Matrix metalloproteinase 12 silencing: a therapeutic approach to treat pathological lung tissue remodeling?

The Function of microRNAs in Pulmonary Embolism: Review and Research Outlook

Pulmonary embolism (PE) is a common pathologic condition that frequently occurs in patients with deep venous thrombosis. Severe PE may critically suppress cardiopulmonary function, thereby threatening the life of patients. Chronic pulmonary hypertension caused by PE may lead to deterioration of respiratory dysfunction, resulting in complete disability. MicroRNAs (miRNAs) are a group of abundantly expressed non-coding RNAs that exert multiple functions in regulating the transcriptome via post-transcriptional targeting of mRNAs. Specifically, miRNAs bind to target mRNAs in a matching mechanism between the miRNA seed sequence and mRNA 3ʹ UTR, thus modulating the transcript stability or subsequent translation activity by RNA-induced silencing complex. Current studies have reported the function of miRNAs as biomarkers of PE, revealing their mechanism, function, and targetome in venous thrombophilia. This review summarizes the literature on miRNA functions and downstream mechanisms in PE. We conclude that various related miRNAs play important roles in PE and have great potential as treatment targets. For clinical application, we propose that miRNA biomarkers combined with traditional biomarkers or miRNA signatures generated from microchips may serve as a great predictive tool for PE occurrence and prognosis. Further, therapies targeting miRNAs or their upstream/downstream molecules need to be developed more quickly to keep up with the progress of routine treatments, such as anticoagulation, thrombolysis, or surgery.

Transcriptomic analysis identifies upregulation of secreted phosphoprotein 1 in silicotic rats

Silicosis is caused by exposure to crystalline silica and the molecular mechanism of silicotic fibrosis remains unclear. Therefore, the present study investigated the mRNA profiles of rats exposed to crystalline silica. RNA-sequencing techniques were used to observe differential expression of mRNAs in silicotic rats induced by chronic inhalation of crystalline silica particulates. Prediction of mRNA functions and signaling pathways was conducted using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Certain differentially expressed mRNAs were verified in lung tissue of silicotic rats by quantitative polymerase chain reaction (qPCR). Secreted phosphoprotein 1 (SPP1) was measured in serum from silicosis patients, lungs of silicotic rats and NR8383 macrophages treated with silica. A total of 1,338 mRNAs were revealed to be differentially expressed in silicotic rat lungs, including 912 upregulated and 426 downregulated mRNAs. In GO analysis of significant changes in mRNAs, the most affected processes were the defense response, extracellular space and chemokine activity in terms of biological process, cellular component and molecular function. In KEGG pathway analysis, dysregulated mRNAs were involved in systemic lupus erythematosus, staphylococcus aureus infection, complement and coagulation cascades, alcoholism and pertussis. qPCR demonstrated that expression of Spp1, Mmp12, Ccl7, Defb5, Fabp4 and Slc26a4 was increased in silicotic rats, while Lpo, Itln1, Lcn2 and Dlk1 expression was decreased. It was also found that SPP1 was increased in serum from silicosis patients, silicotic rats and silica-treated NR8383 macrophages. The expression of mRNAs was altered significantly in silicotic rats, which suggested that certain genes are novel targets for the diagnosis and treatment of silicosis.

First-in-Man Safety, Tolerability, and Pharmacokinetics of a Novel and Highly Selective Inhibitor of Matrix Metalloproteinase-12, FP-025: Results from Two Randomized Studies in Healthy Subjects

BACKGROUND AND OBJECTIVES

Matrix metalloproteinases (MMPs) are proteases with different biological and pathological activities, and many have been linked to several diseases. Targeting individual MMPs may offer a safer therapeutic potential for several diseases. We assessed the safety, tolerability, and pharmacokinetics of FP-025, a novel, highly selective oral matrix metalloproteinase-12 inhibitor, in healthy subjects.

