Epigenetic regulation of mmp-9 gene expression

Neurovascular Interventions for Neurotrauma: From Treatment of Injured Vessels to Treatment of the Injured Brain?

Traumatic brain injury is often associated with a direct or secondary neurovascular pathology. In this review, we present recent advancements in endovascular neurosurgery that enable accurate and effective vessel reconstruction with emphasis on its role in early diagnosis, the expanding use of flow diversion in pseudoaneurysms, and traumatic arteriovenous fistulas. In addition, future directions in which catheter-based interventions could potentially affect traumatic brain injury are described: targeting blood brain barrier integrity using the advantages of intra-arterial drug delivery of blood brain barrier stabilizers to prevent secondary brain edema, exploring the impact of endovascular venous access as a means to modulate venous outflow in an attempt to reduce intracranial pressure and augment brain perfusion, applying selective intra-arterial hypothermia as a neuroprotection method mitigating some of the risks conferred by systemic cooling, trans-vessel wall delivery of regenerative therapy agents, and shifting attention using multimodal neuromonitoring to post-traumatic vasospasm to further characterize the role it plays in secondary brain injury. Thus, we believe that the potential of endovascular tools can be expanded because they enable access to the "highways" governing perfusion and flow and call for further research focused on exploring these routes because it may contribute to novel endovascular approaches currently used for treating injured vessels, harnessing them for treatment of the injured brain.

Levels of Matrix Metalloproteinase 9 Are Elevated in Persons With Schizophrenia or Bipolar Disorder: The Role of Modifiable Factors

Background

Matrix metalloproteinases (MMPs) are a diverse set of enzymes associated with inflammation. MMP-9 is of particular interest because it has been associated with autoimmune and cardiopulmonary disorders, tobacco smoking, and obesity, prevalent in psychiatric populations.

Methods

Sensitive enzyme immunoassays measured MMP-9 in blood samples from 1121 individuals (mean age = 35.6 [SD = 13.0] years; 47.7% male; 440 with schizophrenia, 399 with bipolar disorder, and 282 without a psychiatric disorder). We estimated the odds of diagnosis associated with MMP-9, demographic variables, tobacco smoking, and obesity, and also the partial explained variance using regression methods. We also determined the association between psychiatric medications and MMP-9 levels.

Results

Individuals with elevated MMP-9 levels had higher odds of schizophrenia or bipolar disorder compared with the nonpsychiatric group adjusted for demographic variables. Partial correlation analyses indicated the demographic-adjusted variance associated with MMP-9, smoking, obesity, and their interaction explained 59.6% for schizophrenia and 39.9% for bipolar disorder. Levels of MMP-9 were substantially lower in individuals receiving valproate, particularly relatively high doses.

Conclusions

Individuals with higher levels of MMP-9 have significantly higher odds of schizophrenia or bipolar disorder. Individuals receiving valproate had substantially lower levels of MMP-9, possibly related to its ability to inhibit histone deacetylation. A substantial portion of the variance in clinical disorders associated with MMP-9 can be attributed to smoking or obesity. Interventions to reduce smoking and obesity might reduce the morbidity and mortality associated with elevated MMP-9 levels and improve the health outcomes of individuals with these disorders.

Inhibition of nonsense-mediated mRNA decay reduces the tumorigenicity of human fibrosarcoma cells

Nonsense-mediated mRNA decay (NMD) is a eukaryotic RNA decay pathway with roles in cellular stress responses, differentiation, and viral defense. It functions in both quality control and post-transcriptional regulation of gene expression. NMD has also emerged as a modulator of cancer progression, although available evidence supports both a tumor suppressor and a pro-tumorigenic role, depending on the model. To further investigate the role of NMD in cancer, we knocked out the NMD factor SMG7 in the HT1080 human fibrosarcoma cell line, resulting in suppression of NMD function. We then compared the oncogenic properties of the parental cell line, the SMG7-knockout, and a rescue cell line in which we re-introduced both isoforms of SMG7. We also tested the effect of a drug inhibiting the NMD factor SMG1 to distinguish NMD-dependent effects from putative NMD-independent functions of SMG7. Using cell-based assays and a mouse xenograft tumor model, we showed that suppression of NMD function severely compromises the oncogenic phenotype. Molecular pathway analysis revealed that NMD suppression strongly reduces matrix metalloprotease 9 (MMP9) expression and that MMP9 re-expression partially rescues the oncogenic phenotype. Since MMP9 promotes cancer cell migration and invasion, metastasis and angiogenesis, its downregulation may contribute to the reduced tumorigenicity of NMD-suppressed cells. Collectively, our results highlight the potential value of NMD inhibition as a therapeutic approach.

Regulation of matrix metalloproteinase-9 during monopoiesis and zinc deficiency by chromatin remodeling

INTRODUCTION

Matrix metalloproteinase-9 (MMP-9) cleaves various extracellular matrix proteins, hence significantly contributes to numerous physiological but also pathological processes. Monocytic differentiation is associated with increased MMP-9 gene expression. Interestingly, MMP-9 upregulation during monocytic differentiation is paralleled by a decline in intracellular zinc levels. Hence, an influence of zinc on the regulation of MMP-9 expression may exist. Although, previous studies suggest a vital role of zinc regarding MMP-9 activity, the possible relevance of zinc homeostasis during transcriptional regulation of MMP-9 for example via epigenetic mechanisms is rather unclear.

AIM

This study aims to find a correlation between zinc deficiency and MMP-9 transcriptional regulation, focusing on epigenetics as the possible mechanism behind zinc deficiency-induced changes.

METHODS

The effect of differentiation and zinc deficiency on MMP-9 expression and MMP9 promoter accessibility was investigated using the acute promyelocytic cell line NB4. Intracellular free zinc levels were detected by flow cytometry. MMP-9 gene expression was measured by real-time PCR and ELISA. Analysis of chromatin structures was done using chromatin accessibility by real-time PCR (CHART) assay.

RESULTS

During monocytic differentiation of NB4 cells, the decrease in intracellular zinc levels was paralleled by an increased production of MMP-9. Assessment of chromatin structure revealed increased accessibility of certain regions within the MMP-9 promoter in differentiated cells. Interestingly, upregulated activation-induced MMP-9 gene expression as well as a more accessible MMP-9 promoter were in zinc-deficient NB4 cells whereas zinc resupplementation reversed the effects.

CONCLUSION

These data demonstrate an important role of epigenetic mechanisms in regulating MMP-9 expression under zinc deficiency. This could provide an encouraging step to expand the research on using zinc for the treatment of various pathological conditions such as inflammatory, vascular and autoimmune diseases resulting from MMP-9 deregulation.

Zika virus NS1 suppresses VE-cadherin via hsa-miR-29b-3p/DNMT3b/MMP-9 pathway in human brain microvascular endothelial cells

Zika virus infection has been reported to cause microcephaly in newborns. ZIKV exploits various strategies to cross the blood-brain barrier. ZIKV NS1 may compromise the barrier integrity of endothelial cells by regulating expression of junctional proteins. MicroRNAs play an important role in post-transcriptional gene regulations. We demonstrated that ZIKV-NS1 affected the adherence junction protein in human brain microvascular endothelial cells via hsa-miR-29b-3p/DNMT3b/MMP-9 pathway. The hCMEC/D3 cells were exposed to ZIKV-NS1 with different doses (500 ng/mL and 1000 ng/mL) for 24 h. The expression pattern of DNTM3b, MMP-9, and VE-cadherin were studied using immunoblotting and the distribution of DNMT3b and MMP-9 were studied using immunofluorescence. The quantification of hsa-miR-29b-3p was done through qRT-PCR. Direct regulation of DNMT3b by hsa-miR-29b-3p was demonstrated by overexpression of hsa-miR-29b-3p using hsa-miR-29b-3p mimic, and knockdown of hsa-miR-29b-3p by using hsa-miR-29b-3p inhibitors. The ZIKV-NS1 affected the barrier function of endothelial cells through the increased expression of hsa-miR29b-3p, which suppressed the DNMT3b, thus enhanced expression of MMP-9, which finally suppressed the expression of VE-cadherin. These findings suggested that ZIKV-NS1 alters the expression of Adherens Junction protein in human brain microvascular endothelial cells through hsa-miR-29b-3p/DNMT3b/MMP-9 pathway, which compromised the barrier function of human brain microvascular endothelial cells.

