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Cahill, C.

Publications and source records attributed to Cahill, C..

3 recordsLinked to original sources

Distinct senescent β-cell senotypes differentially drive islet aging and dysfunction

Biological aging greatly impacts the bodys 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 {beta}-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.

cell biology↗

Brief report on the development of patient-derived lung cancer organoids with keratinizing squamous cell carcinoma morphology

IntroductionNovel therapeutic options are urgently required to improve outcomes and survival for patients with lung squamous cell carcinoma (LUSC). In particular, understanding the unique histological features that define LUSC is essential to improving lung cancer mortality. Many pre-clinical models fail to accurately represent intratumour heterogeneity and recapitulate the tumour microenvironment. This is partly responsible for the poor translation of clinical findings to approved therapies. Our objective was to investigate whether patient-derived organoids, replicate the histological morphological, and structural features of keratinizing LUSC, a poor prognostic subtype of lung cancer. MethodsOrganoid cultures were established and maintained from two patients presenting with keratinizing lung squamous cell carcinomas. Immunofluorescent staining of individual organoids and confocal microscopy was performed to confirm expression of tumour markers. Whole organoid domes were fixed, and immunofluorescent staining and imaging was performed to investigate the structural features of the organoid cultures. Findings were compared with histopathological features of the original tumour tissue. ResultsPatient-derived organoids expressed tumour markers specific to the squamous cell carcinoma subtype of non-small cell lung cancer, which were confirmed to be expressed in the parent tissue. Within organoid cultures, keratin pearl structures spontaneously developed, matching the keratinizing pattern demonstrated by hematoxylin and eosin staining of the original tumour. ConclusionsPatient-derived organoids have the capability to replicate key histological features of their parent tumour. This high degree of fidelity makes these 3D models an important and valuable tool for understanding complex tumour biology and as a platform for preclinical drug testing to advance novel therapies into the clinic.

cancer biology↗

A human and mouse subpopulation of senescent β-cells induces pathologic dysfunction through targetable paracrine signaling

Cellular senescence is a stress response mechanism marked by irreversible growth arrest, upregulation of antiapoptotic pathways, loss of cellular function, and remodelling of the cellular secretory profile. In both humans and mice, pancreatic {beta}-cells undergo senescence with age and insulin resistance. Targeted removal of senescent cells in mouse models of diabetes improves glucose homeostasis, demonstrating the role {beta}-cell senescence in diabetes progression. In contrast, {beta}-cell senescence also promotes immune surveillance, promoting {beta}-cell survival and function. Thus, a better understanding of senescent cells phenotypic and functional heterogeneity is needed to develop effective therapeutic strategies. Herein, we show that subpopulations of senescent {beta}-cells in mice and humans, which were identified through the expression of Cdkn1a (encoding p21Cip1) and Cdkn2a (encoding p16Ink4a) by single-cell RNA sequencing (scRNA-seq), flow cytometry, spatial transcriptomics, and spatial proteomics, exhibit distinct transcriptional and functional identities. The predominant senescent {beta}-cell subpopulation expressed Cdkn1a and was characterized by a lack of glucose responsiveness, high basal insulin secretion, and transcription of canonical SASP factors. The SASP of Cdkn1a-expressing {beta}-cells had non-cell autonomous effects on neighbouring cells. A subset of four SASP factors from Cdkn1a+ cells was sufficient to induce secondary senescence and {beta}-cell dysfunction in vitro. JAK inhibitors (JAK1/2 and JAK1/3) counteracted secondary senescence induction and restored {beta}-cell function in high-fat diet-fed mice and human islets from donors with or without type 2 diabetes. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=196 SRC="FIGDIR/small/648438v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@9b8addorg.highwire.dtl.DTLVardef@1b9c4eborg.highwire.dtl.DTLVardef@12f2964org.highwire.dtl.DTLVardef@1468297_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