Regulation of matrix biology by matrix metalloproteinases

Unraveling the Role of Angiogenesis in Cancer Ecosystems

Activation of the tumor and stromal cell-driven angiogenic program is one of the first requirements in the tumor ecosystem for growth and dissemination. The understanding of the dynamic angiogenic tumor ecosystem has rapidly evolved over the last decades. Beginning with the canonical sprouting angiogenesis, followed by vasculogenesis and intussusception, and finishing with vasculogenic mimicry, the need for different neovascularization mechanisms is further explored. In addition, an overview of the orchestration of angiogenesis within the tumor ecosystem cellular and molecular components is provided. Clinical evidence has demonstrated the effectiveness of traditional vessel-directed antiangiogenics, stressing on the important role of angiogenesis in tumor establishment, dissemination, and growth. Particular focus is placed on the interaction between tumor cells and their surrounding ecosystem, which is now regarded as a promising target for the development of new antiangiogenics.

Inspired by Nature: Hydrogels as Versatile Tools for Vascular Engineering

Significance: Diseases related to vascular malfunction, hyper-vascularization, or lack of vascularization are among the leading causes of morbidity and mortality. Engineered, vascularized tissues as well as angiogenic growth factor-releasing hydrogels could replace defective tissues. Further, treatments and testing of novel vascular therapeutics will benefit significantly from models that allow for the study of vascularized tissues under physiological relevant in vitro conditions. Recent Advances: Inspired by fibrin, the provisional matrix during wound healing, naturally derived and synthetic hydrogel scaffolds have been developed for vascular engineering. Today, engineers and biologists use commercially available hydrogels to pre-vascularize tissues, to control the delivery of angiogenic growth factors, and to establish vascular diseases models. Critical Issue: For clinical translation, pre-vascularized tissue constructs must be sufficiently large and stable to substitute function-relevant tissue defects and integrate with host vascular perfusion. Moreover, the continuous integration of knowhow from basic vascular biology with innovative, tailorable materials and advanced manufacturing technologies is key to achieving near-physiological tissue models and new treatments to control vascularization. Future Directions: For transplantation, engineered tissues must comprise hierarchically organized vascular trees of different caliber and function. The development of novel vascularization-promoting or -inhibiting therapeutics will benefit from physiologically relevant vessel models. In addition, tissue models representing treatment-relevant vascular tissue functions will increase the capacity to screen for therapeutic compounds and will significantly reduce the need for animals for their validation.

Dynamic expression of matrix metalloproteinases 2, 9 and 13 in ovariectomy-induced osteoporosis rats

The aim of the present study was to examine the dynamic expression of matrix metalloproteinase (MMP)-2, MMP-9 and MMP-13 in an ovariectomy (OVX)-induced osteoporosis rat model. A total of 80 Sprague-Dawley female rats (age, 3 months) were randomly divided into the OVX and sham groups, with 40 rats in each group. Rats in the sham group received sham surgery, while the remaining rats were ovariectomized. After 12, 16, 20 and 24 weeks, 10 rats from each group were randomly sacrificed, respectively. It was observed that the bone mineral density (BMD) and the trabecular bone area in the OVX group were significantly lower as compared with those in the sham group (P<0.01). The expression levels of MMP-2 and MMP-9 were negatively correlated with the BMD, while MMP-13 was positively correlated with the BMD. The expression levels of MMP-2 and MMP-9 increased more abruptly and were significant higher in the OVX group in comparison with those in the sham group between 12 and 24 weeks after surgery (P<0.01). More specifically, the MMP-9 mRNA expression level in the OVX group increased abruptly between 12 and 24 weeks after surgery. By contrast, in the sham group, the MMP-9 mRNA level was undetectable between 12 and 16 weeks, and increased steadily between 16 and 24 weeks. Furthermore, the mRNA and protein expression levels of MMP-13 initially increased and then decreased in the OVX group (P<0.01 vs. the sham group), whereas they continuously increased in the sham group between 12 and 24 weeks after surgery. In conclusion, MMP-2, MMP-9 and MMP-13 regulated the development of osteoporosis, and MMP-9 may be used as an important marker in the early diagnosis of osteoporosis.

Platelet-Activation Mechanisms and Vascular Remodeling

This overview article for the Comprehensive Physiology collection is focused on detailing platelets, how platelets respond to various stimuli, how platelets interact with their external biochemical environment, and the role of platelets in physiological and pathological processes. Specifically, we will discuss the four major functions of platelets: activation, adhesion, aggregation, and inflammation. We will extend this discussion to include various mechanisms that can induce these functional changes and a discussion of some of the salient receptors that are responsible for platelets interacting with their external environment. We will finish with a discussion of how platelets interact with their vascular environment, with a special focus on interactions with the extracellular matrix and endothelial cells, and finally how platelets can aid and possibly initiate the progression of various vascular diseases. Throughout this overview, we will highlight both the historical investigations into the role of platelets in health and disease as well as some of the more current work. Overall, the authors aim for the readers to gain an appreciation for the complexity of platelet functions and the multifaceted role of platelets in the vascular system. © 2017 American Physiological Society. Compr Physiol 8:1117-1156, 2018.

[Immunotherapy - The New Era of Oncology]

In the field of immunotherapy, essential progress was achieved over the past years partially demonstrating long lasting therapeutic responses in different tumor entities. A better understanding of the interactions between the tumor and the immune system as well as the integration of immunotherapeutic approaches into clinical routine were the foundations for this development. The different approaches intervene on multiple levels of the immune response and directly or indirectly mount the patient‘s own immune defense against tumor cells. Immunotherapeutic approaches are represented by cytokine therapies, vaccinations, the use of oncolytic viruses and monoclonal antibody therapies as well as adoptive cell transfer strategies.

Design, Synthesis, and Biological Evaluation of Tetrahydro-β-carboline Derivatives as Selective Sub-Nanomolar Gelatinase Inhibitors

Targeting matrix metalloproteinases (MMPs) is a pursued strategy for treating several pathological conditions, such as multiple sclerosis and cancer. Herein, a series of novel tetrahydro-β-carboline derivatives with outstanding inhibitory activity toward MMPs are present. In particular, compounds 9 f, 9 g, 9 h and 9 i show sub-nanomolar IC₅₀ values. Interestingly, compounds 9 g and 9 i also provide remarkable selectivity toward gelatinases; IC₅₀ =0.15 nm for both toward MMP-2 and IC₅₀ =0.63 and 0.58 nm, respectively, toward MMP-9. Molecular docking simulations, performed by employing quantum mechanics based partial charges, shed light on the rationale behind binding involving specific interactions with key residues of S1' and S3' domains. Taken together, these studies indicate that tetrahydro-β-carboline represents a promising scaffold for the design of novel inhibitors able to target MMPs and selectively bias gelatinases, over the desirable range of the pharmacokinetics spectrum.

