The significance of matrix metalloproteinases in parasitic infections involving the central nervous system

Pumpkin seed oil: unveiling its potential in controlling inflammation and pathogenicity during experimental trichinellosis

BACKGROUND

This study aimed to investigate the antiparasitic and anti-inflammatory potential of pumpkin seed oil in mice infected with Trichinella spiralis by demonstrating its impact on MMP-9 expression and pathogenesis during the intestinal and muscular phases.

RESULTS

In this study, 100 mice were divided into five groups: an infected group, a pumpkin seed oil-treated group (1.5 mg/kg BW, administered three times per week), an albendazole-treated group, a native control group, and a pumpkin oil control group. Gas chromatography-mass spectrometry analysis of the pumpkin seed oil revealed a broad spectrum of biologically active compounds. The pumpkin seed oil treatment led to a significant reduction in the parasite burden, with a 75% decrease in adult worms and a 66% decrease in encysted larvae. Additionally, the infected animals treated with pumpkin oil exhibited a marked reduction in intestinal inflammation, characterized by a progressive increase in goblet cells. The number of encysted larvae in the diaphragm and muscle tissues was also significantly decreased. Furthermore, pumpkin seed oil treatment significantly reduced MMP-9 levels in both intestinal and muscular tissues, highlighting its potential to attenuate inflammation.

CONCLUSION

These findings underscore the effectiveness of pumpkin seed oil as anti-inflammatory and antiparasitic agent.

MMP-9-dependent proteolysis of the histone H3 N-terminal tail: a critical epigenetic step in driving oncogenic transcription and colon tumorigenesis

Matrix metalloproteinase 9 (MMP-9) is a member of the MMP family and has been recently identified as a nuclear protease capable of clipping histone H3 N-terminal tails (H3NT). This MMP-9-dependent H3NT proteolysis is critical for establishing an active state of gene transcription during osteoclast differentiation and melanoma development. However, whether H3NT cleavage by MMP-9 plays a similar role in other cellular events has not been explored. Here, we dissect the functional contribution of MMP-9-dependent H3NT clipping to colonic tumorigenesis by using a combination of genome-wide transcriptome data, ChIP/ChIPac-qPCR, CRISPR/dCas9 gene-targeting system, and in vivo xenograft models. We show that MMP-9 is overexpressed in colon cancer cells and catalyzes H3NT proteolysis to drive transcriptional activation of growth stimulatory genes. Our studies using knockdown and inhibition approaches clearly indicate that MMP-9 mediates transcriptional activation and promotes colonic tumorigenesis in a manner dependent on its protease activity toward H3NT. Remarkably, artificial H3NT proteolysis at target gene promoters with dCAS9-MMP-9 is sufficient for establishing their transcriptional competence in colon cancer cells, underscoring the importance of MMP-9-dependent H3NT proteolysis per se in the transactivation process. Our data establish new functions and mechanisms for MMP-9 in driving the oncogenic transcription program in colon cancer through H3NT proteolysis, and demonstrate how this epigenetic pathway can be exploited as a potential therapeutic target for cancer treatment.

Machine learning and biological evaluation-based identification of a potential MMP-9 inhibitor, effective against ovarian cancer cells SKOV3

MMP-9, also known as gelatinase B, is a zinc-metalloproteinase family protein that plays a key role in the degradation of the extracellular matrix (ECM). The normal function of MMP-9 includes the breakdown of ECM, a process that aids in normal physiological processes such as embryonic development, angiogenesis, etc. Interruptions in these processes due to the over-expression or downregulation of MMP-9 are reported to cause some pathological conditions like neurodegenerative diseases and cancer. In the present study, an integrated approach for ML-based virtual screening of the Maybridge library was carried out and their biological activity was tested in an attempt to identify novel small molecule scaffolds that can inhibit the activity of MMP-9. The top hits were identified and selected for target-based activity against MMP-9 protein using the kit (Biovision K844). Further, MTT assay was performed in various cancer cell lines such as breast (MCF-7, MDA-MB-231), colorectal (HCT119, DL-D-1), cervical (HeLa), lung (A549) and ovarian cancer (SKOV3). Interestingly, one compound viz., RJF02215 exhibited anti-cancer activity selectively in SKOV3. Wound healing assay and colony formation assay performed on SKOV3 cell line in the presence of RJF02215 confirmed that the compound had a significant inhibitory effect on this cell line. Thus, we have identified a novel molecule that can inhibit MMP-9 activity in vitro and inhibits the proliferation of SKOV3 cells. Novel molecules based on the structure of RJF02215 may become a good value addition for the treatment of ovarian cancer by exhibiting selective MMP-9 activity.Communicated by Ramaswamy H. Sarma.

