Matrix Metalloproteinase Activity Research Articles

Genome-wide DNA methylation analysis in blood identifies differentially methylated regions related to polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is considered a multifactorial disorder caused due to predisposing alleles of various genes and environmental factors which include lifestyle, dietary habits, and exposure to toxicants. Recently the emphasis has shifted to understanding epigenetic alterations due to the poor correlation between genotypes and the clinical profile of women with PCOS. Investigators have been focusing on differential methylation signatures associated with PCOS, therefore, a pilot study was carried out to investigate PCOS-associated differential DNA methylation regions in the population of north India. A cross-sectional study with sixteen participants comprising eight women with PCOS diagnosed under the Rotterdam criterion and eight age and BMI-matched healthy controls. Subjects were classified into four groups based on BMI and two different groups were compared each time making four comparison types in total. Genome-wide DNA methylation in whole blood was evaluated using an Infinium Human Methylation 850k array which identified PCOS-associated differential sites and differential methylation regions (DMRs) with promoter region, and CpG islands considering (p ≤ 0.01) as statistically significant. Multiple significantly associated hypomethylated and hypermethylated loci of genes were identified. Thirty-four hypomethylated and one hundred twenty-six hypermethylated sites of genes were suggested when all the subjects were of low BMI. But when the groups comprised with high BMI, twenty-seven hypomethylated genes and fifty-nine hypermethylated genes were identified. In silico analysis suggests that most of these genes are involved in estrogen biosynthesis, lipid biosynthetic process, and activation of matrix metalloproteinases (MMP). Seven genes that are found common in both of these comparisons are mostly involved in the inflammasome pathway indicated by BioPlanet and Reactome databases. The study provides information about DMRs in the blood tissue which may be investigated further to understand underlying pathogenesis and as therapeutic targets in the future.

Stretch Causes cffDNA and HMGB1-Mediated Inflammation and Cellular Stress in Human Fetal Membranes

Danger-associated molecular patterns (DAMPs) are elevated within the amniotic cavity, and their increases correlate with advancing gestational age, chorioamnionitis, and labor. Although the specific triggers for their release in utero remain unclear, it is thought that they may contribute to the initiation of parturition by influencing cellular stress mechanisms that make the fetal membranes (FMs) more susceptible to rupture. DAMPs induce inflammation in many different tissue types. Indeed, they precipitate the subsequent release of several proinflammatory cytokines that are known to be key for the weakening of FMs. Previously, we have shown that in vitro stretch of human amnion epithelial cells (hAECs) induces a cellular stress response that increases high-mobility group box-1 (HMGB1) secretion. We have also shown that cell-free fetal DNA (cffDNA) induces a cytokine response in FM explants that is fetal sex-specific. Therefore, the aim of this work was to further investigate the link between stretch and the DAMPs HMGB1 and cffDNA in the FM. These data show that stretch increases the level of cffDNA released from hAECs. It also confirms the importance of the sex of the fetus by demonstrating that female cffDNA induced more cellular stress than male fetuses. Our data treating hAECs and human amnion mesenchymal cells with HMGB1 show that it has a differential effect on the ability of the cells of the amnion to upregulate the proinflammatory cytokines and propagate a proinflammatory signal through the FM that may weaken it. Finally, our data show that sulforaphane (SFN), a potent activator of Nrf2, is able to mitigate the proinflammatory effects of stretch by decreasing the levels of HMGB1 release and ROS generation after stretch and modulating the increase of key cytokines after cell stress. HMGB1 and cffDNA are two of the few DAMPs that are known to induce cytokine release and matrix metalloproteinase (MMP) activation in the FMs; thus, these data support the general thesis that they can function as potential central players in the normal mechanisms of FM weakening during the normal distension of this tissue at the end of a normal pregnancy.

Anti-Metastatic Effects of Standardized Polysaccharide Fraction from Diospyros kaki Leaves via GSK3β/β-Catenin and JNK Inactivation in Human Colon Cancer Cells.

