Matrix Metalloproteinase Activity Research Articles

It takes two peroxisome proliferator-activated receptors (PPAR-β/δ and PPAR-γ) to tango idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung epithelial phenotypes, fibroblast activation, and increased extracellular matrix deposition. Transforming growth factor-beta (TGF-β)1-induced Smad signaling and downregulation of peroxisomal genes are involved in the pathogenesis and can be inhibited by peroxisome proliferator-activated receptor (PPAR)-α activation. However, the three PPARs, that is PPAR-α, PPAR-β/δ, and PPAR-γ, are known to interact in a complex crosstalk.MethodsTo mimic the pathogenesis of lung fibrosis, primary lung fibroblasts from control and IPF patients with comparable levels of all three PPARs were treated with TGF-β1 for 24 h, followed by the addition of PPAR ligands either alone or in combination for another 24 h. Fibrosis markers (intra- and extracellular collagen levels, expression and activity of matrix metalloproteinases) and peroxisomal biogenesis and metabolism (gene expression of peroxisomal biogenesis and matrix proteins, protein levels of PEX13 and catalase, targeted and untargeted lipidomic profiles) were analyzed after TGF-β1 treatment and the effects of the PPAR ligands were investigated.ResultsTGF-β1 induced the expected phenotype; e.g. it increased the intra- and extracellular collagen levels and decreased peroxisomal biogenesis and metabolism. Agonists of different PPARs reversed TGF-β1-induced fibrosis even when given 24 h after TGF-β1. The effects included the reversals of (1) the increase in collagen production by repressing COL1A2 promoter activity (through PPAR-β/δ activation); (2) the reduced activity of matrix metalloproteinases (through PPAR-β/δ activation); (3) the decrease in peroxisomal biogenesis and lipid metabolism (through PPAR-γ activation); and (4) the decrease in catalase protein levels in control (through PPAR-γ activation) and IPF (through a combined activation of PPAR-β/δ and PPAR-γ) fibroblasts. Further experiments to explore the role of catalase showed that an overexpression of catalase protein reduced collagen production. Additionally, the beneficial effect of PPAR-γ but not of PPAR-β/δ activation on collagen synthesis depended on catalase activity and was thus redox-sensitive.ConclusionOur data provide evidence that IPF patients may benefit from a combined activation of PPAR-β/δ and PPAR-γ.

Fibulin-3 Regulates Tissue Inhibitor of Metalloproteinases 3 to Inhibit Senescence in Intervertebral Disc Nucleus Pulposus Cells

To investigate the effect of fibulin-3 on the senescence of intervertebral disc nucleus pulposus cells (NPCs) through the regulation of tissue inhibitor of metalloproteinases 3 (TIMP-3) expression and to elucidate the molecular mechanisms involved. 1). The nucleus pulposus tissues and imaging data of 37 patients who had undergone intervertebral disc surgery were collected. The degree of degeneration of the intervertebral discs were classified according to the Pfirrmann grading system. The senescence degree of NPCs was determined using senescence-associated β-galactosidase (SA-β-gal) staining. Fibulin-3 expression levels were determined using Western blot and ELISA. The relationship between fibulin-3 and disc degeneration and NPCs senescence was investigated. 2). Human intervertebral disc NPCs were cultured in vitro. The proliferation and senescence of NPC across continuous passage were observed via CCK-8 assay and SA-β-gal staining, respectively. Fibulin-3 expression levels and the expression of inflammatory cytokines and matrix metalloproteinases were assessed. Exogenous fibulin-3 was added to verify its effect on the proliferation and senescence of NPCs. 3). The effect of fibulin-3 on the apoptosis and proliferation of NPCs was verified through gene overexpression, which was used in combination with an apoptosis inhibitor for bidirectional verification. 4). Bioinformatics analysis was performed to explore the relationship between fibulin-3 and the TIMP family. Experiments overexpressing fibulin-3 and silencing the TIMP-3 gene were performed to verify their role in NPCs senescence. 1). The intervertebral disc degeneration samples from 37 patients were classified according to the Pfirrmann grading system. The higher the degeneration grade, the lower fibulin-3 expression. Spearman correlation analysis showed that the disc grade was negatively correlated with the NPC senescence grade (r=－0.87, P<0.001) and fibulin-3 expression (r=－0.79, P<0.001). 2). As the passage number of NPCs increased, fibulin-3 expression gradually decreased, cell proliferation ability weakened, and the expression of inflammatory cytokines and matrix metalloproteinases increased. After exogenous fibulin-3 was added, cell morphology and growth status were maintained, cell senescence was significantly inhibited, and the expression of inflammatory cytokines and matrix metalloproteinases was markedly reduced. 3). Gene overexpression experiments showed that fibulin-3 reduced NPC apoptosis and promoted cell proliferation, thereby inhibiting NPC senescence. 4). Bioinformatics analysis revealed a significant association between fibulin-3 and TIMP-3 of the TIMP family. Further experiments confirmed that overexpressing fibulin-3 enhanced TIMP-3 expression, while silencing the TIMP-3 gene significantly weakened the inhibitory effect of fibulin-3 on NPCs senescence. This indicates that, through regulating TIMP-3, fibulin-3 inhibits the activity of matrix metalloproteinases, affects the synthesis and degradation of the extracellular matrix, and ultimately inhibits NPCs senescence. This study demonstrates that fibulin-3 plays a crucial role in inhibiting the senescence of intervertebral disc NPCs by regulating TIMP-3. The specific mechanisms involved are as follows, fibulin-3 upregulates TIMP-3 expression, inhibits matrix metalloproteinase activity, and reduces extracellular matrix degradation, thereby promoting extracellular matrix synthesis. Additionally, fibulin-3 inhibits NPCs senescence by reducing apoptosis and promoting cell proliferation. Therefore, fibulin-3 and TIMP-3 have potential therapeutic significance in maintaining intervertebral disc health and delaying degeneration.