Nanocurcumin: A Promising Therapeutic Candidate for Experimental Trichinellosis

In our pursuit of an alternative drug against Trichinella spiralis, we assessed the effectiveness of nanocurcumin in alleviating pathogenesis, parasitological factors, MMP-9 levels, and its expression in the enteral and parenteral phases of infection. The nanocurcumin particles, with a spherical shape and a size of 100 ± 20 nm, were used in the study. Eighty mice were divided into four groups: the control group, the untreated infected group, the nanocurcumin-treated group, and the albendazole-treated group. The nanocurcumin-treated group exhibited a statistically significant increase in the percentage of lymphocytes, along with a reduction in neutrophils, monocytes, and eosinophils compared to the untreated, infected group. Both the nanocurcumin (87.2 and 97.3%) and the albendazole-treated groups (99.8 and 98.2%) showed a significant reduction in the mean number of intestinal worms and encysted larvae, respectively. The treated groups exhibited normal intestinal villi, suppression of the inflammatory process, and fewer instances of degenerated larvae in the diaphragm and muscle compared to the untreated, infected group. Immunohistochemistry and ELISA analyses revealed a significant downregulation of MMP-9 levels in the intestines and muscles of the treated groups. Our data demonstrate that nanocurcumin contains highly versatile molecules capable of modulating biological activity against inflammation and its pathway markers.

Elevated matrix Metalloproteinase-9 associated with reduced cerebellar perineuronal nets in female mice with toxoplasmosis

Brain infection by the parasite Toxoplasma gondii is thought to impair learning and memory, although the underlying mechanisms remain largely unknown. Recent studies suggest that perineuronal nets (PNNs) and their key regulator, matrix metalloproteinase-9 (MMP-9), have essential roles in synaptic plasticity associated with learning and memory. We investigated their roles in a chronic toxoplasmosis model using female mice. In mice with a high parasite burden of chronic infection, we found that MMP-9 expression was increased in the peripheral circulation and the brain. A correlation was found between the serum levels of MMP-9 and antibodies to the Toxoplasma matrix antigen MAG1, a surrogate marker for Toxoplasma tissue cysts in the brain. MMP-9 elevation was accompanied by increased expression of its endogenous regulators, TIMP-1 and NGAL. An increase in the levels of GSK-3α/β was observed, alongside a decrease in inhibitory GSK-3α/β (Ser-21/Ser-9) phosphorylation. MMP-9 expression was notably associated with the loss of PNNs but increased expression of the synaptic vesicle protein synaptophysin. There was a trend toward a negative correlation between MMP-9 and aggrecan expression, a critical PNN component. Together, these results suggest that chronic Toxoplasma infection can cause an increase in MMP-9 expression, resulting in the degradation of PNNs, which provides a possible mechanism for Toxoplasma-associated deficits in learning and memory.

Potential genetic polymorphism of matrix metalloproteinase (MMP)-9 in Iranian migraine patients with Toxoplasma gondii infection

Toxoplasma gondii is an intracellular protozoan parasite that causes neuroinflammation in the brain and a constant need for peripheral leukocyte migration. Matrix metalloproteinase 9 (MMP-9) can play a major role in this neuroinflammation and be implicated in some neurological disorders, such as migraines. Therefore, the genetic polymorphism evaluation of MMP-9 in migraine patients with T. gondii infection was performed. One hundred fourteen migraine patients and 114 healthy controls were evaluated for the presence of anti-Toxoplasma IgG antibodies. Seventy-two migraine patients and 40 healthy controls were randomly selected for assessment of the MMP 9-1562C/T genetic polymorphism. In the preliminary examination, 61 (53.5%) migraine patients and 43 (37.3%) healthy controls were positive for IgG antibodies, with a significant association between T. gondii seropositivity and migraine (OR = 1.90; 95% CI = 1.21-3.223; P = 0.012). Genetic distribution for the polymorphism was not in Hardy-Weinberg equilibrium in cases but showed no significant variation in control groups (P = 0.03 and P = 0.180, respectively). A significant preponderance of the CT + TT genotype was found in migraine subjects compared to controls (P = 0.042) (OR, 1.77, CI, 1.013-2.229). The homozygote muted allele TT had a higher rate in migraine patients (6.9%). There were significant differences in CT + TT genotype between T. gondii positive and negative migraine patients (P = 0.024), but T allele frequencies had no significant variation (OR 1.7 CI, 1.084-2.44 and 0.42 CI, 0.044-3.97, respectively). In conclusion, the results may provide the first evidence for the involvement of the MMP-9 gene polymorphism in the mechanism of migraine pathology following Toxoplasma infection.

Understanding the mechanisms underlying the disruption of the blood-brain barrier in parasitic infections

Parasites have a significant impact on the neurological, cognitive, and mental well-being of humans, with a global population of over 1 billion individuals affected. The pathogenesis of central nervous system (CNS) injury in parasitic diseases remains limited, and prevention and control of parasitic CNS infections remain significant areas of research. Parasites, encompassing both unicellular and multicellular organisms, have intricate life cycles and possess the ability to infect a diverse range of hosts, including the human population. Parasitic illnesses that impact the central and peripheral nervous systems are a significant contributor to morbidity and mortality in low- to middle-income nations. The precise pathways through which neurotropic parasites infiltrate the CNS by crossing the blood-brain barrier (BBB) and cause neurological harm remain incompletely understood. Investigating brain infections caused by parasites is closely linked to studying neuroinflammation and cerebral impairment. The exact molecular and cellular mechanisms involved in this process remain incomplete, but understanding the exact mechanisms could provide insight into their pathogenesis and potentially reveal novel therapeutic targets. This review paper explores the underlying mechanisms involved in the development of neurological disorders caused by parasites, including parasite-derived elements, host immune responses, and modifications in tight junctions (TJs) proteins.

