Notch3 gene polymorphism and ischaemic cerebrovascular disease

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL): A Diagnosis to Consider in Atypical Stroke Presentations

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a hereditary cerebral arteriopathy caused by a neurogenic locus notch homolog protein 3 (NOTCH3) gene mutation. This article describes the case of a man in his early 40s who experienced sudden onset temporary left-sided weakness and facial numbness that resolved in two hours, along with residual weakness in the upper and lower limbs. There was a family history of CADASIL with both his mother and brother having experienced strokes. Clinical investigations on admission were unremarkable including a young stroke screen and computed tomography (CT) of the brain. On CT angiography, there was no evidence of significant carotid artery stenosis. Subsequent cerebral magnetic resonance imaging (MRI) revealed an acute infarction in the right corona radiata extending into the right basal ganglia, with the fluid-attenuated inversion recovery (FLAIR) images revealing considerable bilateral symmetrical white matter hyperintensity in the frontal, parietal, and anterior temporal lobes. Based on his clinical presentation, strong family history, and brain MRI findings, a diagnosis of CADASIL was suspected. He received antiplatelet medication for an acute stroke and later underwent genetic testing, which revealed the presence of a NOTCH3 gene mutation.

A comprehensive review of stroke-related signaling pathways and treatment in western medicine and traditional Chinese medicine

This review provides insight into the complex network of signaling pathways and mechanisms involved in stroke pathophysiology. It summarizes the historical progress of stroke-related signaling pathways, identifying potential interactions between them and emphasizing that stroke is a complex network disease. Of particular interest are the Hippo signaling pathway and ferroptosis signaling pathway, which remain understudied areas of research, and are therefore a focus of the review. The involvement of multiple signaling pathways, including Sonic Hedgehog (SHH), nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), hypoxia-inducible factor-1α (HIF-1α), PI3K/AKT, JAK/STAT, and AMPK in pathophysiological mechanisms such as oxidative stress and apoptosis, highlights the complexity of stroke. The review also delves into the details of traditional Chinese medicine (TCM) therapies such as Rehmanniae and Astragalus, providing an analysis of the recent status of western medicine in the treatment of stroke and the advantages and disadvantages of TCM and western medicine in stroke treatment. The review proposes that since stroke is a network disease, TCM has the potential and advantages of a multi-target and multi-pathway mechanism of action in the treatment of stroke. Therefore, it is suggested that future research should explore more treasures of TCM and develop new therapies from the perspective of stroke as a network disease.

Association of NOTCH3 Gene Polymorphisms with Ischemic Stroke and its Subtypes: A Meta-Analysis

Background and objectives: NOTCH3 gene variations play a significant role in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, the role of NOTCH3 gene polymorphisms in the risk of ischemic stroke, and its subtypes such as atherothrombotic or lacunar strokes, remains unclear. Aims: Hence, we carried out a meta-analysis to examine whether the NOTCH3 rs1043994, rs1044009 and rs3815188 polymorphisms are associated with ischemic stroke and its major subtypes. Materials and Methods: All relevant studies were systematically screened and meta-analyzed using Review Manager (Revman) version 5.3. The strength of the association between NOTCH3 polymorphisms and ischemic stroke risk and its subtypes were measured as odds ratios and 95% confidence intervals, under different genetic models. Results: A total of ten studies were identified, five of which considered NOTCH3 rs1043994 (2077 cases/2147 controls), five of which considered NOTCH3 rs1044009 (2315 cases/3053 controls), and nine of which considered NOTCH3 rs3815188 (2819 cases/2769 controls). These studies were meta-analyzed for their association with ischemic stroke risk. Four studies (874 cases/2002 controls) of the NOTCH3 rs3815188 polymorphism and three studies of the NOTCH3 rs1043994 (643 cases/1552 controls) polymorphism were meta-analyzed for lacunar stroke risk. Three studies (1013 cases/1972 controls) of the NOTCH3 rs3815188 polymorphism were meta-analyzed for atherothrombotic stroke risk. The meta-analysis results showed a lack of association between all of the studied polymorphisms and the risk of ischemic stroke and its major subtypes (i.e., atherothrombotic and lacunar). Conclusions: NOTCH3 polymorphisms are not significantly associated with the risk of ischemic stroke and its subtypes (p < 0.05).

CADASIL with Atypical Clinical Symptoms, Magnetic Resonance Imaging, and Novel Mutations: Two Case Reports and a Review of the Literature

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary microangiopathy with adult onset caused by a missense mutation in the NOTCH3 gene in chromosome 19p13. It presents with autosomal dominant arteriopathy, subcortical infarctions, and leukoencephalopathy. Its common clinical presentations are seen as recurrent strokes, migraine or migraine-like headaches, progressive dementia, pseudobulbar paralysis, and psychiatric conditions. Two patients with CADASIL syndrome, whose diagnosis was made based on clinical course, age of onset, imaging findings, and genetic assays in the patients and family members, are presented here because of new familial polymorphisms. The first patient, with cerebellar and psychotic findings, had widespread non-confluent hyperintense lesions as well as moderate cerebellar atrophy in cranial magnetic resonance scanning. The other patient, with headache, dizziness, and forgetfulness, had gliotic lesions in both cerebral hemispheres. CADASIL gene studies revealed a new polymorphism in exon 33 in the first patient. In the other patient, the NOTCH3 gene was identified as a new variant of p.H243P (c.728A > C heterozygous). By reporting a family presenting with various clinical symptoms in the presence of new polymorphisms, we emphasize that CADASIL syndrome may present with various clinical courses and should be considered in differential diagnoses.

New insights into mechanisms of small vessel disease stroke from genetics

Cerebral small vessel disease (SVD) is a common cause of lacunar strokes, vascular cognitive impairment (VCI) and vascular dementia. SVD is thought to result in reduced cerebral blood flow, impaired cerebral autoregulation and increased blood–brain barrier (BBB) permeability. However, the molecular mechanisms underlying SVD are incompletely understood. Recent studies in monogenic forms of SVD, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and ‘sporadic’ SVD have shed light on possible disease mechanisms in SVD. Proteomic and biochemical studies in post-mortem monogenic SVD patients, as well as in animal models of monogenic disease have suggested that disease pathways are shared between different types of monogenic disease, often involving the impairment of extracellular matrix (ECM) function. In addition, genetic studies in ‘sporadic’ SVD have also shown that the disease is highly heritable, particularly among young-onset stroke patients, and that common variants in monogenic disease genes may contribute to disease processes in some SVD subtypes. Genetic studies in sporadic lacunar stroke patients have also suggested distinct genetic mechanisms between subtypes of SVD. Genome-wide association studies (GWAS) have also shed light on other potential disease mechanisms that may be shared with other diseases involving the white matter, or with pathways implicated in monogenic disease. This review brings together recent data from studies in monogenic SVD and genetic studies in ