An interferon gamma response signature links myocardial aging and immunosenescence.

ABSTRACT:

Aims

Aging entails profound immunological transformations that can impact myocardial homeostasis and predispose to heart failure. However, preclinical research in the immune-cardiology field is mostly conducted in young healthy animals, which potentially weakens its translational relevance. Herein, we sought to investigate how the aging T-cell compartment associates with changes in myocardial cell biology in aged mice.

Methods and results

We phenotyped the antigen-experienced effector/memory T cells purified from heart-draining lymph nodes of 2-, 6-, 12-, and 18-month-old C57BL/6J mice using single-cell RNA/T cell receptor (TCR) sequencing (sc-seq). Simultaneously, we profiled all non-cardiomyocyte cell subsets purified from 2- and 18-month-old hearts and integrated our data with publicly available cardiomyocyte sc-seq datasets. Some of these findings were confirmed at the protein level by flow cytometry. With aging, the heart-draining lymph node and myocardial T cells underwent clonal expansion and exhibited an up-regulated pro-inflammatory transcription signature, marked by an increased interferon-γ (IFN-γ) production. In parallel, all major myocardial cell populations showed increased IFN-γ responsive signature with aging. In the aged cardiomyocytes, a stronger IFN-γ response signature was paralleled by the dampening of expression levels of transcripts related to most metabolic pathways, especially oxidative phosphorylation. Likewise, induced pluripotent stem cells-derived cardiomyocytes (iPSC-CM) exposed to chronic, low grade IFN-γ treatment showed a similar inhibition of metabolic activity.

Conclusions

By investigating the paired age-related alterations in the T cells found in the heart and its draining lymph nodes, we provide evidence for increased myocardial IFN-γ signaling with age, which is associated with inflammatory and metabolic shifts typically seen in heart failure.

SUBMITTER: Ashour D 

PROVIDER: S-EPMC10651211 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature