Pickel, L. | bioRxiv Science

bioRxiv2023

A latent cardiomyocyte regeneration potential in the human heart

Cardiomyocytes in the adult human heart show a regenerative capacity, with an annual renewal rate around 0.5%. Whether this regenerative capacity of human cardiomyocytes is employed in heart failure has been controversial. Using retrospective 14C birth dating we analyzed cardiomyocyte renewal in patients with end-stage heart failure. We show that cardiomyocyte generation is minimal in end-stage heart failure patients at rates 18-50 times lower compared to the healthy heart. However, patients receiving left ventricle support device therapy, who showed significant functional and structural cardiac improvement, had a >6-fold increase in cardiomyocyte renewal relative to the healthy heart. Our findings reveal a substantial cardiomyocyte regeneration potential in human heart disease, which could be exploited therapeutically.

cell biology↗

bioRxiv2022

Circadian reprogramming of adipose progenitor cells regulates intermittent fasting-mediated adipose tissue remodeling and metabolic improvement

White adipose tissue (WAT) fibrosis is a hallmark of dysfunctional WAT that is directly linked to metabolic abnormalities. Recent studies have highlighted the role of dysfunctional adipose progenitor cells (APCs) in WAT fibrosis and impaired adaptive tissue plasticity, leading to systemic insulin resistance. However, therapeutic options for WAT fibrosis are limited. Intermittent fasting (IF) is an effective dietary regimen for weight control and metabolic improvement through various mechanisms, including healthy remodeling of WAT. However, whether IF is effective in improving age-associated WAT fibrosis and metabolic homeostasis is unknown. Here, we show that IF confers therapeutic benefits in aged and obese mice through reduction of WAT fibrosis. Single-cell analyses revealed that IF significantly reduces pro-fibrotic signatures within APCs along with upregulation of the circadian pathways, suggesting that the circadian clock of APCs mediates IF-induced WAT remodeling. Importantly, mice lacking core circadian gene exhibited increased fibrotic signatures in WAT and diminished beneficial response to IF, further supporting the importance of circadian rhythm in IF-mediated metabolic benefits. Lastly, insulin resistance in humans also presented with dysregulated circadian rhythm signatures in APC populations. Collectively, our findings highlight the novel role of the APC circadian rhythm in plasticity of WAT and metabolic response to IF.

molecular biology↗