Cartilage injury and destruction affects over 46 million Americans and is the leading cause of disability in the US. Available clinical therapies include growth factor injection, microfracture, osteochondral autograft transfer, or chondrocyte implantation. However, current therapies are limited by inconsistent efficacy, long recovery times, chondrocyte dedifferentiation during in vitro expansion, and/or donor site morbidity. For example, while microfracture can induce cartilage defect coverage, the tissue formed is a functionally inferior fibrocartilage. Meanwhile, known chondrogenic signaling factors such as bone morphogenetic proteins (BMPs) or transforming growth factor (TGF)-?s also induce undesirable fibrogenesis and osteogenesis. We propose to utilize Nel-like molecule-1 (NELL-1), a differentiation factor with novel, cell- and stage- specific chondrogenic properties. NELL-1 is normally expressed in articular cartilage, and its loss results in abnormal cartilage formation. Remarkably, NELL-1 induces chondrogenic differentiation in both MSC and mature chondrocytes, prevents dedifferentiation, and induces hyaline cartilage formation without mineralization or fibrosis. This has led to our central hypothesis that optimizing NELL-1 formulation/delivery will promote increased chondrogenic differentiation and phenotypic maintenance with increased hyaline cartilage formation rather than fibrocartilage in cartilage injury models. To test this, we propose the following aims:
AIM 1. Optimize NELL-1 formulation and delivery for chondrogenesis.
Our AIM 1 working hypothesis is that optimized NELL-1 bioactivity via PEGylation and controlled release, coupled with a highly conformable, adherent, photocrosslinked hydrogel delivery system, when tested in vitro or in vivo in rabbits, will improve chondrogenic differentiation and function with increased hyaline cartilage formation and superior mechanical properties compared to our published data using a chitosan-based NELL-1 delivery system in rabbit articular subchondral defects.
AIM 2. Define the role of NELL-1 in chondrogenic differentiation and phenotypic maintenance. Our data show that NELL-1 bioactivity exhibits cell-type and stage-specific effects. For example, NELL-1 requires canonical Wnt signaling activation for osteogenesis, but not necessarily chondrogenesis. Meanwhile, NELL-1 requires Indian Hedgehog (Ihh) signaling for chondrogenic effects.
Our AIM 2 working hypothesis is that chondrogenic determination, differentiation and phenotypic maintenance requires coordinated interplay between NELL-1 and Ihh and/or Wnt signaling pathways in chondrocytes and/or chondroprogenitor cells.
AIM 3. Determine NELL-1's efficacy in a large animal microfracture model.
Our AIM 3 working hypothesis is that an optimized NELL-1 formulation with PEGylation, controlled release, and photocrosslinked hydrogel will effectively regenerate more hyaline cartilage with superior mechanical properties than TGF-?3 or microfracture alone in both load and non-load bearing articular knee defects in sheep.

Public Health Relevance

Cartilage injury and arthritic joint destruction is the leading cause of disability in the US, afflicting over 46 million Americans. To address the biomedical burden of such injuries, we will investigate an innovative, cartilage growing growth factor, NELL-1, that we have optimally formulated to promote cartilage repair. If successful, this therapy will be highly translational for the early treatment of cartilage injuries to reduce the likelihood of progressive cartilage injury and development of osteoarthritis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
1R01AR068835-01A1
Application #
9041431
Study Section
Musculoskeletal Tissue Engineering Study Section (MTE)
Program Officer
Wang, Fei
Project Start
2015-09-17
Project End
2020-08-31
Budget Start
2015-09-17
Budget End
2016-08-31
Support Year
1
Fiscal Year
2015
Total Cost
$367,638
Indirect Cost
$128,912
Name
University of California Los Angeles
Department
Surgery
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Li, Chenshuang; Zheng, Zhong; Jiang, Jie et al. (2018) Neural EGFL-Like 1 Regulates Cartilage Maturation through Runt-Related Transcription Factor 3-Mediated Indian Hedgehog Signaling. Am J Pathol 188:392-403
Tanjaya, Justine; Lord, Elizabeth L; Wang, Chenchao et al. (2018) The Effects of Systemic Therapy of PEGylated NEL-Like Protein 1 (NELL-1) on Fracture Healing in Mice. Am J Pathol 188:715-727
Li, Chenshuang; Zheng, Zhong; Zhang, Xinli et al. (2018) Nfatc1 Is a Functional Transcriptional Factor Mediating Nell-1-Induced Runx3 Upregulation in Chondrocytes. Int J Mol Sci 19:
Li, Chenshuang; Jiang, Jie; Zheng, Zhong et al. (2017) Neural EGFL-Like 1 Is a Downstream Regulator of Runt-Related Transcription Factor 2 in Chondrogenic Differentiation and Maturation. Am J Pathol 187:963-972
Shi, J; Lee, S; Pan, H C et al. (2017) Association of Condylar Bone Quality with TMJ Osteoarthritis. J Dent Res 96:888-894
Guo, Mian; James, Aaron W; Kwak, Jin Hee et al. (2016) Cyclophilin A (CypA) Plays Dual Roles in Regulation of Bone Anabolism and Resorption. Sci Rep 6:22378
Li, Chen-Shuang; Zhang, Xinli; PĂ©ault, Bruno et al. (2016) Accelerated Chondrogenic Differentiation of Human Perivascular Stem Cells with NELL-1. Tissue Eng Part A 22:272-85
Shen, Jia; LaChaud, Gregory; Shrestha, Swati et al. (2015) NELL-1 expression in tumors of cartilage. J Orthop 12:S223-9