveness of LoVo cells were evaluated by the migratory test, adhesion test and Transwell chamber experiment. Quantitative real-time reverse transcription PCR (real-time RT-PCR) was performed to quantify the mRNA expression of MMP-2, TIMP-2, CD147, VEGF, nm23-H1, HPA and uPAR.

RESULTS

Allicin had inhibitive effects on growth of LoVo cells in a dose and time-dependent manner. Allicin at non-cytotoxic concentration (3 and 6 microg/ml) could obviously suppress the movement, adhesion and invasive capability of LoVo cells. In the allicin-treated group (3 and 6 microg/ml), after 24 hours, the inhibition rates of migratory time were 24% and 50% (t = 4.543, 12.348, P = 0.010, 0.001), the inhibition rates of adhesion were 19% and 28% (t = 6.145, 6.355, P = 0.004, 0.003), the inhibition rates of migration were 28% and 46% (t = 8.065, 28.435, both P < 0.01), and the inhibition rates of invasion were 44% and 65% respectively (t = 21.274, 26.288, both P < 0.01). Allicin at non-cytotoxic concentration could down-regulate the mRNA levels of VEGF, uPAR and HPA in a dose-dependent manner in LoVo cells (t = 7.129, 6.764, 8.497, P = 0.002, 0.002, 0.001) while the mRNA levels of TIMP-2, CD147 and nm23-H1 remained basically unchanged with the same treatment (t = 0.341, 1.889, 0.914, P = 0.059, 0.132, 0.412). The expression of MMP-2 had not been detected in LoVo cells.

CONCLUSION

Allicin in vitro inhibits invasion and metastasis of human colon carcinoma cell LoVo at non-cytotoxic concentration through down-regulating the expression of VEGF, uPAR and HPA mRNA.

[Effect of high glucose on PKC and MMPs/TIMPs in human mesangial cells]

OBJECTIVE

To explore the relationship between protein kinase C (PKC) and matrix metalloproteinase (MMPs)/tissue inhibitor of metalloproteinase (TIMPs) in human mesangial cells under the high glucose medium, and to analyze the effect of PKC and MMPs/TIMPs in diabetes nephropathy (DN).

METHODS

Normal human mesangial cells (NHMC) were divided into 4 groups: a control group(N, 5 mmol/L glucose), a high glucose group (H, 30 mmol/L glucose), a PKC inhibition group (P, 30 mmol/L glucose plus 10-5 mol/L chelerythrine chloride), and an mannitol group (M, 5 mmol/L glucose plus 25 mmol/L mannitol). Cell proliferation was measured by MTT at 24,48 or 72 hours. The activity of PKC was measured by ELISA and the mRNA and protein expressions of MMP2, 9 and TIMP1, 2 were examined by RT-PCR and Western blot.

RESULTS

High glucose increased the activity of PKC as well as the expressions of mRNA and protein of MMP2, 9 and TIMP1, 2.The ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1 was significantly decreased in the high glucose group compared with that of the control group (P<0.05). The mRNA and protein expressions of MMP2, 9 and TIMP1 were significantly increased in the PKC inhibition group compared with the control group (P<0.01). The ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1 increased in the inhibition group compared with that of the high glucose group (P<0.05 or P<0.01). The activity of PKC was negatively correlated with the protein ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1(rý-0.651,rý-0.702, both P<0.05).

CONCLUSION

High glucose can activate PKC in mesangial cells. The activity of PKC influences the expression of MMPs/TIMPs in the progressing of DN.

Tumour-associated tenascin-C isoforms promote breast cancer cell invasion and growth by matrix metalloproteinase-dependent and independent mechanisms

INTRODUCTION

The stromal microenvironment has a profound influence on tumour cell behaviour. In tumours, the extracellular matrix (ECM) composition differs from normal tissue and allows novel interactions to influence tumour cell function. The ECM protein tenascin-C (TNC) is frequently up-regulated in breast cancer and we have previously identified two novel isoforms - one containing exon 16 (TNC-16) and one containing exons 14 plus 16 (TNC-14/16).

METHODS

The present study has analysed the functional significance of this altered TNC isoform profile in breast cancer. TNC-16 and TNC-14/16 splice variants were generated using PCR-ligation and over-expressed in breast cancer cells (MCF-7, T47D, MDA-MD-231, MDA-MB-468, GI101) and human fibroblasts. The effects of these variants on tumour cell invasion and proliferation were measured and compared with the effects of the large (TNC-L) and fully spliced small (TNC-S) isoforms.

RESULTS

TNC-16 and TNC-14/16 significantly enhanced tumour cell proliferation (P < 0.05) and invasion, both directly (P < 0.01) and as a response to transfected fibroblast expression (P < 0.05) with this effect being dependent on tumour cell interaction with TNC, because TNC-blocking antibodies abrogated these responses. An analysis of 19 matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases 1 to 4 (TIMP 1 to 4) revealed that TNC up-regulated expression of MMP-13 and TIMP-3 two to four fold relative to vector, and invasion was reduced in the presence of MMP inhibitor GM6001. However, this effect was not isoform-specific but was elicited equally by all TNC isoforms.

CONCLUSIONS

These results demonstrate a dual requirement for TNC and MMP in enhancing breast cancer cell invasion, and identify a significant role for the tumour-associated TNC-16 and TNC-14/16 in promoting tumour invasion, although these isoform-specific effects appear to be mediated through MMP-independent mechanisms.

[Expression of matrix metalloproteinases and inhibitors on the scleral tissue of lamina cribrosa in rat with experimental chronic ocular hypertension]

OBJECTIVE

To investigate the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in the sclera of lamina cribrosa in rat chronic elevated intraocular pressure (IOP) and its the relationship with the pathogenesis of glaucoma.

METHODS

It was an experimental study. Chronic ocular hypertension (OHT) model was induced in the left eyes of 43 Wistar rats by cauterizing episcleral venous while the right eyes were used as control. The rats were divided into three groups: 13 for immunohistology, 15 for Western blotting, and 15 for RT-PCR by randomly computerized assignment and sacrificed at week 12 after OHT induction. The expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 in the sclera lamina cribrosa was detected using immunohistology, Western blotting, and RT-PCR technique, respectively. Repeated measures ANOVA of two-factor Studies in SAS statistic software were used to analyze the data.

