Quantification of PCNA+ and Iba1+ cells was obtained from the PCNA/Iba1/A[beta] stained slides, while quantification of GFAP+ cells was obtained from the PCNA/GFAP/A[beta] triple stained sections.
We first studied GFAP+ and PCNA+ cells across cohorts to evaluate any association between the two protein markers.
GFAP+ astrocytes showed a characteristic, spider-like cellular morphology.
The population of A[beta] plaques with invasive hypertrophic GFAP+ astrocytes was increased in the AD population (one-way ANOVA P < 0.001).
Since GFAP+ astrocytes were not colabeled with PCNA, we next used combined Iba1-PCNA double immunocytochemistry to test whether proliferation did occur in microglial cells.
PCNA+ profiles were never observed in mature neurons or GFAP+ astrocytes, indicating that these cell types do not proliferate or reenter the cell cycle during dementia or AD.