bb-1101 and Encephalitis

Matrix metalloproteinase inhibitors (MMPIs) reduce blood-brain barrier (BBB) disruption and prevent cell death. Animal models of multiple sclerosis, cerebral ischemia and hemorrhage, and bacterial meningitis respond to treatment with MMPIs. We have used the intracerebral injection of lipopolysaccharide (LPS) in rat, which induces MMP production and results in a delayed opening of the BBB, to screen MMPIs to identify therapeutic agents. We hypothesized that the mouse would respond similarly to LPS and that the mouse/LPS model of BBB damage would be more useful for screening of MMPIs. Therefore, we adapted the rat LPS model to the mouse and compared the response to LPS and treatment with MMPIs. Wistar-Kyoto rats (WKY) and three strains of mice had stereotactic injections of LPS into the caudate. (14)C-sucrose was used to measure permeability of the BBB 24 h after injection. Initially, we tested three broad-spectrum MMPIs in the rat, BB-1101, BB-94, and BB-2293, and a MMP-2 selective inhibitor, IW449; both BB-1101 and BB-94 significantly suppressed LPS-induced BBB damage (p<0.05). In the 3 mouse strains, C57/BL6, C57/BL10, and C57/BL10HIIIR2, LPS significantly opened the BBB in C57/BL6, and it was the only strain that showed a reduction in BBB permeability with BB-94. Treatment with methylprednisolone and several broad-spectrum MMPIs, including BB-1101, was ineffective in the C57/BL6. There was a significant reduction in BBB permeability seen with 10% dimethyl sulfoxide (DMSO) alone, which was used to dissolve the selective MMP-2 and-9 inhibitor, SB-3CT. The tetracycline derivative, minocycline, reduced the BBB injury in mouse by blocking the production of MMP-9. Our results show variability in rats and mice to LPS and MMPIs, which most likely is based on genetic make-up. Understanding these differences may provide important clues that could guide selection of MMPIs in treatment of neurological diseases.

Topics: Animals; Benzyl Compounds; Blood-Brain Barrier; Dexamethasone; Dimethyl Sulfoxide; Disease Models, Animal; Drug Combinations; Drug Evaluation, Preclinical; Encephalitis; Endothelial Cells; Enzyme Inhibitors; Genetic Variation; Heterocyclic Compounds, 1-Ring; Inflammation Mediators; Lipopolysaccharides; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Pentoxifylline; Phenylalanine; Rats; Rats, Inbred WKY; Solvents; Species Specificity; Succinates; Sulfones; Thiophenes

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. Efficacy was remarkable, as indicated by blocking and reversal of acute disease and reduced number of relapses and diminished mean cumulative disease score in chronic relapsing animals. Also, demyelination and glial scarring were significantly decreased in MMPI-treated mice with chronic relapsing EAE, as was central nervous system gene expression for TNF alpha and fasL. It is interesting that expression of the beneficial cytokine interleukin-4 (IL-4) was increased, and IL-4 was expressed on glial cells. The relevance of these compounds for MS was underscored by their ability to specifically inhibit TNF alpha shedding and cytotoxicity of myelin-autoreactive human cytotoxic CD4+ T-cell clones. This is the first report to show a positive effect by MMPIs on chronic relapsing EAE, its central nervous system cytokine profile, and on TNF alpha shedding by human myelin-autoreactive T cells.

Topics: Animals; Astrocytes; Autoimmune Diseases; Base Sequence; Benzyl Compounds; Chi-Square Distribution; Clone Cells; Cytokines; Demyelinating Diseases; Dexamethasone; Down-Regulation; Drug Combinations; Encephalitis; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Humans; Hydroxamic Acids; Immunohistochemistry; Metalloendopeptidases; Mice; Microglia; Microscopy, Electron; Multiple Sclerosis; Optic Nerve; Organic Chemicals; Pentoxifylline; Protease Inhibitors; Recurrence; RNA; Spinal Cord; Statistics, Nonparametric; Succinates; Tumor Necrosis Factor-alpha; Up-Regulation