scholarly journals Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage

10.3791/56213 ◽  
2018 ◽  
Author(s):  
Xiangduo Kong ◽  
Gladys M.S. Cruz ◽  
Bárbara A. Silva ◽  
Nicole M. Wakida ◽  
Nima Khatibzadeh ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cellular Responses ◽  
Laser Microirradiation

scholarly journals The poly(ADP-ribose)-dependent chromatin remodeler Alc1 induces local chromatin relaxation upon DNA damage

2016 ◽  
Vol 27 (24) ◽  
pp. 3791-3799 ◽  
Author(s):  
Hafida Sellou ◽  
Théo Lebeaupin ◽  
Catherine Chapuis ◽  
Rebecca Smith ◽  
Anna Hegele ◽  
...  
Keyword(s):  
Dna Damage ◽  
Structural Changes ◽  
Cellular Responses ◽  
Dna Lesions ◽  
Fast Kinetics ◽  
Important Player ◽  
Chromatin Relaxation ◽  
Kinetics Of ◽  
Laser Microirradiation

Chromatin relaxation is one of the earliest cellular responses to DNA damage. However, what determines these structural changes, including their ATP requirement, is not well understood. Using live-cell imaging and laser microirradiation to induce DNA lesions, we show that the local chromatin relaxation at DNA damage sites is regulated by PARP1 enzymatic activity. We also report that H1 is mobilized at DNA damage sites, but, since this mobilization is largely independent of poly(ADP-ribosyl)ation, it cannot solely explain the chromatin relaxation. Finally, we demonstrate the involvement of Alc1, a poly(ADP-ribose)- and ATP-dependent remodeler, in the chromatin-relaxation process. Deletion of Alc1 impairs chromatin relaxation after DNA damage, while its overexpression strongly enhances relaxation. Altogether our results identify Alc1 as an important player in the fast kinetics of the NAD+- and ATP-dependent chromatin relaxation upon DNA damage in vivo.

scholarly journals Poly(ADP-ribosyl)ation-dependent Transient Chromatin Decondensation and Histone Displacement following Laser Microirradiation

2015 ◽  
Vol 291 (4) ◽  
pp. 1789-1802 ◽  
Author(s):  
Hilmar Strickfaden ◽  
Darin McDonald ◽  
Michael J. Kruhlak ◽  
Jean-Francois Haince ◽  
John P. H. Th'ng ◽  
...  
Keyword(s):  
Dna Damage ◽  
Histone H1 ◽  
Parp Inhibition ◽  
Chromatin Decondensation ◽  
Strand Breaks ◽  
Photoactivatable Gfp ◽  
Dna Strand ◽  
Kinetics Of ◽  
Laser Microirradiation

Chromatin undergoes a rapid ATP-dependent, ATM and H2AX-independent decondensation when DNA damage is introduced by laser microirradiation. Although the detailed mechanism of this decondensation remains to be determined, the kinetics of decondensation are similar to the kinetics of poly(ADP-ribosyl)ation. We used laser microirradiation to introduce DNA strand breaks into living cells expressing a photoactivatable GFP-tagged histone H2B. We find that poly(ADP-ribosyl)ation mediated primarily by poly(ADP-ribose) polymerase 1 (PARP1) is responsible for the rapid decondensation of chromatin at sites of DNA damage. This decondensation of chromatin correlates temporally with the displacement of histones, which is sensitive to PARP inhibition and is transient in nature. Contrary to the predictions of the histone shuttle hypothesis, we did not find that histone H1 accumulated on poly(ADP-ribose) (PAR) in vivo. Rather, histone H1, and to a lessor extent, histones H2A and H2B were rapidly depleted from the sites of PAR accumulation. However, histone H1 returns to chromatin and the chromatin recondenses. Thus, the PARP-dependent relaxation of chromatin closely correlates with histone displacement.

scholarly journals Application of Laser Microirradiation in the Investigations of Cellular Responses to DNA Damage

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiangduo Kong ◽  
Nicole M. Wakida ◽  
Kyoko Yokomori
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Mammalian Cells ◽  
Cellular Responses ◽  
Future Application ◽  
Cellular Processes ◽  
Damage Response ◽  
Different Types ◽  
Laser Systems ◽  
Laser Microirradiation

