Introduction to the special issue: “Natural Product Discovery and Development in the Genomic Era: 2019”

Journal of Industrial Microbiology & Biotechnology -     

Changes in Autoantibodies against β1-Adrenoceptor and M2-Muscarinic Receptor during Development of Renovascular Hypertension in Rats

In recent years, autoantibodies to β1-adrenoceptor andM2-muscarinic receptor have been successively discoveredin the sera of patients with dilated cardiomyopathy (DCM)[1–3] Iwata et al. [4] found that in a similar protocolwith 6-month myocardial hypertrophy, β1-adrenoceptorreceptor desensitization, increased Gi protein and G pro-tein-coupled receptor kinase-5 expression were in associ-ation with myocyte disorganization and interstitial fibrosis.So far, investigation in this field has focu…     

Lampreys, “Living Fossils,” in Research on Early Development and Regeneration in Vertebrates

Russian Journal of Developmental Biology - Agnathans, the most ancient of the extant vertebrates, evoke steadily increasing interest as the object of research on the basic processes of vertebrate...     

Development of covalent antagonists for β1- and β2-adrenergic receptors

The selective covalent tethering of ligands to a specific GPCR binding site has attracted considerable interest in structural biology, molecular pharmacology and drug design. We recently reported on a covalently binding noradrenaline analog (FAUC37) facilitating crystallization of the β₂-adrenergic receptor (β₂AR^H2.64C) in an active state. We herein present the stereospecific synthesis of covalently binding disulfide ligands based on the pharmacophores of adrenergic β₁- and β₂ receptor antagonists. Radioligand depletion experiments revealed that the disulfide-functionalized ligands were able to rapidly form a covalent bond with a specific cysteine residue of the receptor mutants β₁AR^I2.64C and β₂AR^H2.64C. The propranolol derivative (S)-1a induced nearly complete irreversible blockage of the β₂AR^H2.64C within 30 min incubation. The CGP20712A-based ligand (S)-4 showed efficient covalent blocking of the β₂AR^H2.64C at very low concentrations. The analog (S)-5a revealed extraordinary covalent cross-linking at the β₁AR^I2.64C and β₂AR^H2.64C mutant while retaining a 41-fold selectivity for the β₁AR wild type over β₂AR. These compounds may serve as valuable molecular tools for studying β₁/β₂ subtype selectivity or investigations on GPCR trafficking and dimerization.     

The First Symposium on Frontiers of Biomedical Sciences Organized by Cell Research "Epigenetics in Development and Diseases"

This is the First Symposium on Frontiers of Biomedical Science organized by Cell Research, a peerreviewed journal supported by the Chinese Academy of Sciences. In recent years, epigenetics have shown its growing importance for the understanding of life processes and the control of human diseases in the genome era. I do hope that this timely symposium will     

The Impact of Food and Nutrient-Based Standards on Primary School Children’s Lunch and Total Dietary Intake: A Natural Experimental Evaluation of Government Policy in England

In 2005, the nutritional content of children’s school lunches in England was widely criticised, leading to a major policy change in 2006. Food and nutrient-based standards were reintroduced requiring primary schools to comply by September 2008. We aimed to determine the effect of the policy on the nutritional content at lunchtime and in children’s total diet. We undertook a natural experimental evaluation, analysing data from cross-sectional surveys in 12 primary schools in North East England, pre and post policy. Dietary data were collected on four consecutive days from children aged 4–7 years (n = 385 in 2003–4; n = 632 in 2008–9). We used linear mixed effect models to analyse the effects of gender, year, and lunch type on children’s mean total daily intake. Both pre- and post-implementation, children who ate a school lunch consumed less sodium (mean change −128 mg, 95% CI: −183 to −73 mg) in their total diet than children eating home-packed lunches. Post-implementation, children eating school lunches consumed a lower % energy from fat (−1.8%, −2.8 to −0.9) and saturated fat (−1.0%; −1.6 to −0.5) than children eating packed lunches. Children eating school lunches post implementation consumed significantly more carbohydrate (16.4 g, 5.3 to 27.6), protein (3.6 g, 1.1 to 6.0), non-starch polysaccharides (1.5 g, 0.5 to 1.9), vitamin C (0.7 mg, 0.6 to 0.8), and folate (12.3 µg, 9.7 to 20.4) in their total diet than children eating packed lunches. Implementation of school food policy standards was associated with significant improvements in the nutritional content of school lunches; this was reflected in children’s total diet. School food- and nutrient-based standards can play an important role in promoting dietary health and may contribute to tackling childhood obesity. Similar policy measures should be considered for other environments influencing children’s diet.     

