Hydrolysis of a broad spectrum of extracellular matrix proteins by human macrophage elastase

Implications of MMP-12 in the pathophysiology of ischaemic stroke

This article focuses on the emerging role of matrix metalloproteinase-12 (MMP-12) in ischaemic stroke (IS). MMP-12 expression in the brain increases dramatically in animal models of IS, and its suppression reduces brain damage and promotes neurological, sensorimotor and cognitive functional outcomes. Thus, MMP-12 could represent a potential target for the management of IS. This article provides an overview of MMP-12 upregulation in the brain following IS, its deleterious role in the post-stroke pathogenesis (blood-brain barrier disruption, inflammation, apoptosis and demyelination), possible molecular interactions and mechanistic insights, its involvement in post-ischaemic functional deficits and recovery as well as the limitations, perspectives, challenges and future directions for further research. Prior to testing any MMP-12-targeted therapy in patients with acute IS, additional research is needed to establish the effectiveness of MMP-12 suppression against IS in older animals and in animals with comorbidities. This article also examines the clinical implications of suppressing MMP-12 alone or in combination with MMP-9 for extending the currently limited tissue plasminogen activator therapy time window. Targeting of MMP-12 is expected to have a profound influence on the therapeutic management of IS in the future.

RNA Expression of MMP12 Is Strongly Associated with Inflammatory Bowel Disease and Is Regulated by Metabolic Pathways in RAW 264.7 Macrophages

Macrophage metalloelastase or matrix metalloproteinase-12 (MMP12) is a macrophage-specific proteolytic enzyme involved in the physiopathology of many inflammatory diseases, including inflammatory bowel disease. Although previously published data suggested that the modulation of MMP12 in macrophages could be a determinant for the development of intestinal inflammation, scarce information is available on the mechanisms underlying the regulation of MMP12 expression in those phagocytes. Therefore, in this study, we aimed to delineate the association of MMP12 with inflammatory bowel disease and the molecular events leading to the transcriptional control of this metalloproteinase. For that, we used publicly available transcriptional data. Also, we worked with the RAW 264.7 macrophage cell line for functional experiments. Our results showed a strong association of MMP12 expression with the severity of inflammatory bowel disease and the response to relevant biological therapies. In vitro assays revealed that the inhibition of mechanistic target of rapamycin complex 1 (mTORC1) and the stimulation of the AMP-activated protein kinase (AMPK) signaling pathway potentiated the expression of Mmp12. Additionally, AMPK and mTOR required a functional downstream glycolytic pathway to fully engage with Mmp12 expression. Finally, the pharmacological inhibition of MMP12 abolished the expression of the proinflammatory cytokine Interleukin-6 (Il6) in macrophages. Overall, our findings provide a better understanding of the mechanistic regulation of MMP12 in macrophages and its relationship with inflammation.

Development of Matrix Metalloproteinases-Mediated Extracellular Matrix Remodeling in Regenerative Medicine: A Mini Review

Extracellular matrix (ECM) components confer biomechanical properties, maintain cell phenotype and mediate tissue homeostasis. ECM remodeling is complex and plays a key role in both physiological and pathological processes. Matrix metalloproteinases (MMPs) are a group of enzymes responsible for ECM degradation and have been accepted as a key regulator in ECM remodeling. In this mini-review, we summarize MMPs categories, functions and the targeted substrates. We then discuss current understanding of the role of MMPs-mediated events, including inflammation reaction, angiogenesis, cellular activities, etc., in ECM remodeling in the context of regenerative medicine.

Endothelial glycocalyx in retina, hyperglycemia, and diabetic retinopathy

The endothelial glycocalyx (EG) is a meshlike network present on the apical surface of the endothelium. Membrane-bound proteoglycans, the major backbone molecules of the EG, consist of glycosaminoglycans attached to core proteins. In addition to maintaining the integrity of the endothelial barrier, the EG regulates inflammation and perfusion and acts as a mechanosensor. The loss of the EG can cause endothelial dysfunction and drive the progression of vascular diseases including diabetic retinopathy. Therefore, the EG presents a novel therapeutic target for treatment of vascular complications. In this review article, we provide an overview of the structure and function of the EG in the retina. Our particular focus is on hyperglycemia-induced perturbations in the glycocalyx structure in the retina, potential underlying mechanisms, and clinical trials studying protective treatments against degradation of the EG.

Contribution of adaptive immunity to human COPD and experimental models of emphysema

The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction.

The expression of matrix metalloproteinase-12 in the peritoneum of rats with continuous peritoneal dialysis

BACKGROUND

Peritoneal dialysis (PD) is an important alternative treatment for end-stage renal disease. Continuous exposure to non-physiological fluids during PD is associated with pathological responses, such as sustained microinflammation, leading to tissue fibrosis and angiogenesis. However, the effect of PD fluid on submesothelial cells has not yet been investigated in detail.

METHODS

We investigated the association between macrophages and the expression of matrix metalloproteinase-12 (MMP-12), an elastin proteinase secreted by macrophages, in the peritoneal tissue of rats undergoing continuous PD.

RESULTS

Morphological data revealed that the submesothelial layer of the peritoneum in PD model rats was markedly thickened, with fibrosis and angiogenesis. In the fibrillization area, elastin was disorganized and fragmented, and macrophages accumulated, which tended to have M2 characteristics. The expression of MMP-12 was enhanced by continuous exposure to PD fluid, suggesting that MMP-12 expression may be involved in PD fluid-induced peritoneal damage.

CONCLUSIONS

The results of this study may lead to a better understanding of the mechanisms underlying fibrosis in PD.

Single-cell and spatial transcriptomics reveal aberrant lymphoid developmental programs driving granuloma formation

Granulomas are lumps of immune cells that can form in various organs. Most granulomas appear unstructured, yet they have some resemblance to lymphoid organs. To better understand granuloma formation, we performed single-cell sequencing and spatial transcriptomics on granulomas from patients with sarcoidosis and bioinformatically reconstructed the underlying gene regulatory networks. We discovered an immune stimulatory environment in granulomas that repurposes transcriptional programs associated with lymphoid organ development. Granuloma formation followed characteristic spatial patterns and involved genes linked to immunometabolism, cytokine and chemokine signaling, and extracellular matrix remodeling. Three cell types emerged as key players in granuloma formation: metabolically reprogrammed macrophages, cytokine-producing Th17.1 cells, and fibroblasts with inflammatory and tissue-remodeling phenotypes. Pharmacological inhibition of one of the identified processes attenuated granuloma formation in a sarcoidosis mouse model. We show that human granulomas adopt characteristic aspects of normal lymphoid organ development in aberrant combinations, indicating that granulomas constitute aberrant lymphoid organs.

Molecular Assessment of Healthy Pathological Articular Cartilages in Physically Active People: A Scoping Review

Physiological aging triggers a cascade of negative effects on the human body and the human joint is only one of the several compartments affected by this irreversible and natural process. Osteoarthritis and cartilage degeneration can cause pain and disability; therefore, identifying the molecular processes underlying these phenomena and the biomarkers produced during physical activity is of critical importance. In the present review, the main goal was to identify and discuss the articular cartilage biomarkers analyzed in studies in which physical or sports activities were adopted and eventually to propose a standard operating procedure for the assessment. Articles collected from Pubmed, Web of Science, and Scopus were scrutinized to detect reliable cartilage biomarkers. The principal articular cartilage biomarkers detected in these studies were cartilage oligomeric matrix protein, matrix metalloproteinases, interleukins, and carboxy-terminal telopeptide. The articular cartilage biomarkers identified in this scoping review may aid in a better comprehension of where research on the topic is heading and offer a viable instrument for streamlining investigations on cartilage biomarker discovery.

Macrophage elastase derived from adventitial macrophages modulates aortic remodeling

Abdominal aortic aneurysm (AAA) is pathologically characterized by intimal atherosclerosis, disruption and attenuation of the elastic media, and adventitial inflammatory infiltrates. Although all these pathological events are possibly involved in the pathogenesis of AAA, the functional roles contributed by adventitial inflammatory macrophages have not been fully documented. Recent studies have revealed that increased expression of matrix metalloproteinase-12 (MMP-12) derived from macrophages may be particularly important in the pathogenesis of both atherosclerosis and AAA. In the current study, we developed a carrageenan-induced abdominal aortic adventitial inflammatory model in hypercholesterolemic rabbits and evaluated the effect of adventitial macrophage accumulation on the aortic remodeling with special reference to the influence of increased expression of MMP-12. To accomplish this, we compared the carrageenan-induced aortic lesions of transgenic (Tg) rabbits that expressed high levels of MMP-12 in the macrophage lineage to those of non-Tg rabbits. We found that the aortic medial and adventitial lesions of Tg rabbits were greater in degree than those of non-Tg rabbits, with the increased infiltration of macrophages and prominent destruction of elastic lamellae accompanied by the frequent appearance of dilated lesions, while the intimal lesions were slightly increased. Enhanced aortic lesions in Tg rabbits were focally associated with increased dilation of the aortic lumens. RT-PCR and Western blotting revealed high levels of MMP-12 in the lesions of Tg rabbits that were accompanied by elevated levels of MMP-2 and -3, which was caused by increased number of macrophages. Our results suggest that adventitial inflammation constitutes a major stimulus to aortic remodeling and increased expression of MMP-12 secreted from adventitial macrophages plays an important role in the pathogenesis of vascular diseases such as AAA.

The Damaging Effects of Long UVA (UVA1) Rays: A Major Challenge to Preserve Skin Health and Integrity

Within solar ultraviolet (UV) light, the longest UVA1 wavelengths, with significant and relatively constant levels all year round and large penetration properties, produce effects in all cutaneous layers. Their effects, mediated by numerous endogenous chromophores, primarily involve the generation of reactive oxygen species (ROS). The resulting oxidative stress is the major mode of action of UVA1, responsible for lipid peroxidation, protein carbonylation, DNA lesions and subsequent intracellular signaling cascades. These molecular changes lead to mutations, apoptosis, dermis remodeling, inflammatory reactions and abnormal immune responses. The altered biological functions contribute to clinical consequences such as hyperpigmentation, inflammation, photoimmunosuppression, sun allergies, photoaging and photocancers. Such harmful impacts have also been reported after the use of UVA1 phototherapy or tanning beds. Furthermore, other external aggressors, such as pollutants and visible light (Vis), were shown to induce independent, cumulative and synergistic effects with UVA1 rays. In this review, we synthetize the biological and clinical effects of UVA1 and the complementary effects of UVA1 with pollutants or Vis. The identified deleterious biological impact of UVA1 contributing to clinical consequences, combined with the predominance of UVA1 rays in solar UV radiation, constitute a solid rational for the need for a broad photoprotection, including UVA1 up to 400 nm.

Macrophage elastase (MMP12) critically contributes to the development of subretinal fibrosis

Background

Macular subretinal fibrosis is the end-stage complication of neovascular age-related macular degeneration (nAMD). We previously developed a mouse model of two-stage laser-induced subretinal fibrosis that mimics closely the dynamic course of macular fibrosis in nAMD patients. This study was aimed to understand the molecular mechanism of subretinal fibrosis.

Methods

Subretinal fibrosis was induced in C57BL/6J mice using the two-stage laser-induced protocol. Twenty days later, eyes were collected and processed for RNA sequencing (RNA-seq) analysis. DESeq2 was used to determine the differentially expressed genes (DEGs). Gene Ontology (GO) and KEGG were used to analyze the enriched pathways. The expression of the selected DEGs including Mmp12 was verified by qPCR. The expression of MMP12 in subretinal fibrosis of mouse and nAMD donor eyes was examined by immunofluorescence and confocal microscopy. The expression of collagen 1, αSMA and fibronectin and cytokines in bone marrow-derived macrophages from control and subretinal fibrosis mice were examined by qPCR, immunocytochemistry and Luminex multiplex cytokine assay. The MMP12 specific inhibitor MMP408 was used to evaluate the effect of MMP12 on TGFβ-induced macrophage-to-myofibroblast transition (MMT) in vitro and its role in subretinal fibrosis in vivo.

Results

RNA-seq analysis of RPE-choroid from subretinal fibrosis eyes uncovered 139 DEGs (fold change log2(fc) ≥ 0.5, FDR < 0.05), including 104 up-regulated and 35 were down-regulated genes. The top 25 enrichment GO terms were related to inflammation, blood vessels/cardiovascular development and angiogenesis. One of the most significantly upregulated genes, Mmp12, contributed to 12 of the top 25 GO terms. Higher levels of MMP12 were detected in subretinal fibrotic lesions in nAMD patients and the mouse model, including in F4/80⁺ or Iba1⁺ macrophages. BMDMs from subretinal fibrosis mice expressed higher levels of MMP12, collagen-1, αSMA and fibronectin. MMP408 dose-dependently suppressed TGFβ-induced MMT in BMDMs. In vivo treatment with MMP408 (5 mg/kg) significantly reduced subretinal fibrosis accompanied by reduced F4/80⁺ macrophage infiltration.

Conclusions

MMP12 critically contributes to the development of subretinal fibrosis, partially through promoting MMT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02433-x.

Multiplex quantification of C-terminal alpha-1-antitrypsin peptides provides a novel approach for characterizing systemic inflammation

C-terminal peptides (CAAPs) of the highly abundant serine protease alpha-1-antitrypsin (A1AT) have been identified at various lengths in several human materials and have been proposed to serve as putative biomarkers for a variety of diseases. CAAPs are enzymatically formed and these enzymatic activities are often associated with excessive immune responses (e.g. sepsis, allergies). However, most of those CAAPs have been either detected using in vitro incubation experiments or in human materials which are not easily accessible. To gain a comprehensive understanding about the occurrence and function of CAAPs in health and disease, a LC-MS/MS method for the simultaneous detection of nine CAAPs was developed and validated for human plasma (EDTA and lithium-heparin) and serum. Using this newly developed method, we were able to detect and quantify five CAAPs in healthy individuals thereby providing an initial proof for the presence of C36, C37, C40 and C44 in human blood. Concentrations of four CAAPs in a clinical test cohort of patients suffering from sepsis were significantly higher compared to healthy controls. These results reveal that in addition to C42 other fragments of A1AT seem to play a crucial role during systemic infections. The proposed workflow is simple, rapid and robust; thus this method could be used as diagnostic tool in routine clinical chemistry as well as for research applications for elucidating the diagnostic potential of CAAPs in numerous diseases. To this end, we also provide an overview about the current state of knowledge for CAAPs identified in vitro and in vivo.

