Clinical implications of matrix metalloproteinases

Maternal diabetes increases FOXO1 activation during embryonic cardiac development

Maternal diabetes is known to affect heart development, inducing the programming of cardiac alterations in the offspring's adult life. Previous studies in the heart of adult offspring have shown increased activation of FOXO1 (a transcription factor involved in a wide variety of cellular functions such as apoptosis, cellular proliferation, reactive oxygen species detoxification, and antioxidant and pro-inflammatory processes) and of target genes related to inflammatory and fibrotic processes. In this work, we aimed to evaluate the effects of maternal diabetes on FOXO1 activation as well as on the expression of target genes relevant to the formation of the cardiovascular system during organogenesis (day 12 of gestation). The embryonic heart from diabetic rats showed increased active FOXO1 levels, reduced protein levels of mTOR (a nutrient sensor regulating cell growth, proliferation and metabolism) and reduced mTORC2-SGK1 pathway, which phosphorylates FOXO1. These alterations were related to increases in the levels of 4-hydroxynonenal (an oxidative stress marker) and increased mRNA levels of inducible nitric oxide synthase, angiopoietin-2 and matrix metalloproteinase-2 (MMP2) (all FOXO1 target genes relevant for cardiac development). Results also showed increased extracellular and intracellular immunolocalization of MMP2 in the myocardium and its projection into the lumen of the cavity (trabeculations) together with decreased immunostaining of connexin 43, a protein relevant for cardiac function that is target of MMP2. In conclusion, increases in active FOXO1 induced by maternal diabetes initiate early during embryonic heart development and are related to increases in markers of oxidative stress and of proinflammatory cardiac development, as well to an altered expression of proteolytic enzymes that regulate connexin 43. These alterations may lead to an altered programming of cardiovascular development in the embryonic heart of diabetic rats.

Berberine Regulated miR150-5p to Inhibit P2X7 Receptor, EMMPRIN and MMP-9 Expression in oxLDL Induced Macrophages

Elevated extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase-9 (MMP-9) in oxidized low density lipoprotein (oxLDL)-induced macrophages leads to the progression of vulnerable plaques by degradation of the extracellular matrix. Our previous report showed that berberine regulates the expression of both EMMPRIN and MMP-9. In addition, P2X7 receptor (P2X7R) upregulation plays a crucial role in the development of atherosclerosis. However, it is unclear whether berberine regulated P2X7R level to inhibit both EMMPRIN and MMP-9 expession in macrophages. In the present study, we investigated the impact of berberine on P2X7R expression and the regulation of P2X7R in the expression of EMMPRIN and MMP-9 in oxLDL-induced macrophages. We found that P2X7R expression was increased, miR150-5p was reduced in oxLDL-induced macrophages, relatively. And A-438079 (a P2X7R inhibitor) or miR150-5p mimic treatment greatly reversed the upregulation of EMMPRIN and MMP-9 expression. Moreover, A-438079 significantly reduced oxLDL-induced AMP-activated protein kinase-α (AMPK-α) phosphorylation and reversed the activation of mitogen-activated protein kinase (MAPK), which in turn decreased the expression of EMMPRIN and MMP-9. These findings illustrate that P2X7R suppresses EMMPRIN and MMP-9 expression by inhibiting the AMPK-α/MAPK pathway in oxLDL-induced macrophages. Accordingly, exposure to berberine markedly upregulated miR150-5p, decreased P2X7R expression and downregulated MMP-9 and EMMPRIN levels in oxLDL-induced macrophages, resulting in AMPK-α/MAPK (JNK, p38, and ERK) inactivation. Overall, these results indicate that berberine increased miR150-5p level, subsequently inhibits P2X7R-mediated EMMPRIN and MMP-9 expression by suppressing AMPK-α and MAPK signaling in oxLDL-induced macrophages.

Selective toxicity of antibacterial agents-still a valid concept or do we miss chances and ignore risks?

BACKGROUND

Selective toxicity antibacteribiotics is considered to be due to interactions with targets either being unique to bacteria or being characterized by a dichotomy between pro- and eukaryotic pathways with high affinities of agents to bacterial- rather than eukaryotic targets. However, the theory of selective toxicity oversimplifies the complex modes of action of antibiotics in pro- and eukaryotes.

METHODS AND OBJECTIVE

This review summarizes data describing multiple modes of action of antibiotics in eukaryotes.

RESULTS

Aminoglycosides, macrolides, oxazolidinones, chloramphenicol, clindamycin, tetracyclines, glycylcyclines, fluoroquinolones, rifampicin, bedaquillin, ß-lactams inhibited mitochondrial translation either due to binding to mitosomes, inhibition of mitochondrial RNA-polymerase-, topoisomerase 2ß-, ATP-synthesis, transporter activities. Oxazolidinones, tetracyclines, vancomycin, ß-lactams, bacitracin, isoniazid, nitroxoline inhibited matrix-metalloproteinases (MMP) due to chelation with zinc and calcium, whereas fluoroquinols fluoroquinolones and chloramphenicol chelated with these cations, too, but increased MMP activities. MMP-inhibition supported clinical efficacies of ß-lactams and daptomycin in skin-infections, and of macrolides, tetracyclines in respiratory-diseases. Chelation may have contributed to neuroprotection by ß-lactams and fluoroquinolones. Aminoglycosides, macrolides, chloramphenicol, oxazolidins oxazolidinones, tetracyclines caused read-through of premature stop codons. Several additional targets for antibiotics in human cells have been identified like interaction of fluoroquinolones with DNA damage repair in eukaryotes, or inhibition of mucin overproduction by oxazolidinones.

CONCLUSION

The effects of antibiotics on eukaryotes are due to identical mechanisms as their antibacterial activities because of structural and functional homologies of pro- and eukaryotic targets, so that the effects of antibiotics on mammals are integral parts of their overall mechanisms of action.

Olive oil supplementation prevents extracellular matrix deposition and reduces prooxidant markers and apoptosis in the offspring´s heart of diabetic rats

Maternal diabetes induces fetal programming of cardiovascular diseases. Diabetes induced-cardiac fibrosis is a process that may start in utero and may be related to the prooxidant/proinflammatory environment. The aim of this study was to investigate the effect of a maternal diet enriched in olive oil on the levels of components and regulators of the extracellular matrix, on prooxidant markers and on apoptosis rate in the heart of 21-day-old offspring of diabetic rats. Maternal diabetes was induced by neonatal administration of streptozotocin. During pregnancy, diabetic and control rats were fed with diets supplemented or not with 6% olive oil. The heart of the offspring was studied at 21 days of age. We found increased deposition of collagen IV and fibronectin in the offspring´s heart of diabetic rats, which was prevented by the maternal diets enriched in olive oil. Increases in connective tissue growth factor were also prevented by the maternal diets enriched in olive oil. Prooxidant markers as well as apoptosis, which were increased in the heart of the offspring of diabetic rats, were prevented by the maternal olive oil dietary treatment. Our findings identified powerful effects of a maternal diet enriched in olive oil on the prevention of increased extracellular matrix deposition and increased prooxidant markers in the heart of 21-day-old offspring of diabetic rats.