Matrix metalloproteinases -2 and -9 expression in dogs with visceral leishmaniasis: A systematic review

The matrix metalloproteinases (MMPs) are engaged in the degradation and remodeling of the extracellular matrix and vessels, allowing the progression of pathological processes. Recent studies pointed that MMP -2 and -9 are promising visceral leishmaniasis biomarkers. Thus, the present studystudy aimed to review published scientific literature related to MMP-2 and -9 activity on canine visceral leishmaniasis (CVL). The review followed the PRISMA method, searching for articles in ScienceDirect, PubMed, Scopus, Lilacs, Medline and Google Scholar from inception until 20 March 2022 by employing the following terms: "dog", "matrix metalloproteinases" and "Visceral Leishmaniasis" or "Kala Azar". The selected articles were read in full and only those consistent with the eligibility criteria were included in the review. Of 238 articles from the initial search, only five were deemed eligible, which were conducted between 2010 and 2018. All studies were performed in Brazil. It was observed that there was a higher expression of proMMP-2 in cerebrospinal (CS) fluid and serum and active MMP-2 in different skin areas, mainly in high parasite load areas. As for MMP-9, the pro and active forms were both expressed in CS fluid, serum and different skin areas. The MMP-2 can be considered a biomarker of bad prognostic as it plays an inflammatory role with a greater release in the initial phase of the disease, where MMP-9 is perceived in the chronic phase of CVL. Future research on the subject with greater methodological rigor and bigger sample sizes are mandatory to clarify the role of MMPs on disease progression.

Novel Matrix Metalloproteinase-9 (MMP-9) Inhibitors in Cancer Treatment

Matrix metalloproteinases (MMPs) belong to a family of zinc-dependent proteolytic metalloenzymes. MMP-9, a member of the gelatinase B family, is characterized as one of the most intricate MMPs. The crucial involvement of MMP-9 in extracellular matrix (ECM) remodeling underscores its significant correlation with each stage of cancer pathogenesis and progression. The design and synthesis of MMP-9 inhibitors is a potentially attractive research area. Unfortunately, to date, there is no effective MMP-9 inhibitor that passes the clinical trials and is approved by the FDA. This review primarily focuses on exploring the diverse strategies employed in the design and advancement of MMP-9 inhibitors, along with their anticancer effects and selectivity. To illuminate the essential structural characteristics necessary for the future design of novel MMP-9 inhibitors, the current narrative review highlights several recently discovered MMP-9 inhibitors exhibiting notable selectivity and potency.

The Role of Tissue Inhibitor of Metalloproteinase-1 and 2 in Echinococcus granulosus senso lato-Induced Human Hepatic Fibrosis

INTRODUCTION

The main mechanism underlying hepatic fibrosis is the imbalance between tissue Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs). This study aimed to investigate the potential role of TIMP-1 and TIMP-2 in the process of hepatic fibrosis caused by Echinococcus granulosus senso lato (E. granulosus s.l.).

METHODS

The expressions levels of TIMP-1 and TIMP-2 mRNAs were evaluated in fibrotic and normal hepatic tissues of 30 patients with Cystic Echinococcus (CE) using qRT-PCR. Moreover, their serum levels of TIMP-1 were assessed before CE cyst removal and 6 months after surgery using ELISA.

RESULTS

The qRT-PCR results showed that the expression levels of TIMP-1 and TIMP-2 mRNAs were significantly higher in the fibrotic hepatic tissue compared to the normal liver tissue, in a way that the TIMP-1 and TIMP-2 mRNA expression levels were 19.07 and 6.58 folds higher in the fibrotic tissue compared to the normal liver tissue. Among these TIMPs, TIMP-1 exhibited the higher area under the curve (AUC) value for predicting liver fibrosis. However, we could not find a significant difference in the serum levels of TIMP-1 before and after the cyst removal procedure (p = 0.48).

CONCLUSIONS

For the first time, our study showed that the significant overexpression of both TIMP mRNAs in the fibrotic liver tissue of the CE patients may be due to the increased expression of MMPs in the peri-cystic tissue. However, we could not find a significant difference in the pre- and post-operative TIMP-1 levels, which may be due to recurrence or heterogeneity in the cyst type. Therefore, performing further studies with a larger sample size of the CE patients is recommended.

