Structure and function of matrix metalloproteinases and TIMPs

Unveiling the role of extracellular matrix elements and regulators in shaping ovarian cancer growth and metastasis

Epithelial ovarian cancer (EOC) progression is determined by numerous intracellular interactions and the interplay between malignant cells, normal cells, and the tumor acellular microenvironment, formed largely by the extracellular matrix (ECM). The structure and biochemical functioning of various ECM components, along with the activity of agents that regulate ECM remodeling, impact the disease's expansion (adhesion, proliferation, invasion), spread, and response to therapy. It is important to note that the involvement of ECM components and their regulators in the progression of EOC is bidirectional and distinctly depends on a particular tissue context. In certain situations, certain components of the ECM enhance the activity of cancer cells, but in other scenarios, they suppress it. In this review, we summarize the newest knowledge regarding diverse aspects of ECM engagement in EOC pathophysiology and chemotherapy. Moreover, we delineate conditions that exacerbate the pro-cancerous properties of ECM, including diabetes-associated glycation, aging, and cellular senescence. We also explore methods to therapeutically alter the properties of the ECM, which could be beneficial in ovarian cancer prevention and treatment.

Distinct structural basis and catalytic classification of matrix metalloproteinases and their endogenous tissue inhibitors with glycosylation issue in cellular and tissue regulation

Matrix metalloproteinase (MMP) enzymes cleave proteins on the extracellular matrix (ECM) region. MMPs are categorized as Zn2+-binding endo-proteinases. MMPs are stringently regulated in cancers, inflammatory cells and tissues. There are 29 types of MMPs as initially expressed in inactive zymogens (proMMPs) and activated by proteolysis in vertebrates including human. MMPs consist of three highly conserved parts of pro-MMP in precursor, catalytic and hemopexin domains. The MMPs are composed of systemic complexes with their endogenously expressed inhibitors of the tissue inhibitors of metalloproteinases (TIMPs). Therefore, TIMPs intrinsically control such activated MMPs, indicating the existence of self-modulation capacity. N-linked glycosylation (N-glycosylation) saves biological information than known phosphorylation, ubiquitination and acetylation. The MMPs are roughly present as membrane-merged and secreted glycoproteins. MMPs N-glycans regulate cellular behaviors, immune tolerance, and developing angiogenesis. Aberrant N-glycosylation of MMPs may cause the pathogenic properties. N-glycosylation shapes phenotypes of MMPs-producing cells during early MMPs involved in human. Additionally, issues of MMPs and TIMPs glycosylation have been described to view the importance of the glycans in their interaction with owns and other targets. Most of MMPs and 4 TIMPs are not well studied for their glycosylation and its functional roles.

Matrix metalloproteinases and their tissue inhibitors as indicators of aortic aneurysm and dissection development in extracellular matrix remodeling

Aneurysms and dissections represent some of the most serious cardiovascular diseases. The prevailing theory posits that mechanical overloading of the vessel wall is the underlying cause. Inspired by Barkhordarian et al, the authors present matrix metalloproteinases (MMPs) and their inhibitors in immunohistological analyses as contributing factors in the pathophysiology of aortic aneurysms (AA). Data analysis of MMP-1, MMP-9, tissue inhibitors of metalloproteinases (TIMPs), including TIMP-1 and TIMP-2 expression reveals a varied distribution between the adventitia and media and a non-uniform expression of the investigated markers. These elements, as key components of the extracellular matrix (ECM), indicate that the formation of AA is not solely driven by endoluminal pressure loading of the aortic wall. Instead, degenerative processes within ECM elements contribute significantly. Importantly, AA do not necessarily imply dissection. Tissue destruction, allowing blood flow entry, arises from reduced oxygen supply to the media, primarily due to incomplete capillarization or neocapillarization.

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.

TIMP-1 associates with myelin membrane and preserves myelin in injured peripheral nerve

Myelin enables rapid impulse propagation in axons across long distances. Following peripheral nerve injury, Schwann cells provide trophic, metabolic, and immune support to damaged neurons. To facilitate myelin repair, Schwann cells activate a robust transcriptional program, including the tissue inhibitor of metalloproteinase (TIMP)-1 gene. TIMP-1 is a potent protease inhibitor and neurotrophic factor, traditionally known as a secreted protein. This study presents the first evidence of a myelin/membrane-associated (mm)TIMP-1 protein fraction in the nervous system. Specifically, we identified mmTIMP-1 in the rat sciatic nerve after chronic constriction injury (CCI) using multiple complementary approaches. Dual-immunofluorescence revealed TIMP-1 co-localization with myelin protein in the myelin sheath of CCI nerve. Immunoblotting and mass-spectrometry of sucrose gradient-fractionated nerves further confirmed presence of TIMP-1 in myelin/membrane lipid rafts. Both TIMP-1 and (mm)TIMP-1 levels increased in the nerves during the early phase (day 1) and declined in the late phase (day 28) of CCI. Recombinant (r)TIMP-1 replacement therapy during the late phase CCI, administered by intraneural injection, led to improved myelin neuropathology and accumulation of myelin protein. This study identifies a novel subcellular TIMP-1 fraction associated with the myelin sheath and highlights TIMP-1's reparative activity in peripheral nerve myelin in vivo, opening new avenues for exploring functional activities of TIMP-1 isoforms in the nervous system.

Mechanisms and Therapeutic Strategies of Macrophage Polarization in Intervertebral Disc Degeneration

Background

Intervertebral disc degeneration (IVDD) is a leading cause of low back pain (LBP), contributing significantly to global disability and productivity loss. Its pathogenesis involves complex processes, including inflammation, cellular senescence, angiogenesis, fibrosis, neural ingrowth, and sensitization. Emerging evidence highlights macrophages as central immune regulators infiltrating degenerated discs, with macrophage polarization implicated in IVDD progression. However, the mechanisms linking macrophage polarization to IVDD pathology remain poorly elucidated.

Methods

A comprehensive literature review was conducted by searching major databases (PubMed, Web of Science, and Scopus) for studies published in the last decade (2014-2024). Keywords included "intervertebral disc degeneration," "macrophage polarization," "inflammation," "senescence," and "therapeutic strategies." Relevant articles were selected, analyzed, and synthesized to evaluate the role of macrophage polarization in IVDD.

Results

Macrophage polarization dynamically influences IVDD through multiple pathways. Pro-inflammatory M1 macrophages exacerbate disc degeneration by amplifying inflammatory cytokines (e.g., TNF-α, IL-1β), promoting cellular senescence, and stimulating abnormal angiogenesis and neural ingrowth. In contrast, anti-inflammatory M2 macrophages may mitigate degeneration by suppressing inflammation and enhancing tissue repair. Therapeutic strategies targeting macrophage polarization include pharmacological agents (e.g., cytokines, small-molecule inhibitors), biologic therapies, gene editing, and physical interventions. Challenges persist, such as incomplete understanding of polarization triggers, lack of targeted delivery systems, and limited translational success in preclinical models.

Conclusion

Macrophage polarization is a pivotal regulator of IVDD pathology, offering promising therapeutic targets. Future research should focus on elucidating polarization mechanisms, optimizing spatiotemporal control of macrophage phenotypes, and developing personalized therapies. Addressing these challenges may advance innovative strategies to halt or reverse IVDD progression, ultimately improving clinical outcomes for LBP patients.

Sequence and Structure at Play in Designing Allosteric Drugs and Alleviating the Drug Resistance

The advantages of allosteric drugs in targeting selected members of highly conserved protein families are well established. However, the discovery of allosteric effectors remains largely serendipitous, calling for a rational approach to account for their unique mechanisms and specificity towards protein targets. We show that the high-throughput quantification of allosteric signalling on a single-residue resolution allows one to delineate structural and sequence determinants of allosteric communication that are specific to individual members of a structurally conserved protein family. We demonstrate work of the approach using the matrix metalloproteinases (MMPs), a family of proteases also known to be "undruggable" because of their sequence/structural traits. Specifically, latent allosteric sites and effectors were identified and fine-tuned for precise functional modulation of MMP-7, MMP-12 and MMP-13. We also explored the allosteric effects of mutations in driving pathogenesis and emergence of the drug resistance, arguing that they should be considered in diagnostics and drug design frameworks. The multiplicity of allosteric sites and alternative effectors allow, for example, to rescue the therapeutic actions of orthosteric or allosteric drugs in cases of emerged resistance, because of mutations at the drug binding sites or other distal locations. To conclude, using the matrix metalloproteinases as an example of undruggable targets, we highlighted here advantages of the allosteric paradigm in drug design and illuminated a utility of our directed design protocol for the rational design of allosteric drugs.

A versatile platform based on matrix metalloproteinase-sensitive peptides for novel diagnostic and therapeutic strategies in arthritis

Matrix metalloproteinases (MMPs), coupled with other proteinases and glycanases, can degrade proteoglycans, collagens, and other extracellular matrix (ECM) components in inflammatory and non-inflammatory arthritis, making them important pathogenic molecules and ideal disease indicators and pharmaceutical intervention triggers. For MMP responsiveness, MMP-sensitive peptides (MSPs) are among the most easily synthesized and cost-effective substrates, with free terminal amine and/or carboxyl groups extensively employed in multiple designs. We hereby provide a comprehensive review over the mechanisms and advances in MSP applications for the management of arthritis. These applications include early and precise diagnosis of MMP activity via fluorescence probe technologies; acting as nanodrug carriers to enable on-demand drug release triggered by pathological microenvironments; and facilitating cartilage engineering through MMP-mediated degradation, which promotes cell migration, matrix synthesis, and tissue integration. Specifically, the ultra-sensitive MSP diagnostic probes could significantly advance the early diagnosis and detection of osteoarthritis (OA), while MSP-based drug carriers for rheumatoid arthritis (RA) can intelligently release anti-inflammatory drugs effectively during flare-ups, or even before symptoms manifest. The continuous progress in MSP development may acceleratedly lead to novel management regimens for arthropathy in the future.

Membrane-anchored tissue inhibitor of matrix metalloproteinase (TIMP)-1 promotes cell death in head and neck cancer by inducing DNA damage, accumulating collagen II and disrupting cell survival mechanisms

Head and neck squamous cell carcinoma (HNSCC) remains a significant global health challenge with limited therapeutic options. Here, we investigate a novel membrane-anchored variant of Tissue Inhibitor of Matrix Metalloproteinase-1 (TIMP-1), designated T1Pr, as a potential therapeutic agent against HNSCC. Utilizing a comprehensive approach involving biochemical, cellular, animal, mRNA-sequencing, and omics techniques, we demonstrate that T1Pr exhibits remarkable anti-tumorigenic effects in CAL27 cells in vitro and in vivo. Phospho-proteomics analysis revealed that T1Pr induces profound changes in the cellular phosphorylation landscape, particularly targeting critical cell cycle regulators like CDK1 and CSNK2A1. Further, T1Pr disrupts nuclear transport and cell cycle pathways, causes chromosomal DNA damage possibly by impeding the nuclear localization of membrane-associated MMPs and ADAM proteinases. Notably, T1Pr triggers significant extracellular matrix remodeling, including collagen II accumulation, and suppresses numerous pro-tumor genes and proteins. T1Pr also upregulates tumor-suppressive genes like PAWR, TPM1, and THBS1 linked to cytoskeletal stability and apoptosis induction. Functionally, T1Pr drives CAL27 cells toward apoptosis through persistent DNA damage and disrupted mitotic checkpoints. Importantly, T1Pr does not compromise immune checkpoint mechanisms. These findings position T1Pr as a promising molecular therapeutic approach for targeting invasive cancers, particularly HNSCC, by orchestrating a comprehensive cellular shutdown through multiple interconnected mechanisms.

Targeting tumor extracellular matrix with nanoparticles to circumvent therapeutic resistance

Each stage of tumor development is intrinsically linked to the tumor microenvironment (TME), wherein the extracellular matrix (ECM) serves as a vital and abundant component in tumor tissues. The ECM is a non-cellular, three-dimensional macromolecular network scaffold that provides structural support to cells, stores bioactive molecules, and mediates signaling pathways through specific binding to cell surface receptors. Moreover, the ECM in tumor tissues plays a crucial role in impeding drug diffusion and resisting apoptosis induced by conventional anti-cancer therapies that primarily target cancer cells. Therefore, directing attentions towards the tumor ECM can facilitate the identification of novel targets and the development of new therapies. This review aims to summarize the composition, structure, remodeling, and function of tumor ECM, its association with drug resistance, and current targeting strategies, with a specific emphasis on nanoparticles (NPs).

Unraveling the significance of innate inflammation in vascular disease

Atheroma formation is initiated by the activation of endothelial and smooth muscle cells, as well as immune cells, including neutrophils, lymphocytes, monocytes, macrophages, and dendritic cells. Monocytes, macrophages, and neutrophils are the innate immune cells that provide a rapid initial line of defence against vascular disease. These cells have a short lifespan and cannot retain memories, making them potential therapeutic targets for the inflammatory process associated with atherosclerosis. In addition, macrophages comprise the majority of vessel wall infiltrates and are, therefore, implicated in all stages of atherosclerosis progression. Neutrophils are the most common type of leukocyte found in circulation, and their high levels of matrix-degrading protease explain their significance in fibrous cap destabilization. However, the activation of immune cells becomes more complex by various microenvironmental stimuli and cytokines, which ultimately transform immune cells into their pro-inflammatory state. Different types of macrophage subsets with distinct functions in inflammation, such as M1 macrophages, cause an increase in pro-inflammatory cytokines and produce reactive oxygen species and nitric oxide, further worsening the disease. This review aims to shed light on immune-mediated inflammation in cardiovascular disease by focusing on the role of macrophage subsets in vascular inflammation and plaque stability, as well as the interaction between neutrophils and monocyte-macrophages.

Matrix Metalloproteinases in Glioma: Drivers of Invasion and Therapeutic Targets

Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteolytic enzymes that are crucial for the remodeling of the extracellular matrix, a process that is often co-opted by cancers, including brain tumors, to facilitate growth, invasion, and metastasis. In gliomas, MMPs contribute to a complex interplay involving tumor proliferation, angiogenesis, and immune modulation, thereby influencing tumor progression and patient prognosis. This review provides a comprehensive analysis of the roles of various MMPs in different types of gliomas, from highly malignant gliomas to metastatic lesions. Emphasis is placed on how the dysregulation of MMPs impacts tumor behavior, the association between specific MMPs and the tumor grade, and their potential as biomarkers for diagnosis and prognosis. Additionally, the current therapeutic approaches targeting MMP activity are discussed, exploring both their challenges and future potential. By synthesizing recent findings, this paper aims to clarify the broad significance of MMPs in gliomas and propose avenues for translational research that could enhance treatment strategies and clinical outcomes.

