The heavy metals lead and cadmium are cytotoxic to human bone osteoblasts via induction of redox stress

Autoři: Ayat Al-Ghafari aff001;  Ekramy Elmorsy aff002;  Emad Fikry aff002;  Majed Alrowaili aff005;  Wayne G. Carter aff004
Působiště autorů: Biochemistry Department, Faculty of Science, King AbdulAziz University, Jeddah, Saudi Arabia aff001;  Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura City, Egypt aff002;  Department of Pathology, Faculty of Medicine, Northern Border University, Arar; Saudi Arabia aff003;  School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom aff004;  Department of Surgery, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia aff005
Vyšlo v časopise: PLoS ONE 14(11)
Kategorie: Research Article
doi: 10.1371/journal.pone.0225341


The heavy metals (HMs) lead and cadmium are persistent environmental pollutants capable of inducing ill-health in exposed individuals. One of the primary sites of accumulation and potential damage from HMs is bone, and we therefore examined the acute effects of lead and cadmium on human bone osteoblasts in vitro over a concentration range of 0.1 μM to 1mM, and for 3, 6, 12, 24, and 48 hour exposures. Incubation of osteoblasts with either lead or cadmium reduced cell viability in a concentrations and exposure durations dependent manner, as measured using MTT and LDH assays. Cytotoxicity was significant from 0.1 μM concentrations after 48 hour exposures. Both HMs damaged cellular bioenergetics with reductions of ATP production, mitochondrial complex activities, and aerobic respiration. There was a concomitant elevation of reactive oxygen species, with induction of redox stress measured as increased lipid peroxidation, and depleted cellular redox defense systems via reduced superoxide dismutase and catalase activity and cellular glutathione levels. Both HMs induced nuclear activation of Nrf2, presumably to increase transcription of antioxidant responsive genes to combat oxidative stress. Incubation of osteoblasts with HMs also compromised the secretion of procollagen type 1, osteocalcin, and alkaline phosphatase. Pre-incubation of osteoblasts with reduced glutathione prior to challenge with HMs lessened the cytotoxicity of the HMs, indicative that antioxidants may be a beneficial treatment adjunct in cases of acute lead or cadmium poisoning.

Klíčová slova:

Cadmium – Glutathione – Metallic lead – Mitochondria – MTT assay – Oxidation-reduction reactions – Reactive oxygen species – Osteoblasts


1. Briggs D. Environmental pollution and the global burden of disease. Br Med Bull. 2003;68:1–24. doi: 10.1093/bmb/ldg019 14757707.

2. Jarup L. Hazards of heavy metal contamination. Br Med Bull. 2003;68:167–82. doi: 10.1093/bmb/ldg032 14757716.

3. Davis JM, Otto DA, Weil DE, Grant LD. The comparative developmental neurotoxicity of lead in humans and animals. Neurotoxicol Teratol. 1990;12(3):215–29. doi: 10.1016/0892-0362(90)90093-r 2196421.

4. Finkelstein Y, Markowitz ME, Rosen JF. Low-level lead-induced neurotoxicity in children: an update on central nervous system effects. Brain Res Brain Res Rev. 1998;27(2):168–76. doi: 10.1016/s0165-0173(98)00011-3 9622620.

5. Caito S, Aschner M. Developmental Neurotoxicity of Lead. Adv Neurobiol. 2017;18:3–12. doi: 10.1007/978-3-319-60189-2_1 28889260.

6. Campbell JR, Rosier RN, Novotny L, Puzas JE. The association between environmental lead exposure and bone density in children. Environ Health Perspect. 2004;112(11):1200–3. doi: 10.1289/ehp.6555 15289167.

