[Genomics study of steroid induced femoral head necrosis of rats].
OBJECTIVE
To identify significantly differentially expression genes of steroid-induced femoral head necrosis (SINFH) of rats by gene chip, and to find out the potential factors and molecular mechanisms that oxidative stress originate or strengthen the SINFH.


METHODS
Twenty Wistar rats were divided into experimental group and control group randomly. E. coli endotoxin was given to all rats at a dose of 20 µg/kg body weight by daily i.p. for two times. Then methylprednisolone (40 mg/kg) or saline was daily injected into the left gluteus muscle of the rats in experimental group and control group respectively. Six weeks later, the mRNA was extracted from the femoral head of rats in every group, and the cDNA were obtained by inverse transcript, then carried out microarray detection. The quantitative RT-PCR was used to confirm the result of microarray, and the differentially expressed genes were analyzed for the functional annotation by gene ontology (GO).


RESULTS
Compared to the control group, 190 genes in the experimental group were differentially expressed, with 52 up-regulated and 138 down-regulated. Of these genes, 102 are known (have deposited in GeneBank), while 88 of them are unknown. The known genes can be divided into several families according to their biological functions, such as: oxidative stress, apoptosis, signal transduction, angiogenesis, extracellular matrix, lipid metabolism, and gene transcription related genes. The results of quantitative RT-PCR are consistent with gene-chip results.


CONCLUSIONS
The occurrence of SINFH is a complicated process affected by multiple factors and signaling pathways. Our findings indicate that many genes which are involved in different signaling pathways were differentially expressed between SINFH rats and normal rats.
Institute of Orthopedics and Traumatology, Zhejiang Chinese Medical University, Hangzhou 310053, China.
Cheng-liang
CL
Wu
Qiang
Q
Mao
Hui
H
Liu
Pei-jian
PJ
Tong
Hong-ting
HT
Jin
Lu-wei
LW
Xiao
D000818:Animals; D004731:Endotoxins / Q000633:toxicity; D005260:Female; D005271:Femur Head Necrosis / Q000139:chemically induced* / Q000235:genetics*; D015870:Gene Expression; D023281:Genomics; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D011239:Prednisolone / Q000009:adverse effects; D051381:Rats; D017208:Rats, Wistar
D004731:Endotoxins; D011239:Prednisolone