Matrix metalloproteinase-driven epithelial-mesenchymal transition: implications in health and disease

Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells, defined by apical-basal polarity and tight intercellular junctions, acquire migratory and invasive properties characteristic of mesenchymal cells. Under normal conditions, EMT directs essential morphogenetic events in embryogenesis and supports tissue repair. When dysregulated, EMT contributes to pathological processes such as organ fibrosis, chronic inflammation, and cancer progression and metastasis. Matrix metalloproteinases (MMPs)-a family of zinc-dependent proteases that degrade structural components of the extracellular matrix-sit at the nexus of this transition by dismantling basement membranes, activating pro-EMT signaling pathways, and cleaving adhesion molecules. When normally regulated, MMPs promote balanced ECM turnover and support the cyclical remodeling necessary for proper development, wound healing, and tissue homeostasis. When abnormally regulated, MMPs drive excessive ECM turnover, thereby promoting EMT-related pathologies, including tumor progression and fibrotic disease. This review provides an integrated overview of the molecular mechanisms by which MMPs both initiate and sustain EMT under physiological and disease conditions. It discusses how MMPs can potentiate EMT through TGF-β and Wnt/β-catenin signaling, disrupt cell-cell junction proteins, and potentiate the action of hypoxia-inducible factors in the tumor microenvironment. It discusses how these pathologic processes remodel tissues during fibrosis, and fuel cancer cell invasion, metastasis, and resistance to therapy. Finally, the review explores emerging therapeutic strategies that selectively target MMPs and EMT, ranging from CRISPR/Cas-mediated interventions to engineered tissue inhibitors of metalloproteinases (TIMPs), and demonstrates how such approaches may suppress pathological EMT without compromising its indispensable roles in normal biology.

Phytochemical profiling of Pelargonium graveolens l'Hér and evaluation of its activity against D-galactose induced skin ageing

Pelargonium graveolens L'Hér is an evergreen small shrub with pink flowers. Metabolite profiling of its extract by UHPLC/MS analysis revealed the identification of 51 secondary metabolites. Interestingly, 29 compounds identified for the first time. The colorimetric assays revealed high content of phenolic, flavonoids and tannins (100.19 ± 3.94 µg Gallic acid Eq/mg, 47.38 ± 2.04 µg Rutin Eq/mg and 332.75 ± 8.85 µg Catechin Eq/mg of extract) respectively along with good antioxidant activity. Moreover, the in vitro analysis showed a significant anti-hyaluronidase activity (IC50 ± SD = 15.75 ± 0.8), as compared to standard luteolin. Topical application of the characterised P. graveolens hydrogel (1% and 2% w/w) was tested using the D-galactose-induced ageing model in mice. Histopathological examination demonstrated an increase in the dermal collagen expression, alleviation of ageing-related oxidative stress, and stabilisation of MMP-1/TIMP-1 balance. Ultimately, P. graveolens could be a valuable source of natural antioxidants with a promising antiaging activity.

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.

Cold-induced fibrosis and metabolic remodeling in the turtle (Trachemys scripta) ventricle

AIM

Cardiac fibrosis contributes to systolic and diastolic dysfunction and can disrupt electrical pathways in the heart. There are currently no therapies that prevent or reverse fibrosis in human cardiac disease. However, animals like freshwater turtles undergo seasonal remodeling of their hearts, demonstrating the plasticity of fibrotic remodeling. In Trachemys scripta, cold temperature affects cardiac load, suppresses metabolism, and triggers a cardiac remodeling response that includes fibrosis.

METHODS

We investigated this remodeling using Fourier transform infrared (FTIR) imaging spectroscopy, together with functional assessment of muscle stiffness, and molecular, histological, and enzymatic analyses in control (25°C) T. scripta and after 8 weeks of cold (5°C) acclimation.

RESULTS

FTIR revealed an increase in absorption bands characteristic of protein, glycogen, and collagen following cold acclimation, with a corresponding decrease in bands characteristic of lipids and phosphates. Histology confirmed these responses. Functionally, micromechanical stiffness of the ventricle increased following cold exposure assessed via atomic force microscopy (AFM) and was associated with decreased activity of regulatory matrix metalloproteinases (MMPs) and increased expression of MMP inhibitors (TMPs) which regulate collagen deposition.

CONCLUSIONS

By defining the structural and metabolic underpinnings of the cold-induced remodeling response in the turtle heart, we show commonalities between metabolic and fibrotic triggers of pathological remodeling in human cardiac disease. We propose the turtle ventricle as a novel model for studying the mechanisms underlying fibrotic and metabolic cardiac remodeling.

Decoding the MMP14 integrin link: Key player in the secretome landscape

Rapid progress has been made in the exciting field of secretome research in health and disease. The tumor secretome, which is a significant proportion of the tumor proteome, is secreted into the extracellular space to promote intercellular communication and thus tumor progression. Among the many molecules of the secretome, integrins and matrix metalloproteinase 14 (MMP14) stand out as the interplay of adhesion and proteolysis drives invasion. Integrins serve as mechanosensors that mediate the contact of cells with the scaffold of the extracellular matrix and are significantly involved in the precise positioning and activity control of the membrane-bound collagenase MMP14. As a secretome proteinase, MMP14 influences and modifies the secretome itself. While integrins and MT-MMPs are membrane bound, but can be released and are therefore border crossers between the cell surface and the secretome, the extracellular matrix is not constitutively cell-bound, but its binding to integrins and other cell receptors is a stringently regulated process. To understand the mutual interactions in detail, we first summarize the structure and function of MMP14 and how it is regulated at the enzymatic and cellular level. In particular, the mutual interactions between integrins and MMP14 include the proteolytic cleavage of integrins themselves by MMP14. We then review the biochemical, cell biological and physiological effects of MMP14 on the composition and associated functions in the tumor secretome when either bound to the cell membrane, or located on extracellular microvesicles, or as a proteolytically shed non-membrane-bound ectodomain. Novel methods of proteomics, including the analysis of extravesicular vesicles, and new methods for the quantification of MMP14 will provide new research and diagnostic tools. The proteolytic modification of the tumor secretome, especially by MMP14, may bring an additional aspect to tumor secretome studies and will have an impact on the diagnosis and most likely also on the therapy of cancer patients.

Long Non-coding RNA Involved in the Pathophysiology of Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is a prevalent and chronic cardiovascular disorder associated with various pathophysiological alterations, including atrial electrical and structural remodeling, disrupted calcium handling, autonomic nervous system dysfunction, aberrant energy metabolism, and immune dysregulation. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play a significant role in the pathogenesis of AF.

OBJECTIVE

This discussion aims to elucidate the involvement of AF-related lncRNAs, with a specific focus on their role as miRNA sponges that modulate crucial signaling pathways, contributing to the progression of AF. We also address current limitations in AF-related lncRNA research and explore potential future directions in this field. Additionally, we summarize feasible strategies and promising delivery systems for targeting lncRNAs in AF therapy.

CONCLUSION

In conclusion, targeting AF-related lncRNAs holds substantial promise for future investigations and represents a potential therapeutic avenue for managing AF.

Fish and bovine collagen promote higher migration and adhesion of dermal cells pre-treated with wound-healing herbal extracts

PURPOSE

Dermal cells fabricate and interact with the extracellular matrix to preserve structural integrity and further healthy function during wound healing. Collagen is a critical component of the matrix, challenging collagen's stability during wound injury. Natural sources especially plant extracts can promote wound healing and interact with collagen to increase its action. In this context, we studied the effect of extracted fish and bovine collagen in controlling cell proliferation, migration, and adhesion in dermal cells pretreated with plant extract.

METHODS

An acid-solubilization procedure was used to extract collagen fish (CF) and bovine (CB). Three different hydro-ethanolic extracts were prepared Pistacia lentiscus leaves (PL), Calendula officinalis leaves (FL), and flowers (FS). Migration potency was determined using scratch assay. The covered surface area was estimated after 16 hours and 24 hours after cell seeding. The chemotaxis was determined by the Boyden chamber, and the film was coated with CF or CB (10 µg/mL). or poly-L-lysine (50 µg/mL).

