Inflammation in embryology: A review of neuroinflammation in spina bifida

Abstract

The occurrence of neuroinflammation after the failure of neural tube closure, resulting in spina bifida aperta, is well established but whether or not neuroinflammation contributes to damage to the neuroepithelium prior to and during closure is not known. Neuroinflammation may occur at different time periods after perturbation to the developing spinal cord. Evidence suggests that early neuroinflammation is detrimental, whereas the later chronic phase of neuroinflammation may have useful roles. The role of neuroinflammation in neural tube defects is complex. It is important to make the distinction of whether neuroinflammation is important for neuroprotection or detrimental to the neural tissue. This may directly be influenced by the location, magnitude and duration of the insult, as well as the expression of neurotrophic or neurotoxic molecules. The current understanding remains that the chronic damage to the developing spinal cord is likely due to the chemical and mechanical damage of the exposed neural tissue owing to the aggressive intrauterine environment, described as the “two-hit mechanism”. Astrogliosis in the exposed spinal cord has been described in animal models of spina bifida after the failure of closure during embryonic life. Still, its association with neuroinflammatory processes is poorly understood. In this review, we will discuss the current understanding of neuroinflammation in neural tube defects, specifically spina bifida, and highlight inflammation-targeted strategies that may potentially be used to treat this pathophysiological condition.