Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-28T22:08:26.698Z Has data issue: false hasContentIssue false

Developmental toxicant exposure in a mouse model of Alzheimer’s disease induces differential sex-associated microglial activation and increased susceptibility to amyloid accumulation

Published online by Cambridge University Press:  02 May 2017

A. N. vonderEmbse*
Affiliation:
Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
Q. Hu
Affiliation:
Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
J. C. DeWitt
Affiliation:
Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
*
*Address for correspondence: A. N. vonderEmbse, Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, 600 Moye Blvd., Greenville, NC, 27834 USA.(Email [email protected])

Abstract

As the resident macrophage of the central nervous system, microglia are thought to contribute to Alzheimer’s disease (AD) pathology through lack of neuroprotection. The role of immune dysfunction in AD may be due to disruption of regulatory signals for the activation of microglia that may occur early in development. We hypothesized that early toxicant exposure would systematically activate microglia, possibly reversing the pathological severity of AD. Offspring of a triple transgenic murine model for AD (3×TgAD) were exposed to a model neurotoxicant, lead acetate, from postnatal days (PND) 5–10. Our results indicated that female mice exposed to Pb had a greater and earlier incidence of amyloid burden within the hippocampus, coinciding with decreased markers of microglial activation at PND 50. Pb-exposed males had increased microglial activation at PND 50, as evidence by CD11b expression and microglial abundance, with no significant increase in amyloid burden at that time. There was greater amyloid burden at PND 90 and 180 in both male and female mice exposed to Pb compared with control. Together, these data suggest that activated microglia are neuroprotective against amyloid accumulation early in AD pathology, and that early exposure to Pb could increase susceptibility to later-life neurodegeneration. Likewise, females may be more susceptible to early-life microglial damage, and, subsequently, AD. Further investigation into the sex biased mechanisms by which microglial activation is altered by an early-life immune insult will provide critical insight into the temporal susceptibility of the developing neuroimmune system and its potential role in AD etiopathology.

