scholarly journals Chicken blastoderms and primordial germ cells possess a higher expression of DNA repair genes and lower expression of apoptosis genes to preserve their genome stability

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Deivendran Rengaraj ◽  
Sohyoung Won ◽  
Kyung Min Jung ◽  
Seung Je Woo ◽  
Haerang Lee ◽  
...  

AbstractDNA is susceptible to damage by various sources. When the DNA is damaged, the cell repairs the damage through an appropriate DNA repair pathway. When the cell fails to repair DNA damage, apoptosis is initiated. Although several genes are involved in five major DNA repair pathways and two major apoptosis pathways, a comprehensive understanding of those gene expression is not well-understood in chicken tissues. We performed whole-transcriptome sequencing (WTS) analysis in the chicken embryonic fibroblasts (CEFs), stage X blastoderms, and primordial germ cells (PGCs) to uncover this deficiency. Stage X blastoderms mostly consist of undifferentiated progenitor (pluripotent) cells that have the potency to differentiate into all cell types. PGCs are also undifferentiated progenitor cells that later differentiate into male and female germ cells. CEFs are differentiated and abundant somatic cells. Through WTS analysis, we identified that the DNA repair pathway genes were expressed more highly in blastoderms and high in PGCs than CEFs. Besides, the apoptosis pathway genes were expressed low in blastoderms and PGCs than CEFs. We have also examined the WTS-based expression profiling of candidate pluripotency regulating genes due to the conserved properties of blastoderms and PGCs. In the results, a limited number of pluripotency genes, especially the core transcriptional network, were detected higher in both blastoderms and PGCs than CEFs. Next, we treated the CEFs, blastoderm cells, and PGCs with hydrogen peroxide (H2O2) for 1 h to induce DNA damage. Then, the H2O2 treated cells were incubated in fresh media for 3–12 h to observe DNA repair. Subsequent analyses in treated cells found that blastoderm cells and PGCs were more likely to undergo apoptosis along with the loss of pluripotency and less likely to undergo DNA repair, contrasting with CEFs. These properties of blastoderms and PGCs should be necessary to preserve genome stability during the development of early embryos and germ cells, respectively.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lama Tarayrah-Ibraheim ◽  
Elital Chass Maurice ◽  
Guy Hadary ◽  
Sharon Ben-Hur ◽  
Alina Kolpakova ◽  
...  

AbstractDuring Drosophila embryonic development, cell death eliminates 30% of the primordial germ cells (PGCs). Inhibiting apoptosis does not prevent PGC death, suggesting a divergence from the conventional apoptotic program. Here, we demonstrate that PGCs normally activate an intrinsic alternative cell death (ACD) pathway mediated by DNase II release from lysosomes, leading to nuclear translocation and subsequent DNA double-strand breaks (DSBs). DSBs activate the DNA damage-sensing enzyme, Poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) and the ATR/Chk1 branch of the DNA damage response. PARP-1 and DNase II engage in a positive feedback amplification loop mediated by the release of PAR polymers from the nucleus and the nuclear accumulation of DNase II in an AIF- and CypA-dependent manner, ultimately resulting in PGC death. Given the anatomical and molecular similarities with an ACD pathway called parthanatos, these findings reveal a parthanatos-like cell death pathway active during Drosophila development.


2019 ◽  
Vol 316 (3) ◽  
pp. C299-C311 ◽  
Author(s):  
Jing Luo ◽  
Zhong-Zhou Si ◽  
Ting Li ◽  
Jie-Qun Li ◽  
Zhong-Qiang Zhang ◽  
...  

Hepatocellular carcinoma (HCC) is known for its high mortality rate worldwide. Based on intensive studies, microRNA (miRNA) expression functions in tumor suppression. Therefore, we aimed to evaluate the contribution of miR-146a-5p to radiosensitivity in HCC through the activation of the DNA damage repair pathway by binding to replication protein A3 (RPA3). First, the limma package of R was performed to differentially analyze HCC expression chip, and regulative miRNA of RPA3 was predicted. Expression of miR-146a-5p, RPA3, and DNA damage repair pathway-related factors in tissues and cells was determined. The effects of radiotherapy on the expression of miR-146a-5p and RPA3 as well as on cell radiosensitivity, proliferation, cell cycle, and apoptosis were also assessed. The results showed that there exists a close correlation between miR-146a and the radiotherapy effect on HCC progression through regulation of RPA3 and the DNA repair pathway. The positive rate of ATM, pCHK2, and Rad51 in HCC tissues was higher when compared with that of the paracancerous tissues. SMMC-7721 and HepG2 cell proliferation were significantly inhibited following 8 Gy 6Mv dose. MiR-146a-5p restrained the expression of RPA3 and promoted the expression of relative genes associated with the DNA repair pathway. In addition, miR-146a-5p overexpression suppresses cell proliferation and enhances radiosensitivity and cell apoptosis in HCC cells. In conclusion, the present study revealed that miR-146a-5p could lead to the restriction of proliferation and the promotion of radiosensitivity and apoptosis in HCC cells through activation of DNA repair pathway and inhibition of RPA3.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Miaomiao Bai ◽  
Dongdong Ti ◽  
Qian Mei ◽  
Jiejie Liu ◽  
Xin Yan ◽  
...  

