The four hexamerin genes in the honey bee: structure,molecular evolution and function deduced from expression patterns in queens,workers and drones

Background  

Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens.     

Development of allelic discrimination assay to detect Mediterranean G6PD mutation and its linked inheritance with normal vision and/colorblindness loci for 4 generations among Egyptian and Emirati families

G6PD deficiency c563T is the most common inherent blood disease among the Mediterranean populations and its molecular diagnosis is critical as the enzyme assay fails for heterozygous individuals. The purpose of the study is to estimate the ubiquity of the heterozygous G6PD Med (c563T) variants among Egyptians and UAE nationals living in Dubai. We validated two molecular methods, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and qPCR allelic discrimination assay for detection of G6PD Med variants. Among 100 screened individuals, G6PD c563T variants are 30% of whom 15% are carriers. Sanger sequencing validated the qPCR discrimination assays. In search of a phenotypic marker to detect G6PD heterozygous variants, inheritance of G6PD locus and red-green color vision genes is studied in 1 Egyptian and 2 Emirati families. Among the 3 families, G6PD is polymorphic, displaying 4 phenotypes: in phenotype-1, person is normal, in phenotype-2 the person has no G6PD deficiency but with deuteranopia/deuteranomaly, in phenotype-3 the person is G6PD Med variant with deuteranopia/deuteranomaly and in phenotype 4 the person is G6PD Med variant has normal vision. Based on the molecular analysis of G6PD and Ishihara vision test it can be concluded that the two mutations at the two loci arose independent of each other without any interaction (epistatic effect) between them. Following the pedigree analysis of the two genes for 4 generations it is presumed that it is infeasible to use “deuteranopia /deuteranomaly” as a phenotypic marker to detect G6PD c563T heterozygous individuals among the Egyptian populations.     

Drug-metabolizing enzymes and praziquantel bioavailability in mice harboring Schistosoma mansoni isolates of different drug susceptibilities

The level of drug-metabolizing enzymes (cytochrome P450 [CYP450] and cytochrome b5 [cyt b5]) and the bioavailability of praziquantel (PZQ) were investigated in batches of mice infected with Schistosoma mansoni displaying either a decreased susceptibility to PZQ ("EE2" and "BANL"-isolates), or a normal susceptibility to the drug ("CD" isolate). Each batch was divided into 2 groups. The first group was further subdivided into 5 subgroups. Subgroups 1 to 4 were treated 7 wk postinfection (PI) with oral PZQ at 25, 50, 100, and 200 mg/kg for 5 consecutive days, whereas the fifth subgroup was administered the vehicle only as control. Animals were perfused 9 wk PI, and worms were counted to estimate PZQ ED50. CYP450 and cyt b5 were examined in hepatic microsomes of infected untreated mice and of infected mice treated with 25 and 200 mg/ kg PZQ. The second group was given PZQ 7 wk PI and was further subdivided into 11 subgroups, killed at 2, 5, 15, 30, 60, 90, 120, 150, 180, 240, and 360 min postdosing to study pharmacokinetic parameters of PZQ. Mice harboring S. mansoni isolates having higher PZQ ED50 (170.3 mg/kg for EE2 and 249.9 mg/kg for BANL vs. 82.96 mg/kg for CD) had higher levels of CYP450 and cyt b5, a PZQ Cmax decreased by 19-30% and area under the serum concentration-time curve0-6 hr decreased by 57-74%. Data suggest that S. mansoni isolates that are less sensitive to PZQ induce a lower inhibition of hepatic drug-metabolizing enzymes, with a consequently higher metabolic transformation of PZQ.     