7. Campbell JR, Auinger P. The association between blood lead levels and osteoporosis among adults—results from the third national health and nutrition examination survey (NHANES III). Environ Health Perspect. 2007;115(7):1018–22. doi: 10.1289/ehp.9716 17637916

8. Chisolm JJ Jr. Poisoning from heavy metals (mercury, lead, and cadmium). Pediatr Ann. 1980;9(12):458–68. 7005844.

9. Staessen JA, Roels HA, Emelianov D, Kuznetsova T, Thijs L, Vangronsveld J, et al. Environmental exposure to cadmium, forearm bone density, and risk of fractures: prospective population study. Public Health and Environmental Exposure to Cadmium (PheeCad) Study Group. Lancet. 1999;353(9159):1140–4. doi: 10.1016/s0140-6736(98)09356-8 10209978.

10. Alfven T, Elinder CG, Carlsson MD, Grubb A, Hellstrom L, Persson B, et al. Low-level cadmium exposure and osteoporosis. J Bone Miner Res. 2000;15(8):1579–86. doi: 10.1359/jbmr.2000.15.8.1579 10934657.

11. Honda R, Tsuritani I, Noborisaka Y, Suzuki H, Ishizaki M, Yamada Y. Urinary cadmium excretion is correlated with calcaneal bone mass in Japanese women living in an urban area. Environ Res. 2003;91(2):63–70. doi: 10.1016/s0013-9351(02)00035-x 12584006.

12. Nawrot T, Geusens P, Nulens TS, Nemery B. Occupational cadmium exposure and calcium excretion, bone density, and osteoporosis in men. J Bone Miner Res. 2010;25(6):1441–5. doi: 10.1002/jbmr.22 20200937.

13. Wallin M, Barregard L, Sallsten G, Lundh T, Karlsson MK, Lorentzon M, et al. Low-Level Cadmium Exposure Is Associated With Decreased Bone Mineral Density and Increased Risk of Incident Fractures in Elderly Men: The MrOS Sweden Study. J Bone Miner Res. 2016;31(4):732–41. doi: 10.1002/jbmr.2743 26572678

14. Tsuritani I, Honda R, Ishizaki M, Yamada Y, Kido T, Nogawa K. Impairment of vitamin D metabolism due to environmental cadmium exposure, and possible relevance to sex-related differences in vulnerability to the bone damage. J Toxicol Environ Health. 1992;37(4):519–33. doi: 10.1080/15287399209531690 1464907.

15. Chalkley SR, Richmond J, Barltrop D. Measurement of vitamin D3 metabolites in smelter workers exposed to lead and cadmium. Occup Environ Med. 1998;55(7):446–52. doi: 10.1136/oem.55.7.446 9816377

16. Rani A, Kumar A, Lal A, Pant M. Cellular mechanisms of cadmium-induced toxicity: a review. Int J Environ Health Res. 2014;24(4):378–99. doi: 10.1080/09603123.2013.835032 24117228.

17. Mitra P, Sharma S, Purohit P, Sharma P. Clinical and molecular aspects of lead toxicity: An update. Crit Rev Clin Lab Sci. 2017;54(7–8):506–28. doi: 10.1080/10408363.2017.1408562 29214886.

18. Florencio-Silva R, Sasso GR, Sasso-Cerri E, Simoes MJ, Cerri PS. Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells. Biomed Res Int. 2015;2015:421746. doi: 10.1155/2015/421746 26247020

19. Jilka RL. Biology of the basic multicellular unit and the pathophysiology of osteoporosis. Med Pediatr Oncol. 2003;41(3):182–5. doi: 10.1002/mpo.10334 12868116.

20. Matsuo K, Irie N. Osteoclast-osteoblast communication. Arch Biochem Biophys. 2008;473(2):201–9. doi: 10.1016/ 18406338.

21. Viguet-Carrin S, Garnero P, Delmas PD. The role of collagen in bone strength. Osteoporos Int. 2006;17(3):319–36. doi: 10.1007/s00198-005-2035-9 16341622.

