NF-kappaB binds to a polymorphic repressor element in the MMP-3 promoter

Combating breast cancer progression through combination therapy with hypomethylating agent and glucocorticoid

Breast cancer is the leading cause of cancer-related death in women. Among breast cancer types, triple-negative breast cancer (TNBC) accounts for 15% of all breast cancers with aggressive tumor behavior. By using bioinformatic approaches, we observed that the microRNA-708 promoter is highly methylated in breast carcinomas, and this methylation is linked to a poor prognosis. Moreover, microRNA-708 expression correlates with better clinical outcomes in TNBC patients. Combination treatment with the hypomethylating agent decitabine and synthetic glucocorticoid significantly increased the expression of microRNA-708, reactivated DNMT-suppressed pathways, and decreased the expression of multiple metastasis-promoting genes such as matrix metalloproteinases (MMPs) and IL-1β, leading to the suppression of breast cancer cell proliferation, migration, and invasion, as well as reduced tumor growth and distant metastasis in the TNBC xenograft mouse model. Overall, our study reveals a therapeutic opportunity in which a combined regimen of decitabine with glucocorticoid may have therapeutic potential in treating TNBC patients.

Tumour necrosis factor alpha, interleukin 1 beta and interferon gamma have detrimental effects on equine tenocytes that cannot be rescued by IL-1RA or mesenchymal stromal cell-derived factors

Tendon injuries occur commonly in both human and equine athletes, and poor tendon regeneration leads to functionally deficient scar tissue and an increased frequency of re-injury. Despite evidence suggesting inadequate resolution of inflammation leads to fibrotic healing, our understanding of the inflammatory pathways implicated in tendinopathy remains poorly understood, meaning successful targeted treatments are lacking. Here, we demonstrate IL-1β, TNFα and IFN-γ work synergistically to induce greater detrimental consequences for equine tenocytes than when used individually. This includes altering tendon associated and matrix metalloproteinase gene expression and impairing the cells' ability to contract a 3-D collagen gel, a culture technique which more closely resembles the in vivo environment. Moreover, these adverse effects cannot be rescued by direct suppression of IL-1β using IL-1RA or factors produced by BM-MSCs. Furthermore, we provide evidence that NF-κB, but not JNK, P38 MAPK or STAT 1, is translocated to the nucleus and able to bind to DNA in tenocytes following TNFα and IL-1β stimulation, suggesting this signalling cascade may be responsible for the adverse downstream consequences of these inflammatory cytokines. We suggest a superior approach for treatment of tendinopathy may therefore be to target specific signalling pathways such as NF-κB.

Interleukin-1β triggers matrix metalloprotease-3 expression through p65/RelA activation in melanoma cells

Melanoma shows highly aggressive behavior (i.e., local invasion and metastasis). Matrix metalloprotease-3 (MMP-3), a zinc-dependent endopeptidase, degrades several extracellular substrates and contributes to local invasion by creating a microenvironment suitable for tumor development. Here, we report that interleukin-1β (IL-1β) triggers the MMP-3 expression in canine melanoma cells. The activity of MMP-3 in the culture supernatant was increased in IL-1β-treated melanoma cells. IL-1β time- and dose-dependently provoked the mRNA expression of MMP-3. IL-1β induced the migration of melanoma cells; however, this migration was attenuated by UK356618, an MMP-3 inhibitor. When the cells were treated with the nuclear factor-κB (NF-κB) inhibitor TPCA-1, the inhibition of MMP-3 expression was observed. In IL-1β-treated cells, the phosphorylation both of p65/RelA and p105 was detected, indicating NF-κB pathway activation. In p65/RelA-depleted melanoma cells, IL-1β-mediated mRNA expression of MMP-3 was inhibited, whereas this reduction was not observed in p105-depleted cells. These findings suggest that MMP-3 expression in melanoma cells is regulated through IL-1β-mediated p65/RelA activation, which is involved in melanoma cell migration.

Matrix metalloproteinase 3 and 9 as genetic biomarkers for the occurrence of cardiovascular complications in coronary artery disease: a prospective cohort study

BACKGROUND

Matrix metalloproteinases (MMPs) are widely expressed in atherosclerosis lesions. The disequilibrium of MMPs driving to an overexpression or a lack of its level can be influenced by genetic variations. MMP-3 and MMP-9 may be affected by specific polymorphisms like - 1612 5 A/6A and the - 1562 C/T respectively. We aim in the present study to investigate prospectively the association between the - 1612 5 A/6A MMP-3 and - 1562 C/T MMP-9 polymorphisms and clinical outcomes in patients with coronary artery disease (CAD). This study is elaborated to reveal whether one of these polymorphisms is a probable predictor of cardiovascular complications in this CAD cohort.

METHODS AND RESULTS

A total of 168 patients with CAD were prospectively followed up over a period of 5 years. Genotypes for the MMP-3 (-1612 5 A/6A) and MMP-9 (-1562 C/T) polymorphisms were performed using PCR-RFLP. Their levels were measured by ELISA in Sandwich test during the follow-up period, 39 cardiovascular outcomes occurred with 21 repeat targets for revascularization, 3 patients with Myocardial infarction, 8 for heart failure, 5 for Stroke and 2 for cardiovascular mortality. The MMP-3 5 A/6A polymorphism was related to the disease on the contrary of the MMP-9 -1562 C/T. Patients carrying the 5 A allele had a higher level of MMP-3 level and those who carried the 6 A allele had lower level (p = 0.04). After applied multivariable Cox-hazard models we revealed that the 6 A allele is independently associated to the disease complication. Kaplan-Meier survival test revealed that individuals having the 6 A allele had a lower survival rate than those with the 5 A allele (p = 0.04).

CONCLUSION

Our study suggests the disruption of the MMP-3 level may be due to the existence of the polymorphism - 1612 residing in its promoter region. MMP-3 can be considered as a marker of diagnosis and prediction in cardiovascular events.

CCL5/CCR5 axis in human diseases and related treatments

To defense harmful stimuli or maintain the immune homeostasis, the body produces and recruits a superfamily of cytokines such as interleukins, interferons, chemokines etc. Among them, chemokines act as crucial regulators in defense systems. CCL5/CCR5 combination is known for facilitating inflammatory responses, as well as inducing the adhesion and migration of different T cell subsets in immune responses. In addition, recent studies have shown that the interaction between CCL5 and CCR5 is involved in various pathological processes including inflammation, chronic diseases, cancers as well as the infection of COVID-19. This review focuses on how CCL5/CCR5 axis participates in the pathological processes of different diseases and their relevant signaling pathways for the regulation of the axis. Moreover, we highlighted the gene therapy and chemotherapy studies for treating CCR5-related diseases, including the ongoing clinical trials. The barriers and perspectives for future application and translational research were also summarized.

