High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the ex...High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.展开更多
Traumatic injuries to spinal cord elicit diverse signaling pathways leading to unselective and complex pathological outcomes:death of multiple classes of neural cells,formation of cystic cavities and glial scars,disr...Traumatic injuries to spinal cord elicit diverse signaling pathways leading to unselective and complex pathological outcomes:death of multiple classes of neural cells,formation of cystic cavities and glial scars,disruption of axonal connections,and demyelination of spared axons,all of which can contribute more or less to debilitating functional impairments found in patients with spinal cord injury.展开更多
Subcortical ischemic white matter injury(SIWMI),pathological correlate of white matter hyperintensities or leukoaraiosis on magnetic resonance imaging,is a common cause of cognitive decline in elderly.Despite its high...Subcortical ischemic white matter injury(SIWMI),pathological correlate of white matter hyperintensities or leukoaraiosis on magnetic resonance imaging,is a common cause of cognitive decline in elderly.Despite its high prevalence,it remains unknown how various components of the white matter degenerate in response to chronic ischemia.This incomplete knowledge is in part due to a lack of adequate animal model.The current review introduces various SIWMI animal models and aims to scrutinize their advantages and disadvantages primarily in regard to the pathological manifestations of white matter components.The SIWMI animal models are categorized into 1)chemically induced SIWMI models,2)vascular occlusive SIWMI models,and 3)SIWMI models with comorbid vascular risk factors.Chemically induced models display consistent lesions in predetermined areas of the white matter,but the abrupt evolution of lesions does not appropriately reflect the progressive pathological processes in human white matter hyperintensities.Vascular occlusive SIWMI models often do not exhibit white matter lesions that are sufficiently unequivocal to be quantified.When combined with comorbid vascular risk factors(specifically hypertension),however,they can produce progressive and definitive white matter lesions including diffuse rarefaction,demyelination,loss of oligodendrocytes,and glial activation,which are by far the closest to those found in human white matter hyperintensities lesions.However,considerable surgical mortality and unpredictable natural deaths during a follow-up period would necessitate further refinements in these models.In the meantime,in vitro SIWMI models that recapitulate myelinated white matter track may be utilized to study molecular mechanisms of the ischemic white matter injury.Appropriate in vivo and in vitro SIWMI models will contribute in a complementary manner to making a breakthrough in developing effective treatment to prevent progression of white matter hyperintensities.展开更多
Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord iniury. Both intrinsic and extrinsic factors are responsible for the regeneration fail- u...Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord iniury. Both intrinsic and extrinsic factors are responsible for the regeneration fail- ure, Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in viva still remains elusive. Recent exper- imental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neu- rons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of en- hanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Ma- nipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.展开更多
Hydroxyapatite(HA)is a representative substance that induces bone regeneration.Our research team extracted nanohydroxyapatite(EH)from natural resources,especially equine bones,and developed it as a molecular biologica...Hydroxyapatite(HA)is a representative substance that induces bone regeneration.Our research team extracted nanohydroxyapatite(EH)from natural resources,especially equine bones,and developed it as a molecular biological tool.Polyethylenimine(PEI)was used to coat the EH to develop a gene carrier.To verify that PEI is well coated in the EH,we first observed the morphology and dispersity of PEI-coated EH(pEH)by electron microscopy.The pEH particles were well distributed,while only the EH particles were not distributed and aggregated.Then,the existence of nitrogen elements of PEI on the surface of the pEH was confirmed by EDS,calcium concentration measurement and fourier transform infrared spectroscopy(FT-IR).Additionally,the pEH was confirmed to have a more positive charge than the 25 kD PEI by comparing the zeta potentials.As a result of pGL3 transfection,pEH was better able to transport genes to cells than 25 kD PEI.After verification as a gene carrier for pEH,we induced osteogenic differentiation of DPSCs by loading the BMP-2 gene in pEH(BMP-2/pEH)and delivering it to the cells.As a result,it was confirmed that osteogenic differentiation was promoted by showing that the expression of osteopontin(OPN),osteocalcin(OCN),and runt-related transcription factor 2(RUNX2)was significantly increased in the group treated with BMP-2/pEH.In conclusion,we have not only developed a novel nonviral gene carrier that is better performing and less toxic than 25 kD PEI by modifying natural HA(the agricultural byproduct)but also proved that bone differentiation can be effectively promoted by delivering BMP-2 with pEH to stem cells.展开更多
基金supported by a grant of the M.D.-Ph.D./Medical Scientist Training Program through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(to HK)+3 种基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(MSITMinistry of Science and ICT)(NRF2019R1A5A2026045 and NRF-2021R1F1A1061819)a grant from the Korean Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(HR21C1003)New Faculty Research Fund of Ajou University School of Medicine(to JYC)。
文摘High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.
基金supported by a National Research Foundation of Korea grant funded by the Korean Government(NRF-2014R1A1A2056452 to D.H.H.and NRF-2014M3A9B6034224 to BGK)
文摘Traumatic injuries to spinal cord elicit diverse signaling pathways leading to unselective and complex pathological outcomes:death of multiple classes of neural cells,formation of cystic cavities and glial scars,disruption of axonal connections,and demyelination of spared axons,all of which can contribute more or less to debilitating functional impairments found in patients with spinal cord injury.
基金This work was supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT,Ministry of Science and ICT)(NRF-2018M3A9E8023853(to JYC)NRF-2018R1C1B6006145(to JYC)NRF-2018R1A2A1A05020292(to BGK)and NRF-2019R1A5A2026045(to JYC and BGK).
文摘Subcortical ischemic white matter injury(SIWMI),pathological correlate of white matter hyperintensities or leukoaraiosis on magnetic resonance imaging,is a common cause of cognitive decline in elderly.Despite its high prevalence,it remains unknown how various components of the white matter degenerate in response to chronic ischemia.This incomplete knowledge is in part due to a lack of adequate animal model.The current review introduces various SIWMI animal models and aims to scrutinize their advantages and disadvantages primarily in regard to the pathological manifestations of white matter components.The SIWMI animal models are categorized into 1)chemically induced SIWMI models,2)vascular occlusive SIWMI models,and 3)SIWMI models with comorbid vascular risk factors.Chemically induced models display consistent lesions in predetermined areas of the white matter,but the abrupt evolution of lesions does not appropriately reflect the progressive pathological processes in human white matter hyperintensities.Vascular occlusive SIWMI models often do not exhibit white matter lesions that are sufficiently unequivocal to be quantified.When combined with comorbid vascular risk factors(specifically hypertension),however,they can produce progressive and definitive white matter lesions including diffuse rarefaction,demyelination,loss of oligodendrocytes,and glial activation,which are by far the closest to those found in human white matter hyperintensities lesions.However,considerable surgical mortality and unpredictable natural deaths during a follow-up period would necessitate further refinements in these models.In the meantime,in vitro SIWMI models that recapitulate myelinated white matter track may be utilized to study molecular mechanisms of the ischemic white matter injury.Appropriate in vivo and in vitro SIWMI models will contribute in a complementary manner to making a breakthrough in developing effective treatment to prevent progression of white matter hyperintensities.
文摘Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord iniury. Both intrinsic and extrinsic factors are responsible for the regeneration fail- ure, Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in viva still remains elusive. Recent exper- imental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neu- rons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of en- hanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Ma- nipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.
基金This study was supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science,ICT&Future Planning(NRF-2020R1F1A1067439,NRF-2020R1I1A1A01068262)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(20194210100230).
文摘Hydroxyapatite(HA)is a representative substance that induces bone regeneration.Our research team extracted nanohydroxyapatite(EH)from natural resources,especially equine bones,and developed it as a molecular biological tool.Polyethylenimine(PEI)was used to coat the EH to develop a gene carrier.To verify that PEI is well coated in the EH,we first observed the morphology and dispersity of PEI-coated EH(pEH)by electron microscopy.The pEH particles were well distributed,while only the EH particles were not distributed and aggregated.Then,the existence of nitrogen elements of PEI on the surface of the pEH was confirmed by EDS,calcium concentration measurement and fourier transform infrared spectroscopy(FT-IR).Additionally,the pEH was confirmed to have a more positive charge than the 25 kD PEI by comparing the zeta potentials.As a result of pGL3 transfection,pEH was better able to transport genes to cells than 25 kD PEI.After verification as a gene carrier for pEH,we induced osteogenic differentiation of DPSCs by loading the BMP-2 gene in pEH(BMP-2/pEH)and delivering it to the cells.As a result,it was confirmed that osteogenic differentiation was promoted by showing that the expression of osteopontin(OPN),osteocalcin(OCN),and runt-related transcription factor 2(RUNX2)was significantly increased in the group treated with BMP-2/pEH.In conclusion,we have not only developed a novel nonviral gene carrier that is better performing and less toxic than 25 kD PEI by modifying natural HA(the agricultural byproduct)but also proved that bone differentiation can be effectively promoted by delivering BMP-2 with pEH to stem cells.