Harnessing Endogenous Peptide Compounds as Potential Therapeutics for Severe Influenza.

Background: Excessive pulmonary inflammation and damage are characteristic features of severe influenza virus infections. LAT8881 is a synthetic 16-amino acid cyclic peptide form of a naturally occurring C-terminal fragment of human growth hormone with therapeutic efficacy against influenza. Shorter linear peptides are typically easier to manufacture and formulate for delivery than larger cyclic peptides.

Naturally derived cytokine peptides limit virus replication and severe disease during influenza A virus infection.

Objectives: Novel host-targeted therapeutics could treat severe influenza A virus (IAV) infections, with reduced risk of drug resistance. LAT8881 is a synthetic form of the naturally occurring C-terminal fragment of human growth hormone. Acting independently of the growth hormone receptor, it can reduce inflammation-induced damage and promote tissue repair in an animal model of osteoarthritis.

Targeting toll-like receptors for drug development: a summary of commercial approaches.

Toll-like receptors (TLRs) play a fundamental role in recognizing infectious and noxious agents as well as products of tissue damage. They are capable of initiating both protective and damaging inflammatory and immune responses. Several biotechnology and pharmaceutical companies have programmes to develop new drugs that are either: agonists of TLRs to enhance immune responses against tumours and infectious agents, or to correct allergic responses; or antagonists designed to reduce inflammation due to infection or autoimmune disease.

Characterization of matrix metalloproteinases in denervated muscle.

In a nerve crush model of denervation, we examined muscle matrix metalloproteinase (MMP) expression, localization and activity. In normal muscle, MMP mRNA levels were low, and immunohistochemically MMPs were distributed around the muscle fibre with MMPs-3, -7 and -9 also staining at the neuromuscular junction. Seven days after nerve crush, muscle MMP immunoreactivity, especially MMP-12 and MMP-14, became irregularly distributed.

Characterisation of matrix metalloproteinases and the effects of a broad-spectrum inhibitor (BB-1101) in peripheral nerve regeneration.

The effect of treatment with a broad-spectrum inhibitor (BB1101) of the matrix metalloproteinases (MMPs) on nerve regeneration and functional recovery after nerve crush was examined. Drug treatment had no effect on latency but from 63 days the compound muscle action potential was significantly increased and was no different to that in the sham-operated controls at 72 days. Levels of MMP mRNA expression, and the localisation and activity of MMP proteins, were examined in rats for a 2 month period following a nerve crush injury, and compared with sham-operated controls.

Gelatinase B and TIMP-1 are regulated in a cell- and time-dependent manner in association with neuronal death and glial reactivity after global forebrain ischemia.

Matrix metalloproteinases (MMPs) belong to a large family of endopeptidases that regulate the pericellular environment through the cleavage of protein components of the extracellular matrix, membrane receptors and cytokines. MMP activity is controlled by the multifunctional tissue inhibitors of metalloproteinases (TIMPs). Proteases and their inhibitors are critically involved in developmental and pathological processes in numerous organs, including the brain.

Selective cleavage of human IgG by the matrix metalloproteinases, matrilysin and stromelysin.

We have shown that two of the matrix metalloproteinases (MMPs), matrilysin and stromelysin-1, are capable of cleaving all of the human IgG subclasses. The cleavage occurs at a conserved site in the CH(2) domain of the heavy chain of IgG, releasing a single chain Fc-like fragment. We have not been able to demonstrate cleavage of IgA, IgD, IgM or IgE classes, which lack the cleavage site, nor could we show cleavage of IgG by collagenase, gelatinase, macrophage metalloelastase or membrane-type (MT)-MMP.

Reduction in glial immunity and neuropathology by a PAF antagonist and an MMP and TNFalpha inhibitor in SCID mice with HIV-1 encephalitis.

The effects of anti-inflammatory drugs on glial immunity and neuropathology were determined in a severe combined immune deficiency (SCID) mouse model of HIV-1 encephalitis. HIV-1-infected human monocyte-derived macrophages (MDM) are stereotactically inoculated into basal ganglia resulting in a multinucleated giant cell encephalitis. A platelet activating factor antagonist and a matrix metalloproteinase inhibitor, which also inhibits tumor necrosis factor alpha release, were administered to animals at the time of the MDM inoculation.

Immunohistochemistry of matrix metalloproteinases in reperfusion injury to rat brain: activation of MMP-9 linked to stromelysin-1 and microglia in cell cultures.

Reperfusion damages the blood-brain barrier (BBB). Matrix metalloproteinases (MMPs) are associated with the opening of the BBB, but their cellular localization and activation mechanisms are uncertain. We used immunohistochemistry to determine the cellular localization of the MMPs in reperfused rat brain, and cell cultures to study their activation.

Expression of specific matrix metalloproteinases in inflammatory myopathies.

The family of matrix metalloproteinases (MMPs) comprises endopeptidases that are capable of degrading all extracellular matrix components. Given these actions, it is conceivable that MMPs may play a pathogenic role in inflammatory myopathies. These immune-mediated disorders are characterized by the invasion of mononuclear phagocytes and T lymphocytes and the loss of muscle fibres.

The matrix metalloproteinase inhibitor BB-1101 prevents experimental autoimmune uveoretinitis (EAU).