METHODS

Two randomized, double-blind, placebo-controlled studies were conducted. Study I was a first-in-man study, evaluating eight single ascending doses (SADs) (50-800 mg) in two formulations: i.e., neat FP-025 in capsule (API-in-Capsule) and in an amorphous solid dispersion (ASD-in-Capsule) formulation. In Study II, three multiple ascending doses (MADs) (100, 200, and 400 mg, twice daily) of FP-025 (ASD-in-Capsule) were administered for 8 days, including a food-effect evaluation.

RESULTS

Ninety-six subjects were dosed. Both formulations were well tolerated with one adverse event (AE) reported in the 800 mg API-in-Capsule SAD group and seven AEs throughout the MAD groups. The exposure to FP-025 was low with the API-in-Capsule formulation; it increased dose-dependently with the ASD-in-Capsule formulation, with which exposure to FP-025 increased in a greater-than-dose-proportional manner at lower doses (≤ 100 mg) but less proportionally at higher doses. The elimination half-life (t_1/2) was between 6 (Study I) and 8 h (Study II). Accumulation of FP-025 was approximately 1.7-fold in the MAD study. Food intake delayed the rate of absorption, but without effect in the extent of absorption or bioavailability.

CONCLUSION

FP-025 was well tolerated and showed a favorable pharmacokinetic profile following ASD-in-Capsule dosing. Efficacy studies in target patient populations, including asthma, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis, are warranted.

TRIAL REGISTRATION NUMBER

www.clinicaltrials.gov : NCT02238834 (Study I); NCT03304964 (Study II). Trial registration date: Study I was registered on 12 September 2014 while study II was registered on 9 October 2017.

Selected Matrix Metalloproteinases (MMP-2, MMP-7) and Their Inhibitor (TIMP-2) in Adult and Pediatric Cancer

The tumor microenvironment (TME) consists of numerous biologically relevant elements. One of the most important components of the TME is the extracellular matrix (ECM). The compounds of the ECM create a network that provides structural and biochemical support to surrounding cells. The most important substances involved in the regulation of the ECM degradation process are matrix metalloproteinases (MMPs) and their endogenous inhibitors (tissue inhibitors of metalloproteinases, TIMPs). The disruption of the physiological balance between MMP activation and deactivation could lead to progression of various diseases such as cardiovascular disease, cancer, fibrosis arthritis, chronic tissue ulcers, pathologies of the nervous system (such as stroke and Alzheimer's disease), periodontitis, and atheroma. MMP-TIMP imbalance results in matrix proteolysis associated with various pathological processes such as tumor invasion. The present review discusses the involvement of two MMPs, MMP-2 and MMP-7, in cancer pathogenesis. These two MMPs have been proven in several studies, conducted mostly on adults, to make an important contribution to cancer development and progression. In the current review, several studies that indicate the importance of MMP-TIMP balance determination for the pediatric population are also highlighted. The authors of this review believe that carrying out biochemical and clinical studies focused on metalloproteinases and their inhibitors in tumors in children will be of great relevance for future patient diagnosis, determination of a prognosis, and monitoring of therapy.

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.

Circulating matrix metalloproteinases and tissue metalloproteinase inhibitors in patients with idiopathic pulmonary fibrosis in the multicenter IPF-PRO Registry cohort

Background

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) play important roles in the turnover of extracellular matrix and in the pathogenesis of idiopathic pulmonary fibrosis (IPF). This study aimed to determine the utility of circulating MMPs and TIMPs in distinguishing patients with IPF from controls and to explore associations between MMPs/TIMPs and measures of disease severity in patients with IPF.

Methods

The IPF cohort (n = 300) came from the IPF-PRO Registry, an observational multicenter registry of patients with IPF that was diagnosed or confirmed at the enrolling center in the past 6 months. Controls (n = 100) without known lung disease came from a population-based registry. Generalized linear models were used to compare circulating concentrations of MMPs 1, 2, 3, 7, 8, 9, 12, and 13 and TIMPs 1, 2, and 4 between patients with IPF and controls, and to investigate associations between circulating levels of these proteins and measures of IPF severity. Multivariable models were fit to identify the MMP/TIMPs that best distinguished patients with IPF from controls.

