DHD4, a CONSTANS-like family transcription factor, delays heading date by affecting the formation of the FAC complex in rice.

Heading date (or flowering time) is one of the most important agronomic traits in rice, influencing its regional adaptability and crop yield. Many major-effect genes for rice heading date have been identified, but in practice they are difficult to be used for rice molecular breeding because of their dramatic effects on heading date. Genes with minor effects on heading date, which are more desirable for fine-tuning flowering time without significant yield penalty, were seldom reported. In this study, we identified a new minor-effect heading date repressor, Delayed Heading Date 4 (DHD4). The dhd4 mutant shows a slightly earlier flowering phenotype without a notable yield penalty compared with wild-type plants under natural long-day conditions. DHD4 encodes a CONSTANS-like transcription factor localized in the nucleus. Molecular, biochemical, and genetic assays show that DHD4 can compete with 14-3-3 to interact with OsFD1, thus affecting the formation of the Hd3a-14-3-3-OsFD1 tri-protein FAC complex, resulting in reduced expression of OsMADS14 and OsMADS15, and ultimately delaying flowering. Taken together, these results shed new light on the regulation of flowering time in rice and provide a promising target for fine-tuning flowering time to improve the regional adaptability of rice.

Effects of Fuzheng Huayu recipe on entecavir pharmacokinetics in normal and dimethylnitrosamine-induced hepatic fibrosis rats.

Context: Fuzheng Huayu recipe (FZHY) combined with entecavir (ETV) is used to treat the cirrhosis caused by chronic hepatitis B (CHB) infection.Objective: To investigate the effect of FZHY on ETV pharmacokinetics under different conditions.Materials and methods: A model of liver fibrosis was created by intraperitoneal injection of dimethylnitrosamine (DMN; 10 µg/kg) for 4 weeks in Wistar rats. Ultra-high-performance liquid chromatography-tandem mass spectrometry was used to determine the blood concentration of ETV. Pharmacokinetic characteristics of ETV (0.9 mg/kg) were investigated after co-administration with FZHY (0.55 g/kg) at certain time intervals in normal and model rats.Results: The analytical method for ETV was validated at 0.5-50 µg/L with a correlation coefficient = 0.9996, lower limit of quantitation of 0.5 µg/L and mean accuracy of 104.18 ± 9.46%. Compared with the ETV-N group, the pharmacokinetic parameters of the EF-2 group did not change significantly, but that of the EF-0 group decreased in Cmax to 27.38 µg/L, in AUC0-t from 323.84 to 236.67 µg/h/L, and a delay in Tmax from 0.75 to 6.00 h; that of the EF-0 group presented a decrease in Cmax of 61.92%, delay in t1/2 of 2.45 h and delay in Tmax of 2.92 h. The t1/2e and Vd/F of ETV were increased significantly to 8.01 h and 24.38 L/kg in the ETV-M group.Conclusions: The effects of FZHY on ETV pharmacokinetics were diminished with an increase of interval time. The best time to administer both drugs is >2 h apart.

OsVIN2 encodes a vacuolar acid invertase that affects grain size by altering sugar metabolism in rice.

KEY MESSAGE: OsVIN2, a vacuolar invertase, affects grain size and yield by altering sugar composition, transport, and starch accumulation in rice. Grain size, a major determinant of rice yield, is influenced by many developmental and environmental factors. Sugar metabolism plays vital roles in plant development. However, the way in which sugar metabolism affects rice grain size remains largely elusive. In this study, we characterized the small grain-size rice mutant sgs1. Histological analyses showed that reduced spikelet hull and endosperm size results from decreased cell size rather than cell number. Map-based cloning and complementation tests revealed that a DaiZ7 transposon insertion in a vacuolar invertase gene OsVIN2 is responsible for the mutant phenotype. Subcellular distribution and biochemical analysis indicated that OsVIN2 is located in the vacuolar lumen, and that its sucrose hydrolysis activity is maintained under acidic conditions. Furthermore, an altered sugar content with increased sucrose and decreased hexose levels, as well as changes in invertase and sucrose synthase activities, sugar transport gene expression, and starch constitution in sgs1 implies that OsVIN2 affects sucrose metabolism, including sugar composition, transport, and conversion from the source to the sink organs. Collectively, OsVIN2 is involved in sugar metabolism, and thus regulates grain size; our findings provide insights into grain development and also suggest a potential strategy to improve grain quality and yield in rice.

Post-transcriptional regulation of Ghd7 protein stability by phytochrome and OsGI in photoperiodic control of flowering in rice.

Rice (Oryza sativa) is a facultative short-day (SD) plant, flowering early under SD and late under long-day (LD) conditions. Ghd7 is a major regulator of flowering time in rice, which strongly delays flowering under LD. Induction of Ghd7 expression by phytochromes has been shown to contribute to photoperiodic regulation of flowering in rice. Here, we show that Ghd7 also is regulated by phytochromes at a post-transcriptional level. We found that constitutive expression of Ghd7 delays flowering in the wild-type (WT) background, but not in the se5 mutant background (deficient in functional phytochromes) under LD and that Ghd7 protein fails to accumulate in the se5 mutant. We also found that co-expressing OsGIGANTEA (OsGI) with Ghd7 causes reduced accumulation of Ghd7 protein and partially suppresses the delayed flowering phenotype in the WT background, suggesting that phytochromes and OsGI play antagonist roles in regulating Ghd7 protein stability and flowering time. We show that OsPHYA, OsPHYB and OsGI could directly interact with Ghd7. Interestingly, OsPHYA and OsPHYB could inhibit the interaction between OsGI and Ghd7, thus helping to stabilize Ghd7 protein. Our results revealed a new level of Ghd7 regulation by phytochromes and OsGI in photoperiodic control of flowering in rice.

Vitamin D retards intervertebral disc degeneration through inactivation of the NF-κB pathway in mice.

To determine the efficacy and specific mechanism of vitamin D on intervertebral disc degeneration. The model of intervertebral disc degeneration was established in 3-month-old mice. Furthermore, the levels of intervertebral disc degeneration in the vitamin D group and the control group were detected one month later by X-ray, Western boltting, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) et al. In addition, in vitro, we cultured mouse intervertebral disc nucleus pulposus cells to verify the effect of vitamin D on nucleus pulposus cells and study its mechanism. In vivo, compared with the control group, mice in the vitamin D group showed dose-dependent retardation of intervertebral disc degeneration in terms of reducing inflammatory responses, antioxidant stress, inhibiting apoptosis and delaying cell aging. In vitro, compared with the control group, collagen II was increased and collagen X was decreased in mice treated with vitamin D. In vivo and in vitro experiments, the expression of p65 and IκB kinase α was decreased and the expression of inhibitor of NF-κB was increased in the intervertebral disc tissue or nucleus pulposus cells of the vitamin D treatment group, indicating that vitamin D could suppress the NF-κB pathway. Vitamin D retarded intervertebral disc degeneration by inhibiting NF-κB pathway, which may relieve inflammatory reactions, resist oxidative stress, inhibit apoptosis and delay cell senescence.

Early heading 7 interacts with DTH8, and regulates flowering time in rice.

KEY MESSAGE: EH7/Ghd7 interacts with DTH8, and regulates heading date by controlling the expression of Ehd1 in rice. Heading date, or flowering time, an important agronomic trait, influences regional adaptability and yield of crops. Many genes related to heading date in rice have been identified, and a preliminary regulatory network has been established, but the relationships between proteins involved are poorly understood. We identified a flowering suppressor EH7 (Early heading 7) that represses flowering under long-day (LD) conditions. The eh7 allele caused earlier heading, shorter plant height and less grain per main panicle than did the wild type (WT), but the tiller number and 1000-grain weight were not significantly affected under natural long-day conditions. Biochemical assays showed that EH7 interacts with DTH8. Quantitative PCR showed that EH7 inhibited heading date by downregulating the expression of Ehd1, Hd3a and RFT1. We propose that EH7 interacts with DTH8 to control flowering time by regulating the expression of Ehd1, Hd3a and RFT1.