A polysaccharide fraction from Diospyros kaki (PLE0) leaves was previously reported to possess immunostimulatory, anti-osteoporotic, and TGF-β1-induced epithelial-mesenchymal transition inhibitory activities. Although a few beneficial effects against colon cancer metastasis have been reported, we aimed to investigate the anti-metastatic activity of PLE0 and its underlying molecular mechanisms in HT-29 and HCT-116 human colon cancer cells. We conducted a wound-healing assay, invasion assay, qRT-PCR analysis, western blot analysis, gelatin zymography, luciferase assay, and small interfering RNA gene silencing in colon cancer cells. PLE0 concentration-dependently inhibited metastasis by suppressing cell migration and invasion. The suppression of N-cadherin and vimentin expression as well as upregulation of E-cadherin through the reduction of p-GSK3β and β-catenin levels resulted in the outcome of this effect. PLE0 also suppressed the expression and enzymatic activity of matrix metalloproteinases (MMP)-2 and MMP-9, while simultaneously increasing the protein and mRNA levels of the tissue inhibitor of metalloproteinases (TIMP-1). Furthermore, signaling data disclosed that PLE0 suppressed the transcriptional activity and phosphorylation of p65 (a subunit of NF-κB), as well as the phosphorylation of c-Jun and c-Fos (subunits of AP-1) pathway. PLE0 markedly suppressed JNK phosphorylation, and JNK knockdown significantly restored PLE0-regulated MMP-2/-9 and TIMP-1 expression. Collectively, our data indicate that PLE0 exerts an anti-metastatic effect in human colon cancer cells by inhibiting epithelial-mesenchymal transition and MMP-2/9 via downregulation of GSK3β/β-catenin and JNK signaling.

Varying Properties of Extracellular Matrix Grafts Impact Their Durability and Cell Attachment and Proliferation in an In Vitro Chronic Wound Model

While acute wounds typically progress through the phases of wound healing, chronic wounds often stall in the inflammatory phase due to elevated levels of matrix metalloproteinases (MMPs) and proinflammatory cytokines. Dysregulated expression of MMPs can result in the breakdown of extracellular matrix (ECM) formed during the wound healing process, resulting in stalled wounds. Native collagen-based wound dressings offer a potential wound management option to sequester excess MMPs and support cellular interactions that allow wound progression through the natural healing process. Herein, we utilized commercially available ECM matrices, two derived from porcine small intestinal submucosa (PCMP, 2 layers; PCMP-XT, 5 layers) and one derived from propria submucosa (ovine forestomach matrix, OFM, 1 layer), to demonstrate the impact of processing methodologies (e.g., layering and crosslinking) on functional characteristics needed for the management of chronic wounds. Grafts were evaluated for structural composition using scanning electron microscopy and histology, ability to reduce MMPs using fluorometric assays, and durability in an in vitro degradation chronic wound model. Both intact (nondegraded) and partially degraded grafts were assessed for their ability to serve as a functional cell scaffold using primary human fibroblasts. Grafts differed in matrix substructure and composition. While all grafts demonstrated attenuation of MMP activity, PCMP and PCMP-XT showed larger reductions of MMP levels. OFM rapidly degraded in the in vitro degradation model (<3 hours), while PCMP and PCMP-XT were significantly more durable (>7 days). The ability of PCMP and PCMP-XT to serve as scaffolds for cellular attachment was not impacted by degradation in vitro. Three ECM grafts with varying structural and functional characteristics exhibited differential durability when degraded in a simulated chronic wound model. Those that withstood rapid degradation maintained their ability to function as a scaffold to support attachment and proliferation of fibroblasts, a cell type important for wound healing.

Divergent and Compensatory Effects of BMP2 and BMP4 on the VSMC Phenotype and BMP4's Role in Thoracic Aortic Aneurysm Development.

Vascular smooth muscle cells (VSMCs) play a key role in aortic aneurysm formation. Bone morphogenetic proteins (BMPs) have been implicated as important regulators of VSMC phenotype, and dysregulation of the BMP pathway has been shown to be associated with vascular diseases. The aim of this study was to investigate for the first time the effects of BMP-4 on the VSMC phenotype and to understand its role in the development of thoracic aortic aneurysms (TAAs). Using the angiotensin II (AngII) osmotic pump model in mice, aortas from mice with VSMC-specific BMP-4 deficiency showed changes similar to AngII-infused aortas, characterised by a loss of contractile markers, increased fibrosis, and activation of matrix metalloproteinase 9. When BMP-4 deficiency was combined with AngII infusion, there was a significantly higher rate of apoptosis and aortic dilatation. In vitro, VSMCs with mRNA silencing of BMP-4 displayed a dedifferentiated phenotype with activated canonical BMP signalling. In contrast, BMP-2-deficient VSMCs exhibited the opposite phenotype. The compensatory regulation between BMP-2 and BMP-4, with BMP-4 promoting the contractile phenotype, appeared to be independent of the canonical signalling pathway. Taken together, these results demonstrate the impact of VSMC-specific BMP-4 deficiency on TAA development.

