Matrix metalloproteinases and tissue inhibitors of metalloproteinases: structure, function, and biochemistry

A dual action approach of B-type proanthocyanidins for silencing enzymatic activity and sealing natural caries-affected dentin-resin interfaces

OBJECTIVES

This study explored the potential of dimeric and trimeric B-type proanthocyanidins (PACs) to silence dentin-associated enzymes as well as enhance sealing at the hybrid layer and in the underlying dentin of dentin-resin interfaces in both sound and natural caries-affected dentin (NCAD).

METHODS

Intervention materials were chemically standardized formulations of B-type dimeric (B) and trimeric (BB) PACs from Theobroma cacao (TC), prepared using the DESIGNER approach (Depletion and Enrichment of Select Ingredients Generating Normalized Extract Resources). Human teeth were divided into two groups based on dentin substrate (sound dentin vs. NCAD) and three experimental groups (10 % TC-B primer, 10 % TC-BB primer, and HEPES primer as control). Bonding procedures utilized the etch-and-rinse technique. Specimens were prepared for interfacial in-situ zymography and interfacial micro-permeability assay and evaluated under a fluorescent microscope. Fluorescence intensities were calculated and analyzed using three-way ANOVA and post-hoc tests (α = 0.05).

RESULTS

NCAD at the dentin-resin interface showed higher enzymatic activity when compared to sound dentin (p < 0.001). Enzymatic activity was significantly higher in sound (p < 0.001) and NCAD (p < 0.001) control groups relative to PAC-treated groups, with the latter exhibiting a substantial enzyme-silencing effect. No significant differences were observed between TC-B and T-BB groups (p = 1.0). Interfacial micro-permeability showed a similar trend, with the DESIGNER-treated groups exhibiting a profound sealing in NCAD, reaching depths up to 60 µm.

CONCLUSIONS

Both B-type PAC-DESIGNERs are remarkably effective at reducing the enzymatic activity and sealing the resin-dentin interface as well as the underlying sound and NCAD dentin.

CLINICAL SIGNIFICANCE

This study highlights the relevance of developing functional biomaterials capable of optimizing the adhesion of the dentin-resin interface while preserving the collagen matrix through effective enzymatic inhibition and improved sealing ability, particularly when bonding to caries-affected dentin.

Construction of AgNPs-loaded oriented hydrogel based on Periostracum Cicadae chitosan by electro-assembly for rapid hemostasis and wound healing

Oriented hydrogels have been recognized for their ability to promote cell proliferation and enhance wound repair. Chitosan, valued for its biocompatibility and biodegradability, is widely used in hydrogel preparation. However, chitosan derived from Periostracum Cicadae ("Chantui") has not been explored for creating antibacterial-oriented hydrogels. In this study, we successfully developed a Periostracum Cicadae chitosan-based oriented hydrogel (O-CH) using an electro-assembly method. The O-CH hydrogel exhibited superior hemostatic performance and mechanical strength, with stress levels 7.6 times higher than those of traditional alkali-neutralized hydrogels. Subsequently, silver nanoparticles (AgNPs) were formed in situ on the O-CH hydrogel without the need for additional reducing agents or stabilizers, yielding O-CH@Ag20, which exhibited excellent biocompatibility and enhanced antibacterial properties. In an S. aureus-infected full-thickness rat skin defect model, O-CH@Ag20 reduced bacterial counts at the wound site by 6-fold compared to the gauze group on day 3 and achieved a 97 % wound healing rate by day 10, versus 75 % in the gauze group. Histological analysis revealed that O-CH@Ag20 regulated angiogenesis, collagen deposition, and fibroblast differentiation into myofibroblasts, thereby accelerating wound contraction during remodeling. This study presents a novel approach to addressing clinical challenges in infected wound healing using Periostracum Cicadae chitosan-based antibacterial hydrogels.

A review on animal venom-based matrix metalloproteinase modulators and their therapeutic implications

Matrix Metalloproteinases (MMPs) belong to a family of proteolytic enzymes that degrade extracellular matrix components, such as collagen, elastin, laminin, and fibronectin. They also play a part in tissue remodeling by cleaving and rejoining the tissue proteins. Cancer, neurodegenerative disorders, cardiovascular diseases, arthritis, and chronic inflammatory conditions are just some of the diseases that can start or get worse when different MMPs are not working properly. Venomous Animals such as honeybees, toads, snakes, spiders, scorpions, jellyfish, and sea anemones contain venom-secreting glands, which help them defend against predators and immobilize their prey. The molecules that come from animal venom are a complicated mix of bioactive molecules, such as peptides, enzymes, proteins, and small organic compounds that do a number of biological things. Venom-derived molecules have been found to modulate MMP. These venoms and their components target specific signaling pathways, modifying MMP expression levels to either induce inflammation or exhibit anti-inflammatory effects. In this review, we study and explore different MMPs, such as MMP1, MMP2, MMP3, MMP7, MMP8, and MMP9, and their roles in the progression of certain diseases. We also look at different types of molecules derived from marine and land animal venom that are used as MMP modulators. We look at how they work by targeting specific signaling pathways to change MMPs and how they might be used as a medicine to stop diseases by decreasing MMPs.

Puerarin exerts an inhibitory effect on inflammatory infiltration in the cardiac tissue of EAM mice by regulation of the TNF-α/CCL2/CCR2 signal pathway

Autoimmune myocarditis can result in dilated cardiomyopathy and heart failure, but effective drugs and clear therapeutic targets are still lacking. Experimental autoimmune myocarditis (EAM) serves as the primary animal model utilized for investigating human myocarditis. Puerarin (PUE), a compound derived from the root of Pueraria lobata, exhibits a broad spectrum of antioxidant and anti-inflammatory effects; nevertheless, its underlying mechanism remains elusive. The findings of this study suggested that PUE may attenuate the infiltration of inflammatory cells into the cardiac tissue by suppressing the secretion of chemokine CCL2 from endothelial cells and macrophages at the site of injury, as well as inhibiting the interaction between CCR2 and CCL2 in recruited inflammatory cells such as macrophages and Th1 cells. In this study, the focus was on investigating the impact of PUE on the chemotactic signal axis TNF-α/CCL2/CCR2. Through the utilization of Small Animal Ultrasound, Real-Time quantitative PCR, Co-Immunoprecipitation (Co-IP), and Immunofluorescence techniques on both cellular and animal models, it has been demonstrated that PUE effectively inhibits the production of CCL2 by disrupting the TNF-α/TNFR signaling pathway in macrophages and endothelial cells through its binding affinity with TNF-α. Additionally, PUE disrupts the transmission of chemotactic signals mediated by CCL2/CCR2 interaction through its binding to CCR2.This ultimately leads to a reduction in the infiltration of inflammatory cells into the heart. Moreover, the study highlights that PUE can effectively inhibit the transduction of the TNF-α/CCL2/CCR2 chemotactic signal, resulting in decreased infiltration of macrophages and Th1 cells in the heart and subsequently reducing inflammatory damage to myocardial tissue in EAM mice.

Loss of non-muscle myosin II Zipper leads to apoptosis-induced compensatory proliferation in Drosophila

Drosophila Non-muscle myosin II Zipper (Zip) belongs to a functionally divergent class of molecular motors that play a vital role in various cellular processes including cell adhesion, cell migration, cell protrusion, and maintenance of polarity via its cross-linking property with actin. To further determine its role in cell proliferation and apoptosis, we carried out Zip loss of function studies that led to compromised epithelial integrity in Drosophila wing imaginal discs as evident from the perturbed expression pattern of cell-cell junction proteins Cadherin, Actin, and Armadillo. Disruption of these adhesion proteins resulted in the cells undergoing apoptosis as evident from the increased level of effector caspase, cDcp-1. The induction of cell death due to the loss of function of Zip was accompanied by proliferation as apparent from increased PH3 staining. The control of apoptosis-induced compensatory proliferation lies under the caspase cascade. We carried out experiments that suggested that the apical caspase Dronc is responsible for the apoptosis-induced compensatory proliferation due to the loss of Zip function and not the effector caspase Drice/Dcp-1. Further, it was observed that Dronc leads to the subsequent activation of Jun N-terminal kinase pathway (JNK) pathway and Wingless (Wg) mitogen that diffuse to the neighboring cells and prompt them to undergo cell division. Taken together, our results suggest that loss of function of Zip leads to apoptosis-induced compensatory proliferation.

Nanozyme-driven multifunctional dressings: moving beyond enzyme-like catalysis in chronic wound treatment

The treatment of chronic wounds presents significant challenges due to the necessity of accelerating healing within complex microenvironments characterized by persistent inflammation and biochemical imbalances. Factors such as bacterial infections, hyperglycemia, and oxidative stress disrupt cellular functions and impair angiogenesis, substantially delaying wound repair. Nanozymes, which are engineered nanoscale materials with enzyme-like activities, offer distinct advantages over conventional enzymes and traditional nanomaterials, making them promising candidates for chronic wound treatment. To enhance their clinical potential, nanozyme-based catalytic systems are currently being optimized through formulation advancements and preclinical studies assessing their biocompatibility, anti-oxidant activity, antibacterial efficacy, and tissue repair capabilities, ensuring their safety and clinical applicability. When integrated into multifunctional wound dressings, nanozymes modulate reactive oxygen species levels, promote tissue regeneration, and simultaneously combat infections and oxidative damage, extending beyond conventional enzyme-like catalysis in chronic wound treatment. The customizable architectures of nanozymes enable precise therapeutic applications, enhancing their effectiveness in managing complex wound conditions. This review provides a comprehensive analysis of the incorporation of nanozymes into wound dressings, detailing fabrication methods and emphasizing their transformative potential in chronic wound management. By identifying and addressing key limitations, we introduce strategic advancements to drive the development of nanozyme-driven dressings, paving the way for next-generation chronic wound treatments.

TIMP1 secretion induced by Toxoplasma effector GRA24 via p38 MAPK signaling promotes non-disruptive parasite translocation across polarized brain endothelial monolayers

The protozoan Toxoplasma gondii first crosses the intestinal wall and then the blood-brain barrier (BBB) to establish chronic, latent infections in humans and other warm-blooded vertebrates. However, the molecular mechanisms underlying this stealthy colonization remain poorly understood. In this study, we investigated the passage of T. gondii tachyzoites across polarized monolayers of murine brain endothelial cells (bEnd.3) and human intestinal cells (Caco-2). We found that exposure to live T. gondii tachyzoites, but not to tachyzoite lysate or lipopolysaccharide, induced elevated transcription and secretion of tissue inhibitor of metalloproteinases 1 (TIMP1), a pleiotropic protein linked to BBB maintenance. Recombinant TIMP1 consistently increased T. gondii transmigration across monolayers, while pharmacological inhibition of matrix metalloproteinases (MMPs) non-significantly impacted transmigration. Through a combined approach of pharmacological inhibition and mutant T. gondii lines, we identified the MYR translocon-associated effector GRA24 and host cell p38 mitogen-activated protein kinase (MAPK) signaling as key mediators of Timp1 induction. Moreover, despite T. gondii transmigration, cell polarization and barrier integrity were preserved, suggesting a non-disruptive passage of tachyzoites with minimal or transient barrier dysregulation. These findings reveal a role for GRA24-p38 MAPK signalling and TIMP1's MMP-independent effects in facilitating the translocation of T. gondii across restrictive biological barriers.IMPORTANCEThe parasite Toxoplasma gondii, which is globally widespread, colonizes the brains of humans and other warm-blooded animals. To do so, it first crosses the gut wall before entering the brain via the bloodstream. However, the mechanisms by which Toxoplasma overcomes the body's restrictive biological barriers remain largely unknown. In this study, we used cellular models of the gut and brain barriers to investigate how the parasite passes through. We found that Toxoplasma induces cells to secrete TIMP1, a multifunctional protein that reduces inflammation and is linked to blood-brain barrier protection. Surprisingly, TIMP1 also facilitated Toxoplasma's passage across cellular barriers. This elevated TIMP1 production and secretion by host cells was triggered by a secreted Toxoplasma effector protein (GRA24) and mediated through host cell signaling pathways (p38 MAPK). These findings suggest that Toxoplasma manipulates host cells to produce factors that aid its colonization while suppressing inflammation.

Directed evolution of metalloproteinase inhibitor TIMP-1 for selective inhibition of MMP-9 exploits catalytic and fibronectin domain interactions

Matrix metalloproteinase-9 (MMP-9) is a critical enzyme involved in extracellular matrix degradation and is strongly implicated in many diseases, including triple-negative breast cancer and other poor prognosis cancers. Selective inhibition of MMP-9 is therefore a promising therapeutic strategy. However, development of MMP inhibitors has been hindered by challenges in achieving specificity, with past efforts failing in clinical trials due to off-target effects and associated toxicity. Here, we present a novel approach to overcoming these challenges by engineering tissue inhibitor of metalloproteinases-1 (TIMP-1), a natural broad-spectrum MMP inhibitor, to achieve enhanced specificity and affinity for MMP-9. We demonstrate that TIMP-1 can be strategically engineered to selectively inhibit MMP-9 through modulating interactions not only with the catalytic domain but also with the unique fibronectin (FN) domains. By leveraging yeast surface display with strategic library design, we identified TIMP-1 variants that exploit multiple surface epitopes to optimize interactions with both the catalytic and FN domains of MMP-9. Molecular dynamics simulations further suggest how modifications in the N-terminal and C-terminal domains of TIMP-1 drive these selective interactions. The top engineered TIMP-1 variant exhibited significantly improved selectivity for MMP-9 in a manner dependent upon novel interactions with the FN domains, as validated through inhibition kinetics. This variant also demonstrated potent inhibition of MMP-9-driven triple-negative breast cancer cell invasiveness, underscoring the therapeutic potential of this approach. Our study highlights the versatility of TIMP-1 as a scaffold that can be optimized for highly selective MMP inhibition, providing new avenues for the development of targeted therapies.

Potential drug targets for peripheral artery disease identified through Mendelian randomization analysis

INTRODUCTION

Peripheral Artery Disease (PAD) is a common cardiovascular condition marked by peripheral artery stenosis or occlusion. Despite treatment advancements, patients will still face vascular complications, highlighting the need for innovative therapies. Human proteins play crucial roles in biology and drug research. Mendelian randomization (MR) analysis, a gene-based method, is increasingly used in drug target identification. This study aims to identify PAD-associated plasma proteins through MR analysis for potential therapies.

METHODS

We first used GWAS data and seven pQTL datasets to identify plasma proteins causally linked to PAD through MR analysis. Then, we performed KEGG pathway enrichment analysis, Bayesian colocalization analysis, and MR-BMA analysis were carried out to investigate mechanisms and prioritize these proteins. Finally, we assessed the druggability of the target proteins using the DrugBank database.

RESULTS

MR analysis found four plasma proteins causally linked to PAD: MMP3 positively correlated with PAD, while CASS4, ISG15, and MMP1 exhibited negative associations. Bayesian colocalization analysis confirmed these relationships, and the MR-BMA analysis prioritized MMP1 as the main target. KEGG pathway enrichment analysis highlighted lipid metabolism and atherosclerosis pathways as central to these drug targets. The druggability evaluation indicated that drugs targeting these proteins are either in development or already in clinical use.

CONCLUSION

This study integrates genetic and proteomic data to identify therapeutic targets for PAD and evaluate their potential for drug development. The prioritization of MMP1 and ISG15 as key targets shows promise for PAD treatment, but further validation and clinical exploration of these findings are needed.

A shared inflammatory signature across severe malaria syndromes manifested by transcriptomic, proteomic and metabolomic analyses

Factors governing the clinical trajectory of Plasmodium falciparum infection remain an important area of investigation. Here we present transcriptomic, proteomic and metabolomic analyses comparing clinical subtypes of severe Plasmodium falciparum malaria to matched controls with uncomplicated disease in 79 children from Mali. MMP8, IL1R2, and ARG1 transcription is higher across cerebral malaria, severe malarial anemia, and concurrent cerebral malaria and severe malarial anemia, indicating a shared inflammatory signature. Tissue inhibitor of metalloproteinases 1 is the most upregulated protein in cerebral malaria, which along with elevated MMP8 and MMP9 transcription, underscores the importance of the metalloproteinase pathway in central nervous system pathophysiology. L-arginine metabolites are decreased in cerebral malaria, which coupled with increased ARG1 transcription suggests a putative mechanism impairing cerebral vasodilation. Using multi-omics approaches, we thus describe the inflammatory cascade in severe malaria syndromes, and identify potential therapeutic targets and biological markers.

Antibiofilm properties, cytotoxicity, and effect on protease activity of antibiotics and EGCG-based medications for endodontic purposes

OBJECTIVE

To evaluate the effect of two intracanal medications (IM) containing epigallocatechin-3-gallate (EGCG) with fosfomycin (FOSFO) and a triantibiotic combination of metronidazole, ciprofloxacin and fosfomycin (TRI), compared to controls calcium hydroxide (CH), all dissolved in polyethylene glycol 400 (PEG) on multispecies biofilms, fibroblast toxicity and on collagenolytic and gelatinolytic activities detected in radicular dentin.

METHODS

The antibiofilm effect and cytotoxicity of medications containing EGCG + FOSFO, TRI or CH were evaluated on multispecies biofilms formed in bovine root dentin specimens by confocal microscopy and on fibroblasts by resazurin assays, respectively. The inhibition of protease activity of each IM was evaluated by measuring collagenolytic enzyme activity by ELISA (Enzyme-linked immunosorbent assay) and gelatinolytic activity by metalloproteinases (MMPs) using in situ zymography in radicular dentin specimens.

RESULTS

PEG containing EGCG+FOSFO, PEG+TRI, and PEG+CH significantly reduced multispecies biofilms in radicular dentin tubules. At the concentrations tested, those IM were not toxic to fibroblasts. Additionally, all IM presented anti-collagenolytic activity by reducing telopeptide fragments released from radicular dentin compared to PEG carrier and water controls. In situ gelatinolytic activity, assessed via fluorescence levels, was significantly lower in radicular dentin adjacent to PEG containing CH, EGCG+FOSFO, or TRI compared to PEG and water controls.

CONCLUSION

EGCG+FOSFO and TRI in PEG-400 exhibited antibiofilm, anti-collagenolytic and anti-gelatinolytic properties at concentrations that were non-toxic to fibroblasts, making them feasible intracanal medications for endodontic applications.

CLINICAL SIGNIFICANCE

EGCG-based medications enhance the efficacy of endodontic treatment by providing antibiofilm, anti-collagenolytic, and anti-gelatinolytic properties, contributing to the preservation of root structure and improved treatment outcomes.

Caviar extract inhibits skin photoaging by activating skin stem cells through NF-κB/MMPs/COL17A1 axis

Ultraviolet radiations (UVR) produce harmful entities and reactive oxygen species (ROS) in skin cells, leading to skin photoaging. Caviar extract (CE) showed outstanding effects in delaying skin aging, but the underlying mechanism remains largely unknown. In this study, we prepared CE with acid protease and examined the anti-skin photoaging effects. The results showed that CE performed no cytotoxicity to HaCaT cells. For antioxidant properties, the EC50 values of DPPH and ABTS radical scavenging activity for CE were 1.27 and 5.20 mg/mL, respectively. It significantly reduced NF-κB, MMP-3 and MMP-9 protein expression levels, and increased IκB and TIMP-1 expression level in UVA-irradiated HaCaT cells. In the skin aging mice model, CE reduced the degree of UV-induced skin photoaging. Histological study confirmed that CE can ameliorate the adverse effects of UV exposure on the skin. Moreover, we found that CE could enhance the activities of Superoxide dismutase (SOD), and increased the contents of hydroxyproline (HYP) in photoaged mice skin. And CE elevated the protein expression level of COL17A1, KRT10, and KRT14 in mice skin. Taken together, our results bright systemic and new insights of CE into preventing UV-induced skin photoaging.

Pyropia yezoensis Extract Attenuates Osteoarthritis Progression In Vitro and In Vivo

Osteoarthritis (OA), a degenerative disease characterized by cartilage degradation and inflammation, occurs due to trauma caused by external stimuli or cartilage aging. Pyropia yezoensis is a red alga that belongs to the Porphyra family and is consumed as food in Asia, especially Korea, Japan, and China. P. yezoensis contains various bioactive substances, including carotenoids, flavonoids, and vitamins, that exert anti-inflammatory, antioxidant, and anti-photoaging effects. In the present study, the anti-osteoarthritic effects of 30% fermented alcohol extract of P. yezoensis (30% FEPY) on interleukin-1 beta (IL-1β)-stimulated chondrocytes and a destabilization of the medial meniscus (DMM)-induced OA rat model were investigated. The results showed that pretreatment with 30% FEPY significantly reduced the IL-1β-induced expression of inflammatory factors (e.g., inducible nitric oxide synthase and cyclooxygenase-2) and cartilage-degrading enzymes [matrix metalloproteinase (MMP) 1, MMP3, MMP13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 4, and ADAMTS5], which was analyzed using Griess reaction, enzyme-linked immunosorbent assay, and Western blot analysis. The anti-osteoarthritic effects of 30% FEPY, which were mediated through mitogen-activated protein kinase and nuclear factor kappa-light-chain-enhancer of activated B cell signaling, were analyzed using Western blot analysis. In an in vivo study, Safranin O staining and immunohistochemistry analysis revealed that treatment with 30% FEPY significantly increased cartilage degradation and collagen type II protein expression in the DMM group. These findings collectively suggest that 30% FEPY is a promising candidate for alleviating OA progression and developing new therapeutic drugs.

Evolving role of myocardial fibrosis in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical diagnosis with a heterogeneous pathophysiology and clinical presentation. The hallmark of HFpEF is diastolic dysfunction associated with left ventricular remodeling and fibrosis. Myocardial interstitial fibrosis (MIF) occurs as the result of collagen deposition and is dependent on the underlying etiology of heart failure. Detection of MIF can be done by invasive histopathologic sampling or by imaging. More recently, novel biomarkers have been investigated as an alternative tool for not only the detection of MIF but also for the prognostication of patients with HFpEF which may in turn alleviate the need for invasive and expensive imaging in the future.

Plant-Derived Lapachol Analogs as Selective Metalloprotease Inhibitors Against Bothrops Venom: A Review

Plant compounds that inhibit snake venom activities are relevant and can provide active molecules to counteract snake venom effects. Numerous studies on snake viperid venoms found that metalloproteinases play a significant role in the pathophysiology of hemorrhage that occurs on envenomation. Preclinical studies using vitro and in vivo protocols investigated natural compounds and viperid snake venoms, evaluating the enzymatic, procoagulant, hemorrhagic, edematogenic, myotoxic, and lethal activities. Many studies focused on Bothrops venoms and ascribed that angiorrhexis and hemorrhage resulted from the metalloproteinase action on collagen in the basal lamina. This effect resulted in a combined action with phospholipase A2 and hyaluronidase, inducing hemorrhage, edema, and necrosis. Due to the lack of efficient antivenoms in remote areas, traditional native plant treatments remain common, especially in the Amazon. Our group studied plant extracts, isolated compounds, and lapachol synthetic derivative analogs with selective inhibition for Bothrops venom proteolytic and hemorrhagic activity and devoid of phospholipase activity. We highlight those new synthetic naphthoquinones which inhibit snake venom metalloproteinases and that are devoid of other venom enzyme inhibition. This review shows the potential use of snake venom effects, mainly Bothrops venom metalloproteinase activity, as a tool to identify and develop new active molecules against hemorrhagic effects.

Molecular characterization of suburothelial fibrosis in murine acute recurrent bladder inflammation

Chronic fibrosis replaces functional organ tissue with scar tissue by overproduction of a thick and stiff extracellular matrix. Bladder fibrosis decreases bladder compliance, ultimately resulting in overactive bladder. The phenoconversion of fibroblasts into myofibroblasts is the defining feature of fibrosis. Recently, regionally distinct populations of bladder platelet-derived growth factor receptor alpha positive (PDGFRα+) cells were identified as fibroblasts. Because of this heterogeneity, the identity of the bladder fibroblast cells that undergo phenotypic conversion into myofibroblasts is not clear. The current study utilized cyclophosphamide (CYP)-induced bladder inflammation to identify and characterize bladder PDGFRα+ cells that become myofibroblasts. We found that suburothelial PDGFRα+ cells and detrusor PDGFRα+ cells display different gene expression profiles. Suburothelial PDGFRα+ cells are more abundant than detrusor PDGFRα+ cells and express higher levels of fibrosis-related genes. CYP-treatment increased the number of suburothelial PDGFRα+ cells, increased Pdgfra, Col1a1, and Fn1 transcription in suburothelial PDGFRα+ cells, and increased α-smooth muscle actin, collagen, and fibronectin protein expression. CYP-treatment likely activated TNF-α and TGF-ß pathways, as indicated by nuclear translocation of SMAD2, SMAD3, and NFκB. In conclusion, we identify suburothelial PDGFRα+ cells as the fibroblast population which convert into myofibroblasts via activation of TNF-α and TGF-ß signaling pathways, due to bladder inflammation.

Entamoeba gingivalis induces gingival cell death, collagen breakdown, and host immune response via VAMP8/-3-driven exocytosis pathways

The protozoan Entamoeba gingivalis commonly colonizes anaerobic periodontal pockets, induces a severe innate immune response, invades gingival mucosa, and kills epithelial cells. E. gingivalis infection is associated with the common oral inflammatory disease periodontitis. DNA variants in vesicle-associated membrane proteins (VAMP) -3 and -8 genes are linked to increased periodontitis risk. These genes mediate host-pathogen interactions, including mucin exocytosis to form protective barriers and matrix metalloproteinase (MMP) secretion in intestinal amoebiasis caused by Entamoeba histolytica. This study aimed to investigate the roles of VAMP3/8 in gingival defense and E. gingivalis infection mechanisms. Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing was used to create VAMP3/8-deficient gingival epithelial cells and fibroblasts. Functional analyses included immunofluorescence, enzyme-linked immunosorbent assay (ELISA), cytotoxicity, and collagenase assays. VAMP8 co-localized with mucins in gingival epithelial cells (gECs), and VAMP3 with MMPs in gingival fibroblasts. In gECs, E. gingivalis infection increased mucin (MUC1: 3.6×, MUC21: 14.4×) and interleukin secretion (IL-8, IL-1B: >6×, P = 0.019). VAMP8 deficiency in gECs caused higher cell death (35% vs 4% in controls) with reduced exocytosis of mucins and interleukins. Likewise, E. gingivalis-induced VAMP8 translocation into lipid rafts was lost in VAMP8 knockout cells, validating the participation of VAMP8 in exocytosis. In wild-type but not VAMP3-deficient gingival fibroblasts, E. gingivalis strongly activated collagenases. E. gingivalis effects were more pathogenic than those of the oral anaerobic bacterium Porphyromonas gingivalis. E. gingivalis exploits VAMP8/3-driven exocytosis pathways, driving inflammation and tissue destruction, underscoring its role as a significant periodontal pathogen.

