Factors regulating endogenous retroviral sequences in human and mouse

Area of Science:

• Genomics
• Molecular Biology
• Virology

Background:

• Endogenous retroviruses (ERVs) are ancient viral sequences integrated into vertebrate genomes, comprising a significant portion of the human DNA (5-8%).
• Human ERVs (HERVs) are implicated in regulating adjacent genes, tissue-specific expression, and even encoding functional proteins like syncytin, crucial for placental development.
• Dysregulation of HERVs is increasingly linked to various pathologies, including autoimmunity, reproductive issues, and cancer.

Purpose of the Study:

• To review and synthesize current evidence on factors modulating the expression and activity of endogenous retroviruses, with a focus on human ERVs (HERVs).
• To highlight the potential roles of ERVs in physiological processes and disease pathogenesis.
• To explore the utility of model organisms, such as mice, in understanding HERV regulation.

Main Methods:

• Literature review of studies investigating factors influencing ERV activity.
• Analysis of evidence linking ERVs to specific cell types, differentiation, aging, and external modulators.
• Comparative analysis of ERV regulation in humans and model organisms (mice).

Main Results:

• ERV expression and activity are modulated by diverse factors including cell/tissue type (placenta, germ cells), differentiation, aging, cytokines, DNA hypomethylating agents, and steroids.
• Specific HERV families exhibit distinct expression patterns and potential roles in human health and disease.
• Murine ERV studies offer insights into conserved regulatory mechanisms applicable to HERVs.

Conclusions:

• Endogenous retroviruses are dynamically regulated by a complex interplay of endogenous and exogenous factors.
• Understanding these interactions is crucial for elucidating the roles of ERVs in normal physiology and disease states.
• Targeting ERV modulation presents a potential avenue for future therapeutic strategies.