Cell based regenerative therapy requires the activity of stem progenitor cells for tissue regeneration. Connective tissue progenitors (CTPs) are defined as the heterogeneous population of tissue resident stem and progenitor cells that are capable of proliferating and differentiating into one or more connective tissue phenotypes. The number and heterogeneity of CTPs can be estimated using the colony formation assay, in which colony founding CTPs are detected and measured by their ability to proliferate and colony of progeny that express a connective tissue phenotype in vitro. In addition to measuring the number and prevalence of CTPs in a tissue sample, differences in biological potential between various CTPs can be assessed based on variation in cell number, distribution, morphology and expression patterns between colonies that are formed. While very useful, a very important limitation of traditional colony formation assays is that their only direct measurement is made on the progeny of the founding CTP (the colony). Information about the founding CTP can only be inferred from the number of colonies and their features. Colony assays to not reveal the physical or biological properties of the rare individual colony founding CTPs themselves, before proliferation. To address this limitation, we have developed a live cell, videomicroscopy system that enables systematic characterization of colony founding cells (morphology, expression of surface markers) before colony formation. Using multicolor labeling methods, a mixed tissue derived cell population is labeled for cell markers of interest at the time of plating. Time lapse phase contras images are then captured over 6 days, while colonies form, over a large field of view. At the end of the culture period, colonies are characterized with respect to established markers and colony metrics. By reversing the video, each colony can also be traced back to identify the colony founding cell, as one in a sea of other non-progenitors. Using this method we propose to significantly advance our understanding of the nature of human CTPs, their diversity and subtypes, their location in bone tissue and define factors that can be measured non-invasively and used to predict their biological potential, or select CTP best suited for specific therapeutic purposes.

Public Health Relevance

Connective tissue progenitors (CTPs) are a rare and heterogeneous population of cells which have the promise to contribute to important new therapies for repair and replacement of bone, cartilage and other tissues. This application will utilize new methods to learn important information about the surface markers and physical features of CTPs and how these may predict future performance. This knowledge has the potential to enable the development of more effective cellular therapies, new diagnostic tests that may predict future health or response to treatment, improved methods for cell collection and for manufacturing of cell products for testing new drugs and devices.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21AR067357-01
Application #
8806193
Study Section
Biomaterials and Biointerfaces Study Section (BMBI)
Program Officer
Tyree, Bernadette
Project Start
2014-09-15
Project End
2016-08-31
Budget Start
2014-09-15
Budget End
2015-08-31
Support Year
1
Fiscal Year
2014
Total Cost
$200,133
Indirect Cost
$60,454
Name
Cleveland Clinic Lerner
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
135781701
City
Cleveland
State
OH
Country
United States
Zip Code
44195