Division of Neonatology, Careggi University Hospital of Florence, Florence, Italy.
Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.
Neonatology. 2022;119(5):611-618. doi: 10.1159/000526279. Epub 2022 Sep 12.
We recently demonstrated that oxygen-glucose deprivation (OGD) and unconjugated bilirubin (UCB) can damage mature and immature organotypic hippocampal slices and induce an oxidative stress similar to what occurs in jaundiced term and preterm infants with hypoxic-ischemic encephalopathy (HIE).
To assess the effects of OGD and UCB on the expression of heme-oxygenase 1 (HO-1) and oxidative stress-related enzymes in an in vitro model of HIE.
Mature and immature organotypic hippocampal slices were exposed to 30-min OGD and to 24 h UCB or UCB plus human serum albumin (HSA). The expression of HO-1, superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase (GPX), and nuclear factor erythroid-related factor 2 were analyzed by real-time PCR.
In mature slices, OGD did not affect the expression of HO-1 and oxidative stress-induced enzymes. The addition of UCB was associated with the upregulation of HO-1 and Nrf2 that is abolished by the presence of equimolar amount of HSA. In immature slices, OGD induced the downregulation of CAT, GPX, and Nrf2 expression and the addition of UCB further decreased GPX. The addition of UCB and HSA reverted the effects of OGD and UCB on gene expression.
In an in vitro model of HIE in term infants, we did not observe neuroprotective changes of the expression of HO-1 and genes involved in antioxidant defenses. Conversely, in an in vitro model of HIE in preterm infants, we observed a harmful decrease of the expression of genes encoding for antioxidant enzymes.
我们最近证明，氧葡萄糖剥夺（OGD）和未结合胆红素（UCB）可损伤成熟和未成熟的器官型海马切片，并诱导类似于患有缺氧缺血性脑病（HIE）的足月和早产儿中发生的氧化应激。
评估 OGD 和 UCB 对体外 HIE 模型中血红素加氧酶 1（HO-1）和氧化应激相关酶表达的影响。
将成熟和未成熟的器官型海马切片暴露于 30 分钟的 OGD 和 24 小时的 UCB 或 UCB 加人血清白蛋白（HSA）。通过实时 PCR 分析 HO-1、超氧化物歧化酶 1（SOD1）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPX）和核因子红细胞相关因子 2 的表达。
在成熟切片中，OGD 不影响 HO-1 和氧化应激诱导酶的表达。添加 UCB 与 HO-1 和 Nrf2 的上调有关，而 Nrf2 的上调被等量 HSA 的存在所消除。在未成熟的切片中，OGD 诱导 CAT、GPX 和 Nrf2 表达下调，添加 UCB 进一步降低 GPX。添加 UCB 和 HSA 逆转了 OGD 和 UCB 对基因表达的影响。
在足月婴儿的体外 HIE 模型中，我们没有观察到 HO-1 和抗氧化防御相关基因表达的神经保护变化。相反，在早产儿的体外 HIE 模型中，我们观察到编码抗氧化酶的基因表达有害下降。
