Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.016
Filtrar
1.
Nat Commun ; 13(1): 4547, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35927262

RESUMO

The DNA polymerase theta (Polθ)-mediated end joining (TMEJ) pathway for repair of chromosomal double strand breaks (DSBs) is essential in cells deficient in other DSB repair pathways, including hereditary breast cancers defective in homologous recombination. Strand-break activated poly(ADP) ribose polymerase 1 (PARP1) has been implicated in TMEJ, but the modest specificity of existing TMEJ assays means the extent of effect and the mechanism behind it remain unclear. We describe here a series of TMEJ assays with improved specificity and show ablation of PARP activity reduces TMEJ activity 2-4-fold. The reduction in TMEJ is attributable to a reduction in the 5' to 3' resection of DSB ends that is essential for engagement of this pathway and is compensated by increased repair by the nonhomologous-end joining pathway. This limited role for PARP activity in TMEJ helps better rationalize the combined employment of inhibitors of PARP and Polθ in cancer therapy.


Assuntos
Poli(ADP-Ribose) Polimerases , Ribose , Difosfato de Adenosina , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Reparo do DNA , DNA Polimerase Dirigida por DNA , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo
2.
Biochem Soc Trans ; 50(4): 1169-1177, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35959996

RESUMO

Poly (ADP-ribose) polymerase-1 (PARP1) and 2 (PARP2) are two DNA damage-induced poly (ADP-ribose) (PAR) polymerases in cells and are the targets of PARP inhibitors used for cancer therapy. Strand breaks recruit and activate PARP1 and 2, which rapidly generate PAR from NAD+. PAR promotes the recruitment of other repair factors, relaxes chromatin, and has a role in DNA repair, transcription regulation, and RNA biology. Four PARP1/2 dual inhibitors are currently used to treat BRCA-deficient breast, ovarian, prostate, and pancreatic cancers. In addition to blocking the enzymatic activity of PARP1 and 2, clinical PARP inhibitors extend the appearance of PARP1 and PARP2 on chromatin after damage, termed trapping. Loss of PARP1 confers resistance to PARP inhibitors, suggesting an essential role of trapping in cancer therapy. Yet, whether the persistent PARP1 and 2 foci at the DNA damage sites are caused by the retention of the same molecules or by the continual exchange of different molecules remains unknown. Here, we discuss recent results from quantitative live-cell imaging studies focusing on PARP1 and PARP2's distinct DNA substrate specificities and modes of recruitment and trapping with implications for cancer therapy and on-target toxicities of PARP inhibitors.


Assuntos
Neoplasias , Inibidores de Poli(ADP-Ribose) Polimerases , Cromatina , Reparo do DNA , Humanos , Masculino , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/genética
3.
DNA Repair (Amst) ; 118: 103382, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35963141

RESUMO

ADP-ribosylation (ADPr) is a widespread post-translational modification (PTM) spanning all kingdoms of life. It is employed by bacteria and viruses in their war against the host, and by eukaryotes to regulate many physiological processes, across almost all cellular compartments. PARP1, the founding member of the PARP family, is an early sensor of single- and double-strand breaks and catalyzes ADPr to mediate DNA damage repair. The recent discovery of Serine-ADPr and the PARP1 accessory factor HPF1 has brought a momentous change to the field. Bolstered by innovative ways to study ADPr, new and exciting research directions are rapidly emerging. In this review we explore our understanding of the HPF1/PARP1-mediated ADPr signaling pathway in DNA damage. We focus on the mechanistic steps leading to Serine-ADPr and its relevance in the DNA damage response. We discuss important technological advances that have enabled a nuanced study of Serine-ADPr, and conclude with an overview of the role of PARP inhibitors in cancer therapy.


