Benzene-induced hematopoietic toxicity transmitted by AhR in wild-type mouse and nullified by repopulation with AhR-deficient bone marrow cells: Time after benzene treatment and recovery

doi:10.1016/j.chemosphere.2007.12.033

Chemosphere

Volume 73, Issue 1, Supplement, August 2008, Pages S290-S294

https://doi.org/10.1016/j.chemosphere.2007.12.033 Get rights and content

Abstract

Previously, we found an aryl hydrocarbon receptor (AhR)-transmitted benzene-induced hematotoxicity; that is, AhR-knockout (KO) mice did not show any hematotoxicity after benzene exposure [Yoon, B.I., Hirabayashi, Y., Kawasaki, Y., Kodama, Y., Kaneko, T., Kanno, J., Kim, D.Y., Fujii-Kuriyama, Y., Inoue, T., 2002. Aryl hydrocarbon receptor mediates benzene-induced hematotoxicity. Toxicol. Sci. 70, 150–156]. Furthermore, our preliminary study showed a significant attenuation of benzene-induced hematopoietic toxicity by AhR expression, when the bone marrow (BM) of mice was repopulated with AhR-KO BM cells [Hirabayashi, Y., Yoon, B.I., Li, G., Fujii-Kuriyama, Y., Kaneko, T., Kanno, J., Inoue, T., 2005a. Benzene-induced hematopoietic toxicity transmitted by AhR in the wild-type mouse was negated by repopulation of AhR deficient bone marrow cells. Organohalogen Comp. 67, 2280–2283]. In this study, benzene-induced hematotoxicity and its nullification by AhR-KO BM cells were further precisely reevaluated including the duration of the effect after benzene treatment and recovery after the cessation of exposure. Exposure routes, namely, intraperitoneal (i.p.) injection used in our previous study and intragastric (i.g.) administration used in this study, were also compared in terms of their toxicologic outcomes. From the results of this study, mice that had been lethally irradiated and repopulated with BM cells from AhR-KO mice essentially did not show any benzene-induced hematotoxicity. The AhR-KO BM cells nullified benzene-induced toxicities in notably different hematopoietic endpoints between the i.p. treatment and the i.g. treatment; however, the number of granulo-macrophage colony-forming unit in vitro (CFU-GM) was a common target parameter, the benzene-induced toxicity of which was nullified by the AhR-KO BM cells.

Introduction

Recent studies have shown that the aryl hydrocarbon receptor (AhR) in primitive cells transmits negative signals for the proliferation of such cells (Hirabayashi et al., 2003, Garrett and Gasiewicz, 2005). This observation may require further detailed studies, because previous in vitro studies showed that AhR promotes cellular proliferation on one hand (Ma and Whitlock, 1996, Shimba et al., 2002), but rather suppress on the other hand (Fong et al., 2005). As we previously reported, AhR-knockout (KO) mice showed an increase in number of primitive hematopoietic progenitor cells; on the other hand, a decrease in number of relatively mature progenitor cells in a homeostatic manner (Hirabayashi et al., 2003). Therefore, there are two possibilities: one is the hierarchic positional effect of cellular differentiation and the other is a particular cell-proliferative gene alteration in in vitro cell lines.

We have reported that benzene-induced hematopoietic toxicity is transmitted by AhR (Yoon et al., 2002). We also found that cytochrome P450 2E1 (CYP2E1) that is, related to benzene metabolism is also up-regulated following benzene exposure in the bone marrow (BM) (Yoon et al., 2003). Therefore, it is of interest to hypothesize the important role of BM cells in hematopoietic toxicity with respect to AhR function. Accordingly, on the basis of the latest studies presented at the 25th International Dioxin Symposium, benzene-induced hematopoietic toxicity was evaluated in wild-type (Wt) mice after whole-body irradiation at a lethal dose followed by repopulation with BM cells that lack AhR or, vice versa, in AhR-KO mice after repopulation with Wt BM cells. As for the results, a one-day examination on day 12 after benzene exposure showed that the xenobiotic response of CYP2E1 up-regulation mediated by AhR for benzene hematotoxicity was metabolized specifically in the BM (Hirabayashi et al., 2005a). In this article, the detailed changes in blood parameters during the benzene exposure duration and their recovery three days after the cessation of exposure are shown.