Results

All the MMP/TIMPs analyzed were present at significantly higher levels in patients with IPF compared with controls except for TIMP2. Multivariable analyses selected MMP8, MMP9 and TIMP1 as top candidates for distinguishing patients with IPF from controls. Higher concentrations of MMP7, MMP12, MMP13 and TIMP4 were significantly associated with lower diffusion capacity of the lung for carbon monoxide (DL_CO) % predicted and higher composite physiologic index (worse disease). MMP9 was associated with the composite physiologic index. No MMP/TIMPs were associated with forced vital capacity % predicted.

Conclusions

Circulating MMPs and TIMPs were broadly elevated among patients with IPF. Select MMP/TIMPs strongly associated with measures of disease severity. Our results identify potential MMP/TIMP targets for further development as disease-related biomarkers.

Time-course transcriptomic alterations reflect the pathophysiology of polyhexamethylene guanidine phosphate-induced lung injury in rats

Objective: Humidifier-disinfectant-induced lung injury is a new syndrome associated with a high mortality rate and characterized by severe hypersensitivity pneumonitis, acute interstitial pneumonia, or acute respiratory distress syndrome. Polyhexamethylene guanidine phosphate (PHMG-P), a guanidine-based antimicrobial agent, is a major component associated with severe lung injury. In-depth studies are needed to determine how PHMG-P affects pathogenesis at the molecular level. Therefore, in this study, we analyzed short-term (4 weeks) and long-term (10 weeks) PHMG-P-exposure-specific gene-expression patterns in rats to improve our understanding of time-dependent changes in fibrosis.Materials and methods: Gene-expression profiles were analyzed in rat lung tissues using DNA microarrays and bioinformatics tools.Results: Clustering analysis of gene-expression data showed different gene-alteration patterns in the short- and long-term exposure groups and higher sensitivity to gene-expression changes in the long-term exposure group than in the short-term exposure group. Supervised analysis revealed 34 short-term and 335 long-term exposure-specific genes, and functional analysis revealed that short-term exposure-specific genes were involved in PHMG-P-induced initial inflammatory responses, whereas long-term exposure-specific genes were involved in PHMG-P-related induction of chronic lung fibrosis.Conclusion: The results of transcriptomic analysis were consistent with lung histopathology results. These findings indicated that exposure-time-specific changes in gene expression closely reflected time-dependent pathological changes in PHMG-P-induced lung injury.

Comparative Study of Cytokine Levels in Different Respiratory Samples in Mild-to-Moderate AECOPD Patients

BACKGROUND

Matrix metalloproteinase-12 (MMP-12) and Tissue inhibitor of metalloproteinase-4 (TIMP-4) play important roles in the pathophysiology of chronic obstructive pulmonary disease (COPD). Subjects of many previous studies were patients with severe and very severe COPD. However, there are comparatively few studies on patients with mild-to-moderate COPD. Our aim was to measure MMP-12 and TIMP-4 levels and to compare its levels in various materials in patients with mild-to-moderate acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We also compared which of the two materials of these biomarkers was better correlated with disease severity and DODE index.

METHODS

A total of 39 patients with AECOPD and 25 control subjects were enrolled in our study. MMP-12 and TIMP-4 in different respiratory samples were detected by ELISA.

RESULTS

Expression levels of MMP-12 in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) and TIMP-4 in BALF were significantly higher in AECOPD patients than that in healthy subjects (P < 0.001). However, there was no significant difference in TIMP-4 level in EBC of AECOPD patients compared to healthy subjects (P = 0.0527). The levels of MMP-12 in BALF and EBC and TIMP-4 in BAFL of AECOPD patients were significantly correlated with FEV1% predicted (P < 0.001). However, in AECOPD patients, there was no significant correlation between TIMP-4 levels in EBC and BODE index (r = 0.4175, P = 0.0559).

CONCLUSION

During mild-to-moderate AECOPD, the levels of MMP-12 and TIMP-4 in BALF were better correlated with FEV1% predicted and BODE index than that in EBC, indicating that they may be new target interventions for pharmacology to prevent and/or treat AECOPD.

