Multimodal discovery of bavachinin A: A natural FLT3 agonist for treating thrombocytopenia

Abstract

Background

Radiation-induced thrombocytopenia (RIT) poses a serious risk to patients with cancer undergoing radiotherapy and leads to hemorrhage and mortality. Unfortunately, effective treatment options for RIT are currently limited.

Purpose

This study aimed to discover active compound from Fructus Psoraleae, a traditional Chinese medicine recognized for its hemostatic properties, and to elucidate its mechanism of action in the treatment of RIT.

Methods

The efficacy of Fructus Psoraleae in treating thrombocytopenia was assessed using network pharmacology. A drug-screening model was built using a naive Bayes algorithm to determine the effective compounds in Fructus Psoraleae. Giemsa staining and flow cytometry were used to evaluate the effects of bavachinin A on megakaryocytes (MK) differentiation. RIT and thrombopoietin (TPO) receptor (c-MPL) knockout (c-MPL^−/−) mice were used to assess the therapeutic efficacy of bavachinin A in mitigating thrombocytopenia. Tg (cd41:eGFP) zebrafish were used to investigate the effect of bavachinin A on thrombopoiesis. RNA sequencing (RNA-seq), molecular docking simulations, molecular dynamics simulations, drug affinity responsive target stability assay (DARTS), and biolayer interferometry (BLI) were used to elucidate the molecular mechanisms of action of bavachinin A against thrombocytopenia.

Results

In silico analysis using a drug screening model identified bavachinin A as promising candidate compound derived from Fructus Psoraleae. In vitro experiments demonstrated that Bavachinin A induced MK differentiation. In vivo experiments revealed that bavachinin A augmented platelet levels and improved coagulation in RIT mice, facilitated megakaryopoiesis and platelet levels in c-MPL^−/− mice, and accelerated thrombopoiesis in zebrafish. Furthermore, RNA-seq, molecular docking simulations, molecular dynamics simulations, DARTS, and BLI demonstrated that bavachinin A bound directly to fms-like tyrosine kinase 3 (FLT3). Notably, blocking FLT3 or phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway hindered bavachinin-A-induced MK differentiation. However, repressing the TPO/c-MPL signaling pathway had no significant effect.

Conclusion

Bavachinin A promotes MK differentiation and thrombopoiesis by directly binding to FLT3 and activating PI3K/Akt signaling. Importantly, this effect was not dependent on the conventional TPO/c-MPL signaling pathway. This study underscores the translational potential of bavachinin A as a promising novel therapeutic for thrombocytopenia, offering novel insights into TPO-independent mechanisms of thrombopoiesis and establishing a robust multimodal approach for drug discovery.