Hesperidin protects against aluminum-induced renal injury in rats via modulating MMP-9 and apoptosis: biochemical, histological, and ultrastructural study

Aluminum, one of the most abundant metallic elements, is known to be toxic to multiple organs including the kidneys. This study aimed to investigate the pleiotropic nephroprotective effects of Hesperidin in aluminum chloride (ALCL3)-induced renal injury, highlighting the potential molecular mechanisms underlying. Twenty-four male albino rats were divided into four groups: control, Hesperidin (80 mg/kg BW, orally), ALCL3 (10 mg/kg BW, IP), and ALCL3 + Hesperidin groups. By the end of the study, blood samples were collected, and tissue samples were harvested at sacrifice. ALCL3 rats showed dramatically declined renal function, enhanced intrarenal oxidative stress, inflammation, apoptosis, and extravagant renal histopathological damage with interstitial fibrosis as shown by a higher Endothelial, Glomerular, Tubular, and Interstitial (EGTI) score. Hesperidin significantly reversed all the aforementioned detrimental effects in ALCL3-treated rats. The study verified the nephroprotective effects of Hesperidin on ALCL3-induced renal damage and confirmed the critical role of extracellular matrix (ECM) remodeling and apoptosis inhibition.

Synergistic effects of sodium butyrate and cisplatin against cervical carcinoma in vitro and in vivo

BACKGROUNDS

Cisplatin-based chemotherapy has been considered as the pivotal option for treating cervical cancer. However, some patients may present a poor prognosis due to resistance to chemotherapy. As a metabolite of natural products, sodium butyrate (NaB) could inhibit the proliferation of several malignant cells, but little is known about its combination with cisplatin in the treatment of cervical cancer.

MATERIALS AND METHODS

Flow cytometry, CCK-8 assay, and Transwell assay were utilized to analyze the cellular apoptosis, viability, cellular migration and invasion upon treating with NaB and/or cisplatin. The allograft mice model was established, followed by evaluating the tumor volume and necrotic area in mice treated with NaB and/or cisplatin. Western blot was performed for detecting protein expression involved in epithelial-mesenchymal transition (EMT) and the expression of MMPs. Immunohistochemical staining was conducted with the tumor sections. The transcription, expression, and cellular translocation of β-catenin were determined using luciferase reporter gene assay, Real-Time PCR, Western blot, and confocal laser scanning microscope, respectively.

RESULTS

NaB combined with cisplatin inhibited cell viability by promoting apoptosis of cervical cancer cells. In vivo experiments indicated that NaB combined with cisplatin could inhibit tumor growth and induce cancer cell necrosis. Single application of NaB activated the Wnt signaling pathway and induced partial EMT. NaB alone up-regulated MMP2, MMP7 and MMP9 expression, and promoted the migration and invasion of cervical cancer cells. The combination of cisplatin and NaB inhibited cellular migration and invasion by abrogating the nuclear transition of β-catenin, reverse EMT and down-regulate MMP2, MMP7 and MMP9. Immunohistochemical staining indicated that NaB combined with cisplatin up-regulated the expression of E-cadherin and reverse the EMT phenotype in the mice model.

CONCLUSIONS

NaB serves as a sensitizer for cisplatin, which may be a promising treatment regimen for cervical cancer when combined both. NaB alone should be utilized with caution for treating cervical cancer as it may promote the invasion and migration of cervical cancer cells.

MMP9: A Tough Target for Targeted Therapy for Cancer

Having the capability to proteolyze diverse structural and signaling proteins, matrix metalloproteinase 9 (MMP9), one of the best-studied secretory endopeptidases, has been identified as a crucial mediator of processes closely associated with tumorigenesis, such as the extracellular matrix reorganization, epithelial to mesenchymal transition, cell migration, new blood vessel formation, and immune response. In this review, we present the current state of knowledge on MMP9 and its role in cancer growth in the context of cell adhesion/migration, cancer-related inflammation, and tumor microenvironment formation. We also summarize recent achievements in the development of selective MMP9 inhibitors and the limitations of using them as anticancer drugs.

Targeting Epigenetic Mechanisms in Vascular Aging

Environment, diseases, lack of exercise, and aged tendency of population have becoming crucial factors that induce vascular aging. Vascular aging is unmodifiable risk factor for diseases like diabetes, hypertension, atherosclerosis, and hyperlipidemia. Effective interventions to combat this vascular function decline is becoming increasingly urgent as the rising hospitalization rate caused by vascular aging-related diseases. Fortunately, recent transformative omics approaches have enabled us to examine vascular aging mechanisms at unprecedented levels and precision, which make our understanding of slowing down or reversing vascular aging become possible. Epigenetic viz. DNA methylation, histone modifications, and non-coding RNA-based mechanisms, is a hallmark of vascular aging, its deregulation leads to aberrant transcription changes in tissues. Epigenetics mechanisms by mediating covalent modifications to DNA and histone proteins, consequently, influence the sensitivity and activities of signaling pathways in cells and tissues. A growing body of evidence supports correlations between epigenetic changes and vascular aging. In this article, we will provide a comprehensive overview of epigenetic changes associated with vascular aging based on the recent findings with a focus on molecular mechanisms of action, strategies to reverse epigenetic changes, and future perspectives.

Nafamostat mesylate overcomes endocrine resistance of breast cancer through epigenetic regulation of CDK4 and CDK6 expression

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Nafamostat mesylate (NM) causes apoptosis and suppresses metastasis of endocrine-resistant ER-positive breast cancer (ERPBC).

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Epigenetic downregulation of CDK4/CDK6 by NM in endocrine-resistant ERPBC via disruption of binding of H3K27Ac on promoter region.

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Combination of nafamostat mesylate and CDK4/6 inhibitor synergistically overcomes endocrine resistance of breast cancer.

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Nafamostat mesylate would be a well-efficient drug for endocrine-resistant ERPBC.

Breast cancer is common worldwide, and the estrogen receptor-positive subtype accounts for approximately 70% of breast cancer in women. Tamoxifen and fulvestrant are drugs currently used for endocrinal therapy. Breast cancer exhibiting endocrine resistance can undergo metastasis and lead to the death of breast cancer patients. Drug repurposing is an active area of research in clinical medicine. We found that nafamostat mesylate, clinically used for patients with pancreatitis and disseminated intravascular coagulation, acts as an anti-cancer drug for endocrine-resistant estrogen receptor-positive breast cancer (ERPBC). Epigenetic repression of CDK4 and CDK6 by nafamostat mesylate induced apoptosis and suppressed the metastasis of ERPBC through the deacetylation of Histone 3 Lysine 27. A combination of nafamostat mesylate and CDK4/6 inhibitor synergistically overcame endocrine resistance in ERPBC. Nafamostat mesylate might be an essential adjuvant or alternative drug for the treatment of endocrine-resistant ERPBC due to the low cost-efficiency of the CDK4/6 inhibitor.

DACH1 inhibits breast cancer cell invasion and metastasis by down-regulating the transcription of matrix metalloproteinase 9

Human Dachshund homolog 1 (DACH1) is usually defined as a tumor suppressor, which plays an influential role in tumor growth and metastasis in a variety of cancer cells. However, the underlying mechanisms in these process are not yet fully clarified. In this study, DACH1 inhibited the invasion and metastasis of breast cancer cells by decreasing MMP9 expression. Mechanistically, DACH1 represses the transcriptional level of MMP9 by interacting with p65 and c-Jun at the NF-κB and AP-1 binding sites in MMP9 promoter respectively, and the association of DACH1 and p65 promote the recruitment of HDAC1 to the NF-κB binding site in MMP9 promoter, resulting in the reduction of the acetylation level and the transcriptional activity of p65. Accordingly, the level of MMP9 was decreased. In conclusion, we found a new mechanism that DACH1 could inhibit the metastasis of breast cancer cells by inhibiting the expression of MMP9.

MMP9 mRNA is a potential diagnostic and treatment monitoring marker for PTSD: Evidence from mice and humans

Although matrix metalloproteinase 9 (MMP9) has been found associated with various psychiatric disorders and with threat memories in humans, its role in post-traumatic stress disorder (PTSD) and related animal models is understudied. Thus, we analyzed MMP9 mRNA expression kinetics during two different stress experiments, i.e., the Trier Social Stress Test and the dexamethasone suppression test (DST), in whole blood of two independent cohorts of PTSD patients vs. non-traumatized healthy controls (HC) and, moreover, in a mouse model of PTSD and in dexamethasone-treated mice. Besides MMP9, we quantified mRNA levels of four of its regulators, i.e., interleukin (IL)-1 receptor 1 and 2 (IL1R1, IL1R2), IL-6 receptor and tumor necrosis factor receptor 1 (TNFR1) in 10 patients exposed to the DST before vs. after successful PTSD psychotherapy vs. 13 HC and, except from Il6r, also in different brain regions of the PTSD mouse model. We are the first to show that blood MMP9 mRNA concentrations were elevated after acute dexamethasone in PTSD patients, improved upon partial remission of PTSD and were, furthermore, also elevated, together with its regulator Tnfr1, in the prefrontal cortex of PTSD-like mice. In contrast, blood TNFR1 and IL1R2 were markedly underexpressed in PTSD patients. In conclusion, we found translational evidence supporting that, I, TNFR1 and MMP9 mRNA expression might be involved in PTSD pathobiology, II, might constitute potential diagnostic blood biomarkers for PTSD and, importantly, III, post-dexamethasone blood MMP9 hyperexpression, which speculatively results from post-dexamethasone underexpression of IL1R2, might serve also as potential treatment monitoring biomarker for PTSD.