The role of MMP-12 gene polymorphism - 82 A-to-G (rs2276109) in immunopathology of COPD in polish patients: a case control study

Background

Major symptoms of chronic obstructive pulmonary disease (COPD) are chronic bronchitis and emphysema leading from lung tissue destruction, that is an effect of an imbalance between metalloproteinases (MMPs) and their tissue inhibitors activity. As potential factor involved in this COPD pathogenesis, MMP-12 is considered. We investigated the role of genetic polymorphism and protein level of MMP-12 in the COPD development among Poles.

Methods

We analyzed − 82 A > G SNP in the promoter region of MMP-12 gene (rs2276109) among 335 smoked COPD patients and 309 healthy individuals, including 110 smokers. Additionally, 60 COPD patients and 61 controls (23 smokers) were tested for serum levels of MMP-12 using ELISA. All subjects were analyzed for lung function using spirometry (FEV₁% and FEV₁/FVC parameters).

Results

We observed that -82G allele and -82GG homozygous genotype frequencies of the SNP rs2276109 were significantly lower in COPD patients than in controls (12.5% vs 16.9%, respectively; χ² = 4.742, p = 0.02 for allele and 0.5% vs 3.9%, respectively; χ² = 9.0331, p = 0.01 for genotype). Moreover, −82G allele was more frequent in controls smokers than in non-smokers (22.3% vs 14.1%, χ² = 6.7588, p = 0.01). Serum level of MMP-12 was significantly higher in COPD patients than in controls groups (6.8 ng/ml vs 3.3 ng/ml, respectively; F = 7.433, p < 0.0001), although independently of analyzed gene polymorphisms. Additionally, no correlation between parameters of lung function (FEV₁% and FEV₁/FVC) and protein level was found.

Conclusions

We found that -82G allele of SNP rs2276109 was associated with reduced risk of COPD, and COPD patients released more MMP-12 than healthy individuals, but independently on this SNP.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0751-9) contains supplementary material, which is available to authorized users.

Protective Effects of Nintedanib against Polyhexamethylene Guanidine Phosphate-Induced Lung Fibrosis in Mice

Nintedanib (NDN), a tyrosine kinase inhibitor, has been shown to have anti-tumor, anti-inflammatory, and anti-fibrotic effects in several reports. We investigated the protective effects of NDN against polyhexamethylene guanidine phosphate (PHMG)-induced lung fibrosis in mice. The following three experimental groups were evaluated: (1) vehicle control; (2) PHMG (1.1 mg/kg); and (3) PHMG & NDN (60 mg/kg). PHMG induced pulmonary inflammation and fibrosis by intratracheal instillation in mice. In contrast, NDN treatment effectively alleviated the PHMG induced lung injury, and attenuated the number of total cells and inflammatory cells in the bronchoalveolar lavage fluid, including the fibrotic histopathological changes, and also reduced the hydroxyproline content. NDN also significantly decreased the expression of inflammatory cytokines and fibrotic factors, and the activation of the NLRP3 inflammasome in lung tissues. These results suggest that NDN may mitigate the inflammatory response and development of pulmonary fibrosis in the lungs of mice treated with PHMG.

MMP-12 activates protease-activated receptor-1, upregulates placenta growth factor, and leads to pulmonary emphysema

