Multipotent mesenchymal stromal cells of various origins reduce reactive gliosis in the hippocampal CA1 area during acute ischemia-reperfusion of the rat brain

Abstract

Neuroprotective therapy in acute cerebrovascular disorders is directly aimed at preserving neurons in the penumbra zone, but it also emphasizes the importance of gliogenesis in the affected area. Glial cells exhibit rapid reactivity and are highly sensitive to cerebral ischemic damage. Recent experimental studies have demonstrated the successful application of multipotent mesenchymal stromal cells (MMSCs) in stroke to modulate microglial activation. The aim of the study was to investigate the impact of MMSCs of different origins, MMSC lysate, and citicoline on glial components in a model of cerebral ischemia-reperfusion in rats. Materials and methods. The experiments were conducted on 190 male Wistar rats aged 4 months, weighing 160-190 g. After modeling cerebral ischemia-reperfusion through bilateral 20-minute occlusion of the internal carotid arteries, rats were intravenously administered MMSCs derived from human Wharton’s jelly, human adipose tissue, and rat Wharton’s jelly at a dose of 106 cells per animal. Other groups received fetal rat fibroblasts (106 cells/animal in 0.2 ml of physiological solution) and lysate from human Wharton’s jelly at a dose of 0.2 ml per animal. Control animals received 0.2 ml of physiological solution intravenously. The last group of rats received a single dose of the reference drug citicoline at a dose of 250 mg/kg. On the 7th and 14th days, the area and fluorescence intensity of cells expressing markers of astrocytes (GFAP), microglia (Iba1), and oligodendrocytes (Rip) were quantitatively assessed in CA1 hippocampal region slices using immunohistochemical examination and confocal microscopy. Results. On the 7th and 14th days after cerebral ischemia-reperfusion in rats, the intensity of fluorescence of GFAP-positive astrocytes and Iba1-positive microglial cells increased, indicating pronounced reactive astrogliosis and microglial activation in the CA1 region of the hippocampus. Meanwhile, ischemia-reperfusion had a significant impact on the content of Rip-positive oligodendrocytes in brain slices. The application of all treatments (transplantation of MMSCs of different origins, their lysate, or the reference drug citicoline) had a cytoprotective effect, reducing reactive astrogliosis and microgliosis both on the 7th and 14th days after injury. The best result was demonstrated with the treatment using MSCs from human Wharton’s jelly.s. Conclusion. Cerebral ischemia-reperfusion induces reactive gliosis through the activation of GFAP- and Iba1-positive glial cells in all layers of the hippocampus. The application of MSCs from human Wharton’s jelly and fetal rat fibroblasts significantly reduces its intensity on both the 7th and 14th days after injury modeling.