Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
Department of Anesthesiology, Xiangyang Central Hospital, Affiliated to Hubei University of Arts and Science, 136 Jinzhou Street, Xiangyang, 441021, China.
BMC Neurosci. 2022 Mar 30;23(1):20. doi: 10.1186/s12868-022-00706-y.
C-C motif chemokine ligand 2 (CCL2) is reported to be involved in the pathogenesis of various neurological and/or psychiatric diseases. Tissue or cellular expression of CCL2, in normal or pathological condition, may play an essential role in recruiting monocytes or macrophages into targeted organs, and be involved in a certain pathogenic mechanism. However, few studies focused on tissue and cellular distribution of the CCL2 peptide in brain grey and white matters (GM, WM), and the changes of the GM and WM cellular CCL2 level in septic or endotoxic encephalopathy was not explored. Hence, the CCL2 cellular distribution in the front brain cortex and the corpus callosum (CC) was investigated in the present work by using immunofluorescent staining.
(1) CCL2 like immunoreactivity (CCL2-ir) in the CC is evidently higher than the cortex. When the measurement includes ependymal layer attached to the CC, CCL2-ir intensity is significantly higher than cortex. (2) Structures in perivascular areas, most of them are GFAP positive, contribute major CCL2-ir positive profiles in both GM and WM, but apparently more in the CC, where they are bilaterally distributed in the lateral CC between the cingulate cortex and ventricles. (3) The neuron-like CCL2-ir positive cells in cortex are significantly more than in the CC, and that number is significantly increased in the cortex following systemic lipopolysaccharide (LPS), but not in the CC. (4) In addition to CCL2-ir positive perivascular rings, more CCL2-ir filled cashew shape elements are observed, probably inside of microvasculature, especially in the CC following systemic LPS. (5) Few macrophage/microglia marker-Iba-1 and CCL2-ir co-labeled structures especially the soma is found in normal cortex and CC; the co-localizations are significantly augmented following systemic LPS, and co-labeled amoeba like somata are presented. (6) CCL2-ir and astrocyte marker GFAP or Iba-1 double labeled structures are also observed within the ependymal layer. No accumulation of neutrophils was detected.
There exist differences in the cellular distribution of the CCL2 peptide in frontal cortex GM and subcortical WM-CC, in both the physiological condition and experimental endotoxemia. Which might cause different pathological change in the GM and WM.
细胞因子 C-C 基序趋化因子配体 2（CCL2）被报道参与各种神经和/或精神疾病的发病机制。在正常或病理条件下，CCL2 的组织或细胞表达可能在将单核细胞或巨噬细胞募集到靶器官中发挥重要作用，并参与特定的发病机制。然而，很少有研究关注 CCL2 肽在脑灰质和白质（GM、WM）中的组织和细胞分布，也没有探讨脓毒症或内毒素性脑病时 GM 和 WM 细胞 CCL2 水平的变化。因此，本研究通过免疫荧光染色研究了前脑皮质和胼胝体（CC）中 CCL2 的细胞分布。
（1）CC 中的 CCL2 样免疫反应性（CCL2-ir）明显高于皮质。当测量包括附着在 CC 上的室管膜层时，CCL2-ir 强度明显高于皮质。（2）血管周围区域的结构，其中大多数为 GFAP 阳性，在 GM 和 WM 中均构成主要的 CCL2-ir 阳性轮廓，但在 CC 中更为明显，在 CC 中，它们在扣带皮层和脑室之间的外侧 CC 中双侧分布。（3）皮质中的神经元样 CCL2-ir 阳性细胞明显多于 CC，且全身脂多糖（LPS）后皮质中的细胞数量明显增加，但 CC 中无变化。（4）除 CCL2-ir 阳性血管周围环外，还观察到更多 CCL2-ir 填充的腰果形元素，可能位于微血管内，尤其是在全身 LPS 后 CC 中。（5）在正常皮质和 CC 中很少发现巨噬细胞/小胶质细胞标志物 Iba-1 和 CCL2-ir 共标记的结构，尤其是体部；全身 LPS 后，共定位明显增加，并出现共标记的阿米巴样体部。（6）CCL2-ir 和星形胶质细胞标志物 GFAP 或 Iba-1 的双标记结构也存在于室管膜层内。未检测到中性粒细胞聚集。
在正常和实验性内毒素血症状态下，前额皮质 GM 和皮质下 WM-CC 中 CCL2 肽的细胞分布存在差异，这可能导致 GM 和 WM 中出现不同的病理变化。
