Decreased Matrix Metalloproteinase Activity Research Articles

Deflamin Attenuated Lung Tissue Damage in an Ozone-Induced COPD Murine Model by Regulating MMP-9 Catalytic Activity.

Chronic obstructive pulmonary disease (COPD) is comprised of histopathological alterations such as pulmonary emphysema and peribronchial fibrosis. Matrix metalloproteinase 9 (MMP-9) is one of the key enzymes involved in both types of tissue remodeling during the development of lung damage. In recent studies, it was demonstrated that deflamin, a protein component extracted from Lupinus albus, markedly inhibits the catalytic activity of MMP-9 in experimental models of colon adenocarcinoma and ulcerative colitis. Therefore, in the present study, we investigated for the first time the biological effect of deflamin in a murine COPD model induced by chronic exposure to ozone. Ozone exposure was carried out in C57BL/6 mice twice a week for six weeks for 3 h each time, and the treated group was orally administered deflamin (20 mg/kg body weight) after each ozone exposure. The histological results showed that deflamin attenuated pulmonary emphysema and peribronchial fibrosis, as evidenced by H&E and Masson's trichrome staining. Furthermore, deflamin administration significantly decreased MMP-9 activity, as assessed by fluorogenic substrate assay and gelatin zymography. Interestingly, bioinformatic analysis reveals a plausible interaction between deflamin and MMP-9. Collectively, our findings demonstrate the therapeutic potential of deflamin in a COPD murine model, and suggest that the attenuation of the development of lung tissue damage occurs by deflamin-regulated MMP-9 catalytic activity.

Fragile Gene WWOX Guides TFAP2A/TFAP2C-Dependent Actions Against Tumor Progression in Grade II Bladder Cancer.

IntroductionThe presence of common fragile sites is associated with no-accidental chromosomal instability which occurs prior to carcinogenesis. The WWOX gene spans the second most active fragile site: FRA16D. Chromosomal breakage at this site is more common in bladder cancer patients who are tobacco smokers which suggests the importance of WWOX gene loss regarding bladder carcinogenesis. Tryptophan domains of WWOX are known to recognize motifs of other proteins such as AP-2α and AP-2γ allowing protein-protein interactions. While the roles of both AP-2 transcription factors are important for bladder carcinogenesis, their nature is different. Based on the literature, AP-2γ appears to be oncogenic, whereas AP-2α mainly exhibits tumor suppressor character. Presumably, the interaction between WWOX and both transcription factors regulates thousands of genes, hence the aim of the present study was to determine WWOX, AP-2α, and AP-2γ function in modulating biological processes of bladder cancer.MethodsRT-112 cell line (grade II bladder cancer) was subjected to two stable lentiviral transductions. Overall, this resulted in six variants to investigate distinct WWOX, AP-2α, or AP-2γ function as well as WWOX in collaboration with a particular transcription factor. Cellular models were examined with immunocytochemical staining and in terms of differences in biological processes using assays investigating cell viability, proliferation, apoptosis, adhesion, clonogenicity, migration, activity of metalloproteinases and 3D culture growth.ResultsWWOX overexpression increased apoptosis but decreased cell viability, migration and large spatial colonies. AP-2α overexpression decreased tumor cell viability, migratory potential, matrix metalloproteinase-2 activity and clonogenicity. AP-2γ overexpression decreased matrix metalloproteinase-2 activity but increased wound healing, adhesion, clonogenicity and spatial colony formation. WWOX and AP-2α overexpression induced apoptosis but decreased cell viability, adhesion, matrix metalloproteinase-2 activity, overall number of cultured colonies and migration rate. WWOX and AP-2γ overexpression decreased tumor cell viability, proliferation potential, adhesion, clonogenicity and the ability to create spatial structures, but also increased apoptosis or migration rate.ConclusionCo-overexpression of WWOX with AP-2α or WWOX with AP-2γ resulted in a net anti-tumor effect. However, considering this research findings and the difference between AP-2α and AP-2γ, we suggest that this similarity is due to a divergent behavior of WWOX.