Crosstalk Between Matrix Metalloproteinases and Their Inducer EMMPRIN/CD147: a Promising Therapeutic Target for Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is characterized by the disruption of cerebrovascular integrity, resulting in hematoma enlargement, edema formation, and physical damage in the brain parenchyma. Primary ICH also leads to secondary brain injury contributed by oxidative stress, dysregulated immune responses, and proteolysis. In this context, matrix metalloproteinases (MMPs) represent a ubiquitous superfamily of structurally related zinc-dependent endopeptidases capable of degrading all components of the extracellular matrix. They disrupt the blood-brain barrier and promote neuroinflammation. Importantly, several MMP members are upregulated following ICH, and members may have different functions at specific periods in ICH. Hence, the modulation and function of MMPs are more complex than expected. Extracellular matrix metalloproteinase inducer (EMMPRIN, CD147) is a transmembrane glycoprotein that induces the production of MMPs. In this review, we systematically discuss the biology and functions of MMPs and EMMPRIN/CD147 in ICH and the complex crosstalk between them.

Active-Matrix Metalloproteinase-8, Myeloperoxidase in Relation With Periodontics, Preterm Birth

OBJECTIVE

To investigate serum, placental levels of active-matrix metalloproteinase-8 (aMMP-8), myeloperoxidase (MPO) in preterm-birth with/without pre-eclampsia and term counterparts in relation with clinical periodontal parameters.

METHODS

Clinical periodontal measurements were recorded. Serum and placenta samples were collected during 173 full-term (FT), pre-term (PT) or pre-term complicated by pre-eclampsia (PTPE) deliveries. aMMP-8 levels were measured by IFMA. MPO levels in the serum and placenta samples were determined by ELISA. Data were tested using non-parametric tests.

RESULTS

PTBE group exhibited higher full-mouth probing depth and clinical attachment loss values than the other two groups (p < 0.05). Percentages of sites with plaque and bleeding on probing were lower in the PTBE group than in the other groups (p < 0.05). Serum aMMP-8 and MPO concentrations were higher in PTPE group than in the other groups (p < 0.05). Placenta aMMP-8 level was higher in the control group than in the PTPE group (p < 0.05). There was no significant difference between the groups in the placenta MPO levels (p > 0.05).

CONCLUSIONS

Within the limits of this cross-sectional study, it may be suggested that serum aMMP-8 and MPO concentrations together with placenta aMMP-8 levels may be associated with and reflect adverse pregnancy outcomes. Clinical periodontal findings did not reveal significant associations with these proteolytic and oxidative biomarkers.

Effects of in vitro cytochalasin D and hypoxia on mitochondrial energetics and biogenesis, cell signal status and actin/tubulin/Hsp/MMP entity in air-breathing fish heart

The cardiac actin cytoskeleton has a dynamic pattern of polymerisation. It is uncertain how far actin destabilisation impacts mitochondrial energetics and biogenesis, cell signal status, and structural entities in cardiomyocytes, particularly in hypoxic conditions. We thus tested the in vitro action of cytochalasin D (Cyt D), an inhibitor of actin polymerisation, in hypoxic ventricular explants to elucidate the role of the actin in mitochondrial energetics and biogenesis, cell signals and actin/tubulin/hsps/MMPs dynamics in hypoxic air-breathing fish hearts. The COX activity increased upon Cyt D exposure, whereas hypoxia lowered COX and SDH activities but increased LDH activity. The ROS increased, and NO decreased by Cyt D. COX and LDH activities, and NO content reversed after Cyt D exposure in hypoxic hearts. Cyt D exposure upregulated actin isoform expression (Actc1 and Actb1) but downregulated tubulin isoform (Tedc1). Hypoxia upregulated actin (Acta1a, Actb1, Actb2, Actc1a) tubulin (Tuba, Tubb5, Tedc1, Tubd1) and hsp (Hspa5, Hspa9, Hspa12a, Hspa14, Hspd1, Hsp90) isoform transcript expression and Cyt D in hypoxic hearts reversed these isoform's expression. Hypoxia upregulated Mmp2 and 9 transcript expressions but downregulated Mfn1, Fis1, Nfkb1, Prkacaa, and Aktip expressions, and Cyt D exposure reversed almost all these markers in hypoxic hearts. The data provide novel evidence for the mechanistic role of actin in integrating mitochondrial energetics and biogenesis, cell signal status and actin/tubulin/Hsp/MMP entity, indicating its critical cardioprotective role in defending against hypoxia. Besides proposing an air-breathing fish heart as a model, the study further brings the therapeutic potential of Cyt D towards hypoxia intervention.

A tailored 4G s-triazine-based dendrimer vehicle for quercetin endowed with MMP-2/9 inhibition and VEGF downregulation for targeting breast cancer progression and liver metastasis

Motivated by our recent research progress on the exploitation of s-triazine dendritic platforms as bioactive carriers for well-known anticancer agents and/or targeting ligands, we set out to synthesize new rationally designed dendrimers endowed with MMP-2/9 inhibition potential for halting both breast and liver cancer progression with reduced off-target side effects. New three and four generation s-triazine based dendrimers were developed to incorporate potential ZBGs (Zinc Binding Groups) and carboxyl terminal groups to facilitate direct conjugation of anti-cancer drugs (quercetin) and/or targeting ligands (lactobionic acid) through a biodegradable ester bond. Compared to free quercetin (QUR), MTT assay revealed that all the quercetin-coupled dendrimers displayed better anticancer potential (IC50 = 12.690-29.316, 4.137-29.090 μM) against MCF-7 and HepG-2 cancer cells, respectively within their safe doses (EC100 = 134.35-78.44 μM). Conjugation of lactobionic acid and PEG boosted the anticancer potency against both treated cells, improved apoptosis and down regulated MMP-9 and VEGF gene expression levels in both treated cancer cells. Generally, the more branched G4 dendrimer conjugates exhibited a superior overall anticancer performance compared to their respective G3 analogues, except for their MMP-9 inhibition where G3 conjugate appeared to be more potent and more selective than its G4 analogue.

Unveiling Matrix Metalloproteinase 13's Dynamic Role in Breast Cancer: A Link to Physical Changes and Prognostic Modulation

The biomechanical properties of the extracellular matrix (ECM) including its stiffness, viscoelasticity, collagen architecture, and temperature constitute critical biomechanical cues governing breast cancer progression. Matrix metalloproteinase 13 (MMP13) is an important marker of breast cancer and plays important roles in matrix remodelling and cell metastasis. Emerging evidence highlights MMP13 as a dynamic modulator of the ECM's physical characteristics through dual mechanoregulatory mechanisms. While MMP13-mediated collagen degradation facilitates microenvironmental softening, thus promoting tumour cell invasion, paradoxically, its crosstalk with cancer-associated fibroblasts (CAFs) and tumour-associated macrophages (TAMs) drives pathological stromal stiffening via aberrant matrix deposition and crosslinking. This biomechanical duality is amplified through feedforward loops with an epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) populations, mediated by signalling axes such as TGF-β/Runx2. Intriguingly, MMP13 exhibits context-dependent mechanomodulatory effects, demonstrating anti-fibrotic activity and inhibiting the metastasis of breast cancer. At the same time, angiogenesis and increased metabolism are important mechanisms through which MMP13 promotes a temperature increase in breast cancer. Targeting the spatiotemporal regulation of MMP13's mechanobiological functions may offer novel therapeutic strategies for disrupting the tumour-stroma vicious cycle.

Extracellular matrix in cardiac morphogenesis, fibrosis, and regeneration

The extracellular matrix (ECM) plays a crucial role in providing structural integrity and regulating cell communication essential for organ development, homeostasis, and regeneration, including hearts. Evidence indicates that disruptions in the spatiotemporal expression or alterations in ECM components lead to cardiac malformations, including a wide range of congenital heart diseases (CHDs). Furthermore, research on injured hearts across various vertebrate species, some of which show effective regeneration while others experience irreversible fibrosis, underscores the significance of ECM molecules in cardiac regeneration. This review presents an overview of heart development and the dynamics of ECM during cardiac morphogenesis, beginning with the formation of the contractile heart tube and advancing to the development of distinct chambers separated by valves to facilitate unidirectional blood flow. Furthermore, we discuss research emphasizing the multifaceted roles of secreted molecules in mediating fibrosis and regeneration following myocardial injury.

Machine Learning-Driven Identification of Exosome-Related Genes in Head and Neck Squamous Cell Carcinoma for Prognostic Evaluation and Drug Response Prediction

Background: This study integrated four Gene Expression Omnibus (GEO) datasets to identify disease-specific feature genes in head and neck squamous cell carcinoma (HNSCC) through differential expression analysis with batch effect correction. Methods: The GeneCards database was used to find genes related to exosomes, and samples were categorized into groups with high and low expression levels based on these feature genes. Functional and pathway enrichment analyses (GO, KEGG, and GSEA) were used to investigate the possible biological mechanisms underlying feature genes. A predictive model was produced by using machine learning algorithms (LASSO regression, SVM, and random forest) to find disease-specific feature genes. Receiver operating characteristic (ROC) curve analysis was used to assess the model's effectiveness. The diagnostic model showed excellent predictive accuracy through external data GSE83519 validation. Results: This analysis highlighted 22 genes with significant differential expression. A predictive model based on five important genes (AGRN, TSPAN6, MMP9, HBA1, and PFN2) was produced by using machine learning algorithms. MMP9 and TSPAN6 showed relatively high predictive performance. Using the ssGSEA algorithm, three key genes (MMP9, AGRN, and PFN2) were identified as strongly linked to immune regulation, immune response suppression, and critical signaling pathways involved in HNSCC progression. Matching HNSCC feature gene expression profiles with DSigDB compound signatures uncovered potential therapeutic targets. Molecular docking simulations identified ligands with high binding affinity and stability, notably C5 and Hoechst 33258, which were prioritized for further validation and potential drug development. Conclusions: This study employs a novel diagnostic model for HNSCC constructed using machine learning technology, which can provide support for the early diagnosis of HNSCC and thus contribute to improving patient treatment plans and clinical management strategies.

