Arterial telomere dysfunction may contribute to chronic arterial inflammation by inducing cellular senescence and subsequent senescence-associated inflammation. Though telomere shortening has been associated with arterial aging in humans, age-related telomere uncapping has not been described in non-cultured human tissues and may have substantial prognostic value.
In skeletal muscle feed arteries from 104 younger, middle-aged, and older adults, scientists assessed the potential role of age-related telomere uncapping in arterial inflammation.
Telomere uncapping, measured by p-histone γ-H2A.X, ser139 localized to telomeres (chromatin immunoprecipitation; ChIP) and telomeric repeat binding factor 2 bound to telomeres (ChIP) was greater in arteries from older adults compared with those from younger adults. There was greater tumor suppressor protein p53 (P53)/cyclin-dependent kinase inhibitor 1A (P21)-induced senescence, measured by P53 bound to P21 gene promoter (ChIP), and greater expression of P21, interleukin 8, and monocyte chemotactic protein 1 mRNA (RT-PCR) in arteries from older adults compared with younger adults. Telomere uncapping was a highly influential covariate for the age-group difference in P53/P21-induced senescence.
Despite progressive age-related telomere shortening in human arteries, mean telomere length was not associated with telomere uncapping or P53/P21-induced senescence.
Collectively, these findings demonstrate that advancing age is associated with greater telomere uncapping in arteries, which is linked to P53/P21-induced senescence independent of telomere shortening.
Source: Innovita Research Foundation.