Evaluation of the In Vitro and In Vivo Antitumor Efficacy of Peanut Sprout Extracts Cultivated with Fermented Sawdust Medium Against Bladder Cancer

Peanut sprout extracts reportedly exhibit numerous beneficial effects; however, there are few investigations on the biological effects of peanut sprout extracts cultivated with fermented sawdust medium (PSEFS). Here, we examined whether PSEFS demonstrates antitumor activity against bladder cancer, in vitro and in vivo. The results showed that PSEFS prohibited the proliferation of bladder cancer T24 cells, with this effect attributed to induction of cell cycle arrest at the G1 phase through reduced expression of cyclins and cyclin-dependent kinases caused by a promotion of p21WAF1 expression. Additionally, PSEFS induced phosphorylation of p38 mitogen-activated protein kinase. Moreover, PSEFS treatment attenuated the invasive and migratory potential of T24 cells due to decreased matrix metalloproteinase-9 activity combined with downregulation of the transcriptional binding activity of SP1, activator protein -1, and nuclear factor-kappaB. Furthermore, PSEFS (20 mg/kg) attenuated the tumor-growth rate in xenograft mice bearing T24 cells, with an effect equivalent to that of cisplatin and in the absence of toxicity following weight-loss evaluation and hematobiochemical testing of PSEFS-treated mice. These results demonstrated the antitumor efficacy of PSEFS both in vitro and in vivo, thereby reporting it as a potential candidate for development of novel agents against bladder cancer.

Efficient Suppression of Abdominal Aortic Aneurysm Expansion in Rats through Systemic Administration of Statin-Loaded Nanomedicine.

Abdominal aortic aneurysm (AAA) is a life-threatening disease. However, no systemically injectable drug has been approved for AAA treatment due to low bioavailability. Polymeric micelles are nanomedicines that have the potential to improve therapeutic efficacy by selectively delivering drugs into disease sites, and research has mainly focused on cancer treatments. Here, we developed a statin-loaded polymeric micelle to treat AAAs in rat models. The micelle showed medicinal efficacy by preventing aortic aneurysm expansion in a dose-dependent manner. Furthermore, the micelle-injected group showed decreased macrophage infiltration and decreased matrix metalloproteinase-9 activity in cases of AAA.

THU316 - The FXR agonist obeticholic acid decreases matrix metalloproteinase activity via RECK and TIMP modulation in hepatic ischemia/reperfusion injury

THU316 - The FXR agonist obeticholic acid decreases matrix metalloproteinase activity via RECK and TIMP modulation in hepatic ischemia/reperfusion injury

Antiphotoaging Effects of 3,5-Dicaffeoyl-epi-quinic Acid via Inhibition of Matrix Metalloproteinases in UVB-Irradiated Human Keratinocytes.

UVB exposure is one of the causes of several skin complications including but not limited to premature aging, wrinkle formation, and hyperpigmentation. UV-induced skin aging is called photoaging, and oxidative stress-induced overexpression of matrix metalloproteinases (MMPs) is the main reason behind the photoaging-mediated collagen degradation. Natural origin inhibitors of MMPs are regarded as a promising approach to prevent or treat photoaging. Therefore, the present study investigated the protective effects of 3,5-dicaffeoyl-epi-quinic acid (DCEQA) in human HaCaT keratinocytes against UVB irradiation-related dysregulation of MMPs. Changes in the mRNA and protein expression and release of MMP-1, -2, and -9 were observed after UVB irradiation with or without DCEQA treatment. In addition, the effect of DCEQA on the activation of p38, JNK, and ERK MAPKs was analyzed. Treatment of UVB-irradiated HaCaT cells with 10 μM DCEQA significantly suppressed the overexpression of both mRNA and protein of MMP-1, -2, and -9 while slightly increasing the diminished type I procollagen production. UVB-induced activation of MAPKs was also ameliorated by DCEQA treatment in a dose-dependent manner. Results indicated that DCEQA treatment was able to protect keratinocytes from UVB-induced photoaging by inhibiting the stimulated production of MMPs and the related decrease in collagen production. It was suggested that DCEQA downregulated the collagen degradation via inhibition of MAPK activation, which resulted in decreased MMP activity.