Because of the expansion of aging and smoking populations, chronic obstructive pulmonary disease (COPD) is predicted to be the third leading cause of death worldwide in 2030. Therefore, it is pertinent to develop effective therapy to improve management for COPD. Cigarette smoke-mediated protease-antiprotease imbalance is a major pathogenic mechanism for COPD and results in massive pulmonary infiltration of neutrophils and macrophages, releasing excessive neutrophil elastase (NE) and matrix metalloproteinases (MMPs). Our previous studies indicated that placenta growth factor (PGF) and PGF-triggered downstream signaling molecules mediate NE-induced lung epithelial cell apoptosis, which is a major pathogenic mechanism for pulmonary emphysema. However, the relationship between MMP-directed COPD and PGF remains elusive. We hypothesize that MMPs may upregulate PGF expression and be involved in MMP-mediated pathogenesis of COPD. In this study, we demonstrate that only MMP-12 can increase the expression of PGF by increasing early-growth response protein 1 (Egr-1) level through the activation of protease-activated receptor 1 (PAR-1). The PGF-mediated downstream signaling molecules drive caspase-3 and caspase-9-dependent apoptosis in bronchial epithelial cells. Both the upregulation of PGF by MMP-12 and PGF downstream signaling molecules with pulmonary apoptosis and emphysema were also demonstrated in animals. Given these findings, we suggest that both human COPD-associated elastases, NE, and MMP-12, upregulate PGF expression and promote the progression of emphysema and COPD.

Extracellular microRNA-21 and microRNA-26a increase in body fluids from rats with antigen induced pulmonary inflammation and children with recurrent wheezing

Background

This study aims to find out whether extracellular miRNAs is implicated in recurrent childhood wheezing with asthmatic risk.

Methods

One hundred and forty children of Chinese Han population were recruited for this study. Plasma and intracellular miRNAs from children with recurrent wheezing and rats with antigen induced pulmonary inflammation (AIPI) were detected by using reverse transcription-quantitative PCR. Differential leukocytes in blood were automatically counted. Total IgE was detected by enzyme-linked immunosorbent assay. Clinical implication in diagnosis was evaluated using receiver operating characteristic curves.

Results

The increase of plasma miR-21 and miR-26a was screened out from 11 candidate miRNAs and validated in wheezing children. The level of expression for both miRNAs were comparable in different age and gender. Plasma miR-21 was more preferable to miR-26a and total IgE for diagnosis. Plasma miR-21 and miR-26a levels were not significantly correlated with various leukocyte counts or miRNA expression in blood cells. In acute and chronic AIPI rats, miR-21 levels increased in both plasma and lavaged lung compared with control. Moreover, circulating miR-21 and miR-26a levels were highly positively correlated with infiltrated cell counts in bronchoalveolar lavage fluid of AIPI rats.

Conclusions

Circulating miR-21 and miR-26a increase in wheezing children and AIPI rats. This not only manifests their strong clinical implication in recurrent childhood wheezing with asthma risk, but also provides novel insights into the role of extracellular miRNAs during development of airway inflammation and recurrent wheezing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0216-2) contains supplementary material, which is available to authorized users.

[Research Progress of Biomakers Proteomics-based in Lung Cancer]

蛋白组学技术可以应用于癌症研究来检测差异蛋白质表达以发现癌症生物标志物。肺癌的生物标志物在肺癌早期诊断、指导治疗和预后监测方面起着关键作用。因此，迫切需要确定新的早期诊断和预后指标以开辟新的治疗途径。本文简要介绍了基于蛋白质组学的肺癌生物标志物的最新研究报告。他包括作为诊断、预后和预测性的生物标志物，以及基于最近发表文献的基础上和我们所做的相关工作的总结。

Diverse functions of matrix metalloproteinases during fibrosis

Fibrosis--a debilitating condition that can occur in most organs - is characterized by excess deposition of a collagen-rich extracellular matrix (ECM). At first sight, the activities of proteinases that can degrade matrix, such as matrix metalloproteinases (MMPs), might be expected to be under-expressed in fibrosis or, if present, could function to resolve the excess matrix. However, as we review here, some MMPs are indeed anti-fibrotic, whereas others can have pro-fibrotic functions. MMPs modulate a range of biological processes, especially processes related to immunity and tissue repair and/or remodeling. Although we do not yet know precisely how MMPs function during fibrosis--that is, the protein substrate or substrates that an individual MMP acts on to effect a specific process--experiments in mouse models demonstrate that MMP-dependent functions during fibrosis are not limited to effects on ECM turnover. Rather, data from diverse models indicate that these proteinases influence cellular activities as varied as proliferation and survival, gene expression, and multiple aspects of inflammation that, in turn, impact outcomes related to fibrosis.