Type
Original Article
Copyright
© Cambridge University Press and the International Society for Developmental Origins of Health and Disease 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Barker, DJP. The developmental origins of chronic adult disease. Acta Paediatr. 2004; 93(Suppl.), 2633.CrossRefGoogle ScholarPubMed
2. Basha, MR, Wei, W, Bakheet, SA, et al. The fetal basis of amyloidogenesis: exposure to lead and latent overexpression of amyloid precursor protein and β-amyloid in the aging brain. J Neurosci. 2005; 25, 823829.CrossRefGoogle ScholarPubMed
3. Miller, DB, O’Callaghan, JP. Do early-life insults contribute to the late-life development of Parkinson and Alzheimer diseases? Metabolism. 2008; 57, S44S49.CrossRefGoogle Scholar
4. Bilbo, SD. Early-life infection is a vulnerability factor for aging-related glial alterations and cognitive decline. Neurobiol Learn Mem. 2010; 94, 5764.Google Scholar
5. DeWitt, JC, Peden-Adams, MM, Keil, DE, Dietert, RR. Current status of developmental immunotoxicity: early-life patterns and testing. Toxicol Pathol. 2012; 40, 230236.CrossRefGoogle ScholarPubMed
6. Dietert, RR, Zelikoff, JT. Pediatric immune dysfunction and health risks following early-life immune insult. Curr Pediatr Rev. 2009; 5, 3651.Google Scholar
7. Harry, JG, Kraft, AD. Microglia in the developing brain: a potential target with lifetime effects. Neurotoxicology. 2012; 33, 191206.Google Scholar
8. Streit, WJ, Xue, QS, Tischer, J, Bechmann, I. Microglia pathology. Acta Neuropathol. 2014; 2, 117.Google ScholarPubMed
9. Santambrogio, L, Belyanskaya, SL, Fischer, FR, et al. Developmental plasticity of CNS microglia. Proc Natl Acad Sci U S A. 2001; 98, 62956300.CrossRefGoogle ScholarPubMed
10. Gehrmann, J, Matsumoto, Y, Kreutzberg, GW. Microglia: intrinsic immuneffector cell of the brain. Brain Res Rev. 1995; 20, 269287.CrossRefGoogle ScholarPubMed
11. Olah, M, Biber, K, Vinet, J, WGM, Boddeke H. Microglia phenotype diversity. CNS Neurol Disord Drug Targets. 2011; 10, 111.CrossRefGoogle ScholarPubMed
12. Walker, DG, Lue, LF. Immune phenotype of microglia in human neurodegenerative disease: challenges to detecting microglial polarization in human brains. Alzheimer’s Res Ther. 2015; 7, 56.CrossRefGoogle ScholarPubMed
13. Lenz, KM, Nugent, BM, Haliyur, R, McCarthy, MM. Microglia are essential to masculinization of brain and behavior. J Neurosci. 2013; 33, 27612772.CrossRefGoogle ScholarPubMed
14. Carroll, JC, Rosario, ER, Kreimer, S, et al. Sex differences in β-amyloid accumulation in 3xTg-AD mice: role of neonatal sex steroid hormone exposure. Brain Res. 2010; 1366, 233245.CrossRefGoogle ScholarPubMed
15. Moser, VC, Walls, I, Zoetis, T. Direct dosing of preweaning rodents in toxicity testing and research: deliberations of an ILSI RSI Expert Working Group. Int J Toxicol. 2005; 24, 8794.CrossRefGoogle ScholarPubMed
16. Zoetis, T, Walls, I. Principles and practices for direct dosing of pre-weaning mammals in toxicity testing and research. Report. In ILSI Risk Science Institute Expert Working Group on Direct Dosing of Pre-weaning Mammals in Toxicity Testing, 2005. ILSI Press: Washington, DC.Google Scholar
17. Liu, MC, Liu, XQ, Wang, W, et al. Involvement of microglia activation in the lead induced long-term potentiation impairment. PLoS ONE. 2012; 7, e43924.CrossRefGoogle ScholarPubMed
18. Butchbach, MER, Edwards, JD, Schussler, KR, Burghes, AHM. A novel method for oral delivery of drug compounds to the neonatal SMNΔ7 mouse model of spinal muscular atrophy. J Neurosci Methods. 2007; 161, 285290.CrossRefGoogle Scholar
19. Oddo, S, Caccamo, A, Kitazawa, M, Tseng, BP, LaFerla, FM. Amyloid deposition precedes tangle formation in a triple transgenic model of Alzheimer’s disease. Neurobiol Aging. 2003; 24, 10631070.CrossRefGoogle Scholar
20. Schneider, CA, Rasband, WS, Eliceiri, KW. NIH image to ImageJ: 25 years of image analysis. Nat Methods. 2012; 9, 671675.CrossRefGoogle ScholarPubMed
21. Sedgwick, JD, Schwender, S, Imrich, H, et al. Isolation and direct characterization of resident microglial cells from the normal and inflamed central nervous system. Proc Natl Acad Sci U S A. 1991; 88, 74387442.Google Scholar
22. Ford, AL, Goodsall, AL, Hickey, WF, Sedgwick, JD. Normal adult ramified microglia separated from other central nervous system macrophages by flow cytometry sorting. J Immunol. 1995; 154, 43094321.CrossRefGoogle Scholar
23. Stevens, SL, Bao, J, Hollis, J, et al. The use of flow cytometry to evaluate temporal changes in inflammatory cells following focal cerebral ischemia in mice. Brain Res. 2001; 932, 110119.CrossRefGoogle Scholar
24. Nikodemova, M, Watters, JJ. Efficient isolation of live microglia with preserved phenotypes from adult mouse brain. J Neuroinflammation. 2012; 9, 110.Google Scholar
25. Roy, A, Fung, YK, Liu, X, Pahan, K. Up-regulation of microglial CD11b expression by nitric oxide. J Biol Chem. 2006; 281, 1497114980.CrossRefGoogle ScholarPubMed
26. Kobayashi, K, Imagama, S, Ohgomori, T, et al. Minocycline selectively inhibits M1 polarization of microglia. Cell Death Dis. 2013; 4, e525.CrossRefGoogle ScholarPubMed