MMP-9 drives the melanomagenic transcription program through histone H3 tail proteolysis

Melanoma is a type of skin cancer that develops in pigment-producing melanocytes and often spreads to other parts of the body. Aberrant gene expression has been considered as a crucial step for increasing the risk of melanomagenesis, but how chromatin reorganization contributes to this pathogenic process is still not well understood. Here we report that matrix metalloproteinase 9 (MMP-9) localizes to the nucleus of melanoma cells and potentiates gene expression by proteolytically clipping the histone H3 N-terminal tail (H3NT). From genome-wide studies, we discovered that growth-regulatory genes are selectively targeted and activated by MMP-9-dependent H3NT proteolysis in melanoma cells. MMP-9 cooperates functionally with p300/CBP because MMP-9 cleaves H3NT in a manner that is dependent on p300/CBP-mediated acetylation of H3K18. The functional significance of MMP-9-dependent H3NT proteolysis is further underscored by the fact that RNAi knockdown and small-molecule inhibition of MMP-9 and p300/CBP impede melanomagenic gene expression and melanoma tumor growth. Together, our data establish new functions and mechanisms for nuclear MMP-9 in promoting melanomagenesis and demonstrate how MMP-9-dependent H3NT proteolysis can be exploited to prevent and treat melanoma skin cancer.

Proteomic identification of the contents of small extracellular vesicles from in vivo Plasmodium yoelii infection

Small extracellular vesicles, including exosomes, are formed by the endocytic pathway and contain genetic and protein material which reflect the contents of their cells of origin. These contents have a role in vesicle-mediated information transfer, as well as physiological and pathological functions. Thus, these vesicles are of great interest as therapeutic targets, or as vehicles for immunomodulatory control. In Plasmodium spp. infections, vesicles derived from the parasite or parasite-infected cells have been shown to induce the expression of pro-inflammatory elements, which have been correlated with manifestations of clinical disease. Herein, we characterised the protein cargo of naturally occurring sEVs in the plasma of P. yoelii-infected mice. After in vivo infections, extracellular vesicles in the size range of exosomes were collected by sequential centrifugation/ultracentrifugation followed by isopycnic gradient separation. Analysis of the vesicles was performed by transmission electron microscopy, dynamic light scattering, SDS-PAGE and flow cytometry. LC-MS analysis followed by bioinformatics analysis predicted parasite protein cargo associated with exosomes. Within these small extracellular vesicles, we identified proteins of interest as vaccine candidates, uncharacterized proteins which may be targets of T cell immunoreactivity, and proteins involved in metabolic processes, regulation, homeostasis and immunity. Importantly, the small extracellular vesicles studied in our work were obtained from in vivo infection rather than from the supernatant of in vitro cultures. These findings add to the growing interest in parasite small extracellular vesicles, further our understanding of the interactions between host and parasite, and identify novel proteins which may represent potential targets for vaccination against malaria.

Helminth Coinfection Is Associated With Enhanced Plasma Levels of Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases in Tuberculous Lymphadenitis

Matrix metalloproteinases (MMPs) are crucial for tissue remodeling and repair and are expressed in diverse infections, whereas tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of MMPs. However, the interaction of MMPs and TIMPs in tuberculous lymphadenitis (TBL), an extra-pulmonary form of tuberculosis (EPTB) and helminth (Hel+) coinfection is not known. Therefore, this present study investigates the levels of circulating MMPs (1, 2, 3, 7, 8, 9, 12, 13) and TIMPs (1, 2, 3, 4) in TBL individuals with helminth (Strongyloides stercoralis [Ss], hereafter Hel+) coinfection and without helminth coinfection (hereafter, Hel-). In addition, we have also carried out the regression analysis and calculated the MMP/TIMP ratios between the two study groups. We describe that the circulating levels of MMPs (except MMP-8 and MMP-12) were elevated in TBL-Hel+ coinfected individuals compared to TBL-Hel- individuals. Similarly, the systemic levels of TIMPs (1, 2, 3, 4) were increased in TBL-Hel+ compared to TBL-Hel- groups indicating that it is a feature of helminth coinfection per se. Finally, our multivariate analysis data also revealed that the changes in MMPs and TIMPs were independent of age, sex, and culture status between TBL-Hel+ and TBL-Hel- individuals. We show that the MMP-2 ratio with all TIMPs were significantly associated with TBL-helminth coinfection. Thus, our results describe how helminth infection has a profound effect on the pathogenesis of TBL and that both MMPs and TIMPs could dampen the immunity against the TBL-Hel+ coinfected individuals.

Expression of soluble recombinant human matrix metalloproteinase 9 and generation of its monoclonal antibody

We have successfully produced a recombinant human matrix metalloproteinase 9 (hMMP9) antigen with high yield and purity and used it to generate a hybridoma cell-culture-based monoclonal anti-hMMP9 antibody. We selected the most effective antibody for binding antigens and successfully identified its nucleotide sequence. The entire antigen and antibody developmental procedures described herein can be a practical approach for producing large amounts of monoclonal antibodies against hMMP9 and other antigens of interest. Additionally, the nucleotide sequence information of the anti-hMMP9 monoclonal antibody revealed herein will be useful for the generation of recombinant antibodies or antibody fragments against hMMP9.

