Molecular pharmacology of the DP/EP2 class prostaglandin AL-6598 and quantitative autoradiographic visualization of DP and EP2 receptor sites in human eyes.

DP-class prostaglandins and prostaglandin analogs (collectively, prostaglandins or PGs) such as PGD2, BW245C, ZK110841, and ZK118182, lower intraocular pressure (IOP) in animal models of ocular hypertension. A new analog of ZK118182 (AL-6556; 13,14-dihydro-ZK118182) was synthesized, and the isopropyl ester of AL-6556 (AL-6598) was shown recently to lower IOP in the ocular hypertensive cynomolgus monkey model of glaucoma and in human subjects. AL-6556 and AL-6598 had an affinity (Ki) of 2.66-4.43 microM for DP receptors but a much lower affinity (K(i)s = 38-103 microM) for EP3, FP, IP, and TP receptors (n = 3-5). In addition, AL-6556 and AL-6598 exhibited K(i)s > 100 microM for 19 nonprostanoid receptors. Both PGs stimulated cAMP production (EC50 = 1.07 +/- 0.1 microM and EC50 = 2.64 +/- 0.84 microM; n = 3) by way of DP receptors in embryonic bovine tracheal fibroblasts. While AL-6556 and AL-6598 were partial agonists (EC(50)s = 0.47-0.69 microM; E(max) = 35%-46%) at EP2 receptors in human nonpigmented epithelial cells, neither had any agonist activity at EP4, IP, or FP receptors. The DP antagonist, BWA868C, effectively antagonized the effects of AL-6556 with a high potency (IC50 = 22.8 +/- 3.9 nM; n = 3). DP receptors radiolabeled with [3H]BWA868C on human eye sections by quantitative autoradiography were highly concentrated in the ciliary process (CP), longitudinal (LCM) and circular (CCM) ciliary muscles, and iris with much lower specific binding in the cornea (CN), lens (LNS), and retina (RET). EP2 receptors labeled with [3H]PGE2 were concentrated in the LCM, CM, RET, and iris. In conclusion, AL-6598 and AL-6556 are relatively DP-receptor-selective PGs with full agonist activity at the DP and partial agonist activity at the EP2 receptor. The IOP-lowering activities of these compounds may involve both the inflow and outflow mechanisms, as DP and EP2 receptors were visualized in human ocular tissues involved in such aqueous humor dynamics.     

Inhibitory role of Smad7 in hepatocarcinogenesis in mice and in vitro

Smad7 is a principal inhibitor of the TGFβ–Smad signalling pathway. We have investigated the functional significance of Smad7 in hepatocellular carcinoma (HCC). Smad7 knockout (KO) and wild‐type (WT) mice were injected with diethylnitrosamine (DEN) to induce HCC. The effects of Smad7 on cellular features were examined in HCC cells, using a Smad7 over‐expression or deletion approach. Signalling pathway components modulated by Smad7 in HCC were evaluated using luciferase reporter assay and co‐immunoprecipitation. Smad7 was down‐regulated in human HCCs compared with the adjacent normal tissues (p < 0.001). Smad7 KO mice were more susceptible to DEN‐induced HCC than WT mice (78% versus 22%, p < 0.05). HCCs from KO mice displayed a greater proliferation activity (p < 0.05) and a reduced apoptotic index compared with WT littermates (p < 0.05). Deletion of Smad7 promoted cell proliferation in primary cultured HCC cells. In addition, over‐expression of Smad7 in HCC cell lines markedly suppressed cell growth (p < 0.0001) and colony formation (p < 0.01). Cell cycle analysis revealed an increase in the G₁ phase and a reduction in the S‐phase populations, accompanied by up‐regulation of p27^Kip1 and down‐regulation of cyclin D1. Smad7 increased cell apoptosis (p < 0.01) by mediating an intrinsic [caspase‐9, caspase‐3 and poly(ADP‐ribose) polymerase] apoptotic pathway. Moreover, Smad7 inhibited NF‐κB signalling by interacting with TAB2, an upstream activator of NF‐κB, and inhibited TGFβ signalling by suppressing phosphorylation of Smad3. In conclusion, loss of Smad7 enhances susceptibility to HCC. Smad7 suppresses HCC cell growth by inhibiting proliferation and G₁–S phase transition and inducing apoptosis through attenuation of NF‐κB and TGFβ signalling. Smad7 acts as a potential tumour suppressor in liver. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

The FGF14(F145S) mutation disrupts the interaction of FGF14 with voltage-gated Na+ channels and impairs neuronal excitability

Fibroblast growth factor 14 (FGF14) belongs to the intracellular FGF homologous factor subfamily of FGF proteins (iFGFs) that are not secreted and do not activate tyrosine kinase receptors. The iFGFs, however, have been shown to interact with the pore-forming (alpha) subunits of voltage-gated Na+ (Na(v)) channels. The neurological phenotypes seen in Fgf14-/- mice and the identification of an FGF14 missense mutation (FGF14(F145S)) in a Dutch family presenting with cognitive impairment and spinocerebellar ataxia suggest links between FGF14 and neuronal functioning. Here, we demonstrate that the expression of FGF14(F145S) reduces Na(v) alpha subunit expression at the axon initial segment, attenuates Na(v) channel currents, and reduces the excitability of hippocampal neurons. In addition, and in contrast with wild-type FGF14, FGF14(F145S) does not interact directly with Na(v) channel alpha subunits. Rather, FGF14(F145S) associates with wild-type FGF14 and disrupts the interaction between wild-type FGF14 and Na(v) alpha subunits, suggesting that the mutant FGF14(F145S) protein acts as a dominant negative, interfering with the interaction between wild-type FGF14 and Na(v) channel alpha subunits and altering neuronal excitability.     

