The specificity and role of microglia in epileptogenesis in mouse models of tuberous sclerosis complex
Open accessAbstract
Summary: Objective: Microglial abnormalities have been reported in pathologic specimens from patients with tuberous sclerosis complex (TSC), a genetic disorder characterized by epilepsy, intellectual disability, and autism. However, the pathogenic role of microglia in epilepsy in TSC is poorly understood, particularly whether microglia defects may be a primary contributor to epileptogenesis or are secondary to seizures or simply epiphenomena. In this study, we tested the hypothesis that Tsc1 gene inactivation in microglia is sufficient to cause epilepsy in mouse models of TSC . Methods: Using a chemokine receptor, Cx3cr1, to target microglia, conventional Tsc1 Cx3cr1‐Cre CKO (conditional knockout) mice and postnatal‐inducible Tsc1 Cx3cr1‐Cre ER CKO mice were generated and assessed for molecular and histopathologic evidence of microglial abnormalities, mechanistic target of rapamycin 1 (mTORC1) pathway activation, and epilepsy. Results: Tsc1 Cx3cr1‐Cre CKO mice exhibited a high efficiency of microglia Tsc1 inactivation, mTORC 1 activation, increased microglial size and number, and robust epilepsy, which were rapamycin‐dependent. However, Cre reporter studies demonstrated that constitutive Cx3cr1 expression affected not only microglia, but also a large percentage of cortical neurons, confounding the role of microglia in epileptogenesis in Tsc1 Cx3cr1‐Cre CKO mice. In contrast, postnatal inactivation of Tsc1 utilizing a tamoxifen‐inducible Cx3cr1‐Cre ER resulted in a more‐selective microglia Tsc1 inactivation with high efficiency, mTORC 1 activation, and increased microglial size and number, but no documented epilepsy. Significance: Microglia abnormalities may contribute to epileptogenesis in the context of neuronal involvement in TSC mouse models, but selective Tsc1 gene inactivation in microglia alone may not be sufficient to cause epilepsy, suggesting that microglia have more supportive roles in the pathogenesis of seizures in TSC .
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Zhang et al. (2018) reported that the Parkhurst Cx3cr1-CreERT2 line has significant leakage into neurons.
“However, Zhang et al. (2018) reported that this line has significant leakage into neurons.”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
The Results (page unavailable) report neuronal Cre-recombination, but the large neuronal involvement was found with constitutive Cx3cr1-Cre. For the inducible Cx3cr1-CreER line, they report about 5% of cortical neurons showing recombination; Materials and Methods (page unavailable) identify that line as Litt/Wgan, not Parkhurst. The paper therefore does not establish significant neuronal leakage in the Parkhurst line. (LLM, conf=0.86)
Experimental — accuracy not yet measuredThis potential embryonic deletion of TSC1 may explain the differences in seizure susceptibility observed in these two studies (Jung et al., 2000; Zhang et al., 2018; Zhao et al., 2018).
“which may explain the differences in seizure susceptibility observed in these two studies (Jung et al., 2000; Zhang et al., 2018; Zhao et al., 2018).”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
The Discussion says constitutive Tsc1 deletion involved presumed embryonic induction and that prenatal, unlike postnatal, microglial deletion might be sufficient to cause epilepsy. But it does not propose embryonic deletion as the explanation for the seizure difference between the two studies: it notes that the other study also found seizures after postnatal deletion and discusses neuronal involvement, genetic background, and recombination efficiency as possible factors. Page numbers are unavailable in our copy. (LLM, conf=0.82)
Experimental — accuracy not yet measuredThis cre-independent leakage likely accounts, at least in part, for the GFP-positive non-microglial cells observed in Zhang et al. (2018).
“This cre-independent leakage likely accounts, at least in part, for the GFP-positive non-microglial cells observed in that previous study (Zhang et al., 2018).”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
The leakiness of this Cx3cr1-Cre line was recently reported, but in conjunction with a Rosa-Greenf/f reporter line (Zhang et al., 2018).
