Temporal and Spatial Activation of Microglia Shows Correlation with the Elevated Mtor Signaling in the Ns-pten KO Mouse
Abstract number :
1.071
Submission category :
1. Basic Mechanisms / 1E. Models
Year :
2022
Submission ID :
2204291
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:24 AM
Authors :
Katherine Blandin, BS – Baylor University; David Narvaiz, MA – Baylor University; Paige Womble, MA – Baylor University; D Gregory Sullens, MA – Baylor University; Danielle Santana-Coelho, PhD – Baylor University; Eliesse Kwok, BS – Baylor University; Jacob Pilcher, none – Baylor University; Taylor Wiley, none – Baylor University; Grace O'Neill, none – Baylor University; Joaquin Lugo, PhD – Baylor University
Rationale: Microglia act as a key component in maintaining homeostasis in the central nervous system. Seizures induce brain region dependent enhancements in microglia activation. Regional activation of microglia has been linked to higher seizure susceptibility and cognitive impairment, progressing with age. Neuronal subset specific phosphatase and tensin gene deleted on chromosome 10 (Pten) knockout (KO) mice display hyperactive mammalian target of rapamycin (mTOR) signaling in the hippocampus, cerebellum, and cortex followed by seizures that increase in severity with age.
Methods: In the present study, we investigated region specific microglia activation in NS-Pten KO mice at multiple timepoints across the lifespan. Tissue collection of wildtypes (WT) and KO mice was done at week 5 and 15 weeks for flow cytometry to analyze activated microglia as measured by MHC II in the hippocampus, cortex and cerebellum. Percent MHC II activated myeloid cells comparison was used for percent activation quantification. In a separate cohort of WT and KO mice, tissue collection for immunofluorescence was done at week 4 and 10 weeks of age to stain for activated microglia using Iba1 in the subsections of the dorsal hippocampus (dentate gyrus, CA1, CA2/3). Hippocampal region morphological alterations were recorded and Iba1 positive cells were quantified by region.
Results: Chi squared analysis of myeloid cells in KO mice following flow cytometry at 5 and 15 weeks showed significantly greater activation compared to WT mice across regions. This significant increased activation was apparent in the cortex, hippocampus and cerebellum, p < 0.05. At 15 weeks of age, the KO mice continued to express increased activation over WT mice in the cortex and hippocampus (p < 0.05), but not the cerebellum. Two-way ANOVA analysis of the immunofluorescent imaging revealed that at 4 weeks of age, KO mice had significantly higher Iba1 activation over WT throughout the hippocampus, but not at the subregional level. At 10 weeks of age, KO mice expressed increased Iba1 activation in all hippocampal regions, as well as the total count for the entire structure.
Basic Mechanisms