FINDINGS

We show that CF and CB increase adherence and migration of 3T3-L1 cells, which are pretreated with PL, FL, and FS. In addition, we highlighted a significantly higher cell adhesion on the CF matrix compared to CB. However, in the case of cells pre-treated with PL, the attachment to CF and CB increased significantly compared to untreated cells. The exposition of Hacat cells to plant extracts regulates the secretion of MMP2 and MMP and the production of reactive oxygen species.

CONCLUSION

CF and CB promote higher migration and adhesion of dermal cells pre-treated with wound-healing herbal extracts. In future studies, composite dressings based on collagen, P. lentiscus, and C. officinalis extracts can potentially be developed for tissue regeneration.

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.

Matrix Metalloproteinases in Ureteropelvic Junction Obstruction: Their Role in Pathogenesis and Their Use as Clinical Markers

The obstruction of the urinary tract is responsible for obstructive nephropathy (ON), also known as uropathy, which may then evolve in a renal parenchymal disease (hydronephrosis). Regarding the etiology of ON, it has been linked to the perturbation of processes occurring during the urinary tract development such as morphogenesis, maturation, and growth. Despite the research carried out in recent years, there is still a pressing need to elucidate the molecular processes underlying the disease. This may then result in the definition of novel biomarkers that can help in patient stratification and the monitoring of therapeutic choices. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with key roles in extracellular matrix remodeling due to their wide cleavage specificity and ability to modulate the bioavailability of growth factors. Despite the known changes in the local tissue microenvironment at the site of the urinary tract obstruction, the role of MMPs in ureteropelvic junction obstruction (UPJO) and, therefore, in the pathogenesis of renal damage in ON is not well-documented. In this review, we underline the possible roles of MMPs both in the pathogenesis of UPJO and in the progression of related hydronephrosis. The potential use of MMPs as biomarkers detectable in bodily fluids (such as the patient's urine) is also discussed.

Proinflammatory cytokine-induced matrix metalloproteinase-9 expression in temporomandibular joint osteoarthritis is regulated by multiple intracellular mitogen-activated protein kinase pathways

OBJECTIVES

Temporomandibular joint (TMJ) osteoarthritis (OA) is an inflammatory disease that involves periarthritis of the TMJ and destruction of cartilage tissue in the mandibular condyle. However, the role of proinflammatory cytokines in the expression levels of matrix metalloproteinase (MMP) remains inconclusive. Thus, in this study, we aimed to investigate the effect of proinflammatory cytokines on the expression of MMPs.

METHODS

FLS1 cells (mouse TMJ-derived synovial cell line) were treated with tumor necrosis factor alpha (TNF-α) or interleukin (IL)-1β in the presence or absence of mitogen-activated protein kinase (MAPK) inhibitors. The mRNA expression levels of MMP-2 and MMP-9 were examined by reverse transcription-quantitative polymerase chain reaction. Additionally, the phosphorylation status of extracellular signal-regulated kinase (ERK)1/2 and p38 MAPK in the FLS1 cells treated with TNF-α or IL-1β was evaluated by performing western blotting analysis.

RESULTS

TNF-α and IL-1β significantly increased the expression of MMP-9 in the FLS1 cells; however, MMP-2 expression remained unaffected. Mitogen-activated protein kinase kinase (MEK) and p38 MAPK inhibitors significantly suppressed cytokine-induced MMP-9 upregulation. Conversely, Jun amino-terminal kinase (JNK) inhibitors further increased MMP-9 expression in the cells treated with TNF-α or IL-1β. Moreover, TNF-α and IL-1β enhanced ERK1/2 and p38 MAPK phosphorylation in the FLS1 cells.

CONCLUSIONS

TNF-α and IL-1β induced MMP-9 expression in the FLS1 cells via the MEK/ERK and p38 MAPK pathways and suppressed it via the JNK pathway. Thus, proinflammatory cytokines control MMP-9 expression in TMJ-OA by regulating multiple MAPK pathways.

Senescence as a molecular target in skin aging and disease

Skin aging represents a multifactorial process influenced by both intrinsic and extrinsic factors, collectively known as the skin exposome. Cellular senescence, characterized by stable cell cycle arrest and secretion of pro-inflammatory molecules, has been implicated as a key driver of physiological and pathological skin aging. Increasing evidence points towards the role of senescence in a variety of dermatological diseases, where the accumulation of senescent cells in the epidermis and dermis exacerbates disease progression. Emerging therapeutic strategies such as senolytics and senomorphics offer promising avenues to target senescent cells and mitigate their deleterious effects, providing potential treatments for both skin aging and senescence-associated skin diseases. This review explores the molecular mechanisms of cellular senescence and its role in promoting age-related skin changes and pathologies, while compiling the observed effects of senotherapeutics in the skin and discussing the translational relevance.

High-resolution targeted mass spectrometry for comprehensive quantification of sphingolipids: clinical applications and characterization of extracellular vesicles

Sphingolipids (SL), a class of membrane lipids, play important roles in numerous biological processes. Their significant structural diversity poses challenges for accurate quantification. To address this, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has emerged as a powerful tool for sphingolipidomics, capable of profiling these lipids comprehensively. In this study, we utilized LC-MS/MS with high-resolution mass spectrometry (MRMHR) to develop a targeted method for the identification and quantification of various SL species. This method, based on validated parameters such as precursor/fragment ions (m/z) and retention time, demonstrated high sensitivity and accuracy, successfully identifying SL species across 12 distinct classes. Its open-panel design also facilitates the analysis of new SL-species targets. Notably, using this approach, we identified 40 SL species in plasma samples from COVID-19 patients, and we determined the influence of matrix metalloproteinase-3 (MMP-3) expression on the positive downstream of SL metabolism. Beyond plasma analysis, this method has potential applications in other biomedical contexts, such as extracellular vesicles (EVs), describing the cargo of sphingosine-1-phosphate (S1P) on macrophage-derived EVs. The establishment of this targeted workflow enabling precise quantification of a wide range of SL species, holds promise for identifying novel biomarkers and therapeutic targets.

The developmental and inflammatory disease target protein ADAM17 is vulnerable to off-target interaction by the drug eltrombopag: Insights from molecular modeling

The loss of proteolytic activity of ADAM17 causes birth defects and embryonic lethality. Conversely, inhibiting ADAM17 activity represents a potential strategy for treating inflammatory and autoimmune diseases. ADAM17 has an active site cleft with a divalent Zn ion and hydrophobic S1'/S3' subsites interconnected to form an L shaped cavity. However, it is currently unknown whether the active site of ADAM17 is susceptible to off-target inhibition by the small molecule drug eltrombopag, which contains metal-binding moieties and is classified as pregnancy category C by the FDA. The in-depth molecular modeling analysis in this study revealed that the unique structural features of L-shaped S1'/S3', crucial for determining ADAM17 specificity, along with spatial constraints imposed by active site amino acid residues, create an ideal binding environment for eltrombopag. Interestingly, the structural peculiarity of L-shaped S1'/S3' cavity enabled the carboxylate group rather than the traditionally recognized metal binding domain of eltrombopag to chelate catalytic Zn of ADAM17. Further, eltrombopag's biphenyl and xylene groups embed in the S1'/S3' subsites and pyrazole and hydrazine linker occupy the interconnecting tunnel, forming a stable eltrombopag-ADAM17 complex. These novel findings from molecular modeling suggest that ADAM17 is an off-target of eltrombopag, a drug used to increase platelet production in thrombocytopenia. They stimulate further in vitro and in vivo studies to test the repurposing potential of eltrombopag as an ADAM17 inhibitor to prevent tissue destruction in autoimmune diseases in adults and whether the use of eltrombopag during pregnancy could potentially lead to developmental toxicity due to ADAM17 inhibition.

