# COMPLEMENT EXPRESSION IN ALZHEIMER'S DISEASE BRAIN

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 1991 · $138,236

## Abstract

Complement Expression in Alzheimer's Disease Brain.  This project addresses
the role of the complement (C) system, a major cytotoxic arm of the immune
system, in degenerative and regenerative processes in the brain.  Recent
immunohistochemical evidence demonstrates activated C components associated
with senile plaques, dystrophic neurites and neurofibrillary tangles in AD
brain.  We found several C component mRNAs up-regulated in AD brain,
including SGP-2/CLI, an inhibitor of the C5b-9 membrane attack complex.
Our evidence also shows up-regulation of C1q and C4 and SGP-2/CLI mRNAs in
afferent target sites after deafferenting lesions of rat brain.  These
results suggest involvement of the complement system in Alzheimer pathology
and brain injury response.

Study 1 identifies the C expressing brain cell types and determine whether
C expression correlates with AD brain pathology.  Comparison with rodent
brain lesions addresses the hypothesis that C has a role in AD
neurodegeneration.

Study 2 uses afferent transection and peripheral kainate brain lesion
models to investigate C in cell death and synaptic remodeling processes in
hippocampus.  Afferent transection lesions produce neurodegeneration and
reactive synaptogenesis in distinct sites, allowing examination of both
processes in the same animal.

Study 3 investigates the in vivo effect on C gene expression of amyloid
beta/A4 peptide/purified AD amyloid injection into rat brain.  We will test
the hypothesis that amyloid can activate C (induce C mRNAs, stimulate MAC
production and attract inflammatory cells) and promote neurotoxicity.

Study 4 determines whether responses of the complement system to afferent
pathway transection and b-amyloid peptide/fibril injection vary with the
age of the animal.  Aged humans have elevated serum C which may impinge
upon ability of brain to respond to neurodegeneration.

## Key facts

- **NIH application ID:** 3122605
- **Project number:** 1R01AG010673-01
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **SAM.gov UEI:** G88KLJR3KYT5
- **Principal Investigator:** STEVEN A JOHNSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $138,236
- **Award type:** 1
- **Project period:** 1991-09-29 → 1994-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3122605

## Citation

> US National Institutes of Health, RePORTER application 3122605, COMPLEMENT EXPRESSION IN ALZHEIMER'S DISEASE BRAIN (1R01AG010673-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3122605. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*