Nitrogen addition does not alter symmetric responses of soil respiration to changing precipitation in a semi-arid grassland.

Concurrent changing precipitation regimes and atmospheric nitrogen (N) deposition can have profound influences on soil carbon (C) cycling. However, how N enrichment regulates the responses of soil C fluxes to increasing variability of precipitation remains elusive. As part of a field precipitation gradient experiment with nine levels of precipitation amounts (-60 %, -45 %, -30 %, -15 %, ambient precipitation, +15 %, +30 %, +45 %, and +60 %) and two levels of N addition (0 and 10 g N m-2 yr-1) in a semi-arid temperate steppe on the Mongolian Plateau, this work was conducted to investigate the responses of soil respiration to decreased and increased precipitation (DP and IP), N addition, and their possible interactions. Averaged over the three years from 2019 to 2021, DP suppressed soil respiration by 16.1 %, whereas IP stimulated it by 27.4 %. Nitrogen addition decreased soil respiration by 7.1 % primarily via reducing microbial biomass C. Soil respiration showed symmetric responses to DP and IP within all the four precipitation variabilities (i.e., 15 %, 30 %, 45 %, and 60 %) under ambient N. Nevertheless, N addition did not alter the symmetric responses of soil respiration to changing precipitation due to the comparable sensitivities of microbial biomass and root growth to DP and IP under the N addition treatment. These findings indicate that intensified precipitation variability does not change but N addition could alleviate soil C releases. The unchanged symmetric responses of soil respiration to precipitation variability under N addition imply that N deposition may not change the response pattern of soil C releases to predicted increases in precipitation variability in grasslands, facilitating the robust projections of ecosystem C cycling under future global change scenarios.

The role of hsa_circ_0008945 in juvenile-onset systemic lupus erythematosus.

BACKGROUND: circular RNAs (circRNAs) play a crucial role in many physiological and pathological processes including juvenile-onset systemic lupus erythematosus (JSLE). The aim of this study is to investigate the role of circRNA hsa_circ_0008945 in JSLE and evaluate its significance as diagnosing biomarker. METHODS: RT-qPCR was applied to detect the level of circ_0008945 in JSLE and controls. The Spearman correlation test assessed the correlation between circ_0008945 and clinical variables. The receiver operating characteristic (ROC) curve was calculated for evaluating the diagnostic value. Overexpression or knockdown of circ_0008945 in primary peripheral blood mononuclear cells (PBMCs) was performed to further examine its function in apoptosis. RESULTS: RT-qPCR revealed that there were significantly higher levels of hsa_circ_0008945 in PMBCs from JSLE patients (p < 0.001) compared to healthy controls. In addition, there were significant associations between hsa_circ_0008945 level and the level of C3, C4, anti-ds DNA, IgG, CRP and ESR (p < 0.05) but not associated with the level of Ig A and Ig M. ROC curve of the circ_0008945 showed that the AUC was 0.790 and it may potentially be used as a novel biomarker for the diagnosis of JSLE. The results showed that overexpression of circ-0008945 increased the apoptosis of PBMCs while knockdown of circ-0008945 by siRNA decreased the apoptosis of PBMCs, supporting that circ-0008945 promoted the apoptosis in PBMCs and contributed to the pathogenesis of JSLE. CONCLUSION: The role of circ_0008945 was first investigated in JSLE and proposed herein their possible contribution to the pathogenesis of JSLE. This study provides not only novel insight into the pathological mechanisms but also the potential value as a useful biomarker for JSLE.

Puerarin Inhibits Ferroptosis and Inflammation of Lung Injury Caused by Sepsis in LPS Induced Lung Epithelial Cells.

Background: Ferroptosis is a new type of programmed cell death, which plays an important role in lung injury caused by sepsis. Studies have reported that Puerarin (Pue) can treat lung injury caused by sepsis in children, but whether it plays a role by regulating iron death has not been reported. Methods: LPS induced human alveolar epithelial cell A549 to form a model of lung injury caused by sepsis. MTT detected the effect of Pue on A549 cell viability and the effect of Pue on LPS-induced A549 cell viability. The effects of Pue on LPS-induced inflammatory cytokines TNF-α, IL-8, IL-1ß in A549 cells were determined by ELISA assay. The expression level of MDA was detected by TBARS colorimetric quantitative detection kit. GSH kit was used to detect the expression of GSH in cells. The iron kit detected the total iron level and the expression level of ferric divalent ions in the cells. DCFH-DA fluorescent probe was used to detect ROS levels. Western blot was used to detect the expression of ferroptosis-related proteins in cells. Results: Pue alleviated LPS-induced injury and inflammatory response in A549 cells, and Pue reduced the expression of ROS, MDA and GSH in LPS-induced A549 cells. In addition, Pue reduced total iron levels and ferrous ion levels in LPS-induced A549 cells, and decreased the expression of iron ferroptosis-related proteins. Conclusion: Puerarin inhibited ferroptosis and inflammation of lung injury caused by sepsis in children in LPS induced lung epithelial cells.

A global database of plant production and carbon exchange from global change manipulative experiments.

Numerous ecosystem manipulative experiments have been conducted since 1970/80 s to elucidate responses of terrestrial carbon cycling to the changing atmospheric composition (CO2 enrichment and nitrogen deposition) and climate (warming and changing precipitation regimes), which is crucial for model projection and mitigation of future global change effects. Here, we extract data from 2,242 publications that report global change manipulative experiments and build a comprehensive global database with 5,213 pairs of samples for plant production (productivity, biomass, and litter mass) and ecosystem carbon exchange (gross and net ecosystem productivity as well as ecosystem and soil respiration). Information on climate characteristics and vegetation types of experimental sites as well as experimental facilities and manipulation magnitudes subjected to manipulative experiments are also included in this database. This global database can facilitate the estimation of response and sensitivity of key terrestrial carbon-cycling variables under future global change scenarios, and improve the robust projection of global change‒terrestrial carbon feedbacks imposed by Earth System Models.

[Expression of plasma miRNA-497 in children with sepsis-induced myocardial injury and its clinical significance].

OBJECTIVE: To study the expression of plasma miRNA-497 in children with sepsis-induced myocardial injury and its clinical significance. METHODS: A total of 148 children with sepsis were enrolled. According to the presence or absence of myocardial injury, these children were divided into myocardial injury group (n=58) and non-myocardial injury group (n=90). The two groups were compared in terms of the changes in plasma levels of miRNA-497, cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), procalcitonin (PCT), and C-reactive protein (CRP) and left ventricular ejection fraction (LVEF). The receiver operating characteristic (ROC) curve was plotted to evaluate the value of plasma miRNA-497, cTnI, and CK-MB in the diagnosis of myocardial injury. A Pearson correlation analysis was used to determine the correlation of miRNA-497 with cTnI, CK-MB, NT-proBNP, PCT, CRP, and LVEF. RESULTS: Compared with the non-myocardial injury group, the myocardial injury group had significantly higher plasma levels of miRNA-497, cTnI, CK-MB, NT-proBNP, PCT, and CRP (P<0.05). Plasma miRNA-497, cTnI, and CK-MB when measured alone or in combination had an area under the ROC curve of 0.918, 0.931, 0.775, and 0.940 respectively. At the optimal cut-off value of 2.05, miRNA-497 had a sensitivity of 90.4% and a specificity of 91.2%. The correlation analysis showed that there was a good correlation between plasma miRNA-497 and cTnI in children with myocardial injury (r=0.728, P<0.01). CONCLUSIONS: Plasma miRNA-497 has a similar value as cTnI in the diagnosis of sepsis-induced myocardial injury in children and may be used as a potential marker for early diagnosis of myocardial injury.