Exploration of HSPC aging mechanism based upon in vitro cell modeling and MDS clinical sampling

Abstract:Background The pathogenetic mechanisms of Myelodysplastic Syndromes (MDS) were undefined. Hematopoietic senescence was manifested by association with malignant myeloid blood diseases, aging and immune dysfunction. Hematopoietic stem/progenitor cell (HSPC) aging was the primary determinant of hematopoietic senescence.MethodsIn current study, we used an in vitro HSPC aging mouse model that readily enabled the gather of a large number of aging HSPCs. The followed studies covered mRNA splicing and epigenetics (H3K27me3) relevant to HSPC aging, with methods such as Cut-tag, SA-β-gal assay, CFU-mix assay, RNA-seq, and RNAi knock down (KD). ResultsThe results showed that HSPC aging associated down-regulation of SR and hnRNPs family genes and mRNA splicing inhibitor (SSA) elicited HSPC aging-like phenotype. Cut-tag assay demonstrated that HSPCs aging was linked to global decline in H3K27me3 levels, which however, was systemically up-regulated in occupying the promoter of SR family and hnRNPs family genes. In addition, HSPCs aging exhibited alterations in the splicing patterns of TSS and SKIP.ConclusionsTogether, we proposed the linkages of HSPCs aging with epigenetic repression of SR and HnRNPs genes and inhibition of mRNA splicing pathway to alter TSS and SKIP-relevant alternative splicing. Our study provided insights to the etiopathology of MDS by exposing its connections to HSPC aging.