👤 Guanghua Lv

Interleukin (IL)-18 and IL-12 synergize for the production of interferon (IFN)-γ, which can downregulate ATP-binding cassette transporter A1 (ABCA1) expression. The aim of the present study was to investigate the effect of IL-18 and/or IL-12 on ABCA1 expression. IL-18 combined with IL-12 decreased ABCA1 expression and cellular cholesterol efflux in THP-1 macrophage-derived foam cells, whereas IL-18 or IL-12 alone had no effect. IL-12 increased IL-18 receptor (IL-18R) expression, which was suppressed by small interfering RNA (siRNA) for signal transducer and activator of transcription 3. IL-18R but not IL-12 receptor siRNA completely reversed the effects of IL-18 and IL-12 on ABCA1 expression and cellular cholesterol efflux. Treatment with IL-18 plus IL-12 markedly augmented nuclear translocation of nuclear factor (NF)-κB but had no effect on expression and activity of liver X receptor α. IL-18 and IL-12 also significantly increased zinc finger protein 202 (ZNF202) levels and IFN-γ secretion. Furthermore, siRNA for ZNF202 or IFN-γ significantly impaired IL-18/IL-12-induced suppression of ABCA1, whereas NF-κB siRNA treatment blocked IL-18/IL-12' action on ZNF202 levels, IFN-γ secretion, and ABCA1 expression. IL-18 and IL-12 together can decrease ABCA1 expression and cellular cholesterol efflux in THP-1 macrophage-derived foam cells through the IL-18R/NF-κB signaling pathway. Show less

Metastasis is the spread of cancer cells from their primary location to other parts of the body. Metastatic cancer is responsible for most cancer deaths. Increasing evidence indicates that epithelial-mesenchymal transition (EMT), a crucial developmental program, contributes to control cancer invasion and metastasis. We recently reported that death effector domain-containing DNA-binding protein (DEDD), a key effector molecule for cell death signaling receptors, attenuates EMT and acts as an endogenous suppressor of tumor growth and metastasis. We found that DEDD physically interacts with the class III PtdIns 3-kinase complex containing PIK3C3 and BECN1, which controls critical aspects of autophagy; this interaction activates autophagy and induces the autophagy-mediated lysosomal degradation of SNAI/Snail and TWIST, two master inducers of the EMT process. Further study reveals that the DEDD-PIK3C3 interaction can support the stability of PIK3C3 to maintain autophagic activity and promote the degradation of SNAI and TWIST. Our finding indicates that DEDD is a prognostic marker and a potential therapeutic target for the prevention and treatment of cancer metastasis. Moreover, regulation of the DEDD-PIK3C3 interaction may serve as an entry point to translate modifiers of this interaction into clinical endpoints. Show less

LINGO-1 (leucine-rich repeat and Ig domain-containing, Nogo receptor-interacting protein) is an important component of the NgR receptor complex involved in RhoA activation and axon regeneration. The authors report on passive immunization with LINGO-1 polyclonal antiserum, a therapeutic approach to overcome NgR-mediated growth inhibition after spinal cord injury (SCI). The intrathecally administered high-titer rabbit-derived antiserum can be detected around the injury site within a wide time window; it blocks LINGO-1 in vivo with high molecular specificity. In this animal model, passive immunization with LINGO-1 antiserum significantly decreased RhoA activation and increased neuronal survival. Adult rats immunized in this manner show recovery of certain hindlimb motor functions after dorsal hemisection of the spinal cord. Thus, passive immunotherapy with LINGO-1 polyclonal antiserum may represent a promising repair strategy following acute SCI. Show less

