Title

Knockdown of heterochromatin protein 1 binding protein 3 recapitulates phenotypic, cellular, and molecular features of aging.

Document Type

Article

Publication Date

12-13-2018

JAX Source

Aging Cell 2018 Dec 13:e12886 [Epub ahead of print]

PMID

30549219

DOI

https://doi.org/10.1111/acel.12886

Grant

AG050357, AG054180

Abstract

Identifying genetic factors that modify an individual's susceptibility to cognitive decline in aging is critical to understanding biological processes involved and mitigating risk associated with a number of age-related disorders. Recently, heterochromatin protein 1 binding protein 3 (Hp1bp3) was identified as a mediator of cognitive aging. Here, we provide a mechanistic explanation for these findings and show that targeted knockdown of Hp1bp3 in the hippocampus by 50%-75% is sufficient to induce cognitive deficits and transcriptional changes reminiscent of those observed in aging and Alzheimer's disease brains. Specifically, neuroinflammatory-related pathways become activated following Hp1bp3 knockdown in combination with a robust decrease in genes involved in synaptic activity and neuronal function. To test the hypothesis that Hp1bp3 mediates susceptibility to cognitive deficits via a role in neuronal excitability, we performed slice electrophysiology demonstrate transcriptional changes after Hp1bp3 knockdown manifest functionally as a reduction in hippocampal neuronal intrinsic excitability and synaptic plasticity. In addition, as Hp1bp3 is a known mediator of miRNA biogenesis, here we profile the miRNA transcriptome and identify mir-223 as a putative regulator of a portion of observed mRNA changes, particularly those that are inflammatory-related. In summary, work here identifies Hp1bp3 as a critical mediator of aging-related changes at the phenotypic, cellular, and molecular level and will help inform the development of therapeutics designed to target either Hp1bp3 or its downstream effectors in order to promote cognitive longevity.

Comments

We would like to acknowledge The Jackson Laboratory Genome Technologies core for their assistance with library prep and RNA sequencing and Dr. Vivek Philip for aligning the mRNA and miRNA data.

Share

COinS