Fanconi anemia complementation group C protection against oxidative stress‑induced β‑cell apoptosis
- Authors:
- Published online on: June 14, 2018 https://doi.org/10.3892/mmr.2018.9163
- Pages: 2485-2491
Abstract
Introduction
Fanconi anemia (FA) is a genetic disorder that is caused by an abnormality in genes encoding Fanconi anemia proteins (FA proteins), which comprise a multi-protein nuclear complex that has an essential role in DNA inter-strand crosslink repair (1,2). Dysfunction of FA proteins leads to cytogenetic instability, chromosomal breakage, defective DNA repair and cellular hypersensitivity to DNA crosslinking agents (3), and these effects are known to cause developmental defects, bone marrow failure, aplastic anemia and increased cancer risk in individuals with FA (4–6). To a lesser extent, metabolic disorders associated with FA, including diabetes mellitus (DM), hyperglycemia and insulin disorders, have been reported in ~40% of patients with FA (7–9).
FA complementation group C (FANCC) is a component of the FA multiprotein nuclear complex (2). However, it has been demonstrated that instead of FANCC being an isoform targeted to the nucleus, FANCC localization in cytoplasm is essential for the correction of enhanced cytotoxicity of crosslinks in cells with predominant defects in the FANCC gene (10). Additionally, cytoplasmic FANCC has a role in prevention of oxidative DNA damage (11), and protection against oxidative stress-induced apoptosis (12). Reactive oxygen species (ROS) accumulation and cell apoptosis have been identified in many cell types with FANCC depletion. These cell types include hematopoietic progenitor cells, hepatocytes, and murine embryonic fibroblasts isolated from FA model mice (13–16). It was suggested that FANCC counteraction of oxidative stress is mediated through glutathione S-transferase P1 (GSTP1) and nicotinamide adenine dinucleotide phosphate-cytochrome P450 reductase (17,18). FANCC significantly increased the catalytic activity of GSTP1, which is an inducible antioxidant enzyme that has a major role in the intracellular defense of toxin and ROS (19). Fancc-/- cells were hypersensitive to oxidant stimuli and underwent enhanced oxidant-mediated apoptosis compared with the wild type controls as a result of oxidative stress activating the redox-dependent apoptosis signal-regulating kinase 1 pathway (15). Wang et al (20) reported that overexpression of FANCC protected hematopoietic progenitors from death induced by Fas-mediated apoptosis. A previous study demonstrated that FANCC associated with uncoordinated-5A protein, a pro-apoptotic dependent receptor, and delayed apoptosis in neuroblastoma SH-SY5Y cell line (21). These findings indicate that oxidative stress is a contributor to FA pathogenesis, and that FANCC is a key contributor to oxidative stress response mechanisms in various cell types.
Oxidative stress has also been implicated as an important factor in the progression of DM via interference with insulin signal transduction, insulin production and induction of β-cell apoptosis (22,23). Oxidative stress and DM are commonly observed in patients with FA, and high levels of ROS were detected in insulin-sensitive tissues of Fancc-/- mice (24). Furthermore, insulin receptor and insulin receptor substrate 1 tyrosine phosphorylation were impaired in Fancc knockout mice treated with tumor necrosis factor (TNF)-α compared with their wild-type littermates (24). It was concluded that defects in Fancc led to ROS accumulation in insulin target cells, thus interfering with the insulin signaling pathway, leading to insulin resistance (24).
While most studies in the literature focused on the actions of FANCC on signal transduction in insulin-responsive cells, none has explored the role of FANCC in β-cells with limited expression of antioxidant enzymes [reviewed by Robertson and Harmon (25)]. In the present study, it was hypothesized that depletion of FANCC causes pancreatic β-cell hypersensitivity to oxidative stress-induced apoptosis. Accordingly, the aim of the present study was to investigate the role of FANCC in pancreatic β-cell response to oxidative stress.
Materials and methods
Study approval
The present study was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University (Bangkok, Thailand). Siriraj Hospital is Thailand's largest university-based national tertiary referral center. The protocol for the present study was approved by the Siriraj Institutional Review Board (COA no. Si491/2014).
