Background:Intervertebral disc degeneration(IVDD)is a multifaceted condition characterized by heterogeneity,wherein the balance between catabolism and anabolism in the extracellular matrix of nucleus pulposus(NP)cells...Background:Intervertebral disc degeneration(IVDD)is a multifaceted condition characterized by heterogeneity,wherein the balance between catabolism and anabolism in the extracellular matrix of nucleus pulposus(NP)cells plays a central role.Presently,the available treatments primarily focus on relieving symptoms associated with IVDD without offering an effective cure targeting its underlying pathophysiological processes.D-mannose(referred to as mannose)has demonstrated anti-catabolic properties in various diseases.Nevertheless,its therapeutic potential in IVDD has yet to be explored.Methods:The study began with optimizing the mannose concentration for restoring NP cells.Transcriptomic analyses were employed to identify the mediators influenced by mannose,with the thioredoxin-interacting protein(TXNIP)gene showing the most significant differences.Subsequently,small interfering RNA(siRNA)technology was used to demonstrate that TXNIP is the key gene through which mannose exerts its effects.Techniques such as colocalization analysis,molecular docking,and overexpression assays further confirmed the direct regulatory relationship between mannose and TXNIP.To elucidate the mechanism of action of mannose,metabolomics techniques were employed to pinpoint glutamine as a core metabolite affected by mannose.Next,various methods,including integrated omics data and the Gene Expression Omnibus(GEO)database,were used to validate the one-way pathway through which TXNIP regulates glutamine.Finally,the therapeutic effect of mannose on IVDD was validated,elucidating the mechanistic role of TXNIP in glutamine metabolism in both intradiscal and orally treated rats.Results:In both in vivo and in vitro experiments,it was discovered that mannose has potent efficacy in alleviating IVDD by inhibiting catabolism.From a mechanistic standpoint,it was shown that mannose exerts its anti-catabolic effects by directly targeting the transcription factor max-like protein X-interacting protein(MondoA),resulting in the upregulation of TXNIP.This upregulation,in turn,inhibits glutamine metabolism,ultimately accomplishing its anticatabolic effects by suppressing the mitogen-activated protein kinase(MAPK)pathway.More importantly,in vivo experiments have further demonstrated that compared with intradiscal injections,oral administration of mannose at safe concentrations can achieve effective therapeutic outcomes.Conclusions:In summary,through integrated multiomics analysis,including both in vivo and in vitro experiments,this study demonstrated that mannose primarily exerts its anti-catabolic effects on IVDD through the TXNIP-glutamine axis.These findings provide strong evidence supporting the potential of the use of mannose in clinical applications for alleviating IVDD.Compared to existing clinically invasive or pain-relieving therapies for IVDD,the oral administration of mannose has characteristics that are more advantageous for clinical IVDD treatment.展开更多
Aldehyde dehydrogenase 2（ALDH2）is an important factor in inhibiting oxidative stress and has been shown to protect against renal ischemia/reperfusion injury.Therefore,we hypothesized that ALDH_2 could reduce spinal ...Aldehyde dehydrogenase 2（ALDH2）is an important factor in inhibiting oxidative stress and has been shown to protect against renal ischemia/reperfusion injury.Therefore,we hypothesized that ALDH_2 could reduce spinal cord ischemia/reperfusion injury.Spinal cord ischemia/reperfusion injury was induced in rats using the modified Zivin＇s method of clamping the abdominal aorta.After successful model establishment,the agonist group was administered a daily consumption of 2.5%alcohol.At 7 days post-surgery,the Basso,Beattie,and Bresnahan score significantly increased in the agonist group compared with the spinal cord ischemia/reperfusion injury group.ALDH_2expression also significantly increased and the number of apoptotic cells significantly decreased in the agonist group than in the spinal cord ischemia/reperfusion injury group.Correlation analysis revealed that ALDH_2 expression negatively correlated with the percentage of TUNEL-positive cells（r=-0.485,P〈0.01）.In summary,increased ALDH_2 expression protected the rat spinal cord against ischemia/reperfusion injury by inhibiting apoptosis.展开更多
Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively c...Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018.展开更多
基金supported by the National Key Research and Development Program of China(2020YFB1711505).