RESULTS

After 12 weeks, compared with control eyes, the IOP of rat OHT eyes was significantly (F = 1519.67, P < 0.01) elevated. The expression of MMP-2 and MMP-9 was increased in cell nucleus and cytoplasm in sclera lamina cribrosa in rat OHT when compared to control eyes with negative expression. No expressions of TIMP-1, TIMP-2 in sclera lamina cribrosa were found in both OHT and control eyes. The mean gray-scale values of MMP-2, MMP-9, TIMP-1, and TIMP-2 in OHT were significantly (F = 405.55, F = 436.11, F = 1167.77, and F = 4629.64, P < 0.01) higher than control eye by Western blotting (193.88 +/- 8.84 vs 117.38 +/- 10.76, 202.65 +/- 8.37 vs 134.13 +/- 5.06, 283.63 +/- 5.65 vs 186.88 +/- 7.14, and 284.75 +/- 5.50 vs 183.0 +/- 5.58), while by RT-PCR (200.50 +/- 3.25 vs 181.88 +/- 9.36, 200.13 +/- 2.95 vs 181.75 +/- 5.85, 201.88 +/- 3.14 vs 179.25 +/- 9.21, and 195.50 +/- 3.55 vs 179.75 +/- 7.12), respectively.

CONCLUSION

The increased expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 in lamina cribrosa in rat OHT eye indicates that MMPs and TIMPs may be involved in the pathogenesis of glaucoma.

Inhibition of matrix metalloproteinases improves left ventricular function in mice lacking osteopontin after myocardial infarction

Osteopontin (OPN) plays an important role in left ventricular (LV) remodeling after myocardial infarction (MI) by promoting collagen synthesis and accumulation. This study tested the hypothesis that MMP inhibition modulates post-MI LV remodeling in mice lacking OPN. Wild-type (WT) and OPN knockout (KO) mice were treated daily with MMP inhibitor (PD166793, 30 mg/kg/day) starting 3 days post-MI. LV functional and structural remodeling was measured 14 days post-MI. Infarct size was similar in WT and KO groups with or without MMP inhibition. M-mode echocardiography showed greater increase in LV end-diastolic (LVEDD) and end-systolic diameters (LVESD) and decrease in percent fractional shortening (%FS) and ejection fraction in KO-MI versus WT-MI. MMP inhibition decreased LVEDD and LVESD, and increased %FS in both groups. Interestingly, the effect was more pronounced in KO-MI group versus WT-MI (P < 0.01). MMP inhibition significantly decreased post-MI LV dilation in KO-MI group as measured by Langendorff-perfusion analysis. MMP inhibition improved LV developed pressures in both MI groups. However, the improvement was significantly higher in KO-MI group versus WT-MI (P < 0.05). MMP inhibition increased heart weight-to-body weight ratio, myocyte cross-sectional area, fibrosis and septal wall thickness only in KO-MI. Percent apoptotic myocytes in the non-infarct area was not different between the treatment groups. Expression and activity of MMP-2 and MMP-9 in the non-infarct area was higher in KO-MI group 3 days post-MI. MMP inhibition reduced MMP-2 activity in KO-MI with no effect on the expression of TIMP-2 and TIMP-4 14 days post-MI. Thus, activation of MMPs contributes to reduced fibrosis and LV dysfunction in mice lacking OPN.

Dysregulation of immunoexpression of matrix metalloproteinases in renal chronic allograft injury

The aim of the study was to evaluate tubulointerstitial immunoexpression of MMPs and TIMPs in chronic renal allograft injury, and to assess any relationships between immunoexpression of MMPs and interstitial monocytes/ macrophages and mast cells. Immunohistochemistry with antibodies against MMP-2, MMP-2, MMP-12, TIMP-1, TIMP-2, CD68, and mast cells tryptase was carried out on 17 renal biopsy specimens from patients with chronic allograft injury, and on 11 control kidney tissues. In renal specimens in chronic allograft injury increased expression of MMP-2, MMP-12 and TIMP-1 was noted. The immunoexpression of MMP-9 and TIMP-2 was low, and did not differ in comparison with controls. Increased immunoexpression of MMP-12 was positively correlated with the number of interstitial CD68 + cells. The correlation between immunostaining of MMP-12 and mast cells tended to be positive, however it did not reach statistical significance. There were significant positive correlations between immunostaining of MMP-9 and CD68+ cells, as well as between MMP-9 and the number of mast cells. In conclusion our study revealed that the remodelling of kidney structure in patients with chronic allograft injury is associated with dysregulation of MMPs and TIMPs, and may suggest that interstitial monocytes/macrophages and mast cells may cooperate with MMPs in pathogenesis of renal fibrosis.

[Role of matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) in nephrology]

Metalloproteinases (MMP) and their tissue inhibitors (TIMP) play a crucial role to keep the balance between the synthesis and degradation of extracellular matrix protein. Balance disturbances of those two systems lead to abnormal tissue remodeling. There is evidence that matrix metalloproteinases activity changes in many pathological conditions, including inflammatory, degenerative disorders as well as tumor progression. Recent investigations indicate that MMPs and TIMPs play a pivotal role in pathogenesis of most of kidney diseases. Studies describing dysregulated activity of MMPs and/or their tissue inhibitors in various experimental and clinical models of kidney disease, including chronic kidney disease, glomerulonephritis, pyelonephritis, diabetic and hypertensive nephropathy, polycystic kidney disease and renal cancer are reviewed.

