# Mechanisms Regulating Formation and Growth of Articular Cartilage

> **NIH NIH F32** · CHILDREN'S HOSP OF PHILADELPHIA · 2020 · $67,446

## Abstract

Project Summary/Abstract
Synovial joints are essential for full range of motion and quality of life. Each joint is uniquely shaped to fit
specific anatomical sites and permit relevant body movement and function. Unfortunately, the joints -and
articular cartilage in particular- are highly susceptible to congenital-, injury- and age-related diseases that
affect their structure and function, also a reflection of poor intrinsic joint repair capacity. In addition, current
clinical interventions do not meet the wide range of demands on articular cartilage in vivo due, in large part, to
lack of crucial knowledge on the mechanisms that govern normal growth and structure of the tissue. In order to
advance these strategies, more information is needed on basic mechanisms of articular cartilage development,
growth and morphogenesis. Were such information available, it would inform the improvement of clinical
intervention, and bioengineering and gene therapy strategies as has been accomplished in disease- and injury-
related treatment of many other human tissues. Articular cartilage is uniquely organized and displays distinct
zones each providing specific and important functions for the synovial joint: (i) surface zone cells secrete
lubricants into the joint cavity; (ii) deep zone cells are organized in columns to resist compressive loads; and
(iii) a calcified cartilage zone provides attachment of the tissue to the underlying bone. Little is known about
the mechanisms that drive this specific organization. Recent work from my sponsor and colleagues has
improved our understanding of postnatal articular development using genetic lineage-tracing tools in mouse
models. The data show that cell proliferation plays a more minor role in articular cartilage postnatal growth
than previously thought and suggest, instead, that cell translocation and realignment are major drivers of
growth and organization. Based on the results from these novel studies, I hypothesize that articular cartilage
formation and growth mechanisms are primarily driven by cell intercalation and realignment into stacks and
columns, permitting tissue thickening and organization. To test this hypothesis, in Aim 1 I will examine the
spatio-temporal expression patterns of genes relevant to, and regulating, cell intercalation and alignment
mechanisms. In Aim 2 I will test the function of core components of these pathways that have proven critical
for organization and growth in other tissue contexts. I will use multiple analytical tools including
histomorphometry, in situ hybridization, confocal imaging and cell culture in combination with mouse
transgenic approaches. The proposed studies will provide essential knowledge on mechanisms that underlie
the acquisition of articular cartilage structure and function. The data and insights from the project will prove
essential to envision and test future therapeutic joint strategies, providing broad relevance and importance to
the project and offering a powerfu...

## Key facts

- **NIH application ID:** 10001438
- **Project number:** 5F32AR074227-03
- **Recipient organization:** CHILDREN'S HOSP OF PHILADELPHIA
- **Principal Investigator:** Danielle Renae Rux
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $67,446
- **Award type:** 5
- **Project period:** 2018-09-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10001438

## Citation

> US National Institutes of Health, RePORTER application 10001438, Mechanisms Regulating Formation and Growth of Articular Cartilage (5F32AR074227-03). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10001438. Licensed CC0.

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