Isoniazid and Rifampicin Produce Hepatic Fibrosis through an Oxidative Stress-Dependent Mechanism

METHODS

A combined dose of INH (50 mg) and RMP (100 mg) per kg body weight per day was administered to mice by oral gavage, 6 days a week, for 4 to 24 weeks for the assessment of liver injury, oxidative stress, and development of hepatic fibrosis, including demonstration of changes in key fibrogenesis linked pathways and mediators.

RESULTS

Progressive increase in markers of hepatic stellate cell (HSC) activation associated with changes in matrix turnover was observed between 12 and 24 weeks of INH-RMP treatment along with the elevation of liver collagen content and significant periportal fibrosis. These were associated with concurrent apoptosis of the hepatocytes, increase in hepatic cytochrome P450 2E1 (CYP2E1), NADPH oxidase (NOX) activity, and development of hepatic oxidative stress.

CONCLUSIONS

INH-RMP can activate HSC through generation of NOX-mediated oxidative stress, leading to the development of liver fibrosis.

Correlation of Baseline Plasma and Inguinal Connective Tissue Metalloproteinases and Their Inhibitors With Late High-Pressure Endoleak After Endovascular Aneurysm Repair: Long-term Results

Purpose: To investigate whether plasma and connective tissue matrix metalloproteinases (MMP) and their inhibitors (TIMP) may predict late high-pressure endoleak after endovascular aneurysm repair (EVAR). Materials and Methods: Samples of inguinal fascia and blood were collected in 72 consecutive patients (mean age 73.1 years; 68 men) undergoing primary EVAR with the Endurant stent-graft. Baseline plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 and baseline MMP-2 and MMP-9 activity estimated using gelatin zymography (GZ) were compared between patients who developed late endoleak in follow-up and those who did not. Subgroup analyses were performed between patients with (n=18) and without inguinal hernias and between patients with moderate-diameter (50–59 mm; n=45) or large-diameter (≥60 mm; n=27) abdominal aortic aneurysms (AAA) at primary EVAR. Results: The mean follow-up period was 63.1 months (range 7.5–91.5), during which time 13 (18.1%) patients developed type I (6 Ia and 5 Ib) or 2 type III endoleaks. Only GZ-analyzed proMMP-9 concentrations were higher in the endoleak group than in patients without endoleak (mean difference 8.44, 95% CI −19.653 to −1.087, p=0.03). The patients with primary inguinal hernia at presentation had significantly higher tissue TIMP-2 values (0.8±0.7 vs 0.5±0.4, p=0.018) but lower plasma total (pro- + active) MMP-9 values (11.9±7.8 vs 16.2±7.4, p=0.042) than patients without hernias at the time of EVAR. Patients with AAAs ≥60 mm had significantly higher mean tissue homogenate levels of total (pro- + active) MMP-9 (p=0.025) and total (pro- + active) MMP-2 (p=0.049) as well as higher proMMP-9 (p=0.018) and total (pro- + active) MMP-9 (p=0.021) levels based on GZ compared to patients with moderate-diameter AAAs. Regression analysis revealed a significant association between total (pro- + active) MMP-9 plasma samples and the presence of hernia (OR 0.899, 95% CI 0.817 to 0.989, p=0.029) and between GZ-analyzed proMMP-9 and late endoleak (OR 1.055, 95% CI 1.007 to 1.106, p=0.025). GZ-analyzed proMMP-9 and active MMP-9 were strong predictors of late endoleak in patients with hernia (p=0.012 and p=0.044, respectively) and in patients with AAAs ≥60 mm (p=0.018 and p=0.041 respectively). Conclusion: Inguinal fascial tissue proMMP-9 significantly predicted late endoleak. ProMMP-9 and active MMP-9 biomarkers are significantly associated with late endoleak in hernia patients and in patients with AAAs ≥60 mm. Considering the clinical association between hernia and AAA and the fact that the AAA wall connective tissue environment remains exposed to systemic circulation after EVAR, inguinal fascia extracellular matrix dysregulation and altered MMP activity may reflect similar changes in AAA biology, leading to complications such as endoleak.

Matrix Metalloproteinases in Renal Diseases: A Critical Appraisal

Matrix metalloproteinases (MMPs) are endopeptidases within the metzincin protein family that not only cleave extracellular matrix (ECM) components, but also process the non-ECM molecules, including various growth factors and their binding proteins. MMPs participate in cell to ECM interactions, and MMPs are known to be involved in cell proliferation mechanisms and most probably apoptosis. These proteinases are grouped into six classes: collagenases, gelatinases, stromelysins, matrilysins, membrane type MMPs, and other MMPs. Various mechanisms regulate the activity of MMPs, inhibition by tissue inhibitors of metalloproteinases being the most important. In the kidney, intrinsic glomerular cells and tubular epithelial cells synthesize several MMPs. The measurement of circulating MMPs can provide valuable information in patients with kidney diseases. They play an important role in many renal diseases, both acute and chronic. This review attempts to summarize the current knowledge of MMPs in the kidney and discusses recent data from patient and animal studies with reference to specific diseases. A better understanding of the MMPs' role in renal remodeling may open the way to new interventions favoring deleterious renal changes in a number of kidney diseases.

Altered FOXO1 activation in the programming of cardiovascular alterations by maternal diabetes

Maternal diabetes programs cardiovascular alterations in the adult offspring but the mechanisms involved remain unclarified. Here, we addresed whether maternal diabetes programs cardiac alterations related to extracellular matrix remodeling in the adult offspring, as well as the role of forkhead box transcription factor 1 (FOXO1) in the induction of these alterations. The heart from adult offspring from control and streptozotocin-induced diabetic rats was evaluated. Increased glycemia, triglyceridemia and insulinemia and markers of cardiomyopathy were found in the offspring from diabetic rats. In the heart, an increase in active FOXO1 and mRNA levels of its target genes, Mmp-2 and Ctgf, genes related to an altered extracellular matrix remodeling, together with an increase in collagen deposition and a decrease in the connexin43 levels, were found in the offspring from diabetic rats. Altogether, these results suggest an important role of FOXO1 activation in the cardiac alterations induced by intrauterine programming in maternal diabetes.

Response of decorin to different intensity treadmill running

Decorin is widely understood to affect collagen fibrillogenesis. However, little is understood about its response to various mechanical loading conditions. In the present study, 36 Wistar rats were randomly divided into control (CON), moderate treadmill running (MTR) and strenuous treadmill running (STR) groups. Animals in the MTR and STR groups were subjected to a 4‑ or 8‑week treadmill running protocol. Subsequently, all Achilles tendons were harvested to perform histological and biochemical analyses. Decorin expression was markedly increased in the MTR group compared with the CON group at 4 and 8 weeks. Conversely, decorin expression was markedly decreased in the STR group compared with the CON and MTR group at 4 and 8 weeks. Furthermore, between the two time points, decorin expression levels were significantly increased in the MTR group, whereas they were markedly decreased in the STR group. These results suggested that MTR exercise may induce increased decorin expression via a balance of MMP‑2 and TIMP‑2, improving tendon structure and function. However, STR exercise may result in degradation of decorin due to an imbalance of MMP‑2 and TIMP‑2, with a bias to MMP‑2, resulting in a predisposition to tendinopathy.

