P-选择素、溶酶体蛋白与缺血性脑卒中

血小板在止血和血栓形成过程中发挥极其重要的病理生理作用,血小板与血管内皮的相互作用目前认为是形成血栓的重要因素,其中活化血小板起着关键作用体内处于静止状态的血小板受各种因子的作用被激活后,原来存在于静息血小板胞浆内的P-选择素（CD62p）迅速与血小板质膜融合转移至膜表面,同时血小板内的溶酶体蛋白（CD63）也在血小板活化时表达在血小板膜表面。因此,此2种蛋白已成为识别活化血小板的分子标志物。现对血小板膜表面的CD62p、CD63表达与缺血性脑卒中的关系及其作用综述如下。     

急性缺血性脑卒中患者血小板膜糖蛋白的表达水平与临床伤残严重程度的相关性及其临床意义

目的 分析急性缺血性脑卒中患者血小板膜糖蛋白的表达水平与临床伤残严重程度的相关性及其临床意义。方法 选取本院神经内科2018年1月-2019年3月收治的120例急性缺血性脑卒中患者为研究对象,将其设定为观察组。另选取60例健康者为对照组,通过流式细胞术检测方法来检测2组研究对象的血小板膜糖蛋白CD31、CD62p、CD63以及PAC-1的表达水平,分析其与临床伤残严重程度的相关性。结果 观察组患者的血小板膜糖蛋白CD31、CD62p、CD63、PAC-1表达水平均高于对照组(P<0.05); 观察组患者血小板膜糖蛋白CD62p与PAC-1表达水平和临床伤残严重程度评分呈正相关(Pearson相关系数分别为0.178和0.241,P<0.05); CD31、CD62p和CD63的表达水平与不同神经功能缺损程度有关,其中中度和重度急性缺血性脑卒中患者的CD31、CD62p与CD63表达水平高于轻型患者(P<0.05)。结论 在急性缺血性脑卒中患者体内血小板的活化程度较健康者来说明显升高,血小板膜糖蛋白CD62p与PAC-1的表达水平对临床伤残程度有显著影响,可作为反映急性缺血性脑卒中患者病情变化和预测康复效果的指标。     

氯吡格雷联合奥扎格雷钠治疗急性缺血性卒中疗效评价

研究背景抗血小板治疗已经成为缺血性卒中的常规治疗方法,目前对其作用的肯定主要源于临床应用,迄今尚无一项能够准确评价其有效性的实验室指标。有研究证实,血小板活化程度与动脉粥样硬化和缺血性卒中相关,尤其是血小板α颗粒膜糖蛋白CD62p和溶酶体膜糖蛋白CD63均为血小板活化的重要指标。本研究旨在通过观察急性缺血性卒中患者血小板膜表面CD62p和CD63表达变化,探讨以血小板活化程度反映氯吡格雷(75 mg)、奥扎格雷钠(80 mg)与阿司匹林(0.15 g)的疗效差异。方法采用流式细胞术检测急性缺血性卒中患者氯吡格雷(75 mg)联合奥扎格雷钠(80 mg,联合治疗组)及阿司匹林单药(阿司匹林组)治疗前后血小板CD62p和CD63阳性表达率,美国国立卫生研究院卒中量表(NIHSS)评价神经功能改善程度。结果与正常对照组相比,治疗前急性缺血性卒中组患者血小板CD62p和CD63阳性表达率升高(P=0.001,0.032);治疗后CD62p和CD63阳性表达率、NIHSS评分逐步下降(均P=0.000)。与治疗前相比,治疗后联合治疗组和阿司匹林组患者血小板CD62p和CD63阳性表达率、NIHSS评分逐步下降(均P=0.000),但组间差异无统计学意义(均P>0.05)。CD62p和CD63阳性表达率在不同观察时间点与治疗分组之间不存在交互作用(F=1.403,P=0.250;F=2.830,P=0.063),但NIHSS评分在不同观察时间点与治疗分组之间存在交互作用(F=4.518,P=0.013)。结论抗血小板药物治疗急性缺血性卒中有效,但氯吡格雷与奥扎格雷钠联合治疗之疗效与阿司匹林单药治疗并无差异。缺血性卒中急性期测定血小板CD62p阳性表达率可以用于评价抗血小板药物的疗效,但CD63表达的临床价值尚待进一步研究。     