Since the laser has been invented it has been highly instrumental in ablating different parts of the cell to test their functionality. Through induction of damage in a defined sub-micron region in the cell nucleus, laser microirradiation technique is now established as a powerful real-time and high-resolution methodology to investigate mechanisms of DNA damage response and repair, the fundamental cellular processes for the maintenance of genomic integrity, in mammalian cells. However, irradiation conditions dictate the amounts, types and complexity of DNA damage, leading to different damage signaling responses. Thus, in order to properly interpret the results, it is important to understand the features of laser-induced DNA damage. In this review, we describe different types of DNA damage induced by the use of different laser systems and parameters, and discuss the mechanisms of DNA damage induction. We further summarize recent advances in the application of laser microirradiation to study spatiotemporal dynamics of cellular responses to DNA damage, including factor recruitment, chromatin modulation at damage sites as well as more global damage signaling. Finally, possible future application of laser microirradiation to gain further understanding of DNA damage response will be discussed.

scholarly journals Ionizing radiation induces ataxia telangiectasia mutated kinase (ATM)-mediated phosphorylation of LKB1/STK11 at Thr-366

2002 ◽  
Vol 368 (2) ◽  
pp. 507-516 ◽  
Author(s):  
Gopal P. SAPKOTA ◽  
Maria DEAK ◽  
Agnieszka KIELOCH ◽  
Nick MORRICE ◽  
Aaron A. GOODARZI ◽  
...  
Keyword(s):  
Dna Damage ◽  
Protein Kinase ◽  
Ionizing Radiation ◽  
Ataxia Telangiectasia ◽  
Cellular Responses ◽  
Ataxia Telangiectasia Mutated ◽  
Cancer Syndrome ◽  
Phosphoinositide 3 Kinase

The serine/threonine protein kinase LKB1 functions as a tumour suppressor, and mutations in this enzyme lead to the inherited Peutz—Jeghers cancer syndrome. We previously found that LKB1 was phosphorylated at Thr-366 in vivo, a residue conserved in mammalian, Xenopus and Drosophila LKB1, located on a C-terminal non-catalytic moiety of the enzyme. Mutation of Thr-366 to Ala or Asp partially inhibited the ability of LKB1 to suppress growth of G361 melanoma cells, but did not affect LKB1 activity in vitro or LKB1 localization in vivo. As a first step in exploring the role of this phosphorylation further, we have generated a phosphospecific antibody specifically recognizing LKB1 phosphorylated at Thr-366 and demonstrate that exposure of cells to ionizing radiation (IR) induced a marked phosphorylation of LKB1 at Thr-366 in the nucleus. Thr-366 lies in an optimal phosphorylation motif for the phosphoinositide 3-kinase-like kinases DNA-dependent protein kinase (DNA-PK), ataxia telangiectasia mutated kinase (ATM) and ataxia telangiectasia-related kinase (ATR), which function as sensors for DNA damage in cells and mediate cellular responses to DNA damage. We demonstrate that both DNA-PK and ATM efficiently phosphorylate LKB1 at Thr-366 in vitro and provide evidence that ATM mediates this phosphorylation in vivo. This is based on the finding that LKB1 is not phosphorylated in a cell line lacking ATM in response to IR, and that agents which induce cellular responses via ATR in preference to ATM poorly induce phosphorylation of LKB1 at Thr-366. These observations provide the first link between ATM and LKB1 and suggest that ATM could regulate LKB1.

Curcumin-containing Silver Nanoparticles prevent carbon tetrachlorideinduced hepatotoxicity in mice

2020 ◽  
Vol 23 ◽  
Author(s):  
Hossam Ebaid ◽  
Mohamed Habila ◽  
Iftekhar Hassan ◽  
Jameel Al-Tamimi ◽  
Mohamed S. Omar ◽  
...  
Keyword(s):  
Dna Damage ◽  
Silver Nanoparticles ◽  
Nuclear Dna ◽  
Liquid Paraffin ◽  
Tail Length ◽  
Hepatic Tissue ◽  
Tissue Destruction ◽  
Group 2 ◽  
The Impact