Molecular hydrogen accelerates the reversal of acute obstructive cholangitis‑induced liver dysfunction by restoring gap and tight junctions

Gap junctions (GJs) and tight junctions (TJs) are essential to maintain the function of hepatocytes. Changes in biliary tract pressure and the effect of lipopolysaccharide(LPS) may lead to acute obstructive cholangitis (AOC) and cause liver injury via GJ and TJ dysfunction. Hydrogen has been confirmed to have a protective role in various organs during pathological conditions and inflammation. The present study investigated the function of junction proteins and the potential application of H2 in AOC‑induced liver injury. An AOC rat model was established by LPS injection through a bile duct catheter, while the distal bile duct was closed. The catheter sealing caps were removed and bile was allowed to flow out from the catheters at 12h after LPS infusion. The potential application of H2 was studied in the AOC rat model with biliary drainage. It was observed that AOC induced the disruption of junction proteins of both GJs and TJs. H2 administration reversed AOC‑induced disruption of GJs and TJs after biliary drainage. The mechanism of this phenomenon suggests that H2 may have effectively attenuated AOC‑induced inflammatory and oxidative damage, and decreased matrix metalloproteinase activity. H2 may accelerate the reversal of AOC‑induced liver dysfunction, and this phenomenon may depend on reversing the inhibition of GJs and TJs.

RNA interference screening identifies clathrin-B and cofilin-1 as mediators of MT1-MMP in endometrial cancer

The matrix metalloproteinases (MMPs) are implicated in tumor invasion and metastasis. Given their multiple tumor promoting roles, MMPs are promising targets for the treatment of metastatic cancer. Using a siRNA library screen of 140 membrane trafficking genes, we identified 41 genes in HEC-1B and 36 in Ishikawa cancer cells that decreased metalloproteinases activity. The 16 genes common in both cancer cell lines that decreased MMPs activity are involved in cargo sorting, vesicle formation and vesicle recycling. The top two genes clathrin-B and cofilin-1 were chosen for post hoc functional studies. Higher expression of both genes was confirmed in cancer cells and knockdown with respective siRNAs inhibited their invasive potential and matrix metalloproteinases activity. Membrane Type 1- Matrix Metalloproteinase (MT1-MMP) is a master switch proteinase and regulator of invasion and metastasis. A marked decrease in MT1-MMP expression and activity was seen in clathrin-B and cofilin-1 knockdown cancer cells which was associated with a marked decreased expression of invadopodia formation proteins. Our results suggest that the decreased expression of clathrin-B and cofilin-1 decreases the expression of MT1-MMP and results in attenuation of MT1-MMP at the cell surface, thus inhibiting tumor cell invasion and metastasis.

Extracellular Matrix Regulation and Dysregulation in Exfoliation Syndrome.

Several lines of evidence, such as ultrastructural signs for activated fibrillogenesis and excessive production of elastic microfibrillar components in the anterior segment of the eye and throughout the body, indicate that exfoliation syndrome (XFS) is an elastic microfibrillopathy, leading to the accumulation of an abnormal extracellular fibrillar material (XFM). The upregulation of elastic microfibrillar components is paralleled by the selective upregulation of the cross-linking enzyme lysyl oxidase-like 1 (LOXL1) in the early phase of the disease, suggesting that LOXL1 participates in the stabilization of newly synthesized elastic proteins and finally in the stable accumulation of XFM. Whereas the excessive production of elastic proteins rises from early to late XFS stages, possibly mediated by increasing fibrogenic stimuli in the aqueous humor, LOXL1 is downregulated in late stages of the disease by as yet unknown mechanisms, possibly leading to the well-documented elastotic matrix alterations characteristic of eyes with late stage XFS. Several studies indicate complex changes of the proteolytic balance in the anterior segment of XFS eyes, characterized primarily by decreased matrix metalloproteinase-2 activity, the major aqueous matrix metalloproteinase, potentially leading to a shift from appropriate matrix turnover to progressive matrix accumulation. In contrast, in nearly all tissues of the posterior segment, XFM seems to be absent and differential gene expression is confined to the lamina cribrosa, characterized by a stage-independent, primary, and XFS-specific downregulation of LOXL1 and elastic components in XFS eyes. Concomitant with this deficiency, the laminar elastic fiber network displays prominent ultrastructural alterations, which may lead to increased vulnerability to glaucomatous damage. Various growth factors, stress conditions, or dietary factors have been supposed to potentially influence the manifestation of the disease. However, in spite of increasing knowledge, the pathogenetic factors initiating the abnormal matrix process still remain elusive. Such information would be critical for our understanding of disease progression and would disclose new options for pharmaceutical intervention at the onset of the disease.