To express and purify the fusion protein of extracellular domain of human Ig domain-containing, neurite outgrowth inhibitor (Nogo) receptor-interacting protein-1 (LINGO-1(aa76-319)) in prokaryotic cells and prepare the rabbit anti-LINGO-1 polyclonal antibody (pAb). The 732 bp DNA sequence of hLINGO-1(aa76-319) was obtained from pCMV-SPORT6 by PCR and inserted into pET30a(+) plasmid to construct the prokaryotic expression plasmid pET30a(+)-hLINGO-1(aa76-319), which was subsequently transformed into E.coli. The target fusion protein was expressed with IPTG induction and purified by Ni(2+)-NTA affinity chromatography column. The antiserum against hLINGO-1(aa76-319) was obtained from the rabbits immunized with hLINGO-1(aa76-319), and the titer of the pAb was determined using enzyme linked immunosorbent assay (ELISA) and its specificity identified using Western blotting. The prokaryotic expression plasmid pET30a(+)-hLINGO-1(aa76-319) was constructed successfully. Efficient expression of the target fusion protein was achieved with IPTG induction at the optimal concentration of 0.4 mmol/L and culture temperature at 37 degrees celsius; for 2.5 h. The hLINGO-1(aa76-319) fusion protein was effectively expressed in E.coli as inclusion bodies, and the soluble protein was obtained through denaturation and refolding procedures, and the purified fusion protein showed a purity above 90%. The titer of the anti-hLINGO-1(aa76-319) pAb obtained by immunizing the rabbits with the purified protein reached 1:1.6x10(6), and Western blotting confirmed its good specificity. The fusion protein hLINGO-1(aa76-319) with high purity has been obtained and the anti-hLINGO-1(aa76-319) pAb obtained shows a high titer and good specificity, which provide important experimental basis for further functional investigation of LINGO-1. Show less

Liver X receptors (LXRs) are important transcriptional regulators of lipid homeostasis and proliferation in several cell types. However, the roles of LXRs in pancreatic beta cells have not been fully established. The aim of this study was to investigate the effects of LXRs on pancreatic beta cell proliferation. Gene expression was analysed using real-time RT-PCR. Transient transfection and reporter gene assays were used to determine the transcriptional activity of LXRs in pancreatic beta cells. Cell viability and proliferation were analysed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), DNA fluorometric, BrdU labelling and [(3)H]thymidine incorporation assays. Cell cycle distribution was investigated by flow cytometry analysis. Adenovirus-based RNA interference was used to knockdown LXRalpha, LXRbeta and p27 in MIN6 cells and mouse islets. We found that both Lxralpha (also known as Nr1h3) and Lxrbeta (also known as Nr1h2) were expressed and transactivated the LXR response element in HIT-T15 and MIN6 cells. Activation of LXRs dose-dependently inhibited pancreatic beta cell viability and proliferation. This was accompanied by beta cell cycle arrest at the G1 phase. Furthermore, LXR activation increased levels of the p27 protein by inhibiting its degradation. Knockdown of p27 reversed these effects of LXR activation on growth inhibition and cell cycle arrest. Our observations indicate that LXR activation inhibits pancreatic beta cell proliferation through cell cycle arrest. A well-known regulator of pancreatic beta cell cycle progression, p27, is upregulated and mediates the effects of LXRs on growth inhibition in beta cells. These observations suggest the involvement of aberrant activation of LXR in beta cell mass inadequacy, which is an important step in the development of type 2 diabetes. Show less

Our objective was to analyze the changes in the protein expression profiles of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Peripheral blood was obtained from patients with SLE and healthy controls. 2-D gel electrophoresis was performed, and gels were silver-stained. Differentially expressed protein spots were detected, some of which were identified by MALDI-TOF spectrometry. Match rates of 71% +/- 4% and 72% +/- 4% were gotten for control and patient gels, respectively. 791 +/- 17 spots were detected for control gels and 781 +/- 17 for patient gels. Eleven protein spots were up-regulated, and 9 protein spots were down-regulated in patients with SLE. Five differentially expressed proteins were identified as immunoglobulin J chain, apolipoprotein A-IV precursor, calprotectin L1H and zinc finger protein subfamily 1A (all up-regulated) and glutathione S-transferase (down-regulated), some of which had previously been shown to play a potential role in the pathogenesis of SLE. We conclude there are significant changes in the 2-D maps of PBMCs in patients with SLE and applying this proteomic approach may be a useful way to gain novel insights into SLE. Show less