Department of Neurosurgery, The People's Hospital of Shanghai Pudong New Area Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai, 201299, China.
Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, NanchangJiangxi, 330008, China.
Cell Mol Neurobiol. 2022 Aug;42(6):1887-1895. doi: 10.1007/s10571-021-01070-x. Epub 2021 Mar 16.
Astrocytes are crucial in neural protection after traumatic brain injury (TBI), a global health problem causing severe brain tissue damage. Astrocytic connexin 43 (Cx43), encoded by GJA1 gene, has been demonstrated to facilitate the protection of astrocytes to neural damage with unclear mechanisms. This study aims to explore the role of GJA1-20K/Cx43 axis in the astrocyte-neuron interaction after TBI and the underlying mechanisms. Primarily cultured cortical neurons isolated from embryonic C57BL/6 mice were treated by compressed nitrogen-oxygen mixed gas to simulate TBI-like damage in vitro. The transwell astrocyte-neuron co-culture system were constructed to recapitulate the interaction between the two cell types. Quantitative PCR was applied to analyze mRNA level of target genes. Western blot and immunofluorescence were conducted to detect target proteins expression. GJA1-20K overexpression significantly down-regulated the expression of phosphorylated Cx43 (p-Cx43) without affecting the total Cx43 protein level. Besides, GJA1-20K overexpression obviously enhanced the dendrite length, as well as the expression levels of function and synthesis-related factors of mitochondria in damaged neurons. GJA1-20K up-regulated functional Cx43 expression in astrocytes, which promoted mitochondria transmission from astrocytes to neurons which might be responsible to the protection of astrocyte to neurons after TBI-like damage in vitro.
星形胶质细胞在创伤性脑损伤 (TBI) 后神经保护中起着至关重要的作用，TBI 是一种全球健康问题，会导致严重的脑组织损伤。星形胶质细胞缝隙连接蛋白 43 (Cx43)，由 GJA1 基因编码，已被证明有助于保护星形胶质细胞免受神经损伤，但具体机制尚不清楚。本研究旨在探讨 GJA1-20K/Cx43 轴在 TBI 后星形胶质细胞-神经元相互作用中的作用及其潜在机制。原代培养的来自胚胎 C57BL/6 小鼠的皮质神经元用压缩氮-氧混合气体处理，以模拟体外类似 TBI 的损伤。构建转染星形胶质细胞-神经元共培养系统以重现两种细胞类型之间的相互作用。定量 PCR 用于分析靶基因的 mRNA 水平。Western blot 和免疫荧光用于检测靶蛋白的表达。GJA1-20K 过表达显著下调了磷酸化 Cx43 (p-Cx43) 的表达，而不影响总 Cx43 蛋白水平。此外，GJA1-20K 过表达明显增加了受损神经元的树突长度以及线粒体功能和合成相关因子的表达水平。GJA1-20K 上调了星形胶质细胞中功能性 Cx43 的表达，促进了线粒体从星形胶质细胞向神经元的传递，这可能是体外类似 TBI 损伤后星形胶质细胞对神经元保护的原因。
