β-Sitosterol Inhibits The Proliferation of Endometrial Cells via Regulating Smad7-Mediated TGF-β/Smads Signaling Pathway

• Published in: Cell journal (Yakhteh) 2023-08, Vol.25 (8), p.554-563
• Main Authors: Wen, Yi, Pang, Lili, Fan, Lingxiu, Zhou, Yihan, Li, Ruonan, Zhao, Tingting, Zhang, Manli
• Format: Article
• Language: English
• Subjects: Apoptosis; Assaying; Cell migration; Cell proliferation; Cholecystokinin; Endometriosis; Endometrium; Flow cytometry; Growth factors; Histopathology; Original; Phosphorylation; Signal transduction; Smad protein; Smad2 protein; Smad3 protein; smad7; Smad7 protein; Stromal cells; Transforming growth factor-b; Transforming growth factor-b1; transforming growth factor-β; β-sitosterol
• ISSN: 2228-5806; 2228-5814
• DOI: 10.22074/cellj.2023.1989631.1230

Objective: To investigate the effect of β-sitosterol on endometrial cells to understand the underlying mechanism. Materials and Methods: This is a laboratory-based experimental study conducted on animals and cells. Histological assays were performed to determine the effect of β-sitosterol on endometrial cells. The CCK-8 assay was used to assess the inhibitory effect of β-sitosterol on the proliferation of ectopic endometrial stromal cells (hEM15A). Flow cytometry was performed to evaluate the induction of apoptosis by β-sitosterol in hEM15A cells. The transwell invasion assay was conducted to measure the suppression of hEM15A cell migration by β-sitosterol. Western blot analyses were performed to analyze the effect of β-sitosterol on the expression of Smad family member 7 (Smad7) and the activity of transforming growth factor-β (TGF-β1), as well as the phosphorylation of Smad2 and Smad3. Results: Histological assays showed that β-sitosterol regulates histopathology and induces apoptosis of endometrial cells in vivo. The CCK-8 assay revealed that β-sitosterol could inhibit the proliferation of hEM15A in human endometriosis patients. Flow cytometry showed that apoptosis was triggered by β-sitosterol in hEM15A. The transwell invasion assay indicated that the hEM15A migration under the β-sitosterol treatment group was suppressed. Western blot analyses suggested that β-sitosterol increased the expression of Smad7, decreased the activity of TGF-β1, and reduced the phosphorylation of Smad2 and Smad3. The effect of β-sitosterol was weakened by the silence of Smad7. Conclusion: The results suggest that β-sitosterol can inhibit the proliferation of endometrial cells and relieve endometriosis by inhibiting TGF-β-induced phosphorylation of Smads through regulation of Smad7.