Assuntos
ADP-Ribosilação , Serina , Dano ao DNA , Reparo do DNA , Poli(ADP-Ribose) Polimerase-1/metabolismo , Processamento de Proteína Pós-Traducional , Serina/metabolismo
4.
Int J Mol Sci ; 23(13)2022 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-35806109

RESUMO

Human poly(ADP)-ribose polymerase-1 (PARP1) is a global regulator of various cellular processes, from DNA repair to gene expression. The underlying mechanism of PARP1 action during transcription remains unclear. Herein, we have studied the role of human PARP1 during transcription through nucleosomes by RNA polymerase II (Pol II) in vitro. PARP1 strongly facilitates transcription through mononucleosomes by Pol II and displacement of core histones in the presence of NAD+ during transcription, and its NAD+-dependent catalytic activity is essential for this process. Kinetic analysis suggests that PARP1 facilitates formation of "open" complexes containing nucleosomal DNA partially uncoiled from the octamer and allowing Pol II progression along nucleosomal DNA. Anti-cancer drug and PARP1 catalytic inhibitor olaparib strongly represses PARP1-dependent transcription. The data suggest that the negative charge on protein(s) poly(ADP)-ribosylated by PARP1 interact with positively charged DNA-binding surfaces of histones transiently exposed during transcription, facilitating transcription through chromatin and transcription-dependent histone displacement/exchange.


Assuntos
Histonas , Nucleossomos , Difosfato de Adenosina , DNA/química , Histonas/metabolismo , Humanos , Cinética , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Transcrição Genética
5.
Int J Mol Sci ; 23(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35806303

RESUMO

Differential evolution of apoptosis, programmed necrosis, and autophagy, parthanatos is a form of cell death mediated by poly(ADP-ribose) polymerase 1 (PARP1), which is caused by DNA damage. PARP1 hyper-activation stimulates apoptosis-inducing factor (AIF) nucleus translocation, and accelerates nicotinamide adenine dinucleotide (NAD+) and adenosine triphosphate (ATP) depletion, leading to DNA fragmentation. The mechanisms of parthanatos mainly include DNA damage, PARP1 hyper-activation, PAR accumulation, NAD+ and ATP depletion, and AIF nucleus translocation. Now, it is reported that parthanatos widely exists in different diseases (tumors, retinal diseases, neurological diseases, diabetes, renal diseases, cardiovascular diseases, ischemia-reperfusion injury...). Excessive or defective parthanatos contributes to pathological cell damage; therefore, parthanatos is critical in the therapy and prevention of many diseases. In this work, the hallmarks and molecular mechanisms of parthanatos and its related disorders are summarized. The questions raised by the recent findings are also presented. Further understanding of parthanatos will provide a new treatment option for associated conditions.


Assuntos
Parthanatos , Trifosfato de Adenosina , Fator de Indução de Apoptose/genética , Fator de Indução de Apoptose/metabolismo , Morte Celular/fisiologia , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo
6.
Int J Mol Sci ; 23(14)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35887176

RESUMO

Parthanatos is programmed cell death mediated by poly(ADP-ribose) polymerase 1 (PARP1) after DNA damage. PARP1 acts by catalyzing the transfer of poly(ADP-ribose) (PAR) polymers to various nuclear proteins. PAR is subsequently cleaved, generating protein-free PAR polymers, which are translocated to the cytoplasm where they associate with cytoplasmic and mitochondrial proteins, altering their functions and leading to cell death. Proteomic studies revealed that several proteins involved in endocytosis bind PAR after PARP1 activation, suggesting endocytosis may be affected by the parthanatos process. Endocytosis is a mechanism for cellular uptake of membrane-impermeant nutrients. Rab5, a small G-protein, is associated with the plasma membrane and early endosomes. Once activated by binding GTP, Rab5 recruits its effectors to early endosomes and regulates their fusion. Here, we report that after DNA damage, PARP1-generated PAR binds to Rab5, suppressing its activity. As a result, Rab5 is dissociated from endosomal vesicles, inhibiting the uptake of membrane-impermeant nutrients. This PARP1-dependent inhibition of nutrient uptake leads to cell starvation and death. It thus appears that this mechanism may represent a novel parthanatos pathway.


Assuntos
Parthanatos , Proteômica , Dano ao DNA , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli Adenosina Difosfato Ribose/metabolismo , Polímeros
7.
Bioorg Med Chem ; 69: 116908, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35780655

RESUMO

Poly (ADP-ribose) polymerase (PARP) inhibitors show potent antiproliferative activity in treatment with triple-negative breast cancer (TNBC) when combined with chemotherapeutic drugs. However, the emergence of safety issues and drug-resistance of PARP inhibitors prompt us to search for new strategies. It was proved that Proteolysis Targeting Chimeras (PROTACs) is more effective than traditional small molecule which can induce target proteins degradation rather than inhibition. In this article, based on the Olaparib derivatives and cereblon (CRBN) E3 ligase ligands, a series of PARP1 degraders, with linkers bearing different length and type were designed and synthesized. Among them, compound LB23 showed efficacious antiproliferative activity in various human cancer cells and can induce PARP1 protein degradation effectively. Moreover, LB23 showed 60-fold degradation selectivity in tumor cells with low degradation toxicity in normal cells. This study shows that the PROTAC tumor selectivity can be optimized by tuning the length and composition of the linker.


