Citations

ABSTRACT Biological aging greatly impacts the body’s ability to handle glucose, and represents a major risk factor the development and progression of type 2 diabetes (T2D). Nonetheless, despite advances in cellular senescence research and the development of new senolytic therapies, the heterogeneity of cellular senescence in the human endocrine pancreas, as well as its roles in normal aging, remains to be elucidated at the single-cell level. Here, we performed single-cell–resolved spatial proteomics and transcriptomics on intact pancreas from 26 donors (ages 20–80) and multiplexed single-cell RNA sequencing and functional assays on dispersed islets from 14 donors (ages 34–69). We identify two discrete SnC subpopulations distinguished by relative expression of CDKN1A and CDKN2A. CDKN1A ⁺ senescent cells (SnCs) exhibit loss of β-cell identity, impaired insulin secretion, and a proinflammatory SASP associated with increased islet immune infiltration. In contrast, CDKN2A ⁺ SnCs retain transcriptional identity and functional competence, with lower inflammatory signaling. Together, these findings identify heterogeneous and functionally divergent senotypes in the human pancreas, distinguishing an adaptive ( CDKN2A ⁺) from a maladaptive ( CDKN1A ⁺) senescence program, thus providing a mechanism-guided framework for senescence-targeted therapies in T2D.

Clonal acquisition of multiple chromosomal abnormalities in hematopoietic stem and progenitor cells (HSPCs) is a hallmark of high-risk acute myeloid leukemias with complex karyotype (AML-CK). AML-CK is associated with TP53 mutations and chromosome 5q deletions (del5q); however, the drivers and clonal trajectories of aneuploid evolution in HSPCs remain unknown. We have developed a patient-derived induced pluripotent stem cell (iPSC) model in which preleukemic HSPCs clonally evolve to distinct, highly aneuploid states following transient mitotic inhibition. By tracking chromosome evolution at single cell resolution, we show that TP53-mutant HSPCs with del5q, but not TP53­ mutation alone, evolved complex chromosomal changes. Clonal evolution was marked by stepwise acquisition of numerical and structural chromosome changes seen in AML-CK patients, with individual abnormalities conferring fitness advantage. iPSC-derived aneuploid HSPCs and primary AML-CK patient samples exhibited a conserved gene expression signature marked by upregulation of PTEN, cohesins, and anti-apoptotic factor BCL2, indicative of a shared aneuploid cell state in HSPCs. Clinical BCL2 inhibitor venetoclax eradicated BCL2-dependent aneuploid clones, with resistant clones undergoing a lineage switch to upregulate alternative BCL2 factors. In summary, we demonstrate that mutant TP53 and del5q drive chromosome evolution marked by stepwise acquisition of individual abnormalities. Moreover, aneuploid HSPCs exhibit a shared gene expression state which confers unique targetable therapeutic vulnerabilities in AML-CK.