PML2‐mediated thread‐like nuclear bodies mark late senescence in Hutchinson–Gilford progeria syndrome [RNA-seq]

Regular nuclear structure is critical for genome maintenance and proper gene expression, disorder of which has a causal role in aging. Accumulation of Progerin in Hutchinson-Gilford progeria syndrome (HGPS) disrupts the integrity of nuclear lamina and causes nuclear structure abnormalities, leading to premature aging. However, the nuclear structure/function relationships in HGPS cells have not been well addressed, and roles of nuclear sub-compartments for HGPS pathogenesis are rarely reported. Here, evidence reveals that classical dot-like PML nuclear bodies (PML NBs) are reorganized into thread-like morphology in HGPS cells, and these irregular NBs are strongly associated with cell senescence. We demonstrate that farnesylated Progerin interacts with PML isoform 2 specifically, which accounts for the formation of thread-like PML NBs. Moreover, our findings uncover that irregular PML NBs perturb NBs-associated DNA repair and gene transcription, thereby promoting HGPS cell senescence. Thus, our work helps to clarify the roles of nuclear structure and sub-compartments such as PML NBs in cell aging, and evidence presented in this study strongly support that thread-like PML NBs could be a novel biomarker of human cell senescence. Normal human dermal fibroblasts (NHDF) were transfected with control siRNA (NFcon) or pan-PML siRNA (NFsi) to analyze the expression of PML NBs-associated genes in NHDF cells. Fibroblasts from the Hutchinson-Gilford progeria syndrome (HGPS) patient were treated with control siRNA (HGcon), pan-PML siRNA (HGsi), PML2 siRNA (HGI2si), or FTI (2 uM of farnesylation inhibitor lonafarnib combined with 1 uM of zoledronate, HGFTI) for 3 days. High-throughput RNA sequencing were performed to analyze the differential gene expression between HGPS and NHDF, and to examine the 'rescue effect' of pan-PML siRNA, PML2 siRNA or FTI treatment on expression of PML NBs-associated genes in HGPS cells. Thus, there are total 6 groups of samples for RNA-seq, ie., NFcon, NFsi, HGcon, HGsi, HGI2si and HGFTI. Each group contains 3 replications, and siRNA sequence information was described in the supporting data of the manuscript.