The human body is a complex structure of cells, which are exposed to many types of stress. Cells must utilize various mechanisms to protect their DNA from damage caused by metabolic and external sources to maintain genomic integrity and homeostasis and to prevent the development of cancer. DNA damage inevitably occurs regardless of physiological or abnormal conditions. In response to DNA damage, signaling pathways are activated to repair the damaged DNA or to induce cell apoptosis. During the process, posttranslational modifications (PTMs) can be used to modulate enzymatic activities and regulate protein stability, protein localization, and protein-protein interactions. Thus, PTMs in DNA repair should be studied. In this review, we will focus on the current understanding of the phosphorylation, poly(ADP-ribosyl)ation, ubiquitination, SUMOylation, acetylation, and methylation of six typical PTMs and summarize PTMs of the key proteins in DNA repair, providing important insight into the role of PTMs in the maintenance of genome stability and contributing to reveal new and selective therapeutic approaches to target cancers.


2021 ◽  
Vol 22 (19) ◽  
pp. 10384
Author(s):  
Hirotomo Takatsuka ◽  
Atsushi Shibata ◽  
Masaaki Umeda

Genome integrity is constantly threatened by internal and external stressors, in both animals and plants. As plants are sessile, a variety of environment stressors can damage their DNA. In the nucleus, DNA twines around histone proteins to form the higher-order structure “chromatin”. Unraveling how chromatin transforms on sensing genotoxic stress is, thus, key to understanding plant strategies to cope with fluctuating environments. In recent years, accumulating evidence in plant research has suggested that chromatin plays a crucial role in protecting DNA from genotoxic stress in three ways: (1) changes in chromatin modifications around damaged sites enhance DNA repair by providing a scaffold and/or easy access to DNA repair machinery; (2) DNA damage triggers genome-wide alterations in chromatin modifications, globally modulating gene expression required for DNA damage response, such as stem cell death, cell-cycle arrest, and an early onset of endoreplication; and (3) condensed chromatin functions as a physical barrier against genotoxic stressors to protect DNA. In this review, we highlight the chromatin-level control of genome stability and compare the regulatory systems in plants and animals to find out unique mechanisms maintaining genome integrity under genotoxic stress.


2021 ◽  
Author(s):  
Tomoko Tanaka ◽  
Shinobu Hirai ◽  
Hiroyuki Manabe ◽  
Kentaro Endo ◽  
Hiroko Shimbo ◽  
...  

Aging involves a decline in physiology which is a natural event in all living organisms. An accumulation of DNA damage contributes to the progression of aging. DNA is continually damaged by exogenous sources and endogenous sources. If the DNA repair pathway operates normally, DNA damage is not life threatening. However, impairments of the DNA repair pathway may result in an accumulation of DNA damage, which has a harmful effect on health and causes an onset of pathology. RP58, a zinc-finger transcriptional repressor, plays a critical role in cerebral cortex formation. Recently, it has been reported that the expression level of RP58 decreases in the aged human cortex. Furthermore, the role of RP58 in DNA damage is inferred by the involvement of DNMT3, which acts as a co-repressor for RP58, in DNA damage. Therefore, RP58 may play a crucial role in the DNA damage associated with aging. In the present study, we investigated the role of RP58 in aging. We used RP58 hetero-knockout and wild-type mice in adolescence, adulthood, or old age. We performed immunohistochemistry to determine whether microglia and DNA damage markers responded to the decline in RP58 levels. Furthermore, we performed an object location test to measure cognitive function, which decline with age. We found that the wild-type mice showed an increase in single-stranded DNA and gamma-H2AX foci. These results indicate an increase in DNA damage or dysfunction of DNA repair mechanisms in the hippocampus as age-related changes. Furthermore, we found that, with advancing age, both the wild-type and hetero-knockout mice showed an impairment of spatial memory for the object and increase in reactive microglia in the hippocampus. However, the RP58 hetero-knockout mice showed these symptoms earlier than the wild-type mice did. These results suggest that a decline in RP58 level may lead to the progression of aging.


Immunotherapy ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1205-1213
Author(s):  
Pauline Rochefort ◽  
Françoise Desseigne ◽  
Valérie Bonadona ◽  
Sophie Dussart ◽  
Clélia Coutzac ◽  
...  

