Characterization of cartilage and primary chondrocytes from BALB/c wild-type (WT)
mice and CD44−/− mice. A, Femoral heads
isolated from WT and CD44−/− mice were fixed directly
and stained with Safranin O–fast green (top). Primary murine chondrocytes
isolated from the femoral heads of WT and CD44−/− mice
by collagenase digestion, were plated at high density and observed under
phase-contrast microscopy (bottom). B, Chondrocytes from WT and
CD44−/− mice were characterized for the expression
of CD44 by conventional reverse transcription–polymerase chain reaction
(RT-PCR) using GAPDH as control or by Western blotting using an anti-mouse CD44
antibody, with β-actin antibody as control.
C, The expression of mRNA for aggrecan (Acan), type II collagen
(Col II), and hyaluronan synthase 2 (HAS-2) derived from chondrocytes obtained
from WT and CD44−/− mice was determined by conventional
RT-PCR using GAPDH as control. Results are representative of 2 independent
experiments. D, Chondrocytes from WT and
CD44−/− mice were stained for hyaluronan (green)
either directly or following pretreatment with testicular hyaluronidase (+T) or
Streptomyces hyaluronidase (+S). Results are representative
of 5 experiments.