Respiratory long COVID in aged hamsters features impaired lung function post-exercise with bronchiolization and fibrosis

Long-term consequences of SARS-CoV-2 infection affect millions of people and strain public health systems. The underlying pathomechanisms remain unclear, necessitating further research in appropriate animal models. This study aimed to characterize the trajectory of lung regeneration over 112 days in the male hamster model by combining morphological, transcriptomic and functional readouts. We demonstrate that in the acute phase, SARS-CoV-2 Delta-infected, male, aged hamsters show a severe impairment of lung function at rest. In the chronic phase, similar impairments persisted up to 7 weeks post-infection but were only evident after exercise on a rodent treadmill. The male hamster model recapitulates chronic pulmonary fibrotic changes observed in many patients with respiratory long COVID, but lacks extra-pulmonary long-term lesions. We show that sub-pleural and interstitial pulmonary fibrosis as well as alveolar bronchiolization persist until 112 dpi. Interestingly, CK8+ alveolar differentiation intermediate (ADI) cells are becoming less prominent in the alveolar proliferation areas from 28 dpi on. Instead, CK14+ airway basal cells and SCGB1A1+ club cells, expressing cell proliferation markers, mainly populate alveolar bronchiolization areas at later time-points. We postulate that pulmonary fibrosis and SCGB1A1+ club cell-rich areas of alveolar bronchiolization represent potential risk factors for other diseases in long-COVID survivors.

Unveiling the Mechanisms of Pain in Endometriosis: Comprehensive Analysis of Inflammatory Sensitization and Therapeutic Potential

Endometriosis is a complicated, estrogen-dependent gynecological condition with a high morbidity rate. Pain, as the most common clinical symptom of endometriosis, severely affects women's physical and mental health and exacerbates socioeconomic burden. However, the specific mechanisms behind the occurrence of endometriosis-related pain remain unclear. It is currently believed that the occurrence of endometriosis pain is related to various factors, such as immune abnormalities, endocrine disorders, the brain-gut axis, angiogenesis, and mechanical stimulation. These factors induce systemic chronic inflammation, which stimulates the nerves and subsequently alters neural plasticity, leading to nociceptive sensitization and thereby causing chronic pain. In this paper, we compile and review the articles published on the study of nociceptive sensitization and endometriosis pain mechanisms. Starting from the factors influencing the chronic pain associated with endometriosis, we explain the relationship between these factors and chronic inflammation and further elaborate on the potential mechanisms by which chronic inflammation induces nociceptive sensitization. We aim to reveal the possible mechanisms of endometriosis pain, as well as nociceptive sensitization, and offer potential new targets for the treatment of endometriosis pain.

Mirror-Image Random Nonstandard Peptides Integrated Discovery (MI-RaPID) Technology Yields Highly Stable and Selective Macrocyclic Peptide Inhibitors for Matrix Metallopeptidase 7

Matrix metallopeptidase 7 (MMP7) plays a crucial role in cancer metastasis and progression, making it an attractive target for therapeutic development. However, the development of selective MMP7 inhibitors is challenging due to the conservation of active sites across various matrix metalloproteinases (MMPs). Here, we have developed mirror-image random nonstandard peptides integrated discovery (MI-RaPID) technology to discover innate protease-resistant macrocyclic peptides that specifically bind to and inhibit human MMP7. One identified macrocyclic peptide against D-MMP7, termed D20, was synthesized in its mirror-image form, D'20, consisting of 12 D-amino acids, one cyclic β-amino acid, and a thioether bond. Notably, it potently inhibited MMP7 with an IC50 value of 90 nM, and showed excellent selectivity over other MMPs with similar substrate specificity. Moreover, D'20 inhibited the migration of pancreatic cell line CFPAC-1, but had no effect on the cell proliferation and viability. D'20 exhibited excellent stability in human serum, as well as in simulated gastric and intestinal fluids. This study highlights that MI-RaPID technology can serve as a powerful tool to develop in vivo stable macrocyclic peptides for therapeutic applications.

Differential Remodelling of Endometrial Extracellular Matrix in the Non-Pregnant Uterus of Lagostomus maximus as a Potential Mechanism Underlying Embryonic Death

During development, the remodelling of fibrillar components of the uterine extracellular matrix (ECM), mediated by the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), plays an essential role in embryonic survival. Previously, we observed that in the plains viscacha (Lagostomus maximus), only caudal implantation sites (IS) contain viable embryos, whereas embryos at cranial and middle IS die and are reabsorbed. The objective of this study was to analyse the distribution and expression of key components of the endometrial ECM, including fibrillar collagens, MMPs 2 and 9, and TIMPs 1 and 2, in three uterine segments (US) of the non-pregnant adult viscachas. In sections from three US, we observed a significant craniocaudal increase in collagen fibres (Van Gieson and Picrosirius red staining) and elastic fibres (Verhoeff-Van Gieson trichrome staining), along with the immunolabelling levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 (immunohistochemistry). Zymography revealed similar gelatinolytic activity of MMP-2 in the three US but higher than the MMP-9 activity. However, MMP-9 activity in the caudal segment was significantly higher than that in the cranial and middle ones. These findings suggest that uterine ECM variations along the craniocaudal axis may contribute to uterine remodelling processes that regulate embryonic survival during gestation.

The Crosstalk Between Endothelial Cells, Smooth Muscle Cells, and Macrophages in Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory vascular disease closely tied to cellular metabolism. Recent genome-wide association study data have suggested the significant roles of endothelial cells, smooth muscle cells, and macrophages in the regression and exacerbation of AS. However, the impact of cellular crosstalk and cellular metabolic derangements on disease progression in AS is vaguely understood. In this review, we analyze the roles of the three cell types in AS. We also summarize the crosstalk between the two of them, and the associated molecules and consequences involved. In addition, we emphasize potential therapeutic targets and highlight the importance of the three-cell co-culture model and extracellular vesicles in AS-related research, providing ideas for future studies.

Biological processes and factors involved in soft and hard tissue healing

Wound healing is a complex and iterative process involving myriad cellular and biologic processes that are highly regulated to allow satisfactory repair and regeneration of damaged tissues. This review is intended to be an introductory chapter in a volume focusing on the use of platelet concentrates for tissue regeneration. In order to fully appreciate the clinical utility of these preparations, a sound understanding of the processes and factors involved in soft and hard tissue healing. This encompasses an appreciation of the cellular and biological mediators of both soft and hard tissues in general as well as specific consideration of the periodontal tissues. In light of good advances in this basic knowledge, there have been improvements in clinical strategies and therapeutic management of wound repair and regeneration. The use of platelet concentrates for tissue regeneration offers one such strategy and is based on the principles of cellular and biologic principles of wound repair discussed in this review.

The Diverse Pathways for Cell Surface MT1-MMP Localization in Migratory Cells

Controlled cell migration is an essential biological process in health, while uncontrolled cell migration contributes to disease progression. For cells to migrate through tissue, they must first degrade the extracellular matrix (ECM), which acts as a physical barrier to cell migration. A type I transmembrane-type matrix metalloproteinase, MT1-MMP, is the key enzyme involved in this process. It has been extensively shown that MT1-MMP promotes the migration of different cell types in tissue, including fibroblasts, epithelial cells, endothelial cells, macrophages, mesenchymal stem cells, and cancer cells. MT1-MMP is tightly regulated at different levels, and its localization to leading-edge membrane structures is an essential process for MT1-MMP to promote cellular invasion. Different cells display different motility-associated membrane structures, which contribute to their invasive ability, and there are diverse mechanisms of MT1-MMP localization to these structures. In this article, we will discuss the current understanding of MT1-MMP regulation, in particular, localization mechanisms to these different motility-associated membrane structures.