文摘Background:Intervertebral disc degeneration(IVDD)is a multifaceted condition characterized by heterogeneity,wherein the balance between catabolism and anabolism in the extracellular matrix of nucleus pulposus(NP)cells plays a central role.Presently,the available treatments primarily focus on relieving symptoms associated with IVDD without offering an effective cure targeting its underlying pathophysiological processes.D-mannose(referred to as mannose)has demonstrated anti-catabolic properties in various diseases.Nevertheless,its therapeutic potential in IVDD has yet to be explored.Methods:The study began with optimizing the mannose concentration for restoring NP cells.Transcriptomic analyses were employed to identify the mediators influenced by mannose,with the thioredoxin-interacting protein(TXNIP)gene showing the most significant differences.Subsequently,small interfering RNA(siRNA)technology was used to demonstrate that TXNIP is the key gene through which mannose exerts its effects.Techniques such as colocalization analysis,molecular docking,and overexpression assays further confirmed the direct regulatory relationship between mannose and TXNIP.To elucidate the mechanism of action of mannose,metabolomics techniques were employed to pinpoint glutamine as a core metabolite affected by mannose.Next,various methods,including integrated omics data and the Gene Expression Omnibus(GEO)database,were used to validate the one-way pathway through which TXNIP regulates glutamine.Finally,the therapeutic effect of mannose on IVDD was validated,elucidating the mechanistic role of TXNIP in glutamine metabolism in both intradiscal and orally treated rats.Results:In both in vivo and in vitro experiments,it was discovered that mannose has potent efficacy in alleviating IVDD by inhibiting catabolism.From a mechanistic standpoint,it was shown that mannose exerts its anti-catabolic effects by directly targeting the transcription factor max-like protein X-interacting protein(MondoA),resulting in the upregulation of TXNIP.This upregulation,in turn,inhibits glutamine metabolism,ultimately accomplishing its anticatabolic effects by suppressing the mitogen-activated protein kinase(MAPK)pathway.More importantly,in vivo experiments have further demonstrated that compared with intradiscal injections,oral administration of mannose at safe concentrations can achieve effective therapeutic outcomes.Conclusions:In summary,through integrated multiomics analysis,including both in vivo and in vitro experiments,this study demonstrated that mannose primarily exerts its anti-catabolic effects on IVDD through the TXNIP-glutamine axis.These findings provide strong evidence supporting the potential of the use of mannose in clinical applications for alleviating IVDD.Compared to existing clinically invasive or pain-relieving therapies for IVDD,the oral administration of mannose has characteristics that are more advantageous for clinical IVDD treatment.
基金supported by the Natural Science Research Fund Project of Shanghai Ninth People's HospitalShanghai Jiao Tong University School of Medicine of China,No.syz2014-014
文摘Aldehyde dehydrogenase 2（ALDH2）is an important factor in inhibiting oxidative stress and has been shown to protect against renal ischemia/reperfusion injury.Therefore,we hypothesized that ALDH_2 could reduce spinal cord ischemia/reperfusion injury.Spinal cord ischemia/reperfusion injury was induced in rats using the modified Zivin＇s method of clamping the abdominal aorta.After successful model establishment,the agonist group was administered a daily consumption of 2.5%alcohol.At 7 days post-surgery,the Basso,Beattie,and Bresnahan score significantly increased in the agonist group compared with the spinal cord ischemia/reperfusion injury group.ALDH_2expression also significantly increased and the number of apoptotic cells significantly decreased in the agonist group than in the spinal cord ischemia/reperfusion injury group.Correlation analysis revealed that ALDH_2 expression negatively correlated with the percentage of TUNEL-positive cells（r=-0.485,P〈0.01）.In summary,increased ALDH_2 expression protected the rat spinal cord against ischemia/reperfusion injury by inhibiting apoptosis.
文摘Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018.
