Lipocalin 2 as Putative Modulator of Local Inflammatory Processes in the Spinal Cord and Component of Organ Cross-talk After Spinal Cord Injury

Abstract

Lipocalin 2 (Lcn2), an immunomodulator, regulates various cellular processes such as iron transport and defense against bacterial infection. Under pathological conditions, Lcn2 promotes neuroinflammation via the recruitment and activation of immune cells and glia, particularly microglia and astrocytes. Although it seems to have a negative influence on the functional outcome in spinal cord injury (SCI), the extent of its involvement in SCI and the underlying mechanisms are not yet fully known. In this study, using a SCI contusion mouse model, we first investigated the expression pattern of Lcn2 in different parts of the CNS (spinal cord and brain), blood serum and in the liver. Interestingly, we could note a significant increase in Lcn2 throughout the whole spinal cord, in the brain, liver and in blood serum. This demonstrates the diversity of its possible sites of action in SCI. Further, genetic deficiency of Lcn2 (Lcn2−/−) significantly reduced certain aspects of gliosis in the SCI-mice. Taken together, our studies provide first valuable hints, suggesting that Lcn2 is involved in the local and systemic effects post SCI, and might modulate the impairment of different peripheral organs after injury.