Ramshini Fahimeh, Amini Mahabadi Javad, Bayat Reza, Talaei Sayyed Alireza, Vahidinia Zeinab, Hassani Bafrani Hassan
Anatomical Sciences Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran.
Gametogenesis Research Center, Kashan University of Medical Sciences, Kashan, Iran.
IBRO Neurosci Rep. 2025 Jul 29;19:345-353. doi: 10.1016/j.ibneur.2025.06.018. eCollection 2025 Dec.
Cerebral ischemic injury remains a major cause of high mortality, with limited effective treatments available. Inflammatory responses play a critical role in the pathophysiology of cerebral ischemia/reperfusion (I/R) injury. Suppressing inflammation is a key strategy for mitigating cerebral I/R injury, making it a promising therapeutic target for stroke. Vitamin D supplementation has been revealed to exhibit anti-inflammatory and neuroprotective properties during I/R injury; however, the underlying protective mechanisms are not yet fully understood. This study aimed to investigate the effects of post-ischemic calcitriol treatment on ischemic stroke, focusing specifically on the TLR4/MyD88/NF-κB and FGFR2 signaling pathways.
Male Wistar rats were divided into three main groups: sham, I/R+ Vehicle, and I/R+ Calcitriol. An experimental I/R model was created by occluding the middle cerebral artery (MCA) for 1 h, followed by a 72-h reperfusion period. Calcitriol (1 μg/kg) was administered intraperitoneally for three consecutive days post-stroke. Neurological deficit scores and infarct size were evaluated 72 h after MCAO. Gene expression levels of TLR4, MyD88, NF-κB, and FGFR2 in the brain cortex were measured using RT-PCR. Additionally, histopathological changes in the cortex were examined with Nissl staining. A molecular docking analysis was performed to investigate the interactions of calcitriol with TLR4 and FGFR2, providing insights into their binding affinities and potential functional implications.
Our findings indicated that calcitriol treatment significantly enhanced neurological function (P < 0.05) and reduced infarct volume (P < 0.001) in cerebral I/R injury. Furthermore, calcitriol decreased the number of damaged neurons while markedly increasing the count of neurons with normal morphology (P < 0.001). Consistent with the results from molecular docking showing that calcitriol antagonizes TLR4 and FGFR2, RT-PCR analysis also revealed that calcitriol significantly suppressed the upregulation of TLR4 (P < 0.05), MyD88 (P < 0.01), NF-κB (P < 0.01), and FGFR2 (P < 0.001) mRNA expression levels.
The results demonstrate that calcitriol treatment offers significant neuroprotective benefits following cerebral I/R injury. These protective effects may be mediated, at least in part, by the inhibition of inflammation through the TLR4/MyD88/NF-κB and FGFR2 signaling pathways. This study enhances our understanding of the molecular mechanisms involved in calcitriol's neuroprotective actions.
脑缺血损伤仍然是导致高死亡率的主要原因，有效的治疗方法有限。炎症反应在脑缺血/再灌注（I/R）损伤的病理生理学中起关键作用。抑制炎症是减轻脑I/R损伤的关键策略，使其成为中风有前景的治疗靶点。已发现补充维生素D在I/R损伤期间具有抗炎和神经保护特性；然而，其潜在的保护机制尚未完全了解。本研究旨在探讨缺血后骨化三醇治疗对缺血性中风的影响，特别关注TLR4/MyD88/NF-κB和FGFR2信号通路。
将雄性Wistar大鼠分为三个主要组：假手术组、I/R+溶剂组和I/R+骨化三醇组。通过阻断大脑中动脉（MCA）1小时，随后进行72小时再灌注期，建立实验性I/R模型。中风后连续三天腹腔注射骨化三醇（1μg/kg）。在MCAO后72小时评估神经功能缺损评分和梗死体积。使用RT-PCR测量大脑皮层中TLR4、MyD88、NF-κB和FGFR2的基因表达水平。此外，用尼氏染色检查皮层的组织病理学变化。进行分子对接分析以研究骨化三醇与TLR4和FGFR2的相互作用，从而深入了解它们的结合亲和力和潜在的功能意义。
我们的研究结果表明，骨化三醇治疗可显著增强脑I/R损伤中的神经功能（P<0.05）并减少梗死体积（P<0.001）。此外，骨化三醇减少了受损神经元的数量，同时显著增加了形态正常的神经元数量（P<0.001）。与分子对接结果显示骨化三醇拮抗TLR4和FGFR2一致，RT-PCR分析还显示骨化三醇显著抑制TLR4（P<0.05）、MyD88（P<0.01）、NF-κB（P<0.01）和FGFR2（P<0.001）mRNA表达水平的上调。
结果表明，骨化三醇治疗在脑I/R损伤后具有显著的神经保护作用。这些保护作用可能至少部分是通过TLR4/MyD88/NF-κB和FGFR2信号通路抑制炎症介导的。本研究增进了我们对骨化三醇神经保护作用所涉及分子机制的理解。
