# ROLE OF PHOSPHOLIPIDS IN MINERALIZATION OF OSTEOID

> **NIH NIH R01** · UNIVERSITY OF MIAMI SCHOOL OF MEDICINE · 1987 · $187,098

## Abstract

Continuation of our studies on the chain of events which leads to calcification
of growth plate cartilage is proposed.   Because of new ultramicro biochemical
methodology, we can now examine the interstitial hypertrophic cell cartilage
fluid as well as micro-dissected whole cartilage for the presence and type of
neutral proteases probably engaged hypothetically in degradation of
proteoglycans there, as well as to study the relationship of this process to
preliminary disaggregation of PG aggregate inhibitor by cartilage lysozyme.
Studies on activation of cartilage proteases or removal of an inhibitor as an
alternative will be sought.  The relationship of cartilage proteases to the
proteases brought in by capillary invasion will be studied.  All studies will be
made in 5 separate rat preparations which manifest expanded cartilage growth
plates.
A mineral forming agent already characterized in 2 forms of rickets will be
further purified from the top fifth fraction on capillary ultracentrifugation of
rachitic Cf1s.  Plans for analyzing proteins and phospholipids involved in the
nucleational factor are proposed.  The extremely high efficiency of the native
Cf1 nucleational agent suggests that isolated matrix vesicles or calcifying
phospholipids alone may not constitute the total apparatus involved in
nucleation.  The use of two-dimensional electrophoresis by new methods may
indicate association with other proteins.  It is possible that some of these
proteins are destroyed in two systems used for study, and if this is selective,
their additional role in the nucleational complex will be determined.  Further
evidence to refute or substantiate a role of matrix vesicles as the nucleating
agent per se in cartilage should be ascertained.  The opening of growth plate
functions in the remodelling cartilage of osteoarthritis, a common human
disease, make the finding of a regulator which could turn off the growth plate
function an eventual goal of clinical importance.

## Key facts

- **NIH application ID:** 3154674
- **Project number:** 5R01AR008662-23
- **Recipient organization:** UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
- **SAM.gov UEI:** F8THLJQSAF93
- **Principal Investigator:** DAVID S HOWELL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $187,098
- **Award type:** 5
- **Project period:** 1974-09-01 → 1989-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3154674

## Citation

> US National Institutes of Health, RePORTER application 3154674, ROLE OF PHOSPHOLIPIDS IN MINERALIZATION OF OSTEOID (5R01AR008662-23). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3154674. Licensed CC0.

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