Identification Keys,the “Natural Method,” and the Development of Plant Identification Manuals

The origins of field guides and other plant identification manuals have been poorly understood until now because little attention has been paid to 18th century botanical identification guides. Identification manuals came to have the format we continue to use today when botanical instructors in post-Revolutionary France combined identification keys (step-wise analyses focusing on distinctions between plants) with the “natural method” (clustering of similar plants, allowing for identification by gestalt) and alphabetical indexes. Botanical works featuring multiple but linked techniques to enable plant identification became very popular in France by the first decade of the 19th century. British botanists, however, continued to use Linnaeus’s sexual system almost exclusively for another two decades. Their reluctance to use other methods or systems of classification can be attributed to a culture suspicious of innovation, anti-French sentiment and the association of all things Linnaean with English national pride, fostered in particular by the President of the Linnean Society of London, Sir James Edward Smith. The British aversion to using multiple plant identification technologies in one text also helps explain why it took so long for English botanists to adopt the natural method, even after several Englishmen had tried to introduce it to their country. Historians of ornithology emphasize that the popularity of ornithological guides in the 19th and 20th centuries stems from their illustrations, illustrations made possible by printing technologies that improved illustration quality and reduced costs. Though illustrations are the most obvious features of late 19th century and 20th century guides, the organizational principles that make them functional as identification devices come from techniques developed in botanical works in the 18th century.     

Occurrence of Natural Vertical Transmission of Dengue-2 and Dengue-3 Viruses in Aedes aegypti and Aedes albopictus in Fortaleza, Ceará, Brazil

Background

Aedes aegypti and Aedes albopictus perform an important role in the transmission of the dengue virus to human populations, particularly in the tropical and subtropical regions of the world. Despite a lack of understanding in relation to the maintenance of the dengue virus in nature during interepidemic periods, the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus appears to be of significance in relation to the urban scenario of Fortaleza.

Methods

From March 2007 to July 2009 collections of larvae and pupae of Aedes spp were carried out in 40 neighborhoods of Fortaleza. The collections yielded 3,417 (91%) A. aegypti mosquitoes and 336 (9%) A. albopictus mosquitoes. Only pools containing females, randomly chosen, were submitted to the following tests indirect immunofluorescence (virus isolation), RT-PCR/nested-PCR and nucleotide sequencing at the C-prM junction of the dengue virus genome.

Results

The tests on pool 34 (35 A. albopictus mosquitoes) revealed with presence of DENV-3, pool 35 (50 A. aegypti mosquitoes) was found to be infected with DENV-2, while pool 49 (41 A. albopictus mosquitoes) revealed the simultaneous presence of DENV-2 and DENV-3. Based on the results obtained, there was a minimum infection rate of 0.5 for A. aegypti and 9.4 for A. albopictus. The fragments of 192 bp and 152 bp related to DENV-3, obtained from pools 34 and 49, was registered in GenBank with the access codes {"type":"entrez-nucleotide","attrs":{"text":"HM130699","term_id":"297515956","term_text":"HM130699"}}HM130699 and {"type":"entrez-nucleotide","attrs":{"text":"JF261696","term_id":"340343903","term_text":"JF261696"}}JF261696, respectively.

Conclusions

This study recorded the first natural evidence of the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus collected in Fortaleza, Ceará State, Brazil, opening a discuss on the epidemiological significance of this mechanism of viral transmission in the local scenario, particularly with respect to the maintenance of these viruses in nature during interepidemic periods.     

Effects of Sodium Selenite on Aflatoxin B1-Induced Decrease of Ileac T cell and the mRNA Contents of IL-2, IL-6, and TNF-α in Broilers

The aim of this work was to assess the protective effect of sodium selenite on the ileum mucosal immunologic toxicity induced by aflatoxin B₁ (AFB₁). One hundred and eighty one-day-old healthy male avian broilers were divided into four groups of three replicates and 15 birds per replicate and fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se (+Se group), and 0.3 mg/kg AFB₁?+?0.4 mg/kg Se (AFB₁+Se group), respectively. The ileac T-cell subsets were determined by the methods of flow cytometry (FCM), and the mRNA contents of interleukin-2 (IL-2), interleukin-6(IL-6), and tumor necrosis factor-alpha (TNF-α) by quantitative real-time PCR. Compared with those in control group, the percentages of CD₃ ⁺, CD₃ ⁺CD₄ ⁺, CD₃ ⁺CD₈ ⁺ intraepithelial lymphocytes (IELs) and LPLs, the CD4⁺/CD8⁺ ratio of IELs, and the mRNA contents of IL-2, IL-6, and TNF-α were decreased in AFB₁ group. However, compared with those in AFB₁ group, these parameters of AFB₁+Se group were increased to be close to those in control group. It was concluded that 0.3 mg/kg AFB₁ could reduce the cellular immune function of the ileum mucosa, but 0.4 mg/kg supplemented dietary selenium showed protective effects on AFB₁-induced immunologic injury.     

Reversal of the Mitochondrial Phenotype and Slow Development of Oxidative Biomarkers of Aging in Long-lived Mclk1+/? Mice

Although there is a consensus that mitochondrial function is somehow linked to the aging process, the exact role played by mitochondria in this process remains unresolved. The discovery that reduced activity of the mitochondrial enzyme CLK-1/MCLK1 (also known as COQ7) extends lifespan in both Caenorhabditis elegans and mice has provided a genetic model to test mitochondrial theories of aging. We have recently shown that the mitochondria of young, long-lived, Mclk1^+/− mice are dysfunctional, exhibiting reduced energy metabolism and a substantial increase in oxidative stress. Here we demonstrate that this altered mitochondrial condition in young animals paradoxically results in an almost complete protection from the age-de pend ent loss of mitochondrial function as well as in a significant attenuation of the rate of development of oxidative biomarkers of aging. Moreover, we show that reduction in MCLK1 levels can also gradually prevent the deterioration of mitochondrial function and associated increase of global oxidative stress that is normally observed in Sod2^+/− mutants. We hypothesize that the mitochondrial dysfunction observed in young Mclk1^+/− mutants induces a physiological state that ultimately allows for their slow rate of aging. Thus, our study provides for a unique vertebrate model in which an initial alteration in a specific mitochondrial function is linked to long term beneficial effects on biomarkers of aging and, furthermore, provides for new evidence which indicates that mitochondrial oxidative stress is not causal to aging.Because it is well known that the aging process is characterized by declines in basal metabolic rate and in the general performance of energy-dependent processes, many aging studies have focused on mitochondria because of their central role in producing chemical energy (ATP) by oxidative phosphorylation (1). Among the various theories of aging that have been proposed, the mitochondrial oxidative stress theory of aging is the most widely acknowledged and studied (2–4). It is based on the observation that mitochondrial energy metabolism produces reactive oxygen species (ROS),² that mitochondrial components are damaged by ROS, that mitochondrial function is progressively lost during aging, and that the progressive accumulation of global oxidative damage is strongly correlated with the aged phenotype. However, the crucial question of whether these facts mean that mitochondrial dysfunction and the related ROS production cause aging remains unproven (5–7). Furthermore, recent observations made in various species, including mammals, have begun to directly challenge this hypothesis, notably by relating oxidative stress to long (8) or increased (9) lifespans, by demonstrating that overexpression of the main antioxidant enzymes does not extend lifespan (10) as well as by showing that mitochondrial dysfunction could protect against age-related diseases (11).A direct and powerful approach to attempt to clarify this major question and to test the theory is to characterize the mitochondrial function of long-lived mutants (12). CLK-1/MCLK1 is an evolutionary conserved protein (13) and has been found to be located in the mitochondria of yeast (14), worms (15), and mice (16). The inactivation of the Caenorhabditis elegans gene clk-1 substantially increases lifespan (17). Moreover, the elimination of one functional allele of its murine orthologue also resulted in an extended longevity for Mclk1^+/− mice in three distinct genetic backgrounds (18). These findings have provided for an evolutionarily conserved pathways of animal aging that is affected by the function of a mitochondrial protein (19, 20). In mitochondria CLK1/MCLK1 acts as an hydroxylase and is implicated in the biosynthesis of ubiquinone (coenzyme Q or UQ), a lipid-like molecule primarily known as an electron carrier in the mitochondrial respiratory chain and as a membrane antioxidant but which is also associated with an increasing number of different aspects of cellular metabolism (20, 21). Taken together, these observations indicate that the long-lived Mclk1^+/− mouse is a model of choice for the understanding of the links between mitochondrial energy metabolism, oxidative stress, and the aging process in mammals.Previous analysis of Mclk1^+/− mice, which show the expected reduction of MCLK1 protein levels (22), have revealed that their tissues as well as their mitochondria contain normal levels of UQ at 3 months of age (23). Yet the same study also revealed a host of phenotypes induced by Mclk1 heterozygosity (see below). Thus, it appears that MCLK1 has an additional function that is unrelated to UQ biosynthesis but responsible for the phenotypes observed in young Mclk1^+/− mutants. This is consistent with several results from nematodes which also strongly suggest that CLK-1 has other functions (24, 25).In depth characterization of the phenotype of young Mclk1^+/− mutants has revealed that the reduction of MCLK1 levels in these animals profoundly alters their mitochondrial function despite the fact that UQ production is unaffected (23). In fact, we have shown that Mclk1 heterozygosity induces a severe impairment of mitochondrial energy metabolism as revealed by a reduction in the rates of mitochondrial electron transport and oxygen consumption as well as in ATP synthesis and ATP levels in both the mitochondria and the whole cell. ATP levels in several organs were surprisingly strongly affected with, for example, a 50% reduction of overall cellular ATP levels in the livers of Mclk1^+/− mutants (23). Moreover, we have found that the Mclk1^+/− mice sustain high mitochondrial oxidative stress by a variety of measurements, including aconitase activity, protein carbonylation, and ROS production (23). Additionally, we have shown that this early mitochondrial dysfunction is associated with a reduction in some aspects of cytosolic oxidative damage and global oxidative stress that can be measured via recognized plasma biomarkers such as 8-isoprostanes and 8-hydroxy-2-deoxyguanosine (8-OHdG). Considering that the accumulation of global oxidative damage is known to be tightly linked to the aging process (26), this latter result suggests that the anti-aging effect triggered by low MCLK1 levels might already act at a young age.To further investigate the clk-1/Mclk1-dependent mechanism of aging as well as to try to elucidate the still unclear relation between mitochondrial dysfunction, oxidative stress, and aging, we have now carefully analyzed the evolution of the phenotype of Mclk1^+/− mutants over time. We have also studied the effects of reduced MCLK1 levels on the phenotype of mice heterozygous for the mitochondrial superoxide dismutase (Sod2), which represent a well known model of mitochondrial oxidative stress (27). In addition of confirming the long lifespan phenotype of the Mclk1^+/− mutants in a mixed background (129S6 x BALB/c), we also report here a study of mutants and controls on a completely isogenic background where we find that the condition of Mclk1^+/− mutants unexpectedly results in protection against the age-dependent loss of mitochondrial function. Moreover, we found that the mutants are characterized by a significant attenuation of the age-associated increase in global oxidative stress normally observed in mammals. We also show that the Mclk1^+/− condition can gradually reverse the deterioration of mitochondrial function and the associated increase of global oxidative stress that is normally observed in Sod2^+/− mutants. Thus, this study provides for a unique vertebrate model in which reduced levels of a specific mitochondrial protein causes early mitochondrial dysfunction but has long term beneficial effects that slow down the rate of aging, as established with appropriate biomarkers, and can ultimately prolong lifespan in mice. Furthermore, in line with recent studies that have raised doubts about the validity of the mitochondrial oxidative stress theory of aging (4, 8, 10), our results, which relate to a recognized long-lived mice model, represent a novel and crucial indication that mitochondrial oxidative stress might not by itself be causal to aging.     

Age- and Light-Dependent Development of Localised Retinal Atrophy in CCL2?/?CX3CR1GFP/GFP Mice

Previous studies have shown that CCL2/CX3CR1 deficient mice on C57BL/6N background (with rd8 mutation) have an early onset (6 weeks) of spontaneous retinal degeneration. In this study, we generated CCL2^−/−CX3CR1^GFP/GFP mice on the C57BL/6J background. Retinal degeneration was not detected in CCL2^−/−CX3CR1^GFP/GFP mice younger than 6 months. Patches of whitish/yellowish fundus lesions were observed in 17∼60% of 12-month, and 30∼100% of 18-month CCL2^−/−CX3CR1^GFP/GFP mice. Fluorescein angiography revealed no choroidal neovascularisation in these mice. Patches of retinal pigment epithelium (RPE) and photoreceptor damage were detected in 30% and 50% of 12- and 18-month CCL2^−/−CX3CR1^GFP/GFP mice respectively, but not in wild-type mice. All CCL2^−/−CX3CR1^GFP/GFP mice exposed to extra-light (∼800lux, 6 h/day, 6 months) developed patches of retinal atrophy, and only 20–25% of WT mice which underwent the same light treatment developed atrophic lesions. In addition, synaptophysin expression was detected in the outer nucler layer (ONL) of area related to photoreceptor loss in CCL2^−/−CX3CR1^GFP/GFP mice. Markedly increased rhodopsin but reduced cone arrestin expression was observed in retinal outer layers in aged CCL2^−/−CX3CR1^GFP/GFP mice. GABA expression was reduced in the inner retina of aged CCL2^−/−CX3CR1^GFP/GFP mice. Significantly increased Müller glial and microglial activation was observed in CCL2^−/−CX3CR1^GFP/GFP mice compared to age-matched WT mice. Macrophages from CCL2^−/−CX3CR1^GFP/GFP mice were less phagocytic, but expressed higher levels of iNOS, IL-1β, IL-12 and TNF-α under hypoxia conditions. Our results suggest that the deletions of CCL2 and CX3CR1 predispose mice to age- and light-mediated retinal damage. The CCL2/CX3CR1 deficient mouse may thus serve as a model for age-related atrophic degeneration of the RPE, including the dry type of macular degeneration, geographic atrophy.     

Effects of Selenium-Enriched Yeast Improved Aflatoxin B1-Induced Changes in Growth Performance,Antioxidation Capacity,IL-2 and IFN-γ Contents,and Gene Expression in Mice

Sixty Kunming mice were randomly assigned into three groups. Mice in a control group were fed a basal diet, while mice in AFB1 group and AFB1-Se group were fed the basal diet supplemented with 250 μg/kg AFB1 or the basal diet supplemented with 250 μg/kg AFB1 and 0.2 mg/kg selenium as selenium-enriched yeast, respectively. On day 30 of the experiment, growth performance, glutathione peroxidase (GSH-Px) activities, total antioxidant capacity (T-AOC) levels, and malondialdehyde (MDA) contents in liver, interleukin-2 (IL-2), and interferon-γ (IFN-γ) contents in serum, and cytochrome P3a11 (Cyp3a11), IL-2, IFN-γ, and GSH-Px1 mRNA levels in liver were determined. The results showed that final weights, weight gains, T-AOC levels, GSH-Px1, and IFN-γ mRNA levels in AFB1-Se group and control group were higher or significantly higher than those in AFB1 group (P < 0.05 or P < 0.01), respectively. Body length gains in AFB1 group were lower than those in the control group (P < 0.05), while there was no significant difference between the AFB1-Se and control groups (P > 0.05). IL-2 contents and liver IL-2 mRNA levels in AFB1-Se group were significantly higher than those in the AFB1 group and control group (P < 0.01), and IL-2 contents in the control group were also significantly higher than those in the AFB1 group (P < 0.01). IFN-γ contents in AFB1-Se group and AFB1 group were significantly higher than those in control group (P < 0.01), while IFN-γ contents in AFB1-Se group were significantly lower than those in AFB1 group (P < 0.01). Cyp3a11 mRNA levels in AFB1-Se group and AFB1 group were significantly higher than those in the control group (P < 0.01). The results indicated that selenium-enriched yeast could partly reduce the toxicity induced by AFB1 in mice, including improving growth performance, antioxidation capacity, IL-2 and IFN-γ contents, and enhancing IL-2, IFN-γ, and GSH-Px1 mRNA levels.

     

Interferon-γ Promotes Inflammation and Development of T-Cell Lymphoma in HTLV-1 bZIP Factor Transgenic Mice

Human T-cell leukemia virus type 1 (HTLV-1) is an etiological agent of several inflammatory diseases and a T-cell malignancy, adult T-cell leukemia (ATL). HTLV-1 bZIP factor (HBZ) is the only viral gene that is constitutively expressed in HTLV-1-infected cells, and it has multiple functions on T-cell signaling pathways. HBZ has important roles in HTLV-1-mediated pathogenesis, since HBZ transgenic (HBZ-Tg) mice develop systemic inflammation and T-cell lymphomas, which are similar phenotypes to HTLV-1-associated diseases. We showed previously that in HBZ-Tg mice, HBZ causes unstable Foxp3 expression, leading to an increase in regulatory T cells (Tregs) and the consequent induction of IFN-γ-producing cells, which in turn leads to the development of inflammation in the mice. In this study, we show that the severity of inflammation is correlated with the development of lymphomas in HBZ-Tg mice, suggesting that HBZ-mediated inflammation is closely linked to oncogenesis in CD4⁺ T cells. In addition, we found that IFN-γ-producing cells enhance HBZ-mediated inflammation, since knocking out IFN-γ significantly reduced the incidence of dermatitis as well as lymphoma. Recent studies show the critical roles of the intestinal microbiota in the development of Tregs in vivo. We found that even germ-free HBZ-Tg mice still had an increased number of Tregs and IFN-γ-producing cells, and developed dermatitis, indicating that an intrinsic activity of HBZ evokes aberrant T-cell differentiation and consequently causes inflammation. These results show that immunomodulation by HBZ is implicated in both inflammation and oncogenesis, and suggest a causal connection between HTLV-1-associated inflammation and ATL.     

Development and characterization of an oat TILLING-population and identification of mutations in lignin and β-glucan biosynthesis genes

Background  

Oat, Avena sativa is the sixth most important cereal in the world. Presently oat is mostly used as feed for animals. However, oat also has special properties that make it beneficial for human consumption and has seen a growing importance as a food crop in recent decades. Increased demand for novel oat products has also put pressure on oat breeders to produce new oat varieties with specific properties such as increased or improved β-glucan-, antioxidant- and omega-3 fatty acid levels, as well as modified starch and protein content. To facilitate this development we have produced a TILLING (Targeting Induced Local Lesions IN Genomes) population of the spring oat cultivar SW Belinda.