Chemotactic Responses of Neural Stem Cells to SDF-1α Correlate Closely with Their Differentiation Status

Chemotaxis of neural stem/progenitor cells (NSCs) is regulated by a variety of factors, and much effort has been devoted to the delineation of factors that are involved in NSC migration. However, the relationship between NSC chemotactic migration and differentiation remains uncharacterized. In the present study, by comparing the transfilter migration rate, single-cell migration speed, and directional efficiency of NSCs in stromal cell-derived factor-1 alpha (SDF-1α)-induced Boyden chamber and Dunn chamber chemotaxis assays, we demonstrate that NSCs in varying differentiation stages possess different migratory capacity. Furthermore, F-actin microfilament reorganization upon stimulation varies greatly among separate differentiation states. We show that signaling pathways involved in NSC migration, such as PI3K/Akt and mitogen-activated protein kinase (MAPK) (ERK1/2, JNK, and p38 MAPK) pathways, are differentially activated by SDF-1α among each NSC differentiation stages, and the extent to which these pathways participate in cell chemotaxis exhibits a differentiation stage-dependent manner. Taken together, these results suggest that the differentiation of NSCs influences their chemotactic responses to SDF-1α, providing new insight into the optimization of the therapeutic efficacy of NSCs for neural regeneration and nerve repair after injury.     

SDF-1/CXCR4在神经发生中的作用

间质细胞源性细胞因子-1(stromal cell-derived factor-1,SDF-1)是骨髓间质细胞系产生的一种CXC类趋化蛋白,其不仅对免疫细胞具有趋化吸引作用,对中枢神经系统(CNS)也起到重要的作用。CXCR4为SDF-1的特异性受体。SDF-1/CXCR4在发育中和成熟的CNS中均有表达,并通过促进神经前体细胞增殖、分化和移行,调节GABA能神经元、协助神经环路形成而对成年神经发生发挥作用。缺血性脑卒中时,SDF-1水平升高,并通过CXCR4促进新生神经细胞向受损区域迁移和定位,介导损伤后的神经功能修复。     

VEGF、SDF-1对神经干细胞迁移作用的研究

目的观察在相同时间内不同浓度的血管内皮生长因子(VEGF)、细胞基质衍生因子-1(SDF-1)及两者协同作用下对急性脑卒中(ACI)后神经干细胞迁移的影响。方法提取新生72h的SD大鼠的海马组织中的神经干细胞(NSCs)进行传代培养,取传3代NSCs并测定特异性标志物Nestin蛋白表达;观察在12h内不同浓度VEGF、SDF-1及两者协同下对NSCs迁移的作用。结果不同浓度10μg·L~(-1)、50μg·L~(-1)、100μg·L~(-1)、500μg·L~(-1)、1000μg·L~(-1)的SDF-1与空白对照组之间的差异有统计学意义(P<0.05)。与对照组0μg·L~(-1)相比,25μg·L~(-1)、50μg·L~(-1)、100μg·L~(-1)的VEGF能使NSCs产生显著的趋化迁移效应(P<0.05),然而5μg·L~(-1)的VEGF却不能显著诱导NSCs迁移(P> 0.05)。SDF-1组、VEGF组和VEGF+SDF-1组的差异有统计学意义(P<0.05);VEGF+SDF-1组的迁移细胞数目与SDF-1组和VEGF组相比增多,差异有统计学意义(P<0.05)。结论在相同时间内SDF-1和VEGF在一定范围内可趋化诱导NSCs迁移,并且两者具有协同作用。     

SD大鼠癫痫大发作后海马结构SDF-1表达的研究

目的检测基质细胞衍生因子-1(SDF-1)在癫痫大发作后不同时段的表达情况,探索SDF-1在癫痫大发作后海马结构重塑中发挥的作用,为进一步探讨癫痫的发病机制提供实验依据。方法腹腔注射匹罗卡品22.5 mg/kg体重,制造SD大鼠癫痫大发作模型后,分别于6小时、12小时、24小时、2天,7天、14天、28天处死大鼠,用免疫组化法检测大鼠脑组织海马CA3区的SDF-1表达情况。结果SDF-1在癫痫发作后6小时开始升高,2-7天达峰值后开始下降,28天后基本恢复正常。结论SDF-1在癫痫大发作后的大鼠海马组织中表达明显增加,提示SDF-1在癫痫大发作后内源性神经干细胞向海马部位的定向迁移及海马结构重塑中可能发挥了一定的作用。     

Narcolepsy with cataplexy associated with H1N1 vaccination

IntroductionIt has been suggested that the H1N1 vaccine may be a trigger for the onset of narcolepsy-cataplexy, a rare disease whose autoimmune origin is suspected.ObservationsWe report two patients (a 9-year-old boy and an 18-year-old man) with severe narcolepsy-cataplexy, in whom the illness appeared within 3–4 weeks after H1N1 vaccination. In both cases, symptoms developed unusually abruptly and they presented with severe daytime sleepiness and multiple daily cataplexy attacks. Other similar cases have been recently reported associated with H1N1 vaccine.ConclusionAlthough no formal link can be established, the unusual characteristics of the reported cases and the striking temporal relationship suggests that narcolepsy may be the result of an autoimmune reaction triggered by H1N1 vaccination in susceptible individuals.     

趋化因子SDF-1体外趋化骨髓基质细胞迁移的实验研究

目的探讨趋化因子SDF-1在体外对骨髓基质细胞的迁移作用。方法采用全骨髓法培养成年Wistar大鼠骨髓基质细胞。取第五代骨髓基质细胞行免疫荧光鉴定；后通过细胞免疫荧光及RT-PCR的方法检测骨髓基质细胞表达趋化因子受体CXCR4的情况．利用Boyden小室法探讨趋化因子SDF-1对骨髓基质细胞的体外趋化作用及其特异性。结果第五代骨髓基质细胞都表达间充质干细胞标记物Vimentin、Laminin及Fibronectin；细胞免疫荧光及RT-PCR结果证实骨髓基质细胞表达趋化因子受体CXCR4；趋化因子SDF-1（5、50、500ng／mL）体外可趋化骨髓基质细胞迁移，抗SDF-1多克隆抗体可对抗其趋化迁移作用。结论SDF-1／CXCR4通路参与骨髓基质细胞体外迁移，为进一步研究骨髓基质细胞的迁移机制提供了理论依据。     

A cortical form of CADASIL with cerebral Aβ amyloidosis

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) was diagnosed by genetic testing in a 53-year-old patient, 10 years before death. Following two strokes with partial recovery, he developed rapidly progressive cognitive decline 3 years before death. Neuropathology confirmed CADASIL. Characteristic arteriolar changes were associated with subcortical infarcts, and status cribrosus in basal ganglia and the cortico-subcortical junctions. Leukoencephalopathy was very mild. Severe arteriolar changes in the cerebral cortex and leptomeninges were associated with numerous intracortical microinfarcts. There was abundant Abeta deposition throughout the cerebral cortex, mainly as Aβ42 diffuse plaques, frequently periarteriolar. There was no cerebral amyloid angiopathy apart from rare Aβ40 deposits around Notch3-positive deposits. Amyloid plaques were rare. Tau pathology was minimal. Alzheimer disease associated with CADASIL has been described, but the few reported cases had abundant amyloid plaques, amyloid angiopathy, fibrillar plaques and neurofibrillary tangles. Aβ accumulation could result from abnormal Aβ synthesis or impaired elimination due to the arteriolar changes of CADASIL. We did not find Aβ deposits in our other CADASIL cases with milder cortical arteriolar changes. Additional genetic predisposing factors were not identified. This case suggests that besides the classical, purely subcortical form of CADASIL, a “cortical” form with numerous lacunar infarcts and Aβ deposition in the cerebral cortex may occur and may be difficult to differentiate clinically from Alzheimer disease.     

