Recruited leukocytes and local synthesis account for increased matrix metalloproteinase-9 activity in cerebrospinal fluid of dogs with central nervous system neoplasm

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.

Differential Expression of miRNAs in Hypoxia ("HypoxamiRs") in Three Canine High-Grade Glioma Cell Lines

Dogs with spontaneous high-grade gliomas increasingly are being proposed as useful large animal pre-clinical models for the human disease. Hypoxia is a critical microenvironmental condition that is common in both canine and human high-grade gliomas and drives increased angiogenesis, chemo- and radioresistance, and acquisition of a stem-like phenotype. Some of this effect is mediated by the hypoxia-induced expression of microRNAs, small (~22 nucleotides long), non-coding RNAs that can modulate gene expression through interference with mRNA translation. Using an in vitro model with three canine high-grade glioma cell lines (J3T, SDT3G, and G06A) exposed to 72 h of 1.5% oxygen vs. standard 20% oxygen, we examined the global “hypoxamiR” profile using small RNA-Seq and performed pathway analysis for targeted genes using both Panther and NetworkAnalyst. Important pathways include many that are well-established as being important in glioma biology, general cancer biology, hypoxia, angiogenesis, immunology, and stem-ness, among others. This work provides the first examination of the effect of hypoxia on miRNA expression in the context of canine glioma, and highlights important similarities with the human disease.

Canine Primary Intracranial Cancer: A Clinicopathologic and Comparative Review of Glioma, Meningioma, and Choroid Plexus Tumors

In the dog, primary intracranial neoplasia represents ~2-5% of all cancers and is especially common in certain breeds including English and French bulldogs and Boxers. The most common types of primary intracranial cancer in the dog are meningioma, glioma, and choroid plexus tumors, generally occurring in middle aged to older dogs. Much work has recently been done to understand the characteristic imaging and clinicopathologic features of these tumors. The gross and histologic landscape of these tumors in the dog compare favorably to their human counterparts with many similarities noted in histologic patterns, subtype, and grades. Data informing the underlying molecular abnormalities in the canine tumors have only begun to be unraveled, but reveal similar pathways are mutated between canine and human primary intracranial neoplasia. This review will provide an overview of the clinicopathologic features of the three most common forms of primary intracranial cancer in the dog, delve into the comparative aspects between the dog and human neoplasms, and provide an introduction to current standard of care while also highlighting novel, experimental treatments that may help bridge the gap between canine and human cancer therapies.

Companion animals in comparative oncology: One Medicine in action

Comparative oncology is poised to have a far-reaching impact on both animals and human beings with cancer. The field is gaining momentum and has repeatedly proven its utility in various aspects of oncology, including study of the genetics, development, progression, immunology and therapy of cancer. Companion animals provide many advantages over both traditional rodent models and human beings for studying cancer biology and accelerating the development of novel anti-cancer therapies. In this review, several examples of the ability of companion animals with spontaneous cancers to fill a unique niche in the field of oncology are discussed. In addition, potential caveats of the use of companion animals in research are reviewed, as well as ethical considerations and efforts to standardize veterinary clinical trials.

Matrix metalloproteinases in the brain and blood-brain barrier: Versatile breakers and makers

Matrix metalloproteinases are versatile endopeptidases with many different functions in the body in health and disease. In the brain, matrix metalloproteinases are critical for tissue formation, neuronal network remodeling, and blood-brain barrier integrity. Many reviews have been published on matrix metalloproteinases before, most of which focus on the two best studied matrix metalloproteinases, the gelatinases MMP-2 and MMP-9, and their role in one or two diseases. In this review, we provide a broad overview of the role various matrix metalloproteinases play in brain disorders. We summarize and review current knowledge and understanding of matrix metalloproteinases in the brain and at the blood-brain barrier in neuroinflammation, multiple sclerosis, cerebral aneurysms, stroke, epilepsy, Alzheimer's disease, Parkinson's disease, and brain cancer. We discuss the detrimental effects matrix metalloproteinases can have in these conditions, contributing to blood-brain barrier leakage, neuroinflammation, neurotoxicity, demyelination, tumor angiogenesis, and cancer metastasis. We also discuss the beneficial role matrix metalloproteinases can play in neuroprotection and anti-inflammation. Finally, we address matrix metalloproteinases as potential therapeutic targets. Together, in this comprehensive review, we summarize current understanding and knowledge of matrix metalloproteinases in the brain and at the blood-brain barrier in brain disorders.

