Expression analysis of the entire MMP and TIMP gene families during mouse tissue development

Epigenetic therapeutics attenuate kidney injury and fibrosis by restoring the expression of epigenetically reprogrammed fibrogenic genes and signaling pathways

Kidney fibrosis is a commonly observed pathological condition during development of chronic kidney disease. Therapeutic options currently available are effective only in slowing the progression of kidney fibrosis and there is no cure for this disease. Aberrant expression and excessive accumulation of extracellular matrix (ECM) proteins in the peritubular space is a characteristic pathological feature of fibrotic kidney. However, the molecular basis of aberrant regulation of fibrotic genes in kidneys is not clear. In this context, this study aimed to evaluate the role of epigenetic reprogramming in kidney fibrosis. Folic acid (FA)-induced acute kidney injury (AKI) and kidney fibrosis in mice as an in vivo model and long-term arsenic or FA-exposed fibrogenic HK-2 cells as an in vitro model were used to evaluate the role of DNA methylation and histone modifications in fibrosis. DNA demethylating agent 5aza2 deoxycytidine (5-aza-2-dC) and histone deacetylase inhibitor Trichostatin A (TSA) were used to treat FA-injected mice. Results of histopathological and immunofluorescence staining of kidney tissue, serum albumin- creatinine levels, body weight, and gene expression analysis revealed significant protective effects of 5-aza-2-dC and TSA in FA-induced AKI and fibrosis. Insignificant change in the expression of N-cadherin whereas a significant decrease in E-cadherin as well as an increase in the expression of Vimentin and α-SMA suggest partial EMT associated with fibrosis. Aberrant expression of epithelial-mesenchymal-transition (EMT) and ECM-regulators (MMP2, Smad7, and TIMP3) as well as fibrogenic signaling pathways (Notch, TGF-beta, and Wnt signaling), and their restoration by 5-aza-2-dC and TSA treatments suggest epigenetic reprogramming of these genes and signaling pathways during FA-induced fibrosis. In summary, this study provides new information on the role of epigenetic reprogramming of fibrogenic genes and signaling pathways during the development of kidney fibrosis. Attenuation of fibrosis after 5-aza-2-dC and TSA treatments suggest the promise of these epigenetic-based therapeutics in the clinical management of this disease.

TIMP-2 Promotes Wound Healing by Suppressing Matrix Metalloproteinases and Inflammatory Cytokines in Corneal Epithelial Cells

Tissue inhibitors of metalloproteinases (TIMPs) modulate extracellular matrix (ECM) remodeling for maintaining homeostasis and promoting cell migration and proliferation. Pathological conditions can alter TIMP homeostasis and aggravate disease progression. The roles of TIMPs have been studied in tissue-related disorders; however, their contributions to tissue repair during corneal injury are undefined. Here, the TIMP expression in human corneal epithelial (HCLE) cells under homeostatic and inflammatory milieus was profiled to examine their contribution to the healing of injured cornea epithelia. Transcriptionally, TIMP-2 was highly expressed in HCLE when stimulated with 100 ng/mL IL-1β or scratch-wounded. Unlike TIMP-1, recombinant TIMP-2 (rTIMP-2) significantly promoted epithelial cell wound closure compared to untreated and TIMP-2-neutralizing conditions. At 12 hours, the Ki-67+ cells significantly increased 3-fold compared to untreated cells, suggesting that rTIMP-2 is associated with cell proliferation. Furthermore, rTIMP-2 treatment significantly suppressed inflammatory cytokine expression (IL-1β, IL-6, IL-8, and TNFα) and injury-induced matrix metalloproteinases (MMP-1, -2, -3, -9, -10, and -13). Topical treatment of injured mouse cornea with 0.1 mg/mL rTIMP-2 significantly promoted corneal re-epithelialization and improved tissue integrity. The treatment suppressed the expression of inflammatory cytokines and MMPs, as well as the infiltration of neutrophils at the injury site. These findings indicate that TIMP-2 promotes faster wound healing by suppressing injury-induced inflammation and MMP expression, suggesting a potential therapeutic target for corneal wound management.

The causal relationship between 91 inflammatory cytokines and Gestational Diabetes Mmellitus: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Gestational Diabetes Mellitus (GDM) poses significant risks to maternal and fetal health, yet its precise etiology remains unclear. Observational studies have demonstrated a link between specific inflammatory cytokines and the occurrence of GDM, but the causal relationships remain uncertain.

METHODS

Utilizing publicly accessible genetic data, we performed a bidirectional two-sample mendelian randomization (MR) analysis to elucidate the causal association between 91 inflammatory cytokines and GDM. Sensitivity analysis was carried out to evaluate the robustness, heterogeneity, and potential presence of horizontal pleiotropy within the results.

RESULTS

Elevated levels of Interleukin-7 (IL7) and Neurturin (NRTN) (OR=1.104, 95 % CI=1.003-1.216, p = 0.042; OR=1.102, 95 % CI=1.023-1.187, p = 0.010), along with decreased levels of Glial cell line-derived neurotrophic factor (GDNF), Interleukin-12 subunit beta (IL12β), and Interleukin-20 (IL20) (OR=0.911, 95 % CI=0.849-0.979, p = 0.010;OR=0.955, 95 % CI=0.916-0.996, p = 0.033; OR=0.892, 95 % CI=0.819-0.971, p = 0.008), are associated with increased GDM risk. Additionally, GDM occurrence correlates with increased Matrix metalloproteinase-10 (MMP-10) and decreased Interleukin-20 receptor subunit alpha (IL-20Rα) levels (OR=1.042, 95 % CI=1.002-1.084, p = 0.038; OR=0.949, 95 % CI=0.909-0.992, p = 0.021). Sensitivity analyses detected no significant heterogeneity or pleiotropy.

CONCLUSION

This study has clarified the causal link between inflammatory cytokines and GDM, thereby enhancing our comprehension of the potential mechanisms involved in GDM pathogenesis. These findings offer new insights into the etiology, diagnosis, and therapeutic strategies for GDM.

Endothelial Chromatin-Remodeling Enzymes Regulate the Production of Critical ECM Components During Murine Lung Development

BACKGROUND

The chromatin-remodeling enzymes BRG1 (brahma-related gene 1) and CHD4 (chromodomain helicase DNA-binding protein 4) independently regulate the transcription of genes critical for vascular development, but their coordinated impact on vessels in late-stage embryos has not been explored.

METHODS

In this study, we genetically deleted endothelial Brg1 and Chd4 in mixed background mice (Brg1fl/fl;Chd4fl/fl;VE-Cadherin-Cre), and littermates that were negative for Cre recombinase were used as controls. Tissues were analyzed by immunostaining, immunoblot, and flow cytometry. Quantitative reverse transcription polymerase chain reaction was used to determine gene expression, and chromatin immunoprecipitation revealed gene targets of BRG1 and CHD4 in cultured endothelial cells.

RESULTS

We found Brg1/Chd4 double mutants grew normally but died soon after birth with small and compact lungs. Despite having normal cellular composition, distal air sacs of the mutant lungs displayed diminished ECM (extracellular matrix) components and TGFβ (transforming growth factor-β) signaling, which typically promotes ECM synthesis. Transcripts for collagen- and elastin-related genes and the TGFβ ligand Tgfb1 were decreased in mutant lung endothelial cells, but genetic deletion of endothelial Tgfb1 failed to recapitulate the small lungs and ECM defects seen in Brg1/Chd4 mutants. We instead found several ECM genes to be direct targets of BRG1 and CHD4 in cultured endothelial cells.

CONCLUSIONS

Collectively, our data highlight essential roles for endothelial chromatin-remodeling enzymes in promoting ECM deposition in the distal lung tissue during the saccular stage of embryonic lung development.

Development and Characterization of a Novel FVB-PrkdcR2140C Mouse Model for Adriamycin-Induced Nephropathy

The Adriamycin (ADR) nephropathy model, which induces podocyte injury, is limited to certain mouse strains due to genetic susceptibilities, such as the PrkdcR2140C polymorphism. The FVB/N strain without the R2140C mutation resists ADR nephropathy. Meanwhile, a detailed analysis of the progression of ADR nephropathy in the FVB/N strain has yet to be conducted. Our research aimed to create a novel mouse model, the FVB-PrkdcR2140C, by introducing PrkdcR2140C into the FVB/NJcl (FVB) strain. Our study showed that FVB-PrkdcR2140C mice developed severe renal damage when exposed to ADR, as evidenced by significant albuminuria and tubular injury, exceeding the levels observed in C57BL/6J (B6)-PrkdcR2140C. This indicates that the FVB/N genetic background, in combination with the R2140C mutation, strongly predisposes mice to ADR nephropathy, highlighting the influence of genetic background on disease susceptibility. Using RNA sequencing and subsequent analysis, we identified several genes whose expression is altered in response to ADR nephropathy. In particular, Mmp7, Mmp10, and Mmp12 were highlighted for their differential expression between strains and their potential role in influencing the severity of kidney damage. Further genetic analysis should lead to identifying ADR nephropathy modifier gene(s), aiding in early diagnosis and providing novel approaches to kidney disease treatment and prevention.

