scholarly journals Post-Translational Modifications in Oocyte Maturation and Embryo Development

Author(s):  
Yu Wu ◽  
Mo Li ◽  
Mo Yang

Mammalian oocyte maturation and embryo development are unique biological processes regulated by various modifications. Since de novo mRNA transcription is absent during oocyte meiosis, protein-level regulation, especially post-translational modification (PTM), is crucial. It is known that PTM plays key roles in diverse cellular events such as DNA damage response, chromosome condensation, and cytoskeletal organization during oocyte maturation and embryo development. However, most previous reviews on PTM in oocytes and embryos have only focused on studies of Xenopus laevis or Caenorhabditis elegans eggs. In this review, we will discuss the latest discoveries regarding PTM in mammalian oocytes maturation and embryo development, focusing on phosphorylation, ubiquitination, SUMOylation and Poly(ADP-ribosyl)ation (PARylation). Phosphorylation functions in chromosome condensation and spindle alignment by regulating histone H3, mitogen-activated protein kinases, and some other pathways during mammalian oocyte maturation. Ubiquitination is a three-step enzymatic cascade that facilitates the degradation of proteins, and numerous E3 ubiquitin ligases are involved in modifying substrates and thus regulating oocyte maturation, oocyte-sperm binding, and early embryo development. Through the reversible addition and removal of SUMO (small ubiquitin-related modifier) on lysine residues, SUMOylation affects the cell cycle and DNA damage response in oocytes. As an emerging PTM, PARlation has been shown to not only participate in DNA damage repair, but also mediate asymmetric division of oocyte meiosis. Each of these PTMs and external environments is versatile and contributes to distinct phases during oocyte maturation and embryo development.

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Nan Huang ◽  
Chang Xu ◽  
Liang Deng ◽  
Xue Li ◽  
Zhixuan Bian ◽  
...  

AbstractPhosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an essential enzyme involved in de novo purine biosynthesis, is connected with formation of various tumors. However, the specific biological roles and related mechanisms of PAICS in gastric cancer (GC) remain unclear. In the present study, we identified for the first time that PAICS was significantly upregulated in GC and high expression of PAICS was correlated with poor prognosis of patients with GC. In addition, knockdown of PAICS significantly induced cell apoptosis, and inhibited GC cell growth both in vitro and in vivo. Mechanistic studies first found that PAICS was engaged in DNA damage response, and knockdown of PAICS in GC cell lines induced DNA damage and impaired DNA damage repair efficiency. Further explorations revealed that PAICS interacted with histone deacetylase HDAC1 and HDAC2, and PAICS deficiency decreased the expression of DAD51 and inhibited its recruitment to DNA damage sites by impairing HDAC1/2 deacetylase activity, eventually preventing DNA damage repair. Consistently, PAICS deficiency enhanced the sensitivity of GC cells to DNA damage agent, cisplatin (CDDP), both in vitro and in vivo. Altogether, our findings demonstrate that PAICS plays an oncogenic role in GC, which act as a novel diagnosis and prognostic biomarker for patients with GC.


Open Biology ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 150018 ◽  
Author(s):  
Jessica S. Brown ◽  
Stephen P. Jackson

Failure of accurate DNA damage sensing and repair mechanisms manifests as a variety of human diseases, including neurodegenerative disorders, immunodeficiency, infertility and cancer. The accuracy and efficiency of DNA damage detection and repair, collectively termed the DNA damage response (DDR), requires the recruitment and subsequent post-translational modification (PTM) of a complex network of proteins. Ubiquitin and the ubiquitin-like protein (UBL) SUMO have established roles in regulating the cellular response to DNA double-strand breaks (DSBs). A role for other UBLs, such as NEDD8, is also now emerging. This article provides an overview of the DDR, discusses our current understanding of the process and function of PTM by ubiquitin and NEDD8, and reviews the literature surrounding the role of ubiquitylation and neddylation in DNA repair processes, focusing particularly on DNA DSB repair.


2020 ◽  
Author(s):  
Morgan Dasovich ◽  
Morgan Q. Beckett ◽  
Scott Bailey ◽  
Shao-En Ong ◽  
Marc M. Greenberg ◽  
...  

ABSTRACTPost-translational modification of proteins with poly(ADP-ribose) (PAR) is an important component of the DNA damage response. Four PAR synthesis inhibitors have recently been approved for the treatment of breast, ovarian, and prostate cancers. Despite its clinical significance, a molecular understanding of PAR function, including its binding partners, remains incomplete. In this work, we synthesize a PAR photoaffinity probe that captures and isolates endogenous PAR binders. Our method identified dozens of known PAR-binding proteins and hundreds of novel binders involved in DNA repair, RNA processing, and metabolism. PAR binding by eight candidates was confirmed using pull-down and/or electrophoretic mobility shift assays. Using PAR probes of defined lengths, we detected proteins that preferentially bind to 40-mer over 8-mer PAR, indicating that polymer length may regulate the outcome and timing of PAR signaling pathways. This investigation produces the first census of PAR-binding proteins, provides a proteome-wide view of length-selective PAR binding, and associates PAR binding with RNA metabolism and the formation of biomolecular condensates.


Author(s):  
Monish Ram Makena ◽  
Myungjun Ko ◽  
Allatah X. Mekile ◽  
Donna K. Dang ◽  
John Warrington ◽  
...  

SUMMARYAlthough the mainstay of treatment for hormone responsive breast tumors is targeted endocrine therapy, many patients develop de novo or acquired resistance and are treated with chemotherapeutic drugs. The vast majority (80%) of estrogen receptor positive tumors also express wild type p53 protein that is a major determinant of the DNA damage response. Tumors that are ER+ and p53WT respond poorly to chemotherapy, although the underlying mechanisms are not completely understood. We describe a novel link between store independent Ca2+ entry (SICE) and resistance to DNA damaging drugs, mediated by the secretory pathway Ca2+-ATPase, SPCA2. In luminal ER+/PR+ breast cancer subtypes, SPCA2 levels are high and correlate with poor survival prognosis. Independent of ion pump activity, SPCA2 elevates baseline Ca2+ levels through SICE and drives cell proliferation. Attenuation of SPCA2 or depletion of extracellular Ca2+ increased mitochondrial ROS production, DNA damage and activation of the ATM/ATR-p53 axis leading to G0/G1 phase cell cycle arrest and apoptosis. Consistent with these findings, SPCA2 knockdown confers chemosensitivity to DNA damaging agents including doxorubicin, cisplatin and ionizing radiation. We conclude that elevated SPCA2 expression in ER+ p53WT breast tumors drives pro-survival and chemotherapy resistance by suppressing the DNA damage response. Drugs that target storeindependent Ca2+ entry pathways may have therapeutic potential in treating receptor positive breast cancer.


2022 ◽  
Author(s):  
Ievgeniia Gazo ◽  
Ravindra Naraine ◽  
Ievgen Lebeda ◽  
Aleš Tomčala ◽  
Mariola Dietrich ◽  
...  

Abstract DNA damage during early life stages may have a negative effect on embryo development, inducing malformations that have long-lasting effects during adult life. Therefore, in the current study, we analyzed the effect of DNA damage induced by genotoxicants (camptothecin (CPT) and olaparib) at different stages of embryo development. We analyzed the survival, DNA fragmentation, transcriptome, and proteome of the endangered sturgeon Acipenser ruthenus. Sturgeons are non-model fish species that can provide new insights into the DNA damage response and embryo development. The transcriptomic and proteomic patterns changed significantly after exposure to genotoxicants in a stage-dependent manner. The results of this study indicate a correlation between phenotype formation and changes in transcriptomic and proteomic profiles. CPT and olaparib downregulated oxidative phosphorylation and metabolic pathways, and upregulated pathways involved in nucleotide excision repair, base excision repair, and homologous recombination. We observed the upregulated expression of zona pellucida sperm-binding proteins in all treatment groups, as well as the upregulation of several glycolytic enzymes. The analysis of gene expression revealed several markers of DNA damage response and adaptive stress-response, which could be applied in toxicological studies on fish embryo. This study is the first complex analysis of the DNA damage response in endangered sturgeons.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Diting Qian ◽  
Zhiling Li ◽  
Yuting Zhang ◽  
Yue Huang ◽  
Que Wu ◽  
...  