22. Feng X, McDonald JM. Disorders of bone remodeling. Annu Rev Pathol. 2011;6:121–45. doi: 10.1146/annurev-pathol-011110-130203 20936937

23. World Health Organization (WHO, 2018) Lead poisoning and health: (accessed 17th October 2019).

24. Wani AL, Ara A, Usmani JA. Lead toxicity: a review. Interdiscip Toxicol. 2015;8(2):55–64. doi: 10.1515/intox-2015-0009 27486361

25. World Health Organization (WHO, 2010) Exposure to cadmium: a major health concern (accessed 17th October 2019).

26. World Health Organization (WHO, 2011) International chemical safety cards; cadmium: (accessed 17th October 2019).

27. Manca D, Ricard AC, Trottier B, Chevalier G. Studies on lipid peroxidation in rat tissues following administration of low and moderate doses of cadmium chloride. Toxicology. 1991;67(3):303–23. doi: 10.1016/0300-483x(91)90030-5 1828634.

28. Hart BA, Lee CH, Shukla GS, Shukla A, Osier M, Eneman JD, et al. Characterization of cadmium-induced apoptosis in rat lung epithelial cells: evidence for the participation of oxidant stress. Toxicology. 1999;133(1):43–58. doi: 10.1016/s0300-483x(99)00013-x 10413193.

29. Dorta DJ, Leite S, DeMarco KC, Prado IM, Rodrigues T, Mingatto FE, et al. A proposed sequence of events for cadmium-induced mitochondrial impairment. J Inorg Biochem. 2003;97(3):251–7. doi: 10.1016/s0162-0134(03)00314-3 14511887.

30. Sandhir R, Gill KD. Effect of lead on lipid peroxidation in liver of rats. Biol Trace Elem Res. 1995;48(1):91–7. doi: 10.1007/bf02789081 7626375.

31. Liu J, Qu W, Kadiiska MB. Role of oxidative stress in cadmium toxicity and carcinogenesis. Toxicol Appl Pharmacol. 2009;238(3):209–14. doi: 10.1016/j.taap.2009.01.029 19236887

32. Patra RC, Rautray AK, Swarup D. Oxidative stress in lead and cadmium toxicity and its amelioration. Vet Med Int. 2011;2011:457327. doi: 10.4061/2011/457327 21547215

33. Matovic V, Buha A, Ethukic-Cosic D, Bulat Z. Insight into the oxidative stress induced by lead and/or cadmium in blood, liver and kidneys. Food Chem Toxicol. 2015;78:130–40. doi: 10.1016/j.fct.2015.02.011 25681546.

34. Daunt M, Dale O, Smith PA. Somatostatin inhibits oxidative respiration in pancreatic beta-cells. Endocrinology. 2006;147(3):1527–35. doi: 10.1210/en.2005-0873 16357046.

35. Spinazzi M, Casarin A, Pertegato V, Salviati L, Angelini C. Assessment of mitochondrial respiratory chain enzymatic activities on tissues and cultured cells. Nat Protoc. 2012;7(6):1235–46. doi: 10.1038/nprot.2012.058 22653162.

36. Janssen AJ, Trijbels FJ, Sengers RC, Smeitink JA, van den Heuvel LP, Wintjes LT, et al. Spectrophotometric assay for complex I of the respiratory chain in tissue samples and cultured fibroblasts. Clin Chem. 2007;53(4):729–34. doi: 10.1373/clinchem.2006.078873 17332151.

37. Elmorsy E, Smith PA. Bioenergetic disruption of human micro-vascular endothelial cells by antipsychotics. Biochem Biophys Res Commun. 2015;460(3):857–62. doi: 10.1016/j.bbrc.2015.03.122 25824037.

38. Elmorsy E, Elzalabany LM, Elsheikha HM, Smith PA. Adverse effects of antipsychotics on micro-vascular endothelial cells of the human blood-brain barrier. Brain Res. 2014;1583:255–68. doi: 10.1016/j.brainres.2014.08.011 25139421.

39. Singh R, Wiseman B, Deemagarn T, Jha V, Switala J, Loewen PC. Comparative study of catalase-peroxidases (KatGs). Arch Biochem Biophys. 2008;471(2):207–14. doi: 10.1016/ 18178143.

