Yinchenhao Decoction Protects Against Intrahepatic Cholestasis During Pregnancy Through the miR‐370‐3p/TM9SF4/KIT Axis

<b>Objective:</b> The objective is to explore the potential pathogenesis and therapeutic mechanism of Yinchenhao decoction (YCHD) in intrahepatic cholestasis of pregnancy (ICP) by focusing on the regulatory role of exosomal miR-370-3p on target genes TM9SF4 and KIT. <b>Methods:</b> Exosomes were isolated from the serum samples of normal pregnant women (control), patients with ICP, HTR-8/SVneo cells, and Sprague-Dawley (SD) pregnant rats via differential centrifugation. Characterization of these exosomes was performed using electron microscopy, nanoparticle tracking analysis (NTA), and western blotting. Quantitative reverse transcription PCR (qRT-PCR) and the bioinformatics tool starBase were used to identify miR-370-3p as a candidate miRNA. Dual-luciferase reporter assays were used to confirm that TM9SF4 and KIT are direct targets of miR-370-3p. An in vitro ICP cell model was established using HTR-8/SVneo cells to investigate the interactions between miR-370-3p and its targets. An animal model was established to validate the targeted regulation of miR-370-3p on TM9SF4 and KIT, as well as the therapeutic effect of YCHD <i>in vivo</i>. <b>Results:</b> The exosomal miR-370-3p expression was significantly upregulated, whereas the TM9SF4 and KIT expressions were downregulated as demonstrated by qRT-PCR and western blot analyses. RNA pull-down assays confirmed a direct negative regulatory relationship between miR-370-3p and both TM9SF4 and KIT at the molecular level. Finally, the therapeutic potential of YCHD was verified by its ability to reverse the altered expression patterns of miR-370-3p, TM9SF4, and KIT in the animal ICP model. <b>Conclusion:</b> Our study demonstrates that YCHD protects against ICP through the miR-370-3p/TM9SF4/KIT axis, suggesting miR-370-3p as a potential therapeutic target for ICP.