ABSTRACT
The sustained proliferation of microglia is a key hallmark of Alzheimer’s disease (AD), accelerating its progression. Here, we sought to understand the long-term impact of the early and prolonged microglial proliferation observed in AD, hypothesising that extensive and repeated cycling would engender a distinct transcriptional and phenotypic trajectory. We found that the early and sustained microglial proliferation seen in an AD-like model promotes replicative senescence, characterised by increased βgal activity, a senescence-associated transcriptional signature and telomere shortening, correlating with the appearance of disease-associated microglia (DAM) and senescent microglial profiles in human post-mortem AD cases. Prevention of early microglial proliferation hindered the development of senescence and DAM, impairing the accumulation of Aβ and associated neuritic damage. Overall, our results support that excessive microglial proliferation leads to the generation of senescent DAM, which contribute to early Aβ pathology in AD.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
NOTE FROM THE AUTHORS: Please note this pre-print relates to a submission dated July 2020. Since then, the manuscript and results have been revised once. Unfortunately, the revised version cannot be uploaded as a pre-print due to journal editorial restrictions. The final version will be made available as soon as we can.