BEaTS-β: an open-source electromechanical bioreactor for simulating human cardiac disease conditions

Heart disease remains the leading cause of worldwide mortality. Although the last decades have broadened our understanding of the biology behind the pathologies of heart disease, ex vivo systems capable of mimicking disease progression and abnormal heart function using human cells remain elusive. In this contribution, an open-access electromechanical system (BEaTS-β) capable of mimicking the environment of cardiac disease is reported. BEaTS-β was designed using computer-aided modeling to combine tunable electrical stimulation and mechanical deformation of cells cultured on a flexible elastomer. To recapitulate the clinical scenario of a heart attack more closely, in designing BEaTS-β we considered a device capable to operate under hypoxic conditions. We tested human induced pluripotent stem cell-derived cardiomyocytes, fibroblasts, and coronary artery endothelial cells in our simulated myocardial infarction environment. Our results indicate that, under simulated myocardium infarction, there was a decrease in maturation of cardiomyocytes, and reduced survival of fibroblasts and coronary artery endothelial cells. The open access nature of BEaTS-β will allow for other investigators to use this platform to investigate cardiac cell biology or drug therapeutic efficacy in vitro under conditions that simulate arrhythmia and/or myocardial infarction.

Involvement of metalloproteinase and nitric oxide synthase/nitric oxide mechanisms in early decidual angiogenesis-vascularization of normal and experimental pathological mouse placenta related to maternal alcohol exposure

Successful pregnancy for optimal fetal growth requires adequate early angiogenesis and remodeling of decidual spiral arterioles during placentation. Prior to the initiation of invasion and endothelial replacement by trophoblasts, interactions between decidual stromal cells and maternal leukocytes, such as uterine natural killer cells and macrophages, play crucial roles in the processes of early maternal vascularization, such as proliferation, apoptosis, migration, differentiation, and matrix and vessel remodeling. These placental angiogenic events are highly dependent on the coordination of several mechanisms at the early maternal-fetal interface, and one of them is the expression and activity of matrix metalloproteinases (MMPs) and endothelial nitric oxide synthases (NOSs). Inadequate balances of MMPs and nitric oxide (NO) are involved in several placentopathies and pregnancy complications. Since alcohol consumption during gestation can affect fetal growth associated with abnormal placental development, recently, we showed, in a mouse model, that perigestational alcohol consumption up to organogenesis induces fetal malformations related to deficient growth and vascular morphogenesis of the placenta at term. In this review, we summarize the current knowledge of the early processes of maternal vascularization that lead to the formation of the definitive placenta and the roles of angiogenic MMP and NOS/NO mechanisms during normal and altered early gestation in mice. Then, we propose hypothetical defective decidual cellular and MMP and NOS/NO mechanisms involved in abnormal decidual vascularization induced by perigestational alcohol consumption in an experimental mouse model. This review highlights the important roles of decidual cells and their MMP and NOS balances in the physiological and pathophysiological early maternal angiogenesis-vascularization during placentation in mice.

Whole organism profiling of the Timp gene family

Tissue inhibitor of metalloproteinases (TIMPs/Timps) are an endogenous family of widely expressed matrisome-associated proteins that were initially identified as inhibitors of matrix metalloproteinase activity (Metzincin family proteases). Consequently, TIMPs are often considered simply as protease inhibitors by many investigators. However, an evolving list of new metalloproteinase-independent functions for TIMP family members suggests that this concept is outdated. These novel TIMP functions include direct agonism/antagonism of multiple transmembrane receptors, as well as functional interactions with matrisome targets. While the family was fully identified over two decades ago, there has yet to be an in-depth study describing the expression of TIMPs in normal tissues of adult mammals. An understanding of the tissues and cell-types that express TIMPs 1 through 4, in both normal and disease states are important to contextualize the growing functional capabilities of TIMP proteins, which are often dismissed as non-canonical. Using publicly available single cell RNA sequencing data from the Tabula Muris Consortium, we analyzed approximately 100,000 murine cells across eighteen tissues from non-diseased organs, representing seventy-three annotated cell types, to define the diversity in Timp gene expression across healthy tissues. We describe the unique expression profiles across tissues and organ-specific cell types that all four Timp genes display. Within annotated cell-types, we identify clear and discrete cluster-specific patterns of Timp expression, particularly in cells of stromal and endothelial origins. RNA in-situ hybridization across four organs expands on the scRNA sequencing analysis, revealing novel compartments associated with individual Timp expression. These analyses emphasize a need for specific studies investigating the functional significance of Timp expression in the identified tissues and cell sub-types. This understanding of the tissues, specific cell types and microenvironment conditions in which Timp genes are expressed adds important physiological context to the growing array of novel functions for TIMP proteins.

Protective Effects of Circulating TIMP3 on Coronary Artery Disease and Myocardial Infarction: A Mendelian Randomization Study

Tissue inhibitor of metalloproteinase 3 (TIMP3) is a protease with high expression levels in the heart and plays an essential role in extracellular matrix turnover by maintaining equilibrium with matrix metalloproteinases. Considerable data in experimental models have demonstrated a protective role of TIMP3 in coronary artery disease (CAD) and myocardial infarction (MI). However, causality remains unexplored in population studies. Here, we sought to decipher the potential causality between TIMP3 and CAD/MI using the Mendelian randomization (MR) method. We extracted summary−level datasets for TIMP3 and CAD/MI from the genome−wide association studies performed in the KORA study and CARDIoGRAMplusC4D consortium, respectively. Seven independent SNPs were obtained as instrumental variables for TIMP3. The MR analyses were replicated using FinnGen datasets, and the main results were combined in meta−analyses. Elevated genetically predicted serum TIMP3 levels were causally associated with a lower risk of CAD [odds ratio (OR), 0.97; 95% confidence interval (CI), 0.95, 0.98; p = 5.29 × 10⁻⁵] and MI (OR, 0.96; 95% CI, 0.95, 0.98; p = 3.85 × 10⁻⁵). The association patterns persisted in the meta−analyses combining the different datasets (CAD: OR, 0.97; 95% CI, 0.96, 0.99; p = 4.37 × 10⁻⁵; MI: OR, 0.97; 95% CI, 0.96, 0.99; p = 9.96 × 10⁻⁵) and was broadly consistent across a set of complementary analyses. Evidence of heterogeneity and horizontal pleiotropy was limited for all associations considered. In conclusion, this MR study supports inverse causal associations between serum TIMP3 and the risk of CAD and MI. Strategies for raising TIMP3 levels may offer new avenues for the prevention strategies of atherosclerotic cardiovascular diseases.

Synthesis and In Vivo Evaluation of a Site-specifically Labeled Radioimmunoconjugate for Dual-Modal (PET/NIRF) Imaging of MT1-MMP in Sarcomas

Bone sarcomas are devastating primary bone cancers that mostly affect children, young adults, and the elderly. These aggressive tumors are associated with poor survival, and surgery remains the mainstay of treatment. Surgical planning is increasingly informed by positron emission tomography (PET), and tumor margin identification during surgery is aided by near-infrared fluorescence (NIRF) imaging, yet these investigations are confounded by probes that lack specificity for sarcoma biomarkers. We report the development of a dual-modal (PET/NIRF) immunoconjugate ([⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW) that targets MT1-MMP, a matrix metalloproteinase overexpressed in high-grade sarcomas. [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW was synthesized via site-specific chemoenzymatic glycan modification, characterized, and isolated in high specific activity and radiochemical purity. Saturation binding and immunoreactivity assays indicated only minor perturbation of binding properties. A novel mouse model of dedifferentiated chondrosarcoma based on intrafemoral inoculation of HT1080 WT or KO cells (high and low MT1-MMP expression, respectively) was used to evaluate target binding and biodistribution. Fluorescence and Cerenkov luminescence images of [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW showed preferential uptake in HT1080 WT tumors. Ex vivo gamma counting revealed that uptake in MT1-MMP-positive tumors was significantly higher than that in control groups. Taken together, [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW is a promising dual-modal sarcoma imaging agent for pre-operative surgical planning and intraoperative surgical guidance.

