Assessment of gelatinases (MMP-2 and MMP-9) by gelatin zymography

Development of a dual-responsive injectable GelMA/F127DA hydrogel for enhanced cartilage regeneration in osteoarthritis: Harnessing MMP-triggered and mechanical stress-induced release of therapeutic agents

Osteoarthritis (OA) presents a significant challenge in clinical settings due to the limited self-renewal capability of cartilage tissue. To address this, engineered biomaterials employing biomimetic strategies have been developed to modulate and enhance cell-microenvironment interactions, facilitating cartilage regeneration. Nonetheless, excessive mechanical stress on joint structures can induce inflammatory responses, thereby impeding the process of cartilage repair. In this study, we focus on the OA microenvironment, characterized by the overexpression of matrix metalloproteinases (MMPs), and the mechanical stimuli due to joint movement. We engineered a dual-responsive injectable hydrogel: a blend of MMP-responsive, thermo-sensitive GelMA and mechanically robust, reverse thermo-sensitive F127DA. This hydrogel was designed to deliver TGF-β and KGN in a controlled manner via simple temperature modulation. The hydrophilic properties of GelMA and the hydrophobic nature of F127DA allow for efficient intra-articular delivery of diverse drug types, optimizing their therapeutic effects. Photocrosslinking the hydrogel in situ effectively seals cartilage defects and prevents further degradation. The overexpressed MMP in the OA environment triggers the release of TGF-β, recruiting bone marrow-derived stem cells (BMSCs), while mechanical pressure from joint movements releases KGN, promoting chondrogenic differentiation and mitigating inflammation. In summary, our injectable hydrogel, responsive to both the OA microenvironment and mechanical stress, shows promise in enhancing cartilage regeneration in OA. This approach holds significant potential for advancing the field of OA cartilage tissue engineering.

A multifaceted examination of the action of PDE4 inhibitor rolipram on MMP2/9 reveals therapeutic implications

A PDE4 (phosphodiesterase 4) inhibitor, Rolipram, was previously found to down-regulate (in a manner dependent on cAMP (cyclic adenosine monophosphate)-PKA (protein kinase A)) MMP2 (matrix metalloproteinase 2) and MMP9 protein expression levels, important markers of epithelial-to-mesenchymal transition in human breast cancer cell lines. However, zymographic studies revealed that rolipram could also alter the enzymatic activities of these MMPs, even in the presence of the PKA inhibitor H89. This calls for more detailed investigations of the inhibitory mechanism of rolipram on MMP2 and MMP9. The prediction of ligand-based targets through online reverse screening indicated that proteases are likely targets of rolipram. Computational molecular docking also demonstrated significant binding affinities of rolipram for both MMP2 and MMP9 proteins. Concurrently, a well-known inhibitor of MMPs, SB3CT, was utilized as a positive control for this study. The best models of the docked complexes were used as initial conditions for molecular dynamics (MD) simulations to explore their dynamic behavior and stability. In particular, both the MMP2-rolipram and MMP9-rolipram complexes were found to be stable and compact for the duration of the simulation ([Formula: see text]). Several stable hydrogen bonds were also detected between the proteins and rolipram. In vitro experiments using primary cells from patients with breast cancer also showed that rolipram could alter the enzymatic activities of MMP2 and MMP9, independent of the cAMP-PKA signaling pathway, though it was thought to be cAMP-PKA dependent previously. These observations indicate the ability of rolipram to control breast cancer by regressing the functions of MMP2 and MMP9, thus having 'off-targets' other than PDE4 to have direct control over proteins that are involved in the advancement of metastasis.

The miniaturized isolation of neutrophil granules (MING) method allowed a deep proteome mapping of human neutrophil granules

Neutrophils are the innate immune system's first line of defense, and their storage organelles are essential to their function. The storage organelles are divided into 3 different granule types named azurophilic, specific, and gelatinase granules, besides a fourth component called secretory vesicles. The isolation of neutrophil's granules is challenging, and the existing procedures rely on large sample volumes, about 400 mL of peripheral blood, precluding the use of multiple biological and technical replicates. Therefore, the aim of this study was to develop a miniaturized isolation of neutrophil granules method, using biochemical assays, mass spectrometry-based proteomics and a machine learning approach to investigate the protein content of these organelles. Neutrophils were isolated from 40 mL of blood collected from 3 apparently healthy volunteers and disrupted using nitrogen cavitation; the organelles were fractionated with a discontinuous 3-layer Percoll density gradient. The method was proven successful and allowed for a reasonable separation and enrichment of neutrophil's storage organelles using a gradient approximately 37 times smaller than the methods described in the literature. Moreover, mass spectrometry-based proteomics identified 368 proteins in at least 3 of the 5 analyzed samples, and using a machine learning strategy aligned with markers from the literature, the localization of 50 proteins was predicted with confidence. When using markers determined within our dataset by a clusterization tool, the localization of 348 proteins was confidently determined. Importantly, this study was the first to investigate the proteome of neutrophil granules using technical and biological replicates, creating a reliable database for further studies.

Biodegradable 3D-Printed Conjunctival Inserts for the Treatment of Dry Eyes

PURPOSE

To fabricate 3D-printed, biodegradable conjunctival gelatin methacrylate (GelMA) inserts that can release polyvinyl alcohol (PVA) when exposed to an ocular surface enzyme.

METHOD

In this work, biodegradable conjunctival inserts were 3D-printed using a stereolithography-based technique. The release of PVA from these insert formulations (containing 10% GelMA and 5% PVA (P-Gel-5%)) was assessed along with different mathematical models of drug release. The biodegradation rates of these inserts were studied in the presence of a tear-film enzyme (matrix metalloproteinase-9; MMP9). The morphology of the inserts before and after enzymatic degradation was monitored using scanning electron microscopy.

RESULTS

The 3D-printed P-Gel-5% inserts formed a semi-interpenetrating network, which was mechanically stronger than GelMA inserts. The PVA release graphs demonstrate that at the end of 24 h, 222.7 ± 20.3 µg, 265.5 ± 27.1 µg, and 242.7 ± 30.4 µg of PVA were released when exposed to 25, 50, and 100 µg/mL of MMP9, respectively. The release profiles of the P-Gel-5% containing hydrogels in the presence of different concentrations of MMP9 showed the highest linearity with the Korsmeyer-Peppas model. The results suggest that the degradation rate over 24 h is a function of MMP9 enzyme concentration. Over 80% of P-Gel-5% inserts were degraded at the end of 8 h, 12 h, and 24 h in the presence of 100, 50, and 25 µg/mL MMP9 enzyme solutions, respectively.

CONCLUSIONS

These results demonstrate the potential for 3D printing of GelMA for use as conjunctival inserts. These inserts could be used to deliver PVA, which is a well-known therapeutic agent for dry eye disease. PVA release is influenced by multiple mechanisms, including diffusion and enzymatic degradation, which is supported by morphological studies and biodegradation results.

Investigating the anticancer properties of urolithin B in triple negative breast cancer: In vivo and in vitro insights

Breast cancer (BC) is a leading cause of cancer-related mortality among women worldwide, with incidence rates rising globally. Urolithin B (UB), a bioactive metabolite of ellagic acid, has demonstrated promising anticancer effects in various cancer models. This study aimed to evaluate the effects of UB on the growth, angiogenesis, and metastasis of BC cells using both in vivo and in vitro approaches. Cytotoxic effects of UB were assessed on MDA-MB-231 cells and normal HFF cells using the MTT assay. Scratch assays and gelatin zymography demonstrated UB's suppression of cell migration and reduced enzymatic activities of MMP-2 and MMP-9. In a xenograft mouse model, UB significantly reduced tumor growth, enhanced necrosis, and decreased vascularity in tumor tissues. It downregulated mRNA expression levels of VEGF, VEGFR, MMP-2, and MMP-9, indicating potent anti-angiogenic and anti-metastatic properties. Additionally, UB exhibited antioxidant effects by increasing total thiol content and the activities of superoxide dismutase (SOD) and catalase (CAT) while reducing malondialdehyde (MDA) levels in tumor tissues. In conclusion, our results highlight the anticancer potential of UB, through its ability to suppress the proliferation, angiogenesis, and metastatic properties of BC both in vitro and in vivo. Coupled with its antioxidant properties, UB emerges as a promising and safe candidate for further pre-clinical and clinical research and therapeutic applications in BC management.

Gelatin Zymography: A Simple and Effective Technique to Detect Gelatinases

Matrix metalloproteinases (MMPs) are zinc-dependent enzymes capable of breaking down all extracellular matrix (ECM) components. The gelatinases are a subgroup of MMPs which have two members: gelatinase A (MMP-2) and gelatinase B (MMP-9). They are highly efficient in breaking down denatured collagen I or gelatin. This ability of gelatinases has led to the development of a technique called gelatin zymography. This technique provides a simple, sensitive, and robust way to detect gelatinolytic activity in biological samples. This chapter provides a detailed protocol on how to implement the gelatin zymography and analyze gelatinases in biological samples using this technique.

Measuring Matrix Metalloproteinases Activity by Gelatin Zymography

Gelatin zymography is a widely popular method due to its simplicity, low cost, and quick results, for studying gelatinases in various biological systems. Zymography can detect both the pro and active forms of matrix metalloproteinases MMP-2 (gelatinase A) and MMP-9 (gelatinase B). These MMPs play critical roles in the pathophysiology of many human diseases, particularly in cancer progression. Gelatin zymography is a method based on a suitable protein substrate incorporated into a sodium dodecyl sulfate-polyacrylamide gel. Substrate degradation by protease-containing samples can be visualized through the contrast between the Coomassie blue-stained gel and the white band of substrate degradation. Here, we provide a straightforward, step-by-step methodology for detecting MMP-2 and MMP-9 gelatinases in tumor cells. It is essential to highlight that accurately interpreting the data requires a thorough understanding of the technique's principles.