PH- and Matrix Metalloproteinase-Responsive Multifunctional Bilayer Microneedles Platform for Treatment of Tinea Pedis.

Persistent foot odor and itchiness are common symptoms of tinea pedis, significantly disrupting the daily life of those affected. The cuticular barrier at the site of the tinea pedis is thickened, which impedes the effective penetration of antifungal agents. Additionally, fungi can migrate from the skin surface to deeper tissues, posing challenges in the current clinical treatment for tinea pedis. To effectively treat tinea pedis, we developed a platform of bilayer gelatin methacrylate (GelMA) microneedles (MNs) loaded with salicylic acid (SA) and FK13-a1 (SA/FK13-a1@GelMA MNs). SA/FK13-a1@GelMA MNs exhibit pH- and matrix metalloproteinase (MMP)-responsive properties for efficient drug delivery. The MNs are designed to deliver salicylic acid (SA) deep into the stratum corneum, softening the cuticle and creating microchannels. This process enables the antibacterial peptide FK13-a1 to penetrate through the stratum corneum barrier, facilitating intradermal diffusion and exerting antifungal and anti-inflammatory effects. In severe cases of tinea pedis, heightened local pH levels and MMP activity further accelerate drug release. Our research demonstrates that SA/FK13-a1@GelMA MNs are highly effective against Trichophyton mentagrophytes, Trichophyton rubrum, and Candida albicans. They also reduced stratum corneum thickness, fungal burden, and inflammation in a guinea pig model of tinea pedis induced by T. mentagrophytes. Furthermore, it was discovered that SA/FK13-a1@GelMA MNs exhibit excellent biocompatibility. These findings suggest that SA/FK13-a1@GelMA MNs have significant potential for the clinical treatment of tinea pedis as well as other fungal skin disorders.

Inhibition of Metalloproteinases Extends Longevity and Function of In Vitro Human iPSC-Derived Skeletal Muscle.

In vitro culture longevity has long been a concern for disease modeling and drug testing when using contractable cells. The dynamic nature of certain cells, such as skeletal muscle, contributes to cell surface release, which limits the system's ability to conduct long-term studies. This study hypothesized that regulating the extracellular matrix (ECM) dynamics should be able to prolong cell attachment on a culture surface. Human induced pluripotent stem cell (iPSC)-derived skeletal muscle (SKM) culture was utilized to test this hypothesis due to its forceful contractions in mature muscle culture, which can cause cell detachment. By specifically inhibiting matrix metalloproteinases (MMPs) that work to digest components of the ECM, it was shown that the SKM culture remained adhered for longer periods of time, up to 80 days. Functional testing of myofibers indicated that cells treated with the MMP inhibitors, tempol, and doxycycline, displayed a significantly reduced fatigue index, although the fidelity was not affected, while those treated with the MMP inducer, PMA, indicated a premature detachment and increased fatigue index. The MMP-modulating activity by the inhibitors and inducer was further validated by gel zymography analysis, where the MMP inhibitor showed minimally active MMPs, while the inducer-treated cells indicated high MMP activity. These data support the hypotheses that regulating the ECM dynamics can help maximize in vitro myotube longevity. This proof-of-principle strategy would benefit the modeling of diseases that require a long time to develop and the evaluation of chronic effects of potential therapeutics.

The low expression of matrix metalloproteinases: a key to longevity?

