Intravital imaging of splenic classical monocytes modifying the hepatic CX3CR1+ cells motility to exacerbate liver fibrosis via spleen-liver axis.

CX3CR1+ cells play a crucial role in liver fibrosis progression. However, changes in the migratory behavior and spatial distribution of spleen-derived and hepatic CX3CR1+ cells in the fibrotic liver as well as their influence on the liver fibrosis remain unclear. METHODS: The CX3CR1GFP/+ transgenic mice and CX3CR1-KikGR transgenic mice were used to establish the CCl4-induced liver fibrosis model. Splenectomy, adoptive transfusion of splenocytes, in vivo photoconversion of splenic CX3CR1+ cells and intravital imaging were performed to study the spatial distribution, migration and movement behavior, and regulatory function of CX3CR1+ cells in liver fibrosis. RESULTS: Intravital imaging revealed that the CX3CR1GFP cells accumulated into the fibrotic liver and tended to accumulate towards the central vein (CV) in the hepatic lobules. Two subtypes of hepatic CX3CR1+ cells existed in the fibrotic liver. The first subtype was the interacting CX3CR1GFP cells, most of which were observed to distribute in the liver parenchyma and had a higher process velocity; the second subtype was mobile CX3CR1GFP cells, most of which were present in the hepatic vessels with a faster moving speed. Splenectomy ameliorated liver fibrosis and decreased the number of CX3CR1+ cells in the fibrotic liver. Moreover, splenectomy rearranged CX3CR1GFP cells to the boundary of the hepatic lobule, reduced the process velocity of interacting CX3CR1GFP cells and decreased the number and mobility of mobile CX3CR1GFP cells in the fibrotic liver. Transfusion of spleen-derived classical monocytes increased the process velocity and mobility of hepatic endogenous CX3CR1GFP cells and facilitated liver fibrosis progression via the production of proinflammatory and profibrotic cytokines. The photoconverted splenic CX3CR1+ KikRed+ cells were observed to leave the spleen, accumulate into the fibrotic liver and contact with hepatic CX3CR1+ KikGreen+ cells during hepatic fibrosis. CONCLUSION: The splenic CX3CR1+ monocytes with classical phenotype migrated from the spleen to the fibrotic liver, modifying the migratory behavior of hepatic endogenous CX3CR1GFP cells and exacerbating liver fibrosis via the secretion of cytokines. This study reveals that splenic CX3CR1+ classical monocytes are a key driver of liver fibrosis via the spleen-liver axis and may be potential candidate targets for the treatment of chronic liver fibrosis.

Effective treatment of metastatic sentinel lymph nodes by dual-targeting melittin nanoparticles.

Sentinel lymph node (SLN) metastasis is an important promoter of distant metastasis in breast cancer. Therefore, the timely diagnosis and precise treatment are crucial for patient staging and prognosis. However, the simultaneous diagnosis of metastasis and the implementation of imaging-guided SLN therapy is challenging. Here, we report a melittin-loaded and hyaluronic acid (HA)-conjugated high-density lipoprotein (HDL) mimic phospholipid scaffold nanoparticle (MLT-HA-HPPS), which dually-target to both breast cancer and its SLN and efficiently inhibit SLN metastasis in the LN metastasis model. The melittin peptide was successfully loaded onto HA-HPPS via electrostatic interactions, and MLT-HA-HPPS possesses effective cytotoxicity for breast cancer 4T1 cells. Moreover, the effective delivery of MLT-HA-HPPS from the primary tumor into SLN is monitored by NIR fluorescence imaging, which greatly benefits the prognosis and treatment of metastatic SLNs. After paracancerous administration, MLT-HA-HPPS can efficiently inhibit primary tumor growth with an inhibition rate of 81.3% and 76.5% relative to the PBS-treated control group and HA-HPPS group, respectively. More importantly, MLT-HA-HPPS can effectively inhibit the growth of the metastatic SLNs with an approximately 78.0%, 79.1%, and 64.2% decrease in SLNs weight than those in PBS, HA-HPPS, and melittin-treated mice, respectively. Taken together, the MLT-HA-HPPS may provide an encouraging theranostic of SLN drug delivery strategy to inhibit primary tumor progression and prevent SLN metastasis of breast cancer.

