Signature and function of plasma exosome-derived circular RNAs in patients with hypertensive intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is one of the major causes of death and disability, and hypertensive ICH (HICH) is the most common type of ICH. Currently, the outcomes of HICH patients remain poor after treatment, and early prognosis prediction of HICH is important. However, there are limited effective clinical treatments and biomarkers for HICH patients. Although circRNA has been widely studied in diseases, the role of plasma exosomal circRNAs in HICH remains unknown. The present study was conducted to investigate the characteristics and function of plasma exosomal circRNAs in six HICH patients using circRNA microarray and bioinformatics analysis. The results showed that there were 499 differentially expressed exosomal circRNAs between the HICH patients and control subjects. According to GO annotation and KEGG pathway analyses, the targets regulated by differentially expressed exosomal circRNAs were tightly related to the development of HICH via nerve/neuronal growth, neuroinflammation and endothelial homeostasis. And the differentially expressed exosomal circRNAs could mainly bind to four RNA-binding proteins (EIF4A3, FMRP, AGO2 and HUR). Moreover, of differentially expressed exosomal circRNAs, hsa_circ_00054843, hsa_circ_0010493 and hsa_circ_00090516 were significantly associated with bleeding volume and Glasgow Coma Scale score of the subjects. Our findings firstly revealed that the plasma exosomal circRNAs are significantly involved in the progression of HICH, and could be potent biomarkers for HICH. This provides the basis for further research to pinpoint the best biomarkers and illustrate the mechanism of exosomal circRNAs in HICH.

Extracellular polymeric substances trigger an increase in redox mediators for enhanced sludge methanogenesis.

Artificial redox mediators can be employed to improve the electron transfer efficiency during sludge methanogenesis, whereas these artificial redox mediators have possible deficiencies, such as high cost and non-biodegradability. For large-scale commercial applications, more cost-effective and environmentally friendly alternatives should be developed. Herein, the potential of extracellular polymeric substances (EPS) as natural redox mediators to improve methanogenesis was investigated. Compared to the control test without EPS addition, the methane (CH4) production yield was increased by 83.5 ± 2.4% with an EPS dosage of 0.50 g/L and the lag phase duration was shortened by 45.6 ± 7.0%, along with the enhanced sludge dewaterability. Spectroelectrochemical measurements implied that EPS addition notably changed the intensities of different redox-active groups, which decreased the charge transfer resistance and enhanced the extracellular electron transfer efficiency. These redox-active groups were mainly from the solubilization and hydrolysis of sludge protein due to increased protease activities, thereby leading to a higher acetate concentration during the acidification step. Further investigation showed that EPS addition also improved the activities of both acetotrophic and hydrogenotrophic methanogens, as indicated by a higher abundance of alpha subunit of methyl coenzyme M reductase (mcrA) genes, enhancing CH4 production. This work provides an innovative strategy for improving sludge anaerobic digestion with efficient additives.

Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis.

• Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis. • We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (K(m) of 7.55 µM) transport system for urea-uptake by rice roots (Oryza sativa). • A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a K(m) of c. 10 µM in Xenopus oocytes. • Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice.

Polyamine: A Potent Ameliorator for Plant Growth Response and Adaption to Abiotic Stresses Particularly the Ammonium Stress Antagonized by Urea.

Polyamine(s) (PA, PAs), a sort of N-containing and polycationic compound synthesized in almost all organisms, has been recently paid considerable attention due to its multifarious actions in the potent modulation of plant growth, development, and response to abiotic/biotic stresses. PAs in cells/tissues occur mainly in free or (non- or) conjugated forms by binding to various molecules including DNA/RNA, proteins, and (membrane-)phospholipids, thus regulating diverse molecular and cellular processes as shown mostly in animals. Although many studies have reported that an increase in internal PA may be beneficial to plant growth under abiotic conditions, leading to a suggestion of improving plant stress adaption by the elevation of endogenous PA via supply or molecular engineering of its biosynthesis, such achievements focus mainly on PA homeostasis/metabolism rather than PA-mediated molecular/cellular signaling cascades. In this study, to advance our understanding of PA biological actions important for plant stress acclimation, we gathered some significant research data to succinctly describe and discuss, in general, PA synthesis/catabolism, as well as PA as an internal ameliorator to regulate stress adaptions. Particularly, for the recently uncovered phenomenon of urea-antagonized NH4 +-stress, from a molecular and physiological perspective, we rationally proposed the possibility of the existence of PA-facilitated signal transduction pathways in plant tolerance to NH4 +-stress. This may be a more interesting issue for in-depth understanding of PA-involved growth acclimation to miscellaneous stresses in future studies.

Response of enhanced sludge methanogenesis by red mud to temperature: Spectroscopic and electrochemical elucidation of endogenous redox mediators.

