Effect of TGF-β1/Smad7 on Lumican mRNA Expression in Tooth Germ Epithelioid Cells of Rats

doi:10.13701/j.cnki.kqyxyj.2025.12.011

Abstract

Abstract: Objective: To investigate the effect of the transforming growth factor-β1 (TGF-β1)/Smad7 signaling pathway on lumican expression in primary cultured cells. Methods: Epithelioid cells from the tooth germs of SD rats were isolated, cultured, purified, and identified in vitro. Well-grown cells were selected for study. Smad7 mRNA expression was detected using quantitative real-time reverse transcription PCR (qRT-PCR). RNA interference via electroporation was employed to explore its impact on Smad7 expression. Cells were treated with varying concentrations of TGF-β1 (0, 0.1, and 10 ng/mL) to assess its effect on lumican mRNA expression. Results: Primary culture of SD rat tooth germ epithelioid cells was established via enzymatic digestion. Microscopic observation revealed cells with homogeneous morphology, exhibiting round or oval shapes, single nuclei, and abundant cytoplasm. Immunohistochemical staining confirmed the epithelial origin of the cells: cytokeratin 14 (epithelial marker) was positively expressed, while vimentin (mesenchymal marker) was negative. qRT-PCR demonstrated detectable Smad7 mRNA expression in these cells, though at lower levels compared to GAPDH. Electroporation-based transfection with the pRNAi-Smad1949 interference fragment significantly downregulated Smad7 expression. Compared to the control group, treatment with 10 ng/mL TGF-β1 markedly increased lumican mRNA expression (P<0.05), indicating TGF-β1 enhanced lumican transcription. Intriguingly, suppression of Smad7 via pRNAi-Smad1949 transfection also led to elevated lumican mRNA expression. Conclusion: TGF-β1 upregulates lumican mRNA expression in tooth germ epithelioid cells by activating Smad7 signaling, with a dose-dependent effect. This mechanism may influence epithelial-mesenchymal interactions, thereby affecting tooth formation and differentiation.

Key words: transforming growth factor-β, Smad7, lumican

CUI Yingying, SUN Yiqun, ZHANG Bin, LIU Zhen, TIAN Jiangang, HUANG Ruizhe. Effect of TGF-β1/Smad7 on Lumican mRNA Expression in Tooth Germ Epithelioid Cells of Rats[J]. Journal of Oral Science Research, 2025, 41(12): 1074-1080.

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