Cutaneous lymphocyte antigen expression on activated lymphocytes and its association with IL-12R (beta1 and beta2), IL-2Ralpha, and CXCR3

The majority of T lymphocytes that infiltrate psoriatic lesions express cutaneous lymphocyte antigen (CLA), a skin homing receptor involved in the influx of memory T cells to cutaneous sites. We investigated CLA expression on normal human peripheral blood mononuclear cells (PBMCs) and evaluated its association with IL-12 receptors, chemokine receptor, CXCR3, and IL-2Ralpha. PBMCs were stimulated in vitro with or without polyclonal activators (mitogen, or superantigens, or anti-CD3+anti-CD28) in the presence or absence of exogenous rhIL-12. The percentage of CLA+ T lymphocytes increased significantly after superantigen stimulation compared to anti-CD3+anti-CD28 or mitogen activation. The majority of activation induced CLA+ T lymphocytes co-expressed IL-12Rbeta1, IL-12Rbeta2, CXCR3, and CD25 in the presence of rhIL-12. Our results indicate that CLA expression on activated T lymphocytes is IL-12 and activation dependent and correlates with the expression of IL-12 receptors, IL-2Ralpha, and CXCR3. Monitoring the levels of Th1 differentiation markers such as CXCR3 and IL-12Rbeta2 along with activation marker, CD25 on skin homing CLA+ T lymphocytes may provide insight into the mechanism of action of immunotherapies directed against Th1 type skin inflammatory diseases.     

Modulation of Lactate Dehydrogenase Isozymes by Modified Base Queuine

The modified base queuine is a nutrient factor for lower and higher eukaryotes except yeast. It is synthesized in eubacteria and inserted into the wobble position of specific tRNAs (tRNA_GUN) in exchange of guanine at position 34. The tRNAs of Q family are completely modified in terminally differentiated somatic cells. However, mainly free queuine is present in embryonic and fast proliferating cells, tRNA remains Q deficient. Lactate dehydrogenase (LDH) A mRNA and LDH A protein is known to increase when cells are grown in hypoxic conditions. In the present study, the level of LDH isozymes is analyzed in different tissues of normal and cancerous (DLA) mice and the effect of queuine treatment on LDH isozyme is observed. LDH A isozyme is shown to increase in serum and liver of DLA mice. The level and activity of LDH A decreases on queuine treatment. In skeletal muscle and heart, LDH A isozyme decreases while LDH B increases in DLA mice. Queuine administration leads to change back towards normal. In case of brain, LDH A increases but LDH B decreases in DLA mice. Queuine treatment leads to decrease in A4 anaerobic isozymes of LDH. The results suggest that queuine suppresses anaerobic glycolytic pathway, which leads to tumor suppression of DLA mice.     

RNA interference of dual oxidase in the plant nematode Meloidogyne incognita

RNA interference (RNAi) is a powerful tool for the analysis of gene function in model organisms such as the nematode Caenorhabditis elegans. Recent demonstrations of RNAi in plant parasitic nematodes provide a stimulus to explore the potential of using RNAi to investigate disruption of gene function in Meloidogyne incognita, one of the most important nematode pests of global agriculture. We have used RNAi to examine the importance of dual oxidases (peroxidase and NADPH oxidase), a class of enzyme associated with extracellular matrix cross-linking in C. elegans. RNAi uptake by M. incognita juveniles is highly efficient. In planta infection data show that a single 4-h preinfection treatment with double-stranded RNA derived from the peroxidase region of a dual oxidase gene has effects on gene expression that are phenotypically observable 35 days postinfection. This RNAi effect results in a reduction in egg numbers at 35 days of up to 70%. The in vitro feeding strategy provides a powerful tool for identifying functionally important genes, including those that are potential targets for the development of new agrochemicals or transgenic resistance strategies.     