Gene therapy with antisense oligonucleotides silencing c-myc reduces neointima formation and vessel wall thickness in a mouse model of vein graft disease

Gene therapy for avoiding intimal hyperplasia of vein grafts after coronary artery bypass grafting is still discussed controversially. A promising application of gene therapy in vein grafts is the use of antisense oligonucleotides to block the expression of genes encoding cell cycle regulatory proteins in vascular smooth muscle cells. C-myc, either directly or by regulating the expression of other proteins, controls cell proliferation, apoptosis and cell survival, tissue remodeling, angiogenesis, cell metabolism, production of inflammatory and anti-inflammatory cytokines, and also participates in cell transformation. Forty C57BL/6J mice underwent interposition of the inferior vena cava from isogenic donor mice into the common carotid artery using a previously described cuff technique. Twenty mice received periadventitial administration of antisense oligonucleotides directed against c-myc (treatment group), the other twenty mice received no treatment (control group). All vein grafts were harvested two weeks after surgery, dehydrated, wax embedded, cut into slides of 2 μm thickness, stained and histologically and immunohistochemically examined under light microscope. In our study, we could show the promising effects of antisense oligonucleotide treatment in a mouse model of vein graft disease including the significant reduction of neointimal, media and total vessel wall thickness with a significantly lower percentage of SMA positive cells, elastic fibres and acid mucopolysaccharides in the neointima and media, a decreased vascularization, and a lower expression of PDGFR ß, MMP-9 and VEGF-A positive cells throughout the whole vein graft wall.

Delivery of bevacizumab by intracranial injection: assessment in glioma model

Background

Many reports have indicated that the intravenous administration of bevacizumab produces a number of systemic side effects. Therefore, we investigated the therapeutic effects of intratumoral bevacizumab administration using a glioma animal model.

Methods

The glioma cell lines U251 and U87 that carried luciferase were implanted into the brains of mice to develop glioma models. Glioma-bearing mice were treated with bevacizumab intravenously or intratumorally by Alzet micro-osmotic pumps, and the survival time of mice was monitored. Tumor volumes and location were observed by fluorescence imaging and histological analysis. Levels of microvessel marker, cancer stem cell marker as well as angiogenesis-, invasion-, and inflammation-related factors in tumors were examined by immunohistochemical staining.

Results

Mice treated with intratumoral low-dose bevacizumab had smaller tumor volumes, longer survival time, lower microvessel density, and fewer cancer stem cells as compared with untreated and intravenously treated mice. Furthermore, expression levels of inflammation-related factors increased signifiwhereas that of angiogenesis- and invasion-related factors decreased in intratumorally treated animals, compared with intravenously treated mice.

Conclusion

These results implied bevacizumab delivery by intratumoral injection via Alzet micro-osmotic pumps may be a more effective and safer protocol for treating gliomas.

Mechanisms of Aquaporin-Facilitated Cancer Invasion and Metastasis

Cancer is a leading cause of death worldwide, and its incidence is rising with numbers expected to increase 70% in the next two decades. The fact that current mainline treatments for cancer patients are accompanied by debilitating side effects prompts a growing demand for new therapies that not only inhibit growth and proliferation of cancer cells, but also control invasion and metastasis. One class of targets gaining international attention is the aquaporins, a family of membrane-spanning water channels with diverse physiological functions and extensive tissue-specific distributions in humans. Aquaporins−1,−2,−3,−4,−5,−8, and−9 have been linked to roles in cancer invasion, and metastasis, but their mechanisms of action remain to be fully defined. Aquaporins are implicated in the metastatic cascade in processes of angiogenesis, cellular dissociation, migration, and invasion. Cancer invasion and metastasis are proposed to be potentiated by aquaporins in boosting tumor angiogenesis, enhancing cell volume regulation, regulating cell-cell and cell-matrix adhesions, interacting with actin cytoskeleton, regulating proteases and extracellular-matrix degrading molecules, contributing to the regulation of epithelial-mesenchymal transitions, and interacting with signaling pathways enabling motility and invasion. Pharmacological modulators of aquaporin channels are being identified and tested for therapeutic potential, including compounds derived from loop diuretics, metal-containing organic compounds, plant natural products, and other small molecules. Further studies on aquaporin-dependent functions in cancer metastasis are needed to define the differential contributions of different classes of aquaporin channels to regulation of fluid balance, cell volume, small solute transport, signal transduction, their possible relevance as rate limiting steps, and potential values as therapeutic targets for invasion and metastasis.

Interplay between stiffness and degradation of architectured gelatin hydrogels leads to differential modulation of chondrogenesis in vitro and in vivo

The limited capacity of cartilage to heal large lesions through endogenous mechanisms has led to extensive effort to develop materials to facilitate chondrogenesis. Although physical-chemical properties of biomaterials have been shown to impact in vitro chondrogenesis, whether these findings are translatable in vivo is subject of debate. Herein, architectured 3D hydrogel scaffolds (ArcGel) (produced by crosslinking gelatin with ethyl lysine diisocyanate (LDI)) were used as a model system to investigate the interplay between scaffold mechanical properties and degradation on matrix deposition by human articular chondrocytes (HAC) from healthy donors in vitro and in vivo. Using ArcGel scaffolds of different tensile and shear modulus, and degradation behavior; in this study, we compared the fate of ex vivo engineered ArcGels-chondrocytes constructs, i.e. the traditional tissue engineering approach, with thede novoformation of cartilaginous tissue in HAC laden ArcGels in an ectopic nude mouse model. While the softer and fast degrading ArcGel (LNCO3) was more efficient at promoting chondrogenic differentiation in vitro, upon ectopic implantation, the stiffer and slow degrading ArcGel (LNCO8) was superior in maintaining chondrogenic phenotype in HAC and retention of cartilaginous matrix. Furthermore, surprisingly the de novo formation of cartilage tissue was promoted only in LNCO8. Since HAC cultured for only three days in the LNCO8 environment showed upregulation of hypoxia-associated genes, this suggests a potential role for hypoxia in the observed in vivo outcomes. In summary, this study sheds light on how immediate environment (in vivo versus in vitro) can significantly impact the outcomes of cell-laden biomaterials.

STATEMENT OF SIGNIFICANCE

In this study, 3D architectured hydrogels (ArcGels) with different mechanical and biodegradation properties were investigated for their potential to promote formation of cartilaginous matrix by human articular chondrocytes in vitro and in vivo. Two paradigms were explored (i) ex vivo engineering followed by in vivo implantation in ectopic site of nude mice and (ii) short in vitro culture (3 days) followed by implantation to induce de novo cartilage formation. Softer and fast degrading ArcGel were better at promoting chondrogenesis in vitro, while stiffer and slow degrading ArcGel were strikingly superior in both maintaining chondrogenesis in vivo and inducing de novo formation of cartilage. Our findings highlight the importance of the interplay between scaffold mechanics and degradation in chondrogenesis.

MT2-MMP induces proteolysis and leads to EMT in carcinomas

Epithelial-mesenchymal transition (EMT) is critical for carcinoma invasiveness and metastasis. To investigate the role of membrane-type-2 matrix metalloproteinase (MT2-MMP) in EMT, we generated lentiviral constructs of wild-type (WT) and an inactive Glu260Ala (E260A) mutant MT2-MMP and derived stably transfected HCT116 and A549 cell lines. WT-transfected cells appeared mesenchymal-like, whereas cells transfected with the E260A mutant were epithelial-like, as were cells treated with an MMP inhibitor (GM6001). Expression of E-cadherin, β-catenin, and zonula occludens-1 was lower in cells transfected with WT MT2-MMP compared to vector controls, cells treated with GM6001, or cells transfected with the E260A mutant. An 80-kD N-terminal fragment of E-cadherin was immunoprecipitated in conditioned medium from WT MT2-MMP cells, but not in the medium from vector controls, cells treated with GM6001, or E260A mutant cells. When endogenous expression of MT2-MMP in A2780 human ovarian cancer cells was inhibited using GM6001 or MT2-MMP-specific siRNA, levels of the 80-kD E-cadherin fragment in conditioned medium were decreased. Chick embryo chorioallantoic membrane invasion assays demonstrated that cells transfected with WT MT2-MMP were more invasive than cells transfected with control vector, treated with GM6001, or transfected with the E260A mutant. These results suggest that MT2-MMP degrades adherens and tight junction proteins and results in EMT, making it a potential mediator of EMT in carcinomas.

