Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada.
Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada.
Comp Biochem Physiol A Mol Integr Physiol. 2023 Nov;285:111511. doi: 10.1016/j.cbpa.2023.111511. Epub 2023 Sep 9.
Insects experience different kinds of environmental stresses that can impair neural performance, leading to spreading depolarization (SD) of nerve cells and neural shutdown underlying coma. SD is associated with a sudden loss of ion, notably K, homeostasis in the central nervous system. The sensitivity of an insect's nervous system to stress (e.g., anoxia) can be modulated by acute pre-treatment. Rapid cold hardening (RCH) is a form of preconditioning, in which a brief exposure to low temperature can enhance the stress tolerance of insects. We used a pharmacological approach to investigate whether RCH affects anoxia-induced SD in the locust, Locusta migratoria, via one or more of the following homeostatic mechanisms: (1) Na/K-ATPase (NKA), (2) Na/K/2Cl co-transporter (NKCC), and (3) voltage-gated K (K) channels. We also assessed abundance and phosphorylation of NKCC using immunoblotting. We found that inhibition of NKA or K channels delayed the onset of anoxia-induced SD in both control and RCH preparations. However, NKCC inhibition preferentially abrogated the effect of RCH. Additionally, we observed a higher abundance of NKCC in RCH preps but no statistical difference in its phosphorylation level, indicating the involvement of NKCC expression or degradation as part of the RCH mechanism.
昆虫会经历各种环境压力，这些压力会损害其神经性能，导致细胞的去极化扩散（SD）和昏迷状态下的神经停止活动。SD 与中枢神经系统中离子（尤其是 K）稳态的突然丧失有关。昆虫神经系统对压力（例如缺氧）的敏感性可以通过急性预处理来调节。快速冷驯化（RCH）是一种预处理形式，短暂暴露在低温下可以增强昆虫的应激耐受性。我们使用药理学方法来研究 RCH 是否通过以下一种或多种稳态机制来影响蝗虫（Locusta migratoria）的缺氧诱导的 SD：（1）Na+/K+-ATP 酶（NKA），（2）Na+/K+/2Cl 协同转运蛋白（NKCC），和（3）电压门控 K（K）通道。我们还使用免疫印迹法评估了 NKCC 的丰度和磷酸化。我们发现，NKA 或 K 通道的抑制作用会延迟缺氧诱导的 SD 在对照和 RCH 制剂中的发生。然而，NKCC 的抑制作用优先消除了 RCH 的作用。此外，我们观察到 RCH 预处理中 NKCC 的丰度更高，但磷酸化水平没有统计学差异，表明 NKCC 的表达或降解参与了 RCH 机制。
