Nitric Oxide Induces Ataxia Telangiectasia Mutated (ATM) Protein-dependent γH2AX Protein Formation in Pancreatic β Cells

Oleson, Bryndon J.; Broniowska, Katarzyna A.; Schreiber, Katherine H.; Tarakanova, Vera L.; Corbett, John A.

doi:10.1074/jbc.m113.531228

Cited by 29 publications

(56 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent with previous studies, the donor DEA/NO stimulates ␥H2AX formation in INS 832/13 cells following a 120-min treatment (Fig. 1A) (18). This temporal induction of ␥H2AX formation is surprising, because DEA/NO has a short half-life (3 min), leading to a rapid induction of DNA damage (increase in mean tail moment) that is detectable within 15 min of treatment, yet ␥H2AX formation does not occur until most of the nitric oxide is liberated from the donor (Fig.…”

Section: Resultssupporting

confidence: 79%

“…The formation of ␥H2AX is detectable within minutes of DSB induction (29). In pancreatic ␤ cells, nitric oxide produced endogenously following cytokine treatment or added exogenously using donors stimulates the formation of ␥H2AX (18). Consistent with previous studies, the donor DEA/NO stimulates ␥H2AX formation in INS 832/13 cells following a 120-min treatment (Fig.…”

Section: Resultssupporting

confidence: 76%

“…Whether supplied exogenously or produced endogenously following cytokine treatment, nitric oxide causes DNA base oxidation and deamination, resulting in single-strand breaks (16,17,19) When these breaks become sufficiently extensive, DSBs arise, and this results in DDR activation and ␥H2AX formation (18). The ability of nitric oxide to induce DNA damage and DDR activation has been shown in multiple cell types, including pancreatic ␤ cells (18,42,43,44).…”

Section: Discussionmentioning

confidence: 99%

“…Ataxia telangiectasia mutated (ATM) is a primary transducer of the DDR that phosphorylates a number of substrates in response to DNA double-strand breaks (DSBs) (15). Nitric oxide induces single-strand breaks in ␤-cell DNA that, when sufficiently extensive, can lead to DSB formation (16)(17)(18)(19). Recently, we have shown that the formation of DSBs in cytokine-treated ␤ cells results in nitric oxide-dependent ATM activation and an ATM-dependent induction of ␤-cell apoptosis (18).…”

mentioning

confidence: 99%

“…Islets from male SpragueDawley rats were isolated and cultured as described previously (21). INS 832/13 cells, RAW 264.7 cells, MEFs, and EndoC-␤H1 cells were cultured and plated as previously described (18,(22)(23)(24). HepG2 cells were maintained in MEM alpha containing 10% heat-inactivated fetal bovine serum, 100 U/ml penicillin, 100 g/ml streptomycin and cultured at 37°C at 5% CO 2 and 95% air.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Nitric Oxide Suppresses β-Cell Apoptosis by Inhibiting the DNA Damage Response

Oleson

Broniowska

Naatz

et al. 2016

Molecular and Cellular Biology

Self Cite

View full text Add to dashboard Cite

c Nitric oxide, produced in pancreatic ␤ cells in response to proinflammatory cytokines, plays a dual role in the regulation of ␤-cell fate. While nitric oxide induces cellular damage and impairs ␤-cell function, it also promotes ␤-cell survival through activation of protective pathways that promote ␤-cell recovery. In this study, we identify a novel mechanism in which nitric oxide prevents ␤-cell apoptosis by attenuating the DNA damage response (DDR). Nitric oxide suppresses activation of the DDR (as measured by ␥H2AX formation and the phosphorylation of KAP1 and p53) in response to multiple genotoxic agents, including camptothecin, H 2 O 2 , and nitric oxide itself, despite the presence of DNA damage. While camptothecin and H 2 O 2 both induce DDR activation, nitric oxide suppresses only camptothecin-induced apoptosis and not H 2 O 2 -induced necrosis. The ability of nitric oxide to suppress the DDR appears to be selective for pancreatic ␤ cells, as nitric oxide fails to inhibit DDR signaling in macrophages, hepatocytes, and fibroblasts, three additional cell types examined. While originally described as the damaging agent responsible for cytokine-induced ␤-cell death, these studies identify a novel role for nitric oxide as a protective molecule that promotes ␤-cell survival by suppressing DDR signaling and attenuating DNA damage-induced apoptosis.

show abstract

Section: Resultssupporting

confidence: 79%

Section: Resultssupporting

confidence: 76%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Nitric Oxide Suppresses β-Cell Apoptosis by Inhibiting the DNA Damage Response

