Is tetherin a true antiviral: The influenza a virus controversy

Tetherin, an interferon‐inducible gene was first discovered to be an antiviral factor in 2008. A vast range of viruses, such as influenza A virus (IAV), dengue virus, Ebola virus, HIV, and RSV, have been reported to be susceptible to the antiviral activity of tetherin. Multiple reports have been published encompassing the role of tetherin in the IAV life cycle. To date, nine reports have been published regarding the role of tetherin in the IAV life cycle, with four reports supporting tetherin as an antiviral factor while five other reports suggesting no effect. To this end, this review summarizes the list of viruses currently known to be inhibited by tetherin and describes mechanisms used by viruses to overcome the antiviral potential of tetherin. Further, using IAV as disease model, we provide existing evidence in favor and against tetherin being considered as an antiviral candidate. Subsequent analysis of the experimental procedures across IAV‐tetherin published reports revealed that the experimental setup (ie, cell lines, transfection reagents, and multiplicity of infection), strain‐specific activity of NS1, and differing roles of NS1 in different cell lines may add up to the contributing factors leading to the discrepancies observed.     

Concomitant and noncanonical JAK2 and MPL mutations in JAK2V617F‐ and MPLW515 L‐positive myelofibrosis

Sequential genotyping for phenotype‐driver mutations in JAK2 (exon 14), CALR (exon 9), and MPL (exon 10) is recommended in patients with myeloproliferative neoplasms. Yet, atypical JAK2‐ and MPL‐mutations were described in some triple‐negative patients. Whether noncanonical and/or concomitant JAK2‐ and MPL‐mutations exist in myelofibrosis (MF) regardless of phenotype‐driver mutations is not yet elucidated. For this, next‐generation sequencing (NGS) was performed using blood genomic DNA from 128 MF patients (primary MF, n = 93; post‐ET–MF, n = 18; post‐PV–MF, n = 17). While no atypical JAK2‐ or MPL‐mutations were seen in 24 CALR‐positive samples, two JAK2‐mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected in two of the 21 (9.5%) triple‐negative patients. Twelve of the 82 (14.6%) JAK2V617F‐positive cases had coexisting germline JAK2‐mutations [JAK2R1063H, n = 6; JAK2R893T, n = 1; JAK2T525A, n = 1] or at least one somatic MPL‐mutation [MPLY591D, n = 3; MPLW515 L, n = 2; MPLE335K, n = 1]. Overall, MPL‐mutations always coexisted with JAK2V617F and/or other MPL‐mutations. None of the JAK2V617F plus a second JAK2‐mutation carried a TET2‐mutation but all patients with JAK2V617F plus an MPL‐mutation harbored a somatic TET2‐mutation. Four genomic clusters could be identified in the JAK2V617F‐positive cohort. Cluster‐I (10%) (noncanonical JAK2_{mutated (mut)} + TET2_{wildtype (wt)}) were younger and had less proliferative disease compared with cluster‐IV (5%) (TET2_mut + MPL_mut). In conclusion, recurrent concomitant classical and/or noncanonical JAK2‐ and MPL‐mutations could be detected by NGS in 15.7% of JAK2V617F‐ and MPLW515‐positive MF patients with genotype‐phenotype associations. Many of the germline and/or somatic mutations might act as “Significantly Mutated Genes” contributing to the pathogenesis and phenotypic heterogeneity. A cost‐effective NGS‐based approach might be an important step towards patient‐tailored medicine.     

New 1,2,3‐triazole‐based analogues of benznidazole for use against Trypanosoma cruzi infection: In vitro and in vivo evaluations

Chagas disease has spread throughout the world mainly because of the migration of infected individuals. In Brazil, only benznidazole (Bnz) is used; however, it is toxic and not active in the chronic phase, and cases of resistance are described. This work aimed at the synthesis and the trypanocidal evaluation in vitro and in vivo of six new Bnz analogues ( 3–8 ). They were designed by exploring the bioisosteric substitution between the amide group contained in Bnz and the 1,2,3‐triazole ring. All the compounds were synthesized in good yields. With the exception of compound 7 , the in vitro biological evaluation shows that all Bnz analogues were active against the amastigote form, whereas only compounds 3 , 4 , 5 , and 8 were active against trypomastigote. Compounds 4 and 5 showed the most promising activities in vitro against the form of trypomastigote, being more active than Bnz. In vivo evaluation of compounds, 3–8 showed lower potency and higher toxicity than Bnz. Although the 1,2,3‐triazole ring has been described in the literature as an amide bioisostere, its substitution here has reduced the activity of the compounds and made them more toxic. Thus, further molecular optimization could provide novel therapeutic agents for Chagas’ disease.     