Inhibition of collagenase and melanogenesis by ethanol extracts of Orostachys japonicus A. Berger: possible involvement of Erk and Akt signaling pathways in melanoma cells

Orostachys japonicus is an herb that contains several functional components and has traditionally been used to treat various diseases in Asia. In this study, bioactive components from different parts of the O. japonicus plant were investigated, and the contents of the functional components in ethanol extracts of O. japonicus cultivated in Korea and China were compared. The antioxidant effects of O. japonicus ethanol extracts were investigated using Raw 264.7 cells. It was found that 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity was significantly decreased in the cells treated with the extracts. Moreover, the novel inhibitory functions of O. japonicus extracts on collagenase, elastase, and tyrosinase were established. We also found that O. japonicus extracts strongly inhibited melanin synthesis in B16F10 melanoma cells by decreasing MITF protein levels and activating the Erk and Akt signaling pathways. Thus, these findings would be useful for developing new cosmetic and pharmaceutical formulations based on O. japonicus extracts.

Danshen attenuates osteoarthritis-related cartilage degeneration through inhibition of NF-κB signaling pathway in vivo and in vitro

Danshen (Salvia miltiorrhiza) is a traditional Chinese medicine herb that can alleviate the symptoms of osteoarthritis (OA) (Söder et al. 2006) in animals. However, the underlying mechanisms remain poorly understood and require further investigation. In this study, rabbits with experimentally induced OA were given an intra-articular injection of danshen (0.7 mL/day) for 5 weeks. In addition to attenuating the cartilage degeneration of OA in the rabbits, danshen decreased the expression and activity of matrix metalloproteinase 9 (MMP-9) and MMP-13, and increased the expression of their natural inhibitors: tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) and TIMP-2. Apoptosis in osteoarthritic cartilage tissues was attenuated by danshen, accompanied with increased expression of B cell lymphoma 2 (Bcl-2) and decreased levels of Bcl-2-associated X protein (Bax). Further, danshen inhibited the nuclear accumulation of nuclear factor kappa-B (NF-κB) p65 in osteoarthritic cartilage. The therapeutic effects of danshen in vivo were comparable to that of sodium hyaluronate, which is a drug used clinically for the treatment OA. In vitro, sodium nitroprusside (SNP) was used to stimulate apoptosis in primary rabbit chondrocytes. We found that the SNP-induced apoptosis was mitigated by danshen. BAY11-7028, an inhibitor of the NF-κB pathway, augmented danshen's anti-apoptotic effects in cells exposed to SNP. When these results are considered together, they indicate that danshen alleviates the cartilage injury in rabbit OA through inhibition of the NF-κB signaling pathway.

Inflammation, oxidative stress and apoptosis cascade implications in bisphenol A-induced liver fibrosis in male rats

Bisphenol A (BPA) is a key monomer in the production of plastics. It has been shown to be hepatotoxic. Inflammation and oxidative stress are closely linked with liver fibrosis, the major contributing factor to hepatic failure. Therefore, the aim of this study was to evaluate the impact of chronic exposure to BPA on the development of hepatic fibrosis in male rats and to determine the cross-talk between the hepatic cytokine network, oxidative stress and apoptosis. For this purpose, 30 male Wistar albino rats were divided into three equal groups as follows: the first group was given no treatment (normal control group); the second group was given corn oil once daily by oral gavage for 8 weeks (vehicle control group); and the third group received BPA (50 mg/kg body weight/day, p.o.) for 8 weeks. BPA administration induced liver fibrosis as reflected in an increase in serum hepatic enzymes activities, hepatic hydroxyproline content and histopathological changes particularly increased collagen fibre deposition around the portal tract. In addition, there was inflammation (as reflected in increase in interleukin-1beta 'IL-1β', decrease in interleukin-10 'IL-10' serum levels and increase in IL-1β/IL-10 ratio), oxidative stress (as reflected in increase in malondialdehyde (MDA) level, reduction in reduced glutathione (GSH) content and inhibition of catalase (CAT) activity) and apoptosis [as reflected in an increase in caspase-3 level and a decrease in numbers of B-cell lymphoma 2 (BCL2)-immunopositive hepatocytes]. Interestingly, BPA had an upregulating effect on an extracellular matrix turnover gene [as reflected in matrix metalloproteinase-9 (MMP-9)] and a downregulating effect on its inhibitor gene [as reflected in tissue inhibitor of matrix metalloproteinase-2 (TIMP-2)] expression. Thus, the mechanism by which BPA induced liver fibrosis seems to be related to stimulation of the inflammatory response, along with oxidative stress, the apoptotic pathway and activation of extracellular matrix turnover.

Trichostatin A increases the TIMP-1/MMP ratio to protect against osteoarthritis in an animal model of the disease

The histone deacetylase inhibitor trichostatin A (TSA) has been demonstrated to alleviate certain symptoms associated with osteoarthritis (OA). However, the exact mechanisms underlying this protective effect remain to be elucidated. The present study therefore examined the effects of TSA on the expression levels of interleukin-1β (IL-1β)-induced matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in vitro and in vivo. In vitro, reverse transcription-quantitative polymerase chain reaction was performed to investigate alterations in mRNA expression levels in TSA-treated chondrocytes in the presence or absence of IL-1β; in addition, protein expression and acetylation levels were assessed by western blotting. In vivo, TSA was administered to rats by intra-articular injection, following which the mRNA and protein expression levels were analyzed. In addition, macroscopic and histological observations were conducted. Chondrocytes treated with IL-1β demonstrated increased mRNA and protein expression levels of MMP-1, MMP-3 and MMP-13, and decreased expression levels of TIMP-1 mRNA and protein; these alterations were significantly attenuated by TSA treatment. In addition, increased MMPs and decreased TIMP-1 expression levels were observed in vivo in the OA rat model. TSA treatment demonstrated in vivo efficacy through the attenuation of various OA-associated molecular and physiological changes. Taken together, the results of the present study suggest that TSA has potential therapeutic value for the treatment of OA.

A comparative study of MMP-1, MMP-2, and TNF-α expression in different acne vulgaris lesions

Many inflammatory mediators and cytokines play important roles in the pathogenesis of acne vulgaris (AV). Information about the roles of these factors in the pathogenesis of the disease is limited. The purpose of this study was to evaluate levels of matrix metalloproteinase-1 (MMP-1), MMP-2, and tumor necrosis factor-α (TNF-α) in AV lesions. We selected 80 patients who presented at our dermatology department with AV. Their lesions included papules, pustules, nodules, and comedones. Each specimen was evaluated by histopathology with hematoxylin and eosin staining, and subsequently by immunohistochemical analysis for MMP-1, MMP-2, and TNF-α antibodies. A statistically significant difference between lesion groups emerged for MMP-1 (P = 0.012) and TNF-α (P = 0.029) scores. The MMP-1 score was highest in nodules and lowest in comedones. The TNF-α score was also highest in nodules but lowest in papules. We conclude that different levels of MMP expression can contribute to the development of different types of acne lesion and that the amount of TNF-α released may contribute to lesion development. Further studies of novel treatment modalities might evaluate the different clinical types of AV.

Effects of oxygen tension and dextran-shelled/2H,3H-decafluoropentane-cored oxygen-loaded nanodroplets on secretion of gelatinases and their inhibitors in term human placenta

Matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) need to be finely modulated in physiological processes. However, oxygen tension influences MMP/TIMP balances, potentially leading to pathology. Intriguingly, new 2H,3H-decafluoropentane-based oxygen-loaded nanodroplets (OLNDs) have proven effective in abrogating hypoxia-dependent dysregulation of MMP and TIMP secretion by single cell populations. This work explored the effects of different oxygen tensions and dextran-shelled OLNDs on MMP/TIMP production in an organized and multicellular tissue (term human placenta). Chorionic villous explants from normal third-trimester pregnancies were incubated with/without OLNDs in 3 or 20% O2. Explants cultured at higher oxygen tension released constitutive proMMP-2, proMMP-9, TIMP-1, and TIMP-2. Hypoxia significantly altered MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios enhancing TIMP-2 and reducing proMMP-2, proMMP-9, and TIMP-1 levels. Intriguingly, OLNDs effectively counteracted the effects of low oxygen tension. Collectively, these data support OLND potential as innovative, nonconventional, and cost-effective tools to counteract hypoxia-dependent dysregulation of MMP/TIMP balances in human tissues.

Influence of gentamicin-coded PVDF suture material on the healing of intestinal anastomosis in a rat model

PURPOSE

Intestinal anastomosis is a fundamental procedure in general surgery and required to restore intestinal continuity following resection. The aim of this study was to evaluate whether a gentamicin-coated polyvinylidene fluoride (PVDF) suture material has beneficial effect on anastomotic healing.

METHODS

Ninety Sprague-Dawley rats were divided into three groups: a PVDF-suture group, a gentamicin-coated PVDF (GPVDF)-suture group and a control group using Maxon® (polyglycolid-co-trimethylene carbonate). For each animal, a colonic anastomosis was performed. Ten animals from each group were sacrificed on postoperative days 3, 5, and 14. Measurements of anastomotic bursting pressure were performed on days 3 and 5. At each time, collagen type I/III ratio, MMP 2 and MMP-9 expression and the proliferation index (Ki67) were analyzed.

RESULTS

In total, 90 animals underwent surgery without postoperative complications. Bursting strength in the GPVDF group was significantly elevated on day 5. Immunohistochemistry showed significant increase of the collagen type I/III ratio for PVDF and GPVDF on days 3 and 5. MMP2 was significantly increased for PVDF on days 3 and 5 and for GPVDF on day 5. The analysis of MMP9 revealed significant increase compared to control on day 3 and 5 (GPVDF) as well as on day 5 (PVDF). Staining for Ki67 revealed a significant elevation on postoperative day 3 for the PVDF and the GPVDF group.

CONCLUSIONS

The present data shows the feasibility of PVDF as suture material for colonic anastomosis and confirms the ability of gentamicin to increase the stability of colonic anastomosis when used as coating material.

Impact of 4-hydroxynonenal on matrix metalloproteinase-9 regulation in lipopolysaccharide-stimulated RAW 264.7 cells

Tissue degradation and leukocyte extravasation suggest proteolytic destruction of the extracellular matrix (ECM) during severe malaria. Matrix metalloproteinases (MMPs) play an established role in ECM turnover, and increased MMP-9 protein abundance is correlated with malarial infection. The malaria pigment hemozoin (Hz) is a heme detoxification biomineral that is produced during infection and associated with biologically active lipid peroxidation products such as 4-hydroxynonenal (HNE) adsorbed to its surface. Hz has innate immunomodulatory activity, and many of its effects can be reproduced by exogenously added HNE. Hz phagocytosis enhances MMP-9 expression in monocytes; thus, this study was designed to examine the ability of HNE to alter MMP-9 regulation in activated cells of macrophage lineage. Data show that treatment of lipopolysaccharide-stimulated RAW 264.7 cells with HNE increased MMP-9 secretion and activity. HNE treatment abolished the cognate tissue inhibitor of metalloproteinase-1 protein levels, further decreasing MMP-9 regulation. Phosphorylation of both p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase was induced by HNE, but only p38 MAPK inhibition lessened MMP-9 secretion. These results demonstrate the in vitro ability of HNE to cause MMP-9 dysregulation in an activated cell model. The findings may extend to myriad pathologies associated with lipid peroxidation and elevated MMP-9 levels leading to tissue damage.

Association between expression of MMP-2 and MMP-9 genes and pathogenesis of intracranial hemorrhage in severe coagulation factor XIII deficiency

Background Matrix metalloproteinases (MMPs) play a key role in the degradation of basement membrane and extracellular matrix in tissue remodeling, and are involved in pathogenesis of intracranial hemorrhage (ICH). Despite replacement therapy, ICH is by far the main cause of bleeding-related death among patients with severe factor XIII deficiency (FXIIID). The aim of this study is to evaluate the association between MMP-2 and MMP-9 genes expression and ICH in these patients. Materials and methods Quantitative real-time reverse transcription (RT)-PCR assay was used to quantify MMP-2 and MMP-9 mRNAs in 42 specimens of patients with FXIIID including 18 case and 24 control groups. The comparative method of relative quantification (2-Delta-Delta-cCt) was utilized to analyze the expression level of each target gene. The expression level of glyceraldehyde-3-phosphate dehydrogenase was used to standardize the expression levels of MMPs. Results Umbilical bleeding was the most common clinical manifestation among all patients. We found expression upregulation of MMP-9 gene in 13 patients (72.2%) in case and 3 patients (12.5%) in control group, indicating a significant difference between cases and controls for MMP-9 gene expression level (P = 0.001%)(CI 2.8-95.3). Conclusions Our patients present with a wide spectrum of clinical symptoms, which are important in screening and diagnosis of patients with FXIIID. We hypothesized that the overexpression of MMP-9 due to polymorphisms or inflammation was associated with pathogenesis of ICH in FXIIID. This effect can be attenuated by nonspecific MMP inhibition to reduce hospitalization and death rates in these patients.

Matrix metalloproteinases: potential therapeutic target for diabetic neuropathic pain

INTRODUCTION

MMPs are zinc-dependent endopeptidases that play a key role in the remodeling of extracellular matrix (ECM). Various pathogenic mediators trigger abnormal MMP activity that leads to ECM abnormality. Hyperglycemia is one of the strong stimuli among oxidative stress and inflammation that upregulate MMP expression in the central and peripheral nervous system. MMP-mediated ECM abnormality hypersensitizes peripheral as well as central nerves that precipitate neuropathic pain in diabetic patients.

AREAS COVERED

Molecular mechanisms associated with MMP-mediated diabetic neuropathic pain have been discussed. Various endogenous, natural and synthetic MMP inhibitors are also explored.

EXPERT OPINION

In diabetes, hyperglycemia activates MMPs that along with the other pathogenic mediators cause neuronal injury and precipitates neuropathic pain. Thus, MMPs play a crucial role in the development of neuropathic pain among diabetics. However, MMPs are not only responsible for deleterious ECM abnormalities but are also required for beneficial remodeling of ECM under normal physiological conditions. Therefore, highly selective and specific inhibitors must be designed and explored for their clinical potential for treatment/prevention of diabetic neuropathic pain.

Antioxidants: potential antiviral agents for Japanese encephalitis virus infection

Japanese encephalitis (JE) is prevalent throughout eastern and southern Asia and the Pacific Rim. It is caused by the JE virus (JEV), which belongs to the family Flaviviridae. Despite the importance of JE, little is known about its pathogenesis. The role of oxidative stress in the pathogenesis of viral infections has led to increased interest in its role in JEV infections. This review focuses mainly on the role of oxidative stress in the pathogenesis of JEV infection and the antiviral effect of antioxidant agents in inhibiting JEV production. First, this review summarizes the pathogenesis of JE. The pathological changes include neuronal death, astrocyte activation, and microglial proliferation. Second, the relationship between oxidative stress and JEV infection is explored. JEV infection induces the generation of oxidants and exhausts the supply of antioxidants, which activates specific signaling pathways. Finally, the therapeutic efficacy of a variety of antioxidants as antiviral agents, including minocycline, arctigenin, fenofibrate, and curcumin, was studied. In conclusion, antioxidants are likely to be developed into antiviral agents for the treatment of JE.