Assuntos
Inibidores de Poli(ADP-Ribose) Polimerases , Neoplasias de Mama Triplo Negativas , Linhagem Celular Tumoral , Humanos , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Proteólise , Ubiquitina-Proteína Ligases/metabolismo
8.
Sci Rep ; 12(1): 12501, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35864202

RESUMO

The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/farmacologia , Cromatina , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Humanos , Neoplasias/genética , Ftalazinas/farmacologia , Ftalazinas/uso terapêutico , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Poli(ADP-Ribose) Polimerases/genética , Fatores de Transcrição da Família Snail/genética
9.
Mol Cell ; 82(16): 2939-2951.e5, 2022 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-35793673

RESUMO

PARP1 rapidly detects DNA strand break damage and allosterically signals break detection to the PARP1 catalytic domain to activate poly(ADP-ribose) production from NAD+. PARP1 activation is characterized by dynamic changes in the structure of a regulatory helical domain (HD); yet, there are limited insights into the specific contributions that the HD makes to PARP1 allostery. Here, we have determined crystal structures of PARP1 in isolated active states that display specific HD conformations. These captured snapshots and biochemical analysis illustrate HD contributions to PARP1 multi-domain and high-affinity interaction with DNA damage, provide novel insights into the mechanics of PARP1 allostery, and indicate how HD active conformations correspond to alterations in the catalytic region that reveal the active site to NAD+. Our work deepens the understanding of PARP1 catalytic activation, the dynamics of the binding site of PARP inhibitor compounds, and the mechanisms regulating PARP1 retention on DNA damage.


Assuntos
Dano ao DNA , NAD , Domínio Catalítico , Reparo do DNA , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli Adenosina Difosfato Ribose , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia
10.
Bioorg Med Chem ; 70: 116912, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35830778

RESUMO

Poly ADP-ribose polymerase 1 (PARP1) plays an essential role in DNA repair signaling, rendering it an attractive target for cancer treatment. Despite the success of PARP1 inhibitors (PARPis), only a few patients can currently benefit from PARPis. Moreover, drug resistance to PARPis occurs during clinical treatment. Natural and acquired resistance to PARPis has forced us to seek new therapeutic approaches that target PARP1. Here, we synthesized a series of compounds by proteolysis-targeting chimera (PROTAC) technology to directly degrade the PARP1 protein. We found that CN0 (compound 3) with no polyethylene glycol (PEG) linker can degrade the PARP1 protein through the proteasome pathway. More importantly, CN0 could inhibit DNA damage repair, resulting in highly efficient accumulation of cytosolic DNA fragments due to unresolved unrepaired DNA lesions when combined with daunorubicin (DNR). Therefore, CN0 can activate the cyclic GMP-AMP synthase/stimulator of the interferon gene (cGAS/STING) pathway of innate immunity and then spread the resulting inflammatory signals, thereby reshaping the tumor microenvironment, which may eventually enhance T cell killing of tumor cells.


Assuntos
Interferons , Nucleotidiltransferases , Quimera/metabolismo , DNA/metabolismo , Daunorrubicina/farmacologia , Humanos , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular , Interferons/metabolismo , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteólise
11.
Cell Commun Signal ; 20(1): 93, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715817

