Applying a highly specific and reproducible cDNA RDA method to clone garlic up-regulated genes in human gastric cancer cells

AIM: To develop and optimize cDNA representational difference analysis (cDNA RDA) method and to identify and clone garlic up-regulated genes in human gastric cancer (HGC) cells. METHODS: We performed cDNA RDA method by using abundant double-stranded cDNA messages provided by two self-constructed cDNA libraries (Allitridi-treated and paternal HGC cell line BGC823 cells cDNA libraries respectively). Bam H I and Xho I restriction sites harbored in the library vector were used to select representations. Northern and Slot blots analyses were employed to identify the obtained difference products. RESULTS: Fragments released from the cDNA library vector after restriction endonuclease digestion acted as good marker indicating the appropriate digestion degree for library DNA. Two novel expressed sequence tags (ESTs) and a recombinant gene were obtained. Slot blots result showed a 8-fold increase of glia-derived nexin/protease nexin 1 (GDN/PN1) gene expression level and 4-fold increase of hepatitis B virus x-interacting protein (XIP) mRNA level in BGC823 cells after Allitridi treatment for 72h. CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAs induced by Allitridi provide valuable molecular evidence for elucidating the garlic's efficacies against neurodegenerative and inflammatory diseases. Isolation of a recombinant gene and two novel ESTs further show cDNA RDA based on cDNA libraries to be a powerful method with high specificity and reproducibility in cloning differentially expressed genes.

Danggui Buxue Tang ameliorates bleomycin-induced pulmonary fibrosis in rats through inhibiting transforming growth factor-β1/Smad3/plasminogen activator inhibitor-1 signaling pathway

OBJECTIVE: To investigate the effect of Danggui Buxue Tang(DBT), a decoction from Traditional Chinese Medicine, on bleomycin-induced pulmonary fibrosis in rats, and to propose the possible underlying mechanism.METHODS: Forty male Sprague-Dawley rats were randomly divided into sham group, model group,prednisone group and DBT group. Pulmonary fibrosis rat model was established by intratracheal injection with bleomycin. Body weight and lung index were monitored. Histopathologic examination and collagen deposition were determined using Hematoxylin and eosin(HE) and Masson's trichrome staining. Immunohistochemistry staining was applied to observe the expression of alpha-smooth muscle actin(α-SMA). m RNA expression of α-SMA,collagen Ⅰ and collagen Ⅲ were measured by realtime fluorescence quantitative PCR(RT-q PCR). Inflammatory cytokines, including tumor necrosis factor alpha(TNF-α), interleukin-6(IL-6) and IL-1β in serum were detected by Enzyme-linked immunosorbent assay. Alkali hydrolysis method was conducted to investigate the content of hydroxyproline(HYP). Transforming growth factor-β1(TGF-β1),Smad3 and plasminogen activator inhibitor-1(PAI-1) protein level were examined by Western blot assay.RESULTS: DBT significantly reduced the severity of bleomycin-induced pulmonary fibrosis and inflammation as indicated by minimizing the lost of weight, and by lowering the levels of lung index, inflammation score, Ashcroft score, collagen volume fraction(%), HYP, α-SMA, collagen Ⅰ, collagen Ⅲ,TNF-α, IL-6, IL-1β, TGF-β1, Smad3 and PAI-1, consistent with the effect of prednisone.CONCLUSION: Our findings suggest that DBT is able to ameliorate the pulmonary fibrosis, the possible mechanism may involve inhibition of pulmonary inflammation and collagen deposition, possibly via suppressing TGF-β1/Smad3/PAI-1 signaling pathway.