TSPO KO mice show normal alveolar macrophage population.

<p>(A) FACS analysis of BALF and alveolar macrophages was identified as F4/80+, CD206+. (B) The percentages of alveolar macrophages in BALF from WT and TSPO KO mice are shown as the mean ± S.E.M. from four animals in each group (n = 4). NS, not significant by Student’s <i>t</i>-test.</p

Generation of TSPO KO mice.

<p>(A) Schematic of generation of TSPO Floxed mice and conditional KO mice by Cre-LoxP System. Conditional TSPO KO mice were generated by targeting exon 2 and exon 3 of the mouse genomic locus, a NEO selection cassette Floxed by Frt sites. (B) Schematic of crossing program for TSPO global knockout mice, Protamine-Cre is a transgenic mouse where Cre recombinase expression is driven by sperm specific protamine promotor. (C) Genotyping of TSPO Floxed mice and KO mice by a TSPO genotyping primer pair 1 & 3, and Flp primers. (D) Genotyping of TSPO Floxed mice and KO mice by three TSPO genotyping primers 1, 2 and 3, and Protamine-Cre primers.</p

TSPO expression was abolished in global KO mice without pathological changes.

<p>TSPO expression in different tissues from WT and KO mice were detected by western blotting (A) and IHC (B); (C) H&E staining of different tissues from WT and TSPO KO mice. Scale Bars, 100μm.</p

Polymer-Coated NaYF₄:Yb³⁺, Er³⁺ Upconversion Nanoparticles for Charge-Dependent Cellular Imaging

Lanthanide-doped upconversion nanoparticles (UCNPs) are considered promising novel near-infrared (NIR) bioimaging agents with the characteristics of high contrast and high penetration depth. However, the interactions between charged UCNPs and mammalian cells have not been thoroughly studied, and the corresponding intracellular uptake pathways remain unclear. Herein, our research work involved the use of a hydrothermal method to synthesize polyvinylpyrrolidone-coated UCNPs (UCNP-PVP), and then a ligand exchange reaction was performed on UCNP-PVP, with the help of polyethylenimine (PEI) and poly(acrylic acid) (PAA), to generate UCNP-PEI and UCNP-PAA. These polymer-coated UCNPs demonstrated good dispersibility in aqueous medium, had the same elemental composition and crystal phase, shared similar TEM and dynamic light scattering (DLS) size distribution, and exhibited similar upconversion luminescence efficiency. However, the positively charged UCNP-PEI evinced greatly enhanced cellular uptake in comparison with its neutral or negative counterparts, as shown by multiphoton confocal microscopy and inductively coupled plasma mass spectrometry (ICP-MS) measurements. Meanwhile, we found that cationic UCNP-PEI can be effectively internalized mainly through the clathrin endocytic mechanism, as revealed by colocalization, chemical, and genetic inhibitor studies. This study elucidates the role of the surface polymer coatings in governing UCNP–cell interactions, and it is the first report on the endocytic mechanism of positively charged lanthanide-doped UCNPs. Furthermore, this study provides important guidance for the development of UCNPs as specific intracellular nanoprobes, allowing us to control the UCNP–cell interactions by tuning surface properties

TSPO deletion does not affect viability by Het x Het and KO x KO breeding.

<p>(A) Birth rate of offspring of TSPO Het x Het breeding. (B) One litter Pups born 4 days from TSPO KO x KO breeding. (C) One litter pups born 9 days from TSPO KO x KO breeding. (D) Birth rate of offspring in TSPO KO x KO breeding. Chi-Squared Test was used to determine significant difference compared with Mendel’s Law.</p