In Vivo Assessment of Cold Tolerance through Chlorophyll-a Fluorescence in Transgenic Zoysiagrass Expressing Mutant Phytochrome A

Chlorophyll-a fluorescence analysis provides relevant information about the physiology of plants growing under abiotic stress. In this study, we evaluated the influence of cold stress on the photosynthetic machinery of transgenic turfgrass, Zoysia japonica, expressing oat phytochrome A (PhyA) or a hyperactive mutant phytochrome A (S599A) with post-translational phosphorylation blocked. Biochemical analysis of zoysiagrass subjected to cold stress revealed reduced levels of hydrogen peroxide, increased proline accumulation, and enhanced specific activities of antioxidant enzymes compared to those of control plants. Detailed analyses of the chlorophyll-a fluorescence data through the so-called OJIP test exhibited a marked difference in the physiological status among transgenic and control plants. Overall, these findings suggest an enhanced level of cold tolerance in S599A zoysiagrass cultivars as reflected in the biochemical and physiological analyses. Further, we propose that chlorophyll-a fluorescence analysis using OJIP test is an efficient tool in determining the physiological status of plants under cold stress conditions.     

Screening of marine actinobacteria for amylase enzymes inhibitors

Amylase inhibitor producing actinobacteria were isolated and characterized from terrestrial environment and there is no much report found from marine environment, hence in the present study, 17 strains isolated from the rhizosphere sediments of mangroves were tested for their amylase inhibition ability. Seawater requirement test for the growth of actinobacteria found that the strains SSR-3, SSR-12 and SSR-16 requires at least 50% and SSR-6 requires at least 25% seawater for their growth. The inhibition activity of both prokaryotic and eukaryotic amylase was tested by using Bacillus subtilis and Aspergillus niger. The maximum amylase activity (40mm) produced by the A. niger was taken as positive control, when the test actinobacteria strains grown in the medium they inhibited amylase activity and was evidenced by the reduction in inhibition zone (14–37 mm) similarly the amylase produced by the Bacillus subtilis was also recorded maximum (35 mm) amylase activity and was taken as positive control, and the test atinobacterial strains reduced enzyme action(12–33 mm) it varied levals. This indicates that the actinobacteria strains were controlled amylase enzyme activity in both the cases. The strain SSR-10 was highly effective and SSR-8 was less effective in inhibiting eukaryotic amylase produced by A. niger. The strain SSR-2 was effective and SSR-6 showed very less effect in inhibiting the prokaryotic amylase produced by the B subtilis.     

Epigenetic regulator MLL2 shows altered expression in cancer cell lines and tumors from human breast and colon

Background  

MLL2, an epigenetic regulator in mammalian cells, mediates histone 3 lysine 4 tri-methylation (H3K4me3) through the formation of a multiprotein complex. MLL2 shares a high degree of structural similarity with MLL, which is frequently disrupted in leukemias via chromosomal translocations. However, this structural similarity is not accompanied by functional equivalence. In light of this difference, and previous reports on involvement of epigenetic regulators in malignancies, we investigated MLL2 expression in established cell lines from breast and colon tissues. We then investigated MLL2 in solid tumors of breast and colon by immunohistochemistry, and evaluated potential associations with established clinicopathologic variables.     

Disrupted-In-Schizophrenia 1 regulates integration of newly generated neurons in the adult brain

Adult neurogenesis occurs throughout life in discrete regions of the adult mammalian brain. Little is known about the mechanism governing the sequential developmental process that leads to integration of new neurons from adult neural stem cells into the existing circuitry. Here, we investigated roles of Disrupted-In-Schizophrenia 1 (DISC1), a schizophrenia susceptibility gene, in adult hippocampal neurogenesis. Unexpectedly, downregulation of DISC1 leads to accelerated neuronal integration, resulting in aberrant morphological development and mispositioning of new dentate granule cells in a cell-autonomous fashion. Functionally, newborn neurons with DISC1 knockdown exhibit enhanced excitability and accelerated dendritic development and synapse formation. Furthermore, DISC1 cooperates with its binding partner NDEL1 in regulating adult neurogenesis. Taken together, our study identifies DISC1 as a key regulator that orchestrates the tempo of functional neuronal integration in the adult brain and demonstrates essential roles of a susceptibility gene for major mental illness in neuronal development, including adult neurogenesis.     