Laminin-111 peptide C16 regulates invadopodia activity of malignant cells through β1 integrin, Src and ERK 1/2

Laminin peptides influence tumor behavior. In this study, we addressed whether laminin peptide C16 (KAFDITYVRLKF, γ1 chain) would increase invadopodia activity of cells from squamous cell carcinoma (CAL27) and fibrosarcoma (HT1080). We found that C16 stimulates invadopodia activity over time in both cell lines. Rhodamine-conjugated C16 decorates the edge of cells, suggesting a possible binding to membrane receptors. Flow cytometry showed that C16 increases activated β1 integrin, and β1 integrin miRNA-mediated depletion diminishes C16-induced invadopodia activity in both cell lines. C16 stimulates Src and ERK 1/2 phosphorylation, and ERK 1/2 inhibition decreases peptide-induced invadopodia activity. C16 also increases cortactin phosphorylation in both cells lines. Based on our findings, we propose that C16 regulates invadopodia activity over time of squamous carcinoma and fibrosarcoma cells, probably through β1 integrin, Src and ERK 1/2 signaling pathways.

The effects of interleukin-33 on airways collagen deposition and matrix metalloproteinase expression in a murine surrogate of asthma

It has been suggested that interleukin-33 (IL-33) plays an important role in the pathogenesis of asthma through a variety of pathways, but its role in airways fibrosis in asthma has not been fully elucidated. In the present study we evaluated changes in the expression of extracellular matrix proteins (ECMs) as well as matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in an IL-33-induced, antigen-independent murine surrogate of asthma as well as a conventional surrogate employing per-nasal challenge of mice previously sensitized to produce an IgE response to ovalbumin (OVA). In addition, in in vitro experiments we explored the direct effects of IL-33 on the proliferation and function of murine fibroblasts. Per-nasal administration of IL-33 alone was sufficient to induce airways deposition of ECMs, including collagens I, III, V and fibronectin, to a degree comparable with that observed in the OVA-sensitized and challenged mice. These changes were associated with a local imbalance between the expression of extracellular MMPs and TIMPs. Per-nasal challenge of mice with IL-33 also induced elevated airways expression of connective tissue growth factor and fibroblast growth factor receptor 4, two key facilitators of local fibrosis, again to a degree compatible with that observed in OVA-sensitized and challenged mice. Deletion of the ST2 gene, which encodes the IL-33 receptor, abrogated these fibrotic changes in the airways in the OVA surrogate. In vitro, IL-33 significantly increased the proliferation and expression of collagen III by murine lung fibroblasts. These data suggest that direct exposure of murine airways to IL-33 is able to induce local fibrotic changes, at least partially through effects of signalling through the IL-33/ST2 axis on fibroblast function and local expression of MMPs and their inhibitors, and other fibrosis-related proteins.

Interleukin-33 enhanced the migration and invasiveness of human lung cancer cells

Aim

Interleukin-33 (IL-33), belonging to IL-1 family cytokines, has been reported to participate in cancer growth and metastasis. The clinical values of IL-33 in lung cancer have been previously investigated. We aimed to elucidate the probable role of IL-33 in the migration and invasion of lung cancer cells.

Methods

Cell migration and invasiveness were tested by Transwell assay. Western blotting analysis was performed to detect protein expression.

Results

We found that IL-33 treatment in human lung A549 cells dose-dependently enhanced their migratory and invasive ability, accompanied by elevated expression of matrix metallo-proteinase (MMP) 2 and MMP9. Meanwhile, IL-33-induced cell migration and invasion were significantly abolished by small interfering RNA-targeting ST2, the specific receptor of IL-33. Furthermore, IL-33 exposure induced the phosphorylation of AKT. Pretreatment with an AKT inhibitor LY294002 markedly attenuated IL-33-induced cell migration and invasion.

Conclusion

IL-33/ST2 promoted the migration and invasiveness of lung cancer cells through AKT pathway. Our findings strongly suggest that IL-33 may serve as a promising therapeutic strategy for lung cancer.

The Many Facets of Metzincins and Their Endogenous Inhibitors: Perspectives on Ovarian Cancer Progression

Approximately sixty per cent of ovarian cancer patients die within the first five years of diagnosis due to recurrence associated with chemoresistance. The metzincin family of metalloproteinases is enzymes involved in matrix remodeling in response to normal physiological changes and diseased states. Recently, there has been a mounting awareness of these proteinases and their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), as superb modulators of cellular communication and signaling regulating key biological processes in cancer progression. This review investigates the role of metzincins and their inhibitors in ovarian cancer. We propose that understanding the metzincins and TIMP biology in ovarian cancer may provide valuable insights in combating ovarian cancer progression and chemoresistance-mediated recurrence in patients.

Emerging Technologies for Cancer Research: Towards Personalized Medicine with Microfluidic Platforms and 3D Tumor Models

In the present review, we describe three hot topics in cancer research such as circulating tumor cells, exosomes, and 3D environment models. The first section is dedicated to microfluidic platforms for detecting circulating tumor cells, including both affinity-based methods that take advantage of antibodies and aptamers, and "label-free" approaches, exploiting cancer cells physical features and, more recently, abnormal cancer metabolism. In the second section, we briefly describe the biology of exosomes and their role in cancer, as well as conventional techniques for their isolation and innovative microfluidic platforms. In the third section, the importance of tumor microenvironment is highlighted, along with techniques for modeling it in vitro. Finally, we discuss limitations of two-dimensional monolayer methods and describe advantages and disadvantages of different three-dimensional tumor systems for cell-cell interaction analysis and their potential applications in cancer management.

Rheumatic Disease: Protease-Activated Receptor-2 in Synovial Joint Pathobiology

Protease-activated receptor-2 (PAR2) is one member of a small family of transmembrane, G-protein-coupled receptors. These receptors are activated via cleavage of their N terminus by serine proteases (e.g., tryptase), unveiling an N terminus tethered ligand which binds to the second extracellular loop of the receptor. Increasing evidence has emerged identifying key pathophysiological roles for PAR2 in both rheumatoid arthritis (RA) and osteoarthritis (OA). Importantly, this includes both pro-inflammatory and destructive roles. For example, in murine models of RA, the associated synovitis, cartilage degradation, and subsequent bone erosion are all significantly reduced in the absence of PAR2. Similarly, in experimental models of OA, PAR2 disruption confers protection against cartilage degradation, subchondral bone osteosclerosis, and osteophyte formation. This review focuses on the role of PAR2 in rheumatic disease and its potential as an important therapeutic target for treating pain and joint degradation.