Umbilical cord mesenchymal stem cells: the new gold standard for mesenchymal stem cell-based therapies?

Due to their self-renewal capacity, multilineage differentiation potential, paracrine effects, and immunosuppressive properties, mesenchymal stromal cells (MSCs) are an attractive and promising tool for regenerative medicine. MSCs can be isolated from various tissues but despite their common immunophenotypic characteristics and functional properties, source-dependent differences in MSCs properties have recently emerged and lead to different clinical applications. Considered for a long time as a medical waste, umbilical cord appears these days as a promising source of MSCs. Several reports have shown that umbilical cord-derived MSCs are more primitive, proliferative, and immunosuppressive than their adult counterparts. In this review, we aim at synthesizing the differences between umbilical cord MSCs and MSCs from other sources (bone marrow, adipose tissue, periodontal ligament, dental pulp,…) with regard to their proliferation capacity, proteic and transcriptomic profiles, and their secretome involved in their regenerative, homing, and immunomodulatory capacities. Although umbilical cord MSCs are until now not particularly used as an MSC source in clinical practice, accumulating evidence shows that they may have a therapeutic advantage to treat several diseases, especially autoimmune and neurodegenerative diseases.

Monocyte-derived dendritic cell subpopulations use different types of matrix metalloproteinases inhibited by GM6001

Matrix metalloproteinases (MMPs) are endopeptidases with the potential to cleave extracellular matrix, support tissue renewal and regulate cell migration. Functional activities of MMPs are regulated by tissue inhibitors of MMPs (TIMPs) and disruption of the MMP-TIMP balance has pathological consequences. Here we studied the expression and secretion of MMPs and TIMPs in CD1a(-) and CD1a(+) monocyte-derived dendritic cell (DC) subpopulations. Our results showed that monocytes express TIMPs but lack MMPs, whereas upon differentiation to moDCs and in response to activation signals the expression of MMPs is increased and that of TIMPs is decreased. MMP-9 is expressed dominantly in the CD1a(-) subpopulation, while MMP-12 is preferentially expressed in CD1a(+) cells. Experiments performed with the synthetic MMP inhibitor GM6001 revealed that this drug efficiently inhibits the migration of moDCs through inactivation of MMPs. We conclude that modulation of MMP activity by GM6001 emerges as a novel approach to manipulate DC migration under inflammatory conditions.

Isoflavonoid-Rich Flemingia macrophylla Extract Attenuates UVB-Induced Skin Damage by Scavenging Reactive Oxygen Species and Inhibiting MAP Kinase and MMP Expression

In this study, we investigated the antioxidant activity and anti-photoaging properties of an extract of Flemingia macrophylla, a plant rich in isoflavonoid content. Pretreatment of fibroblasts with Flemingia macrophylla extract (FME) inhibited elastase activity, promoted the protein expression of type I procollagen, and attenuated the phosphorylation of mitogen-activated protein (MAP) kinase and the protein expression of matrix-metalloproteinase- (MMP-) 1, 3, and 9. The IC₅₀ values were 2.1 μg/mL for DPPH radical scavenging ability, 366.8 μg/mL for superoxide anion scavenging ability, 178.9 μg/mL for hydrogen peroxide scavenging ability, and 230.9 μg/mL for hydroxyl radical scavenging ability. Also, exposure of erythrocytes to various concentrations of FME (50–500 μg/mL) resulted in a dose- and time-dependent inhibition of AAPH-induced hemolysis. In human fibroblasts, FME at 10 μg/mL was shown to be a potent scavenger of UV-induced reactive oxygen species (ROS). The antioxidant and anti-photoaging properties of FME make it an ideal anti-intrinsic aging and anti-photoaging agent.

Matrix metalloproteinase, tissue inhibitor of metalloproteinase and transforming growth factor-beta 1 in frozen shoulder, and their changes as response to intensive stretching and supervised neglect exercise

BACKGROUND

Frozen shoulder is characterized with thickening and contracture of joint capsular. The mechanism of this disorder is not yet clear, however, some proteins have been related to frozen shoulder. This study was to compare the serum levels of proteins related to frozen shoulder, such as matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP) and transforming growth factor-beta (TGF-β) between frozen shoulder and normal subjects; and before and after physical exercise active stretching and gentle thawing in frozen shoulder patients.

METHODS

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 was measured from frozen shoulder and normal subjects by using ELISA. Functional assessment of shoulder joint in frozen shoulder patients was based on abbreviated Constant score. Frozen shoulder patients were randomly divided into intensive stretching and supervised neglect groups. Abbreviated Constant score and serum samples of frozen shoulder patients were evaluated at baseline, week-6, and week-12 after exercise, while only baseline serum samples of control were measured. MMP/TIMP ratio was calculated from the total sum of MMP-1 and MMP-2 levels divided by the total sum of TIMP-1 and TIMP-2 levels.

RESULTS

Baseline MMP-1 and MMP-2 levels were significantly lower, while TIMP-1, TIMP-2, and TGF-β1 levels were significantly higher in frozen shoulder group than in control. Increased MMPs and decreased TIMPs were significantly greater after intensive stretching than after supervised neglect exercise. Abbreviated Constant score improvement was significantly higher in intensive stretching group than in supervised neglect group.

CONCLUSIONS

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 may be associated to frozen shoulder. Active stretching can improve frozen shoulder better than supervised neglect, as demonstrated by the improvement of Constant score.

Metalloproteases and tendinopathy

Matrix metalloproteinases (MMP) are involved in the development of tendinopathy. These potent enzymes completely degrade all components of the connective tissue, modify the extracellular matrix (ECM), and mediate the development of painful tendinopathy. To control the local activity of activated proteinases, the same cells produce tissue inhibitors of metalloproteinases (TIMP). These latter bind to the enzyme and prevent degradation. The balance between the activities of MMPs and TIMPs regulates tendon remodeling, whereas an imbalance produces a collagen dis-regulation and disturbances in tendons. ADAMs (a disintegrin and metalloproteinase) are cell membrane-linked enzymes with proteolytic and cell signaling functions. ADAMTSs (ADAM with thrombospondin motifs) are secreted into the circulation and constitute a heterogenous family of proteases with both anabolic and catabolic functions. Further studies are needed to better define the mechanism of action, and whether these new strategies are safe and effective in larger models.

Cerebrospinal fluid matrix metalloproteinases are elevated in cerebral adrenoleukodystrophy and correlate with MRI severity and neurologic dysfunction

Background

X-linked adrenoleukodystrophy results from mutations in the ABCD1 gene disrupting the metabolism of very-long-chain fatty acids. The most serious form of ALD, cerebral adrenoleukodystrophy (cALD), causes neuroinflammation and demyelination. Neuroimaging in cALD shows inflammatory changes and indicates blood-brain-barrier (BBB) disruption. We hypothesize that disruption may occur through the degradation of the extracellular matrix defining the BBB by matrix metalloproteinases (MMPs). MMPs have not been evaluated in the setting of cALD.