A new role for matrix metalloproteinase-3 in the NGF metabolic pathway: Proteolysis of mature NGF and sex-specific differences in the continuum of Alzheimer's pathology

Matrix metalloproteinase-3 (MMP-3) has been associated with risk of Alzheimer's disease (AD). In this study we introduce a novel role for MMP-3 in degrading nerve growth factor (NGF) in vivo and examine its mRNA and protein expression across the continuum of AD pathology. We provide evidence that MMP-3 participates in the degradation of mature NGF in vitro and in vivo and that it is secreted from the rat cerebral cortex in an activity-dependent manner. We show that cortical MMP-3 is upregulated in the McGill-R-Thy1-APP transgenic rat model of AD-like amyloidosis. A similar upregulation was found in AD and MCI brains as well as in cognitively normal individuals with elevated amyloid deposition. We also observed that frontal cortex MMP-3 protein levels are higher in males. MMP-3 protein correlated with more AD neuropathology, markers of NGF metabolism, and lower cognitive scores in males but not in females. These results suggest that MMP-3 upregulation in AD might contribute to NGF dysmetabolism, and therefore to cholinergic atrophy and cognitive deficits, in a sex-specific manner. MMP-3 should be further investigated as a biomarker candidate or as a therapeutic target in AD.

Analysis of cardiovascular disease-related NF-κB-regulated genes and microRNAs in TNFα-treated primary mouse vascular endothelial cells

Activated nuclear factor-κB (NF-κB) plays an important role in the development of cardiovascular disease (CVD) through its regulated genes and microRNAs (miRNAs). However, the gene regulation profile remains unclear. In this study, primary mouse vascular endothelial cells (pMVECs) were employed to detect CVD-related NF-κB-regulated genes and miRNAs. Genechip assay identified 77 NF-κB-regulated genes, including 45 upregulated and 32 downregulated genes, in tumor necrosis factor α (TNFα)-treated pMVECs. Ten of these genes were also found to be regulated by NF-κB in TNFα-treated HeLa cells. Quantitative real-time PCR (qRT-PCR) assay confirmed the up-regulation of Egr1, Tnf, and Btg2 by NF-κB in the TNFα-treated pMVECs. The functional annotation revealed that many NF-κB-regulated genes identified in pMVECs were clustered into classical NF-κB-involved biological processes. Genechip assay also identified 26 NF-κB-regulated miRNAs, of which 21 were upregulated and 5 downregulated, in the TNFα-treated pMVECs. Further analysis showed that nine of the identified genes are regulated by seven of these miRNAs. Finally, among the identified NF-κB-regulated genes and miRNAs, 5 genes and 12 miRNAs were associated with CVD by miRWalk and genetic association database analysis. Taken together, these findings show an intricate gene regulation network raised by NF-κB in TNFα-treated pMVECs. The network provides new insights for understanding the molecular mechanism underlying the progression of CVD.

Interleukin 1β and Prostaglandin E2 affect expression of DNA methylating and demethylating enzymes in human gingival fibroblasts

Periodontitis is a common chronic inflammatory condition that results in increased levels of inflammatory cytokines and inflammatory mediators. In addition to oral disease and tooth loss, it also causes low-grade systemic inflammation that contributes to development of systemic conditions including cardiovascular disease, pre-term birth, diabetes and cancer. Chronic inflammation is associated with epigenetic change, and it has been suggested that such changes can alter cell phenotypes in ways that contribute to both ongoing inflammation and development of associated pathologies. Here we show that exposure of human gingival fibroblasts to IL-1β increases expression of maintenance methyltransferase DNMT1 but decreases expression of de novo methyltransferase DNMT3a and the demethylating enzyme TET1, while exposure to PGE2 decreases expression of all three enzymes. IL-1β and PGE2 both affect global levels of DNA methylation and hydroxymethylation, as well as methylation of some specific CpG in inflammation-associated genes. The effects of IL-1β are independent of its ability to induce production of PGE2, and the effects of PGE2 on DNMT3a expression are mediated by the EP4 receptor. The finding that exposure of fibroblasts to IL-1β and PGE2 can result in altered expression of DNA methylating/demethylating enzymes and in changing patterns of DNA methylation suggests a mechanism through which inflammatory mediators might contribute to the increased risk of carcinogenesis associated with inflammation.

Epigenetic Regulation of Vascular Smooth Muscle Cells by Histone H3 Lysine 9 Dimethylation Attenuates Target Gene-Induction by Inflammatory Signaling

OBJECTIVE

Vascular inflammation underlies cardiovascular disease. Vascular smooth muscle cells (VSMCs) upregulate selective genes, including MMPs (matrix metalloproteinases) and proinflammatory cytokines upon local inflammation, which directly contribute to vascular disease and adverse clinical outcome. Identification of factors controlling VSMC responses to inflammation is therefore of considerable therapeutic importance. Here, we determine the role of Histone H3 lysine 9 di-methylation (H3K9me2), a repressive epigenetic mark that is reduced in atherosclerotic lesions, in regulating the VSMC inflammatory response. Approach and Results: We used VSMC-lineage tracing to reveal reduced H3K9me2 levels in VSMCs of arteries after injury and in atherosclerotic lesions compared with control vessels. Intriguingly, chromatin immunoprecipitation showed H3K9me2 enrichment at a subset of inflammation-responsive gene promoters, including MMP3, MMP9, MMP12, and IL6, in mouse and human VSMCs. Inhibition of G9A/GLP (G9A-like protein), the primary enzymes responsible for H3K9me2, significantly potentiated inflammation-induced gene induction in vitro and in vivo without altering NFκB (nuclear factor kappa-light-chain-enhancer of activated B cell) and MAPK (mitogen-activated protein kinase) signaling. Rather, reduced G9A/GLP activity enhanced inflammation-induced binding of transcription factors NFκB-p65 and cJUN to H3K9me2 target gene promoters MMP3 and IL6. Taken together, these results suggest that promoter-associated H3K9me2 directly attenuates the induction of target genes in response to inflammation in human VSMCs.

CONCLUSIONS

This study implicates H3K9me2 in regulating the proinflammatory VSMC phenotype. Our findings suggest that reduced H3K9me2 in disease enhance binding of NFκB and AP-1 (activator protein-1) transcription factors at specific inflammation-responsive genes to augment proinflammatory stimuli in VSMC. Therefore, H3K9me2-regulation could be targeted clinically to limit expression of MMPs and IL6, which are induced in vascular disease.

Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis

The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.

MTG16 is a tumor suppressor in colitis-associated carcinoma

MTG16 is a member of the myeloid translocation gene (MTG) family of transcriptional corepressors. While MTGs were originally identified in chromosomal translocations in acute myeloid leukemia, recent studies have uncovered a role in intestinal biology. For example, Mtg16-/- mice have increased intestinal proliferation and are more sensitive to intestinal injury in colitis models. MTG16 is also underexpressed in patients with moderate/severe ulcerative colitis. Based on these findings, we postulated that MTG16 might protect against colitis-associated carcinogenesis. MTG16 was downregulated at the protein and RNA levels in patients with inflammatory bowel disease and in those with colitis-associated carcinoma. Mtg16-/- mice subjected to inflammatory carcinogenesis modeling exhibited worse colitis and increased tumor multiplicity and size. Loss of MTG16 also increased severity of dysplasia, apoptosis, proliferation, DNA damage, and WNT signaling. Moreover, transplantation of WT marrow into Mtg16-/- mice failed to rescue the Mtg16-/- protumorigenic phenotypes, indicating an epithelium-specific role for MTG16. While MTG dysfunction is widely appreciated in hematopoietic malignancies, the role of this gene family in epithelial homeostasis, and in colon cancer, was unrealized. This report identifies MTG16 as an important modulator of colitis and tumor development in inflammatory carcinogenesis.