纳米羟基磷灰石沉积层/钛酸钾薄层/钛合金生物复合材料体外培养成骨细胞的研究

在制备出具有表面活性的纳米羟基磷灰石沉积层/钛酸钾薄层/钛合金（HA/K2Ti6O13/β-Ti）生物复合材料的基础上,将体外培养的成骨细胞与HA/K2Ti6O13/β-Ti生物复合材料、未经处理β钛合金两种骨替代材料共同培养,在既定时间内观察两种骨替代材料对成骨细胞生长、附着的影响。结果表明两种骨替代材料对成骨细胞生长无明显抑制或促进作用,均具有良好的细胞相容性,它们皆能使成骨细胞附着于各自材料表面,分泌形成胶原纤维样基质。HA/K2Ti6O13/β-Ti生物复合材料较β钛合金具有更优异的的生物活性和成骨性能,是一种很好的生物植入材料。     

Comparison Between Living Donor Liver Transplantation Recipients Who Met the Milan and UCSF Criteria After Successful Downstaging Therapies

Background and Aims

Various downstaging therapies were introduced to liver recipients who could not meet the relative criteria for liver transplantation, and many endpoints were reported. The most common criteria used were the Milan criteria and the University of California, San Francisco (UCSF) criteria. However, no comparison was made between them, and we attempted to find possible differences between the living donor liver transplantation (LDLT) patients who met the Milan criteria and those who met the UCSF criteria after accepting preoperative downstaging therapies.

Materials and Methods

We performed a retrospective study of all 72 patients at our center from January 2003 to March 2009 who were diagnosed with advanced hepatocellular carcinoma but accepted various downstaging therapies. Some patients met the Milan criteria (group 1), and some met the UCSF criteria (group 2) but not the Milan criteria. We collected the data from the two groups and then compared the preoperative demographic data, downstaging therapies, intraoperative data from LDLT, and the recovery and complications after LDLT. Survival rates were compared using Kaplan?CMeier analysis.

Results

Only 44 patients (61.1?%) met the criteria for liver transplantation, 21 cases met the Milan criteria (group 1), and 23 cases met the UCSF criteria (group 2) but not the Milan criteria. All of the 44 patients accepted right lobe living liver donor liver transplantation in our center. The difference in the baseline characteristics between the two groups did not reach statistical significance. The mean number of downstaging treatments per patient was 1.81?±?0.35 in group 1 and 1.83?±?0.41 in group 2 (P?=?0.928). Most of the patients received only one downstaging treatment, and transcatheter arterial chemoembolization (TACE) was the most common downstaging therapy. Four patients suffered complications after downstaging therapies: intra-abdominal hemorrhage after right hepatectomy, upper gastrointestinal hemorrhage after TACE, biliary fistula after resection, and hand?Cfoot syndrome after taking sorafenib. All complications after LDLT, classified according to the Clavien?CDindo system, were compared within the two groups, and the calculated score of the complications in group 1 was 1.48?±?1.63, which was greater than that of group 2 (1.39?±?1.64), but this difference did not reach statistical significance (P?=?0.865). The 1-, 3-, and 5-year survival rates were 90.4, 76.2, and 71.4?% in group 1 and 91.3, 73.9, and 69.6?% in group 2, respectively (P?>?0.05). Seven patients (three in group 1 and four in group 2) had tumor recurrence after a median follow-up period of 72?months. The pathology findings were not different between the two groups.

Conclusion

Recipients who meet the Milan or UCSF criteria after accepting successful preoperative downstaging therapy in LDLT can achieve the same result.     

Increases in Na+,K+-ATPase activity of erythrocytes and skeletal muscle after chronic ethanol consumption: evidence for reduced efficiency of the enzyme.

Increased Na+,K+-ATPase activity observed after chronic ethanol consumption has been examined to determine whether the increase is due to changes in the kinetic properties of the enzyme or increases in the amount of enzyme in the membranes examined. In skeletal muscle and erythrocyte ghosts from rat, as well as from humans, increased Na+,K+-ATPase activity in ethanol-consuming individuals was not accompanied by an increase in the number of ouabain binding sites. In studies with intact human erythrocytes, similar ouabain-sensitive 22Na+ and 86Rb+ pumping rates were observed between normal and ethanol-consuming individuals and the Na+ to Rb+ pumping ratio was found to be 1.5 in all cases. However, ouabain-sensitive lactate plus Pi formation was increased in cells from alcoholic individuals. Thus these data suggest that increased enzyme activity may be due to a kinetic alteration of the Na+,K+-ATPase and that the enzyme may be less efficient in coupling ion pumping to ATP hydrolysis than the enzyme in normal cells.     

5-脂氧合酶促癌机制研究进展

5-脂氧合酶蛋白是花生四烯酸代谢途径中的一种关键酶,在恶性肿瘤的发生、发展过程中起了重要作用．抑制5-脂氧合酶及其产物的表达有可能预防和逆转恶性肿瘤的发生,本文结合国内外文献,就5-脂氧合酶分子生物学特征及促癌机制的研究进展作一综述．