Methodology/Principal Findings

We used a multiplex assay to correlate the concentration of MMPs in cerebrospinal fluid and plasma to the severity of brain inflammation as determined by the ALD MRI (Loes) score and the neurologic function score. There were significant elevations of MMP2, MMP9, MMP10, TIMP1, and total protein in the CSF of boys with cALD compared to controls. Levels of MMP10, TIMP1, and total protein in CSF showed significant correlation [p<0.05 for each with pre-transplant MRI Loes Loes scores (R² = 0.34, 0.20, 0.55 respectively). Levels of TIMP1 and total protein in CSF significantly correlated with pre-transplant neurologic functional scores (R² = 0.22 and 0.48 respectively), and levels of MMP10 and total protein in CSF significantly correlated with one-year post-transplant functional scores (R² = 0.38 and 0.69). There was a significant elevation of MMP9 levels in plasma compared to control, but did not correlate with the MRI or neurologic function scores.

Conclusions/Significance

MMPs were found to be elevated in the CSF of boys with cALD and may mechanistically contribute to the breakdown of the blood-brain-barrier. MMP concentrations directly correlate to radiographic and clinical neurologic severity. Interestingly, increased total protein levels showed superior correlation to MRI score and neurologic function score before and at one year after transplant.

Transforming growth factor beta1 gene expression during vaginal wound healing in a rabbit menopause model

OBJECTIVE

Surgical outcome following reconstructive pelvic surgery is largely dependent on the vaginal wound healing process. As peri- and post-menopausal women are the most likely candidates to undergo these surgeries, it is important to understand the effect of estrogen deficiency on this process. Transforming growth factor beta (TGFβ) is an important mediator of wound healing. We sought to assess TGFβ1 gene expression during the vaginal incisional wound healing process in a rabbit menopause model.

DESIGN

Animal study.

SETTING

Animal laboratory.

SAMPLE

Sixty-three rabbits were used for this study.

METHODS

Twenty-one underwent bilateral oophorectomy, 21 underwent a sham surgery, and 21 served as controls. Eight weeks later, standardised full-thickness 6-mm diameter circular segments were excised from the vagina of all rabbits. Animals were killed sequentially, before wounding, and at 0, 4, 7, 14, 21 and 35 days after wounding, and the wounds were harvested.

MAIN OUTCOME MEASURES

Wound closure and TGFβ1 gene transcription, as measured by real-time polymerase chain reaction (PCR).

RESULTS

Wound closure was significantly protracted (P < 0.02), whereas TGFβ1 gene expression was significantly increased (P < 0.0001) during the wound healing process in oophorectomised rabbits, as compared with both control and sham groups.

CONCLUSION

Oophorectomised rabbits show protracted incisional vaginal wound healing associated with increased TGFβ1 gene transcription.

Immunoexpression of matrix metalloproteinases and their inhibitors in different areas of oral squamous cell carcinoma

BACKGROUND

Several studies have shown the participation of MMPs in oral squamous cell carcinoma, the most frequent malignant neoplasm of the oral cavity. The expression of some MMPs correlates with a more aggressive biological behaviour. The objective of this study was to determine which MMPs and TIMPs were expressed in both neoplastic and peritumoural stromal cells in different histopathology areas.

METHODS

Patients who underwent primary tumour neck dissection for oral squamous cell carcinoma were included. Immunoexpression of MMP-1, -2, -3, -7, -9, -11, -13, and TIMP-1 and -2 in different areas of pathologic specimens (in situ carcinoma, primary tumour, invasive front, distant invasion carcinoma, and lymph node metastasis) was evaluated. Enzyme expression on mucosa adjacent to tumour served as control.

RESULTS

Thirty cases were included. Only 6 MMPs and 1 TIMP were expressed in the studied areas. Statistically significant differences in the number of cases with positive MMPs or TIMP expression, in both neoplastic and peritumoural cells, between control and the rest of the areas were observed. MMP-2 expression was constant in the areas with a more aggressive biological behaviour.

CONCLUSIONS

MMP-2 expression may represent a dynamic interaction between host and tumour that favours the establishment of neoplastic cells at distant sites.

Pimaric acid from Aralia cordata has an inhibitory effect on TNF-α-induced MMP-9 production and HASMC migration via down-regulated NF-κB and AP-1

Many studies have indicated that activation of matrix metalloproteinase (MMP)-9 and smooth muscle cell (SMC) migration are involved in neointimal formation and atherosclerosis. In this study, we revealed that pimaric acid (PiMA) purified from Aralia cordata had an inhibitory effect on MMP-9 production and migration of human aortic smooth muscle cells (HASMCs) induced by tumor necrosis factor (TNF)-α. Down-regulated MMP-9 mRNA transcription was detected in PiMA-treated cells using RT-PCR and the luciferase-tagged MMP-9 promoter assay. Results of an electrophoretic mobility shift assay indicated that PiMA-treated HASMCs showed decreased binding activity of nuclear factor (NF)-κB and activator protein-1 transcription factors. A Western-blot analysis using nuclear extract demonstrated that PiMA reduced the levels of NF-κB p65, c-Fos, p-c-Jun, Jun-D, and p-ATF2 proteins in the nucleus. In addition, TNF-α stimulated mitogen activated protein kinase (MAPK) containing extracellular signal regulated kinase 1 and 2, p38, and c-Jun N-terminal kinase was inhibited by PiMA. Using the Transwell system, we found that PiMA inhibited TNF-α stimulated HASMC migration/invasion in a dose-dependent manner. To confirm whether MAPK mediated MMP-9 expression, we used MAPK inhibitors including U0126, SB253580, and SP600125 and found that those inhibitors reduced MMP-9 expression and HASMC migration/invasion. These results suggest that PiMA has potent anti-atherosclerotic activity with inhibitory action on MMP-9 production and cell migration in TNF-α-induced HASMCs.

Preoperative serum levels of matrix metalloproteinase-2 (MMP-2) and survival of breast cancer among Korean women

BACKGROUND

Matrix metalloproteinase-2 (MMP-2) has been thought of as a predictor of recurrence or metastasis risk or prognostic markers in cancer. We evaluated whether preoperative serum levels of MMP-2 work as a prognostic biomarker in breast cancer prognosis.

METHODS

Preoperative serum levels of MMP-2 were measured with ELISA in 303 patients with histologically confirmed breast cancer. The median follow-up time for all patients was 4.24 years. The relationship of MMP-2 to survival was investigated using Cox proportional hazard regression model adjusted for the tumor-node-metastasis (TNM) stage and estrogen receptor (ER) status.

RESULTS

In the multivariate analysis, disease-free survival (DFS) was worse among patients with the third tertile of MMP-2 level than with the first tertile of MMP-2 level [hazard ratio, 1.80; 95% confidence interval (CI), 1.04-3.11; P = 0.04]. However, when the patients were stratified by age, ER status, histologic grade, and nuclear grade, inverse correlation was shown between serum MMP-2 levels and prognostic factors, and the associations between MMP-2 and DFS were only significant among patients with poor prognostic factors (HR, 2.75; 95% CI, 1.32-5.73 in ER-negative; HR, 2.90; 95% CI, 1.42-5.92 in histologic grade III; and HR, 2.61; 95% CI, 1.26-5.39 in nuclear grade III).

