Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, El Llano Subercaseaux #2801, Santiago 8910060, Chile.
Departamento de Neurología, Escuela de Medicina y Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
Int J Mol Sci. 2022 Sep 3;23(17):10097. doi: 10.3390/ijms231710097.
Connexin 43 (Cx43) is expressed in kidney tissue where it forms hemichannels and gap junction channels. However, the possible functional relationship between these membrane channels and their role in damaged renal cells remains unknown. Here, analysis of ethidium uptake and thiobarbituric acid reactive species revealed that treatment with TNF-α plus IL-1β increases Cx43 hemichannel activity and oxidative stress in MES-13 cells (a cell line derived from mesangial cells), and in primary mesangial cells. The latter was also accompanied by a reduction in gap junctional communication, whereas Western blotting assays showed a progressive increase in phosphorylated MYPT (a target of RhoA/ROCK) and Cx43 upon TNF-α/IL-1β treatment. Additionally, inhibition of RhoA/ROCK strongly antagonized the TNF-α/IL-1β-induced activation of Cx43 hemichannels and reduction in gap junctional coupling. We propose that activation of Cx43 hemichannels and inhibition of cell-cell coupling during pro-inflammatory conditions could contribute to oxidative stress and damage of mesangial cells via the RhoA/ROCK pathway.
缝隙连接蛋白 43（Cx43）在肾脏组织中表达，在那里它形成半通道和间隙连接通道。然而，这些膜通道之间可能存在的功能关系及其在受损肾脏细胞中的作用仍不清楚。在这里，分析溴化乙锭摄取和硫代巴比妥酸反应性物质表明，TNF-α加 IL-1β 处理增加了 MES-13 细胞（一种来源于肾小球系膜细胞的细胞系）和原代肾小球系膜细胞中 Cx43 半通道的活性和氧化应激。后者还伴有缝隙连接通讯的减少，而 Western blot 分析显示，在 TNF-α/IL-1β 处理后，磷酸化 MYPT（RhoA/ROCK 的靶标）和 Cx43 逐渐增加。此外，RhoA/ROCK 的抑制强烈拮抗了 TNF-α/IL-1β 诱导的 Cx43 半通道的激活和缝隙连接偶联的减少。我们提出，在促炎条件下 Cx43 半通道的激活和细胞间连接的抑制可能通过 RhoA/ROCK 途径导致肾小球系膜细胞的氧化应激和损伤。