Matrix Metalloproteinase MMP-12 Promotes Macrophage Transmigration Across Intestinal Epithelial Tight Junctions and Increases Severity of Experimental Colitis

BACKGROUND AND AIMS

Matrix metalloproteinases [MMPs] play an important role in extracellular matrix regulation during cell growth and wound healing. Increased expression of MMP-12 [human macrophage elastase] has been reported in inflammatory bowel disease [IBD] which is characterised by the loss of epithelial tight junction [TJ] barrier function and an excessive inflammatory response. The aim of this study was to investigate the role of MMP-12 in intestinal TJ barrier function and inflammation.

METHODS

Wild type [WT] and MMP-12-/- mice were subjected to experimental acute or chronic dextran sodium sulphate [DSS] colitis. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon and ex vivo by Ussing chamber studies.

RESULTS

DSS administration increased colonic permeability through modulation of TJ proteins and also increased MMP-12 expression in the colonic mucosa of WT mice. The acute as well as chronic DSS-induced increase in colonic TJ permeability and the severity of DSS colitis was found to be markedly attenuated in MMP-12-/- mice. The resistance of MMP-12-/- mice to DSS colitis was characterised by reduced macrophage infiltration and transmigration, and reduced basement membrane laminin degradation. Further in vitro and in vivo studies show that macrophage transmigration across the epithelial layer is MMP-12 dependent and the epithelial TJ barrier is compromised during macrophage transmigration. Conclusions: Together, these data demonstrate that MMP-12 mediated degradation of basement membrane laminin, macrophage transmigration, and associated loss of intestinal TJ barrier are key pathogenic factors for intestinal inflammation.

Single-cell RNA-seq reveals functionally distinct biomaterial degradation-related macrophage populations

Macrophages play crucial roles in host tissue reaction to biomaterials upon implantation in vivo. However, the complexity of biomaterial degradation-related macrophage subpopulations that accumulate around the implanted biomaterials in situ is not fully understood. Here, using single cell RNA-seq, we analyze the transcriptome profiles of the various cell types around the scaffold to map the scaffold-induced reaction, in an unbiased approach. This enables mapping of all biomaterial degradation-associated cells at high resolution, revealing distinct subpopulations of tissue-resident macrophages as the major cellular sources of biomaterial degradation in situ. We also find that scaffold architecture can affect the mechanotransduction and catabolic activity of specific material degradation-related macrophage subpopulations in an Itgav-Mapk1-Stat3 dependent manner, eventually leading to differences in scaffold degradation rate in vivo. Our work dissects unanticipated aspects of the cellular and molecular basis of biomaterial degradation at the single-cell level, and provides a conceptual framework for developing functional tissue engineering scaffolds in future.

Protective effects of HBOC on pulmonary vascular leakage after haemorrhagic shock and the underlying mechanisms

Volume resuscitation is an important early treatment for haemorrhagic shock. Haemoglobin-based oxygen carrier (HBOC) can expand the volume and provide oxygen for tissues. Vascular leakage is common complication in the process of haemorrhagic shock and resuscitation. The aim of this study was to observe the effects of HBOC (a bovine-derived, cross-linked tetramer haemoglobin oxygen-carrying solution, 0.5 g/L) on vascular leakage in rats after haemorrhagic shock. A haemorrhagic shock rat model and hypoxic vascular endothelial cells (VECs) were used. The role of intercellular junctions and endothelial glycocalyx in the protective effects of HBOC and the relationship with mitochondrial function were analysed. After haemorrhagic shock, the pulmonary vascular permeability to FITC-BSA, Evans Blue was increased, endothelial glycocalyx was destroyed and the expression of intercellular junction proteins was decreased. After haemorrhagic shock, a small volume of HBOC solution (6 ml/kg) protected pulmonary vascular permeability, increased structural thickness of endothelial glycocalyx, the levels of its components and increased expression levels of the intercellular junction proteins ZO-1, VE-cadherin and occludin. Moreover, HBOC significantly increased oxygen delivery and consumption in rats, improved VEC mitochondrial function and structure. In conclusion, HBOC mitigates endothelial leakage by protecting endothelial glycocalyx and intercellular junctions through improving mitochondrial function and tissue oxygen delivery.

Genetic variations associated with non-contact muscle injuries in sport: A systematic review

INTRODUCTION

Non-contact muscle injuries (NCMI) account for a large proportion of sport injuries, affecting athletes' performance and career, team results and financial aspects. Recently, genetic factors have been attributed a role in the susceptibility of an athlete to sustain NCMI. However, data in this field are only just starting to emerge.

OBJECTIVES

To review available knowledge of genetic variations associated with sport-related NCMI.

METHODS

The databases Pubmed, Scopus, and Web of Science were searched for relevant articles published until February 2021. The records selected for review were original articles published in peer-reviewed journals describing studies that have examined NCMI-related genetic variations in adult subjects (17-60 years) practicing any sport. The data extracted from the studies identified were as follows: general information, and data on genetic polymorphisms and NCMI risk, incidence and recovery time and/or severity.

RESULTS

Seventeen studies examining 47 genes and 59 polymorphisms were finally included. 29 polymorphisms affecting 25 genes were found significantly associated with NCMI risk, incidence, recovery time, and/or severity. These genes pertain to three functional categories: (i) muscle fiber structural/contractile properties, (ii) muscle repair and regeneration, or (iii) muscle fiber external matrix composition and maintenance.

CONCLUSION

Our review confirmed the important role of genetics in NCMI. Some gene variants have practical implications such as differences of several weeks in recovery time detected between genotypes. Knowledge in this field is still in its early stages. Future studies need to examine a wider diversity of sports and standardize their methods and outcome measures.

Macrophage depletion induces edema through release of matrix-degrading proteases and proteoglycan deposition

Colony-stimulating factor 1 receptor (CSF1R) blockade abates tumor-associated macrophage (TAM) infiltrates and provides marked clinical benefits in diffuse-type tenosynovial giant cell tumors. However, facial edema is a common adverse event associated with TAM elimination in patients. In this study, we examined molecular and cellular events associated with edema formation in mice and human patients with cancer treated with a CSF1R blocking antibody. Extended antibody treatment of mice caused marked body weight gain, an indicator of enhanced body fluid retention. This was associated with an increase of extracellular matrix-remodeling metalloproteinases (MMPs), namely MMP2 and MMP3, and enhanced deposition of hyaluronan (HA) and proteoglycans, leading to skin thickening. Discontinuation of anti-CSF1R treatment or blockade of MMP activity restored unaltered body weight and normal skin morphology in the mice. In patients, edema developed at doses well below the established optimal biological dose for emactuzumab, a CSF1R dimerization inhibitor. Patients who developed edema in response to emactuzumab had elevated HA in peripheral blood. Our findings indicate that an early increase of peripheral HA can serve as a pharmacodynamic marker for edema development and suggest potential interventions based on MMP inhibition for relieving periorbital edema in patients treated with CSF1R inhibitors.