Rational Design of High-Performance Hemithioindigo-Based Photoswitchable AIE Photosensitizer and Enabling Reversible Control Singlet Oxygen Generation.

A photosensitizer furnishing with reversible control singlet oxygen generation (1O2) is highly desirable for precise photodynamic therapy (PDT), lessening non-specific harm to healthy tissues. Here, a novel photoswitchable aggregation-induced emission (AIE) photosensitizer based on a triarylamine (TPA)-modified hemithioindigo (HTI), 6Br-HTI-TPA-OMe, was rationally designed. The triarylamine AIE photosensitizing moiety and HTI switch unit were covalently linked in one molecule, permitting reversible regulation of 1O2 production. The photophysical evaluations revealed that 6Br-HTI-TPA-OMe possessed excellent AIE properties and Z/E photoswitch performance in different solvents. Additionally, the amphiphilic phospholipid-fabricated nanoparticles (NPs) also exhibited photochromic behavior in water. The Z-NPs initiated the generation of 1O2 upon 520 nm light-emitting diode (LED) irradiation, but after switching to E-NPs, the generation of 1O2 was inhibited by the competitive energy transfer, suggesting that reversible Z/E isomerization could photocontrol 1O2 generation. The in vitro anti-tumor experiment verified that the 6Br-HTI-TPA-OMe can act as a photoswitchable AIE photosensitizer. This is the first report on the photoswitchable AIE photosensitizer of HTI-based molecules, to the best of our knowledge.

Biflavones from Ginkgo biloba as novel pancreatic lipase inhibitors: Inhibition potentials and mechanism.

Reduction of lipid absorption has been recognized as an attractive approach for the discovery of new drugs to treat obesity and overweight. The leave extract of Ginkgo biloba has been widely used for the treatment of metabolic diseases (such as hyperlipidemia) in both eastern and western countries, but the bioactive compounds in Ginkgo biloba and the underlying mechanism have not been fully characterized. This study aimed to investigate the inhibition potentials and mechanism of major biflavones from G. biloba on pancreatic lipase (PL), a key target regulating lipid absorption. The results clearly demonstrated that all tested biflavones in G. biloba including isoginkgetin, bilobetin, ginkgetin and sciadopitysin, displayed strong to moderate inhibitory effects on PL with the IC50 values ranging from 2.90 µM to 12.78 µM. Further investigations on both inhibition kinetic analyses and docking simulations demonstrated that isoginkgetin, bilobetin and ginkgetin were potent PL inhibitors (Ki < 2.5 µM), which could create strong interactions with the catalytic triad of PL via hydrogen bonding. These findings provided a new powerful evidence for explaining the hypolipidemic effects of G. biloba, while these newly identified PL inhibitors from G. biloba could serve as lead compounds for the development of biflavonoid-type PL inhibitors.

Natural constituents from Cortex Mori Radicis as new pancreatic lipase inhibitors.

Pancreatic lipase (PL), a key enzyme responsible for the hydrolysis of triacylglycerides in the gastrointestinal tract, has been identified as the therapeutic target for the regulation of lipid absorption. In the present study, six major constituents from a famous Chinese herbal medicine Cortex Mori Radicis (also named sangbaipi in Chinese), have been collected and their inhibitory effects on PL have been carefully investigated and well characterized by a fluorescence-based assay. The results clearly demonstrated that all tested bioactive constituents from Cortex Mori Radicis including sanggenone C (SC), sanggenone D (SD), kuwanon C (KC), kuwanon G (KG), morin and morusin displayed strong to moderate inhibitory effects towards PL with the IC50 values ranging from 0.77 µM to 20.56 µM. Further investigations on inhibition kinetics demonstrated that SC, SD, KC and KG functioned as potent and mixed inhibitors against PL-mediated 4-MU oleate hydrolysis, with the Ki values less than 5.0 µM. Furthermore, molecular docking simulations demonstrated that SD (the most potent PL inhibitor from Cortex Mori Radicis) could create strong interaction with Ser152 (the key amino acid in the catalytic triad) of PL via hydrogen bonding. All these findings provided a new powerful evidence for explaining the hypolipidemic effect of Cortex Mori Radicis, also suggested that some abundant natural compounds in this herbal medicine could be served as lead compounds for the development of new PL inhibitors.