Cell culture
Human 1.1B4 pancreatic β-cell line (American Type Culture Collection, Manassas, VA, USA) was maintained in RPMI-1640 medium (Invitrogen; Thermo Fisher Scientific, Inc., Waltham, MA, USA) containing 10% fetal bovine serum (Gibco; Thermo Fisher Scientific, Inc.), 100 IU/ml penicillin, and 100 mg/ml streptomycin at 37°C in a 95% humidified atmosphere containing 5% CO2.
Small interfering RNA (siRNA) transfection
Human FANCC SMARTpool ON-TARGETplus siRNA (siRNA-FANCC; cat. no. L-011033-00-0005) and siRNA ON-TARGETplus Non-targeting Pool (siRNA-control; cat. no. D-001810-10-20) were purchased from Dharmacon (GE Healthcare; Dharmacon, Inc., Lafayette, CO, USA). The day prior to transfection, 1.6×105 cells/well were seeded into 6-well plates. Knockdown was performed at 24 and 48 h after seeding. siRNA-FANCC and siRNA-control were transfected at a concentration of 100 pmol using Lipofectamine® 2000 Transfection Reagent (Invitrogen; Thermo Fisher Scientific, Inc.) according to the manufacturer's protocol. At 48 h after transfection, the cells were harvested and FANCC expression levels were determined by western blot analysis.
Plasmid construct and transfection
To generate FANCC recombinant plasmids, FANCC coding sequence NM_000136.2 and FLAG-tag sequence DYKDDDDK were amplified with the following primer sequences: Forward, 5′-CGGGATCCATGGCTCAAGATTCAGTAG-3′ and reverse, 5′-GCTCTAGACTACTTATCGTCGTCATCCTTGTAATCGACTTGAGTTCGCAGCTCTTTAAGG-3′. The product was cloned into pcDNA3.1 plasmids (Invitrogen; Thermo Fisher Scientific, Inc.). All plasmids were amplified in Escherichia coli (DH5α) and purified using QIAamp DNA Mini Kit (Qiagen GmbH, Hilden, Germany). The day prior to transfection, 2×105 cells/well were seeded into 6-well plates. After 24 h, the cells were transfected with 500 ng FANCC-constructed plasmid or pcDNA3.1 empty plasmid using the same conditions as the ones described for siRNA transfection. At 48 h after transfection, the cells were harvested and FANCC protein expression levels were determined by western blot analysis.
RNA isolation and RT-qPCR
Total RNA from 1.1B4 cells (5×105) was isolated using TRIzol Reagent (Invitrogen; Thermo Fisher Scientific, Inc.). Subsequently, RNA was reverse transcribed into cDNA using a RevertAid First Strand cDNA Synthesis Kit (Thermo Fisher Scientific, Inc.) Gene-specific primer pairs were designed using Primer3Plus program (www.bioinformatics.nl/cgi-bin/primer3plus/primer3plus.cgi) or derived from previous studies (26–28). All primers (Table I) were checked against National Center for Biotechnology Information Primer-BLAST. RT-qPCR was performed in a LightCycler 480 Instrument (Roche Diagnostics GmbH, Mannheim, Germany) using LightCycler® 480 SYBR Green I Master (Roche Diagnostics GmbH). Initial enzyme activation proceeded at 95°C for 10 min, followed by 45 cycles at 95°C for 30 sec, 60–62°C for 20 sec, and 72°C for 20 sec. β-actin was used as an internal control to normalize input cDNA. Relative mRNA expression levels were calculated using the 2-ΔΔCq method (29). All assays were performed in triplicate.