Hypoxia Activates Src and Promotes Endocytosis Which Decreases MMP-2 Activity and Aggravates Renal Interstitial Fibrosis.

The aggravation of renal interstitial fibrosis in the advanced-stage of chronic kidney disease is related to decreased matrix metalloproteinase-2 (MMP-2) activity, which is induced by hypoxia in the kidney; however, the specific mechanism remains unclear. We previously demonstrated that inhibition of Caveolin-1, a key gene involved in endocytosis, increased MMP-2 activity in hypoxic HK-2 cells. It has been reported that activated Src (phospho-Src Tyr416) is a key molecule in multiple fibrotic pathways. However, whether Src functions on the regulation of Caveolin-1 and MMP-2 activity in hypoxic HK-2 cells remains poorly understood. To explore the underlying mechanism, a rat model of renal interstitial fibrosis was established, then we observed obvious hypoxia in fibrotic kidney tissue and the protein levels of phospho-Src and Caveolin-1 increased, while MMP-2 activity decreased. Next, we treated HK-2 cells with the phospho-Src inhibitor PP1. Compared with normal cells grown in hypoxia, in cells treated with PP1, the protein levels of phospho-Src and Caveolin-1 decreased, as did the protein levels of the MMP-2-activity-regulated molecules RECK (reversion-inducing-cysteine-rich protein with kazal motifs) and TIMP-2 (tissue inhibitor of metalloproteinase-2), while the protein level of MT1-MMP (membrane type 1-matrix metalloproteinase) increased and MMP-2 activity was enhanced. Therefore, hypoxia promotes the phosphorylation of Src and phospho-Src can enhance the endocytosis of HK-2 cells, which leads to decreased MMP-2 activity and aggravates renal interstitial fibrosis.

Rat supraspinatus tendon responds acutely and chronically to exercise.

The objective of this study was to identify acute responses and chronic adaptations of supraspinatus tendon to noninjurious exercise. We hypothesized that chronic exercise (EX) increases tendon mechanical properties, and a single exercise bout increases matrix metalloproteinase (MMP) activity acutely. Rats were divided into acute or chronic EX or cage activity groups. Animals in acute EX groups were euthanized, 3, 12, 24, 48, or 72 h upon completion of a single bout of exercise (10 m/min, 1 h) on a flat treadmill. Animals in chronic EX groups walked on a flat treadmill for 3 days or 1, 2, or 8 wk. Tendon histology, MMP activity, and mechanics were measured. A single bout of exercise trended toward reducing tendon mechanical properties, but 2 or 8 wk of chronic EX increased tendon mechanics. Cell density was not affected. Cells became rounder with chronic EX. All tendons were highly organized. MMP activity decreased after a single bout of exercise and returned to baseline by 72 h. MMP activity decreased after 8 wk of chronic EX. Decreased MMP activity may indicate an anabolic instead of catabolic response in contrast to injury. Results suggest that mild, acute decreases in MMP activity and tendon mechanics following a single exercise bout lead to enhanced tendon mechanical adaptations with repeated exercise bouts. This study defines acute and chronic changes of MMP activity, mechanical properties, and histology of the rat supraspinatus tendon in response to beneficial exercise and proposes a mechanism by which acute responses translate to chronic adaptations.NEW & NOTEWORTHY The line between beneficial exercise and overuse has not been elucidated. This study defines the acute and chronic temporal response to exercise of supraspinatus tendon in an in vivo model. We found that decreased matrix metalloproteinase activity and tendon mechanics after a single bout of exercise are followed by beneficial chronic adaptations of the tendon with repeated bouts. How the acute responses to exercise lead to chronic adaptations may distinguish beneficial exercise from overuse.

Long-term miR-29b suppression reduces aneurysm formation in a Marfan mouse model.