Current Perspectives on the Role of Matrix Metalloproteinases in the Pathogenesis of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common skin malignancy, which rarely metastasizes but has a great ability to infiltrate and invade the surrounding tissues. One of the molecular players involved in the metastatic process are matrix metalloproteinases (MMPs). MMPs are enzymes that can degrade various components of the extracellular matrix. In the skin, the expression of MMPs is increased in response to various stimuli, including ultraviolet (UV) radiation, one of the main factors involved in the development of BCC. By modulating various processes that are linked to tumor growth, such as invasion and angiogenesis, MMPs have been associated with UV-related carcinogenesis. The sources of MMPs are multiple, as they can be released by both neoplastic and tumor microenvironment cells. Inhibiting the action of MMPs could be a useful therapeutic option in BCC management. In this review that reunites the latest advances in this domain, we discuss the role of MMPs in the pathogenesis and evolution of BCC, as molecules involved in tumor aggressiveness and risk of recurrence, in order to offer a fresh and updated perspective on this field.

Epilobium angustifolium L. Extracts as Valuable Ingredients in Cosmetic and Dermatological Products

Epilobium angustifolium L. is a popular and well-known medicinal plant. In this study, an attempt to evaluate the possibility of using this plant in preparations for the care and treatment of skin diseases was made. The antioxidant, antiaging and anti-inflammatory properties of ethanolic extracts from Epilobium angustifolium (FEE) were assessed. Qualitative and quantitative evaluation of extracts chemically composition was performed by gas chromatography with mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The total polyphenol content (TPC) of biologically active compounds, such as the total content of polyphenols (TPC), flavonoids (TFC), and assimilation pigments, as well as selected phenolic acids, was assessed. FEE was evaluated for their anti-inflammatory and antiaging properties, achieving 68% inhibition of lipoxygenase activity, 60% of collagenase and 49% of elastase. FEE also showed high antioxidant activity, reaching to 87% of free radical scavenging using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 59% using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Additionally, in vitro penetration studies were performed using two vehicles, i.e., a hydrogel and an emulsion containing FEE. These studies showed that the active ingredients contained in FEE penetrate through human skin and accumulate in it. The obtained results indicate that E. angustifolium may be an interesting plant material to be applied as a component of cosmetic and dermatological preparations with antiaging and anti-inflammatory properties.

Elastic fibers: formation, function, and fate during aging and disease

Elastic fibers are extracellular components of higher vertebrates and confer elasticity and resilience to numerous tissues and organs such as large blood vessels, lungs, and skin. Their formation and maturation take place in a complex multistage process called elastogenesis. It requires interactions between very different proteins but also other molecules and leads to the deposition and crosslinking of elastin's precursor on a scaffold of fibrillin-rich microfibrils. Mature fibers are exceptionally resistant to most influences and, under healthy conditions, retain their biomechanical function over the life of the organism. However, due to their longevity, they accumulate damages during aging. These are caused by proteolytic degradation, formation of advanced glycation end products, calcification, oxidative damage, aspartic acid racemization, lipid accumulation, carbamylation, and mechanical fatigue. The resulting changes can lead to diminution or complete loss of elastic fiber function and ultimately affect morbidity and mortality. Particularly, the production of elastokines has been clearly shown to influence several life-threatening diseases. Moreover, the structure, distribution, and abundance of elastic fibers are directly or indirectly influenced by a variety of inherited pathological conditions, which mainly affect organs and tissues such as skin, lungs, or the cardiovascular system. A distinction can be made between microfibril-related inherited diseases that are the result of mutations in diverse microfibril genes and indirectly affect elastogenesis, and elastinopathies that are linked to changes in the elastin gene. This review gives an overview on the formation, structure, and function of elastic fibers and their fate over the human lifespan in health and disease.

A guide to the composition and functions of the extracellular matrix

Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.

RNA sequencing identifies transcriptional changes in the rabbit larynx in response to low humidity challenge

BACKGROUND

Voice disorders are a worldwide problem impacting human health, particularly for occupational voice users. Avoidance of surface dehydration is commonly prescribed as a protective factor against the development of dysphonia. The available literature inconclusively supports this practice and a biological mechanism for how surface dehydration of the laryngeal tissue affects voice has not been described. In this study, we used an in vivo male New Zealand white rabbit model to elucidate biological changes based on gene expression within the vocal folds from surface dehydration. Surface dehydration was induced by exposure to low humidity air (18.6% + 4.3%) for 8 h. Exposure to moderate humidity (43.0% + 4.3%) served as the control condition. Ilumina-based RNA sequencing was performed and used for transcriptome analysis with validation by RT-qPCR.

RESULTS

There were 103 statistically significant differentially expressed genes identified through Cuffdiff with 61 genes meeting significance by both false discovery rate and fold change. Functional annotation enrichment and predicted protein interaction mapping showed enrichment of various loci, including cellular stress and inflammatory response, ciliary function, and keratinocyte development. Eight genes were selected for RT-qPCR validation. Matrix metalloproteinase 12 (MMP12) and macrophage cationic peptide 1 (MCP1) were significantly upregulated and an epithelial chloride channel protein (ECCP) was significantly downregulated after surface dehydration by RNA-Seq and RT-qPCR. Suprabasin (SPBN) and zinc activated cationic channel (ZACN) were marginally, but non-significantly down- and upregulated as evidenced by RT-qPCR, respectively.

CONCLUSIONS

The data together support the notion that surface dehydration induces physiological changes in the vocal folds and justifies targeted analysis to further explore the underlying biology of compensatory fluid/ion flux and inflammatory mediators in response to airway surface dehydration.

Comparison of the Antiaging and Protective Properties of Plants from the Apiaceae Family

Plant materials play a very significant role as components of products being used both for medicinal and cosmetic purposes. Due to the high content of active substances, they can play an important role as extracts with antioxidant, regenerative, and antiaging properties. The skin aging process depends on various pathological and physiological processes, among which the degradation of extracellular matrix biomolecules such as collagen and elastin, which significantly affect the maintenance of good skin condition, is very important. The secondary metabolites and plant extracts may have collagenase and elastase inhibitory activity. This activity is mainly due to the high content of a wide range of various biologically active compounds, such as polyphenols, which include, among others, flavonoids, phenolic acids, tocopherols, and tannins. The work involved a comprehensive assessment of the plant from Apiaceae family such as Meum athamanticum L., Centella asiatica L., and Aegopodium podagraria L. extract as a multifunctional raw material. During study antioxidant properties, phenolic compounds and flavonoids content, effect on collagenase and elastase enzyme activity (antiaging effect), cytotoxic properties on skin cells (keratinocytes and fibroblasts), and cell migration capacity were analyzed. It has been shown that the highest antioxidant capacity can be observed for the extract of herb of Aegopodium podagraria L. When the concentration reached 5% all tested extracts had a positive effect on the cell proliferation of both keratinocytes and fibroblasts. It turned out that the most promising inhibitor of collagenase and elastase enzymes was the extract from Aegopodium podagraria, which inhibits the activity of both enzymes by over 70% in the concentration of 5% positively affecting the condition of skin cells.

