Exogenous carbon monoxide suppresses LPS-Induced platelet SNAREs complex assembly and α-granule exocytosis via integrin αIIbβ3-Mediated PKCθ/Munc18a pathway

Qihuang Zhuyu formula alleviates coronary microthrombosis by inhibiting PI3K/Akt/αIIbβ3-mediated platelet activation

BACKGROUND

Coronary microembolism (CME) is commonly seen in the peri-procedural period of Percutaneous Coronary Intervention (PCI), where local platelet activation and endothelial cell inflammation crosstalk may lead to micro thrombus erosion and rupture, with serious consequences. Qihuang Zhuyu Formula (QHZYF) is a Chinese herbal compound with high efficacy against coronary artery disease, but its antiplatelet mechanism is unclear.

HYPOTHESIS/PURPOSE

This study aimed to elucidate the effects and mechanisms of QHZYF on sodium laurate-induced CME using network pharmacology and in vitro and in vivo experiments.

METHODS

We employed high-performance liquid chromatography mass spectrometry to identify the main components of QHZYF. Network pharmacology analysis, molecular docking and surface plasmon resonance (SPR) were utilized to predict the primary active components, potential therapeutic targets, and intervention pathways mediating the effects of QHZYF on platelet activation. Next, we pretreated a sodium laurate-induced minimally invasive CME rat model with QHZYF. In vivo experiments were performed to examine cardiac function in rats, to locate coronary arteries on heart sections to observe internal microthrombi, to extract rat Platelet-rich plasma (PRP) for adhesion assays and CD62p and PAC-1 (ITGB3/ITGA2B) flow assays, and to measure platelet-associated protein expression in PRP. In vitro clot retraction and Co-culture of HUVECs with PRP were performed and the gene pathway was validated through flow cytometry and immunofluorescence.

RESULTS

Combining UPLC-Q-TOF/MS technology and database mining, 78 compounds were finally screened as the putative and representative compounds of QHZYF, with 75 crossover genes associated with CME. QHZYF prevents CME mainly by regulating key pathways of the inflammation and platelets, including Lipid and atherosclerosis, Fluid shear stress, platelet activation, and PI3K-Akt signaling pathways. Five molecules including Calyson, Oroxin A, Protosappanin A,Kaempferol and Geniposide were screened and subjected to molecular docking and SPR validation in combination with Lipinski rules (Rule of 5, Ro5). In vivo experiments showed that QHZYF not only improved myocardial injury but also inhibited formation of coronary microthrombi. QHZYF inhibited platelet activation by downregulating expression of CD62p receptor and platelet membrane protein αIIbβ3 and reduced the release of von Willebrand Factor (vWF), Ca2+ particles and inflammatory factor IL-6. Further analysis revealed that QHZYF inhibited the activation of integrin αIIbβ3, via modulating the PI3K/Akt pathways. In in vitro experiments, QHZYF independently inhibited platelet clot retraction. Upon LPS induction, the activation of platelet membrane protein ITGB3 was inhibited via the PI3K/Akt pathway, revealing an important mechanism for attenuating coronary microthrombosis. We performed mechanistic validation using PI3K inhibitor LY294002 and Akt inhibitor MK-2206 to show that QHZYF inhibited platelet membrane protein activation and inflammation to improved coronary microvessel embolism by regulating PI3K/Akt/αIIbβ3 pathways, mainly by inhibiting PI3K and Akt phosphorylation.

CONCLUSION

QHZYF interferes with coronary microthrombosis through inhibition of platelet adhesion, activation and inflammatory crosstalk, thus has potential in clinical anti-platelet applications. Calyson, Oroxin A, Protosappanin A, Kaempferol and Geniposide may be the major active ingredient groups of QHZYF that alleviate coronary microthrombosis.

β1-Integrin-A Key Player in Controlling Pancreatic Beta-Cell Insulin Secretion via Interplay With SNARE Proteins

Shortcomings in cell-based therapies for patients with diabetes have been revealed to be, in part, a result of an improper extracellular matrix (ECM) environment. In vivo, pancreatic islets are emersed in a diverse ECM that provides physical support and is crucial for healthy function. β1-Integrin receptors have been determined to be responsible for modulation of beneficial interactions with ECM proteins influencing beta-cell development, proliferation, maturation, and function. β1-Integrin signaling has been demonstrated to augment insulin secretion by impacting the actin cytoskeleton via activation of focal adhesion kinase and downstream signaling pathways. In other secretory cells, evidence of a bidirectional relationship between integrins and exocytotic machinery has been demonstrated, and, thus, this relationship could be present in pancreatic beta cells. In this review, we will discuss the role of ECM-β1-integrin interplay with exocytotic proteins in controlling pancreatic beta-cell insulin secretion through their dynamic and unique signaling pathway.