CONCLUSIONS

Our results suggest that the preoperative serum levels of MMP-2 were associated with the survival in patients with breast cancer in ER-negative, higher histologic grade, or higher nuclear grade breast cancers.

IMPACT

Our results indicate that serum levels of MMP-2 may play a role as prognostic biomarker in breast cancer survival.

Regulation of matrix metalloproteinases 2 and 9 activities by peroxynitrites in term placentas from type 2 diabetic patients

Matrix metalloproteinases (MMPs) are proteolytic enzymes related to a proinflammatory environment in several diseases, including diabetes, which can be activated by reactive nitrogen species. This work aimed to determine MMP-2 and MMP-9 activities and nitration in term placentas from type 2 diabetic patients and verify the hypothesis that peroxynitrites are positive regulators of placental MMP-2 and MMP-9 activities. For this purpose, term placentas from healthy and type 2 diabetic patients were analyzed for MMP-2 and MMP-9 levels and activities, protein nitration, and nitration of MMP-2 and MMP-9. Villous explants were cultured in the presence of peroxynitrites for further evaluation of MMP-2 and MMP-9 activities. We found that MMP-2 and MMP-9 activities were increased in term placentas from diabetic patients. These changes were found even when MMP-2 protein concentrations were diminished and MMP-9 protein concentrations were not changed in the diabetic group. Increased protein nitration and specific nitration of MMP-2 and MMP-9 were found in term placentas from diabetic patients. Peroxynitrites were able to increase the activity of placental MMP-2 and MMP-9. Taken together, this study has shown for first time that peroxynitrites can nitrate and activate MMP-2 and MMP-9 in the placenta, a nitrative pathway possibly related to MMPs overactivity in the placentas from type 2 diabetic patients.

Genetic variations in the ADAMTS12 gene are associated with schizophrenia in Puerto Rican patients of Spanish descent

ADAMTS12 belongs to the family of metalloproteinases that mediate a communication between specific cell types and play a key role in the regulation of normal tissue development, remodeling, and degradation. Members of this family have been implicated in neurodegenerative and neuroinflammatory, as well as in muscular-skeletal, cardiovascular, respiratory and renal diseases, and cancer. Several metalloproteinases have been associated with schizophrenia. In our previous study of the pedigree from a genetic isolate of Spanish origin in Puerto Rico, we identified a schizophrenia susceptibility locus on chromosome 5p13 containing ADAMTS12. This gene, therefore, is not only a functional but also a positional candidate gene for susceptibility to the disorder. In order to examine possible involvement of ADAMTS12 in schizophrenia, we performed mutation analysis of the coding, 5'- and 3'-untranslated, and putative promoter regions of the gene in affected members of the pedigree and identified 18 sequence variants segregated with schizophrenia. We then tested these variants in 135 unrelated Puerto Rican schizophrenia patients of Spanish origin and 203 controls and identified the intronic variant rs256792 (P = 0.0035; OR = 1.59; 95% CI = 1.16-2.17) and the two-SNP haplotype rs256603-rs256792 (P = 0.0023; OR = 1.62; 95% CI = 1.19-2.21) associated with the disorder. The association remained significant after correction for multiple testing. Our data support the hypothesis that genetic variations in ADAMTS12 influence the risk of schizophrenia.

Metalloproteases and rotator cuff disease

The molecular changes occurring in rotator cuff tears are still unknown, but much attention has been paid to better understand the role of matrix metalloproteinases (MMP) in the development of tendinopathy. These are potent enzymes that, once activated, can completely degrade all components of the connective tissue, modify the extracellular matrix (ECM), and mediatethe development of painful tendinopathy and tendon rupture. To control the local activity of activated proteinases, the same cells produce tissue inhibitors of metalloproteinases (TIMP) that bind to the enzymes and prevent degradation. The balance between the activities of MMPs and TIMPs regulates tendon remodeling, whereas an imbalance produces a collagen dis-regulation and disturbances intendons. ADAMs (a disintegrin and metalloproteinase) are cell membrane-linked enzymes with proteolytic and cell signaling functions. ADAMTSs (ADAM with thrombospondin motifs) are secreted into the circulation, and constitute a heterogenous family of proteases with both anabolic and catabolic functions. Biologic modulation of endogenous MMP activity to basal levels may reduce pathologic tissue degradation and favorably influence healing after rotator cuff repair. Further studies are needed to better define the mechanism of action, and whether these new strategies are safe and effective in larger models.

Japanese encephalitis virus induces matrix metalloproteinase-9 expression via a ROS/c-Src/PDGFR/PI3K/Akt/MAPKs-dependent AP-1 pathway in rat brain astrocytes

BACKGROUND

Japanese encephalitis virus (JEV) infection is a major cause of acute encephalopathy in children, which destroys central nervous system (CNS) cells, including astrocytes and neurons. Matrix metalloproteinase (MMP)-9 has been shown to degrade components of the basal lamina, leading to disruption of the blood-brain barrier (BBB) and to contribute to neuroinflammatory responses in many neurological diseases. However, the detailed mechanisms of JEV-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells) are largely unclear.

METHODS

In this study, the effect of JEV on expression of MMP-9 was determined by gelatin zymography, western blot analysis, RT-PCR, and promoter assay. The involvement of AP-1 (c-Jun and c-Fos), c-Src, PDGFR, PI3K/Akt, and MAPKs in these responses were investigated by using the selective pharmacological inhibitors and transfection with siRNAs.

RESULTS

Here, we demonstrate that JEV induces expression of pro-form MMP-9 via ROS/c-Src/PDGFR/PI3K/Akt/MAPKs-dependent, AP-1 activation in RBA-1 cells. JEV-induced MMP-9 expression and promoter activity were inhibited by pretreatment with inhibitors of AP-1 (tanshinone), c-Src (PP1), PDGFR (AG1296), and PI3K (LY294002), and by transfection with siRNAs of c-Jun, c-Fos, PDGFR, and Akt. Moreover, JEV-stimulated AP-1 activation was inhibited by pretreatment with the inhibitors of c-Src, PDGFR, PI3K, and MAPKs.

CONCLUSION

From these results, we conclude that JEV activates the ROS/c-Src/PDGFR/PI3K/Akt/MAPKs pathway, which in turn triggers AP-1 activation and ultimately induces MMP-9 expression in RBA-1 cells. These findings concerning JEV-induced MMP-9 expression in RBA-1 cells imply that JEV might play an important role in CNS inflammation and diseases.

Gentamicin supplemented polyvinylidenfluoride mesh materials enhance tissue integration due to a transcriptionally reduced MMP-2 protein expression

Background

A beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level.

Methods

A PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 μg/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-ß-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration.

Results

The perifilamentary ß-galactosidase expression as well as the collagen type I/III ratio increased up to the 90^th day for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 μg/mg gentamicin group showed significantly reduced levels of ß-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 μg/mg: p < 0.05 each; 8 μg/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 μg/mg group at all 3 time points (p < 0.05 each).

Conclusions

Our current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 μg/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.