Ascorbate-induced osteoblast differentiation recruits distinct MMP-inhibitors: RECK and TIMP-2

The bone formation executed by osteoblasts represents an interesting research field both for basic and applied investigations. The goal of this work was to evaluate the molecular mechanisms involved during osteoblast differentiation in vitro. Accordingly, we demonstrated that, during the osteoblastic differentiation, TIMP-2 and RECK presented differential expressions, where RECK expression was downregulated from the 14th day in contrast with an increase in TIMP-2. Concomitantly, our results showed a temporal regulation of two major signaling cascades during osteoblast differentiation: proliferation cascades in which RECK, PI3 K, and GSK-3beta play a pivotal role and latter, differentiation cascades with participation of Ras, Rho, Rac-1, PKC alpha/beta, and TIMP-2. Furthermore, we observed that phosphorylation level of paxillin was downregulated while FAK(125) remained unchangeable, but active during extracellular matrix (ECM) remodeling. Concluding, our results provide evidences that RECK and TIMP-2 are involved in the control of ECM remodeling in distinct phases of osteoblast differentiation by modulating MMP activities and a multitude of signaling proteins governs these events.

Regulation of mRNAs encoding MMP-9 and MMP-2, and their inhibitors TIMP-1 and TIMP-2 by androgens in the rat ventral prostate

The relative activities of matrix metalloproteinases (MMPs) and their natural inhibitors (tissue inhibitors of matrix metalloproteinases, TIMPs) determine the extent of matrix degradation in any tissue. Their identification and characterization is key towards understanding remodeling of the prostate in the context of both castration induced atrophy and tumor invasion and metastasis. Although the expression of MMPs and TIMPs in prostate tumors has been reported, their regulation by androgens has not been studied. Here, we show that androgen ablation by castration increases the steady state mRNA levels of MMP-9, MMP-2, TIMP-1 and TIMP-2. Blockade of the androgen receptor using flutamide, however, has differential effects on the steady state mRNA expressions of these genes. We also show that both castration and flutamide treatment cause enhanced expression of a high molecular weight gelatinolytic activity in the rat ventral prostate (RVP). Actinomycin D does not affect the increase in steady state mRNA levels of MMP-9 and TIMP-1. Furthermore we show that actinomycin D alone enhances the steady state mRNA and protein levels of these genes. Using RNA gel shift assay with 3'-UTR of TIMP-1, we show that an RNA binding protein is induced following castration. Taken together our data suggest that the induction of MMP-2, MMP-9, TIMP-1 and TIMP-2 mRNAs post-castration could be at least in part due to post-transcriptional stabilization.

Effect of Long-Term Inhalation of Toner on Extracellular Matrix in the Lungs of Rats In Vivo

We assessed the effects of long-term inhalation of toner on the pathological changes and gene expression with the synthesis and degradation of collagenous extracellular matrix in a rat model. Female Wistar rats (10 wk old) were divided evenly into a high concentration exposure group (H: 15.2 mg/m3), a low concentration exposure group (L: 5.5 mg/m3), and a control group. The mass median aerodynamic diameter of toner was 4.5 microm. The rats were sacrificed at the termination of a 1-yr or 2-yr inhalation period. Pathological examination was performed from the left lung, and transcriptional levels of mRNA extracted from the right lung were assessed by semiquantitative reverse-transcription polymerase chain polymerase (RT-PCR). The pathological findings showed mild pulmonary fibrosis in 20% (L, 1 yr), 40% (H, 1 yr), 56% (L, 2 yr) and 62% (H, 2 yr), while lung cancer was not observed in any of the exposed groups. In the 1-yr high-concentration group, gene expression of matrix metalloproteinase-2 (MMP-2) and type I collagen mRNA in the rat lungs increased, while tissue inhibitors of metalloproteinase-2 (TIMP-2) decreased. The 2-yr high-concentration group increased in message level of type I collagen and TIMP-2 but not that of MMP-2. These data suggested that results of gene expression of MMP, TIMP, and collagen in the 2-yr exposure may lead to accumulation of collagen compared to the 1-yr exposure, and that the imbalance of the expression of MMPs, TIMPs, and extracellular matrix might be associated with pulmonary fibrosis induced by toner.

[The effects of FRNK on expressions of MMP-2 mRNA and TIMP-2 mRNA in hepatic stellate cells]

OBJECTIVES

To investigate the effects of FAK-related non-kinase (FRNK) on expressions of type I collagen and matrix metalloproteinase-2 (MMP-2) mRNA and tissue inhibitor of metalloproteinase-2 (TIMP-2) mRNA in rat hepatic stellate cells (HSC).

METHODS

Using in vitro cell culture technique, FRNK plasmids were transfected into HSC mediated by cationic liposome. Type I collagen synthesis capability in HSC was examined by 3H-Pro incorporation assay. The levels of FRNK in HSC were assayed by Western blot, and the expressions of MMP-2 and TIMP-2 were assayed by RT-PCR on mRNA levels.

RESULTS

The exposure of HSC to FRNK caused the expression of FRNK protein to be up-regulated, and the FRNK protein contents reached the highest point at 48 h after the transfection, P less than 0.05. The expressions of MMP-2 mRNA were up-regulated by FRNK; the expressions of TIMP-2 mRNA were down-regulated by FRNK; the ratios of MMP-2 mRNA/TIMP-2 mRNA were enhanced by FRNK.

CONCLUSION

After FRNK was transfected, the capability of type I collagen synthesis in HSC was inhibited, which may be related to the up-regulation of MMP-2 mRNA/TIMP-2 mRNA.

Idiopathic gingival hypertrophy--a morphological study and a review of literature

Gingival overgrowth occurs as a response to several drugs, in some systemic diseases, as a consequence of a genetic predisposition or could be idiopathic, the last being less studied. Independently of the etiological factor involved, histological changes are maintained and intensified by the presence of the bacterial plaque.

MATERIAL AND METHODS

Fibrotic mucosa clinically diagnosed with idiopathic hypertrophy was included in paraffin and studied using usual histological stains and immunohistochemical techniques for vimentin, MMP-3 and TIMP-2.

RESULTS

Evaluation of histological changes revealed an unspecific pattern like the thickening of the epithelium, with acanthosis and acantholysis and massive deposition of connective tissue in the lamina propria. Keratinocytes from the areas with acantholysis express MMP-3. In the fibrous areas we noted few fibroblasts and a discrete expression of MMP-3. Extended areas of inflammatory tissue with numerous de novo capillaries were observed among the collagen bundles. Proinflammatory and endothelial cells expressed both MMP-3 and TIMP-2. The last antibody had an intense expression deeper in the epithelium. Our results were discussed in accordance with reference data.