Hyperoside protects the blood-brain barrier from neurotoxicity of amyloid beta 1-42

Mounting evidence indicates that amyloid β protein (Aβ) exerts neurotoxicity by disrupting the blood-brain barrier (BBB) in Alzheimer's disease. Hyperoside has neuroprotective effects both in vitro and in vivo against Aβ. Our previous study found that hyperoside suppressed Aβ_1–42-induced leakage of the BBB, however, the mechanism remains unclear. In this study, bEnd.3 cells were pretreated with 50, 200, or 500 µM hyperoside for 2 hours, and then exposed to Aβ_1–42 for 24 hours. Cell viability was determined using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay were used to analyze cell apoptosis. Western blot assay was carried out to analyze expression levels of Bax, Bcl-2, cytochrome c, caspase-3, caspse-8, caspase-9, caspase-12, occludin, claudin-5, zonula occludens-1, matrix metalloproteinase-2 (MMP-2), and MMP-9. Exposure to Aβ_1–42 alone remarkably induced bEnd.3 cell apoptosis; increased ratios of cleaved caspase-9/caspase-9, Bax/Bcl-2, cleaved caspase-8/caspase-8, and cleaved caspase-12/caspase-12; increased expression of cytochrome c and activity of caspase-3; diminished levels of zonula occludens-1, claudin-5, and occludin; and increased levels of MMP-2 and MMP-9. However, hyperoside pretreatment reversed these changes in a dose-dependent manner. Our findings confirm that hyperoside alleviates fibrillar Aβ_1–42-induced BBB disruption, thus offering a feasible therapeutic application in Alzheimer's disease.

The interplay between extracellular matrix remodelling and kinase signalling in cancer progression and metastasis

The extracellular matrix (ECM) is a master regulator of cellular phenotype and behaviour. It plays a crucial role in both normal tissue homeostasis and complex diseases such as cancer. The interplay between the intrinsic factors of cancer cells themselves, including their genotype and signalling networks; and the extrinsic factors of the tumour stroma, such as the ECM and ECM remodelling; together determine the fate and behaviour of cancer cells. As a consequence, tumour progression, metastatic spread and response to therapy are ultimately controlled by ECM-driven fine-tuning of intracellular kinase signalling. The ability to target and uncouple this interaction presents an emerging and promising potential in the treatment of cancer.

Extracellular matrix remodeling and TGF-β1/Smad signaling in diabetic colon mucosa

Diabetes is associated with metabolic and functional alterations in the gut. Using an experimental model of streptozotocin (STZ)-induced diabetes in rodents, we analyzed the extracellular matrix (ECM) and TGF-β/Smad signaling in the colon mucosa. Male rats were divided into normal control, diabetic and insulin treated diabetic groups during 4 and 9 weeks. Sirius red staining showed marked increase in the extracellular matrix deposition in diabetic mucosa. High levels of fibrillar collagen (I and III) and fibronectin mRNAs were also detected with an imbalance between MMPs/TIMPs activities. Moreover, an increased mesenchymal cell proliferation together with an enhanced expression of myofibroblasts markers vimentin and α-SMA were observed. TGF-β/Smad signaling-related genes were determined using RT-PCR, Western blotting, and immunohistochemistry. Diabetic rats showed a significant up-regulation of TGF-β1, TGF-β receptors and the effectors p-Smad2/3 in the mucosa compared with control rats. Insulin treatment attenuated the stimulating effect of diabetes on colon ECM deposition and TGF-β/Smad signaling. In conclusion, the overall results showed a deregulation of the TGFβ1 pathway associated with the appearance of myofibroblasts and the accumulation of ECM in the mucosa of diabetic colon. These data provide the first in vivo evidence that TGF-β1/Smad is a key component of intestinal tissue remodeling in diabetes.

Post-ischemic treatment with azithromycin protects ganglion cells against retinal ischemia/reperfusion injury in the rat

Purpose

Retinal ischemic phenomena occur in several ocular diseases that share the degeneration and death of retinal ganglion cells (RGCs) as the final event. We tested the neuroprotective effect of azithromycin, a widely used semisynthetic macrolide antibiotic endowed with anti-inflammatory and immunomodulatory properties, in a model of retinal ischemic injury induced by transient elevation of intraocular pressure in the rat.

Methods

Retinal ischemia was induced in adult rats with transient elevation of intraocular pressure. RGCs were retrogradely labeled with Fluoro-Gold, and survival was assessed following a single dose of azithromycin given systemically at the end of the ischemia. The expression of death-associated proteins and extracellular signal-regulated kinase (ERK) activation was studied with western blotting. Expression and activity of matrix metalloproteinase-2 (MMP-2) and -9 were analyzed with gelatin zymography.

Results

Acute post-injury administration of azithromycin significantly prevented RGC death. This effect was accompanied by reduced calpain activity and prevention of Bcl-2-associated death promoter (Bad) upregulation. The observed neuroprotection was associated with a significant inhibition of MMP-2/-9 gelatinolytic activity and ERK1/2 phosphorylation.

Conclusions

Azithromycin provides neuroprotection by modifying the inflammatory state of the retina following ischemia/reperfusion injury suggesting potential for repurposing as a drug capable of limiting or preventing retinal neuronal damage.

Effect of different resistance-training protocols on the extracellular matrix of the calcaneal tendon of rats

The calcaneal tendon extracellular matrix (ECM) is composed of collagen, non-collagenous glycoproteins and proteoglycans, and able to adapt to various biomechanical stimuli. The objective of this study was to analyze the response of different resistance-training protocols, such as hypertrophy, strength and resistance, on the organization of the calcaneal tendon after training. Wistar rats were divided into four groups: untrained (UT), resistance training (RT), hypertrophy training (HT), and strength training (ST). The protocol in a vertical climbing platform was performed thrice per week over twelve weeks. For biochemical study, the tendons of each group were minced and analyzed for gelatinases, quantification of non-collagenous proteins, sulfated glycosaminoglycans, and hydroxyproline. For morphological analysis, sections were stained with HE and toluidine blue. Non-stained sections were used for birefringence analysis under polarization microscopy. The highest hydroxyproline concentrations were found in HT (154.8±14.2) and RT (173.6±25.2) compared with UT (122.4±27.0). A higher concentration of non-collagenous proteins was detected in the RT group (14.98mg/g) compared with the other groups. In polarization microscopy, major birefringence was observed in HT and the lowest in ST compared with UT, indicating higher organization of collagen bundles in HT. In analysis for zymography, the presence of latent MMP-9 was more prominent in the ST group and the active MMP-9 more prominent in the HT group. For MMP-2, significant differences in the latent isoform between the HT (184,867±6765) and UT (173,018±9696) groups were found. In sections stained with toluidine blue (TB), higher metachromasia was observed in the tendon's distal region in HT and RT groups, indicating a greater amount of proteoglycans. We conclude that the different training protocols produced different responses in the ECM. The remarkable presence of MMP-2 and -9 in the hypertrophy training group may be related to the highest organization of collagen bundles and possibly a more efficient remodeling process, observed in that group, as demonstrated by images and measurements of birefringence.

