ToxStrategies, LLC, Katy, Texas, USA.
ToxStrategies, LLC, Asheville, North Carolina, USA.
Toxicol Pathol. 2023 Jan;51(1-2):4-14. doi: 10.1177/01926233231159078. Epub 2023 Mar 29.
Ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate (HFPO-DA) is a short chain member of per- and polyfluoroalkyl substances (PFAS). To better understand the relevance of histopathological effects seen in livers of mice exposed to HFPO-DA for human health risk assessment, histopathological effects were summarized from hematoxylin and eosin (H&E)-stained sections in several repeat-dose toxicity studies in mice. Findings across studies revealed histopathological changes consistent with peroxisomal proliferation, whereas two reports of steatosis could not be confirmed in the published figures. In addition, mechanisms of hepatocellular death were assessed in H&E sections as well as with the apoptotic marker cleaved caspase-3 (CCasp3) in newly cut sections from archived liver blocks from select studies. A comparison of serially CCasp3 immunolabeled and H&E-stained sections revealed that mechanisms of hepatocellular death cannot be clearly discerned in H&E-stained liver sections alone as several examples of putatively necrotic cells were positive for CCasp3. Published whole genome transcriptomic data were also reevaluated for enrichment of various forms of hepatocellular death in response to HFPO-DA, which revealed enrichment of apoptosis and autophagy, but not ferroptosis, pyroptosis, or necroptosis. These morphological and molecular findings are consistent with transcriptomic evidence for peroxisome proliferator-activated receptor alpha (PPARα) signaling in HFPO-DA exposed mice.
2,3,3,3-四氟-2-(七氟丙氧基)-丙基 2,3,3,3-四氟丙酸盐(HFPO-DA)是全氟和多氟烷基物质(PFAS)的短链成员。为了更好地了解暴露于 HFPO-DA 的小鼠肝脏中观察到的组织病理学效应与人类健康风险评估的相关性,我们总结了几项在小鼠中进行的重复剂量毒性研究中用苏木精和伊红(H&E)染色切片的组织病理学效应。研究结果显示,存在与过氧化物酶体增殖一致的组织病理学变化,而在已发表的图中无法确认两份关于脂肪变性的报告。此外,还在 H&E 切片中以及在从选定研究的存档肝块中新切的切片中用凋亡标志物 cleaved caspase-3(CCasp3)评估了肝细胞死亡的机制。对连续进行的 CCasp3 免疫标记和 H&E 染色切片进行比较表明,单独使用 H&E 染色切片无法清楚地区分肝细胞死亡的机制,因为几个假定的坏死细胞呈 CCasp3 阳性。还重新评估了发表的全基因组转录组数据,以研究 HFPO-DA 对各种形式的肝细胞死亡的富集情况,结果显示凋亡和自噬增加,但铁死亡、细胞焦亡或坏死减少。这些形态和分子发现与 HFPO-DA 暴露小鼠过氧化物酶体增殖物激活受体α(PPARα)信号的转录组证据一致。