GSK-3 Inhibition Modulates Metalloproteases in a Model of Lung Inflammation and Fibrosis

Idiopathic pulmonary fibrosis (IPF) is mainly characterized by aberrant extracellular matrix deposition, consequent to epithelial lung injury and myofibroblast activation, and inflammatory response. Glycogen synthase kinase 3 (GSK-3) is a serine-threonine kinase involved in several pathways, and its inhibition has been already suggested as a therapeutic strategy for IPF patients. There is evidence that GSK-3 is able to induce matrix metalloproteinase (MMP) expression and that its inhibition modulates MMP expression in the tissues. The aim of our study was to investigate the role of GSK-3 and its inhibition in the modulation of MMP-9 and -2 in an in vivo mouse model of lung fibrosis and in vitro using different cell lines exposed to pro-inflammatory or pro-fibrotic stimuli. We found that GSK-3 inhibition down-modulates gene expression and protein levels of MMP-9, MMP-2, and their inhibitors TIMP-1 and TIMP-2 in inflammatory cells harvested from bronchoalveolar lavage fluid (BALF) of mice treated with bleomycin as well as in interstitial alveolar macrophages and cuboidalized epithelial alveolar cells. To the same extent, GSK-3 inhibition blunted the increased MMP-9 and MMP-2 activity induced by pro-fibrotic stimuli in a human lung fibroblast cell line. Moreover, the αSMA protein level, a marker of fibroblast-to-myofibroblast transition involved in fibrosis, was decreased in primary fibroblasts treated with TGFβ following GSK-3 inhibition. Our results confirm the implication of GSK-3 in lung inflammation and fibrosis, suggesting that it might play its role by modulating MMP expression and activity but also pushing fibroblasts toward a myofibroblast phenotype and therefore enhancing extracellular matrix deposition. Thus, its inhibition could represent a possible therapeutic strategy.

EZH2 Promotes Extracellular Matrix Degradation via Nuclear Factor-κB (NF-κB) and p38 Signaling Pathways in Pulpitis

Pulpitis is a complicated chronic inflammatory process which can be in a dynamic balance between damage and repair. The extracellular matrix plays an important regulatory role in wound healing and tissue repair. The aim of this study was to explore the role of the epigenetic mark, enhancer of zeste homolog 2 (EZH2) on the degradation of extracellular matrix during pulpitis. Quantitative polymerase chain reaction was used to assess the expression of matrix metalloproteinases (MMPs) and type I collagen in human dental pulp cells (HDPCs) upon EZH2 and EI1 (EZH2 inhibitor) stimulation. The mechanism of EZH2 affecting extracellular matrix was explored through quantitative polymerase chain reaction and Western blot. A rat model of dental pulp inflammation was established, and the expression of type I collagen in dental pulp under EZH2 stimulation was detected by immunohistochemical staining. EZH2 upregulated the expression of MMP-1, MMP-3, MMP-8, and MMP-10 and decreased the production of type I collagen in HDPCs, while EI1 had the opposite effect. EZH2 activated the nuclear factor-kappa B (NF-κB) and p38 signaling pathways in HDPCs, the inhibition of which reversed the induction of MMPs and the suppression of type I collagen. EZH2 can downregulate the type I collagen levels in an experimental model of dental pulpitis in rats. EZH2 promotes extracellular matrix degradation via nuclear factor-κB (NF-κB) and P38 signaling pathways in pulpitis. EZH2 can decrease the type I collagen levels in vivo and in vitro.

Epigenetics and expression of key genes associated with cardiac fibrosis: NLRP3, MMP2, MMP9, CCN2/CTGF and AGT

Aims:

Excessive inflammatory signaling and pathological remodeling of the extracellular matrix drive cardiac fibrosis and require changes in gene expression.

Materials and methods:

Using bioinformatics, both tissue-specific expression profiles and epigenomic profiles of some genes critical for cardiac fibrosis were examined, namely, NLRP3, MMP2, MMP9, CCN2/CTGF, AGT (encodes angiotensin II precursors) and hsa-mir-223 (post-transcriptionally regulates NLRP3).

Results:

In monocytes, neutrophils, fibroblasts, venous cells, liver and brain, enhancers or super-enhancers were found that correlate with high expression of these genes. One enhancer extended into a silent gene neighbor. These enhancers harbored tissue-specific foci of DNA hypomethylation, open chromatin and transcription factor binding.

Conclusions:

This study identified previously undescribed enhancers containing hypomethylated transcription factor binding subregions that are predicted to regulate expression of these cardiac fibrosis-inducing genes.

Luteolin suppresses androgen receptor-positive triple-negative breast cancer cell proliferation and metastasis by epigenetic regulation of MMP9 expression via the AKT/mTOR signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC) represents up to 20% of all breast cancers. This cancer lacks the expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The current therapeutic strategy for patients with this subtype is the use of cytotoxic chemotherapy and surgery. Luteolin is a natural herbal flavonoid and a potential therapeutic candidate for multiple diseases. The use of a treatment that combines Chinese herbal medicine and western medicine is rising in Asia.

PURPOSE

The present study evaluates the effects and molecular mechanisms involved with luteolin treatment and evaluates whether this herb affects androgen receptor-positive breast cancer cell proliferation or metastasis.

STUDY DESIGN

In vitro evaluation of the effect of luteolin on androgen receptor-positive TNBC cell proliferation and metastasis METHODS: Cell viability analysis was used for the cytotoxicity test. Colony formation and Bromodeoxyuridine (BrdU) staining-based proliferation experiments were used for cell proliferation. Wound healing and transwell assays were used for in vitro migration/invasion. The RT-qPCR analysis was used for gene expression. Furthermore, ChIP-qPCR analysis was used for epigenetic modification of gene promoters.

RESULTS

Luteolin significantly inhibited the proliferation and metastasis of androgen receptor-positive TNBC. Furthermore, luteolin inactivated the AKT/mTOR signaling pathway and reversed the epithelial-mesenchymal transition (EMT). The combination of luteolin and inhibitors of AKT/mTOR synergistically repressed an androgen receptor-positive TNBC cell proliferation and metastasis. Luteolin also downregulated MMP9 expression by decreasing the levels of the AKT/mTOR promoting H3K27Ac and H3K56A on the MMP9 promoter region.

CONCLUSION

Our findings indicate that luteolin inhibited the proliferation and metastasis of androgen receptor-positive TNBC by regulating MMP9 expression through a reduction in the levels of AKT/mTOR-inducing H3K27Ac and H3K56Ac.

Epigenetic regulation of matrix metalloproteinases in inflammatory diseases: a narrative review

With the acceleration of urbanization and aging and the change of lifestyle, inflammatory diseases have become one of the important threats to the health of the global population. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are involved in the metabolism of extracellular matrix (ECM). They play a key role in inflammation-related diseases. Factors such as inflammation, oxidative stress and growth factors stimulate the production of MMPs with subsequent ECM remodeling. Recently, the studies of epigenetic regulation, including the ability to predict disease progression, important pathophysiological deficiencies as well as treatment methods have been extensively discussed. This article reviews the current studies on epigenetic alterations in MMPs during inflammatory response. It is likely to provide new insights into development of efficient medications of epigenetic therapy for inflammatory diseases.

Intra-arterial neuroprotective therapy as an adjunct to endovascular intervention in acute ischemic stroke: A review of the literature and future directions

Mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion has been shown to significantly improve outcomes. However, despite efficient rates of recanalization (60-90%), the rates of functional independence remain suboptimal (14-58%), most likely due to pathways of cell death in the brain that have already committed despite successful reperfusion. Pharmacologic neuroprotection provides a potential means of preventing this inevitable damage through targeting excitotoxicity, reactive oxygen species, cellular apoptosis, and inflammation. Numerous clinical trials using various neuroprotective agents have failed, but the majority of these trials did not include endovascular reperfusion, and thus the drugs were not reaching the therapeutic target. Intra-arterial delivery of neuroprotective agents via the guide catheter already in place for mechanical thrombectomy could provide a way to deliver high doses directly to the affected territory while limiting systemic exposure. Agents that have shown promise via the intra-arterial route in preclinical as well as some clinical models include magnesium sulfate, verapamil, cold saline, stem cells, and various combined approaches. Targeted hypothermia, achieved with intra-carotid infusion of cold saline, may provide an effective means of achieving hypothermia of the ischemic tissue while avoiding the systemic effects that have limited its use previously. Combination therapy of targeted hypothermia and a cocktail of drugs that provide anti-excitotoxic, anti-oxidant, anti-apopototic, and anti-inflammatory effects may provide an ideal approach that deserves further study in clinical trials.

