Publications (10) View all
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Article: Poly(ADP-ribose) polymerase during reperfusion after transient forebrain ischemia
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ABSTRACT: The activation of poly(ADP-ribose) polymerase (PARP) in the reperfused brain after ischemia has been assumed but never has been directly presented. Our studies indicate a different dynamic of PARP activity alteration in hippocampus during reperfusion after 3 and 10 min of transient forebrain ischemia in gerbils. The phasic stimulation of PARP activity was observed during reperfusion 15 min, 120 min, and 4 d after 3 min of ischemia with subsequent lowering of its activity close to control value on the seventh day of reperfusion. After 10 min of ischemic insult, PARP activity significantly increased from the third to the seventh day of reperfusion. The protein level of PARP was not significantly changed during reperfusion after 3 and 10 min of ischemia, with one exception: On the third day after 10 min of ischemia, PARP protein level was 28% lower compared to control; however, no enhancement of 85-kDa protein immunoreactivity was observed. These data indicate the lack of PARP cleavage in hippocampus of gerbils subjected to ischemia-reperfusion injury. The inhibitor of PARP, 3-aminobenzamide (3-AB) in a dose of 30 mg/kg b.w. (body weight) injected intravenously directly after 3 min of ischemia protects >60% of neuronal cells against death in the CA1 layer of hippocampus but has no effect after 10 min of ischemic episode. 3-AB decreased forebrain edema significantly after 3 and 10 min of ischemia. Our data indicate that PARP inhibitor(s) might offer a potent therapeutic strategy for short global ischemia. The combination of PARP inhibitor with potent antioxidant might enhance its ameliorating effect.Journal of Molecular Neuroscience 04/2012; 20(1):61-71. · 2.50 Impact Factor -
Article: Poly(ADP-ribose) polymerase
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ABSTRACT: Poly(ADP-ribose) polymerase (PARP)-1 is a DNA nick sensor that transforms ADP-ribose from βNAD+ in the form of polymer to over 40 nuclear proteins, particularly to histones, several transcription factors, and PARP itself, modulating their activities and functions. PARP-1 activated by DNA breaks facilitates transcription, replication, and DNA base excision repair. The last studies indicate that PARP-1 is the new nuclear target for fast signals evoked in cell membranes by depolarization and cholinergic and glutaminergic receptors stimulation. Excessive activation of PARP-1 by peroxynitrate-evoked DNA damage during oxidative stress can cause cell death by NAD+/ATP depletion after ischemia-reperfusion injury, inflammation, and diabetes mellitus. The PARP-1 through interaction with nuclear factor-κB, p53, and other transcription factors might significantly modulate cell survival and death and a type of death pathway. The pharmacological modulation of PARP-1 might offer a new effective approach for neuroprotection.Molecular Neurobiology 04/2012; 31(1):149-167. · 5.74 Impact Factor -
Article: Lipoxygenases and poly(ADP-ribose) polymerase in amyloid beta cytotoxicity.
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ABSTRACT: The 12/15-lipoxygenase(s) (LOX), poly(ADP-ribose) polymerase (PARP-1) activity and mitochondrial apoptosis inducing factor (AIF) protein in the amyloid β (Aβ) toxicity were investigated in PC12 cells that express either wild-type (APPwt) or double Swedish mutation (APPsw) forms of human Aβ precursor protein. Different levels of Aβ secretion and free radicals formation characterize these cells. The results demonstrated a relationship between the Aβ levels and LOX protein expression and activity. High Aβ concentration in APPsw cells correlated with a significant increase in free radicals and LOX activation, which leads to translocation of p65/NF-κB into the nucleus. An increase in AIF expression in mitochondria was observed concurrently with inhibition of PARP-1 activity in the nuclear fraction of APPsw cells. We suggested that AIF accumulation in mitochondria may be involved in adaptive/protective processes. However, inhibition of PARP-1 may be responsible for the disturbances in transcription and DNA repair as well as the degeneration of APP cells. Under conditions of increased nitrosative stress, evoked by the nitric oxide donor, sodium nitroprusside (SNP, 0.5 mM), 70-80% of all cells types died after 24 h, significantly more in APPsw cells. There was no further significant change in mitochondrial AIF level and PARP-1 activity compared to corresponding non-treated cells. Only one exception was observed in PC12 control, where SNP significantly inhibits PARP-1 activity. Moreover, SNP significantly activated gene expression for 12/15-LOX in all types of investigated cells. Inhibitors of all LOX isoforms and specific inhibitor of 12-LOX enhanced the survival of cells that were subjected to SNP. We conclude that the LOX pathways may play a role in Aβ toxicity and in nitrosative-stress-induced cell death and that inhibition of these pathways offers novel protective strategies.Neurochemical Research 02/2011; 36(5):839-48. · 2.24 Impact Factor -
Article: Poly(ADP-ribose) metabolism in brain and its role in ischemia pathology.
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ABSTRACT: The biological roles of poly(ADP-ribose) polymers (PAR) and poly(ADP-ribosyl)ation of proteins in the central nervous system are diverse. The homeostasis of PAR orchestrated by poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) is crucial for cell physiology and pathology. Both enzymes are ubiquitously distributed in neurons and glia; however, they are segregated at the subcellular level. PARP-1 serves as a "nick sensor" for single- or double-stranded breaks in DNA and is involved in long and short patch base-excision repair, while PARG breaks down PAR. The stimulation of PARP-1 and PAR formation can activate proinflammatory transcription factors, including nuclear factor kappa B. However, hyperactivation of PARP-1 can result in depletion of NAD/ATP, and in PAR-dependent mitochondrial pore formation leading to release of apoptosis inducing factor and cell death. The role of PAR as a death signaling molecule in brain ischemia-reperfusion and inflammation as well as the effect of gender and aging is presented in this review. Modulating the PAR level through pharmacological or genetic intervention on PARP-1/PARG activity and gene expression should be a valuable way for neuroprotective strategy.Molecular Neurobiology 06/2010; 41(2-3):187-96. · 5.74 Impact Factor -
Article: Effect of aging and oxidative/genotoxic stress on poly(ADP-ribose) polymerase-1 activity in rat brain.
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ABSTRACT: Poly(ADP-ribose) polymerase-1 (PARP-1, EC 2.4.2.30), a DNA-bound enzyme, plays a key role in genome stability, but after overactivation can also be responsible for cell death. The aim of the present study was to investigate PARP-1 activity in the hippocampus, brain cortex, striatum and cerebellum in adult (4 months) and aged (24 months) specific pathogen free Wistar rats and to correlate it with PARP-1 protein level and p53 expression. Moreover, the response of PARP-1 in adult and aged hippocampus to oxidative/genotoxic stress was evaluated. Our data indicated a statistically significant enhancement of PARP-1 activity in aged hippocampus and cerebral cortex comparing to adults without statistically significant changes in PARP-1 protein level. The expression of p53 mRNA was elevated in all aged brain parts with the exception of the cerebral cortex. Our data suggest that enhancement of PARP-1 activity and p53 expression in aged brain may indicate higher DNA damage. Our data also indicate that during excessive oxidative/genotoxic stress there is no response of PARP-1 activity in aged hippocampus in contrast to a significant enhancement of PARP-1 activity in adults which may have important consequences for the physiology and pathology of the brain.Acta biochimica Polonica 02/2005; 52(4):909-14. · 1.49 Impact Factor
