Targeting choline phospholipid metabolism: GDPD5 and GDPD6 silencing decrease breast cancer cell proliferation,migration, and invasion

Abnormal choline phospholipid metabolism is associated with oncogenesis and tumor progression. We have investigated the effects of targeting choline phospholipid metabolism by silencing two glycerophosphodiesterase genes, GDPD5 and GDPD6, using small interfering RNA (siRNA) in two breast cancer cell lines, MCF‐7 and MDA‐MB‐231. Treatment with GDPD5 and GDPD6 siRNA resulted in significant increases in glycerophosphocholine (GPC) levels, and no change in the levels of phosphocholine or free choline, which further supports their role as GPC‐specific regulators in breast cancer. The GPC levels were increased more than twofold during GDPD6 silencing, and marginally increased during GDPD5 silencing. DNA laddering was negative in both cell lines treated with GDPD5 and GDPD6 siRNA, indicating absence of apoptosis. Treatment with GDPD5 siRNA caused a decrease in cell viability in MCF‐7 cells, while GDPD6 siRNA treatment had no effect on cell viability in either cell line. Decreased cell migration and invasion were observed in MDA‐MB‐231 cells treated with GDPD5 or GDPD6 siRNA, where a more pronounced reduction in cell migration and invasion was observed under GDPD5 siRNA treatment as compared with GDPD6 siRNA treatment. In conclusion, GDPD6 silencing increased the GPC levels in breast cancer cells more profoundly than GDPD5 silencing, while the effects of GDPD5 silencing on cell viability/proliferation, migration, and invasion were more severe than those of GDPD6 silencing. Our results suggest that silencing GDPD5 and GDPD6 alone or in combination may have potential as a new molecular targeting strategy for breast cancer treatment. Copyright © 2016 John Wiley & Sons, Ltd.     

肺泡表面活性物质治疗新生儿肺透明膜病的疗效观察

目的探讨肺泡表面活性物质治疗新生儿肺透明膜病的疗效。方法按照治疗方案不同将40例新生儿肺透明膜病患儿分为A组(注射用牛肺表面活性剂+辅助通气)20例和B组(猪肺磷脂注射液+辅助通气)20例,比较两组患儿预后情况、机械通气情况、住院情况、并发症情况以及治疗前后血气分析指标[氧分压(PaO_2)、二氧化碳分压(PaCO_2)、pH]变化情况。结果两组治疗总有效率均为95.00%,并无统计学差异(P0.05);两组患儿治疗后PaO_2、pH水平高于同组治疗前,PaCO_2、OI水平低于同组治疗前,差异显著(P0.05);两组患儿治疗后血气分析指标并无统计学差异(P0.05);两组患儿机械通气总时间、总吸氧时间、总住院时间并无统计学差异(P0.05);A组患儿总治疗费用低于B组,差异显著(P0.05);两组患儿并发症总发生率并无统计学差异(P0.05)。结论肺泡表面活性物质治疗新生儿肺透明膜病疗效确切,其中注射用牛肺表面活性剂药效优异且药物经济性良好。     

Selective HPLC Method Development for Soy Phosphatidylcholine Fatty Acids and Its Mass Spectrometry

A novel, efficient and simple approach for soy phosphatidylcholine analysis according to its fatty acid composition was studied with reverse-phase high-performance liquid chromatography. The reverse-phase high-performance liquid chromatography analysis was performed isocratically using UV detector and simple mobile phase solvents consisting of isopropyl alcohol, methanol, and deionized water in the proportion of 70:8:22 v/v. The uniqueness of the proposed method was the separation of individual fatty acids of soy phosphatidylcholine. The high-performance liquid chromatography method for soy phosphatidylcholine was validated for linearity with correlation coefficient of above 0.99 for all the peaks separated according to their fatty acid composition. The intra-day and the inter-day precision studies provided the relative standard deviation of less than 2%. The limit of detection and limit of quantitation values were also calculated for all the resolved peaks of soy phosphatidylcholine. Also system performance parameters such as number of theoretical plates, capacity factor, tailing factor, separation factor, and peak resolution were studied systematically and found well within the acceptable range. The proposed high-performance liquid chromatography method was successfully applied to soy phosphatidylcholine extracted and purified from deoiled soy lecithin without any interference of impurities or solvent peaks. Individually, the collected peaks of sample soy phosphatidylcholine were subjected for mass spectroscopy. The mass spectra showed all the peaks having different saturated or unsaturated fatty acid chains attached to glyerophosphocholine moiety of soy phosphatidylcholine. The method developed is economic and well suited for estimation of soy phosphatidylcholine with its fatty acid composition.     

