Livin in synergy with Ras induces and sustains corticosteroid resistance in the airway mucosa

Rationale: Corticosteroid resistance (CR) seriously affects the therapeutic effects of steroids on many chronic inflammatory disorders, including airway allergy. The mechanism of CR development is unclear. Recent research indicates that livin, an apoptosis inhibitor, is associated with the regulation in cell activities. This study investigates the role of livin in the inducing and sustaining CR in the airway mucosa.Methods: Nasal epithelial cells (NECs) were isolated from surgically removed nasal mucosal tissues of patients with allergic rhinitis (AR) and nasal polyps with or without CR. Differentially expressed genes in NECs were analyzed by the RNA sequencing. A CR mouse model was developed to test the role of livin in CR development.Results: The results showed that NECs of AR patients with CR expressed high levels of livin, that was positively correlated with the thymic stromal lymphopoietin (TSLP) expression and the high Ras activation status in NECs. Livin and Ras activation mutually potentiating each other in the inducing and sustaining the TSLP expression in NECs. TSLP induced eosinophils and neutrophils to express glucocorticoid receptor-β (GRβ). Eosinophils and neutrophils with high CRβ expression were resistant to corticosteroids. Depletion of livin or inhibition of TSLP markedly attenuated CR and airway allergy.Conclusions: Livin facilitates CR development in the airways by promoting TSLP expression in epithelial cells and the GRβ expression in eosinophils and neutrophils. Depletion of livin or inhibiting TSLP attenuates CR development and inhibits airway allergy, this has the translational potential to be used in the treatment of airway allergy.     

Characteristics of stem cells derived from the degenerated human intervertebral disc cartilage endplate

Mesenchymal stem cells (MSCs) derived from adult tissues are an important candidate for cell-based therapies and regenerative medicine due to their multipotential differentiation capability. MSCs have been identified in many adult tissues but have not reported in the human intervertebral disc cartilage endplate (CEP). The initial purpose of this study was to determine whether MSCs exist in the degenerated human CEP. Next, the morphology, proliferation capacity, cell cycle, cell surface epitope profile and differentiation capacity of these CEP-derived stem cells (CESCs) were compared with bone-marrow MSCs (BM-MSCs). Lastly, whether CESCs are a suitable candidate for BM-MSCs was evaluated. Isolated cells from degenerated human CEP were seeded in an agarose suspension culture system to screen the proliferative cell clusters. Cell clusters were chosen and expanded in vitro and were compared with BM-MSCs derived from the same patient. The morphology, proliferation rate, cell cycle, immunophenotype and stem cell gene expression of the CESCs were similar to BM-MSCs. In addition, the CESCs could be induced into osteoblasts, adipocytes, chondrocytes, and are superior to BM-MSCs in terms of osteogenesis and chondrogenesis. This study is first to demonstrate the presence of stem cells in the human degenerated CEP. These results may improve our understanding of intervertebral disc (IVD) pathophysiology and the degeneration process, and could provide cell candidates for cell-based regenerative medicine and tissue engineering.     

Comparison of the roles of estrogens and androgens in breast cancer and prostate cancer

Breast cancer (BC) and prostate cancer (PC) are the second most common malignant tumors in women and men in western countries, respectively. The risks of death are 14% for BC and 9% for PC. Abnormal estrogen and androgen levels are related to carcinogenesis of the breast and prostate. Estradiol stimulates cancer development in BC. The effect of estrogen on PC is concentration-dependent, and estrogen can regulate androgen production, further affecting PC. Estrogen can also increase the risk of androgen-induced PC. Androgen has dual effects on BC via different metabolic pathways, and the role of the androgen receptor (AR) in BC also depends on cell subtype and downstream target genes. Androgen and AR can stimulate both primary PC and castration-resistant PC. Understanding the mechanisms of the effects of estrogen and androgen on BC and PC may help us to improve curative BC and PC treatment strategies.     

不同野化训练条件下朱鹮的行为差异

2010年7月至201 1年1月,在陕西省洋县朱鹮生态园和华阳镇朱鹮野化训练基地,采用瞬时扫描取样法和行为取样法,对2处野化训练大网笼中朱鹮(Nipponia nippon)(n洋县=30只;n华阳=22只)的行为进行研究,同时调查2处大网笼野化训练条件的不同.结果表明,在觅食行为的时间分配中,秋季洋县群的划动寻觅、探...     

Molecular characterization and expression analysis on two isogenes encoding 3-deoxy-<Emphasis Type="SmallCaps">d</Emphasis>-<Emphasis Type="Italic">arabino</Emphasis>-heptulosonate 7-phosphate synthase in grapes

3-Deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAHPS) is an entry enzyme of the shikimate pathway that connects primary carbohydrate metabolism with the biosynthesis of most secondary metabolites in plants. In the present study, two DAHPS cDNAs were cloned from grape berries (Vitis vinifera) and designated as VvDAHPS-1 and VvDAHPS-2. These two cDNA sequences share 75.7% of the identities. Their DNA corresponding to the two isogenes both contain four introns. The deduced proteins from two cDNAs had different NH₄-terminal regions and putative mature regions sharing sequence, molecular size and pI value similarity. Both of VvDAHPSs had a close evolution relationship with Populus trichocarpa DAHPSs. The prokaryotically-expressed VvDAHPSs both manifested DAHPS catalytic activity and Mn²⁺-activated effects. Analysis by real time-PCR showed that VvDAHPS-1 and VvDAHPS-2 were expressed in all the tested tissues, but their expression patterns accompanying with berry mature varied in the skin, pulp and seeds. The results give new insight into further study on regulatory mechanism of grape phenolics biosynthesis.     

