• MeSH
• apoptóza MeSH
• genom MeSH
• kaspasy MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• oprava DNA MeSH
• PARP inhibitory MeSH
• poly(ADP-ribosa)polymerasy terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• recenze MeSH

Cisplatin is one of the most potent chemotherapy drugs against cancer, but its major side effect such as nephrotoxicity limits its use. Inhibition of poly(ADP-ribose) polymerase (PARP) protects against various renal diseases via gene transactivation and/or ADP-ribosylation. However, the role of PARP in necrotic cell death during cisplatin nephrotoxicity remains an open question. Here we demonstrated that pharmacological inhibition of PARP by postconditioning dose-dependently prevented tubular injury and renal dysfunction following cisplatin administration in mice. PARP inhibition by postconditioning also attenuated ATP depletion during cisplatin nephrotoxicity. Systemic release of high mobility group box 1 (HMGB1) protein in plasma induced by cisplatin administration was significantly diminished by PARP inhibition by postconditioning. In in vitro kidney proximal tubular cell lines, PARP inhibition by postconditioning also diminished HMGB1 release from cells. These data demonstrate that cisplatin-induced PARP1 activation contributes to HMGB1 release from kidney proximal tubular cells, resulting in the promotion of inflammation during cisplatin nephrotoxicity.

• MeSH
• akutní poškození ledvin chemicky indukované   metabolismus   MeSH
• cisplatina toxicita   MeSH
• ledvinové kanálky účinky léků   metabolismus   sekrece   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• poly(ADP-ribosa)polymerasa 1 metabolismus   MeSH
• protein HMGB1 sekrece   MeSH
• protinádorové látky toxicita   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Poly(ADP-ribose) is synthesized by PARP enzymes during the repair of stochastic DNA breaks. Surprisingly, however, we show that most if not all endogenous poly(ADP-ribose) is detected in normal S phase cells at sites of DNA replication. This S phase poly(ADP-ribose) does not result from damaged or misincorporated nucleotides or from DNA replication stress. Rather, perturbation of the DNA replication proteins LIG1 or FEN1 increases S phase poly(ADP-ribose) more than 10-fold, implicating unligated Okazaki fragments as the source of S phase PARP activity. Indeed, S phase PARP activity is ablated by suppressing Okazaki fragment formation with emetine, a DNA replication inhibitor that selectively inhibits lagging strand synthesis. Importantly, PARP activation during DNA replication recruits the single-strand break repair protein XRCC1, and human cells lacking PARP activity and/or XRCC1 are hypersensitive to FEN1 perturbation. Collectively, our data indicate that PARP1 is a sensor of unligated Okazaki fragments during DNA replication and facilitates their repair.

• MeSH
• "flap" endonukleasy metabolismus   MeSH
• buněčné linie MeSH
• DNA vazebné proteiny metabolismus   MeSH
• DNA-ligasa ATP metabolismus   MeSH
• DNA genetika   metabolismus   MeSH
• lidé MeSH
• oprava DNA MeSH
• poly(ADP-ribosa)polymerasa 1 metabolismus   MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• polyadenosindifosfátribosa metabolismus   MeSH
• poškození DNA MeSH
• protein XRCC1 metabolismus   MeSH
• replikace DNA fyziologie   MeSH
• S fáze fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Poly(ADP-ribose) polymerase 1 (PARP1) is implicated in the detection and processing of unligated Okazaki fragments and other DNA replication intermediates, highlighting such structures as potential sources of genome breakage induced by PARP inhibition. Here, we show that PARP1 activity is greatly elevated in chicken and human S phase cells in which FEN1 nuclease is genetically deleted and is highest behind DNA replication forks. PARP inhibitor reduces the integrity of nascent DNA strands in both wild-type chicken and human cells during DNA replication, and does so in FEN1-/- cells to an even greater extent that can be detected as postreplicative single-strand nicks or gaps. Collectively, these data show that PARP inhibitors impede the maturation of nascent DNA strands during DNA replication, and implicate unligated Okazaki fragments and other nascent strand discontinuities in the cytotoxicity of these compounds.

