P-Selectin is a Critical Factor for Platelet-Mediated Protection on Restraint Stress-Induced Gastrointestinal Injury in Mice

Abstract

Psychological stress is associated with increased risk of gastrointestinal (GI) tract diseases. Evidence indicated that platelets facilitate GI tissue repair in intestinal anastomosis models. However, whether platelets are involved in native mechanism of the rescue of stress-induced GI injury for maintaining the GI homeostasis remains elusive. Because P-selectin-deficient (Selp−/−) mice displayed higher stress-induced GI injury compared to the wild-type (Selp+/+) mice, and P-selectin is specifically expressed in platelets, we hypothesize that P-selectin-expressing platelets play a protective role in the rescue of stress-induced GI injury. Our goal is to clarify the putative protective role of platelets in a GI system, thereby develop a feasible intervention strategy, such as platelet transfer, to overcome stress-induced GI injury. Through monitoring the plasma levels of GI-nonabsorbable Evans blue dye to reveal the progression course of GI injury in live mice, we found that intravenous treatments of purified platelets ameliorated stress-induced GI leakage. The transfer of platelets from wild-type mice was more potent than from Selp−/− mice in the rescue of stress-induced-GI leakage in the recipients. As such, platelet transfer-mediated rescue was conducted in a P-selectin dependent manner. Additionally, platelet-mediated protection is associated with corrections of stress-induced aberrant GI mRNA expressions, including tight junctions claudin 3 and occludin, as well as stress-induced genes activating transcription factor 3 and AMP-activated protein kinase, after the transfer of wild-type platelets into wild-type and Selp−/− mice. Furthermore, the stress-induced apoptosis of CD326+ GI epithelial cells was rescued by the transfer of wild type, but not P-selectin-deficient platelets. These results suggest that platelet plays a protective role for maintaining the GI homeostasis during stress in vivo, and that P-selectin is a molecular target for managing stress-induced GI tract injury.

Restraint Stress-Induced Immunosuppression Is Associated with Concurrent Macrophage Pyroptosis Cell Death in Mice

“…Therefore, using P-selectin antagonists would not be effective in suppressing this type of immunosuppression. However, it is worth noting that P-selectin does play a critical role in protecting against restraint-stress-induced GI leakage, as demonstrated in previous studies [ 15 ]. This suggests that although P-selectin is not involved in the induction of immunosuppression, it still plays a significant role in preventing injury associated with restraint stress.…”

“…Here we utilized a previously established mouse model that involved administering Evan blue dye to measure GI leakage levels at various time courses during restraint stress [ 14 , 15 , 16 , 17 ]. By employing this Evans-blue-fed mouse model, we made several noteworthy observations.…”

“…The reasons behind the significant level of immunosuppression induced by restraint stress and the different pathways through which various stressors, such as ambient cold exposure and restraint stress, induce immunosuppression remain unclear. Through the use of an experimental model involving the administration of Evans blue dye to restrained mice [ 14 , 15 , 16 , 17 ], we have demonstrated that restraint stress causes gut leakage in mice ( Figure 4 A, experiment outline, Figure 4 B). Since the spleen serves as a key lymphoid organ responsible for filtering blood, including blood from the GI system, to remove pathogens and foreign substances, it is reasonable to observe leukocyte infiltration into the spleen of mice following restraint stress ( Figure 4 C and Figure 7 D).…”

“…However, the impact of psychological alterations linked to acute restraint stress on the induction of an immunosuppressive response remains unclear. We have previously used a modified acute restraint stress mouse model by administering the non-absorbable dye Evans blue via gavage, which does not normally appear in the circulation when orally fed [ 14 , 15 , 16 , 17 ]. Through the analysis of plasma levels of Evans blue, a substance that leaks from the gastrointestinal (GI) tract, we can assess the extent of stress-induced GI leakage.…”

Platelet-derived circulating soluble P-selectin is sufficient to induce hematopoietic stem cell mobilization

“…This injection was administered for 3 consecutive days in conjunction with the last three doses of G-CSF (250 μg/kg/day). The platelet purification and transfer procedures followed the prior study’s methods [ 53 ]. After Ficoll–Paque PLUS purification, the mouse plasma underwent two rounds of centrifugation at room temperature, each at 9170 × g for 10 min, to eliminate any residual platelets.…”