Interaction of antivirals with a heptameric bundle model of the p7 protein of hepatitis C virus

A series of ligands are known experimentally to affect the infectivity cycle of the hepatitis C virus. The target protein for the ligands is proposed to be p7, a 63 amino acid polytopic channel‐forming protein, with possibly two transmembrane domains. Protein p7 is found to assemble into functional oligomers of various sizes, depending on the genotype (GT). Nine ligands are docked to various sites of a computationally derived heptameric bundle of p7 of GT1a. The energy of interaction, here binding energy, is calculated using three different docking programs (Autodock , MOE , LeadIT ). Three protein regions are defined to which the ligands are placed, the loop region and the site with the termini as well as the mid‐region which is supposed to track poses inside the putative pore. A common feature is that the loop sites and poses either within the pore or at the intermonomer space of the bundle are preferred for all ligands with proposed binding energies smaller than −10 kJ/mol. BIT225, benzamine, amantadine, and NN‐DNJ show good overall scoring.     

Graphene oxide regulates cox2 in human embryonic kidney 293T cells via epigenetic mechanisms: dynamic chromosomal interactions

To extend the applications of engineered nanomaterials, such as graphene oxide (GO), it is necessary to minimize cytotoxicity. However, the mechanisms underlying this cytotoxicity are unclear. Dynamic chromosomal interactions have been used to illustrate the molecular bases of gene expression, which offers a more sensitive and cutting-edge technology to elucidate complex biological processes associated with epigenetic regulations. In this study, the role of GO-triggered chromatin interactions in the activation of cox2, a hallmark of inflammation, was investigated in normal human cells. Using chromosome conformation capture technology, we showed that GO triggers physical interactions between the downstream enhancer and the cox2 promoter in human embryonic kidney 293T (293T) via p65 and p300 complex-mediated dynamic chromatin looping, which was required for high cox2 expression. Moreover, tumor necrosis factor-α (TNF-α), located upstream of the p65 signaling pathway, contributed to the regulation of cox2 activation through dynamic chromatin architecture. Compared with pristine GO and aminated GO (GO-NH₂), poly (acrylic acid)-functionalized GO (GO-PAA) induced a weaker inflammatory response and a weaker effect on chromatin architecture. Our results mechanistically link GO-mediated chromatin interactions with the regulation of cox2 and suggest that GO derivatives may minimize toxicity in practical applications.     

Satiety and memory enhancing effects of a high-protein meal depend on the source of protein

Objective: High- protein diets have become increasingly popular with various touted benefits. However, the extent to which protein quantity and source affects cognitive functioning through altering postprandial amino acid profiles has not been investigated. Further, whether all protein sources are similarly anorexigenic is uncertain. The objective of this study was to determine the influence of protein level and source on Barnes maze performance, satiety and plasma amino acid levels in male Sprague-Dawley rats.

Methods: Rats were entrained to a meal-feeding schedule consisting of a 30 minutes meal, equivalent to 20% of average daily intake, one hour into the dark phase then ad libitum access to food for 5 h. On test days, rats received one of three isocaloric diets as their first meal, hereafter referred to as Egg White (EW), Wheat Gluten (WG), or Basal, and then were measured for cognitive performance, feeding behavior, or plasma amino acid levels via jugular catheter. Percentage energy from protein was 35% for both EW and WG and 20% for Basal with equal amounts provided by EW and WG proteins.

Results: Rats provided EW performed similarly to Basal on the Barnes maze, whereas WG performed worse. EW increased satiety, whereas WG reduced satiety relative to Basal. Both EW and WG increased postprandial concentrations of large neutral and branched chain amino acids relative to Basal, but in EW, concentrations were slower to peak, and peaked to a higher level than WG.

Discussion: Results demonstrate the importance of protein source for cognition and satiety enhancing effects of a high-protein meal.     

An indoor air quality evaluation in a residential retrofit project using spray polyurethane foam

