The systemic costs of hematopoietic stem cell aging

Area of Science:

• Immunology
• Stem Cell Biology
• Gerontology

Background:

• Stem cell behavior is regulated by immune microenvironments.
• Immune cells are crucial for tissue-resident stem cell (TSC) maintenance, activation, and differentiation.
• Aging hematopoietic stem cells (HSCs) can impair regeneration in various tissues.

Purpose of the Study:

• To review the interplay between HSC aging and TSC function.
• To emphasize how age-related immune changes from HSCs affect tissue homeostasis.
• To explore mechanisms of HSC-TSC communication and strategies for rejuvenation.

Main Methods:

• Literature review synthesizing current knowledge.
• Analysis of HSC-derived immune outputs and their impact on tissue regeneration.
• Exploration of communication pathways like inflammaging and cytokine signaling.

Main Results:

• HSC aging leads to immune dysfunction that disrupts TSC function and tissue regeneration.
• Age-related changes in HSCs impair local tissue homeostasis through altered immune signaling.
• Mechanisms include inflammaging, cytokine signaling, and secretion of bioactive factors.

Conclusions:

• HSC aging is a central driver of age-related decline in tissue regenerative capacity.
• Restoring immune equilibrium by rejuvenating HSCs is a potential strategy for enhancing regeneration.
• A hierarchical model linking systemic immune remodeling to local niche dysfunction is proposed.