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Proteolysis-targeting chimeras (PROTACs) selectively eliminate detrimental proteins by exploiting the ubiquitin-proteasome system (UPS), representing a promising therapeutic strategy against various diseases. Effective adaptations of degradation signal sequences and E3 ligases for PROTACs remain limited. Here, we employed three amino acidsâGly, Pro, and Lysâas the ligand to recruit the corresponding E3 ligases: CRL2ZYG11B/ZER1, GID4, and UBRs, to degrade EML4-ALK and mutant EGFR, two oncogenic drivers in NSCLC. We found that the extent of EML4-ALK and EGFR reduction can be easily fine-tuned by using different degradation signals. These amino acid-based PROTACs, termed AATacs, hindered proliferation and induced cell cycle arrest and apoptosis of NSCLC cells in vitro. Compared to other PROTACs, AATacs are small, interchangeable but with different degradation efficiency. Our study further expands the repertoire of E3 ligases and their ligands for PROTAC application, improving the versatility and utility of targeted protein degradation for therapeutic purposes.
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The Dll4-Notch signaling pathway plays a crucial role in the regulation of angiogenesis and is a promising therapeutic target for diseases associated with abnormal angiogenesis, such as cancer and ophthalmic diseases. Here, we find that polyethylenimine (PEI), a cationic polymer widely used as nucleic acid transfection reagents, can target the Notch ligand Dll4. By immunostaining and immunoblotting, we demonstrate that PEI significantly induces the clearance of cell-surface Dll4 and facilitates its degradation through the lysosomal pathway. As a result, the activation of Notch signaling in endothelial cells is effectively inhibited by PEI, as evidenced by the observed decrease in the generation of the activated form of Notch and expression of Notch target genes Hes1 and Hey1. Furthermore, through blocking Dll4-mediated Notch signaling, PEI treatment enhances angiogenesis in vitro. Together, our study reveals a novel biological effect of PEI and establishes a foundation for the development of a Dll4-targeted biomaterial for the treatment of angiogenesis-related disease.
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Coal mining can significantly impact vegetation evolution, yet the limited information on its patterns and driving factors hampers efforts to mitigate these effects and reclaim abandoned mines. This study aimed to 1) examine vegetation evolution in a semiarid steppe watershed in northeast China; and 2) characterize the driving factors behind this evolution. We analyzed the impact of twelve selected driving factors on fractional vegetation coverage (FVC) from 2000 to 2021 using a dimidiate pixel model, Sen's slope analysis, Mann-Kendall trend test, coefficient of variation analysis, and Geodetector model. At a significance level of α = 0.05, our findings revealed a south-to-north decline pattern in FVC, a significant decrease trend in proximity to coal mines, and a notable increase trend adjacent to river channels. Approximately 37% of the watershed exhibited low FVC, while the overall temporal trend across the watershed was deemed insignificant. Areas surrounding the mines experienced a substantial reduction in FVC due to coal mining activities, while FVC variations across the watershed were linked to precipitation, temperature, and soil type. FVC predictions improved notably when interactions between multiple two-way factors were considered. Each driving factors displayed an optimal range (e.g., precipitation = 63-71 mm) for maximizing FVC. Given the study watershed's status as a national energy base, understanding vegetation responses to coal mining and climate-environment changes is crucial for sustaining fragile terrestrial ecosystems and socioeconomic development. Achieving a long-time balance between coal extraction and ecological protection is essential. The study outcomes hold significant promise for advancing ecological conservation, vegetation restoration, and mitigation of environmental degradation in semiarid regions affected by extensive coal mining and climate fluctuations. These findings contribute to the strategic management of such areas, promoting sustainable practices amidst evolving environmental challenges.
Assuntos
Minas de Carvão , Ecossistema , Pradaria , Temperatura , China , Carvão MineralRESUMO
Taking the Tugeligaole sub-basin of the Jilantai Salt Lake Basin in Inner Mongolia as the typical study area, the groundwater samples of 22 points were collected, and their main characteristic indexes were tested during the wet season and the dry season separately in 2021. Mathematical statistics, Piper triangular diagrams, a Gibbs plot, ionic relations, and factor analysis were used to analyze and discuss the hydrochemical characteristics and formation mechanism of groundwater in different periods. Based on the evaluation of the groundwater quality using the water quality index(WQI) method, the potential risks of groundwater Cr6+ and F- were evaluated using the health risk evaluation model. The results showed that the groundwater was overall weakly alkaline; the dominant anions and cations during the different periods were Cl- and Na+, and the water chemistry type was mainly Cl--Na+; the groundwater quality was generally good, and the difference in water quality between the wet season and the dry season was not significant; adults and children had higher carcinogenic health risks in the dry season than that in the wet season, and the health risks of children were significantly higher than those in adults. The maximum carcinogenic health risk of drinking water exposure to Cr6+ in adults and children was higher than the maximum acceptable risk level(5×10-5). The chemical evolution of groundwater was mainly affected by evaporative concentration, evaporative salt rock dissolution, and cation exchange, and the main control factors were evaporative concentration(contribution rate of 54.19%), native geological environment factors(contribution rate of 12.99%), and carbonate rock dissolution(contribution rate of 11.66%). The study results have significance to some degree to the sustainable exploitation and utilization of groundwater resources and environmental protection of the salt lake basin.