Zafirlukast in combination with pseudohypericin attenuates spinal cord injury and motor function in experimental mice

LC-MS/MS-based arachidonic acid metabolomics in acute spinal cord injury reveals the upregulation of 5-LOX and COX-2 products

Arachidonic acid (AA) plays a critical role in inflammatory regulation and secondary injury after spinal cord injury (SCI). However, the overall AA metabolism profile in the acute phase of SCI remains elusive. Here we quantified AA metabolomics by High Performance Liquid Chromatography-Tandem Mass Spectrometry-Based Method (LC-MS/MS) using spinal cord tissue collected at 4 h, 24 h and 48 h after contusive SCI in rats. Remarkably, Prostaglandin E2 (PGE2) and Leukotriene B4 (LTB4) were significantly increased throughout the acute SCI. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), the key enzymes involved in the production of PGE2 and LTB4, were elevated in the lesioned spinal cord tissue, validated by both western blot and immunofluorecnce. The spatial-temporal changes of COX-2 and 5-LOX mainly occurs in neurons both in epicenter and rostral and caudal spinal cord segments after SCI. Our study sheds light on the dynamic microenvironment changes in acute SCI by characterizing the profile of AA metabolism. The COX-2 and 5-LOX may be promising therapeutic target for SCI.

Trehalose inhibits ferroptosis via NRF2/HO-1 pathway and promotes functional recovery in mice with spinal cord injury

Spinal cord injury (SCI) is the main cause of severe damage to the central nervous system and leads to irreversible tissue loss and neurological dysfunction. Ferroptosis is a cell death pattern, newly discovered in recent years. Ferroptosis is an oxidizing cell death induced by small molecules, and is an iron-dependent process caused by the imbalance between the generation and degradation of lipid reactive oxygen species (ROS) in cells. As an antioxidant, trehalose can effectively prevent lipid peroxidation. Studies have reported that trehalose can improve the prognosis of SCI. However, it is unclear whether these benefits are related to ferroptosis. In this study, we demonstrated for the first time that trehalose reduces the degeneration and iron accumulation of neurons by inhibiting the production of ROS and ferroptosis caused by lipid peroxides after SCI, thus promoting the survival of neurons and improving the recovery of motor function. More specifically, we found that trehalose inhibited the expansion of cavities in the nerve tissue of mice with SCI, inhibited neuron loss, and improved functional recovery. In terms of mechanism, our results indicate that the neuroprotective effect of trehalose is due to the activation of the NRF2/HO-1 pathway, which in turn inhibits ferroptosis and ferroptosis-related inflammation. Our findings provide important insights into the previously unknown role of trehalose in SCI, as well as new evidence supporting the hypothesis that suppression of ferroptosis plays a key neuroprotective role in SCI.

Bioactive Lipids in Inflammation After Central Nervous System Injury

Despite the progress made over the last decades to understand the mechanisms underlying tissue damage and neurological deficits after neurotrauma, there are currently no effective treatments in the clinic. It is well accepted that the inflammatory response in the CNS after injury exacerbates tissue loss and functional impairments. Unfortunately, the use of potent anti-inflammatory drugs, such as methylprednisolone, fails to promote therapeutic recovery and also gives rise to several undesirable side effects related to immunosuppression. The injury-induced inflammatory response is complex, and understanding the mechanisms that regulate this inflammation is therefore crucial in the quest to develop effective treatments. Bioactive lipids have emerged as potent molecules in controlling the initiation, coordination, and resolution of inflammation and in promoting tissue repair and recovery of homeostasis. These bioactive lipids are produced by cells involved in the inflammatory response, and their defective synthesis leads to persistent chronic inflammation, tissue damage, and fibrosis. The present chapter discusses recent evidence for the role of some of these bioactive lipids, in particular, eicosanoid and pro-resolving lipid mediators, in the regulation of inflammation after neurotrauma and highlights the therapeutic potential of some of these lipids in enhancing neurological outcomes after CNS injuries.