Western blot analysis
Total protein was extracted by lysing cells in radioimmunoprecipitation assay lysis buffer (Thermo Fisher Scientific Inc.). Protein concentrations were quantified by Bradford protein assay (Bio-Rad Laboratories, Inc., Hercules, CA, USA) using a NanoDrop 2000 spectrophotometer (Thermo Fisher Scientific, Inc.). Proteins (50–100 µg) were separated onto 10% SDS polyacrylamide gel, and then electroblotted onto nitrocellulose membrane (Bio-Rad Laboratories, Inc.) using a semi-dry electrophoretic transfer cell (Bio-Rad Laboratories, Inc.). Primary goat polyclonal antibody against human FANCC (C-14; cat. no. sc-18110; 1:500; Santa Cruz Biotechnology Inc., Dallas, TX, USA), mouse monoclonal antibody against FLAG-tag (1:2,000; cat. no. F3165; Sigma-Aldrich; Merck KGaA, Darmstadt, Germany), and mouse monoclonal antibody against β-actin (1:1,000; cat. no. s-47778; Santa Cruz Biotechnology, Inc.) were incubated with the membranes for 2 h at room temperature. Following this, membranes were incubated with horseradish peroxidase-linked rabbit anti-goat or goat anti-mouse secondary antibody (1:1,000; cat. no. P044701-2; Dako; Agilent Technologies, Inc., Santa Clara, CA, USA) for 1 h at room temperature. Binding antibodies were visualized using an enhanced chemiluminescence detection kit (SuperSignal West Pico PLUS Chemiluminescent Substrate; Roche Diagnostics GmbH), and bands were detected by biomolecular imager (ImageQuant LAS 4010; GE Healthcare Life Sciences, Little Chalfont, UK). β-actin staining was used as an internal control in all experiments. Expressed bands were quantified by computer-assisted scanning densitometry using ImageJ version 1.4.3.x (National Institutes of Health, Bethesda, MD, USA).
Flow cytometry
Following knockdown or overexpression of FANCC in 1.1B4 β-cells for 48 h, 1.4×106 cells were treated with 0.5 mM H2O2 for 4 h. Subsequently, Annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining was performed using Annexin V-FITC/PI Apoptosis Detection Kit (ImmunoTools GmbH, Friesoythe, Germany) according to the manufacturer's protocol. Apoptosis was analyzed using a BD FACSVerse flow cytometer (BD Biosciences, San Jose, CA, USA) and FlowJo software version 10.4 (FlowJo LLC, Ashland, OR, USA). Each experiment was independently performed three times.
Caspase activity
Luminescent type Caspase-Glo 3/7 Assay (Promega Corporation, Madison, WI, USA) was used to measure caspase 3/7 activity. Cells were seeded in a Corning 96-well white flat bottom plate (Corning Life Sciences, Tewksbury, MA, USA) at 8×103 and 1×104 cells per well for knockdown and overexpression, respectively. Following 24 h, the cells were transfected with 500 ng plasmids (FANCC-pcDNA3.1 or empty vector) or 100 pmol siRNA (siRNA-FANCC or siRNA-control). In order to increase the population of cells successfully transfected with either FANCC-pcDNA3.1, empty vector, siRNA-FANCC or siRNA-control, the transfected cells were transfected twice with the same type and amount of plasmid 24 h after initial transfection. At 24 h after the second transfection, cells were treated with 0.5 mM H2O2 for 4 h. Following this, 100 µl Caspase-Glo 3/7 Reagent (Promega Corporation) was added into each well. The plate was then shaken at 300 to 500 rpm in a dark room for 30 min at room temperature (~25°C). Luminescence was measured using a multi-detection microplate reader (Synergy H1; BioTek Instruments, Inc., Winooski, VT, USA).
Statistical analysis
Data analysis was performed using SPSS Statistics version 18.0 (SPSS, Inc., Chicago, IL, USA). Student's t-test was used to evaluate differences of the mean ± standard error of the mean. P<0.05 was considered to indicate a statistically significant difference.