Genome-Wide Identification and Analysis of Carbohydrate-Binding Modules in Colletotrichum graminicola

Colletotrichum graminicola is the causative agent of both maize stem rot and leaf blight, which are among the most damaging diseases affecting maize. Carbohydrate-binding modules (CBMs) are protein domains that lack catalytic activity and are commonly found alongside carbohydrate-hydrolyzing enzymes in fungi. A comprehensive examination of the C. graminicola TZ-3 genome resulted in the identification of 83 C. graminicola CBM (CgCBM) genes, which are characterized by distinct gene structures and protein motifs. Subcellular localization analysis revealed that the majority of CgCBM proteins were localized in the extracellular space. Investigation of the promoter regions of CgCBM genes uncovered a variety of responsive elements associated with plant hormones, including abscisic acid and methyl jasmonate response elements, as well as various stress-related response elements for drought, cold, defense, and other stress factors. Gene ontology analysis identified the primary functions of CgCBM genes as being linked to polysaccharide metabolism processes. Furthermore, the 83 CgCBM genes exhibited varying responses at different time points during C. graminicola infection, indicating their contribution to the fungus-maize interaction and their potential roles in the fungal pathogenic process. This study provides essential insights into CgCBMs, establishing a crucial foundation for further exploration of their functions in the mechanisms of fungal pathogenicity.

Molecular Regulation of Cardiomyocyte Maturation

PURPOSE OF THE REVIEW

This review aims to discuss the process of cardiomyocyte maturation, with a focus on the underlying molecular mechanisms required to form a fully functional heart. We examine both long-standing concepts associated with cardiac maturation and recent developments, and the overall complexity of molecularly integrating all the processes that lead to a mature heart.

RECENT FINDINGS

Cardiac maturation, defined here as the sequential changes that occurring before the heart reaches full maturity, has been a subject of investigation for decades. Recently, there has been a renewed, highly focused interest in this process, driven by clinically motivated research areas where enhancing maturation may lead to improved therapeutic opportunities. These include using pluripotent stem cell models for cell therapy and disease modeling, as well as recent advancements in adult cardiac regeneration approaches. We highlight key processes underlying maturation of the heart, including cellular and organ growth, and electrophysiological, metabolic, and contractile maturation. We further discuss how these processes integrate and interact to contribute to the overall complexity of the developing heart. Finally, we emphasize the transformative potential for translating relevant maturation concepts to emerging models of heart disease and regeneration.

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.

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.

Ovarian steroids modulate mRNA expression of ECM associated genes and collagen deposition induced by TGF β1 in equine endometrium in vitro

Equine endometrosis is a major cause of infertility in mares and is characterized by degenerative, functional and fibrotic changes in the endometrium with increased collagen (COL) deposition. Transforming growth factor (TGF)-β1 is one of the major pro-fibrotic factors involved in the excessive deposition of extracellular matrix (ECM) components in the equine endometrium. It has been demonstrated that ovarian steroids, specifically 17β-estradiol (E2) and progesterone (P4), not only regulate the cyclicity of the estrous cycle, but also have been implicated as anti- or pro-fibrotic factors. This study aimed to evaluate (i) the effect of E2 and P4 on the expression of ECM-associated genes including COL1A1, COL3A1, matrix metalloproteases (MMPs): MMP-1, MMP-2, MMP-3, MMP-9, and MMP-13, and tissue inhibitors of MMPs (TIMPs): TIMP-1 and TIMP-2 in equine endometrial fibroblasts, and (ii) the effect of ovarian steroids on TGF-β1-induced COL1 expression in equine endometrial explants from the follicular and mid-luteal phases of the estrous cycle. The mRNA expression of ECM-associated genes in endometrial fibroblasts and TGF-β1-induced COL1 expression in endometrial explants was modulated by ovarian steroids, with variations depending on the type of steroid and the duration of treatment. Moreover, P4 decreased TGF-β1-induced COL1 protein abundance in the mid-luteal phase of the estrous cycle after 48 h (p < 0.05). The results of our study indicate that during the estrous cycle, the ovarian steroids E2 or P4 may act directly on endometrial fibroblasts, thereby affecting the expression of genes involved in tissue remodeling, namely MMPs and TIMPs. Furthermore, P4 appears to affect not only the ECM-associated genes in endometrial fibroblasts, but also to attenuate the pro-fibrotic action of TGF-β1 in the mid-luteal stage of the estrous cycle.

Diabetes-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk

AIMS

Diabetes mellitus (DM) links the risk of cardiovascular diseases. Inverse to the enhanced expression of matrix metalloproteinases (MMPs), the development of aortic aneurysm is lower in diabetic population. We examined the hypothesis that DM-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk.

METHODS & RESULTS

By culturing vascular smooth muscle cells (VSMCs) or macrophages with different concentrations of glucose in the medium, we confirmed that high glucose significantly increased the expression of fibronectin and CTGF in VSMCs, and induced MMP2 expression and MMP9 secretion in macrophages. We also established an abdominal aortic aneurysm model in streptozotocin-induced diabetic mice and evaluated aneurysm development six weeks later. Compared to the healthy controls, diabetic mice had significantly lower levels of Zn2+ and Mg2+ in serum and developed significantly smaller sizes of aneurysms with higher expression of fibronectin and CTGF; but dietary zinc supplementation to diabetic mice effectively neutralized these differences. Gelatin zymography assay indicated that the enzymatic digestion activity of MMP2 was changed under different concentrations of ZnSO4 and MgSO4. Clinical data analysis also confirmed that DM, serum Zn2+ level, and aortic aneurysm risk closely correlated with each other.

CONCLUSION

It seems that DM-induced alteration of metal ion levels declines the activity of MMPs to negate aortic aneurysm development. Our data provide novel mechanistical insight and therapeutic strategy for aortic aneurysms.

MMP-2 inhibition attenuates ER stress-mediated cell death during myocardial ischemia-reperfusion injury by preserving IRE1α

Endoplasmic reticulum (ER) stress is one of the major events accompanying myocardial ischemia-reperfusion (IR) injury, as hypoxia and oxidative stress disrupt protein folding in the ER. As a result, the unfolded protein response (UPR) is activated through different sensors including inositol-requiring enzyme 1α (IRE1α) and protein kinase R-like ER kinase (PERK). Failure of the UPR to reduce ER stress induces cellular dysfunction. Matrix metalloproteinase-2 (MMP-2) is a ubiquitous protease that is activated intracellularly in response to oxidative stress and partially localizes near the ER. However, its role in ER homeostasis is unknown. We hypothesized that MMP-2 is involved in the regulation of the UPR and ER stress-mediated apoptosis during IR injury. Isolated mouse hearts subjected to IR injury showed impaired recovery of post-ischemic contractile function compared to aerobically perfused controls. Ventricular extracts from IR hearts had higher levels of glucose-regulated protein-78 and protein disulfide isomerase and lower levels of IRE1α and PERK compared to aerobic controls. MMP-2 inhibitors, ARP-100 or ONO-4817, given 10 min before ischemia, improved cardiac post-ischemic recovery and preserved IRE1α level in hearts subjected to 30 min ischemia/40 min reperfusion. IR also increased the levels of CHOP and mitochondrial Bax and caspase-3 and -9 activities, indicating induction of apoptosis, all of which were attenuated by MMP-2 inhibitors, regardless of the reperfusion time. Immunoprecipitation showed an association between MMP-2 and IRE1α in aerobic and IR hearts. During myocardial IR injury MMP-2 may impair the UPR and induce apoptosis by proteolysis of IRE1α. Inhibition of MMP-2 activity protects against cardiac contractile dysfunction in part by preserving IRE1α and preventing the progression to myocardial cell death.