选择素与缺血性脑卒中

选择素属于细胞间黏附分子家族，包括P-选择素（CD62P）、E-选择素（CD62E）、L-选择素（CD62L）三个成员。选择素家族始动了白细胞血小板和内皮细胞间的相互作用，参与了血栓形成和炎症反应，在缺血性脑卒中的早期阶段发挥了重要作用。文章对选择素的结构、分布及在缺血性脑卒中中的作用和机制作了简要介绍。     

脑出血患者血小板CD42b、CD62p的表达及临床意义

目的研究脑出血急性期血小板表面糖蛋白CD42b、CD62p的表达及其与血肿周围脑水肿形成的关系。方法20例中等量脑出血患者,利用流式细胞仪(FCM)测定其血小板CD42b和CD62p的表达,并根据头颅CT测量血肿周围脑水肿带的大小,对两者进行相关性分析。结果与正常健康人比较,脑出血急性期血小板CD42b的表达减少,CD62p的表达增加;血小板CD42b、CD62p表达量与血肿周围脑水肿带的大小有相关性(rCD42b=-0.489,P<0.05;rCD62p=0.646,P<0.01)。结论脑出血急性期血小板活化,活化的血小板可能参与了血肿周围脑水肿形成这一病理损伤过程。     

氯吡格雷联合奥扎格雷钠对急性缺血性卒中患者血小板CD62p、CD63的影响

目的评价氯吡格雷联合奥扎格雷钠治疗急性缺血性卒中的疗效。方法选取我院神经内科于2012-08—2013-08收治的120例急性缺血性卒中患者为研究对象,随机分为观察组与对照组。观察组60例给予氯吡格雷联合奥扎格雷钠治疗,对照组60例给予阿司匹林治疗。治疗结束后对比2组患者血小板CD62p、CD63表达情况、NIHSS评分及疗效。结果2组患者治疗前后的CD62p、CD63表达阳性率及NIHSS评分均无显著差异(P0.05)。观察组治疗总有效率95.00%,对照组96.67%,2组比较差异无统计学意义(P0.05)。结论抗血小板药物治疗急性缺血性卒中疗效肯定,且与阿司匹林疗效无差异,CD62p、CD63蛋白可以有效反映血小板活化情况。     

糖尿病性腔隙性脑梗死患者细胞黏附分子表达的观察

目的 :探讨血糖对黏附分子的影响及其在LI发病机制中的作用。方法 :采用流式细胞术对LI合并Ⅱ型糖尿病及非糖尿病LI病人外周血白细胞的膜糖蛋白CD11b、CD18和血小板膜糖蛋白CD62p的表达进行检测。结果 :两组病人比较血小板膜糖蛋白CD62p、白细胞膜糖蛋白CD11b、CD18表达在腔隙性脑梗死合并糖尿病组明显高于非糖尿病腔隙性脑梗死组 ;血糖与CD62p、CD11b呈正相关 ;CD62p、CD11b、CD18及血糖与LI腔梗个数无关。结论 :超负荷血糖时血小板、白细胞均处于高活化状态。超负荷血糖导致的细胞黏附分子的高表达参与LI微血管病变的损伤过程。     

血小板活化指标与短暂性脑缺血发作的转归

目的探讨短暂性脑缺血发作(TIA)患者疾病转归与血小板活化指标α颗粒膜糖蛋白(CD62p)、溶酶体颗粒膜糖蛋白(CD63)、血小板膜表面糖蛋白(CD41)的关系.方法57例TIA患者随访2个月,分别在服药后1 d、1周、1个月和2个月时采用流式细胞仪检测血小板CD62p、CD63和CD41表达的百分率,同时监测病情发展趋向.结果TIA缓解组、TIA反复发作组与TIA进展为脑梗死组的血小板CD62p、CD63、CD41阳性百分率逐级升高(P＜0.05～＜0.001),尤其以进展为脑梗死组指标升高最为明显(P＜0.01～0.001).结论血小板活化CD62p,CD63及CD41可作为TIA发展演变的估测指标.     

TIA患者血小板活化功能的变化及奥扎格雷对其影响

目的 探讨TIA患者血小板活化功能的变化及奥扎格雷对其影响.方法 应用流式细胞仪和单克隆抗体技术测定丹参治疗组和奥扎格雷治疗组不同时段的颗粒膜蛋白140(CD62p)、溶酶体整合膜糖蛋白(CD63)值.结果 TIA患者血小板表达CD62p、CD63明显增高,经奥扎格雷治疗后CD62p、CD63快速下降,较丹参治疗组有显著差异(P<0.01).结论 血小板表达CD62p、CD63在TIA患者中明显增强,并与病情转归相关;奥扎格雷干预治疗可使CD62p、CD63快速下降,提高治疗的有效率.     