TIMP2 rs2277698 polymorphism associated with adverse IVF outcomes in Han Chinese women

Background

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are critical regulators of extracellular matrix (ECM) proteolysis and play a pivotal role in trophoblast invasion during embryo implantation. This study aimed to investigate the effects of single-nucleotide polymorphisms (SNPs) in MMP and TIMP genes on clinical outcomes in women undergoing in vitro fertilization (IVF).

Methods

This retroprospective study included 1014 women undergoing their first fresh IVF cycle without donor eggs at Lee Women's Hospital between January 2014 and December 2015. Peripheral blood samples were collected from all participants for DNA extraction and SNP genotyping using real-time polymerase chain reaction. The study focused on three SNPs: TIMP1 (rs4898 C/T), TIMP2 (rs2277698 C/T), and MMP2 (rs243865 C/T). Associations between these SNPs and IVF outcomes, including clinical pregnancy, embryo implantation, abortion, and live birth rates, were analyzed.

Results

Among 560 patients analyzed, no significant differences were observed in baseline characteristics between the live birth and non-live birth groups. However, the minor alleles (CT+TT) of MMP2 (rs243865) and TIMP2 (rs2277698) were significantly more frequent in the non-live birth group (MMP2: 24.4% vs. 17.7%, p = 0.044; TIMP2: 48.1% vs. 34.4%, p = 0.001). In contrast, no significant differences in the genotype distribution of TIMP1 (rs4898) were noted between the groups. Logistic regression analysis identified the minor T allele of TIMP2 as a significant predictor of non-live birth (adjusted odds ratio: 1.725; 95% CI: 1.217-2.445; p = 0.002). Combined genotypes of MMP2/TIMP2, such as CC/CT+TT and CT+TT/CT+TT, were associated with an increased risk of non-live birth, even after adjusting for covariates.

Conclusions

The study demonstrates that the minor T allele of TIMP2 (rs2277698 C/T) is associated with poor IVF outcomes, particularly non-live birth. This finding highlights the potential role of genetic variations in TIMP2 in influencing clinical outcomes of IVF. Further research is warranted to elucidate the underlying mechanisms in larger and more diverse populations.

Multi-omics analysis of synovial tissue and fluid reveals differentially expressed proteins and metabolites in osteoarthritis

BACKGROUND

Knee osteoarthritis is a common degenerative joint disease involving multiple pathological processes, including energy metabolism, cartilage repair, and osteogenesis. To investigate the alterations in critical metabolic pathways and differential proteins in osteoarthritis patients through metabolomic and proteomic analyses and to explore the potential mechanisms underlying synovial osteogenesis during osteoarthritis progression.

METHODS

Metabolomics was used to analyze metabolites in the synovial fluid and synovium of osteoarthritis patients (osteoarthritis group: 10; control group: 10), whereas proteomics was used to examine differential protein expression. Alkaline phosphatase activity was assessed to evaluate osteogenesis.

RESULTS

Upregulation of the tricarboxylic acid cycle: Significant upregulation of the tricarboxylic acid cycle in the synovial fluid and synovium of osteoarthritis patients indicated increased energy metabolism and cartilage repair activity. Arginine metabolism and collagen degradation: Elevated levels of ornithine, proline, and hydroxyproline in the synovial fluid reflect active collagen degradation and metabolism, contributing to joint cartilage breakdown. Abnormal Phenylalanine Metabolism: Increased phenylalanine and tyrosine metabolite levels in osteoarthritis patients suggest their involvement in cartilage destruction and osteoarthritis progression. Synovial osteogenesis: Increased expression of type I collagen in the synovium and elevated alkaline phosphatase activity confirmed the occurrence of osteogenesis, potentially driven by the differentiation of synovial fibroblasts, mesenchymal stem cells, and hypertrophic chondrocytes. Relationships between differential proteins and osteogenesis: FN1 and TGFBI are closely associated with synovial osteogenesis, while the upregulation of energy metabolism pathways provides the energy source for osteogenic transformation.

CONCLUSIONS

Alterations in energy metabolism, cartilage repair, and osteogenic mechanisms are critical. The related metabolites and proteins have potential as diagnostic and therapeutic targets for osteoarthritis.

Proapoptotic and antimigration properties of osthole in combination with LY294002 against human glioma cells

Anaplastic astrocytoma and glioblastoma multiforme are infiltrating and vascularized gliomas with a high degree of chemoresistance and metastasis. Our previous studies have shown that osthole may be of great importance in the treatment of gliomas. Therefore, in this work, for the first time, coumarin was used in combination with LY294002-an inhibitor of the PI3K-Akt/PKB-mTOR pathway, which is overly active in gliomas. MOGGCCM and T98G cells were incubated with osthole and LY294002, alone and in combination. Staining with specific fluorochromes was used to visualize cell death and the scratch test to assess the migration. The level of proteins was estimated by immunoblotting. Forming protrusions were visualized by SEM, and immunocytochemistry was used to determine the localization of proteins. Additionally, the expression of Bcl-2, beclin 1 and Raf kinase was silenced using specific siRNA. The obtained results showed that osthole in combination with LY294092 effectively inhibited the migration of glioma cells by reducing the level of metaloproteinases and Rho family proteins, as well as decreasing the level of N-cadherin. In addition, the combination of compounds induced apoptosis. New combination of compounds shows a high pro-apoptotic potential and also inhibits the migration of gliomas cells.

Comparative effects of various extracellular vesicle subpopulations derived from clonal mesenchymal stromal cells on cultured fibroblasts in wound healing-related process

INTRODUCTION

Non-healing wounds pose significant challenges and require effective therapeutic interventions. Extracellular vesicles (EVs) have emerged as promising cell-free therapeutic agents in tissue regeneration. However, the functional differences between different subpopulations of EVs in wound healing remain understudied. This study aimed to evaluate the effects of two distinct subpopulations of clonal mesenchymal stromal cells (cMSC)-derived EVs (cMSC-EVs), namely 20 K and 110K-cMSC-EVs, primarily on in vitro wound healing process, providing fast and cost-effective alternatives to animal models.

METHODS

In vitro assays were conducted to compare the effects of 20 K and 110K-cMSC-EVs, isolated through high-speed centrifugation and differential ultracentrifugation, respectively. For evaluation the main mechanisms of wound healing, including cell proliferation, cell migration, angiogenesis, and contraction. Human dermal fibroblasts (HDF) were considered as the main cells for analysis of these procedures. Moreover, gene expression analysis was performed to assess the impact of these EV subpopulations on the related process of wound healing on HDF.

RESULTS

The results demonstrated that both 20 K and 110K-cMSC-EVs exhibited beneficial effects on cell proliferation, cell migration, angiogenesis, and gel contraction. RT-qPCR revealed that both EV types downregulated interleukin 6 (IL6), induced proliferation by upregulating proliferating cell nuclear antigen (PCNA), and regulated remodeling by upregulating matrix metallopeptidase 1 (MMP1) and downregulating collagen type 1 (COL1).

DISCUSSION

This study highlights the effects of both 20 K and 110K-cMSC-EVs on the potency of HDFs in wound healing-related process. As the notable finding, 20K-cMSC-EVs offer a more feasible and cost-effective subpopulation for isolation and follow the GMP standard, recommended to utilize this fraction for therapeutic application.

Sensitivity Analysis to Isolate the Effects of Proteases and Protease Inhibitors on Extracellular Matrix Turnover

Matrix metalloproteinases (MMPs) are a family of proteases that drive degradation of extracellular matrix (ECM) across many tissues. MMP activity is antagonized by tissue inhibitors of metalloproteinases (TIMPs), resulting in a complex multivariate system with many MMP isoforms and TIMP isoforms interacting across a network of biochemical reactions - each with their own distinct kinetic rates. This system complexity makes it very difficult to identify which specific molecules are most responsible for driving ECM turnover in vivo and therefore the most promising therapeutic targets. To help elucidate the specific roles of various MMP and TIMP isoforms, we present a computational systems biology model of collagen turnover capturing all possible interactions between type I collagen, four different MMP isoforms (MMP-1, -2, -8, and -9), and three different TIMP isoforms (TIMP-1, -2, and -4). We used dye-quenched fluorescent collagen to monitor the degradation of collagen in the presence of various MMP+TIMP cocktails, and we then used these experimental data to fit hypothetical reaction system topologies in order to investigate their respective accuracies. We determined kinetic rate constants for this system and used post-myocardial infarct time courses of collagen, MMP, and TIMP levels to perform a parameter sensitivity analysis across the model reaction rates and predict which molecules and interactions are the important regulators of ECM in the infarcted heart. Notably, the model suggested that MMP degradation and inactivation terms were more important for driving collagen levels than TIMP interaction terms. In sum, this work highlights the need for systems-level analyses to distinguish the roles of various biomolecules operating with a complex system, prioritizes therapeutic targets for post-infarct cardiac remodeling, and presents a computational framework that can be applied to many other collagen-rich tissues.

