Biliary atresia is a progressive obliterative cholangiopathy, but the etiology of this disorder remains uncertain. Identifying genes specifically expressed in biliary atresia and analyzing the pattern of expression may lead to a better understanding of the pathogenesis. Liver tissues were taken from a recipient with biliary atresia and a normal donor during liver transplantation. Total RNA was extracted from each sample and reversely transcribed to cDNA. Then radiolabeled cDNA probe pools were made by random primed DNA labeling method and used for screening of differentially expressed genes by hybridizing with expressed sequence tags (EST) dot blot panel. Northern blot hybridization was done to confirm that these genes are also differentially expressed in other liver tissues. Among 1,730 EST clones, 26 cDNA clones were significantly overexpressed in biliary cirrhosis, while 2 clones were significantly decreased in biliary atresia. By Northern blot hybridization, the results of tissue inhibitor of metalloproteinase (TIMP)-1 and IGFBP-2 were well correlated with differential EST screening (DES). This study identified the pattern of differentially expressed genes in the biliary cirrhosis due to biliary atresia using DES technique.
Biliary Atresia/*genetics ; Blotting, Northern ; Gene Expression Profiling/*methods ; Gene Library ; Human ; Insulin-Like Growth Factor-Binding Protein 2/genetics ; Tissue-Inhibitor of Metalloproteinase-1/genetics

BACKGROUNDSterol regulatory element binding protein (SREBP)-2 plays a key role in lipid homeostasis by stimulating gene expression of cholesterol biosynthetic pathways. The insulin-like growth factor binding protein (IGFBP) family regulates growth and metabolism, especially bone cell metabolism, and correlates with osteonecrosis. However, association of their gene polymorphisms with risk of avascular necrosis of the femoral head (ANFH) has rarely been reported. We determined whether SREBP-2 and IGFBP-3 gene polymorphisms were associated with increased ANFH risk in the Chinese population.

METHODSTwo single nucleotide polymorphisms of SREBP2 gene, rs2267439 and rs2267443, and one of IGFBP-3 gene, rs2453839, were selected and genotyped in 49 ANFH patients and 42 control individuals by direct sequencing assay.

RESULTSThe frequencies of rs2267439 TT and rs2267443 GA of SREBP2 and rs2453839 TT and CT of IGFBP-3 in the ANFH group showed increased and decreased tendencies (against normal control group), respectively. Interaction analysis of genes revealed that the frequency of carrying rs2267439 TT and rs2267443 GA genotypes of SREBF-2 in ANFH patients was significantly higher than in the control group (P < 0.05). Association analysis between polymorphisms and clinical phenotype demonstrated that the disease course in ANFH patients with the rs2453839 TT genotype of IGFBP-3 was significantly shorter than that of CT + CC carriers (P < 0.01). CT + CC genotype frequency in patients with stage III/IV bilateral hip lesions was significantly higher than in those with stage III/IV unilateral lesions and stage II/III bilateral lesions (P < 0.05 - 0.02).

CONCLUSIONSOur results suggested that interaction of SREBP-2 gene polymorphisms and the relationship between the polymorphisms and clinical phenotype of IGFBP-3 were closely related to increased ANFH risk in the Chinese population. The most significant finding was that the CT + CC genotype carriers of IGFBP-3 rs2453839 were highly associated with the development of ANFH.

Adult ; Asian Continental Ancestry Group ; genetics ; Female ; Femur Head Necrosis ; genetics ; Genetic Predisposition to Disease ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; genetics ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Sterol Regulatory Element Binding Protein 2 ; genetics