CONCLUSIONS

We conclude that the histological changes observed were not specific for the idiopathic gingival hypertrophy and the imbalance of tissue homeostasis was due to the interaction between keratinocytes and connective cells in the milieu of specific changes induced by the inflammatory conditions.

[The role of disequilibrium of expression of matrix metalloproteinase-2/9 and their tissue inhibitors in pathogenesis of hyperoxia-induced acute lung injury in mice]

OBJECTIVE

To investigate the role of matrix metalloproteinase-2/9 (MMP-2/9) and their tissue inhibitors (TIMP-1/2) in pathogenesis of acute lung injury (ALI) induced by hyperoxia.

METHODS

Seventy-two C57BL/6 mice were randomly divided into normal control group, hyperoxia for 24 hours group, hyperoxia for 48 hours group, and hyperoxia for 72 hours group, with 18 mice in each group. The mice in hyperoxia groups were exposed to >98% oxygen in sealed cages, and the normal control group were placed outside of the cage to breathe room air. At the end of the exposure time the animals were euthanized, the right lung was removed and phosphate buffer solution (PBS) was used to lavage the lung through the endotracheal catheter. The wet/dry weight ratio, broncho-alveolar lavage fluid (BALF) protein content and the volume of pleural fluid were measured, the severity of lung injury was assessed; the expression of MMP-2/9 and TIMP-1/2 mRNA in lung tissue at 24, 48 and 72 hours of hyperoxia were assessed by reverse transcript-polymerase chain reaction (RT-PCR); the amount of MMP-2/9 and TIMP-1/2 protein in lung tissue were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Hyperoxia caused ALI as evidenced by the increase in lung wet/dry weight ratio, BALF protein content and the volume of pleural fluid as compared with the normal control group (P<0.05 or P<0.01). RT-PCR study showed increased expression of MMP-2/9 and TIMP-1 mRNA in lung tissues (P<0.05 or P<0.01), and ELISA assay also demonstrated upregulation of MMP-2/9 and an increase in TIMP-1 amount in BALF compared with their normal control group (P<0.05 or P<0.01). The ratios of both MMP-2 mRNA/TIMP-2 mRNA and MMP-2 protein/TIMP-2 protein were all increased in hyperoxia groups as compared with their normal control group (all P<0.01).

CONCLUSION

Hyperoxia causes ALI in mice, and disturbance of MMP-2/TIMP-2 balance plays an important role in the development of hyperoxia-induced ALI in mice.

Overexpression of TIMP-2 mediated by recombinant adenovirus in rat abdominal aorta inhibits extracellular matrix degradation

To investigate the effects of a tissue inhibitor of the matrix metalloproteinase-2 (TIMP-2) gene on the extracellular matrix of the abdominal aorta, models of rat abdominal aortic aneurysm were utilized and a solution of AdTIMP-2 was perfused into the abdominal aorta. The models of rat abdominal aortic aneurysm were constructed with intraluminal perfusion of the abdominal aorta with porcine pancreatic elastase, and an adenovirus solution carrying the TIMP-2 gene was transferred into the aorta by local perfusion. After 14 days, aortic wall elastin and collagen concentrations were measured with an image analysis system and fixed aortic tissues were examined by light microscopy for inflammation. No abdominal aortic aneurysms developed in TIMP-2 gene-transferred rat models, representing a marked decreased from control rats (p < 0.01). The elastic fibers and collagenous fibers were preserved with greater integrity in the AdTIMP-2 group than in the control group and inflammatory cells were seen in adventitial areas. The TIMP-2 gene mediated by adenovirus can renew the balance of degradation of the extracellular matrix caused by elastase and inhibit the formation of an abdominal aortic aneurysm. This finding provides a new strategy for treatment of abdominal aortic aneurysms.

Equine laminitis: membrane type matrix metalloproteinase-1 (MMP-14) is involved in acute phase onset

REASONS FOR PERFORMING STUDY

Enzymatic separation at the hoof lamellar dermal-epidermal interface may play a role in the development of laminitis and characterising and locating matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of MMPs or TIMPs) in lamellar tissues may further understanding of pathogenesis.

OBJECTIVES

To clone and sequence the cDNA encoding lamellar MMP-14 and TIMP-2, and quantify their transcription in normal and laminitic tissue; and to develop antibody to locate MMP-14 in lamellar tissues.

METHODS

Tissue samples were obtained from an oligofructose induced model of laminitis. Total RNA was isolated, amplified by RT-PCR, cloned into a vector and sequenced. Real-time PCR was used to quantify MMP-14 and TIMP-2 expression. Rabbit anti-equine MMP-14 antibody was developed to analyse MMP-14 proteins from hoof tissues.

RESULTS

Immunohistochemistry detected MMP-14 in the cytoplasm of normal lamellar basal and parabasal cells in close proximity to the lamellar basement membrane. In laminitis affected tissue MMP-14 immunostaining was depleted in lamellar basal cells. Quantitative real-time PCR showed MMP-14 and TIMP-2 expression significantly (P<0.05) elevated and lowered respectively in laminitis affected tissues.

CONCLUSION

MMP-14, located in the cytoplasm of normal lamellar basal cells, disappears during laminitis development. The pathology of laminitis is associated with increased and lowered transcription of MMP-14 and TIMP-2, respectively.

POTENTIAL RELEVANCE

Enzymes have a role in laminitis pathology and inhibition of their activity may prevent laminitis.

