# Mechanisms and consequences of sickle cell disease-induced cycling in hematopoietic stem cells

> **NIH NIH F32** · ST. JUDE CHILDREN'S RESEARCH HOSPITAL · 2022 · $67,582

## Abstract

Project Summary
Sickle cell disease (SCD) is a painful debilitating life-long condition resulting from mutations in the gene encoding
hemoglobin β subunit, causing abnormal hemoglobin polymerization leading to hemolysis, repeated
vasooclusion, and chronic systemic inflammation resulting in substantial global morbidity and early mortality.
Curative therapy for SCD relies on hematopoietic stem cell (HSC) transplantation, however the damaging effects
of SCD pathophysiology on HSCs remain uncharacterized and we seek to fill this gap in current knowledge. Our
preliminary studies show that HSCs display increased cycling in a transgenic SCD mouse model upon aging,
and myeloid lineage biased in vitro differentiation of SCD patient derived HSCs. As a postdoctoral fellow in the
McKinney-Freeman laboratory, I will investigate the functional consequences and molecular mechanisms
underlying SCD mediated HSC cycling in a murine model and translate these findings to human HSC during
SCD. In Aim 1, I will use colony formation assays, limiting dilution primary and secondary HSC transplantation,
and serial exposure to chemotherapy to assess the detrimental impact of SCD-induced cycling on HSC
frequency and function. In Aim 2, I will probe the molecular and epigenetic dysregulation underlying increased
HSC cycling during SCD. HSCs isolated from SCD and control mice will be subjected to bulk RNA-seq and
ATAC-seq to define transcriptional dysregulation correlated with changes in gene promoter accessibility
meditating increased cycling. Finally, I will translate our findings to humans by interrogating cell cycle
dysregulation in HSCs isolated from SCD patients (Aim 3). SCD patient-derived bone marrow aspirates will be
profiled for frequency of phenotypic HSCs and alterations in cell cycle status by flow cytometry and ex vivo EdU
incorporation. Lineage potential and hematopoietic output of SCD HSCs will be analyzed by colony formation
and in vitro single HSC differentiation assays. Lastly, SCD HSC repopulating potential and self-renewal will be
examined by limiting dilution primary and secondary transplantation into human cytokine expressing immune
deficient mice. Together the proposed studies serve to deepen our understanding of a previously unexplored
aspect of HSC biology by examining the impact of SCD. Greater understanding of SCD mediated mechanisms
of HSC impairment become exceptionally important as autologous HSC transplantation following gene editing
or gene therapy for SCD improve and increase in frequency. These aims draw on my prior training in cancer
biology of hematologic malignancies but also provide abundant novel training opportunities in the field of HSC
biology and for professional career development. The McKinney-Freeman lab and St. Jude Children’s Research
Hospital are ideal environments in which to receive training in the study HSC biology, combining state-of-the-art
institutional resources, career development resources, and excellent mentorship wi...

## Key facts

- **NIH application ID:** 10464657
- **Project number:** 1F32HL164095-01
- **Recipient organization:** ST. JUDE CHILDREN'S RESEARCH HOSPITAL
- **Principal Investigator:** Aditya Shirish Barve
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $67,582
- **Award type:** 1
- **Project period:** 2022-04-01 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10464657

## Citation

> US National Institutes of Health, RePORTER application 10464657, Mechanisms and consequences of sickle cell disease-induced cycling in hematopoietic stem cells (1F32HL164095-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10464657. Licensed CC0.

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