Evidence for Decreased Nucleolar PARP-1 as an Early Marker of Cognitive Impairment

Figure 1

PARP-1 prevalence in CA pyramidal nucleoli is reduced in MCI. (a) Representative examples of pyramidal cells with distinct (closed arrows), diffuse (open arrows) or absent (arrowhead) PARP-1 stained nucleoli. (b) Percentage of PARP-1 positive nucleoli (distinct + diffuse) in the CA is lower in MCI compared to both Control and AD groups. The subset of PARP-1 nucleoli that had distinct (black bars) staining is also significantly lower in MCI compared to both Control and AD, whereas diffusely stained nucleoli (grey bars) show similar percentages. (c) Percentage of PARP-1 positive nucleoli in each of the four CA subregions. In CA1, PARP-1 positive nucleoli (distinct + diffuse) are smaller in MCI than AD, which are in turn smaller than Control. Other subregions do not show significant differences. When compared the subset of PARP-1 nucleoli that had distinct (black bars) staining, MCI and AD are both significantly lower compared to Control, whereas diffusely stained nucleoli (grey bars) show similar percentages. denotes significant differences with p < .05 for percentage of PARP-1 positive nucleoli. denotes significant differences with for percentage of PARP-1 positive nucleoli. ^# denotes significant differences with for percentage of distinct PARP-1 nucleoli subgroup. ^### denotes significant differences with for percentage of distinct PARP-1 nucleoli subgroup.

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