Aortic root aneurysm formation and subsequent dissection and/or rupture remain the leading cause of death in patients with Marfan syndrome. Our laboratory has reported that miR‐29b participates in aortic root/ascending aorta extracellular matrix remodeling during early aneurysm formation in Fbn1 C1039G/+ Marfan mice. Herein, we sought to determine whether miR‐29b suppression can reduce aneurysm formation long‐term. Fbn1 C1039G/+ Marfan mice were treated with retro‐orbital LNA‐anti‐miR‐29b inhibitor or scrambled‐control‐miR before aneurysms develop either (1) a single dose prenatally (pregnant Fbn1 C1039G/+ mice at 14.5 days post‐coitum) (n = 8–10, each group) or (2) postnatally every other week, from 2 to 22 weeks of age, and sacrificed at 24 weeks (n = 8–10, each group). To determine if miR‐29b blockade was beneficial even after aneurysms develop, a third group of animals were treated every other week, starting at 8 weeks of age, until sacrificed (n = 4–6, each group). miR‐29b inhibition resulted in aneurysm reduction, increased elastogenesis, decreased matrix metalloproteinase activity and decreased elastin breakdown. Prenatal LNA‐anti‐miR‐29b inhibitor treatment decreased aneurysm formation up to age 32 weeks, whereas postnatal treatment was effective up to 16 weeks. miR‐29b blockade did not slow aortic growth once aneurysms already developed. Systemic miR‐29b inhibition significantly reduces aneurysm development long‐term in a Marfan mouse model. Drug administration during aortic wall embryologic development appears fundamental. miR‐29b suppression could be a potential therapeutic target for reducing aneurysm formation in Marfan syndrome patients.

Elevated MTSS1 expression associated with metastasis and poor prognosis of residual hepatitis B-related hepatocellular carcinoma.

BackgroundHepatectomy generally offers the best chance of long-term survival for patients with hepatocellular carcinoma (HCC). Many studies have shown that hepatectomy accelerates tumor metastasis, but the mechanism remains unclear.MethodsAn orthotopic nude mice model with palliative HCC hepatectomy was performed in this study. Metastasis-related genes in tumor following resection were screened; HCC invasion, metastasis, and some molecular alterations were examined in vivo and in vitro. Clinical significance of key gene mRNA expression was also analyzed.ResultsMetastasis suppressor 1 (MTSS1) located in the central position of gene function net of residual HCC. MTSS1 was up-regulated in residual tumor after palliative resection. In hepatitis B-related HCC patients undergone palliative hepatectomy, those with higher MTSS1 mRNA expression accompanied by activation of matrix metalloproteinase 2 (MMP2) in residual HCC, had earlier residual HCC detection after hepatectomy and poorer survival when compared to those with lower MTSS1. In different cell lines, the levels of MTSS1 mRNA increased in parallel with metastatic potential. MTSS1 down regulation via siRNA decreased MMP2 activity, reduced invasive potentials of HCC by 28.9 % in vitro, and averted the deteriorated lung metastatic extent in vivo.ConclusionsThe poor prognosis of hepatitis B-related HCC patients following palliative hepatectomy associates with elevated MTSS1 mRNA expression; therefore, MTSS1 may provide a new research field for HCC diagnosis and treatment.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0361-8) contains supplementary material, which is available to authorized users.

Light-emitting diode therapy increases collagen deposition during the repair process of skeletal muscle.

This study analyzed the effects of light-emitting diode (LED) therapy on the morphology of muscle tissue as well as collagen remodeling and matrix metalloproteinase 2 (MMP-2) activity in the skeletal muscle of rats following acute injury. Wistar rats were divided into four groups: (1) control, (2) sham, (3) untreated cryoinjury, and (4) cryoinjury treated with LED. Cryoinjury was induced by two applications of a metal probe cooled in liquid nitrogen directly onto the belly of the tibialis anterior muscle. For treatment, the LED equipment (wavelength 850 nm, output power 30 mW, and total energy 3.2 J) was used daily. The study periods were 1, 3, and 7 days after cryoinjury. Morphological aspects were evaluated through hematoxylin-eosin staining. The amount of collagen fibers was evaluated using Picro Sirius Red staining under polarized light. The gelatinase activity of MMP-2 was evaluated using zymography. The results showed significant reductions in inflammatory infiltrate after 3 days and an increased number of immature muscle fibers after 7 days. Furthermore, treatment induced a reduction in the gelatinolytic activity of MMP-2 after 1, 3, and 7 days in comparison to the untreated injury groups and increased the collagen deposition after 3 and 7 days in the treated groups. LED therapy at 850 nm induced a significant reduction in inflammation, decreased MMP-2 activity, and increased the amount of immature muscle and collagen fibers during the muscle repair process following acute injury.