Elastases and elastokines: elastin degradation and its significance in health and disease

Elastin is an important protein of the extracellular matrix of higher vertebrates, which confers elasticity and resilience to various tissues and organs including lungs, skin, large blood vessels and ligaments. Owing to its unique structure, extensive cross-linking and durability, it does not undergo significant turnover in healthy tissues and has a half-life of more than 70 years. Elastin is not only a structural protein, influencing the architecture and biomechanical properties of the extracellular matrix, but also plays a vital role in various physiological processes. Bioactive elastin peptides termed elastokines - in particular those of the GXXPG motif - occur as a result of proteolytic degradation of elastin and its non-cross-linked precursor tropoelastin and display several biological activities. For instance, they promote angiogenesis or stimulate cell adhesion, chemotaxis, proliferation, protease activation and apoptosis. Elastin-degrading enzymes such as matrix metalloproteinases, serine proteases and cysteine proteases slowly damage elastin over the lifetime of an organism. The destruction of elastin and the biological processes triggered by elastokines favor the development and progression of various pathological conditions including emphysema, chronic obstructive pulmonary disease, atherosclerosis, metabolic syndrome and cancer. This review gives an overview on types of human elastases and their action on human elastin, including the formation, structure and biological activities of elastokines and their role in common biological processes and severe pathological conditions.

Sirtuin 1 and endothelial glycocalyx

Sirtuin1 deficiency or reduced activity comprises one of the hallmarks of diseases as diverse as chronic cardiovascular, renal, and metabolic, some malignancies, and infections, as well as aging-associated diseases. In a mouse model of endothelium-limited defect in sirtuin 1 deacetylase activity, we found a dramatic reduction in the volume of endothelial glycocalyx. This was associated with the surge in the levels of one of key scaffolding heparan sulfate proteoglycans of endothelial glycocalyx, syndecan-4, and specifically, its extracellular domain (ectodomain). We found that the defect in endothelial sirtuin 1 deacetylase activity is associated with (a) elevated basal and stimulated levels of superoxide generation (via the FoxO1 over-acetylation mechanism) and (b) increased nuclear translocation of NF-kB (via p65 over-acetylation mechanism). These findings laid the foundation for the proposed novel function of sirtuin 1, namely, the maintenance of endothelial glycocalyx, particularly manifest in conditions associated with sirtuin 1 depletion. In the forthcoming review, we summarize the emerging conceptual framework of the enhanced glycocalyx degradation in the states of defective endothelial sirtuin 1 function, thus explaining a broad footprint of the syndrome of endothelial dysfunction, from impaired flow-induced nitric oxide production, deterrent leukocytes infiltration, increased endothelial permeability, coagulation, and pro-inflammatory changes to development of microvascular rarefaction and progression of an underlying disease.

The Role of Macrophages in Aortic Dissection

Aortic dissection (AD) is a fatal disease that accounts for a large proportion of aortic-related deaths and has an incidence of about 3–4 per 100,000 individuals every year. Recent studies have found that inflammation plays an important role in the development of AD, and that macrophages are the hub of inflammation in the aortic wall. Aortic samples from AD patients reveal a large amount of macrophage infiltration. The sites of macrophage infiltration and activity vary throughout the different stages of AD, with involvement even in the tissue repair phase of AD. Angiotensin II has been shown to be an important factor in the stimulation of macrophage activity. Stimulated macrophages can secrete metalloproteinases, inflammatory factors and other substances to cause matrix destruction, smooth muscle cell apoptosis, neovascularization and more, all of which destroy the aortic wall structure. At the same time, there are a number of factors that regulate macrophages to reduce the formation of AD and induce the repair of torn aortic tissues. The aim of this review is to take a close look at the roles of macrophages throughout the course of AD disease.

Remodeling of the interstitial extracellular matrix in white matter multiple sclerosis lesions: Implications for remyelination (failure)

The extracellular matrix (ECM) provides protection, rigidity, and structure toward cells. It consists, among others, of a wide variety of glycoproteins and proteoglycans, which act together to produce a complex and dynamic environment, most relevant in transmembrane events. In the brain, the ECM occupies a notable proportion of its volume and maintains the homeostasis of central nervous system (CNS). In addition, remodeling of the ECM, that is transient changes in ECM proteins regulated by matrix metalloproteinases (MMPs), is an important process that modulates cell behavior upon injury, thereby facilitating recovery. Failure of ECM remodeling plays an important role in the pathogenesis of multiple sclerosis (MS), a neurodegenerative demyelinating disease of the CNS with an inflammatory response against protective myelin sheaths that surround axons. Remyelination of denuded axons improves the neuropathological conditions of MS, but this regeneration process fails over time, leading to chronic disease progression. In this review, we uncover abnormal ECM remodeling in MS lesions by discussing ECM remodeling in experimental demyelination models, that is when remyelination is successful, and compare alterations in ECM components to the ECM composition and MMP expression in the parenchyma of demyelinated MS lesions, that is when remyelination fails. Inter- and intralesional differences in ECM remodeling in the distinct white matter MS lesions are discussed in terms of consequences for oligodendrocyte behavior and remyelination (failure). Hence, the review will aid to understand how abnormal ECM remodeling contributes to remyelination failure in MS lesions and assists in developing therapeutic strategies to promote remyelination.

MMP-14 degrades tropoelastin and elastin

Matrix metalloproteinases are a class of enzymes, which degrade extracellular matrix components such as collagens, elastin, laminin or fibronectin. So far, four matrix metalloproteinases have been shown to degrade elastin and its precursor tropoelastin, namely matrix metalloproteinase-2, -7, -9 and -12. This study focuses on investigating the elastinolytic capability of membrane-type 1 matrix metalloproteinase, also known as matrix metalloproteinase-14. We digested recombinant human tropoelastin and human skin elastin with matrix metalloproteinase-14 and analyzed the peptide mixtures using complementary mass spectrometric techniques and bioinformatics tools. The results and additional molecular docking studies show that matrix metalloproteinase-14 cleaves tropoelastin as well as elastin. While tropoelastin was well degraded, fewer cleavages occurred in the highly cross-linked mature elastin. The study also provides insights into the cleavage preferences of the enzyme. Similar to cleavage preferences of matrix metalloproteinases-2, -7, -9 and -12, matrix metalloproteinase-14 prefers small and medium-sized hydrophobic residues including Gly, Ala, Leu and Val at cleavage site P1'. Pro, Gly and Ala were preferably found at P1-P4 and P2'-P4' in both tropoelastin and elastin. Cleavage of mature skin elastin by matrix metalloproteinase-14 released a variety of bioactive elastin peptides, which indicates that the enzyme may play a role in the development and progression of cardiovascular diseases that go along with elastin breakdown.