Novel multitarget analgesic candidate SZV-1287 demonstrates potential disease-modifying effects in the monoiodoacetate-induced osteoarthritis mouse model.

Monoiodoacetate (MIA)-induced osteoarthritis (OA) is the most commonly used rodent model for testing anti-OA drug candidates. Herein, we investigated the effects of our patented multitarget drug candidate SZV-1287 (3-(4,5-diphenyl-1,3-oxazol-2-yl) propanal oxime) that is currently under clinical development for neuropathic pain and characterized the mouse model through complex functional, in vivo imaging, and morphological techniques. Knee OA was induced by intraarticular MIA injection (0.5 and 0.8mg). Spontaneous pain was assessed based on weight distribution, referred pain by paw mechanonociception (esthesiometry), edema by caliper, neutrophil myeloperoxidase activity by luminescence, matrix metalloproteinase activity, vascular leakage and bone remodeling by fluorescence imaging, bone morphology by micro-CT, histopathological alterations by semiquantitative scoring, and glia activation by immunohistochemistry. Then, SZV-1287 (20mg/kg/day) or its vehicle was injected intraperitoneally over a 21-day period. MIA induced remarkably decreased thresholds of weight bearing and paw withdrawal, alterations in the tibial and femoral structures (reactive sclerosis, increased trabeculation, and cortical erosions), histopathological damage (disorganized cartilage structure, hypocellularity, decreased matrix staining and tidemark integrity, and increased synovial hyperplasia and osteophyte formation), and changes in the astrocyte and microglia density in the lumbar spinal cord. There were no major differences between the two MIA doses in most outcome measures. SZV-1287 inhibited MIA-induced weight bearing reduction, hyperalgesia, edema, myeloperoxidase activity, histopathological damage, and astrocyte and microglia density. SZV-1287 may have disease-modifying potential through analgesic, anti-inflammatory, and chondroprotective effects. The MIA mouse model is valuable for investigating OA-related mechanisms and testing compounds in mice at an optimal dose of 0.5mg.

Doxycycline versus Curcumin for Inhibition of Matrix Metalloproteinase Expression and Activity Following Chemically Induced Inflammation in Corneal Cells.

Sulfur mustard (SM) is a potent blistering agent. This alkylating chemical agent has extremely toxic effects on the eye. MMP-2 and MMP-9 are the two most important matrix metalloproteinase enzymes involved in the pathology of chemical eye injuries. Curcumin is regarded as a natural anti-inflammatory agent. This study aims to compare the anti-inflammatory effects of curcumin versus doxycycline on chemically induced corneal injuries. The HCE-2 cell line was used as a model for corneal cells. The effective concentrations of 2-chloroethyl ethyl sulfide (CEES) - as an analog of SM - doxycycline, and curcumin were determined using the MTT assay. The gene expression of MMP-2, MMP-9, and tissue inhibitors of metalloproteinase (TIMP-1) was evaluated by the real-time PCR method. Also, the activity of MMP-2 and MMP-9 enzymes was determined by zymography. The expression of the MMP-2 and MMP-9 genes increased 5- and 3.3-fold after exposure to CEES, respectively. Following the treatment with curcumin and doxycycline, MMP-2 expression decreased significantly. Also, after treatment with curcumin and doxycycline, the MMP-9 expression decreased 2.5- and 1.6-fold, respectively. The reduction in activity was 32% for MMP-2 and 56% for MMP-9 after treatment with curcumin. The corresponding values were 12% and 40% following doxycycline treatment. There was no significant difference between the effects of curcumin and doxycycline on reducing MMP-2 expression, but the difference was statistically significant in the case of MMP-9. Doxycycline and curcumin can inhibit MMP expression and activity in chemically exposed corneal cells. Curcumin has a greater ability than doxycycline to inhibit MMP-2 and MMP-9 enzymes; however, the difference is statistically significant only in the case of MMP-9. After further validation, these substances can be introduced as anti- inflammatory agents to treat corneal chemical burns.

