title: Depth-varying density and organization of chondrocytes in immature and mature bovine articular cartilage assessed by 3d imaging and analysis.
abstract: Articular cartilage is a heterogeneous tissue, with cell density and organization varying with depth from the surface. The objectives of the present study were to establish a method for localizing individual cells in three-dimensional (3D) images of cartilage and quantifying depth-associated variation in cellularity and cell organization at different stages of growth. Accuracy of nucleus localization was high, with 99% sensitivity relative to manual localization. Cellularity (million cells per cm3) decreased from 290, 310, and 150 near the articular surface in fetal, calf, and adult samples, respectively, to 120, 110, and 50 at a depth of 1.0 mm. The distance/angle to the nearest neighboring cell was 7.9 microm/31 degrees , 7.1 microm/31 degrees , and 9.1 microm/31 degrees for cells at the articular surface of fetal, calf, and adult samples, respectively, and increased/decreased to 11.6 microm/31 degrees , 12.0 microm/30 degrees , and 19.2 microm/25 degrees at a depth of 0.7 mm. The methodologies described here may be useful for analyzing the 3D cellular organization of cartilage during growth, maturation, aging, degeneration, and regeneration.
authors.affiliation: Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive, MC 0412, La Jolla, CA 92093-0412, USA.
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Jadin
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Wong
authors.forename: Won C
authors.initials: WC
authors.lastname: Bae
authors.forename: Kelvin W
authors.initials: KW
authors.lastname: Li
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Williamson
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Schumacher
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Price
authors.forename: Robert L
authors.initials: RL
authors.lastname: Sah
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology* / Q000196:embryology / Q000254:growth & development; D002417:Cattle; D002452:Cell Count; D002467:Cell Nucleus / Q000648:ultrastructure; D019902:Chondrocytes / Q000166:cytology* / Q000648:ultrastructure; D021621:Imaging, Three-Dimensional; D018613:Microscopy, Confocal