Lack of ceramide synthase 2 suppresses the development of experimental autoimmune encephalomyelitis by impairing the migratory capacity of neutrophils

Ceramide synthases (CerS) synthesise ceramides of defined acyl chain lengths, which are thought to mediate cellular processes in a chain length-dependent manner. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed a significant elevation of CerS2 and its products, C24-ceramides, in CD11b⁺ cells (monocytes and neutrophils) isolated from blood. This result correlates with the clinical finding that CerS2 mRNA expression and C24-ceramide levels were significantly increased by 2.2- and 1.5-fold, respectively, in white blood cells of MS patients. The increased CerS2 mRNA/C24-ceramide expression in neutrophils/monocytes seems to mediate pro-inflammatory effects, since a specific genetic deletion of CerS2 in blood cells or a total genetic deletion of CerS2 significantly delayed the onset of clinical symptoms, due to a reduced infiltration of immune cells, in particular neutrophils, into the central nervous system. CXCR2 chemokine receptors, expressed on neutrophils, promote the migration of neutrophils into the central nervous system, which is a prerequisite for the recruitment of further immune cells and the inflammatory process that leads to the development of MS. Interestingly, neutrophils isolated from CerS2 null EAE mice, as opposed to WT EAE mice, were characterised by significantly lower CXCR2 receptor mRNA expression resulting in their reduced migratory capacity towards CXCL2. Most importantly, G-CSF-induced CXCR2 expression was significantly reduced in CerS2 null neutrophils and their migratory capacity was significantly impaired. In conclusion, our data strongly indicate that G-CSF-induced CXCR2 expression is regulated in a CerS2-dependent manner and that CerS2 thereby promotes the migration of neutrophils, thus, contributing to inflammation and the development of EAE and MS.     

2例胰岛素自身免疫综合征临床病例分析

通过回顾分析我院2例确诊为胰岛素自身免疫综合征(IAS)患者的临床资料,并复习相关文献,总结发病机制及治疗方法,探讨IAS患者的临床特点,提高对低血糖症的诊治水平。     

Aminotransferases During Treatment Predict Long-Term Survival in Patients With Autoimmune Hepatitis Type 1: A Landmark Analysis

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富亮氨酸胶质瘤失活1蛋白抗体阳性边缘性脑炎 临床分析及文献复习

目的：总结富亮氨酸胶质瘤失活1蛋白（LGI1）抗体阳性边缘性脑炎的临床和影像特点及诊疗预后。 方法：报道我院1例LGI1抗体阳性相关边缘性脑炎并文献复习。结果：患者女性，60岁，表现为渐进性加重 的记忆力减退、癫痫发作（全身强直阵挛发作，面-臂肌张力障碍发作）、低钠血症和轻度精神行为异常。颅 脑MRI-T2/Flair序列提示双侧颞叶（左侧为甚）内侧、海马异常高信号。脑脊液抗LGI1抗体阳性（++）。经激 素治疗症状有所改善。检索既往报道LGI1抗体阳性边缘性脑炎患者237例，多数呈急性、亚急性起病，最 常见是记忆障碍、癫痫（含面-臂肌张力障碍发作）和低钠血症，头颅MRI（特别是MRI-T2/Flair序列）显示单 侧或者双侧海马区、颞叶异常多见，早期免疫治疗预后良好。结论：LGI1抗体阳性相关边缘性脑炎有其特 有的临床特点，免疫治疗可明显改善患者预后。