# Bone Marrow Niche dysfunction in sickle cell disease

> **NIH NIH R01** · BECKMAN RESEARCH INSTITUTE/CITY OF HOPE · 2021 · $23,626

## Abstract

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 ...

## Key facts

- **NIH application ID:** 10250697
- **Project number:** 3R01HL146632-02S1
- **Recipient organization:** BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
- **Principal Investigator:** Nadia Carlesso
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $23,626
- **Award type:** 3
- **Project period:** 2021-02-04 → 2022-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10250697

## Citation

> US National Institutes of Health, RePORTER application 10250697, Bone Marrow Niche dysfunction in sickle cell disease (3R01HL146632-02S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10250697. Licensed CC0.

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