Results
Increased apoptosis of FANCC-deficient β-cells
In order to investigate the role of FANCC in β-cell response to oxidative stress, FANCC-depleted 1.1b4 cells were generated via siRNA-mediated transient silencing. Knockdown efficiency is demonstrated in Fig. 1A. The results demonstrated that FANCC knockdown cells exhibited increased apoptosis compared with si-control cells, in non-induced and H2O2-induced oxidative stress conditions (Fig. 1B-D). In non-induced condition, Annexin V-FITC/PI staining revealed 12.6 and 1.6% of control cells to be in late and early apoptotic states, respectively; while, 13.6 and 5.3% of FANCC knockdown cells were in late and early apoptotic states, respectively (Fig. 1B, left). Under H2O2-induced oxidative stress induction, 19.9 and 2.7% of control cells were in late and early apoptotic states, respectively, while 24.9 and 6.7% of FANCC knockdown cells were in late and early apoptotic states, respectively (Fig. 1B, right). Overall, in non-induced condition, ~14.2 and ~18.9% of control cells and FANCC knockdown cells, respectively, were apoptotic (P<0.05). Under oxidative stress induction, the percentage of apoptotic cells in control cells and FANCC knockdown cells increased to 22.6 and 31.3%, respectively (P<0.01; Fig. 1C). Caspase 3/7 activities of FANCC knockdown cells were 1.33-fold and 1.43-fold higher than control cells under non-induced and H2O2-induced oxidative stress conditions, respectively (P<0.01 and P<0.001, respectively; Fig. 1D).
Overexpression of FANCC protects β-cells from oxidative stress-induced apoptosis
To further elucidate the effect of FANCC in attenuating β-cell apoptosis, plasmid construct for FANCC overexpression was transfected into 1.1B4 β-cells, and the percentage of apoptosis in cells overexpressing FANCC was investigated. Annexin V-FITC/PI staining (Fig. 2A and B) demonstrated that 1.1B4 β-cells overexpressing FANCC had lower total percentage of apoptotic cells than control cells transfected with empty vector (22.5 vs. 25.1%, respectively; P=0.067). Additionally, under oxidative stress induction, the percentage of apoptotic cells in 1.1B4 β-cells overexpressing FANCC was significantly lower than that of control cells transfected with empty vector (25.7 vs. 32.2%, respectively; P<0.05; Fig. 2C). In addition, 1.1B4 β-cells overexpressing FANCC had lower caspase 3/7 activity compared to control cells (0.75-fold; P<0.05) under H2O2-induced oxidative stress conditions (Fig. 2D). However, the significant protective effect of FANCC against apoptosis was not observed in non-induced condition.
Depletion of FANCC alters expression of genes involved in insulin expression, secretion and apoptosis pathways
To confirm the anti-apoptotic effect of FANCC in the human β-cell line, the expression of anti-apoptotic [BCL2 apoptosis regulator (BCL-2)] and pro-apoptotic genes [BCL2 associated X, apoptosis regulator (BAX)] were investigated. The results demonstrated that in FANCC-deficient 1.1b4 β-cells, BCL-2 mRNA expression decreased by 2.59 fold (P<0.001), while BAX mRNA level increased by 1.93 fold (P<0.01), compared to the expressions of control cells (Fig. 3). Depletion of FANCC also led to a 3.15-fold increase in dickkopf WNT signaling pathway inhibitor 1 (DKK1) expression (P<0.01). As DKK1 encodes a negative regulator of Wnt signaling, a pathway implicated in β-cell apoptotic defenders (30), increased DKK1 expression level in FANCC-deficient cells thereby reaffirms the crucial role of FANCC in protection against β-cell apoptosis. Notably, the expression levels of insulin (INS) and glucokinase (GCK) genes, which are critical for insulin synthesis and secretion, were decreased [0.77-fold (P<0.01) and 0.82-fold (P<0.05), respectively] compared to cells transfected with siRNA-control.
Discussion
DM and abnormalities of glucose and insulin metabolism are common among patients with FA (7–9). However, little is known regarding the role of FA proteins in maintenance of glucose homeostasis. While previous studies focused on the link between ROS accumulation and insulin resistance in FANCC-deficient state (24), the results of the current study provide evidence linking FANCC insufficiency to DM via deterioration of β-cell ability to defend against oxidative stress-induced apoptosis.