“The leakiness of this Cx3cr1-Cre line was recently reported, but in conjunction with a Rosa-Greenf/f reporter line (Zhang et al., 2018).”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
The Rosa-Greenf/f reporter line used in a previous study by Zhang et al. (2018) shows spontaneous leakiness into non-microglial cells in the absence of cre recombinase.
“In the present study, we unexpectedly found that the Rosa-Greenf/f reporter line used in a previous study by other researchers (Zhang et al., 2018) shows spontaneous leakiness into non-microglial cells in the absence of cre recombinase.”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
Our study suggests the Rosa-Greenf/f reporter line itself could contribute to the leakage into neurons and other cells noted by others (Zhang et al., 2018).
“Our study suggests that the Rosa-Greenf/f reporter line itself could contribute to the leakage into neurons and other cells that was noted by others (Zhang et al., 2018).”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
No spontaneous seizures were observed in the Zhang et al. (2018) study that used the Parkhurst Cx3cr1-CreERT2 line.
“In contrast, no spontaneous seizures were observed in the other study (Zhang et al., 2018) that used the Cx3cr1-CreERT2 mouse line developed by Parkhurst et al. (2013).”
From Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity (2019) · cites this paper as Zhang et al., 2018
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
Meikle, L., Talos, D. M., Onda, H., Pollizzi, K., Rotenberg, A., Sahin, M., Jensen, F. E., & Kwiatkowski, D. J. (2007) · The Journal of Neuroscience · doi:10.1523/jneurosci.5540-06.2007 · Cited by 462 · see citing works
Expression of CX <sub>3</sub> CR1 chemokine receptors on neurons and their role in neuronal survival
Meucci, O., Fatatis, A., Simen, A. A., & Miller, R. J. (2000) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.090017497 · Cited by 385 · see citing works
Microglia, seen from the CX3CR1 angle
Wolf, Y., Yona, S., Kim, K.-W., & Jung, S. (2013) · Frontiers in Cellular Neuroscience · doi:10.3389/fncel.2013.00026 · Cited by 316 · see citing works
Noninflammatory Changes of Microglia Are Sufficient to Cause Epilepsy
Zhao, X., Liao, Y., Morgan, S., Mathur, R., Feustel, P., Mazurkiewicz, J., Qian, J., Chang, J., Mathern, G. W., Adamo, M. A., et al. (2018) · Cell Reports · doi:10.1016/j.celrep.2018.02.004 · Cited by 190 · see citing works
Ischemia-induced Neuronal Cell Death Is Mediated by Chemokine Receptor CX3CR1
Wang, J., Gan, Y., Han, P., Yin, J., Liu, Q., Ghanian, S., Gao, F., Gong, G., & Tang, Z. (2018) · Scientific Reports · doi:10.1038/s41598-017-18774-0 · Cited by 58 · see citing works
Yeo, S.-I., Kim, J.-E., Ryu, H. J., Seo, C. H., Lee, B. C., Choi, I.-G., Kim, D.-S., & Kang, T.-C. (2011) · Journal of Neuroimmunology · doi:10.1016/j.jneuroim.2011.03.005 · Cited by 55 · see citing works
Flagged first, then by citations
Research works printed but not linked: 28
- [1]Orlova KA, Crino PB. The tuberous sclerosis complex. Ann N Y Acad Sci 2010; 1184: 87– 105. 20146692 PMC2892799
- [2]DiMario FJ Jr., Sahin M, Ebrahimi-Fakhari D. Tuberous Sclerosis Complex. Pediatr Clin North Am 2015; 62: 633– 648. 26022167
- [3]Chu-Shore CJ, Major P, Camposano S, The natural history of epilepsy in tuberous sclerosis complex. Epilepsia 2010; 51: 1236– 1241. 20041940 PMC3065368