27. Schwarz, JM, Sholar, PW, Bilbo, SD. Sex differences in microglial colonization of the developing rat brain. J Neurochem. 2012; 120, 948963.CrossRefGoogle ScholarPubMed
28. Overk, CR, Perez, SE, Ma, C, et al. Sex steroid levels and AD-like pathology in 3xTgAD mice. J Neuroendocrinol. 2013; 25, 131144.CrossRefGoogle ScholarPubMed
29. Banati, RB, Gehrmann, J, Schubert, P, Kreutzberg, GW. Cytotoxicity of microglia. Glia. 1993; 7, 111118.CrossRefGoogle ScholarPubMed
30. El Khoury, J, Hickman, SE, Thomas, CA, Loike, JD, Silverstein, SC. Microglia, scavenger receptors, and the pathogenesis of Alzheimer’s disease. Neurobiol Aging. 1998; 19(Suppl.), S81S84.Google Scholar
31. Hooper, C, Pinteaux-Jones, F, Fry, VAH, et al. Differential effects of albumin on microglia and macrophages; implications for neurodegeneration following blood-brain barrier damage. J Neurochem. 2009; 109, 694705.CrossRefGoogle ScholarPubMed
32. Solito, E, Sastre, M. Microglia function in Alzheimer’s disease. Front Pharmacol. 2012; 3, 110.CrossRefGoogle ScholarPubMed
33. Wu, J, Basha, MR, Brock, B, et al. Alzheimer’s disease (AD)-like pathology in aged monkeys after infantile exposure to environmental metal lead (Pb): evidence for a developmental origin and environmental link for AD. J Neurosci. 2008; 28, 39.CrossRefGoogle Scholar
34. Leifer, CA, Dietert, RR. Early life environment and developmental immunotoxicity in inflammatory dysfunction and disease. Toxicol Environ Chem. 2001; 93, 14631485.Google Scholar
35. Krstic, D, Madhusudan, A, Doehner, J, et al. Systemic immune challenges trigger and drive Alzheimer-like neuropathology in mice. J Neuroinflammation. 2012; 9, 151.Google Scholar
36. Perry, VH, Teeling, J. Microglia and macrophages of the central nervous system: the contribution of microglia priming and systemic inflammation to chronic neurodegeneration. Semin Immunopathol. 2013; 35, 601612.CrossRefGoogle ScholarPubMed
37. Nayak, D, Roth, TL, McGavern, DB. Microglia development and function. Annu Rev Immunol. 2014; 32, 367402.CrossRefGoogle ScholarPubMed
38. Paolicelli, RC, Bolasco, G, Pagani, F, et al. Synaptic pruning by microglia is necessary for normal brain development. Science. 2011; 333, 14561458.Google Scholar
39. Schwarz, JM, Bilbo, SD. Sex, glia, and development: interactions in health and disease. Horm Behav. 2012; 62, 243253.Google Scholar
40. Lenz, KM, McCarthy, MM. A starring role for microglia in brain sex differences. Neuroscientist. 2015; 21, 306321.CrossRefGoogle ScholarPubMed
41. Crain, JM, Nikodemova, M, Watters, JJ. Microglia express distinct M1 and M2 phenotypic markers in the postnatal and adult central nervous system in male and female mice. J Neurosci Res. 2013; 91, 11431151.Google Scholar
42. Sobin, C, Montoya, MGF, Parisi, N, et al. Microglial disruption in young mice with early chronic lead exposure. Toxicol Lett. 2013; 220, 4452.CrossRefGoogle ScholarPubMed
43. Bunn, TL, Parsons, PJ, Kao, E, Dietert, RR. Exposure to lead during critical windows of embryonic development: differential immunotoxic outcomes based on stage of exposure and gender. Toxicol Sci. 2001; 64, 5766.Google Scholar
44. Zurich, MG, Eskes, C, Honegger, P, Bérode, M, Monnet-Tschudi, F. Maturation-dependent neurotoxicity of lead acetate in vitro: implications of glial reactions. J Neurosci Res. 2002; 70, 108116.CrossRefGoogle ScholarPubMed
45. Kumawat, KL, Kaushik, DK, Goswami, P, Basu, A. Acute exposure to lead acetate activates microglia and induces subsequent bystander neuronal death via caspase-3 activation. Neurotoxicology. 2014; 41, 143153.CrossRefGoogle ScholarPubMed
46. Grathwohl, SA, Kälin, RE, Bolmont, T, et al. Formation and maintenance of Alzheimer’s disease β-amyloid plaques in the absence of microglia. Nat Neurosci. 2009; 11, 13611363.Google Scholar
47. Spangenberg, EE, Lee, RJ, Najafi, AR, et al. Eliminating microglia in Alzheimer’s mice prevents neuronal loss without modulating amyloid-β pathology. Brain. 2016; 139, 12651281.CrossRefGoogle ScholarPubMed
48. Cras, P, Kawai, M, Siedlak, S, et al. Neuronal and microglial involvement in β-amyloid protein deposition in Alzheimer’s disease. Am J Pathol. 1990; 137, 241246.Google ScholarPubMed
49. Stalder, M, Phinney, A, Probst, A, et al. Association of microglia with amyloid plaques in brains of APP23 transgenic mice. Am J Pathol. 1999; 154, 16731684.CrossRefGoogle ScholarPubMed
50. Combs, CK, Karlo, JC, Kao, SC, Landreth, GE. β-Amyloid stimulation of microglia and monocytes results in TNFα-dependent expression of inducible nitric oxide synthase and neuronal apoptosis. J Neurosci. 2001; 21, 11791188.Google Scholar
51. Bolmont, T, Haiss, F, Eicke, D, et al. Dynamics of microglial/amyloid interaction indicate a role in plaque maintenance. Neurobiol Dis. 2008; 28, 42834292.Google Scholar
52. Hickman, SE, Allison, EK, Khoury, JE. Microglial dysfunction and defective β-amyloid clearance pathways in aging Alzheimer’s disease mice. J Neurosci. 2008; 28, 83548360.CrossRefGoogle ScholarPubMed
53. Marlatt, MW, Bauer, J, Aronica, E, et al. Proliferation in the Alzheimer hippocampus is due to microglia, not astroglia, and occurs at sites of amyloid deposition. Neural Plast. 2014; 2014, 693851.Google Scholar