van Solingen, C. | bioRxiv Science

bioRxiv2025

Ischemic Injury Drives Tumor Growth via Accelerated Hematopoietic Aging

BackgroundPatients with peripheral artery disease have increased risk of cancer development. Aging-associated changes in hematopoietic stem and progenitor cells (HSPCs), including inflammation and increased myelopoiesis, are implicated in both cardiovascular disease (CVD) and cancer, but their contributions to CVD-driven tumor progression are unclear. ObjectivesTo study cancer growth following peripheral ischemia and consequent changes within the HSPC bone marrow compartment to uncover mechanisms through which altered hematopoiesis promotes oncogenesis. MethodsMammary cancer cell (E0771) growth was monitored in C57BL/6J mice after hind limb ischemia (HLI) or sham surgery. The tumor immune microenvironment, circulatory immune cells, and HSPC compartment were assessed by flow cytometry. Next-generation single-cell RNA and ATAC sequencing of HSPCs was performed to assess transcriptomic and epigenetic changes. The functional impact on tumor progression and persistence of ischemia-induced epigenetic reprogramming of HSPCs and their myeloid progeny was examined by bone marrow transplantation. ResultsPeripheral ischemia increased monocyte and neutrophil output at the expense of lymphocytes, driven by a shift toward CD150hi myeloid-biased hematopoietic stem cells (HSCs). This was associated with accelerated breast cancer growth and increased accumulation of tumoral immunosuppressive regulatory T cells and monocytes. Increased myelopoiesis was also supported by multiomic analyses showing HLI-induced transcriptional and epigenetic enrichment for inflammatory (NLRP3 inflammasome) and aging-associated (Neogenin-1, Thrombospondin-1) signatures in subsets of monocyte/dendritic progenitors. HLI-accelerated tumor growth and myeloid-skewing was transmissible via bone marrow transplantation, indicating long-term reprogramming of innate immune responses. ConclusionsPeripheral ischemia promotes inflammaging of HSCs and long-lasting alterations to anti-tumoral immunity, accelerating breast tumor growth.

immunology↗

bioRxiv2025

Cell Type-Specific and Diabetic Kidney Disease-Associated Expression of Long Non-Coding RNAs in Human Kidneys

BackgroundLong non-coding RNAs (lncRNAs) play essential roles in cellular processes, often exhibiting cell type-specific expression and influencing kidney function. While single-cell RNA sequencing (scRNA-seq) has advanced our understanding of cellular specificity, past studies focus solely on protein-coding genes. We hypothesize that lncRNAs, due to their cell-specific nature, have crucial functions within particular renal cells and thereby play essential roles in renal cell function and disease. MethodsUsing single-nucleus RNA sequencing (snRNA-seq) data from kidney samples of five healthy individuals and six DKD patients, we explored the non-coding transcriptome. Cell type-specific lncRNAs were identified, and their differential expression in DKD was assessed. Integrative analyses included expression quantitative trait loci (eQTL), genome-wide association studies (GWAS) for estimated glomerular filtration rate (eGFR), and gene regulatory networks. Functional studies focused on TARID, a lncRNA with podocyte-specific expression, to elucidate its role in podocyte health. Resultswe identified 349 lncRNAs with cell type-specific expression across kidney cell types. Of these, 104 lncRNAs were differentially expressed in DKD. Integrative analyses, including eQTL data, GWAS results for eGFR and gene regulatory networks, pinpointed TARID, a podocyte-specific lncRNA, as a key candidate upregulated in DKD. Functional studies confirmed TARIDs podocyte-specific expression and revealed its central role in actin cytoskeleton reorganization, a critical process in podocyte health. ConclusionsOur study provides a comprehensive resource of single-cell lncRNA expression in the human kidney and highlights the importance of cell type-specific lncRNAs in kidney function and disease. Specifically, we demonstrate the functional relevance of TARID in podocyte health. This work underscores the utility of integrating scRNA-seq with functional genomics to uncover novel regulatory mechanisms in kidney biology. Key pointsO_LIThis provides a resource for kidney (cell type-specific) lncRNA expression and demonstrates the importance of lncRNAs in renal health. C_LIO_LIWe identified 349 cell type-specific lncRNAs in the human kidney, with 104 showing altered expression in diabetic kidney disease (DKD). C_LIO_LITARID, a podocyte-specific lncRNA upregulated in DKD, is crucial for actin cytoskeleton reorganization in podocytes. C_LI

bioinformatics↗