Folic acid and safflower oil supplementation interacts and protects embryos from maternal diabetes-induced damage

Maternal diabetes increases the risk of embryo malformations. Folic acid and safflower oil supplementations have been shown to reduce embryo malformations in experimental models of diabetes. In this study we here tested whether folic acid and safflower oil supplementations interact to prevent embryo malformations in diabetic rats, and analyzed whether they act through the regulation of matrix metalloproteinases (MMPs), their endogenous inhibitors (TIMPs), and nitric oxide (NO) and reactive oxygen species production. Diabetes was induced by streptozotocin administration prior to mating. From Day 0.5 of pregnancy, rats did or did not receive folic acid (15 mg/kg) and/or a 6% safflower oil-supplemented diet. Embryos and decidua were explanted on Day 10.5 of gestation for further analysis of embryo resorptions and malformations, MMP-2 and MMP-9 activities, TIMP-1 and TIMP-2 levels, NO production and lipid peroxidation. Maternal diabetes induced resorptions and malformations that were prevented by folic acid and safflower oil supplementation. MMP-2 and MMP-9 activities were increased in embryos and decidua from diabetic rats and decreased with safflower oil and folic acid supplementations. In diabetic animals, the embryonic and decidual TIMPs were increased mainly with safflower oil supplementation in decidua and with folic acid in embryos. NO overproduction was decreased in decidua from diabetic rats treated with folic acid alone and in combination with safflower oil. These treatments also prevented increases in embryonic and decidual lipid peroxidation. In conclusion, folic acid and safflower oil supplementations interact and protect the embryos from diabetes-induced damage through several pathways related to a decrease in pro-inflammatory mediators.

Matrix metalloproteinase imbalance in inguinal hernia formation

BACKGROUND

Emerging evidence supports the role of matrix metalloproteinases (MMPs) in hernia formation. However, the imbalance between the proteolytic activity of MMPs and their endogenous inhibitors (TIMPs) has not been investigated. The aim of the present study was to determine changes of MMP and TIMP levels in patients with inguinal hernia.

METHODS

Two matrix metalloproteinases (MMP-9 and MMP-2) and their main inhibitors TIMP-1 and TIMP-2 were evaluated in consecutive patients undergoing inguinal hernia repair and control subjects. MMP/TIMP quantification was performed using ELISA in abdominal fascia tissue specimens and preoperative plasma samples.

RESULTS

Tissue explants from hernia patients produced significantly higher levels of MMP-9 and MMP-2, and reduced TIMP-1 and TIMP-2 concentrations compared to those of controls. In plasma, a reverse correlation was found regarding the concentrations of MMPs; the circulating levels of MMP-9 and MMP-2 were significantly lower in patients with inguinal hernia than controls. Furthermore, hernia patients were found to have elevated plasma levels of TIMP-2 and reduced plasma levels of TIMP-1.

CONCLUSIONS

The imbalance in MMP/TIMP activity indicates a dysregulation of the extracellular matrix degradation process in patients with inguinal hernia. The results of the present study suggest that impaired collagen metabolism may be an underlying pathophysiological mechanism of inguinal hernia formation.

Contribution of matrix metalloproteinase-9 to cerebral edema and functional outcome following experimental subarachnoid hemorrhage

BACKGROUND

Cerebral edema is an important risk factor for death and poor outcome following subarachnoid hemorrhage (SAH). However, underlying mechanisms are still poorly understood. Matrix metalloproteinase (MMP)-9 is held responsible for the degradation of microvascular basal lamina proteins leading to blood-brain barrier dysfunction and, thus, formation of vasogenic cerebral edema. The current study was conducted to clarify the role of MMP-9 for the development of cerebral edema and for functional outcome after SAH.

METHODS

SAH was induced in FVB/N wild-type (WT) or MMP-9 knockout (MMP-9(-/-)) mice by endovascular puncture. Intracranial pressure (ICP), regional cerebral blood flow (rCBF), and mean arterial blood pressure (MABP) were continuously monitored up to 30 min after SAH. Mortality was quantified for 7 days after SAH. In an additional series neurological function and body weight were assessed for 3 days after SAH. Subsequently, ICP and brain water content were quantified.

RESULTS

Acute ICP, rCBF, and MABP did not differ between WT and MMP-9(-/-) mice, while 7 days' mortality was lower in MMP-9(-/-) mice (p = 0.03; 20 vs. 60%). MMP-9(-/-) mice also exhibited better neurological recovery, less brain edema formation, and lower chronic ICP.

CONCLUSIONS

The results of the current study suggest that MMP-9 contributes to the development of early brain damage after SAH by promoting cerebral edema formation. Hence, MMP- 9 may represent a novel molecular target for the treatment of SAH.

Matrix metalloproteinase-12 leads to elastin degradation in BALB/c mice with eosinophilic meningitis caused by Angiostrongylus cantonensis

The rat lugworm Angiostrongylus cantonensis can cause eosinophilic meningitis. The purpose of this study was to determine whether matrix metalloproteinase (MMP)-12 and its substrate elastin participate in this inflammatory response. We showed that the MMP-12/tissue inhibitor of metalloproteinase-1 ratio was significantly increased in the CSF of A. cantonensis-infected mice from day 10 p.i., and reached high levels on days 20 and 25 p.i. MMP-12 production was correlated with elastin degradation, eosinophil count, blood-CSF barrier permeability and pathological changes in the subarachnoid space. Also, MMP-12 might contribute to elastin degradation in the meningeal vessel of the subarachnoid space. Simultaneous administration of albendazole and doxycycline significantly reduced the levels of MMP-12, elastin and Evans blue in mice with meningitis. These results imply that MMP-12 contributes to the elastin degradation that occurs in angiostrongyliasis meningitis, and doxycycline can reverse related inflammatory events by inhibition of MMP-12.

Japanese encephalitis virus induces matrix metalloproteinase-9 in rat brain astrocytes via NF-κB signalling dependent on MAPKs and reactive oxygen species

BACKGROUND AND PURPOSE

Japanese encephalitis virus (JEV) is a member of the family Flaviviridae and JEV infection is a major cause of acute encephalopathy in children, which destroys cells in the CNS, including astrocytes and neurons. However, the detailed mechanisms underlying the inflammatory action of JEV are largely unclear.

EXPERIMENTAL APPROACH

The effect of JEV on the expression of matrix metalloproteinase (MMP)-9 was determined by gelatin zymography, Western blot analysis, real-time PCR and promoter assay. The involvement of the NADPH oxidase and reactive oxygen species (ROS), MAPKs, and the transcription factor NF-κB in these responses was investigated by using selective pharmacological inhibitors and transfection with appropriate siRNAs.

KEY RESULTS

JEV induced the expression of the pro-form of MMP-9 in rat brain astrocytes (RBA-1 cells). In RBA-1 cells, JEV induced MMP-9 expression and promoter activity, which was inhibited by pretreatment with inhibitors of NADPH oxidase (diphenylene iodonium chloride or apocynin), MAPKs (U0126, SB203580 or SP600125) and a ROS scavenger (N-acetylcysteine), or transfection with siRNAs of p47(phox) , ERK1, JNK2 and p38. In addition, JEV-induced MMP-9 expression was reduced by pretreatment with an inhibitor of NF-κB (helenalin) or transfection with p65 siRNA. Moreover, JEV-stimulated NF-κB activation was inhibited by pretreatment with the inhibitors of NADPH oxidase and MAPKs.

CONCLUSIONS AND IMPLICATIONS

MMP-9 expression induced by JEV infection of RBA-1 cells was mediated through the generation of ROS and activation of p42/p44 MAPK, p38 MAPK and JNK1/2, leading to NF-κB activation.