Metalloproteinases are involved in the regulation of prenatal tooth morphogenesis

During development, tooth germs undergo various morphological changes resulting from interactions between the oral epithelium and ectomesenchyme. These processes are influenced by the extracellular matrix, the composition of which, along with cell adhesion and signaling, is regulated by metalloproteinases. Notably, these include matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), and a disintegrin and metalloproteinases with thrombospondin motifs (ADAMTSs). Our analysis of previously published scRNAseq datasets highlight that these metalloproteinases show dynamic expression patterns during tooth development, with expression in a wide range of cell types, suggesting multiple roles in tooth morphogenesis. To investigate this, Marimastat, a broad-spectrum inhibitor of MMPs, ADAMs, and ADAMTSs, was applied to ex vivo cultures of mouse molar tooth germs. The treated samples exhibited significant changes in tooth germ size and morphology, including an overall reduction in size and an inversion of the typical bell shape. The cervical loop failed to extend, and the central area of the inner enamel epithelium protruded. Marimastat treatment also disrupted proliferation, cell polarization, and organization compared with control tooth germs. In addition, a decrease in laminin expression was observed, leading to a disruption in continuity of the basement membrane at the epithelial-mesenchymal junction. Elevated hypoxia-inducible factor 1-alpha gene (Hif-1α) expression correlated with a disruption to blood vessel development around the tooth germs. These results reveal the crucial role of metalloproteinases in tooth growth, shape, cervical loop elongation, and the regulation of blood vessel formation during prenatal tooth development.NEW & NOTEWORTHY Inhibition of metalloproteinases during tooth development had a wide-ranging impact on molar growth affecting proliferation, cell migration, and vascularization, highlighting the diverse role of these proteins in controlling development.

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.

Single-cell RNA sequencing reveals the heterogeneity of myofibroblasts in wound repair

Skin wound repair involves myofibroblasts crucial for tissue integrity. This study utilized single-cell RNA sequencing to explore myofibroblast diversity in various wound healing scenarios. Analysis of 89,148 cells from skin ulcers, keloids, and normal scars identified 13 cell clusters. Myofibroblast subcluster analysis unveiled 11 subsets, with subclusters 1 and 9 predominant in ulcers. Subcluster 1 exhibited heightened matrix metalloproteinase expression and involvement in bacterial response and angiogenesis, crucial in inflammation. Tissue validation confirmed subcluster 1 significance., while animal models supported upregulated CA12, TDO2, and IL-7R in chronic ulcers. These findings illuminate myofibroblast heterogeneity and their impact on wound healing, offering insights into potential therapeutic targets.

Eye on the horizon: The metabolic landscape of the RPE in aging and disease

To meet the prodigious bioenergetic demands of the photoreceptors, glucose and other nutrients must traverse the retinal pigment epithelium (RPE), a polarised monolayer of cells that lie at the interface between the outer retina and the choroid, the principal vascular layer of the eye. Recent investigations have revealed a metabolic ecosystem in the outer retina where the photoreceptors and RPE engage in a complex exchange of sugars, amino acids, and other metabolites. Perturbation of this delicate metabolic balance has been identified in the aging retina, as well as in age-related macular degeneration (AMD), the leading cause of blindness in the Western world. Also common in the aging and diseased retina are elevated levels of cytokines, oxidative stress, advanced glycation end-products, increased growth factor signalling, and biomechanical stress - all of which have been associated with metabolic dysregulation in non-retinal cell types and tissues. Herein, we outline the role of these factors in retinal homeostasis, aging, and disease. We discuss their effects on glucose, mitochondrial, lipid, and amino acid metabolism in tissues and cell types outside the retina, highlighting the signalling pathways through which they induce these changes. Lastly, we discuss promising avenues for future research investigating the roles of these pathological conditions on retinal metabolism, potentially offering novel therapeutic approaches to combat age-related retinal disease.

Assessing Gelatinase Activity in Normal and Disease Uterine Tissue and Cells Via Gelatin Zymography

Matrix metalloproteinases (MMPs) are critical for the maintenance and remodeling of the extracellular matrix (ECM) under normal physiological conditions such as pregnancy and wound healing. However, an increase of MMPs in uterine diseases, such as adenomyosis, endometrial cancer, endometriosis, and uterine fibroids, has been observed and suspected to contribute to important pathophysiology phenotypes like invasion and migration. Of note, MMP-2 (also referred to as gelatinase A) and MMP-9 (also referred to as gelatinase B) are common gelatinases that have demonstrated increased activity in uterine diseases and in several cancer types, such as breast cancer, to promote cancerous phenotypes like increased invasion and migration. In-gel zymography is a useful technique for the detection of MMP activity via degradation of gelatin in gelatin-based gels. Using zymography, it is possible to assess the activity levels of MMP-2 and MMP-9 via gelatin degradation during the zymography process. Here, we will describe the process of zymography and assessment of MMP activity levels (MMP-2 and MMP-9) for both uterine tissues and cancerous cell lines.

Investigating tissue factor pathway inhibitor and other protease and protease inhibitors and their association with major adverse aortic events in patients with abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) is characterized by the proteolytic breakdown of the extracellular matrix, leading to dilatation of the aorta and increased risk of rupture. Biomarkers that can predict major adverse aortic events (MAAEs) are needed to risk stratify patients for more rigorous medical treatment and potential earlier surgical intervention.

Objectives

The primary objective was to identify the association between baseline levels of these biomarkers and MAAEs over a period of 5 years.

Methods

Baseline levels of 3 proteases (matrix metalloproteinases 7, 8, and 10) and 3 protease inhibitors (tissue factor pathway inhibitor [TFPI], SerpinA12, SerpinB3) were investigated. Plasma levels of these biomarkers were quantified in 134 patients with AAA and 134 matched controls. Patients were followed for a 5-year period during which MAAEs were documented. The association between these markers and MAAEs was evaluated using Cox regression and Kaplan-Meier survival curves.

Results

TFPI was significantly elevated in patients with AAA and significantly associated with MAAE during the 5-year period (hazard ratio, 1.52; 95% CI, 1.15-2.01; P = .003) after adjusting for covariates. Kaplan-Meier survival analyses demonstrated that patients in the high TFPI group (defined as plasma levels >25.961 ng/mL) had significantly reduced freedom from the need for aortic repair and MAAEs.

Conclusion

These findings suggest that TFPI may serve as a valuable prognostic marker for the risk of MAAEs within 5 years in patients with AAA, potentially offering new tools for the medical management of patients with AAA.

Zymography: Unveiling Matrix Metalloproteinase Dynamics

Zymography is a laboratory technique used to study the activity of enzymes, particularly proteases and glycosidases, in biological samples. It involves the separation of enzymatic proteins by gel electrophoresis under non-denaturing conditions, followed by their renaturation and incubation with specific substrates that mimic natural substrates. The resulting enzymatic activity leads to the degradation of the substrate within the gel, producing clear bands or zones of decreased staining that indicate the presence of active enzymes.There are several variants of zymography, including gelatin zymography, casein zymography, and substrate-specific zymography, each tailored to detect specific enzyme activities. Gelatin zymography, for example, is commonly used to detect protease activity against gelatin, while casein zymography employs casein as the substrate for a broader range of proteases.Zymography can be applied in various fields, including basic research, clinical diagnostics, and drug development. It provides valuable insights into enzyme function, substrate specificity, and regulation, and can serve as a biomarker for diseases associated with dysregulated enzyme activities.Overall, zymography is a versatile and widely used technique that offers qualitative information about enzyme activities and their role in biological processes. It contributes to our understanding of enzyme function and has potential applications in both research and clinical settings.