Low frequency and low intensity pulsed electromagnetic field exerts its antiinflammatory effect through restoration of plasma membrane calcium ATPase activity

Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting 1% of the population worldwide. Pulsed electromagnetic field (PEMF) has a number of well-documented physiological effects on cells and tissues including antiinflammatory effect. This study aims to explore the antiinflammatory effect of PEMF and its possible mechanism of action in amelioration of adjuvant induced arthritis (AIA). Arthritis was induced by a single intradermal injection of heat killed Mycobacterium tuberculosis at a concentration of 500 μg in 0.1 ml of paraffin oil into the right hind paw of rats. The arthritic animals showed a biphasic response regarding changes in the paw edema volume. During the chronic phase of the disease, arthritic animals showed an elevated level of lipid peroxides and depletion of antioxidant enzymes with significant radiological and histological changes. Besides, plasma membrane Ca²⁺ ATPase (PMCA) activity was inhibited while intracellular Ca²⁺ level as well as prostaglandin E₂ levels was noticed to be elevated in blood lymphocytes of arthritic rats. Exposure of arthritic rats to PEMF at 5 Hz × 4 μT × 90 min, produced significant antiexudative effect resulting in the restoration of the altered parameters. The antiinflammatory effect could be partially mediated through the stabilizing action of PEMF on membranes as reflected by the restoration of PMCA and intracellular Ca²⁺ levels in blood lymphocytes subsequently inhibiting PGE₂ biosynthesis. The results of this study indicated that PEMF could be developed as a potential therapy for RA in human beings.     

Robust anti-tumor immunity and memory in Rag-1-deficient mice following adoptive transfer of cytokine-primed splenocytes and tumor CD80 expression

Successful immunotherapy of solid tumors has proven difficult to achieve. The aim of the current study was to further investigate the effects of peripheral CD80-mediated co-stimulation on the efficacy of polyclonal anti-tumor effector CTL in an adoptive transfer model. Splenocytes obtained from wild-type mice immunized with CD80-transduced EL4 tumor cells were expanded in vitro in the presence of either IL-12 or IL-15 and irradiated CD80-transduced EL4 tumor cells. Polyclonal CD8 T cells were the major subset in the effector population. Primed effector cells were adoptively transferred into immuno-deficient Rag-1-deficient mice which were then challenged with syngeneic vector-control or CD80-transduced EL4 tumor cells. Expression of CD80 enhanced the elimination of EL4 tumors and mouse survival. Both IL-12 and IL-15 cultured cells had enhanced cytotoxicity. Importantly, anti-tumor memory was maintained without tumor evasion following re-challenge with either CD80-transduced and vector-control EL4 cells. We also show, using antibody-mediated depletion, that endogenous NK cells present in Rag-1-deficent mice exert anti-EL4 tumor activity that is enhanced by CD80 expression. Collectively these data show that peripheral co-stimulation by tumor expression of CD80 results in enhanced anti-tumor efficacy of NK and polyclonal effector T cells, and suggest that TCR repertoire diversity helps protect against tumor escape and provides memory with resultant robust immunity to subsequent tumor challenge irrespective of CD80 status.     

Synthesis, antimalarial, antileishmanial, antimicrobial, cytotoxicity, and methemoglobin (MetHB) formation activities of new 8-quinolinamines

We report the synthesis, in vitro antiprotozoal (against Plasmodium and Leishmania), antimicrobial, cytotoxicity (Vero and MetHb-producing properties), and in vivo antimalarial activities of two series of 8-quinolinamines. N1-{4-[2-(tert-Butyl)-6-methoxy-8-quinolylamino]pentyl}-(2S/2R)-2-aminosubstitutedamides (21-33) and N1-[4-(4-ethyl-6-methoxy-5-pentyloxy-8-quinolylamino)pentyl]-(2S/2R)-2-aminosubstitutedamides (51-63) were synthesized in six steps from 6-methoxy-8-nitroquinoline and 4-methoxy-2-nitro-5-pentyloxyaniline, respectively. Several analogs displayed promising antimalarial activity in vitro against Plasmodium falciparum D6 (chloroquine-sensitive) and W2 (chloroquine-resistant) clones with high selectivity indices versus mammalian cells. The most promising analogs (21-24) also displayed potent antimalarial activity in vivo in a Plasmodium berghei-infected mouse model. Most interestingly, many analogs exhibited promising in vitro antileishmanial activity against Leishmania donovani promastigotes, and antimicrobial activities against a panel of pathogenic bacteria and fungi. Several analogs, notably 21-24, 26-32, and 60, showed less MetHb formation compared to primaquine indicating the potential of these compounds in 8-quinolinamine-based antimalarial drug development.