Ectodysplasin-A mRNA in exosomes released from activated hepatic stellate cells stimulates macrophage response

Introduction: The interaction between activated hepatic stellate cells (aHSCs) and macrophages is central to liver fibrosis development. The cargo contained within aHSC exosomes (aHSC-EXOs) and how aHSC-EXOs affect macrophage function is poorly understood. Methods: RNA from aHSC-EXOs was separated into small (<200-basepairs) and large (>= 200-basepairs) RNA species, transfected into macrophages, and macrophage IL-6 and TNF alpha mRNA expression and protein secretion measured. Next generation sequencing was performed on EXOs from rat quiescent and aHSCs and human aHSCs. aHSCs were transfected with siRNA against ectodysplasin-A (EDA), EXOs collected, and their effect on macrophage function analyzed. Human cirrhotic liver was analyzed for EDA mRNA expression and compared to non-tumor liver (NTL). Results: Transfection with large RNA from aHSC-EXOs stimulated macrophage IL-6 and TNF alpha mRNA expression and protein secretion. EDA mRNA was highly expressed in aHSCs and transfection of aHSCs with EDA-siRNA decreased aHSC-EXO EDA mRNA and blunted the effect of aHSC-EXOs on macrophage function (IL-6/TNF alpha expression and macrophage migration). Human cirrhotic liver exhibited high EDA mRNA compared to NTL. Conclusions: HSC activation leads to altered EXO mRNA/miRNA profiles with aHSC-EXOs mRNAs exerting a dominant role in altering macrophage function. Ectodysplasin-A mRNA is an important component in aHSC-EXOs in regulating macrophage function.

Automated summary

The interaction between activated hepatic stellate cells (aHSCs) and macrophages play a crucial role in liver fibrosis development. Research shows that aHSC-EXOs contain mRNA that dominantly alters macrophage function and Ectodysplasin-A mRNA is an important component in regulating this process.