Spinal cord injury causes chronic bone marrow failure

Area of Science:

• Immunology
• Hematology
• Neuroscience

Background:

• Spinal cord injury (SCI) is known to cause immune dysfunction, increasing susceptibility to infections.
• Bone marrow hematopoiesis is critical for maintaining a healthy immune system.

Purpose of the Study:

• To investigate the impact of SCI on bone marrow hematopoiesis.
• To determine if SCI disrupts the normal function and release of hematopoietic stem and progenitor cells (HSPCs).

Main Methods:

• Induction of SCI in a mouse model.
• Analysis of bone marrow hematopoietic stem and progenitor cell (HSPC) proliferation and egress.
• Administration of Plerixafor (AMD3100), a CXCR4 inhibitor, to assess HSPC mobilization.
• Competitive repopulation assays to evaluate long-term HSPC function.

Main Results:

• SCI leads to excessive proliferation of HSPCs in the bone marrow.
• HSPCs are sequestered in the bone marrow after SCI, failing to mobilize even with inflammatory stimuli.
• Plerixafor treatment successfully mobilizes HSPCs and mature immune cells.
• Despite mobilization, SCI mice exhibit impaired long-term functional capacity of HSPCs.

Conclusions:

• SCI induces an acquired bone marrow failure syndrome.
• This bone marrow failure, characterized by HSPC sequestration and functional impairment, may underlie chronic immune dysfunction post-SCI.