The protective effect of melatonin in lungs of newborn rats exposed to maternal nicotine

We investigated possible healing effects of melatonin (MEL) on biochemical and histological changes in the lungs of rat offspring caused by exposure to nicotine (NT) in utero. Pregnant rats were divided randomly into five groups. The SP group was treated with physiological saline. The EA group was treated with ethyl alcohol. The MEL group was treated with MEL. The NT group was treated with NT. The NT + MEL group was treated with NT and MEL. At the end of the study, the biochemistry and histopathology of lung tissue of the offspring were examined. Reduced alveolar development and increased numbers of alveolar macrophages and mast cells were observed in the NT group compared to the SP, EA and MEL groups. We also found increased malondialdehyde (MDA) levels and decreased total glutathione (GSH) levels in the NT group. Application of MEL ameliorated the histological and biochemical damage caused by NT. The number of alveoli was greater in the NT + MEL group than in the NT group. Also, the increased numbers of alveolar macrophages and mast cells resulting from exposure to NT were decreased following MEL treatment. We found that MEL caused a significant decrease in the level of MDA. Maternal exposure to NT caused significant structural and biochemical changes in the lungs of the offspring and administration of MEL ameliorated the changes.     

New nitric oxide donating 1,2,4-triazole/oxime hybrids: Synthesis,investigation of anti-inflammatory,ulceroginic liability and antiproliferative activities

A series of novel nitric oxide (NO) donating triazole/oxime hybrids was prepared and evaluated for their anti-inflammatory activity. Most of the tested compounds showed significant anti-inflammatory activity using carrageenan-induced rat paw edema method compared to indomethacin. Calculation of the ulcer indices and histopathological investigation indicated that the prepared NO-donating oximes exhibited less ulcerogenicity compared to their intermediate ketones and indomethacin. The NO-donating oxime 6i revealed significant activity against renal cancer A498 cell lines with 50.52 cell growth inhibition.     

Post-transcriptional gene silencing of root-knot nematode in transformed soybean roots

RNAi constructs targeted to four different genes were examined to determine their efficacy to reduce galls formed by Meloidogyne incognita in soybean roots. These genes have high similarity with essential soybean cyst nematode (Heterodera glycines) and Caenorhabditis elegans genes. Transformed roots were challenged with M. incognita. Two constructs, targeted to genes encoding tyrosine phosphatase (TP) and mitochondrial stress-70 protein precursor (MSP), respectively, strongly interfered with M. incognita gall formation. The number of galls formed on roots transformed with constructs targeting the M. incognita TP and MSP genes was reduced by 92% and 94.7%, respectively. The diameter of M. incognita inside these transformed roots was 5.4 and 6.5 times less than the diameter of M. incognita found inside control plants transformed with the empty vector. These results indicate that silencing the genes encoding TP and MSP can greatly decrease gall formation and shows a promising solution for broadening resistance of plants against this plant-parasitic nematode.     

Synthesis and in vitro cytotoxic activity of novel pyrazolo[3,4-d]pyrimidines and related pyrazole hydrazones toward breast adenocarcinoma MCF-7 cell line

New series of pyrazolo[3,4-d]pyrimidines (7a-e and 13a-d) and pyrazole hydrazones 17a-d were synthesized and evaluated for their antiproliferative activity against human breast adenocarcinoma MCF-7 cell line. Most of the tested compounds exploited potent to moderate growth inhibitory activity, in particular compound 7e exhibited superior potency to the reference drug cisplatin (IC(50)=7.60 and 13.29 μM, respectively). The antitumor activity of the new compounds was accompanied by significant increase in the activity of superoxide dismutase with concomitant decrease in the activities of catalase and glutathione peroxidase and reduced glutathione level. Accordingly, the overproduction of hydrogen peroxide, nitric oxide and other free radicals allowed reactive oxygen species (ROS)-mediated tumor cells death, as monitored by reduction in the synthesis of protein and nucleic acids.     