Pancreatic β-cells have inherently low levels of antioxidants (31), which may be due to the need to maintain a low level of ROS to facilitate insulin production. Accordingly, this specialized cell type is extremely susceptible to oxidative stress. Previous studies addressed the deleterious effects of oxidative stress on β-cell function and survival (24,32), and a link between inability of β-cells to adequately secrete insulin and the development of type 2 DM was demonstrated (33,34). Furthermore, hypersensitivity to oxidative agents and enhancement of oxidant-mediated apoptosis were evident in FANCC-deficient cells isolated from mice (35). In addition, Zhang et al (36) demonstrated that TNF-α-induced senescence was associated with the accumulation of ROS and oxidative DNA damage in Fancc−/− mice compared with wild-type littermates. In the present study, the role of FANCC in antioxidant defense mechanisms of the human 1.1b4 β-cell line was investigated. It was also demonstrated that without H2O2-induced oxidative stress, siRNA-mediated FANCC suppression led to a significant increase in β-cell apoptosis, while transient overexpression of FANCC decreased β-cell apoptosis. However, the significant protective effect of FANCC overexpression and empty vector against apoptosis was not observed in non-induced conditions. This may be due to the presence of endogenous FANCC expression in 1.1b4 cells, which may have been sufficient enough to prevent apoptosis in physiological conditions. These results suggest the necessity of a physiological level of FANCC as a requirement for β-cell survival. Under oxidative stress-induced conditions, apoptosis was more pronounced in FANCC-depleted cells, while FANCC-overexpressed cells were resistant to H2O2-induced oxidative stress. These data reaffirm the critical role of FANCC in protection against oxidative stress-induced β-cell apoptosis. However, the data indicated a minor increase of apoptosis level in FANCC knockdown cells as compared with control cells. Potentially, other pathways besides FANCC are involved in cell apoptosis or there may be compensatory mechanisms that counteract the apoptosis. Additionally, the increased or decrease in caspase 3/7 activities were marginal, although statistically significant. BCL2 expression was decreased and BAX expression was increased >2-fold in FANCC knockdown cells compared with controls. The difference in apoptotic indicator expression is not surprising, as BCL2 and BAX were detected at the mRNA level while caspase 3/7 activity was determined at the protein level; furthermore, numerous molecules and signaling pathways are involved. However, it can be concluded that lack of FANCC increases caspase 3/7 activity, increases BAX and decreases BCL-2 RNA level.
Although a comprehensive and conclusive mechanism that explains how FANCC facilitates β-cell survival was not elucidated in the present study, the finding that DKK1 expression level was increased in FANCC-depleted β-cells suggests the possibility of Wnt signal transduction involvement, which required further investigation. DKK1 is known to be a Wnt signaling antagonist that sequesters Wnt receptors (30,37). Upregulation of DKK1 inhibits Wnt signal transduction, thus promoting apoptosis (38), and DKK1 upregulation was observed in FANCC-depleted cells (39). FANCC forms a complex with C-terminal-binding protein-1 and β-catenin, and acts as a transcriptional repressor that directly inhibits DKK1 expression (40). It is, therefore, possible that FANCC modulates DKK1 expression via nuclear activity. The exact mechanism by which FANCC regulates DKK1 requires further investigation.
In addition to loss of protection against oxidative stress-induced apoptosis in FANCC-depleted 1.1B4 β-cells, the expression of genes involved in insulin synthesis (such as, INS), a key hormone for regulating glucose uptake into peripheral cells, and secretion (such as, GCK), a rate-limiting enzyme in glycolysis that is a sensor of glucose-stimulated insulin secretion (41), was decreased. Reduction in INS and GCK expression is common in pancreatic β-cells exposed to oxidative stress, and in islets isolated from DM subjects (42–44). Taken together, the data from the present study reveal an association between FANCC depletion and loss of oxidative defense in pancreatic β-cells and reduction in insulin production (Fig. 4). Furthermore, the mechanism underpinning the association of FANCC knockdown with upregulation of DKK1 in human β-cells will be explored in future studies. These findings may explain the development of DM and abnormal glucose metabolism in patients with FA (7). Finally, the finding that FANCC overexpression reduced β-cell apoptosis advances the possibility of an alternative approach to the treatment of DM caused by FANCC defects.
Acknowledgements
We thank the members of Siriraj Center of Research Excellence for Diabetes and Obesity (SiCORE-DO) for their assistance.