Effects of hyperinsulinemia on hepatic metalloproteinases and their tissue inhibitors

To gain insight into the pathogenesis of hepatic fibrosis related to insulin resistance, we have examined the effects of euglycemic hyperinsulinemia on three matrix metalloproteinases (MMP-2, MMP-9, and MT1-MMP) and on two major tissue inhibitors of MMPs (TIMP-1 and TIMP-2) in liver of insulin-sensitive and insulin-resistant rats. Four hours of insulin infusion (4.8 mU.kg(-1).min(-1)) without or with lipid-heparin infusion (to produce insulin resistance) decreased hepatic MMP-2 mRNA (by RT-PCR), pro-MMP-2, MMP-2, MMP-9, and MT1-MMP (all by Western blots) and the gelatinolytic activity of MMP-2 (by gelatin zymography) by approximately 60-80%. Hyperinsulinemia ( approximately 1.6 mmol/l) increased TIMP-1 and TIMP-2 concentrations (by ELISA) in insulin-sensitive and insulin-resistant rats. Phosphoinositide 3-kinase was activated by insulin in insulin-sensitive rats and inhibited in insulin-resistant rats. Extracellular signal-regulated kinases 1/2 (ERK1/2) were activated by insulin in insulin-sensitive rats and partially inhibited in insulin-resistant rats; c-jun NH(2)-terminal kinase-1 (JNK1), JNK2/3, or p38 MAPK were only activated by lipid but not by insulin. We conclude that hyperinsulinemia, whether or not associated with insulin resistance, shifts the MMP/TIMP balance toward reduction of extracellular matrix degradation and thus may promote the development of hepatic fibrosis.

Identification and characterization of the precursor of chicken matrix metalloprotease 2 (pro-MMP-2) in hen egg

Using zymography and mass spectrometry, we identified for the first time the precursor of chicken matrix metalloprotease 2 (pro-MMP-2) as a complex with TIMP-2 (tissue inhibitor of metalloproteinases) in egg white and yolk. Real-time polymerase chain reaction confirmed that MMP-2 and its inhibitors TIMP-2 and TIMP-3 were expressed all along the oviduct and in the liver of laying hens. We also demonstrated that the processing of pro-MMP-2 into mature MMP-2 by serine proteases does not occur in vivo, although purified pro-MMP-2 undergoes proteolytic maturation by these proteases in vitro. Moreover, the relative pro-MMP-2 activity assessed by gelatin zymography was shown to decrease in egg white during the storage of unfertilized or fertilized eggs. However, the mature form of 62 kDa MMP-2 could not be detected. The fact that MMP-2 is found as a proform in fresh eggs suggests that the activity of this metalloprotease is regulated under specific conditions during embryonic development.

Plasmin induces degradation and dysfunction of laminin 332 (laminin 5) and impaired assembly of basement membrane at the dermal-epidermal junction

BACKGROUND

The epidermal basement membrane (BM), located at the dermal-epidermal junction (DEJ), plays important roles not only in adhesion between epidermis and dermis, but also in controlling skin functions. In sun-exposed skin, the BM becomes disrupted and multilayered. In order to explore the impairment of BM assembly, we have used a skin-equivalent (SE) as a model of BM damage and previously clarified the involvement of matrix metalloproteinases (MMPs) in impairment of BM assembly.

OBJECTIVES

In this work, we examined the role of urokinase-type plasminogen activator (uPA) and plasmin in impairment of BM assembly at the DEJ by using the SE, as ultraviolet irradiation to the skin increases uPA as well as MMPs.

METHODS

SEs were used as a model of formation and damage of BM. Human uPA was detected by enzyme-linked immunosorbent assay and zymography, and gelatinases such as MMP-2 and MMP-9 were detected by zymography. Human plasminogen was added at 0.06 micromol L(-1) (about 3% of plasma level) to increase plasmin to a pathological level. N-terminal peptide sequence analysis of plasmin-treated laminin 332 was carried out to identify alpha3, beta3 and gamma2 chains of laminin 332 and their cleavage sites of each chain. Plasmin-treated laminin 332 was analysed in keratinocyte adhesion activity and binding to type VII collagen.

RESULTS

Human uPA was detected in addition to MMP-2 and MMP-9, in conditioned medium of SE. Although the BM was well organized in the presence of an MMP inhibitor alone, the activated plasmin disorganized the BM even in the presence of the inhibitor. The impairment of BM assembly made the epidermis thinner as compared with that of a control cultured in the presence of MMP inhibitor, indicating that the BM affects the polarity and differentiation of the epidermis. The addition of aprotinin, a serine proteinase inhibitor, and tranexamic acid, a uPA-plasmin inhibitor, inhibited the plasmin-induced impairment of BM assembly and facilitated BM reorganization, thereby improving the epidermal structure. N-terminal peptide sequence analysis of plasmin-treated laminin 332 revealed the removal of a 5- or 10-kDa fragment, including the cell adhesion region, from the G3 domain of the alpha3 chain, and the LN domain, which binds to the noncollagenous 1 domain in type VII collagen, from the beta3 chain. Plasmin-treated laminin 332 showed lower keratinocyte adhesion activity and reduced binding to type VII collagen.

CONCLUSIONS

These results suggest that uPA and plasmin are involved in the impairment of BM assembly and epidermal differentiation, and that these effects arise at least partly through direct degradation of laminin 332.

Endothelin and gelatinases in renal changes following blockade of nitric oxide synthase in hypertensive rats

We investigated the involvement of matrix metalloproteinases (MMPs), tissue inhibitor (TIMP) and endothelin-1 (ET-1) in the renal damage in spontaneously hypertensive rats (SHR) following nitric oxide (NO) deprivation. SHR received Nomega-nitro-L-arginine methyl ester (L-NAME) from 5 wk-old for a period of 30 days. An ETA antagonist, FR139317 was used. We gave SHR FR139317 alone and cotreatment with L-NAME. L-NAME caused systemic hypertension, decrease in plasma nitrate/nitrite, increases in blood urea nitrogen and creatinine, impairment of glomerular dynamics. NO deprivation reduced the renal tissue cGMP, but it increased the collagen volume fraction, number of sclerotic glomeruli, arteriolar injury score and glomerular injury score. In addition, L-NAME elevated the plasma ET-1 at day 5. Cotreatment with FR139317 alleviated the L-NAME-induced functional and structural changes of renal glomeruli. L-NAME administration for 5 to 10 days resulted in decreases in MMP2 and MMP9 with increasing TIMP2. After L-NAME for 15 days, opposite changes (increases in MMP2 and MMP9 with a decrease in TIMP2) were observed. FR139317 cotreatment ameliorated the L-NAME-induced changes in MMP2 and MMP9 throughout the 30-day observation period. The ETA antagonist cotreatment attenuated the L-NAME-induced increase in TIMP2 before day 15, but not after day 20. The results indicate that ET-1, MMPs and TIMP are involved at the early stage (before 10 days) of glomerular sclerosis and arteriosclerosis with functional impairment following NO deprivation. The changes in MMPs and TIMP at the late stage (after 20 days) may be a compensatory response to prevent further renal damage.