Mangiferin, a novel nuclear factor kappa B-inducing kinase inhibitor, suppresses metastasis and tumor growth in a mouse metastatic melanoma model

Advanced metastatic melanoma, one of the most aggressive malignancies, is currently without reliable therapy. Therefore, new therapies are urgently needed. Mangiferin is a naturally occurring glucosylxanthone and exerts many beneficial biological activities. However, the effect of mangiferin on metastasis and tumor growth of metastatic melanoma remains unclear. In this study, we evaluated the effect of mangiferin on metastasis and tumor growth in a mouse metastatic melanoma model. We found that mangiferin inhibited spontaneous metastasis and tumor growth. Furthermore, mangiferin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated NF-κB-inducing kinase (NIK), inhibitor of kappa B kinase (IKK), and inhibitor of kappa B (IκB) and increases the expression of IκB protein in vivo. In addition, we found that mangiferin inhibited the expression of matrix metalloproteinases (MMPs) and very late antigens (VLAs) in vivo. Mangiferin treatment also increased the expression of cleaved caspase-3, cleaved Poly ADP ribose polymerase-1 (PARP-1), p53 upregulated modulator of apoptosis (PUMA), p53, and phosphorylated p53 proteins, and decreased the expression of Survivin and Bcl-associated X (Bcl-xL) proteins in vivo. These results indicate that mangiferin selectivity suppresses the NF-κB pathway via inhibition of NIK activation, thereby inhibiting metastasis and tumor growth. Importantly, the number of reported NIK selective inhibitors is limited. Taken together, our data suggest that mangiferin may be a potential therapeutic agent with a new mechanism of targeting NIK for the treatment of metastatic melanoma.

Breast Cancer Genetic and Molecular Subtype Impacts Response to Omega-3 Fatty Acid Ethyl Esters

Epidemiological studies have correlated frequent omega-3 (n-3) fatty acid consumption with a lower risk for breast cancer; however, recent prospective studies have been less conclusive. Efforts in the preventive setting have focused on the use of n-3 fatty acids, and the pharmaceutical ethyl esters (EE) of these natural compounds, for high-risk patient populations. Limited understanding of specific mechanisms by which these agents function has hampered identification of the cancer subtype(s) that would gain the greatest therapeutic benefit. In this study, we investigated the in vitro effects of n-3 EEs in four distinct breast cancer subtypes and explored how they affect not only breast cancer cell survival but also modulate the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptor gamma signaling pathways. Similar to the high variance in response observed in human studies, we found that the effectiveness of n-3 EEs depends on the molecular characteristics of the MCF-7, CAMA-1, MDA-MB-231, and SKBR3 breast cancer cell lines and is closely associated with the suppression of NF-κB. These data strongly suggest that the use of n-3 fatty acids and their pharmaceutical ether esters in the prevention and therapeutic setting should be guided by specific tumor characteristics.

Genetic Influences on the Development of Fibrosis in Crohn's Disease

Fibrostenotic strictures are an important complication in patients with Crohn’s disease (CD), very often necessitating surgery. This fibrotic process develops in a genetically susceptible individual and is influenced by an interplay with environmental, immunological, and disease-related factors. A deeper understanding of the genetic factors driving this fibrostenotic process might help to unravel the pathogenesis, and ultimately lead to development of new, anti-fibrotic therapy. Here, we review the genetic factors that have been associated with the development of fibrosis in patients with CD, as well as their potential pathophysiological mechanism(s). We also hypothesize on clinical implications, if any, and future research directions.

Association of Common Variants in MMPs with Periodontitis Risk

Background. Matrix metalloproteinases (MMPs) are considered to play an important role during tissue remodeling and extracellular matrix degradation. And functional polymorphisms in MMPs genes have been reported to be associated with the increased risk of periodontitis. Recently, many studies have investigated the association between MMPs polymorphisms and periodontitis risk. However, the results remain inconclusive. In order to quantify the influence of MMPs polymorphisms on the susceptibility to periodontitis, we performed a meta-analysis and systematic review. Results. Overall, this comprehensive meta-analysis included a total of 17 related studies, including 2399 cases and 2002 healthy control subjects. Our results revealed that although studies of the association between MMP-8 −799 C/T variant and the susceptibility to periodontitis have not yielded consistent results, MMP-1 (−1607 1G/2G, −519 A/G, and −422 A/T), MMP-2 (−1575 G/A, −1306 C/T, −790 T/G, and −735 C/T), MMP-3 (−1171 5A/6A), MMP-8 (−381 A/G and +17 C/G), MMP-9 (−1562 C/T and +279 R/Q), and MMP-12 (−357 Asn/Ser), as well as MMP-13 (−77 A/G, 11A/12A) SNPs are not related to periodontitis risk. Conclusions. No association of these common MMPs variants with the susceptibility to periodontitis was found; however, further larger-scale and multiethnic genetic studies on this topic are expected to be conducted to validate our results.

Celecoxib and fish oil: a combination strategy for decreased inflammatory mediators in early stages of experimental mammary cancer

Chronic inflammation has been directly linked to cancer progression. Therefore, current study was designed to understand the mechanism of action of chemo-preventive effect of celecoxib and fish oil on inflammatory mediators in experimental mammary carcinoma. Female Wistar rats were distributed into control and DMBA treated groups and further subdivided based on pretreatment with celecoxib and/or fish oil. Inflammation was measured by assessing expression of NF-κB, COX-2 and cytokines. The results indicated an elevation in expression of NF-κB, COX-2 and cytokines' levels (IFN-γ, IL-4 and IL-10) in DMBA group as compared to controls. On pretreatment with celecoxib and/or fish oil in DMBA treated animals, a significant reduction in expression of NF-κB, COX-2 and cytokines' levels was observed. The decrease was more pronounced with combinatorial regimen than either celecoxib or fish oil alone. To conclude, a combinatorial strategy of celecoxib and fish oil may generate an immune response against the tumor cell by altering cytokine repertoire and decrease the tendency of tumor cells to escape immune surveillance.

USP22 promotes epithelial-mesenchymal transition via the FAK pathway in pancreatic cancer cells

Epithelial-mesenchymal transition (EMT) contributes to the occurrence and development of tumors, particularly to the promotion of tumor invasion and metastasis. As a newly discovered ubiquitin hydrolase family member, USP22 plays a key role in the malignant transformation of tumors and the regulation of the cell cycle. However, recent studies on USP22 have primarily focused on its role in cell cycle regulation, and the potential mechanism underlying the promotion of tumor invasion and metastasis by abnormal USP22 expression has not been reported. Our studies revealed that the overexpression of USP22 in PANC-1 cells promoted Ezrin redistribution and phosphorylation and cytoskeletal remodeling, upregulated expression of the transcription factors Snail and ZEB1 to promote EMT, and increased cellular invasion and migration. In contrast, blockade of USP22 expression resulted in the opposite effects. In addition, the focal adhesion kinase (FAK) signaling pathway was shown to play a key role in the process of EMT induction in PANC-1 cells by USP22. Thus, the present study suggests that USP22 acts as a regulatory protein for EMT in pancreatic cancer, which may provide a new approach for the targeted therapy of pancreatic cancer.