MMP-12 deficiency attenuates angiotensin II-induced vascular injury, M2 macrophage accumulation, and skin and heart fibrosis

MMP-12, a macrophage-secreted elastase, is elevated in fibrotic diseases, including systemic sclerosis (SSc) and correlates with vasculopathy and fibrosis. The goal of this study was to investigate the role of MMP-12 in cardiac and cutaneous fibrosis induced by angiotensin II infusion. Ang II-induced heart and skin fibrosis was accompanied by a marked increase of vascular injury markers, including vWF, Thrombospondin-1 (TSP-1) and MMP-12, as well as increased number of PDGFRβ⁺ cells. Furthermore Ang II infusion led to an accumulation of macrophages (Mac3⁺) in the skin and in the perivascular and interstitial fibrotic regions of the heart. However, alternatively activated (Arg 1⁺) macrophages were mainly present in the Ang II infused mice and were localized to the perivascular heart regions and to the skin, but were not detected in the interstitial heart regions. Elevated expression of MMP-12 was primarily found in macrophages and endothelial cells (CD31⁺) cells, but MMP-12 was not expressed in the collagen producing cells. MMP-12 deficient mice (MMP12KO) showed markedly reduced expression of vWF, TSP1, and PDGFRβ around vessels and attenuation of dermal fibrosis, as well as the perivascular fibrosis in the heart. However, MMP-12 deficiency did not affect interstitial heart fibrosis, suggesting a heterogeneous nature of the fibrotic response in the heart. Furthermore, MMP-12 deficiency almost completely prevented accumulation of Arg 1⁺ cells, whereas the number of Mac3⁺ cells was partially reduced. Moreover production of profibrotic mediators such as PDGFBB, TGFβ1 and pSMAD2 in the skin and perivascular regions of the heart was also inhibited. Together, the results of this study show a close correlation between vascular injury markers, Arg 1⁺ macrophage accumulation and fibrosis and suggest an important role of MMP-12 in regulating these processes.

Analysis of the expression of nine secreted matrix metalloproteinases and their endogenous inhibitors in the brain of mice subjected to ischaemic stroke

Matrix metalloproteinases (MMPs) are a family of more than twenty secreted and cell-surface endopeptidases. Among them, MMP2, MMP3 and MMP9 are involved in blood-brain barrier injury and neuronal death after cerebral ischaemia. On the other hand, very little is known about the expression of the other secreted MMPs. Herein, we compared the global changes in MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP12 and MMP13, and their endogenous inhibitors TIMP1 and TIMP2, both at the mRNA and protein levels, during the hyperacute (6 h), acute (24 h) and subacute (72 h) stages following transient focal cerebral ischaemia and treatment with recombinant tissue plasminogen activator (rtPA). We observed a significant increase in MMP1, MMP2, MMP9, MMP10, MMP13 and TIMP1 levels during the acute stage of reperfusion, which was further amplified during the subacute stage for MMP1, MMP2, MMP10 and TIMP1. In general, no change of MMP3, MMP7, MMP8, MMP12 and TIMP2 was observed. However, rtPA treatment induced a rapid increase in MMP1/TIMP2, MMP2/TIMP2, MMP8/TIMP2 and MMP9/TIMP2 ratios during the hyperacute stage of reperfusion compared to saline treatment, which may have potential implications in the early disruption of the blood-brain barrier after rtPA treatment.

[Significance of comprehensive gene expression analysis for evaluation of biological effects of manufactured nanomaterials]

The industrial applications of manufactured nanomaterials (MNs) are expected to be extended to next-generation devices. On the other hand, concern over the effects of MNs on human health has risen owing to advances in the development of nanotechnology. Indeed, little is known about the mechanism of action of MNs. The New Energy and Industrial Technology Development Organization of Japan (NEDO) launched a new research project entitled "Evaluating risks associated with manufactured nanomaterials (P10024)" in 2006. The project demonstrated no adverse effects of MN inhalation exposure on the rat lungs, as determined by histopathological examination and bronchoalveolar lavage (BAL) fluid analysis. In parallel with this research, we have performed comparative gene expression analysis using DNA microarrays in rat lungs after inhalation exposure (4 weeks, 6 hours a day, 5 days a week) to single-wall nanotubes (SWCNTs), multiwall nanotubes (MWCNTs), C<inf>60</inf> fullerene and ultrafine nickel oxide particles (Uf-NiO) as reference materials for the purpose of gaining insights into the molecular events following the exposure. In this review, we introduce an outline of the project, and discuss about the significance of comparative gene expression analysis for evaluation of the biological effects of MNs.

