Scholarlink

<p><i>Objective </i>Condyloma acuminatum (CA), a common sexually transmitted disease caused by human papillomavirus (HPV) infection, is closely associated with the abnormal proliferation and differentiation of host keratinocytes. Brusatol (BRU), a quassinoid compound derived from the medicinal plant Brucea javanica, has gained attention for its ability to regulate multiple biological processes through the phosphoinositide 3-kinase/Protein Kinase B (PI3K/AKT) signaling pathway. It may also reduce Nuclear factor erythroid 2-related factor 2 (Nrf2) expression to induce ferroptosis in cancer cells. However, its regulatory role in ferroptosis of HPV-infected keratinocytes remains unreported. Therefore, this study was designed to examine the role of BRU in inducing ferroptosis in CA keratinocytes via the PI3K/AKT/Nrf2 pathway, with the aim of identifying a promising therapeutic strategy for CA. <i>Methods </i>To simulate the pathological process of CA, a pEGFP-N1-HPV6 recombinant plasmid vector was transfected into HaCaT human epidermal keratinocyte cells. The cytotoxicity of BRU was determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell membrane integrity was assessed via the Lactate Dehydrogenase release assay. Lipid peroxidation accumulation was detected using C11-BODIPY581/591 fluorescent staining. The oxidative stress level was evaluated by measuring the glutathione/oxidized glutathione (GSH/GSSG) ratio. Cellular iron content was measured to assess iron homeostasis. Nrf2 nuclear translocation was examined by immunofluorescence. Cell proportions were analyzed by flow cytometry. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome enrichment analyses were performed to identify signaling pathways involved in BRU-induced ferroptosis. The protein expression levels of Glutathione Peroxidase 4 (GPX4), Solute Carrier Family 7 Member 11 (SLC7A11), Nrf2, phosphorylated-PI3K (p-PI3K)/total-PI3K, and p-AKT/total-AKT were detected by Western blot. The mRNA expression levels of GPX4, SLC7A11, Nrf2, Heme Oxygenase-1, and NAD(P)H Quinone Dehydrogenase 1 (NQO1) were measured by quantitative real-time polymerase chain reaction (RT-qPCR). <i>Results </i>BRU inhibited the viability of CA keratinocytes (HPV-HaCaT) and induced characteristic features of ferroptosis, including lipid reactive oxygen species (ROS) accumulation (lipid ROS), GSH depletion, increased ferrous iron levels, and downregulation of key ferroptosis regulators (GPX4, SLC7A11). BRU also reduced Nrf2 protein expression and its nuclear translocation. These effects were partially reversed by Ferrostatin-1. KEGG and Reactome pathway enrichment analyses using R software revealed that the PI3K/AKT signaling pathway was the most significantly enriched pathway in KEGG, while the ‘Negative regulation of the PI3K/AKT network’ pathway was also significantly enriched in Reactome. In vitro, BRU inhibited PI3K and AKT phosphorylation, reduced Nrf2 expression and nuclear translocation, and ultimately induced ferroptosis in CA keratinocytes. <i>Conclusion </i>BRU may induce ferroptosis in CA keratinocytes by inhibiting the PI3K/AKT pathway and associated downregulation of Nrf2 expression.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Brusatol Induces Ferroptosis in Condyloma Acuminatum Keratinocytes by Suppressing Nrf2 via Inhibition of the PI3K/AKT Pathway

  • 期刊论文

  • 发表日期：

    2026年6月26日

查看全文
  • WeiQi Wu,
  • Juan Yang,
  • XiuYi Lu,
  • LieHua Deng,
  • LiuYan Wen

摘要

Objective Condyloma acuminatum (CA), a common sexually transmitted disease caused by human papillomavirus (HPV) infection, is closely associated with the abnormal proliferation and differentiation of host keratinocytes. Brusatol (BRU), a quassinoid compound derived from the medicinal plant Brucea javanica, has gained attention for its ability to regulate multiple biological processes through the phosphoinositide 3-kinase/Protein Kinase B (PI3K/AKT) signaling pathway. It may also reduce Nuclear factor erythroid 2-related factor 2 (Nrf2) expression to induce ferroptosis in cancer cells. However, its regulatory role in ferroptosis of HPV-infected keratinocytes remains unreported. Therefore, this study was designed to examine the role of BRU in inducing ferroptosis in CA keratinocytes via the PI3K/AKT/Nrf2 pathway, with the aim of identifying a promising therapeutic strategy for CA. Methods To simulate the pathological process of CA, a pEGFP-N1-HPV6 recombinant plasmid vector was transfected into HaCaT human epidermal keratinocyte cells. The cytotoxicity of BRU was determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell membrane integrity was assessed via the Lactate Dehydrogenase release assay. Lipid peroxidation accumulation was detected using C11-BODIPY581/591 fluorescent staining. The oxidative stress level was evaluated by measuring the glutathione/oxidized glutathione (GSH/GSSG) ratio. Cellular iron content was measured to assess iron homeostasis. Nrf2 nuclear translocation was examined by immunofluorescence. Cell proportions were analyzed by flow cytometry. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome enrichment analyses were performed to identify signaling pathways involved in BRU-induced ferroptosis. The protein expression levels of Glutathione Peroxidase 4 (GPX4), Solute Carrier Family 7 Member 11 (SLC7A11), Nrf2, phosphorylated-PI3K (p-PI3K)/total-PI3K, and p-AKT/total-AKT were detected by Western blot. The mRNA expression levels of GPX4, SLC7A11, Nrf2, Heme Oxygenase-1, and NAD(P)H Quinone Dehydrogenase 1 (NQO1) were measured by quantitative real-time polymerase chain reaction (RT-qPCR). Results BRU inhibited the viability of CA keratinocytes (HPV-HaCaT) and induced characteristic features of ferroptosis, including lipid reactive oxygen species (ROS) accumulation (lipid ROS), GSH depletion, increased ferrous iron levels, and downregulation of key ferroptosis regulators (GPX4, SLC7A11). BRU also reduced Nrf2 protein expression and its nuclear translocation. These effects were partially reversed by Ferrostatin-1. KEGG and Reactome pathway enrichment analyses using R software revealed that the PI3K/AKT signaling pathway was the most significantly enriched pathway in KEGG, while the ‘Negative regulation of the PI3K/AKT network’ pathway was also significantly enriched in Reactome. In vitro, BRU inhibited PI3K and AKT phosphorylation, reduced Nrf2 expression and nuclear translocation, and ultimately induced ferroptosis in CA keratinocytes. Conclusion BRU may induce ferroptosis in CA keratinocytes by inhibiting the PI3K/AKT pathway and associated downregulation of Nrf2 expression.

Graphical Abstract