Section snippets

Animals

The establishment of homozygous AhR-KO (AhR^−/−) mice originating from the 129/SvJ strain has been described elsewhere (Mimura et al., 1997, Yoon et al., 2002). The crossing of heterozygous AhR-KO (AhR^+/−) males with AhR^+/− females generated wild-type (AhR^+/+), AhR^+/−, and AhR^−/−mice. The neonates were genotyped by PCR screening of DNA from the tail. Male AhR-KO (AhR^−/−) mice and their Wt littermates (12 weeks old) were used in the study as donors. Eight-week-old C57BL/6 male mice from Japan SLC

Results and discussion

As previously reported, the AhR-KO mice showed a significantly higher WBC counts than the Wt mice (Fig. 1a). This was also consistent with the high number of myeloid progenitor cells, that is, CFU-S-9 and CFU-S-13, observed in the AhR-KO mice (Fig. 1b). Thus, steady-state hemopoiesis in the Wt mice, on the other hand, is presumed to be suppressed by AhR signaling because of the possible presence of a physiological ligand, which is not readily observed in the AhR-KO mice. In contrast, the

Conclusions

Mice that had been lethally irradiated and repopulated with BM cells from AhR-KO mice essentially did not show any benzene-induced hematotoxicity. The present study elucidated the following: first, benzene-induced decrease in BM cellularity was clearly nullified by BM cells in mice that had been repopulated with AhR-KO BM cells. Second, we observed some differences in toxicologic phenotypes depending on the exposure route, that is, intraperitoneal, used in the previous study, or intragastric,

Acknowledgments

This work was supported in part by a Grant-in-Aid for Scientific Research C, 15510064 and also by the MHLW-Research Fund (H16-Chemistry 003), National Institute of Health Sciences.

We thank Ms. E. Tachihara, Ms. Y. Usami, Ms. Y. Shinzawa, and Ms. M. Uchiyama for excellent technical assistance, and Ms. N. Kikuchi, M. Yoshizawa, and Ms. M. Hojo for secretarial assistance.

References (18)

E.P. Cronkite et al.
Benzene inhalation produces leukemia in mice
Toxicol. Appl. Pharmacol.
(1984)
C.J. Fong et al.
Comparative microarray analysis of basal gene expression in mouse Hepa-1c1c7 wild-type and mutant cell lines
Toxicol. Sci.
(2005)
Garrett, R.W., Gasiewicz, T.A., 2005. The arylhydrocaron receptor (AhR) is a regulator of hematopoietic stem and...
Y. Hirabayashi et al.
Chapter 24. Toxicogenomics applied to hematotoxicology
Y. Hirabayashi et al.
Hemopoietic neoplasms in lethally irradiated mice repopulated with bone marrow cells carrying the human c-myc oncogene: a repopulation assay
Exp. Hematol.
(1992)
Y. Hirabayashi et al.
Serial transplantation of p53-deficient hemopoietic progenitor cells to assess their infinite growth potential
Exp. Biol. Med. (Maywood)
(2002)
Y. Hirabayashi et al.
Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on B cell differentiation in mouse pre-B colonization model regulated by artificially introduced human IL-3 receptors
Organohalogen Comp.
(2002)
Y. Hirabayashi et al.
AhR suppresses hemopoiesis during steady state but accelerates cell cycle as an early response: a study of AhR-knockout mice
Organohalogen Comp.
(2003)
Y. Hirabayashi et al.
Benzene-induced hematopoietic toxicity transmitted by AhR in the wild-type mouse was negated by repopulation of AhR deficient bone marrow cells
Organohalogen Comp.
(2005)

There are more references available in the full text version of this article.