RANKL promotes migration and invasion of hepatocellular carcinoma cells via NF-κB-mediated epithelial-mesenchymal transition

Background

Metastasis accounts for the most deaths in patients with hepatocellular carcinoma (HCC). Receptor activator of nuclear factor kappa B ligand (RANKL) is associated with cancer metastasis, while its role in HCC remains largely unknown.

Methods

Immunohistochemistry was performed to determine the expression of RANK in HCC tissue (n = 398). Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to examine the expression of RANK, E-cadherin, N-cadherin, vimentin, Snail, Slug, Twist and MMPs in HCC cells. Wound healing and Transwell assays were used to evaluate cell migration and invasion ability.

Results

We found that expression of RANK, the receptor of RANKL, was significantly higher in HCC tumor tissues than in peritumor liver tissues (p<0.001). Constitutive expression of RANK was detected in HCC cell lines, which can be up-regulated when HCC cells were stimulated with RANKL. Notably, in vitro experiments showed that activation of RANKL-RANK axis significantly promoted migration and invasion ability of HCC cells. In addition, RANKL stimulation increased the expression levels of N-cadherin, Snail, and Twist, while decreased the expression of E-cadherin, with concomitant activation of NF-κB signaling pathway. Moreover, administration of the NF-κB inhibitor attenuated RANKL-induced migration, invasion and epithelial-mesenchymal transition of HCC cells.

Conclusions

RANKL could potentiate migration and invasion ability of RANK-positive HCC cells through NF-κB pathway-mediated epithelial-mesenchymal transition, which means that RANKL-RANK axis could be a potential target for HCC therapy.

The inhibitor of kappa B kinase-epsilon regulates MMP-3 expression levels and can promote lung metastasis

The factors that determine the ability of metastatic tumor cells to expand and grow in specific secondary site(s) are not yet fully understood. Matrix metalloproteinases (MMP) were identified as potential regulators of the site-specificity of metastasis. We found that lung carcinoma cells ectopically expressing high levels of the receptor for the type I insulin like growth factor receptor (M27^R cells) had a significant reduction in MMP-3 expression levels and this coincided with reduced metastasis to the lung. We used these cells to further investigate signaling pathways regulating MMP-3 expression and the role that MMP-3 plays in lung metastasis. We show that ectopic IκB kinase ɛ (IKKɛ) expression in these cells partly restored MMP-3 expression levels and also sensitized MMP-3 transcription to induction by phorbol 12-myristate 13-acetate (PMA). This increase in MMP-3 production was due to increased activation of several signal transduction mediators, including protein kinase C alpha, ERK2, Akt and the transcription factor p65. Furthermore, reconstitution of MMP-3 expression in M27^R cells restored their ability to colonize the lung whereas silencing of MMP-3 in M27 cells reduced metastases. Collectively, our results implicate IKKɛ as a central regulator of PMA-induced cell signaling and MMP-3 expression and identify MMP-3 as an enabler of tumor cell expansion in the lung.

Fish oil suppresses cell growth and metastatic potential by regulating PTEN and NF-κB signaling in colorectal cancer

Homeostasis in eukaryotic tissues is tightly regulated by an intricate balance of the prosurvival and antisurvival signals. The tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10), a dual-specificity phosphatase, plays a functional role in cell cycle arrest and apoptosis. NF-κB and its downstream regulators (such as VEGF) play a central role in prevention of apoptosis, promotion of inflammation and tumor growth. Therefore, we thought to estimate the expression of PTEN, Poly-ADP-ribose polymerase (PARP), NF-κBp50, NF-κBp65 and VEGF to evaluate the effect of supplementation of fish oil on apoptotic and inflammatory signaling in colon carcinoma. Male wistar rats in Group I received purified diet while Group II and III received modified diet supplemented with FO∶CO(1∶1)&FO∶CO(2.5∶1) respectively. These were further subdivided into controls receiving ethylenediamine-tetra acetic-acid and treated groups received dimethylhydrazine-dihydrochloride (DMH)/week for 4 weeks. Animals sacrificed 48 hours after last injection constituted initiation phase and that sacrificed after 16 weeks constituted post-initiation phase. We have analysed expression of PTEN, NF-κBp50, NF-κBp65 by flowcytometer and nuclear localization of NF-κB by immunofluorescence. PARP and VEGF were assessed by immunohistochemistry. In the initiation phase, animals receiving DMH have shown increased % of apoptotic cells, PTEN, PARP, NF-κBp50, NF-κBp65 and VEGF however in post-initiation phase no significant alteration in apoptosis with decreased PTEN and increased PARP, NF-κBp50, NF-κBp65 and VEGF were observed as compared to control animals. On treatment with both ratios of fish oil in both the phases, augmentation in % of apoptotic cells, decreased PTEN, PARP, NF-κBp50, NF-κBp65 and VEGF were documented with respect to DMH treated animals with effect being more exerted with higher ration in post-initiation phase. Hence, fish oil activates apoptosis, diminishes DNA damage and inhibits inflammatory signalling in a dose and time dependent manner so as to inhibit progression of colon cancer.

In an in vitro model of human tuberculosis, monocyte-microglial networks regulate matrix metalloproteinase-1 and -3 gene expression and secretion via a p38 mitogen activated protein kinase-dependent pathway

Background

Tuberculosis (TB) of the central nervous system (CNS) is characterized by extensive tissue inflammation, driven by molecules that cleave extracellular matrix such as matrix metalloproteinase (MMP)-1 and MMP-3. However, relatively little is known about the regulation of these MMPs in the CNS.

Methods

Using a cellular model of CNS TB, we stimulated a human microglial cell line (CHME3) with conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb). MMP-1 and MMP-3 secretion was detected using ELISAs confirmed with casein zymography or western blotting. Key results of a phospho-array profile that detects a wide range of kinase activity were confirmed with phospho-Western blotting. Chemical inhibition (SB203580) of microglial cells allowed investigation of expression and secretion of MMP-1 and MMP-3. Finally we used promoter reporter assays employing full length and MMP-3 promoter deletion constructs. Student’s t-test was used for comparison of continuous variables and multiple intervention experiments were compared by one-way ANOVA with Tukey’s correction for multiple pairwise comparisons.

Results

CoMTb up-regulated microglial MMP-1 and MMP-3 secretion in a dose- and time-dependent manner. The phospho-array profiling showed that the major increase in kinase activity due to CoMTb stimulation was in p38 mitogen activated protein kinase (MAPK), principally the α and γ subunits. p38 phosphorylation was detected at 15 minutes, with a second peak of activity at 120 minutes. High basal extracellular signal-regulated kinase activity was further increased by CoMTb. Secretion and expression of MMP-1 and MMP-3 were both p38 dependent. CoMTb stimulation of full length and MMP-3 promoter deletion constructs demonstrated up-regulation of activity in the wild type but a suppression site between -2183 and -1612 bp.

Conclusions

Monocyte-microglial network-dependent MMP-1 and MMP-3 gene expression and secretion are dependent upon p38 MAPK in tuberculosis. p38 is therefore a potential target for adjuvant therapy in CNS TB.