- [4]Lipton JO, Sahin M. The neurology of mTOR. Neuron 2014; 84: 275– 291. 25374355 PMC4223653
- [5]Laplante M, Sabatini DM. mTOR signaling in growth control and disease. Cell 2012; 149: 274– 293. 22500797 PMC3331679
- [6]Saxton RA, Sabatini DM. mTOR Signaling in Growth, Metabolism, and Disease. Cell 2017; 168: 960– 976. 28283069 PMC5394987
- [7]Wong M Mechanisms of epileptogenesis in tuberous sclerosis complex and related malformations of cortical development with abnormal glioneuronal proliferation. Epilepsia 2008; 49: 8– 21. PMC3934641 17727667
- [9]Uhlmann EJ, Wong M, Baldwin RL, Astrocyte-specific TSC1 conditional knockout mice exhibit abnormal neuronal organization and seizures. Ann Neurol 2002; 52: 285– 296. 12205640
- [10]Sosunov AA, Wu X, Weiner HL, Tuberous sclerosis: a primary pathology of astrocytes? Epilepsia 2008; 49 Suppl 2: 53– 62. 18226172
- [11]Town T, Nikolic V, Tan J. The microglial “activation” continuum: from innate to adaptive responses. J Neuroinflammation 2005; 2: 24. 16259628 PMC1298325
- [12]Devinsky O, Vezzani A, Najjar S, Glia and epilepsy: excitability and inflammation. Trends Neurosci 2013; 36: 174– 184. 23298414
- [13]Paolicelli RC, Bolasco G, Pagani F, Synaptic pruning by microglia is necessary for normal brain development. Science 2011; 333: 1456– 1458. 21778362
- [14]Boer K, Jansen F, Nellist M, Inflammatory processes in cortical tubers and subependymal giant cell tumors of tuberous sclerosis complex. Epilepsy Res 2008; 78: 7– 21. 18023148
- [15]Boer K, Troost D, Jansen F, Clinicopathological and immunohistochemical findings in an autopsy case of tuberous sclerosis complex. Neuropathology 2008; 28: 577– 590. 18410267
- [17]Jung S, Aliberti J, Graemmel P, Analysis of fractalkine receptor CX(3)CR1 function by targeted deletion and green fluorescent protein reporter gene insertion. Mol Cell Biol 2000; 20: 4106– 4114. 10805752 PMC85780
- [18]Parkhurst CN, Yang G, Ninan I, Microglia promote learning-dependent synapse formation through brain-derived neurotrophic factor. Cell 2013; 155: 1596– 1609. 24360280 PMC4033691
- [19]Zhao L, Zabel MK, Wang X, Microglial phagocytosis of living photoreceptors contributes to inherited retinal degeneration. EMBO Mol Med 2015; 7: 1179– 1197. 26139610 PMC4568951
- [20]Zhang B, Zou J, Han L, Microglial activation during epileptogenesis in a mouse model of tuberous sclerosis complex. Epilepsia 2016; 57: 1317– 1325. 27263494 PMC4972670
- [21]Zeng LH, Xu L, Gutmann DH, Rapamycin prevents epilepsy in a mouse model of tuberous sclerosis complex. Ann Neurol 2008; 63: 444– 453. 18389497 PMC3937593
- [22]Erbayat-Altay E, Zeng LH, Xu L, The natural history and treatment of epilepsy in a murine model of tuberous sclerosis. Epilepsia 2007; 48: 1470– 1476. 17484760 PMC3898798
- [23]Wieghofer P, Knobeloch KP, Prinz M. Genetic targeting of microglia. Glia 2015; 63: 1– 22. 25132502
- [25]Najjar S, Pearlman D, Miller DC, Refractory epilepsy associated with microglial activation. Neurologist 2011; 17: 249– 254. 21881466
- [26]Shapiro LA, Wang L, Ribak CE. Rapid astrocyte and microglial activation following pilocarpine-induced seizures in rats. Epilepsia 2008; 49 Suppl 2: 33– 41. 18226170
- [27]Yrjanheikki J, Keinanen R, Pellikka M, Tetracyclines inhibit microglial activation and are neuroprotective in global brain ischemia. Proc Natl Acad Sci U S A 1998; 95: 15769– 15774. 9861045 PMC28119
