Antioxidant Responses and Growth Impairment in Cucurbita moschata Infected by Meloidogyne incognita

Pumpkins (Cucurbita moschata), valued for their nutritional, medicinal, and economic significance, face threats from Meloidogyne incognita, a critical plant-parasitic nematode. This study extensively examines the impact of M. incognita on the growth, physiological, and biochemical responses of C. moschata. We demonstrate that M. incognita infection leads to significant growth impairment in C. moschata, evidenced by reduced plant height and biomass, along with the significant development of nematode-induced galls. Concurrently, a pronounced oxidative stress response was observed, characterized by elevated levels of hydrogen peroxide and a significant increase in antioxidant defense mechanisms, including the upregulation of key antioxidative enzymes (superoxide dismutase, glutathione reductase, catalase, and peroxidase) and the accumulation of glutathione. These responses highlight a dynamic interaction between the plant and the nematode, wherein C. moschata activates a robust antioxidant defense to mitigate the oxidative stress induced by nematode infection. Despite these defenses, the persistence of growth impairment underscores the challenge posed by M. incognita to the agricultural production of C. moschata. Our findings contribute to the understanding of plant-nematode interactions, paving the way for the development of strategies aimed at enhancing resistance in Cucurbitaceae crops against nematode pests, thus supporting sustainable agricultural practices.

Metabolomic assessment of African snail (Achatina fulica) meal on growth performance of giant river prawn (Macrobrachium rosenbergii)

This study aimed to investigate the effects of replacing fishmeal (FM) with African giant snail (Achatina fulica) meal (SM) on the growth performance of giant river prawn (Macrobrachium rosenbergii), as well as to analyze the associated metabolomic changes. Six diets were formulated, replacing FM with SM at different inclusion levels ranging from 0 % to 100 %. Growth performance and feed conversion ratio of prawns fed diets with FM replaced by SM up to 80 % were not significantly different from control. In contrast, significantly decreased growth performance and higher feed conversion ratio (FCR) occurred with diets containing 100 % SM. To gain insights into the metabolic regulation of prawns fed different diets, a 1H NMR metabolomics approach was used to assess the metabolic changes in prawns fed diets containing 0 % and 80 % SM. The results revealed up-regulated metabolites significantly involved in several metabolic pathways, including alanine, aspartate, and glutamate metabolism; citrate cycle (TCA cycle); aminoacyl-tRNA biosynthesis; and valine, leucine, and isoleucine biosynthesis. These findings imply that including SM in the diet might modulate the regulation of muscle amino acids and tRNA synthesis, suggesting a potential impact on protein biosynthesis mechanisms. Additionally, alterations in the TCA cycle may reflect changes in carbon utilization, potentially contributing to the growth performance of giant river prawns when fishmeal is replaced with SM without adversely affecting their growth. In conclusion, this study demonstrated that SM could be a promising alternative protein source in aquafeed. The metabolomic approach provides valuable insights into the metabolic changes in prawns fed different diets, aiding in the development of more effective aquafeeds in the future. The study's limitations, such as the simplified diet formulation and the limited scope of the metabolomic analysis, were acknowledged and discussed, highlighting the need for further research to build upon these findings.

Heat inactive Bacillus subtilis var. natto regulate Nile tilapia (Oreochromis niloticus) intestine microbiota and metabolites involved in the intestine phagosome response

In this study, we evaluated the intestinal microbiota, intestinal and fecal metabolites production and the intestinal RNA-seq analysis of the Nile tilapia intestine after feeding with 10⁵and 10⁷ of the inactive Bacillus subtilis var. natto. First, we assessed the influence of heat inactive Bacillus subtilis var. natto on the growth performance, biochemical blood analysis, and evaluated the liver/body, spleen/body and intestine/body ratio. This evidence was known feeding with inactive Bacillus subtilis var. natto was able to improve the growth performance after 4 weeks, but not to affect the inflammatory biochemical blood parametres total protein (T-pro), albumin (Alb), Alb/T-pro ratio, creatine-phospho-kinase (CPK) and lactate dehydrogenase (LDH). Further, in the intestine microbiota, the Lactobacillaceae, Firmicutes, Chromatiales, and Rhodobacteria, was significantly higher than the control and the Firmicutes/Bacteroidetes ratio (F/B), which was indicated with a significantly increased. The intestine tissue metabolites OPLS-DA analysis indicated that the prominent bioactive metabolites changed. The peonidin-3-glucoside, l-Tyrosine, 1-Deoxy-1-(N6-lysino)-d-fructose was significantly increased. The feces metabolite OPLS-DA analysis indicated that the palmitelaidic acid, 5-KETE, tangeritin was significantly increased. In the transcriptome, the Gene Ontology (GO) analysis was found to enhance the intestine intestinal immune network. Combine of these evidence, feeding of the heat inactive Bacillus subtilis var. natto exactly improved the O. niloticus growth performance and regulation of the microbiota to promote the metabolites. In the transcriptome analysis, it was found to involve in the intestine immune phagosome response. Summarized of this study, the heat inactive Bacillus subtilis var. natto was reported to affect Nile tilapia intestine microbiota, and could positively regulate the intestine and fecal metabolites production to improve the intestine immune network.

Red Algae “Sarcodia suieae” Acetyl-Xylogalactan Downregulate Heat-Induced Macrophage Stress Factors Ddit3 and Hyou1 Compared to the Aquatic Animal Model of Nile Tilapia (Oreochromis niloticus) Brain Arachidonic Acid Expression

Anthropogenic climate change is known to be an increased stress that affects aquatic animal behavior and physiological alternations, which can induce the animal's death. In order to known whether the extracted acetyl-xylogalactan function on the regulation of the external high temperature induced death, we first selected the mammalian cell line "RAW 264.7" used in the previous experiment to evaluate the extracted acetyl-xylogalactan function. We aimed to evaluate the effects of the acetyl-xylogalactan on the RAW 264.7 macrophages and Nile Tilapia stress factor expression under the heat environment. In the in vitro cell observation, we assessed the cell survival, phagocytic activity, intracellular Ca²⁺ level, mitochondria potential exchange, apoptotic assay findings, galactosidase activity, RNA-seq by NGS and real-time polymerase chain reaction (QPCR) expression. In the in vivo Nile Tilapia observation aimed to evaluate the blood biochemical indicator, brain metabolites exchange and the liver morphology. In our evaluation of RAW 264.7 macrophages, the RNA sequencing and real-time polymerase chain reaction (PCR) was shown to upregulate the expression of the anti-apoptosis Cflar gene and downregulate the expression of the apoptosis factors Ddit3 and Hyou1 to protect macrophages under heat stress. We already knew the extracted acetyl-xylogalactan function on the mammalian "RAW 264.7" system. Following, we used the aquatic Nile Tilapia model as the anthropogenic climate change high temperature experiment. After feeding the Nile Tilapia with the acetyl-xylogalactan, it was found to reduce the brain arachidonic acid (AA) production, which is related to the NF-κB-induced apoptosis mechanism. Combined with the in vitro and in vivo findings, the acetyl-xylogalactan was able to reduce the heat induced cell or tissue stress.

