PDIA3 通过 STAT3 信号抑制脑内皮细胞和秀丽隐杆线虫中的线粒体呼吸功能，并降低 OGD 后的存活率。
PDIA3 inhibits mitochondrial respiratory function in brain endothelial cells and C. elegans through STAT3 signaling and decreases survival after OGD.
机构信息
Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, PO Box 70582, Johnson City, TN, 37614, USA.
Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK.
出版信息
Cell Commun Signal. 2021 Dec 18;19(1):119. doi: 10.1186/s12964-021-00794-z.
BACKGROUND
Protein disulfide isomerase A3 (PDIA3, also named GRP58, ER-60, ERp57) is conserved across species and mediates protein folding in the endoplasmic reticulum. PDIA3 is, reportedly, a chaperone for STAT3. However, the role of PDIA3 in regulating mitochondrial bioenergetics and STAT3 phosphorylation at serine 727 (S727) has not been described.
METHODS
Mitochondrial respiration was compared in immortalized human cerebral microvascular cells (CMEC) wild type or null for PDIA3 and in whole organism C. Elegans WT or null for pdi-3 (worm homologue). Mitochondrial morphology and cell signaling pathways in PDIA3-/- and WT cells were assessed. PDIA3-/- cells were subjected to oxygen-glucose deprivation (OGD) to determine the effects of PDIA3 on cell survival after injury.
RESULTS
We show that PDIA3 gene deletion using CRISPR-Cas9 in cultured CMECs leads to an increase in mitochondrial bioenergetic function. In C. elegans, gene deletion or RNAi knockdown of pdi-3 also increased respiratory rates, confirming a conserved role for this gene in regulating mitochondrial bioenergetics. The PDIA3-/- bioenergetic phenotype was reversed by overexpression of WT PDIA3 in cultured PDIA3-/- CMECs. PDIA3-/- and siRNA knockdown caused an increase in phosphorylation of the S727 residue of STAT3, which is known to promote mitochondrial bioenergetic function. Increased respiration in PDIA3-/- CMECs was reversed by a STAT3 inhibitor. In PDIA3-/- CMECs, mitochondrial membrane potential and reactive oxygen species production, but not mitochondrial mass, was increased, suggesting an increased mitochondrial bioenergetic capacity. Finally, PDIA3-/- CMECs were more resistant to oxygen-glucose deprivation, while STAT3 inhibition reduced the protective effect.
CONCLUSIONS
We have discovered a novel role for PDIA3 in suppressing mitochondrial bioenergetic function by inhibiting STAT3 S727 phosphorylation.
背景
蛋白二硫键异构酶 A3（PDIA3，也称为 GRP58、ER-60、ERp57）在物种间保守，在内质网中介导蛋白质折叠。据报道，PDIA3 是 STAT3 的伴侣蛋白。然而，PDIA3 在调节线粒体生物能学和 STAT3 丝氨酸 727（S727）磷酸化方面的作用尚未描述。
方法
比较了具有 PDIA3 野生型或缺失型的永生人脑血管细胞（CMEC）以及具有 pdi-3 野生型或缺失型的整个生物体秀丽隐杆线虫（线虫同源物）的线粒体呼吸。评估了 PDIA3-/-和 WT 细胞中的线粒体形态和细胞信号通路。将 PDIA3-/-细胞进行氧葡萄糖剥夺（OGD），以确定 PDIA3 在损伤后对细胞存活的影响。
结果
我们表明，在培养的 CMEC 中使用 CRISPR-Cas9 基因敲除 PDIA3 会导致线粒体生物能功能增加。在秀丽隐杆线虫中，pdi-3 的基因缺失或 RNAi 敲低也增加了呼吸率，证实了该基因在调节线粒体生物能学方面的保守作用。在培养的 PDIA3-/-CMEC 中过表达 WT PDIA3 可逆转 PDIA3-/-的生物能表型。PDIA3-/-和 siRNA 敲低导致 STAT3 的 S727 残基磷酸化增加，已知这可促进线粒体生物能功能。PDIA3-/-CMEC 中的呼吸增加可被 STAT3 抑制剂逆转。在 PDIA3-/-CMEC 中，线粒体膜电位和活性氧产生增加，而线粒体质量没有增加，表明线粒体生物能能力增加。最后，PDIA3-/-CMEC 对氧葡萄糖剥夺更耐受，而 STAT3 抑制降低了保护作用。
结论
我们发现了 PDIA3 通过抑制 STAT3 S727 磷酸化来抑制线粒体生物能功能的新作用。
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