Environmental influences on clonal hematopoiesis

Area of Science:

• Hematology
• Genetics
• Environmental Health

Background:

• Clonal hematopoiesis (CH) involves the overrepresentation of genetically distinct hematopoietic stem cell clones in peripheral blood, linked to adverse health outcomes in the elderly.
• While genetic mutations driving CH are well-studied, the environmental factors influencing the emergence of dominant clones remain underexplored.
• Individual variation in latency between mutation acquisition and CH emergence suggests a significant role for environmental influences.

Purpose of the Study:

• To review the current literature on the interplay between environmental factors and the genetic landscape of clonal hematopoiesis.
• To highlight critical areas for future research into the environmental triggers and modifiers of CH.
• To emphasize the need for mutation-specific understanding of environmental effects on CH emergence for preventive medicine.

Main Methods:

• Review of existing epidemiologic and mechanistic studies on clonal hematopoiesis.
• Analysis of murine models investigating environmental stressors and their impact on specific CH-associated mutations.
• Synthesis of literature focusing on the role of factors like smoking, chemotherapy, inflammation, and metabolic syndromes.

Main Results:

• Epidemiologic data suggest smoking and prior chemotherapy exposure are contributors to certain forms of CH.
• Mechanistic studies in mice reveal mutation-specific responses of CH clones to environmental stressors.
• For example, PPM1D-mutated clones exhibit resistance to chemotherapy-induced genotoxic stress, conferring a competitive advantage.

Conclusions:

• Environmental factors play a crucial, mutation-specific role in the emergence and dominance of hematopoietic stem cell clones.
• Understanding these genotype-environment interactions is essential for developing targeted preventive strategies.
• Further research is needed to elucidate the precise mechanisms by which environmental stressors influence CH development across different genetic backgrounds.