Acid external and internal environment exchange the Oreochromis niloticus tissue immune gene expression compared to the mouse macrophage polarization model

The water environment plays an important role in animal physiology. In this study, we sought to evaluate the effect of the acid environment on the Oreochromis niloticus (Nile tilapia) internal microenvironment immune response compare to the mouse macrophage model (J77A.1). The acid environment treated mouse macrophage J774A.1 model have shown that acidic treatment is able to polarize macrophages into M2-like macrophages via an increase in Ym1, Tgm2, Arg1, Fizz1, and IL-10 expression. Metabolic analysis of mouse macrophages (J774A.1) at pH 2 vs. pH 7 and pH 4 vs. pH 7 have been shown to promote the expression of intracellular acetylcholine, choline, prochlorperazine, L-leucine, and bisphenol A,2-amino-3-methylimidazo[4,5-f] quinolone metabolites in the M2-like macrophage. Immune gene expression of the O. niloticus spleen and liver treated at pH 2, 4, and 7 was shown to reduce TNF-α, IL-1 β, IL-8, and IL-12 expression compared to pH 7 treatment. Immune gene was induced in O. niloticus following culture at pH 5, 6, and 7 fresh water environment. Taken together, we found that the acid internal environment polarizes tissues into an M2 macrophage developmental microenvironment. However, if the external environment is acid, tissues are exposed to an M1 macrophage developmental microenvironment.

Agrobacterium-Mediated Genetic Transformation of Taiwanese Isolates of Lemna aequinoctialis

Duckweed (Lemna aequinoctialis) is one of the smallest flowering plants in the world. Due to its high reproduction rate and biomass, duckweeds are used as biofactors and feedstuff additives for livestock. It is also an ideal system for basic biological research and various practical applications. In this study, we attempt to establish a micropropagation technique and Agrobacterium-mediated transformation in L. aequinoctialis. The plant-growth regulator type and concentration and Agrobacterium-mediated transformation were evaluated for their effects on duckweed callus induction, proliferation, regeneration, and gene transformation efficiency. Calli were successfully induced from 100% of explants on Murashige and Skoog (MS) medium containing 25.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.0 μM thidiazuron (TDZ). MS medium containing 4.5 μM 2,4-D and 2.0 μM TDZ supported the long-lasting growth of calli. Fronds regenerated from 100% of calli on Schenk and Hildebrandt (SH) medium containing 1.0 μM 6-benzyladenine (6-BA). We also determined that 200 μM acetosyringone in the cocultivation medium for 1 day in the dark was crucial for transformation efficiency (up to 3 ± 1%). Additionally, we propose that both techniques will facilitate efficient high-throughput genetic manipulation in Lemnaceae.

Transcriptomic analysis elucidates the molecular processes associated with hydrogen peroxide-induced diapause termination in Artemia-encysted embryos

Treatment with hydrogen peroxide (H₂O₂) raises the hatching rate through the development and diapause termination of Artemia cysts. To comprehend the upstream genetic regulation of diapause termination activated by exterior H₂O₂ elements, an Illumina RNA-seq analysis was performed to recognize and assess comparative transcript amounts to explore the genetic regulation of H₂O₂ in starting the diapause termination of cysts in Artemia salina. We examined three groupings treated with no H₂O₂ (control), 180 μM H₂O₂ (low) and 1800 μM H₂O₂ (high). The results showed a total of 114,057 unigenes were identified, 41.22% of which were functionally annotated in at least one particular database. When compared to control group, 34 and 98 differentially expressed genes (DEGs) were upregulated in 180 μM and 1800 μM H₂O₂ treatments, respectively. On the other hand, 162 and 30 DEGs were downregulated in the 180 μM and 1800 μM H₂O₂ treatments, respectively. Cluster analysis of DEGs demonstrated significant patterns among these types of 3 groups. GO and KEGG enrichment analysis showed the DEGs involved in the regulation of blood coagulation (GO: 0030193; GO: 0050818), regulation of wound healing (GO:0061041), regulation of hemostasis (GO: 1900046), antigen processing and presentation (KO04612), the Hippo signaling pathway (KO04391), as well as the MAPK signaling pathway (KO04010). This research helped to define the diapause-related transcriptomes of Artemia cysts using RNA-seq technology, which might fill up a gap in the prevailing body of knowledge.

Sarcodia suieae acetyl-xylogalactan regulate RAW 264.7 macrophage NF-kappa B activation and IL-1 beta cytokine production in macrophage polarization

In this study, the effects of acetyl-xylogalactan extracted from Sarcodia suieae on RAW 264.7 macrophage polarisation were evaluated. This extracted acetyl-xylogalactan had a monosaccharide composition of 91% galactose and 9% xylose, with polysaccharide and acetyl contents of 80.6% and 19.3%, respectively. MALDI-TOF mass spectrometry and NMR spectroscopy revealed the molecular weight of the acetyl-xylogalactan to be 88.5 kDa. After acetyl-xylogalactan treatment, RAW 264.7 macrophage polarisation was noted, along with enhanced phagocytic ability. Furthermore, the Cell Counting Kit-8 (CCK-8) assay was performed and the results demonstrated non-significant alteration in lactate dehydrogenase levels in the treated cells. Next, interleukin (IL) 1β, TNF, and Malt-1 expression in RAW 264.7 macrophages treated with the S. suieae acetyl-xylogalactan was investigated through real-time quantitative polymerase chain reaction, and the results demonstrated that S. suieae acetyl-xylogalactan induced IL-1β and Malt-1 expression. RNA sequencing analysis results indicated the S. suieae acetyl-xylogalactan positively regulated cytokine production and secretion, protein secretion, and response to IL-1 activation, based on the observed GO terms. The predicted target genes in the GO enrichment analysis were found to upregulate NF-κB signalling and M0 to M1 macrophage conversion through the observed cytokine production. Thus, acetyl-xylogalactan can positively regulate RAW 264.7 macrophage polarisation.