Funding
The present study was supported by Mahidol University Grant, Siriraj Research Grant for Research and Development, Faculty of Medicine, Siriraj Hospital R015810001 (to NP), Thailand Research Fund IRG5980006 (to PY), Mahidol University Postdoctoral Fellowship Grant (to SK) and Chalermprakiat Grants and Research Fund (R016034011) from the Faculty of Medicine Siriraj Hospital (to PJ and PY).
Availability of data and materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Authors' contributions
SK, PTY and NP conceived and designed the study. SK performed the cell experiments and molecular biology analysis. PJ and WT analyzed and interpreted the data. SK was a major contributor in writing the manuscript. All authors read and approved the final manuscript.
Ethics approval and consent to participate
Not applicable.
Patient consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
References
|
Pagano G and Youssoufian H: Fanconi anaemia proteins: Major roles in cell protection against oxidative damage. Bioessays. 25:589–595. 2003. View Article : Google Scholar : PubMed/NCBI | |
|
Pace P, Johnson M, Tan WM, Mosedale G, Sng C, Hoatlin M, de Winter J, Joenje H, Gergely F and Patel KJ: FANCE: The link between Fanconi anaemia complex assembly and activity. EMBO J. 21:3414–3423. 2002. View Article : Google Scholar : PubMed/NCBI | |
|
Kalb R, Neveling K, Nanda I, Schindler D and Hoehn H: Fanconi anemia: Causes and consequences of genetic instability. Genome Dyn. 1:218–242. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Bagby GC Jr: Genetic basis of Fanconi anemia. Curr Opin Hemato. 10:68–76. 2003. View Article : Google Scholar | |
|
de Winter JP and Joenje H: The genetic and molecular basis of Fanconi anemia. Mutat Res. 668:11–19. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Mathew CG: Fanconi anaemia genes and susceptibility to cancer. Oncogene. 25:5875–5884. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Elder DA, D'Alessio DA, Eyal O, Mueller R, Smith FO, Kansra AR and Rose SR: Abnormalities in glucose tolerance are common in children with fanconi anemia and associated with impaired insulin secretion. Pediatr Blood Cancer. 51:256–260. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Swift M, Sholman L and Gilmour D: Diabetes mellitus and the gene for Fanconi's anemia. Science. 178:308–310. 1972. View Article : Google Scholar : PubMed/NCBI | |
|
Giri N, Batista DL, Alter BP and Stratakis CA: Endocrine abnormalities in patients with Fanconi anemia. J Clin Endocrinol Metab. 92:2624–2631. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Youssoufian H: Localization of Fanconi anemia C protein to the cytoplasm of mammalian cells. Proc Natl Acad Sci USA. 91:7975–7979. 1994. View Article : Google Scholar : PubMed/NCBI | |
|
Lackinger D, Ruppitsch W, Ramirez MH, Hirsch-Kauffmann M and Schweiger M: Involvement of the Fanconi anemia protein FA-C in repair processes of oxidative DNA damages. FEBS Lett. 440:103–106. 1998. View Article : Google Scholar : PubMed/NCBI | |
|
Youssoufian H: Cytoplasmic localization of FAC is essential for the correction of a prerepair defect in Fanconi anemia group C cells. J Clin Inves. 97:2003–2010. 1996. View Article : Google Scholar | |
|
Cumming RC, Liu JM, Youssoufian H and Buchwald M: Suppression of apoptosis in hematopoietic factor-dependent progenitor cell lines by expression of the FAC gene. Blood. 88:4558–4567. 1996.PubMed/NCBI | |
|
Hadjur S, Ung K, Wadsworth L, Dimmick J, Rajcan-Separovic E, Scott RW, Buchwald M and Jirik FR: Defective hematopoiesis and hepatic steatosis in mice with combined deficiencies of the genes encoding Fancc and Cu/Zn superoxide dismutase. Blood. 98:1003–1011. 2001. View Article : Google Scholar : PubMed/NCBI | |
|
