The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological condition...The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological conditions associated with central nervous system trauma. Therefore, we hypothesized that a decrease in SFK activation by a long-term treatment with 4-amino-5-（4- chlorophenyl）-7-（t-butyl）pyrazolo[3,4-d]pyramidine （PP2）, a selective SFK inhibitor, after spinal cord contusion with the New York University （NYU） impactor device would generate a permissive environment that improves axonal sprouting and/or behavioral activity. Results demonstrated that long-term blockade of SFK activation with PP2 increases locomotor activity at 7, 14, 21 and 28 days post-iniury in the Basso, Beattie, and Bresnahan open field test, round and square beam crossing tests. In addition, an increase in white matter spared tissue and serotonin fiber density was observed in animals treated with PP2. However, blockade of SFK activity did not change the astrocytic response or infiltration of cells from the immune system at 28 days post-injury. Moreover, a reduced SFK activity with PP2 diminished Ephexin （a guanine nudeotide exchange factor） phosphorylation in the acute phase （4 days post-injury） after trauma. Together, these findings suggest a potential role of SFK in the regulation of spared tissue and/or axonal outgrowth that may result in functional locomotor recovery during the pathophysiology generated after spinal cord injury. Our study also points out that ephexinl phosphorylation （activation） by SFK action may be involved in the repulsive microenvironment generated after spinal cord injury.展开更多
基金partially supported by the MBRS-RISE Program(R25 GM061838)MBRS-SCORE(SO6-GM08224)+2 种基金COBRE(5P20-GM103642)SNRP(NS39405)RCMI(8G12MD007600)
文摘The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological conditions associated with central nervous system trauma. Therefore, we hypothesized that a decrease in SFK activation by a long-term treatment with 4-amino-5-（4- chlorophenyl）-7-（t-butyl）pyrazolo[3,4-d]pyramidine （PP2）, a selective SFK inhibitor, after spinal cord contusion with the New York University （NYU） impactor device would generate a permissive environment that improves axonal sprouting and/or behavioral activity. Results demonstrated that long-term blockade of SFK activation with PP2 increases locomotor activity at 7, 14, 21 and 28 days post-iniury in the Basso, Beattie, and Bresnahan open field test, round and square beam crossing tests. In addition, an increase in white matter spared tissue and serotonin fiber density was observed in animals treated with PP2. However, blockade of SFK activity did not change the astrocytic response or infiltration of cells from the immune system at 28 days post-injury. Moreover, a reduced SFK activity with PP2 diminished Ephexin （a guanine nudeotide exchange factor） phosphorylation in the acute phase （4 days post-injury） after trauma. Together, these findings suggest a potential role of SFK in the regulation of spared tissue and/or axonal outgrowth that may result in functional locomotor recovery during the pathophysiology generated after spinal cord injury. Our study also points out that ephexinl phosphorylation （activation） by SFK action may be involved in the repulsive microenvironment generated after spinal cord injury.
