Precision medicine for rare diseases: The times they are A-Changin'

The greatest challenge of current biomedicine is to identify curative therapies for every disease in a personalized way so that every individual gets benefit. To that end, however, we need fully understand mechanisms of disease that will drive the design of novel therapies and innovative approaches.For rare diseases (RDs) which individually affect low numbers of people (< 1:2000), but together, affect 300 million (∼10% of the world population) the constraints are greater. This is because: 1) there is limited knowledge on RD physiopathology; 2) the low number of patients strongly limits clinical trials; 3) there is low commercial interest by pharma; 4) when specific drugs reach the market, their high cost precludes their reaching all those who need them.Several possibilities that can help mitigate these barriers are discussed here, including orphan drug designation, drug repurposing, break-down into theratypes (as currently in place for Cystic Fibrosis), or novel precision-medicine-based approaches.     

Emerging drugs for cystic fibrosis

Introduction: Cystic fibrosis is an autosomal recessive disease, which is the result of a genetic defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Pulmonary disease accounts for over 90% of the morbidity and mortality associated with the disease. Conventionally, CF treatment has focused on symptomatic therapy.

Areas covered: In the past, the emphasis for the development of CF therapeutics has previously been on addressing complications of the manifestations rather than on the underlying disease process. However, in the past few decades there has been a paradigm shift with new attention on the underlying biological mechanisms and therapies targeted at curing the disease rather than simply controlling it. This review summarizes the current CF therapeutics pipeline. These developing therapies include CFTR gene therapy, CFTR pharmacotherapeutics, osmotically active agents and anti-inflammatory therapies, as well as novel inhaled antibiotics.

Expert opinion: The CF therapeutics pipeline currently holds great promise both for novel therapies directly targeting the underlying biological mechanisms of CFTR dysfunction and new symptomatic therapies. While CFTR-directed therapy has the highest potential to improve patients' outcome, it is important to continue to develop better treatment options for all aspects of CF lung disease.     

牙龈蛋白酶在诱导成骨细胞凋亡中的作用及对Bim、整合素α5的影响

目的：探讨牙龈蛋白酶诱导成骨细胞凋亡的作用及对与Bcl-2蛋白相互作用的细胞死亡调节子( Bim)蛋白、整合素ɑ5的影响。方法分离并提取牙龈蛋白酶,测定其活性,实验分为两组,其中实验组采用浓度为1.812 U/L的牙龈蛋白酶处理小鼠成骨细胞(MC3T3-E1)48 h,对照组采用牙龈蛋白酶特异性抑制剂(TCLK)对牙龈蛋白酶进行预处理,采用TUNEL-DAPI法测定两组MC3T3-E1细胞的凋亡率,采用免疫印迹法测定不同时间两组Bim蛋白、整合素ɑ5表达变化。结果实验组牙龈蛋白酶中精氨酸牙龈蛋白酶( Rgp)、赖氨酸牙龈蛋白酶( Kgp)的活性均显著高于对照组(P<0．01);在0 h,两组MC3T3-E1细胞凋亡率差异无统计学意义(P>0．05),在第16、24、48 h实验组的MC3T3-E1细胞凋亡率均显著高于对照组(P<0．05);在第8、16、24、48 h实验组的Bim蛋白表达均显著高于本组0 h(P<0．05),在第24 h时达到最高值,同时也显著高于对照组(P<0．05);在第16、24、48 h实验组的整合素ɑ5表达较本组0 h均显著降低( P<0．05);同时显著低于对照组( P<0．05)。结论牙龈蛋白酶能成功诱导成骨细胞凋亡,这一作用机制可能与增强Bim蛋白表达、下调整合素ɑ5表达有关。     

蚊虫对微生物和昆虫生长调节剂杀幼剂的抗药性及其管理

微生物和昆虫生长调节剂杀幼剂因具有相对靶生物特异性与环境保护理念越来越广泛用于蚊虫控制。该文回顾了这些杀虫剂的作用原理、在蚊虫控制方面的使用概况、抗药性发展及管理的策略与措施。涉及到的杀虫剂包括天然微生物杀虫剂苏云金杆菌以色列变种、球形芽孢杆菌、刺糖多孢菌多杀菌素,以及人工合成的昆虫生长调节剂如烯虫酯、吡丙醚和除虫脲。抗药性发展的预防和控制是可持续性蚊虫综合治理成功的关键之一。     

Novel action of the chalcone isoliquiritigenin as a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor: potential therapy for cholera and polycystic kidney disease

Overstimulation of cAMP-activated Cl(-) secretion can cause secretory diarrhea. Isoliquiritigenin (ISLQ) is a plant-derived chalcone that has a wide range of biological activities. The present study thus aimed to investigate the effect of ISLQ on cAMP-activated Cl(-) secretion in human intestinal epithelium, especially the underlying mechanism and therapeutic application. Short-circuit current analysis of human intestinal epithelial (T84) cell monolayers revealed that ISLQ dose-dependently inhibited cAMP-activated Cl(-) secretion with an IC(50) of approximately 20 μM. ISLQ had no effect on either basal short-circuit current or Ca(2+)-activated Cl(-) secretion. Apical Cl(-) current analysis of T84 cell monolayers indicated that ISLQ blocked mainly the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels, but not other unidentified cAMP-dependent Cl(-) channels. ISLQ did not affect intracellular cAMP levels or cell viability. ISLQ completely abolished the cholera toxin-induced transepithelial Cl(-) secretion in T84 cells and reduced the cholera toxin-induced intestinal fluid secretion in mouse closed loop models by 90%. Similarly, ISLQ completely inhibited the cAMP-activated apical Cl(-) current across monolayers of Madin-Darby Canine Kidney (MDCK) cells and retarded cyst growth in MDCK cyst models by 90%. This study reveals a novel action of ISLQ as a potent CFTR inhibitor with therapeutic potential for treatment of cholera and polycystic kidney disease.     