Detection of Proteolytic Enzymes in Polyacrylamide Gels Supplemented with Diverse Biological Substrates

Zymography is a powerful technique for detecting and identifying proteolytic enzyme activity through gel electrophoresis based on molecular weights determined by substrate degradation. Gelatin zymography specifically detects proteolytic enzymes that degrade gelatin, such as matrix metalloproteinases MMP-2 (gelatinase A) and MMP-9 (gelatinase B). In contrast, plasminogen-casein zymography detects plasminogen-dependent serine proteases, such as tissue-type plasminogen activator and urokinase plasminogen activator. Various cells, tissues, and fluids can be assayed using these techniques, with methodologies for collecting and processing reproductive fluids to accurately detect protease activities detailed herein. General considerations for performing these experiments, including major troubleshooting and safety issues, are also outlined. Proper interpretation of gelatin and plasminogen-casein zymography data requires a thorough understanding of the technique's principles and pitfalls, which is crucial when evaluating enzyme levels and the presence of active gelatinase species and plasminogen-dependent proteases. When properly utilized, gelatin and plasminogen-casein zymography are excellent tools for studying metalloproteases and serine proteases in different biological systems.

Assessing MMP-2/9 Proteolytic Activity and Activation Status by Zymography in Preclinical and Clinical Tissue Samples

Zymography is a powerful technique that can be exploited to specifically assess the relative expression levels of a group of proteolytic enzymes termed matrix metalloproteinases (MMPs) through their catalytic activity. It is further used to monitor the ratios status of activated over latent MMP forms that provide more accurate insights in their physiological roles in regulating the degradation of the extracellular matrix. Clinical tissue biopsies, in vitro primary cell culture lysates, or media conditioned by tumor-derived preclinical in vitro cell cultures can be used by researchers to assess by zymography clinical treatment efficacy or pharmacological impact of drugs in development on MMPs level. As increases in MMPs protein levels do not necessarily correlate with increased enzymatic activity, assessing MMPs in clinical tissue samples or from preclinical cell models using zymography is the best indicator of the impact of a given therapy on the activation status of these enzymes, or the impact on an invasive molecular phenotype in the case of tumor biopsies. In this chapter, the proteolytic activity of MMP-2 and MMP-9, two gelatinases, is detected as unstained clear digested bands against a stained gelatin background in polyacrylamide gels. Zymography's strengths are its cost-effectiveness, rapidity, and adaptability since it can be used with a relatively small amount of starting material to assess the activation status and proteolytic activity of other MMPs types when used in gel with their specific substrates.

Human iPSC-based disease modeling studies identify a common mechanistic defect and potential therapies for AMD and related macular dystrophies

Age-related macular degeneration (AMD) and related macular dystrophies (MDs) primarily affect the retinal pigment epithelium (RPE) in the eye. A hallmark of AMD/MDs that drives later-stage pathologies is drusen. Drusen are sub-RPE lipid-protein-rich extracellular deposits, but how drusen forms and accumulates is not known. We utilized human induced pluripotent stem cell (iPSC)-derived RPE from patients with AMD and three distinct MDs to demonstrate that reduced activity of RPE-secreted matrix metalloproteinase 2 (MMP2) contributes to drusen in multiple maculopathies in a genotype-agnostic manner by instigating sterile inflammation and impaired lipid homeostasis via damage-associated molecular pattern molecule (DAMP)-mediated activation of receptor for advanced glycation end-products (RAGE) and increased secretory phospholipase 2-IIA (sPLA2-IIA) levels. Therapeutically, RPE-specific MMP2 supplementation, RAGE-antagonistic peptide, and a small molecule inhibitor of sPLA2-IIA ameliorated drusen accumulation in AMD/MD iPSC-RPE. Ultimately, this study defines a causal role of the MMP2-DAMP-RAGE-sPLA2-IIA axis in AMD/MDs.

Electrochemiluminescence biosensor for MMP-2 determination using CRISPR/Cas13a and EXPAR amplification: a novel approach for anti-aging research

Matrix metalloproteinase-2 (MMP-2) plays a pivotal role in anti-aging research. Developing advanced detection platforms for MMP-2 with high specificity, sensitivity, and accessibility is crucial. This study introduces a novel electrochemiluminescence (ECL) biosensor for MMP-2 determination, leveraging the CRISPR/Cas13a system and Exponential Amplification Reaction (EXPAR). The biosensor operates by utilizing the T7 RNA polymerase to transcribe RNA from a DNA template upon MMP-2 interaction. This RNA activates Cas13a, leading to signal amplification and ECL detection. The incorporation of the "photoswitch" molecule [Ru(phen)2dppz]2+ streamlines the process by eliminating the need for extensive electrode modification and cleaning. Under optimized conditions, the biosensor achieved an impressive detection limit of 12.8 aM for MMP-2. The platform demonstrated excellent selectivity, reproducibility, and stability, making it highly suitable for detecting MMP-2 in complex biological samples. This innovative approach shows great potential for applications in molecular diagnostics and anti-aging research.

Repeated Silica exposures lead to Silicosis severity via PINK1/PARKIN mediated mitochondrial dysfunction in mice model

BACKGROUND AND OBJECTIVES

Silicosis, one of the occupational health illnesses is caused by inhalation of crystalline silica. Deposition of extracellular matrix and fibroblast proliferation in lungs are linked to silicosis development. Mitochondrial dysfunction plays critical role in some diseases, but how these processes progress and regulated in silicosis, remains limited. Detailed study of silica induced pulmonary fibrosis in mouse model, its progression and severity may be helpful in designing future therapeutic strategies.

METHODS

In present study, mice model of silicosis has been developed after repeated silica exposures which may closely resemble clinical symptoms of silicosis in human. In addition to efficiently mimicking the acute/chronic transformation processes of silicosis, this is practical and efficient in terms of time and output, which avoids mechanical injury to the upper respiratory tract due to surgical interventions. Sonicated sterile silica suspension (120 mg/kg) was administered through intranasal route thrice a week at regular intervals (21, 28 and 35 days).

RESULTS

Presence of minute to larger silicotic nodules in H&E-stained lung sections were observed in all silica induced model groups. Enhanced ECM deposition was noted in MT stained lung sections of silica exposure groups as compared to control which were confirmed by significantly higher MMP9 expression levels and hydroxyproline content in silica 35 days group. Increase in Reactive oxygen species (ROS), inflammatory cell recruitment mainly, neutrophils and macrophage were observed in all three silica exposure groups. Transmission electron microscopic analysis has confirmed presence of many aberrant shaped mitochondria (swollen, round shape) in 35 days model where autophagosomes were minimum. Western blot analysis of mitophagy and autophagy markers such as Pink1, Parkin, Cytochrome c, SQSTM1/p62, the ratio of light chain LC3B II/LC3B I was found higher in 21 and 28 days which were significantly reduced in 35 days silica model.

CONCLUSIONS

Higher MMP9 activity and MMP9 /TIMP1 ratio demonstrate excessive extracellular matrix damage and deposition in 35 days model. Significantly reduced expressions of autophagy and mitophagy markers have also confirmed progression in fibrosis severity and its association with repeated silica exposures in 35 days model group.

Understanding the molecular basis of anti-fibrotic potential of intranasal curcumin and its association with mitochondrial homeostasis in silica-exposed mice

Silicosis is an occupational disease of the lungs brought in by repeated silica dust exposures. Inhalation of crystalline silica leads to persistent lung inflammation characterized by lung lesions due to granuloma formation. The specific molecular mechanism has not yet been identified, though. The Present study investigated the impact of silica-exposed lung fibrosis and probable molecular mechanisms. Here, Curcumin, derived from Curcuma longa shown to be an effective anti-inflammatory and anti-fibrotic molecule has been taken to investigate its therapeutic efficacy in silica-induced lung fibrosis. An experimental model of silicosis was established in mice where curcumin was administered an hour before intranasal silica exposure every alternate day for 35 days. Intranasal Curcumin treatment reduced silica-induced oxidative stress, inflammation marked by inflammatory cell recruitment, and prominent granuloma nodules along with aberrant collagen repair. Its protective benefits were confirmed by reduced MMP9 activities along with EMT markers (Vimentin and α-SMA). It has restored autophagy and suppressed the deposition of damaged mitochondria after silica exposure. Intranasal Curcumin also inhibited oxidative stress by boosting antioxidant enzyme activities and enhanced Nrf2-Keap1 expressions. Higher levels of PINK1, PARKIN, Cyt-c, P62/SQSTM, and damaged mitochondria in the silicosis group were significantly lowered after curcumin and dexamethasone treatments. Curcumin-induced autophagy resulted in reduced silica-induced mitochondria-dependent apoptosis. We report that intranasal curcumin treatment showed protective properties on pathological features prompted by silica particles, suggesting that the compound may constitute a promising strategy for the treatment of silicosis in the near future.

Ablation of the dystrophin Dp71f alternative C-terminal variant increases sarcoma tumour cell aggressiveness

Alterations in Dp71 expression, the most ubiquitous dystrophin isoform, have been associated with patient survival across tumours. Intriguingly, in certain malignancies, Dp71 acts as a tumour suppressor, while manifesting oncogenic properties in others. This diversity could be explained by the expression of two Dp71 splice variants encoding proteins with distinct C-termini, each with specific properties. Expression of these variants has impeded the exploration of their unique roles. Using CRISPR/Cas9, we ablated the Dp71f variant with the alternative C-terminus in a sarcoma cell line not expressing the canonical C-terminal variant, and conducted molecular (RNAseq) and functional characterisation of the knockout cells. Dp71f ablation induced major transcriptomic alterations, particularly affecting the expression of genes involved in calcium signalling and ECM-receptor interaction pathways. The genome-scale metabolic analysis identified significant downregulation of glucose transport via membrane vesicle reaction (GLCter) and downregulated glycolysis/gluconeogenesis pathway. Functionally, these molecular changes corresponded with, increased calcium responses, cell adhesion, proliferation, survival under serum starvation and chemotherapeutic resistance. Knockout cells showed reduced GLUT1 protein expression, survival without attachment and their migration and invasion in vitro and in vivo were unaltered, despite increased matrix metalloproteinases release. Our findings emphasise the importance of alternative splicing of dystrophin transcripts and underscore the role of the Dp71f variant, which appears to govern distinct cellular processes frequently dysregulated in tumour cells. The loss of this regulatory mechanism promotes sarcoma cell survival and treatment resistance. Thus, Dp71f is a target for future investigations exploring the intricate functions of specific DMD transcripts in physiology and across malignancies.

