Plasma P-Selectin Is Inversely Associated with Lung Function and Corticosteroid Responsiveness in Asthma

Dual phenotypic characteristics of P-selectin in a mouse model of hemorrhagic shock and hepatectomy

BACKGROUND

Membrane-bound P-selectin induces endothelial adhesion of leucocytes and amplifies organ inflammations during major trauma, while soluble P-selectin (sP-sel) mediates survival rescue properties. This study characterized the differential effects of P-selectin in a "2-hit" model of hemorrhagic shock (HS) and partial hepatectomy (PH).

MATERIALS AND METHODS

HS was induced by withdrawing blood (0.3 mL) directly from the mouse femoral arteries. 70% or 50% of liver volumes were resected after inducing HS. Time of survival in P-selectin deficient (Selp -/-) mice treated with and without intraperitoneal injections of recombinant P-sel IgG-Fc fusion proteins (rP-sel-Fc, 1.5 mg/kg) were recorded for up to 72h after injury. In addition, liver regeneration at 72h after HS and 50% PH was assessed in wild-type and Selp -/- mice.

RESULTS

Compared to wild-types, Selp -/- mice had significantly higher mortality rates post HS and 70% PH, as none of these animals survived up to 48h postoperatively. The survival curve was restored in Selp -/- mice pre-treated with rP-sel-Fc. In the HS followed by 50% PH experimental arm, liver remnant growth ratios were significantly higher in Selp -/- mice (15.7 ± 3.1 vs 11.7 ± 4.9, P = 0.040). The elevated serum concentrations of alanine aminotransferase post-PH were significantly reduced in Selp -/- mice. Hepatocyte proliferation indices (CYP7a1 and PCNA) expression were enhanced and myeloperoxidase activity in the regenerated remnant liver was reduced in the Selp -/- mice.

CONCLUSION

In critical conditions induced by HS and PH, P-selectin mediates two distinct phenotypic characteristics. Soluble-form circulating P-selectin improves survival in the acute stage of HS and extensive loss of liver parenchyma; membrane-bound P-selectin induces regional pro-inflammatory reactions in the remnant liver after the acute stage of two insults, thereby inhibiting hepatic regeneration. The results of this pre-clinical study may provide molecular mechanistic insight and clinical therapeutic applications of P-selectin in the acute and regenerative phases of traumatic hepatic injury.

Tuo-Min-Ding-Chuan Decoction Alleviate Ovalbumin-Induced Allergic Asthma by Inhibiting Mast Cell Degranulation and Down-Regulating the Differential Expression Proteins

Allergic asthma is a stubborn chronic inflammatory disease, and is considered a co-result of various immune cells, especially mast cells, eosinophils and T lymphocytes. At present, the treatment methods of allergic asthma are limited and the side effects are obvious. Traditional Chinese medicine has been used to treat diseases for thousands of years in China. One such example is the treatment of allergic asthma, which take the characteristics of less adverse reactions and obvious curative effect. Tuo-Min-Ding-Chuan Decoction (TMDCD) is a traditional Chinese medicine compound for the treatment of allergic asthma optimized from Ma-Xing-Gan-Shi Decoction (MXGSD), which was put forward in Treatise on Febrile Diseases by Zhang Zhongjing in the Eastern Han Dynasty. The compound shows a significant clinical effect, but the mechanism of its influence on the immune system is still unclear. The purpose of this study was to observe whether TMDCD could alleviate the symptoms of ovalbumin (OVA) challenged allergic asthma mice, and to explore its immune regulatory mechanism, especially on mast cell (MC) degranulation. The results showed TMDCD could not only reduce the airway hyperresponsiveness (AHR), inflammatory cell infiltration and mucus secretion in the lung tissue of OVA challenged mice, but also decrease the levels of total IgE, OVA-specific IgE, histamine and LTC4 in serum. We found that TMDCD can downregulate the expression of Fractalkine, Tryptase ε, IL-25, CCL19, MCP-1, OX40L, Axl, CCL22, CD30, G-CSF, E-selectin, OPN, CCL5, P-selectin, Gas6, TSLP in OVA challenged mice serum by using mouse cytokines antibody array. It has been reported in some literatures that these differentially expressed proteins are related to the occurrence of allergic asthma, such as tryptase ε, MCP-1, CCL5, etc. can be released by MC. And the results of in vitro experiments showed that TMDCD inhibited the degranulation of RBL-2H3 cells stimulated by DNP-IgE/BSA. Taken together, we made the conclusion that TMDCD could reduce the infiltration of inflammatory cells in lung tissue and alleviate airway remodeling in mice with allergic asthma, showed the effects of anti-inflammatory and antiasthmatic. TMDCD could also reduce the levels of IgE, histamine, LTC4, Tryptase ε, and other MC related proteins in the serum of allergic asthma mice, and the in vitro experiments showed that TMDCD could inhibit IgE mediated degranulation and histamine release of RBL-2H3 cells, proved its anti allergic effect.

The Role of P-Selectin in COVID-19 Coagulopathy: An Updated Review

In severe COVID-19, which is characterized by blood clots and neutrophil-platelet aggregates in the circulating blood and different tissues, an increased incidence of cardiovascular complications and venous thrombotic events has been reported. The inflammatory storm that characterizes severe infections may act as a driver capable of profoundly disrupting the complex interplay between platelets, endothelium, and leukocytes, thus contributing to the definition of COVID-19-associated coagulopathy. In this frame, P-selectin represents a key molecule expressed on endothelial cells and on activated platelets, and contributes to endothelial activation, leucocyte recruitment, rolling, and tissue migration. Briefly, we describe the current state of knowledge about P-selectin involvement in COVID-19 pathogenesis, its possible use as a severity marker and as a target for host-directed therapeutic intervention.