Adding conductive materials can promote methanogenesis via facilitating electron exchange between syntrophic bacteria and methanogenic archaea. However, little is known about how temperature would interact with such an addition and thus affect the compositions and characteristics of endogenous redox mediators (ERMs). In particular, it is of strong interest to understand how the temperature variation would affect the improvement on methanogenesis induced by ERMs with conductive materials. Herein, we have investigated the response of sludge methanogenesis to temperature variation (from 15 to 35 °C) and spectroscopically detected the ERMs induced by conductive red mud. It was demonstrated that the increasing temperature enhanced the stimulating effect of conductive red mud on methane accumulation, and the methane production potential showed a linear relationship with redox parameters such as areal capacitance (Ca), free charges (R2) and electron exchange capacity (EEC). 2DCOS spectra further indicated that ν(C-O) and δ(O-H) in humic acids, ß-turn type III amide I νs(C=O) in Cytochrome c, and δ(C-H) in amines and lipids became the main redox groups in ERMs at 35 °C with the addition of red mud. The model revealed that the contribution of ERMs to the CO2 reduction to CH4 increased from 35.2 ±â€¯1.4% to 58.6 ±â€¯1.5% when the temperature increased from 15 to 35 °C. Our finding that conductive materials stimulated the formation and electroactivity of ERMs with the increasing temperature during anaerobic digestion can have important implications for the improvement of engineered methanogenic processes.

Coding-Sequence Identification and Transcriptional Profiling of Nine AMTs and Four NRTs From Tobacco Revealed Their Differential Regulation by Developmental Stages, Nitrogen Nutrition, and Photoperiod.

Although many members encoding different ammonium- and nitrate-transporters (AMTs, NRTs) were identified and functionally characterized from several plant species, little is known about molecular components for [Formula: see text]- and [Formula: see text] acquisition/transport in tobacco, which is often used as a plant model for biological studies besides its agricultural and industrial interest. We reported here the first molecular identification in tobacco (Nicotiana tabacum) of nine AMTs and four NRTs, which are respectively divided into four (AMT1/2/3/4) and two (NRT1/2) clusters and whose functionalities were preliminarily evidenced by heterologous functional-complementation in yeast or Arabidopsis. Tissue-specific transcriptional profiling by qPCR revealed that NtAMT1.1/NRT1.1 mRNA occurred widely in leaves, flower organs and roots; only NtAMT1.1/1.3/2.1NRT1.2/2.2 were strongly transcribed in the aged leaves, implying their dominant roles in N-remobilization from source/senescent tissues. N-dependent expression analysis showed a marked upregulation of NtAMT1.1 in the roots by N-starvation and resupply with N including [Formula: see text], suggesting a predominant action of NtAMT1.1 in [Formula: see text] uptake/transport whenever required. The obvious leaf-expression of other NtAMTs e.g., AMT1.2 responsive to N indicates a major place, where they may play transport roles associated with plant N-status and ([Formula: see text]-)N movement within aerial-parts. The preferentially root-specific transcription of NtNRT1.1/1.2/2.1 responsive to N argues their importance for root [Formula: see text] uptake and even sensing in root systems. Moreover, of all NtAMTs/NRTs, only NtAMT1.1/NRT1.1/1.2 showed their root-expression alteration in a typical diurnal-oscillation pattern, reflecting likely their significant roles in root N-acquisition regulated by internal N-demand influenced by diurnal-dependent assimilation and translocation of carbohydrates from shoots. This suggestion could be supported at least in part by sucrose- and MSX-affected transcriptional-regulation of NtNRT1.1/1.2. Thus, present data provide valuable molecular bases for the existence of AMTs/NRTs in tobacco, promoting a deeper understanding of their biological functions.

Molecular identification of tobacco NtAMT1.3 that mediated ammonium root-influx with high affinity and improved plant growth on ammonium when overexpressed in Arabidopsis and tobacco.

Although biological functions of ammonium (NH4+) transporters (AMTs) have been intensively studied in many plant species, little is known about molecular bases responsible for NH4+ movement in tobacco. Here, we reported the identification and functional characterization of a putative NH4+ transporter NtAMT1.3 from tobacco (Nicotiana tabacum). Analysis in silico showed that NtAMT1.3 encoded an integral membrane protein containing 464 amino acid residues and exhibiting 10 predicted transmembrane α-helices. Heterologous functionality study demonstrated that NtAMT1.3 expression facilitated NH4+ entry across plasma membrane of NH4+-uptake defective yeast and Arabidopsis qko mutant, allowing a restored growth of both yeast and Arabidopsis mutant on low NH4+. qPCR assay revealed that NtAMT1.3 was expressed in both roots and leaves and significantly up-regulated by nitrogen starvation and resupply of its putative substrate NH4+ and even nitrate, suggesting that NtAMT1.3 should represent a nitrogen-responsive gene. Critically, constitutive overexpression of NtAMT1.3 in tobacco per se improved obviously the growth of transgenic plants on NH4+ and enhanced leaf nitrogen (15% more) accumulation, consistent with observation of 35% more NH4+ uptake by the roots of transgenic lines in 20min root-influx test. Together with data showing its plasma membrane localization and saturated transport nature with Km of about 50µM for NH4+, we suggest that NtAMT1.3 acts an active NH4+ transporter that plays a significant role in NH4+ acquisition and utilization in tobacco.