The cystic fibrosis mutation G1349D within the signature motif LSHGH of NBD2 abolishes the activation of CFTR chloride channels by genistein

Cystic fibrosis (CF) is a common lethal genetic disease caused by autosomal recessive mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel that belongs to the ATP-Binding Cassette (ABC) family of transporters. The class III CF mutations G551D and G1349D are located within the "signature" sequence LSGGQ and LSHGH of NBD1 and NBD2, respectively. We have constructed by site-directed mutagenesis vectors encoding green fluorescent protein (GFP)-tagged wild-type (wt) CFTR or CFTR containing delF508, G551D, G1349D and G551D/G1349D to study their pharmacology after transient expression in COS-7 cells. We show that IBMX and the benzo[c]quinolizinium derivative MPB-91 stimulates the activity of G1349D-, G551D- and G551D/G1349D-CFTR only in the presence of cAMP-promoting agents like forskolin or cpt-cAMP. Similar half-maximal effective concentrations (EC(50)) of MPB-91 (22-36microM) have been determined for wt-, G551D-, G1349D- and G551D/G1349D-CFTR. The isoflavone genistein stimulates wild-type (wt)- and delF508-CFTR channel activity in a non-Michaelis-Menten manner. By contrast, the response of G1349D- and G551D-CFTR to genistein is dramatically altered. First, genistein is not able to stimulate G1349D- and G551D/G1349D-CFTR. Second, genistein stimulates G551D-CFTR without any inhibition at high concentration. We conclude from these results that whereas G551 in NBD1 is an important molecular site for inhibition of CFTR by genistein, the symmetrical G1349 in NBD2 is also one major site but for the activation of CFTR by genistein. Because both mutations alter specifically the mechanism of CFTR channel activation by genistein, we believe that the signature sequences of CFTR act as molecular switches that upon interaction with genistein turn on and off the channel.     

治疗阿尔茨海默病药物的研究进展

阿尔茨海默病(AD)为中枢神经退化性疾病,是危害人类健康的一大综合征,治疗AD药物是近年来研究的一大热点.综述了近5年来治疗AD药物的研究进展,根据作用机制的不同对临床应用的抗AD和有促智活性的药物进行分类详述,主要分为乙酰胆碱酯酶抑制剂等改善胆碱功能的药物、M1受体激动剂、抗氧化药物、消炎镇痛药物、抑制Aβ蛋白形成的药物、神经生长因子、钙调节剂、晚期糖基化终产物(AGE)抑制剂以及中药复方等几类.     

植物生长延缓剂烯效唑对丹参植株形态及生物量分配的影响

采用盆栽试验,研究叶面喷施不同浓度烯效唑对丹参植株生长的影响。在丹参整个生长期内,动态观测植株株高、株幅及地径的变化,并对收获期丹参叶、茎、花果、根的生物量及其所占生物量比进行测定。结果表明,叶面喷施烯效唑后,丹参植株形态发生明显变化,主要表现为株高降低、株幅减小、高径比减小等。同时,丹参各器官的生物量分配情况也发生了较大变化,茎、叶所占生物量比显著减少,而根所占生物量比显著增加。因此,在丹参生长期叶面喷施一定浓度烯效唑具有明显的矮化植株、修整株型、增强抗倒伏能力的作用,在丹参规范化生产中对其合理密植,提高产量具有一定的实际意义。     

Mediation of annexin 1 secretion by a probenecid-sensitive ABC-transporter in rat inflamed mucosa

Annexin 1 is secreted by mammalian cells but lacks a leader signal sequence necessary to lead it to the classical secretory pathway via the endoplasmic reticulum. The mechanisms involved in the secretion of leaderless proteins remain uncertain. It has been suggested to involve membrane translocation via an ABC-transporter (ATP binding cassette). Using cultured inflamed mucosa from rectocolitis induced in rats, we studied if annexin 1 secretion followed the two main characteristics of ABC-transporter substrates: dependency on ATP hydrolysis and competitive inhibition by several other ABC-transporter substrates. Annexin 1 secretion is inhibited in a dose-dependent manner by two ATPase inhibitors. The inhibition reached 63.2+/-3.2%, 66.1+/-3.73% and 88.6+/-1.4% in the presence of 2mM vanadate, 0.5 and 1mM pervanadate, respectively. The efflux of calcein, a known ABC-transporter substrate, is similarly inhibited by 69.4+/-2.8% in the presence of 1mM pervanadate. Probenecid, an inhibitor of several ABC-transporters of the subfamilly ABCC or MRP (multidrug resistant associated protein), also inhibited annexin 1 secretion in a dose-dependent manner. As compared to control, 10mM probenecid reduced annexin 1 secretion by 72+/-20% and 20mM by 95.0+/-9%. By contrast, annexin 1 secretion is not blocked by other inhibitors of MRP1 (indomethacin, MK571), MRP2 (ochratoxin A1 or MK571), MRP5 (trequinsin or sulfinpyrazone) or by verapamil, cyclosporin A or glyburide. Taken together, our results show that annexin 1 secretion appears to share the efflux properties of ABC-transporter substrates.