Novel Perspectives of TSLP and RXR Signaling in Corticosteroid-Resistant Asthma: Updates on TSLP Blockers

Previous studies described that asthma patients who received corticosteroid therapy have been constrained by the corticosteroid resistance subsequently fostered to severe refractory asthma. In this review, we discussed the implications of TSLP, RXR, the role of STAT5-activating cytokines, and IL-33/NH-cell signaling pathways, and recent clinical evidence on TSLP blockers in steroid-resistant asthma. We have searched several public databases such as Pubmed, Scopus, and Relemed and obtained information pertinent to the TSLP, RXR, TSLP blockers, the STAT5-activating cytokines, and IL-33. We discussed the multiple cell signaling mechanisms underlying steroid resistance. Blocking the TSLP and other key signaling molecules like STAT5 can retrieve the sensitivity of natural helper-cells to corticosteroids. RXR derivatives treatment can modulate the activity of TSLP, which further modulates steroid resistance in severe asthmatic patients and in patients with refractory asthma. We discussed the steroid-resistance mediated by the Th2 cells and Th2-driven eosinophilia upon corticosteroid intake. Thus, this review will be beneficial for clinicians and molecular biologists to explore the inflammatory pathways associated with refractory asthma conditions and develop novel therapies against corticosteroid-resistant asthma.