Proteases as prognostic markers in human and canine cancers

The extracellular matrix (ECM) is composed of several types of proteins, which interact and form dynamic networks. These components can modulate cell behaviour and actively influence the growth and differentiation of tissues. ECM is also important in several pathological processes, such as cancer invasion and metastasis, by creating favourable microenvironments. Proteolysis in neoplastic tissues is mediated by proteinases, whose regulation involves complex interactions between neoplastic cells and non-neoplastic stromal cells. In this review, we discuss aspects of proteinase expression and tumor behaviour in humans and dogs. Different classes of proteases are summarized, with special emphasis being placed on molecules that have been shown to correlate with prognosis, reinforcing the need for a better understanding of the regulation of this microenvironment and its influences in tumor progression and metastasis, which should significantly aid the development of improved prognosis and treatment.

Evaluation of endothelin-1 and MMPs-2, -9, -14 in cerebrospinal fluid as indirect indicators of blood-brain barrier dysfunction in chronic canine hypothyroidism

Chronic canine hypothyroidism is associated with blood-brain barrier (BBB) disruption. We hypothesized that this change is mediated by endothelin-1(ET-1) and matrix metalloproteinases (MMP) -2, -9, and -14, as evidenced by increased concentrations of these proteins in cerebrospinal fluid (CSF) compared to controls. CSF from 18 dogs, 9 controls and 9 with experimentally induced hypothyroidism was collected before and 6, 12, and 18 months after induction of hypothyroidism. Concentrations of ET-1 using an ELISA kit, and for MMP-2, -9, and -14 using gelatinase zymography were measured in CSF. ET-1 was undetectable in CSF of control and hypothyroid dogs at all time-points. Constitutively expressed MMP-2 was detectable in CSF samples in all dogs at all time-points. No other MMPs were detectable in CSF. No differences in CSF concentrations of ET-1 and MMP-2, 9, and 14 were found between hypothyroid and euthyroid dogs. Therefore, ET-1 and MMP-2, 9, and 14 are unlikely to be primary mediators of BBB damage in chronically hypothyroid dogs.

Implications of MMP9 for Blood Brain Barrier Disruption and Hemorrhagic Transformation Following Ischemic Stroke

Numerous studies have documented increases in matrix metalloproteinases (MMPs), specifically MMP-9 levels following stroke, with such perturbations associated with disruption of the blood brain barrier (BBB), increased risk of hemorrhagic complications, and worsened outcome. Despite this, controversy remains as to which cells release MMP-9 at the normal and pathological BBB, with even less clarity in the context of stroke. This may be further complicated by the influence of tissue plasminogen activator (tPA) treatment. The aim of the present review is to examine the relationship between neutrophils, MMP-9 and tPA following ischemic stroke to elucidate which cells are responsible for the increases in MMP-9 and resultant barrier changes and hemorrhage observed following stroke.

Advances in diagnostic and treatment modalities for intracranial tumors

Intracranial neoplasia is a common clinical condition in domestic companion animals, particularly in dogs. Application of advances in standard diagnostic and therapeutic modalities together with a broad interest in the development of novel translational therapeutic strategies in dogs has resulted in clinically relevant improvements in outcome for many canine patients. This review highlights the status of current diagnostic and therapeutic approaches to intracranial neoplasia and areas of novel treatment currently in development.

Marked MMP-2 transcriptional up-regulation in mononuclear leukocytes invading the subarachnoidal space in aseptic suppurative steroid-responsive meningitis-arteritis in dogs

Canine Steroid-Responsive Meningitis-Arteritis (SRMA) is a suitable animal model for studies on the development of neutrophilic pleocytosis in aseptic meningitis. Samples of dogs in the acute phase of SRMA (n=16) were examined for gene expression of matrix metalloproteinases (MMP)-2 and -9 and tissue inhibitors of metalloproteinases (TIMP)-1 and -2. Results were compared to those of dogs under glucocorticosteroid treatment for SRMA (n=16) and dogs with other inflammatory and neoplastic diseases of the central nervous system (CNS) (n=19). Samples included mononuclear (PBMCs) and polymorphonuclear cells (PBPMNs) of peripheral blood and cerebrospinal fluid white blood cells (CSF WBCs). In the acute phase of SRMA CSF WBCs showed mRNA expression for MMP-2 and -9 and TIMP-1 and -2, highlighting a contribution of these cells to the overall content of MMPs and TIMPs in CSF. MMP-2 mRNA levels in CSF WBCs were significantly up-regulated in comparison to PBMC expression levels, suggesting that MMP-2 is relevant for PBMC invasion into the subarachnoidal space and that the expression is influenced by migratory activity through the blood-CSF-barrier.