Background: Hepatotoxicity remains an important clinical challenge. Hepatotoxicity observed in response to toxins and hazardous chemicals may be alleviated by delivery of the curcumin in silver nanoparticles (AgNPs-curcumin). In this study, we examined the impact of AgNPs-curcumin in a mouse model of carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Male C57BL/6 mice were divided into three groups (n=8 per group). Mice in group 1 were treated with vehicle control alone, while mice in Group 2 received a single intraperitoneal injection of 1 ml/kg CCl4 in liquid paraffin (1:1 v/v). Mice in group 3 were treated with 2.5 mg/kg AgNPs-curcumin twice per week for three weeks after the CCl4 challenge. Results: Administration of CCL4 resulted in oxidative dysregulation, including significant reductions in reduced glutathione and concomitant elevations in the level of malondialdehyde (MDA). CCL4 challenge also resulted in elevated levels of serum aspartate transaminase (AST) and alanine transaminase (ALT); these findings were associated with the destruction of hepatic tissues. Treatment with AgNPs-curcumin prevented oxidative imbalance, hepatic dysfunction, and tissue destruction. A comet assay revealed that CCl4 challenge resulted in significant DNA damage as documented by a 70% increase in nuclear DNA tail-length; treatment with AgNPs-curcumin inhibited the CCL4-mediated increase in nuclear DNA tail-length by 34%. Conclusion: Administration of AgNPs-curcumin resulted in significant antioxidant activity in vivo. This agent has the potential to prevent the hepatic tissue destruction and DNA damage that results from direct exposure to CCL4.

Corilagin Inhibits Esophageal Squamous Cell Carcinoma by Inducing DNA Damage and Down-Regulation of RNF8

2019 ◽  
Vol 19 (8) ◽  
pp. 1021-1028 ◽  
Author(s):  
Fanghua Qiu ◽  
Lifang Liu ◽  
Yu Lin ◽  
Zetian Yang ◽  
Feng Qiu
Keyword(s):  
Cell Proliferation ◽  
Dna Damage ◽  
Squamous Cell Carcinoma ◽  
Esophageal Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Cell Apoptosis ◽  
Cell Counting ◽  
Antitumor Effects

Background:Esophageal squamous cell carcinoma (ESCC), the most prevalent histologic subtype of esophageal cancer, is an aggressive malignancy with poor prognosis and a high incidence in the East. Corilagin, an active component present in Phyllanthus niruri L., has been shown to suppress tumor growth in various cancers. However, the effects of corilagin on ESCC and the mechanisms for its tumor suppressive function remain unknown.Methods:Cell proliferation was measured by Cell Counting Kit-8 assay and colony formation assays. Annexin V/PI double-staining was performed to assess cell apoptosis. Immunofluorescence staining and western blotting were used to evaluate the protein expression. A xenograft mice model was used to assess the in vivo antitumor effects of corilagin alone or in combination with cisplatin.Results:We for the first time showed that corilagin was effectively able to inhibit ESCC cell proliferation and induce cell apoptosis. Additionally, our results validated its antitumor effects in vivo using a xenograft mouse model. Mechanistically, we found that corilagin caused significant DNA damage in ESCC cells. We found that corilagin could significantly attenuate the expression of the E3 ubiquitin ligase RING finger protein 8 (RNF8) through ubiquitin-proteasome pathway, leading to the inability of DNA damage repair response and eventually causing cell apoptosis. Furthermore, we also showed that corilagin substantially enhanced the antitumor effects of chemotherapy drug cisplatin both in vitro and in vivo.Conclusion:Our results not only provided novel and previously unrecognized evidences for corilagin-induced tumor suppression through inducing DNA damage and targeting RNF8 in ESCC, but also highlighted that corilagin might serve as an adjunctive treatment to conventional chemotherapeutic drugs in ESCC patients.

A Novel Camptothecin Derivative 3j Inhibits Nsclc Proliferation Via Induction of Cell Cycle Arrest By Topo I-Mediated DNA Damage

2019 ◽  
Vol 19 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Yang Liu ◽  
Jingyin Zhang ◽  
Shuyun Feng ◽  
Tingli Zhao ◽  
Zhengzheng Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Dna Damage ◽  
Cyclin D ◽  
Dna Relaxation ◽  
Cycle Arrest ◽  
H460 Cell ◽  
H1975 Cell