Cited by (15)

Hydroquinone triggers pyroptosis and endoplasmic reticulum stress via AhR-regulated oxidative stress in human lymphocytes
2023, Toxicology Letters
Benzene is a frequent component of environmental pollution and is abundant in petrochemicals, decorative materials, motor vehicle exhaust and cigarette smoke. Benzene is a well-known carcinogen in humans and animals, but the molecular mechanism has not yet been elucidated. Our earlier research indicated that hydroquinone (HQ), one of the main reactive metabolites of benzene, could activate aryl hydrocarbon receptor (AhR), which is essential for HQ-induced toxicity, including apoptosis and DNA damage. Since AhR is an important regulator of the immune system that integrates the environmental stimulus and immune response, we examined whether and how HQ-induced AhR activity could lead to NLRP3 inflammasome-dependent pyroptosis in JHP cells. Our results showed that HQ could cause inflammation process and resultant pyroptosis. In JHP cells, HQ also induced endoplasmic reticulum stress (ERS) by releasing excessive reactive oxygen species (ROS). The activation of pyroptosis induced by HQ treatment was reversed by an antioxidant (NAC) and an ERS inhibitor (4-PBA). Interestingly, the treatment of CH223191, an AhR inhibitor, reversed HQ-induced oxidative stress, ERS and pyroptosis. These data suggested that AhR-mediated HQ-induced ERS, ROS and inflammasome activation may play vital roles in the toxic effects of benzene. This work provides insights and prospective strategies into potential mechanisms for reducing benzene-induced hematotoxicity.
Ligand-independent activation of AhR by hydroquinone mediates benzene-induced hematopoietic toxicity
2022, Chemico-Biological Interactions
Citation Excerpt :
Ligand binding leads to dimerization of the AhR with aryl hydrocarbon receptor nuclear translocator (ARNT) and transcriptional activation of cytochrome P450 (CYP) metabolizing enzymes, triggering the release of additional ROS [35]. Yoon et al. reported that AhR−/−mice did not show obvious hematotoxicity after benzene exposure [17]; Hirabayashi et al. transplanted bone marrow from AhR−/− mice into normal mice and they found there were still no hematological toxicity in normal mice, these results suggested AhR plays an essential role in benzene induced hemotoxicity [36]. Recent studies have demonstrated that AhR can directly regulate the Nrf2 signaling pathway [37].
Although it has been well recognized that benzene exposure can cause hematopoietic disorders such as aplastic anemia and leukemia, the underlying molecular mechanism remains to be fully understood. Emerging evidence indicated that aryl hydrocarbon receptor (AhR) plays important roles in hematopoietic and immune systems. This study investigated the activation of aryl hydrocarbon receptor (AhR) by hydroquinone (HQ) and its role in HQ-induced DNA damage and apoptosis in cultured human lymphocytes (JHP cells). We also investigated the effect of ROS on AhR activation and functions in JHP cells exposed to HQ with and without regulator including N-acetyl-l-cysteine (NAC), a potent antioxidant, and tert-butylhydroquinone (TBHQ), a Nrf2 activator. Results showed that HQ can cause oxidative stress, DNA damage and apoptosis. Pretreatment of an AhR antagonist (CH223191) can significantly increase the cell survival and mitigate HQ-induced toxicities such as DNA damage and apoptosis. We found that HQ can obviously increase expressions of total protein of AhR and prompt nuclear translocation compared to the control group. Interestingly, NAC can block HQ-induced AhR activation and DNA damage and apoptosis. Conclusively, our results indicated that HQ toxicity is mediated by AhR which is in turn regulated by ROS generated by HQ. The interaction between AhR and ROS drive and amplify the hematopoietic toxicity of HQ. This study provided new insights of mechanism and potential targets for the prevention and treatment to benzene-induced hematopoietic toxicity.
Pyridoxine deficiency modulates benzene inhalation-induced hematotoxicity associated with hepatic CYP2E1 activity in B<inf>6</inf>C<inf>3</inf>F<inf>1</inf> mice
2021, Toxicology Reports
Citation Excerpt :
Benzene also causes oxidative DNA damage in humans, and levels of a urinary benzene metabolite (t,t-muconic acid) and 8-hydroxydeoxyguanosine have been used as biomarkers for the investigation of benzene exposure and early biological changes that could be indicative of increased risk for future disease, respectively [35]. Benzene exposure also induces anemia, neutrophilia, and lymphocytopenia in C57BL/6 mice [36] and increases the incidence of lymphoma and acute myeloid leukemia (AML) in the same animal model [37]. Acute inhalation exposure of CD-1 mice to 100 ppm benzene (6 h/d, 5 d) significantly depressed peripheral leukocyte levels [38] and repeated exposure of B6C3F1 mice to the same benzene dose (100 ppm, 6 h/d, 5 d/wk, for 2 wk) decreased peripheral white blood cells numbers and bone marrow cells [39,40].
Pyridoxine is a co-factor in many enzymatic reactions and impacts of deficiency have been observed in affected populations. A possible modifying effect of pyridoxine deficiency on benzene toxicity was assessed in male B₆C₃F₁ mice fed either a pyridoxine-deficient diet or a control diet. This treatment was combined with benzene inhalation exposure (100 ppm) or no benzene treatment. Pyridoxine-deficient mice exposed to 100 ppm benzene had significantly lower body, thymus and spleen weights. While total white blood cell counts, percentage of lymphocytes, hematocrit and hemoglobin levels were lower, the percentage of neutrophils was significantly higher in deficient and benzene-exposed mice compared to non-exposed controls. Hepatic CYP2E1 protein expression and activity in the deficient and exposed mice were also significantly higher compared to the non-exposed controls. A significant correlation between CYP2E1 activity and several hematological parameters was observed. These results demonstrated that pyridoxine deficiency significantly impacted benzene-induced hematotoxicity. Moreover, the observed agonistic effect of pyridoxine deficiency and benzene inhalation exposure on CYP2E1 would seem to indicate an involvement of metabolism, but this needs to be further assessed.
