Peripheral leukocytes can exacerbate brain damage by release of cytotoxic mediators that disrupt blood-brain barrier (BBB) function. One of the oxidants released by activated leukocytes is hypochlorous acid (HOCl) formed via the myeloperoxidase (MPO)-H2O2-Cl(-) system. In the present study we examined the role of leukocyte activation, leukocyte-derived MPO and MPO-generated oxidants on BBB func...

Myeloperoxidase (MPO) is a glycosylated hemoprotein contained in the azurophil granules of human polymorphonuclear leukocytes (PMNs). MPO is thought to play a role in the oxidative antimicrobial activity of neutrophils by catalyzing the formation of hypochlorous acid, a potent microbicide, from hydrogen peroxide and chloride anions. Seven unrelated individuals with complete MPO deficiency, a re...

Myeloperoxidase (MPO) functions as a key molecular component of the host defense system against diverse pathogens. We have previously reported that increased MPO levels and activity is a distinguishing feature of rotenone-exposed glial cells, and that either overactivation or deficiency of MPO leads to pathological conditions in the brain. Here, we provide that modulation of MPO levels in glia ...

Polymorphonuclear neutrophil granulocytes have a central role in innate immunity and their programmed cell death and removal are critical for efficient resolution of acute inflammation. Myeloperoxidase (MPO), a heme protein abundantly expressed in neutrophils, is generally associated with killing of bacteria and oxidative tissue injury. Because MPO also binds to neutrophils, we investigated whe...

Hereditary deficiency of myeloperoxidase (MPO) is a common disorder but its genetic basis is unknown. We have reported that neutrophils from individuals with MPO deficiency lack enzymatic and immunochemical evidence for mature MPO but have a 90-kDa precursor protein. We have thus hypothesized that hereditary MPO deficiency reflects a defect in processing of a mutated primary translation product...

To evaluate the possible effect of sampling technique and sequential sampling on gingival crevicular fluid (GCF) volume and myeloperoxidase (MPO) activity, 14 patients presenting at least two symmetrical maxillary sites with mild/moderate periodontitis were selected. Two sites in each individual were sequentially sampled using either the deep-intracrevicular or orifice technique. Spectrophotome...

OBJECTIVES We evaluated whether myeloperoxidase (MPO) predicts future cardiovascular disease (CVD) events in asymptomatic adults and whether subclinical atherosclerosis may affect this relation. BACKGROUND Myeloperoxidase is a leukocyte-derived enzyme-generating reactive oxidant species that has been shown to predict risk of CVD in selected populations. METHODS We studied 1,302 asymptomatic...

The adipokines, leptin and adiponectin, have a prominent role in the pathogenesis of coronary artery disease (CAD). The inflammatory enzyme, myeloperoxidase (MPO) also has an important role in the pathogenesis of CAD. Association of the adipokines with MPO remains to be resolved in patients with CAD. In this case-control study, 100 patients with CAD and 100 control subjects were appropriately r...

Antineutrophil cytoplasmic antibodies (ANCA) are important serologic markers for ANCA-associated vasculitis (AAV). Our previous studies in propylthiouracil (PTU)-induced AAV demonstrated that withdrawal of PTU resulted in clinical remission and significant decrease of avidity of PTU-induced myeloperoxidase (MPO)-ANCA. This study investigated the changes in avidity and titer of MPO-ANCA in seque...