奥扎格雷对进展性脑血栓形成患者血小板活化功能变化的影响

目的：探讨奥扎格雷对进展性脑血栓形成患者血小板活化功能变化的影响。方法：68例颈内动脉系统进展性脑血栓形成患者随机分为奥扎格雷治疗组和丹参治疗组。应用流式细胞仪和单克隆抗体动态测定CD62p、CD63，行血小板活化指标和临床疗效对照观察。结果：进展性脑血栓形成患者发病早期（24h内）CD62p、CD63值较对照组显著增高（P〈0．001）。患者经丹参治疗后，血小板表达CD62p、CD63缓慢下降，14d时其值仍高于健康对照组（P〈0．05）。经奥扎格雷治疗后血小板表达CD62p、CD63快速下降，至14d时已接近健康对照组（P〉0．05）。奥扎格雷组临床疗效明显优于丹参组。结论：进展性脑血栓形成患者中血小板表达CD62p、CD63明显增加，并与病情转归相关。奥扎格雷治疗后可使CD62p、CD63快速下降、提高临床疗效。     

Environmental factors in the development and progression of late-onset Alzheimer＇s disease

Late-onset Alzheimer＇s disease （LOAD） is an age-related neurodegenerative disorder characterized by gradual loss of synapses and neurons, but its pathogenesis remains to be clarified. Neurons live in an environment constituted by neurons themselves and glial cells. In this review, we propose that the neuronal degeneration in the AD brain is partially caused by diverse environmental factors. We first discuss various environmental stresses and the corresponding responses at different levels. Then we propose some mechanisms underlying the specific pathological changes, in particular, hypothalamic-pituitary adrenal axis dysfunction at the systemic level; cerebrovascular dysfunction, metal toxicity, glial activation, and Aβ toxicity at the intercellular level; and kinase-phosphatase imbalance and epigenetic modification at the intracellular level. Finally, we discuss the possibility of developing new strategies for the prevention and treatment of LOAD from the perspective of environmental stress. We conclude that environmental factors play a significant role in the development of LOAD through multiple pathological mechanisms.     

Disrupted structural and functional brain connectomes in mild cognitive impairment and Alzheimer＇s disease

Alzheimer＇s disease （AD） is the most common type of dementia, comprising an estimated 60-80% of all dementia cases. It is clinically characterized by impairments of memory and other cognitive functions. Previous studies have demonstrated that these impairments are associated with abnormal structural and functional connections among brain regions, leading to a disconnection concept of AD. With the advent of a combination of non-invasive neuroimaging （structural magnetic resonance imaging （MRI）, diffusion MRI, and functional MRI） and neurophysiological techniques （electroencephalography and magnetoencephaJography） with graph theoretical analysis, recent studies have shown that patients with AD and mild cognitive impairment （MCI）, the prodromal stage of AD, exhibit disrupted topological organization in large-scale brain networks （i.e., connectomics） and that this disruption is significantly correlated with the decline of cognitive functions. In this review, we summarize the recent progress of brain connectomics in AD and MCI, focusing on the changes in the topological organization of large-scale structural and functional brain networks using graph theoretical approaches. Based on the two different perspectives of information segregation and integration, the literature reviewed here suggests that AD and MCI are associated with disrupted segregation and integration in brain networks. Thus, these connectomics studies open up a new window for understanding the pathophysiological mechanisms of AD and demonstrate the potential to uncover imaging biomarkers for clinical diagnosis and treatment evaluation for this disease.     

ACA与缺血性脑卒中的相关性研究

炎症和免疫反应在卒中生物标志物的认证、动脉粥样硬化和缺血性脑损伤中的作用显得越来越重要,直接影响到疾病的发展、转归、预后.抗心磷脂抗体(ACA)与免疫性缺血性脑血管内皮细胞损伤、动脉硬化、C—反应蛋白(CRP)等因子密切相关[1].抗心磷脂抗体(anti- cardiolipin antibodies,ACA)是一种自身抗体,是抗磷脂抗体的主要成分,是一组能与负性或中性磷脂特异性结合的多克隆免疫球蛋白,它与许多免疫介导的血栓性疾病密切相关.近年来研究发现,ACA与急性脑梗死(acute cerebral infarction,ACI)关系密切,是ACI的一个重要的独立危险因素[1-2].自身免疫性疾病、病毒感染、其他疾病,如支原体感染、血栓性疾病等可损伤机体细胞,暴露细胞膜上的磷脂成分,刺激机体产生ACA[3].     