CTGF (CCN2): a multifaceted mediator in breast cancer progression and therapeutic targeting

Breast cancer, with its diverse subtypes like ER-positive, HER-2-positive, and triple-negative, presents complex challenges demanding personalized treatment approaches. The intricate interplay of genetic, environmental, and lifestyle factors underscores its status as a primary contributor to cancer-related fatalities in women globally. Understanding the molecular drivers specific to each subtype is crucial for developing effective therapies. In this landscape, connective tissue growth factor (CTGF), also referred to as cellular communication network factor 2 (CCN2), emerges as a significant player. CTGF regulates critical biological activities like cell growth, invasion, and migration, impacting breast cancer development and progression. It modulates breast tumor microenvironment by promoting angiogenesis, activating cancer-associated fibroblasts (CAFs), and inducing inflammation. The activity of CTGF depends on several factors including oxygen levels, hormone signals, and growth factors and differs according to the type of breast cancer. CTGF can regulate breast cancer cells by activating various signaling pathways and modulating the transcription of other genes that are involved in tumor development and metastasis including S100A4, glucose transporter 3 (GLUT3), and vascular endothelial growth factor (VEGF). The matricellular protein can be considered a potential therapeutic target, as it can promote tumor growth and confer drug resistance in breast cancer. Numerous tactics, including neutralizing antibodies, antisense oligonucleotides, natural compounds, recombinant proteins, and short hairpin RNAs have been suggested to block its function. This review highlights the structure of CTGF, regulation of its expression, and current knowledge of its oncogenic role in breast cancer, as well as focusing on potential therapeutic strategies for targeting CTGF in breast cancer.

Vimentin intermediate filaments coordinate actin stress fibers and podosomes to determine the extracellular matrix degradation by macrophages

Macrophages possess the capacity to degrade extracellular matrix (ECM), but the specific roles of different cytoskeletal structures in controlling this process are incompletely understood. Here, we report that the inward flow of actin stress fibers delivers endocytosed ECM for lysosomal elimination, replenishing the pool of enzymes for extracellular ECM hydrolysis in actin-rich podosomes. Vimentin deficiency disrupted the balance between stress fibers and podosomes, impairing ECM degradation through integrin CD11b in THP-1 macrophages. In lung adenocarcinoma patient samples, M2-type macrophages exhibit a tighter podosome organization, surrounded by compact vimentin filaments, than M1-type. In vitro experiments verified that the invasion ability of A549 lung carcinoma cells was enhanced when accompanied by wild type, but not vimentin knockout M2-type THP-1, macrophages. Subcutaneous injections of macrophages and tumor cells in nude mice showed that vimentin in macrophages can reduce tumor collagen fibers. Together, our findings provide insights into the cytoskeletal dynamics governing macrophage ECM degradation.

Tissue-specific and spatially dependent metabolic signatures perturbed by injury in skeletally mature male and female mice

Joint injury is a risk factor for post-traumatic osteoarthritis. However, metabolic and microarchitectural changes within the joint post-injury in both sexes remain unexplored. This study identified tissue-specific and spatially-dependent metabolic signatures in male and female mice using matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) and LC-MS metabolomics. Male and female C57Bl/6J mice were subjected to non-invasive joint injury. Eight days post-injury, serum, synovial fluid, and whole joints were collected for metabolomics. Analyses compared between injured, contralateral, and naïve mice, revealing local and systemic responses. Data indicate sex influences metabolic profiles across all tissues, particularly amino acid, purine, and pyrimidine metabolism. MALDI-MSI generated 2D ion images of bone, the joint interface, and bone marrow, highlighting increased lipid species in injured limbs, suggesting physiological changes across injured joints at metabolic and spatial levels. Together, these findings reveal significant metabolic changes after injury, with notable sex differences.

Myeloid Cell mPGES-1 Deletion Attenuates Calcium Phosphate-induced Abdominal Aortic Aneurysm in Male Mice

Microsomal PGE2 synthase (mPGES)-1 is the key enzyme responsible for synthesizing inflammatory prostaglandin E2 (PGE2). Our previous studies have shown that deletion mPGES-1 in myeloid cells hinders atherogenesis, suppresses vascular proliferative response to injury and enhances survival after myocardial infarction. Here we aimed to further explore the influence of myeloid cell mPGES-1 deletion in abdominal aortic aneurysm (AAA) formation. The AAA was triggered by applying 0.5 M calcium phosphate (CaPO4) to the infrarenal aorta of both myeloid mPGES-1 knockout (Mac-mPGES-1-KO) and their littermate control Mac-mPGES-1-WT mice. AAA induction was assessed by calculating the expansion of the infrarenal aortic diameter 4 weeks after CaPO4 application. The maximum diameters of the aortas were measured by morphometry and the mean maximal diameters were calculated. Paraffin sections of the infrarenal aortas were examined for morphological analysis and immunohistochemical staining. The results showed that myeloid cell mPGES-1 deletion significantly mitigated AAA formation, including reducing expansion of the infrarenal aorta, preventing elastic lamellar degradation, and decreasing aortic calcium deposition. Immunohistochemical staining further indicated that macrophage infiltration and matrix metalloproteinase 2 (MMP2) expression was attenuated in the Mac-mPGES-1-KO aortas. Consistently, in vitro experiments showed that expression of pro-inflammatory cytokines and MMPs was significantly reduced when mPGES-1 was lacking in the primary cultured peritoneal macrophages. These data altogether demonstrated that deletion of mPGES-1 in myeloid cells may attenuate AAA formation and targeting myeloid cell mPGES-1 could potentially offer an effective strategy for the treatment and prevention of vascular inflammatory diseases.

The evolution of adhesive dentistry: From etch-and-rinse to universal bonding systems

OBJECTIVES

This review aimed at presenting the mechanisms and pitfalls of adhesion to enamel and dentin, advances in the materials science and in the development of strategies to improve hybrid layer (HL) longevity.

METHODS

Search of the literature was performed on PubMed, Scopus and Web of Science with keywords related to the structure of the dental substrate, HL degradation mechanisms and strategies to contrast them.

RESULTS

Albeit the advances in the dental materials' properties, HL degradation is still a relevant and current issue in adhesive dentistry. However, adhesive materials have become more resistant and less operator sensitive, and good adhesion is currently in the hands of every practitioner. Numerous novel strategies are being developed, able to improve the resistance of adhesive resins to degradation, their ability to infiltrate and chemically bond to dentin, to remove the unbound/residual water within the HL, reinforce the dentin collagen matrix, and inhibit endogenous metalloproteinases. Many of the strategies have turned to nature in search for powerful biomodifying compounds, and for the inspiration as to mimic naturally occurring regenerative processes.

SIGNIFICANCE

Extensive knowledge on the structure of the dental substrate and the complexity of adhesion to dentin has led to the development of improved formulations of dental adhesives and numerous valid strategies to improve the strength and longevity of the HL. Nevertheless, for many of them the road from bench to chairside still seems long. We encourage practitioners to know their materials well and use the strategies readily available to them.

FFA intervention on LO2 cells mediates SNX-10 synthesis and regulates MMP9 secretion in LX2 cells via TGF-β1

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a public health concern. Transforming growth factor-β1(TGF-β1) plays an important regulatory role in multiple MAFLD stages, as it can promote the expression of matrix metalloproteinase-9 (MMP9) and promote liver fibrosis. Sorting nexin protein-10 (SNX-10) may be involved in the occurrence and development of fatty liver disease.

METHODS

Free fatty acids (FFA) treatment was used to simulate the cellular lipid deposition stage of MAFLD and the interactions between cells were simulated via LX2 and LO2 coculture. The molecular interaction between the two cell types was studied via ELISA, immunoprecipitation, qPCR, and western blotting.

RESULTS

In FFA-treated LO2 cells, intracellular TGF-β1 expression increased as lipid deposition increased. FFA-treated LO2 cells promoted the expression and secretion of MMP9 by LX2 cells through paracrine pathways. MMP9 secretion decreased with decreasing SNX-10 expression in LX2 cells. The interaction between MMP9 and SNX-10 was confirmed by coimmunoprecipitation. TGF-β1 promoted the synthesis of SNX-10 through the p38 MAPK pathway, and SNX-10 affected the secretion of MMP9 through protein interactions, thereby affecting the development of liver fibrosis.

CONCLUSIONS

FFA induced lipid deposition in LO2 cells, and TGF-β1 mediated the p38 MAPK pathway to promote SNX-10 synthesis and stimulate MMP9 secretion, thereby regulating the involvement of LX2 in the process of liver fibrosis.

