Cell permeable ROS scavengers, Tiron and Tempol, rescue PC12 cell death caused by pyrogallol or hypoxia/reoxygenation

“…This fact necessitated the verification of this association with direct indicators of oxidative stress. Superoxide radical (O 2˙2 ) is such an indicator because it is among the main initiators of oxidative stress (Halliwell & Gutteridge, 1999 Intracellular SOD can be modulated by molecular genetics (introducing multicopy plasmids with a cloned SOD gene) or by certain chemicals (SOD mimetics) that mimic its activity (Day et al, 1995;Gardner et al, 1996;Kubota & Yang, 1984;MacKenzie & Martin, 1998;Mok et al, 1998;Yamada et al, 2003). The fungal strains were grown in 25 ml liquid medium (in Petri dishes) consisting of 0.1 M glucose, 15 mM NH 4 NO 3 , 2 mM NaCl, 0.5 mM MgSO 4 , 0.01 mM FeCl 3 , 0.015 mM MnCl 2 , 0.07 mM ZnCl 2 , 0.001 mM thiamine and 0.1 % (w/v) yeast extract, in 10 mM potassium phosphate buffer, pH 7.…”

Section: Introductionmentioning

confidence: 99%

“…Organisms possess the antioxidant extra-and intracellular superoxide dismutase (SOD) to protect against the deleterious actions of O 2˙2 by catalysing its dismutation to H 2 O 2 and O 2 . Intracellular SOD can be modulated by molecular genetics (introducing multicopy plasmids with a cloned SOD gene) or by certain chemicals (SOD mimetics) that mimic its activity (Day et al, 1995;Gardner et al, 1996;Kubota & Yang, 1984;MacKenzie & Martin, 1998;Mok et al, 1998;Yamada et al, 2003). In this work, we studied the effect of O 2˙2 in the degree of differentiation of S. rolfsii, S. minor, S. sclerotiorum and R. solani by modulating intracellular concentrations of O 2˙2 and SOD with the SOD mimetics Tiron and TEMPOL in relation to the indirect marker of oxidative stress, lipid peroxidation.…”

Section: Introductionmentioning

confidence: 99%

Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study

Papapostolou

Georgiou

2010

Microbiology

View full text Add to dashboard Cite

This study shows that the superoxide radical (O 2˙" ), a direct indicator of oxidative stress, is involved in the differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, shown by using superoxide dismutase (SOD) mimetics to decrease their sclerotial differentiation. The production rate of O 2˙" and SOD levels in these fungi, as expected, were significantly lowered by the SOD mimetics, with concomitant decrease of the indirect indicator of oxidative stress, lipid peroxidation. INTRODUCTIONSclerotial differentiation is a primitive form of differentiation exhibited by certain phytopathogenic filamentous fungi. It is expressed by four main types of sclerotia (compact bodies of aggregated hyphae), which are loose, terminal, lateral-chained and lateral-simple. These types are represented mainly, but not solely, by Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, respectively (Chet et al., 1967(Chet et al., , 1969Chet & Henis, 1975;Le Tourneau, 1979;Willetts, 1971Willetts, , 1978Willetts, , 1997Willetts & Wong, 1980). These fungi are of great agricultural interest because they cause stem-rot diseases in a wide variety of economically important agricultural crops. Therefore, elucidating the mechanisms of sclerotium biogenesis of these fungi may lead to the development of non-toxic ways to combat plant diseases, which could be used as alternatives to the traditional toxic fungicides. Moreover, understanding sclerotial differentiation is very important because it will help to understand more complex forms of differentiation in other organisms as well as whether their mechanisms share common biochemical pathways.It has been proposed that sclerotial differentiation is related to high oxidative stress (Georgiou, 1997), based on the finding that sclerotium biogenesis in S. rolfsii was accompanied by the accumulation of high levels of lipid peroxidation products. This finding has been supported by other studies that developed into a theory of oxidative stress as an inducer of sclerotial metamorphosis (Georgiou et al., 2006). Specifically, hydroxyl radical scavengers, vitamin C and b-carotene (both also acting as endogenous fungal antioxidants), decreased sclerotial differentiation in S. rolfsii, S. minor, S. sclerotiorum and R. solani. In more recent studies, we demonstrated a strong relationship between the thiol redox state of these fungi and their sclerotial differentiation (Patsoukis & Georgiou, 2007a, b, 2008a. Specifically, in R. solani, S. rolfsii and S. minor, there was a decrease in the total amount of reduced thiols during transformation of the undifferentiated mycelium into sclerotium, which, for S. sclerotiorum was accompanied by an increase in the total oxidized components. Moreover, the antioxidant thiol redox state modulator N-acetylcysteine inhibited sclerotial differentiation in S. rolfsii, R. solani and S. sclerotiorum.Until now, our studies have associated only indirect indicators ...

show abstract

“…•-generator (10,11). This compound is often used to investigate the role of O 2 •-in biological systems.…”

Section: Introductionmentioning

confidence: 99%

Pyrogallol as a glutathione depletorinduces apoptosis in HeLa cells

Han

Kim²,

Kim³

et al. 2008

Int J Mol Med

View full text Add to dashboard Cite

Abstract. Pyrogallol, a polyphenol, is known to be a superoxide anion (O 2 •-) generator. We investigated the involvement of glutathione (GSH) and reactive oxygen species (ROS) in pyrogallol-induced HeLa cell death. We measured the changes of ROS levels, GSH levels, sub-G1 cells, annexin V/PI staining cells and mitochondria membrane potential (ΔΨ m ) in HeLa cells treated with pyrogallol and/or ROS scavenger. The intracellular ROS levels were decreased or increased depending on the concentration of pyrogallol. The level of O 2•-was significantly increased and superoxide dismutase (SOD) activity was down-regulated by pyrogallol. Pyrogallol reduced intracellular GSH content in HeLa cells. The ROS scavengers, Tempol, Tiron, Trimetazidine and N-acetylcysteine (NAC), did not down-regulate the production of O 2•-. However, treatment with NAC showed the recovery of GSH depletion and significantly rescued cells from pyrogallolinduced apoptosis. In addition, the recovery of GSH depletion by SOD and catalase was accompanied by the decrease of apoptosis levels. Furthermore, NAC and SOD significantly inhibited CMF-negative (GSH-depleted) and PI-positive cells induced by pyrogallol. Taken together, pyrogallol potently increased intracellular O 2•-levels and decreased GSH content in HeLa cells, and NAC, SOD and catalase significantly rescued HeLa cells from pyrogallol-induced apoptosis accompanied by the recovery of GSH depletion.

show abstract

Cell permeable ROS scavengers, Tiron and Tempol, rescue PC12 cell death caused by pyrogallol or hypoxia/reoxygenation

Cited by 135 publications

References 52 publications

Reduction of paraquat-induced renal cytotoxicity by manganese and copper complexes of EGTA and EHPG

Reduction of paraquat-induced renal cytotoxicity by manganese and copper complexes of EGTA and EHPG

Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study

Pyrogallol as a glutathione depletorinduces apoptosis in HeLa cells

Contact Info

Product

Resources

About