TET2-interacting long noncoding RNA promotes active DNA demethylation of the MMP-9 promoter in diabetic wound healing

Wound healing in diabetic skin is impaired by excessive activation of matrix metalloproteinase-9 (MMP-9). MMP-9 transcription is activated by Ten-eleven translocation 2 (TET2), a well-known DNA demethylation protein that induces MMP-9 promoter demethylation in diabetic skin tissues. However, how TET2 is targeted to specific loci in the MMP-9 promoter is unknown. Here, we identified a TET2-interacting long noncoding RNA (TETILA) that is upregulated in human diabetic skin tissues. TETILA regulates TET2 subcellular localization and enzymatic activity, indirectly activating MMP-9 promoter demethylation. TETILA also recruits thymine-DNA glycosylase (TDG), which simultaneously interacts with TET2, for base excision repair-mediated MMP-9 promoter demethylation. Together, our results suggest that the TETILA serves as a genomic homing signal for TET2-mediated demethylation specific loci in MMP-9 promoter, thereby disrupting the process of diabetic skin wound healing.

HMGA1 exacerbates tumor progression by activating miR-222 through PI3K/Akt/MMP-9 signaling pathway in uveal melanoma

High-mobility group A1 (HMGA1), an architectural transcription factor, participates in different human tumors' biological progression. HMGA1 overexpression is associated with malignant cellular behavior in a wide range of cancers but the underlying mechanism remains poorly illuminated. In this study, we showed PI3K/Akt/MMP9 pathway activity could be positively regulated by HMGA1 using western blotting, real-time polymerase chain reaction (RT-PCR) and immunochemistry both in vitro (C918 and MUM-2B cell lines) and in vivo (xenograft mouse model). Later, MiRTarBase was used to identify the relationship between HMGA1 and miR-222-3p, we found miR-222 is positively regulated by HMGA1. Moreover, the proliferation and migration of UM cells significantly increased in the miR-222 mimics group and decreased in the miR-222 inhibitor group detected by the Annexin V-FITC apoptosis detection kit, CCK-8 and scratch wound-healing. The p-PI3K, p-Akt and MMP9 expressions were elevated in UM cells transfected with miR-222 mimics, and suppressed in the miR-222 inhibitor group. Together, our study highlights that HMGA1 acts as a pivotal regulator in UM tumor growth, proposing a critical viewpoint that HMGA1 expedites progression through the PI3K/Akt/MMP9 pathway and oncogenic miR-222 in UM.

Chronic Intermittent Ethanol Exposure Induces Upregulation of Matrix Metalloproteinase-9 in the Rat Medial Prefrontal Cortex and Hippocampus

Matrix metalloproteinase-9 (MMP-9, Gelatinase B), an extracellular-acting Zn²⁺-dependent endopeptidase, are involved in brain pathologies including ischemia, glioma, and epilepsy. Recent studies suggested that MMP-9 plays an important role in neuronal plasticity, specifically in learning and memory. To determine whether and how MMP-9 plays role in alcohol-related behaviors, male Sprague-Dawley (SD) rats were subjected to chronic intermittent ethanol (CIE) exposure for 4 weeks, following which we collected tissue samples from the hippocampus, medial prefrontal cortex (mPFC), and amygdala at different stages (acute and chronic exposure) during alcohol exposure. Real-time PCR and western blot assays were used to detect changes in the mRNA and protein expression of MMP-9. Our results indicated that both acute and chronic alcohol exposure induced up-regulation of MMP-9 mRNA levels in the hippocampus and mPFC, but not in the amygdala. Furthermore, acute and chronic alcohol exposure up regulated the expression of total MMP-9 and active MMP-9 in these two brain regions. Moreover, the increase of active MMP-9 expression was larger than those in total MMP-9 expression. Immunoprecipitation analyses identified potential MMP-9-interacting proteins, including Itgb1, Src, Eef1a2, tubulin, actin, and histone H2B. These results demonstrate that both acute and CIE exposure induced increases in MMP-9 expression in the mPFC and hippocampus, suggesting that MMP-9 plays a key role in chronic alcohol exposure and dependence.

Intra-arterial administration of cell-based biological agents for ischemic stroke therapy

INTRODUCTION

Ischemic stroke is becoming a primary cause of disability and death worldwide. To date, therapeutic options remain limited focusing on mechanical thrombolysis or administration of thrombolytic agents. However, these therapies do not promote neuroprotection and neuro-restoration of the ischemic area of the brain.

AREAS COVERED

This review highlights the option of minimal invasive, intra-arterial, administration of biological agents for stroke therapy. The authors provide an update of all available studies, discuss issues that influence outcomes and describe future perspectives which aim to improve clinical outcomes. New therapeutic options based on cellular and molecular interactions following an ischemic brain event, will be highlighted.

EXPERT OPINION

Intra-arterial administration of biological agents during trans-catheter thrombolysis or thrombectomy could limit neuronal cell death and facilitate regeneration or neurogenesis following ischemic brain injury. Despite the initial progress, further meticulous studies are needed in order to establish the clinical use of stem cell-induced neuroprotection and neuroregeneration.

Inhibition of MMPs and ADAM/ADAMTS

Matrix metalloproteinases (MMPs), A Disintegrin and Metalloproteinase (ADAM) and A Disintegrin and Metalloproteinase with Thrombospondin Motif (ADAMTS) are zinc-dependent endopeptidases that play a critical role in the destruction of extracellular matrix proteins and, the shedding of membrane-bound receptor molecules in various forms of arthritis and other diseases. Under normal conditions, MMP, ADAM and ADAMTS gene expression aids in the maintenance of homeostasis. However, in inflamed synovial joints characteristic of rheumatoid arthritis and osteoarthritis. MMP, ADAM and ADAMTS production is greatly increased under the influence of pro-inflammatory cytokines. Analyses based on medicinal chemistry strategies designed to directly inhibit the activity of MMPs have been largely unsuccessful when these MMP inhibitors were employed in animal models of rheumatoid arthritis and osteoarthritis. This is despite the fact that these MMP inhibitors were largely able to suppress pro-inflammatory cytokine-induced MMP production in vitro. A focus on ADAM and ADAMTS inhibitors has also been pursued. Thus, recent progress has identified the "sheddase" activity of ADAMs as a viable target and the development of GW280264X is an experimental ADAM17 inhibitor. Of note, a monoclonal antibody, GLPG1972, developed as an ADAMTS-5 inhibitor, entered a Phase I OA clinical trial. However, the failure of many of these previously developed inhibitors to move beyond the preclinical testing phase has required that novel strategies be developed that are designed to suppress both MMP, ADAM and ADAMTS production and activity.

Opioids and matrix metalloproteinases: the influence of morphine on MMP-9 production and cancer progression

Opioids are widely administered to alleviate pain, including chronic pain in advanced cancer patients. Among opioids, morphine is one of the most clinically effective drugs for the palliative management of severe pain. In the last few decades, there has been a debate around the possible influence of opioids such as morphine on tumour growth and metastasis. Whilst several in vitro and in vivo studies suggest the possible modulatory effects of morphine on tumour cells, little is known about the impact of this analgesic drug on other mediators such as matrix metalloproteinases (MMPs) that play a key role in the control of cancer cell invasion and metastasis. MMP-9 has been considered as one of the principal mediators in regulation of not only the initial steps of cancer but during the invasion and spreading of cancer cells to distant organs. Herein, current studies regarding the direct and indirect effects of morphine on regulation of MMP-9 production are discussed. In addition, drawing from previous in vivo and in vitro studies on morphine action in regulating MMP-9 production, the potential roles of several underlying factors are summarised, including nuclear factor kappa-B and intracellular molecules such as nitric oxide.