The vasoprotective role of IGF-1 signaling in the cerebral microcirculation: prevention of cerebral microhemorrhages in aging.

Aging is closely associated with various cerebrovascular pathologies that significantly impact brain function, with cerebral small vessel disease (CSVD) being a major contributor to cognitive decline in the elderly. Consequences of CSVD include cerebral microhemorrhages (CMH), which are small intracerebral bleeds resulting from the rupture of microvessels. CMHs are prevalent in aging populations, affecting approximately 50% of individuals over 80, and are linked to increased risks of vascular cognitive impairment and dementia (VCID). Hypertension is a primary risk factor for CMHs. Vascular smooth muscle cells (VSMCs) adapt to hypertension by undergoing hypertrophy and producing extracellular matrix (ECM) components, which reinforce vessel walls. Myogenic autoregulation, which involves pressure-induced constriction, helps prevent excessive pressure from damaging the vulnerable microvasculature. However, aging impairs these adaptive mechanisms, weakening vessel walls and increasing susceptibility to damage. Insulin-like Growth Factor 1 (IGF-1) is crucial for vascular health, promoting VSMC hypertrophy, ECM production, and maintaining normal myogenic protection. IGF-1 also prevents microvascular senescence, reduces reactive oxygen species (ROS) production, and regulates matrix metalloproteinase (MMP) activity, which is vital for ECM remodeling and stabilization. IGF-1 deficiency, common in aging, compromises these protective mechanisms, increasing the risk of CMHs. This review explores the vasoprotective role of IGF-1 signaling in the cerebral microcirculation and its implications for preventing hypertension-induced CMHs in aging. Understanding and addressing the decline in IGF-1 signaling with age are crucial for maintaining cerebrovascular health and preventing hypertension-related vascular injuries in the aging population.

Bimetallic clusterzymes-loaded dendritic mesoporous silica particle regulate arthritis microenvironment via ROS scavenging and YAP1 stabilization

Clusterzymes are synthetic enzymes exhibiting substantial catalytic activity and selectivity, which are uniquely driven by single-atom constructs. A dramatic increase in antioxidant capacity, 158 times more than natural trolox, is noted when single-atom copper is incorporated into gold-based clusterzymes to form Au24Cu1. Considering the inflammatory and mildly acidic microenvironment characteristic of osteoarthritis (OA), pH-dependent dendritic mesoporous silica nanoparticles (DMSNs) coupled with PEG have been employed as a delivery system for the spatial-temporal release of clusterzymes within active articular regions, thereby enhancing the duration of effectiveness. Nonetheless, achieving high therapeutic efficacy remains a significant challenge. Herein, we describe the construction of a Clusterzymes-DMSNs-PEG complex (CDP) which remarkably diminishes reactive oxygen species (ROS) and stabilizes the chondroprotective protein YAP by inhibiting the Hippo pathway. In the rabbit ACLT (anterior cruciate ligament transection) model, the CDP complex demonstrated inhibition of matrix metalloproteinase activity, preservation of type II collagen and aggregation protein secretion, thus prolonging the clusterzymes' protective influence on joint cartilage structure. Our research underscores the efficacy of the CDP complex in ROS-scavenging, enabled by the release of clusterzymes in response to an inflammatory and slightly acidic environment, leading to the obstruction of the Hippo pathway and downstream NF-κB signaling pathway. This study illuminates the design, composition, and use of DMSNs and clusterzymes in biomedicine, thus charting a promising course for the development of novel therapeutic strategies in alleviating OA.

Matrix Metalloproteinases on Skin Photoaging.

Skin aging is characterized by an imbalance between the generation and degradation of extracellular matrix molecules (ECM). Matrix metalloproteinases (MMPs) are the primary enzymes responsible for ECM breakdown. Intrinsic and extrinsic stimuli can induce different MMPs. However, there is limited literature especially on the summary of skin MMPs and potential inhibitors. We aim to focus on the upregulation of MMP expression or activity in skin cells following exposure to UV radiation. We also would like to offer valuable insights into potential clinical applications of MMP inhibitors for mitigating skin aging. This article presents the summary of prior research, which involved an extensive literature search across diverse academic databases including Web of Science and PubMed. Our findings offer a comprehensive insight into the effects of MMPs on skin aging after UV irradiation, including their substrate preferences and distinct roles in this process. Additionally, a comprehensive list of natural plant and animal extracts, proteins, polypeptides, amino acids, as well as natural and synthetic compounds that serve as inhibitors for MMPs is compiled. Skin aging is a complex process influenced by environmental factors and MMPs. Research focuses on UV-induced skin damage and the formation of Advanced Glycosylation End Products (AGEs), leading to wrinkles and impaired functionality. Inhibiting MMPs is crucial for maintaining youthful skin. Natural sources of MMP inhibitor substances, such as extracts from plants and animals, offer a safer approach to obtain inhibitors through dietary supplements. Studying isolated active ingredients can contribute to developing targeted MMP inhibitors.