TSV, a putative plastidic oxidoreductase, protects rice chloroplasts from cold stress during development by interacting with plastidic thioredoxin Z.

Rice is vulnerable to cold stress. Seedlings are very sensitive to cold stress and this harms global rice production. The effects of cold on chloroplast development are well known, but little is known about the underlying molecular mechanisms. Here, we isolated a temperature-sensitive virescent (tsv) mutant that is extremely sensitive to cold stress. It displayed defective chloroplasts, decreased chlorophyll and zero survivorship under cold stress. We isolated and identified TSV by map-based cloning and rescue experiments, combined with genetic, cytological and molecular biological analyses. We found that TSV, a putative plastidic oxidoreductase, is a new type of virescent protein. A mutation in tsv causes premature termination of the gene product. The activity of plastid-encoded RNA polymerase (PEP) and the expression of genes participating in chlorophyll synthesis were severely reduced in the tsv mutant under cold stress, but not at normal temperatures. TSV expression was induced by low temperatures. Strikingly, TSV interacted with OsTrxZ (a subunit of PEP in chloroplasts) and enhanced OsTrxZ stability under low temperatures. We demonstrated that TSV protects rice chloroplasts from cold stress by interacting with OsTrxZ. These results provide novel insights into ways in which rice chloroplast development and chlorophyll synthesis are protected by TSV under cold stress.

Screening of different sample types associated with sheep and cattle for the presence of nematophagous fungi in China.

A total of 1502 samples, including feces of sheep (793) and cattle (348), pasture soil (118), dung compost (147) and barn soil (96), were examined between October 2012 and August 2014 to discover potential strains of nematophagous fungi for the biological control of livestock-parasitic nematodes. These samples were collected from 87 sites located in 48 counties of 20 provinces (autonomous regions/municipalities) of China. Fungi were identified down to a species level. Four hundred and seventy-seven isolates, which were distributed in 8 genera and 28 taxa, were identified as nematophagous fungi. Nematode-trapping fungi included 17 species and one unidentified species of Arthrobotrys, two of Dactylella, Drechslerella dactyloides, and Duddingtonia flagrans. Five identified species and two unidentified species of endoparasitic fungi were isolated. The predominant species from all regions were Arthrobotrys oligospora, followed by Arthrobotrys musiformis, Arthrobotrys (Monacrosporium) thaumasiun, and Arthrobotrys (Monacrosporium) microscaphoides. Species with adhesive networks were the most frequently isolated. Among the endoparasitic fungi, Podocrella harposporifera (Harposporium anguillulae) was the most common species, followed by Harposporium lilliputanum and Harposporium arcuatum. Based on Shannon diversity index, the diversity levels of nematophagous fungi were relatively higher in samples associated with cattle, barn soil, and subtropical monsoon climate zone. Three species isolated from this study, namely, Duddingtonia flagrans, Arthrobotrys salina (Monacrosporium salinum), and Arthrobotrys oligospora var. sarmatica, are newly recorded in China, and 20 species (including one unidentified species) are newly recorded in sheep and cattle barn soils worldwide.

[Effect of Fuzheng Huayu recipe on CYP450 isozymes in normal and liver fibrosis rats].

To study the effect of Fuzheng Huayu recipe (FZHY) on five types of isozymes of cytochrome P450 (CYP450) of normal and liver fibrosis rats by using the cocktail probe method. Dimethylnitrosamine ( DMN) was injected to induce the liver fibrosis model. After the tail vein injection with Cocktail probe solutions prepared with five CYP450s probe substrates (phenacetin-CYP1A2, omeprazole-CYP2C9, tolbutamide-CYP2C19, dextromethorphan-CYP2D6, midazolam-CYP3A4), the plasma concentrations of the five probe substrates were determined by LC-MS/MS, and the pharmacokinetic parameters were calculated by PK solutions 2. After the oral administration with FZHY, normal rats given phenacetin, omeprazole, tolbutamide and dextromethorphan showed increase in AUC(0-t) and decrease in CL to varying degrees, indicating that FZHY obviously inhibited the activities of CYP1A2, CYP2C9, CYP2C19 and CYP2D6 in normal rats, but with no obvious effect on the activity of CYP3A4. After the oral administration with FZHY, liver fibrosis rats treated with CYP2C9 showed the significant increase in AUC(0-t) and significant decrease in Vd, hut with no obvious changes in the pharmacokinetic parameters of other four types of prove substances, suggesting that FZHY could significantly inhibit the activity of CYP2C9 in rats but had no effect on the activities of CYP1A2, CYP2C19, CYP2D6 and CYP3A4. The changes in the activity of CYP450 isozymes in liver fibrosis rats may be the reason for FZHY's different effects on CYP450 isozymes in normal and liver fibrosis rats.

Isolation, identification, and characterization of the nematophagous fungus Monacrosporium salinum from China.

Nematophagous fungi are considered to have the best potential as biological agents for the control of gastrointestinal nematodes in domestic animals. However, relatively few studies have been conducted with the genus Monacrosporium, especially with strains native to China. In the present study, we isolated and identified nematophagous fungi from fresh sheep feces. A pure fungal strain was molecularly characterized, and its nematophagous activity was evaluated. The morphological plasticity of the isolated strain, as well as its interaction with the nematode targets, was observed by scanning electron microscopy of the infected Trichostrongylus colubriformis L3 and the free-living nematode Caenorhabditis elegans. Three isolated fungal strains from the 30 fresh fecal samples of sheep from Inner Mongolia, China exhibited predatory activity; however, only a single strain was successfully purified (SF 0459). The SF 0459 strain was characterized by morphological analysis of its conidia and sequencing of its ITS1-5.8S rDNA-ITS2 region. This strain was identified to be Monacrosporium salinum (GenBank ID: KP036623). Nematophagous fungus helper bacteria were found at the interaction points between fungi and nematodes. The percentage of live T. colubriformis L3 was reduced by 83.79-88.69% based on the in vitro assay.

Comparative pharmacokinetics and tissue distribution profiles of lignan components in normal and hepatic fibrosis rats after oral administration of Fuzheng Huayu recipe.

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzheng Huayu recipe (FZHY) is formulated on the basis of Chinese medicine theory in treating liver fibrosis. AIM OF THE STUDY: To illuminate the influence of the pathological state of liver fibrosis on the pharmacokinetics and tissue distribution profiles of lignan components from FZHY. MATERIALS AND METHODS: Male Wistar rats were randomly divided into normal group and Hepatic fibrosis group (induced by dimethylnitrosamine). Six lignan components were detected and quantified by ultrahigh performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in the plasma and tissue of normal and hepatic fibrosis rats. RESULTS: A rapid, sensitive and convenient UHPLC-MS/MS method has been developed for the simultaneous determination of six lignan components in different rat biological samples successfully. After oral administration of FZHY at a dose of 15g/kg, the pharmacokinetic behaviors of schizandrin A (SIA), schizandrin B (SIB), schizandrin C (SIC), schisandrol A (SOA), Schisandrol B (SOB) and schisantherin A (STA) have been significantly changed in hepatic fibrosis rats compared with the normal rats, and their AUC(0-t) values were increased by 235.09%, 388.44%, 223.30%, 669.30%, 295.08% and 267.63% orderly (P<0.05). Tissue distribution results showed the amount of SIA, SIB, SOA and SOB were significant increased in heart, lung, spleen and kidney of hepatic fibrosis rats compared with normal rats at most of the time point (P<0.05). Meanwhile, the result also reveals that the hepatic fibrosis could delay the peak time of lignans in liver. CONCLUSION: The results proved that the established UHPLC-MS/MS method could be applied to the comparative study on pharmacokinetics and tissue distribution of lignan components in normal and hepatic fibrosis rats. The hepatic fibrosis could alter the pharmacokinetics and tissue distribution properties of lignan components in rats after administration of FZHY. The results might be helpful for guide the clinical application of this medicine.

In vivo evaluation of the antitussive, expectorant and bronchodilating effects of extract and fractions from aerial parts of Peganum harmala linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Aerial parts of Peganum harmala Linn (APP) is used as traditional medical herb in Uighur medicine in China, and it is traditionally used for treatment of cough and asthma.The aim of the present study is to evaluate the antitussive, expectorant and bronchodilating effects of extract and fractions (alkaloids and flavonoids) from APP, and to support its folk use with scientific evidence, and lay a foundation for its further researches. MATERIALS AND METHODS: APP was extracted with 50% ethanol by reflux, extracts were concentrated in vacuum to afford total extract of APP (EXT). EXT was separated to provide alkaloid fraction (ALK) and flavonoid fraction (FLA) by macroporous resin. Antitussive evaluations were carried out with cough models in mice and guinea pigs induced by ammonia liquor, capsaicin, and citric acid. Phenol red secretion experiments in mice were performed to evaluate the expectorant activity. Bronchodilating activities were evaluated with a bronchoconstrictive challenge induced by acetylcholine chloride and histamine in guinea pigs. RESULTS: In all the three antitussive tests, the EXT and ALK could significantly inhibit the frequency of cough, and prolong the cough latent period in animals. High dose of EXT (1650 mg/kg) and ALK (90 mg/kg) in mice and in guinea pigs created therapeutic activities as good as that of codeine phosphate (30 mg/kg). EXT could significantly increase phenol red secretion in mice for 0.64, 1.08 and 1.29 fold averagely at dosages of 183, 550, and 1650 mg/kg, ALK for 0.63, 0.96, 1.06 fold averagely at dosages of 10, 30, and 90 mg/kg, and ammonium chloride (1500 mg/kg, standard expectorant drug) for 0.97 fold, comparing with control group. Aminophylline could dramatically prolong the preconvulsive time for 162.28% in guinea pigs, EXT for 67.34%, 101.96% and 138.00% at dosages of 183, 550, and 1650 mg/kg, ALK for 55.47%, 97.74% and 126.77% at dosages of 10, 30, and 90 mg/kg, and FLA for 84.69%, 95.94% and 154.52% at dosages of 10, 30, and 90 mg/kg, comparing with pretreatment. CONCLUSIONS: APP is an effective traditional folk medicine for the treatment of cough with potent antitussive, expectorant and bronchodilating activities. The alkaloid fraction is proved to be the most effective components of APP. The alkaloids from APP may be valuable lead compounds for drug development of respiratory diseases.

[Applications of retrospective electrocardiogram editing in dual-source computed tomography coronary angiography in patients with arrhythmia].

OBJECTIVE: To evaluate the clinical value of retrospective electrocardiogram (ECG) -editing technique in dual-source computed tomography (CT) coronary angiography in patients with arrhythmia. METHODS: Totally 73 patients with arrhythmia during dual-source CT coronary angiography were included into this study. A retrospective gating technique and ECG-editing technique (Insert Sync; Disable Sync; Delete Sync; Shift R-peak) were used in patients who needed ECG-editing. Two experienced radiologists evaluated in consensus all pre-editing and post-editing reconstructed images and recorded scores according to the American Heart Association guidelines on coronary segmentation on a per segment basis. Image quality of all coronary segments was assessed using a four-point grading scale from excellent (4 scores) to non-assessable (1 score) . RESULTS: The overall mean image quality of 34 patients who did not need ECG-editing was 3.42 ± 0.20. In 39 patients who needed ECG-editing, the overall mean image quality before and after ECG-editing was 2.39?0.37 and 3.22?0.24. The mean image quality in every segment between pre-editing and post-editing was also significantly different (P<0.01) . CONCLUSION: ECG-editing technique can remarkably improve image quality of coronary artery segments by reducing or even eliminating the artifact produced by arrhythmia during dual-source CT coronary angiography.