The effect of sodium butyrate and cisplatin on expression of EMT markers

Histone modifications play a key role in the epigenetic regulation of gene transcription in cancer cells. Histone acetylations are regulated by two classes of enzymes, histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs are increased in ovarian carcinomas and they are involved in carcinogenesis and resistance to chemotherapeutic agents. In our study we investigated anticancer effect of HDAC inhibitor sodium butyrate (NaBu) on cisplatin-sensitive and cisplatin-resistant ovarian cell lines A2780 and A2780cis. A2780 and A2780cis were treated with NaBu alone or in combination with cisplatin (CP). NaBu inhibited the growth of both cell lines and enhanced cytotoxic effect of CP. Exposure to NaBu for 24 h induced cell cycle arrest. The expressions of EMT-related genes and proteins were further investigated by qPCR and western blot analysis. Loss of E-cadherin has been shown to be crucial in ovarian cancer development. We found that NaBu dramatically induce expression of E-cadherin gene (CDH1) and protein levels in A2780 and A2780cis. We investigated correlation between transcription and methylation of CDH1gene. Methylation level analysis in 32 CpG sites in CDH1 gene (promoter/exon1 regions) was performed using bisulfite NGS (Next Generation Sequencing). We found that cisplatin-resistant cell line A2780cis cells differ from their cisplatin-sensitive counterparts in the CDH1 methylation. Methylation in A2780cis cells is elevated compared to A2780. However, NaBu-induced expression of CDH1 was not accompanied by CDH1 demethylation. NaBu treatment induced changes in expression of EMT-related genes and proteins. Interestingly E-cadherin zinc finger transcriptional repressor SNAIL1 was upregulated in both cell lines. Mesenchymal marker vimentin was downregulated. Matrix metalloproteases (MMPs) are necessary for pericellular proteolysis and facilitate migration and invasion of tumour cells. NaBu induced mRNA expression of MMPs, mild changes in activities of gelatinases MMP2 and MMP9 were detected. Our data demonstrate that NaBu sensitizes cisplatin-resistant ovarian cancer cells, re-established E-cadherin expression, but it was not able to reverse the EMT phenotype completely.

HIV Reprograms Human Airway Basal Stem/Progenitor Cells to Acquire a Tissue-Destructive Phenotype

While highly active anti-retroviral therapy has dramatically improved the survival of HIV-infected individuals, there is an increased risk for other co-morbidities, such as COPD, manifesting as emphysema. Given that emphysema originates around the airways and that human airway basal cells (BCs) are adult airway stem/progenitor cells, we hypothesized that HIV reprograms BCs to a distinct phenotype that contributes to the development of emphysema. Our data indicate that HIV binds to but does not replicate in BCs. HIV binding to BCs induces them to acquire an invasive phenotype, mediated by upregulation of MMP-9 expression through activation of MAPK signaling pathways. This HIV-induced "destructive" phenotype may contribute to degradation of extracellular matrix and tissue damage relevant to the development of emphysema commonly seen in HIV⁺ individuals.

Th17 cells regulate the production of CXCL1 in breast cancer

Recently, the link between inflammation and cancer has been targeted for the prevention or treatment of malignant tumours. We aimed to investigate the relationship between Th17 cells and CXCL1 in breast cancer and the biological effects of CXCL1 on breast cancer. In vivo, the Th17 cell frequency in the peripheral blood was determined by flow cytometry. Secretion of IL-17 and CXCL1 in the blood serum was determined by enzyme-linked immunosorbent assay (ELISA). Expression of IL-17A and CXCL1 mRNA was determined by qRT-PCR. In vitro, the effects of Th17/CXCL1 during breast cancer were assessed in the human breast cancer cell lines MCF-7 and MDA-MB-231. Cell proliferation was measured using the CCK8 assay. Cell invasion and migration ability were assessed using a transwell cell invasion and wound- healing assay. In vivo, Th17 cells and CXCL1 were increased in breast cancer patients. Moreover, their changes were correlated in breast cancer cells. Th17 cells upregulate the production of CXCL1 during breast cancer progression. CXCL1, which is produced by breast cancer cells, can promote cancer growth and development, and may also point to a specific histogenetic pathway.

GADD45a Promotes Active DNA Demethylation of the MMP-9 Promoter via Base Excision Repair Pathway in AGEs-Treated Keratinocytes and in Diabetic Male Rat Skin

Diabetes elevates matrix metalloproteinase (MMP)-9 levels in the skin and its keratinocytes, and activated MMP-9 impairs skin wound healing. Epigenetic regulation of the DNA methylation status within the MMP-9 promoter plays an important role in the alteration of MMP-9 expression. Our aim was to investigate the role and mechanism of growth arrest and DNA damage-inducible 45a (GADD45a), a well-known DNA demethylation regulatory protein that mediates DNA methylation, in the regulation of MMP-9 expression. In this study, we showed that GADD45a was markedly upregulated in skin tissues from patients with diabetic foot ulcers, in diabetic rats, and in human keratinocyte (HaCaT) cells exposed to advanced glycation end products. We observed a substantial positive correlation between the levels of GADD45a and MMP-9 expression. Knockdown of GADD45a ameliorated the increase in MMP-9 transcription induced by a diabetic condition by inhibiting demethylation in the MMP-9 promoter and promoted diabetic HaCaT cell migration, but GADD45a knockdown did not affect HaCaT cell proliferation or apoptosis. Additionally, we demonstrated that overexpression of GADD45a activated MMP-9 expression by inducing promoter demethylation. Moreover, we found that GADD45a binds to the promoter of MMP-9 and recruits thymine-DNA glycosylase for base excision repair-mediated demethylation in diabetic HaCaT cells and diabetic rat skin. Our results reveal a mechanism in which GADD45a is required for demethylation of the MMP-9 promoter and the induction of diabetic wound healing. The inhibition of GADD45a might be a therapeutic strategy for diabetic foot ulcers.

Anti-invasive and antiproliferative effects of Pleurotus ostreatus extract on acute leukemia cell lines

BACKGROUND

Currently, mushrooms have been used in traditional and folk medicines for their therapeutic activities, such as antibiotic, antitumor, anti-inflammatory, anticancer, antileukemic and immunomodulatory actions. This investigation evaluates the anti-invasive, antiproliferative and cytotoxic effects of Pleurotus ostreatus (Pleurotaceae) on leukemia cell lines.

METHODS

The proliferation of KG-1 cells was measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after treatment with gradient dilutions of P. ostreatus extract. Then, the minimum inhibitory concentration (MIC) of the extract was determined. Moreover, the proliferation of Jurkat cells and bone marrow mesenchymal stem cells (BMSCs), a cancerous cell line and normal body cells, respectively, was considered. The apoptotic morphology of treated KG-1 cells was evaluated with Giemsa staining. The invasion and migration of cells were evaluated using transwell invasion assay. Thereafter, the rates of apoptosis and necrosis were measured by using flow cytometry, and BAX and MMP-9 gene expression were evaluated using quantitative reverse transcription-polymerase chain reaction as apoptotic and metastatic genes, respectively.

RESULTS

The MIC of the extract was determined to be 1 mg/mL after 48 h. According to the results, the extract decreased the proliferation of leukemia cell lines (KG-1 and Jurkat cells) but had no antiproliferative effects on BMSCs. Moreover, KG-1 cell migration and MMP-9 gene expression decreased after the treatment, and the rate of apoptosis and BAX gene expression increased significantly.

CONCLUSIONS

According to the efficient therapeutic properties of P. ostreatus on leukemia cell lines, this mushroom could be introduced as a natural medicine to cure leukemic patients who suffer from the harmful side effects and enormous costs of chemotherapy.

MMP-9 overexpression is associated with intragenic hypermethylation of MMP9 gene in melanoma

Tumor spreading is associated with the degradation of extracellular matrix proteins, mediated by the overexpression of matrix metalloproteinase 9 (MMP-9). Although, such overexpression was linked to epigenetic promoter methylation, the role of intragenic methylation was not clarified yet. Melanoma was used as tumor model to investigate the relationship between the DNA intragenic methylation of MMP9 gene and MMP-9 overexpression at transcriptional and protein levels. Computational analysis revealed DNA hypermethylation within the intragenic CpG-2 region of MMP9 gene in melanoma samples with high MMP-9 transcript levels. In vitro validation showed that CpG-2 hotspot region was hypermethylated in the A375 melanoma cell line with highest mRNA and protein levels of MMP-9, while low methylation levels were observed in the MEWO cell line where MMP-9 was undetectable. Concordant results were demonstrated in both A2058 and M14 cell lines. This correlation may give further insights on the role of MMP-9 upregulation in melanoma.