Understanding of indoor air quality (IAQ) during and after spray polyurethane foam (SPF) application is essential to protect the health of both workers and building occupants. Previous efforts such as field monitoring, micro-chamber/spray booth emission studies, and fate/transport modeling have been conducted to understand the chemical exposure of SPF and guide risk mitigation strategies. However, each type of research has its limitation and can only reveal partial information on the relationship between SPF and IAQ. A comprehensive study is truly needed to integrate the experimental design and analytical testing methods in the field/chamber studies with the mathematical tools employed in the modeling studies. This study aims to bridge this gap and provide a more comprehensive understanding on the impact of SPF to IAQ. The field sampling plan of this research aims to evaluate the airborne concentrations of methylene diphenyl diisocyanate (MDI), formaldehyde, acetaldehyde, propionaldehyde, tris(1-chlor-2-propyl)phosphate (TCPP), trans-1-chloro-3,3,3-trifluoropropene (Solstice^TM), and airborne particles. Modifications to existing MDI sampling and analytical methods were made so that level of quantification was improved. In addition, key fate and transport modeling input parameters such as air changes per hour and airborne particle size distribution were measured. More importantly, TCPP accumulation onto materials was evaluated, which is important to study the fate and transport of semi-volatile organic compounds. The IAQ results showed that after spray application was completed in the entire building, airborne concentrations decreased for all chemicals monitored. However, it is our recommendation that during SPF application, no one should return to the application site without proper personal protection equipment as long as there are active spray activities in the building. The comparison between this field study and a recent chamber study proved surface sorption and particle deposition is an important factor in determining the fate of airborne TCPP. The study also suggests the need for further evaluation by employing mathematical models, proving the data generated in this work as informative to industry and the broader scientific community.     

Dephosphorylation of myo-inositol phosphates in the in vitro intestinal Caco-2 cell model

Plant and microbial phytases present in raw materials can cause a dephosphorylation of phytate (myo-inositol hexakisphosphate) (InsP₆)) during food processing resulting in a broad range of different myo-inositol phosphates such as pentakisphosphate (InsP₅) and tetrakisphosphate (InsP₄) in foods. Here, we investigated whether the human intestinal epithelium is able to dephosphorylate myo-inositol phosphates (InsP₆, InsP₅-, InsP₄-, InsP₃-isomers) using an in vitro model with differentiated human Caco-2 cells cultured on semipermeable inserts. Incubation of InsP₆ and an InsP₅-isomer with cells for 3?h showed no dephosphorylation of both InsPs. Treatment of cells with a mixture of different InsP₄-isomers, however, caused a formation of about 3.5% of an InsP₃-isomer (Ins(1,5,6)P₃) and treatment with a mixture of different InsP₃-isomers caused about 20% formation of InsP₂-isomers, respectively. Thus, human intestinal cells can contribute to the dephosphorylation of myo-inositol phosphates of partly dephosphorylated forms such as InsP₃ and InsP₄.     

Immunoprotection elicited in rabbit by a chimeric protein containing B-cell epitopes of Sphingomyelinases D from Loxosceles spp. spiders

Accidents with venomous animals pose a health issue in Brazil, and those involving brown spiders (Loxosceles sp.) figure between the most frequent ones. The accidental envenomation by brown spiders causes a strong local dermonecrotic effect, which can be followed by systemic manifestations that in some cases lead to death. The production of antivenoms for the treatments of such accidents relies on a variety of animal experiments, from the spider venom extraction to the production of antivenom in horses. In the present work, there is an attempt to reduce and optimize animal experiments with the construction and production of a chimeric protein, named Lil, containing immunodominant epitopes previously mapped from the main proteins of the Loxosceles venom, the Sphingomyelinases D. The Lil protein contains epitopes from Sphinomyelinases D of the three-main species found in Brazil and this chimeric protein was found capable of inducing antibodies with the potential to partially neutralize the toxic effects of Loxosceles intermedia venom in an animal model. Therefore, in order to reduce spider usage and to improve the lifespan of the horses used for immunization we suggest the Lil protein as a potential candidate to replace the venom usage in the antivenom production protocols.     

南京市城区居民家庭人均收入与自我报告2型糖尿病关系

目的了解江苏省南京市城区居民以家庭人均收入为指标的社会经济状况与自我报告2型糖尿病之间的关系。方法采用横断面研究方法,于2011年8—9月对南京市4个城区的年满35岁并在当地居住满5年的9 446名常住居民进行调查。结局变量为调查对象自我报告的2型糖尿病,解释性变量为家庭人均收入(三等分)。结果南京市城区居民中自我报告2型糖尿病的患病率为8.2%(95%CI=7.59%~8.80%),存在明显的年龄分布差异,但性别间的分布差异无统计学意义。经多因素调整后,家庭人均收入与自我报告2型糖尿病的患病风险之间存在正向的剂量–反应关系,与低收入相比,中、高收入者患2型糖尿病的风险分别增加35%(OR=1.35,95%CI=1.06~1.74)和58%(OR=1.58,95%CI=1.23~2.02);年龄越大、高收入者患2型糖尿病的风险越大。结论家庭人均收入与南京市城区居民自我报告2型糖尿病存在密切的流行病学联系。