Trichinella spiralis excretory-secretory products downregulate MMP-9 in Dark Agouti rats affected by experimental autoimmune encephalomyelitis

Matrix metalloproteinases (MMPs), are implicated in the pathogenesis of multiple sclerosis (MS) and in its animal model, experimental autoimmune encephalomyelitis (EAE). Our aim was to investigate whether amelioration of EAE in Dark Agouti (DA) rats, induced by Trichinella spiralis muscle larvae excretory-secretory products (ES L1), could be related to the level and activity of gelatinases, MMP-9 and MMP-2. Serum levels of MMP-9, MMP-2, NGAL/MMP-9, TIMP-1, and cytokines, evaluated by gel-zymography or ELISA, as well as gelatinases and TIMP-1 expression in the spinal cord (SC), were determined in: i) EAE induced, ii) ES L1-treated EAE induced animals. Milder clinical signs in ES L1-treated EAE induced DA rats were accompanied with lower serum levels of MMP-9 and NGAL/MMP-9 complex. However, the correlation between the severity of EAE and the level of serum MMP-9 was found only in the peak of the disease, with MMP-9/TIMP-1 ratio higher in EAE animals without ES L1 treatment. Lower expression of MMP-9 in SC of ES L1-treated, EAE induced rats, correlated with the reduced number of SC infiltrating cells. In SC infiltrates, in the effector and the recovery phase, production of anti-inflammatory cytokines IL-4 and IL-10 was higher in animals treated with ES L1 prior to EAE induction, compared to untreated EAE animals. Reduced expression of MMP-9 in SC tissue, which correlated with the reduced number of infiltrating cells, might be ascribed to regulatory mechanisms, among which is IL-10.

[Contribution of endopeptidases to changes in scleral biomechanics in axial elongation of the eye]

The article describes the main properties of the sclera in patients with axial eye elongation depending on the degree of axial myopia, and presents basic information on the structure, mechanism of action and regulatory activity of matrix metalloproteinases (MMPs). MMPs play the key role in the development of abnormal catabolism of extracellular matrix components of the fibrous capsule - the process leading to changes in scleral structure and biomechanical properties in eyes with anterior-posterior axis elongation.

Modulation of Matrix Metalloproteinases by Plant-derived Products

Matrix metalloproteinases (MMPs) are a group of zinc-dependent metalloendopeptidases that are responsible for the degradation, repair, and remodeling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases, such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic, and food industries. This review summarises the current knowledge of plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signaling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviors, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.

Immunopathogenicity of Acanthamoeba spp. in the Brain and Lungs

Free-living amoebas, including Acanthamoeba spp., are widely distributed in soil, water, and air. They are capable of causing granulomatous amebic encephalitis, Acanthamoeba pneumonia, Acanthamoeba keratitis, and disseminated acanthamoebiasis. Despite low occurrence worldwide, the mortality rate of Acanthamoeba spp. infections is very high, especially in immunosuppressed hosts. Acanthamoeba infections are a medical problem, owing to limited improvement in diagnostics and treatment, which is associated with incomplete knowledge of pathophysiology, pathogenesis, and the host immune response against Acanthamoeba spp. infection. The aim of this review is to present the biochemical and molecular mechanisms of Acanthamoeba spp.-host interactions, including the expression of Toll-like receptors, mechanisms of an immune response, the activity of metalloproteinases, the secretion of antioxidant enzymes, and the expression and activity of cyclooxygenases. We show the relationship between Acanthamoeba spp. and the host at the cellular level and host defense reactions that lead to changes in the selected host's organs.

Transcriptome of Sphaerospora molnari (Cnidaria, Myxosporea) blood stages provides proteolytic arsenal as potential therapeutic targets against sphaerosporosis in common carp

Background

Parasites employ proteases to evade host immune systems, feed and replicate and are often the target of anti-parasite strategies to disrupt these interactions. Myxozoans are obligate cnidarian parasites, alternating between invertebrate and fish hosts. Their genes are highly divergent from other metazoans, and available genomic and transcriptomic datasets are limited. Some myxozoans are important aquaculture pathogens such as Sphaerospora molnari replicating in the blood of farmed carp before reaching the gills for sporogenesis and transmission. Proliferative stages cause a massive systemic lymphocyte response and the disruption of the gill epithelia by spore-forming stages leads to respiratory problems and mortalities. In the absence of a S. molnari genome, we utilized a de novo approach to assemble the first transcriptome of proliferative myxozoan stages to identify S. molnari proteases that are upregulated during the first stages of infection when the parasite multiplies massively, rather than in late spore-forming plasmodia. Furthermore, a subset of orthologs was used to characterize 3D structures and putative druggable targets.

Results

An assembled and host filtered transcriptome containing 9436 proteins, mapping to 29,560 contigs was mined for protease virulence factors and revealed that cysteine proteases were most common (38%), at a higher percentage than other myxozoans or cnidarians (25–30%). Two cathepsin Ls that were found upregulated in spore-forming stages with a presenilin like aspartic protease and a dipeptidyl peptidase. We also identified downregulated proteases in the spore-forming development when compared with proliferative stages including an astacin metallopeptidase and lipases (qPCR). In total, 235 transcripts were identified as putative proteases using a MEROPS database. In silico analysis of highly transcribed cathepsins revealed potential drug targets within this data set that should be prioritised for development.