- [28]Wang N, Mi X, Gao B, Minocycline inhibits brain inflammation and attenuates spontaneous recurrent seizures following pilocarpine-induced status epilepticus. Neuroscience 2015; 287: 144– 156. 25541249
- [29]Abraham J, Fox PD, Condello C, Minocycline attenuates microglia activation and blocks the long-term epileptogenic effects of early-life seizures. Neurobiol Dis 2012; 46: 425– 430. 22366182 PMC3323726
- [30]Meucci O, Fatatis A, Simen AA, Expression of CX3CR1 chemokine receptors on neurons and their role in neuronal survival. Proc Natl Acad Sci U S A 2000; 97: 8075– 8080. 10869418 PMC16672
- [33]Pun RY, Rolle IJ, Lasarge CL, Excessive activation of mTOR in postnatally generated granule cells is sufficient to cause epilepsy. Neuron 2012; 75: 1022– 1034. 22998871 PMC3474536
Cited by
Sorted by citations
Targeting Microglia Using Cx3cr1-Cre Lines: Revisiting the Specificity
Zhao, X.-F., Alam, M. M., Liao, Y., Huang, T., Mathur, R., Zhu, X., & Huang, Y. (2019) · eneuro · doi:10.1523/eneuro.0114-19.2019 · Cited by 92 · see citing works
Zimmer, T. S., Broekaart, D. W. M., Gruber, V.-E., van Vliet, E. A., Mühlebner, A., & Aronica, E. (2020) · Frontiers in Neurology · doi:10.3389/fneur.2020.01028 · Cited by 48 · see citing works
- Authors
- Zhang, B., Zou, J., Han, L., Beeler, B., Friedman, J. L., Griffin, E., Piao, Y., Rensing, N. R., & Wong, M.
- Affiliations
- Washington University in St. Louis (US)
- Department of Neurology and the Hope Center for Neurological Disorders Washington University School of Medicine St. Louis Missouri
- Corresponding author
- Wong, Michael
- Venue
- Epilepsia
- Publisher
- Wiley
- Published
- 2018-08-05
- Volume
- 59
- Issue
- 9
- Pages
- 1796-1806
- ISSN
- 0013-9580 (ISSN-L)
- 1528-1167
- PMC
- PMC6121723
- OpenAlex
- W2887447835
- Cited by
- 50
- References
- 6
- Citations by year
- 2026: 4 · 2025: 10 · 2024: 9 · 2023: 3 · 2022: 8 · 2021: 1 · 2020: 9 · 2019: 5 · 2018: 1
- FWCI
- 2.75
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Epilepsia (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- McDonnell Center for Systems Neuroscience
- National Institute of Neurological Disorders and Stroke (R01 NS056872, S10 RR027552)
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (U54 HD087011)
- Topics
- Health Sciences › Medicine › Physiology › Tuberous Sclerosis Complex Research
- Health Sciences › Medicine › Psychiatry and Mental health › Epilepsy research and treatment
- Life Sciences › Neuroscience › Neurology › Neuroinflammation and Neurodegeneration Mechanisms
- Keywords
- tuberous sclerosis complex, microglia, epileptogenesis, TSC1, mTORC1 signaling, epilepsy, CX3CR1, conditional knockout mice, rapamycin, microglial activation, intellectual disability
- MeSH terms
- CX3C Chemokine Receptor 1, Mechanistic Target of Rapamycin Complex 1, Tuberous Sclerosis Complex 1 Protein, Animals, Animals, Newborn, Brain, Calcium-Binding Proteins, Disease Models, Animal, Electroencephalography, Estrogen Antagonists, Gene Expression Regulation, Glial Fibrillary Acidic Protein, Mice, Inbred C57BL, Mice, Transgenic, Microfilament Proteins, Phosphopyruvate Hydratase, Tamoxifen, Tuberous Sclerosis, Video Recording, Microglia, Statistics, Nonparametric, Sirolimus, Mice
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