Myricetin Modulates Matrix Metalloproteinases Expression Induced by TEGDMA in Human Odontoblast-Like Cells

The activity of matrix metalloproteinases (MMPs) plays a crucial role in the aging of the resin-dentin interface. The in situ action of MMP-2 and MMP-9 has been confirmed in the process of dentin-collagen degradation. However, the involvement of dental pulp cells in MMP secretion as a response to oxidative stress induced by contact with resin monomers has not been fully elucidated. Myricetin (MYR), like proanthocyanidin (PAC), has antioxidant properties and may help prevent extracellular matrix degradation. The objective was to evaluate the effect of MYR on the MMP expression and activity in response to reactive oxygen species (ROS) increase induced by triethylene glycol dimethacrylate (TEGDMA) in human odontoblast-like cells (hOLCs). hOLCs differentiated from dental pulp mesenchymal stem cells were exposed to TEGDMA released from dentin blocks using a barrier model with transwell inserts for 18, 24, and 36 h. Intracellular oxidation was evaluated using the 2',7'-dichlorofluorescein probe. The effect of 600 μM MYR on the MMP-2 and MMP-9 expression was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The extracellular MMP levels were quantified using enzyme-linked immunosorbent assay, and their activation by means of a proteolytic fluorometric assay. The results were analyzed by one-way analysis of variance and Tukey's post hoc test, p ≤ 0.05. TEGDMA exposure increased intracellular ROS and upregulated MMP-2 and MMP-9 mRNA in hOLCs (p < 0.001). The levels of MMPs increased significantly 24 h after TEGDMA exposure (p = 0.013). These secreted proteases exhibited high activation ability. MYR reduced ROS production and downregulated MMP expression and activity at both mRNA and protein levels, similar to the effect found for PAC, which was used as a control. A relationship was observed between MMP-2 and MMP-9 expression, secretion, and early activation with ROS increase due to TEGDMA exposure. MYR showed potential as a therapeutic strategy to control MMP expression and modulate redox imbalance, offering a protective effect on cellular response.

The interplay of senescence and MMPs in myocardial infarction: implications for cardiac aging and therapeutics

Aging is associated with a marked increase in cardiovascular diseases, such as myocardial infarction (MI). Cellular senescence is also a crucial factor in the development of age-related MI. Matrix metalloproteinases (MMPs) interaction with cellular senescence is a critical determinant of MI development and outcomes, most notably in the aged heart. After experiencing a heart attack, senescent cells exhibit a Senescence-Associated Secretory Phenotype (SASP) and are involved in tissue regeneration and chronic inflammation. MMPs are necessary for extracellular matrix proteolysis and have a biphasic effect, promoting early heart healing and detrimental change if overexpressed shortly. This review analyses the complex connection between senescence and MMPs in MI and how it influences elderly cardiac performance. Critical findings suggest that increasing cellular senescence in aged hearts elevates MMP activity and aggravates extended ventricular remodeling and dysfunction. Additionally, we explore potential therapeutics that address MMPs and senescence to enhance old MI patient myocardial performance and regeneration.

Bond strength to eroded dentin as per chlorhexidine use for controlling erosive wear or interface aging: an 18-month assay

The aim of this study was to assess the effect of a chlorhexidine digluconate solution (CHX) applied as an antiproteolytic agent for controlling erosive tooth wear or as part of the adhesive treatment on long-term bond strength to eroded dentin. Dentin specimens were abraded with a 600-grit silicon carbide (SiC) paper for 1 min (sound dentin - S), subsequently treated with 2% CHX for 1 min (with excess removed, followed by a 6-hour rest), and eroded by exposure to Coca-Cola for 5 min, three times a day, for 5 days (CHX-treated and eroded dentin - CHXE), or only eroded (eroded dentin - E). The specimens were acid-etched (15 s), rinsed (30 s), dried (15 s), and rehydrated with 1.5 μL of distilled water for 1 min, with excess removed (control - S.C/CHXE.C/E.C) or 2% CHX (S.CHX/CHXE.CHX/E.CHX). Adper Single Bond 2 was scrubbed twice on the surface for 15 s each and then light-cured for 10 s, and resin composite cores were built up. Specimens were sectioned into beams and microtensile bond strength was tested (μTBS; 0.5 mm/min) immediately or after 18-month aging. Failure modes were analyzed using a digital microscope. Data (μTBS/MPa) were analyzed by three-way ANOVA, followed by Tukey's test (α = 0.05). μTBS to E and CHXE, irrespective of the rehydration solution and aging period, were equivalent to each other and lower than that to S. CHX as the rehydration solution reduced immediate and long-term µTBS to S. Aging reduced μTBS. By controlling tooth wear or interface aging, CHX could not influence long-term bonding to eroded dentin.

Galectin-3 disrupts tight junctions of airway epithelial cell monolayers by inducing expression and release of matrix metalloproteinases upon influenza A infection

Galectins are β-galactosyl-binding lectins with key roles in early development, immune regulation, and infectious disease. Influenza A virus (IAV) infects the airway epithelia, and in severe cases may lead to bacterial superinfections and hypercytokinemia, and eventually, to acute respiratory distress syndrome (ARDS) through the breakdown of airway barriers. The detailed mechanisms involved, however, remain poorly understood. Our prior in vivo studies in a murine model system revealed that upon experimental IAV and pneumococcal primary and secondary challenges, respectively, galectin-1 and galectin-3 (Gal-3) are released into the airway and bind to the epithelium that has been desialylated by the viral neuraminidase, contributing to secondary bacterial infection and hypercytokinemia leading to the clinical decline and death of the animals. Here we report the results of in vitro studies that reveal the role of the extracellular Gal-3 in additional detrimental effects on the host by disrupting the integrity of the airway epithelial barrier. IAV infection of the human airway epithelia cell line A549 increased release of Gal-3 and its binding to the A549 desialylated cell surface, notably to the transmembrane signaling receptors CD147 and integrin-β1. Addition of recombinant Gal-3 to A549 monolayers resulted in enhanced expression and release of matrix metalloproteinases, leading to disruption of cell-cell tight junctions, and a significant increase in paracellular permeability. This study reveals a critical mechanism involving Gal-3 that may significantly contribute to the severity of IAV infections by promoting disruption of tight junctions and enhanced permeability of the airway epithelia, potentially leading to lung edema and ARDS.

Mechanisms Underlying Vascular Inflammaging: Current Insights and Potential Treatment Approaches

Inflammaging refers to chronic, low-grade inflammation that becomes more common with age and plays a central role in the pathophysiology of various vascular diseases. Key inflammatory mediators involved in inflammaging contribute to endothelial dysfunction and accelerate the progression of atherosclerosis. In addition, specific pathological mechanisms and the role of inflammasomes have emerged as critical drivers of immune responses within the vasculature. A comprehensive understanding of these processes may lead to innovative treatment strategies that could significantly improve the management of age-related vascular diseases. Emerging therapeutic approaches, including cytokine inhibitors, senolytics, and specialized pro-resolving mediators, aim to counteract inflammaging and restore vascular health. This review seeks to provide an in-depth exploration of the molecular pathways underlying vascular inflammaging and highlight potential therapeutic interventions.

Identification of potential MMP-8 inhibitors through virtual screening of natural product databases

Matrix metalloproteinase-8 (MMP-8), a type II collagenase, is a key enzyme in the degradation of collagens and is implicated in various pathological processes, making it a promising target for drug discovery. Despite advancements in the development of MMP-8 inhibitors, concerns over potential adverse effects persist. This study aims to address these concerns by focusing on the development of novel compounds with improved safety profiles while maintaining efficacy. In this study, we employed a computational approach to screen potent and safe inhibitors of MMP-8 from the Natural Product Activity and Species Source Database (NPASS). Initially, we constructed a pharmacophore model based on the crystal structure of the MMP-8-FIN complex (PDB ID: 4EY6) utilizing the Pharmit tool. This model then guided the selection of 44 promising molecules from NPASS, setting the stage for further analysis and evaluation. We comprehensively evaluated their drug-likeness and toxicity profiles. Molecules 21, 4, and 44 were identified as potentially effective MMP-8 inhibitors through a robust pipeline that included ADMET profiling, molecular docking, and molecular dynamics simulations. Notably, molecule 21 stood out for its low toxicity, high binding stability, and favorable ADMET profile, while molecule 44 demonstrated excellent affinity. These compounds offer structural novelty compared to known MMP-8 inhibitors. These computational results can be combined with in vitro experiments in the future to validate their activity and safety. These findings provide an important reference for drug design of MMP-8 inhibitors.

MMP-9 and TIMPs profiles in sulfur mustard-exposed individuals with serious lung complications

Sulfur mustard (SM), a chemical weapon used in the Iraq-Iran war, can pose severe health risks, especially to the lungs. Dysregulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been implicated in various inflammatory lung diseases. This study compares the levels of MMPs and TIMPs in the serum and sputum of veterans with serious lung complications to a control group. Serum and sputum samples were collected and analyzed using the ELISA sandwich method. Differences between SM-exposed and control groups were assessed statistically. The serum levels of TIMP-4 and MMP-9/TIMP-4 were significantly lower and higher in the SM-exposed group respectively compared to the control group. In SM-exposed individuals resembling Bronchiolitis Obliterans (BO), Chronic Bronchitis (CB), and Asthma, TIMP-4 levels were lower than controls, while TIMP-2 levels were higher in those with CB. Although the increased TIMP-2 levels in these patients align with COPD studies, differences were observed in other factors with COPD and asthma-related MMP-9 and TIMP-4 findings. Assessment of serum levels of these factors based on severity reveals lower MMP-9/TIMP-4 levels in the severe group compared to the mild-moderate group. Individuals exposed to SM exhibit distinct MMP and TIMP profiles, with significantly lower TIMP-4 levels and higher MMP-9/TIMP-4 ratios, compared to controls. These profiles vary across different lung conditions, indicating a unique disease mechanism in SM-exposed individuals. This distinctive profile supports the classification of this condition as 'Mustard Lung.' Further research is needed to elucidate these mechanisms for targeted therapeutic interventions.

