Dysregulation of Histone Deacetylases Inhibits Trophoblast Growth during Early Placental Development Partially through TFEB-Dependent Autophagy-Lysosomal Pathway

Dysregulated biological behaviors of trophoblast cells can result in recurrent spontaneous abortion (RSA)-whose underlying etiology still remains insufficient. Autophagy, a conserved intracellular physiological process, is precisely monitored throughout whole pregnancy. Although the exact mechanism or role remains elusive, epigenetic modification has emerged as an important process. Herein, we found that a proportion of RSA patients exhibited higher levels of autophagy in villus tissues compared to controls, accompanied with impaired histone deacetylase (HDAC) expression. The purpose of this study is to explore the connection between HDACs and autophagy in the pathological course of RSA. Mechanistically, using human trophoblast cell models, treatment with HDAC inhibitor (HDACI)-trichostatin A (TSA) can induce autophagy by promoting nuclear translocation and transcriptional activity of the central autophagic regulator transcription factor EB (TFEB). Specifically, overactivated autophagy is involved in the TSA-driven growth inhibition of trophoblast, which can be partially reversed by the autophagy inhibitor chloroquine (CQ) or RNA interference of TFEB. In summary, our results reveal that abnormal acetylation and autophagy levels during early gestation may be associated with RSA and suggest the potential novel molecular target TFEB for RSA treatment.