Sarcoplasmic reticulum calcium ATPase (SERCA) proteolysis by matrix metalloproteinase-2 contributes to vascular dysfunction in early hypertension

AimsHypertension is associated with an increased activity of matrix metalloproteinase (MMP)-2 in the vasculature, which, in turn, proteolyzes extra- and intracellular proteins that lead to vascular dysfunction. The activity of sarcoplasmic reticulum calcium ATPase (SERCA) is decreased in the aortas of hypertensive rats. Increased activity of MMP-2 proteolyzed SERCA in rat heart during ischemia and reperfusion injury, thus impairing cardiac function. Therefore, we examined whether increased activity of MMP-2 in early hypertension contributes to proteolyze SERCA in the aortas, thus leading to maladaptive vascular remodeling and dysfunction. Main methodsMale Sprague-Dawley rats were submitted to two kidney-one clip (2K-1C) or Sham surgery and treated with doxycycline. Systolic blood pressure (SBP) was assessed by tail-cuff plethysmography. After 7 days, aortas were collected for zymography assays, Western blot to SERCA, ATPase activity assay, vascular reactivity, Ki-67 immunofluorescence and hematoxylin/eosin stain. Key findingsSBP was increased in 2K-1C rats and doxycycline did not reduce it, but decreased MMP-2 activity and prevented SERCA proteolysis in aortas. Cross sectional area, media to lumen ratio and Ki-67 were all increased in the aortas of hypertensive rats and doxycycline decreased Ki-67. In 2K-1C rats, arterial relaxation to acetylcholine was impaired and doxycycline ameliorated it. Significancedoxycycline reduced MMP-2 activity in aortas of 2K-1C rats and prevented proteolysis of SERCA and its dysfunction, thus ameliorating hypertension-induced vascular dysfunction.

Liposome-encapsulated dextrazide modifies spleen extracellular matrix composition in mice with chronic BCG-induced inflammation

Fibrosis of parenchymal organs is a common complication of tuberculosis. In a model of BCG-induced inflammation in mice, changes in the metabolism of the extracellular matrix (ECM) of the spleen were demonstrated with the introduction of a liposome-encapsulated dextrazide (LEDZ) containing isoniazid and oxidized dextran.The mice were divided into 4 groups: 1 – intact animals; 2 – infected mice after a single intravenous injection of BCG vaccine. 6 mo after infection, a solution of LEDZ was administered intraperitoneally to mice of group 3 for 3 mo, and inhaled to mice of group 4. Group 2 mice showed the signs of pronounced spleen fibrosis (increased content of hyaluronan, hydroxyproline fractions) with activation of hyaluronidases, matrix metalloproteinases (MMP), α2-macroglobulin and an increased content of tissue inhibitors of MMP (TIMP-1 and TIMP-2) with respect to group 1 data. In group 3, changesin the structure of proteoglycans were noted (an increase in the content of uronic acids and galactose), a decrease in the content of hyaluronan and free hydroxyproline, an increase in the activity of hyaluronidases. The MMP activity and the TIMP content corresponded to the data of group 2. In group 4, the content of uronic acids and galactose in proteoglycans also increased, but peptide-bound hydroxyproline decreased and the hyaluronan content more noticeably decreased. The activity of all enzymes regulating the ECM metabolism reduced with respect to the data of group 2.Thus, intraperitoneal administration of LEDZ to infected mice led to activating hyaluronidases, changing the structure of proteoglycans, and decreasing the free hydroxyproline content. Inhalation administration of LEDZ, along with changes in the structure of proteoglycans, reduced the activity of MMP, hyaluronidases, α2-macroglobulin, the content of TIMP-1 and TIMP-2, peptide-bound hydroxyproline. The antifibrotic effect of LEDZ with inhalation administration was manifested in a decrease in peptide-bound hydroxyproline and in a more significant decrease in hyaluronan compared with intraperitoneal administration.Thus, intraperitoneal administration of LEDZ to infected mice led to activating hyaluronidases, changing the structure of proteoglycans, and decreasing the free hydroxyproline content. Inhalation administration of LEDZ, along with changes in the structure of proteoglycans, reduced the activity of MMP, hyaluronidases, α2-macroglobulin, the content of TIMP-1 and TIMP-2, peptide-bound hydroxyproline. The antifibrotic effect of LEDZ with inhalation administration was manifested in a decrease in peptide-bound hydroxyproline and in a more significant decrease in hyaluronan compared with intraperitoneal administration.

