Zhang Yunfeng, Wang Yun, Wu Xiaofeng, Gao Heng, Zhang Ting
Department of Neurosurgery, Jiangyin Clinical College of Xuzhou Medical University, Wuxi, China.
Department of Neurology, Jiangyin Clinical College of Xuzhou Medical University, Wuxi, China.
Brain Inj. 2025 Dec;39(14):1329-1337. doi: 10.1080/02699052.2025.2558956. Epub 2025 Sep 24.
Neonatal hypoxic-ischemic encephalopathy (HIE) is brain damage caused by reduced blood/oxygen supply during the perinatal period. There is no adequate treatment currently. The kinase WNK3 is associated with cerebral edema and stroke prognosis, so we assessed its expression in a neonatal rat model of HIE.
The Rice method was used to induce HIE in 7-day-old rat pups by ligating the left carotid artery followed by hypoxia exposure. Rats were divided into sham, 6 h, 12 h, 24 h, and 48 h groups ( = 5 each). Neurological function was evaluated by negative geotaxis, righting reflex, and Morris water maze tests. WNK3 expression was measured by Western blotting, RT-PCR, immunohistochemistry, and immunofluorescence in brain samples.
HIE rats showed significant neurological impairments in short and long-term tests compared to shams. Negative geotaxis and righting reflex times were prolonged in HIE rats (all < 0.01), and Morris water maze performance was impaired at 4 weeks ( < 0.05). Western blotting revealed an approximate three-fold increase in cortical WNK3 protein expression by 48 h post-HIE ( < 0.001), while RT-PCR showed reduced WNK3 mRNA expression with a nadir at 6 h, a partial rebound at 24 h, and a decline again at 48 h. Histological staining confirmed increased proportions of WNK3-positive cells in peri-infarct cortex after HIE ( < 0.001).
Our study demonstrated a dissociation between WNK3 protein (upregulated ~3-fold) and mRNA (downregulated except for a transient 24 h rebound) in neonatal HIE, suggesting post-transcriptional regulation. The WNK3 upregulation may contribute to cerebral edema formation and neurological deficits. These findings are correlative; larger, sex-balanced studies incorporating WNK3 inhibition, direct brain water measurements, and integration with hypothermia therapy are warranted to test WNK3 as a therapeutic target in neonatal HIE.
新生儿缺氧缺血性脑病（HIE）是围产期因血液/氧气供应减少所致的脑损伤。目前尚无充分的治疗方法。激酶WNK3与脑水肿和中风预后相关，因此我们在新生大鼠HIE模型中评估了其表达情况。
采用赖斯法，通过结扎左侧颈动脉并暴露于低氧环境，在7日龄幼鼠中诱导HIE。将大鼠分为假手术组、6小时组、12小时组、24小时组和48小时组（每组n = 5）。通过负趋地性、翻正反射和莫里斯水迷宫试验评估神经功能。采用蛋白质免疫印迹法、逆转录-聚合酶链反应（RT-PCR）、免疫组织化学和免疫荧光法检测脑样本中WNK3的表达。
与假手术组相比，HIE大鼠在短期和长期试验中均表现出明显的神经功能障碍。HIE大鼠的负趋地性和翻正反射时间延长（均P < 0.01），4周时莫里斯水迷宫表现受损（P < 0.05）。蛋白质免疫印迹法显示，HIE后48小时皮质WNK3蛋白表达增加约3倍（P < 0.001），而RT-PCR显示WNK3 mRNA表达降低，在6小时时达到最低点，24小时时部分反弹，48小时时再次下降。组织学染色证实HIE后梗死灶周围皮质中WNK3阳性细胞比例增加（P < 0.001）。
我们的研究表明，新生HIE中WNK3蛋白（上调约3倍）和mRNA（除24小时短暂反弹外下调）之间存在解离，提示存在转录后调控。WNK3上调可能导致脑水肿形成和神经功能缺损。这些发现具有相关性；有必要开展更大规模、性别均衡的研究，纳入WNK3抑制、直接脑含水量测量以及与低温治疗相结合，以测试WNK3作为新生HIE治疗靶点的效果。
