Topical application of DEET for schistosomiasis

N, N-diethyl-m-toluamide (also known as DEET) is a broad-spectrum insect repellent that is used extensively against both human and animal pests, worldwide. Recent studies show that topical lipid formulations of DEET, such as LipoDEET, are highly effective in killing schistosome cercariae in the skin. Minimal systemic absorption, low manufacturing cost, and a wide range of activity against insects and schistosomes potentially makes compounds such as LipoDEET an excellent prophylactic agent against human and animal schistosomiasis in endemic areas, especially for travelers, until an effective vaccine is available.     

Lysyl oxidase: from basic science to future cancer treatment

In this mini-review, we discuss the physiological and pathological roles of lysyl oxidase (LOX) and its family, LOX-like proteins (LOXL), in relation to prognosis of major cancers. The number of reports on LOX family is numerous. We have decided to review the articles that were recently published (i.e. past 5 years). Experimental techniques in molecular biology have advanced surprisingly in the past decade. Accordingly, the results of the studies are more reliable. Most studies reached the same conclusion; a higher LOX- or LOXL- expression is associated with a poor prognosis. Molecular experiments have already started aiming for clinical application, and the results are encouraging. Suppressing LOX or LOXL activities resulted in lower cell motility in collagen gel and, moreover, succeeded in reducing metastases in mice. LOX family members were originally recognized as molecules that cross-link collagen fibers in the extracellular matrix. Recent studies demonstrated that they are also involved in a phenomenon called Epithelial Mesenchymal Transition (EMT). This may affect cell movement and cancer cell invasiveness. LOX and LOXL2 are regulated by hypoxia, a major factor in the failure of cancer treatment. Here we discuss the molecular biology of the LOX family in relation to its role in tumor biology.     

Eukaryotic phylotypes in aquatic moss pillars inhabiting a freshwater lake in East Antarctica, based on 18S rRNA gene analysis

Aquatic mosses of Leptobryum species form unique tower-like pillars of vegetation termed “moss pillars” in Antarctic lakes. Moss pillars have distinct redox-affected sections: oxidative exteriors and reductive interiors. We have proposed that a “pillar” is a community and habitat of functionally interdependent organisms and may represent a mini-biosphere. Batteries of 16S rRNA genotypes, or phylotypes, of eubacteria and cyanobacteria, but no archaea, have been identified in moss pillars. However, detailed identification or phylogenetic analyses of the moss and their associated eukaryotic microbiota have not been performed. This study analyzed near-full-length 18S rRNA gene sequences obtained from two whole moss pillars. In total, 28 PCR clone libraries from two whole moss pillars were constructed, and 96 clones from each library (total 2,688 clones) were randomly selected and sequenced. Molecular phylogenetic analysis revealed that the phylotype belonging to Bryophyta, considered to be derived from moss, was closely related (99.9?%) to the 18S rRNA gene sequence from Leptobryum pyriforme. Unexpectedly, phylotypes belonging to a novel clade of fungi dominated (approximately 27–75?%) the moss pillar libraries. This suggests that fungi may contribute to carbon cycling in the moss pillar as parasites or decomposers. In addition, phylotypes related to ciliates and tardigrades were subdominant in the exterior, while the phylotype of the ameba-like, single-celled eukaryote, Cercomonas (Cercozoa), was detected only in the interior. These features were shared by both moss pillars. The 18S rRNA gene-based profiles demonstrated that redox-related factors may control distribution of some eukaryotic microbes in a whole moss pillar.     

Independent domestication of Asian rice followed by gene flow from japonica to indica

Results from studies on the domestication process of Asian rice Oryza sativa have been controversial because of its complicated evolutionary history. Previous studies have yielded two alternative hypotheses about the origin(s) of the two major groups of O. sativa: japonica and indica. One study proposes a single common wild ancestor, whereas the other suggests that there were multiple domestication events of different types of wild rice. Here, we provide clear evidence of the independent domestication of japonica and indica obtained via high-throughput sequencing and a large-scale comparative analysis of two wild rice accessions (W1943 and W0106) and two cultivars (a japonica cultivar called "Nipponbare" and an indica cultivar called "Guangluai-4"). The different domestication processes of the two cultivar groups appear to have led to distinct patterns of molecular evolution in protein-coding regions. The intensity of purifying selection was relaxed only in the japonica group, possibly because of a bottleneck effect. Moreover, a genome-wide comparison between Nipponbare, Guangluai-4, and another indica cultivar (93-11) suggests multiple hybridization events between japonica and indica, both before and after the divergence of the indica cultivars. We found that a large amount of genomic DNA, including domestication-related genes, was transferred from japonica to indica, which might have been important in the development of modern rice. Our study provides an overview of the dynamic process of Asian rice domestication, including independent domestication events and subsequent gene flow.     

Polyunsaturated fatty acids are incorporated into maturating male mouse germ cells by lysophosphatidic acid acyltransferase 3

Long-chain polyunsaturated fatty acids (PUFAs) accumulate in mammalian testis during puberty and are essential for fertility. To investigate whether lysophospholipid acyltransferases determine the PUFA composition of testicular phospholipids during pubertal development, we compared their mRNA expression, in vitro activity, and specificity with the lipidomic profile of major phospholipids. The accumulation of PUFAs in phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine correlated with an induced lysophosphatidic acid acyltransferase (LPAAT)3 mRNA expression, increased microsomal LPAAT3 activity, and shift of LPAAT specificity to PUFA-coenzyme A. LPAAT3 was induced during germ cell maturation, as shown by immunofluorescence microscopy. Accordingly, differentiation of mouse GC-2spd(ts) spermatocytes into spermatides up-regulated LPAAT3 mRNA, increased the amount of polyunsaturated phospholipids, and shifted the specificity for the incorporation of deuterium-labeled docosahexaenoic acid toward phosphatidylcholine and phosphatidylethanolamine. Stable knockdown of LPAAT3 in GC-2spd(ts) cells significantly decreased microsomal LPAAT3 activity, reduced levels of polyunsaturated phosphatidylethanolamine species, and impaired cell proliferation/survival during geneticin selection. We conclude that the induction of LPAAT3 during germ cell development critically contributes to the accumulation of PUFAs in testicular phospholipids, thereby possibly affecting sperm cell production.     

Identification of Valine- or Leucine-Containing Glycopeptidolipids from Mycobacterium avium–intracellulare Complex

Mycobacterium avium-intracellulare complex is a species of acid-fast microorganisms that cause opportunistic infections in immuno-compromised hosts. The cell wall of this microbe is rich in glycopeptidolipids (GPLs), which are composed of a fatty acyl moiety, several sugar moieties and a tripeptide-amino alcohol, D-Phe-D-alloThr-D-Ala-L-Alaninol. GPLs have molecular diversity in the hydrocarbon chain variety of the acyl moiety, and methyl and acetyl modifications of the sugar moiety, but there has been no report of any variety in the tripeptide-amino alcohol component. In this study, we showed two atypical GPL ions of 34 or 48 Da less than the dominant ions of GPLs by mass spectrometry. These ions could not be explained as resulting from conventional molecular diversity. To investigate the reasons why these ions appeared, we made a preparation of the lipopeptide component from intact GPLs and structurally analyzed the molecules. The results suggested that these atypical ions differed from the typical ions in amino acid composition. We further determined its composition by amino acid analysis, and the results showed that the tripeptide portion of the two atypical ions is composed of the Val-alloThr-Ala or the Leu-alloThr-Ala amino acid sequence. In this study, we present novel variations in the tripeptide portion of GPL molecules.     

Serratia marcescens Induces Apoptotic Cell Death in Host Immune Cells via a Lipopolysaccharide- and Flagella-dependent Mechanism

Injection of Serratia marcescens into the blood (hemolymph) of the silkworm, Bombyx mori, induced the activation of c-Jun NH₂-terminal kinase (JNK), followed by caspase activation and apoptosis of blood cells (hemocytes). This process impaired the innate immune response in which pathogen cell wall components, such as glucan, stimulate hemocytes, leading to the activation of insect cytokine paralytic peptide. S. marcescens induced apoptotic cell death of silkworm hemocytes and mouse peritoneal macrophages in vitro. We searched for S. marcescens transposon mutants with attenuated ability to induce apoptosis of silkworm hemocytes. Among the genes identified, disruption mutants of wecA (a gene involved in lipopolysaccharide O-antigen synthesis), and flhD and fliR (essential genes in flagella synthesis) showed reduced motility and impaired induction of mouse macrophage cell death. These findings suggest that S. marcescens induces apoptosis of host immune cells via lipopolysaccharide- and flagella-dependent motility, leading to the suppression of host innate immunity.