• MeSH
• DNA genetika   MeSH
• oprava DNA MeSH
• PARP inhibitory * farmakologie   MeSH
• poly(ADP-ribosa)polymerasa 1 genetika   MeSH
• poškození DNA MeSH
• replikace DNA * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In response to DNA damage, the histone PARylation factor 1 (HPF1) regulates PARP1/2 activity, facilitating serine ADP-ribosylation of chromatin-associated factors. While PARP1/2 are known for their role in DNA single-strand break repair (SSBR), the significance of HPF1 in this process remains unclear. Here, we investigated the impact of HPF1 deficiency on cellular survival and SSBR following exposure to various genotoxins. We found that HPF1 loss did not generally increase cellular sensitivity to agents that typically induce DNA single-strand breaks (SSBs) repaired by PARP1. SSBR kinetics in HPF1-deficient cells were largely unaffected, though its absence partially influenced the accumulation of SSB intermediates after exposure to specific genotoxins in certain cell lines, likely due to altered ADP-ribosylation of chromatin. Despite reduced serine mono-ADP-ribosylation, HPF1-deficient cells maintained robust poly-ADP-ribosylation at SSB sites, possibly reflecting PARP1 auto-poly-ADP-ribosylation at non-serine residues. Notably, poly-ADP-ribose chains were sufficient to recruit the DNA repair factor XRCC1, which may explain the relatively normal SSBR capacity in HPF1-deficient cells. These findings suggest that HPF1 and histone serine ADP-ribosylation are largely dispensable for PARP1-dependent SSBR in response to genotoxic stress, highlighting the complexity of mechanisms that maintain genomic stability and chromatin remodeling.

• MeSH
• buněčné linie MeSH
• chromatin metabolismus   MeSH
• DNA vazebné proteiny metabolismus   genetika   MeSH
• histony metabolismus   MeSH
• jaderné proteiny metabolismus   genetika   MeSH
• jednořetězcové zlomy DNA * MeSH
• lidé MeSH
• oprava DNA * MeSH
• poly-ADP-ribosylace MeSH
• poly(ADP-ribosa)polymerasa 1 * metabolismus   genetika   MeSH
• poly(ADP-ribosa)polymerasy metabolismus   genetika   MeSH
• protein XRCC1 metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The essential components of splicing are the splicing factors accumulated in nuclear speckles; thus, we studied how DNA damaging agents and A-type lamin depletion affect the properties of these regions, positive on the SC-35 protein. We observed that inhibitor of PARP (poly (ADP-ribose) polymerase), and more pronouncedly inhibitors of RNA polymerases, caused DNA damage and increased the SC35 protein level. Interestingly, nuclear blebs, induced by PARP inhibitor and observed in A-type lamin-depleted or senescent cells, were positive on both the SC-35 protein and another component of the spliceosome, SRRM2. In the interphase cell nuclei, SC-35 interacted with the phosphorylated form of RNAP II, which was A-type lamin-dependent. In mitotic cells, especially in telophase, the SC35 protein formed a well-visible ring in the cytoplasmic fraction and colocalized with β-catenin, associated with the plasma membrane. The antibody against the SRRM2 protein showed that nuclear speckles are already established in the cytoplasm of the late telophase and at the stage of early cytokinesis. In addition, we observed the occurrence of splicing factors in the nuclear blebs and micronuclei, which are also sites of both transcription and splicing. This conclusion supports the fact that splicing proceeds transcriptionally. According to our data, this process is A-type lamin-dependent. Lamin depletion also reduces the interaction between SC35 and β-catenin in mitotic cells.