MMP12 preferentially attenuates axial stiffening of aging arteries

Arterial stiffening is a hallmark of aging, but how aging affects the arterial response to pressure is still not completely understood, especially with regard to specific matrix metalloproteinases (MMPs). Here, we used pressure myography of carotid arteries from C57BL/6 mice to study the effects of age and MMP12, a major arterial elastase, on arterial biomechanics. Aging from 2 to 24 months leads to both circumferential and axial stiffening with stretch, and these changes are associated with an increased wall thickness, decreased inner radius, and a decreased in vivo axial stretch ratio (IVSR). Analysis of IVSR and stress-stretch curves with arteries from age- and sex-matched wild-type and MMP12-null arteries demonstrate that MMP12 deletion attenuates age-dependent arterial stiffening, mostly in the axial direction. MMP12 deletion also prevents the aging-associated decrease in the in vivo stretch ratio and, in general, leads to an axial mechanics phenotype characteristic of much younger mice. Circumferential arterial mechanics were much less affected by deletion of MMP12. We conclude that the induction of MMP12 during aging preferentially controls axial arterial mechanics.

A combined microfluidic-transcriptomic approach to characterize the extravasation potential of cancer cells

The reciprocal interaction between circulating tumor cells (CTCs) and tissue-specific cells is influential for the progression of metastases. In particular, the process of extravasation relies on the complex cross-talk between cancer cells and other cellular players such as the endothelium and the secondary tissue. However, most in vitro studies only focus on one heterotypic cell-cell interaction and often lack of physiological relevance. In this project, we investigated both CTC-endothelium and CTC-secondary site interactions during cancer cell extravasation. We first used a microarray analysis of extravasated MDA-MB-231 breast cancer cells to identify key markers involved in extravasation. Then, we developed a tri-culture microfluidic platform combining cancer cells, endothelium and a bone-mimicking (BMi) microenvironment to assess how organ tropism influences the extravasation potential of cancer cells from different tissues. Through the microarray analyses of extravasated cancer cells we found that extravasation is associated with upregulation of late-metastatic markers along with specific proteases, such as matrix metalloprotease (MMP), a-disintegrin and metalloprotease (ADAM) and a-disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family members, which are all involved in endothelium glycocalyx shedding. Through the microfluidic extravasation assay, we found that the bone-like microenvironment increased invasion and motility of breast, bladder and ovarian cancer cell (MDA-MB-231, T24 and OVCAR-3). Among the three cell types, ovarian cancer cells presented the lowest migration rate and bladder cancer cells the highest, hence recapitulating their different level of bone tropism observed in vivo. Taken together, our results shed light on the importance of intercellular communication between CTCs and other non-tumor cells essential for promoting cancer cell extravasation.

A Hydroxypyrone-Based Inhibitor of Metalloproteinase-12 Displays Neuroprotective Properties in Both Status Epilepticus and Optic Nerve Crush Animal Models

Recently, we showed that matrix metalloproteinase-12 (MMP-12) is highly expressed in microglia and myeloid infiltrates, which are presumably involved in blood–brain barrier (BBB) leakage and subsequent neuronal cell death that follows status epilepticus (SE). Here, we assessed the effects of a hydroxypyrone-based inhibitor selective for MMP-12 in the pilocarpine-induced SE rat model to determine hippocampal cell survival. In the hippocampus of rats treated with pilocarpine, intra-hippocampal injections of the MMP-12 inhibitor protected Cornu Ammonis 3 (CA3) and hilus of dentate gyrus neurons against cell death and limited the development of the ischemic-like lesion that typically develops in the CA3 stratum lacunosum-moleculare of the hippocampus. Furthermore, we showed that MMP-12 inhibition limited immunoglobulin G and albumin extravasation after SE, suggesting a reduction in BBB leakage. Finally, to rule out any possible involvement of seizure modulation in the neuroprotective effects of MMP-12 inhibition, neuroprotection was also observed in the retina of treated animals after optic nerve crush. Overall, these results support the hypothesis that MMP-12 inhibition can directly counteract neuronal cell death and that the specific hydroxypyrone-based inhibitor used in this study could be a potential therapeutic agent against neurological diseases/disorders characterized by an important inflammatory response and/or neuronal cell loss.

MMP-12 and S100s in saliva reflect different aspects of periodontal inflammation

Matrix metalloproteinase (MMP)-12, S100A8/A9, and S100A12 are involved in innate immune responses. We addressed whether different aspects of oral health and non-disease-related covariates influence their levels in saliva. 436 participants were clinically examined, completed a health questionnaire, and provided stimulated saliva. Salivary levels of MMP-12, S100A8/A9, and S100A12 were determined by enzyme-linked immunosorbent assays. Lower MMP-12 levels were observed in individuals 40-64 years old (yo) compared to < 40 yo, and higher S100A8/A9 levels were found in individuals > 64 yo compared to 40-64 yo. Smokers exhibited lower MMP-12 and S100A12 levels compared to non-smokers. All three proteins were elevated in individuals with bleeding on probing (BOP) > 20% compared to those with BOP ≤ 20%, and the S100A8/A9 levels were higher in individuals having ≥ 10% gingival pocket depths (PPD) ≥ 4 mm compared to the ones with shallow pockets < 4 mm. The extent of alveolar bone loss or presence of manifest caries did not alter any of the markers. MMP-12, S100A8/A9, and S100A12 levels were higher in participants with high periodontal inflammatory burden. All three proteins correlated positively to BOP, PPD, and to several inflammatory mediators. The explanatory variables for MMP-12 in saliva were age, smoking, presence of any tumor, and percentage of PPD ≥ 4 mm. The determinant of salivary S100A8/A9 was percentage of BOP, while S100A12 levels were associated with percentage of BOP and presence of any tumor. Taken together, MMP-12 and the S100/calgranulin levels in saliva reflect different aspects of periodontal inflammation. Smoking and age should be taken into account in further investigation of these proteins as biomarker candidates of periodontal disease.

A Selective Extracellular Matrix Proteomics Approach Identifies Fibronectin Proteolysis by A Disintegrin-like and Metalloprotease Domain with Thrombospondin Type 1 Motifs (ADAMTS16) and Its Impact on Spheroid Morphogenesis

Secreted and cell-surface proteases are major mediators of extracellular matrix (ECM) turnover, but their mechanisms and regulatory impact are poorly understood. We developed a mass spectrometry approach using a cell-free ECM produced in vitro to identify fibronectin (FN) as a novel substrate of the secreted metalloprotease ADAMTS16. ADAMTS16 cleaves FN between its (I)5 and (I)6 modules, releasing the N-terminal 30 kDa heparin-binding domain essential for FN self-assembly. ADAMTS16 impairs FN fibrillogenesis as well as fibrillin-1 and tenascin-C assembly, thus inhibiting formation of a mature ECM by cultured fibroblasts. Furthermore ADAMTS16 has a marked morphogenetic impact on spheroid formation by renal tubule-derived MDCKI cells. The N-terminal FN domain released by ADAMTS16 up-regulates MMP3, which cleaves the (I)5-(I)6 linker of FN similar to ADAMTS16, therefore creating a proteolytic feed-forward mechanism. Thus, FN proteolysis not only regulates FN turnover, but also FN assembly, with potential long-term consequences for ECM assembly and morphogenesis.