Synthesis of two new alkyne-bearing linkers used for the preparation of siRNA for labeling by click chemistry with fluorine-18

Oligonucleotides (ONs) and more particularly siRNAs are promising drugs but their pharmacokinetics and biodistribution are widely unknown. Positron Emission Tomography (PET) using fluorine-18 is a suitable technique to quantify these biological processes. Click chemistry (Huisgen cycloaddition) is the current method for labeling siRNA. In order to study the influence of a linker bearing by [(18)F] labeled ONs, on the in vivo pharmacokinetic and metabolism, we have developed two modified ONs by two new linkers. Here we report the synthesis of two alkyne-bearing linkers, the incorporation onto a ONs and the conjugation by click chemistry with a [(18)F] prosthetic group.

Elastin in asthma

Extracellular matrix is generally increased in asthma, causing thickening of the airways which may either increase or decrease airway responsiveness, depending on the mechanical requirements of the deposited matrix. However, in vitro studies have shown that the altered extracellular matrix produced by asthmatic airway smooth muscle cells is able to induce increased proliferation of non-asthmatic smooth muscle cells, which is a process believed to contribute to airway hyper-responsiveness in asthma. Elastin is an extracellular matrix protein that is altered in asthmatic airways, but there has been no systematic investigation of the functional effect of these changes. This review reveals divergent reports of the state of elastin in the airway wall in asthma. In some layers of the airway it has been described as increased, decreased and/or fragmented, or unchanged. There is also considerable evidence for an imbalance of matrix metalloproteinases, which degrade elastin, and their respective inhibitors the tissue inhibitors of metalloproteinases, which collectively help to explain observations of both increased elastin and elastin fragments. A loss of lung elastic recoil in asthma suggests a mechanical role for disordered elastin in the aetiology of the disease, but extensive studies of elastin in other tissues show that elastin fragments elicit cellular effects such as increased proliferation and inflammation. This review summarises the current understanding of the role of elastin in the asthmatic airway.

The emerging role of microRNAs in asthma

Asthma is a common chronic airways disease that worldwide affects people from all ethnic backgrounds. MicroRNAs (miRNAs) are small non-coding RNAs of 18-25 nucleotides that have been shown to regulate gene expression via the RNA interference pathway and found to play fundamental roles in diverse biological and pathological processes. Intriguingly, changes in the expression of several miRNAs are associated with development of asthma. In this review, we summarize the current understanding of the role of miRNAs in asthma to both better understand the pathogenesis of this disease and aid in the formulation of more effective therapeutic strategies.

General method for labeling siRNA by click chemistry with fluorine-18 for the purpose of PET imaging

The alkyne-azide Cu(I)-catalyzed Huisgen cycloaddition, a click-type reaction, was used to label a double-stranded oligonucleotide (siRNA) with fluorine-18. An alkyne solid support CPG for the preparation of monostranded oligonucleotides functionalized with alkyne has been developed. Two complementary azide labeling agents (1-(azidomethyl)-4-[(18)F]fluorobenzene) and 1-azido-4-(3-[(18)F]fluoropropoxy)benzene have been produced with 41% and 35% radiochemical yields (decay-corrected), respectively. After annealing with the complementary strand, the siRNA was directly labeled by click chemistry with [(18)F]fluoroazide to produce the [(18)F]-radiolabeled siRNA with excellent radiochemical yield and purity.