Pterostilbene Inhibits Vascular Smooth Muscle Cells Migration and Matrix Metalloproteinase-2 through Modulation of MAPK Pathway.

Smooth muscle cells (SMCs) migration and matrix metalloproteinase-2 (MMP-2) activation are main roles in atherosclerosis. Pterostilbene (trans-3, 5-dimethoxy-4-hydroxystilbene) is known to have various pharmacologic effects such as anti-inflammatory and anticarcinogenic properties. The present study aimed to investigate the anti-atheroscleroic property of pterostilbene in the rat smooth muscle cell (SMC) A7r9 cell lines and the underlying mechanisms. In this study, pterostilbene treatment significantly inhibited migration/invasion capacities of in A7r9 cell. Pterostilbene was also found to significantly decreased MMP-2 activity and expression by gelatin zymography and western blot assay in SMC. In the MAPK signaling pathway, western blot assay also indicated that pterostilbene up-regulated the phosphorylation of extracellular-signal-regulated kinase (Erk)1/2. Moreover, inhibition of Erk1/2 by specific inhibitors significantly abolished the pterostilbene-decreased expression of MMP-2 and migration/invasion capacities. These findings suggest that pterostilbene inhibited SMC migration and that MMP-2 activation could be mediated via Erk1/2 phosphorylation. It is further possible that pterostilbene could play a novel role in the treatment of atherosclerosis. Pterostilbene is a plant polyphenol compound that is principally found in blueberries. In this study, we found that pterostilbene could inhibit SMCs migration via down-regulation of MMP-2. Particularly, expression of MMP-2 was found to be strongly associated with the phosphorylation of Erk1/2.

Dimethyl fumarate attenuates cerebral edema formation by protecting the blood–brain barrier integrity

Brain edema is a hallmark of various neuropathologies, but the underlying mechanisms are poorly understood. We aim to characterize how tissue hypoxia, together with oxidative stress and inflammation, leads to capillary dysfunction and breakdown of the blood–brain barrier (BBB). In a mouse stroke model we show that systemic treatment with dimethyl fumarate (DMF), an antioxidant drug clinically used for psoriasis and multiple sclerosis, significantly prevented edema formation in vivo. Indeed, DMF stabilized the BBB by preventing disruption of interendothelial tight junctions and gap formation, and decreased matrix metalloproteinase activity in brain tissue. In vitro, DMF directly sustained endothelial tight junctions, inhibited inflammatory cytokine expression, and attenuated leukocyte transmigration. We also demonstrate that these effects are mediated via activation of the redox sensitive transcription factor NF-E2 related factor 2 (Nrf2). DMF activated the Nrf2 pathway as shown by up-regulation of several Nrf2 target genes in the brain in vivo, as well as in cerebral endothelial cells and astrocytes in vitro, where DMF also increased protein abundance of nuclear Nrf2. Finally, Nrf2 knockdown in endothelial cells aggravated subcellular delocalization of tight junction proteins during ischemic conditions, and attenuated the protective effect exerted by DMF. Overall, our data suggest that DMF protects from cerebral edema formation during ischemic stroke by targeting interendothelial junctions in an Nrf2-dependent manner, and provide the basis for a completely new approach to treat brain edema.

Acute eccentric resistance exercise decreases matrix metalloproteinase activity in obese elderly women.