Targeting Invasion: The Role of MMP-2 and MMP-9 Inhibition in Colorectal Cancer Therapy

Colorectal cancer (CRC) remains one of the most prevalent and lethal cancers worldwide, prompting ongoing research into innovative therapeutic strategies. This review aims to systematically evaluate the role of gelatinases, specifically MMP-2 and MMP-9, as therapeutic targets in CRC, providing a critical analysis of their potential to improve patient outcomes. Gelatinases, specifically MMP-2 and MMP-9, play critical roles in the processes of tumor growth, invasion, and metastasis. Their expression and activity are significantly elevated in CRC, correlating with poor prognosis and lower survival rates. This review provides a comprehensive overview of the pathophysiological roles of gelatinases in CRC, highlighting their contribution to tumor microenvironment modulation, angiogenesis, and the metastatic cascade. We also critically evaluate recent advancements in the development of gelatinase inhibitors, including small molecule inhibitors, natural compounds, and novel therapeutic approaches like gene silencing techniques. Challenges such as nonspecificity, adverse side effects, and resistance mechanisms are discussed. We explore the potential of gelatinase inhibition in combination therapies, particularly with conventional chemotherapy and emerging targeted treatments, to enhance therapeutic efficacy and overcome resistance. The novelty of this review lies in its integration of recent findings on diverse inhibition strategies with insights into their clinical relevance, offering a roadmap for future research. By addressing the limitations of current approaches and proposing novel strategies, this review underscores the potential of gelatinase inhibitors in CRC prevention and therapy, inspiring further exploration in this promising area of oncological treatment.

Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA): A Targeted Antioxidant Strategy to Counter Oxidative Stress in Retinopathy

Omega-3 fatty acids are critical components of cell membranes, including those in the retina. Specifically, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the primary omega-3 fatty acids that have been studied for their potential benefits in retinal health, preventing the progression of retinopathy. Several studies have shown that a higher intake of omega-3 fatty acids is associated with a lower risk of developing diabetic retinopathy and age-related macular degeneration (AMD). Reviewing clinical trials and observational studies that support the protective role of omega-3s in retinal disorders is essential. This comprehensive review aims to evaluate the current literature on the role of omega-3 fatty acids, exploring their mechanisms of action and anti-inflammatory, anti-angiogenic, and neuroprotective roles in the retina. Omega-3s have been shown to inhibit abnormal blood vessel growth in the retina, which is a significant factor in proliferative diabetic retinopathy and neovascular AMD. Furthermore, omega-3 fatty acids are often studied with other nutrients, such as lutein, zeaxanthin, and vitamins, for their synergistic effects on retinal health. Reviewing these combinations can help understand how omega-3s can be part of a comprehensive approach to preventing or treating retinopathies, especially in diabetic patients. This review emphasizes the preventive function of EPA and DHA in alleviating oxidative stress-related damage in retinal diseases, concentrating on their antioxidative mechanisms.

Metalloproteases and their inhibitors in the postpartum endometrial remodeling in dairy cows: their relationship with days to conception after parturition

In dairy herds, it is expected that cows will be cycling and the uterus will be ready for a new conception before the fourth week postpartum. However, an alteration in the endometrial remodeling can delay conception, increasing the parturition-to-conception interval, and consequently decreasing the reproductive performance. The endometrial matrix has a relevant participation in the processes of postpartum uterine remodeling. In this sense, the matrix metalloprotease (MMP) system and its inhibitors (TIMPs) are directly involved in the proteolytic degradation of the matrix and their action is related to the concentration of steroid hormones. The aim of this study was to evaluate the protein expression of MMP2, MMP14, MMP9, and their inhibitors, TIMP1 and TIMP2, in the luminal epithelium, glandular epithelium and stroma of endometrial biopsies from dairy cows, at 60 days in milk. Together, the results obtained provide evidence about the expression of MMP2, MMP14 and MMP9, and their inhibitors, TIMP1 and TIMP2, in the postpartum uterus of dairy cows, and about how the balance in their expression could be associated with the achievement of pregnancy. The high protein expression of MMP2, MMP14 and TIMP1 in dairy cows with short parturition-to-conception interval could be important for uterine remodeling and early conception in dairy cows. In addition, the imbalance observed in the MMP9/TIMP1 ratio could be generating an excess of gelatinase activity in the endometrium, causing a delayed conception.

Machine learning-based prognostic model of lactylation-related genes for predicting prognosis and immune infiltration in patients with lung adenocarcinoma

BACKGROUND

Histone lactylation is a novel epigenetic modification that is involved in a variety of critical biological regulations. However, the role of lactylation-related genes in lung adenocarcinoma has yet to be investigated.

METHODS

RNA-seq data and clinical information of LUAD were downloaded from TCGA and GEO datasets. Unsupervised consistent cluster analysis was performed to identify differentially expressed genes (DEGs) between the two clusters, and risk prediction models were constructed by Cox regression analysis and LASSO analysis. Kaplan-Meier (KM) survival analysis, ROC curves and nomograms were used to validate the accuracy of the models. We also explored the differences in risk scores in terms of immune cell infiltration, immune cell function, TMB, TIDE, and anticancer drug sensitivity. In addition, single-cell clustering and trajectory analysis were performed to further understand the significance of lactylation-related genes. We further analyzed lactate content and glucose uptake in lung adenocarcinoma cells and tissues. Changes in LUAD cell function after knockdown of lactate dehydrogenase (LDHA) by CCK-8, colony formation and transwell assays. Finally, we analyzed the expression of KRT81 in LUAD tissues and cell lines using qRT-PCR, WB, and IHC. Changes in KRT81 function in LUAD cells were detected by CCK-8, colony formation, wound healing, transwell, and flow cytometry. A nude mouse xenograft model and a KrasLSL-G12D in situ lung adenocarcinoma mouse model were used to elucidate the role of KRT81 in LUAD.

RESULTS

After identifying 26 lactylation-associated DEGs, we constructed 10 lactylation-associated lung adenocarcinoma prognostic models with prognostic value for LUAD patients. A high score indicates a poor prognosis. There were significant differences between the high-risk and low-risk groups in the phenotypes of immune cell infiltration rate, immune cell function, gene mutation frequency, and anticancer drug sensitivity. TMB and TIDE scores were higher in high-risk score patients than in low-risk score patients. MS4A1 was predominantly expressed in B-cell clusters and was identified to play a key role in B-cell differentiation. We further found that lactate content was abnormally elevated in lung adenocarcinoma cells and cancer tissues, and glucose uptake by lung adenocarcinoma cells was significantly increased. Down-regulation of LDHA inhibits tumor cell proliferation, migration and invasion. Finally, we verified that the model gene KRT81 is highly expressed in LUAD tissues and cell lines. Knockdown of KRT81 inhibited cell proliferation, migration, and invasion, leading to cell cycle arrest in the G0/G1 phase and increased apoptosis. KRT81 may play a tumorigenic role in LUAD through the EMT and PI3K/AKT pathways. In vivo, KRT81 knockdown inhibited tumor growth.

CONCLUSION

We successfully constructed a new prognostic model for lactylation-related genes. Lactate content and glucose uptake are significantly higher in lung adenocarcinoma cells and cancer tissues. In addition, KRT81 was validated at cellular and animal levels as a possible new target for the treatment of LUAD, and this study provides a new perspective for the individualized treatment of LUAD.