Insights into the mechnisms of the differential abilities of two N2O reducers, Pseudomonas sp., isolated from paddy soil

Microbial reduction of nitrous oxide (N 2 O) in soil plays an important role in mitigating N 2 O emission, and it is the only known biological process for N 2 O sink. However, it is not clear about the mechnisms of differential N 2 O reducing function of N 2 O reducers. In this study, the N 2 O reducing activities and nosZ gene transcript abundance of two N 2 O reducers named P. veronii DM15 (DM15) and P. frederiksbergensis DM22 (DM22) were determined under varied temperature and oxygen concentration conditions, as well as the whole genomes were sequenced by Illumina sequencing. The results showed that DM15 generally exhibited significantly higher abilities in N 2 O reduction than DM22 in regardless of low or high temperature and aerobic or anaerobic conditions. Coincidently, DM15 expressed significantly more nosZ gene transcripts under above environments. Genomic analysis further revealed that DM15 possessed about 30% more transcription related genes than DM22 and the nos cluster of the former contained a transcriptional regulator gene of dnr which not found in that of the later. Additionally, the nos genes of DM15 possessed obviously higher expression potentials (CAI value). In conclusion, the transcriptional regulation of nos gene region would be a crucial factor in determining the differences of N 2 O reducing abilities of the two N 2 O reducing isolates.

Evolution of the nitric oxide synthase family in vertebrates and novel insights in gill development

Nitric oxide (NO) is an ancestral key signaling molecule essential for life and has enormous versatility in biological systems, including cardiovascular homeostasis, neurotransmission, and immunity. Although our knowledge of nitric oxide synthases (Nos), the enzymes that synthesize NO in vivo, is substantial, the origin of a large and diversified repertoire of nos gene orthologs in fish with respect to tetrapods remains a puzzle. The recent identification of nos3 in the ray-finned fish spotted gar, which was considered lost in the ray-finned fish lineage, changed this perspective. This prompted us to explore nos gene evolution and expression in depth, surveying vertebrate species representing key evolutionary nodes. This study provides noteworthy findings: first, nos2 experienced several lineage-specific gene duplications and losses. Second, nos3 was found to be lost independently in two different teleost lineages, Elopomorpha and Clupeocephala. Third, the expression of at least one nos paralog in the gills of developing shark, bichir, sturgeon, and gar but not in arctic lamprey, suggest that nos expression in this organ likely arose in the last common ancestor of gnathostomes. These results provide a framework for continuing research on nos genes roles, highlighting subfunctionalization and reciprocal loss of function that occurred in different lineages during vertebrate genome duplications.

Analysis of NOS Gene Polymorphisms in Relation to Cluster Headache and Predisposing Factors in Sweden

Cluster headache is characterized by activation of the autonomic-trigeminal reflex. Nitric oxide can trigger headaches in patients, and nitric oxide signaling is known to be affected in cluster headache. Based on the hypothesis of nitric oxide being involved in cluster headache pathophysiology we investigated nitric oxide synthases as potential candidate genes for cluster headache. We analyzed eight variants in the three forms of nitric oxide synthase (NOS) genes, inducible NOS (iNOS), endothelial NOS (eNOS) and neuronal NOS (nNOS), and tested for association with cluster headache. Swedish cluster headache patients (n = 542) and controls (n = 581) were genotyped using TaqMan® assays on an Applied Biosystems 7500 qPCR cycler. This is the largest performed genetic study on NOS involvement in cluster headache so far. We found an association between cluster headache and one iNOS haplotype consisting of the minor alleles of rs2297518 and rs2779249 (p = 0.022). In addition, one of the analyzed nNOS variants, rs2682826, was associated with reported triptan use (p = 0.039). Our data suggest that genetic variants in NOS genes do not have a strong influence on cluster headache pathophysiology, but that certain combinations of genetic variants in NOS genes may influence the risk of developing the disorder or triptan use.

Nitric oxide radicals are emitted by wasp eggs to kill mold fungi

Detrimental microbes caused the evolution of a great diversity of antimicrobial defenses in plants and animals. Insects developing underground seem particularly threatened. Here we show that the eggs of a solitary digger wasp, the European beewolf Philanthus triangulum, emit large amounts of gaseous nitric oxide (NO⋅) to protect themselves and their provisions, paralyzed honeybees, against mold fungi. We provide evidence that a NO-synthase (NOS) is involved in the generation of the extraordinary concentrations of nitrogen radicals in brood cells (~1500 ppm NO⋅ and its oxidation product NO2⋅). Sequencing of the beewolf NOS gene revealed no conspicuous differences to related species. However, due to alternative splicing, the NOS-mRNA in beewolf eggs lacks an exon near the regulatory domain. This preventive external application of high doses of NO⋅ by wasp eggs represents an evolutionary key innovation that adds a remarkable novel facet to the array of functions of the important biological effector NO⋅.