Over the past few decades, it has become clear that an excessive activity of matrix metalloproteinases (MMPs) can accelerate the progression and fatal outcomes of several serious age-related diseases, including atherosclerotic coronary heart disorders and various types of malignancies. These proteolytic enzymes mediate the degradation and remodeling of the extracellular matrix through cleaving its various components, thereby affecting many critical functions of surrounding cells and intercellular communication. Consequently, the low expression levels of MMPs can be important in the prevention and treatment of such chronic life-threatening pathologies, contributing to the better quality of life and longer life expectancy. In this review article, the pathogenic proteolytic roles of MMPs are examined in more detail, especially in the cases of heart attack and stroke as well as cancer invasion and metastasis, showing that these enzymes can be considered not only as diagnostic and prognostic biomarkers but also as important therapeutic targets in the fight against many age- and lifestyle-related serious disorders. The identification and development of suppressing agents with a selective activity towards specific MMPs have, however, still remained a complex and complicated challenge, in which natural plant-derived compounds are increasingly recognized as promising leads for the new-generation inhibitors.

Natural Products as Regulators against Matrix Metalloproteinases for the Treatment of Cancer.

Cancers are currently the major cause of mortality in the world. According to previous studies, matrix metalloproteinases (MMPs) have an impact on tumor cell proliferation, which could lead to the onset and progression of cancers. Therefore, regulating the expression and activity of MMPs, especially MMP-2 and MMP-9, could be a promising strategy to reduce the risk of cancers. Various studies have tried to investigate and understand the pathophysiology of cancers to suggest potent treatments. In this review, we summarize how natural products from marine organisms and plants, as regulators of MMP-2 and MMP-9 expression and enzymatic activity, can operate as potent anticancer agents.

Early Growth Response Protein 1 Exacerbates Murine Inflammatory Bowel Disease by Transcriptional Activation of Matrix Metalloproteinase 12.

Inflammatory bowel disease (IBD) is an inflammatory condition affecting the colon and small intestine, with Crohn's disease and ulcerative colitis being the major types. Individuals with long-term IBD are at an increased risk of developing colorectal cancer. Early growth response protein 1 (Egr1) is a nuclear protein that functions as a transcriptional regulator. Egr1 is known to control the expression of numerous genes and play a role in cell growth, proliferation, and differentiation. While IBD has been associated with severe inflammation, the precise mechanisms underlying its pathogenesis remain unclear. This study aimed to investigate the role of Egr1 in the development of IBD. High levels of Egr1 expression were observed in a mouse model of colitis induced by dextran sulfate sodium (DSS), as determined by immunohistochemical (IHC) staining. Chronic DSS treatment showed that Egr1 knockout (KO) mice exhibited resistance to the development of IBD, as determined by changes in their body weight and disease scores. Additionally, enzyme-linked immunosorbent assay (ELISA) and IHC staining demonstrated decreased expression levels of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α, as well as matrix metalloproteinase 12 (MMP12). Putative Egr1 binding sites were identified within the MMP12 promoter region. Through reporter assays and chromatin immunoprecipitation (ChIP) analysis, it was shown that Egr1 binds to the MMP12 promoter and regulates MMP12 expression. In conclusion, we found that Egr1 plays a role in the inflammation process of IBD through transcriptionally activating MMP12.

Calix[6]arene dismantles extracellular vesicle biogenesis and metalloproteinases that support pancreatic cancer hallmarks

Many challenges are faced in pancreatic cancer treatment due to late diagnosis and poor prognosis because of high recurrence and metastasis. Extracellular vesicles (EVs) and matrix metalloproteinases (MMPs), besides acting in intercellular communication, are key players in the cancer cell plasticity responsible for initiating metastasis. Therefore, these entities provide valuable targets for the development of better treatments. In this context, this study aimed to evaluate the potential of calix[6]arene to disturb the release of EVs and the activity of MMPs in pancreatic cancer cells. We found a correlation between the endocytic-associated mediators and the prognosis of pancreatic cancer patients. We observed a more active EV machinery in the pancreatic cancer cell line PANC-1, which was reduced three-fold by treatment with calix[6]arene at subtoxic concentration (5 μM; p 〈0,001). We observed the modulation of 186 microRNAs (164 miRNAs upregulated and 22 miRNAs downregulated) upon calix[6]arene treatment. Interestingly, some of them as miR-4443 and miR-3909, regulates genes HIF1A e KIF13A that are well known to play a role in transport of vesicles. Furthermore, Calix[6]arene downmodulated matrix metalloproteinases (MMPs) -2 and − 9 and disturbed the viability of pancreatic organoids which recapitulate the cellular heterogeneity, structure, and functions of primary tissues. Our findings shed new insights on calix[6]arene's antitumor mechanism, including its intracellular effects on vesicle production and trafficking, as well as MMP activity, which may harm the tumor microenvironment and contribute to a reduction in cancer cell dissemination, which is one of the challenges associated with high mortality in pancreatic cancer.