RESUMO

BACKGROUND: Targeting AKT suppresses tumor growth through inducing apoptosis, however, during which whether other forms of cell death occurring is poorly understood. METHODS: The effects of increasing PARP1 dependent cell death (parthanatos) induced by inhibiting AKT on cell proliferation were determined by CCK-8 assay, colony formation assay, Hoechst 33,258 staining and analysis of apoptotic cells by flow cytometry. For the detailed mechanisms during this process, Western blot analysis, qRT-PCR analysis, immunofluorescence and co-immunoprecipitation were performed. Moreover, the inhibition of tumor growth by inducing p53/SIRT6/PARP1-dependent parthanatos was further verified in the xenograft mouse model. RESULTS: For the first time, we identified that inhibiting AKT triggered parthanatos, a new form of regulated cell death, leading to colon cancer growth suppression. For the mechanism investigation, we found that after pharmacological or genetic AKT inhibition, p53 interacted with SIRT6 and PARP1 directly to activate it, and promoted the formation of PAR polymer. Subsequently, PAR polymer transported to outer membrane of mitochondria and resulted in AIF releasing and translocating to nucleus thus promoting cell death. While, blocking PARP1 activity significantly rescued colon cancer from death. Furthermore, p53 deletion or mutation eliminated PAR polymer formation, AIF translocation, and PARP1 dependent cell death, which was promoted by overexpression of SIRT6. Meanwhile, reactive oxygen species production was elevated after inhibition of AKT, which might also play a role in the occurrence of parthanatos. In addition, inhibiting AKT initiated protective autophagy simultaneously, which advanced tumor survival and growth. CONCLUSION: Our findings demonstrated that AKT inhibition induced p53-SIRT6-PARP1 complex formation and the activation of parthanatos, which can be recognized as a novel potential therapeutic strategy for cancer. Video Abstract.


Assuntos
Neoplasias do Colo , Parthanatos , Poli(ADP-Ribose) Polimerase-1 , Proteínas Proto-Oncogênicas c-akt , Sirtuínas , Proteína Supressora de Tumor p53 , Animais , Apoptose , Fator de Indução de Apoptose/metabolismo , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Xenoenxertos , Humanos , Camundongos , Poli(ADP-Ribose) Polimerase-1/metabolismo , Polímeros/metabolismo , Polímeros/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Sirtuínas/metabolismo , Proteína Supressora de Tumor p53/metabolismo
12.
Bioorg Med Chem ; 69: 116892, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35764034

RESUMO

Poly(ADP-ribose) polymerase-1 (PARP1) is an enzyme that catalyzes the polymerization of ADP-ribose units to target proteins, and it is a potential target for anti-cancer drug discovery, especially for BRAC1/2 mutated tumors. In this study, a series of 2-aminoimidazole Lissodendrins B derivatives were designed, synthesized, and evaluated as PARP1 inhibitors. We found that compound D3 is better due to its PARP enzyme inhibitory activity and in vitro anti-cancer activity compared with other tested compounds. It could inhibit PARP1 enzymatic activity (IC50 = 17.46 µM) in the non-cell system and BRCA1-deficient HCC1937 and MDA-MB-436 cells growth (IC50 = 17.81 and 12.63 µM, respectively). Further study demonstrated that compound D3 inhibits tumor growth through multiple mechanisms, such as reduction of PARylation, accumulation of cellular DNA double-strand breaks, induction of G2/M cell cycle arrest, and subsequent apoptosis of BRCA1-deficient cells. Besides, the molecular docking study also confirmed that compound D3 could effectively occupy the active pocket of PARP1. Our findings provide a new skeleton structure for PARP1 inhibitor, and the results suggested that the compound D3 may serve as a potential lead compound to develop novel PARP1 inhibitors for cancer therapy.


Assuntos
Antineoplásicos , Inibidores de Poli(ADP-Ribose) Polimerases , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Dupla , Pontos de Checagem da Fase G2 do Ciclo Celular , Simulação de Acoplamento Molecular , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/química
13.
Oncogene ; 41(31): 3846-3858, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35773412