Topical Application of Autologous Plasma-Derived Plasminogen Accelerates Healing of Chronic Foot Ulcers in Type 2 Diabetes Patients

Plasminogen (Pg) is currently considered a master regulator of wound healing, but the molecular mechanisms of its efficacy in improving impaired closure of chronic skin ulcers in type 2 diabetes patients remain unclear. Here, we investigated wound healing effects of autologous plasma-derived Pg in diabetes patients with chronic foot ulcers and evaluated Pg-induced changes in levels of key protein markers related to wound repair. Type 2 diabetes patients with chronic wounds of lower extremities were included in the study and received topical applications of Pg in a dose of 1.0 mg/mL every 2 days during 20 days, in addition to the standard wound management treatment. Patients treated only according to conventional protocol served as a control. Wound closure rates were monitored by digital planimetry of wound areas. Plasminogen supplementary treatment significantly accelerated relative wound closure as compared with diabetes patients from the control group (24 ± 4 days vs 120 ± 17 days, respectively, P < .01). As shown by Western blot, Pg application reduced expression of protein regulators of hypoxia events, angiogenesis, and autophagy such as hypoxia-inducible factor-1α (by 6.3-folds, P < .01), angiostatins (by 2.5-folds, P < .05), and autophagy marker LC3-II/LC3-I (by 8.6-folds, P < .05), while increasing vascular endothelial growth factor level by 1.9-folds (P < .05). Gelatin zymography showed that Pg-supplemented therapy decreased activity of matrix metalloproteinase-9 (MMP-9) by 3.5-folds at the end of treatment period (P < .01). We report here for the first time that topically applied plasma-derived Pg has a pronounced beneficial effect in promoting foot ulcer healing in patients with type 2 diabetes through preventing hypoxia-induced signaling, reducing autophagy flux, diminishing excessive MMP activity, and enhancing angiogenesis.

Standardized Pre-clinical Surgical Animal Model Protocol to Investigate the Cellular and Molecular Mechanisms of Ischemic Flap Healing

BACKGROUND

Some of the most complex surgical interventions to treat trauma and cancer include the use of locoregional pedicled and free autologous tissue transfer flaps. While the techniques used for these reconstructive surgery procedures have improved over time, flap complications and even failure remain a significant clinical challenge. Animal models are useful in studying the pathophysiology of ischemic flaps, but when repeatability is a primary focus of a study, conventional in-vivo designs, where one randomized subset of animals serves as a treatment group while a second subset serves as a control, are at a disadvantage instigated by greater subject-to-subject variability. Our goal was to provide a step-by-step methodological protocol for creating an alternative standardized, more economical, and transferable pre-clinical animal research model of excisional full-thickness wound healing following a simulated autologous tissue transfer which includes the primary ischemia, reperfusion, and secondary ischemia events with the latter mimicking flap salvage procedure.

RESULTS

Unlike in the most frequently used classical unilateral McFarlane's caudally based dorsal random pattern skin flap model, in the herein described bilateral epigastric fasciocutaneous advancement flap (BEFAF) model, one flap heals under normal and a contralateral flap-under perturbed conditions or both flaps heal under conditions that vary by one within-subjects factor. We discuss the advantages and limitations of the proposed experimental approach and, as a part of model validation, provide the examples of its use in laboratory rat (Rattus norvegicus) axial pattern flap healing studies.

CONCLUSIONS

This technically challenging but feasible reconstructive surgery model eliminates inter-subject variability, while concomitantly minimizing the number of animals needed to achieve adequate statistical power. BEFAFs may be used to investigate the spatiotemporal cellular and molecular responses to complex tissue injury, interventions simulating clinically relevant flap complications (e.g., vascular thrombosis) as well as prophylactic, therapeutic or surgical treatment (e.g., flap delay) strategies in the presence or absence of confounding risk factors (e.g., substance abuse, irradiation, diabetes) or favorable wound-healing promoting activities (e.g., exercise). Detailed visual instructions in BEFAF protocol may serve as an aid for teaching medical or academic researchers basic vascular microsurgery techniques that focus on precision, tremor management and magnification.

Curcumin and PCI-34051 combined treatment ameliorates inflammation and fibrosis by affecting MAP kinase pathway

OBJECTIVE

Bronchoconstriction, along with inflammation and hyperresponsiveness is the characteristic feature associated with asthma, contributing to variable airflow obstruction, which manifests shortness of breath, cough and wheeze, etc. Histone deacetylases 8 (HDAC8) is the member of class I HDAC family and known to regulate microtubule integrity and muscle contraction. Therefore, we aimed to investigate the effects of HDAC8 inhibition in murine model of asthma using Pan-HDAC inhibitor curcumin (CUR) and HDAC8-specific inhibitor PCI-34051 (PCI), alone and in combination.

MATERIALS AND METHODS

To develop asthmatic mouse model, Balb/c mice were sensitized and challenged with ovalbumin (OVA). CUR (10 mg/kg, pre, post, alone and combined treatment) and PCI (0.5 mg/kg), were administered through intranasal (i.n) route, an hour before OVA aerosol challenge. Effects of HDAC8 inhibition by CUR and PCI pretreatments were evaluated in terms of inflammation, oxidative stress and fibrosis markers. Efficacy of curcumin post-treatment (CUR(p)) was also evaluated simultaneously.

RESULTS

Inflammatory cell recruitment, oxidative stress (reactive oxygen species, nitric oxide), histamine and Immunoglobulin E (IgE) levels and expression of fibrosis markers including hydroxyproline, matrix metalloproteinases-9 and alpha smooth muscle actin (MMP-9 and α-SMA) were significantly reduced by CUR, CUR(p), PCI-alone and combined treatments. Protein expressions of HDAC8, Nuclear factor-κB (NF-κB) accompanied by MAPKs (mitogen-activated protein kinases) were significantly reduced by the treatments. Structural alterations were examined by histopathological analysis and linked with the fibrotic changes.

CONCLUSIONS

Present study indicates protective effects of HDAC8 inhibition in asthma using HDAC8 using CUR and PCI alone or in combination, attenuates airway inflammation, fibrosis and remodeling; hence, bronchoconstriction was accompanied through modulation of MAP kinase pathway.

Carboxyl nanodiamonds inhibit melanoma tumor metastases by blocking cellular motility and invasiveness

Carboxyl nanodiamond (cND) nanoparticles are actively internalized by B16F10 melanoma cells in culture. Treatment of B16F10 tumor cells with cNDs in vitro inhibited their ability to (i) migrate and invade through porous membranes in a transwell culture system, (ii) secrete matrix metalloproteinases (MMPs) MMP-2 and MMP-9, and (iii) express selected epithelial-mesenchymal transition markers critical for cell migration and invasion. Administration of luciferase-transfected B16F10-Luc2 melanoma cells resulted in a rapid growth of the tumor and its metastasis to different organs that could be monitored by in vivo bioluminescence imaging as well as by ex vivo BLI of the mouse organs. After tumor cells were administered intravenously in C57Bl/6 mice, administration of cNDs (50 μg i.v. every alternate day) resulted in marked suppression of the tumor growth and metastasis in different organs of mice. Subcutaneous administration of B16F10 cells resulted in robust growth of the primary tumor subcutaneously as well as its metastasis to the lungs, liver, spleen, and kidneys. Intravenous treatment with cNDs did not affect the growth of the primary tumor mass but essentially blocked the metastasis of the tumor to different organs. Histological examination of mouse organs indicated that the administration of cNDs by itself was safe and did not cause toxic changes in mouse organs. These results indicate that the cND treatment may have an antimetastatic effect on the spread of B16F10 melanoma tumor cells in mice. Further exploration of cNDs as a possible antimetastatic therapeutic agent is suggested.

Toll-like receptor 2, hyaluronan, and neutrophils play a key role in plaque erosion: the OPTICO-ACS study

BACKGROUND AND AIMS

In one-third of patients with acute coronary syndrome (ACS), thrombosis occurs despite an intact fibrous cap (IFC) (IFC-ACS, 'plaque erosion'). Recent studies emphasize neutrophils as the immediate inflammatory response in this pathology, but their exact molecular activation patterns are still poorly understood and may represent future therapeutic targets.

METHODS AND RESULTS

Thirty-two patients with IFC-ACS and matched patients with ACS with ruptured fibrous cap (RFC) (RFC-ACS) from the OPTICO-ACS study were included, and blood samples were collected from the local site of the culprit lesion and the systemic circulation. Neutrophil surface marker expression was quantified by flow cytometry. Neutrophil cytotoxicity towards endothelial cells was examined in an ex vivo co-culture assay. Secretion of active matrix metalloproteinase 9 (MMP9) by neutrophils was evaluated using zymography in supernatants and in plasma samples. Optical coherence tomography (OCT)-embedded thrombi were used for immunofluorescence analysis. Toll-like receptor 2 (TLR2) expression was higher on neutrophils from IFC-ACS than RFC-ACS patients. TLR2 stimulation increased the release of active MMP9 from local IFC-ACS-derived neutrophils, which also aggravated endothelial cell death independently of TLR2. Thrombi of IFC-ACS patients exhibited more hyaluronidase 2 with concomitant increase in local plasma levels of the TLR2 ligand: hyaluronic acid.