Association of a functional polymorphism in the matrix metalloproteinase-12 promoter region with systemic sclerosis in an Italian population

OBJECTIVE

To investigate the possible implication of the matrix metalloproteinase-12 (MMP-12) gene in the genetic predisposition to systemic sclerosis (SSc) susceptibility and clinical phenotype.

METHODS

The MMP-12 rs2276109 A/G functional polymorphism was selected as a genetic marker and genotyped by polymerase chain reaction-restriction fragment length polymorphism assay in 513 unrelated subjects of Italian white ancestry: 250 patients with SSc [146 limited cutaneous SSc (lcSSc), 104 diffuse cutaneous SSc (dcSSc)] and 263 healthy individuals.

RESULTS

A significant difference was observed in MMP-12 rs2276109 genotype distribution between patients with SSc and controls (p = 0.0003), and between lcSSc and dcSSc (p = 0.003). The A allele frequency was significantly higher in patients with SSc than in controls (p = 0.0002), and higher in dcSSc than in lcSSc (p = 0.003). After adjustment for age and sex, the homozygosity for the A allele significantly influenced the predisposition to SSc and to dcSSc (OR 2.44, 95% CI 1.61-3.71, p < 0.0001; OR 4.69, 95% CI 2.36-9.33, p < 0.0001, respectively). A trend toward an association between the AA genotype and lcSSc was observed (p = 0.06). The homozygosity for the A allele was also significantly and independently associated with antitopoisomerase I antibody positivity (OR 6.39, 95% CI 2.18-18.76, p = 0.001) and interstitial lung disease (OR 2.94, 95% CI 1.25-6.95, p = 0.01).

CONCLUSION

The MMP-12 rs2276109 gene polymorphism may contribute to susceptibility to SSc, and in particular to dcSSc and pulmonary fibrosis.

Possible involvements of nuclear factor-kappa B and activator protein-1 in the tumor necrosis factor-alpha-induced upregulation of matrix metalloproteinase-12 in human alveolar epithelial A549 cell line

Matrix metalloproteinase-12 (MMP-12) has been suggested to play an important role in airway inflammatory diseases. Tumor necrosis factor-alpha (TNF-alpha) is known to cause an upregulation of MMP-12 via an activation of activator protein-1 (AP-1) in monocytes. In the present study, we investigated the effect of TNF-alpha on the expressions of MMP-12 in airway epithelial cells, one of the sources of MMP-12 in the airway, and its underlying mechanism. MMP-12 mRNA and protein expressions induced by TNF-alpha in the absence or presence of BMS-345541 (a selective IkappaB kinase inhibitor) or SP600125 [a selective c-Jun N-terminal kinase (JNK) inhibitor] were measured by quantitative real-time PCR and Western blotting, respectively. Furthermore, siRNAs for p65 and JNK2 were used to confirm the involvements of nuclear factor-kappaB (NF-kappaB) and AP-1 in the MMP-12 mRNA expression induced by TNF-alpha in A549 cells. Both MMP-12 mRNA and protein were upregulated by the treatment with TNF-alpha in time- and concentration-dependent manners. Both BMS-345541 and SP600125 inhibited the upregulation of MMP-12 induced by TNF-alpha. Furthermore, both the depletion of p65 and JNK2 by siRNAs significantly attenuated the upregulation of MMP-12 induced by TNF-alpha. These findings suggest that both NF-kappaB and JNK / AP-1 pathways are important for the MMP-12 upregulation induced by TNF-alpha in A549 cells.

Identification of an orally efficacious matrix metalloprotease 12 inhibitor for potential treatment of asthma

MMP-12 plays a significant role in airway inflammation and remodeling. Increased expression and production of MMP-12 have been observed in the lungs of asthmatic patients. Compound 27 was identified as a potent and selective MMP-12 inhibitor possessing good physicochemical properties. In pharmacological studies, the compound was orally efficacious in an MMP-12 induced ear-swelling inflammation model in the mouse with a good dose response. This compound also exhibited oral efficacy in a naturally Ascaris-sensitized sheep asthma model showing significant inhibition of the late phase response to allergen challenge. This compound has been considered for further development as a treatment therapy for asthma.