RESUMO

Aldo-keto reductase family 1 member C3 (AKR1C3) serves as a contributor to numerous kinds of tumors, and its expression is elevated in patients with hepatocellular carcinoma (HCC). However, the biological function of AKR1C3 in HCC remains unclear. Here we investigated the role of AKR1C3 in liver carcinogenesis using in vitro and in vivo models. We determined that AKR1C3 is frequently increased in HCC tissues with poor prognosis. Genetically manipulated cells with AKR1C3 construction were examined to highlight the pro-tumoral growth of both wild-type AKR1C3 and mutant in vitro and in vivo. We observed promising treatment effects of AKR1C3 shRNA by intratumoral injection in mice. Mechanically, we demonstrated that the transcription factor heterodimer NRF2/MAFG was able to bind directly to AKR1C3 promoter to activate its transcription. Further, AKR1C3 stabilized PARP1 by decreasing its ubiquitination, which resulted in HCC cell proliferation and low sensitivity of Cisplatin. Moreover, we discovered that the tumorigenic role of AKR1C3 was non-catalytic dependent and the NRF2/MAFG-AKR1C3-PARP1 axis might be one of the important proliferation pathways in HCC. In conclusion, blockage of AKR1C3 expression provides potential therapeutic benefits against HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , 3-Hidroxiesteroide Desidrogenases/genética , Membro C3 da Família 1 de alfa-Ceto Redutase/metabolismo , Animais , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Hidroxiprostaglandina Desidrogenases/genética , Neoplasias Hepáticas/genética , Fator de Transcrição MafG/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteínas Repressoras/metabolismo
14.
Genes Dev ; 36(9-10): 601-617, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35654456

RESUMO

The differentiation of embryonic stem cells (ESCs) into a lineage-committed state is a dynamic process involving changes in cellular metabolism, epigenetic modifications, post-translational modifications, gene expression, and RNA processing. Here we integrated data from metabolomic, proteomic, and transcriptomic assays to characterize how alterations in NAD+ metabolism during the differentiation of mouse ESCs lead to alteration of the PARP1-mediated ADP-ribosylated (ADPRylated) proteome and mRNA isoform specialization. Our metabolomic analyses indicate that mESCs use distinct NAD+ biosynthetic pathways in different cell states: the de novo pathway in the pluripotent state, and the salvage and Preiss-Handler pathways as differentiation progresses. We observed a dramatic induction of PARP1 catalytic activity driven by enhanced nuclear NAD+ biosynthesis during the early stages of mESC differentiation (e.g., within 12 h of LIF removal). PARP1-modified proteins in mESCs are enriched for biological processes related to stem cell maintenance, transcriptional regulation, and RNA processing. The PARP1 substrates include core spliceosome components, such as U2AF35 and U2AF65, whose splicing functions are modulated by PARP1-mediated site-specific ADP-ribosylation. Finally, we observed that splicing is dysregulated genome-wide in Parp1 knockout mESCs. Together, these results demonstrate a role for the NAD+-PARP1 axis in the maintenance of mESC state, specifically in the splicing program during differentiation.


Assuntos
NAD , Poli(ADP-Ribose) Polimerases , ADP-Ribosilação , Animais , Células-Tronco Embrionárias/metabolismo , Camundongos , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Proteômica
15.
Int Immunopharmacol ; 109: 108809, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35504207

RESUMO

Regulated cell death profoundly affects on the progress of inflammatory and immune responses in various acute inflammatory diseases, as seen in sepsis and trauma. However, the mechanisms underlying CD4 T cells death have not yet been fully addressed. We demonstrated that interferon genes (STING) promoted excessive Poly (ADP-ribose) polymerase 1 (PARP-1) activity stimulated by endotoxin, which in turn induced apoptosis-inducing factor (AIF)-independent but PARP-1 dependent programmed cell death. Elevated PARP-1 activity triggered a cascade of molecular events, including PAR polymer release from the nucleus and the nicotinamide adenine dinucleotide (NAD+) and ATP depletion. Interestingly, translocation of AIF, a biochemical signature for PARP-1-dependent parthanatos, was not observed in the present study, suggesting a non-canonical mechanism of CD4 T cells parthanatos. In this study, we also identify a STING-mediated mechanism of necrotic cell death in CD4 T cells in septic animals. Furthermore, we revealed wider effects of STING on the mortality in mice when PARP-1 gene inhibited. These findings reveal that STING signaling and targeting PARP-1/PAR pathway in CD4 T cells may present a new therapeutic strategy for the treatment of acute systemic inflammatory diseases.


