Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, College of Health Sciences, University of KwaZulu-Natal (Howard College Campus), Durban, 4041, South Africa.
Mycotoxin Res. 2021 Feb;37(1):97-103. doi: 10.1007/s12550-020-00418-4. Epub 2021 Jan 5.
Patulin (PAT) is a mycotoxin produced by various fungal species that commonly contaminate apples and other fruit products. PAT is associated with glutathione (GSH) depletion and oxidative stress. Cytoprotective and antioxidant (AO) enzymes limit toxic outcomes and confer resistance to oxidative stress by influencing the expression of cytoprotective genes. The induction of these genes is tightly regulated by transcription factor nuclear factor erythroid 2 p45-related factor 2 (NRF2), a potential target of microRNA (miR)-144. This study aims to determine a possible role for miR-144 in NRF2 pathway activation following PAT exposure in human embryonic kidney (HEK293) cells. HEK293 cells were exposed to varying PAT concentrations (0, 0.2, 0.5, 1 μmol/L; 24 h). Protein expression of Keap1, NRF2, and phosphorylated (p) NRF2 (ser40) was quantified using western blotting. Gene expression of NRF2, SOD2, CAT, GPx, NQO1, GSTA1, HMOX, and miR-144 were evaluated by qPCR. PAT significantly decreased miR-144 (p = 0.0249) and concomitantly increased NRF2 protein expression, stability, and activation as evidenced by increased pNRF2 (p = 0.0216) expression and decreased total NRF2 (p = 0.0237). This was consistent with qPCR data which showed increased transcript levels of NRF2 (p = 0.0378) as well as the target genes CAT (p = 0.0273), NQO1 (p = 0.0156), HMOX (p = 0.0249), and GSTA1 (p = 0.0237). No changes were observed in Keap1 expression (p = 0.6444). This study implicates microRNAs in a mechanistic role in PAT-induced toxicity. PAT decreased miR-144 expression leading to NRF2 pathway activation and elevated AO gene expression.
棒曲霉素（PAT）是一种由多种真菌物种产生的真菌毒素，常见于苹果和其他水果产品中。PAT 与谷胱甘肽（GSH）耗竭和氧化应激有关。细胞保护和抗氧化（AO）酶通过影响细胞保护基因的表达来限制毒性作用并赋予对氧化应激的抗性。这些基因的诱导受到转录因子核红细胞 2 p45 相关因子 2（NRF2）的紧密调节，NRF2 是 microRNA（miR）-144 的潜在靶点。本研究旨在确定 miR-144 在 PAT 暴露后在人胚肾（HEK293）细胞中激活 NRF2 途径中的可能作用。HEK293 细胞暴露于不同 PAT 浓度（0、0.2、0.5、1μmol/L；24 小时）。使用 Western 印迹定量测定 Keap1、NRF2 和磷酸化（p）NRF2（ser40）的蛋白表达。通过 qPCR 评估 NRF2、SOD2、CAT、GPx、NQO1、GSTA1、HMOX 和 miR-144 的基因表达。PAT 显著降低了 miR-144（p=0.0249），并同时增加了 NRF2 蛋白的表达、稳定性和激活，这表现为 pNRF2（p=0.0216）表达增加和总 NRF2（p=0.0237）表达减少。这与 qPCR 数据一致，该数据显示 NRF2 转录物水平增加（p=0.0378）以及 CAT（p=0.0273）、NQO1（p=0.0156）、HMOX（p=0.0249）和 GSTA1（p=0.0237）的靶基因。Keap1 表达无变化（p=0.6444）。本研究将 microRNAs 纳入 PAT 诱导毒性的机制作用。PAT 降低了 miR-144 的表达，导致 NRF2 途径的激活和 AO 基因表达的升高。