Conclusions

In silico surveys for proteins are essential in drug discovery and understanding host-parasite interactions in non-model systems. The present study of S. molnari’s protease arsenal reveals previously unknown proteases potentially used for host exploitation and immune evasion. The pioneering dataset serves as a model for myxozoan virulence research, which is of particular importance as myxozoan diseases have recently been shown to emerge and expand geographically, due to climate change.

Relationship between Toxoplasma gondii seropositivity and schizophrenia in the Lebanese population: potential implication of genetic polymorphism of MMP-9

BACKGROUND

Toxoplasma multiplication and its persistence into the brain cause a local neuroinflammatory reaction, resulting synthesis of neurotransmitters involved in neurological disorders, especially schizophrenia. The Matrix metallopeptidase 9 (MMP-9) protein can play a major role in this neuroinflammation. It can promote extravasation and migration of infected immune cells into the brain. The objectives of this study are to determine the possible association between schizophrenia and toxoplasmosis and highlight the existence of gene polymorphism encoding MMP-9 protein's in patients presented both schizophrenia and toxoplasmosis.

METHODS

A case-control study was conducted on 150 patients with schizophrenia (case group), and 150 healthy persons (control group). Groups were matched with age, gender, and place of residence. The survey was conducted using a questionnaire and a serological profile assay for specific IgG and IgM antibodies against T. gondii. Reverse transcription-polymerase chain reaction (RT-PCR) of gene polymorphism encoding MMP-9 was performed on 83 cases selected randomly.

RESULTS

Data show a significant association between toxoplasmosis (IgM+/IgG+ serological profile) and schizophrenia. Significant effects of raw meat consumption and contact with cats have been associated with the occurrence of schizophrenia. RT-PCR shows the presence of muted allele of MMP-9 gene in selected cases whose present T. gondii serological profile IgM+/IgG+ and IgM-/IgG+ respectively.

CONCLUSION

Toxoplasmosis may be one of the etiological causes of schizophrenia, and MMP-9 gene polymorphism could be involved in the occurrence mechanism of this pathology following Toxoplasma infection.

The Treponema pallidum outer membrane protein Tp92 activates endothelial cells via the chemerin/CMKLR1 pathway

Endothelium damage caused by Treponema pallidum is the key step in the systemic dissemination and pathophysiology of syphilis, particularly cardiovascular syphilis and neurosyphilis. However, the molecular mechanisms supporting endothelium damage of syphilis are undefined. The outer membrane proteins were thought to be involved. Tp92 was first identified as an outer membrane protein of T. pallidum. Homologous proteins to Tp92 play important roles in cell attachment, inflammation, and tissue destruction in other bacterial species. In this study, we investigated the effect of Tp92 on endothelial cells activation. The data showed that Tp92 induced chemerin production in activated endothelial cells. Endothelial cell-derived chemerin upregulated the expression of TNF-α and ICAM-1 in endothelial cells via CMKLR1. In addition, endothelial cell-derived chemerin promoted THP-1-derived macrophage migration towards endothelial cells. These findings suggest that Tp92 may play an important role in mediating endothelial cell activation by inducing the secretion of chemerin.

In vitro model of postoncosphere development, and in vivo infection abilities of Taenia solium and Taenia saginata

Taenia solium is known to cause human cysticercosis while T. saginata does not. Comparative in vitro and in vivo studies on the oncosphere and the postoncospheral (PO) forms of T. solium and T. saginata may help to elucidate why cysticercosis can occur from one and not the other. The aim of this study was to use in vitro culture assays and in vivo models to study the differences in the development of the T. solium and T. saginata oncosphere. Furthermore, this study aimed to evaluate the expression of cytokines and metalloproteinases (MMPs) in human peripheral blood mononuclear cells (PBMCs), which were stimulated by these oncospheres and PO antigens. T. solium and T. saginata activated oncospheres (AO) were cultured in INT-407 and HCT-8 intestinal cells for 180 days. The T. solium began to die while the T. saginata grew for 180 days and developed to cysticerci in INT-407 cells. Rats were inoculated intracranially with AO and PO forms of either T. saginata or T. solium. Rats infected with T. solium AO and PO forms developed neurocysticercosis (NCC), while those infected with the T. saginata did not. Human PMBCs were stimulated with antigens of AO and PO forms of both species, and the production of cytokines and metalloproteinases (MMPs) was measured. The T. solium AO antigen stimulated a higher production of IL-4, IL-5, IL-13, IFN-γ, and IL-2 cytokines compared to T. saginata AO. In the PO form, the T. saginata PO antigen increased the production of IL-4, IL-5, IL-13, IFN-γ, IL-1β, IL-6, IL-10, TNF-α and IL-12 cytokines compared to T. solium, suggesting that this global immune response stimulated by different forms could permit survival or destruction of the parasite depending of their life-cycle stage. Regarding MMPs, T. solium AO antigen stimulated a higher production of MMP-9 compared to T. saginata AO antigen, which may be responsible for altering the permeability of intestinal cells and facilitating breakdown of the blood-brain barrier during the process of invasion of host tissue.