C-terminal truncation of IFN-γ inhibits proinflammatory macrophage responses and is deficient in autoimmune disease

Controlled macrophage differentiation and activation in the initiation and resolution of inflammation is crucial for averting progression to chronic inflammatory and autoimmune diseases. Here we show a negative feedback mechanism for proinflammatory IFN-γ activation of macrophages driven by macrophage-associated matrix metalloproteinase 12 (MMP12). Through C-terminal truncation of IFN-γ at 135Glu↓Leu136 the IFN-γ receptor-binding site was efficiently removed thereby reducing JAK-STAT1 signaling and IFN-γ activation of proinflammatory macrophages. In acute peritonitis this signature was absent in Mmp12^–/– mice and recapitulated in Mmp12^+/+ mice treated with a MMP12-specific inhibitor. Similarly, loss-of-MMP12 increases IFN-γ–dependent proinflammatory markers and iNOS⁺/MHC class II⁺ macrophage accumulation with worse lymphadenopathy, arthritic synovitis and lupus glomerulonephritis. In active human systemic lupus erythematosus, MMP12 levels were lower and IFN-γ higher compared to treated patients or healthy individuals. Hence, macrophage proteolytic truncation of IFN-γ attenuates classical activation of macrophages as a prelude for resolving inflammation.

IFN-γ is central in inflammatory pathogenesis, response to infection and autoimmune diseases. Here the authors show that MMP12 expression is reduced in patients with SLE and that MMP12 post-translationally truncates IFN-y, inhibiting its function and affecting pathogenesis of mouse models of peritonitis, SLE and rheumatoid arthritis.

Perioperative implication of the endothelial glycocalyx

The endothelial glycocalyx (EG) is a gel-like layer lining the luminal surface of healthy vascular endothelium. Recently, the EG has gained extensive interest as a crucial regulator of endothelial funtction, including vascular permeability, mechanotransduction, and the interaction between endothelial and circulating blood cells. The EG is degraded by various enzymes and reactive oxygen species upon pro-inflammatory stimulus. Ischemia-reperfusion injury, oxidative stress, hypervolemia, and systemic inflammatory response are responsible for perioperative EG degradation. Perioperative damage of the EG has also been demonstrated, especially in cardiac surgery. However, the protection of the EG and its association with perioperative morbidity needs to be elucidated in future studies. In this review, the present knowledge about EG and its perioperative implication is discussed from an anesthesiologist's perspective.

Role of the Glycocalyx as a Barrier to Leukocyte-Endothelium Adhesion

Leukocyte (WBC) to endothelial cell (EC) adhesion is a receptor-mediated process governed by the avidity and affinity of selectins, which modulate adhesive forces during WBC rolling, and integrins, which determine the strength of firm adhesion. Adhesion receptors on the EC surface lie below an endothelial surface layer (ESL) comprised of the EC glycocalyx and adsorbed proteins which, in vivo, have a thickness on the order 500 nm. The glycocalyx consists of a matrix of the glycosaminoglycans heparan sulfate and chondroitin sulfate, bound to proteoglycans and encased in hyaluronan. Together, these carbohydrates form a layer that varies in glycan content along the length of post-capillary venules where WBC-EC adhesion occurs. Thickness and porosity of the glycocalyx can vary dramatically during the inflammatory response as observed by increased infiltration and diffusion of macromolecules within the layer following activation of the EC by cytokines and chemoattractants. In models of inflammation in the living animal, the shedding of glycans and diminished thickness of the glycocalyx rapidly occur to facilitate penetration by the WBCs and adhesion to the EC. The primary effectors of glycan shedding appear to be metalloproteases and heparanase released by the EC. Retardation of glycan shedding and WBC-EC adhesion has been demonstrated in vivo using MMP inhibitors and low-molecular-weight heparin (LMWH), where the latter competitively binds to heparanase liberated by the EC. Together, these agents may serve to stabilize the ESL and provide a useful strategy for treatment of inflammatory disorders.

Targeting the endothelial glycocalyx in acute critical illness as a challenge for clinical and laboratory medicine

The purpose of this manuscript is to review the role of endothelial glycocalyx (EG) in the field of critical and perioperative medicine and to discuss possible future directions for investigations in this area. Under physiological conditions, EG has several well-defined functions aimed to prevent the disruption of vessel wall integrity. Under pathological conditions, the EG represent one of the earliest sites of injury during inflammation. EG structure and function distortion contribute to organ dysfunction related to sepsis, trauma, or global ischemia of any origin. Discovering new therapeutic approaches (either pharmacological or non-pharmacological) aimed to protect the EG against injury represents a promising direction in clinical medicine. Further, the currently-used common interventions in the acutely ill - fluids, blood products, nutritional support, organ-supporting techniques (e.g. continuous renal replacement therapy, extracorporeal circulation), temperature modulation and many others - should be re-evaluated during acute illness in terms of their EG "friendliness". To assess new therapies that protect the EG, or to evaluate the effect of currently-used interventions on EG integrity, a relevant marker or method to determine EG damage is needed. Such marker or method should be available to clinicians within hours, preferably in the form of a point-of-care test at the bedside. Collaborative research between clinical disciplines and laboratory medicine is warranted, and targeting the EG represents major challenges for both.

Influence of narrowband ultraviolet-B phototherapy on plasma concentration of matrix metalloproteinase-12 in psoriatic patients

INTRODUCTION

Matrix metalloproteinase-12 (MMP-12) may play an important role in the pathogenesis and spread of psoriatic disease.

AIM

To investigate plasma levels of the selected enzyme in plaque psoriasis patients before and after the course of narrowband UVB (NBUVB) therapy with respect to disease advancement.

MATERIAL AND METHODS

The cohort included 49 patients suffering from plaque psoriasis, divided into groups according to severity of the disease. The control group consisted of 40 healthy volunteers. Plasma levels of MMP-12 were determined using immunoenzyme assay (ELISA), while the Psoriasis Area and Severity Index (PASI) was used to define disease advancement.

RESULTS

The results have shown a significantly decreased plasma level of MMP-12 in the total psoriasis patient group compared to healthy individuals, declining with the increase in disease advancement. The NBUVB therapy caused a decrease in the concentration of the analyzed enzyme, but this change was not statistically significant in the total group of psoriatic patients, while a significant change was detected in patients with a mild advancement of the disease.

CONCLUSIONS

Decreased synthesis of MMP-12 may lead to the stimulation of the epidermal angiogenesis process, which results in the appearance and spread of psoriatic scales. Based on the obtained results, macrophage metalloelastase seems to be a negatively reacting plasma biomarker of the studied disease.

Changes in the extracellular matrix surrounding human chronic wounds revealed by 2-photon imaging

Chronic wounds are a growing problem worldwide with no effective therapeutic treatments available. Our objective was to understand the composition of the dermal tissue surrounding venous leg ulcers and diabetic foot ulcers (DFU). We used novel 2-photon imaging techniques alongside classical histology to examine biopsies from the edges of two common types of chronic wound, venous leg ulcers and DFU. Compared to normal intact skin, we found that collagen levels are significantly reduced throughout the dermis of venous leg ulcer biopsies and DFU, with a reduction in both fibril thickness and abundance. Both wound types showed a significant reduction in elastin in the upper dermis, but in DFU, the loss was throughout the dermis. Loss of extracellular matrix correlated with high levels of CD68- and CD18-positive leukocytes. 2-photon imaging of the extracellular matrix in the intact tissue surrounding a chronic wound with a hand-held device may provide a useful clinical indicator on the healing progression or deterioration of these wounds.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.