EAU is characterized by breakdown of the blood-retinal barrier and extravasation of leucocytes into retinal tissue leading to destruction of photoreceptor cells. Matrix metalloproteinases (MMP) have been implicated in trafficking of cells into tissues, but their role in inflammatory eye disease is unclear. A synthetic MMP inhibitor, BB-1101, was administered subcutaneously, from either day 0 or day 7, to Lewis rats challenged with bovine S-antigen to induce EAU.

Differential expression of matrix metalloproteinases in bacterial meningitis.

Matrix metalloproteinases (MMPs) are implicated in the pathogenesis of various inflammatory diseases of the central nervous system. Evidence is accumulating that gelatinase B (MMP-9) might be involved in the pathogenesis of meningitis, but the spectrum of different MMPs involved in the inflammatory reaction of this disease has not been determined. We investigated the temporal and spatial mRNA expression pattern of gelatinase B in experimental meningococcal meningitis in rats.

Preclinical and clinical studies of MMP inhibitors in cancer.

The role of matrix metalloproteinases in tumor angiogenesis and growth is now well recognized for models of both human and animal cancer. Clinical studies currently under way with the prototype matrix metalloproteinase inhibitor, marimastat, will establish whether inhibitors of these enzymes are of benefit in the treatment of different types of human cancer. On chronic therapy in humans, marimastat induces a reversible tendinitis that can also be detected in certain animal species.

A central role for astrocytes in the inflammatory response to beta-amyloid; chemokines, cytokines and reactive oxygen species are produced.

Alzheimer's disease (AD) is the commonest form of adult onset dementia and is characterised neuropathologically by the accumulation of plaques containing beta-amyloid (A beta) fibrils, reactive astrocytes, activated microglia, and leukocytes. A beta plays a role in the pathology of AD by directly causing neuronal cytotoxicity and stimulating microglia to secrete cytokines and reactive oxygen species (ROS) which also damage neurons. Here, we demonstrate that A beta activates astrocytes and oligodendrocytes (the most common cell types in the brain) to produce chemokines, in particular MCP-1 and RANTES, which serve as potent in vitro microglial and macrophage chemoattractants.

Serum gelatinase B, TIMP-1 and TIMP-2 levels in multiple sclerosis. A longitudinal clinical and MRI study.

Metalloproteinases have been implicated in the pathogenesis of multiple sclerosis. We report longitudinal serum levels of gelatinase B and of the tissue inhibitors of matrix metalloproteinases (TIMP), TIMP-1 and TIMP-2, in 21 patients with relapsing multiple sclerosis. Patients had monthly clinical and gadolinium-enhanced MRI follow-up for 10 months.

Matrix metalloproteinase expression in an experimentally-induced DTH model of multiple sclerosis in the rat CNS.

In an experimentally-induced DTH model of MS, we examined mRNA and protein expression of a range of MMPs and of TNFalpha to establish the contribution that individual MMPs might make to the pathogenesis. In control rat brain, mRNA for all of the MMPs examined was detectable. However, by immunohistochemistry, only MMP-2 could be detected.

Serum concentrations of soluble adhesion molecules in patients with colorectal cancer.

The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 48 patients with colorectal cancer before treatment, and their relation to clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with colorectal cancer in comparison with a group of healthy subjects (P < 0.

Effective treatment of models of multiple sclerosis by matrix metalloproteinase inhibitors.

The proinflammatory Th1 cytokine, tumor necrosis factor-alpha (TNF alpha), the cell death signaling molecule FasL, and several extracellular matrix degrading metalloproteinases have been implicated in the pathogenesis of multiple sclerosis (MS). The latter enzymes, as well as TNF alpha-converting enzyme and FasL-converting enzyme, can be blocked by matrix metalloproteinase inhibitors (MMPIs). In this study, we show that a potent MMPI was clinically effective in an animal model for MS, experimental autoimmune encephalomyelitis (EAE) in the SJL/J mouse.

Adhesion molecule expression in the lung: a comparison between normal and diffuse interstitial lung disease.

Cellular adhesion molecules are crucial determinants of the migration of immune effector cells to the tissues. In chronic inflammatory diseases, upregulation of the expression of these molecules may contribute to the persistent inflammatory process. The aim of this study was to determine whether there is evidence of adhesion molecule expression in chronically inflamed lung.

Matrix metalloproteinase expression during experimental autoimmune neuritis.

Experimental autoimmune neuritis (EAN) is an animal model of Guillain-Barré syndrome. We have shown recently that BB-1101, a broad-spectrum matrix metalloproteinase (MMP) inhibitor, prevents development of EAN when given from the day of immunization and, more important clinically, reduces disease severity when given from symptom onset. This suggests the involvement of MMP activity in the pathogenesis of EAN.

Matrix metalloproteinase-9 and -7 are regulated in experimental autoimmune encephalomyelitis.

Matrix metalloproteinases (MMPs) comprise a group of proteolytic enzymes that are implicated in the pathogenesis of inflammatory diseases of the nervous system such as multiple sclerosis. However, the exact function and expression pattern of MMPs in the inflamed nervous system are not known. In the present study we investigated the expression of 92-kDa gelatinase (MMP-9) in spinal cord from animals with adoptive transfer experimental autoimmune encephalomyelitis (AT-EAE), using a semiquantitative competitive reverse transcriptase-polymerase chain reaction assay.