Detection of Gelatinases by Substrate Zymography

Zymography is a method of electrophoretic separation of matrix metalloproteinases (MMPs) in a polyacrylamide gel-containing substrate (called zymogram gel) for the assay of various MMPs in different biological samples. In particular, gelatin-zymography allows to determine simultaneously both active and latent forms of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) in biological fluids as well as in tissue extracts with high sensitivity (order of pg) and in a semiquantitative manner.In this procedure, the proteins are separated by electrophoresis under denaturing but nonreducing conditions (to maintain enzymatic activity) in a polyacrylamide gel (SDS-PAGE) co-polymerized with a gelatin (denatured collagen) substrate. In the presence of SDS the enzymes are denatured exposing their active site, which permits both the latent and active forms of the gelatinases to exhibit gelatinolytic activity after their removal from the gel by a nonionic detergent (e.g., Triton X-100). After incubation in a calcium-containing buffer, the partially renatured enzymes can degrade the gelatin leaving a cleared zone that can be detected after staining of the gel. Coomassie blue staining of the gel reveals sites of proteolysis as white bands on a blue background of stained, undigested gelatin, that can be quantified by using an image analysis software.

Gel Diffusion-Based Gelatin Zymography to Analyze MMP-2 and MMP-9 Activity in Cell Culture

Matrix metalloproteinases (MMPs) are proteolytic enzymes regulating the degradation of collagen as well as other proteins in the extracellular matrix (ECM), tissue repair, and remodeling. Validating MMPs as current drug targets can potentially establish the clinical relevance of their quantitative expression and distribution and open new therapeutic venues in tumor and metastasis. Zymography is a technique used for the identification of the proteolytic activity of MMPs in diverse biological samples. In gel diffusion zymography, analysis of the functional activity of the gelatinases (MMP-2 and MMP-9) by the digestion of gelatin as a substrate, added to agarose gel to assess the active forms of MMPs, is done. Here we describe a detailed experimental protocol to quantitate the gelatinase activity within the cell culture.

Zymography as a Tool for Exploring Protease Activity in Dental Research

The presence and activity of matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs) in dentin significantly affect the progress of carious and erosive lesions into dentin, as well as the durability and integrity of dental restorations. Understanding the mechanisms involved on this proteolytic activity could therefore provide valuable insights into the pathogenesis of these conditions and inform the development of novel therapeutic strategies. This manuscript provides a comprehensive overview of zymographic techniques applied in dental research, with a focus on the sample's preparation and different measurements of the enzymatic activity through substrate hydrolysis. Standard zymography assays using dentin as a substrate to evaluate the gelatinolytic activity of metalloproteinases (MMPs) and cysteine cathepsins (CCs) are presented, including gel zymography, in situ zymography using fluorescent gelatin-substrate, and reverse zymography for investigating proteolytic activity in dentin.

In Situ Zymography and Localization of Bright Green Fluorescent Gelatinase Activity in Tissue Sections

In situ zymography is an efficient and low-cost technique to detect the activity of the gelatinases matrix metalloproteinase (MMP)-2 and MMP-9 in various tissues from humans and experimental animal models. This technique also shows the precise localization of gelatinases in large or small tissues and in cells. It is a one-day technique that uses a dye-quenched fluorescent gelatin (Dq-gelatin). The Dq-gelatin is loaded into tissue sections and upon its interaction with local active gelatinases, it is proteolyzed into highly fluorescent peptides that emit bright green fluorescence, thus reflecting the level of activity and localization of the gelatinases. Combined with other biochemical techniques in tissue homogenates and fractions, the in situ zymography provides a fluorescence microscopy and digital imaging technique to assess the subcellular localization and the role of gelatinases in tissue remodeling in health and disease.

Exploring the effectiveness of doxycycline in restorative dentistry: a systematic review of in vitro studies

This systematic review evaluated the efficacy of doxycycline in MMP inhibition, its antibacterial action, and other properties relevant to dental materials testing. The study protocol was registered at the Open Science Framework ( https://doi.org/10.17605/OSF.IO/ZVK2T ). Reporting was based on PRISMA statement. The search was carried out in the databases: PubMed, Scopus, Web of Science, Embase, Lilacs, and Google Scholar. Articles were restricted to Portuguese, English, and Spanish, with no date limit. In vitro studies were selected based on the following outcomes: DOX antibacterial and anti-metalloproteinase activity and its influence in physico-chemical properties. Two researchers independently selected the articles and collected the data. Of 1507 documents, 82 were fully evaluated and 21 were included. Different forms of doxycycline incorporation were found, both as free form and incorporated into carrier agents. The drug was tested as primers, incorporated in adhesive or glass ionomer cement. No studies were found that evaluated its incorporation in resin composite or resin cement. The results confirmed the therapeutic properties of the medication, with more significant results when incorporated in an adhesive. However, although promising, the use of this substance requires standardization in application methods and adopted concentrations, allowing for more direct comparisons between studies. Furthermore, long-term studies are interesting to conduct, ensuring biocompatibility and complete understanding of long-term effects on dental materials.

Advances focusing on the application of decellularization methods in tendon-bone healing

BACKGROUND

The tendon or ligament is attached to the bone by a triphasic but continuous area of heterogeneous tissue called the tendon-bone interface (TBI). The rapid and functional regeneration of TBI is challenging owing to its complex composition and difficulty in self-healing. The development of new technologies, such as decellularization, has shown promise in the regeneration of TBI. Several ex vivo and in vivo studies have shown that decellularized grafts and decellularized biomaterial scaffolds achieved better efficacy in enhancing TBI healing. However further information on the type of review that is available is needed.

AIM OF THE REVIEW

In this review, we discuss the current application of decellularization biomaterials in promoting TBI healing and the possible mechanisms involved. With this work, we would like to reveal how tissues or biomaterials that have been decellularized can improve tendon-bone healing and to provide a theoretical basis for future related studies.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

Decellularization is an emerging technology that utilizes various chemical, enzymatic and/or physical strategies to remove cellular components from tissues while retaining the structure and composition of the extracellular matrix (ECM). After decellularization, the cellular components of the tissue that cause an immune response are removed, while various biologically active biofactors are retained. This review further explores how tissues or biomaterials that have been decellularized improve TBI healing.

Single Nucleotide Polymorphisms and Tendon/Ligament Injuries in Athletes: A Systematic Review and Meta-analysis

This systematic review and meta-analysis aimed to identify the association between genetic polymorphisms and tendon and ligament injuries in adolescent and adult athletes of multiple competition sports. The PubMed, Web of Science, EBSCO, Cochrane Library, and MEDLINE databases were searched until July 7, 2023. Eligible articles included genetic studies on tendon and ligament injuries and comparisons between injured and non-injured athletes. This review included 31 articles, comprising 1,687 injury cases and 2,227 controls, from a meta-analysis of 12 articles. We identified 144 candidate gene polymorphisms (only single nucleotide polymorphisms were identified). The meta-analyses included vascular endothelial growth factor A (VEGFA) rs699947, collagen type I alpha 1 rs1800012, collagen type V alpha 1 rs12722, and matrix metalloproteinase 3 rs679620. The VEGFA rs699947 polymorphism showed a lower risk of injuries in athletes with the C allele ([C vs. A]: OR=0.80, 95% CI: 0.65-0.98, I 2 =3.82%, p=0.03). The risk of these injuries were not affected by other polymorphisms. In conclusion, the VEGFA rs699947 polymorphism is associated with the risk of tendon and ligament injuries in athletes. This study provides insights into genetic variations that contribute to our understanding of the risk factors for such injuries in athletes.

The effects of coagulation factors on the risk of autoimmune diseases: A Mendelian randomization study

The objective of this study was to investigate the potential causal relationship between coagulation factors and autoimmune diseases (ADs). We employed Mendelian randomization to investigate the associations between selected 7 coagulation factors and 10 ADs, leveraging genetic variants as instrumental variables to assess causal relationships between exposures of interest and outcomes. Within the scope of this investigation, coagulation factors were designated as the exposure source, while ADs were observed to manifest as the consequent outcome. Our analysis using the inverse-variance weighted (IVW) method revealed that Factor VIII (FVIII) (P = .0067) exhibited significant causal associations with a reduced risk of multiple sclerosis. In contrast, fibrinogen (P = .0004) was associated with an increased risk of multiple sclerosis. The analysis also indicated that activated partial thromboplastin time (P = .0047) was implicated in elevating the risk of urticaria. The results also showed that protein C (P = .0188) was inversely associated with the risk of systemic lupus erythematosus. The results unveiled a significant positive correlation between fibrinogen (P = .0318) and the risk of rheumatoid arthritis. Similarly, Factor VII (P = .0119), FVIII (P = .0141), and von Willebrand Factor (P = .0494) were also found to be positively associated with the risk of inflammatory bowel disease. The IVW analysis demonstrated a causal relationship between von Willebrand Factor (P = .0316) and FVIII (P = .0408) and a decreased risk of primary sclerosing cholangitis. IVW results confirmed that protein C (P = .0409) had a protective effect on vitiligo. No significant associations were found between psoriatic arthritis, rosacea, and the 7 coagulation factors in this study. This is of significant importance for advancing the prevention, diagnosis, and treatment of ADs.