Symposium
Impact of new advances in the DAMPs/alarmins and neuroinflammation researches on diverse neuronal diseases
シンポジウム
多様な神経疾患にインパクトを与えるDAMPs/alarminsと神経炎症に関する新研究展開 |
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| 7月25日（木）9:03～9:28 第6会場（朱鷺メッセ 2F 201A）
1S06m-1
Sex and cell dependent roles of disulfide HMGB1 in spinal and peripheral pain mechanisms
Camilla Svensson（Svensson Camilla）
Dept. Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
High-mobility group box-1 protein (HMGB1) has emerged as a danger-associated molecular pattern molecule protein with roles in various conditions, including arthritis-induced pain. We have previously shown that blocking the actions of extracellular spinal HMGB1 reverses pain-like behavior in the collagen antibody-induced arthritis model. The extracellular activities of HMGB1 depend on the redox state of the protein. Disulfide HMGB1 is in a toll like receptor 4 (TLR4) activating conformation. Intrathecal injection of disulfide HMGB1, but not not all-thiol HMGB1, induces mechanical hypersensitivity after intrathecal and intra-articular injections. As spinal TLR4 and microglia has been linked to nociception predominantly in males, we examined if the pronociceptive properties of disulfide HMGB1 depend on TLR4 and microglia in the spinal cord and myeloid cells the joint in a sex-dependent fashion. Interestingly, intrathecal administration of minocycline, frequently used as a microglia inhibitor, attenuated disulfide HMGB1-induced mechanical hypersensitivity in male but not in female mice. Male mice lacking TLR4 in microglia did not develop HMGB1 induced hypersensitivity, while females did. Furthermore, we found that pain-like behavior induced by intra-articular injection of disulfide HMGB1 is dependent on TLR4 expressed on myeloid cells to a greater extent in male compared to in female mice, and that TLR4 expressed on nociceptors were critical for development of mechanical hypersensitivity in female mice. In order to advance our understanding of the underlying basis for the sex-dependent spinal minocycline effect, we examined the global spinal protein expression profile in male and female mice injected intrathecally with disulfide HMGB1 followed by either minocycline or vehicle using LC-MS/MS. Using a 2x2 factorial design we found that male and females subjected to only disulfide HMGB1, and in response to the additional minocycline treatment, showed differential regulation of spinal proteins. This presentation will provide support for pronociceptive properties of disulfide HMGB1 in both male and female mice and highlight the importance of mapping sex-associated differences in pain mechanisms. In addition, it will give an example of how examining global protein expression profiles can aid in advancing our understanding of pain mechanisms and effects of pharmacological intervention. | | 7月25日（木）9:28～9:50 第6会場（朱鷺メッセ 2F 201A）
1S06m-2
神経障害性疼痛における末梢組織中のHMGB1とトロンボモジュリン／トロンビン系の役割
Atsufumi Kawabata（川畑 篤史）
近畿大薬病態薬理
High mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) protein, once released from the nucleus into the extracellular space in response to cell death or inflammatory stimuli, activates pattern-recognition receptors (PRRs) such as Toll-like receptors (TLRs) 2, 4 and 5, receptor for advanced glycation end-products (RAGE), etc., thereby playing a role in the pathogenesis of diverse neuronal diseases including neuropathic pain. Thrombomodulin (TM), an endothelial membrane protein, and recombinant human soluble TM (TMa) sequester HMGB1 and promote its thrombin-dependent degradation. Actually, we have shown that intraplantar administration of HMGB1 causes hyperalgesia/allodynia, an effect abolished by an anti-HMGB1-neutralizing antibody as well as TMa. Interestingly, HMGB1 is involved in the development of lipopolysaccharide-induced inflammatory pain, chemotherapy-induced peripheral neuropathy (CIPN), and also visceral pain associated with cystitis and pancreatitis in rodents. The somatic and visceral pain signals in any of those pain models are prevented by TMa. The preventive effect of TMa against CIPN is abolished by direct thrombin inhibitors and distinct anti-coagulants that reduce thrombin formation. In addition, the thrombin inhibitors/anti-coagulants in combination with subeffective doses of chemotherapeutics cause CIPN and elevate plasma HMGB1 levels, although they, administered separately, do not induce neuropathy or plasma HMGB1 increase. Our studies thus suggest that peripheral HMGB1 plays a key role in the pathogenesis of diverse types of persistent pain, particularly CIPN, and that TMa prevents the HMGB1-depedent pain in a thrombin-dependent manner. We also propose that the endogenous TM/thrombin system might function to suppress CIPN by inactivating extracellular HMGB1 released in response to chemotherapeutics. | | 7月25日（木）9:50～10:12 第6会場（朱鷺メッセ 2F 201A）
1S06m-3
抗HMGB1抗体投与による脊髄損傷部保全効果と脊髄損傷治療への応用
Kinichi Nakashima（中島 欽一）
九大院・医・応用幹細胞・基盤幹細胞学
