Hyper-aging in systemic sclerosis: linking genome instability, mitochondrial dysfunction, and inflammaging to fibrosis.

Abstract

Purpose of review: Systemic sclerosis (SSc) is a progressive autoimmune disease characterized by fibrosis, vasculopathy, and immune dysregulation. Emerging evidence indicates that SSc shares multiple hallmarks of accelerated biological aging, including genomic instability, telomere attrition, mitochondrial dysfunction, cellular senescence, and chronic innate immune activation. This review summarizes recent advances published during the last 18 months supporting the concept of SSc as a disorder of maladaptive or 'hyper-aging'.

Recent findings: Recent epigenetic clock studies, including DunedinPACE and other DNA methylation-based aging models, demonstrate accelerated biological aging in SSc, particularly in patients with interstitial lung disease and severe organ involvement. Gene expression meta-analysis has confirmed that aging and senescence signatures are markedly enriched in SSc-ILD lung tissue. Multiple aging-associated mechanisms contribute to disease progression, including telomere shortening, mitochondrial dysfunction, micronuclei formation, and chromosomal instability. Cytosolic DNA derived from damaged nuclei or mitochondria activates the cGAS-STING pathway, sustaining type I interferon signaling, inflammaging, and fibrotic remodeling. Recent transcriptomic and spatial studies further support a close relationship between metabolic collapse, mitochondrial stress, immune dysregulation, and tissue fibrosis in SSc.

Summary: Current evidence supports the concept that SSc represents a state of accelerated and dysregulated biological aging involving persistent innate immune activation, mitochondrial stress, and defective genome surveillance. Therapeutic strategies targeting aging-associated pathways, particularly mitochondrial dysfunction, cGAS-STING signaling, and cellular senescence, may provide new opportunities to modulate fibrosis, inflammation, and immune imbalance in SSc.