The influence of soluble fragments of extracellular matrix (ECM) on tumor growth and morphology

A major challenge in matrix-metalloproteinase (MMP) target validation and MMP-inhibitor-drug development for anti-cancer clinical trials is to better understand their complex roles (often competing with each other) in tumor progression. While there is extensive research on the growth-promoting effects of MMPs, the growth-inhibiting effects of MMPs has not been investigated thoroughly. So we develop a continuum model of tumor growth and invasion including chemotaxis and haptotaxis in order to examine the complex interaction between the tumor and its host microenvironment and to explore the inhibiting influence of the gradients of soluble fragments of extracellular matrix (ECM) density on tumor growth and morphology. Previously, it was shown both computationally (in one spatial dimension) and experimentally that the chemotactic pull due to soluble ECM gradients is anti-invasive, contrary to the traditional view of the role of chemotaxis in malignant invasion [1]. With two-dimensional numerical simulation and using a level set based tumor-host interface capturing method, we examine the effects of chemotaxis on the progression and morphology of a tumor growing in nutrient-rich and nutrient-poor microenvironments which was not investigated before. In particular we examine how the geometry of the growing tumor is affected when placed in different environments. We also investigate the effects of varying ECM degradation rate, the production rate of matrix degrading enzymes (MDE), and the conversion of ECM into soluble ECM. We find that chemotaxis due to ECM-fragment gradients strongly influences tumor growth and morphology, and that the instabilities caused by tumor cell proliferation and haptotactic movements can be prevented if chemotaxis is sufficiently strong. The influence of chemotaxis and the above factors on tumor growth and morphology are found to be more prominent in nutrient-poor environments than in nutrient-rich environments. So we extend our investigations of these antinvasive chemotactic influences by examining the effects of cell-cell and cell-ECM adhesion and low proliferation rate for tumors growing in low-nutrient environments. We find that as the extent of chemotaxis increases, the effects of adhesion on tumor growth and shape become negligible. Under conditions of low cell mitosis, chemotaxis may cause the tumor to shrink, as the extent of chemotaxis increases. Both stable and unstable tumor shrinkage are predicted by our model. Unexpectedly, in some cases chemotaxis may contribute toward developing instability where haptotaxis alone induces stable growth.

MMP proteolytic activity regulates cancer invasiveness by modulating integrins

Cancer invasion through dense extracellular matrices (ECMs) is mediated by matrix metalloproteinases (MMPs) which degrade the ECM thereby creating paths for migration. However, how this degradation influences the phenotype of cancer cells is not fully clear. Here we address this question by probing the function of MMPs in regulating biophysical properties of cancer cells relevant to invasion. We show that MMP catalytic activity regulates cell spreading, motility, contractility and cortical stiffness by stabilizing integrins at the membrane and activating focal adhesion kinase. Interestingly, cell rounding and cell softening on stiff gels induced by MMP inhibition is attenuated on MMP pre-conditioned surfaces. Together, our results suggest that MMP catalytic activity regulates invasiveness of cancer cells by modulating integrins.

Stress-induced plasticity of dynamic collagen networks

The structure and mechanics of tissues is constantly perturbed by endogenous forces originated from cells, and at the same time regulate many important cellular functions such as migration, differentiation, and growth. Here we show that 3D collagen gels, major components of connective tissues and extracellular matrix (ECM), are significantly and irreversibly remodeled by cellular traction forces, as well as by macroscopic strains. To understand this ECM plasticity, we develop a computational model that takes into account the sliding and merging of ECM fibers. We have confirmed the model predictions with experiment. Our results suggest the profound impacts of cellular traction forces on their host ECM during development and cancer progression, and suggest indirect mechanical channels of cell-cell communications in 3D fibrous matrices.The structure and mechanics of tissues is constantly perturbed by endogenous forces originated from cells. Here the authors show that 3D collagen gels, major components of connective tissues and extracellular matrix, are significantly and irreversibly remodelled by cellular traction forces and by macroscopic strains.

Model of vascular desmoplastic multispecies tumor growth

We present a three-dimensional nonlinear tumor growth model composed of heterogeneous cell types in a multicomponent-multispecies system, including viable, dead, healthy host, and extra-cellular matrix (ECM) tissue species. The model includes the capability for abnormal ECM dynamics noted in tumor development, as exemplified by pancreatic ductal adenocarcinoma, including dense desmoplasia typically characterized by a significant increase of interstitial connective tissue. An elastic energy is implemented to provide elasticity to the connective tissue. Cancer-associated fibroblasts (myofibroblasts) are modeled as key contributors to this ECM remodeling. The tumor growth is driven by growth factors released by these stromal cells as well as by oxygen and glucose provided by blood vasculature which along with lymphatics are stimulated to proliferate in and around the tumor based on pro-angiogenic factors released by hypoxic tissue regions. Cellular metabolic processes are simulated, including respiration and glycolysis with lactate fermentation. The bicarbonate buffering system is included for cellular pH regulation. This model system may be of use to simulate the complex interactions between tumor and stromal cells as well as the associated ECM and vascular remodeling that typically characterize malignant cancers notorious for poor therapeutic response.

Matrix Metalloproteinases, Vascular Remodeling, and Vascular Disease

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation through removal of the propeptide domain from their latent zymogen form. MMPs are often secreted in an inactive proMMP form, which is cleaved to the active form by various proteinases including other MMPs. MMPs degrade various protein substrates in ECM including collagen and elastin. MMPs could also influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in vascular tissue remodeling during various biological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension, preeclampsia, atherosclerosis, aneurysm formation, as well as excessive venous dilation and lower extremity venous disease. MMPs are often regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs may serve as biomarkers and potential therapeutic targets for certain vascular disorders.

Selenoproteins and Metastasis

Cancer survival is largely impacted by the dissemination of cancer cells from the original tumor site to secondary tissues or organs through metastasis. Targets for antimetastatic therapies have recently become a focus of research, but progress will require a better understanding of the molecular mechanisms driving metastasis. Selenoproteins play important roles in many of the cellular activities underlying metastasis including cell adhesion, matrix degradation and migration, invasion into the blood and extravasation into secondary tissues, and subsequent proliferation into metastatic tumors along with the angiogenesis required for growth. In this review the roles identified for different selenoproteins in these steps and how they may promote or inhibit metastatic cancers is discussed. These roles include selenoenzyme modulation of redox tone and detoxification of reactive oxygen species, calcium homeostasis and unfolded protein responses regulated by endoplasmic reticulum selenoproteins, and the multiple physiological responses influenced by other selenoproteins.

Role of the extracellular matrix in cancer-associated epithelial to mesenchymal transition phenomenon

The epithelial to mesenchymal transition (EMT) program is a crucial component in the processes of morphogenesis and embryonic development. The transition of epithelial to mesenchymal phenotype is associated with numerous structural and functional changes, including loss of cell polarity and tight cell-cell junctions, the acquisition of invasive abilities, and the expression of mesenchymal proteins. The switch between the two phenotypes is involved in human pathology and is crucial for cancer progression. Extracellular matrices (ECMs) are multi-component networks that surround cells in tissues. These networks are obligatory for cell survival, growth, and differentiation as well as tissue organization. Indeed, the ECM suprastructure, in addition to its supportive role, can process and deliver a plethora of signals to cells, which ultimately regulate their behavior. Importantly, the ECM derived signals are critically involved in the process of EMT during tumorigenesis. This review discusses the multilayer interaction between the ECM and the EMT process, focusing on contributions of discrete mediators, a strategy that may identify novel potential target molecules. Developmental Dynamics 247:368-381, 2018. © 2017 Wiley Periodicals, Inc.