Since a large number of tracts are disrupted and the majority of host neurons die around the lesion site in the spinal cord as the damage spreads, minimizing this spreading and preserving the microenvironment around the lesion are important for attaining further improvements in reconstruction. High mobility group box-1 (HMGB1) is a damage-associated molecular pattern protein that triggers sterile inflammation after tissue injury. Using a spinal cord injury (SCI) model mouse, we have previously found that anti-HMGB1 antibody treatment alleviated blood-spinal cord barrier disruption and edema formation, and increased the number of neurites from spared axons and the survival of host neurons, resulting in functional recovery. However, this recovery was greatly enhanced by the subsequent human iPSC-derived neural stem cell (hiPSC-NSC) transplantation, reaching an extent that has never before been reported. We also found that this improved recovery was directly associated with connections established between surviving host neurons and transplant-derived neurons. Taken together, our results highlight combinatorial treatment with anti-HMGB1 antibody and hiPSC-NSC transplantation as a promising novel therapy for SCI. Nevertheless, there still exit concerns about transplantation of iPSC-derived cells, such as immunorejection and tumorigenesis. We then try to find a drug which can collaboratively improve functional recovery after SCI with anti-HMGB1 antibody. Epothilone B (epoB) has been shown to decrease scar and enhance axonal growth after SCI. We here show that epoB further enhances functional recovery induced by anti-HMGB1 antibody alone after SCI, raising a possibility for therapeutic treatment of SCI without engrafting iPSC-derived cells. | | 7月25日（木）10:12～10:34 第6会場（朱鷺メッセ 2F 201A）
1S06m-4
脳虚血ストレス等により誘発されるAlarminsの非古典的、非小胞性遊離と脳保護
Hiroshi Ueda（植田 弘師）1,2
1長崎大学院医歯薬学総合創薬薬理
2京都大学院薬
Prothymosin alpha (ProTa) was discovered in the conditioned medium of cultured cortical neuron under the condition of serum-free/non-supplemental starvation. ProTa converts starvation/ischemic stress-induced neuronal necrosis to apoptosis through putative Gi protein-coupled receptor and protein kinase C-mediated signaling (Ueda et al., JCB 2007). Our study using retinal ischemia/reperfusion model demonstrated that ProTa converts necrosis to apoptosis, which in turn inhibited by ProTa-dependently upregulated BDNF (Fujita et al, CDD 2009). Further studies revealed that two types of ProTa receptors may play roles in these beneficial actions. One of them is mediated through Toll-like receptor 4 and its downstream TRIF-system without involvement of MyD88-system (Halder et al., J Neurochem 2015). The action was in a manner of preconditional protection, but it was partial. Another type of ProTa action was in a post ischemic protection and its was complete(Fujita et al, CDD 2009). The latter mechanism may be related to the extracellular release of ATP by an activation of extracellular F0/F1 ATPase (Ueda et al., Expert Opin Biol Ther, 2018). As F0/F1 ATPase is expected to locally convert ATP to ADP, we are trying to examine whether further activation of Gi-coupled P2Y receptors underlies potent neuroprotection. Here I will also show the recent advances in the mechanisms of damage stress-induced release of neuroprotective ProTa and various beneficial actions of ProTa and its derived small peptides in terms of blockade of cerebral hemorrhage and chronic pain. | | 7月25日（木）10:34～10:56 第6会場（朱鷺メッセ 2F 201A）
1S06m-5
てんかん病態におけるHMGB1動態と末梢投与抗HMGB1抗体の治療効果
Masahiro Nishibori（西堀 正洋）1，Li Fu（富 麗）1，Hideo Kohka Takahashi（高橋 小岡 英夫）2，Shuji Mori（森 秀治）3
1岡山大学大学院医歯薬学総合研究科薬理学
2近畿大学医学部薬理学
3就実大学薬学部薬理学
High mobility group box-1 (HMGB1) is a representative damage-associated molecular pattern and has been suggested to be involved in many inflammatory diseases. In the previous studies, we demonstrated the beneficial effects of anti-HMGB1 mAb on brain ischemia- and trauma-induced brain injuries in rats through the inhibition of HMGB1 translocation, protection of BBB and suppression of inflammatory responses. A growing body of evidence has shown the relationship between BBB function and epilepsy. In the present study, we focused on whether anti-HMGB1 antibody treatment could relieve status epilepticus-triggered BBB breakdown and inflammation response in addition to the seizure behavior itself.
Anti-HMGB1 mAb showed inhibitory effects on leakage of the BBB, and on the HMGB1 translocation induced by pilocarpine. The expression of inflammation-related factors, such as MCP-1, CXCL-1, TLR-4, and IL-6 in hippocampus and cerebral cortex were down-regulated by anti-HMGB1 mAb associated with the number of activated astrocytes, microglial cells as well as the expression of IL-1β. Both hematoxylin & eosin and TUNEL staining showed that the apoptotic cells could be reduced after anti-HMGB1 mAb treatment. The onset and latency of Racine stage five were significantly prolonged in the anti-HMGB1 mAb group. In the analysis of localization of therapeutic mAb, we found that the immunoreactivities of i.v. injected anti-HMGB1 mAb were present on/around vascular endothelial cells of brain in pilocarpine-induced seizure mice. The immunostaing of HMGB1 in vascular endothelial cells in pilocarpine-induced seizure mice revealed the release of HMGB1 from vascular endothelial cells.
These results suggested that anti-HMGB1 mAb prevented the BBB permeability, reduced HMGB1 translocation while inhibiting the expression of inflammation-related factors, protected against neural cell apoptosis and prolonged Racine stage 5 seizure onset and latency, leading to the inhibition of status epilepticus and epileptogenesis. | | | |
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