Contracting skeletal muscle produces reactive oxygen species (ROS) that have been shown to affect muscle function and adaptation. However, real-time measurement of ROS in contracting myofibers has proven to be difficult. We used amphibian (Xenopus laevis) muscle to test the hypothesis that ROS are formed during contractile activity in isolated single skeletal muscle fibers and that this contrac...

Background: Free radicals and reactive oxygen species(ROS) are the most important factors in formation of oxidative stress reaction. Now, radical damage has been suggested to contribute to a wide variety of diseases such as Alzheimer, atherosclerosis and cancer. Transition metal ions in the presence of the various biomolecules produce these active compounds. The aim of this study is introducing...

Many inflammatory diseases, as well as infections, are accompanied by elevation in cellular levels of Reactive Oxygen Species (ROS). Here we report that MPYS, a.k.a. STING, which was recently shown to mediate activation of IFNβ expression during infection, is a ROS sensor. ROS induce intermolecular disulfide bonds formation in MPYS homodimer and inhibit MPYS IFNβ stimulatory activity. Cys-64, -...

Dacarbazine is an antitumor prodrug which is used for the treatment of malignant metastatic melanoma and Hodgkin’s disease. It requires initial activation in liver through an N-demethylationreaction. The active metabolite prevents the progress of disease via alkylation of guanine bases in DNA strands. In order to investigate the importance of imidazole ring and its dynamictautomerization in ant...

background: clinical evidence indicates the diabetes-induced impairment of osteogenesis caused by a decrease in osteoblast activity. flavonoids can increase the differentiation and mineralization of osteoblasts in a high-glucose state. however, some flavonoids such as luteolin may have the potential to induce cytotoxicity in osteoblast-like cells. this study was performed to investigate whether...

rheumatoid arthritis is a disease associated with painful joints that affects approximately 1% of the population worldwide, and for which no effective cure is available. it is characterized by chronic joint inflammation and variable degrees of bone and cartilage erosion. oxygen metabolism has an important role in the pathogenesis of rheumatoid arthritis. reactive oxygen species (ros) are produc...

it has already been reported that muscle necrosis induced by various phenylenediamine derivatives are correlated with their autoxidation rate. now in a more detailed investigation of the cytotoxic mechanism using a model system of isolated hepatocytes and ring-methylated structural isomer durenediamine (dd) we have shown that under aerobic conditions, phenylenediamine induced cytotoxicity and r...

Ceramide is a key intermediate in the pathway of sphingolipid biosynthesis and is an important intracellular messenger. We recently generated a ceramide synthase 2 (CerS2) null mouse that cannot synthesize very long acyl chain (C22-C24) ceramides. This mouse displays severe and progressive hepatopathy. Significant changes were observed in the sphingolipid profile of CerS2 null mouse liver, incl...

Peroxiredoxins are ubiquitous thiol-specific proteins that have multiple functions in stress protection, including protection against oxidative stress. Tsa1 is the major yeast peroxiredoxin and we show that it functions as a specific antioxidant to protect the cell against the oxidative stress caused by nascent-protein misfolding and aggregation. Yeast mutants lacking TSA1 are sensitive to misf...

The cGMP phosphodiesterase (PDE) of retinal rod outer segments (ROS) is activated by the GTP-bound form of the G protein, transducin (Gt alpha). This activation can be reversed by the inhibitory gamma subunit of PDE through two distinct mechanisms: acceleration of GTP hydrolysis and direct inactivation independent of GTP hydrolysis. We have found that acceleration of Gt alpha GTPase by PDE gamm...