Expression of leukemia inhibitory factor in osteoarthritic tissues in rabbits and human:an experimental and clinical study / 中华创伤骨科杂志

ABSTRACT

Objective To investigate the regulation expression of leukemia inhibitory factor(LIF)in hu- man and animal osteoarthritic(OA)tissues and its clinical relevance.Methods 1)Thirty-five Japanese rabbits, aged eight months,were used to make models of experimental osteoarthritis.Operations were performed at the right knee and the sham ones at the left knee in each rabbit.Rabbits were sacrificed on the 3,7,14,28,42,56 and 84 days after operation respectively.Cartilage and synovium of the knee were collected to observe histological changes of osteoarthritis at different times;immunohistochemistry analysis was conducted to observe the LIF expression and distribution in the cartilage and synovium of the animals.2)From April 2003 to October 2003,32 samples of human articular tissues(cartilage,subchondral bone and synovium)were obtained in the operational procedures and a good quantity of RNA was isolated using Magnetic Beads.The patients who underwent articular operations donated the samples.In the reverse transcription-polymerase chain reaction(RT-PCR),the mRNA expression of LIF was mea- sured by semi-quantity analysis and the location of LIF protein was determined by enzyme-linked immunosorbent assay (ELISA).Results A slight expression of LIF was seen in normal cartilage but less in synovium.However,the expression of LIF was remarkable in synovial lining cells,superficial and middle layers of cartilage in animal os- teoarthritis.There was a significant difference in expression between the animal osteoarthritis and the control group (P＜0.05 ).In human tissue study,LIF mRNA was expressed to a very low level in normal articular tissues and there was no significant difference(P＞0.05)between different anatomical locations.In moderate degrading sub- chondral bone,LIF mRNA was expressed to its highest level.LIF was expressed to the highest level in seriously degrading cartilage tissues.The results were similar to ELISA testing results.LIF extents varied in different articular tissue sections.Conclusions LIF is an important mediator that can contribute to tbe pathogenesis of OA.The different temporal and spatial distributions of LIF in normal and OA tissues imply that LIF may play some important roles in pathogenesis of OA.