Identification of sites in adenovirus hexon for foreign peptide incorporation

Adenovirus type 5 (Ad5) is one of the most promising vectors for gene therapy applications. Genetic engineering of Ad5 capsid proteins has been employed to redirect vector tropism, to enhance infectivity, or to circumvent preexisting host immunity. As the most abundant capsid protein, hexon modification is particularly attractive. However, genetic modification of hexon often results in failure of rescuing viable viruses. Since hypervariable regions (HVRs) are nonconserved among hexons of different serotypes, we investigated whether the HVRs could be used for genetic modification of hexon by incorporating oligonucleotides encoding six histidine residues (His6) into different HVRs in the Ad5 genome. The modified viruses were successfully rescued, and the yields of viral production were similar to that of unmodified Ad5. A thermostability assay suggested the modified viruses were stable. The His6 epitopes were expressed in all modified hexon proteins as assessed by Western blotting assay, although the intensity of the reactive bands varied. In addition, we examined the binding activity of anti-His tag antibody to the intact virions with the enzyme-linked immunosorbent assay and found the His6 epitopes incorporated in HVR2 and HVR5 could bind to anti-His tag antibody. This suggested the His6 epitopes in HVR2 and HVR5 were exposed on virion surfaces. Finally, we examined the infectivities of the modified Ad vectors. The His6 epitopes did not affect the native infectivity of Ad5 vectors. In addition, the His6 epitopes did not appear to mediate His6-dependent viral infection, as assessed in two His6 artificial receptor systems. Our study provided valuable information for studies involving hexon modification.     

5-Aminosalicylic acid reverses endosulfan-induced testicular toxicity in male rats

Pre-treatment with 5-aminosalicylic acid (5-ASA) significantly reduced sperm-shape abnormalities in endosulfan-treated rats. The number of abnormal sperm in the epididymis was markedly increased by endosulfan treatment but pre-treatment with 5-ASA kept these values close to normal. Treatment with 5-ASA at a dose of 25 mg/kg bw was more effective in reducing sperm-shape abnormality and sperm count than at a dose of 50 mg/kg bw. Endosulfan significantly increased the level of lactate dehydrogenase (LDH) in rats but a marked decrease was observed upon pre-treatment with 25 mg/kg bw 5-ASA. Changes in plasma testosterone levels were not significantly correlated with 5-ASA pre-treatment but histopathological analysis of seminiferous tubules and Leydig cells showed significant protection from endosulfan-induced tissue damage such as necrosis. The population of Sertoli cells increased and the lumen of the seminiferous tubules contained a greater number of spermatids. There was a corresponding increase in the number of Leydig cells. A curative study with 5-ASA showed a similar protection from endosulfan-induced toxicity and cellular damage, but the extent of protection was significantly lower.     

Tigerinins: novel antimicrobial peptides from the Indian frog Rana tigerina

Four broad-spectrum, 11 and 12 residue, novel antimicrobial peptides have been isolated from the adrenaline-stimulated skin secretions of the Indian frog Rana tigerina. Sequences of these peptides have been determined by automated Edman degradation, by mass spectral analysis and confirmed by chemical synthesis. These peptides, which we have named as tigerinins, are characterized by an intramolecular disulfide bridge between two cysteine residues forming a nonapeptide ring. This feature is not found in other amphibian peptides. Conformational analysis indicate that the peptides tend to form beta-turn structures. The peptides are cationic and exert their activity by permeabilizing bacterial membranes. Tigerinins represent the smallest, nonhelical, cationic antimicrobial peptides from amphibians.     