Oxidative stress mediates cardiac fibrosis by enhancing transforming growth factor-beta1 in hypertensive rats

Cardiac fibrosis represented as perivascular/interstial fibrosis occurs in patients with hypertension. Oxidative stress has been demonstrated to contribute to such structural remodeling. The underlying mechanisms, however, remain to be elucidated. Herein, we tested the hypothesis that oxidative stress mediates cardiac fibrogenesis by stimulating transforming growth factor (TGF)-beta1 expression, which in turn triggers a series of fibrogenic responses. Sprague-Dawley rats were treated with angiotensin (Ang)II (9 microg/h s) for 4 weeks with/without co-treatment of combined antioxidants, apocynin, and tempol (120 mg/kg/day each, oral). Untreated rats served as controls. Appearance of cardiac oxidative stress and its potential effect on the expression of TGF-beta1, population of myofibroblasts, collagen synthesis/degradation, and fibrosis in hearts were examined. Chronic AngII infusion elevated systemic blood pressure (210 +/- 5 mmHg). Extensive perivascular and interstitial fibrosis was found in both ventricles, which were co-localized with oxidative stress represented as upregulated NADPH oxidase (gp91(phox) subunit) expression. Co-treatment with antioxidants led to: (1) markedly decreased cardiac gp91(phox); (2) significantly attenuated gene expression of TGF-beta1, type-I collagen, and tissue inhibitors of matrix metalloproteinase (TIMP)-I/II in the heart; (3) largely reduced population of myofibroblasts at sites of fibrosis; (4) significantly reduced cardiac collagen volume; (5) and partially suppressed blood pressure (190 +/- 4 mmHg). Thus, cardiac oxidative stress promotes the development of cardiac fibrosis by upregulating TGF-beta1 expression, which subsequently enhances cardiac collagen synthesis and suppresses collagen degradation in hypertensive rats.

Indian hedgehog promotes the migration of rat activated pancreatic stellate cells by increasing membrane type-1 matrix metalloproteinase on the plasma membrane

Indian hedgehog (Ihh) is a member of hedgehog peptides family that exerts diverse effects on multiple cellular functions. Since Ihh expression is elevated in the pancreas of chronic pancreatitis patients, Ihh has been assumed to participate in the chronic pancreatic injury, especially in pancreatic fibrosis. However, its function in pancreatic fibrosis is still unknown. We thus examined Ihh effects on rat activated pancreatic stellate cells (PSCs) that play a central role in pancreatic fibrosis. Activated PSCs express both patched-1 and smoothened that are essential components of hedgehog receptor system. Ihh did not alter the PSC expression of collagen-1 or alpha-smooth muscle actin, a parameter of PSC transformation, or did not change PSC proliferation. However, Ihh enhanced PSC migration in both chemotactic and chemokinetic manners. Furthermore, Ihh increased the amount of membrane-type 1 matrix metalloproteinase (MT1-MMP) and altered its localization on the plasma membrane, which plays a stimulatory role in cellular migration. In addition, tissue inhibitor of metalloproteinase-2 (TIMP-2) attenuated Ihh-stimulated PSC migration. Since most hedgehog intracellular signals are mediated by Gli-1 transcription factor, we investigated its contribution to Ihh-enhancement of PSC migration. Ihh induced Gli-1 nuclear accumulation in PSCs, indicating that Ihh stimulates Gli-1-dependent signaling pathway in PSCs. Unexpectedly, however, adenovirus-mediated Gli-1 overexpression blocked the Ihh enhancement of both MT1-MMP localization on the plasma membrane and PSC migration. Furthermore, reduction of Gli-1 expression with RNA interference augmented Ihh-stimulated PSC migration. These data indicate that Ihh promotes PSC migration by enhancing MT1-MMP localization on the plasma membrane but is negatively regulated by Gli-1.

[Study on the anti-invasion effect of SEPT7 gene for U251MG glioma cell in vitro]

OBJECTIVE

To study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism.

METHODS

Recombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively.

RESULTS

The invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells.

CONCLUSION

SEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.

Molecular dissection of TIMP3 mutation S156C associated with Sorsby fundus dystrophy

Sorsby fundus dystrophy (SFD) is an autosomal dominant macular degeneration of late onset. A key feature of the disease is the thickening of Bruch's membrane, an ECM structure located between the RPE and the choroid. SFD is caused by mutations in the gene encoding the ECM-associated tissue inhibitor of metalloproteases-3 (TIMP3). We have recently generated two Timp3 gene-targeted mouse lines, one deficient for the murine gene (Timp3-/-) and one carrying an SFD-related S156C mutation. Based on extracts and cell cultures derived from tissues of these animals we now evaluated TIMP3 functionality and its contribution to SFD. We show that the activity levels of TIMP3 target proteases including TACE, ADAMTS4/5 and aggrecan-cleaving MMPs are similar in Timp3S156/+ and Timp3S156C/S156C mice when compared to controls. In Timp3-/- mice, a significant enhancement of enzyme activity was observed for TACE but not for ADAMTS4/5 and MMPs indicating a compensatory effect of other inhibitors regulating the latter two groups of proteases. Fibrin bead assays show that angiogenesis in Timp3S156/+ and Timp3S156C/S156C mice is not altered whereas increased formation of capillary tubes was observed in Timp3-/- animals over controls. Rescue experiments using recombinant proteins demonstrate that the inhibitory activities of TIMP3 towards TACE and aggrecan-cleaving MMPs as well as the anti-angiogenic properties of TIMP3 are not impaired by SFD mutation S156C. We finally demonstrate that wild-type and S156C-TIMP3 proteins block the binding of VEGF to its receptor VEGFR2 to a similar extent. Taken together, this study shows that S156C-TIMP3 retains its known functional properties suggesting that causes other than an imbalance in protease or angiogenic activities represent the primary molecular defect underlying SFD.