Objective: The aim of this study is to investigate the inhibitory effect of camptothecin derivative 3j on Non-Small Cell Lung Cancer (NSCLCs) cells and the potential anti-tumor mechanisms. Background: Camptothecin compounds are considered as the third largest natural drugs which are widely investigated in the world and they suffered restriction because of serious toxicity, such as hemorrhagic cystitis and bone marrow suppression. Methods: Using cell proliferation assay and S180 tumor mice model, a series of 20(S)-O-substituted benzoyl 7- ethylcamptothecin compounds were screened and evaluated the antitumor activities in vitro and in vivo. Camptothecin derivative 3j was selected for further study using flow cytometry in NSCLCs cells. Cell cycle related protein cyclin A2, CDK2, cyclin D and cyclin E were detected by Western Blot. Then, computer molecular docking was used to confirm the interaction between 3j and Topo I. Also, DNA relaxation assay and alkaline comet assay were used to investigate the mechanism of 3j on DNA damage. Results: Our results demonstrated that camptothecin derivative 3j showed a greater antitumor effect in eleven 20(S)-O-substituted benzoyl 7-ethylcamptothecin compounds in vitro and in vivo. The IC50 of 3j was 1.54± 0.41 µM lower than irinotecan with an IC50 of 13.86±0.80 µM in NCI-H460 cell, which was reduced by 8 fold. In NCI-H1975 cell, the IC50 of 3j was 1.87±0.23 µM lower than irinotecan (IC50±SD, 5.35±0.38 µM), dropped by 1.8 fold. Flow cytometry analysis revealed that 3j induced significant accumulation in a dose-dependent manner. After 24h of 3j (10 µM) treatment, the percentage of NCI-H460 cell in S-phase significantly increased (to 93.54 ± 4.4%) compared with control cells (31.67 ± 3.4%). Similarly, the percentage of NCI-H1975 cell in Sphase significantly increased (to 83.99 ± 2.4%) compared with control cells (34.45 ± 3.9%) after treatment with 10µM of 3j. Moreover, increased levels of cyclin A2, CDK2, and decreased levels of cyclin D, cyclin E further confirmed that cell cycle arrest was induced by 3j. Furthermore, molecular docking studies suggested that 3j interacted with Topo I-DNA and DNA-relaxation assay simultaneously confirmed that 3j suppressed the activity of Topo I. Research on the mechanism showed that 3j exhibited anti-tumour activity via activating the DNA damage response pathway and suppressing the repair pathway in NSCLC cells. Conclusion: Novel camptothecin derivative 3j has been demonstrated as a promising antitumor agent and remains to be assessed in further studies.

Protective effect of argan oil on DNA damage in vivo and in vitro

Biomarkers ◽  
2021 ◽  
pp. 1-9
Author(s):  
Habiba Bouchab ◽  
Abbas Ishaq ◽  
Riad EL Kebbaj ◽  
Boubker Nasser ◽  
Gabriele Saretzki
Keyword(s):  
Dna Damage ◽  
Protective Effect ◽  
Argan Oil

scholarly journals An ARF GTPase module promoting invasion and metastasis through regulating phosphoinositide metabolism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marisa Nacke ◽  
Emma Sandilands ◽  
Konstantina Nikolatou ◽  
Álvaro Román-Fernández ◽  
Susan Mason ◽  
...  
Keyword(s):  
Metastatic Cancer ◽  
Cellular Responses ◽  
Signalling Pathways ◽  
External Signal ◽  
Phosphoinositide Metabolism ◽  
Invasion And Metastasis ◽  
3 Dimensional

AbstractThe signalling pathways underpinning cell growth and invasion use overlapping components, yet how mutually exclusive cellular responses occur is unclear. Here, we report development of 3-Dimensional culture analyses to separately quantify growth and invasion. We identify that alternate variants of IQSEC1, an ARF GTPase Exchange Factor, act as switches to promote invasion over growth by controlling phosphoinositide metabolism. All IQSEC1 variants activate ARF5- and ARF6-dependent PIP5-kinase to promote PI(3,4,5)P3-AKT signalling and growth. In contrast, select pro-invasive IQSEC1 variants promote PI(3,4,5)P3 production to form invasion-driving protrusions. Inhibition of IQSEC1 attenuates invasion in vitro and metastasis in vivo. Induction of pro-invasive IQSEC1 variants and elevated IQSEC1 expression occurs in a number of tumour types and is associated with higher-grade metastatic cancer, activation of PI(3,4,5)P3 signalling, and predicts long-term poor outcome across multiple cancers. IQSEC1-regulated phosphoinositide metabolism therefore is a switch to induce invasion over growth in response to the same external signal. Targeting IQSEC1 as the central regulator of this switch may represent a therapeutic vulnerability to stop metastasis.

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