Chitin-supplemented formulations improve biocontrol and plant growth promoting efficiency of Bacillus subtilis AF 1

Formulations of a chitinolytic biocontrol and a plant growth promoting Bacillus subtilis AF 1 were prepared in peat, in peat supplemented with either 0.5% chitin or Aspergillus niger mycelium, or in spent compost obtained from Agaricus bisporus cultivation and were evaluated for biocontrol of two fungal pathogens and plant growth promoting activities on pigeon pea and groundnut. A steady increase in cell numbers of introduced B. subtilis AF 1 was observed in all the formulations at 30 degrees C. The increase in cell numbers was about 5.0 log units. Peat or spent compost inoculated with physiologically active and dormant states of B. subtilis AF 1 showed different time period requirements to attain maximum cell numbers. The presence of chitin or A. niger (in peat) or A. bisporus (in spent compost) as supplement in the carrier material improved the multiplication of B. subtilis AF 1. When used as seed treatments, formulations of AF 1 in peat supplemented with chitin or chitin-containing materials showed better control of A. niger (causing crown rot of groundnut) and Fusarium udum (causing wilt of pigeon pea) than AF 1 culture alone, in both groundnut and pigeon pea. Bacillus subtilis AF 1 formulations promoted seed germination and biomass of both groundnut and pigeon pea even under pathogen pressure. Survival of AF 1 on fresh culture-treated and formulation product-treated plants was similar in pathogen-infested soil.     

Bromodomain and extra-terminal (BET) family proteins: New therapeutic targets in major diseases

The bromodomains and extra-terminal domain (BET) family proteins recognize acetylated chromatin through their bromodomains (BDs) and help in regulating gene expression. BDs are chromatin ‘readers’: by interacting with acetylated lysines on the histone tails, they recruit chromatin-regulating proteins on the promoter region to regulate gene expression and repression. Extensive efforts have been employed by scientific communities worldwide to identify and develop potential inhibitors of BET family BDs to regulate protein expression by inhibiting acetylated histone (H3/H4) interactions. Several small molecule inhibitors have been reported, which not only have high affinity but also have high specificity to BET BDs. These developments make BET family proteins an important therapeutic targets for major diseases such as cancer, neurological disorders, obesity and inflammation. Here, we review and discuss the structural biology of BET family BDs and their applications in major diseases.     

α-Tocopherol prevents lymphoma by improving antioxidant defence system of mice

Increased level of ROS causes oxidative stress and leads to various pathological conditions including cancer. Therefore antioxidants should contribute to cancer prevention by improving antioxidant defense system and thereby protecting the cell from oxidative damage. In the present study we have validated the hypothesis by evaluating the antioxidant action of α-tocopherol. The effect of α-tocopherol is analyzed on oxidative stress as well as its regulation on antioxidant defense system. Oxidative stress is measured in terms of reduced glutathione and protein carbonylation. To evaluate the role of α-tocopherol on antioxidant defense system, the activities and expressions of antioxidant enzymes like glutathione peroxidase, catalase and superoxide dismutase are analyzed by activity gel assay and by RT-PCR respectively. These enzyme activities and/or expressions are found to be improved by α-tocopherol in lymphoma bearing mice which brings down the oxidative stress as reflected by increased level of reduced glutathione as well as decreased protein carbonylation. The effect of α-tocopherol is further analyzed on general characteristics of lymphoma growth like body weight, longevity, accumulation of ascites fluid, angiogenesis in peritoneum, morphology of liver and abundance of lymphocytes. The antioxidant α-tocopherol is found to check lymphoma growth. The results suggest that α-tocopherol contributes to lymphoma prevention by improving antioxidant defence system of mice.     

Choline: Selective enhancement of serial learning and encoding of low imagery words in man

The effect of a single oral dose of choline chloride (10g) on two kinds of memory measures (serial learning and a selective reminding task) was studied in 10 normal volunteers. Choline decreased significantly the number of trials required to master a serial learning word test. On the selective reminding task only the recall of poorly imageable words (which are ordinarily difficult to remember) was enhanced by choline. Words which were highly imageable (and ordinarily easy to remember) were unaffected. The degree of enhancement with choline correlated inversely with performance of subjects on placebo. Our data indicate that brain acetylcholine may play a facilitatory role in encoding and storage of specific information items in man.