[Inulicin inhibits activation and expression of vascular remodeling enzymes induced by de-endothelium]

AIM

To observe the effects of inulicin on the neointimal hyperplasia and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) after balloon injury in rat aorta.

METHODS

The intimal hyperplasia model was replicated by balloon injury. The histological changes in vascular wall were observed by HE staining. MMP-2 activation was tested by gelatin zymogram analysis; MMP-2 and TIMP-2 expression was detected by Western blot and immunohistochemistry analysis.

RESULTS

Neointimal hyperplasia induced by balloon injury was significantly inhibited by inulicin. The proteolytic activity and the expression of MMP-2 and ratio of MMP-2 and TIMP-2 were also returned to control level by inulicin after balloon injury.

CONCLUSION

Inulicin inhibits hyperplasia of neointima by modulating the balance of MMP-2 and TIMP-2.

Comparative assessment of matrix metalloproteinase (MMP)-2 and MMP-9, and their inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in preeclampsia and gestational hypertension

OBJECTIVES

To compare the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and the MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in preeclampsia and gestational hypertension with those found in normotensive pregnancies.

DESIGN AND METHODS

We studied 83 pregnant women (30 healthy pregnant women with uncomplicated pregnancies, 26 with gestational hypertension, and 27 with preeclampsia) and 30 healthy nonpregnant women in a cross-sectional study. MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively.

RESULTS

We found higher plasma pro-MMP-9 levels, and higher pro-MMP-9/TIMP-1 ratios in women with gestational hypertension (95%-CI: 1.031 to 2.357, and 0.012 to 0.031, respectively), but not with preeclampsia, compared with those found in normotensive pregnant women (95%-CI: 0.810 to 1.350, and 0.006 to 0.013, respectively; both P<0.05). We found no significant differences in pro-MMP-2 levels (P>0.05).

CONCLUSIONS

The higher net MMP-9 (but not MMP-2) activity in gestational hypertension compared with normotensive pregnancy suggests that MMP-9 plays a role in the pathophysiology of gestational hypertension. Conversely, the lack of such alterations in preeclampsia is consistent with the notion that different pathophysiological mechanisms are involved in these hypertensive disorders.

The cloning and expression of matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase 2 in normal canine lymph nodes and in canine lymphoma

Matrix metalloproteinase-2 (MMP-2) and its inhibitor, tissue inhibitor of matrix metalloproteinase 2 (TIMP2), are known to be important in cancer. The purposes of this study were to determine the cDNA sequence of canine MMP-2 and to investigate the expression patterns of MMP-2 and TIMP2 in normal canine lymph nodes and spontaneously arising canine lymphomas. We cloned and sequenced a PCR product containing most (1901 base pairs) of the coding sequence of canine MMP-2 that translates into a 623 amino acid protein. The cDNA and deduced amino acid sequences are highly homologous to those of other mammalian species. Canine MMP-2 and TIMP2 mRNAs were detectable in the majority of normal lymph node and lymphomatous samples evaluated. No statistical difference was identified when comparing the expression of either gene with regard to normal versus neoplastic nodes, nodal versus extranodal lymphoma, lymphoma grade, or B versus T cell immunophenotype.

Soybean saponin inhibits tumor cell metastasis by modulating expressions of MMP-2, MMP-9 and TIMP- 2

The antimetastatic properties of soybean saponin were investigated by evaluating matrix metalloproteinase (MMP-2 and MMP-9) production in HT-1080 cells. The mRNA expression levels of MMP-2 and MMP-9 were determined by RT-PCR analysis. The levels of secreted MMP-2, MMP-9 and tissue inhibitor of metalloproteinase-2 (TIMP-2) were determined by gelatin zymography and/or ELISA. The invasion of a Matrigel-coated membrane by human fibrosarcoma HT-1080 and HT-29 colon cancer cells was quantitatively assessed by counting the migrated cells. The treatment of HT-1080 cells with soybean saponin inhibited the mRNA expression of and reduced the amounts of secreted MMP-2 and MMP-9, whereas it increased the amount of secreted TIMP-2 dose-dependently. Soybean saponin significantly inhibited the invasion of HT-1080 cells through a Matrigel-coated membrane. The antimetastatic properties by soybean saponin were further confirmed by in vivo mice experiment via the tail vein injection of CT-26 colon cancer cells after feeding the mice the dietary soybean saponin. The incidence of metastatic tumor colonization of lungs of mice moderately decreased 2 weeks after the tail vein injection of CT-26 cells. Our current data support the notion that soybean saponin inhibits tumor cell metastasis by suppressing MMP-2 and MMP-9 productions, and stimulating TIMP-2 secretion, thereby suggesting that soybean saponin has a chemopreventive property against cancer metastasis.

[Inhibitory effect of recombinant anti-angiogenic peptide of tumstatin on growth and metastasis of human ovarian cancer transplanted in nude mice]

OBJECTIVE

To evaluate the anti-angiogenic activity of peptide 21 obtained by modification of tumstatin, and its inhibitory effect on the growth and metastasis of human ovarian cancer transplanted in nude mice.

METHODS

The peptide 21 was purified by affinity chromatography. Human ovarian cancer SKOV3 cells were inoculated in nude mice and the transplanted tumor was treated with the peptide 21 to observe the tumor growth and metastasis. The microvessel density (MVD) and immunohistochemical staining index of PCNA, VEGF and MMP-2 and TIMP-2 were performed to assess the inhibitory effect of the peptide 21.

RESULTS

In the nude mice at 21 days after peptide 21 treatment, the inhibition rate of tumor growth was 53.17%, the tumor microvessel density was significantly reduced (P <0.05), the expression of PCNA, VEGF and MMP-2 were significantly lower (P <0.01), and TIMP-2 expression was significantly higher (P <0.01) in comparison with that of control group.