Oleson

Broniowska

Naatz

et al. 2016

Molecular and Cellular Biology

Self Cite

View full text Add to dashboard Cite

show abstract

PAX4 preserves endoplasmic reticulum integrity preventing beta cell degeneration in a mouse model of type 1 diabetes mellitus

et al. 2016

View full text Add to dashboard Cite

Aims/hypothesisA strategy to enhance pancreatic islet functional beta cell mass (BCM) while restraining inflammation, through the manipulation of molecular and cellular targets, would provide a means to counteract the deteriorating glycaemic control associated with diabetes mellitus. The aims of the current study were to investigate the therapeutic potential of such a target, the islet-enriched and diabetes-linked transcription factor paired box 4 (PAX4), to restrain experimental autoimmune diabetes (EAD) in the RIP-B7.1 mouse model background and to characterise putative cellular mechanisms associated with preserved BCM.MethodsTwo groups of RIP-B7.1 mice were genetically engineered to: (1) conditionally express either PAX4 (BPTL) or its diabetes-linked mutant variant R129W (mutBPTL) using doxycycline (DOX); and (2) constitutively express luciferase in beta cells through the use of RIP. Mice were treated or not with DOX, and EAD was induced by immunisation with a murine preproinsulin II cDNA expression plasmid. The development of hyperglycaemia was monitored for up to 4 weeks following immunisation and alterations in the BCM were assessed weekly by non-invasive in vivo bioluminescence intensity (BLI). In parallel, BCM, islet cell proliferation and apoptosis were evaluated by immunocytochemistry. Alterations in PAX4- and PAX4R129W-mediated islet gene expression were investigated by microarray profiling. PAX4 preservation of endoplasmic reticulum (ER) homeostasis was assessed using thapsigargin, electron microscopy and intracellular calcium measurements.ResultsPAX4 overexpression blunted EAD, whereas the diabetes-linked mutant variant PAX4R129W did not convey protection. PAX4-expressing islets exhibited reduced insulitis and decreased beta cell apoptosis, correlating with diminished DNA damage and increased islet cell proliferation. Microarray profiling revealed that PAX4 but not PAX4R129W targeted expression of genes implicated in cell cycle and ER homeostasis. Consistent with the latter, islets overexpressing PAX4 were protected against thapsigargin-mediated ER-stress-related apoptosis. Luminal swelling associated with ER stress induced by thapsigargin was rescued in PAX4-overexpressing beta cells, correlating with preserved cytosolic calcium oscillations in response to glucose. In contrast, RNA interference mediated repression of PAX4-sensitised MIN6 cells to thapsigargin cell death.Conclusions/interpretationThe coordinated regulation of distinct cellular pathways particularly related to ER homeostasis by PAX4 not achieved by the mutant variant PAX4R129W alleviates beta cell degeneration and protects against diabetes mellitus. The raw data for the RNA microarray described herein are accessible in the Gene Expression Omnibus database under accession number GSE62846.Electronic supplementary materialThe online version of this article (doi:10.1007/s00125-016-3864-0) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

show abstract

Exposure to chronic hyperglycemic conditions results in Ras-related C3 botulinum toxin substrate 1 (Rac1)-mediated activation of p53 and ATM kinase in pancreatic β-cells

Sidarala

Kowluru

2017

Apoptosis

View full text Add to dashboard Cite

Chronic hyperglycemia (HG) promotes pancreatic islet dysfunction which leads to the onset of T2DM. This study is aimed at defining regulatory roles of Rac1, a small G-protein, in the activation of p53 and ATM kinase in pancreatic β-cells, under the duress of HG conditions. We report significant stimulatory effects of HG (20 mM; 24 h) on p53 activation in INS-1 832/13 cells, normal rodent and human islets. Pharmacological inhibition of Rac1 (EHT1864 or NSC23766) significantly suppressed HG-induced p53 activation in INS-1 832/13 cells and rat islets, suggesting novel roles for this small G-protein in the activation of p53. Inhibition of Rac1 geranylgeranylation with simvastatin or GGTI-2147, significantly attenuated HG-induced p53 activation, suggesting requisite roles for this signaling step in HG-mediated effects on β-cells. HG-induced p53 activation was also suppressed by SB203580, a known inhibitor of p38MAPK. Additionally, we observed increased activation of ATM kinase under HG conditions, which was blocked in presence of EHT1864. Furthermore, pharmacological inhibition of ATM kinase (KU55933) reduced activation of ATM kinase, but not p53, suggesting that HG-mediated activation of p53 and ATM could represent independent pro-apoptotic events. In conclusion, these data indicate that sustained activation of Rac1-p38MAPK signaling axis leads to activation of p53 leading to β-cell dysfunction under the duress of chronic hyperglycemic conditions.

show abstract

Nitric Oxide Induces Ataxia Telangiectasia Mutated (ATM) Protein-dependent γH2AX Protein Formation in Pancreatic β Cells

Cited by 29 publications

References 61 publications

Nitric Oxide Suppresses β-Cell Apoptosis by Inhibiting the DNA Damage Response

Nitric Oxide Suppresses β-Cell Apoptosis by Inhibiting the DNA Damage Response

PAX4 preserves endoplasmic reticulum integrity preventing beta cell degeneration in a mouse model of type 1 diabetes mellitus

Exposure to chronic hyperglycemic conditions results in Ras-related C3 botulinum toxin substrate 1 (Rac1)-mediated activation of p53 and ATM kinase in pancreatic β-cells

Contact Info

Product

Resources

About