CONCLUSION

The current study provides first in-human evidence for distinct TLR2-mediated neutrophil activation in IFC-ACS, presumably triggered by elevated soluble hyaluronic acid. Together with disturbed flow conditions, neutrophil-released MMP9 might be promoting endothelial cell loss-triggered thrombosis and therefore providing a potential future target for a phenotype-specific secondary therapeutic approach in IFC-ACS.

Allyl isothiocyanate inhibits cell migration and invasion in human gastric cancer AGS cells via affecting PI3K/AKT and MAPK signaling pathway in vitro

Metastasis is commonly occurred in gastric cancer, and it is caused and responsible for one of the major cancer-related mortality in gastric cancer patients. Allyl isothiocyanate (AITC), a natural product, exhibits anticancer activities in human many cancer cells, including gastric cancer. However, no available report shows AITC inhibits gastric cancer cell metastasis. Herein, we evaluated the impact of AITC on cell migration and invasion of human gastric cancer AGS cells in vitro. AITC at 5-20 μM did not induce significant cell morphological damages observed by contrast-phase microscopy but decreased cell viability assayed by flow cytometry. After AGS cells were further examined by atomic force microscopy (AFM), which indicated AITC affected cell membrane and morphology in AGS cells. AITC significantly suppressed cell motility examined by scratch wound healing assay. The results of the gelatin zymography assay revealed that AITC significantly suppressed the MMP-2 and MMP-9 activities. In addition, AITC suppressed cell migration and invasion were performed by transwell chamber assays at 24 h in AGS cells. Furthermore, AITC inhibited cell migration and invasion by affecting PI3K/AKT and MAPK signaling pathways in AGS cells. The decreased expressions of p-AKTThr308 , GRB2, and Vimentin in AGS cells also were confirmed by confocal laser microscopy. Our findings suggest that AITC may be an anti-metastasis candidate for human gastric cancer treatment.

Gelatin Zymography Can Be Performed on Fixed Brain Tissue

Gelatin zymography is widely used to detect gelatinase activity, which is performed on unfixed tissue because it is assumed that fixation inactivates enzymes. However, using fixed tissues has several advantages over using fresh tissues for such prevention of tissue decay, thereby preserving the proteins as well as the morphology and structure of the specimens. In this study, we investigated the effects of the four commonly used fixatives (ethanol, acetone, zinc-based fixative (ZBF), and paraformaldehyde (PFA)) on the gelatinolytic activity in mouse brain tissue. Multiple protocols were employed to extract proteins from the fixed brain tissue. Western blotting and in-gel zymography (IGZ) were used to detect the gelatinase proteins and gelatinolytic activity of the extractions, respectively. In situ zymography (ISZ) revealed that ethanol, acetone, ZBF, and short-time PFA fixation did not inhibit gelatinolytic activity. Neither 1% Triton + 1 M NaCl nor 10% DMSO + 1 M NaCl was effective in extracting proteins from ethanol-, acetone-, ZBF-, or PFA-fixed brain tissues. However, 8 M urea + 4% CHAPS effectively extracted gelatinase proteins from ethanol- and acetone-fixed tissues while retaining the gelatinolytic activity. 2% SDS effectively extracted gelatinase proteins from ethanol-, acetone-, and ZBF-fixed tissues while retaining the gelatinolytic activity. Although 2% SDS + heating extracted gelatinase proteins from ethanol-, acetone-, ZBF-, and even long-term PFA-fixed tissues, the gelatinolytic activity was not retained. Our findings suggest that both ISZ and IGZ can be performed on fixed brain tissue, which is anticipated to be an improvement over the conventionally used gelatin zymography methods. (J Histochem Cytochem 71: 481-493, 2023).

Chlorin E6-Curcumin-Mediated Photodynamic Therapy Promotes an Anti-Photoaging Effect in UVB-Irradiated Fibroblasts

Skin photoaging due to ultraviolet B (UVB) exposure generates reactive oxygen species (ROS) that increase matrix metalloproteinase (MMP). Chlorin e6-photodynamic therapy (Ce6-PDT), in addition to being the first-line treatment for malignancies, has been shown to lessen skin photoaging, while curcumin is well known for reducing the deleterious effects of ROS. In the current study, PDT with three novel Ce6-curcumin derivatives, a combination of Ce6 and curcumin with various linkers, including propane-1,3-diamine for Ce6-propane-curcumin; hexane-1,6-diamine for Ce6-hexane-curcumin; and 3,3'-((oxybis(ethane-2,1-diyl))bis(oxy))bis(propan-1-amine) for Ce6-dipolyethylene glycol (diPEG)-curcumin, were studied for regulation of UVB-induced photoaging on human skin fibroblast (Hs68) and mouse embryonic fibroblast (BALB/c 3T3) cells. We assessed the antiphotoaging effects of Ce6-curcumin derivatives on cell viability, antioxidant activity, the mechanism of matrix metalloproteinase-1 and 2 (MMP-2) expression, and collagen synthesis in UVB-irradiated in vitro models. All three Ce6-curcumin derivatives were found to be non-phototoxic in the neutral red uptake phototoxicity test. We found that Ce6-hexane-curcumin-PDT and Ce6-propane-curcumin-associated PDT exhibited less cytotoxicity in Hs68 and BALB/c 3T3 fibroblast cell lines compared to Ce6-diPEG-curcumin-PDT. Ce6-diPEG-curcumin and Ce6-propane-curcumin-associated PDT showed superior antioxidant activity in Hs68 cell lines. Further, in UVB-irradiated in vitro models, the Ce6-diPEG-curcumin-PDT greatly attenuated the expression levels of MMP-1 and MMP-2 by blocking mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and tumor necrosis factor-α (NF-κB) signaling. Moreover, Ce6-diPEG-curcumin effectively inhibited inflammatory molecules, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, while accelerating collagen synthesis. These results demonstrate that Ce6-diPEG-curcumin may be a potential therapy for treating skin photoaging.

A Dual-Enzyme Amplification Loop for the Sensitive Biosensing of Endopeptidases

A rapid and sensitive approach for the detection of endopeptidases via a new analyte-triggered mutual emancipation of linker-immobilized enzymes (AMELIE) mechanism has been developed and demonstrated using a matrix metallopeptidase, a collagenase, as the model endopeptidase analyte. AMELIE involves an autocatalytic loop created by a pair of selected enzymes immobilized on solid substrates via linkers with specific sites that can be proteolyzed by one another. These bound enzymes are spatially separated so that they cannot act upon their corresponding substrates until the introduction of the target endopeptidase analyte that can also cleave one of the linkers. This triggers the self-sustained loop of enzymatic activities to emancipate all the immobilized enzymes. In this proof of concept, signal transduction was achieved by a colorimetric horseradish peroxidase-tetramethylbenzidine (HRP-TMB-H₂O₂) reaction with HRP that are also being immobilized by one of the linkers. The pair of immobilized enzymes were collagenase and alginate lyase, and they were immobilized by an alginate linker and a short peptide chain containing the amino acid sequence of Leu-Gly-Pro-Ala for collagenase. A detection limit of 2.5 pg collagenase mL^-1 with a wide linear range up to 4 orders of magnitude was achieved. The AMELIE biosensor can detect extracellular collagenase in the supernatant of various bacteria cultures, with a sensitivity as low as 10³ cfu mL^-1 of E. coli. AMELIE can readily be adapted to provide the sensitive detection of other endopeptidases.

Targeting and arginine-driven synergizing photodynamic therapy with nutritional immunotherapy nanosystems for combating MRSA biofilms

The resistance and immune escape of methicillin-resistant Staphylococcus aureus (MRSA) biofilms cause recalcitrant infections. Here, we design a targeting and synergizing cascade PDT with nutritional immunotherapy nanosystems (Arg-PCN@Gel) containing PCN-224 as PDT platform for providing reactive oxygen species (ROS), incorporating arginine (Arg) as nitric oxide (NO) donor to cascade with ROS to produce more lethal ONOO- and promote immune response, and coating with gelatin as targeting agent and persistent Arg provider. The nanosystems adhered to the autolysin of MRSA and inhibited Arg metabolism by down-regulating icdA and icaA. It suppressed polysaccharide intercellular adhesin and extracellular DNA synthesis to prevent biofilm formation. The NO broke mature biofilms and helped ROS and ONOO- penetrate into biofilms to inactivate internal MRSA. Arg-PCN@Gel drove Arg to enhance immunity via inducible NO synthase/NO axis and arginase/polyamine axis and achieve efficient target treatment in MRSA biofilm infections. The targeting and cascading PDT synergized with nutritional immunotherapy provide an effective promising strategy for biofilm-associated infections.

Cell Cycle and Senescence Regulation by Podocyte Histone Deacetylase 1 and 2

SIGNIFICANCE STATEMENT

The loss of integrity of the glomerular filtration barrier results in proteinuria that is often attributed to podocyte loss. Yet how damaged podocytes are lost remains unknown. Germline loss of murine podocyte-associated Hdac1 and Hdac2 ( Hdac1/2 ) results in proteinuria and collapsing glomerulopathy due to sustained double-stranded DNA damage. Hdac1/2 deletion induces loss of podocyte quiescence, cell cycle entry, arrest in G1, and podocyte senescence, observed both in vivo and in vitro . Through the senescence secretory associated phenotype, podocytes secrete proteins that contribute to their detachment. These results solidify the role of HDACs in cell cycle regulation and senescence, providing important clues in our understanding of how podocytes are lost following injury.

BACKGROUND

Intact expression of podocyte histone deacetylases (HDAC) during development is essential for maintaining a normal glomerular filtration barrier because of its role in modulating DNA damage and preventing premature senescence.