40. Beauchamp C, Fridovich I. Superoxide dismutase: improved assays and an assay applicable to acrylamide gels. Anal Biochem. 1971;44(1):276–87. doi: 10.1016/0003-2697(71)90370-8 4943714.

41. Ullah H, Khan MF, Hashmat F. Determination of glutathione concentration after its interaction with cadmium nitrate tetrahydrate by using Ellman’s modified method. Gomal University Journal of Research. 2011;27:2.

42. Armstrong D, Browne R. The analysis of free radicals, lipid peroxides, antioxidant enzymes and compounds related to oxidative stress as applied to the clinical chemistry laboratory. In Free radicals in diagnostic medicine 1994 (pp. 43–58). Springer, Boston, MA.

43. Alam MN, Bristi NJ, Rafiquzzaman M. Review on in vivo and in vitro methods evaluation of antioxidant activity. Saudi Pharm J. 2013;21(2):143–52. doi: 10.1016/j.jsps.2012.05.002 24936134

44. Czekanska EM, Stoddart MJ, Ralphs JR, Richards RG, Hayes JS. A phenotypic comparison of osteoblast cell lines versus human primary osteoblasts for biomaterials testing. J Biomed Mater Res A. 2014;102(8):2636–43. doi: 10.1002/jbm.a.34937 23983015.

45. Sachdeva C, Thakur K, Sharma A, Sharma KK. Lead: Tiny but Mighty Poison. Indian J Clin Biochem. 2018;33(2):132–46. doi: 10.1007/s12291-017-0680-3 29651203

46. Barry V, Todd AC, Steenland K. Bone lead associations with blood lead, kidney function and blood pressure among US, lead-exposed workers in a surveillance programme. Occup Environ Med. 2019;76(5):349–54. doi: 10.1136/oemed-2018-105505 30661026.

47. Coonse KG, Coonts AJ, Morrison EV, Heggland SJ. Cadmium induces apoptosis in the human osteoblast-like cell line Saos-2. J Toxicol Environ Health A. 2007;70(7):575–81. doi: 10.1080/15287390600882663 17365611.

48. Brama M, Politi L, Santini P, Migliaccio S, Scandurra R. Cadmium-induced apoptosis and necrosis in human osteoblasts: role of caspases and mitogen-activated protein kinases pathways. J Endocrinol Invest. 2012;35(2):198–208. doi: 10.3275/7801 21697648.

49. Zhao H, Liu W, Wang Y, Dai N, Gu J, Yuan Y, et al. Cadmium induces apoptosis in primary rat osteoblasts through caspase and mitogen-activated protein kinase pathways. J Vet Sci. 2015;16(3):297–306. doi: 10.4142/jvs.2015.16.3.297 26425111

50. He L, Poblenz AT, Medrano CJ, Fox DA. Lead and calcium produce rod photoreceptor cell apoptosis by opening the mitochondrial permeability transition pore. J Biol Chem. 2000;275(16):12175–84. doi: 10.1074/jbc.275.16.12175 10766853.

51. Liu Z, Li D, Zhao W, Zheng X, Wang J, Wang E. A potent lead induces apoptosis in pancreatic cancer cells. PLoS One. 2012;7(6):e37841. doi: 10.1371/journal.pone.0037841 22745658

52. Meyer JN, Leung MC, Rooney JP, Sendoel A, Hengartner MO, Kisby GE, et al. Mitochondria as a target of environmental toxicants. Toxicol Sci. 2013;134(1):1–17. doi: 10.1093/toxsci/kft102 23629515

53. Nemmiche S. Oxidative Signaling Response to Cadmium Exposure. Toxicol Sci. 2017;156(1):4–10. doi: 10.1093/toxsci/kfw222 27803385.

54. Elmorsy E, Al-Ghafari A, Aggour AM, Mosad SM, Khan R, Amer S. Effect of antipsychotics on mitochondrial bioenergetics of rat ovarian theca cells. Toxicol Lett. 2017;272:94–100. doi: 10.1016/j.toxlet.2017.03.018 28322891.