H2O2-Based Method for Rapid Detection of Transgene-Free Rice Plants from Segregating CRISPR/Cas9 Genome-Edited Progenies

Genome-editing techniques such as CRISPR/Cas9 have been widely used in crop functional genomics and improvement. To efficiently deliver the guide RNA and Cas9, most studies still rely on Agrobacterium-mediated transformation, which involves a selection marker gene. However, several limiting factors may impede the efficiency of screening transgene-free genome-edited plants, including the time needed to produce each life cycle, the response to selection reagents, and the labor costs of PCR-based genotyping. To overcome these disadvantages, we developed a simple and high-throughput method based on visual detection of antibiotics-derived H₂O₂ to verify transgene-free genome-edited plants. In transgenic rice containing hygromycin phosphotransferase (HPT), H₂O₂ content did not change in the presence of hygromycin B (HyB). In contrast, in transgenic-free rice plants with 10-h HyB treatment, levels of H₂O₂ and malondialdehyde, indicators of oxidative stress, were elevated. Detection of H₂O₂ by 3,3′-diaminobenzidine (DAB) staining suggested that H₂O₂ could be a marker to efficiently distinguish transgenic and non-transgenic plants. Analysis of 24 segregating progenies of an HPT-containing rice plant by RT-PCR and DAB staining verified that DAB staining is a feasible method for detecting transformants and non-transformants. Transgene-free genome-edited plants were faithfully validated by both PCR and the H₂O₂-based method. Moreover, HyB induced overproduction of H₂O₂ in leaves of Arabidopsis, maize, tobacco, and tomato, which suggests the potential application of the DAB method for detecting transgenic events containing HPT in a wide range of plant species. Thus, visual detection of DAB provides a simple, cheap, and reliable way to efficiently identify transgene-free genome-edited and HPT-containing transgenic rice.

Glutathione biosynthesis plays an important role against 4-tert-octylphenol-induced oxidative stress in Ceratophyllum demersum

4-tert-octylphenol (OP) is a persistent environmental pollutant with an endocrine-disrupting property. In the present study, we examined the effect of various concentrations of OP (0, 0.5, 1, 1.5, 2 and 3 mg L^-1) applied to an aquatic plant, the submersed macrophyte Ceratophyllum demersum. The toxic effect caused by OP inhibited the plant's growth rate, reduced total chlorophyll content and increased levels of the reactive oxygen species (ROS) O₂^•- and H₂O₂. OP treatment significantly increased the activities of antioxidant enzymes including superoxide dismutase, guaiacol peroxidase, glutathione reductase and ascorbate peroxidase. The contents of the non-enzymatic antioxidant glutathione (GSH) and ratio of GSH to glutathione disulfide were markedly increased with OP treatment. Pretreatment with buthionine sulfoximine, a specific and potent inhibitor of GSH biosynthesis, significantly reduced total GSH content and conferred a more severe toxic phenotype on OP exposure. Thus, with OP-induced oxidative stress, C. demersum might actively regulate the antioxidant machinery, especially the biosynthesis and redox state of GSH.

A set of GFP-based organelle marker lines combined with DsRed-based gateway vectors for subcellular localization study in rice (Oryza sativa L.)

In the post-genomic era, many useful tools have been developed to accelerate the investigation of gene functions. Fluorescent proteins have been widely used as protein tags for studying the subcellular localization of proteins in plants. Several fluorescent organelle marker lines have been generated in dicot plants; however, useful and reliable fluorescent organelle marker lines are lacking in the monocot model rice. Here, we developed eight different GFP-based organelle markers in transgenic rice and created a set of DsRed-based gateway vectors for combining with the marker lines. Two mitochondrial-localized rice ascorbate peroxidase genes fused to DsRed and successfully co-localized with mitochondrial-targeted marker lines verified the practical use of this system. The co-localization of GFP-fusion marker lines and DsRed-fusion proteins provide a convenient platform for in vivo or in vitro analysis of subcellular localization of rice proteins.

Hygromycin B-induced cell death is partly mediated by reactive oxygen species in rice (Oryza sativa L.)

The aminoglycoside antibiotic hygromycin B (Hyg) inhibits prokaryotic, chloroplast and mitochondrial protein synthesis. Because of the toxic effect of Hyg on plant cells, the HPT gene, encoding hygromycin phosphotransferase, has become one of the most widely used selectable markers in plant transformation. Yet the mechanism behind Hyg-induced cell lethality in plants is not clearly understood. In this study, we aimed to decipher this mechanism. With Hyg treatment, rice calli exhibited cell death, and rice seedlings showed severe growth defects, leaf chlorosis and leaf shrinkage. Rice seedlings also exhibited severe lipid peroxidation and protein carbonylation, for oxidative stress damage at the cellular level. The production of reactive oxygen species such as O2(·-), H2O2 and OH(·) was greatly induced in rice seedlings under Hyg stress, and pre-treatment with ascorbate increased resistance to Hyg-induced toxicity indicating the existence of oxidative stress. Overexpression of mitochondrial Alternative oxidase1a gene without HPT selection marker in rice enhanced tolerance to Hyg and attenuated the degradation of protein content, whereas the rice plastidial glutathione reductase 3 mutant showed increased sensitivity to Hyg. These results demonstrate that Hyg-induced cell lethality in rice is not only due to the inhibition of protein synthesis but also mediated by oxidative stress.