METHODS

Germline podocyte-specific Hdac1 and 2 ( Hdac1 / 2 ) double-knockout mice were generated to examine the importance of these enzymes during development.

RESULTS

Podocyte-specific loss of Hdac1 / 2 in mice resulted in severe proteinuria, kidney failure, and collapsing glomerulopathy. Hdac1 / 2 -deprived podocytes exhibited classic characteristics of senescence, such as senescence-associated β-galactosidase activity and lipofuscin aggregates. In addition, DNA damage, likely caused by epigenetic alterations such as open chromatin conformation, not only resulted in podocyte cell-cycle entry as shown in vivo by Ki67 expression and by FUCCI-2aR mice, but also in p21-mediated cell-cycle arrest. Through the senescence secretory associated phenotype, the damaged podocytes secreted proinflammatory cytokines, growth factors, and matrix metalloproteinases, resulting in subsequent podocyte detachment and loss, evidenced by senescent podocytes in urine.

CONCLUSIONS

Hdac1 / 2 plays an essential role during development. Loss of these genes in double knockout mice leads to sustained DNA damage and podocyte senescence and loss.

Riemerella anatipestifer GldG is necessary for secretion of effectors by type IX secretion system

Riemerella anatipestifer secretes proteins through the type IX secretion system (T9SS). Recent studies have shown that the R. anatipestifer T9SS component proteins GldM and GldK also act as crucial virulence factors. In our previous study, the disruption of AS87_RS00460 gene, which encodes the predicted protein GldG, significantly reduced the bacterial virulence of R. anatipestifer wild-type strain Yb2, but the mechanism was unclear. In this study, we investigated the function of the GldG in bacterial virulence and protein secretion using the mutant strain Yb2ΔgldG and complementation strain cYb2ΔgldG. Our results demonstrate that the gldG gene encodes a gliding-motility-associated ABC transporter substrate-binding protein GldG, which was localized to the bacterial membrane in an immunoblotting analysis, and functions in the bacterium's adherence to and invasion of host cells and its survival in host blood. The resistance of mutant strain Yb2ΔgldG to complement-dependent killing was significantly reduced. Yb2ΔgldG displayed reduced gliding motility and deficient protein secretion. Label-free quantification (LFQ) with liquid chromatography-mass spectrometry (LC-MS) showed that 10 proteins with a conserved T9SS C-terminal domain were differentially secreted by Yb2ΔgldG and Yb2. The secretion levels of those 10 proteins were determined with immunoblotting, and the results were consistent with the LFQ LC-MS data. All of these effects were rescued by complementation with a plasmid encoding Yb2 gldG. Our results demonstrate that the R. anatipestifer gldG gene encodes the protein GldG, which is involved in bacterial virulence and protein secretion.

Effects of Physiological and Pathological Urea Concentrations on Human Microvascular Endothelial Cells

Urea is the uremic toxin accumulating with the highest concentration in the plasma of chronic kidney disease (CKD) patients, not being completely cleared by dialysis. Urea accumulation is reported to exert direct and indirect side effects on the gastrointestinal tract, kidneys, adipocytes, and cardiovascular system (CVS), although its pathogenicity is still questioned since studies evaluating its side effects lack homogeneity. Here, we investigated the effects of physiological and pathological urea concentrations on a human endothelial cell line from the microcirculation (Human Microvascular Endothelial Cells-1, HMEC-1). Urea (5 g/L) caused a reduction in the proliferation rate after 72 h of exposure and appeared to be a potential endothelial-to-mesenchymal transition (EndMT) stimulus. Moreover, urea induced actin filament rearrangement, a significant increase in matrix metalloproteinases 2 (MMP-2) expression in the medium, and a significant up- or down-regulation of other EndMT biomarkers (keratin, fibrillin-2, and collagen IV), as highlighted by differential proteomic analysis. Among proteins whose expression was found to be significantly dysregulated following exposure of HMEC-1 to urea, dimethylarginine dimethylaminohydrolase (DDAH) and vasorin turned out to be down-regulated. Both proteins have been directly linked to cardiovascular diseases (CVD) by in vitro and in vivo studies. Future experiments will be needed to deepen their role and investigate the signaling pathways in which they are involved to clarify the possible link between CKD and CVD.

Effects of edaravone on oxidative protein modification and activity of gelatinases after intracerebral hemorrhage in rats with nicotinamide-streptozotocin induced diabetes

Stroke, especially hemorrhagic form, is one of the most serious comorbidity disease of diabetes mellitus, often associated with high mortality, particularly in type 2 DM (T2DM). Therefore, it is relevant the search for drugs with a metabolically justified protective effect. Edaravone (Eda) is widely used for treating ischemic stroke but its biochemical effects in intracerebral hemorrhage (ICH) associated with T2DM is not still confirmed. The aim of the study was to assess the impact of Eda on the markers of oxidative modification of proteins (OMP), such as advanced oxidation protein products (AOPP), neutral and basic carbonyls (PC370 and PC430), advanced glycation end products (AGE) and ischemia modified albumin (IMA) as well as on the activity of matrix metalloproteinases MMP2/MMP9 (gelatinases) in rats with experimental T2DM after collagenase-induced ICH. Metformin was used as a comparative drug. The data obtained indicate that ICH in diabetic rats is accompanied by an increase in AOPP, PC370, AGE, and mature forms of both gelatinases. On the contrary, IMA and proMMP9 were below normal level after ICH. Both studied drugs decreased the OMP markers to the levels of intact rats or lower, and Eda show a more potent effect. Besides, Eda significantly decreased the activity of MMP9 and changed progelatinases activity. We conclude that Eda has a perspective to be useful in the treatment of comorbid brain hemorrhage in T2DM due to inhibiting of oxidative stress and modulation of gelatinases activity.

Decoding the molecular cascade of embryonic-uterine modulators in pregnancy loss of PCOS mother- an "in vivo" study

BACKGROUND

Polycystic ovary syndrome is associated with an increased rate of spontaneous abortion/early pregnancy loss and pups delivered to PCOS animals were abnormal. Currently, assisted reproductive technology has been used to help numerous infertile couples to have their babies. However, there is a low implantation rate after the transfer of embryos. Till now, it could not be concluded whether the reduced pregnancy rates observed were due to abnormal embryos or endometrial modification. Further, transgenic mouse models have been used to find out the molecular deficits behind early pregnancy complications. But, the deletion of crucial genes could lead to systemic deficiencies/embryonic lethality. Also, pregnancy is a complex process with overlapping expression patterns making it challenging to mimic their stage-specific role. Therefore, the motive of the current study was to investigate the probable molecular cascade to decipher the early pregnancy loss in the letrozole-induced PCOS mouse model.

METHODS

PCOS was induced in mice by oral administration of letrozole daily for 21 days. Following, the pregnancy was established and animals were sacrificed on the day 6th of pregnancy. Animals were assessed for early pregnancy loss, hormonal profile, mRNA expression of steroid receptors (Ar, Pr, Esr1/2), decidualization markers (Hox10/11a), adhesion markers (Itgavb3, Itga4b1), matrix metalloproteinases and their endogenous inhibitor (Mmp2/9, Timp1/2) and key mediators of LIF/STAT pathway (Lif, Lifr, gp130, stat3) were analyzed in the embryo implanted region of the uterus. Morphological changes in ovaries and implanted regions of the uterus were assessed.

RESULTS

Mice treated with letrozole demonstrated significant increases in testosterone levels along with a decline in progesterone levels as compared to control animals. PCOS animals also exhibited decreased fertility index and disrupted ovarian and embryo-containing uterus histopathology. Altered gene expression of the steroid receptors and reduced expression of Hox10a, integrins, Mmp9, Timp1/3, Gp130 & Stat3 was observed in the implanted region of the uterus of PCOS animals.

CONCLUSION

Our results reveal that majority of the molecular markers alteration in the establishment of early pregnancy could be due to the aberrant progesterone signaling in the embryonic-uterine tissue of PCOS animals, which further translates into poor fetal outcomes as observed in the current study and in several IVF patients.

Effect of Holoptelea integrifolia (Roxb.) Planch. n-Hexane Extract and Its Bioactive Compounds on Wound Healing and Anti-Inflammatory Activity

The stem bark of Holoptelea integrifolia (Roxb.) Planch. has been applied for the treatment of human cutaneous diseases as well as canine demodicosis in several countries. However, no detailed mechanistic studies have been reported to support their use. In this study, thin-layer chromatography and gas chromatography were used to screen phytochemicals from the fresh stem bark extract of H. integrifolia. We found the two major bioactive compounds, friedelin and lupeol, and their activity on wound healing was further investigated in keratinocytes. Both bioactive compounds significantly reduced wound area and increased keratinocyte migration by increasing matrix metalloproteinases-9 production. Subsequently, we found that the mRNA gene expressions of cadherin 1 and desmoglobin 1 significantly decreased, whereas the gene expression involved in keratinocyte proliferation and homeostasis (keratin-17) increased in compound-treated human immortalized keratinocytes cells. The expression of inflammatory genes (cyclooxygenase-2 and inducible nitric oxide synthase) and pro-inflammatory cytokine genes (tumor necrosis factor-alpha and interleukin-6) was reduced by treatment with n-hexane extract of H. integrifolia and its bioactive compounds. Our results revealed that H. integrifolia extract and its bioactive compounds, friedelin and lupeol, exhibit wound-healing activity with anti-inflammatory properties, mediated by regulating the gene expression involved in skin re-epithelialization.

