中国神经再生研究（英文版）2020，Vol.15Issue(10)：1920-1931,12.DOI:10.4103/1673-5374.280321
Neuroprotective mechanism of L-cysteine after subarachnoid hemorrhage
摘要
Abstract
Hydrogen sulfide, which can be generated in the central nervous system from the sulfhydryl-containing amino acid, L-cysteine, by cystathi-onine-β-synthase, may exert protective effects in experimental subarachnoid hemorrhage; however, the mechanism underlying this effect is unknown. This study explored the mechanism using a subarachnoid hemorrhage rat model induced by an endovascular perforation technique. Rats were treated with an intraperitoneal injection of 100 mM L-cysteine (30 μL) 30 minutes after subarachnoid hemorrhage. At 48 hours after subarachnoid hemorrhage, hematoxylin-eosin staining was used to detect changes in prefrontal cortex cells. L-cysteine significantly reduced cell edema. Neurological function was assessed using a modified Garcia score. Brain water content was measured by the wet-dry method. L-cysteine significantly reduced neurological deficits and cerebral edema after subarachnoid hemorrhage. Immuno-fluorescence was used to detect the number of activated microglia. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the levels of interleukin 1β and CD86 mRNA in the prefrontal cortex. L-cysteine inhibited microglial activation in the prefrontal cortex and reduced the mRNA levels of interleukin 1β and CD86. RT-PCR and western blot analysis of the complement system showed that L-cysteine reduced expression of the complement factors, C1q, C3α and its receptor C3aR1, and the deposition of C1q in the prefrontal cortex. Dihydroethidium staining was applied to detect changes in reactive oxygen species, and immunohistochemistry was used to detect the number of NRF2- and HO-1-positive cells. L-cysteine reduced the level of reactive oxygen species in the prefrontal cortex and the number of NRF2- and HO-1-positive cells. Western blot assays and immunohistochemistry were used to detect the protein levels of CHOP and GRP78 in the prefrontal cortex and the number of CHOP- and GRP78-positive cells. L-cysteine reduced CHOP and GRP78 levels and the number of CHOP- and GRP78-positive cells. The cystathionine-β-synthase inhibitor, aminooxyacetic acid, significantly reversed the above neuroprotective effects of L-cysteine. Taken together, L-cysteine can play a neuroprotective role by regulating neuroinflammation, complement deposition, oxidative stress and endoplasmic reticulum stress. The study was approved by the Animals Ethics Committee of Shandong University, China on February 22, 2016 (approval No. LL-201602022).关键词
aminooxyacetic acid/central nervous system/complement deposition/cystathionine-β-synthase/early brain injury/endoplasmic reticulum stress/hydrogen sulfide/neuroinflammation/oxidative stress/subarachnoid hemorrhageKey words
aminooxyacetic acid/central nervous system/complement deposition/cystathionine-β-synthase/early brain injury/endoplasmic reticulum stress/hydrogen sulfide/neuroinflammation/oxidative stress/subarachnoid hemorrhage引用本文复制引用
Ye Xiong,Zhen Wang,Dan-Qing Xin,Quan Hu,Ling-Xiao Wang,Jie Qiu,Hong-Tao Yuan,Xi-Li Chu,De-Xiang Liu,Gang Li..Neuroprotective mechanism of L-cysteine after subarachnoid hemorrhage[J].中国神经再生研究（英文版）,2020,15(10):1920-1931,12.基金项目
The study was supported by the National Natural Science Foundation of China, Nos. 81873768 and 81671213 (to ZW), 81571284 and 81874083 (to GL) （to ZW）
the Key Research and Development Foundation of Shandong Province of China, No. 2017GSF218091 (to ZW) （to ZW）
the Natural Science Foundation of Shandong Province of China, No. ZR2016HM33 (to DXL) （to DXL）
the Shandong Medical and Health Science and Technology Development Plan Project of China, No. 2017WS068 (to QH) （to QH）
the Taishan Scholars of Shandong Province of China, No. ts201511093 (to GL). （to GL）