Review Article on Molecular Basis of Zinc and Copper Interactions in Cancer Physiology.

Various clinical manifestations associated with measurable abnormalities of Zn and Cu in serum and tissue were determined in Cancer-Patients (CP), and therefore, these two metals are drawing more and more attention presently than ever before. Cancer is a disease of uncontrolled-abnormal-cell-division with invasion-potential which was exhibited to occur due to dys-regulation/dys-homeostasis of fundamental-biological-pathways (FBP) including antioxidant-enzyme-defense-system, anti-inflammatory and immune-systems, and DNA-damage-repair-system in the human-body resulting in generation of chronic-oxidative-stress induced DNA-damage and gene-mutations, inflammation and compromised immune-system, tumor-induced increased angiogenesis, and inhibition of apoptosis processes. Zn and Cu were recognized to be the most crucial components of FBP and imbalance in Zn/Cu ratios in CP asserted to generate chronic toxicity in human body through various mechanisms including increased chronic oxidative stress linked compromised DNA integrity and gene mutations due to malfunctioning of DNA damage repair enzymes; increased angiogenesis process due to Zn- and Cu-binding proteins metallothionein and ceruloplasmin-induced enhanced expression of tumor growth factors; and elevation in inflammatory response which was further shown to down/upregulate gene expression of multiple Zn transporter proteins leading to dys-homeostasis of intracellular Zn concentrations, and it was determined to disturb the equilibrium between cell growth and division, proliferation, differentiation, and apoptosis processes which lead to cancer progression. Moreover, Zn was reported to affect matrix metalloproteinase activity and influence immune system cells to respond differently to different cytokines and enhance immune-suppressive effects accelerating the angiogenesis, invasion, and metastasis potential in cancer. Further, the most significant use of serum Cu/Zn ratio was recommended in clinical diagnosis, prognosis, tumor stage, patient survival, and cancer follow-up studies which need further investigations to elucidate and explore their roles in cancer physiology for clinical perspective.

Turmeric extract alleviates airway inflammation via oxidative stress-driven MAPKs/MMPs pathway

Turmeric (Curcuma longa L.) extract (CLE) has been shown to elicit several pharmacological properties and is widely used in Asian traditional medicine. Herein, we assessed the impact of CLE on airway inflammation in BALB/c mice and A549 cells to clarify the underlying mechanism. An asthmatic mouse model was established by administering ovalbumin (OVA). CLE (100 or 300 mg/kg/day) was orally administered daily from days 18 to 23, with dexamethasone (3 mg/kg/day) used as the positive control. Human airway epithelial cells, A549, were stimulated using recombinant tumor necrosis factor-α. The CLE100 and CLE400 groups exhibited a significant downregulation in eosinophil counts, cytokine levels, and immunoglobulin-E levels. Moreover, CLE administration dose-dependently suppressed oxidative stress and airway inflammation in the lung tissue. CLE administration inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and the expression and activity of matrix metalloproteinase (MMP)‐9. In vitro, CLE treatment reduced mRNA levels of proinflammatory cytokines, MAPK phosphorylation, and the expression and activity of MMP-2 and MMP-9. Additionally, 50 µg/mL CLE and 2.5 µg/mL curcumin showed similar anti-inflammatory effects. Collectively, our findings revealed that CLE could suppress airway inflammation in asthmatic mice and A549 cells via oxidative stress-driven MAPK/MMPs signaling, suggesting that CLE could be developed as a potential treatment option for patients with asthma.

Virtual screening reveals fluorescent probes for detecting Pan-Zinc center activity in serum MMPs: A potential biomarker for early tumor screening

