sodium-bromide and Disease-Models--Animal

Autism Spectrum Disorders (ASD) are neurodevelopmental disorders whose diagnosis relies on deficient social interaction and communication together with repetitive behavior. To date, no pharmacological treatment has been approved that ameliorates social behavior in patients with ASD. Based on the excitation/inhibition imbalance theory of autism, we hypothesized that bromide ions, long used as an antiepileptic medication, could relieve core symptoms of ASD. We evaluated the effects of chronic sodium bromide (NaBr) administration on autistic-like symptoms in three genetic mouse models of autism: Oprm1

Topics: Animals; Autism Spectrum Disorder; Autistic Disorder; Behavior, Animal; Bromides; Disease Models, Animal; Fragile X Mental Retardation Protein; Mice; Mice, Knockout; Microfilament Proteins; Nerve Tissue Proteins; Receptors, GABA-A; Social Behavior; Sodium Compounds

A seminal study recently demonstrated that bromide (Br-) has a critical function in the assembly of type IV collagen in basement membrane (BM), and suggested that Br- supplementation has therapeutic potential for BM diseases. Because salts of bromide (KBr and NaBr) have been used as antiepileptic drugs for several decades, repositioning of Br- for BM diseases is probable. However, the effects of Br- on glomerular basement membrane (GBM) disease such as Alport syndrome (AS) and its impact on the kidney are still unknown. In this study, we administered daily for 16 weeks 75 mg/kg or 250 mg/kg (within clinical dosage) NaBr or NaCl (control) via drinking water to 6-week-old AS mice (mouse model of X-linked AS). Treatment with 75 mg/kg NaBr had no effect on AS progression. Surprisingly, compared with 250 mg/kg NaCl, 250 mg/kg NaBr exacerbated the progressive proteinuria and increased the serum creatinine and blood urea nitrogen in AS mice. Histological analysis revealed that glomerular injury, renal inflammation and fibrosis were exacerbated in mice treated with 250 mg/kg NaBr compared with NaCl. The expressions of renal injury markers (Lcn2, Lysozyme), matrix metalloproteinase (Mmp-12), pro-inflammatory cytokines (Il-6, Il-8, Tnf-α, Il-1β) and pro-fibrotic genes (Tgf-β, Col1a1, α-Sma) were also exacerbated by 250 mg/kg NaBr treatment. Notably, the exacerbating effects of Br- were not observed in wild-type mice. These findings suggest that Br- supplementation needs to be carefully evaluated for real positive health benefits and for the absence of adverse side effects especially in GBM diseases such as AS.

Topics: Animals; Blood Urea Nitrogen; Bromides; Creatinine; Disease Models, Animal; Glomerular Basement Membrane; Kidney; Kidney Diseases; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Nephritis; Nephritis, Hereditary; Nitrogen; Potassium Compounds; Proteinuria; Sodium Compounds

Eosinophilic endocarditis is a potentially lethal complication of chronic peripheral blood hypereosinophilia. We hypothesized that eosinophil peroxidase (EPO), an abundant eosinophil (EO) cationic granule protein, promotes eosinophilic endocarditis by binding to negatively charged endocardium, and there generating cytotoxic oxidants. Using an immunocytochemical technique, we demonstrated endocardial deposition of EPO in the heart of a patient with hypereosinophilic heart disease. Because EPO preferentially oxidizes Br- to hypobromous acid (HOBr) rather than Cl- to hypochlorous acid (HOCl) at physiologic halide concentrations, we characterized the Br(-)-dependent toxicity of both activated EOs and purified human EPO towards several types of endothelial cells and isolated working rat hearts. In RPMI supplemented with 100 microM Br-, phorbol myristate acetate-activated EOs, but not polymorphonuclear leukocytes, caused 1.8-3.6 times as much 51Cr release from four types of endothelial cell monolayers as in RPMI alone. H2O2 and purified human EPO, especially when bound to cell surfaces, mediated extraordinarily potent, completely Br(-)-dependent cytolysis of endothelial cells that was reversed by peroxidase inhibitors, HOBr scavengers, and competitive substrates. We further modeled eosinophilic endocarditis by instilling EPO into the left ventricles of isolated rat hearts, flushing unbound EPO, then perfusing them with a buffer containing 100 microM Br- and 1 microM H2O2. Acute congestive heart failure (evidenced by a precipitous decrement in rate pressure product, stroke volume work, aortic output, and MVO2 to 0-33% of control values) ensued over 20 min, which deletion of EPO, Br-, or H2O2 completely abrogated. These findings raise the possibility that EPO bound to endocardial cells might utilize H2O2 generated either by overlying phagocytes or endogenous cardiac metabolism along with the virtually inexhaustible supply of Br- from flowing blood to fuel HOBr-mediated cell damage. By this mechanism, EPO may play an important role in the pathogenesis of eosinophilic endocarditis.

Topics: Animals; Bromides; Disease Models, Animal; Endocarditis; Endocardium; Endothelium, Vascular; Eosinophil Peroxidase; Eosinophilia; Eosinophils; Humans; Hydrogen Peroxide; In Vitro Techniques; Male; Peroxidases; Rats; Rats, Inbred Strains; Sodium; Sodium Compounds