# CONTROL OF BONE CELL AND CHONDROCYTE GROWTH AND FUNCTION

> **NIH NIH R01** · JEWISH HOSPITAL OF SAINT LOUIS · 1988 · $209,133

## Abstract

The overall goal of this research is to understand the regulation of bone
and cartilage cell growth and specialization.  Ongoing in vitro studies
using osteoblast-like cells and chondrocytes isolated from the calvaria of
rat fetuses as experimental models have yielded two observations which have
generated our present specific aims.  First, in testing the hypothesis that
cells of the monocyte-macrophage series regulate bone formation, we have
found that macrophages elaborate a bone cell and chondrocyte mitogenic
protein (macrophage-derived growth factor, MDGF).  Second, in exploring
possible mechanisms for the activation of bone remodeling, we found that
certain agents, including prostaglandins of the E series, cause acute
alterations in bone cell shape and cell-cell contact which may facilitate
activation and intercellular communication.  The specific aims of this
proposal extend each of these lines of inquiry.  We will:  a) undertake the
purification to homogeneity and characterization of MDGF from incubation
media conditioned by a macrophage-like cell line (monoclonal antibodies
will be prepared to MDGF, in order to aid in its purification, its
detection in cells and in biological fluids, and in understanding its mode
of action); b) study specific macrophage subtypes and macrophage-like cell
lines engaged in MDGF synthesis; c) explore the regulation of MDGF
synthesis by humoral agents (such as prostaglandins, glucocorticoids,
estrogens, 1 Alpha,25(OH)2 vitamin D3) and by non-humoral manipulations
(exposure to bone tissue and its components, and lymphokines); and d)
examine the nature of bone cell and chondrocyte responses to MDGF and the
effect of MDGF on bone resorption.  We will probe the mechanisms of and
relationships among bone cell shape change, collagenase production and gap
junction formation in response to osteotropic hormones.  These studies are
expected to enhance our knowledge of bone formation, remodeling and repair,
so crucial to understanding skeletal disease, and could lead to novel
strategies for disease prevention and treatment.

## Key facts

- **NIH application ID:** 3155083
- **Project number:** 5R01AR019855-11
- **Recipient organization:** JEWISH HOSPITAL OF SAINT LOUIS
- **Principal Investigator:** SU-LI CHENG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $209,133
- **Award type:** 5
- **Project period:** 1978-08-01 → 1989-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155083

## Citation

> US National Institutes of Health, RePORTER application 3155083, CONTROL OF BONE CELL AND CHONDROCYTE GROWTH AND FUNCTION (5R01AR019855-11). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155083. Licensed CC0.

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