Early tumor screening is pivotal for enhancing tumor treatment efficacy and patient survival rates, yet identifying reliable biomarkers for early detection remains a challenge. Previous studies have explored different isoforms of matrix metalloproteinases (MMPs) in serum for their predictive value in tumor, but their results have been inconsistent. Herein, we introduce a novel fluorescent probe, C9 (N-oxide-8-hydroxyquinoline-5-sulfonic acid), designed to specifically label the pan zinc center activity of MMPs (PZCA-MMPs), which in a sense represents the overall MMPs activity in serum. The rational design of fluorescent probe C9 is based on its ability to bind the zinc ions in the structure of MMPs, facilitated by the oxides on hydroxyl (–OH) and nitro oxide (N→O) groups present in C9, as supported by theoretical calculations such as Gaussian and Schrödinger. Experimental validation confirmed its efficacy for detecting PZCA-MMPs in vitro and for fluorescence imaging of MMPs’ zinc ions in cellular contexts, validated through absolute integrated fluorescence intensity measurements at 510 nm. We also demonstrated through in vitro fluorescent analysis that neither metal ions nor abundant serum proteins such as albumin (BSA) and other metalloproteins interfere with the signal response of C9. Notably, in comparative analysis of serum samples from healthy controls and breast tumor patients, PZCA-MMPs showed a highly discriminatory area under the ROC curve (AUC) of 0.9377, surpassing established tumor biomarkers such as CA125, CA15-3, CA19-9, and CA72-4. In particular, for tumor patients, PZCA-MMPs can effectively distinguish between metastatic and non-metastatic patients (*P<0.05). Therefore, this provides a potential alternative biomarker for tumor screening. Future studies aim to further elucidate the clinical utility of PZCA-MMPs using a broader spectrum of clinical samples.

Low Ventricular Stiffness Is Associated With Suboptimal Outcomes in Patients With a Single Right Ventricle After the Fontan Operation: A Novel Phenotype.

Despite a rigorous screening process, including cardiac catheterization, a subset of patients with a single right ventricle (SRV) demonstrates suboptimal short-term outcomes after the Fontan operation. The goal of this study was to perform a comprehensive assessment of diastolic function in pre-Fontan patients with an SRV using invasive reference-standard measures and determine their associations with post-Fontan outcomes. Children aged 2 to 6 years with SRV physiology undergoing pre-Fontan heart catheterization were recruited prospectively. Patients were divided into those who had an optimal or suboptimal outcome. A suboptimal outcome was defined as length of stay ≥14 days or heart transplant/cardiac death in first year after Fontan. Patients underwent pressure-volume loop analysis using reference-standard methods. The measure of ventricular stiffness, β, was obtained via preload reduction. Cardiac magnetic resonance imaging for extracellular volume and serum draws for matrix metalloproteinase activity were performed. Of 19 patients with an SRV, 9 (47%) had a suboptimal outcome. Mean age was 4.2±0.7 years. Patients with suboptimal outcomes had lower ventricular stiffness (0.021 [0.009-0.049] versus 0.090 [0.031-0.118] mL-1; P=0.02), lower extracellular volume (25% [28%-32%] versus 31% [28%-33%]; P=0.02), and lower matrix metalloproteinase-2 (90 [79-104] versus 108 [79-128] ng/mL; P=0.01) compared with patients with optimal outcomes. The only invasive measure that had an association with suboptimal outcome was β (P=0.038). Patients with an SRV with suboptimal outcome after the Fontan operation had lower ventricular stiffness and evidence of maladaptive extracellular matrix metabolism compared with patients with optimal outcome. This appears to be a novel phenotype that may have important clinical implications and requires further study.

Hydrogen Sulfide Modulation of Matrix Metalloproteinases and CD147/EMMPRIN: Mechanistic Pathways and Impact on Atherosclerosis Progression.

Atherosclerosis is a chronic inflammatory condition marked by endothelial dysfunction, lipid accumulation, inflammatory cell infiltration, and extracellular matrix (ECM) remodeling within arterial walls, leading to plaque formation and potential cardiovascular events. Key players in ECM remodeling and inflammation are matrix metalloproteinases (MMPs) and CD147/EMMPRIN, a cell surface glycoprotein expressed on endothelial cells, vascular smooth muscle cells (VSMCs), and immune cells, that regulates MMP activity. Hydrogen sulfide (H₂S), a gaseous signaling molecule, has emerged as a significant modulator of these processes including oxidative stress mitigation, inflammation reduction, and vascular remodeling. This systematic review investigates the mechanistic pathways through which H₂S influences MMPs and CD147/EMMPRIN and assesses its impact on atherosclerosis progression. A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science databases, focusing on studies examining H₂S modulation of MMPs and CD147/EMMPRIN in atherosclerosis contexts. Findings indicate that H₂S modulates MMP expression and activity through transcriptional regulation and post-translational modifications, including S-sulfhydration. By mitigating oxidative stress, H₂S reduces MMP activation, contributing to plaque stability and vascular remodeling. H₂S also downregulates CD147/EMMPRIN expression via transcriptional pathways, diminishing inflammatory responses and vascular cellular proliferation within plaques. The dual regulatory role of H₂S in inhibiting MMP activity and downregulating CD147 suggests its potential as a therapeutic agent in stabilizing atherosclerotic plaques and mitigating inflammation. Further research is warranted to elucidate the precise molecular mechanisms and to explore H₂S-based therapies for clinical application in atherosclerosis.