Saadatzadeh MR, Bijangi-Vishehsaraei K, Hong P, Bergmann H and Haneline LS: Oxidant hypersensitivity of Fanconi anemia type C-deficient cells is dependent on a redox-regulated apoptotic pathway. J Biol Chem. 279:16805–16812. 2004. View Article : Google Scholar : PubMed/NCBI | |
|
Rathbun RK, Faulkner GR, Ostroski MH, Christianson TA, Hughes G, Jones G, Cahn R, Maziarz R, Royle G, Keeble W, et al: Inactivation of the Fanconi anemia group C gene augments interferon-gamma-induced apoptotic responses in hematopoietic cells. Blood. 90:974–985. 1997.PubMed/NCBI | |
|
Cumming RC, Lightfoot J, Beard K, Youssoufian H, O'Brien PJ and Buchwald M: Fanconi anemia group C protein prevents apoptosis in hematopoietic cells through redox regulation of GSTP1. Nat Med. 7:814–820. 2001. View Article : Google Scholar : PubMed/NCBI | |
|
Kruyt FA, Hoshino T, Liu JM, Joseph P, Jaiswal AK and Youssoufian H: Abnormal microsomal detoxification implicated in Fanconi anemia group C by interaction of the FAC protein with NADPH cytochrome P450 reductase. Blood. 92:3050–3056. 1998.PubMed/NCBI | |
|
Pinkus R, Weiner LM and Daniel V: Role of quinone-mediated generation of hydroxyl radicals in the induction of glutathione S-transferase gene expression. Biochemistry. 34:81–88. 1995. View Article : Google Scholar : PubMed/NCBI | |
|
Wang J, Otsuki T, Youssoufian H, Foe JL, Kim S, Devetten M, Yu J, Li Y, Dunn D and Liu JM: Overexpression of the fanconi anemia group C gene (FAC) protects hematopoietic progenitors from death induced by Fas-mediated apoptosis. Cancer Res. 58:3538–3541. 1998.PubMed/NCBI | |
|
Huang F, Ben Aissa M, Magron A, Huard CC, Godin C, Lévesque G and Carreau M: The Fanconi anemia group C protein interacts with uncoordinated 5A and delays apoptosis. PLoS One. 9:e928112014. View Article : Google Scholar : PubMed/NCBI | |
|
Rains JL and Jain SK: Oxidative stress, insulin signaling, and diabetes. Free Radic Biol Med. 50:567–575. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Bloch-Damti A and Bashan N: Proposed mechanisms for the induction of insulin resistance by oxidative stress. Antioxid Redox Signal. 7:1553–1567. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Li J, Sipple J, Maynard S, Mehta PA, Rose SR, Davies SM and Pang Q: Fanconi anemia links reactive oxygen species to insulin resistance and obesity. Antioxid Redox Signal. 17:1083–1098. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Robertson RP and Harmon JS: Pancreatic islet beta-cell and oxidative stress: The importance of glutathione peroxidase. FEBS Lett. 581:3743–3748. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Vasu S, McClenaghan NH, McCluskey JT and Flatt PR: Cellular responses of novel human pancreatic β-cell line, 1.1B4 to hyperglycemia. Islets. 5:170–177. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Floros KV, Thomadaki H, Florou D, Talieri M and Scorilas A: Alterations in mRNA expression of apoptosis-related genes BCL2, BAX, FAS, caspase-3, and the novel member BCL2L12 after treatment of human leukemic cell line HL60 with the antineoplastic agent etoposide. Ann N Y Acad Sci. 1090:89–97. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Zhou Y, Li W, Xu Q and Huang Y: Elevated expression of Dickkopf-1 increases the sensitivity of human glioma cell line SHG44 to BCNU. J Exp Clin Cancer Res. 29:1312010. View Article : Google Scholar : PubMed/NCBI | |
|
Livak KJ and Schmittgen TD: Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) method. Methods. 25:402–408. 2001. View Article : Google Scholar : PubMed/NCBI | |
|
Niida A, Hiroko T, Kasai M, Furukawa Y, Nakamura Y, Suzuki Y, Sugano S and Akiyama T: DKK1, a negative regulator of Wnt signaling, is a target of the beta-catenin/TCF pathway. Oncogene. 23:8520–8526. 2004. View Article : Google Scholar : PubMed/NCBI | |