Our study aimed to develop embryo models to evaluate the impact of oxidative stress on embryo development. Mouse zygotes, which stayed at G1 phase, were treated with prepared culture medium (containing 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, or 0.1 mM hydrogen peroxide (H2O2)) for 30 min in experiment 1. The dose-effects of H2O2on embryo development were investigated via comparisons of the formation rate at each stage (2- and 4-cell embryos and blastocysts). Experiment 2 was carried out to compare behaviors of embryos in a mild oxidative-stressed status (0.03 mM H2O2) with those in a control (0 mM H2O2). Reactive oxygen species (ROS) levels, variation of mitochondrial membrane potential (MMP), expression ofγH2AX, and cell apoptosis rate of blastocyst were detected. We observed a dose-dependent decrease on cleavage and blastocyst rates. Besides, higher level of ROS, rapid reduction of MMP, and the appearance ofγH2AX revealed that embryos are injured early in mild oxidative stress. Additionally,γH2AX may involve during DNA damage response in early embryos. And the apoptotic rate of blastocyst may significantly increase when DNA damage repair is inadequate. Most importantly, our research provides embryo models to study cell cycle regulation and DNA damage response under condition of different levels of oxidative stress.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 799-799
Author(s):  
Dagmar Walter ◽  
Amelie Lier ◽  
Anja Geiselhart ◽  
Sina Huntscha ◽  
David Brocks ◽  
...  

Abstract Long-term quiescence has been proposed to preserve the genomic stability of hematopoietic stem cells (HSCs) during aging. The current models of HSC aging are limited in their ability to observe both DNA damage in vivo and the consequences of this damage upon hematopoiesis. Fanconi Anemia (FA) is a hereditary multisystem disorder, characterized by defective DNA damage response and progressive bone marrow failure in most patients. However, the existing genetic models of FA do not develop aplastic anemia, suggesting that cell-extrinsic factors may play a causal role. We sought to identify whether physiologic mediators of HSC activation could be used as agonists to provoke DNA damage and HSC attrition in vivo. Mice were treated with a range of agonists that promote the in vivo exit of HSC from a dormant state into active cycling (polyI:polyC; Interferon-α; G-CSF; TPO; and serial bleeding). Highly purified HSC demonstrated a rapid 3-5-fold induction of DNA damage after treatment with all agonists (p<0.01), as assessed by both enumerating γ-H2AX foci and by alkaline comet assay. Mechanistically, stress-induced exit from quiescence correlated with increased mitochondrial metabolism in HSC, as evaluated by elevated mitochondrial membrane potential (2-fold increased, p<0.01) and superoxide levels (1.5-fold increased, p<0.05). Critically, we could directly implicate these reactive oxygen species in DNA damage as we observed a 1.4-fold increase in 8-Oxo-dG lesions in HSC that had been activated into cycle in vivo(p<0.05). At 48 h post-treatment, γ-H2AX levels began to decrease and this repair was concomitant with an induction of the FA signaling pathway in HSC, as demonstrated by both increased levels of FA gene expression and elevated FANCD2 foci (4-fold induction, p<0.01). Treatment of Fanca-/- mice with polyI:polyC led to a HSC proliferative response comparable to wild type (WT) mice but resulted in a 2-fold higher level of activation-induced DNA damage (p<0.05), demonstrating that this repair pathway is involved in resolving activation-induced DNA damage. Four rounds of serial in vivo activation led to a permanent depletion of the most primitive label-retaining Fanca-/- HSC and this correlated with a 4-fold depletion of functional HSC (p<0.01) as defined by competitive repopulation assays. Subsequent rounds of HSC activation with polyI:polyC resulted in the onset of a severe aplastic anemia (SAA) in 33% of treated Fanca-/- mice but not in any of the WT controls. SSA was characterized by a dramatic reduction in bone marrow (BM) cellularity, profound thrombocytopenia (21-246x106 platelets/ml), leukocytopenia (0.4-0.5x106 WBC/ml), neutropenia (0.03-0.1x106/ml) and anemia (1.5-2.3 g/dL Hb). Examination of BM HSC/progenitors demonstrated nearly complete loss of HSC, MPP, CMP and CLP (depletion of ≥33x, 8x, 4x and 12x respectively compared to PBS-treated Fanca-/-controls). Taken together, these data demonstrates that enforced exit from dormancy in vivo leads to de novo DNA damage in HSC, which is repaired by activation of a FA-dependent DNA damage response. Furthermore, the highly penetrant bone marrow failure observed in Fanconi anemia patients can be recapitulated by the serial application of a physiologic HSC activating signal to Fanca-/- mice. This suggests that the BM failure in FA may be caused by an aberrant response to HSC activation, most likely during exposure to infection or other physiologic stressors. These data provides a novel link between pro-inflammatory cytokines, DNA damage and HSC dysfunction and may have important clinical implications relevant to both prevention of BM failure in FA and in the study of age-related hematopoietic defects in non-FA patients. Moreover, these data provide the first evidence that FA knockout mouse models accurately recapitulate and provide novel insights into the etiology of BM failure in patients with FA. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3234-3234
Author(s):  
Fernando V Pericole ◽  
Fernanda Marconi Roversi ◽  
Adriana Silva Santos Duarte ◽  
Bruna Palodetto ◽  
Flavia Adolfo Corrocher ◽  
...  

