Cellular oxidant stress and advanced glycation endproducts of albumin: caveats of the dichlorofluorescein assay.

In order to understand the mechanism by which advanced glycation endproducts (AGEs) elicit oxidative stress, macrophage-like RAW264.7 cells were exposed to various AGE-albumins, and oxidant stress was estimated from the fluorescence of oxidized dichlorofluorescein using the microtiter plate assay. Strongest fluorescence was observed with methylglyoxal modified albumin (MGO-BSA) compared with native albumin.

Oxidative stress and increased expression of growth factors in lesions of failed hemodialysis access.

The pathological role of oxidative stress in patients treated by hemodialysis has gained increasing recognition in recent years. Because complications related to vascular access are a major source of morbidity, immunohistochemical evidence of oxidative stress and activation of growth factors were examined in native arteriovenous (AV) fistulae (n = 11) and expanded polytetrafluoroethylene (ePTFE) grafts (n = 15) recovered from hemodialysis patients at the time of surgical revision or resection. To show the presence of oxidative stress in tissues, three markers were chosen: N(epsilon)(carboxymethyl)lysine, a structurally identified advanced glycation end product; 4-hydroxy-2,3-nonenol, a lipid peroxidation product; and redox-active transition metals bound to proteins, a source of Fenton chemistry-generated free radicals.

AGEs induce oxidative stress and activate protein kinase C-beta(II) in neonatal mesangial cells.

Increased activation of specific protein kinase C (PKC) isoforms and increased nonenzymatic glycation of intracellular and extracellular proteins [the accumulation of advanced glycation end products (AGEs)] are major mechanistic pathways implicated in the pathogenesis of diabetic complications. Blocking PKC-beta(II) has been shown to decrease albuminuria in animal models of diabetes. To demonstrate a direct relationship between AGEs and the induction and translocation of PKC-beta(II), studies were carried out in rat neonatal mesangial cells, known to express PKC-beta(II) in association with rapid proliferation in post-natal development.

Peroxynitrite protects RAW 264.7 macrophage from Lipopolysaccharide/Interferon-gamma-induced cell death.

Peroxynitrite, formed by the interaction of superoxide with nitric oxide, has previously been implicated mostly as a cytotoxic agent. In contrast, its physiological and, possibly, beneficial effects are largely unknown. We have previously shown [Journal of Biological Chemistry, 1997, 272, 7253] that RAW 264.

In vitro immunoglobulin production in relatives of patients with IgA nephropathy.

We hypothesized that the altered immunoglobulin synthesis and/or lymphocyte function apparent in patients with IgA nephropathy might be, at least partially, genetically determined. To address this hypothesis, immunoglobulin production by peripheral blood mononuclear cells in 22 patients with IgA nephropathy and 44 of their first degree relatives was investigated. Spontaneous overproduction of IgA1 and IgM from patients' PBMC was found.