Near-infrared lipid droplets polarity fluorescent probe for early diagnosis of nonalcoholic fatty liver disease.

Nowadays, it has been proven that lipid droplets (LDs) not only maintain the fundamental cellular functions, but also play an essential role in the pathogenesis of numerous diseases. Non-alcoholic fatty liver disease (NAFLD) is among these diseases. In this work, we designed two polarity sensitive fluorescent probes TST and TSO with D-π-A-D structure by introducing different electron acceptor groups according to the low polarity of LDs. The experimental discovered that probe TST exhibited the characteristics of near-infrared emission, high selectivity towards polarity, large Stokes shift, rapid targeting ability of LDs, and robust wash-free biological imaging capability. Confocal images illustrated that probe TST has been successfully applied in monitoring LDs polarity during ferroptosis, as well as visualizing changes in LDs polarity at both tissue and organ levels in fatty liver conditions. With these exceptional properties, probe TST was anticipated to make further contributions to the field of LDs research.

Red-emissive Dual-state Fluorogenic Probe for Wash-free Imaging of Lipid Droplets in Living Cells and Fatty Liver Tissues.

Lipid droplet (LD) dysfunction can result in various diseases, such as nonalcoholic fatty liver disease. Imaging agents built on dual-state emission (DSE) molecules that fluoresce in both dilute solutions and the aggregated state are receiving attention as this type of probe could provide bright fluorescence signals at variable concentrations, avoiding false signal readout caused by the concentration fluctuation in living systems. Herein, we identified a red emissive molecule featuring DSE, from three newly synthesized molecules, for specific detection of LDs in live cells. The bioimaging abilities have been well confirmed by optical spectroscopies, theoretical calculations, cell experiments, as well as animal studies. The DSE probe is effective for LD detection at concentrations ranging from 1 µM to 100 µM while retaining high brightness and signal fidelity. This study provides a knowledge base for the future design of DSE-active fluorescent probes for understanding LD-related diseases.

Relationship between phytoplankton community and environmental factors in landscape water with high salinity in a coastal city of China.

Relationship between phytoplankton community and environmental variables was explored in three landscape water bodies (namely Jiyun River Oxbow (JRO), Qingjing Lake (QL), and Jiyun River (JR)) with high salinity, located in Sino-Singapore Tianjin Eco-city of China, using redundancy analysis (RDA). A total of 48 species of phytoplankton were identified during the study period, in which Chlorophyta and Bacillariophyta accounted for 35.42 and 31.25%, respectively. The most dominant species of the studied water bodies were Cyclotella meneghiniana (Bacillariophyta) and Aphanocapsa elachista (Cyanophyta). The diversity index ranged from 0.56 to 1.42, with an average of 1.11, reflecting low biodiversity in the phytoplankton community. Moreover, the average density of phytoplankton was 42.39 × 106 cells/L, indicating that those landscape water bodies belonged to moderate eutrophication. The results of RDA revealed that the most significant environmental factors influencing phytoplankton community were water temperature (WT), dissolved total phosphorus (DTP), salinity, and total nitrogen (TN) (p < 0.05, Monte Carlo permutation test). Meanwhile, Aphanocapsa elachista was positively correlated with WT, TN, and salinity, while Cyclotella meneghiniana was positively related to salinity and negatively related to TP. The results suggested that salinity was a non-negligible key factor affecting the phytoplankton community of the water body with high salinity.