Measuring clinically relevant endpoints in a serum-free, three-dimensional, primary cell culture system of human osteoarthritic articular chondrocytes

Osteoarthritis (OA) is characterized by degeneration of articular cartilage within the joint, inflammation and pain. The purpose of this study was to develop a primary, serum free cell culture system of human osteoarthritic articular chondrocytes (HOACs) with which to study manifestations of the disease process. Joint tissues were obtained from OA patients undergoing total knee arthroplasty (TKA). HOACs isolated from the femoral condyles and tibial plateau of the same side were combined, plated in three-dimensional, alginate beads and cultured for five days in serum, hormone and protein free medium. More living cells were obtained from the femoral condyles than the tibial plateau. The optimal plating density was 2.5 × 10⁶ cells/ml of alginate. The amounts of DNA, RNA, proteoglycans and total collagen were similar in cultures prepared from the sides of least and greatest pathology. More type 1 than type 2 collagen was detected in the medium on days 2 and 5. A greater percentage of type 1 than type 2 collagen was degraded. The inflammatory cytokine interleukin-1 beta was present in the medium and alginate associated matrix. Although variation in the metabolic profiles between subjects was observed, HOACs from all patients continued to reflect the OA phenotype for five days in culture. This serum free, three-dimensional primary culture system of HOACs provides a platform with which to measure clinically relevant endpoints of OA and screen potential disease modifying OA therapeutics.

Membrane-Tethered Metalloproteinase Expressed by Vascular Smooth Muscle Cells Limits the Progression of Proliferative Atherosclerotic Lesions

BACKGROUND

The MMP (matrix metalloproteinase) family plays diverse and critical roles in directing vascular wall remodeling in atherosclerosis. Unlike secreted-type MMPs, a member of the membrane-type MMP family, MT1-MMP (membrane-type 1 MMP; MMP14), mediates pericellular extracellular matrix degradation that is indispensable for maintaining physiological extracellular matrix homeostasis. However, given the premature mortality exhibited by MT1-MMP-null mice, the potential role of the proteinase in atherogenesis remains elusive. We sought to determine the effects of both MT1-MMP heterozygosity and tissue-specific gene targeting on atherogenesis in APOE (apolipoprotein E)-null mice.

METHODS AND RESULTS

MT1-MMP heterozygosity in the APOE-null background (Mmp14+/-Apoe-/- ) significantly promoted atherogenesis relative to Mmp14+/+Apoe-/- mice. Furthermore, the tissue-specific deletion of MT1-MMP from vascular smooth muscle cells (VSMCs) in SM22α-Cre(+)Mmp14F/FApoe-/- (VSMC-knockout) mice likewise increased the severity of atherosclerotic lesions. Although VSMC-knockout mice also developed progressive atherosclerotic aneurysms in their iliac arteries, macrophage- and adipose-specific MT1-MMP-knockout mice did not display this sensitized phenotype. In VSMC-knockout mice, atherosclerotic lesions were populated by hyperproliferating VSMCs (smooth muscle actin- and Ki67-double-positive cells) that were characterized by a proinflammatory gene expression profile. Finally, MT1-MMP-null VSMCs cultured in a 3-dimensional spheroid model system designed to mimic in vivo-like cell-cell and cell-extracellular matrix interactions, likewise displayed markedly increased proliferative potential.

CONCLUSIONS

MT1-MMP expressed by VSMCs plays a key role in limiting the progression of atherosclerosis in APOE-null mice by regulating proliferative responses and inhibiting the deterioration of VSMC function in atherogenic vascular walls.

Extracellular matrix remodeling and matrix metalloproteinases (ajMMP-2 like and ajMMP-16 like) characterization during intestine regeneration of sea cucumber Apostichopus japonicus

Remodeling of extracellular matrix (ECM) regulated by matrix metalloproteinases (MMPs) is essential for tissue regeneration. In the present study, we used immunohistochemistry (IHC) techniques against ECM components to reveal changes of ECM during intestine regeneration of Apostichopus japonicus. The expression of collagen I and laminin reduced apparently from the eviscerated intestine, while fibronectin exhibited continuous expression in all regeneration stages observed. Meanwhile, we cloned two MMP genes from A. japonicus by RACE PCR. The full-length cDNA of ajMMP-2 like is 2733bp and contains a predicted open reading frame (ORF) of 1716bp encoding 572 amino acids. The full-length cDNA of ajMMP-16 like is 2705bp and contains an ORF of 1452bp encoding 484 amino acids. The predicted protein sequences of each MMP contain two conserved domains, ZnMc_MMP and HX. Homology and phylogenetic analysis revealed that ajMMP-2 like and ajMMP-16 like share high sequence similarity with MMP-2 and MMP-16 from Strongylocentrotus purpuratus, respectively. Then we investigated spatio-temporal expression of ajMMP-2 like and ajMMP-16 like during different regeneration stages by qRT-PCR and IHC. The expression pattern of them showed a roughly opposite trend from that of ECM components. According to our results, a fibronectin-dominate temporary matrix is created in intestine regeneration, and it might provide structural integrity for matrix and promote cell movement. We also hypothesize that ajMMP-2 like and ajMMP-16 like could accelerate cell migration and regulate interaction between ECM components and growth factors. This work provides new evidence of ECM and MMPs involvement in sea cucumber regeneration.

Coexpressed modular gene expression reveals inverse correlation between immune responsive transcription and aggressiveness in gastric tumours

The existing large number of gene expression profiles of tumour samples offers a great advantage for the integrative functional genomic exploration of molecular dysregulation in cancers. The clusters of genes (modules) derived from a gastric cancer (GC) coexpression network were explored to understand their clinical and functional significance. Among the modules derived from the GC mRNA expression network, six modules were relatively highly expressed in diffuse type gastric tumours. Elevated expression of genes related to extracellular matrix (ECM), angiogenesis, collagen and intracellular cytoskeletal components and immune response were identified in these modules. ECM-related modules exhibited an inverse correlation with modules representing the expression of immune response genes. A reduced expression of immune response genes was identified as the key factor associated with the aggressive features of diffuse gastric tumours, which is indicative of tumour progression involving the escape from immune surveillance in diffuse tumours. A part of the identified aggressive factors was common between intestinal and diffuse type tumours. The coexpressed modules and their expression patterns delineate the fine transition involved in cancer progression in the later stages of tumours. The identified modules could serve as surrogate gene-sets, indicating the molecular staging of GC aggressiveness with underlying biological interaction.

Clinical and prognostic significance of prokineticin 1 in human gliomas

The objective of this study was to explore the expression and the clinical and prognostic significance of prokineticin 1 (PROK1) in human gliomas. The expression of PROK1 in 60 patients with glioma and in eight control cases (patients with traumatic brain injury) by immunohistochemistry (IHC). The associations between the differences in expression and pathology grades were analyzed statistically. The positive rates of PROK1 expression in normal brain and glioma tissue were 25.0% (2/8) and 93.3% (56/60), respectively. PROK1 expression in glioma tissue was higher than that in normal tissue (P<0.05). The positive rates of PROK1 expression in low-grade gliomas (LGGs, grades I and II) and high-grade gliomas (HGGs, grades III and IV) were 66.7% (8/12) and 100% (48/48), respectively, the positive rates in HGG were higher than those in LGG (P<0.01). PROK1 is an angiogenic growth factor that is related with metastatic ability of tumor, we also correlated PROK1 expression with NFAT expression. Expression of PROK1correlated significantly with expression of NFAT (r=0.524, P<0.01), but not with patient sex and age. Glioma patients with higher expressing PROK1 had a significantly shorter progression-free survival time, increasing levels of PROK1 expression significantly correlated with reduced survival times when all patients with glioma were considered (P<0.01). These results suggested that PROK1 positivity and protein expression levels are of significant clinical and prognostic value in human gliomas, which significantly correlates with the survival in gliomas, PROK1 may regulate the progression of glioma via the NFAT pathway.

