TY - JOUR
T1 - Microglial cell response in α7 nicotinic acetylcholine receptor-deficient mice after systemic infection with Escherichia coli
AU - Hoogland, Inge C. M.
AU - Yik, Jutka
AU - Westhoff, Dunja
AU - Engelen-Lee, Joo-Yeon
AU - Valls Seron, Merche
AU - Man, Wing Kit
AU - Houben-Weerts, Judith H. P. M.
AU - Tanck, Michael W. T.
AU - van Westerloo, David J.
AU - van der Poll, Tom
AU - van Gool, Willem A.
AU - van de Beek, Diederik
N1 - Funding Information: This work was supported by ZonMW (WAvG., TOP Grant #40-00812-98-10017). DvdB is supported by ZonMW (Vici Grant #91819627). Publisher Copyright: © 2022, The Author(s).
PY - 2022/12/1
Y1 - 2022/12/1
N2 - Background: Development of neurodegeneration in older people has been associated with microglial cell activation triggered by systemic infection. We hypothesize that α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulation of this process. Methods: 8- to 10-week-old male wild-type (WT) and α7nAChR knock-out (α7nAChR−/−) mice were intraperitoneally inoculated with live Escherichia (E.) coli or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 h and killed at 2 or 3 days. The microglial response was characterized by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. To quantify inflammatory response, mRNA expression of pro- and anti-inflammatory mediators was measured in brain and spleen. Results: We observed no differences in Iba-1 positive cell number or morphology and flow cytometry (CD11b, CD45 and CD14) of microglial cells between WT and α7nAChR−/− mice after systemic infection. Infected α7nAChR−/− mice showed significantly higher mRNA expression in brain for tumor necrosis factor alpha (TNF-α) at day 2 and 3, interleukin 6 (IL-6) at day 2 and monocyte chemotactic protein 1 (MCP-1) and suppressor of cytokine signaling 1 (SOCS1) at day 3, there was significantly lower mRNA expression in brain for mitogen-activated protein kinase 1 (MAPK1) at day 2 and 3, high-mobility group 1 (HMGB-1) and CD11b at day 2, and deubiquitinase protein A20 (A20) at day 3 compared to infected WT mice. Interpretation: Loss of function of α7nAChR during systemic infection led to an increased expression of TNF-α and IL-6 in brain after systemic infection with E. coli, but not to distinct differences in microglial cell number or morphological activation of microglia.
AB - Background: Development of neurodegeneration in older people has been associated with microglial cell activation triggered by systemic infection. We hypothesize that α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulation of this process. Methods: 8- to 10-week-old male wild-type (WT) and α7nAChR knock-out (α7nAChR−/−) mice were intraperitoneally inoculated with live Escherichia (E.) coli or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 h and killed at 2 or 3 days. The microglial response was characterized by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. To quantify inflammatory response, mRNA expression of pro- and anti-inflammatory mediators was measured in brain and spleen. Results: We observed no differences in Iba-1 positive cell number or morphology and flow cytometry (CD11b, CD45 and CD14) of microglial cells between WT and α7nAChR−/− mice after systemic infection. Infected α7nAChR−/− mice showed significantly higher mRNA expression in brain for tumor necrosis factor alpha (TNF-α) at day 2 and 3, interleukin 6 (IL-6) at day 2 and monocyte chemotactic protein 1 (MCP-1) and suppressor of cytokine signaling 1 (SOCS1) at day 3, there was significantly lower mRNA expression in brain for mitogen-activated protein kinase 1 (MAPK1) at day 2 and 3, high-mobility group 1 (HMGB-1) and CD11b at day 2, and deubiquitinase protein A20 (A20) at day 3 compared to infected WT mice. Interpretation: Loss of function of α7nAChR during systemic infection led to an increased expression of TNF-α and IL-6 in brain after systemic infection with E. coli, but not to distinct differences in microglial cell number or morphological activation of microglia.
KW - Escherichia coli
KW - Knock-out
KW - Microglia
KW - Microglial activation
KW - Mouse model
KW - Neuro-inflammation
KW - Systemic infection
KW - α7 acetylcholine receptor
KW - α7nAChR
UR - http://www.scopus.com/inward/record.url?scp=85128144390&partnerID=8YFLogxK
U2 - https://doi.org/10.1186/s12974-022-02452-8
DO - https://doi.org/10.1186/s12974-022-02452-8
M3 - Article
C2 - 35413868
SN - 1742-2094
VL - 19
SP - 94
JO - Journal of neuroinflammation
JF - Journal of neuroinflammation
IS - 1
M1 - 94
ER -