Elevated temperature inhibits recruitment of transferrin-positive vesicles and induces iron-deficiency genes expression in Aiptasia pulchella host-harbored Symbiodinium

Coral bleaching is the consequence of disruption of the mutualistic Cnidaria-dinoflagellate association. Elevated seawater temperatures have been proposed as the most likely cause of coral bleaching whose severity is enhanced by a limitation in the bioavailability of iron. Iron is required by numerous organisms including the zooxanthellae residing inside the symbiosome of cnidarian cells. However, the knowledge of how symbiotic zooxanthellae obtain iron from the host cells and how elevated water temperature affects the association is very limited. Since cellular iron acquisition is known to be mediated through transferrin receptor-mediated endocytosis, a vesicular trafficking pathway specifically regulated by Rab4 and Rab5, we set out to examine the roles of these key proteins in the iron acquisition by the symbiotic Symbiodinium. Thus, we hypothesized that the iron recruitments into symbiotic zooxanthellae-housed symbiosomes may be dependent on rab4/rab5-mediated fusion with vesicles containing iron-bound transferrins and will be retarded under elevated temperature. In this study, we cloned a novel monolobal transferrin (ApTF) gene from the tropical sea anemone Aiptasia pulchella and confirmed that the association of ApTF with A. pulchella Rab4 (ApRab4) or A. pulchella Rab5 (ApRab5) vesicles is inhibited by elevated temperature through immunofluorescence analysis. We confirmed the iron-deficient phenomenon by demonstrating the induced overexpression of iron-deficiency-responsive genes, flavodoxin and high-affinity iron permease 1, and reduced intracellular iron concentration in zooxanthellae under desferrioxamine B (iron chelator) and high temperature treatment. In conclusion, our data are consistent with algal iron deficiency being a contributing factor for the thermal stress-induced bleaching of symbiotic cnidarians.

Improvement in non-specific immunity and disease resistance of barramundi, Lates calcarifer (Bloch), by diets containing Daphnia similis meal

A 42-day study was conducted with barramundi, Lates calcarifer, to evaluate the effects of Daphnia meal derived from Daphnia similis on fish growth, immune response, and disease resistance to Aeromonas hydrophila. Three isonitrogenous (45%) and isolipid (10%) experimental diets were formulated to contain 0% (control), 5% (D5), and 10% (D10) Daphnia meal. Growth was depressed when fish were fed with the D10 diet for 42 days compared to control. However, the growth in fish fed with control and D5 diets for 42 days was not significantly different. By day 42, the leukocyte phagocytic activity and respiratory burst activity were significantly increased in D5 and D10 groups compared to control. Mx gene expression in the spleen and head kidney of fish after being injected with nerve necrosis virus was also significantly up-regulated in both groups compared to control. In an increased immune response, D5 and D10 fish had significantly higher survival rates than control after being challenged by A. hydrophila. Therefore, we suggest that a 5% Daphnia-meal diet could improve the barramundi immune response and disease resistance without a negative impact on growth.

Gene knockout of glutathione reductase 3 results in increased sensitivity to salt stress in rice

Glutathione reductase (GR) is one of important antioxidant enzymes in plants. This enzyme catalyzes the reduction of glutathione disulfide (GSSG) to reduced glutathione (GSH) with the accompanying oxidation of NADPH. Previously, we showed that salt-stress-responsive GR3 is a functional protein localized in chloroplasts and mitochondria in rice. To learn more about the role of GR3 in salt-stress tolerance, we investigated the response to 100 mM NaCl treatment in wild-type rice (WT); GR3 knockout mutant of rice (gr3); and the functional gr3-complementation line (C1). Rice GR3 was primarily expressed in roots at the seedling stage and ubiquitously expressed in all tissues except the sheath at heading stage. GR3 promoter-GUS was expressed in the vascular cylinder and cortex of root tissues in rice seedlings, vascular tissue of nodes, embryo and aleurone layer of seeds, and young flowers. Under both normal and salt-stress conditions, total GR activity was decreased by 20 % in gr3. Oxidative stress, indicated by malondialdehyde content, was greater in gr3 than the WT under salt stress. As compared with the WT, gr3 was sensitive to salt and methyl viologen; it showed inhibited growth, decreased maximal efficiency of photosystem II, decreased GSH and GSSG contents, and the ratio of GSH to GSSG. Conversely, the gr3-complementation line C1 rescued the tolerance to methyl viologen and salinity and recovered the growth and physiological damage caused by salinity. These results reveal that GR3 plays an important role in salt stress tolerance by regulating the GSH redox state in rice.

A novel soybean (Glycine max) gene encoding a family 3 β-glucosidase has high isoflavone 7-O-glucoside-hydrolyzing activity in transgenic rice

A previous study demonstrated that purified Glycine max β-glucosidase (GmBGL) could hydrolyze glucosyl isoflavone to the aglyconic form. This study reports the cloning and functional characterization of a soybean cDNA encoding the β-glucosidase. GmBGL was isolated by use of a purified soybean N-terminal amino acid sequence and conserved sequences of β-glucosidase genes from other plants. Sequence analysis of GmBGL revealed an open reading frame of 1884 bp encoding a polypeptide of 627 amino acids with a calculated molecular mass of 69 kDa. Phylogenetic analysis classified the GmBGL into the glycosyl hydrolase 3 family. In soybean, the GmBGL transcript was predominantly accumulated in roots and leaves. To examine the enzymatic activity and substrate specificity, GmBGL was ectopically expressed in transgenic rice. Purified GmBGL protein from transgenic rice could catalyze the hydrolysis of genistin and daidzin to produce genistein and daidzein, respectively, which confirmed GmBGL as a functional β-glucosidase with isoflavone glucoside-hydrolyzing activity. This paper reveals that GmBGL is a key enzyme in transforming glucosyl isoflavones to aglycones in soybean, which may help in genetic manipulation of aglycone-rich soybean seeds.

Organ- and stress-specific expression of the ASR genes in rice

Rice ASR genes respond distinctly to abscisic acid, dehydration and cold stress. Their tissue-specific expression provides new hints about their possible roles in plant responses to stress. Plant ASR proteins have emerged as an interesting distinct group of proteins with apparent roles in protecting cellular structures as well as putative regulators of gene expression, both important responses of plants to environmental stresses. Regardless of the possible functions proposed by different studies, little is known about their role in cereals. To further understand the function of these proteins in the Gramineae, we investigated the expression pattern of the six ASR genes present in the rice genome in response to ABA, stress conditions and in different organs. Although transcription of most OsASRs is transiently enhanced by ABA treatment, the genes present a differential response under cold and drought stress as well as specific expression in certain tissues and organs. Analysis of their promoters reveals regulatory cis-elements associated to hormonal, sugar and stress responses. The promoters of two genes, OsASR1 and OsASR5, direct the expression of the GUS reporter gene especially to leaf vascular tissue in response to dehydration and low temperature. In control conditions, a GUS reporter assay also indicates specific expression of these two genes in roots, anthers and seed scutellar tissues. These results provide new clues about the possible role of ASRs in plant stress responses and development.