• MeSH
• HeLa buňky MeSH
• laminy metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• PARP inhibitory terapeutické užití   MeSH
• poly(ADP-ribosa)polymerasa 1 MeSH
• RNA-polymerasa II metabolismus   MeSH
• sestřihové faktory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mammalian DNA base excision repair (BER) is accelerated by poly(ADP-ribose) polymerases (PARPs) and the scaffold protein XRCC1. PARPs are sensors that detect single-strand break intermediates, but the critical role of XRCC1 during BER is unknown. Here, we show that protein complexes containing DNA polymerase β and DNA ligase III that are assembled by XRCC1 prevent excessive engagement and activity of PARP1 during BER. As a result, PARP1 becomes "trapped" on BER intermediates in XRCC1-deficient cells in a manner similar to that induced by PARP inhibitors, including in patient fibroblasts from XRCC1-mutated disease. This excessive PARP1 engagement and trapping renders BER intermediates inaccessible to enzymes such as DNA polymerase β and impedes their repair. Consequently, PARP1 deletion rescues BER and resistance to base damage in XRCC1-/- cells. These data reveal excessive PARP1 engagement during BER as a threat to genome integrity and identify XRCC1 as an "anti-trapper" that prevents toxic PARP1 activity.

• MeSH
• buněčné linie MeSH
• DNA vazebné proteiny metabolismus   MeSH
• DNA-ligasa ATP metabolismus   MeSH
• DNA-polymerasa beta metabolismus   MeSH
• DNA genetika   MeSH
• fibroblasty účinky léků   metabolismus   MeSH
• jednořetězcové zlomy DNA MeSH
• lidé MeSH
• oprava DNA účinky léků   genetika   MeSH
• PARP inhibitory farmakologie   MeSH
• poly(ADP-ribosa)polymerasa 1 metabolismus   MeSH
• poly(ADP-ribosa)polymerasy metabolismus   MeSH
• poškození DNA účinky léků   genetika   MeSH
• protein XRCC1 metabolismus   MeSH
• vazba proteinů účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Replication factor C (RFC), a heteropentamer of RFC1-5, loads PCNA onto DNA during replication and repair. Once DNA synthesis has ceased, PCNA must be unloaded. Recent findings assign the uloader role primarily to an RFC-like (RLC) complex, in which the largest RFC subunit, RFC1, has been replaced with ATAD5 (ELG1 in Saccharomyces cerevisiae). ATAD5-RLC appears to be indispensable, given that Atad5 knock-out leads to embryonic lethality. In order to learn how the retention of PCNA on DNA might interfere with normal DNA metabolism, we studied the response of ATAD5-depleted cells to several genotoxic agents. We show that ATAD5 deficiency leads to hypersensitivity to methyl methanesulphonate (MMS), camptothecin (CPT) and mitomycin C (MMC), agents that hinder the progression of replication forks. We further show that ATAD5-depleted cells are sensitive to poly(ADP)ribose polymerase (PARP) inhibitors and that the processing of spontaneous oxidative DNA damage contributes towards this sensitivity. We posit that PCNA molecules trapped on DNA interfere with the correct metabolism of arrested replication forks, phenotype reminiscent of defective homologous recombination (HR). As Atad5 heterozygous mice are cancer-prone and as ATAD5 mutations have been identified in breast and endometrial cancers, our finding may open a path towards the therapy of these tumours.

• MeSH
• ATPázy spojené s různými buněčnými aktivitami genetika   metabolismus   MeSH
• buněčné linie MeSH
• chromatin enzymologie   MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• DNA metabolismus   MeSH
• ftalaziny farmakologie   MeSH
• kur domácí MeSH
• mutageny toxicita   MeSH
• nádorové buněčné linie MeSH
• nestabilita genomu MeSH
• PARP inhibitory farmakologie   MeSH
• piperaziny farmakologie   MeSH
• poly(ADP-ribosa)polymerasa 1 metabolismus   MeSH
• poškození DNA * MeSH
• protinádorové látky farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Vztah zárodečných BRCA-mutací k incidenci ovariálního karcinomu je dobře znám. Celoživotní riziko vzniku karcinomu vaječníků činí u nosiček mutace genu BRCA1 60 % a nosiček mutace genu BRCA2 přibližně 10–20 %. Geny BRCA1 a BRCA2 patří mezi reparační geny, účastní se opravy zlomů dvojité šroubovice DNA prostřednictvím homologní rekombinace. Při jejich mutaci dochází k poruše reparace DNA. Ovariální tumory u pacientek s mutací BRCA mají relativně uniformní chování charakterizované vyšší odpovědí na chemoterapii založenou na platině v první i dalších liniích léčby, delším celkovým přežitím a obvykle i histologií, nejčastěji v podobě high-grade serózního karcinomu. Díky specifiku mutace v BRCA genech 1 a 2 se dostávají u pacientek s ovariálním karcinomem, ale i karcinomem prsu do popředí nové molekuly, a to především inhibitory poly(ADP-ribose) polymerázy (PARP). Inhibice PARP u nádorových buněk s mutacemi BRCA vede k potlačení schopnosti opravy DNA a zlepšení efektu cytotoxické léčby, jsou však účinné i v monoterapii.

