结节性硬化症家系 TSC1/TSC2基因变异的分析及产前诊断

目的:对29个结节性硬化症(tuberous sclerosis complex,TSC)家系进行TSC1、TSC2基因的变异筛查,并对其中14个家系的高危胎儿进行产前诊断,探讨二代测序(next generation sequencing,NGS)联合多重连接探针扩增(multiple ligation-depend...     

一例结节性硬化症家系的 TSC基因变异分析及产前诊断

目的:分析1个结节性硬化症(tuberous sclerosis complex,TSC)家系 TSC1和 TSC2基因变异位点并进行产前诊断。 方法:应用Sanger测序法分别对先证者及其家庭成员进行 TSC1和 TSC2基因变异检测分析。 结果:家...     

一例 TSC2基因嵌合变异致结节性硬化症患者的遗传学分析

目的:对1个结节性硬化症(tuberous sclerosis complex, TSC)家系进行 TSC1和 TSC2基因变异分析,明确其可能的致病原因。 方法:采集患者及其父母的外周血样,提取基因组DNA,应用靶向二代测序联合Sanger测序进行患者及其父母 TSC1和...     

一例结节性硬化症新生儿的 TSC2基因变异分析

目的分析一例结节性硬化症(tuberous sclerosis complex, TSC)新生儿的临床特点及遗传学特征。方法采集1例以发色黄为首发表现的新生儿及其父母的外周血样, 提取DNA进行基因高通量测序分析。结果基因测序显示患儿TSC2基因第33外显子存在c.3914del(p.P1305Rfs*20)杂合变异, 该变异为移码变异, 可导致多肽链合成提前终止。结论本例TSC新生儿以发色黄为首发表现, 既往未见报道。TSC2基因第33外显子c.3914del(p.P1305Rfs * 20)杂合变异可能为该患儿的致病原因。上述发现丰富了TSC2基因的变异谱。     

结节性硬化症家系的基因诊断及产前诊断

目的 对结节性硬化症(tuberous sclerosis complex,TSC)患者进行基因突变检测,并在基因诊断结果明确的基础上应用于产前诊断.方法 应用聚合酶链反应-变性高效液相色谱(polymerase chain reaction-denaturing high-performance liquid chromatography,PCR-DHPLC)、DNA测序技术,对19个家系的21例TSC患者进行TSC1和TSC2基因的突变检测.结果 在19个家系21例患者中发现17种不同的基因突变,其中13种突变未见报道,包括TSCj基因的c.2672delA、c.2672insA和TSC2基因的c.4918insCGCC、c.1143delG、Intron27+1 G＞A、c.1957-1958delAG、Intron5+1 G＞A、c.910insCT、c.2753C＞G、c.4078dupAGCAAGTCCAGCTCCTC、Intron 11-1 G＞A、Intron 14+1 G＞A、c.684 C＞A.对7个家系进行了产前诊断,其中6个家系的胎儿均未发现其家系先证者所具有的突变,胎儿出生后电话随访至1～4岁无TSC的症状出现.而另一家系的胎儿携带有和母亲一样的突变,经遗传咨询后,家属选择了引产.结论 本研究证实的TSC基因突变中,有76.5%(13/17)的突变均未在其他研究中被发现,说明中国人群TSC基因的突变谱可能与其他人群具有较明显的差异;本研究中TSC基因诊断率为89.5%(17/19),提示TSC的发生可能还有其它未知的遗传病因;在有家族史的病例中,TSC1与TSC2有相似的突变比例,而在散发病例中,TSC2的突变更加常见;13种新突变患者的父母均无类似突变,说明TSC致病基因具有较高的自发突变率.     

