Bioactive Lipid Mediators in the Initiation and Resolution of Inflammation after Spinal Cord Injury

Neuroinflammation is a prominent feature of the response to CNS trauma. It is also an important hallmark of various neurodegenerative diseases in which inflammation contributes to the progression of pathology. Inflammation in the CNS can contribute to secondary damage and is therefore an excellent therapeutic target for a range of neurological conditions. Inflammation in the nervous system is complex and varies in its fine details in different conditions. It involves a wide variety of secreted factors such as chemokines and cytokines, cell adhesion molecules, and different cell types that include resident cell of the CNS, as well as immune cells recruited from the peripheral circulation. Added to this complexity is the fact that some aspects of inflammation are beneficial, while other aspects can induce secondary damage in the acute, subacute and chronic phases. Understanding these aspects of the inflammatory profile is essential for developing effective therapies. Bioactive lipids constitute a large group of molecules that modulate the initiation and the resolution of inflammation. Dysregulation of these bioactive lipid pathways can lead to excessive acute inflammation, and failure to resolve this by specialized pro-resolution lipid mediators can lead to the development of chronic inflammation. The focus of this review is to discuss the effects of bioactive lipids in spinal cord trauma and their potential for therapies.

An upregulation of SENP3 after spinal cord injury: implications for neuronal apoptosis

SENP3 (SUMO-specific proteases 3), a member of the small ubiquitin-like modifier specific protease family, was identified as a molecule that deconjugates SUMOylation of modified protein substrates and functions as an isopeptidase by disrupting SUMO homeostasis to facilitate cancer development and progression. However, its expression and function in nervous system injury and repair are still unclear. In this study, we employed an acute spinal cord injury (SCI) model in adult rats and investigated the dynamic changes of SENP3 expression in the spinal cord. Western blot analysis indicated a gradual increase in SENP3 expression, which peaked 3 days after SCI, and then declined over the following days. Immunohistochemistry results further confirmed that SENP3 was expressed at low levels in the gray and white matter in the non-injured condition and increased after SCI. Moreover, immunofluorescence double-labeling showed that SENP3 was co-expressed with the neuronal marker, NeuN. Furthermore, the SENP3-positive cells that were co-expressed with NeuN had also expressed active caspase-3 after injury. To investigate whether SENP3 plays a role in neuronal apoptosis, we applied H(2)O(2) to induce neuronal apoptosis in vitro. Western blot analysis showed a significant upregulation of SENP3 and active caspase-3 following H(2)O(2) stimulation. Taken together, these results suggest that SENP3 may play important roles in the pathophysiology of SCI.