# Role of NF-kB in sympathetic hyperreflexia after spinal cord injury

> **NIH NIH F31** · DREXEL UNIVERSITY · 2021 · $46,036

## Abstract

PROJECT SUMMARY / ABSTRACT
 Cardiovascular disease and immune dysfunction are the two leading causes of morbidity and mortality
in individuals with high-level spinal cord injuries (SCI). This is primarily due to the development of sympathetic
hyperreflexia, which is immediately apparent as an episode of autonomic dysreflexia (AD). AD is a condition
occurring in up to 90% of patients with SCI above thoracic segment 6 that is characterized by life-threatening
hypertension and reflexive bradycardia in response to below-level noxious sensory input. The frequency and
severity of AD episodes progressively increase over time and contribute to increased risk for life-threatening
infections, myocardial infarction, and stroke. The progressive exacerbation of sympathetic hyperreflexia is
thought to be due to maladaptive plasticity within the spinal sympathetic reflex (SSR) circuit which contributes to
heightened sensitivity and exaggerated sympathetic output to critical effector organs, such as vasculature and
the spleen. This neurogenic sympathetic hyperreflexia thereby impairs peripheral immune function and
contributes to systemic immunosuppression that further propagates infection susceptibility. Limiting SSR circuit
plasticity and the development of sympathetic hyperreflexia could therefore have enormous therapeutic
implications in mitigating injury-induced immunosuppression and greatly improve quality of life in individuals with
SCI. Interestingly, the neuroimmune system is implicated as a major underling factor that contributes to the
development of SSR circuit plasticity. Specifically, continued activation of resident microglia local and remote to
the injury site is associated with the production of various proinflammatory cytokines, including soluble tumor
necrosis factor-alpha (sTNFα), that are known to modulate neural circuits. Despite long-term inhibition of sTNFα
after SCI, microglia continue to exhibit a reactive phenotype and there is persistent activation of NF-kB, a
transcription factor complex that is activated by multiple cytokines, well below the SCI. This suggests that reactive
microglia continue to produce a variety of cytokine factors in addition to sTNFα, which continue to activate NF-
kB and thereby establish a pro-inflammatory autocrine loop. Furthermore, NF-kB has been implicated as a key
mediator in chronic inflammatory disorders, such as rheumatoid arthritis, and directly contributes to synaptic and
cellular plasticity. This proposal will focus on the hypothesis that activation of NF-kB after SCI contributes to
driving SSR circuit plasticity that results in the development of sympathetic hyperreflexia and associated AD, as
well as peripheral immune dysfunction. Moreover, we hypothesize that microglial NF-kB signaling alters neuronal
excitability within the SSR circuit. The primary goals of this proposal are to: 1) investigate the role of NF-kB
signaling in the development of sympathetic hyperreflexia (indicated by AD) and resulta...

## Key facts

- **NIH application ID:** 10234288
- **Project number:** 1F31NS118841-01A1
- **Recipient organization:** DREXEL UNIVERSITY
- **Principal Investigator:** Micaela Lucy O'Reilly
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $46,036
- **Award type:** 1
- **Project period:** 2021-04-01 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10234288

## Citation

> US National Institutes of Health, RePORTER application 10234288, Role of NF-kB in sympathetic hyperreflexia after spinal cord injury (1F31NS118841-01A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10234288. Licensed CC0.

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