Distribution of chromosome breakpoints in benzene-exposed and unexposed AML patients
2017, Environmental Toxicology and Pharmacology
Citation Excerpt :
A proposed mode of action (MOA) has been developed for benzene-induced leukemia which identifies several key events in leukemia development following benzene exposure; enzyme-dependent metabolism, interaction with bone marrow target cells, formation of mutated target cells, and development of leukemia (Meek and Klaunig, 2010). Additionally, identification of genes, pathways, and genetic damage associated with leukemia development that are altered following benzene exposure has been proposed as an alternative or supplement to MOA analysis (McHale et al., 2012; Zhang et al., 2012; Yoon et al., 2002; Hirabayashi et al., 2008). The existing MOA does not include recently described cases of benzene-associated disease which have more thorough molecular and pathological descriptions than found in earlier reports, and recent approaches have not involved evaluation of humans with both benzene exposure and disease.
Results of laboratory studies and investigations of occupationally exposed healthy individuals have been used to develop a mode of action for benzene-induced leukemia that mirrors disease following treatment with chemotherapeutic agents. Recently we have described series of AML and MDS cases with benzene exposure history, and have provided cytogenetic, molecular, and pathologic evidence that these cases differ significantly in many features from therapy-related disease. Here we have extended this work, and describe chromosome breakpoints across 441 identifiable regions, in terms of gains or losses, in 710 AML cases collected during the Shanghai Health Study, which include 75 with a history of benzene exposure. Using FISH and cytogenetic analysis, we developed prevalence information and risk ratios for benzene exposure across all regions with a lesion in at least one exposed and unexposed case. These results indicate that AML following benzene exposure mirrors de novo disease, and supports a mechanism for development of hematopoietic disease that bears no resemblance to therapy-related disease.
Benzene toxicity: The role of the susceptibility factor NQO1 in bone marrow endothelial cell signaling and function
2011, Chemico-Biological Interactions
The homozygous NQO1*2 polymorphism results in a null NQO1 phenotype and is a susceptibility factor for occupational benzene poisoning. NQO1 plays an important role in detoxification of benzene-derived quinones but plays a role in numerous other non-metabolic cellular functions. NQO1 is expressed in endothelial cells of bone marrow which form the vascular stem cell niche important in stem cell homing and mobilization. We therefore employed a transformed human bone marrow endothelial cell (HBMEC) line to define the effects of compromising NQO1 on endothelial function. Either inhibition or knockdown of NQO1 led to decreased expression of the adhesion molecules E-selectin, VCAM-1 and ICAM-1 and decreased functional adhesion of CD34+ progenitor cells after TNFα stimulation. Suicide inhibition or knockdown of NQO1 decreased NFκB p105 precursor and NFκB p50 subunit levels as well as leading to decreased nuclear levels of NFκB phospho-p65. An additional function of endothelial cells is tube formation and angiogenesis which was inhibited by the benzene metabolite hydroquinone suggesting that endothelial function may be affected at multiple levels after exposure of NQO1*2 polymorphic individuals to benzene. These data demonstrate that NQO1 plays an upstream role in NFκB signaling and adhesion molecule expression in HBMEC and that NQO1 has important regulatory effects in its own right in addition to being a marker for Nrf-2 activation. Metabolic susceptibility factors such as NQO1 have roles in addition to detoxification of reactive intermediates and interrogation of these novel roles can inform both mechanisms of toxicity and human risk assessment.
The aryl hydrocarbon receptor has an important role in the regulation of hematopoiesis: Implications for benzene-induced hematopoietic toxicity
2010, Chemico-Biological Interactions
The aryl hydrocarbon receptor (AhR) belongs to the basic helix–loop–helix (bHLH) Per-Arnt-Sim (PAS) family of transcription factors. Many of these proteins are involved in regulating responses to signals in the tissue environment such as hypoxia, oxidation–reduction status, and circadian rhythms. Although the AhR is well studied as a mediator of the toxicity of certain xenobiotics, the normal physiological function remains unknown. However, accumulating data support a hypothesis that the AhR has an important function in the regulation of hematopoietic stem cells (HSCs). Persistent AhR activation by dioxin, a potent xenobiotic AhR agonist, results in altered numbers and function of HSCs in mouse bone marrow. Analysis of HSCs from AhR null-allele mice also indicates that lack of AhR expression results in altered characteristics and function of these cells. HSCs from these animals are hyperproliferative and have altered cell cycle. In addition, aging AhR-KO mice show characteristics consistent with premature bone marrow senescence and are prone to hematopoietic disease. Finally, some data suggest that the expression of the Ahr gene is regulated under conditions that control HSC proliferation. The presence of a normal functioning AhR may provide an important advantage to organisms by regulating the balance between quiescence and proliferation and preventing the premature exhaustion of HSCs and sensitivity to genetic alterations. This function assists in the preservation of HSC function and long-term multi-lineage generation over the lifespan of the organism. This also implicates a role for the AhR in the aging process. Furthermore, these functions may affect the sensitivity of HSCs to certain xenobiotics, including benzene. Defining the molecular mechanisms by which these events occur may lead to the identification of previously undefined roles of this transcription factor in human diseases, particularly those caused or affected by xenobiotics.