Myocardial proteases and cardiac remodeling

Cardiac hypertrophy (CH), characterized by the enlargement of cardiomyocytes, fibrosis and apoptosis, is one of the leading causes of death worldwide. Despite the advances in cardiovascular research, there remains a need to further investigate the signaling pathways that mediate CH in order to identify novel therapeutic targets. One of the hallmarks of CH is the remodeling of the extracellular matrix (ECM). Multiple studies have shown an important role of cysteine proteases and matrix metalloproteinases (MMPs) in the remodeled heart. This review focuses on the role of cysteine cathepins and MMPs in cardiac remodeling.

Orthodontic tensile strain induces angiogenesis via type IV collagen degradation by matrix metalloproteinase-12

BACKGROUND AND OBJECTIVE

During orthodontic tooth movement (OTM), periodontal ligament (PDL) is remodeled dynamically, which requires sufficient blood supply for the regeneration of PDL. However, little is known about the remodeling of blood vessels during OTM. In this study, we hypothesized that the orthodontic tensile strain upregulates matrix metalloproteinase-12 (MMP-12) expression in the tension zone and induces angiogenesis via degradation of type IV collagen (Col-IV) in vascular endothelial basement membrane during the early stage of OTM.

MATERIAL AND METHODS

Temporal and spatial MMP-12 expression in the tension zone of PDL, during the early stage of OTM, were examined by immunohistochemistry in rats. Continuous tensile strain was applied to cultured human immortalized PDL cell lines (HPL cells) and MMP-12 expression was examined in vitro. Colocalization of MMP-12 and Col-IV in vivo were examined by immunohistochemistry. To investigate whether MMP-12 produced by HPL cells could degrade Col-IV, recombinant Col-IV was incubated in the culture supernatants of HPL cells. Intact Col-IV in vitro was also examined by western blot analysis. Finally, the changes in blood vessels in the PDL were examined by micro-computed tomography analysis with perfused contrast agents and by conventional histological analysis.

RESULTS

Orthodontic tensile strain induced MMP-12 expression in PDL cells in vivo and in vitro. Immunohistochemistry revealed that MMP-12-positive cells were observed adjacent to the Col-IV-positive tubular area in the tension zone of PDL. MMP-12 in culture supernatant of HPL cells degraded recombinant Col-IV, and specific MMP-12 inhibitor blocked the Col-IV degradation. Micro-computed tomography analysis and conventional histological analysis demonstrated that the areas of blood vessels were increased in the tension zone of the PDL after OTM.

CONCLUSION

We discovered that the orthodontic tensile strain upregulates MMP-12 expression in the tension zone of PDL and induces angiogenesis via degradation of Col-IV in the vascular endothelial basement membrane.

Matrix Metalloproteinases in Myocardial Infarction and Heart Failure

Cardiovascular disease is the leading cause of death, accounting for 600,000 deaths each year in the United States. In addition, heart failure accounts for 37% of health care spending. Matrix metalloproteinases (MMPs) increase after myocardial infarction (MI) and correlate with left ventricular dysfunction in heart failure patients. MMPs regulate the remodeling process by facilitating extracellular matrix turnover and inflammatory signaling. Due to the critical role MMPs play during cardiac remodeling, there is a need to better understand the pathophysiological mechanism of MMPs, including the biological function of the downstream products of MMP proteolysis. Future studies developing new therapeutic targets that inhibit specific MMP actions to limit the development of heart failure post-MI are warranted. This chapter focuses on the role of MMPs post-MI, the efficiency of MMPs as biomarkers for MI or heart failure, and the future of MMPs and their cleavage products as targets for prevention of post-MI heart failure.

MMP-12, a Promising Therapeutic Target for Neurological Diseases

The role of matrix metalloproteinase-12 (MMP-12) in the pathogenesis of several inflammatory diseases such as chronic obstructive pulmonary disease, emphysema, and asthma is well established. Several new studies and recent reports from our laboratory and others highlighted the detrimental role of MMP-12 in the pathogenesis of several neurological diseases. In this review, we discuss in detail the pathological role of MMP-12 and the possible underlying molecular mechanisms that contribute to disease pathogenesis in the context of central nervous system diseases such as stroke, spinal cord injury, and multiple sclerosis. The available information on the specific MMP-12 inhibitors used in several preclinical and clinical studies is also reviewed. Based on the reported studies to date, MMP-12 suppression could emerge as a promising therapeutic target for several CNS diseases that were discussed in this review.

The Scaffold Immune Microenvironment: Biomaterial-Mediated Immune Polarization in Traumatic and Nontraumatic Applications<sup/>

The immune system mediates tissue growth and homeostasis and is the first responder to injury or biomaterial implantation. Recently, it has been appreciated that immune cells play a critical role in wound healing and tissue repair and should thus be considered potentially beneficial, particularly in the context of scaffolds for regenerative medicine. In this study, we present a flow cytometric analysis of cellular recruitment to tissue-derived extracellular matrix scaffolds, where we quantitatively describe the infiltration and polarization of several immune subtypes, including macrophages, dendritic cells, neutrophils, monocytes, T cells, and B cells. We define a specific scaffold-associated macrophage (SAM) that expresses CD11b⁺F4/80⁺CD11c^+/-CD206^hiCD86⁺MHCII⁺ that are characteristic of an M2-like cell (CD206^hi) with high antigen presentation capabilities (MHCII⁺). Adaptive immune cells tightly regulate the phenotype of a mature SAM. These studies provide a foundation for detailed characterization of the scaffold immune microenvironment of a given biomaterial scaffold to determine the effect of scaffold changes on immune response and subsequent therapeutic outcome of that material.

Therapy of psoriasis with narrowband ultraviolet-B light influences plasma concentrations of MMP-2 and TIMP-2 in patients

BACKGROUND

Matrix metalloproteinases (MMPs), which show a significant ability to cleave the components of extracellular matrix, and tissue inhibitors of metalloproteinases (TIMPs), which slow down the activity of those enzymes, may be implicated in the pathogenesis and spread of psoriatic disease. This study aims to analyze plasma levels of MMP-2 and TIMP-2 in plaque psoriasis patients before and after the course of narrowband ultraviolet-B (NBUVB) therapy with respect to disease advancement.

PATIENTS AND METHODS

A total of 49 patients suffering from plaque psoriasis and 40 healthy volunteers were enrolled into the study. Plasma levels of MMP-2 and TIMP-2 were determined using enzyme-linked immunosorbent assay, while Psoriasis Area and Severity Index (PASI) was used to define the disease advancement.

RESULTS

The results showed increased plasma levels of MMP-2 and TIMP-2, but this change was significant only in case of MMP-2 in total psoriatic group compared to healthy subjects. Moreover, there was an increase in the concentrations of chosen factors with an increase in the severity of the disease. The NBUVB therapy causes a decline in the concentration of the analyzed enzyme and its inhibitor, although this change was statistically significant in the total psoriatic group only in case of MMP-2. There was also a positive correlation between MMP-2, TIMP-2, and PASI score value.

CONCLUSION

Our study highlights a possible important role of MMP-2 in the activity of psoriasis and clearance of disease symptoms. Moreover, plasma MMP-2 seems to be a valuable psoriasis biomarker.