Polo‐like kinase‐1 triggers histone phosphorylation by Haspin in mitosis

Histone modifications coordinate the chromatin localization of key regulatory factors in mitosis. For example, mitotic phosphorylation of Histone H3 threonine‐3 (H3T3ph) by Haspin creates a binding site for the chromosomal passenger complex (CPC). However, how these histone modifications are spatiotemporally controlled during the cell cycle is unclear. Here we show that Plk1 binds to Haspin in a Cdk1‐phosphorylation‐dependent manner. Reducing Plk1 activity decreases the phosphorylation of Haspin and inhibits H3T3ph, particularly in prophase, suggesting that Plk1 is required for initial activation of Haspin in early mitosis. These studies demonstrate that Plk1 can positively regulate CPC recruitment in mitosis.     

Synovial T cell hyporesponsiveness to myeloid dendritic cells is reversed by preventing PD-1/PD-L1 interactions

Introduction

The aim of this study was to investigate PD-1/PD-L1 involvement in the hyporesponsiveness of rheumatoid arthritis (RA) synovial fluid (SF) CD4 T cells upon stimulation by thymic stromal lymphopoietin (TSLP)–primed CD1c myeloid dendritic cells (mDCs).

Methods

Expression of PD-1 on naïve (Tn), central memory (Tcm) and effector memory (Tem) CD4 T cell subsets was assessed by flow cytometry. PD-L1 expression and its regulation upon TSLP stimulation of mDCs from peripheral blood (PB) and SF of RA patients were investigated by quantitative RT-PCR and flow cytometry. The involvement of PD-1/PD-L1 interactions in SF T cell hyporesponsiveness upon (TSLP-primed) mDC activation was determined by cell culture in the presence of PD-1 blocking antibodies, with or without interleukin 7 (IL-7) as a recognized suppressor of PD-1 expression.

Results

PD-1 expression was increased on CD4 T cells derived from SF compared with PB of RA patients. TSLP increased PD-L1 mRNA expression in both PB and SF mDCs. PD-L1 protein expression was increased on SF mDCs compared with PB mDCs and was associated with T cell hyporesponsiveness. Blockade of PD-1, as well as IL-7 stimulation, during cocultures of memory T cells and (TSLP-primed) mDCs from RA patients significantly recovered T cell proliferation.

Conclusion

SF T cell hyporesponsiveness upon (TSLP-primed) mDC stimulation in RA joints is partially dependent on PD-1/PD-L1 interactions, as PD-1 and PD-L1 are both highly expressed on SF T cells and mDCs, respectively, and inhibiting PD-1 availability restores T cell proliferation. The potential of IL-7 to robustly reverse this hyporesponsiveness suggests that such proinflammatory cytokines in RA joints strongly contribute to memory T cell activation.     

Magnetite Nanoparticles Inhibit Tumor Growth and Upregulate the Expression of P53/P16 in Ehrlich Solid Carcinoma Bearing Mice

Background

Magnetite nanoparticles (MNPs) have been widely used as contrast agents and have promising approaches in cancer treatment. In the present study we used Ehrlich solid carcinoma (ESC) bearing mice as a model to investigate MNPs antitumor activity, their effect on expression of p53 and p16 genes as an indicator for apoptotic induction in tumor tissues.

Method

MNPs coated with ascorbic acid (size: 25.0±5.0 nm) were synthesized by co-precipitation method and characterized. Ehrlich mice model were treated with MNPs using 60 mg/Kg day by day for 14 injections; intratumorally (IT) or intraperitoneally (IP). Tumor size, pathological changes and iron content in tumor and normal muscle tissues were assessed. We also assessed changes in expression levels of p53 and p16 genes in addition to p53 protein level by immunohistochemistry.

Results

Our results revealed that tumor growth was significantly reduced by IT and IP MNPs injection compared to untreated tumor. A significant increase in p53 and p16 mRNA expression was detected in Ehrlich solid tumors of IT and IP treated groups compared to untreated Ehrlich solid tumor. This increase was accompanied with increase in p53 protein expression. It is worth mentioning that no significant difference in expression of p53 and p16 could be detected between IT ESC and control group.

Conclusion

MNPs might be more effective in breast cancer treatment if injected intratumorally to be directed to the tumor tissues.