Neuroprotective role of Noggin in spinal cord injury

Spinal cord injury is one of the leading causes of morbidity and mortality among young adults in many countries including the United States.Difficulty in the regeneration of neurons is one of the main obstacles that leave spinal cord injury patients with permanent paralysis in most instances.Recent research has found that preventing acute and subacute secondary cellular damages to the neurons and supporting glial cells can help slow the progression of spinal cord injury pathogenesis,in part by reactivating endogenous regenerative proteins including Noggin that are normally present during spinal cord development.Noggin is a complex protein and natural inhibitor of the multifunctional bone morphogenetic proteins,and its expression is high during spinal cord development and after induction of spinal cord injury.In this review article,we first discuss the change in expression of Noggin during pathogenesis in spinal cord injury.Second,we discuss the current research knowledge about the neuroprotective role of Noggin in preclinical models of spinal cord injury.Lastly,we explain the gap in the knowledge for the use of Noggin in the treatment of spinal cord injury.The results from extensive in vitro and in vivo research have revealed that the therapeutic efficacy of Noggin treatment remains debatable due to its neuroprotective effects observed only in early phases of spinal cord injury but little to no effect on altering pathogenesis and functional recovery observed in the chronic phase of spinal cord injury.Furthermore,clinical information regarding the role of Noggin in the alleviation of progression of pathogenesis,its therapeutic efficacy,bioavailability,and safety in human spinal cord injury is still lacking and therefore needs further investigation.

Bone morphogenic protein signaling in spinal cord injury

Spinal cord injury(SCI)is a debilitating injury that results from traumatic or non-traumatic insults to the spinal cord,causing significant impairment of the patient's activity and quality of life.Bone morphogenic proteins(BMPs)are a group of polyfunctional cytokines belonging to the transforming growth factor beta superfamily that regulates a wide variety of cellular functions in healthy and disease states.Recent studies suggest that dysregulation of BMP signaling is involved in neuronal demyelination and death after traumatic SCI.The focus of this article is to describe our current understanding of the role of BMP signaling in the regulation of cell fate,proliferation,apoptosis,autophagy,and inflammation in traumatic SCI.First,we will describe the expression of BMPs and pattern of BMP signaling before and after traumatic SCI in rodent models and in vitro.Next,we will discuss the role of BMP in the regulation of neuronal and glial cell differentiation,survival,functional recovery from traumatic SCI,and the gap in knowledge in this area that requires further investigation to improve SCI prognosis.