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Biology subjects

McDonnell, C.

Publications and source records attributed to McDonnell, C..

3 recordsLinked to original sources

Tumor Cell Death Drives Tumor-Promoting IL-6+ iCAF formation via P2X7-activation

Chemotherapy resistance in pancreatic ductal adenocarcinoma is commonly attributed to tumor cell-intrinsic mechanisms, yet how cytotoxic therapy reshapes the tumor microenvironment remains incompletely understood. Here we show that PDAC cells exposed to cytotoxic agents reprogram pancreatic stellate cells toward an inflammatory cancer-associated fibroblast phenotype. Mechanistically, chemotherapy triggers the release of ATP from dying PDAC cells, which activates P2X7 signaling in PSCs in a paracrine manner, leading ERK activation and inflammatory polarization. In turn, therapy-educated PSCs promote tumor cell proliferation, induce resistance-associated transcriptional programs and impair CD8 T cell-mediated cytotoxicity in an IL-6-dependent manner. Pharmacological inhibition of P2X7 suppressed stromal IL-6 induction and enhanced gemcitabine efficacy in vivo. These findings identify a therapy-induced ATP-P2X7-IL-6 axis that links tumor cell death to stromal reprogramming and adaptive resistance in PDAC.

cancer biology↗

Impaired Macrophage DNase Secretion Promotes Neutrophil Extracellular Trap Mediated Defective Efferocytosis in Atherosclerosis

Neutrophil extracellular traps (NETs) drive atherosclerosis progression and are associated with adverse clinical outcomes like myocardial infarction and stroke. While the triggers of NETosis in atherosclerotic plaque are well-characterized, the mechanisms underlying NET degradation and clearance remain unclear. Moreover, the impact of impaired NET clearance on atherosclerosis progression have not been elucidated. Here we show that macrophages are critical for the release of DNases, which degrade NETs. We identified endoplasmic reticulum (ER) stress mediated activation of PERK-ATF4 pathway as a key driver of impaired macrophage DNase secretion, leading to delayed NET clearance and their persistence. Elevated NET levels trigger cleavage of the efferocytosis receptor Mertk leading to defective macrophage efferocytosis and exacerbation of plaque necrosis. Human atherosclerotic plaques and Ldlr-/- mice treated with ISRIB, a PERK inhibitor, show enhanced DNase secretion and clearance of NETs. Together, the identification of key mechanisms of NET clearance in atherosclerosis offers new therapeutic strategies to stabilize plaques.

pathology↗

Using genetics to disentangle the complex relationship between food choices and health status

Despite food choices being one of the most important factors influencing health, efforts to identify individual food groups and dietary patterns that cause disease have been challenging, with traditional nutritional epidemiological approaches plagued by biases and confounding. After identifying 302 individual genetic determinants of dietary intake in 445,779 individuals in the UK Biobank study, we develop a statistical genetics framework that enables us, to directly assess the impact of food choices on health outcomes. We show that the biases which affect observational studies extend also to GWAS, genetic correlations and causal inference through genetics, which can be corrected by applying our methods. Finally, by applying Mendelian Randomization approaches to the corrected results we identify some of the first robust causal associations between eating patterns and cancer, heart disease, obesity, and several other health related risk factors, distinguishing between the effects of specific foods or dietary patterns.

genetics↗