Expression of Parvalbumin, Osteopontin and Glypican 4 in Neurons of Lumbar Region Distant from the Epicenter of Traumatic Spinal Cord Injury

Spinal cord injury (SCI) is manifested by pathologic changesin the areas significantly distant from the area of primary injury.In order to find new potential therapeutic targets to restore motorfunction, it is particularly relevant to identify the causes andmechanisms of these shifts in the lumbar spinal cord when injuryoccurs in the proximal spinal cord. On the rat model of dosed SCIat the Th8 segment level the expression of Ca-binding protein parvalbumin(PARV), osteopontin (OPN), and glypican 4 (GPC4) in neurons of laminaeVII, VIII and IX within segments L3-4 on 7 and 60 days of the experimentwas studied. Laminas VII and IX show a decrease in the number ofPARV+ neurons during the acute and chronic phase of SCI, which mayindicate a decrease in calcium binding in ventral horn neurons atthe level of segments L3-4. Decreased PARV expression in these neuronsindicates an increased risk of their vulnerability and impairedmotor function. The pattern of OPN expression in lumbar horn neurons distantfrom the epicenter of traumatic injury was studied for the firsttime. In all the studied laminae in the ventral horns of the graymatter, we did not observe shifts in the number of OPN+ neuronsboth in the acute and chronic phases of SCI. In lamina IX of thelumbar spinal cord, we found an increase in the number of GPC4+neurons in the acute posttraumatic period, which can be regardedas a key positive adaptive reaction of neurons in the lumbar spinalcord remote from the epicenter of injury. The assessment of thisreaction as positive is based on the data on the binding of GPC4anchored on the neuron surface to various molecules with neuroprotectiveactivity and stimulating neuroregeneration.