Does Chitosan Introduce Protection Against Methotrexate-Induced Hepatorenal Injury in Rats?

Objective: Chitosan possesses antioxidant properties and exhibits anti-inflammatory characteristics. The objective of the investigation was to assess the effectiveness of chitosan in protecting against hepatorenal injury induced by methotrexate (MTX), a medication utilized for immunosuppression and chemotherapy.
 Methods: Wistar albino rats were allocated into 3 different groups, each consisting of six animals (n=6). The control group received saline for 5 days (i.p.), the MTX group was administrated a single dose MTX (60 mg/kg, i.p.) along with saline for four days (i.p.), while MTX+Chitosan group received a single dose of MTX (60 mg/kg, i.p.) followed by Chitosan administration (200 mg/kg, i.p.) for four days. On the sixth day, the animals were decapitated, and blood and tissue samples were collected. BUN, creatinine and tissue inhibitors of metalloproteinase-1 (TIMP-1) levels and activities of AST, ALT, ALP, LDH, matrix metalloproteinases (MMP-3, MMP-8, MMP-9) activities were quantified in the blood. The liver and kidney were evaluated for caspase-3 and-9 through western blotting, while structural damage was examined using light microscopy.
 Results: In the MTX administered group, blood and tissues values except for all TIMP-1 statistically increased when compared to the control group, while activity of TIMP-1 decreased significantly. The Chitosan-treated MTX group had comparable values to the control group.
 Conclusion: Based on its influence on metalloproteinases and caspases, our findings lead to the conclusion that Chitosan offers a protective effect against liver and kidney damage induced by MTX.

Effects of Anti-Fibrotic Drugs on Transcriptome of Peripheral Blood Mononuclear Cells in Idiopathic Pulmonary Fibrosis.

Two anti-fibrotic drugs, pirfenidone (PFD) and nintedanib (NTD), are currently used to treat idiopathic pulmonary fibrosis (IPF). Peripheral blood mononuclear cells (PBMCs) are immunocompetent cells that could orchestrate cell-cell interactions associated with IPF pathogenesis. We employed RNA sequencing to examine the transcriptome signature in the bulk PBMCs of patients with IPF and the effects of anti-fibrotic drugs on these signatures. Differentially expressed genes (DEGs) between "patients with IPF and healthy controls" and "before and after anti-fibrotic treatment" were analyzed. Enrichment analysis suggested that fatty acid elongation interferes with TGF-β/Smad signaling and the production of oxidative stress since treatment with NTD upregulates the fatty acid elongation enzymes ELOVL6. Treatment with PFD downregulates COL1A1, which produces wound-healing collagens because activated monocyte-derived macrophages participate in the production of collagen, type I, and alpha 1 during tissue damage. Plasminogen activator inhibitor-1 (PAI-1) regulates wound healing by inhibiting plasmin-mediated matrix metalloproteinase activation, and the inhibition of PAI-1 activity attenuates lung fibrosis. DEG analysis suggested that both the PFD and NTD upregulate SERPINE1, which regulates PAI-1 activity. This study embraces a novel approach by using RNA sequencing to examine PBMCs in IPF, potentially revealing systemic biomarkers or pathways that could be targeted for therapy.

Parabens promotes invasive properties of multiple human cells: A potential cancer-associated adverse outcome pathway