结节性硬化症患儿2例的临床特征及遗传学分析

目的探讨2例结节性硬化症(TSC)患儿的临床表现及基因变异特点。方法选取2020年6月至2021年7月于郑州大学附属儿童医院就诊的2例TSC患儿为研究对象。收集2例患儿的临床资料, 采用全外显子组测序(WES)筛选患儿的致病基因, 针对可疑变异位点, 进行Sanger测序家系验证。结果患儿1为7月29日龄男性, 患儿2为2岁6月龄男性。2例患儿均表现为癫痫发作和多发性色素脱失斑。基因检测结果显示2例患儿分别携带TSC2基因c.3239₃240insA和c.3330delC新发变异, 既往均未见报道, 根据美国医学遗传学和基因组学学会相关指南, 均评级为致病性变异(PVS1+PS2+PM2_Supporting)。结论本研究明确2例TSC患儿的遗传学病因, 丰富了中国人群TSC的表型和基因变异谱。     

一个结节性硬化症家系的临床表现及遗传学分析

目的明确1例临床诊断为结节性硬化症(tuberous sclerosis complex, TSC)患者的致病基因, 为临床诊断及遗传咨询提供依据。方法应用高通量测序分析先证者TSC1与TSC2的外显子区域, 确定候选致病位点, 应用Sanger测序对患者及家系成员的候选位点进行验证, 依据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics, ACMG)指南, 对位点致病性进行判定。结果先证者的TSC2 (NM₀00548.5)存在c.52delC(p.Leu18CysfsTer28)杂合变异, 为移码变异, 该位点在公共数据库均未见频率报道;Mutation Taster软件预测该变异为有害变异;先证者父母均未发现该变异, 依据ACMG指南, 该变异为疑似致病性变异(PVS1 +PM2)。结论 TSC2基因c.52delC变异为为该患者致病的原因, 本研究结果丰富了TSC患者TSC2的变异谱, 为该家系产前诊断和遗传咨询提供理论依据。     

结节性硬化症5个家系致病变异的鉴定

目的 对5个结节性硬化症(TSC)家系进行致病变异鉴定,为相关家系的遗传咨询和产前诊断提供依据。方法 选取2020年1月至2021年7月间在中国医学科学院基础医学研究所进行远程遗传咨询的5个无关TSC家系的8例患者为研究对象;抽取患者及其家系成员静脉外周血3～5 mL,应用常规酚/氯仿法提取基因组DNA;通过panel测序(PS)发现候选致病变异,经PCR-Sanger测序验证并联合生物信息学分析对先证者及其家系成员进行TSC1/TSC2致病变异鉴定。结果 5个TSC家系患者均存在TSC1或TSC2的变异,包括3个已报道致病变异和2个新发现的疑似致病变异。2个新变异,TSC2:c.245G>A和TSC2:c.235delG,预测可分别造成无义变异p.(Trp82^*)和移码变异p.(Val79Lysfs27^*),形成提前终止密码子,并经家系共分离和生物信息学分析判定为致病性变异。结论 本研究为相关家庭的遗传咨询和产前诊断提供了依据,进一步拓展了TSC2致病变异谱。     

一个结节性硬化症家系的临床特征及基因突变分析

目的分析一个中国人结节性硬化症家系的临床特征,并探讨其发病的分子机制。方法收集先证者及其家系成员的临床资料,采用全外显子组测序技术对先证者外周血DNA的TSC1和TSC2基因变异进行鉴定。经生物信息学分析后,对发现的潜在致病变异采用Sanger测序法对父母进行验证。结果先证者及其母亲均携带TSC2基因新的c.4183C>T(p.Q1395X)杂合变异,生物信息学分析提示该变异为潜在的致病变异。先证者母亲同样诊断为结节性硬化症,但症状轻于患者。另外4名未患病的家系成员未发现上述突变。结论TSC2基因新的c.4183C>T(p.Q1395X)杂合变异可能是该家系的致病原因。上述发现扩大了TSC2基因的突变谱。先证者症状重于其母亲考虑与表型异质性有关。     

