Bone Marrow Niche dysfunction in sickle cell disease

镰状细胞病的骨髓生态位功能障碍

• 批准号: 10250697
• 负责人: Nadia Carlesso
• 金额: $ 2.36万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-04 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10250697
• 关键词: Abnormal Hemoglobins; Acute Pain; Address; Affect; Age; American; Anemia; Biology; Biopsy; Blood flow; Bone Marrow; Bone Marrow Diseases; Bone Marrow Transplantation; Bone marrow biopsy; CD34 gene; Cells; Cellular Stress; Cessation of life; Chronic; Clinical; Coagulation Process; Data; Endothelial Cells; Engraftment; Enrollment; Erythrocytes; Exhibits; Frequencies; Functional disorder; Genes; Hematological Disease; Heterogeneity; Histologic; Human; IL8 gene; Immune; Infection; Inflammation; Inflammatory; Inherited; Interleukin-6; Intervention; Lead; Mesenchymal; Molecular; Molecular Analysis; Molecular Profiling; Morphology; NF-kappa B; Organ; Organ failure; Outcome; Oxidative Stress; Pain; Pain management; Pathway interactions; Patients; Phenotype; Population; Prevention; Process; Reperfusion Injury; Risk; Sampling; Severity of illness; Sickle Cell Anemia; Specimen; Stroke; TLR4 gene; Therapeutic; Time; Tissues; Transplantation; acute chest syndrome; base; chronic pain; curative treatments; cytokine; functional status; gene therapy; improved; insight; novel; novel therapeutic intervention; parent grant; premature; sickle vasoocclusion; single-cell RNA sequencing; transcriptome sequencing; transcriptomics

SUMMARY/ABSTRACT Background. Sickle cell disease (SCD) is the most common form of inherited blood disorder affecting approximately 100,000 Americans. Patients with SCD suffer from repeated red cell sickling and vaso-occlusion episodes, which, since early age, lead to acute and chronic pain, stroke, anemia, infections, organ failure and premature death. Vaso-occlusion episodes cause ischemia-reperfusion injury, activation of endothelial cells, immune cells and the coagulation cascade. These processes lead to a state of chronic inflammation in SCD, associated with increased pro-inflammatory cytokines and induction of TLR4/NF-kB activation and oxidative stress in all organs, including the bone marrow (BM). To date, little is known about how inflammation impacts the BM microenvironment and HSC functions in SCD. Notably, few and limited studies have been conducted on human samples. To address this gap, we will examine the impact of SCD in the molecular profile and functional status of bone marrow-resident cells. Preliminary results. We observed that SCD patients enrolled for transplant could be divided in two groups based on the frequency of CD34+ cells. Group 1 displayed reduced frequency of CD34+ population whereas group 2 exhibited higher or similar frequency when compared to controls. Single cell RNA-sequencing (scRNA-seq) of CD34+ enriched cells from one patient assigned in group 1 showed changes in the number of distinct cell populations and their transcriptomic profiles, with enrichment in pathway related to cellular stress. We also found that SCD BM-derived mesenchymal cells exhibit an inflammatory profile, compared to controls, characterized by increased expression of the proinflammatory related genes miR-155, miR-146a, IL-8, and IL-6 by qPCR. Furthermore, we observed that BM tissue biopsies of patients at pre-transplant show evidence of dysfunctional stroma. We hypothesize that a pro-inflammatory state induced by SCD alters the composition of the BM microenvironment and damages bone-marrow resident HSPC cells. Aims and Strategy. This study will be conducted on BM specimens of SCD patients (minimum n=10) prior HSCT and at different times after HSCT. To better understand the heterogeneity of SCD BM samples and correlate it with disease severity and clinical outcome after transplant, we propose an in-depth molecular analysis,which will be integrated with data from the parent grant. We will examine: i) the transcriptomic landscape of the HSCs in the BM of SCD patients by single cell RNA-sequencing (scRNA-seq); ii) determine the molecular pathways contributing to a pro-inflammatory phenotype in BM-derived mesenchymal cells by bulk RNA-seq, and iii) characterize the morphological and histological features in the BM biopsies of SCD patients. Relevance. This study represents a unique opportunity to better understand the biology of SCD in human specimens. It will also provide critical insights into the function of SCD CD34+ cells and the BM niche to explore new therapeutic approaches for improving current HSCT and gene therapy strategies.

摘要/文摘