IL-4 inhibition of IL-1 induced Matrix metalloproteinase-3 (MMP-3) expression in human fibroblasts involves decreased AP-1 activation via negative crosstalk involving of Jun N-terminal kinase (JNK)

Matrix metalloproteinase-3 (MMP-3) over-expression is associated with tissue destruction in the context of chronic inflammation. Previous studies showed that IL-4 inhibits induction of MMP-3 by IL-1β, and suggested that AP-1 might be involved. Here we show that IL-1 induced binding of transcription factor AP-1 to the MMP-3 promoter consists primarily of c-Jun, JunB, and c-Fos and that binding of c-Jun and c-Fos is inhibited by the combination of cytokines while binding of Jun B is not. Mutation of the AP-1 site in the MMP-3 promoter decreased the ability of IL-4 to inhibit its transcription in transfected MG-63 cells. Western blotting showed that both cytokines activate Jun N-terminal kinase (JNK), but with somewhat different kinetics, and that activation of JNK by both cytokines individually is inhibited by the combination. These results indicate that IL-4 inhibition of MMP-3 expression is associated with reduction of IL-1 induced binding of active forms of the AP-1 dimer, while less active JunB-containing dimers remain, and suggest that these changes are associated with decreased activation of JNK.

MMP3 and TIMP1 variants contribute to chronic periodontitis and may be implicated in disease progression

AIM

Matrix metalloproteinases (MMPs) play a key role in the tissue destruction characteristic of chronic periodontitis. The purpose of this study was to investigate the association of MMP and TIMP polymorphisms with chronic periodontitis in two populations.

MATERIAL AND METHODS

A total of 34 polymorphisms spanning 12 MMP and 2 TIMP genes were genotyped in 401 individuals from Brazil (99 cases with chronic periodontitis and 302 controls), and 274 individuals from the US (70 cases and 204 controls). Individuals were considered cases if presenting at least three teeth exhibiting sites of clinical attachment loss ≥ 5 mm in two different quadrants. Controls were characterized by absence of clinical attachment loss and no sites with probing depth >3 mm. MMP3 and TIMP1 mRNA expression was evaluated in healthy and diseased periodontal tissues.

RESULTS

TIMP1 showed association with chronic periodontitis in the Brazilian population (for rs5906435, p = 0.0004), whereas MMP3 showed association in the US population (for rs679620, p = 0.0003; and rs650108, p = 0.002) and in the Brazilian population (for rs639752, p = 0.005). MMP3 and TIMP1 mRNA expression was significantly higher in diseased tissues when compared to control tissues.

CONCLUSIONS

Our results further support a role for variations in MMP3 in chronic periodontitis and report a novel association with TIMP1. These genes may be considered additional candidate genes for chronic periodontitis.

Genetic polymorphisms of matrix metalloproteinase 3 in primary sclerosing cholangitis

BACKGROUND

The damaging cholestasis inherent to primary sclerosing cholangitis (PSC) results from bile duct stricturing because of progressive fibrosis. The matrix metalloproteinase 3 (MMP3) degrades a wide range of matrix components and is expressed by activated liver stellate cells, and so is a candidate for involvement with the fibrotic processes underlying PSC. Moreover, the MMP3 gene harbours polymorphisms associated with variation in its activity directly impacting clinical phenotypes.

AIMS

We aimed to examine the influence of MMP3 polymorphisms on PSC risk and progression.

METHODS

Nine single nucleotide polymorphisms (SNPs) tagging the common genetic variation of MMP3 were genotyped in 266 PSC patients and 407 controls. SNPs and inferred haplotypes were assessed for PSC association by logistic regression and score tests. The effect of SNPs on survival to liver transplant or death was analysed using Cox regression, and Kaplan-Meier curves were constructed.

RESULTS

No association of PSC with individual SNPs or haplotypes of MMP3 was detected. However, progression to death or liver transplant was significantly associated with homozygosity for minor alleles of rs522616, rs650108 and rs683878, particularly among PSC patients with concurrent ulcerative colitis (UC) (strongest in redundant SNPs rs650108/rs683878, hazard ratio=3.23, 95% confidence interval 1.45-7.25, P=0.004).

CONCLUSIONS

Genetic variation in MMP3 influences PSC progression, possibly in the context of coexisting UC. While the functional variants and specific mechanisms remain unknown, this finding implicates the turnover of the extracellular matrix as an important and variable component of PSC pathogenesis. Efforts to understand this process could form the basis for developing effective treatments, which are currently lacking for PSC.

Genetic variation in the matrix metalloproteinase genes and diabetic nephropathy in type 1 diabetes

Genetic data support the notion that polymorphisms in members of the matrix metalloproteinase (MMP) family of genes play an important role in extracellular matrix remodeling and contribute to the pathogenesis of vascular disease. To identify novel genetic markers for diabetic nephropathy (DN), we examined the relationship between MMP gene polymorphisms and DN in the Genetics of Kidneys in Diabetes (GoKinD) population. Genotypic data from the Genetic Association Information Network (GAIN) type 1 DN project were analyzed for associations across 21 MMP genes in 1705 individual with type 1 diabetes, including 885 normoalbuminuric control subjects and 820 advanced DN case subjects. In total, we investigated the role of 1283 SNPs (198 genotyped SNPs and 1085 imputed SNPs) mapping to the MMP genes. We identified associations at several correlated SNPs across a 29.2kb interval on chromosome 11q at the MMP-3/MMP-12 locus. The strongest associations occurred at 2 highly-correlated SNPs, rs610950 (OR=0.50, P=1.6×10(-5)) and rs1277718 (OR=0.50, P=2.1×10(-5)). Further examination of this locus identified 17 SNPs (2 genotyped SNPs and 15 imputed SNPs) in complete linkage disequilibrium associated with DN (P-values<2.5×10(-4)), including a non-synonymous SNP (rs652438, Asn357Ser) located in exon 8 of MMP-12 that significantly reduced the risk of DN among carriers of the serine substitution relative to homozygous carriers of asparagine (OR=0.51; 95% CI=0.37-0.71, P=6.2×10(-5)). Taken together, our study suggests that genetic variations within the MMP-3/MMP-12 locus influence susceptibility of DN in type 1 diabetes.

Prolonged upright posture induces degenerative changes in intervertebral discs of rat cervical spine

STUDY DESIGN

An in vivo study of the cervical intervertebral discs (IVDs) response to upright posture was performed using an amputated bipedal rat model.

OBJECTIVE

To investigate the effects of upright posture on IVDs of rat cervical spine.

SUMMARY OF BACKGROUND DATA

The distinct arrangement of human neck muscle from that of cat and rhesus indicated that in the evolution process, upright posture might have affected cervical spine of human ancestors. However, the effects of upright posture on cervical spine have not been assessed.

METHODS

Forty-one-month-old rats were randomly divided into 5-month-control, 5-month-surgery, 7-month-control, and 7-month surgery group (n = 10 per group). Both forelimbs of 2 surgery group rats were amputated, and those rats were then induced to be upright in the custom-made cages. Two control group rats were kept in regular cages. These rats were respectively killed at the fifth and seventh month after surgery and the IVD samples of lumbar spine were harvested for histologic and immunohistochemical studies. Total RNA isolated from these samples were used for real-time polymerase chain reaction of type II collagen (Col2a1), type X collagen, matrix metalloproteinase 13 (MMP-13), MMP-3, aggre-can, and aggrecanase-2 (ADAMTS-5).