55. Elmorsy E, Attalla SM, Fikry E, Kocon A, Turner R, Christie D, et al. Adverse effects of anti-tuberculosis drugs on HepG2 cell bioenergetics. Hum Exp Toxicol. 2017;36(6):616–25. doi: 10.1177/0960327116660751 27461009.

56. Ramachandran A, Visschers RGJ, Duan L, Akakpo JY, Jaeschke H. Mitochondrial dysfunction as a mechanism of drug-induced hepatotoxicity: current understanding and future perspectives. J Clin Transl Res. 2018;4(1):75–100. doi: 10.18053/jctres.04.201801.005 30873497

57. Jezek P, Hlavata L. Mitochondria in homeostasis of reactive oxygen species in cell, tissues, and organism. Int J Biochem Cell Biol. 2005;37(12):2478–503. doi: 10.1016/j.biocel.2005.05.013 16103002.

58. Zorova LD, Popkov VA, Plotnikov EY, Silachev DN, Pevzner IB, Jankauskas SS, et al. Mitochondrial membrane potential. Anal Biochem. 2018;552:50–9. doi: 10.1016/j.ab.2017.07.009 28711444

59. Garcon G, Leleu B, Zerimech F, Marez T, Haguenoer JM, Furon D, et al. Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring of adverse effects of occupational exposure to lead and cadmium. J Occup Environ Med. 2004;46(11):1180–6. doi: 10.1097/01.jom.0000141665.22881.69 15534506.

60. Gurer-Orhan H, Sabir HU, Ozgunes H. Correlation between clinical indicators of lead poisoning and oxidative stress parameters in controls and lead-exposed workers. Toxicology. 2004;195(2–3):147–54. doi: 10.1016/j.tox.2003.09.009 14751670.

61. Ma Q. Role of nrf2 in oxidative stress and toxicity. Annu Rev Pharmacol Toxicol. 2013;53:401–26. doi: 10.1146/annurev-pharmtox-011112-140320 23294312

62. Tonelli C, Chio IIC, Tuveson DA. Transcriptional Regulation by Nrf2. Antioxid Redox Signal. 2018;29(17):1727–45. doi: 10.1089/ars.2017.7342 28899199

63. He X, Chen MG, Ma Q. Activation of Nrf2 in defense against cadmium-induced oxidative stress. Chem Res Toxicol. 2008;21(7):1375–83. doi: 10.1021/tx800019a 18512965.

64. Wu KC, Liu JJ, Klaassen CD. Nrf2 activation prevents cadmium-induced acute liver injury. Toxicol Appl Pharmacol. 2012;263(1):14–20. doi: 10.1016/j.taap.2012.05.017 22677785.

65. Moser SC, van der Eerden BCJ. Osteocalcin-A Versatile Bone-Derived Hormone. Front Endocrinol (Lausanne). 2018;9:794. doi: 10.3389/fendo.2018.00794 30687236

66. Flora SJ, Pachauri V. Chelation in metal intoxication. Int J Environ Res Public Health. 2010;7(7):2745–88. doi: 10.3390/ijerph7072745 20717537

67. Kianoush S, Sadeghi M, Balali-Mood M. Recent Advances in the Clinical Management of Lead Poisoning. Acta Med Iran. 2015;53(6):327–36. 26069169.

68. McKay CA Jr. Role of chelation in the treatment of lead poisoning: discussion of the Treatment of Lead-Exposed Children Trial (TLC). J Med Toxicol. 2013;9(4):339–43. doi: 10.1007/s13181-013-0341-8 24178899

69. Kasperczyk S, Dobrakowski M, Kasperczyk A, Romuk E, Rykaczewska-Czerwinska M, Pawlas N, et al. Effect of N-acetylcysteine administration on homocysteine level, oxidative damage to proteins, and levels of iron (Fe) and Fe-related proteins in lead-exposed workers. Toxicol Ind Health. 2016;32(9):1607–18. doi: 10.1177/0748233715571152 25731901.

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2019 Číslo 11