A Transcriptional Regulatory Role for the Membrane Type-1 Matrix Metalloproteinase in Carcinogen-Induced Inflammasome Gene Expression

Signal-transducing functions driven by the cytoplasmic domain of membrane type-1 matrix metalloproteinase (MT1-MMP) are believed to regulate many inflammation-associated cancer cell functions including migration, proliferation, and survival. Aside from upregulation of the inflammation biomarker cyclooxygenase-2 (COX-2) expression, MT1-MMP’s role in relaying intracellular signals triggered by extracellular pro-inflammatory cues remains poorly understood. Here, we triggered inflammation in HT1080 fibrosarcoma cells with phorbol-12-myristate-13-acetate (PMA), an inducer of COX-2 and of MT1-MMP. To assess the global transcriptional regulatory role that MT1-MMP may exert on inflammation biomarkers, we combined gene array screens with a transient MT1-MMP gene silencing strategy. Expression of MT1-MMP was found to exert both stimulatory and repressive transcriptional control of several inflammasome-related biomarkers such as interleukin (IL)-1B, IL-6, IL-12A, and IL-33, as well as of transcription factors such as EGR1, ELK1, and ETS1/2 in PMA-treated cells. Among the signal-transducing pathways explored, the silencing of MT1-MMP prevented PMA from phosphorylating extracellular signal–regulated kinase, inhibitor of κB, and p105 nuclear factor κB (NF-κB) intermediates. We also found a signaling axis linking MT1-MMP to MMP-9 transcriptional regulation. Altogether, our data indicate a significant involvement of MT1-MMP in the transcriptional regulation of inflammatory biomarkers consolidating its contribution to signal transduction functions in addition to its classical hydrolytic activity.

Glycosylation of matrix metalloproteases and tissue inhibitors: present state, challenges and opportunities

Current knowledge about the glycosylation of matrix metalloproteinases (MMPs) and the inhibitors of metalloproteinases (TIMPs) is reviewed. Whereas structural and functional aspects of the glycobiology of many MMPs is unknown, research on MMP-9 and MMP-14 glycosylation reveals important functional implications, such as altered inhibitor binding and cellular localization. This, together with the fact that MMPs contain conserved and many potential attachment sites for N-linked and O-linked oligosaccharides, proves the need for further studies on MMP glycobiology.

Matrix metalloproteases (MMPs) are crucial components of a complex and dynamic network of proteases. With a wide range of potential substrates, their production and activity are tightly controlled by a combination of signalling events, zymogen activation, post-translational modifications and extracellular inhibition. Slight imbalances may result in the initiation or progression of specific disease states, such as cancer and pathological inflammation. As glycosylation modifies the structures and functions of glycoproteins and many MMPs contain N- or O-linked oligosaccharides, we examine, compare and evaluate the evidence for whether glycosylation affects MMP catalytic activity and other functions. It is interesting that the catalytic sites of MMPs do not contain O-linked glycans, but instead possess a conserved N-linked glycosylation site. Both N- and O-linked oligosaccharides, attached to specific protein domains, endow these domains with novel functions such as the binding to lectins, cell-surface receptors and tissue inhibitors of metalloproteases (TIMPs). Validated glycobiological data on N- and O-linked oligosaccharides of gelatinase B/MMP-9 and on O-linked structures of membrane-type 1 MMP/MMP-14 indicate that in-depth research of other MMPs may yield important insights, e.g. about subcellular localizations and functions within macromolecular complexes.

Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries

Cardiovascular diseases are the leading causes of death in industrialized countries. Atherosclerotic coronary arteries are commonly treated with percutaneous transluminal coronary intervention followed by stent deployment. This treatment has significantly improved the clinical outcome. However, triggered vascular smooth muscle cell (SMC) proliferation leads to in-stent restenosis in bare metal stents. In addition, stent thrombosis is a severe side effect of drug eluting stents due to inhibition of endothelialization. The aim of this study was to develop and test a stent surface polymer, where cytotoxic drugs are covalently conjugated to the surface and released by proteases selectively secreted by proliferating smooth muscle cells. Resting and proliferating human coronary artery smooth muscle cells (HCASMC) and endothelial cells (HCAEC) were screened to identify an enzyme exclusively released by proliferating HCASMC. Expression analyses and enzyme activity assays verified selective and exclusive activity of the matrix metalloproteinase-9 (MMP-9) in proliferating HCASMC. The principle of drug release exclusively triggered by proliferating HCASMC was tested using the biodegradable stent surface polymer poly-l-lactic acid (PLLA) and the MMP-9 cleavable peptide linkers named SRL and AVR. The specific peptide cleavage by MMP-9 was verified by attachment of the model compound fluorescein. Fluorescein release was observed in the presence of MMP-9 secreting HCASMC but not of proliferating HCAEC. Our findings suggest that cytotoxic drug conjugated polymers can be designed to selectively release the attached compound triggered by MMP-9 secreting smooth muscle cells. This novel concept may be beneficial for stent endothelialization thereby reducing the risk of restenosis and thrombosis.

Inhibition of glycogen synthase kinase-3β attenuates organ injury and dysfunction associated with liver ischemia-reperfusion and thermal injury in the rat

Glycogen synthase kinase 3 (GSK-3) is a serine-threonine kinase discovered decades ago to have an important role in glycogen metabolism. Today, we know that this kinase is involved in the regulation of many cell functions, including insulin signaling, specification of cell fate during embryonic development, and the control of cell division and apoptosis. Insulin and TDZD-8 (4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione) are inhibitors of GSK-3β that have been shown to possess organ-protective effects in inflammatory-mediated organ injury models. We aimed to evaluate the cytoprotective effect of GSK-3β inhibition on rat models of liver ischemia-reperfusion and thermal injury. In the liver ischemia-reperfusion model, TDZD-8 and insulin were administered at 5 mg/kg (i.v.) and 1.4 IU/kg (i.v.), respectively, 30 min before induction of ischemia and led to the significant reduction of the serum concentration of aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, and lactate dehydrogenase. Beneficial effects were found to be independent from blood glucose levels. In the thermal injury model, TDZD-8 was administered at 5 mg/kg (i.v.) 5 min before induction of injury and significantly reduced multiple organ dysfunction markers (liver, neuromuscular, and lung). In the lung, TDZD-8 reduced the histological signs of tissue injury, inflammatory markers (cytokines), and neutrophil chemotaxis/infiltration; reduced GSK-3β, nuclear factor-κB, and Akt activation; reduced caspase-3 and metalloproteinase-9 activation. Our study provides a new insight on the beneficial effects of GSK-3β inhibition on systemic inflammation and further elucidates the mechanism and pathway crosstalks by which TDZD-8 reduces the multiple organ injury elicited by thermal injury.

lnflammation-induced epigenetic switches in cancer

The link between inflammation and cancer is well established. Chronic inflammation promotes cancer initiation and progression. Various studies showed that the underlying mechanisms involve epigenetic alterations. These epigenetic alterations might culminate into an epigenetic switch that transforms premalignant cells into tumor cells or non-invasive into invasive tumor cells, thereby promoting metastasis. Epigenetic switches require an initiating event, which can be inflammation, whereas the resulting phenotype is inherited without the initiating signal. Epigenetic switches are induced and maintained by DNA methylation, histone modifications, polycomb group (PcG)/trithorax group (TrxG) proteins, and feedback loops consisting of transcription factors and microRNAs. Since epigenetic switches are reversible, they might represent an important basis for the design of novel anticancer therapeutics. This review summarizes published evidence of epigenetic switches in cancer development that are induced by inflammation.

Intraarterial administration of norcantharidin attenuates ischemic stroke damage in rodents when given at the time of reperfusion: novel uses of endovascular capabilities

OBJECT Matrix metalloprotease-9 (MMP-9) plays a critical role in infarct progression, blood-brain barrier (BBB) disruption, and vasogenic edema. While systemic administration of MMP-9 inhibitors has shown neuroprotective promise in ischemic stroke, there has been little effort to incorporate these drugs into endovascular modalities. By modifying the rodent middle cerebral artery occlusion (MCAO) model to allow local intraarterial delivery of drugs, one has the ability to mimic endovascular delivery of therapeutics. Using this model, the authors sought to maximize the protective potential of MMP-9 inhibition by intraarterial administration of an MMP-9 inhibitor, norcantharidin (NCTD). METHODS Spontaneously hypertensive rats were subjected to 90-minute MCAO followed immediately by local intraarterial administration of NCTD. The rats' neurobehavioral performances were scored according to the ladder rung walking test results and the Garcia neurological test for as long as 7 days after stroke. MRI was also conducted 24 hours after the stroke to assess infarct volume and BBB disruption. At the end of the experimental protocol, rat brains were used for active MMP-9 immunohistochemical analysis to assess the degree of MMP-9 inhibition. RESULTS NCTD-treated rats showed significantly better neurobehavioral scores for all days tested. MR images also depicted significantly decreased infarct volumes and BBB disruption 24 hours after stroke. Inhibition of MMP-9 expression in the ischemic region was depicted on immunohistochemical analysis, wherein treated rats showed decreased active MMP-9 staining compared with controls. CONCLUSIONS Intraarterial NCTD significantly improved outcome when administered at the time of reperfusion in a spontaneously hypertensive rat stroke model. This study suggests that supplementing endovascular revascularization with local neuroprotective drug therapy may be a viable therapeutic strategy.

