[Effects of Extracellular Vesicles on the Drug Resistance of Lung Adenocarcinoma Cells by Modulating the ATP Binding Cassette Transporter G2].

Objective: To investigate the regulatory role of extracellular vesicles (EVs) carrying ATP binding cassette transporter G2 (ABCG2) on the drug resistance of lung adenocarcinoma cells and the relevant molecular mechanisms. Methods: A549 cells, human lung adenocarcinoma cells, were used to form cisplatin (or cis-Diaminedichloroplatinum, CDDP)-resistant lung adenocarcinoma cells, i.e., A549/CDDP cells. EVs from A549 and A549/CDDP cells were extracted by gradient centrifugation method and were hence named EVs 1 and EVs 2, respectively. The A549 cells were treated with EVs 1 and EVs 2 for 48 hours, and the cells were named A549-EVs 1 and A549-EVs 2 cells, respectively. A549/ ABCG2 cells were established by transfecting A549 cells with pCDNA3.1- ABCG2 recombinant plasmids. On the other hand, A549 cells transfected with empty vectors were named A549/pCDNA3.1 cells. MTT assay was conducted to calculate the 24-hour cell drug resistance index for CDDP. The ABCG2 gene expression in cells and EVs were assessed with real-time PCR. A549 and A549-EVs 2 cells were transplanted subcutaneously into nude mice, which were labeled the control group and the experimental group accordingly. After tumor formation, 3 mg/kg CDDP was intraperitoneally injected once a week for two times. The ABCG2 gene expression of subcutaneous transplanted tumor cells was examined by real-time PCR. The cell apoptosis rate of subcutaneous transplanted tumor cells was examined by flow cytometry. Results: Using the parental A549 cells as reference, the 24-h CDDP-resistance indexes of 549/CDDP, A549/ ABCG 2, A549/pCDNA3.1, A549-EVs 1, A549-EVs 2 cells were 7.17, 10.06, 1.02, 1.19 and 5.40, respectively. When comparing the ABCG2 gene expression levels in all cells and EVs, the findings were higher in A549/CDDP cells than those inA549 cells, higher in A549/ ABCG2 cells than those in A549/pCDNA3.1 or A549 cells, higher in EVs 2 than those in EVs 1, and higher in A549-EVs 2 than those in A549-EVs 1 cells ( P<0.01) . The volume of transplanted tumor and the ABCG2 gene expression level in the experimental group were higher than those in the control group, while the apoptosis rate was lower than that in the control group ( P<0.01). Conclusion: EVs carrying ABCG2 gene can regulate the drug resistance of lung adenocarcinoma cells.

Predicting potential distribution of Ziziphus spinosa (Bunge) H.H. Hu ex F.H. Chen in China under climate change scenarios.

Ziziphus spinosa (Bunge) H.H. Hu ex F.H. Chen is a woody plant species of the family Rhamnaceae (order Rhamnales) that possesses high nutritional and medicinal value. Predicting the effects of climate change on the distribution of Z. spinosa is of great significance for the investigation, protection, and exploitation of this germplasm resource. For this study, optimized maximum entropy models were employed to predict the distribution patterns and changes of its present (1970-2000) and future (2050s, 2070s, and 2090s) potential suitable regions in China under multiple climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 & SSP5-8.5). The results revealed that the total area of the present potential suitable region for Z. spinosa is 162.60 × 104 km2, which accounts for 16.94% of China's territory. Within this area, the regions having low, medium, and high suitability were 80.14 × 104 km2, 81.50 × 104 km2, and 0.96 × 104 km2, respectively, with the high suitability regions being distributed primarily in Shanxi, Hebei, and Beijing Provinces. Except for SSP-1-2.6-2070s, SSP-5-8.5-2070s, and SSP-5-8.5-2090s, the suitable areas for Z. spinosa in the future increased to different degrees. Meanwhile, considering the distribution of Z. spinosa during different periods and under different climate scenarios, our study predicted that the low impact areas of Z. spinosa were mainly restricted to Shanxi, Shaanxi, Ningxia, Gansu, Liaoning, Inner Mongolia, and Jilin Provinces. The results of core distributional shifts showed that, except for SSP1-2.6, the center of the potential suitable region of Z. spinosa exhibited a trend of gradually shifting to the northwest.

[Temporal and Spatial Variations in Water Quality of Hanjiang River and Its Influencing Factors in Recent Years].

Hanjiang River is the main water source and influence area of the Middle Route of the South to North Water Transfer Project. In recent years, the water quality and ecological environment in the middle and lower reaches of the Hanjiang River has become seriously degraded and water blooms occur frequently. Scientific identification of the temporal and spatial variations in water environment quality (and the main driving factors) has become an important management requirement for optimizing the upstream water transfer project. The temporal and spatial variations and influencing factors of water quality in the Hanjiang River basin were systematically analyzed, based on multi-source data and using the Daniel trend test, Mann Kendall test, K-means cluster analysis, dissimilarity analysis, and redundancy analysis. Results showed that: ① in recent years, the main stream of the Hanjiang River had generally good water quality, which was generally classified as class Ⅱ of GB 3838-2002, while the water quality of some sections in the middle and lower reaches was classified as class Ⅲ. However, the total phosphorus (TP) and total nitrogen (TN) load was relatively high, with 10 stations in the Hanjiang River basin showing averaged concentrations of 0.028-0.263 mg·L-1 and 0.630-1.852 mg·L-1, respectively, during 2014-2018. ② From 2004 to 2018, TP and TN at Zongguan station did not show significant variation, and other water quality indexes did not exhibit any regular patterns. The concentrations of TN, NH4+-N, and BOD5 in the dry season were higher than those in the wet season. In the wet season. the permanganate index showed different variation patterns, while TP concentration did not decrease significantly. ③ Different sections showed obvious differences in the variation of water quality indexes. However, the ten stations can be clustered into three categories: the upstream stations showed the best water quality, followed by the middle reaches, and the downstream stations showed the worst. The water quality at Xiaohe station improved significantly over the study period, which may be related to protection measures implemented in recent years, such as source control, emission reduction, and removal of aquaculture. ④ Water discharge and temperature were important factors affecting the water quality of the three regions in Hanjiang River. According to redundancy analysis, the contribution of discharge to water quality in the upstream and downstream areas was much larger, while the contribution of water temperature was greatest in the middle reaches of the river.