OUP accepted manuscript

Tissue inhibitors of metalloproteinases (TIMPs) are a conserved family of proteins that were originally identified as endogenous inhibitors of matrixin and adamalysin endopeptidase activity. The matrixins and adamalysins are the major mediators of extracellular matrix (ECM) turnover, thus making TIMPs important regulators of ECM structure and composition. Despite their high sequence identity and relative redundancy in inhibitory profiles, each TIMP possesses unique biological characteristics that are independent of their regulation of metalloproteinase activity. As our understanding of TIMP biology has evolved, distinct roles have been assigned to individual TIMPs in cancer progression. In this respect, data regarding TIMP2's role in cancer have borne conflicting reports of both tumor suppressor and, to a lesser extent, tumor promoter functions. TIMP2 is the most abundant TIMP family member, prevalent in normal and diseased mammalian tissues as a constitutively expressed protein. Despite its apparent stable expression, recent work highlights how TIMP2 is a cell stress-induced gene product and that its biological activity can be dictated by extracellular posttranslational modifications. Hence an understanding of TIMP2 molecular targets, and how its biological functions evolve in the progressing tumor microenvironment may reveal new therapeutic opportunities. In this review, we discuss the continually evolving functions of TIMP proteins, future perspectives in TIMP research, and the therapeutic utility of this family, with a particular focus on TIMP2.

Modulation of Cardiac Fibrosis in and Beyond Cells

The extracellular matrix (ECM) plays important roles in maintaining physiological structure and functions of various tissues and organs. Cardiac fibrosis is the excess deposition of ECM, including both fibrillar (collagens I and III) and non-fibrillar proteins. Characteristics of fibrosis can vary depending on the pathology, with focal fibrosis occurring following myocardial infarction (MI), and diffuse interstitial and perivascular fibrosis mainly in non-ischemic heart diseases. Compliance of the fibrotic tissue is significantly lower than the normal myocardium, and this can compromise the diastolic, as well as systolic dysfunction. Therefore, strategies to combat cardiac fibrosis have been investigated. Upon injury or inflammation, activated cardiac fibroblasts (myofibroblasts) produce more ECM proteins and cause fibrosis. The activation could be inhibited or the myofibroblasts could be ablated by targeting their specific expressed proteins. Modulation of tissue inhibitors of metalloproteinases (TIMPs) and moderate exercise can also suppress cardiac fibrosis. More recently, sex differences in cardiac fibrosis have come to light with differential fibrotic response in heart diseases as well as in fibroblast functions in vitro. This mini-review discusses recent progress in cardiac fibroblasts, TIMPs, sex differences and exercise in modulation of cardiac fibrosis.

Dynamic Expression of Membrane Type 1-Matrix Metalloproteinase (Mt1-mmp/Mmp14) in the Mouse Embryo

MT1-MMP/MMP14 belongs to a subgroup of the matrix metalloproteinases family that presents a transmembrane domain, with a cytosolic tail and the catalytic site exposed to the extracellular space. Deficient mice for this enzyme result in early postnatal death and display severe defects in skeletal, muscle and lung development. By using a transgenic line expressing the LacZ reporter under the control of the endogenous Mt1-mmp promoter, we reported a dynamic spatiotemporal expression pattern for Mt1-mmp from early embryonic to perinatal stages during cardiovascular development and brain formation. Thus, Mt1-mmp shows expression in the endocardium of the heart and the truncus arteriosus by E8.5, and is also strongly detected during vascular system development as well as in endothelial cells. In the brain, LacZ reporter expression was detected in the olfactory bulb, the rostral cerebral cortex and the caudal mesencephalic tectum. LacZ-positive cells were observed in neural progenitors of the spinal cord, neural crest cells and the intersomitic region. In the limb, Mt1-mmp expression was restricted to blood vessels, cartilage primordium and muscles. Detection of the enzyme was confirmed by Western blot and immunohistochemical analysis. We suggest novel functions for this metalloproteinase in angiogenesis, endocardial formation and vascularization during organogenesis. Moreover, Mt1-mmp expression revealed that the enzyme may contribute to heart, muscle and brain throughout development.

miR-496/MMP10 Is Involved in the Proliferation of IL-1β-Induced Fibroblast-Like Synoviocytes Via Mediating the NF-κB Signaling Pathway

Rheumatoid arthritis (RA) is a common chronic autoimmune disease featured by synovial inflammation. miR-496 is closely involved in various pathologic conditions. However, its role in RA has not yet been elucidated. Expression of miR-496 and MMP10 was determined based on the clinical samples with RA retrieved from the Gene Expression Omnibus (GEO) datasets. In vitro model of RA was constructed in MH7A cells stimulated by IL-1β (10 ng/mL). Cell counting kit 8 (CCK-8) and flow cytometry experiments were implemented to investigate the cell viability and apoptosis rate of MH7A cells. TargetScan was applied to identify the targets of miR-496, and the regulation of miR-496 on MMP10 expression was validated by a dual-luciferase reporter gene assay. qRT-PCR and western blot analyses were conducted to examine the expression. miR-496 expression was decreased in RA tissues and MH7A cells after IL-1β treatment. Overexpression of miR-496 significantly inhibited IL-1β-treated MH7A cell viability. MMP10 was identified as a target of miR-496 and its expression was negatively regulated by miR-496. The effects of miR-496 on MH7A cell proliferation and apoptosis were reversed by MMP10. The activity of NF-κB pathway was associated with the miR-496/MMP10 axis in IL-1β-stimulated MH7A cells. To summarize, this study demonstrated that miR-496 can impair the proliferative ability and facilitate the apoptosis of IL-1β-treated MH7A through regulating MMP10 expression and NF-κB signaling pathway.

Emerging roles of MT-MMPs in embryonic development

Membrane-type matrix metalloproteinases (MT-MMPs) are cell membrane-tethered proteinases that belong to the family of the MMPs. Apart from their roles in degradation of the extracellular milieu, MT-MMPs are able to activate through proteolytic processing at the cell surface distinct molecules such as receptors, growth factors, cytokines, adhesion molecules, and other pericellular proteins. Although most of the information regarding these enzymes comes from cancer studies, our current knowledge about their contribution in distinct developmental processes occurring in the embryo is limited. In this review, we want to summarize the involvement of MT-MMPs in distinct processes during embryonic morphogenesis, including cell migration and proliferation, epithelial-mesenchymal transition, cell polarity and branching, axon growth and navigation, synapse formation, and angiogenesis. We also considered information about MT-MMP functions from studies assessed in pathological conditions and compared these data with those relevant for embryonic development.

Allergen-Specific Treg Cells Upregulated by Lung-Stage S. japonicum Infection Alleviates Allergic Airway Inflammation

Schistosoma japonicum infection showed protective effects against allergic airway inflammation (AAI). However, controversial findings exist especially regarding the timing of the helminth infection and the underlying mechanisms. Most previous studies focused on understanding the preventive effect of S. japonicum infection on asthma (infection before allergen sensitization), whereas the protective effects of S. japonicum infection (allergen sensitization before infection) on asthma were rarely investigated. In this study, we investigated the protective effects of S. japonicum infection on AAI using a mouse model of OVA-induced asthma. To explore how the timing of S. japonicum infection influences its protective effect, the mice were percutaneously infected with cercaria of S. japonicum at either 1 day (infection at lung-stage during AAI) or 14 days before ovalbumin (OVA) challenge (infection at post–lung-stage during AAI). We found that lung-stage S. japonicum infection significantly ameliorated OVA-induced AAI, whereas post–lung-stage infection did not. Mechanistically, lung-stage S. japonicum infection significantly upregulated the frequency of regulatory T cells (Treg cells), especially OVA-specific Treg cells, in lung tissue, which negatively correlated with the level of OVA-specific immunoglobulin E (IgE). Depletion of Treg cells in vivo partially counteracted the protective effect of lung-stage S. japonicum infection on asthma. Furthermore, transcriptomic analysis of lung tissue showed that lung-stage S. japonicum infection during AAI shaped the microenvironment to favor Treg induction. In conclusion, our data showed that lung-stage S. japonicum infection could relieve OVA-induced asthma in a mouse model. The protective effect was mediated by the upregulated OVA-specific Treg cells, which suppressed IgE production. Our results may facilitate the discovery of a novel therapy for AAI.