Taenia solium and Taenia saginata are two parasites that cause the tissue infection cysticercosis in their intermediate hosts, pigs and cows, respectively. One major difference between them is that T. solium can also cause neurocysticercosis in the human brain, while T. saginata cannot. Neurocysticercosis is thought to be the major cause of adult-onset seizures in developing countries. It is not well understood why only T. solium can survive in human tissue; however, the host inflammatory response likely plays an important role. The authors found that human immune cells stimulated with T. solium in the early stages of the parasite life cycle produced a more robust cytokine response than T. saginata. However, in the mature stage, which occurs once T. solium reaches the brain, T. solium antigens stimulated a lower inflammatory response compared to T. saginata, suggesting the parasite is able to manipulate the host immune response in some way to evade destruction. These findings may support the differences in growth observed by the authors when rat brains were inoculated with either parasite species. This study provides new insights into the different ways T. solium and T. saginata activate the immune response to survive and develop within the host.

The Activity of Matrix Metalloproteinases (MMP-2, MMP-9) and Their Tissue Inhibitors (TIMP-1, TIMP-3) in the Cerebral Cortex and Hippocampus in Experimental Acanthamoebiasis

The pathological process occurring within the central nervous system (CNS) as a result of the infection by Acanthamoeba spp. is not fully understood. Therefore, the aim of this study was to determine whether Acanthamoeba spp. may affect the levels of matrix metalloproteinases (MMP-2,-9), their tissue inhibitors (TIMP-1,-3) and MMP-9/TIMP-1, MMP-2/TIMP-3 ratios in the cerebral cortex and hippocampus, in relation to the host’s immunological status. Our results showed that Acanthamoeba spp. infection can change the levels of MMP and TIMP in the CNS and may be amenable targets for limiting amoebic encephalitis. The increase in the activity of matrix metalloproteinases during acanthamoebiasis may be primarily the result of inflammation process, probably an increased activity of proteolytic processes, but also (to a lesser extent) a defense mechanism preventing the processes of neurodegeneration.

Matrix Metalloproteinase-9 (MMP-9) as a Cancer Biomarker and MMP-9 Biosensors: Recent Advances

As one of the most widely investigated matrix metalloproteinases (MMPs), MMP-9 is a significant protease which plays vital roles in many biological processes. MMP-9 can cleave many extracellular matrix (ECM) proteins to regulate ECM remodeling. It can also cleave many plasma surface proteins to release them from the cell surface. MMP-9 has been widely found to relate to the pathology of cancers, including but not limited to invasion, metastasis and angiogenesis. Some recent research evaluated the value of MMP-9 as biomarkers to various specific cancers. Besides, recent research of MMP-9 biosensors discovered various novel MMP-9 biosensors to detect this enzyme. In this review, some recent advances in exploring MMP-9 as a biomarker in different cancers are summarized, and recent discoveries of novel MMP-9 biosensors are also presented.

Expression of matrix metalloproteinases in Naegleria fowleri and their role in invasion of the central nervous system

Naegleria fowleri is a free-living amoeba found in freshwater lakes and ponds and is the causative agent of primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system (CNS). PAM occurs when amoebae attach to the nasal epithelium and invade the CNS, a process that involves binding to, and degradation of, extracellular matrix (ECM) components. This degradation is mediated by matrix metalloproteinases (MMPs), enzymes that have been described in other pathogenic protozoa, and that have been linked to their increased motility and invasive capability. These enzymes also are upregulated in tumorigenic cells and have been implicated in metastasis of certain tumours. In the present study, in vitro experiments linked MMPs functionally to the degradation of the ECM. Gelatin zymography demonstrated enzyme activity in N. fowleri whole cell lysates, conditioned media and media collected from invasion assays. Western immunoblotting indicated the presence of the metalloproteinases MMP-2 (gelatinase A), MMP-9 (gelatinase B) and MMP-14 [membrane type-1 matrix metalloproteinase (MT1-MMP)]. Highly virulent mouse-passaged amoebae expressed higher levels of MMPs than weakly virulent axenically grown amoebae. The functional relevance of MMPs in media was indicated through the use of the MMP inhibitor, 1,10-phenanthroline. The collective in vitro results suggest that MMPs play a critical role in vivo in invasion of the CNS and that these enzymes may be amenable targets for limiting PAM.

A new gallium complex inhibits tumor cell invasion and matrix metalloproteinase MMP-14 expression and activity

In this study, we investigated the effect of [N-(5-chloro-2-hydroxyphenyl)-l-aspartato] chlorogallate (GS2) on tumor cell invasion and on the expression and activity of MMPs.

The restorative role of annexin A1 at the blood-brain barrier

Annexin A1 is a potent anti-inflammatory molecule that has been extensively studied in the peripheral immune system, but has not as yet been exploited as a therapeutic target/agent. In the last decade, we have undertaken the study of this molecule in the central nervous system (CNS), focusing particularly on the primary interface between the peripheral body and CNS: the blood-brain barrier. In this review, we provide an overview of the role of this molecule in the brain, with a particular emphasis on its functions in the endothelium of the blood-brain barrier, and the protective actions the molecule may exert in neuroinflammatory, neurovascular and metabolic disease. We focus on the possible new therapeutic avenues opened up by an increased understanding of the role of annexin A1 in the CNS vasculature, and its potential for repairing blood-brain barrier damage in disease and aging.

