摘要
In chronic phase of spinal cord injury, functional recovery is more untreatable compared with early intervention in acute phase of spinal cord injury. In the last decade, several combination therapies successfully improved motor dysfunction in chronic spinal cord injury. However, their effectiveness is not sufficient. We previously found a new effective compound for spinal cord injury, matrine, which induced axonal growth and functional recovery in acute spinal cord injury mice via direct activation of extracellular heat shock protein 90. Although our previous study clarified that matrine was an activator of extracellular heat shock protein 90, the potential of matrine for spinal cord injury in chronic phase has not been sufficiently evaluated. Thus, this study aimed to investigate whether matrine ameliorates chronic spinal cord injury in mice. Once daily intragastric administration of matrine(100 μmol/kg per day) to spinal cord injury mice were starte at 28 days after injury, and continued for 154 days. Continuous mat rine treatment improved hindlimb motor function in chronic spinal cord injury mice. In injured spinal cords of the matrine-treated mice, the density of neurofilament-H-positive axons was increased. Moreover, matrine treatment increased the density of bassoon-positive presynapses in contact with choline acetyltransferase-positive motor neurons in the lumbar spinal cord. These findings suggest that matrine promotes remodeling and reconnection of neural circuits to regulate hindlimb movement. All protocols were approved by the Committee for Animal Care and Use of the Sugitani Campus of the University of Toyama(approval No. A2013 INM-1 and A2016 INM-3) on May 7, 2013 and May 17, 2016, respectively.
In chronic phase of spinal cord injury, functional recovery is more untreatable compared with early intervention in acute phase of spinal cord injury. In the last decade, several combination therapies successfully improved motor dysfunction in chronic spinal cord injury. However, their effectiveness is not sufficient. We previously found a new effective compound for spinal cord injury, matrine, which induced axonal growth and functional recovery in acute spinal cord injury mice via direct activation of extracellular heat shock protein 90. Although our previous study clarified that matrine was an activator of extracellular heat shock protein 90, the potential of matrine for spinal cord injury in chronic phase has not been sufficiently evaluated. Thus, this study aimed to investigate whether matrine ameliorates chronic spinal cord injury in mice. Once daily intragastric administration of matrine(100 μmol/kg per day) to spinal cord injury mice were starte at 28 days after injury, and continued for 154 days. Continuous mat rine treatment improved hindlimb motor function in chronic spinal cord injury mice. In injured spinal cords of the matrine-treated mice, the density of neurofilament-H-positive axons was increased. Moreover, matrine treatment increased the density of bassoon-positive presynapses in contact with choline acetyltransferase-positive motor neurons in the lumbar spinal cord. These findings suggest that matrine promotes remodeling and reconnection of neural circuits to regulate hindlimb movement. All protocols were approved by the Committee for Animal Care and Use of the Sugitani Campus of the University of Toyama(approval No. A2013 INM-1 and A2016 INM-3) on May 7, 2013 and May 17, 2016, respectively.
基金
supported by a Grant-in-Aid for Challenging Exploratory Research(No.26670044)from the Ministry of Education,Culture,Sports,Science,and Technology of Japan(to CT)
a Grant-in-Aid for a Cooperative Research Project from the Institute of Natural Medicine,University of Toyama,in 2014 and 2015(to CT)
discretionary funds of the President of the University of Toyama,in 2014,2015,and 2016(to CT)
the Natural Medicine and Biotechnology Research of Toyama Prefecture,Japan(to CT)