结节性硬化症合并癫痫的手术治疗

目的：探讨结节性硬化症（TSC）合并难治性癫痫的手术适应征和手术方式,并介绍手术效果与经验。方法：回顾性分析行手术治疗的19例TSC合并难治性癫痫患者的临床资料。术前评估包括同步录像脑电图（V—EEG）监测、PET或SPECT检查、MRI和CT检查以及智商测试。本组病例中8例为局灶性癫痫、11例为双侧或多灶性癫痫,其中10例患者进行了皮层电图（ECoG）检查,4例不能而6例可以确定局限性癫痫起源灶。9例患者的IQ低于70分,3例IQ正常,7例有轻度的IQ缺陷。手术行胼胝体切开1例,病灶切除术4例,脑叶切除术5例,病灶切除联合脑叶切除术6例,胼胝体切开联合病灶切除术2例,胼胝体切开、病灶切除联合脑叶切除术1例。结果：预后11例患者达到EngleI级,5例Ⅱ级,3例为Ⅲ～Ⅳ级。不能进行致痫灶确切定位的4例术后仍有癫痫发作,与术前定位明确、术后无发作的患者比较差异有显著意义。性别、癫痫起始年龄和IQ与预后无明显相关性。结论：TSC合并局灶性癫痫患者手术治疗效果良好,是进行外科手术的适应征。手术对于TSC合并多灶性癫痫患者的效果比局灶性癫痫患者的效果差,但仍可能通过颅内电极EEG定位进行手术治疗。病灶切除和脑叶切除是治疗TSC的基本手术方式。     

Regulation of mTOR function in response to hypoxia by REDD1 and the TSC1/TSC2 tumor suppressor complex

Mammalian target of rapamycin (mTOR) is a central regulator of protein synthesis whose activity is modulated by a variety of signals. Energy depletion and hypoxia result in mTOR inhibition. While energy depletion inhibits mTOR through a process involving the activation of AMP-activated protein kinase (AMPK) by LKB1 and subsequent phosphorylation of TSC2, the mechanism of mTOR inhibition by hypoxia is not known. Here we show that mTOR inhibition by hypoxia requires the TSC1/TSC2 tumor suppressor complex and the hypoxia-inducible gene REDD1/RTP801. Disruption of the TSC1/TSC2 complex through loss of TSC1 or TSC2 blocks the effects of hypoxia on mTOR, as measured by changes in the mTOR targets S6K and 4E-BP1, and results in abnormal accumulation of Hypoxia-inducible factor (HIF). In contrast to energy depletion, mTOR inhibition by hypoxia does not require AMPK or LKB1. Down-regulation of mTOR activity by hypoxia requires de novo mRNA synthesis and correlates with increased expression of the hypoxia-inducible REDD1 gene. Disruption of REDD1 abrogates the hypoxia-induced inhibition of mTOR, and REDD1 overexpression is sufficient to down-regulate S6K phosphorylation in a TSC1/TSC2-dependent manner. Inhibition of mTOR function by hypoxia is likely to be important for tumor suppression as TSC2-deficient cells maintain abnormally high levels of cell proliferation under hypoxia.     

The variation of AkT/TSC1-TSC1/mTOR signal pathway in hepatocytes after partial hepatectomy in rats

Objective

The aim of this study was to investigate the role and regulatory mechanisms of Akt/TSC1-TSC2/mTOR signal pathway on the hepatocyte growth and proliferation after partial hepatectomy in rats.

Methods

We used the animal model of 70% hepatectomy, separated and cultivated hepatocytes. According to the different time points after partial hepatectomy, it could be grouped into 0 h, 2 h, 6 h, 24 h and 72 h. According to the different kinds of specific inhibitor in the nutritive medium after the separation of hepatocytes, it could be grouped into Triciribine (TR), Rapamycin (RA) and Control (CO). We investigated ³H-Leucine incorporation into protein, the cross section areas of hepatocytes, and detected cell cycle through FCM. The expressions of phosphorylated protein TSC2 and mTOR were observed.