The association of ageing with obesity commits elderly women and has been correlated with multiple degenerative processes, which could be occasioned by an enhancing in levels of matrix metalloproteinase-2 and metalloproteinase-9 (MMPs) as well by an cytokine unbalance that included an enhancing on interleukin-6 (IL-6). Furthermore, other factors could be also related to degenerative process, as they could be reduced by eccentric resistance exercise (ERE), which seems particularly important to initiate resistance training in obese older adults. In this view, this study aims to determinate the effects of an acute ERE session on serum MMP-2, MMP-9 and IL-6 in elderly obese women. Ten elderly obese women participated in this study and completed a 10 repetitions maximum test (10 RM) utilizing leg extension exercise. Subjects then completed an acute ERE session consisting of seven sets of 10 repetitions at 110% of 10 RM with a rest of 3 min between sets. Blood samples were collected before, immediately after, 3, 24 and 48 h following the ERE session. Zymograms were utilized to measure the MMP-2 and MMP-9 enzymes from all individuals. Moreover, IL-6 concentration was also determinated. After ERE session, MMP-2 and MMP-9 decreased, remaining significantly below baseline values after 48 h (P<0·05). Although not statistically significant, there was a tendency for IL-6 to decrease 48 h after the ERE when compared with 3 h (P = 0·06). An acute ERE session decreases MMP-9, MMP-2 and IL-6 in elderly obese women, possibly indicating a transient protection against the low grade inflammation present in this specific population.

Antioxidant effect of doxycycline decreases MMP activity and blood pressure in SHR

Increased matrix metalloproteinase (MMP) levels are involved in vascular remodeling of hypertension. In this study, we hypothesized that doxycycline (a MMP inhibitor) could exert antioxidant effects, reverse establish vascular remodeling, and lower blood pressure in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto rats received either doxycycline at 30mg/kg/day by gavage or vehicle. Systolic blood pressure (SBP) was assessed weekly by tail cuff. After 5weeks of treatment, morphologic changes in the aortic wall were studied in hematoxylin/eosin sections. MMP activity and expression were determined by in situ zymography using DQ gelatin and immunofluorescence for MMP-2. Dihydroethidium was used to evaluate aortic reactive oxygen species (ROS) production by fluorescence microscopy. Doxycycline reduced SBP by 25mmHg. However, the antihypertensive effects were not associated with significant reversal of hypertension-induced vascular hypertrophy. SHR showed increased aortic MMP-2 levels which co-localized with higher aortic MMP activity and ROS levels, and all those biochemical alterations associated with hypertension were blunted by treatment with doxycycline. These results show that MMP inhibition with doxycycline in SHR with established hypertension resulted in antioxidant effects, lower gelatinolytic activity, and antihypertensive effects which were not associated with reversal of hypertension-induced vascular remodeling.

Effect of proton beam irradiation on the regulation of metastasis-enhancing factors in MCF-7 human breast cancer cells

Metastasis is a major cause of poor prognosis and recurrence in cancer patients. We have previously reported that cancer metastasis may be prevented by proton beam irradiation via the induction of tissue inhibitor of matrix metalloproteases-1 and -2, known as anti-metastatic factors, and the suppression of aromatase in MCF-7 human breast cancer cells. However, the prior report did not show the effect of proton beam irradiation on metastasis-enhancing factors. Therefore, in this study, the effects of proton beam irradiation on the regulation of metastasis-enhancing factors, including cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9), urokinase plasminogen activator (uPA) and uPA receptor (uPAR), were investigated in MCF-7 human breast cancer cells. 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced expression of COX-2, an important protein in metastasis and tumor growth in breast cancer, was down-regulated in a dose-dependent manner in MCF-7 human breast cancer cells irradiated by a proton beam. Proton beam irradiation also decreased MMP-9 activity and expression induced by TPA. Furthermore, proton beam irradiation dose-dependently inhibited uPA and uPA receptor (uPAR) expression. In conclusion, the present investigation demonstrated that TPA-induced metastatic activity in MCF-7 human breast cancer cells is effectively lessened by proton beam irradiation via the reversal of COX-2, MMP-9, uPA and uPAR expressions and MMP-9 activity.

Overexpression of Catalase in Vascular Smooth Muscle Cells Prevents the Formation of Abdominal Aortic Aneurysms

Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species promotes the development of AAA remains unclear. Here, we investigate the effect of hydrogen peroxide (H2O2)-degrading enzyme catalase on the formation of AAA. AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.91 ± 0.1 versus 0.76 ± 0.09 mm). Similarly, in a transgenic mouse model, catalase overexpression in the vascular smooth muscle cells preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85 ± 0.14 versus 0.57 ± 0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacological administration or genetic overexpression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and vascular smooth muscle cell apoptosis was evident in aortas of catalase-overexpressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic overexpression of catalase in vascular smooth muscle cells did not alter the total aortic H2O2 levels. The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic vascular smooth muscle cell survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity.