Kynurenine aminotransferase 3/glutamine transaminase L/cysteine conjugate beta-lyase 2 is a major glutamine transaminase in the mouse kidney

AbstractBackgroundKynurenine aminotransferase 3 (KAT3) catalyzes the transamination of Kynurenine to kynurenic acid, and is identical to cysteine conjugate beta-lyase 2 (CCBL2) and glutamine transaminase L (GTL). GTL was previously purified from the rat liver and considered as a liver type glutamine transaminase. However, because of the substrate overlap and high sequence similarity of KAT3 and KAT1, it was difficult to assay the specific activity of each KAT and to study the enzyme localization in animals.MethodsKAT3 transcript and protein levels as well as enzyme activity in the liver and kidney were analyzed by regular reverse transcription-polymerase chain reaction (RT-PCR), real time RT-PCR, biochemical activity assays combined with a specific inhibition assay, and western blotting using a purified and a highly specific antibody, respectively.ResultsThis study concerns the comparative biochemical characterization and localization of KAT 3 in the mouse. The results showed that KAT3 was present in both liver and kidney of the mouse, but was much more abundant in the kidney than in the liver. The mouse KAT3 is more efficient in transamination of glutamine with indo-3-pyruvate or oxaloacetate as amino group acceptor than the mouse KAT1.ConclusionsMouse KAT3 is a major glutamine transaminase in the kidney although it was named a liver type transaminase.General significanceOur data highlights KAT3 as a key enzyme for studying the nephrotoxic mechanism of some xenobiotics and the formation of chemopreventive compounds in the mouse kidney. This suggests tissue localizations of KAT3/GTL/CCBL2 in other animals may be carefully checked

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Injury by Inhibiting ROS-Activated ERK1/2 and p38MAPK Signaling Pathways in PC12 Cells

Hydrogen sulfide (H2S) has been proposed as a novel neuromodulator and neuroprotective agent. Cobalt chloride (CoCl2) is a well-known hypoxia mimetic agent. We have demonstrated that H2S protects against CoCl2-induced injuries in PC12 cells. However, whether the members of mitogen-activated protein kinases (MAPK), in particular, extracellular signal-regulated kinase1/2(ERK1/2) and p38MAPK are involved in the neuroprotection of H2S against chemical hypoxia-induced injuries of PC12 cells is not understood. We observed that CoCl2 induced expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α), decreased cystathionine-β synthase (CBS, a synthase of H2S) expression, and increased generation of reactive oxygen species (ROS), leading to injuries of the cells, evidenced by decrease in cell viability, dissipation of mitochondrial membrane potential (MMP) , caspase-3 activation and apoptosis, which were attenuated by pretreatment with NaHS (a donor of H2S) or N-acetyl-L cystein (NAC), a ROS scavenger. CoCl2 rapidly activated ERK1/2, p38MAPK and C-Jun N-terminal kinase (JNK). Inhibition of ERK1/2 or p38MAPK or JNK with kinase inhibitors (U0126 or SB203580 or SP600125, respectively) or genetic silencing of ERK1/2 or p38MAPK by RNAi (Si-ERK1/2 or Si-p38MAPK) significantly prevented CoCl2-induced injuries. Pretreatment with NaHS or NAC inhibited not only CoCl2-induced ROS production, but also phosphorylation of ERK1/2 and p38MAPK. Thus, we demonstrated that a concurrent activation of ERK1/2, p38MAPK and JNK participates in CoCl2-induced injuries and that H2S protects PC12 cells against chemical hypoxia-induced injuries by inhibition of ROS-activated ERK1/2 and p38MAPK pathways. Our results suggest that inhibitors of ERK1/2, p38MAPK and JNK or antioxidants may be useful for preventing and treating hypoxia-induced neuronal injury

Static-dynamic rockburst risk assessment method in near-vertical coal seams

The existing rockburst risk assessment methods generally belong to static assessment method which normally depends on the geological and mining conditions that are revealed prior to mining. There is commonly a certain gap between the assessment results and the real situation. How to combine with the monitoring data in the mining process to get more realistic evaluation results is a problem that needs to be further solved. To this end, this work proposes a static-dynamic coupling rockburst risk assessment method taking into account the geological and mining conditions as well as the monitoring data, and the method has been being applied in typical panels in near-vertical coal seams. Firstly, a static evaluation method used before mining based on the improved comprehensive index method is proposed. The evaluation indicators contained in the comprehensive index method are linearly normalized to obtain the single indicator risk index. The AHP method is used to assign weights to each evaluation indicator, and the weighted summation of all indicator risk indexes is calculated to obtain the risk indexes determined by geological factors and mining technology factors, respectively. Then the weighted mean of the two risk indexes is used as the static evaluation risk index. Secondly, a dynamic evaluation method used during mining by utilizing the monitoring data is constructed. According to the characteristics of microseismic monitoring and borehole stress monitoring and their relationship with rockburst risk, the dynamic evaluation indicators are constructed based on the microseismic energy density and borehole stress variation. The evaluation indicators are linearly normalized to obtain two evaluation indexes. The weighted mean of the two indexes is used as the dynamic evaluation risk index. Finally, the two proposed methods are combined to get a static-dynamic coupling evaluation model. The coupling evaluation risk index is obtained by weighted average of the static evaluation risk index and the dynamic evaluation risk index, and then the risk grade and risk area are determined. The method is applied in +450B3+6 panel of Wudong Coal Mine. Results show that the static evaluation method demarcates 4 medium risk areas and 1 weak risk area before the mining of the panel, the dynamic evaluation method determines that the rock pillar side has high risk level in the mining process of the panel, and the static dynamic coupling evaluation re-evaluates the weak risk area of the static evaluation to the medium risk area. By investigating the monitoring data of support pressure, the numerical simulation results and the rockburst occurrence on site during the mining process of the panel, the evaluation results are verified, and it is found that the static and dynamic coupling evaluation results are more consistent with the actual situation. This work provides a new method and a new idea for the risk assessment of rock burst

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Cytotoxicity and Inflammation in HaCaT Cells through Inhibition of ROS/NF-κB/COX-2 Pathway

Hydrogen sulfide (H2S) has been shown to protect against oxidative stress injury and inflammation in various hypoxia-induced insult models. However, it remains unknown whether H2S protects human skin keratinocytes (HaCaT cells) against chemical hypoxia-induced damage. In the current study, HaCaT cells were treated with cobalt chloride (CoCl2), a well known hypoxia mimetic agent, to establish a chemical hypoxia-induced cell injury model. Our findings showed that pretreatment of HaCaT cells with NaHS (a donor of H2S) for 30 min before exposure to CoCl2 for 24 h significantly attenuated CoCl2-induced injuries and inflammatory responses, evidenced by increases in cell viability and GSH level and decreases in ROS generation and secretions of IL-1β, IL-6 and IL-8. In addition, pretreatment with NaHS markedly reduced CoCl2-induced COX-2 overexpression and PGE2 secretion as well as intranuclear NF-κB p65 subunit accumulation (the central step of NF-κB activation). Similar to the protective effect of H2S, both NS-398 (a selective COX-2 inhibitor) and PDTC (a selective NF-κB inhibitor) depressed not only CoCl2-induced cytotoxicity, but also the secretions of IL-1β, IL-6 and IL-8. Importantly, PDTC obviously attenuated overexpression of COX-2 induced by CoCl2. Notably, NAC, a ROS scavenger, conferred a similar protective effect of H2S against CoCl2-induced insults and inflammatory responses. Taken together, the findings of the present study have demonstrated for the first time that H2S protects HaCaT cells against CoCl2-induced injuries and inflammatory responses through inhibition of ROS-activated NF-κB/COX-2 pathway

Effect of Seeding Options on Interspecific Competition in Oat (<i>Avena sativa</i> L.)–Common Vetch (<i>Vicia sativa</i> L.) Forage Crops

Mixing cereal with legume crops is an efficient approach for improving forage production and ensuring the sustainable development of agriculture and livestock. However, the knowledge of the relationship between forage production and interspecific competition in the forage oat (Avena sativa L.) and common vetch (Vicia sativa L.) mixed cropping system remains unclear. A 2-year field experiment was conducted in 2020 and 2021 to investigate the effects of different mixed cropping systems (peer mixing (PM), alternate-row mixing (AM), cross mixing (CM), bar mixing (BM), sole forage oat (SO), and sole common vetch (SV)) on the dry matter production, forage quality, land equivalent ratio (LER), and competition parameters. The results showed that the system forage yield increased by 13.4–202.8% when forage oat was mixed with common vetch (p p < 0.05). The LER values were greater than the one when forage oat was mixed with common vetch, especially for the AM system (averaged 1.38). In addition, forage oat was the dominant crop and had higher aggressiveness and competitive ratios compared to common vetch, but without a significant difference in the aggressiveness and competitive ratio in mixed cropping systems. It indicated that mixing of cereal with legume crops was helpful in enhancing resource use efficiency without obvious interspecific competition. Consequently, the AM mixed cropping system is recommended for supporting the sustainable development of agriculture and livestock production in the arid region of China when considering both forage production and nutritional quality

Modeling for the Prediction of Soil Moisture in Litchi Orchard with Deep Long Short-Term Memory

Soil moisture is an important factor determining yield. With the increasing demand for agricultural irrigation water resources, evaluating soil moisture in advance to create a reasonable irrigation schedule would help improve water resource utilization. This paper established a continuous system for collecting meteorological information and soil moisture data from a litchi orchard. With the acquired data, a time series model called Deep Long Short-Term Memory (Deep-LSTM) is proposed in this paper. The Deep-LSTM model has five layers with the fused time series data to predict the soil moisture of a litchi orchard in four different growth seasons. To optimize the data quality of the soil moisture sensor, the Symlet wavelet denoising algorithm was applied in the data preprocessing section. The threshold of the wavelets was determined based on the unbiased risk estimation method to obtain better sensor data that would help with the model learning. The results showed that the root mean square error (RMSE) values of the Deep-LSTM model were 0.36, 0.52, 0.32, and 0.48%, and the mean absolute percentage error (MAPE) values were 2.12, 2.35, 1.35, and 3.13%, respectively, in flowering, fruiting, autumn shoots, and flower bud differentiation stages. The determination coefficients (R2) were 0.94, 0.95, 0.93, and 0.94, respectively, in the four different stages. The results indicate that the proposed model was effective at predicting time series soil moisture data from a litchi orchard. This research was meaningful with regards to acquiring the soil moisture characteristics in advance and thereby providing a valuable reference for the litchi orchard’s irrigation schedule