CONCLUSION

The peptide 21 generated in this study has a significant anti-angiogenetic activity, showing significant inhibitory effect on the growth of human ovarian cancer transplanted in nude mice. The mechanism of its inhibitory action on ovarian cancer growth may be mediated by reduction of neovascularization and reduction of expression of angiogenetic factors.

Gamma-irradiation enhances RECK protein levels in Panc-1 pancreatic cancer cells

Radiotherapy is an important treatment for many malignant tumors, but there are recent reports that radiation may increase the malignancy of cancer cells by stimulating expression of type IV collagenases. In this study, we examined changes in matrix metalloproteinase (MMP) inhibitors, such as the tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2 and RECK, in response to irradiation in Panc-1 pancreatic cancer cells. Irradiation increased RECK protein levels but not mRNA levels, whereas no significant changes were found in TIMP-1 and TIMP-2. The enhanced RECK protein levels were associated with an increase in MMP inhibitory activity. However, irradiation slightly but reproducibly increased the invasiveness of the Panc-1 cells. Like irradiation, treatment of Panc-1 cells with transforming growth factor (TGF)-Beta1 led to a 2-fold increase in RECK protein levels. Transient transfection with Smad3 also increased RECK protein levels, but transfection with Smad7 markedly reduced them. Stable expression of Smad7 and treatment with SB431542, an inhibitor of TGF-Beta receptor I kinase, abolished TGF-Beta1- and radiation-mediated effects on RECK. Furthermore, irradiation increased levels of phosphorylated Smad3. We conclude that radiation post-transciptionally enhances RECK protein levels in Panc-1 cells, at least in part, via TGF-Beta signaling, and that irradiation increases Panc-1 invasiveness via a mechanism that may not be linked to MMP-2 activity.

[Changes of matrix metalloproteinase 2,9 and tissue inhibitor of metalloproteinase 1, 2, 3 expression level in aged rat lung]

OBJECTIVES

To investigate the underlying mechanism of age related increase of pulmonary fibrosis incidence

METHODS

The levels of pulmonary collagen and TGF-beta1 protein, MMP2,9 mRNA and TIMP 1,2,3 mRNA expression were measured by ELISA and realtime PCR.

RESULTS

As compared with adult rats [(756 +/- 160) pg/g vs (1 000 +/- 246) pg/g, P<0.05] the aged rats had more extracellular matrix components, increased TGF-beta1 protein level, lower (3.15 +/- 1.76 vs 0.17 +/- 0.13, P<0.01) MMP2 mRNA expression and TIMP 1,2,3 mRNA expressions (TIMP1 2.00 +/- 1.74 vs 0.11 +/- 0.06,TIMP2 7.60 +/- 2.51 vs 2.69 +/- 1.76, TIMP3 1.32 +/- 0.46 vs 0.29 +/- 0.16, P<0.01). No difference was observed in MMP9 (1.66 +/- 0.67 vs 1.74 +/- 0.87, P>0.05) mRNA expression.

CONCLUSION

elevation in TGF-beta1 protein level, changes in the expression of MMP2/9 and decreased expression of TIMPS mRNA could be the underlying mechanism of age related increase of pulmonary incidence.

Altered expression of genes regulating angiogenesis in experimental androgen-independent prostate cancer

BACKGROUND

The aim of this study was to investigate how the expression of genes regulating angiogenesis is altered when prostate cancer cells progress into androgen-independency.

METHODS

A gene array specific for angiogenesis was used to compare the human prostate cancer cell line LNCaP (androgen-dependent) with its more angiogenic and tumorigenic subline LNCaP-19 (androgen-independent). Results were verified with real-time RT-PCR, and further investigations were focused on the angiogenesis inhibitor a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1). Expression of ADAMTS1 was investigated in vitro as well as in subcutaneous tumors with real-time RT-PCR and Western blotting. Microvessel density (MVD), versican proteolysis and protein levels of TIMP-2 and TIMP-3, known as ADAMTS1 inhibitors, were also analyzed in tumor xenografts.

RESULTS

The gene array revealed decreased expression of ADAMTS1, ephrin-A5, fibronectin 1, and neuropilin 1 in LNCaP-19 compared to LNCaP, while expression of midkine and VEGF were increased. Further studies showed that mRNA and protein levels of ADAMTS1 were significantly lower in LNCaP-19 compared to LNCaP, both in vitro and in subcutaneous tumors. The amount of ADAMTS1 correlated negatively with MVD, but no relation was found between ADAMTS1 and versican proteolysis.

CONCLUSIONS

Expression of several genes associated with angiogenesis was altered during transition into androgen-independency. Among these, a significant decrease was found for ADAMTS1, whose expression inversely correlated with MVD. Its role in progression of prostate cancer needs further investigation, but this inhibitor of angiogenesis could be an interesting candidate for future anti-angiogenic therapy.

Activities of matrix metalloproteinases and tissue inhibitor of metalloproteinase-2 in idiopathic hemotympanum and otitis media with effusion

CONCLUSION

The expression profile of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-2 (TIMP-2) was specific to the type of middle ear effusion. Further studies are necessary for elucidating its correlation with the sequelae of otitis media with effusion (OME) and idiopathic hemotympanum.

OBJECTIVES

We aimed to investigate the relative activities of gelatinases (MMP-2 and -9), stromelysin-1 (MMP-3), and matrilysin-1 (MMP-7), as well as measuring TIMP-2 levels in the serous and mucous effusions of OME and hemorrhagic effusion of the idiopathic hemotympanum.

MATERIALS AND METHODS

Middle ear effusions were collected from patients with OME and idiopathic hemotympanum, and were classified as mucoid, serous, or hemorrhagic. MMP activity in the effusion samples was examined by gelatin and casein zymography. Levels of TIMP-2 were measured by ELISA. Human temporal bone sections, with and without otitis media (OM), were examined histologically.

RESULTS

One case showed tympanic membrane thinning in the OM group, but none in the control group. While MMP-2 was present in all effusions, the active form of MMP-2 was found only in mucous effusions. MMP-3 and MMP-7 activity was detected only in the mucous effusions. MMP-9 exhibited activity in all effusions, with the highest levels in mucous effusions. TIMP-2 levels were markedly elevated in serous effusions.