Exploring the interrelations and driving factors among typical ecosystem services in the Yangtze river economic Belt, China.

Exploring the spatiotemporal characteristics of ecosystem services (ESs) and their drivers is crucial for managers to develop significant scientific policies that further sustainable development. We used the Yangtze River Economic Belt (YREB) to explore the trends, hotspots, and drivers of water yield (WY), soil conservation (SC), carbon sequestration (CS), and food supply (FS) between 2000 and 2020. Similarly, we analyzed relationships among ESs and drivers of the multiple ecosystem services landscape index (MESLI). We used the self-organizing map method to obtain the types and distribution of the ES bundles, revealing the bundles, trade-offs, and synergies among ESs. The four ESs had an increasing trend, with CS having the highest increase; ES hotspot analysis showed differences among upper, middle, and lower reaches. Constraint lines among ESs and drivers were diverse; the corresponding SC and WY reached thresholds when CS values were 1477.81 and 460.5 t km-2, respectively. When FS values were 67.34 and 86.17 × 104 Yuan·km-2, CS and WY reached their thresholds. All critical drivers of the four ESs were natural factors. The thresholds that the MESLI reached with driver status were 1000 mm (evapotranspiration), 2121 mm (precipitation), 2.42° (slope), 1.46% (soil organic matter), 36.08% (sand), 30.75% (proportion of non-agricultural population), 18.57% (cropland proportion), 1.05 × 104 persons·km-2 (population density), and 84.84% (proportion of non-agricultural industries in total gross domestic product), respectively. FS, water supply, and ecological conservation bundles changed over the 20 years, and trade-offs and synergies among ESs within bundles differed. We revealed the complexity of ESs from multiple perspectives, which will enable the development of ecosystem management and conservation recommendations for the YREB and large-scale economic zones worldwide.

Empagliflozin improves renal ischemia-reperfusion injury by reducing inflammation and enhancing mitochondrial fusion through AMPK-OPA1 pathway promotion.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is one reason for renal transplantation failure. Recent studies have shown that mitochondrial dynamics is closely related to IRI, and that inhibition or reversal of mitochondrial division protects organs against IRI. Optic atrophy protein 1 (OPA1), an important factor in mitochondrial fusion, has been shown to be upregulated by sodium-glucose cotransporter 2 inhibitor (SGLT2i). Also, the antiinflammatory effects of SGLT2i have been demonstrated in renal cells. Thus, we hypothesized that empagliflozin could prevent IRI through inhibiting mitochondrial division and reducing inflammation. METHODS: Using hematoxylin-eosin staining, enzyme linked immunosorbent assay (ELISA), flow cytometry, immunofluorescent staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining, real-time PCR, RNA-sequencing, and western blot, we analyzed renal tubular tissue from in vivo and in vitro experiments. RESULTS: Through animal experiments and sequencing analysis, we first confirmed the protection against IRI and the regulation of mitochondrial dynamics-related factors and inflammatory factors by empagliflozin pretreatment. Then, through hypoxia/reoxygenation (H/R) cellular experiments, we confirmed that empagliflozin could inhibit mitochondrial shortening and division and upregulate OPA1 in human renal tubular epithelial cell line (HK-2) cells. Subsequently, we knocked down OPA1, and mitochondrial division and shortening were observed, which could be alleviated by empagliflozin treatment. Combined with the previous results, we concluded that OPA1 downregulation leads to mitochondrial division and shortening, and empagliflozin can alleviate the condition by upregulating OPA1. We further explored the pathway through which empagliflozin functions. Related studies have shown the activation of AMPK pathway by empagliflozin and the close correlation between the AMPK pathway and OPA1. In our study, we blocked the AMPK pathway, and OPA1 upregulation by empagliflozin was not observed, thus demonstrating the dependence of empagliflozin on the AMPK pathway. CONCLUSION: The results indicated that empagliflozin could prevent or alleviate renal IRI through antiinflammatory effects and the AMPK-OPA1 pathway. Ischemia-reperfusion injury is an inevitable challenge in organ transplantation. It is necessary to develop a new therapeutic strategy for IRI prevention in addition to refining the transplantation process. In this study, we confirmed the preventive and protective effects of empagliflozin in renal ischemia-reperfusion injury. Based on these findings, empagliflozin is promising to be a preventive agent for renal ischemia-reperfusion injury and can be applied for preemptive administration in kidney transplantation.

[Trade-off and Synergy of Ecosystem Services in the Yangtze River Economic Belt and Its Driving Factors].

Ecosystem services (ESs) and their changes are complex processes driven by multiple factors. Understanding the trade-off and synergy between ESs and their driving factors is essential for achieving effective management of ESs and human well-being. Taking the Yangtze River Economic Belt as the research area, this study analyzed the temporal and spatial variation characteristics of four ESs including water yield, soil conservation, carbon sequestration, and food supply from 2000 to 2020. Correlation analysis and geographically weighted regression were used to identify and quantify the trade-off and synergy between ESs. On this basis, the partial least squares structural equation model was used to explore the impact of natural and human activities on ESs, and then the driving mechanism of ESs relationship change was analyzed via GeoDetector. The results showed that:① During the 20 years, the average annual carbon sequestration increased from 946.14 t·km-2 to 1 202.73 t·km-2, and the average food supply increased from 32.73×104 Yuan·km-2 to 127.22×104 Yuan·km-2. Water yield and soil conservation increased to a lesser degree. ② On the whole, carbon sequestration and soil conservation and food supply and water yield showed synergy, and other ESs were trade-offs. The relationship between ESs varied in different regions. ③ Terrain and climate were important driving factors for ESs and the trade-off and synergy of multiple ESs. Among them, structural equation model results showed that climate had a positive impact on water yield (S=0.73), and terrain had a negative impact on food supply (S=-0.57). GeoDetector results revealed that the main driving factors affecting the spatial relationship between carbon sequestration and water yield were elevation (q=0.38) and precipitation (q=0.19). The results of this study can provide a scientific reference for the sustainable management of ESs in the Yangtze River Economic Belt and the realization of the coordinated development of ecological environment protection and social economy in the region.