Legumain is a predictor of all-cause mortality and potential therapeutic target in acute myocardial infarction

The prognostic impact of extracellular matrix (ECM) modulation and its regulatory mechanism post-acute myocardial infarction (AMI), require further clarification. Herein, we explore the predictive role of legumain—which showed the ability in ECM degradation—in an AMI patient cohort and investigate the underlying mechanisms. A total of 212 AMI patients and 323 healthy controls were enrolled in the study. Moreover, AMI was induced in mice by permanent ligation of the left anterior descending artery and fibroblasts were adopted for mechanism analysis. Based on the cut-off value for the receiver-operating characteristics curve, AMI patients were stratified into low (n = 168) and high (n = 44) plasma legumain concentration (PLG) groups. However, PLG was significantly higher in AMI patients than that in the healthy controls (median 5.9 μg/L [interquartile range: 4.2–9.3 μg/L] vs. median 4.4 μg/L [interquartile range: 3.2–6.1 μg/L], P < 0.001). All-cause mortality was significantly higher in the high PLG group compared to that in the low PLG group (median follow-up period, 39.2 months; 31.8% vs. 12.5%; P = 0.002). Multivariate Cox regression analysis showed that high PLG was associated with increased all-cause mortality after adjusting for clinical confounders (HR = 3.1, 95% confidence interval (CI) = 1.4–7.0, P = 0.005). In accordance with the clinical observations, legumain concentration was also increased in peripheral blood, and infarcted cardiac tissue from experimental AMI mice. Pharmacological blockade of legumain with RR-11a, improved cardiac function, decreased cardiac rupture rate, and attenuated left chamber dilation and wall thinning post-AMI. Hence, plasma legumain concentration is of prognostic value in AMI patients. Moreover, legumain aggravates cardiac remodelling through promoting ECM degradation which occurs, at least partially, via activation of the MMP-2 pathway.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Role of extra cellular proteins in gastric cancer progression and metastasis: an update

Background

Gastric cancer (GC) is one of the most common cancers in the world with a high ratio of mortality. Regarding the late diagnosis, there is a high ratio of distant metastasis among GC cases. Despite the recent progresses in therapeutic modalities, there is not still an efficient therapeutic method to increase survival rate of metastatic GC cases.

Main body

Apart from the various intracellular signaling pathways which are involved in tumor cell migration and metastasis, the local microenvironment is also a critical regulator of tumor cell migration. Indeed, the intracellular signaling pathways also exert their final metastatic roles through regulation of extra cellular matrix (ECM). Therefore, it is required to assess the role of extra cellular components in biology of GC.

Conclusion

In the present review, we summarize 48 of the significant ECM components including 17 ECM modifying enzymes, seven extracellular angiogenic factors, 13 cell adhesion and cytoskeletal organizers, seven matricellular proteins and growth factors, and four proteoglycans and extra cellular glycoproteins. This review paves the way of determination of a specific extra cellular diagnostic and prognostic panel marker for the GC patients.

MicroRNA-29a Exhibited Pro-Angiogenic and Anti-Fibrotic Features to Intensify Human Umbilical Cord Mesenchymal Stem Cells-Renovated Perfusion Recovery and Preventing against Fibrosis from Skeletal Muscle Ischemic Injury

This study was conducted to elucidate whether microRNA-29a (miR-29a) and/or together with transplantation of mesenchymal stem cells isolated from umbilical cord Wharton’s jelly (uMSCs) could aid in skeletal muscle healing and putative molecular mechanisms. We established a skeletal muscle ischemic injury model by injection of a myotoxin bupivacaine (BPVC) into gastrocnemius muscle of C57BL/6 mice. Throughout the angiogenic and fibrotic phases of muscle healing, miR-29a was considerably downregulated in BPVC-injured gastrocnemius muscle. Overexpressed miR-29a efficaciously promoted human umbilical vein endothelial cells proliferation and capillary-like tube formation in vitro, crucial steps for neoangiogenesis, whereas knockdown of miR-29a notably suppressed those endothelial functions. Remarkably, overexpressed miR-29a profitably elicited limbic flow perfusion and estimated by Laser Dopple. MicroRNA-29a motivated perfusion recovery through abolishing the tissue inhibitor of metalloproteinase (TIMP)-2, led great numbers of pro-angiogenic matrix metalloproteinases (MMPs) to be liberated from bondage of TIMP, thus reinforced vascular development. Furthermore, engrafted uMSCs also illustrated comparable effect to restore the flow perfusion and augmented vascular endothelial growth factors-A, -B, and -C expression. Notably, the combination of miR29a and the uMSCs treatments revealed the utmost renovation of limbic flow perfusion. Amplified miR-29a also adequately diminished the collagen deposition and suppressed broad-wide miR-29a targeted extracellular matrix components expression. Consistently, miR-29a administration intensified the relevance of uMSCs to abridge BPVC-aggravated fibrosis. Our data support that miR-29a is a promising pro-angiogenic and anti-fibrotic microRNA which delivers numerous advantages to endorse angiogenesis, perfusion recovery, and protect against fibrosis post injury. Amalgamation of nucleic acid-based strategy (miR-29a) together with the stem cell-based strategy (uMSCs) may be an innovative and eminent strategy to accelerate the healing process post skeletal muscle injury.

Metalloprotease inhibitor TIMP proteins control FGF-2 bioavailability and regulate skeletal growth

Saw et al. show via the combinatorial deletion of Timp family members in mice that metalloprotease regulation of FGF-2 is a crucial event in the chondrocyte maturation program, underlying the growth plate development and bone elongation responsible for attaining proper body stature.

Regulated growth plate activity is essential for postnatal bone development and body stature, yet the systems regulating epiphyseal fusion are poorly understood. Here, we show that the tissue inhibitors of metalloprotease (TIMP) gene family is essential for normal bone growth after birth. Whole-body quadruple-knockout mice lacking all four TIMPs have growth plate closure in long bones, precipitating limb shortening, epiphyseal distortion, and widespread chondrodysplasia. We identify TIMP/FGF-2/IHH as a novel nexus underlying bone lengthening where TIMPs negatively regulate the release of FGF-2 from chondrocytes to allow IHH expression. Using a knock-in approach that combines MMP-resistant or ADAMTS-resistant aggrecans with TIMP deficiency, we uncouple growth plate activity in axial and appendicular bones. Thus, natural metalloprotease inhibitors are crucial regulators of chondrocyte maturation program, growth plate integrity, and skeletal proportionality. Furthermore, individual and combinatorial TIMP-deficient mice demonstrate the redundancy of metalloprotease inhibitor function in embryonic and postnatal development.

Association Study between the Polymorphisms of Matrix Metalloproteinase (MMP) Genes and Idiopathic Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) refers to two or more consecutive pregnancy losses. It is estimated that fewer than 5% of women experience RPL. Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that play important roles in providing a safe and conducive environment for the stable development of the fetus. In this case-control study, we evaluated the associations between RPL and single nucleotide polymorphisms (SNPs) in MMP-8 and MMP-27. We recruited 375 Korean women with a history of RPL and 240 ethnically-matched healthy parous controls, and we performed genotyping for the MMP-8 rs2509013 C>T, MMP-8 rs11225395 G>A, and MMP-27 rs3809017 T>C polymorphisms. All SNPs were genotyped via the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay. In the genotype frequency analyses, the TT genotype of the MMP-8 rs2509013 C>T (age-adjusted odds ratio, 0.415; 95% confidence interval, 0.257–0.671; P = 0.0003) and TC genotype of MMP-27 rs3809017 T>C (age-adjusted odds ratio, 0.681; 95% confidence interval, 0.483–0.961; P = 0.029) were associated with decreased RPL susceptibility. Moreover, these trends were maintained in the haplotype and genotype combination analyses. Interestingly, amongst the RPL patients, higher levels of homocysteine (P = 0.042) and uric acid (P = 0.046) were associated with MMP-27 rs3809017 T>C. In conclusion, the two polymorphisms of MMP-8 and MMP-27 were significantly associated with RPL risk, both individually and in combination. Therefore, these two polymorphisms are potential biomarkers for RPL susceptibility.

Exosomes Derived from TIMP2-Modified Human Umbilical Cord Mesenchymal Stem Cells Enhance the Repair Effect in Rat Model with Myocardial Infarction Possibly by the Akt/Sfrp2 Pathway

Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) are a promising new therapeutic option for myocardial infarction (MI). The tissue matrix metalloproteinase inhibitor 2, also known as TIMP2, is a member of the tissue inhibitor family of metalloproteinases. Since TIMP2-mediated inhibition of matrix metalloproteinases (MMPs) is a key determinant of post-MI remodeling, we analyzed the therapeutic effects of exosomes derived from TIMP2-overexpressing hucMSCs (huc-exo^TIMP2) on the MI rat model. The huc-exo^TIMP2 significantly improved in vivo cardiac function as measured by echocardiography and promoted angiogenesis in MI injury. It also restricted extracellular matrix (ECM) remodeling, as indicated by the reduced collagen deposition. In addition, huc-exo^TIMP2 administration increased the in situ expression of the antiapoptotic Bcl-2 and decreased that of the proapoptotic Bax and pro-caspase-9 in the infracted myocardium. Meanwhile, huc-exo^TIMP2 upregulated superoxide dismutase (SOD) as well as glutathione (GSH) and decreased the malondialdehyde (MDA) level in MI models. In vitro huc-exo^TIMP2 pretreatment could inhibit H₂O₂-mediated H9C2-cardiomyocyte apoptosis and promote human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation, as well as decrease TGFβ-induced MMP2, MMP9, and α-SMA secretion by cardiac fibroblasts (CFs). Besides that, huc-exo^TIMP2 pretreatment also increased the expression of Akt phosphorylation in the infarcted myocardium, which may relate to a high level of secreted frizzled-related protein 2 (Sfrp2) in huc-exo^TIMP2, indicating a mechanistic basis of its action. Importantly, Sfrp2 knockdown in huc-exo^TIMP2 abrogated the protective effects. Taken together, huc-exo^TIMP2 improved cardiac function by alleviating MI-induced oxidative stress and ECM remodeling, partly via the Akt/Sfrp2 pathway.

Intratumoral fate of functional nanoparticles in response to microenvironment factor: Implications on cancer diagnosis and therapy

The extraordinary growth and progression of tumor require enormous nutrient and energy. Unregulated behaviors of cancer cell progressing and persistently change of tumor microenvironment (TME) which acts as the soil for cancer growth and metastasis are the ubiquitous features. The tumor microenvironment exhibits some unique features which differ with the normal tissues. While the nanoparticles get through the blood vessel leakage, they encounter immediately and interact directly with these microenvironment factors. These factors may inhibit the diffusion of nanoparticles from penetrating through the tumor, or induce the dissociation of nanoparticles. Different nanoparticles encountered with different intratumoral microenvironment factors end up in different way. Therefore, in this review, we first briefly introduced the formations, distributions, features of some intratumoral microenvironment, and their effects on the tumor progression. They include extracellular matrix (ECM), matrix metalloproteinases (MMPs), acidic/hypoxia environment, redox environment, and tumor associated macrophages (TAMs). We then exemplified how these factors interact with nanoparticles and emphasized the potentials and challenges of nanoparticle-based strategies facing in enhancing intratumoral penetration and tumor microenvironment remodeling. We hope to give a simple understanding of the interaction between these microenvironment factors and the nanoparticles, thus, favors the designing and constructing of more ideal functional nanoparticles.

Spatio-temporal expression profile of matrix metalloproteinase (Mmp) modulators Reck and Sparc during the rat ovarian dynamics

BACKGROUND

Matrix metalloproteinases (Mmps) and their tissue inhibitors (Timps) are widely recognized as crucial factors for extracellular matrix remodeling in the ovary and are involved in follicular growth, ovulation, luteinization, and luteolysis during the estrous cycle. Recently, several genes have been associated to the modulation of Mmps activity, including Basigin (Bsg), which induces the expression of Mmps in rat ovaries; Sparc, a TGF-β modulator that is related to increased expression of Mmps in cancer; and Reck, which is associated with Mmps inhibition. However, the expression pattern of Mmp modulators in ovary dynamics is still largely uncharacterized.

METHODS

To characterize the expression pattern of Mmps network members in ovary dynamics, we analyzed the spatio-temporal expression pattern of Reck and Sparc, as well as of Mmp2, Mmp9 and Mmp14 proteins, by immunohistochemistry (IHC), in pre-pubertal rat ovaries obtained from an artificial cycle induced by eCG/hCG, in the different phases of the hormone-induced estrous cycle. We also determined the gene expression profiles of Mmps (2, 9, 13 14), Timps (1, 2, 3), Sparc, Bsg, and Reck to complement this panel.

RESULTS

IHC analysis revealed that Mmp protein expression peaks at the early stages of folliculogenesis and ovulation, decreases during ovulation-luteogenesis transition and luteogenesis, increasing again during corpus luteum maintenance and luteolysis. The protein expression patterns of these metalloproteinases and Sparc were inverse relative to the pattern displayed by Reck. We observed that the gene expression peaks of Mmps inhibitors Reck and Timp2 were closely paraleled by Mmp2 and Mmp9 suppression. The opposite was also true: increased Mmp2 and Mmp9 expression was concomitant to reduced Reck and Timp2 levels.

CONCLUSION

Therefore, our results generate a spatio-temporal expression profile panel of Mmps and their regulators, suggesting that Reck and Sparc seem to play a role during ovarian dynamics: Reck as a possible inhibitor and Sparc as an inducer of Mmps.

Matrix metalloproteinases in emphysema

Several studies have implicated a causative role for specific matrix metalloproteinases (MMPs) in the development and progression of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) and its severe sequela, emphysema. However, the precise function of any given MMP in emphysema remains an unanswered question. Emphysema results from the degradation of alveolar elastin - among other possible mechanisms - a process that is often thought to be caused by elastolytic proteinases made by macrophages. In this article, we discuss the data suggesting, supporting, or refuting causative roles of macrophage-derived MMPs, with a focus on MMPs-7, -9, -10, -12, and 28, in both the human disease and mouse models of emphysema. Findings from experimental models suggest that some MMPs, such as MMP-12, may directly breakdown elastin, whereas others, particularly MMP-10 and MMP-28, promote the development of emphysema by influencing the proteolytic and inflammatory activities of macrophages.

Detection of Matrix Metalloproteinase Activity by Bioluminescence via Intein-Mediated Biotinylation of Luciferase

We report bioluminescence analysis of matrix metalloproteinase (MMP) activity in biological substances using a surface-bound luciferase probe. Intein-fused luciferase protein enables site-specific biotinylation of luciferase in the presence of N-terminus cysteine-biotin via intein-mediated splicing process, resulting in a strong association with high bioluminescence signal onto a NeutrAvidin-coated surface. When the peptide substrate for MMP-7 was inserted into a region between luciferase and intein, the biotinylated probe detected MMP-7 activity by cleaving the peptide, and surface-induced bioluminescence signal was strongly reduced in the MMP-secreted media or mouse tissue extracts, compared with that in MMP-deficient control set. Our approach is anticipated to be useful for generating biotinylated proteins and for their applications in diagnosing MMP activity in human diseases.

Molecular background of the regional lymph node metastasis of gastric cancer

Gastric cancer (GC) is one of the deadliest types of cancer in the world. Lymph node (LN) metastasis is a complex and malignant behavior of GC, involving a sequence of biological processes, including decreased adherence to adjacent cells, extracellular matrix (ECM) degradation and lymphatic channel permeation. LN metastasis is directly associated with the treatment response, local recurrence and long-term survival of patients with GC. Therefore, the molecular mechanisms of LN metastasis in GC development require further investigation. Recently, a large number of clinical studies have focused on the molecular mechanisms and biological markers of tumor invasion and metastasis. However, few articles have broadly summarized LN metastasis in GC, and the molecular mechanisms of LN metastasis are not yet fully understood. In the present review, the molecular mechanisms of LN metastasis in GC will be discussed, including the following aspects: Cell adhesion and movement, ECM degradation, new vessel formation, and molecular pattern differences between metastatic LNs and the primary tumor. This review may lead to a better understanding of LN metastasis in GC, and the identification of new diagnostic markers.

Mycobacterium tuberculosis subverts negative regulatory pathways in human macrophages to drive immunopathology

Tuberculosis remains a global pandemic and drives lung matrix destruction to transmit. Whilst pathways driving inflammatory responses in macrophages have been relatively well described, negative regulatory pathways are less well defined. We hypothesised that Mycobacterium tuberculosis (Mtb) specifically targets negative regulatory pathways to augment immunopathology. Inhibition of signalling through the PI3K/AKT/mTORC1 pathway increased matrix metalloproteinase-1 (MMP-1) gene expression and secretion, a collagenase central to TB pathogenesis, and multiple pro-inflammatory cytokines. In patients with confirmed pulmonary TB, PI3Kδ expression was absent within granulomas. Furthermore, Mtb infection suppressed PI3Kδ gene expression in macrophages. Interestingly, inhibition of the MNK pathway, downstream of pro-inflammatory p38 and ERK MAPKs, also increased MMP-1 secretion, whilst suppressing secretion of TH1 cytokines. Cross-talk between the PI3K and MNK pathways was demonstrated at the level of eIF4E phosphorylation. Mtb globally suppressed the MMP-inhibitory pathways in macrophages, reducing levels of mRNAs encoding PI3Kδ, mTORC-1 and MNK-1 via upregulation of miRNAs. Therefore, Mtb disrupts negative regulatory pathways at multiple levels in macrophages to drive a tissue-destructive phenotype that facilitates transmission.

Matrix-metalloproteinases as targets for controlled delivery in cancer: An analysis of upregulation and expression

While commonly known for degradation of the extracellular matrix, matrix metalloproteinases (MMPs) exhibit broad potential for use in targeting of bioactive and imaging agents in cancer treatment. MMPs are upregulated at all stages of expression in cancers. A comprehensive analysis of published literature on expression of all MMP subtypes at the genetic, protein, and activity levels in normal and diseased tissues indicate targeting applicability in a variety of cancers. This expression significantly increases at advanced cancer stages, providing an improved opportunity for controlled release in higher-stage patients. Since MMPs are integral at every stage of metastasis, MMP roles in cancer are discussed with a focus on MMP distribution and mobility within cells and tumors for cancer targeting applications. Several strategies for MMP utilization in targeting - such as matrix degradation, MMP cleavage, MMP binding, and MMP-induced environmental changes - are addressed.

TIMPs: versatile extracellular regulators in cancer

A compelling long-term goal of cancer biology is to understand the crucial players during tumorigenesis in order to develop new interventions. Here, we review how the four non-redundant tissue inhibitors of metalloproteinases (TIMPs) regulate the pericellular proteolysis of a vast range of matrix and cell surface proteins, generating simultaneous effects on tumour architecture and cell signalling. Experimental studies demonstrate the contribution of TIMPs to the majority of cancer hallmarks, and human cancers invariably show TIMP deregulation in the tumour or stroma. Of the four TIMPs, TIMP1 overexpression or TIMP3 silencing is consistently associated with cancer progression or poor patient prognosis. Future efforts will align mouse model systems with changes in TIMPs in patients, will delineate protease-independent TIMP function, will pinpoint therapeutic targets within the TIMP-metalloproteinase-substrate network and will use TIMPs in liquid biopsy samples as biomarkers for cancer prognosis.

tPA-MMP-9 Axis Plays a Pivotal Role in Mobilization of Endothelial Progenitor Cells from Bone Marrow to Circulation and Ischemic Region for Angiogenesis

We examined the role of tissue plasminogen activator- (tPA-) matrix metalloproteinase- (MMP-) 9 in mobilizing endothelial progenitor cells (EPCs) from bone marrow to circulation and critical limb ischemia (CLI) region. Male C57BL/6J mice having been irradiated were categorized into wild-type mice (WT) receiving WT bone marrow cell (BMC) transfusion (group 1), WT mice receiving MMP-9 knockout (MMP-9^−/−) BMC (group 2), MMP-9^−/− receiving MMP-9^−/− BMC (group 3), and MMP-9^−/− receiving WT BMC (group 4), each of which was subdivided into sham control (SC), CLI, SC-tPA, and CLI-tPA. In groups 1 and 4, by post-CLI 18 h and day 14, circulating EPC (C-kit+/CD31+, Sca-1+/KDR+) levels were highest in CLI-tPA subgroup. In groups 2 and 3, EPC levels did not differ among all subgroups. The EPC levels in bone marrow were higher in groups 2 and 3 than those in groups 1 and 4. By day 14, in animals with CLI, expression levels of proangiogenic factors (CXCR4, SDF-1α, and VEGF) showed similar trends as circulating EPC levels. Moreover, the number of infiltrated neutrophils and macrophages in quadriceps was higher in groups 1 and 4 than groups in 2 and 3. In conclusion, tPA-MMP-9 axis plays a crucial role in EPC mobilization and angiogenesis in experimental CLI.

Stromelysin-2 (MMP10) Moderates Inflammation by Controlling Macrophage Activation

Several members of the matrix metalloproteinase (MMP) family control a range of immune processes, such as leukocyte influx and chemokine activity. Stromelysin-2 (MMP10) is expressed by macrophages in numerous tissues after injury; however, little is known of its function. In this study, we report that MMP10 is expressed by macrophages in human lungs from patients with cystic fibrosis and induced in mouse macrophages in response to Pseudomonas aeruginosa infection both in vivo and by isolated resident alveolar and bone marrow-derived macrophages (BMDM). Our data indicates that macrophage MMP10 serves a beneficial function in response to acute infection. Whereas wild-type mice survived infection with minimal morbidity, 50% of Mmp10(-/-) mice died and all showed sustained weight loss (morbidity). Although bacterial clearance and neutrophil influx did not differ between genotypes, macrophage numbers were ∼3-fold greater in infected Mmp10(-/-) lungs than in wild-types. Adoptive transfer of wild-type BMDM normalized infection-induced morbidity in Mmp10(-/-) recipients to wild-type levels, demonstrating that the protective effect of MMP10 was due to its production by macrophages. Both in vivo and in cultured alveolar macrophages and BMDM, expression of several M1 macrophage markers was elevated, whereas M2 markers were reduced in Mmp10(-/-) tissue and cells. Global gene expression analysis revealed that infection-mediated transcriptional changes persisted in Mmp10(-/-) BMDM long after they were downregulated in wild-type cells. These results indicate that MMP10 serves a beneficial role in response to acute infection by moderating the proinflammatory response of resident and infiltrating macrophages.

Role of matrix metalloproteinases in the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and devastating lung disorder of unknown origin, with very poor prognosis and no effective treatment. The disease is characterized by abnormal activation of alveolar epithelial cells, which secrete numerous mediators involved in the expansion of the fibroblast population, its differentiation to myofibroblasts, and in the exaggerated accumulation of extracellular matrix provoking the loss of lung architecture. Among the excessively produced mediators are several matrix metalloproteases (MMPs) which may contribute to modify the lung microenvironment by various mechanisms. Thus, these enzymes can not only degrade all the components of the extracellular matrix, but they are also able to release, cleave and activate a wide range of growth factors, cytokines, chemokines and cell surface receptors affecting numerous cell functions including adhesion, proliferation, differentiation, recruiting and transmigration, and apoptosis. Therefore, dysregulated expression of MMPs may have profound impact on the biopathological mechanisms implicated in the development of IPF. This review focuses on the current and emerging evidence regarding the role of MMPs on the fibrotic processes in IPF as well as in mouse models of lung fibrosis.

Role of ADAMTS1 and ADAMTS5 in male infertility

The aim of this study was to investigate the relationship of infertility with metalloproteinases ADAMTS1 and ADAMTS5, which are known to be responsible for the degradation of extracellular matrix (ECM) proteins associated with many diseases. ECM is the noncellular component that provides structural and biochemical support to the surrounding cells required for tissue morphogenesis, differentiation and homoeostasis. Sixty infertile individuals and 10 healthy semen donors were included in this study. The infertile individuals were classified as normozoospermia (NS; n = 20), oligozoospermia (OS; n = 20), azoospermia (AS; n = 20) groups. ADAMTS1 and ADAMTS5 protein levels in semen were analysed by Western blot. ADAMTS1 protein level was 3.0-, 3.3- and 1.6-fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). ADAMTS5 protein level was 3.2-, 2.7- and 1.4-fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). Sperm count and sperm motility showed a negative correlation with the levels of ADAMTS1 and ADAMTS5 protein expression: r = -0.477, r = -0.470; and r = -0.332, r = -0.275 respectively (P < 0.001). In conclusion, ADAMTS1 and ADAMTS5 protein expressions in semen are significantly related with sperm production. It is very important to understand molecular function and organisation of ADAMTSs which will be significant in enlightening the process of spermatogenesis in male infertility.