Identification and characterization of a novel chloroplast/mitochondria co-localized glutathione reductase 3 involved in salt stress response in rice

Glutathione reductases (GRs) are important components of the antioxidant machinery that plants use to respond against abiotic stresses. In rice, one cytosolic and two chloroplastic GR isoforms have been identified. In this work, we describe the cloning and characterization of the full-length cDNA encoding OsGR3, a chloroplast-localized GR that up to now was considered as a non-functional enzyme because of assumed lack of N-terminal conserved domains. The expression of OsGR3 in E. coli validated that it can be translated as a protein with GR activity. OsGR3 shows 76 and 53 % identity with OsGR1 (chloroplastic) and OsGR2 (cytosolic), respectively. Phylogenetic analysis revealed 2 chloroplastic GRs in Poaceae species, including rice, sorghum and brachypodium, but only one chloroplastic GR in dicots. A plastid transit peptide is located at the N terminus of OsGR3, and genetic transformation of rice with a GR3-GFP fusion construct further confirmed its localization in chloroplasts. Furthermore, OsGR1 and OsGR3 are also targeted to mitochondria, which suggest a combined antioxidant mechanism in both chloroplasts and mitochondria. However, both isoforms showed a distinct response to salinity: the expression of OsGR3 but not OsGR1 was induced by salt stress. In addition, the transcript level of OsGR3 was greatly increased with salicylic acid treatment but was not significantly affected by methyl jasmonate, dehydration or heat shock stress. Our results provide new clues about the possible roles of functional OsGR3 in salt stress and biotic stress tolerance.

Expression of genes involved in redox homeostasis and antioxidant defense in a marine macroalga Ulva fasciata by excess copper

The expression of genes involved in the control of redox homeostasis and antioxidant defense was studied in macroalga Ulva fasciata Delile in response to 5 and 50 microM CuSO(4). Redox-related genes, methionine sulfoxide reductase A (UfMsrA), thioredoxin (UfTrx), cyclophilin (UfCyp), and ferritin (UfFer) that were up-regulated by excess Cu [Wu, T.M., Lee, T.M., 2008. Regulation of activity and gene expression of antioxidant enzymes in Ulva fasciata Delile (Ulvales, Chlorophyta) in response to excess copper. Phycologia 47, 346-360] were cloned and their expression was compared to superoxide dismutase (UfMnsod and UfFesod), ascorbate peroxidase (UfApx), glutathione reductase (UfGr), and catalase (UfCat). Transcripts of UfMsrA, UfCyp, and UfFer were increased by excess Cu with a peak at 3h and that of UfTrx increased after 6-9h, but not affected by 4-day exposure to excess Cu, except an increase in UfMsrA transcript. Transcripts of UfMnsod, UfFesod, UfApx, UfGr and UfCat can be increased by 4-day exposure to Cu excess [Wu, T.M., Lee, T.M., 2008. Regulation of activity and gene expression of antioxidant enzymes in Ulva fasciata Delile (Ulvales, Chlorophyta) in response to excess copper. Phycologia 47, 346-360] but not by short-term excess Cu treatment, except UfGr whose transcript increased after 3h. Reactive oxygen species involved in up-regulation of antioxidant defense enzymes genes. These results suggest that the expression of genes of antioxidant defense enzymes and UfMsrA are associated with long-term adaptation of U. fasciata to Cu excess and transcription of redox-related genes and UfGr is up-regulated for short-term acclimation.

Effect of genistein and quercetin on proliferation, collagen synthesis, and type I procollagen mRNA levels of rat hepatic stellate cells

AIM

To study the effects of genistein (GE) and quercetin (QU) on proliferation, collagen synthesis, and procollagen messenger RNA (mRNA) expression of rat hepatic stellate cell line HSC-T6 cells.

METHODS

Cell proliferation was measured by crystal violet staining assay. Collagen synthesis was determined by [3H]proline incorporation assay. Type I mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

GE (25 - 70 micromol/L) and QU (6.25 - 50 micromol/L) concentration-dependently reduced serum-driven HSC-T6 cell proliferation and collagen synthesis associated with a suppression of type I procollagen mRNA level.

CONCLUSION

GE and QU inhibited hepatic stellate cell proliferation and collagen synthesis that might have a protective role against liver fibrosis.

[Antifibrotic effects of genistein and quercetin in vitro]

AIM

To study the antifibrotic effects of genistein (GE) and quercetin (QU) on rat hepatic stellate HSC-T6 cell proliferation stimulated with platelet-derived growth factor (PDGF), collagen synthesis and type I procollagen messenger RNA (mRNA) expression stimulated with transforming growth factor beta 1 (TGF beta 1).

METHODS

Cell proliferation was measured by crystal violet staining assay. Collagen synthesis was determined by 3H-proline incorporation assay. Type I procollagen mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

GE (25-70 mumol.L-1) and QU (6.25-50 mumol.L-1) concentration-dependently attenuated PDGF-drive HSC-T6 cell proliferative activity. TGF beta 1-stimulated collagen synthesis was also reduced. This was associated with a decrease of type I procollagen mRNA, indicating an effect at a pretranslational level.

CONCLUSION

GE and QU may have therapeutic potential against liver fibrosis by regulating PDGF and TGF beta 1 actions.

Beneficial effect of HCL-31D in murine models of endotoxaemia

We evaluated the effect of HCL-31D, a novel cAMP-specific phosphodiesterase inhibitor, on the induction of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated rat aortic smooth muscle cells (RASMC) and on survival in a murine model of severe endotoxaemia. Treatment of cultured RASMC with LPS and IFN-gamma resulted in an increase of nitrite, tumour necrosis factor (TNF-alpha) production and induction of iNOS mRNA. However, incubation with HCL-31D (1 approximately 50 microM) for 24 h caused significant attenuation of nitrite and TNF-alpha formation as well as iNOS mRNA induction in a dose-dependent manner but no effect on iNOS activity in RASMC. In addition, administration of HCL-31D (5 mg/kg, i.p.) resulted in that the increase of both plasma nitrate and TNF-alpha levels induced by LPS in vivo was significantly reduced in LPS-treated rats. Treatment of conscious mice with a high dose of LPS (60 mg/kg, i.p.) to ICR mice resulted in a 24-h survival rate of only 10%. However, administration of HCL-31D (5 mg/kg, i.p. at 0 h and 6 h after LPS) improved the 24-h survival to 50%, indicating that HCL-31D has a beneficial effect in murine model endotoxaemia. These effects may be mainly due to inhibition of TNF-alpha formation and of the induction of iNOS. We proposed that the elevation of cAMP levels by HCL-31D may be involved in the prevention of TNF-alpha formation and iNOS induction.

Quantitative assessments of physiological and biological parameters in psoriatic lesions and its correlations to the clinical severity of psoriasis

Twenty-nine psoriatics were examined using a model with clinical, physiological and pathological assessment parameters. The three parts in this assessment model include: (1) clinical assessment: psoriasis area and severity index (PASI); (2) assessment of skin physiology and microcirculation: water content of stratum corneum, water-holding capacity of stratum corneum, transepidermal water loss, intravital dynamic videocapillaroscopy-measuring the capillary diameters and blood cell velocity in proximal nailfold of ring finger, and fluorescence angiography-measuring transcapillary Na-fluorescein(NAF) diffusion; and (3) immunohistochemistry examination: markers of proliferation (Ki67Ag), differentiation (involucrin), and inflammation (neutrophil elastase, intercellular adhesion molecule-1(ICAM-1), endothelial leukocyte adhesion molecule-1(ELAM-1)). Our results showed both the transcapillary diffusion of NAF and the expression of cell markers-dermal neutrophil elastase, epidermal ELAM-1 and Ki67Ag--correlated significantly to PASI scores (P < 0.05, linear regression). According to our results, the increased capillary permeability and inflammation markers, and enhanced expression of Ki67Ag correlated very well with PASI score. These markers could serve as alternative methods for assessment of the clinical severity of psoriatic patients.

Gene expression profiling in the human hypothalamus-pituitary-adrenal axis and full-length cDNA cloning

The primary neuroendocrine interface, hypothalamus and pituitary, together with adrenals, constitute the major axis responsible for the maintenance of homeostasis and the response to the perturbations in the environment. The gene expression profiling in the human hypothalamus-pituitary-adrenal axis was catalogued by generating a large amount of expressed sequence tags (ESTs), followed by bioinformatics analysis (http://www.chgc.sh.cn/ database). Totally, 25,973 sequences of good quality were obtained from 31,130 clones (83.4%) from cDNA libraries of the hypothalamus, pituitary, and adrenal glands. After eliminating 5,347 sequences corresponding to repetitive elements and mtDNA, 20,626 ESTs could be assembled into 9, 175 clusters (3,979, 3,074, and 4,116 clusters in hypothalamus, pituitary, and adrenal glands, respectively) when overlapping ESTs were integrated. Of these clusters, 2,777 (30.3%) corresponded to known genes, 4,165 (44.8%) to dbESTs, and 2,233 (24.3%) to novel ESTs. The gene expression profiles reflected well the functional characteristics of the three levels in the hypothalamus-pituitary-adrenal axis, because most of the 20 genes with highest expression showed statistical difference in terms of tissue distribution, including a group of tissue-specific functional markers. Meanwhile, some findings were made with regard to the physiology of the axis, and 200 full-length cDNAs of novel genes were cloned and sequenced. All of these data may contribute to the understanding of the neuroendocrine regulation of human life.

Inhibitory effect of hexapeptide (RGRHGD) on platelet aggregation

The B chain of beta-bungarotoxin 1-6 sequence, RGRHGD, presents the highest local average hydrophilicity measured by Kyte and Doolittle modeling analysis. The RGRHGD holds parts of both RGD and KGD peptides, which have been reported as having high binding affinity to GPIIb-IIIa. The present study evaluates whether the synthesized hexapeptide, RGRHGD, has an antiplatelet effect and further elucidates the possible mechanisms of action. RGRHGD dose-dependently inhibited rabbit platelet aggregation and adenosine triphosphate release induced by arachidonic acid, collagen, platelet-activating factor, thrombin, or U46619 with the IC50 range of 82.7 to 510 microg/mL. The platelet thromboxane B2 formation induced by collagen or thrombin was also significantly decreased by RGRHGD, but there was no effect on arachidonic acid-induced thromboxane B2 formation. In addition, RGRHGD also inhibited the rise of intracellular calcium level stimulated by arachidonic acid, collagen, or thrombin in Fura 2-AM-loaded platelets. The adenosine 3',5'-cyclic monophosphate level of washed platelets was not affected by RGRHGD. In conclusion, these data indicate that the inhibitory effect of RGRHGD on platelet aggregation may be due to the attenuation of thromboxane A2 formation and intracellular calcium mobilization. In addition, this study may provide a useful method of finding potential therapeutic agents by using molecular modeling analysis.

Mechanism of inhibition of platelet aggregation by HCL-31D

The antiplatelet effect of the pyridazinone analogue, 4, 5-dihydro-6-[4-[2-hydroxy-3-(3,4 dimethoxybenzylamino)propoxy]naphth-1-yl]-3(2H)-pyridazinone (HCL-31D), was investigated in vitro with rabbit platelets. HCL-31D dose-dependently inhibited the platelet aggregation and ATP release induced by collagen (10 microg/ml), arachidonic acid (100 microM) or thrombin (0.1 U/ml) with an IC(50) of about 0.95-5.41 microM. HCL-31D (0.5-5 microM) increased the platelet cyclic AMP level in a dose-dependent manner. Furthermore, HCL-31D potentiated cyclic AMP formation caused by prostaglandin E(1) but not that caused by 3-isobutyl-1-methylxanthine (IBMX). HCL-31D also attenuated phosphoinositide breakdown and intracellular Ca(2+) elevation induced by collagen, arachidonic acid or thrombin. HCL-31D inhibited the formation of thromboxane B(2) induced by collagen or thrombin but not by arachidonic acid. In addition, HCL-31D did not affect platelet cylooxygenase and thromboxane synthase activity. These data indicate that HCL-31D is an inhibitor of phosphodiesterase and that its antiplatelet effect is mainly mediated by elevation of cyclic AMP levels.

Antimicrobial activity of synthetic all-D mastoparan M

Mastoparan M, a tetradecapeptide toxin (INKAIAALAKKLL-NH2) from hornet venom and its D-form mastoparan M were synthesized chemically. All D- and L-mastoparan M forms were found to adopt 28% alpha-helical structures in a 30% trifluroethanol solution as shown by the circular dichroism spectrum. All-D mastoparan M caused 3H-thymidine release from labeled bacterial cells after incubation for 1 h and complete cell lysis by 4 h. Both L- and D-mastoparan M showed strong activity against gram-positive and gram-negative bacteria. All-D mastoparan M showed 2-fold higher antibacterial activity than L-mastoparan M. The effects of all-D mastoparan M on the surface morphology of Staphylococcus aureus (ATCC29213) and Escherichia coli (ATCC25922) were studied by scanning-beam electron microscopy. Blast-like bleb extrusions on the surface of some S. aureus and swellings on the end of E. coli were seen after culture with all-D mastoparan M. These findings indicated the all-D mastoparan M could kill bacteria by disrupting cells.

Stimulation of TNF-alpha, IL-1beta and nitrite release from mouse cultured spleen cells and lavaged peritoneal cells by mastoparan M

Chemically synthesized mastoparan M, a tetradecapeptide toxin of venom (INLKAIAALAKKLL), was used in the experiments described. After addition of mastoparan M to cultures of mouse macrophages in vitro, tumour necrosis factor-alpha (TNF-alpha) and interleukin 1beta (IL-1beta) were detected in the culture fluids by 12 h and their highest accumulation was observed by 24 h. Mastoparan M induced increases in both TNF-alpha secretion and mRNA level at the same time. Nitrite levels, which reflect nitric oxide synthesis, were also found to increase in the macrophage cultures at 24 h after mastoparan M addition. In vivo studies showed that mastoparan M induced the formation and accumulation of TNF-alpha, IL-1beta and nitrite in the peritoneal exudates of mice much faster at 90 min, 120 min and 180 min after mastoparan M injection, respectively. Similarly, significant increases in myeloperoxidase activity, a marker for neutrophil and macrophage content, were observed in the peritoneal lavage cells after intraperitoneal injection of mastoparan M. However, induction of nitrite by mastoparan M was completely inhibited by simultaneous addition of antimouse TNF-alpha antibody to the macrophage cultures. These results suggest that modulation of both neutrophil and macrophage influx by mastoparan M may be conveyed through TNF-alpha and IL-1beta secretion accompanied by nitrite formation.

The cytolytic action of all-D mastoparan M on tumor cell lines

All-D and all-L mastoparan M, a tetradecapeptide toxin (INLKAIAALAKKLL-NH2) from hornet venom, were chemically synthesized in this study. Under circular dichroism investigation, all-D and L-mastoparan M adopted a 30% alpha-helical structure in 30% trifluroethanol solution but only a 10% á-helical structure in phosphate solution. After being added to the cultures of tumor cell lines in vitro, D-mastoparan (12.5 micrograms/ml) directly inhibited the growth of the tumor cell lines Colo 225 (59%), KB (38%), Hep-2 (63%), H226Br (43%) and HeLa (54%) determined by the MTT assay. We also found that D-mastoparan M has a higher potency of antitumor cell activity in vitro than L-mastoparan M. When examined under the scanning-beam electron microscope, hollow, shrunk and collapsed structures of tumor cells could be seen, after being mixed with D-mastoparan M. The appearance of these morphological alterations indicated that mastoparan M inhibits the growth of tumor cells by direct lysis of target cells.

Inhibitory effect of quercetin on tumor necrosis factor and interleukin-1 beta pro-osteoclastic activities

AIM

To study the effects of quercetin on tumor necrosis factor (TNF) and interleukin-1 beta (IL-1 beta) pro-osteoclastic activities.

METHODS

[3H] TdR uptake by osteoblasts was used to measure cell proliferation, microspectrophotometer for cellular AIP activity using p-nitrophenyl phosphate as enzyme substrate, and radioimmunoassay for prostaglandin E2.

RESULTS

Quercetin 5-40 mumol.L-1 reduced the inhibition of cell proliferation and AIP activity induced by TNF or IL-1 beta in a concentration-dependent manner. PGE2 production stimulated by either cytokines was also reduced by quercetin at 20 and 40 mumol.L-1.

CONCLUSION

quercetin exerted a marked inhibitory effect on TNF and IL-1 activities, related to their pro-osteoclastic function.

[Inhibitory effects of protein kinase C inhibitors on tumor necrosis factor induced bovine pulmonary artery endothelial cell injuries]

The effects of protein kinase C(PKC) inhibitors 1-(5-isoquino-linylsulfonyl)-2-methylpeperazine (H-7) and quercetin on tumor necrosis factor (TNF) were studied in cultured bovine pulmonary artery endothelial cells (BPAEC) in vitro. Incubation of BPAEC with TNF caused a significant increase in percent lactate dehydrogenase (LDH) release, stimulation of EC-dependent neutrophils (PMN) adhesion to BPAEC and inhibition of BPAEC DNA synthesis and proliferation. All these were restored by both H-7 and quercetin. The IC50 of H-7 and quercetin was 9.7 and 10.8 mumol.L-1 for the inhibition of LDH% release; 19.5 and 16.7 mumol.L-1 for the inhibition of TNF-induced PMN-EC adhesion; 7.0 and 6.1 mumol.L-1 for TNF-induced inhibition of DNA synthesis and 8.7 and 11.36 mumol.L-1 for proliferation. These results suggest that PKC inhibitors H-7 and quercetin protect BPAEC from TNF induced injuries and PKC play an important role in EC activation by TNF.

The avian eggshell extracellular matrix as a model for biomineralization

The avian eggshell is a complex, extracellularly assembled structure which contains both mineralized and non-mineralized regions. The composition of the hen eggshell organic matrix was examined by immunohistochemistry with antibodies to different extracellular matrix molecules. Type I collagen is found in the shell membranes, but only after treatment of the tissue sections with pepsin. When incomplete eggshells are removed from the oviduct and immunostained, type I collagen can be detected in the shell membranes without pepsin treatment. The shell membranes, which are non-mineralized, also contain type X collagen, and this immunostaining does not require pepsin treatment. The occurrence of type X collagen in the shell membranes is surprising, since this collagen has not been found in any tissue other than hypertrophic cartilage. Immunostaining for various glycosaminoglycans shows the presence of keratan sulfate and dermatan sulfate. Several different antibodies to keratan sulfate stain different regions of the eggshell; one keratan sulfate epitope is prominent in the calcium reserve assemblies. Dermatan sulfate staining is very intense in the palisade region. Demineralized matrix from the palisade region was extracted with guanidine and fractionated by ion exchange chromatography. A approximately 200-kDa dermatan sulfate proteoglycan is found in these extracts, along with a number of protein components. This preparation was tested for its ability to affect calcium carbonate crystal formation in vitro. Pieces of demineralized shell membranes were used as a substrate for crystal formation and various amounts of the palisade matrix dermatan sulfate proteoglycan preparation were added to the solution from which the crystals were formed. This material causes a concentration-dependent change in crystal morphology to one in which the crystals are smaller and more rounded, which more closely approximates the crystals normally observed in eggshells. These results suggest that the dermatan sulfate proteoglycans may be important in modulating crystal morphology in the hen eggshell and correlate with mineralization-modulating biomolecules from other calcified tissue, which are generally anionic.

Protein kinase C inhibitor H-7 blocks effects of tumor necrosis factor on bone cells

AIM

To study the effects of tumor necrosis factor (TNF) on the neonatal mouse osteoblast-enriched calvarial cells and effects of protein kinase C (PK C) inhibitor, 1-(5-isoquinolinesulfonyl)-2 -methylpiperazine (H-7) on the TNF actions.

METHODS

[3H]TdR uptake by the osteoblasts was used to measure cell proliferation. Cellular alkaline phosphatase (AIP) and tartrate resistant acid phosphatase (trAcP) activities were determined spectrophotometrically.

RESULTS

TNF (1-100 kU . L-1) inhibited both proliferation and expression of AIP activity, but stimulated trAcP activity. These TNF-induced actions were blocked by simultaneous addition of H-7 (5-20 mumol . L-1).

CONCLUSION

TNF has potent effects on the osteoblasts, and the blockade of TNF actions by H-7 suggests that TNF exert its effects through PK C.

Crystallization studies on avian eggshell membranes: implications for the molecular factors controlling eggshell formation

The avian eggshell is a natural biopolymer and mineral composite. It is a very useful model for biomimetic mineralization, since it is among the fastest forming hard tissues known. Isolated eggshell membranes, which were demineralized in vitro, were used to investigate the in vitro modulation of CaCO3 crystal deposition by organic matrix materials. Crystallization on the demineralized eggshell membrane occurred almost exclusively at the peripheries of residual calcium reserve assemblies, which contain a high concentration of sulfur. Similar structures are observed for eggshell membranes after natural demineralization. The characteristic rhombohedral crystal morphologies of the calcite crystals grown in this in vitro system are much less regular when grown in the presence of organic matrix or partially purified dermatan sulfate proteoglycans obtained from the eggshell. The effect of these macromolecules on the morphology and size of CaCO3 crystals is concentration-dependent. These studies indicate the complexity of the molecular and ionic interactions involved in the initiation and formation of the eggshell, with the focus on the role of the organic matrix.

Mastoparan B, synthesis and its physical and biological properties

Mastoparan B, a tetradecapeptide toxin (LKLKSIVSWAKKVL) isolated from the hornet (Vespa basalis) venom, was synthesized chemically. The physical and biological properties of both the native and synthetic peptides were studied and proved to be identical. Mastoparan B was found to have a potent antibacterial activity to both Gram negative and Gram positive bacteria.

Seroma prevention after modified radical mastectomy

The most common mastectomy-associated complication is seroma formation. Seromas can be associated with other more serious complications such as skin flap necrosis, delayed wound healing, infection, and lymphedema. The flap tacking procedure that closes the axillary fossa dead space and tacks the mastectomy flaps to the chest wall has been suggested as one potential technique to reduce the incidence of postmastectomy seromas. This institution-wide study of modified radical mastectomies demonstrated a significant decrease (P < 0.0381) in the incidence of seroma when flap tacking was performed. Women who developed a seroma, compared to those who did not, averaged nearly twice as any office visits in the first 2 months after the operation. Distribution of office visits between the seroma patients and nonseroma patients was significant (P < 0.0001). When practiced by several surgeons, the flap tacking procedure 1) reduces postmastectomy seromas and 2) reduces the amount of postoperative patient office visits and care.

Maintenance error reduction strategies in nuclear power plants, using root cause analysis

This study proposes a conceptual model of maintenance tasks to facilitate the identification of root causes of human errors in carrying out such tasks in nuclear power plants. Based on this model, an external/internal classification scheme was developed to discover the root causes of human errors. As a consequence, certain policies pertaining to human error prevention or correction were proposed.

Serogrouping, plasmid and drug resistance of Pseudomonas aeruginosa in Taiwan

The Pseudomonas aeruginosa isolates in Taiwan were grouped with antisera against O antigens and tested with 13 different antimicrobial agents. Group E (28%) lead in serogrouping, followed by Group G (19%), Group F (16%), Group B and Group H (12%, respectively), and there were no significant differences in distribution of serogroups among the isolates from different areas in Taiwan. Amikacin (75%) and piperacillin (74%) were the most effective antibiotics, followed by tobramycin (63%), carbenicillin (62%), ticarcillin (57%) and gentamicin (56%). Group F strains were relatively more susceptible to most of the antibiotics tested than strains of other serogroups. All strains tested were multiple drug resistance. Thirty percent (67/224) of P. aeruginosa carried plasmids. The average number of resistant markers per strain was 8.7 for plasmid-carrying strains as compared to 7.6 for plasmid-free strains. The plasmid-carrying strains showed higher drug resistance than plasmid-free strains. Twenty-seven percent (13/48) of plasmid-carrying strains contained R plasmids which were detected by transformation (6/23) and conjugation (7/25). These R plasmids totally encoded at least seven different resistant markers. The R plasmid from P. aeruginosa 119 was not modified after transforming into Escherichia coli RR1. The R plasmids of P. aeruginosa transferred into E. coli RR1 or Serratia marcescens 73 caused some changes in the outer membrane of transformants or transconjugants. Some R plasmid-carrying strains and their transformants or transconjugants exhibited the ability to produce acetyltransferase.