Objective      To determine the relationship of structure of cytoskeletal proteins with cell phenotypes in chondrocyte.       Methods      Chondrocytes isolated from the knee joints of New Zealand rabbits were cultured in 3-D pellet

and then divided into control group

colchicine group

cytochalasin B group and acrylamide group. The cells were exposed to colchicine

acrylamide

or cytochalasin B to disrupt tubulin microtubules

vimentin intermediate filaments

or actin microfilaments

respectively. The chondrocyte phenotypes were determined by gross observation

histological staining

immunohistochemistry

and RT-PCR.       Results      The chondrocytes were in more dense and uniform distribution in control group

colchicine treated group

and cytochalasin B treated group

while those in acrylamide treated group were in dispersed distribution. The expression levels of type Ⅱ collagen and aggrecan were higher

while that of typeⅠcollagen was lower in the control

colchicine and cytochalasin B groups. But their expression profiles were opposite in acrylamide treated group. RT-PCR analysis showed that there was no significant differences in the expression levels of typeⅠcollagen and type Ⅱ collagen in the control group (1.21±0.21

1.10±0.12) compared to the colchicine group (1.55±0.0

0.91±0.21) and cytochalasin group (1.70±0.07

0.90±0.30

P0.05). But the expression of type II collagen was obviously higher

and that of typeⅠcollagen expression was lower in the control than the acrylamide group (1.10±0.12 vs 0.26±0.06

1.21±0.21 vs 9.63±0.38

P0.05).       Conclusion      Acrylamide-induced modulation of vimentin intermediate filaments down-regulates the expression of type II collagen and aggrecan in the chnodrocytes.