血清SDF-1、Ang-1与急性缺血性脑卒中预后的关系及其预测价值

目的 探讨急性缺血性脑卒中(AIS)患者血清基质细胞衍生因子-1(SDF-1)、血管生成素-1(Ang-1)水平变化的临床意义。方法 选取2017年2月-2019年2月本院收治的AIS患者107例作为观察组,并根据mRS评分将观察组分为预后良好组(n=72, mRS评分≤2分)和预后不良组(n=35, mRS评分>2分); 另选取同期来本院行体检的健康志愿者50例为对照组; 比较对照组、观察组不同预后的血清SDF-1、Ang-1水平的动态变化; 采用多元 Logistic回归分析预后的影响因素; 采用ROC曲线评估SDF-1、Ang-1水平对患者预后的预测价值。结果 与对照组比较,观察组入院第1、7、14、21 d的SDF-1、Ang-1水平均存在一定的波动性变化(P<0.05)。预后良好组入院第1、7、14、21 d的SDF-1水平低于预后不良组,Ang-1水平高于预后不良组(P<0.05)。单因素分析显示,房颤、大面积脑梗死、血尿酸、血肌酐、血浆脑钠肽水平、NIHSS评分与AIS预后有关(P<0.05)。多因素Logistic回归分析显示,血清SDF-1水平升高、Ang-1水平降低、大面积脑梗死、房颤、血浆脑钠肽水平≥280 ng/L、NIHSS评分≥13分是AIS预后的独立危险因素(P<0.05)。ROC分析显示,SDF-1、Ang-1水平用于预测AIS患者预后的AUC、敏感度、特异度均高于0.7,二者联合检测的敏感度和特异度分别为0.857(30/35),0.819(59/72),均高于两指标单独检测。结论 AIS患者血清SDF-1、Ang-1水平呈异常波动,且其表达水平与患者的预后密切相关,二者联合检测对患者预后有较高的预测价值     

细胞趋化因子SDF-1α对小胶质细胞趋化作用的研究

目的观察细胞趋化因子SDF-1对小胶质细胞的趋化作用以及机制探讨。方法体外培养BV2细胞系,给予不同浓度SDF-1α,进行迁移实验以确定SDF-1α对小胶质细胞趋化作用的浓度;将C6小鼠分为对照组和SDF-1α干预组,分别予以侧脑室注射PBS和SDF-1α各8周,采用免疫荧光组织化学方法观察注射后小鼠脑内小胶质细胞的数量,进一步采用Western Blot检测小胶质细胞标志物Iba-1的表达水平。结果予以SDF-1干预6 h后BV2细胞的迁移指数增加,SDF-1的受体CXCR4拮抗剂AMD3100能抑制SDF-1所致的小胶质细胞迁移;长程的SDF-1α侧脑室注射能够增加C6小鼠皮层和海马小胶质细胞的数量;Western Blot检测发现SDF-1α干预组脑组织中Iba-1表达量也明显增加。结论 SDF-1在离体和在体实验中均能趋化小胶质细胞的迁移。     

A boy with the Rett syndrome?

A 13-year-old Kuwaiti boy met all necessary and almost all supportive criteria for the Rett syndrome. Electron microscopy of muscle biopsy specimen revealed abnormal mitochondria, a finding that has recently been reported for girls with the Rett syndrome. The results of other laboratory investigations were normal, besides a blood ammonia level of 100 microM/L. The mitochondrial changes observed in girls may be the consequence of an X-borne gene mutation, in which case only the female zygote survives because of the normal allele on the second X-chromosome. However, another genetic possibility discussed is inheritance according to "metabolic interference" of an X-borne allele, which does not rule out the possibility of a male being affected. We assume that the case reported might be a male variant of the Rett syndrome.     

Susceptibility to Guillain-Barré syndrome is not associated with CD1A and CD1E gene polymorphisms

Immune responses to microbial glycolipids that cross-react to neural epitopes may trigger the Guillain-Barré syndrome (GBS). CD1 molecules are involved in antigen presentation of glycolipids and variation in CD1 genes was recently reported to confer susceptibility to develop GBS. This hypothesis was tested by comparing single nucleotide polymorphisms (SNPs) of CD1A and CD1E in 312 well defined GBS patients and 212 healthy controls. SNPs in CD1A and CD1E were not associated with GBS susceptibility, specific clinical subgroups, anti-ganglioside antibodies, antecedent infections and prognosis. Based on this study, CD1 polymorphisms are not a susceptibility or disease modifying factor in GBS.     

