# MOLECULAR MECHANISMS IN SCLERODERMA--SCL-70/TOPO I

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 1990 · $130,284

## Abstract

Scleroderma is a disorder manifested by an overproduction of
dermal collagen, by a high frequency of chromosome breaks, and
by autoantibody production.  These seemingly unrelated
phenomena may be linked to the mechanism of action of Scl-70, a
topoisomerase I (topo I) which reacts with autobodies in
scleroderma. Like other topo I enzymes, which nick DNA and
stimulate transcription, Scl-70/topo I is activated by
phosphorylation.  Two major goals of this research are:  (a) to
investigate the relation between Scl-70/topo I activation,
chromosome breaks, and collagen gene expression in scleroderma,
and (b) to learn more about the mechanisms responsible for
increased collagen gene transcription.  A previously characterized
Scl-kinase and DNA footprinting and sequencing will be used to
investigate the effects of phosphorylation on the DNA binding
specificity of Scl-70/topo I.  Cultured fibroblasts will be employed
to determine if agents which increase or decrease procollagen
mRNA levels (serum factors and retinoids, respectively) also
affect levels of endogenous Scl-70/topo I phosphorylation.
Conversely, the effects of the topo I inhibitor camptothecin on
procollagen mRNA levels will be investigated by dot blot
hybridization.  DNase I-fractionated chromatin from scleroderma
fibroblasts and controls will be compared for differences in the
distribution, absolute levels and extent of phosphorylation of Scl-
70/topo I.  We will also look for increases in the DNase I
sensitivity of collagen genes in scleroderma chromatin.  Pulse
field gradient gel electrophoresis combined with Southern
blotting, hybridization with gene probes, and end-labeling
techniques will be employed to determine the extent of DNA
breakage and gene disruption in scleroderma.  Mobility shift
studies will be employed to determine if there are more topo I-
induced breaks in the collagen regulatory DNA of scleroderma
patients than normals.  Finally, restriction endonuclease mapping
will be performed to rule out collagen gene rearrangement.  These
in vitro studies will be corroborated by cytogenetic analysis.  The
proposed investigations will allow us to distinguish among several
possible mechanisms of collagen overproduction in scleroderma
and will provide evidence for or against a direct role for Scl-
70/topo I.  Based on the outcome of these studies it may be
possible to design more specific and effective therapies for this
disorder.

## Key facts

- **NIH application ID:** 3159654
- **Project number:** 5R01AR039554-03
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **SAM.gov UEI:** G88KLJR3KYT5
- **Principal Investigator:** ANGELINE DOUVAS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $130,284
- **Award type:** 5
- **Project period:** 1988-07-01 → 1992-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3159654

## Citation

> US National Institutes of Health, RePORTER application 3159654, MOLECULAR MECHANISMS IN SCLERODERMA--SCL-70/TOPO I (5R01AR039554-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3159654. Licensed CC0.

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