Abstract INTRODUCTION: Epigenetic pathways can regulate gene expression by controlling and interpreting chromatin modifications. BRD4 is a BET member of bromodomain-containing proteins, known as epigenome readers, exerting key roles in chromatin remodeling and transcriptional regulation. BRD4 gene encodes two major isoforms, short (BRD4S) and long (BRD4L). Recently, Floyd SR et al (Nature, 2013) described BRD4S as an endogenous inhibitor of the DNA damage response (DDR). Under normal conditions, damaged DNA induces histone phosphorylation of H2AX at Ser 139 (γ-H2AX) and activates a protective signaling network that blocks cell cycle and recruits DNA repair factors. Despite having been described as a therapeutic target in acute myeloid leukemia (AML) by Zuber J et al (Nature, 2011), BRD4 has never been studied in myelodysplastic syndrome (MDS) and its role in the pathogenesis is currently unknown. AIMS: To evaluate BRD4L and BRD4S expression in MDS and AML patients, correlating with clinical data, progression and survival. We also explored the BRD4 role in DDR signaling using human leukemia cell line models. MATERIAL AND METHODS: Diagnostic total bone marrow (BM) samples from 24 healthy donors (HD) and 99 patients, including 48 MDS (22 higher-risk MDS and 36 lower-risk MDS) and 51 AML (16 of them with MDS-related changes, AML-MRC), were collected. We also isolated CD34+ cells from 7 HD, 5 de novo AML, 4 AML-MRC and 14 MDS (6 higher-risk and 8 lower-risk MDS). BRD4L and BRD4S gene expressions were assessed through q-PCR and expressed as median (minimum-maximum). MDS patients were stratified according IPSS, WHO classification, R-IPSS and cytogenetic risk. Samples were age-adjusted when significant differences were observed, using ANOVA and Tukey’s test. Progression-free and overall survival curves were estimated by Kaplan-Meier method and were analyzed by the Wilcoxon´s test and Cox regression. JQ1, a specific BRD4 inhibitor, was kindly provided by James Bradner. A panel of human myeloid leukemia cell lines (KG1a, HEL, HL60, U937) in exponential growth was treated with increasing doses of JQ1 for 48 hours and cell growth (MTT colorimetric assay), apoptosis (annexin-V/PI) and cell cycle (flow cytofluorometric analysis detecting nuclear PI incorporation) were evaluated. We also determined the expression of p-γH2AX (DDR signaling) by western blot, after 12 hours of JQ1 treatment. RESULTS: A higher expression of BRD4S was observed in total BM cells from AML (4.01 [0.33-2.58], P=.01) and MDS patients (4.21 [0.01-56.17], P=.01) compared with HD (2.11 [0.04-10.32], P=.01). When stratified according WHO classification, AML-MRC (4.5 [0.33-25.22], P=.04) and higher-risk MDS (4.66 [0.17-56.17], P=.04) subgroups showed higher BRD4S expression. In CD34+ cells, BRD4S expression was increased in de novo AML (0.28 [0.21-0.45]) compared with lower-risk MDS (0.02 [0.00-0.44], P=.01). BRD4L mRNA expression was not modulated in total BM and CD34+ cells from any subgroup. With median follow-up time of 34.4 months, we found that higher BRD4S gene expression was a worse prognostic factor for MDS transformation and survival, along with IPSS, R-IPSS, low hemoglobin (less than 10g/dL) and higher BM blast percentage. After multivariate analysis, BRD4S gene expression and higher-risk (very high, high and intermediate) R-IPSS remained as independent prognostic factors for MDS progression and overall survival. KG1a and U937 cells showed greater resistance to JQ1, with lower apoptosis rate and proliferation (IC50 not reached, over 3000nM), whereas HEL and HL60 were more responsive (IC50 under 800nM in both cell lines). JQ1 suppressed cell proliferation, induced G0/G1 cell cycle arrest and apoptosis and caused a progressive increase in histone phosphorylation of γ-H2AX, indicating activation of DDR signaling. CONCLUSIONS: MDS is a clonal myeloid neoplasm characterized by profound epigenetic modifications. Our data establishes BRD4S as a novel MDS prognostic factor, related to aggressive phenotype, higher progression rate and shorter survival. Biologically, BRD4S plays a role in the inappropriate DNA Damage Response of MDS, favoring the disease towards genetic instability and clonal evolution. Disclosures No relevant conflicts of interest to declare.


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