Environmental Correlation Analysis for Genes Associated with Protection against Malaria

Genome-wide searches for loci involved in human resistance to malaria are currently being conducted on a large scale in Africa using case-control studies. Here, we explore the utility of an alternative approach-"environmental correlation analysis, ECA," which tests for clines in allele frequencies across a gradient of an environmental selection pressure-to identify genes that have historically protected against death from malaria. We collected genotype data from 12,425 newborns on 57 candidate malaria resistance loci and 9,756 single nucleotide polymorphisms (SNPs) selected at random from across the genome, and examined their allele frequencies for geographic correlations with long-term malaria prevalence data based on 84,042 individuals living under different historical selection pressures from malaria in coastal Kenya. None of the 57 candidate SNPs showed significant (P < 0.05) correlations in allele frequency with local malaria transmission intensity after adjusting for population structure and multiple testing. In contrast, two of the random SNPs that had highly significant correlations (P < 0.01) were in genes previously linked to malaria resistance, namely, CDH13, encoding cadherin 13, and HS3ST3B1, encoding heparan sulfate 3-O-sulfotransferase 3B1. Both proteins play a role in glycoprotein-mediated cell-cell adhesion which has been widely implicated in cerebral malaria, the most life-threatening form of this disease. Other top genes, including CTNND2 which encodes δ-catenin, a molecular partner to cadherin, were significantly enriched in cadherin-mediated pathways affecting inflammation of the brain vascular endothelium. These results demonstrate the utility of ECA in the discovery of novel genes and pathways affecting infectious disease.

Matrix metalloproteinases in neural development: a phylogenetically diverse perspective

The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases originally characterized as secreted proteases responsible for degrading extracellular matrix proteins. Their canonical role in matrix remodelling is of significant importance in neural development and regeneration, but emerging roles for MMPs, especially in signal transduction pathways, are also of obvious importance in a neural context. Misregulation of MMP activity is a hallmark of many neuropathologies, and members of every branch of the MMP family have been implicated in aspects of neural development and disease. However, while extraordinary research efforts have been made to elucidate the molecular mechanisms involving MMPs, methodological constraints and complexities of the research models have impeded progress. Here we discuss the current state of our understanding of the roles of MMPs in neural development using recent examples and advocate a phylogenetically diverse approach to MMP research as a means to both circumvent the challenges associated with specific model organisms, and to provide a broader evolutionary context from which to synthesize an understanding of the underlying biology.

Matrix metalloproteinase (MMP)-9: A realiable marker for inflammation in early human trichinellosis

Matrix Metalloproteinases (MMPs) are involved in many physiological and pathological processes. As regards parasitic infections, the role of these proteins has been particularly studied in malaria, neurocysticercosis and angiostrongyloidosis. Recently, we evaluated serum levels of MMP-9 and -2 (gelatinases) in mice experimentally infected with Trichinella spiralis or Trichinella pseudospiralis, which cause different degrees of myositis and we found their significant increase in the former and, at a lesser extent, in the latter, thus suggesting the possibility that these gelatinases, particularly MMP-9, represent a marker of inflammation. Our aim was to evaluate the levels of MMP-9 and 2 in trichinellosis patients, to assess their possible clinical significance. Serum samples from 31 Trichinella britovi-infected individuals (20 males and 11 females), living in Tuscany, Central Italy, were analysed for MMP-9 and MMP-2 serum levels. Patients acquired infection with Trichinella after consuming raw or undercooked meat of wild boar. Their median age was 49±0.33years (range from 7 to 91). Sera was collected before starting anti-inflammatory treatment, aliquoted and stored at -20°C until use. Sera from healthy subjects was considered as controls. The gelatinolytic activity of MMPs was analysed by gelatin zymography on 8% polyacrylamide-SDS gels containing 0.1% porcine gelatin, under non-reducing conditions. Clear bands corresponding to the digested areas were evaluated with an appropriate software. MMP-9 levels were additionally determined in 15 patients using a commercial ELISA kit for human MMP-9. The zymographic analysis of the gels showed the presence in serum samples of gelatinase bands at approximately 125-kDa, 92-kDa and 72-kDa, corresponding to the MMP-9/Neutrophil gelatinase-associated lipocalin (NGAL) complex and proenzyme forms of MMP-9 and MMP-2, respectively. A significant (p<0.01) increase in gelatinolytic activity in patients compared to the control group was observed for pro-MMP-9 in 25 out of 31. The mean increase in activity was 39.25%±16.67%. No significant differences were observed for pro-MMP-2 activity. The MMP-9 levels detected by ELISA showed significant correlation with zymographic data (r²=0.62, p<0.003) and were higher in more affected patients (suffering diarrhea, facial edemas and myalgia). In conclusion, MMP-9 might be considered as a marker of inflammation in T. britovi patients. On the contrary, MMP-2 did not result significantly different in patients, compared to controls.