A new nonsense mutation in the NF1 gene with neurofibromatosis–Noonan syndrome phenotype

Purpose

Neurofibromatosis–Noonan syndrome is a rare autosomal dominant disorder which combines neurofibromatosis type 1 (NF1) features with Noonan syndrome. NF1 gene mutations are reported in the majority of these patients.

Method

Sequence analysis of the established genes for Noonan syndrome revealed no mutation; a heterozygous NF1 point mutation c.7549C>T in exon 51, creating a premature stop codon (p.R2517X), had been demonstrated.

Result

Neurofibromatosis–Noonan syndrome recently has been considered a subtype of NF1 and caused by different NF1 mutations.

Conclusion

We report the case of a 14-year-old boy with neurofibromatosis type 1 with Noonan-like features, who complained of headache with triventricular hydrocephaly and a heterozygous NF1 point mutation c.7549C>T in exon 51.     

Inheritance of Charcot–Marie–Tooth disease 1A with rare nonrecurrent genomic rearrangement

Rare copy number variations by the nonrecurrent rearrangements involving PMP22 have been recently suggested to be associated with CMT1A peripheral neuropathy. As a mechanism of the nonrecurrent rearrangement, replication-based fork stalling template switching (FoSTeS) by microhomology-mediated break-induced replication (MMBIR) has been proposed. We found three Korean CMT1A families with putative nonrecurrent duplication. The duplications were identified by microsatellite typing and applying a CGH microarray. The breakpoint sequences in two families suggested an Alu–Alu-mediated rearrangement with the FoSTeS by the MMBIR, and a two-step rearrangement of the replication-based FoSTeS/MMBIR and meiosis-based recombination. The two-step mechanism has still not been reported. Segregation analysis of 17p12 microsatellite markers and breakpoint junction analysis suggested that the nonrecurrent rearrangements are stably inherited without alteration of junction sequence; however, they may allow some alteration of the genomic contents in duplication across generations by recombination event. It might be the first study on the pedigree analysis of the large CMT1A families with nonrecurrent rearrangements. It seems that the exact mechanism of the nonrecurrent rearrangements in the CMT1A may have a far more complex process than has been expected.     

A combined voxel-based morphometry and 1H-MRS study in patients with Friedreich’s ataxia

Friedreich’s ataxia (FA) is the most frequent autosomal recessive ataxia and essentially considered a disease of the dorsal root ganglia and spinal cord. It is caused by homozygous GAA expansions in the Frataxin gene in most cases. Although only a few studies have addressed cerebral involvement in FA, cognitive symptoms have lately been emphasized. To evaluate brain damage in vivo, we employed whole-brain VBM and analysis of pre-defined regions of interest (ROIs) over the cerebellum to compare 24 patients with 24 age-and-sex-matched normal controls. ¹H-MRS of deep cerebral white matter (WM) was subsequently performed. Mean age of patients was 28 years (range 14–45), mean duration of disease was 14 years (range 5–28) and 11 were men. Mean length of shorter (GAA1) and longer (GAA2) alleles were 735 and 863, respectively. VBM analysis identified WM atrophy in the posterior cyngulate gyrus, paracentral lobule and middle frontal gyrus. ROIs over the infero-medial cerebellar hemispheres and dorsal brainstem presented gray matter atrophy, which correlated with duration of disease (r = −0.4). NAA/Cr ratios were smaller among patients (P = 0.006), but not Cho/Cr (P = 0.08). Our results provide evidence of axonal damage in the cerebellum, brainstem and subcortical WM in FA. This suggests that neuronal dysfunction is more widespread than previously thought in FA.     

SDF-1/CXCR4生物学轴与颅内转移瘤相关性的研究进展

趋化因SDF-1（CXCL12）与其特异性受体CXCR4构成的CXCL12/CXCR4生物学轴在神经系统转移瘤细胞的生长、迁移中起到重要的作用,对这一特殊生物学轴的研究可以为肿瘤转移的防治提供新的思路。本文将对CXCL12/CXCR4生物学轴与脑转移瘤发生发展关系的研究现状,做一综述。