RESULTS

Upright posture affects histologic changes of the cervical IVDs such as fissures of anulus fibrosus and decreased height of disc, decreased protein level of Col2a1 at nucleus pulposus and anulus fibrosus, up-regulated MMP-13, MMP-3, ADAMTS-5, and type X collagen mRNA expression, and downregulated mRNA expression of Col2a1 and aggrecan.

CONCLUSION

Upright stance accelerates cervical disc degeneration in rats.

ZBP-89 enhances Bak expression and causes apoptosis in hepatocellular carcinoma cells

ZBP-89 can enhance tumor cells to death stimuli. However, the molecular mechanism leading to the inhibitory effect of ZBP-89 is unknown. In this study, 4 liver cell lines were used to screen for the target of ZBP-89 on cell death pathway. The identified Bak was further analyzed for its role in ZBP-89-mediated apoptosis. The result showed that ZBP-89 significantly and time-dependently induced apoptosis. It significantly upregulated the level of pro-apoptotic Bak. ZBP-89 targeted a region between -457 and -407 of human Bak promoter to stimulate Bak expression based on the findings of Bak promoter luciferase report gene assay and electrophoretic mobility shift assay. ZBP-89-induced Bak increase and ZBP-89-mediated apoptosis were markedly suppressed by Bak siRNA, confirming that Bak was specifically targeted by ZBP-89 to facilitate apoptosis. In conclusion, this study demonstrated that ZBP-89 significantly induced apoptosis of HCC cells via promoting Bak level.

Allele-specific regulation of matrix metalloproteinase-3 gene by transcription factor NFkappaB

Background

Matrix metalloproteinase-3 (MMP3) is implicated in the pathogenesis and progression of atherosclerotic lesions. Previous studies suggested that MMP3 expression is influenced by a polymorphism (known as the 5A/6A polymorphism) in the promoter of the MMP3 gene and that this polymorphism is located within a cis-element that interacts with the transcription factor NFκB. In the present study, we sought to investigate whether MMP3 and NFκB were co-localized in atherosclerotic lesions and whether NFκB had differential effects on the two alleles of the MMP3 5A/6A polymorphism.

Methodology/Principal Findings

Immunohistochemical examination showed that MMP3 and both the NFκB p50 and p65 subunits were expressed abundantly in macrophages in atherosclerotic lesions and that MMP3 expression was co-localized with p50 and p65. Chromatin immunoprecipitation experiments showed interaction of p50 and p65 with the MMP3 promoter in macrophages, with greater binding to the 5A allele than to the 6A allele. Reporter gene assays in transiently transfected macrophages showed that the 5A allele had greater transcriptional activity than the 6A allele, and that this allele-specific effect was augmented when the cells were treated with the NFκB activator lipopolysaccharides or co-transfected with p50 and/or p65 expressing plasmids, but was reduced when the cells were treated with the NFκB inhibitor 6-Amino-4-(4-phenoxyphenylethylamino)-quinazoline or transfected with a dominant negative mutant of IkB kinase-β.

Conclusion

These results corroborate an effect of the 5A/6A polymorphism on MMP3 transcription and indicate that NFκB has differential effects on the 5A and 6A alleles.

Polymorphisms of MMP-3 and TIMP-4 genes affect angiographic coronary plaque progression in non-diabetic and type 2 diabetic patients

BACKGROUND

This study examined whether genetic variants of matrix metallopeptidases (MMPs) and their tissue inhibitors (TIMPs) were associated with angiographic coronary plaque progression (PP) in type 2 diabetic and non-diabetic patients.

METHODS

Four hundred and ninety-nine patients were grouped, who underwent coronary angiography and received repeat examinations after 1-y follow-up. Twelve functional polymorphisms of MMPs and TIMPs were characterized.

RESULTS

Genotype distribution and allele frequency of -1612 5A/6A MMP-3 and 3'UTR C/T TIMP-4 differed between patients with PP and those without in both diabetic and non-diabetic groups after Bonferroni's correction (all P<0.0041667, except for allele frequency of MMP-3 [P=0.007] and genotype/allele frequency of TIMP-4 [P=0.04 and P=0.016, respectively] in diabetes). MMP-3 and TIMP-4 polymorphisms were associated with changes in percent diameter stenosis and minimal lumen diameter in diabetic patients, and changes in cumulative coronary obstruction in both diabetic and non-diabetic patients (all P<0.05). Multivariable regression analysis revealed that hypertension, low HDL-C and genotypes of MMP-3 and TIMP-4 were independent determinants of PP in the whole patients, with these 2 genetic factors being associated with PP in diabetic and non-diabetic subgroups.

CONCLUSION

This study demonstrated that MMP-3 and TIMP-4 polymorphisms affect angiographic coronary PP in type 2 diabetic and non-diabetic patients.

ZBP-89 reduces the cell death threshold in hepatocellular carcinoma cells by increasing caspase-6 and S phase cell cycle arrest

ZBP-89 inhibits the some tumor cells but its role in HCC is unknown. We investigated effect of ZBP-89 on cell death of 5 HCC cell lines with different status of p53. We found that ZBP-89 significantly induced cell death of all HCC cells particularly those with wild-type p53. The inhibition was well correlated with the induction of caspase-6 activity. The inhibition of caspase-6 abolished the effect of ZBP-89. ZBP-89 reduced the cells in G2-M but increased them in S phase. With the changes in caspase-6 and cell cycle, ZBP-89 greatly enhanced the killing effectiveness of 5-fluorouracil or staurosporine in HCC cells.

NF-kappaB and ZBP-89 regulate MMP-3 expression via a polymorphic site in the promoter

A 5T/6T polymorphism in the human MMP-3 promoter affects gene expression and impacts the risk and/or severity of various pathological conditions. Chromatin immunoprecipitation (ChIP) in human fibroblasts homozygous for the 6T site demonstrate that it is bound by NF-kappaB and ZBP-89 transcription factors in its native chromatin. ChIP in COS-1 cells transfected with plasmids containing the 5T and 6T sites in the context of 2kb of the MMP-3 promoter showed that NF-kappaB p50 binds preferentially to the 6T site, while more ZBP-89 binding is detected to the 5T site. Over-expressed ZBP-89 increased transcription from the 5T promoter but not from the 6T, while NF-kappaB decreased transcription from both promoters, even in the presence of excess ZBP-89. A model is suggested in which the physiological impact of the polymorphism is dependent on the relative levels and activities of these competing factors in various cell types and conditions.

Epithelial-mesenchymal transition and the invasive potential of tumors

The development of metastasis requires the movement and invasion of cancer cells from the primary tumor into the surrounding tissue. To acquire such invasive abilities, epithelial cancer cells must undergo several phenotypic changes. Some of these, including alterations in cell adhesion and migration, are reminiscent of those observed during the developmental process termed epithelial-mesenchymal transition (EMT). Several master gene regulatory programs known to promote EMT during development have recently been discovered to play key roles in cancer progression. In particular, the regulation of cell adhesion molecules and the signaling pathways linking them to mechanisms of gene regulation has emerged as an important determinant of tumor cell invasion and metastasis. A deeper understanding of these mechanisms should allow both better diagnosis and the development of specific treatments for invasive cancer.

Prognostic significance of nuclear factor-kappaB p105/p50 in human melanoma and its role in cell migration

Transcriptional factor nuclear factor-kappaB (NF-kappaB) family has been shown to play an important role in tumor pathogenesis and serve as a potential target in cancer therapy. However, it is necessary to clarify the specific functions of NF-kappaB members, which would provide the basis for the selective blockade and reduction of therapeutic side effects resulting from unspecific inhibition of NF-kappaB members. In this study, we explored the role of NF-kappaB p105/p50 in melanoma pathogenesis in vitro and in vivo. We found that the expression of NF-kappaB p105/p50 significantly increased in dysplastic nevi, primary melanoma, and metastatic melanoma compared with normal nevi (P = 0.0004, chi(2) test). Furthermore, NF-kappaB p105/p50 nuclear staining increased with melanoma progression and strong NF-kappaB p105/p50 nuclear staining was inversely correlated with disease-specific 5-year survival of patients with tumor thickness >2.0 mm (P = 0.014, log-rank test). Multivariate Cox regression analysis revealed that nuclear expression of NF-kappaB p105/p50 is an independent prognostic factor in this subgroup. Moreover, we found that up-regulation of NF-kappaB p50 enhanced melanoma cell migration, whereas small interfering RNA knockdown inhibited cell migration. In addition, overexpression of NF-kappaB p50 induced RhoA activity and Rock-mediated formation of stress fiber in melanoma cells. Taken together, our data indicate that NF-kappaB p105/p50 may be an important marker for human melanoma progression and prognosis as well as a potentially selective therapeutic target.

Genome-wide identification of novel expression signatures reveal distinct patterns and prevalence of binding motifs for p53, nuclear factor-kappaB and other signal transcription factors in head and neck squamous cell carcinoma

Microarray profiling of ten head and neck cancer lines revealed novel p53 and NF-κB transcriptional gene expression signatures which distinguished tumor cell subsets in association with their p53 status.

Background

Differentially expressed gene profiles have previously been observed among pathologically defined cancers by microarray technologies, including head and neck squamous cell carcinomas (HNSCCs). However, the molecular expression signatures and transcriptional regulatory controls that underlie the heterogeneity in HNSCCs are not well defined.

Results

Genome-wide cDNA microarray profiling of ten HNSCC cell lines revealed novel gene expression signatures that distinguished cancer cell subsets associated with p53 status. Three major clusters of over-expressed genes (A to C) were defined through hierarchical clustering, Gene Ontology, and statistical modeling. The promoters of genes in these clusters exhibited different patterns and prevalence of transcription factor binding sites for p53, nuclear factor-κB (NF-κB), activator protein (AP)-1, signal transducer and activator of transcription (STAT)3 and early growth response (EGR)1, as compared with the frequency in vertebrate promoters. Cluster A genes involved in chromatin structure and function exhibited enrichment for p53 and decreased AP-1 binding sites, whereas clusters B and C, containing cytokine and antiapoptotic genes, exhibited a significant increase in prevalence of NF-κB binding sites. An increase in STAT3 and EGR1 binding sites was distributed among the over-expressed clusters. Novel regulatory modules containing p53 or NF-κB concomitant with other transcription factor binding motifs were identified, and experimental data supported the predicted transcriptional regulation and binding activity.

Conclusion

The transcription factors p53, NF-κB, and AP-1 may be important determinants of the heterogeneous pattern of gene expression, whereas STAT3 and EGR1 may broadly enhance gene expression in HNSCCs. Defining these novel gene signatures and regulatory mechanisms will be important for establishing new molecular classifications and subtyping, which in turn will promote development of targeted therapeutics for HNSCC.

Role of matrix metalloproteinase, tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM: To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1, -2, -3, -9, tissue inhibitors of metalloproteinases (TIMP)-1, -2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD), that may enhance susceptibility and/or disease severity.

METHODS: Genomic DNA from 134 Crohn’s disease (CD), 111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR.

RESULTS: The TIMP-1 genotype TT in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%, P = 0.018 and 67.9% vs 51.6%, P = 0.055, respectively), while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%, P = 0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 < P < 0.01). The 5T5T genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during follow-up (91.2% vs 71.8%, P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%, P = 0.017).

CONCLUSION: Allelic composition at the examined SNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype, i.e., fistulizing disease, stricture pathogenesis and first disease localisation. These findings reinforce the important role of these proteins in IBD.

Interleukin-4 inhibition of interleukin-1-induced expression of matrix metalloproteinase-3 (MMP-3) is independent of lipoxygenase and PPARgamma activation in human gingival fibroblasts

Background

Interleukin 4 (IL-4) has been shown to suppress interleukin-1 (IL-1) induced expression of matrix metalloproteinase-3 (MMP-3) in human synovial and gingival fibroblasts, but the mechanism of suppression has not been determined. Activators of peroxisome proliferator-activated receptor-γ (PPARγ) have been shown to inhibit cytokine induced expression of MMPs in other cell types, and IL-4 has been shown to activate PPARγ by stimulating production of ligands through the lipoxygenase pathway. It has been suggested that PPARγ may inhibit expression of MMPs by competing with transcription factor AP-1 for binding to a putative composite binding element in the promoters. The objective of this study was to determine whether the suppressive effects of IL-4 on the IL-1 induced expression of MMP-3 involve activation of lipoxygenase and/or PPARγ.

Results

Western blotting revealed the presence of PPARγ in nuclear extract of HGF. IL-1 induced binding of nuclear extract to the putative composite PPRE/AP-1 site was diminished in the presence of pioglitazone, but there was no evidence of any change in the composition of the retarded complexes, and no evidence of PPARγ binding to this site. Nordihydroguaiaretic acid (NDGA), a non-selective lipoxygenase inhibitor, and MK886, a specific inhibitor of 5-lipoxygenase, induced MMP-3 expression synergistically with IL-1. However IL-4 was still able to inhibit MMP-3 expression in the presence of NDGA or MK886 and IL-1. Activation of PPARγ with pioglitazone not only failed to inhibit IL-1 induced expression of MMP-3 mRNA, but rather super-induced MMP-3 in the presence of IL-1. PPARγ antagonist GW9662 failed to abolish the suppressive effects of IL-4. Another PPARγ activator, 15-deoxy-Delta12,14prostaglandin J2 (15dPGJ2), also super-induced MMP-3 mRNA, and this was due at least in part to increased transcription.

Conclusion

IL-4 suppression of IL-1-induced MMP-3 expression in HGF is independent of lipoxygenase activity and activation of PPARγ. Super-induction of MMP-3 by pioglitazone may have important implications for patients using pioglitazone to treat type II diabetes in the presence of chronic inflammation.

Proteinase systems and thoracic aortic aneurysm progression

Thoracic aortic aneurysms (TAAs) are a rare but potentially devastating condition. Current surgical treatment of TAAs usually involves a major operation, which conveys many risks to the patient. Better knowledge of the cellular events that lead to aneurysm formation may elucidate less morbid treatment options for this condition. A number of recent studies have identified that the relative abundance and activity of extracellular matrix (ECM) proteolytic systems are increased with TAAs. Specifically, the matrix metalloproteinases (MMPs) have been linked through numerous studies to TAA formation. MMPs comprise a family of ECM-degrading proteinases. Endogenous tissue inhibitors (TIMPs) normally regulate MMP activity, and the activation of MMPs is complex and tightly controlled. Aneurysm formation may be related to relative changes in the balance between MMP/TIMP abundance favoring proteolysis. Through ECM degradation, the medial layer will undergo structural remodeling and a loss of structural integrity, leading to TAA formation. The goals of this review are to examine the structure of the normal and aneurysmal thoracic aorta and to place the new findings regarding ECM proteolysis in perspective with regard to TAA formation and progression. Through an integration of basic and clinical studies regarding the underlying molecular basis for proteolysis of the thoracic aorta, improved diagnostic, prognostic, and therapeutic strategies for this disease process are likely to be realized.

Effect of the anti-tumor necrosis factor-alpha antibody infliximab on the ex vivo mucosal matrix metalloproteinase-proteolytic phenotype in inflammatory bowel disease

BACKGROUND

Previous studies have shown an upregulation of matrix metalloproteinases (MMPs) in intestinal tissue of patients with inflammatory bowel disease (IBD) and significant clinical improvement after administration of the anti-TNF-a antibody infliximab. The aims of our study were to determine expression and secretion of MMP-1, -2, -3, -9, and their inhibitors TIMP-1, -2 by IBD versus control intestinal mucosa ex vivo and to assess the regulatory capacity by infliximab of the proteolytic phenotype.

METHODS

Intestinal mucosal explants from 20 IBD and 15 control patients were cultured with or without infliximab and/or the T-cell activator pokeweed mitogen (PWM). Explants and culture supernatants were analyzed for MMPs, TIMPs, and TNF-alpha protein, activity and/or mRNA levels. All patients were genotyped for functional TNF-alpha, MMP, and TIMP single nucleotide polymorphism (SNP) loci.

RESULTS

Expression of MMP and TIMP protein/activity in basal medium was higher in IBD versus control explants. Dependent on genotype at SNP loci, infliximab downregulated MMP-1, -3, and -9 relative to TIMP-1 and -2 and also decreased MMP-1 and -3 activities, while PWM enhanced these levels, partly counteracted again by infliximab. The expression of MMP-2 relative to TIMP did not change by treatment with infliximab and/or PWM.

CONCLUSIONS

The high expression of MMPs in patients with IBD suggests a role for these proteinases in the pathogenesis of this disease. Infliximab seems to induce a genotype-associated matrix protective phenotype, which may contribute to the observed therapeutic efficacy of this drug in IBD, particularly at the mucosal surface.

Matrix metalloproteinase-3 secretion from human pancreatic periacinar myofibroblasts in response to inflammatory mediators

OBJECTIVES

Matrix metalloproteinases (MMPs) play roles in the pathophysiology of pancreatic disorders. However, the regulation of MMP-3 secretion in the pancreas remains unclear. In this study, we assessed the expression of MMP-3 in human pancreatic periacinar myofibroblasts.

METHODS

MMP-3 secretion and MMP-3 mRNA expression were determined by enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively.

RESULTS

In human pancreatic myofibroblasts, MMP-3 secretion and mRNA expression were induced by interleukin (IL)-17, IL-1beta, and tumor necrosis factor (TNF) -alpha, respectively. The effects of IL-17 were detected as similar in extent to those induced by IL-1beta or TNF-alpha. Costimulation by IL-17 plus IL-1beta and/or IL-17 plus TNF-alpha induced a synergistic increase in MMP-3 secretion, although the costimulatory effects of these combinations were not detected in tissue inhibitor of matrix metalloproteinase-1 secretion. Adenovirus-mediated transfer of a stable form of IkappaBalpha markedly inhibited the effects of IL-17, IL-1beta, and TNF-alpha. Mitogen-activated protein kinase inhibitors (U0126, PD098059, and SB203580) also blocked MMP-3 secretion. These findings indicate a role for nuclear factor-kappaB and mitogen-activated protein kinases in cytokine-induced MMP-3 secretion.

CONCLUSIONS

Pancreatic periacinar myofibroblasts actively secrete MMP-3 in response to IL-17, IL-1beta, and TNF-alpha. Pancreatic myofibroblasts may play an important role in extracellular matrix turnover via MMP-3 secretion in the pancreas.

Differential expression of matrix metalloproteinase 3 (MMP3) in preadipocytes/stromal vascular cells from nonobese nondiabetic versus obese nondiabetic Pima Indians

Prior microarray studies comparing global gene expression patterns in preadipocytes/stromal vascular cells isolated from nonobese nondiabetic versus obese nondiabetic Pima Indians showed that matrix metalloproteinase 9 (MMP9) is upregulated in obese subjects. The current study targeted analysis of nine additional MMP genes that cluster to a region on chromosome 11q22 that is linked to BMI and percent body fat. Differential-display PCR showed that MMP3 is downregulated in preadipocytes/stromal vascular cells from obese subjects, and real-time PCR showed that MMP3 expression levels are negatively correlated with percent body fat. To determine whether variants within MMP3 are responsible for its altered expression, MMP3 was sequenced, and seven representative variants were genotyped in 1,037 Pima subjects for association analyses. Two variants were associated with both BMI and type 2 diabetes, and two additional variants were associated with type 2 diabetes alone; however, none of these variants were associated with MMP3 expression levels. We propose that the MMP3 pathway is altered in human obesity, but this alteration may be the result of a combination of genetic variation within the MMP3 locus itself, as well as variation in additional factors, either primary or secondary to obesity, that regulate expression of the MMP3 gene.

Allele-specific MMP-3 transcription under in vivo conditions

A common matrix metalloproteinases-3 (MMP-3) -1612 5A/6A promoter polymorphism is associated with risk for cardiovascular disease, rheumatoid arthritis, and other diseases. Here we used the haplotype chromatin immunoprecipitation method to study allele-specific MMP-3 expression under in vivo conditions in heterozygous THP-1 cells. Pyrosequencing was used to analyse the ratio of 5A-allele to 6A-allele after chromatin immunoprecipitation using an antibody against phosphorylated active RNA polymerase II. There was no allele-specific difference in transcriptional activity during basal conditions, i.e., in unstimulated monocytic THP-1 cells. However, after stimulation of MMP-3 expression by monocyte differentiation or incubation with IL-1beta, the haplotype containing the 5A-allele was associated with higher transcriptional activity compared with the 6A-containing haplotype. Electromobility shift assay demonstrated increased binding of nuclear proteins to the 5A-allele after monocyte differentiation. In conclusion, the common MMP-3 5A/6A promoter polymorphism appears to be functional only during specific environmental conditions involving inflammation.

Role of nuclear factor-kappa B in melanoma

Nuclear Factor-kappa B (NF-kappa B) is an inducible transcription factor that regulates the expression of many genes involved in the immune response. Recently, NF-kappa B activity has been shown to be upregulated in many cancers, including melanoma. Data indicate that the enhanced activation of NF-kappa B may be due to deregulations in upstream signaling pathways such as Ras/Raf, PI3K/Akt, and NIK. Multiple studies have shown that NF-kappa B is involved in the regulation of apoptosis, angiogenesis, and tumor cell invasion, all of which indicate the important role of NF-kappa B in tumorigenesis. Thus, understanding the molecular mechanism of melanoma progression will aid in designing new therapeutic approaches for melanoma. In this review, the association between NF-kappa B and melanoma tumorigenesis are discussed. Additionally, the potential of emerging selective NF-kappa B inhibitors for the treatment of melanoma is reviewed.