Assuntos
Linfócitos T CD4-Positivos , Inflamação , Proteínas de Membrana , Necrose , Poli(ADP-Ribose) Polimerase-1 , Animais , Fator de Indução de Apoptose , Linfócitos T CD4-Positivos/metabolismo , Morte Celular , Inflamação/patologia , Proteínas de Membrana/metabolismo , Camundongos , NAD , Poli(ADP-Ribose) Polimerase-1/metabolismo
16.
Environ Toxicol ; 37(8): 1891-1901, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35396826

RESUMO

Methylmercury (MeHg) is an environmental neurotoxic substance, which can easily cross the blood-brain barrier, causing irreversible damage to the human central nervous system. Reactive oxygen species (ROS) are involved in various ways of intracellular physiological or pathological processes including neuronal apoptosis. This study attempted to explore the role of ROS-mediated poly ADP-ribose polymerase (PARP)/apoptosis-inducing factor (AIF) apoptosis signaling pathway in the process of MeHg-induced cell death of human neuroblastoma cells (SH-SY5Y). Here, we found that SH-SY5Y cells underwent apoptosis in response to MeHg, which was accompanied by the increased levels of ROS and calcium ion, and the activation of caspase cascades and PARP. Inhibiting the production of ROS can reduce the apoptosis rate to a certain extent. PARP/AIF apoptotic pathway is independent of caspase dependent signaling pathway and regulates it. In conclusion, these results suggest that ROS mediated activation of caspase pathway and PARP/AIF signaling pathway are involved in MeHg induced apoptosis, and these two pathways interact with each other.


Assuntos
Compostos de Metilmercúrio , Neuroblastoma , Adenosina Difosfato Ribose/farmacologia , Apoptose , Fator de Indução de Apoptose/metabolismo , Fator de Indução de Apoptose/farmacologia , Caspases/metabolismo , Humanos , Compostos de Metilmercúrio/toxicidade , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Espécies Reativas de Oxigênio/metabolismo
17.
Exp Cell Res ; 417(1): 113163, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35447104

RESUMO

Protein targets of polyADP-ribosylation undergo covalent modification with high-molecular-weight, branched poly(ADP-ribose) (PAR) of lengths up to 200 or more ADP-ribose residues derived from NAD+. PAR polymerase 1 (PARP1) is the most abundant and well-characterized enzyme involved in PAR biosynthesis. Extensive studies have been carried out to determine how polyADP-ribosylation (PARylation) regulates cell proliferation during cell cycle, with conflicting conclusions. Since significant activation of PARP1 occurs during cell lysis in vitro, we changed the standard method for cell lysis, and using our sensitive ELISA system, quantified without addition of a PAR glycohydrolase inhibitor and clarified that the PAR level is significantly higher in S phase than that in G1. Under normal condition in the absence of exogenous DNA-damaging agent, PAR turns over with a half-life of <40 s; consistent with significant decrease of NAD+ levels in S phase, which is rescued by PARP inhibitors, in line with the observed rapid turnover of PAR. PARP inhibitors delayed cell cycle in S phase and decreased cell proliferation. Our results underscore the importance of a suitable assay system to measure rapid PAR chain dynamics in living cells and aid our understanding of the function of PARylation during the cell cycle.


Assuntos
Poli Adenosina Difosfato Ribose , Inibidores de Poli(ADP-Ribose) Polimerases , Ciclo Celular , Divisão Celular , Células HeLa , Humanos , NAD , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli Adenosina Difosfato Ribose/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo
18.
Mol Cell ; 82(11): 2032-2049.e7, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35460603

RESUMO

Virus infection modulates both host immunity and host genomic stability. Poly(ADP-ribose) polymerase 1 (PARP1) is a key nuclear sensor of DNA damage, which maintains genomic integrity, and the successful application of PARP1 inhibitors for clinical anti-cancer therapy has lasted for decades. However, precisely how PARP1 gains access to cytoplasm and regulates antiviral immunity remains unknown. Here, we report that DNA virus induces a reactive nitrogen species (RNS)-dependent DNA damage and activates DNA-dependent protein kinase (DNA-PK). Activated DNA-PK phosphorylates PARP1 on Thr594, thus facilitating the cytoplasmic translocation of PARP1 to inhibit the antiviral immunity both in vitro and in vivo. Mechanistically, cytoplasmic PARP1 interacts with and directly PARylates cyclic GMP-AMP synthase (cGAS) on Asp191 to inhibit its DNA-binding ability. Together, our findings uncover an essential role of PARP1 in linking virus-induced genome instability with inhibition of host immunity, which is of relevance to cancer, autoinflammation, and other diseases.