ADAMs family and relatives in cardiovascular physiology and pathology

A disintegrin and metalloproteinases (ADAMs) are a family of membrane-bound proteases. ADAM-TSs (ADAMs with thrombospondin domains) are a close relative of ADAMs that are present in soluble form in the extracellular space. Dysregulated production or function of these enzymes has been associated with pathologies such as cancer, asthma, Alzheimer's and cardiovascular diseases. ADAMs contribute to angiogenesis, hypertrophy and apoptosis in a stimulus- and cell type-dependent manner. Among the ADAMs identified so far (34 in mouse, 21 in human), ADAMs 8, 9, 10, 12, 17 and 19 have been shown to be involved in cardiovascular development or cardiomyopathies; and among the 19 ADAM-TSs, ADAM-TS1, 5, 7 and 9 are important in development of the cardiovascular system, while ADAM-TS13 can contribute to vascular disorders. Meanwhile, there remain a number of ADAMs and ADAM-TSs whose function in the cardiovascular system has not been yet explored. The current knowledge about the role of ADAMs and ADAM-TSs in the cardiovascular pathologies is still quite limited. The most detailed studies have been performed in other cell types (e.g. cancer cells) and organs (nervous system) which can provide valuable insight into the potential functions of ADAMs and ADAM-TSs, their mechanism of action and therapeutic potentials in cardiomyopathies. Here, we review what is currently known about the structure and function of ADAMs and ADAM-TSs, and their roles in development, physiology and pathology of the cardiovascular system.

Expression and localization of matrix metalloproteinases (MMP-2, -7, -9) and their tissue inhibitors (TIMP-2, -3) in the chicken oviduct during maturation

Although participation of matrix metalloproteinases (MMPs) in reproductive tract remodeling has been strongly suggested in mammalian species, the role of MMPs in the avian oviduct has received little attention. To gain a better understanding of the potential role of the MMP system in avian oviduct development, mRNA and protein expression, localization of selected MMPs and their tissue inhibitors (TIMPs), and gelatinolytic activity in the oviduct of growing chickens were examined. The oviducts were collected from Hy-Line Brown hens before (10, 12, 14 and 16 weeks of age) and after (week 17) the onset of egg laying. The MMP-2, -7, -9 and TIMP-2 and -3 genes were found to be differentially expressed in all examined oviductal sections: the infundibulum, magnum, isthmus and shell gland on both mRNA (by real time polymerase chain reaction) and protein (by western blotting and immunohistochemistry) levels. In the course of oviduct development, the relative expression of all genes decreased in most sections. Protein level of MMP-9 was diminished, while MMP-7 and TIMP-3 were elevated in the oviduct of growing birds. MMP-2 and TIMP-2 protein levels remained constant, with a slight increase in MMP-2 concentration just before reaching maturity. The relative activity of MMP-2 and -9 (assessed by gelatin zymography) was higher (P < 0.05, P < 0.01) in immature birds compared with adults. Immunohistochemistry demonstrated cell- and tissue-specific localization of MMPs and TIMPs in the wall of the chicken oviduct. We concluded that changes in the expression of examined MMPs and their inhibitors, as well as alterations in MMP activity occurring simultaneously with changes in the morphology of the chicken oviduct, suggest the involvement of the MMP system in the proper development and functioning of this organ. Mechanisms regulating the expression and activity of MMPs require further clarification.

Tissue inhibitor of metalloproteases-4 (TIMP-4) modulates adipocyte differentiation in vitro

Tissue inhibitors of metalloproteases (TIMPs) are multifunctional proteins that inhibit matrix metalloproteases (MMPs). The latest described member of the family, TIMP-4, is expressed mainly in adipose tissue, with detectable levels in the brain and heart. Besides its high expression in fat, the role of this inhibitor in adipose tissue is unknown. In order to study the role of TIMP-4 during adipogenesis in vitro, 3T3-L1 cells were stably transfected with a TIMP-4 specific shRNA or a control shRNA. Unexpectedly, upon TIMP-4 knockdown, 3T3-L1 cells differentiated faster into mature adipocytes. To get better insight of TIMP-4's role in adipogenesis, microarray expression analyses were performed. Network enrichment analyses uncovered 25 significant upstream signaling pathways, among which the NFκB cascade was found. Previous works have shown that NFκB is a key regulator of adipogenesis. In accordance, we found that TIMP-4 knockdown decreased NFκB activity during adipogenesis. The present work suggests that TIMP-4 might act as a negative regulator of adipogenesis through NFκB cascade modulation.

TNF-α stimulates MMP-3 production via PGE2 signalling through the NF-kB and p38 MAPK pathway in a murine cementoblast cell line

BACKGROUND

Cementoblasts are considered to play an important role in the homeostasis of periodontal tissues under both physiologic and pathologic conditions. Matrix metalloproteinases (MMPs) is the key family of enzymes participating in extracellular matrix remodelling. In the present study, the effects and regulatory mechanisms of tumour necrosis factor (TNF)-α on the expression of MMPs and their inhibitors (tissue inhibitor of metalloproteinases; TIMPs) were investigated.

MATERIALS AND METHODS

OCCM-30, an immortalised murine cementoblast cell line, was stimulated with TNF-α at 1 and 10ng/ml for 24h. The expression of Mmp-2, Mmp-3, Mmp-13, Mmp-14, Timp-1, and Timp-2 as well as PGE2 was determined. Inhibitors of MAPKs, PI3K/Akt, NF-kB and Cox-2 were employed to reveal possible TNF-α induced regulatory signalling pathway(s). The mRNA and protein expression were analysed by (semi)quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

TNF-α dose-dependently stimulated MMP-3 expression by cementoblasts. This was found for mRNA as well as protein expression. No significant differences were found in the mRNA expression of Mmp-2, Mmp-13, Mmp-14, Timp-1, and Timp-2 upon TNF-α stimulation. The level of PGE2, however, was significantly increased along with MMP-3. Treatment with a selective Cox-2 inhibitor resulted in partial suppression of TNF-α-induced Mmp-3 mRNA expression. Addition of PGE2 enhanced Mmp-3 mRNA in a dose dependent manner, suggesting an inductive effect of TNF-α partly via PGE2. The up-regulation of Mmp-3 by TNF-α was completely suppressed by a combination of NF-kB and p38 MAPK inhibitors, while partial suppression was found with each inhibitor. The effect of PGE2 on Mmp-3 expression was abolished by treating cells with an NF-kB inhibitor; a p38 MAPK inhibitor had only a small effect.

CONCLUSIONS

The present study indicates that cementoblasts respond to TNF-α by increasing MMP-3 production partially via PGE2 and signalling through the NF-kB and p38 MAPK pathway. MMP-3 may participate in periodontal tissue degradation/remodelling.

The Elsevier Trophoblast Research Award Lecture: Importance of metzincin proteases in trophoblast biology and placental development: a focus on ADAM12

Placental development is a highly regulated process requiring signals from both fetal and maternal uterine compartments. Within this complex system, trophoblasts, placental cells of epithelial lineage, form the maternal-fetal interface controlling nutrient, gas and waste exchange. The commitment of progenitor villous cytotrophoblasts to differentiate into diverse trophoblast subsets is a fundamental process in placental development. Differentiation of trophoblasts into invasive stromal- and vascular-remodeling subtypes is essential for uterine arterial remodeling and placental function. Inadequate placentation, characterized by defects in trophoblast differentiation, may underlie the earliest cellular events driving pregnancy disorders such as preeclampsia and fetal growth restriction. Molecularly, invasive trophoblasts acquire characteristics defined by profound alterations in cell-cell and cell-matrix adhesion, cytoskeletal reorganization and production of proteolytic factors. To date, most studies have investigated the importance of the matrix metalloproteinases (MMPs) and their ability to efficiently remodel components of the extracellular matrix (ECM). However, it is now becoming clear that besides MMPs, other related proteases regulate trophoblast invasion via mechanisms other than ECM turnover. In this review, we will summarize the current knowledge on the regulation of trophoblast invasion by members of the metzincin family of metalloproteinases. Specifically, we will discuss the emerging roles that A Disintegrin and Metalloproteinases (ADAMs) play in placental development, with a particular focus on the ADAM subtype, ADAM12.

Effect of Antiadhesion Barrier Solution and Fibrin on Capsular Formation After Silicone Implant Insertion in a White Rat Model

INTRODUCTION

One of the most serious complications of breast reconstruction and augmentation using silicone implants is capsular contracture. Several preventive treatments, including vitamin E, steroids, antibiotics, and cysteinyl leukotriene inhibitors, have been studied, and their clinical effects have been reported. However, the problem of capsular contracture has not yet been completely resolved. This study was performed to compare anti-adhesion barrier solution (AABS) and fibrin in their ability to prevent fibrotic capsule formation and simultaneously evaluated their effect when used in combination by capsular thickness analysis and quantitative analysis of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and type I collagen within the fibrous capsule.

MATERIALS AND METHODS

This study used female six-week-old Sprague-Dawley rats. Eighty rats were equally subdivided into the four following groups: AABS-treated, fibrin-treated, AABS and fibrin combined-treated, and untreated control groups. Each rat received two silicone chips under the panniculus carnosus muscle layer. The test materials were applied around the silicon chips. Four weeks later, the implantation sites including the skin and muscle were excised to avoid the risk of losing the fibrous capsule around the implants. The capsular thickness was analyzed by Masson's trichrome stain. Quantitative analysis of type I collagen, MMPs, and TIMPs was performed by real-time PCR, Western blot, and zymography.

RESULTS

The mean capsular thickness was 668.10 ± 275.12 μm in the control group, 356.97 ± 112.11 μm in the AABS-treated group, 525.96 ± 130.97 μm in the fibrin-treated group, and 389.24 ± 130.51 μm in the AABS and fibrin combined-treated group. Capsular thickness was significantly decreased in all experimental groups (p < 0.05). Capsular thickness was greater in the fibrin-treated group than in the AABS-treated group (p < 0.05). There was no statistically significant difference in capsular thickness between the AABS and fibrin combined-treated group and the AABS- or fibrin-treated group (p > 0.05). Compared to the control group, the experimental groups had significantly lower expressions of type I collagen and MMP-1 (p < 0.05), but there was no statistically significant difference in expressions of type I collagen and MMP-1 between the AABS-, fibrin-, and AABS and fibrin combined-treated groups (p > 0.05). The expressions of MMP-2 and TIMP-2 were not significantly different between the control and the experimental groups (p > 0.05).

CONCLUSION

AABS is more effective in reducing capsular thickness compared with fibrin treatment in a white rat model.

Human cardiac fibroblast extracellular matrix remodeling: dual effects of tissue inhibitor of metalloproteinase-2

OBJECTIVE

Tissue inhibitor of metalloproteinase-2 (TIMP-2) is an endogenous inhibitor of matrix metalloproteinases (MMPs) that attenuates maladaptive cardiac remodeling in ischemic heart failure. We examined the effects of TIMP-2 on human cardiac fibroblast activation and extracellular matrix (ECM) remodeling.

METHODS

Human cardiac fibroblasts within a three-dimensional collagen matrix were assessed for phenotype conversion, ECM architecture and key molecular regulators of ECM remodeling after differential exposure to TIMP-2 and Ala+TIMP-2 (a modified TIMP-2 analogue devoid of MMP inhibitory activity).

RESULTS

TIMP-2 induced opposite effects on human cardiac fibroblast activation and ECM remodeling depending on concentration. TIMP-2 activated fibroblasts into contractile myofibroblasts that remodeled ECM. At higher concentrations (>10 nM), TIMP-2 inhibited fibroblast activation and prevented ECM remodeling. As compared to profibrotic cytokine transforming growth factor (TGF)-beta1, TIMP-2 activated fibroblasts and remodeled ECM without a net accumulation of matrix elements. TIMP-2 increased total protease activity as compared to TGF-beta1. Ala+TIMP-2 exposure revealed that the actions of TIMP-2 on cardiac fibroblast activation are independent of its effects on MMP inhibition. In the presence of GM6001, a broad-spectrum MMP inhibitor, TIMP-2-mediated ECM contraction was completely abolished, indicating that TIMP-2-mediated fibroblast activation is MMP dependent.

CONCLUSION

TIMP-2 functions in a contextual fashion such that the effect on cardiac fibroblasts depends on the tissue microenvironment. These observations highlight potential clinical challenges in using TIMP-2 as a therapeutic strategy to attenuate postinjury cardiac remodeling.

Mouse matrix metalloprotease-1a (Mmp1a) gives new insight into MMP function

Matrix metalloprotease-1 (MMP1) has been implicated in many human disease processes, however the lack of a well characterized murine homologue has significantly limited the study of MMP1 and the development of MMP-targeted therapeutics. The discovery of murine Mmp1a in 2001, the functional mouse homologue of MMP1, offers a valuable tool for modeling MMP1-mediated processes in mice. Variation in physiologic expression levels of Mmp1a in mice as compared to MMP1 in humans highlights the importance of understanding the similarities and differences between the homologues. Recent studies have demonstrated tumor growth-, invasion-, and angiogenesis-promoting functions of Mmp1a in lung cancer models, consistent with the analogous functions observed for human MMP1. Biochemical investigations have shown that point mutations in the pro-domain of mouse Mmp1a weaken docking between the pro- and catalytic domains, generating an unstable zymogen primed for activation. The difficulty to effectively maintain Mmp1a in the zymogen form may account for the tight control of Mmp1a expression and reduced expression in normal tissue as compared to inflammatory states or cancer. This discovery raises important questions about the activation mechanisms and regulation of the MMP family in general.

New insights into germ cell migration and survival/apoptosis in spermatogenesis: Lessons from CD147

CD147, also named basigin (Bsg) or extracellular matrix (ECM) metalloproteinase inducer (EMMPRIN), is a highly glycosylated protein first identified as a tumor cell surface molecule. In cancer, it is well established that CD147 promotes metastasis by stimulating the production of MMPs. Recent studies have also suggested that it may be associated with tumor growth and angiogenesis. Interestingly, CD147 is expressed in germ cells of different development stages in the testis and its knockout mice are infertile, indicating an essential role of CD147 in spermatogenesis. While the detailed involvement of CD147 in spermatogenesis remains elusive, our recent findings have revealed a dual role of CD147 in germ cell development. On the one hand, it regulates the migration of spermatogonia and spermatocytes via the induction of MMP-2 production; on the other hand, it specifically regulates the survival/apoptosis of spermatocytes but not spermatogonia through a p53-independent pathway. In this review, we aim to provide an overview on the functions of CD147, comparing its roles in cancer and the testis, thereby providing new insights into the regulatory mechanisms underlying the process of spermatogenesis.

Myocardial recovery from ischemia-reperfusion is compromised in the absence of tissue inhibitor of metalloproteinase 4

BACKGROUND

Myocardial reperfusion after ischemia (I/R), although an effective approach in rescuing the ischemic myocardium, can itself trigger several adverse effects including aberrant remodeling of the myocardium and its extracellular matrix. Tissue inhibitor of metalloproteinases (TIMPs) protect the extracellular matrix against excess degradation by matrix metalloproteinases (MMPs). TIMP4 levels are reduced in myocardial infarction; however, its causal role in progression of post-I/R injury has not been explored.

METHODS AND RESULTS

In vivo I/R (20-minute ischemia, 1-week reperfusion) resulted in more severe systolic and diastolic dysfunction in TIMP4(-/-) mice with enhanced inflammation, oxidative stress (1 day post-I/R), hypertrophy, and interstitial fibrosis (1 week). After an initial increase in TIMP4 (1 day post-I/R), TIMP4 mRNA and protein decreased in the ischemic myocardium from wild-type mice by 1 week post-I/R and in tissue samples from patients with myocardial infarction, which correlated with enhanced activity of membrane-bound MMP, membrane-type 1 MMP. By 4 weeks post-I/R, wild-type mice showed no cardiac dysfunction, elevated TIMP4 levels (to baseline), and normalized membrane-type 1 MMP activity. TIMP4-deficient mice, however, showed exacerbated diastolic dysfunction, sustained elevation of membrane-type 1 MMP activity, and worsened myocardial hypertrophy and fibrosis. Ex vivo I/R (20- or 30-minute ischemia, 45-minute reperfusion) resulted in comparable cardiac dysfunction in wild-type and TIMP4(-/-) mice.

CONCLUSIONS

TIMP4 is essential for recovery from myocardial I/R in vivo, primarily because of its membrane-type 1 MMP inhibitory function. TIMP4 deficiency does not increase susceptibility to ex vivo I/R injury. Replenishment of myocardial TIMP4 could serve as an effective therapy in post-I/R recovery for patients with reduced TIMP4.