Post-conditioning protects rat cardiomyocytes via PKCepsilon-mediated calcium-sensing receptors

Protein kinase C (PKC) plays a role in cardioprotection through reduction of intracellular Ca(2+) concentration [Ca(2+)](i) during ischemic preconditioning (IPC). Cardioprotection against ischemic post-conditioning (PC) could be associated with reduced [Ca(2+)](i) through PKC. The calcium-sensing receptor (CaR), G protein-coupled receptor, causes accumulation of inositol phosphate (IP) to increase the release of intracellular Ca(2+). However, this phenomenon can be negatively regulated by PKC through phosphorylation of Thr-888 of the CaR. This study tested the hypothesis that the prevention of cardiomyocyte damage by PC is associated with [Ca(2+)](i) reduction through an interaction of PKC with the CaR. Isolated rat hearts were subjected to 40min of ischemia followed by 90min of reperfusion. The hearts were post-conditioned after the 40min of ischemia by three cycles of 30s of reperfusion and 30s of re-ischemia applied before the 90min of reperfusion. Immunolocalization of PKCepsilon in the cell membrane was observed with IPC and PC, and in hearts exposed to GdCl(3) during PC. CaR was expressed in cardiac cell membrane and interacted with PKC in IPC, PC, and exposure to GdCl(3) during PC groups. On laser confocal microscopy, intracellular Ca(2+) was significantly decreased with IPC, PC, and exposure to GdCl(3) during PC compared with the I/R and PKC inhibitor groups, and cell structure was better preserved and promoted the recovery of cardiac function after reperfusion in the same groups. These results suggested that PKC is involved in cardioprotection against PC through negative feedback of a CaR-mediated reduction in [Ca(2+)](i).     

Tolerance induction between two different strains of parental mice prevents graft-versus-host disease in haploidentical hematopoietic stem cell transplantation to F1 mice

Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) has been employed worldwide in recent years and led to favorable outcome in a group of patients who do not have human leukocyte antigen (HLA)-matched donors. However, the high incidence of severe graft-versus-host disease (GVHD) is a major problem for Haplo-HSCT. In the current study, we performed a proof of concept mouse study to test whether induction of allogeneic tolerance between two different parental strains was able to attenuate GVHD in Haplo-HSCT to the F1 mice. We induced alloantigen tolerance in C3H mice (H-2k) using ultraviolet B (UVB) irradiated immature dendritic cells (iDCs) derived from the cultures of Balb/c bone marrow cells. Then, we performed Haplo-HSCT using tolerant C3H mice as donors to F1 mice (C3H × Balb/c). The results demonstrated that this approach markedly reduced GVHD-associated death and significantly prolonged the survival of recipient mice in contrast to the groups with donors (C3H mice) that received infusion of non-UVB-irradiated DCs. Further studies showed that there were enhanced Tregs in the tolerant mice and alloantigen-specific T cell response was skewed to more IL-10-producing T cells, suggesting that these regulatory T cells might have contributed to the attenuation of GVHD. This study suggests that it is a feasible approach to preventing GVHD in Haplo-HSCT in children by pre-induction of alloantigen tolerance between the two parents. This concept may also lead to more opportunities in cell-based immunotherapy for GVHD post Haplo-HSCT.     

Development of a phosphatase-stable phosphotyrosyl mimetic suitably protected for the synthesis of high-affinity Grb2 SH2 domain-binding ligands

Synthesis of (2R)-2-carboxymethyl-3-(4-(phosphonomethyl)phenyl) proprionic acid (5) in tert-butyl-protected form (6) and its use for the preparation of a Grb2 SH2 domain-directed tripeptide (8a) is reported. In extracellular ELISA-based assays, 8a exhibits potent Grb2 SH2 domain binding affinity (IC(50)=8 nM). Against cultures of MDA-MB-453 breast cancer cells, which over-express erbB-2 tyrosine kinase, 8a is also antimitogenic at concentrations equivalent to those required to inhibit intracellular association of Grb2 protein with phosphorylated p185(erbB-2) protein (IC(50)=8 microM). Analogue 6 may be useful for the preparation of a variety of phosphatase-stable SH2 domain-directed ligands.     

降胆固醇植物乳杆菌的紫外诱变选育

通过对植物乳杆菌进行紫外线诱变处理,采用胆固醇梯度平板的初筛方法和体外降胆固醇能力的测试,结果得到二株降胆固醇能力强且性能比较稳定的植物乳杆菌突变菌株Lp-UVs 29和Lp-UVs 44,胆固醇的降解率分别为48.7%和44.2%,分别比诱变前提高了97.97%和79.67%.