Suppression of serum lipid transfer proteins involved in high-density lipoprotein cholesterol metabolism by intensive insulin therapy in the first year of type 1 diabetes mellitus: Prospective InLipoDiab1 study

Background and aimsCholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) are crucial proteins in reverse cholesterol transport. There are insufficient data on regulating these proteins by insulin therapy in type 1 diabetes mellitus (T1DM). We aimed to assess prospectively the impact of insulin therapy initiation on transfer proteins serum levels in adults with newly diagnosed T1DM.Methods and results57 adults with newly diagnosed T1DM were enrolled in the InLipoDiab1 Study. All participants were treated with subcutaneous insulin in the model of intensive insulin therapy since the diagnosis of diabetes. Serum PLTP and CETP concentrations were measured at diagnosis, after three weeks, six months, and after one year of insulin treatment, using the immunoenzymatic method ELISA.A significant decrease in PLTP and CETP concentrations were demonstrated during twelve months of insulin therapy in newly diagnosed T1DM. The dynamics of changes in the level of these proteins varied depending on the occurrence of remission after a year of the disease. In the group without remission, a significant decrease in PLTP and CETP levels appeared after six months of follow-up. The remission group was characterized by a decrease in proteins concentration only after one year of treatment. In the non-remission group, significant negative correlations were found between the daily dose of insulin and levels of PLTP and CETP.ConclusionExogenous insulin is an inhibitor of lipid transfer proteins involved in high-density lipoprotein cholesterol metabolism in the first year of treatment.     

外翻肠囊法研究氧化苦参碱磷脂复合物的肠吸收特性

目的 通过对比研究氧化苦参碱及其磷脂复合物大鼠离体肠吸收情况,考察磷脂复合物对氧化苦参碱肠吸收的影响。方法 采用大鼠离体外翻肠囊模型研究氧化苦参碱磷脂复合物的肠吸收特性。HPLC测定不同剂量的氧化苦参碱及氧化苦参碱磷脂复合物在大鼠十二指肠、空肠、回肠和结肠内的累积吸收量。结果 氧化苦参碱磷脂复合物在不同肠段的吸收较氧化苦参碱均有提高,低剂量组氧化苦参碱磷脂复合物在空肠、结肠处的吸收较氧化苦参碱有显著提高;中剂量组氧化苦参碱磷脂复合物在十二指肠、空肠、结肠处的累积吸收量较氧化苦参碱有显著提高;高剂量组氧化苦参碱磷脂复合物在空肠的吸收较氧化苦参碱有显著提高。结论 与氧化苦参碱相比,磷脂复合物对氧化苦参碱在大鼠肠道的吸收有显著的促进作用。     

AFM观察囊泡融合法形成支撑磷脂膜的微观形成过程

目的利用原子力显微镜（AFM）观察支撑磷脂膜的微观形成过程。方法冰浴超声法制备磷脂脂质体溶液,囊泡融合法形成人工磷脂双分子层,用AFM进行观察。结果利用AFM观察到磷脂膜的微观形成过程为：脂质体囊泡吸附一脂质体囊泡之间发生黏着,一脂双层之间形成接触点一磷脂囊泡破裂一形成磷脂分子层一磷脂分子层间流动进行融合形成大片磷脂膜。结论AFM可观察磷脂膜的微观形成过程,进而为细胞膜和膜蛋白的功能研究提供基础。     

Leishmaniasis: vaccine candidates and perspectives

Leishmania is a protozoan parasite and a causative agent of the various clinical forms of leishmaniasis. High cost, resistance and toxic side effects of traditional drugs entail identification and development of therapeutic alternatives. The sound understanding of parasite biology is key for identifying novel drug targets, that can induce the cell mediated immunity (mainly CD4+ and CD8+ IFN-gamma mediated responses) polarized towards a Th1 response. These aspects are important in designing a new vaccine along with the consideration of the candidates with respect to their ability to raise memory response in order to improve the vaccine performance. This review is an effort to identify molecules according to their homology with the host and their ability to be used as potent vaccine candidates.     

Phospholipid N-methylation as a Signal Transduction Mechanism in Normal and Failing Hearts

The phospholipid N-methylation pathway comprises of three successive N-terminal methylations of phosphatidylethanolamine where S-adenosyl-L-methionine acts as the physiological donor. Under optimal conditions in cardiac membranes, the catalytic sites I, II, and III of methyltransferase have been identified which are responsible for the synthesis of the major product, phosphatidyl-N-monomethylethanolamine, phosphatidyl-N,N-dimethylethanolamine, and phosphatidylcholine, respectively. The characterization of the phosphatidylethanolamineN-methyltransferase system has shown that each of the catalytic sites exhibits different biochemical properties. The phospholipid N-methylation pathway has also been observed to regulate heart function by inducing localized structural, compositional, and functional changes in cardiac membranes under different pathological conditions of chronic nature. This review deals with the phosphatidylethanolamine N-methylation–mediated signal transduction mechanism involving modification of the Ca2+-transporting activities of the sarcolemmal and sarcoplasmic reticular membranes of the cardiomyocyte. In this regard, special attention is given to the status of this pathway and its relevance for the functioning of membrane-related Ca2+-transport systems in heart dysfunction due to different cardiac pathologies, such as diabetes-induced cardiomyopathy, catecholamine-induced cardiomyopathy, genetically linked cardiomyopathy, and adriamycin-induced cardiomyopathy. In addition, changes in phosphatidylethanolamine N-methylation in heart dysfunction due to cardiac hypertrophy, Ca2+-paradox hearts, and ischemic-reperfused hearts have been described. It is suggested that an increase in phosphatidylethanolamine N-methylation activity may play an adaptive role, whereas a depression may contribute towards contractile dysfunction. This revised version was published online in July 2006 with corrections to the Cover Date.