Assuntos
Antivirais , Nucleotidiltransferases , Antivirais/farmacologia , Citoplasma/genética , Citoplasma/metabolismo , DNA , Dano ao DNA , Instabilidade Genômica , Humanos , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo
19.
Cell Metab ; 34(5): 702-718.e5, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35417665

RESUMO

Emerging evidence indicates that the accretion of senescent cells is linked to metabolic disorders. However, the underlying mechanisms and metabolic consequences of cellular senescence in obesity remain obscure. In this study, we found that obese adipocytes are senescence-susceptible cells accompanied with genome instability. Additionally, we discovered that SREBP1c may play a key role in genome stability and senescence in adipocytes by modulating DNA-damage responses. Unexpectedly, SREBP1c interacted with PARP1 and potentiated PARP1 activity during DNA repair, independent of its canonical lipogenic function. The genetic depletion of SREBP1c accelerated adipocyte senescence, leading to immune cell recruitment into obese adipose tissue. These deleterious effects provoked unhealthy adipose tissue remodeling and insulin resistance in obesity. In contrast, the elimination of senescent adipocytes alleviated adipose tissue inflammation and improved insulin resistance. These findings revealed distinctive roles of SREBP1c-PARP1 axis in the regulation of adipocyte senescence and will help decipher the metabolic significance of senescence in obesity.


Assuntos
Resistência à Insulina , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Humanos , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
20.
Mol Med Rep ; 25(6)2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35475506

RESUMO

It has been reported that oxidative stress plays a prominent role in diabetic macrovascular diseases. 3,4­Dihydroxyacetophenone (3,4­DHAP) has been found to have a variety of biological activities. However, few studies have assessed the antioxidant capacity of 3,4­DHAP and the underlying mechanisms. Thus, the aim of the present study was to explore the effects of 3,4­DHAP on oxidative stress in human umbilical vein endothelial cells (HUVECs). HUVECs were pre­treated with 3,4­DHAP and then exposed to high glucose conditions. Cell viability and cytotoxicity were measured using an MTT assay. Reactive oxygen species (ROS) levels were measured using an inverted fluorescence microscope and a fluorescent enzyme labeling instrument. Protein expression levels of nuclear factor E2­related factor 2 (Nrf2), heme oxygenase­1 (HO­1), microtubule­associated protein 1A/1B­light chain 3 (LC3) and poly ADP­ribose polymerase­1 (PARP­1) were measured using western blotting, and mRNA expression of Nrf2 and HO­1 were measured through reverse transcription­quantitative PCR (RT­qPCR). Nrf2 nuclear translocation was evaluated using immunofluorescence analysis and autophagosomes were observed using transmission electron microscope (TEM). The results of the present study demonstrated that compared with the control group, cell viability of the high glucose group was reduced and cell cytotoxicity of the high glucose group was increased. ROS production in the high glucose group was clearly enhanced. In addition, high glucose upregulated Nrf2 and HO­1 protein and mRNA expression levels. Nuclear translocation of Nrf2 in the high glucose group was also increased. The formation of autophagosomes in the high glucose group was also higher than that in the control group. Furthermore, LC3­II/LC3­I and PARP­1 protein expression levels were increased after treatment with high glucose. However, compared to the high glucose group, 3,4­DHAP (10 µmol/l) significantly enhanced cell viability. 3,4­DHAP markedly decreased the production of ROS, increased Nrf2 and HO­1 protein and mRNA expression levels, and promoted nuclear translocation of Nrf2 in HUVECs. In addition, 3,4­DHAP promoted the formation of autophagosomes, and notably increased the protein expression levels of LC3­II/LC3­I and PARP­1. Moreover, it was determined that compared to the 3,4­DHAP group, treatment with 3,4­DHAP and ML385 enhanced cell viability, and decreased ROS production, Nrf2 and HO­1 protein and mRNA expression levels, nuclear translocation of Nrf2, and LC3­II/LC3­I and PARP­1 protein expression levels. Collectively, the results of the present study showed that 3,4­DHAP protected HUVECs against oxidative stress via regulation of the Nrf2/HO­1 pathway, by increasing autophagy and promoting DNA damage repair.


Assuntos
Heme Oxigenase-1 , Fator 2 Relacionado a NF-E2 , Acetofenonas , Glucose/metabolismo , Heme Oxigenase-1/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...