Diagnostically important predictive factors for in-stent resteosis in patients with ischemic heart disease

В последние годы все больше внимания уделяется интервенционным способам лечения ИБС. Однако, несмотря на многочисленные клинические исследования остается нерешенным вопрос рестенозирования стентов после интервенционных вмешательств. На сегодняшний день становится актуальным изучение молекулярных механизмов рестенозирования коронарных артерий, а также поиск новых генетически обусловленных предикторов развития рестеноза после стентирования. Воздействие NO-синтаз на развитие дисфункции эндотелия не вызывает сомнения, в то же время исследования, посвященные изучению влияния полиморфизма генов NOS на вероятность рестенозирования в стенте единичны и основаны на небольшом количестве клинических наблюдений. Вышесказанное свидетельствует об актуальности данного исследования, результаты которого сформировали новые представления о роли генов NO-синтаз в формировании предрасположенности к гиперпролиферации стентов у больных с ИБС. Цель работы - выделение диагностически значимых факторов-предикторов рестеноза после стентирования коронарных артерий у паицентов с ИБС и определение их чувствительности и специфичности при помощи ROC-кривых. Методика: в основу данного исследования положены результаты целенаправленного обследования 484 пациентов с верифицированным диагнозом ИБС, находившихся на лечении в отделении атеросклероза и хронической ишемической болезни сердца ФГБНУ «Научно-исследовательский институт кардиологии» СО РАН. Стентирование коронарных артерий было проведено у 210 чел. - группа рестеноза (n = 60) и группа без рестеноза (n = 150). Исследование генотипа проводили путем выделения геномной ДНК из цельной венозной крови обследуемых по стандартной неэнзиматической методике, а также исследования полиморфизмов генов NOS методом полимеразной цепной реакции (ПЦР). Результаты. Установлено 6 предикторов развития рестенозирования после стентирования при ИБС: протяженность стеноза, сужение коронарной артерии (% стеноза), полиморфизм 894G/T, наличие в анамнезе АГ, наличие у больного гаплотипов TCabGT11 и TTabGG11, определена их чувствительность и специфичность при помощи ROC-кривых. Установлено, что в Сибирской популяции у носителей гаплотипа TCabGT11 наиболее вероятно развитие рестенозирования в стенте, а при наличии гаплотипа TTabGG11 риск рестенозирования минимален. Заключение. Полиморфизмы 894 G/T гена eNOS ассоциированы с риском развития рестеноза, что может быть использовано как дополнительные маркеры риска развития рестеноза после стентирования коронарных артерий. In recent years, growing attention has been paid to interventional treatment of ischemic heart disease (IHD). However, despite numerous clinical studies, the issue of in-stent restenosis following interventions remains unsolved. At present, studying molecular mechanisms of coronary restenosis along with searching for new, genetically determined predictors of in-stent restenosis has become relevant. Effects of NO synthases on development of endothelial dysfunction are above any doubt; however, studies focusing on the effect of NOS gene polymorphism on probability of in-stent restenosis are scarce and based on a small number of clinical observations. Therefore, the present study is highly relevant as it has resulted in development of new concepts on the role of NO-synthase genes in predisposition to in-stent hyperproliferation in patients with IHD. The aim of this study was to identify diagnostically significant, predictive factors for in-stent coronary restenosis in patients with ischemic heart disease and to determine their sensitivity and specificity using ROC curves. Methods. This study was based on data from a targeted evaluation of 484 patients with a verified diagnosis of IHD who were managed at the Department of Atherosclerosis and Chronic Ischemic Heart Disease of the Research Institute of Cardiology, Siberian Branch of the Russian Academy of Medical Sciences. Coronary artery stenting was performed for 210 patients divided into two groups, with restenosis (n = 60) and without restenosis (n = 150). The genotype was studied on isolated genomic DNA from whole venous blood using a standard non-enzymatic technique, as well as by studying NOS gene polymorphisms using the polymerase chain reaction (PCR). Results. Six predictors for in-stent restenosis in IHD were identified - stenosis length, per cent narrowing of the coronary artery (% stenosis), 894G/T polymorphism, history of arterial hypertension, presence of TCabGT11 and TTabGG11 haplotypes, and their sensitivity and specificity determined with ROC curves. In the Siberian population, development of in-stent restenosis most likely occurred in carriers of the TCabGT11 haplotype while the risk for restenosis was minimal in the presence of the TTabGG11 haplotype. Сonclusion. The 894 G/T eNOS gene polymorphisms are associated with a risk for restenosis and might be used as additional markers for the risk of restenosis following coronary stenting.