Vitamin D attenuates cytokine-induced remodeling in human fetal airway smooth muscle cells

Asthma in the pediatric population remains a significant contributor to morbidity and increasing healthcare costs. Vitamin D3 insufficiency and deficiency have been associated with development of asthma. Recent studies in models of adult airway diseases suggest that the bioactive Vitamin D3 metabolite, calcitriol (1,25-dihydroxyvitamin D3 ; 1,25(OH)2 D3 ), modulates responses to inflammation; however, this concept has not been explored in developing airways in the context of pediatric asthma. We used human fetal airway smooth muscle (ASM) cells as a model of the early postnatal airway to explore how calcitriol modulates remodeling induced by pro-inflammatory cytokines. Cells were pre-treated with calcitriol and then exposed to TNFα or TGFβ for up to 72 h. Matrix metalloproteinase (MMP) activity, production of extracellular matrix (ECM), and cell proliferation were assessed. Calcitriol attenuated TNFα enhancement of MMP-9 expression and activity. Additionally, calcitriol attenuated TNFα and TGFβ-induced collagen III expression and deposition, and separately, inhibited proliferation of fetal ASM cells induced by either inflammatory mediator. Analysis of signaling pathways suggested that calcitriol effects in fetal ASM involve ERK signaling, but not other major inflammatory pathways. Overall, our data demonstrate that calcitriol can blunt multiple effects of TNFα and TGFβ in developing airway, and point to a potentially novel approach to alleviating structural changes in inflammatory airway diseases of childhood.

The Effect of Progestins on Tumor Necrosis Factor α-Induced Matrix Metalloproteinase-9 Activity and Gene Expression in Human Primary Amnion and Chorion Cells In Vitro

BACKGROUND

Current treatment modalities for preventing preterm premature rupture of membranes are limited, but progestins may play a role. Tumor necrosis factor α (TNFα) enhances matrix metalloproteinase-9 (MMP-9) gene expression and activity in fetal membranes, contributing to membrane weakening and rupture. We previously demonstrated that progestins attenuate TNFα-induced MMP-9 activity in a cytotrophoblast cell line. However, whether they have a similar effect in primary amnion and chorion cells of fetal membranes is unknown. In this study, we evaluated the effect of progestins on basal and TNFα-induced MMP-9 activity and gene expression in primary chorion and amnion cells harvested from the fetal membranes of term nonlaboring patients.

METHODS

Primary amnion and chorion cells were isolated from fetal membranes obtained from term uncomplicated nonlaboring patients following elective cesarean delivery (n = 11). Confluent primary amnion and chorion cell cultures were both pretreated with vehicle (control), progesterone (P4), 17α-hydroxyprogesterone caproate (17P), or medroxyprogesterone acetate (MPA) at 10 M concentration for 6 hours followed by stimulation with TNFα at 10 ng/mL for an additional 24 hours. Cell cultures pretreated with the vehicle only served as the unstimulated control and the vehicle stimulated with TNFα served as the stimulated control. Both controls were assigned a value of 100 units. Cell culture medium was harvested for MMP-9 enzymatic activity quantification using gelatin zymography. Total RNA was extracted for quantifying MMP-9 gene expression using real-time quantitative PCR. Basal MMP-9 activity and gene expression data were normalized to the unstimulated control. TNFα-stimulated MMP-9 activity and gene expression were normalized to the stimulated control. The primary outcome was the effect of progestins on TNFα-induced MMP-9 enzymatic activity in term human primary amnion and chorion cells in vitro. Secondary outcomes included the effect of progestin therapy on TNFα-induced MMP-9 gene expression and on basal MMP-9 activity and gene expression in primary amnion and chorion cells in vitro.

RESULTS

Primary cells were harvested from 11 patients. Compared with the unstimulated control, TNFα increased MMP-9 activity (P = 0.005 versus control in primary amnion cells and P < 0.001 versus control in primary chorion cells) and MMP-9 gene expression (P = 0.030 versus control in primary amnion cells, P < 0.001 versus control in primary chorion cells). Compared with the unstimulated controls, MPA, but not P4 or 17P, reduced basal MMP-9 activity [mean difference (95% CI) -49.6 (-81.9, -17.3) units, P = 0.001] and gene expression [mean difference (95% CI) -53.4 (-105.9, -0.9) units, P = 0.045] in primary amnion cells. Compared with the stimulated control, MPA also reduced TNFα-induced MMP-9 activity [mean difference (95% CI) -69.0 (-91.8, -46.3) units, P < 0.001] and gene expression [mean difference (95% CI) -86.0 (-120.7, -51.3) units, P < 0.001] in primary amnion cells. Progestin pretreatment had no significant effect on basal or TNFα-induced MMP-9 activity and gene expression in primary chorion cells.

CONCLUSIONS

The inhibitory effect of MPA on both basal and TNFα-induced MMP-9 activity and gene expression in primary amnion cells demonstrate a possible mechanism by which progestins may prevent fetal membrane weakening leading to preterm premature rupture of membranes.

Two-dimensional zymography differentiates gelatinase isoforms in stimulated microglial cells and in brain tissues of acute brain injuries

Excessive activation of gelatinases (MMP-2/-9) is a key cause of detrimental outcomes in neurodegenerative diseases. A single-dimension zymography has been widely used to determine gelatinase expression and activity, but this method is inadequate in resolving complex enzyme isoforms, because gelatinase expression and activity could be modified at transcriptional and posttranslational levels. In this study, we investigated gelatinase isoforms under in vitro and in vivo conditions using two-dimensional (2D) gelatin zymography electrophoresis, a protocol allowing separation of proteins based on isoelectric points (pI) and molecular weights. We observed organomercuric chemical 4-aminophenylmercuric acetate-induced activation of MMP-2 isoforms with variant pI values in the conditioned medium of human fibrosarcoma HT1080 cells. Studies with murine BV-2 microglial cells indicated a series of proform MMP-9 spots separated by variant pI values due to stimulation with lipopolysaccharide (LPS). The MMP-9 pI values were shifted after treatment with alkaline phosphatase, suggesting presence of phosphorylated isoforms due to the proinflammatory stimulation. Similar MMP-9 isoforms with variant pI values in the same molecular weight were also found in mouse brains after ischemic and traumatic brain injuries. In contrast, there was no detectable pI differentiation of MMP-9 in the brains of chronic Zucker obese rats. These results demonstrated effective use of 2D zymography to separate modified MMP isoforms with variant pI values and to detect posttranslational modifications under different pathological conditions.

Multilevel regulation of matrix metalloproteinases in tissue homeostasis indicates their molecular specificity in vivo

The matrix metalloproteinases (MMPs) play a crucial role in irreversible remodeling of the extracellular matrix (ECM) in normal homeostasis and pathological states. Accumulating data from various studies strongly suggest that MMPs are tightly regulated, starting from the level of gene expression all the way to zymogen activation and endogenous inhibition, with each level controlled by multiple factors. Recent in vivo findings indicate that cell-ECM and cell-cell interactions, as well as ECM bio-active products, contribute an additional layer of regulation at all levels, indicating that individual MMP expression and activity in vivo are highly coordinated and tissue specific processes.

Macrophage-specific NOX2 contributes to the development of lung emphysema through modulation of SIRT1/MMP-9 pathways

Reactive oxygen species (ROS) participate in the pathogenesis of emphysema. Among ROS-producing enzymes, NOX NADPH oxidases are thought to be responsible for tissue injury associated with several lung pathologies. To determine whether NOX2 and/or NOX1 participate in the development of emphysema, their expression patterns were first studied by immunohistochemistry in the lungs of emphysematous patients. Subsequently, we investigated their contribution to elastase-induced emphysema using NOX2- and NOX1-deficient mice. In human lung, NOX2 was mainly detected in macrophages of control and emphysematous lungs, while NOX1 was expressed in alveolar epithelium and bronchial cells. We observed an elevated number of NOX2-positive cells in human emphysematous lungs, as well as increased NOX2 and NOX1 mRNA expression in mouse lungs following elastase exposure. Elastase-induced alveolar airspace enlargement and elastin degradation were prevented in NOX2-deficient mice, but not in NOX1-deficient mice. This protection was independent of inflammation and correlated with reduced ROS production. Concomitantly, an elevation of sirtuin 1 (SIRT1) level and a decrease of matrix metalloproteinase-9 (MMP-9) expression and activity were observed in alveolar macrophages and neutrophils. We addressed the specific role of macrophage-restricted functional NOX2 in elastase-induced lung emphysema using Ncf1 mutant mice and Ncf1 macrophage rescue mice (Ncf1 mutant mice with transgenic expression of Ncf1 only in CD68-positive mononuclear phagocytes; the MN mouse). Compared to WT mice, the lack of functional NOX2 led to decreased elastase-induced ROS production and protected against emphysema. In contrast, ROS production was restored specifically in macrophages from Ncf1 rescue mice and contributes to emphysema. Taken together, our results demonstrate that NOX2 is involved in the pathogenesis of human emphysema and macrophage-specific NOX2 participates in elastase-induced emphysema through the involvement of SIRT1/MMP-9 pathways in mice.