JNK2-MMP-9 axis facilitates the progression of intracranial aneurysms

Intracranial aneurysm (IA) can cause subarachnoid hemorrhage or some other hemorrhagic stroke after rupture. Because of the poor outcome in spite of the intensive medical care after the onset of hemorrhage, the development of a novel therapeutic strategy like medical therapy to prevent the progression of the disease becomes a social need. As the reduction of arterial stiffness due to the degeneration of the extracellular matrix via Matrix Metalloproteinases (MMPs) becomes one of the central machineries leading to the progression of IAs through a series of studies, factors regulating the expression or the activity of MMPs could be a therapeutic target. In the present study, specimens from human IA lesions and the animal model of IAs were used to examine the expression of c-Jun N-terminal kinase (JNK) which might exacerbate expressions of MMPs in the lesions to weaken arterial walls resulting in the progression of the disease. In some human IA lesions examined, the expression of p-JNK, the activated form of JNK, could be detected mostly in the medial smooth muscle cells. In IA lesions induced in rats, the activation of JNK was induced during the progression of the disease and accompanied with the activation of downstream transcriptional factor c-Jun and importantly with the expression of MMP-2 or -9. The genetic deletion of Jnk2, not Jnk1, in mice significantly prevented the incidence of IAs with the suppression of the expression of MMP-2 or MMP-9. These results combined together have suggested the crucial role of JNK in the progression of IAs through regulating the expression of MMPs. The results from the present study provides the novel insights about the pathogenesis of IA progression and also about the therapeutic target.

Restoration of TFPI2 by LSD1 inhibition suppresses tumor progression and potentiates antitumor immunity in breast cancer

Histone lysine-specific demethylase 1 (LSD1) is frequently overexpressed in triple negative breast cancer (TNBC), which is associated with worse clinical outcome in TNBC patients. However, the underlying mechanisms by which LSD1 promotes TNBC progression remain to be identified. We recently established a genetically engineered murine model by crossing mammary gland conditional LSD1 knockout mice with Brca1-deficient mice to explore the role of LSD1 in TNBC pathogenesis. Cre-mediated Brca1 loss led to higher incidence of tumor formation in mouse mammary glands, which was hindered by concurrent depletion of LSD1, indicating a critical role of LSD1 in promoting Brca1-deficient tumors. We also demonstrated that the silencing of a tumor suppressor gene, Tissue Factor Pathway Inhibitor 2 (TFPI2), is functionally associated with LSD1-mediated TNBC progression. Mouse Brca1-deficient tumors exhibited elevated LSD1 expression and decreased TFPI2 level compared to normal mammary tissues. Analysis of TCGA database revealed that TFPI2 expression is significantly lower in aggressive ER-negative or basal-like BC. Restoration of TFPI2 through LSD1 inhibition increased H3K4me2 enrichment at the TFPI2 promoter, suppressed tumor progression, and enhanced antitumor efficacy of chemotherapeutic agent. Induction of TFPI2 by LSD1 ablation downregulates activity of matrix metalloproteinases (MMPs) that in turn increases the level of cytotoxic T lymphocyte attracting chemokines in tumor environment, leading to enhanced tumor infiltration of CD8+ T cells. Moreover, induction of TFPI2 potentiates antitumor effect of LSD1 inhibitor and immune checkpoint blockade in poorly immunogenic TNBC. Together, our study identifies previously unrecognized roles of TFPI2 in LSD1-mediated TNBC progression, therapeutic response, and immunogenic effects.

Short-Term Atorvastatin Therapy in Healthy Individuals Results in Unaltered Plasma MMP Levels and Disrupted MMP-7 Correlation with Blood Lipids and Blood Count-Derived Inflammatory Markers.

Background: Matrix metalloproteinases (MMPs) play an important role in the pathophysiology of atherosclerosis. Reportedly, statins can decrease MMP activity in patients with atherosclerotic cardiovascular disease, but this effect has not been studied in healthy individuals. Methods: MMPs 2, 7, and 9 and several other parameters were measured before and after a four-week course of moderate-dose atorvastatin (20 mg/day) in 21 healthy individuals. Results: Atorvastatin treatment resulted in lower total cholesterol, LDL-cholesterol, non-HDL-cholesterol, and triglycerides (p < 0.001 for all), but higher levels of plasma enzymes AST, ALT, CK, and LDH (p < 0.05 for all). No effect of atorvastatin on plasma MMP median concentrations was recorded. Before treatment, moderate positive significant correlations were found between MMP-7 and age, blood lipids, and blood count-derived inflammatory markers. Pre-treatment MMP-7 was best predicted by the total cholesterol-to-HDL cholesterol ratio in a remnant cholesterol-weighted least squares regression model. After atorvastatin treatment, MMP-7 no longer correlated with these markers. Conclusions: While the effect of statins on plasma MMPs in atherosclerosis is controversial, short-term moderate-dose atorvastatin treatment does not seem to affect levels of MMPs 2, 7, and 9 in healthy individuals. However, an intriguing correlation between MMP-7 and atherosclerosis-related blood lipids and neutrophil-associated inflammatory biomarkers seems to be disrupted by atorvastatin independently of hsCRP, possibly via pleiotropic effects.