Parabens are esters of p-hydroxybenzoic acid, which have been used as preservatives and considered safe for nearly a century, until the last two decades when concerns began to be raised about their association with cancers. Knowledge of the mode of action of parabens on the metastatic properties of different cancer cells is still very limited. In the present study, we investigated the effects of methylparaben (MP) and propylparaben (PP) on cell invasion and/or migration in multiple human cancerous and noncancerous cells, including hepatocellular carcinoma cells (HepG2), cervical carcinoma cells (HeLa), breast carcinoma cells (MCF-7), and human placental trophoblasts (HTR-8/SVneo). MP and PP at concentrations in a range of 5–500 μg/L significantly promoted the invasion of four cell lines, with a minimum effective concentration of 5 μg/L. MP and PP up-regulated the expression levels and enzymatic activities of matrix metalloproteinase 2 and 9 (MMP2 and MMP9), as well as altered the expression of the tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) in four cell lines, suggesting MMPs/TIMPs as potential key events (KEs) for paraben-induced cell invasion. Activation of the p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal protein kinases 1/2 (JNK1/2) signaling pathways was required for MP- and PP-promoted invasion of four cell lines, suggesting MAPK signaling pathways as candidates for KEs in cancer or noncancerous cells response to paraben exposure. This study showed for the first time that the two widely used parabens, MP and PP, promoted invasive capacity of multiple human cells through a common mode of action. This study provides evidence for the establishment of a potential cancer-associated AOP for parabens based on pathway-specific mechanism(s), which contributes towards assessing the health risks of these environmental chemicals.

Abstract 462: Developing the miR-888 cluster as a therapeutic target for prostate cancer

Abstract Prostate Cancer (PCa) is a serious health crisis in the United States. 20% of men diagnosed with PCa will progress to fast-growing, advanced disease. There are no curative treatment options for PCa that has spread to distant sites and the 5-year survival rate for metastatic disease remains 30%. Recognizing the need for better PCa therapeutics, we are developing novel anti-microRNA delivery reagents targeted against the noncoding RNA miR-888 cluster to block prostate tumor progression. Our lab identified these oncomiRs in a biomarker discovery screen as elevated in human metastatic PCa cell lines and prostatic fluids from patients with high-grade PCa. We noted that over-expression of miR-888 cluster members (miR-888, miR-891a) promoted prostate cell growth and induced invasiveness in vitro. miR-888 and miR-891a also accelerated xenograft tumor growth in mice. Treatment of aggressive PCa cells in culture with synthetic antisense inhibitors against individual cluster members reversed these growth and invasion phenotypes, highlighting their clinical potential. We are testing pH Low Insertion Peptide (pHLIP)-Peptide Nucleic Acid (PNA)-based antimiR conjugates against miR-888 and miR-891a. The delivery vehicle pHLIP is a 36-amino acid peptide that at low pH (< pH 6.5) adopts an alpha-helical conformational change and facilitates the insertion of its C-terminus across lipid bilayers to transport conjugated anti-miRNA cargo into cells. When administered systemically, pHLIP effectively targets solid tumors with acidic microenvironments. We found that these reagents are readily internalized by human PCa cells cultured at pH 6.0 and in prostate xenograft tumors when delivered systemically in mice. Treatment significantly repressed miR-888 and miR-891a and acted to slow prostate cell growth in vitro. We are currently moving these studies into mouse prostate models. Furthermore, we are investigating the downstream signaling pathways for the miR-888 cluster. Our work indicates that the miR-888 cluster network coordinates the repression of the Tissue Inhibitors of Metalloproteinase (TIMP) and SMAD4 anti-metastatic pathways to drive extracellular matrix degradation and prostate cell invasion, and as a consequence, induces matrix metalloproteinase (MMP) activity. Expression profiling arrays and luciferase reporter assays indicated that multiple members of the miR-888 cluster co-suppress TIMPs in the prostate and similarly elevate multiple MMPs as well as cadherins, fibronectin and heparinase, and co-modulated several immune response genes. We are currently studying the consequence of various CRISPR-mediated miR-888 cluster deletions to understand how this non-coding RNA cluster functionally overlaps to promote aggressive PCa. This work will establish new clinical tools for aggressive PCa and optimize patient treatment management. Citation Format: Katherine Routon, Trevor Fachko, Vishal Kasina, Raman Bahal, Aurora Esquela Kerscher. Developing the miR-888 cluster as a therapeutic target for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 462.