青年与中老年脑梗死TOAST分型及危险因素的对照研究

目的 比较青年与中老年脑梗死TOAST分型及各亚型危险因素的异同点,为不同年龄脑梗死的防治提供依据.方法 对64例青年脑梗死及75例中老年脑梗死的TOAST分型及各亚型的危险因素进行回顾性分析.结果 青年组TOAST分型构成比从高到低依次为:LAA型43.8％(28/64)、OD型25.0％(16/64)、SAO型15.6％(10/64)、UD型12.5％(8/64)、CE型3.1％(2/64);而中老年组TOAST分型构成比以高到低依次为:LAA型44.0％(33/75)、SAO型30.7％(23/75)、UD型13.3％(10/75)、CE型8.0％(6/75)、OD型4.0％(3/75).青年组与中老年组小动脉闭塞型患者危险因素暴露率差异无统计学意义(P＞0.05);青年组与中老年组大动脉粥样硬化型患者糖尿病的暴露率差异有统计学意义(P＜0.05).青年组与中老年组UD型和OD型的危险因素差异明显.结论 青年与中老年脑梗死TOAST分型构成比不同,但本研究中均以LAA型为最常见类型.不同亚型暴露的危险因素有所不同,应针对不同亚型的特点采取相应的防治措施.     

50例脑动脉重度狭窄（闭塞）分布及相关危险因素分析

目的研究脑动脉重度狭窄（闭塞）的血管分布及其相关危险因素,为缺血性脑卒中的发病机制、临床诊断、治疗以及预防提供重要依据。方法通过对50例DSA和（或）CTA诊断为脑动脉重度狭窄（或闭塞）的缺血性脑卒中患者计算其重度狭窄或闭塞动脉数目及其分布,同时测血压、血糖（GLU）、尿酸（UA）、甘油三酯（TC）、总胆固醇（TG）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）、极低密度脂蛋白（VLDL-C）、外周血白细胞数（WBC）、血小板数（PLT）、血小板分布宽度（PDW）、平均血小板体积（MPV）、大血小板比率（P—LCR）及纤维蛋白原（FIB）,与无脑动脉狭窄纽比较以上相关因素的差异。结果颅内动脉重度狭窄率（84．6％）明显高于颅外动脉（15．4％）,比较脑动脉存在重度狭窄与无狭窄的两组缺血性脑卒中患者,其舒张压、UA、TC、LDL-C、VLDL-C、WBC、PLT、PDW、MPV、P—LCR差异均无统计学意义（P〉0．05）,而收缩压、FIB、GLU、TG、HDL-C、年龄因素差异有统计学意义（P〈0．05或P〈0．01）,Logistic回归发现高血压、糖尿病与缺血性脑卒中脑动脉重度狭窄呈明显相关性（P〈0．05）。结论缺血性脑卒中患者颅内动脉重度狭窄发生率高于颅外动脉,HDL-C水平与脑动脉狭窄呈负相关,高血压、糖尿病与脑动脉重度狭窄有关,而高血压是脑动脉重度狭窄的独立危险因素。     

DWI与TIA预后关系的研究进展

磁共振弥散加权成像(diffusion weight imaging,DWI)对急性脑缺血病变的检测较传统头部磁共振(Magnetic resonance imaging,MRI)检查敏感性更高.国外研究发现21％～67％传统定义下的短暂性脑缺血发作(transient ischemic attack,TIA)患者可见MRI- DWI异常[1],因此MRI- DWI的异常与否对判断TIA的短期预后有重要价值.而这方面的综述报道较少,我们将近年国内外这方面的研究进展综述如下.     