Complement C3a/C3aR inhibition alleviates the formation of aortic aneurysm in Marfan syndrome mice

Mutations in fibrillin 1 (FBN1) is the main cause of Marfan syndrome (MFS) with thoracic aortic aneurysm (TAA) as the main complication. Activation of the complement system plays a key role in the formation of thoracic and abdominal aortic aneurysms. However, the role of the complement system in MFS-associated aortic aneurysms remains unclear. In this study, we observed increased levels of complement C3a and C5a in the plasma of MFS patients and mouse, and the increased deposition of the activated complement system product C3b/iC3b was also observed in the elastic fiber rupture zone of 3-month-old MFS mice. The expression of C3a receptor (C3aR) was increased in MFS aortas, and recombinant C3a promoted the expression of cytokines in macrophages. The administration of a C3aR antagonist (C3aRA) attenuated the development of thoracic aortic aneurysms in MFS mice. The increased inflammation response and matrix metalloproteinases activities were also attenuated by C3aRA treatment in MFS mice. Therefore, these findings indicate that the complement C3a/C3aR inhibition alleviates the formation of aortic aneurysm in Marfan syndrome mice.

(Invited) C60-Based Switchable Fluorescent Probes

Photodynamic therapy (PDT), an emerging non-invasive tumor treatment, requires suitable photosensitizer (PS) molecules that generate reactive oxygen species (ROSs) efficiently under long wavelength of light with deep tissue penetration, ideally activated in the diseased tissue. C60 is known as an excellent acceptor molecule in both electron- and energy-transfer reactions and exhibits biocompatibility and efficient ROS generation, rendering it a promising candidate as a PS for PDT.In this study, we developed a C60-based dual-functional molecular probe containing a water-soluble C60-peptide and a donor fluorophore connected with a ligand peptide specific for matrix metalloproteinases (MMP) (Figure 1). We expect that such a molecular probe can be used in both diagnostic imaging and concurrent treatment. The probe revealed increased fluorescence signal and 1O2 generation in the presence of MMP2/9 enzymes that are known to be overexpressed in tumor cells. Furthermore, in vitro cellular tests demonstrated the probe's abilities in imaging MMP activity and photocytotoxicity on MMP-expressing tumor cells. Figure 1

Role of blood-brain barrier dysfunction in the development of poststroke epilepsy.

Stroke is a major contributor to mortality and morbidity worldwide and the most common cause of epilepsy in the elderly in high income nations. In recent years, it has become increasingly evident that both ischemic and hemorrhagic strokes induce dysfunction of the blood-brain barrier (BBB), and that this impairment can contribute to epileptogenesis. Nevertheless, studies directly comparing BBB dysfunction and poststroke epilepsy (PSE) are largely absent. Therefore, this review summarizes the role of BBB dysfunction in the development of PSE in animal models and clinical studies. There are multiple mechanisms whereby stroke induces BBB dysfunction, including increased transcytosis, tight junction dysfunction, spreading depolarizations, astrocyte and pericyte loss, reactive astrocytosis, angiogenesis, matrix metalloproteinase activation, neuroinflammation, adenosine triphosphate depletion, oxidative stress, and finally cell death. The degree to which these effects occur is dependent on the severity of the ischemia, whereby cell death is a more prominent mechanism of BBB disruption in regions of critical ischemia. BBB dysfunction can contribute to epileptogenesis by increasing the risk of hemorrhagic transformation, increasing stroke size and the amount of cerebral vasogenic edema, extravasation of excitatory compounds, and increasing neuroinflammation. Furthermore, albumin extravasation after BBB dysfunction contributes to epileptogenesis primarily via increased transforming growth factor β signaling. Finally, seizures themselves induce BBB dysfunction, thereby contributing to epileptogenesis in a cyclical manner. In repairing this BBB dysfunction, pericyte migration via platelet-derived growth factor β signaling is indispensable and required for reconstruction of the BBB, whereby astrocytes also play a role. Although animal stroke models have their limitations, they provide valuable insights into the development of potential therapeutics designed to restore the BBB after stroke, with the ultimate goal of improving outcomes and minimizing the occurrence of PSE. In pursuit of this goal, rapamycin, statins, losartan, semaglutide, and metformin show promise, whereby modulation of pericyte migration could also be beneficial.