|
Tiedge M, Lortz S, Drinkgern J and Lenzen S: Relation between antioxidant enzyme gene expression and antioxidative defense status of insulin-producing cells. Diabetes. 46:1733–1742. 1997. View Article : Google Scholar : PubMed/NCBI | |
|
Keane KN, Cruzat VF, Carlessi R, de Bittencourt PI Jr and Newsholme P: Molecular events linking oxidative stress and inflammation to insulin resistance and β-cell dysfunction. Oxid Med Cell Longev. 2015:1816432015. View Article : Google Scholar : PubMed/NCBI | |
|
Maechler P, Jornot L and Wollheim CB: Hydrogen peroxide alters mitochondrial activation and insulin secretion in pancreatic beta cells. J Biol Chem. 274:27905–27913. 1999. View Article : Google Scholar : PubMed/NCBI | |
|
Zraika S, Aston-Mourney K, Laybutt DR, Kebede M, Dunlop ME, Proietto J and Andrikopoulos S: The influence of genetic background on the induction of oxidative stress and impaired insulin secretion in mouse islets. Diabetologia. 49:1254–1263. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Bijangi-Vishehsaraei K, Saadatzadeh MR, Werne A, McKenzie KA, Kapur R, Ichijo H and Haneline LS: Enhanced TNF-alpha-induced apoptosis in Fanconi anemia type C-deficient cells is dependent on apoptosis signal-regulating kinase 1. Blood. 106:4124–4130. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang X, Sejas DP, Qiu Y, Williams DA and Pang Q: Inflammatory ROS promote and cooperate with the Fanconi anemia mutation for hematopoietic senescence. J Cell Sci. 120:1572–1583. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang QG, Wang R, Khan M, Mahesh V and Brann DW: Role of Dickkopf-1, an antagonist of the Wnt/beta-catenin signaling pathway, in estrogen-induced neuroprotection and attenuation of tau phosphorylation. J Neurosci. 28:8430–8441. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Gui S, Yuan G, Wang L, Zhou L, Xue Y, Yu Y, Zhang J, Zhang M, Yang Y and Wang DW: Wnt3a regulates proliferation, apoptosis and function of pancreatic NIT-1 beta cells via activation of IRS2/PI3K signaling. J Cell Biochem. 114:1488–1497. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Huard CC, Tremblay CS, Helsper K, Delisle MC, Schindler D, Lévesque G and Carreau M: Fanconi anemia proteins interact with CtBP1 and modulate the expression of the Wnt antagonist Dickkopf-1. Blood. 121:1729–1739. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Huard CC, Tremblay CS, Magron A, Lévesque G and Carreau M: The Fanconi anemia pathway has a dual function in Dickkopf-1 transcriptional repression. Proc Natl Acad Sci USA. 111:2152–2157. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Gloyn AL, Odili S, Buettger C, Njolstad PR, Shiota C, Matschinsky FM and Magnuson MA: Glucokinase and Glycemic Disease: From Basics to Novel Therapeutics. 16. Karger; Basel: pp. 92–109. 2004 | |
|
Vasu S, McClenaghan NH and Flatt PR: Molecular mechanisms of toxicity and cell damage by chemicals in a human pancreatic beta cell line, 1.1B4. Pancreas. 45:1320–1329. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Iype T, Francis J, Garmey JC, Schisler JC, Nesher R, Weir GC, Becker TC, Newgard CB, Griffen SC and Mirmira RG: Mechanism of insulin gene regulation by the pancreatic transcription factor Pdx-1: Application of pre-mRNA analysis and chromatin immunoprecipitation to assess formation of functional transcriptional complexes. J Biol Chem. 280:16798–16807. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang C, Moriguchi T, Kajihara M, Esaki R, Harada A, Shimohata H, Oishi H, Hamada M, Morito N, Hasegawa K, et al: MafA is a key regulator of glucose-stimulated insulin secretion. Mol Cell Biol. 25:4969–4976. 2005. View Article : Google Scholar : PubMed/NCBI |