Targeting myeloperoxidase to stabilize unruptured aneurysm: an imaging-guided approach

Inflammation plays a key role in pathogenesis and rupture of aneurysms. Non-invasively and dynamically monitoring aneurysm inflammation is critical. This study evaluated myeloperoxidase (MPO) as an imaging biomarker and therapeutic target for aneurysm inflammation using an elastase-induced rabbit model treated with or without 4-aminobenzoic acid hydrazide (ABAH), an irreversible inhibitor of MPO. Myeloperoxidase-sensitive magnetic resonance imaging (MRI) using Mn-TyrEDTA, a peroxidase activity-dependent contrast agent, revealed weak contrast enhancement in contralateral arteries and decreased contrast enhancement in aneurysm walls with ABAH treatment, indicating MPO activity decreased and inflammation mitigated. This was supported by reduced immune cell infiltration, matrix metalloproteinases (MMP-2 and − 9) activity, ROS production and arterial wall destruction on histology. Finally, the aneurysm expansion rate remained < 50% throughout the study in the ABAH(+) group, but increased gradually in the ABAH(-) group. Our results suggest that inhibition of MPO attenuated inflammation and expansion of experimental aneurysm and MPO-sensitive MRI showed promise as a noninvasive tool for monitoring aneurysm inflammation.

LOX-1 and MMP-9 Inhibition Attenuates the Detrimental Effects of Delayed rt-PA Therapy and Improves Outcomes After Acute Ischemic Stroke.

Acute ischemic stroke triggers endothelial activation that disrupts vascular integrity and increases hemorrhagic transformation leading to worsened stroke outcomes. rt-PA (recombinant tissue-type plasminogen activator) is an effective treatment; however, its use is limited due to a restricted time window and hemorrhagic transformation risk, which in part may involve activation of MMPs (matrix metalloproteinases) mediated through LOX-1 (lectin-like oxLDL [oxidized low-density lipoprotein] receptor 1). This study's overall aim was to evaluate the therapeutic potential of novel MMP-9 (matrix metalloproteinase 9) and LOX-1 inhibitors in combination with rt-PA to improve stroke outcomes. A rat thromboembolic stroke model was utilized to investigate the impact of rt-PA delivered 4 hours poststroke onset as well as selective LOX-1 (BI-0115) and MMP-9 (JNJ0966) inhibitors given before rt-PA administration. Infarct size, perfusion, and hemorrhagic transformation were evaluated by 9.4-T magnetic resonance imaging, vascular and parenchymal MMP-9 activity via zymography, and neurological function was assessed using sensorimotor functioning testing. Human brain microvascular endothelial cells were exposed to hypoxia plus glucose deprivation/reperfusion (hypoxia plus glucose deprivation 3 hours/R 24 hours) and treated with ±rt-PA, ±MMP-9, and LOX-1 inhibitors. Barrier function was assessed via transendothelial electrical resistance, MMP-9 activity was determined with zymography, and LOX-1 and barrier gene expression/levels were measured using qRT-PCR and Western blot. Stroke and subsequent rt-PA treatment increased edema, hemorrhage, MMP-9 activity, LOX-1 expression, and worsened neurological outcomes. LOX-1 inhibition improved neurological function, reduced edema, and improved endothelial barrier integrity. Elevated MMP-9 activity correlated with increased edema, infarct volume, and decreased neurological function. MMP-9 inhibition reduced MMP-9 activity and LOX-1 expression. In human brain microvascular endothelial cells, LOX-1/MMP-9 inhibition differentially attenuated MMP-9 levels, inflammation, and activation following hypoxia plus glucose deprivation/R. Our findings indicate that MMP-9 and LOX-1 inhibition attenuates negative aspects of ischemic stroke with an rt-PA therapy, thus resulting in improved neurological function. While no synergistic effect was observed with simultaneous LOX-1 and MMP-9 inhibition, a distinct interaction is evident.

Evaluation of Antimicrobial Properties, Cell Viability, and Metalloproteinase Activity of Bioceramic Endodontic Materials Used in Vital Pulp Therapy.