Salvianolic Acid B Strikes Back: New Evidence in the Modulation of Expression and Activity of Matrix Metalloproteinase 9 in MDA-MB-231 Human Breast Cancer Cells

Salvianolic acid B (SalB) is a bioactive compound from Salviae miltiorrhizae, one of the most important traditional herbal medicines widely used in several countries for the treatment of cardiovascular diseases. The aim of this study was to evaluate the in vitro effect of SalB on the expression and the activity of matrix metalloproteinase 9 (MMP-9), a zinc-dependent proteolytic enzyme, in human MDA-MB-231 breast cancer cells. This cellular model is characterized by a marked invasive phenotype, supported by a high constitutive expression of MMPs, especially gelatinases. SalB was first of all evaluated by in silico approaches primarily aimed at predicting the main pharmacokinetic parameters. The most favorable interaction between the natural compound and MMP-9 was instead tested by molecular docking analysis that was subsequently verified by an enzymatic inhibition assay. MDA-MB-231 cells were treated with SalB 5 µM and 50 µM for 24 h and 48 h. The conditioned media obtained from treated cells were then analyzed by gelatin zymography and reverse zymography to, respectively, evaluate the MMP-9 activity and the presence of TIMP-1. The expression of the enzyme was then evaluated by Western blot on conditioned media and by analysis of transcripts through reverse transcriptase-polymerase chain reaction (RT-PCR). The in silico approach showed the ability of SalB to interact with the catalytic zinc ion of the enzyme, with a plausible competitive mode of action. The analysis of conditioned culture media showed a reduction in MMP-9 activity and the concomitant decrease in the enzyme concentration, partially confirmed by analysis of transcripts. SalB showed the ability to modulate the function of MMP-9 in MDA-MB-231 cells. To our knowledge, this is the first time in which the role of SalB on MMP-9 in a highly invasive cellular model is investigated. The obtained results impose further and more specific evaluations in order to obtain a better understanding of the biochemical mechanisms that regulate the interaction between this natural compound and the MMP-9.

The Therapeutic Potential of Mesenchymal Stem Cells in the Treatment of Diabetes Mellitus

Mesenchymal stem cells (MSCs) exist in many tissues and can differentiate into cells of multiple lineages, such as adipocytes, osteoblasts, or chondrocytes. MSC administration has demonstrated therapeutic potential in various degenerative and inflammatory diseases (e.g., graft-vs.-host disease, multiple sclerosis, Crohn's disease, organ fibrosis, and diabetes mellitus [DM]). The mechanisms involved in the therapeutic effects of MSCs are multifaceted. Generally, implanted MSCs can migrate to sites of injury, where they establish an anti-inflammatory and regenerative microenvironment in damaged tissues. In addition, MSCs can modulate innate and adaptive immune responses through immunosuppressive mechanisms that involve immune cells, inflammatory cytokines, chemokines, and immunomodulatory factors. DM has a high prevalence worldwide; it also contributes to a high rate of mortality worldwide. MSCs offer a promising therapeutic agent to prevent or repair damage from DM and diabetic complications through properties such as multilineage differentiation, homing, promotion of angiogenesis, and immunomodulation (e.g., prevention of oxidative stress, fibrosis, and cell death). In this study, we review current findings regarding the immunomodulatory and regenerative mechanisms of MSCs, as well as their therapeutic applications in DM and DM-related complications.

Photodynamic Therapy with Nebulized Nanocurcumin on A549 Cells, Model Vessels, Macrophages and Beyond

This study aimed to determine the damage mechanisms caused by naturally targeted nanoarchaeosomes made of diether lipids from Halorubrum tebenquichense loaded with curcumin (CUR, nATC), which mediated photodynamic therapy (PDT) on A549 cells and on THP-1-macrophages, two cell types found in airway cancers. The effect of nATC- PDT on vessels modeled with a chicken embryo chorioallantoic membrane (CAM), after dropping the formulations on its surface covered with mucins, was also determined. nATCs are known to efficiently trap CUR for at least six months, constituting easy-to-prepare, stable formulations suitable for nebulization. CUR instead, is easily released from carriers such as liposomes made of ordinary phospholipids and cholesterol after a few weeks. Irradiated at 9 J/cm², nATC (made of archaeolipids: Tween 80: CUR at 1:0.4:0.04 w:w, size 180 ± 40 nm, ζ potential -24 mV, 150 μg CUR/15 mg lipids/mL) was phototoxic (3.7 ± 0.5 μM IC₅₀), on A549 cells after 24 h. The irradiation reduced mitochondrial membrane potential (ΔΨm), ATP levels and lysosomal functionalism, and caused early apoptotic death and late necrosis of A549 cells upon 24 h. nATC induced higher extra and intracellular reactive oxygen species (ROS) than free CUR. nATC-PDT impaired the migration of A549 cells in a wound healing assay, reduced the expression of CD204 in THP-1 macrophages, and induced the highest levels of IL-6 and IL-8, suggesting a switch of macrophage phenotype from pro-tumoral M2 to antitumoral M1. Moreover, nATC reduced the matrix metalloproteinases (MMP), -2 and -9 secretion, by A549 cells with independence of irradiation. Finally, remarkably, upon irradiation at 9 J/cm² on the superficial vasculature of a CAM covered with mucins, nATC caused the vessels to collapse after 8 h, with no harm on non-irradiated zones. Overall, these results suggest that nebulized nATC blue light-mediated PDT may be selectively deleterious on superficial tumors submerged under a thick mucin layer.

Down regulation of fatty acid synthase via inhibition of PI3K/AKT/mTOR in ovarian cancer cell line by novel organoselenium pseudopeptide

Ovarian cancer (OC) is the 7th most common cancer in women world-wide and the 3rd most common female cancer. For the treatment of OC, there is no successful therapeutic. The medications that are currently available have significant side effects and a low therapeutic index. This work aimed to evaluate the anticancer activity of organoselenium pseudopeptide compound against OC cell lines. After treatment with 50 ​μM of compound 4 (CPD 4), the viability was determined. The anticancer activity was further investigated by different methods including cell cycle and apoptosis analysis, colony formation assay, zymography, comet assay and Western blot. In comparison to a positive control, compound 4 showed cytotoxicity toward A2780CP cells rather than A2780 and SKOV-3 ​cells. Compound 4 was more selective to OC cells rather than HSF cells. Moreover, Compound 4 was able to inhibit cell migration and proliferation. The anticancer effect of compound 4 was found to be partially via cell cycle arrest, overexpression of p27 ​cell cycle inhibitor and induction of apoptosis through DNA fragmentation and activated production of ROS. Compound 4 had a differential effect on the modulation of PI3K/AKT/mTOR signaling pathway in the OC treated cell lines, also inhibited lipogenesis process via downregulation of FASN expression. Conclusion: This work highlights the unique role of Compound 4 against OC via modulation of oxidative stress, inhibition of survival PI3K/AKT/mTOR pathway. Compound 4 was found to be a promising alternative therapy for the treatment of OC in this investigation.

Histone Deacetylase 3 Inhibition Decreases Cerebral Edema and Protects the Blood–Brain Barrier After Stroke

We have previously shown that selective inhibition of histone deacetylase 3 (HDAC3) decreases infarct volume and improves long-term functional outcomes after stroke. In this study, we examined the effects of HDAC3 inhibition on cerebral edema and blood–brain barrier (BBB) leakage and explored its underlying mechanisms. Adult male Wistar rats were subjected to 2-h middle cerebral artery occlusion (MCAO) and randomly treated i.p. with either vehicle or a selective HDAC3 inhibitor (RGFP966) at 2 and 24 h after stroke. Modified neurological severity scores (mNSS) were calculated at 2 h, 1 day, and 3 days. H&E, Evans blue dye (EBD) assay, and fluorescein isothiocyanate (FITC)-dextran were employed to assess cerebral edema and BBB leakage. Western blot for matrix metalloproteinase-9 (MMP9), MMP-9 zymography, and immunostaining for HDAC3, GFAP, Iba-1, albumin, aquaporin-4, claudin-5, ZO-1, and NF-kB were performed. Early RGFP966 administration decreased cerebral edema (p = 0.002) and BBB leakage, as measured by EBD assay, FITC-dextran, and albumin extravasation (p < 0.01). RGFP966 significantly increased tight junction proteins (claudin-5 and ZO-1) in the peri-infarct area. RGFP966 also significantly decreased HDAC3 in GFAP + astrocytes, which correlated with better mNSS (r = 0.67, p = 0.03) and decreased cerebral edema (r = 0.64, p = 0.04). RGFP966 decreased aquaporin-4 in GFAP + astrocytes (p = 0.002), as well as, the inflammatory markers Iba-1, NF-kB, and MMP9 in the ischemic brain (p < 0.05). Early HDAC3 inhibition decreases cerebral edema and BBB leakage. BBB protection by RGFP966 is mediated in part by the upregulation of tight junction proteins, downregulation of aquaporin-4 and HDAC3 in astrocytes, and decreased neuroinflammation.

Capric Acid Behaves Agonistic Effect on Calcitriol to Control Inflammatory Mediators in Colon Cancer Cells

Inflammation prompts cancer development and promotes all stages of tumorigenesis. Calcitriol is a nutraceutical essential regulator for host health benefits. However, the influence of calcitriol on inflammatory mediators involved in cancer cells is not clear. This study aimed to assess the sensitivity of calcitriol alone and combined with capric acid, and identify the possible influence of calcitriol on inflammatory mediators. The colorectal cancer cell line (HCT116) was induced by LPS/TNF-α and the inflammation and metastatic mediators (IL-1β, IL-6, IL-17) were quantified in calcitriol and capric acid supplemented colon cancer cells. The mRNA and protein expression of MMP-2, NF-κB and COX-2 were quantified. The significant reduction in MMP-2 expression was confirmed at combination treatment by zymogram analysis. Our findings demonstrated the anti-inflammatory and anti-metastatic potentials of capric acid and calcitriol in individual exposure in a combination of human colon cancer cell lines (HCT116). These abilities may be due to the inhibition of COX-2 mediators and NF-κB transcription factor and reciprocally regulated MMP-2 and MMP-9 signaling pathways. These findings elucidate the activation of COX-2 and NF-κB via disruption of the cellular outer matrix could be considered a novel molecular target suitable for colorectal cancer therapy. This study confirmed that capric acid activates calcitriol sensitization in colon cancer cells and could be used as a successful supplement for intestinal diseases and colon aberrations.

The role of cathepsin L on structural changes of collagen fibers involved in textural deterioration of chilled grass carp (Ctenopharyngodon idella) fillets

BACKGROUND

Textural deterioration is a serious problem in chilled fish flesh. Cysteine proteinases are proposed to participate in disintegration of collagen fibers during this process, while its mechanism remains elusive. In the present study, a cysteine proteinase was purified from grass carp muscle and identified by mass spectrometry, and its effect on structural changes of collagen fibers was investigated.

RESULTS

During storage at 4 °C, cysteine proteinase activity in fillets increased to 1.53-fold at day 5 and maintained a high level later, and this variable was related to a decline in shear force and an increase in drip loss. A 29 kDa cysteine proteinase was purified through ammonium sulfate precipitation and column chromatography, and identified as cathepsin L. Cathepsin L caused collagen fibers to partly disintegrate into fibril bundles and individual fibrils at 48 h, while the triple helical structure of collagen molecules remained stable. Release of soluble proteins and glycosaminoglycans from cathepsin L-treated collagen fibers was time dependent, coinciding with a release of 4.12 ± 0.13% and 8.57 ± 0.03% at 48 h respectively. However, 0.85 ± 0.02% of hydroxyproline was freed from cathepsin L-treated collagen fibers at 48 h. Furthermore, scanning electron microscopy revealed that the inhibitory effect of cathepsin L could retard the destruction of intramuscular connective tissues (IMCTs).

CONCLUSION

These results indicated that cathepsin L might be involved in collagen fiber breakdown by degrading collagen-associated proteoglycans during textural deterioration of grass carp. © 2022 Society of Chemical Industry.

Cancer cells produce liver metastasis via gap formation in sinusoidal endothelial cells through proinflammatory paracrine mechanisms

Intracellular gap (iGap) formation in liver sinusoidal endothelial cells (LSECs) is caused by the destruction of fenestrae and appears under pathological conditions; nevertheless, their role in metastasis of cancer cells to the liver remained unexplored. We elucidated that hepatotoxin-damaged and fibrotic livers gave rise to LSECs-iGap formation, which was positively correlated with increased numbers of metastatic liver foci after intrasplenic injection of Hepa1-6 cells. Hepa1-6 cells induced interleukin-23-dependent tumor necrosis factor-α (TNF-α) secretion by LSECs and triggered LSECs-iGap formation, toward which their processes protruded to transmigrate into the liver parenchyma. TNF-α triggered depolymerization of F-actin and induced matrix metalloproteinase 9 (MMP9), intracellular adhesion molecule 1, and CXCL expression in LSECs. Blocking MMP9 activity by doxycycline or an MMP2/9 inhibitor eliminated LSECs-iGap formation and attenuated liver metastasis of Hepa1-6 cells. Overall, this study revealed that cancer cells induced LSEC-iGap formation via proinflammatory paracrine mechanisms and proposed MMP9 as a favorable target for blocking cancer cell metastasis to the liver.

Untargeted Metabolomics Analysis of Crocus cancellatus subsp. damascenus (Herb.) B. Mathew Stigmas and Their Anticarcinogenic Effect on Breast Cancer Cells

Safranal, crocin, crocetin, and picrocrocin are major known compounds in the stigma extract of Crocus sativus with various medicinal properties. Crocus cancellatus is another Crocus species that grows extensively in Iran's various regions, such as the Kurdistan province. The predominant metabolites and biological properties of C. cancellatus have not yet been investigated. The ingredients of the stigma ethanol extract of C. cancellatus were investigated using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with tandem mass spectrometry (LC-MS). The ROIMCR approach was performed to analyze the LC-MS full scan data sets. This method searches the MS regions of interest (ROI) data in the m/z domain and analyses the results using the multivariate curve-resolution alternating least squares (MCR-ALS) chemometrics technique for simultaneous resolution of two extracts. Also, the antiproliferative properties of C. cancellatus against MDA-MB-231 and MCF-7 cancer cells were examined by MTT, dual acridine orange/ethidium bromide test, Annexin V-FITC/PI, and zymography. The GC-MS and LC-MS untargeted metabolomics data analysis of the extract indicated the presence of cytotoxic agents including safranal, crocin, picrocrocin, and crocetin in the stigma ethanol extract of C. cancellatus. Biological tests showed that the viability of MDA-MB-231 and MCF-7 cancer cells is decreased following C. cancellatus treatment in a time- and dose-dependent way in both monolayer and 3D cell cultures. The MCF-7 cell spheroids had greater resistance to the cytotoxic activity of the extract in 3D cell culture than the MDA-MB-231 cell spheroids. The morphological changes of the cells treated with C. cancellatus stigmas extract were indicative of apoptosis. Zymography analysis revealed a similar trend of matrix metallopeptidase-2 (MMP-2) and matrix metallopeptidase-9 (MMP-9) activity in the treated cells with C. cancellatus extract in comparison with doxorubicin treatment as a positive control. The findings of this research indicate that the ethanolic extract of C. cancellatus stigmas was a good source of bioactive metabolites with anticancer activity.

Antioxidant Polyphenols of Antirhea borbonica Medicinal Plant and Caffeic Acid Reduce Cerebrovascular, Inflammatory and Metabolic Disorders Aggravated by High-Fat Diet-Induced Obesity in a Mouse Model of Stroke

Metabolic disorders related to obesity and type 2 diabetes are associated with aggravated cerebrovascular damages during stroke. In particular, hyperglycemia alters redox and inflammatory status, leading to cerebral endothelial cell dysfunction, blood–brain barrier (BBB) disruption and brain homeostasis loss. Polyphenols constitute the most abundant dietary antioxidants and exert anti-inflammatory effects that may improve cerebrovascular complications in stroke. This study evaluated the effects of the characterized polyphenol-rich extract of Antirhea borbonica medicinal plant and its major constituent caffeic acid on a high-fat diet (HFD)-induced obesity mouse model during ischemic stroke, and murine bEnd3 cerebral endothelial cells in high glucose condition. In vivo, polyphenols administered by oral gavage for 12 weeks attenuated insulin resistance, hyperglycemia, hyperinsulinemia and dyslipidemia caused by HFD-induced obesity. Polyphenols limited brain infarct, hemorrhagic transformation and BBB disruption aggravated by obesity during stroke. Polyphenols exhibited anti-inflammatory and antioxidant properties by reducing IL-1β, IL-6, MCP-1, TNF-α and Nrf2 overproduction as well as total SOD activity elevation at the cerebral or peripheral levels in obese mice. In vitro, polyphenols decreased MMP-2 activity that correlated with MCP-1 secretion and ROS intracellular levels in hyperglycemic condition. Protective effects of polyphenols were linked to their bioavailability with evidence for circulating metabolites including caffeic acid, quercetin and hippuric acid. Altogether, these findings show that antioxidant polyphenols reduced cerebrovascular, inflammatory and metabolic disorders aggravated by obesity in a mouse model of stroke. It will be relevant to assess polyphenol-based strategies to improve the clinical consequences of stroke in the context of obesity and diabetes.

AGEs-induced MMP-9 activation mediated by Notch1 signaling is involved in impaired wound healing in diabetic rats

AIMS

To elucidate the relationship between advanced glycation end products (AGEs), Notch1 signaling, nuclear factor-kappa B (NF-κB), and matrix metalloproteinase-9 (MMP-9) in diabetic wound healing in vitro and in vivo.

METHODS

We incubated primary keratinocytes with AGEs alone or AGEs along with γ-secretase inhibitor DAPT, and established diabetic rat wound model by intraperitoneal streptozotocin treatment. The Notch1 signaling components and MMP-9 expression were detected by qPCR, western blotting and gelatin zymography.

RESULTS

The exposure of primary keratinocytes to AGEs led to a significant increase in Notch intracellular domain (NICD), Delta-like 4 (Dll4), and Hes1; however, Notch1 expression was inhibited by the RAGE siRNA. Furthermore, MMP-9 activation was up-regulated, secondary to AGEs treatment. In contrast, increased MMP-9 expression by AGEs-stimulation was eliminated after treatment with DAPT. NF-κB activation participated in the Notch1-modulated MMP-9 expression. Notably, in the diabetic animal model, inhibition of the Notch signaling pathway with DAPT attenuated NICD and MMP-9 overexpression, improved collagen accumulation, and ultimately accelerated diabetic wound healing.

CONCLUSIONS

These findings identified that activation of the Notch1/NF-κB/MMP-9 pathway, in part, mediates the repressive effects of AGEs on diabetic wound healing and that targeting this pathway may be a potential strategy to improve impaired diabetic wound healing.

Assessment of gelatinolytic proteinases in chilled grass carp (Ctenopharyngodon idellus) fillets: characterization and contribution to texture softening

BACKGROUND

Texture softening is always a problem during chilling of grass carp fillets. To solve this problem and provide for better quality of flesh, understanding the mechanism of softening is necessary. Gelatinolytic proteinases are suspected to play an essential role in the disintegration of collagen in softening of fish flesh. In the present study, the types and contribution of gelatinolytic proteinases in chilled fillets were investigated.

RESULTS

Four active bands (G1, 250 kDa; G2, 68 kDa; G3, 66 kDa; G4, 29 kDa) of gelatinolytic proteinases were identified in grass carp fillets by gelatin zymography. The effect of inhibitors and metal ions revealed that G1 was possibly a serine proteinase, G2 and G3 were calcium-dependent metalloproteinases and G4 was a cysteine proteinase. The effect of the inhibitors phenylmethanesulfonyl fluoride (PMSF), l-3-carboxy-trans-2,3-epoxy-propionyl-l-leucine-4-guanidinobutylamide (E-64) and 1,10-phenanthroline (Phen) on chilled fillets revealed that gelatinolytic proteinase activities were significantly suppressed. Collagen solubility indicated that metalloproteinase and serine proteinase played critical roles in collagen breakdown during the first 3 days, and cysteine proteinase revealed its effect after 3 days. Meanwhile, during chilled storage for 11 days, the final values of shear force increased 19.68% and 24.33% in PMSF and E-64 treatments when compared to control fillets respectively, whereas the increase after Phen treatment was 49.89%.

CONCLUSION

Our study concluded that the disintegration of collagen in post-mortem softening of grass carp fillets was mainly mediated by metalloproteinase and to a lesser extent by serine proteinase and cysteine proteinase. © 2021 Society of Chemical Industry.

Ropivacaine Inhibits Lung Cancer Cell Malignancy Through Downregulation of Cellular Signaling Including HIF-1α In Vitro

Background: Ropivacaine is widely used to induce regional anesthesia during lung cancer surgery. Previous studies reported that amide-linked local anesthetics, e.g., ropivacaine, affected the biological behavior of lung adenocarcinoma cells, but the conclusion is controversial and warrants further study. This study set out to investigate the biological effects of ropivacaine on cultured lung cancer cells and underlying mechanisms.

Methods: Lung cancer cell lines (A549 and H1299) were cultured and then treated with or without ropivacaine (0.5, 1, and 2 mM) for 48 or 72 h. Their proliferation, migration, and invasion together with cell death and molecules including hypoxia inducible factor (HIF)-1α, VEGF, matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 expression associated with these changes were determined.

Results: Ropivacaine significantly inhibited proliferation and migration, invasion, and cell death in a concentration-dependent manner in both cell lines. Ropivacaine also promoted cell death and induced a concentration- and time-dependent cell arrest towards the G0/G1 phase. Expression of VEGF, MMP-1, MMP-2, MMP-9, and HIF-1α in both cell lines was also inhibited by ropivacaine in a concentration-related manner.

Conclusion: Our data indicated that ropivacaine inhibited lung cancer cell malignancy, which may be associated with downregulation of cell-survival-associated cellular molecules. The translational value of the current work is subjected to further study.

Survey of In Vitro Model Systems for Investigation of Key Cellular Processes Associated with Atherosclerosis

Atherosclerosis progression is associated with a complex array of cellular processes in the arterial wall, including endothelial cell activation/dysfunction, chemokine-driven recruitment of immune cells, differentiation of monocytes to macrophages and their subsequent transformation into lipid laden foam cells, activation of inflammasome and pro-inflammatory signaling, and migration of smooth muscle cells from the media to the intima. The use of in vitro model systems has considerably advanced our understanding of these atherosclerosis-associated processes and they are also often used in drug discovery and other screening platforms. This chapter will describe key in vitro model systems employed frequently in atherosclerosis research.

Surface coating materials regulates the attachment and differentiation of mouse embryonic stem cell derived embryoid bodies into mesoderm at culture conditions

Abstract

Pluripotent stem cells as a promising cell source with unlimited proliferation and differentiation capacity hold great promise for cell-based therapies in regenerative medicine. Establishment of appropriate culture conditions might enable the control of cellular fate decision in cell culture. Transfer of three-dimensional (3D) embryoid bodies to two-dimensional (2D) monolayer culture systems for initiation of cell differentiation and specialization requires an adaptation of cells which can be managed by extracellular matrix (ECM) materials. Here we compare the characteristics of four different cell culture coating materials and their effect on attachment and differentiation of cells spreading from mouse embryonic stem cell (mESC) derived embryoid bodies (EBs) in mesoderm inducing culture conditions. Atomic force microscope (AFM) and scanning electron microscope (SEM) analysis along with Water Contact Angle technique were used to analyze physical properties of ECM materials and to evaluate cellular behavior on surfaces. Cell migration and differentiation were performed initially by using mesoderm inducing culture conditions and then three germ layer specification conditions. We investigated properties of coating materials such as roughness and wettability control cell attachment, migration and differentiation of mESCs. Matrigel-Gelatin combination is suitable for cell attachment and migration of cells spreading from 3D EBs followed by transfer onto coated surfaces. Matrigel-Gelatin coating enhanced differentiation of cells into mesoderm like cells via EMT process. Our data demonstrated that the Matrigel-Gelatin combination as a cell culture coating matrix might serve as a suitable platform to transfer EBs for differentiation and might influence pluripotent stem cell fate decision into mesoderm and further mesoderm derivative cell populations.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-022-00529-z.

Human placental mesenchymal stromal cells are ciliated and their ciliation is compromised in preeclampsia

BACKGROUND

The development of the human placenta is tightly coordinated by a multitude of placental cell types, including human chorionic villi mesenchymal stromal cells (hCV-MSCs). Defective hCV-MSCs have been reported in preeclampsia (PE), a gestational hypertensive disease characterized by maternal endothelial dysfunction and systemic inflammation. Our goal was to determine whether hCV-MSCs are ciliated and whether altered ciliation is responsible for defective hCV-MSCs in preeclamptic placentas, as the primary cilium is a hub for signal transduction, which is important for various cellular activities.

METHODS

In the present work, we collected placental tissues from different gestational stages and we isolated hCV-MSCs from 1st trimester, term control, and preeclamptic placentas. We studied their ciliation, functionality, and impact on trophoblastic cell lines and organoids formed from human trophoblast stem cells (hTSCs) and from the trophoblastic cell line JEG-3 with various cellular and molecular methods, including immunofluorescence staining, gene analysis, spheroid/organoid formation, motility, and cellular network formation assay. The statistical evaluation was performed using a Student's t test (two-tailed and paired or homoscedastic) or an unpaired Mann-Whitney U test (two-tailed).

RESULTS

The results show that primary cilia appeared abundantly in normal hCV-MSCs, especially in the early development of the placenta. Compared to control hCV-MSCs, the primary cilia were truncated, and there were fewer ciliated hCV-MSCs derived from preeclamptic placentas with impaired hedgehog signaling. Primary cilia are necessary for hCV-MSCs' proper signal transduction, motility, homing, and differentiation, which are impaired in preeclamptic hCV-MSCs. Moreover, hCV-MSCs derived from preeclamptic placentas are significantly less capable of promoting growth and differentiation of placental organoids, as well as cellular network formation.

CONCLUSIONS

These data suggest that the primary cilium is required for the functionality of hCV-MSCs and primary cilia are impaired in hCV-MSCs from preeclamptic placentas.

The role of Leishmania GP63 in the modulation of innate inflammatory response to Leishmania major infection

Leishmaniasis is a disease caused by the protozoan parasite Leishmania and is known to affect millions of individuals worldwide. In recent years, we have established the critical role played by Leishmania zinc-metalloprotease GP63 in the modulation of host macrophage signalling and functions, favouring its survival and progression within its host. Leishmania major lacking GP63 was reported to cause limited infection in mice, however, it is still unclear how GP63 may influence the innate inflammatory response and parasite survival in an in vivo context. Therefore, we were interested in analyzing the early innate inflammatory events upon Leishmania inoculation within mice and establish whether Leishmania GP63 influences this initial inflammatory response. Experimentally, L. major WT (L. majorWT), L. major GP63 knockout (L. majorKO), or L. major GP63 rescue (L. majorR) were intraperitoneally inoculated in mice and the inflammatory cells recruited were characterized microscopically and by flow cytometry (number and cell type), and their infection determined. Pro-inflammatory markers such as cytokines, chemokines, and extracellular vesicles (EVs, e.g. exosomes) were monitored and proteomic analysis was performed on exosome contents. Data obtained from this study suggest that Leishmania GP63 does not significantly influence the pathogen-induced inflammatory cell recruitment, but rather their activation status and effector function. Concordantly, internalization of promastigotes during early infection could be influenced by GP63 as fewer L. majorKO amastigotes were found within host cells and appear to maintain in host cells over time. Collectively this study provides a clear analysis of innate inflammatory events occurring during L. major infection and further establish the prominent role of the virulence factor GP63 to provide favourable conditions for host cell infection.

MAP Kinase Phosphatase-5 Deficiency Protects Against Pressure Overload-Induced Cardiac Fibrosis

Cardiac fibrosis, a pathological condition due to excessive extracellular matrix (ECM) deposition in the myocardium, is associated with nearly all forms of heart disease. The processes and mechanisms that regulate cardiac fibrosis are not fully understood. In response to cardiac injury, macrophages undergo marked phenotypic and functional changes and act as crucial regulators of myocardial fibrotic remodeling. Here we show that the mitogen-activated protein kinase (MAPK) phosphatase-5 (MKP-5) in macrophages is involved in pressure overload-induced cardiac fibrosis. Cardiac pressure overload resulting from transverse aortic constriction (TAC) leads to the upregulation of Mkp-5 gene expression in the heart. In mice lacking MKP-5, p38 MAPK and JNK were hyperactivated in the heart, and TAC-induced cardiac hypertrophy and myocardial fibrosis were attenuated. MKP-5 deficiency upregulated the expression of the ECM-degrading matrix metalloproteinase-9 (Mmp-9) in the Ly6Clow (M2-type) cardiac macrophage subset. Consistent with in vivo findings, MKP-5 deficiency promoted MMP-9 expression and activity of pro-fibrotic macrophages in response to IL-4 stimulation. Furthermore, using pharmacological inhibitors against p38 MAPK, JNK, and ERK, we demonstrated that MKP-5 suppresses MMP-9 expression through a combined effect of p38 MAPK/JNK/ERK, which subsequently contributes to the inhibition of ECM-degrading activity. Taken together, our study indicates that pressure overload induces MKP-5 expression and facilitates cardiac hypertrophy and fibrosis. MKP-5 deficiency attenuates cardiac fibrosis through MAPK-mediated regulation of MMP-9 expression in Ly6Clow cardiac macrophages.