# METABOLISM OF OSTEOARTHRITIC ARTICULAR CARTILAGE

> **NIH NIH R01** · TUFTS UNIVERSITY BOSTON · 1988 · $269,623

## Abstract

Osteoarthritis is a pathological condition characterized, in part, by an
excessive breakdown of the articular cartilage.  A decreased content and
reduced state of aggregation of proteoglycans, major components of this
tissue, are found early on in the disease process.  The purpose of the
described three related lines of investigation is directed toward a better
understanding of the regulation of proteoglycan metabolism.

The structure, biochemical properties, mechanisms of action, and the
systems of regulation of human cartilage arylsulfatases A and B will be
studied with specific reference to their role in proteoglycan catabolism.
Production of monospecific antibodies will allow development of an
immunoassay to quantitate and localize enzyme production and to determine
whether increased activities result from increased synthesis or
activation.  Conditions will be sought to increase enzyme production by
chondrocytes and thus permit the elucidation of their primary sequence with
the use of recombinant DNA techniques.  In this way, it will be possible to
compare their enzymology in normal and osteoarthritic cartilage.

We have shown that proteoglycans from human articular cartilage are
phosphorylated on serine residues of the core protein.  The location of
phosphoserine sites along this protein core, the "in vitro" rates of
phosphorylation, and the number of phosphoserine residues per subunit will
be determined and compared in normal and osteoarthritic cartilage.  The
phosphorylating and dephosphorylating enzymes present in cartilage will be
isolated and characterized.  The role of phosphorylation on aggregate
formation, chain termination and catabolism via endocytosis will be tested
with a view to defining how phosphorylation modulates proteoglycan
metabolism.

The development of the application of HPLC to the study of proteoglycans
will be continued.  Various combinations of stationary and mobile phases
will be tested to achieve efficient separation of proteoglycan monomers and
aggregates as well as other cartilage matrix components from each other.

Findings from these studies should increase our knowledge of cartilage
metabolic regulation and thus facilitate early diagnosis and provide a
rationale for non-surgical therapy in osteoarthritis.

## Key facts

- **NIH application ID:** 3155236
- **Project number:** 5R01AR022057-11
- **Recipient organization:** TUFTS UNIVERSITY BOSTON
- **SAM.gov UEI:** C1F5LNUF7W86
- **Principal Investigator:** EDITH RICHMOND SCHWARTZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $269,623
- **Award type:** 5
- **Project period:** 1978-02-01 → 1989-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155236

## Citation

> US National Institutes of Health, RePORTER application 3155236, METABOLISM OF OSTEOARTHRITIC ARTICULAR CARTILAGE (5R01AR022057-11). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155236. Licensed CC0.

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