Relationship BRCA germline mutations to the incidence of ovarian cancer is well known. The lifetime risk of deve­lopment ovarian cancer is among BRCA1 gene mutation carriers 60 % and of BRCA2 gene mutation carriers around 10–20 %. The genes BRCA1 and BRCA2 belong to group of reparation genes, which participates in the repair of the DNA strand breaks by homologous recombination. Mutation in these cases leads to failure of DNA repair. Ovarian tumors in patients with BRCA mutations are relatively uniform behavior, characterized by higher response rates to platinum-based chemotherapy in the first as well as the other lines of treatment, longer survival, and usually high-grade serous carcinoma histology. In patients with ovarian or breast cancer, due to particularity of mutations in the BRCA genes 1 and 2, new molecules especially inhibitors of poly (ADP- ribose) polymerase (PARP), gets to forefront of the treatment. Inhibition of PARP activity in tumor cells with BRCA mutations leads to the suppression of the ability of DNA repair and improves the effect of cytotoxic treatment, but PARP inhibitors are also effective in monotherapy.

• MeSH
• buněčná smrt genetika   MeSH
• cílená genová oprava MeSH
• dvojitá slepá metoda MeSH
• fyziologie buňky MeSH
• geny BRCA1 * účinky léků   MeSH
• geny BRCA2 * účinky léků   MeSH
• histologie MeSH
• klinické zkoušky, fáze II jako téma MeSH
• kombinovaná farmakoterapie MeSH
• lidé MeSH
• mutace MeSH
• nádory vaječníků * patofyziologie   terapie   MeSH
• PARP inhibitory MeSH
• poly(ADP-ribosa)polymerasy * aplikace a dávkování   genetika   terapeutické užití   MeSH
• poruchy opravy DNA MeSH
• přežití MeSH
• randomizované kontrolované studie jako téma MeSH
• recidiva MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

Autophagy and poly(ADP-ribose) polymerase 1 (PARP-1) are activated and involved in a series of cell processes under oxidative stress, which is associated with pathogenesis of atherosclerosis. Research on their relationship under oxidative stress has been limited. In this study, we aimed to investigate the activation, relationship, and role of autophagy and PARP-1 in vascular smooth muscle cell (VSMC) death under oxidative stress. This study explored the signal molecule PARP-1 and autophagy in VSMCs using gene silencing and the hydrogen peroxide (H2O2)-stimulated oxidative stress model. We observed that H2O2 could induce autophagy in VSMCs, and the inhibition of autophagy could protect VSMCs against oxidative stress-mediated cell death. Meanwhile, PARP-1 could also be activated by H2O2. Additionally, we analysed the regulatory role of PARP-1 in oxidative stress-mediated autophagy and found that PARP-1 was a novel factor involved in the H2O2-induced autophagy via the AMPK-mTOR pathway. Finally, PARP-1 inhibition protected VSMCs against caspase-dependent apoptosis. These data suggested that PARP-1 played a critical role in H2O2-mediated autophagy and both of them were involved in apoptosis of VSMCs.

• MeSH
• apoptóza * účinky léků   MeSH
• autofagie * účinky léků   MeSH
• kaspasy metabolismus   MeSH
• myocyty hladké svaloviny účinky léků   metabolismus   patologie   MeSH
• myši inbrední C57BL MeSH
• oxidační stres * účinky léků   MeSH
• peroxid vodíku toxicita   MeSH
• poly(ADP-ribosa)polymerasy metabolismus   MeSH
• svaly hladké cévní patologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH