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Biomedical subjects

Chiara Giannarelli

Publications and source records attributed to Chiara Giannarelli.

2 recordsLinked to original sources

Multimodal atlas of human atherosclerosis links granular vascular cell states to coronary artery disease risk.

Advances in single-cell and spatial assays have revolutionized the scale and resolution of molecular tissue profiling. Here we present MetaPlaq, a multimodal atlas of human atherosclerotic arterial beds comprising over a million cells across single-cell transcriptomics, epigenomics and high-resolution spatial expression assays. We map granular cell states and disease-relevant transcriptional programs within the native tissue context of coronary arteries. Furthermore, we map cardiovascular GWAS signals to smooth muscle cells (SMCs) and endothelial cells (ECs) and uncover the cis-regulatory architecture governing their phenotypic transitions. Our comprehensive epigenomic reference allowed us to build cell-specific enhancer-gene link maps and multimodal gene regulatory networks (GRNs) underlying disease-relevant states such as osteogenic SMCs and ECs undergoing mesenchymal transition. We also integrate SMC and EC disease-associated gene sets with GRNs to nominate key transcription factors such as PRRX1, BNC2 and ELK3 regulating atherosclerosis-relevant transcriptional programs. Finally, we layer single-cell and spatial modalities to fine-map GWAS variants with improved cell and anatomical context. We highlight candidate cell-specific regulatory mechanisms at less characterized CAD loci, including FGD5 and MCF2L in ECs. Together, this atlas represents an important step towards fully interpreting genetic risk loci and informing new therapeutic strategies for cardiovascular disease.

Journal Article

Ischemic Injury Drives Nascent Tumor Growth Via Accelerated Hematopoietic Aging.

BACKGROUND: Patients with peripheral artery disease have an 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 and cancer, but their contributions to cardiovascular disease-driven tumor progression are unclear. OBJECTIVES: This study sought to study tumor growth after peripheral ischemia and consequent changes within the HSPC bone marrow compartment to uncover mechanisms through which altered hematopoiesis promotes cancer. METHODS: Mammary cancer (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 assay for transposase-accessible chromatin sequencing of bone marrow progenitors was performed to assess the distinct and synergistic transcriptomic and epigenetic changes of cancer and peripheral ischemia. 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. RESULTS: Peripheral ischemia increased monocyte and neutrophil output at the expense of lymphocytes, driven by a shift toward CD150hi myeloid-biased hematopoietic stem cells. This was associated with accelerated cancer growth and enrichment of tumors with myeloid cells (monocytes, macrophages, neutrophils) and regulatory T cells. Increased myelopoiesis was also supported by sequencing analyses showing HLI and tumor-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. CONCLUSIONS: Peripheral ischemia enhances inflammaging of hematopoietic stem cells and long-lasting alterations to antitumoral immunity, accelerating breast tumor growth.

bone marrow transplantation