Blockade of MMP-2 and MMP-9 inhibits corneal lymphangiogenesis

PURPOSE

To investigate the roles of a selective MMP-2 and -9 inhibitor (SB-3CT) in corneal inflammatory lymphangiogenesis.

METHODS

The expression of MMP-2 and -9 in the cornea after suture inplacement, treated with SB-3CT or negative control, was detected by real-time polymerase chain reaction (PCR). Inflammatory corneal neovascularization (NV) was induced by corneal suture placement. Mice were treated with SB-3CT eye drops (twice daily for 1 week, 5 μL per drop; 50, 100, or 200 μM). The outgrowth of blood and lymphatic vessels, and macrophage recruitment were analyzed by immunofluorescence assay. The expressions of vascular endothelial growth factor-C (VEGF-C) and its receptor VEGFR-3 were tested by real-time PCR.

RESULTS

MMP-2 and -9 expression were suppressed significantly by treatment with SB-3CT. The data demonstrated, for the first time, that SB-3CT strongly reduced corneal lymphangiogenesis and macrophage infiltration during inflammation. Furthermore, expressions of VEGF-C and its receptor VEGFR-3 were significantly inhibited by SB-3CT during corneal lymphangiogenesis.

CONCLUSIONS

These novel findings indicated that blockade of MMP-2 and -9 could inhibit lymphangiogenesis. Further investigation of this factor may provide novel therapies for transplant rejection and other lymphatic disorders.

Effects of omega-3 on matrix metalloproteinase-9, myoblast transplantation and satellite cell activation in dystrophin-deficient muscle fibers

In Duchenne muscular dystrophy (DMD), lack of dystrophin leads to progressive muscle degeneration, with DMD patients suffering from cardiorespiratory failure. Cell therapy is an alternative to life-long corticoid therapy. Satellite cells, the stem cells of skeletal muscles, do not completely compensate for the muscle damage in dystrophic muscles. Elevated levels of proinflammatory and profibrotic factors, such as metalloproteinase 9 (MMP-9), impair muscle regeneration, leading to extensive fibrosis and poor results with myoblast transplantation therapies. Omega-3 is an anti-inflammatory drug that protects against muscle degeneration in the mdx mouse model of DMD. In the present study, we test our hypothesis that omega-3 affects MMP-9 and thereby benefits muscle regeneration and myoblast transplantation in the mdx mouse. We observe that omega-3 reduces MMP-9 gene expression and improves myoblast engraftment, satellite cell activation, and muscle regeneration by mechanisms involving, at least in part, the regulation of macrophages, as shown here with the fluorescence-activated cell sorting technique. The present study demonstrates the benefits of omega-3 on satellite cell survival and muscle regeneration, further supporting its use in clinical trials and cell therapies in DMD.

Synergic and antagonistic relationship between MMP-2 and MMP-9 with fibrosis and inflammation in Chagas' cardiomyopathy

Cardiomyopathy is the most important clinical manifestation in the chronic phase of Chagas' disease because of its frequency, severity and impact on morbidity and mortality. The extracellular matrix degradation during cardiac remodeling in Trypanosoma cruzi infection is driven by matrix metalloproteinases (MMPs), primarily the MMP-2 and MMP-9 gelatinases. MMPs also regulate some molecules related to inflammation, such as growth factors, cytokines and chemokines. The involvement of MMP-2 and MMP-9 is not yet fully understood in Chagas' disease. It has been proposed that the gelatinases may have opposite effect on inflammation/regulation and cardiac remodeling. MMP-2 would participate in regulation, offering a protective role for cardiac damage in asymptomatic patients and would be a good marker for the initiation of changes in the heart. On the other hand, MMP-9 can be used as a marker for serious changes on the heart and would be associated with inflammation and fibrosis. Here, we consolidate all characteristics involving MMP-2 and MMP-9 in Chagas' disease based on current studies to clarify their participation on the inflammation/regulation and fibrosis, and the synergistic or antagonistic role between them.

Matrix metalloproteases expression in different histological types of colorectal polyps

INTRODUCTION

Colorectal carcinoma (CC) may begin as benign polyps, which may be classified in different histological types with a different risk to develop cancer. Matrix metalloproteases (MMPs) are able to degrade all components in the extracellular matrix and are important tissue-remodeling enzymes and key elements in tumor invasion and metastasis. The aim of this study was to investigate the expression and clinical relevance of MMPs in different histological types of colorectal polyps.

METHODS

The expression levels of MMP-1, 2, 7, 9, 11, 13 and 14 were analyzed by real-time PCR, Western-blot and immunohistochemistry in 50 patients with different histological types of colorectal polyps, 28 of which developed CC.

RESULTS

The results indicate that hyperplastic polyps had the lowest levels of MMP-1 and MMP-7, tubular polyps showed higher levels of both MMP-7 and MMP-14, and tubulovillous adenoma showed higher levels of MMP-1, MMP-7 and MMP-14.

CONCLUSION

MMP expression was decreased in hyperplastic, tubular and tubulovillous adenoma polyps from patients who developed CC. Our findings suggest that MMP expression may be a pathological marker of colorectal polyps and for cancer susceptibility, which may improve strategies for CC prevention based on screening colonoscopy.

Early and late gene expression profiles of the ovine mucosa in response to Haemonchus contortus infection employing Illumina RNA-seq technology

We conducted herein transcriptome sequencing of the ovine abomasal tissues using the Illumina HiSeq 4000 platform to segregate early and late H. contortus-infected sheep (7 and 50days post-infected groups, respectively) from the control naive ones. A total of 548, 357 and 7 were substantially induced genes in 7days post-infection versus uninfected-control group, 50days post-infection versus 7days post-infection (7dpi), and 50days post-infection (50dpi) versus uninfected-control group, respectively. However, a total of 301, 355 and 11 were significantly repressed genes between 7dpi versus uninfected-control group, 50dpi versus 7dpi, and 50dpi versus uninfected-control group, correspondingly. This indicates that H. contortus infection induced a more potent activation of abomasal gene expression in the early stage of infection as compared to the late stage. Seven pathways were annotated by Kyoto Encyclopedia of Genes, and Genomes pathway analysis accounted for the significant percentage in early H. contortus infection. This study shows for the first time that both galectin-11 and matricellular protein osteopontin are up-regulated in abomasal tissue after chronic H. contortus infection, while galectin-4 is specifically down-regulated in the early infection. Additionally, our results showed that the induction or repression of these molecules is likely to determine the infection progression.

Folic Acid Modulates Matrix Metalloproteinase-2 Expression, Alleviates Neuropathic Pain, and Improves Functional Recovery in Spinal Cord-Injured Rats

BACKGROUND

The molecular underpinnings of spinal cord injury (SCI) associated with neuropathic pain (NP) are unknown. Recent studies have demonstrated that matrix metalloproteinases (MMPs) such as MMP2 play a critical role in inducing NP following SCI. Promoter methylation of MMPs is known to suppress their transcription and reduce NP. In this context, it has been shown in rodents that folic acid (FA), an FDA approved dietary supplement and key methyl donor in the central nervous system (CNS), increases axonal regeneration and repair of injured CNS in part via methylation.

PURPOSE

Based on above observations, in this study, we test whether FA could decrease MMP2 expression and thereby decrease SCI-induced NP.

METHODS

Sprague-Dawley male rats weighing 250-270 g received contusion spinal cord injuries (cSCIs) with a custom spinal cord impactor device that drops a 10 g weight from a height of 12.5 mm. The injured rats received either i.p. injections of FA (80 µg/kg) or water (control) 3 days prior and 17 days post-cSCI (mid phase) or for 3 days pre-cSCI and 14 days post-cSCI ending on the 42nd day of cSCI (late phase). The functional neurological deficits due to cSCI were then assessed by Basso, Beattie, and Bresnahan (BBB) scores either on post-impaction days 0 through 18 post-cSCI (mid phase) or on days 0, 2, 7, 14, 21, 28, 35, and 42 (late phase). Baseline measurements were taken the day before starting treatments. Thermal hyperalgesia (TH) testing for pain was performed on 4 days pre-cSCI (baseline data) and on days 18, 21, 28, 35, and 42 post-cSCI. Following TH testing, animals were euthanized and spinal cords harvested for MMP-2 expression analysis.

RESULT

The FA-treated groups showed higher BBB scores during mid phase (day 18) and in late phase (day 42) of injury compared to controls, suggesting enhanced functional recovery. There is a transient decline in TH in animals from the FA-treated group compared to controls when tested on days 18, 21, 28, and 35, indicative of a decrease in NP. However, when tested 25 days after stopping FA administration on day 42 of cSCI, no significant difference in TH was observed between FA-treated and control animals. Western blot analysis of the injured spinal cord from FA-treated animals showed significant decline in MMP2 expression compared to spinal cord samples from water-treated controls.

CONCLUSION

Together, these data suggest that FA could alleviate NP and improve functional recovery post-SCI, possibly by reducing the expression of MMP2. Further studies will open up a novel and easy natural therapy, ideal for clinical translation with minimal side effects, for managing SCI-induced NP. Such studies might also throw light on a possible epigenetic mechanism in FA-induced recovery after SCI.

Matrix Metalloproteinase Inhibitors as Investigational and Therapeutic Tools in Unrestrained Tissue Remodeling and Pathological Disorders

Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes that degrade various proteins in the extracellular matrix (ECM). MMPs may also regulate the activity of membrane receptors and postreceptor signaling mechanisms and thereby affect cell function. The MMP family includes collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs, and other MMPs. Inactive proMMPs are cleaved by other MMPs or proteases into active MMPs, which interact with various protein substrates in ECM and cell surface. MMPs regulate important biological processes such as vascular remodeling and angiogenesis and may be involved in the pathogenesis of cardiovascular disorders such as hypertension, atherosclerosis, and aneurysm. The role of MMPs is often assessed by measuring their mRNA expression, protein levels, and proteolytic activity using gel zymography. MMP inhibitors are also used to assess the role of MMPs in different biological processes and pathological conditions. MMP activity is regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP balance could determine the net MMP activity, ECM turnover, and tissue remodeling. Also, several synthetic MMP inhibitors have been developed. Synthetic MMP inhibitors include a large number of zinc-binding globulins (ZBGs), in addition to non-ZBGs and mechanism-based inhibitors. MMP inhibitors have been proposed as potential tools in the management of osteoarthritis, cancer, and cardiovascular disorders. However, most MMP inhibitors have broad-spectrum actions on multiple MMPs and could cause undesirable musculoskeletal side effects. Currently, doxycycline is the only MMP inhibitor approved by the Food and Drug Administration. New generation biological and synthetic MMP inhibitors may show greater MMP specificity and fewer side effects and could be useful in targeting specific MMPs, reducing unrestrained tissue remodeling, and the management of MMP-related pathological disorders.

Spondyloarthritis: Matrix Metalloproteinasesas Biomarkers of Pathogenesis and Response to Tumor Necrosis Factor (TNF) Inhibitors

The term spondyloarthritis (SpA) is used to describe a group of multifactorial chronic inflammatory diseases characterized by a predisposing genetic background and clinical manifestations typically involving the sacroiliac joint. The absence of pathognomonic clinical and/or laboratory findings generally results in a delay in diagnosis and, consequently, in treatment. In addition, 20–40% of SpA patients are non-responders to tumor necrosis factor (TNF) inhibitor therapies. Given these considerations, it is important to identify biomarkers that can facilitate the diagnosis and assessment of disease activity. As inflammation plays a key role in the pathogenesis of SpA, inflammatory mediators have been investigated as potential biomarkers for diagnosing the disease and predicting response to therapy. Some investigators have focused their attention on the role of matrix metalloproteinases (MMPs), which are known to be markers of synovial inflammation that is generated in the joint in reaction to inflammatory stimuli. Several studies have been carried out to verify if serum MMPs levels could be useful to diagnose SpA, to assess disease severity, and to predict response to TNF inhibitor therapy. The current review focuses on MMPs’ role in SpA pathogenesis, diagnosis and therapeutic implications.

Endoplasmic Reticulum Stress and Homeostasis in Reproductive Physiology and Pathology

The endoplasmic reticulum (ER), comprises 60% of the total cell membrane and interacts directly or indirectly with several cell organelles i.e., Golgi bodies, mitochondria and proteasomes. The ER is usually associated with large numbers of attached ribosomes. During evolution, ER developed as the specific cellular site of synthesis, folding, modification and trafficking of secretory and cell-surface proteins. The ER is also the major intracellular calcium storage compartment that maintains cellular calcium homeostasis. During the production of functionally effective proteins, several ER-specific molecular steps sense quantity and quality of synthesized proteins as well as proper folding into their native structures. During this process, excess accumulation of unfolded/misfolded proteins in the ER lumen results in ER stress, the homeostatic coping mechanism that activates an ER-specific adaptation program, (the unfolded protein response; UPR) to increase ER-associated degradation of structurally and/or functionally defective proteins, thus sustaining ER homeostasis. Impaired ER homeostasis results in aberrant cellular responses, contributing to the pathogenesis of various diseases. Both female and male reproductive tissues undergo highly dynamic cellular, molecular and genetic changes such as oogenesis and spermatogenesis starting in prenatal life, mainly controlled by sex-steroids but also cytokines and growth factors throughout reproductive life. These reproductive changes require ER to provide extensive protein synthesis, folding, maturation and then their trafficking to appropriate cellular location as well as destroying unfolded/misfolded proteins via activating ER-associated degradation mediated proteasomes. Many studies have now shown roles for ER stress/UPR signaling cascades in the endometrial menstrual cycle, ovarian folliculogenesis and oocyte maturation, spermatogenesis, fertilization, pre-implantation embryo development and pregnancy and parturition. Conversely, the contribution of impaired ER homeostasis by severe/prolong ER stress-mediated UPR signaling pathways to several reproductive tissue pathologies including endometriosis, cancers, recurrent pregnancy loss and pregnancy complications associated with pre-term birth have been reported. This review focuses on ER stress and UPR signaling mechanisms, and their potential roles in female and male reproductive physiopathology involving in menstrual cycle changes, gametogenesis, preimplantation embryo development, implantation and placentation, labor, endometriosis, pregnancy complications and preterm birth as well as reproductive system tumorigenesis.

Using Small Angle X-Ray Scattering (SAXS) to Characterize the Solution Conformation and Flexibility of Matrix Metalloproteinases (MMPs)

Small angle X-ray scattering (SAXS) provides information about the conformation and flexibility of proteins in solution, and hence provides complementary structural information to that obtained from X-ray crystallography and nuclear magnetic resonance spectroscopy. In this chapter, we describe the methods for the preparation of matrix metalloproteinase (MMP) samples for SAXS analyses, and for the acquisition, processing and interpretation of the SAXS data.