脑血管反应性与缺血性卒中

目的观察缺血性卒中患者脑血管反应性（CVR）变化,确定两者之间的相关性。方法采用经颅多普勒超声（TCD）结合屏气试验检测76例缺血性卒中患者及62例对照病例的屏气指数（BHI）。结果缺血性卒中患者组的BHI明显低于对照组（P〈0.001）,Logistic 回归显示,由BHI所表示的CVR是缺血性卒中的独立影响因素（P=0.000）。结论降低的CVR是缺血性脑卒中的独立危险因素,应该重视CVR在脑缺血发生、发展过程中的独立影响作用。     

短暂性脑缺血发作患者颈动脉粥样硬化斑块与血浆胆红素、尿酸的关系

目的 探讨短暂性脑缺血发作(TIA)患者颈动脉粥样硬化与血清胆红素和尿酸的关系.方法 对156例TIA患者行彩色多普勒超声检测观察颈动脉有无粥样硬化斑块,根据结果分成斑块组和无斑块组,比较两组间血清胆红素和尿酸水平的差异.结果 有斑块组血清总胆红素水平、间接胆红素水平均明显低于无斑块组(P＜0.001),有斑块组血尿酸水平显著高于无斑块组,差异有显著性(P＜0.05).Logistic多元回归分析发现,血清胆红素、尿酸均为TlA患者颈动脉粥样硬化的独立危险因素.结论 在TIA患者颈动脉粥样硬化的发生发展中,血清胆红素、尿酸起了非常重要的作用.     

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.     

Total saponins of Panax ginseng effects on proliferation and differentiation of human embryonic neural stem cells and in a Parkinson’s disease mouse model

BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells （NSCs） proliferation and differentiation into dopaminergic neurons using in vitro studies, and to observe NSC differentiation in a mouse model of Parkinson＇s disease, as well as behavioral changes before and after transplantation. DESIGN, TIME AND SETTING： In vitro neural cell biology trial and in vivo randomized, controlled animal trial were performed at the Institute of Basic Medical Sciences, Chongqing Medical University between September 2004 and December 2007. MATERIALS： TSPG （purity 〉 95%） was isolated, extracted, and identified by Chongqing Academy of Chinese Materia Medica. Recombinant human basic fibroblast growth factor （bFGF） and recombinant human epidermal growth factor （EGF） were purchased from PeproTech, USA. A total of 25 C57/BL6J mice, aged 18-20 weeks were included. Twenty were used to establish a Parkinson＇s disease model with i.p. injection of MPTP （1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine） and TSPG alone or combined with interleukin-1 （IL-1）-treated NSCs prior to transplantation into the corpus striatum. The remaining five mice were pretreated for 3 days with TSPG prior to MPTP injection, serving as the TSPG prevention group. METHODS： Primary NSCs were isolated, cultured and purified from embryonic cerebral cortex. Immunocytochemistry was employed to detect specific antigen expression in the NSCs. In vitro experiment： （1） to induce proliferation, NSCs were treated with TSPG, EGF＋bFGF, or TSPG＋EGF＋bFGF, respectively; （2） to induce dopaminergic neuronal differentiation, NSCs were treated with TSPG, IL-1, or TSPG＋IL-1, respectively. MAIN OUTCOME MEASURES： In vitro experiment： the effects of TSPG on NSCs proliferation were evaluated with flow cytometry and MTT assay. Tyrosine hydroxylase expression was determined by immunocytochemistry assay to observe effects of TSPG on dopaminergic neuronal differentiation. In vivo experiment： differentiation of grafted NSCs in the mouse brain was determined by immunohistochemical staining. Behavioral changes were evaluated by spontaneous activity frequency, memory function, and score of paralysis agitans. RESULTS： （1） NSCs were cultured and passaged for more than three passages. Immunocytochemistry revealed positive nestin staining, as well as neurofilament protein and glial fibrillary acidic protein. （2） TSPG significantly increased NSC proliferation, in particular when combined with EGF and bFGF, which was twice as effective as FGF or bFGF alone. TSPG also induced dopaminergic differentiation in NSCs, in particular when TSPG was added together with IL-1, resulting in an effect five times greater than that of IL-1 alone. （3） At day 30 following transplantation, most NSCs in the TSPG prevention group differentiated into dopaminergic neurons, and the scores of paralysis agitans, spontaneous activity, and memory function were significantly increased compared with TSPG alone or TSPG＋IL-1 groups （P 〈 0.05）. CONCLUSION： TSPG stimulated NSC proliferation, in particular when combined with FGF and bFGF. TSPG significantly induced dopaminergic neuronal differentiation of NSCs, and the effect was greater when combined with IL-1. In addition, TSPG greatly improved behavior in the Parkinson＇s disease mouse model following NSC transplantation. Following NSC transplantation, TSPG pretreatment exhibited superior efficacy over either TSPG alone or TSPG in combination with IL-1, in terms of behavioral improvements in the Parkinson＇s disease mouse model.