Objective To evaluate the role of heparanase in endotoxemia-induced destruction of vascular endothelial glycocalyx in rats.Methods Forty-eight pathogen-free male Sprague-Dawley rats, aged 8-10 weeks, weighing 200-250 g, were randomly divided into 3 groups (n=16 each) using a random number table: control group (group C), lipopolysaccharide (LPS) group (group L) and LPS+ heparin group (group LH).Endotoxemia was induced by intravenous LPS 15 mg/kg in L and LH groups, and heparin sodium 100 U · kg-1 · h-1 was infused simultaneously in group LH.At 3 and 6 h after LPS injection, blood samples were collected from the femoral vein for determination of the serum concentrations of serum heparin sulfate (HS), syndecan-1, E-selectin and intercellular adhesion molecule-1 (ICAM-1) concentrations.The rats were then sacrificed, and lungs were removed for microscopic examination and for determination of wet/dry lung weight ratio (W/D ratio).Results Compared with group C, the serum HS, syndecan-1, E-selectin and ICAM-1 concentrations and W/D ratio were significantly increased in group L, and the serum HS and ICAM-1 concentrations were increased in group LH (P＜0.05).Compared with group L, the serum HS, syndecan-1, E-selectin and ICAM-1 concentrations and W/D ratio were significantly decreased in group LH (P＜0.05).The pathological changes of lungs were obvious in group L, and were significantly mitigated in group LH.Conclusion Heparanase is involved in endotoxemiainduced destruction of vascular endothelial glycocalyx in rats.

Objective To solve the problem that the rat retina paraffin sections are easily exfoliated from the slides and each layer are easily separation and fracture,we need to find a way to improve the retina paraffin section method and evaluate the tissue fixation. Methods We used 4 fixation liquids including 10%paraformaldehyde,4%paraformaldehyde, 4% paraformaldehyde and 95% alcohol and glacial acetic acid mixed liquid (FAA fixatiue solution ) combined with paraformaldehyde to fix the retinal tissue, and observed the fixation efficacy under microscope after HE staining. Results The effects of 10%paraformaldehyde and 4%paraformaldehyde fixed samples showed moderate separation and fracture of retina,but the HE staining retinal slices pre-treated by the FAA fixafive solution had bright and uniform color,although occasionally some parts of the retina were exfoliated from the slide, but it was not easy to take off,and had complete structure without separation and rupture. Conclusion The retina paraffin section fixed by FAA ixafive solution with 4% paraformaldehyde is superior to pure paraformaldehyde, and the paraformaldehyde concentration has no obviously influence on HE staining results.

The immune checkpoint blockade (ICB) targeting on PD-1/PD-L1 has shown remarkable promise in treating cancers. However, the low response rate and frequently observed severe side effects limit its broad benefits. It is partially due to less understanding of the biological regulation of PD-L1. Here, we systematically and comprehensively summarized the regulation of PD-L1 from nuclear chromatin reorganization to extracellular presentation. In PD-L1 and PD-L2 highly expressed cancer cells, a new TAD (topologically associating domain) (chr9: 5,400,000-5,600,000) around CD274 and CD273 was discovered, which includes a reported super-enhancer to drive synchronous transcription of PD-L1 and PD-L2. The re-shaped TAD allows transcription factors such as STAT3 and IRF1 recruit to PD-L1 locus in order to guide the expression of PD-L1. After transcription, the PD-L1 is tightly regulated by miRNAs and RNA-binding proteins via the long 3'UTR. At translational level, PD-L1 protein and its membrane presentation are tightly regulated by post-translational modification such as glycosylation and ubiquitination. In addition, PD-L1 can be secreted via exosome to systematically inhibit immune response. Therefore, fully dissecting the regulation of PD-L1/PD-L2 and thoroughly detecting PD-L1/PD-L2 as well as their regulatory networks will bring more insights in ICB and ICB-based combinational therapy.