AFM-based detection of glycocalyx degradation and endothelial stiffening in the db/db mouse model of diabetes.

Degradation of the glycocalyx and stiffening of endothelium are important pathophysiological components of endothelial dysfunction. However, to our knowledge, these events have not been investigated in tandem in experimental diabetes. Here, the mechanical properties of the glycocalyx and endothelium in ex vivo mouse aorta were determined simultaneously in indentation experiments with an atomic force microscope (AFM) for diabetic db/db and control db/+ mice at ages of 11-19 weeks. To analyze highly heterogeneous aorta samples, we developed a tailored classification procedure of indentation data based on a bi-layer brush model supplemented with Hertz model for quantification of nanomechanics of endothelial regions with and without the glycocalyx surface. In db/db mice, marked endothelial stiffening and reduced glycocalyx coverage were present already in 11-week-old mice and persisted in older animals. In contrast, reduction of the effective glycocalyx length was progressive and was most pronounced in 19-week-old db/db mice. The reduction of the glycocalyx length correlated with an increasing level of glycated haemoglobin and decreased endothelial NO production. In conclusion, AFM nanoindentation analysis revealed that stiffening of endothelial cells and diminished glycocalyx coverage occurred in early diabetes and were followed by the reduction of the glycocalyx length that correlated with diabetes progression.

3D Raman imaging of systemic endothelial dysfunction in the murine model of metastatic breast cancer.

It was recently reported in the murine model of metastatic breast cancer (4T1) that tumor progression and development of metastasis is associated with systemic endothelial dysfunction characterized by impaired nitric oxide (NO) production. Using Raman 3D confocal imaging with the analysis of the individual layers of the vascular wall combined with AFM endothelial surface imaging, we demonstrated that metastasis-induced systemic endothelial dysfunction resulted in distinct chemical changes in the endothelium of the aorta. These changes, manifested as a significant increase in the protein content (18%) and a slight decrease in the lipid content (4%), were limited to the endothelium and did not occur in the deeper layers of the vascular wall. The altered lipid to protein ratio in the endothelium, although more pronounced in the fixed vascular wall, was also observed in the freshly isolated unfixed vascular wall samples in the aqueous environment (12 and 7% change of protein and lipid content, respectively). Our results support the finding that the metastasis induces systemic endothelial dysfunction that may contribute to cancer progression.

Liver sinusoidal endothelial cells (LSECs) function and NAFLD; NO-based therapy targeted to the liver.

Liver sinusoidal endothelial cells (LSECs) present unique, highly specialised endothelial cells in the body. Unlike the structure and function of typical, vascular endothelial cells, LSECs are comprised of fenestrations, display high endocytic capacity and play a prominent role in maintaining overall liver homeostasis. LSEC dysfunction has been regarded as a key event in multiple liver disorders; however, its role and diagnostic, prognostic and therapeutic significance in nonalcoholic fatty liver disease (NAFLD) is still neglected. The purpose of this review is to provide an overview of the importance of LSECs in NAFLD. Attention is focused on the LSECs-mediated NO-dependent mechanisms in NAFLD development. We briefly describe the unique, highly specialised phenotype of LSECs and consequences of LSEC dysfunction on function of hepatic stellate cells (HSC) and hepatocytes. The potential efficacy of liver selective NO donors against liver steatosis and novel treatment approaches to modulate LSECs-driven liver pathology including NAFLD are also highlighted.

[The benefits of using basophil activation test as a diagnostic tool prior to specific immunotherapy with inhalant allergens]. / Korzysci z wykonywania testu aktywacji bazofilów w kwalifikacji do immunoterapii swoistej w alergii wziewnej.

BACKGROUND: Routine qualification for specific immunotherapy (SIT) is based on clinical history and skin prick tests (SPT) or specific IgE (sIgE). In cases of discordance between these two, basophil activation test (BAT) may be decisive. The aim of the present study was to determine the specificity and sensitivity of BAT, sIgE, and SPT, and to analyse cases, in which clinical data and SPT alone would result in wrongful qualification for SIT. PATIENTS AND METHODS: BAT results and sIgE levels to Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) were determined in 52 pediatric patients qualified for SIT based on clinical history and positive SPT. The group included 21 children qualified for SIT with birch or timothy grass, used as reference for specificity and sensitivity calculations for BAT, sIgE and SPT. RESULT: The sensitivity and specificity of BAT, using SPT as "gold standard" was 96.9% and 88.9% for Dp, and 89.3% and 100% for Df, respectively and the sensitivity and specificity of sIgE were 89.7%, 88.9% for Dp, and 92.9% and 94.4% for Df. When using BAT as "gold standard", the sensitivity and specificity of SPT was 90% and 90.5% for Dp, 92% and 84,6% for Df, and these indices for sIgE were 87.1% and 90.5% for Dp, 100% and 87.5% for Df. BAT did not confirm the initial qualification for SIT in 2 patients, revealing an unspecific basophil activation. Negative nasal provocation test ultimately confirmed the false-positive SPT, which could be explained by the co-existence of urticaria in those children. In further 2 children qualified for SIT with timothy and birch, BAT revealed lack of reactivity to respective allergens. Altogether BAT helped in avoiding unnecessary SIT in 4 out of 52 children (7.7%). CONCLUSIONS: In most cases, SPT, sIgE and BAT provide comparable information, however, SPT results care is advised in patients with co-existing urticaria. BAT is useful in verifying the actual relevance of allergens selected for SIT and helps in avoiding long-lasting, arduous, costly, and ineffective immunotherapy of wrongly qualified cases.