{Reference Type}: Journal Article
{Title}: IL-4-STAT6 axis amplifies histamine-induced vascular endothelial dysfunction and hypovolemic shock.
{Author}: Krempski J;Yamani A;Thota LNR;Marella S;Ganesan V;Sharma A;Kaneshige A;Bai L;Zhou H;Foster PS;Wang S;Obi AT;Hogan SP;
{Journal}: J Allergy Clin Immunol
{Volume}: 0
{Issue}: 0
{Year}: 2024 May 20
{Factor}: 14.29
{DOI}: 10.1016/j.jaci.2024.05.009
{Abstract}: <B>BACKGROUND: </B>Mast cell-derived mediators induce vasodilatation and fluid extravasation, leading to cardiovascular failure in severe anaphylaxis. We previously revealed a synergistic interaction between the cytokine IL-4 and the mast cell-derived mediator histamine in modulating vascular endothelial (VE) dysfunction and severe anaphylaxis. The mechanism by which IL-4 exacerbates histamine-induced VE dysfunction and severe anaphylaxis is unknown.<BR><B>OBJECTIVE: </B>We sought to identify the IL-4-induced molecular processes regulating the amplification of histamine-induced VE barrier dysfunction and the severity of IgE-mediated anaphylactic reactions.<BR><B>METHODS: </B>RNA sequencing, Western blot, Ca2+ imaging, and barrier functional analyses were performed on the VE cell line (EA.hy926). Pharmacologic degraders (selective proteolysis-targeting chimera) and genetic (lentiviral short hairpin RNA) inhibitors were used to determine the roles of signal transducer and activator of transcription 3 (STAT3) and STAT6 in conjunction with in vivo model systems of histamine-induced hypovolemic shock.<BR><B>RESULTS: </B>IL-4 enhancement of histamine-induced VE barrier dysfunction was associated with increased VE-cadherin degradation, intracellular calcium flux, and phosphorylated Src levels and required transcription and de novo protein synthesis. RNA sequencing analyses of IL-4-stimulated VE cells identified dysregulation of genes involved in cell proliferation, cell development, and cell growth, and transcription factor motif analyses revealed a significant enrichment of differential expressed genes with putative STAT3 and STAT6 motif. IL-4 stimulation in EA.hy926 cells induced both serine residue 727 and tyrosine residue 705 phosphorylation of STAT3. Genetic and pharmacologic ablation of VE STAT3 activity revealed a role for STAT3 in basal VE barrier function; however, IL-4 enhancement and histamine-induced VE barrier dysfunction was predominantly STAT3 independent. In contrast, IL-4 enhancement and histamine-induced VE barrier dysfunction was STAT6 dependent. Consistent with this finding, pharmacologic knockdown of STAT6 abrogated IL-4-mediated amplification of histamine-induced hypovolemia.<BR><B>CONCLUSIONS: </B>These studies unveil a novel role of the IL-4/STAT6 signaling axis in the priming of VE cells predisposing to exacerbation of histamine-induced anaphylaxis.