Results

(1) The content of phosphorylated protein TSC2 in group CO began to increase at 2 h and got to the peak at 6 h but declined at 24 h. The content of phosphorylated protein TSC2 in group RA had the same variation with that of phosphorylated protein TSC2 in group CO. (2) At the time point of 0 h, 2 h, 6 h and 24 h after operation, the incorporation efficiency of ³H-Leucine in groups RA and TR was different from that in group CO in statistics (P < 0.01). (3) It could be seen that the cross section areas of hepatocytes in groups RA and TR were different from that in group CO in statistics at 2 h and 6 h after operation (P < 0.05). (4) Comparing with the other two inhibitor groups (TR and RA), the number of cells during the period of G₀/G₁ in group CO became fewer, while the number of cells during the period of S and G₂/M grew obviously (referring to Fig. 8). After operation, each time point was different from the inhibitor groups obviously (P < 0.05 or P < 0.01). The peak declined greatly at 24 h and 72 h after operation.

Conclusions

These data strongly suggest the effects of Akt/TSC1-TSC2/mTOR signal pathway on hepatocyte growth, protein synthesis and cell cycle, and prove its contribution to liver regeneration.     

MFG-E8的生物学功能及应用

乳脂球表皮生长因子8(milk fat globule EGF factor Ⅷ,MFG-E8)是一种乳汁脂肪小球表面的亲脂性糖蛋白,广泛参与多种细胞间的相互作用,如介导精子与卵子外膜间的结合、维持附睾上皮细胞与精子细胞膜的黏附、参与肠上皮细胞的维持与修复、促进乳腺支化形成和成人组织新生血管形成、增强树突状细胞外泌体功能以及参与吞噬清除凋亡细胞的过程.此外,MFG-E8也显示良好的应用前景,有可能作为潜在的治疗和检测手段.     

Analysis of 65 tuberous sclerosis complex (TSC) patients by TSC2 DGGE, TSC1/TSC2 MLPA, and TSC1 long-range PCR sequencing, and report of 28 novel mutations

Tuberous sclerosis complex (TSC) is a severe autosomal-dominant disorder characterized by the development of benign tumors (hamartomas) in many organs. It can lead to intellectual handicap, epilepsy, autism, and renal or heart failure. An inactivating mutation in either of two tumor-suppressor genes-TSC1 and TSC2-is the cause of this syndrome, with TSC2 mutations accounting for 80-90% of all mutations. Molecular diagnosis of TSC is challenging, since TSC1 and TSC2 consist of 21 and 41 coding exons, respectively, and the mutation spectrum is very heterogeneous. Here we report a new approach for detecting mutations in TSC: a denaturing gradient gel electrophoresis (DGGE) analysis for small TSC2 mutations, a multiplex ligation-dependent probe amplification (MLPA) analysis for large deletions and duplications in TSC1 or TSC2, and a long-range PCR/sequencing-based analysis for small TSC1 mutations. When applied in this order, the three methods provide a new sensitive and time- and cost-efficient strategy for the molecular diagnosis of TSC. We analyzed 65 Danish patients who had been clinically diagnosed with TSC, and identified pathogenic mutations in 51 patients (78%). These included 36 small TSC2 mutations, four large deletions involving TSC2, and 11 small TSC1 mutations. Twenty-eight of the small mutations are novel. For the missense mutations, we established a functional assay to demonstrate that the mutations impair TSC2 protein function. In conclusion, the strategy presented may greatly help small- and medium-sized laboratories in the pre- and postnatal molecular diagnosis of TSC.     

KNSL4基因的结构及生物学功能

驱动蛋白样DNA结合蛋白(kinesinlikeDNAbindingprotein,KNSL4)基因是驱动蛋白(kinesin)基因家族中的成员。KNSL4基因及其蛋白产物Kid的分子结构和在促有丝分裂中影响纺锤体形成、维持纺锤体形态、驱动染色体列队和分离的功能已为大量研究结果所证实;Kid直接作用于cerbB2基因的启动子区域的顺式作用元件,也可能通过相连基因MAZ间接调控cMyc基因的转录,KNSL4基因的表达量与性激素依赖的肿瘤细胞增殖、血管内皮细胞生长因子(VEGF)和肝细胞生长因子(HGF)的促血管生成等成正相关。