Faithful DNA replication is necessary to maintain genome stability and implicates a complex network with several pathways depending on DNA damage type: homologous repair, nonhomologous end joining, base excision repair, nucleotide excision repair and mismatch repair. Alteration in components of DNA repair machinery led to DNA damage accumulation and potentially carcinogenesis. Preclinical data suggest sensitivity to immune checkpoint inhibitors in tumors with DNA repair deficiency. Here, we review clinical studies that explored the use of immune checkpoint inhibitor in patient harboring tumor with DNA repair deficiency.


Author(s):  
Paulina Nguyen-Powanda ◽  
Bernard Robaire

Abstract The efficiency of antioxidant defense system decreases with aging, thus resulting in high levels of reactive oxygen species (ROS) and DNA damage in spermatozoa. This damage can lead to genetic disorders in the offspring. There are limited studies investigating the effects of the total loss of antioxidants, such as superoxide dismutase-1 (SOD1), in male germ cells as they progress through spermatogenesis. In this study, we evaluated the effects of aging and removing SOD1 (in male germ cells of SOD1-null (Sod1−/−) mice) in order to determine the potential mechanism(s) of DNA damage in these cells. Immunohistochemical analysis showed an increase in lipid peroxidation and DNA damage in the germ cells of aged wild-type (WT) and Sod1−/− mice of all age. Immunostaining of OGG1, a marker of base excision repair (BER), increased in aged WT and young Sod1−/− mice. In contrast, immunostaining intensity of LIGIV and RAD51, markers of non-homologous end-joining (NHEJ) and homologous recombination (HR), respectively, decreased in aged and Sod1−/− mice. Gene expression analysis showed similar results with altered mRNA expression of these key DNA repair transcripts in pachytene spermatocytes and round spermatids of aged and Sod1−/− mice. Our study indicates that DNA repair pathway markers of BER, NHEJ, and HR are differentially regulated as a function of aging and oxidative stress in spermatocytes and spermatids, and aging enhances the repair response to increased oxidative DNA damage, whereas impairments in other DNA repair mechanisms may contribute to the increase in DNA damage caused by aging and the loss of SOD1.


2020 ◽  
Vol 79 (5) ◽  
pp. 836-845.e7 ◽  
Author(s):  
Robin Sebastian ◽  
Eri K. Hosogane ◽  
Eric G. Sun ◽  
Andy D. Tran ◽  
William C. Reinhold ◽  
...  

2019 ◽  
Vol 20 (5) ◽  
pp. 1146 ◽  
Author(s):  
Marta Włodarczyk ◽  
Grażyna Nowicka

Obesity has been recognized to increase the risk of such diseases as cardiovascular diseases, diabetes, and cancer. It indicates that obesity can impact genome stability. Oxidative stress and inflammation, commonly occurring in obesity, can induce DNA damage and inhibit DNA repair mechanisms. Accumulation of DNA damage can lead to an enhanced mutation rate and can alter gene expression resulting in disturbances in cell metabolism. Obesity-associated DNA damage can promote cancer growth by favoring cancer cell proliferation and migration, and resistance to apoptosis. Estimation of the DNA damage and/or disturbances in DNA repair could be potentially useful in the risk assessment and prevention of obesity-associated metabolic disorders as well as cancers. DNA damage in people with obesity appears to be reversible and both weight loss and improvement of dietary habits and diet composition can affect genome stability.


2019 ◽  
Vol 41 (3) ◽  
pp. 257-266
Author(s):  
Ilaria Dutto ◽  
Claudia Scalera ◽  
Micol Tillhon ◽  
Giulio Ticli ◽  
Gianluca Passaniti ◽  
...  

Abstract Rubinstein-Taybi syndrome (RSTS) is an autosomal-dominant disorder characterized by intellectual disability, skeletal abnormalities, growth deficiency and an increased risk of tumors. RSTS is predominantly caused by mutations in CREBBP or EP300 genes encoding for CBP and p300 proteins, two lysine acetyl-transferases (KAT) playing a key role in transcription, cell proliferation and DNA repair. However, the efficiency of these processes in RSTS cells is still largely unknown. Here, we have investigated whether pathways involved in the maintenance of genome stability are affected in lymphoblastoid cell lines (LCLs) obtained from RSTS patients with mutations in CREBBP or in EP300 genes. We report that RSTS LCLs with mutations affecting CBP or p300 protein levels or KAT activity, are more sensitive to oxidative DNA damage and exhibit defective base excision repair (BER). We have found reduced OGG1 DNA glycosylase activity in RSTS compared to control cell extracts, and concomitant lower OGG1 acetylation levels, thereby impairing the initiation of the BER process. In addition, we report reduced acetylation of other BER factors, such as DNA polymerase β and Proliferating Cell Nuclear Antigen (PCNA), together with acetylation of histone H3. We also show that complementation of CBP or p300 partially reversed RSTS cell sensitivity to DNA damage. These results disclose a mechanism of defective DNA repair as a source of genome instability in RSTS cells.


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