Histone Methyltransferase hSETD1A Is a Novel Regulator of Metastasis in Breast Cancer

Epigenetic alteration is a hallmark of all cancers. Such alterations lead to modulation of fundamental cancer-related functions, such as proliferation, migration, and invasion. In particular, methylation of Histone H3 Lysine 4 (H3K4), a histone mark generally associated with transcriptional activation, is altered during progression of several human cancers. While the depletion of H3K4 demethylases promotes breast cancer metastasis, the effect of H3K4 methyltransferases on metastasis is not clear. Nevertheless, gene duplications in the human SETD1A (hSETD1A) H3K4 methyltransferase are present in almost half of breast cancers. Herein, expression analysis determined that hSETD1A is upregulated in multiple metastatic human breast cancer cell lines and clinical tumor specimens. Ablation of hSETD1A in breast cancer cells led to a decrease in migration and invasion in vitro and to a decrease in metastasis in nude mice. Furthermore, a group of matrix metalloproteinases (including MMP2, MMP9, MMP12, MMP13, and MMP17) were identified which were downregulated upon depletion of hSETD1A and demonstrated a decrease in H3K4me3 at their proximal promoters based on chromatin immunoprecipitation analysis. These results provide evidence for a functional and mechanistic link among hSETD1A, MMPs, and metastasis in breast cancer, thereby supporting an oncogenic role for hSETD1A in cancer.

IMPLICATIONS

This study reveals that hSETD1A controls tumor metastasis by activating MMP expression and provides an epigenetic link among hSETD1A, MMPs, and metastasis of breast cancer.

Ezh2-mediated repression of a transcriptional pathway upstream of Mmp9 maintains integrity of the developing vasculature

Maintenance of vascular integrity is required for embryogenesis and organ homeostasis. However, the gene expression programs that stabilize blood vessels are poorly understood. Here, we show that the histone methyltransferase Ezh2 maintains integrity of the developing vasculature by repressing a transcriptional program that activates expression of Mmp9. Inactivation of Ezh2 in developing mouse endothelium caused embryonic lethality with compromised vascular integrity and increased extracellular matrix degradation. Genome-wide approaches showed that Ezh2 targets Mmp9 and its activators Fosl1 and Klf5. In addition, we uncovered Creb3l1 as an Ezh2 target that directly activates Mmp9 gene expression in the endothelium. Furthermore, genetic inactivation of Mmp9 rescued vascular integrity defects in Ezh2-deficient embryos. Thus, epigenetic repression of Creb3l1, Fosl1, Klf5 and Mmp9 by Ezh2 in endothelial cells maintains the integrity of the developing vasculature, potentially linking this transcriptional network to diseases with compromised vascular integrity.

Long non-coding RNAs drive metastatic progression in melanoma (Review)

Metastatic melanoma is the leading cause of skin-cancer related deaths and while in recent years some progress has been made with targeted therapies, there remains an urgent unmet need for novel therapeutic treatments and reliable diagnostic, prognostic and predictive biomarkers. The emergence of next generation sequencing (NGS) has seen a growing appreciation for the role played by non-coding genomic transcripts in regulating gene expression and by extension impacting on disease progression. The long non-coding RNAs (lncRNAs) represent the most enigmatic of these new regulatory molecules. Our understanding of how lncRNAs regulate biological functions and their importance to disease aetiology, while still limited, is rapidly improving, in particular with regards to their role in cancer. Herein we review the identification of several lncRNAs shown to impact on melanoma disease progression and discuss how these molecules are operating at the molecular level.

Tumor progression driven by pathways activating matrix metalloproteinases and their inhibitors

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is still a problem worldwide. In some publications interactions between the expression of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and their tissue inhibitors (TIMPs) implicated during cancer progression were suggested.

METHODS

The immunohistochemical staining using primary antibody against MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 were performed. The research group consists of primary N(0) LSCC (20 cases), primary N(+) LSCC (17 cases), and 18 cases of normal mucosa.

RESULTS

Studied MMPs and TIMPs were localized in tumor cells and tumor stroma compartment. MMP-2 expression was higher in stroma compared to tumor cells. MMP-9, TIMP-1, TIMP-2, and TIMP-3 expression was higher in tumor cells than in tumor stroma (P < 0.05). In tumor stroma MMP-2, MMP-9, TIMP-1, and TIMP-3 expression, in LSCC N(0) vs. LSCC N(+) was significantly higher (P < 0.05). The ratios between MMP-2 and TIMP-3 expression were statistically significant (N(0) vs. N(+); P = 0.012). The analyses using classification trees predicted the probability of metastases according to TIMP-3/MMP-14/MMP-2 and MMP-9/TIMP-1 expression levels.

CONCLUSIONS

The presence of MMP-2, MMP-9, TIMP-1, TIMP-2, TIMP-3 expression in tumor cells and in tumor stroma, and additionally different expression according to lymph node involvement suggested of their impact during cancer progression. The significant correlation between TIMP-3 expression and the presence of lymph node metastases and MMP-2 expression might suggest the importance of TIMP-3 as a prognostic factor during tumor progression. The evaluation of molecular markers which participate in MMP-2 activation pathway have a major impact during metastasis.

MMP-9 expression varies according to molecular subtypes of breast cancer

Background

In 2014, breast cancer remains a major cause of mortality worldwide mostly due to tumor relapse and metastasis. There is currently a great interest in identifying cancer biomarkers and signalling pathways mechanistically related to breast cancer progression. Matrix metalloproteinase-9 (MMP-9) is a member of matrix degrading enzymes involved in cancer development, invasion and metastasis. Our objective was to investigate MMP-9 expression in normal human breast tissue and to compare it to that of breast cancer of various histological grades and molecular subtypes. We also sought to correlate MMP-9 expression with the incidence of metastasis, survival rates and relapse in breast cancer patients.

Methods

MMP-9 was first studied using in silico analysis on available DNA microarray and RNA sequencing data of human breast cancer tissues and human breast cancer cell lines. We next ascertained MMP-9 expression in both normal breast tissue and in human breast carcinoma tissue microarrays.

Results

Significant increase in MMP-9 expression was found in breast cancer cells where compared to normal breast tissue. A positive correlation could also be established between elevated levels of MMP-9 and breast cancer of high histological grade. Furthermore, our results indicate that not only MMP-9 is differentially expressed between each molecular subset but also, more importantly MMP-9 overexpression revealed itself as a startling feature of triple-negative and HER2-positive breast cancers. Lastly, the clinical relevance of MMP-9 overexpression is strongly supported by its significant association with a higher incidence of metastasis and relapse.

Conclusions

Differential expression of MMP-9 reflects the extent of cellular differentiation in breast cancer cells and is closely related to the most aggressive subtypes of breast cancer. Hence, MMP-9 is a promising prognostic biomarker of high-grade breast cancer. In our opinion, MMP-9 expression could help segregate subsets of aggressive breast cancer into clinically meaningful subtypes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-609) contains supplementary material, which is available to authorized users.

Matrix metalloproteinase-9 involvement in the structural plasticity of dendritic spines

Dendritic spines are the locus for excitatory synaptic transmission in the brain and thus play a major role in neuronal plasticity. The ability to alter synaptic connections includes volumetric changes in dendritic spines that are driven by scaffolds created by the extracellular matrix (ECM). Here, we review the effects of the proteolytic activity of ECM proteases in physiological and pathological structural plasticity. We use matrix metalloproteinase-9 (MMP-9) as an example of an ECM modifier that has recently emerged as a key molecule in regulating the morphology and dysmorphology of dendritic spines that underlie synaptic plasticity and neurological disorders, respectively. We summarize the influence of MMP-9 on the dynamic remodeling of the ECM via the cleavage of extracellular substrates. We discuss its role in the formation, modification, and maintenance of dendritic spines in learning and memory. Finally, we review research that implicates MMP-9 in aberrant synaptic plasticity and spine dysmorphology in neurological disorders, with a focus on morphological abnormalities of dendritic protrusions that are associated with epilepsy.