This study aimed to evaluate the antimicrobial properties, cell viability, and matrix metalloproteinase (MMP) inhibition capacity of several endodontic materials aimed at vital pulp therapy: Pro Root MTA®, EndoSequence®, Biodentine®, MTA Angelus®, TheraCal LC®, and BioC Repair®. The materials were prepared according to the manufacturer's instructions. Antimicrobial tests were conducted using a microcosm biofilm model, cell viability was assessed using murine fibroblasts (L929), and MMP activity was analyzed through electrophoresis. The results showed that BioC Repair®, Biodentine®, and EndoSequence® exhibited similar antimicrobial properties, while MTA Angelus® and ProRoot MTA® had inferior results but were comparable to each other. In terms of cell viability, no significant differences were observed among the materials. EndoSequence® demonstrated the highest MMP inhibition capacity. In conclusion, BioC Repair®, Biodentine®, EndoSequence®, and TheraCal® showed better antimicrobial properties among the tested materials. The materials did not exhibit significant differences in terms of cytotoxicity. However, EndoSequence® displayed superior MMP inhibition capacity.

Nitric oxide nano-reactor DNMF/PLGA enables tumor vascular microenvironment and chemo-hyperthermia synergetic therapy

BackgroundBreast cancer ranks first among malignant tumors, of which triple-negative breast cancer (TNBC) is characterized by its highly invasive behavior and the worst prognosis. Timely diagnosis and precise treatment of TNBC are substantially challenging. Abnormal tumor vessels play a crucial role in TNBC progression and treatment. Nitric oxide (NO) regulates angiogenesis and maintains vascular homeostasis, while effective NO delivery can normalize the tumor vasculature. Accordingly, we have proposed here a tumor vascular microenvironment remodeling strategy based on NO-induced vessel normalization and extracellular matrix collagen degradation with multimodality imaging-guided nanoparticles against TNBC called DNMF/PLGA.ResultsNanoparticles were synthesized using a chemotherapeutic agent doxorubicin (DOX), a NO donor L-arginine (L-Arg), ultrasmall spinel ferrites (MnFe2O4), and a poly (lactic-co-glycolic acid) (PLGA) shell. Nanoparticle distribution in the tumor was accurately monitored in real-time through highly enhanced magnetic resonance imaging and photoacoustic imaging. Near-infrared irradiation of tumor cells revealed that MnFe2O4 catalyzes the production of a large amount of reactive oxygen species (ROS) from H2O2, resulting in a cascade catalysis of L-Arg to trigger NO production in the presence of ROS. In addition, DOX activates niacinamide adenine dinucleotide phosphate oxidase to generate and supply H2O2. The generated NO improves the vascular endothelial cell integrity and pericellular contractility to promote vessel normalization and induces the activation of endogenous matrix metalloproteinases (mainly MMP-1 and MMP-2) so as to promote extravascular collagen degradation, thereby providing an auxiliary mechanism for efficient nanoparticle delivery and DOX penetration. Moreover, the chemotherapeutic effect of DOX and the photothermal effect of MnFe2O4 served as a chemo-hyperthermia synergistic therapy against TNBC.ConclusionThe two therapeutic mechanisms, along with an auxiliary mechanism, were perfectly combined to enhance the therapeutic effects. Briefly, multimodality image-guided nanoparticles provide a reliable strategy for the potential application in the fight against TNBC.Graphical

Causal Association of Telomere Length and Loss of Bone: a Directional Mendelian Randomization Study of Multi-Outcomes.

This study employed a genome-wide association study (GWAS) to investigate the relationship between telomere length and marginal bone loss (MBL), a marker of bone health and aging. Telomere length, a biological indicator of aging, was analyzed alongside several serum markers of bone loss. Following a screen for appropriate instrumental variables, telomere length was designated as the exposure variable. We conducted the main analysis using random-effects inverse variance weighting (IVW) and supplemented it with MR Egger, weighted median, simple mode, and weighted mode analyses, employing a total of five methods. Positive outcomes underwent scrutiny through heterogeneity analysis, horizontal multiplicity analysis, and leave-one-out plot. Subsequently, the effective gene locus was chosen for a reverse MR analysis, with positive results serving as the exposure variable. We found a causal relationship between telomere length and the expression of osteocalcin (OC), matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-12 (MMP-12), key markers of bone metabolism. Our findings suggest that telomere wear and shortening may contribute to increased activity of OC, MMP-3, and MMP-12, thus affecting bone metabolism. However, reverse Mendelian randomization analysis did not indicate a significant impact of OC, MMP-3, and MMP-12 on telomere length, implying a unidirectional relationship. Overall, this meta-analysis underscores the association between telomere length and bone loss, highlighting the importance of timing and duration of telomere wear and shortening in influencing bone metabolism.