View all citing articles on Scopus

¹: Present address: Department of Veterinary Medicine, College of Animal Resource, Kangwon National University, Kangwon-Do 200-701, Republic of Korea.

View full text

Benzene-induced hematopoietic toxicity transmitted by AhR in wild-type mouse and nullified by repopulation with AhR-deficient bone marrow cells: Time after benzene treatment and recovery

Abstract

Introduction

Section snippets

Animals

Results and discussion

Conclusions

Acknowledgments

Benzene inhalation produces leukemia in mice

Toxicol. Appl. Pharmacol.

Comparative microarray analysis of basal gene expression in mouse Hepa-1c1c7 wild-type and mutant cell lines

Toxicol. Sci.

Chapter 24. Toxicogenomics applied to hematotoxicology

Hemopoietic neoplasms in lethally irradiated mice repopulated with bone marrow cells carrying the human c-myc oncogene: a repopulation assay

Exp. Hematol.

Serial transplantation of p53-deficient hemopoietic progenitor cells to assess their infinite growth potential

Exp. Biol. Med. (Maywood)

Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on B cell differentiation in mouse pre-B colonization model regulated by artificially introduced human IL-3 receptors

Organohalogen Comp.

AhR suppresses hemopoiesis during steady state but accelerates cell cycle as an early response: a study of AhR-knockout mice

Organohalogen Comp.

Benzene-induced hematopoietic toxicity transmitted by AhR in the wild-type mouse was negated by repopulation of AhR deficient bone marrow cells

Organohalogen Comp.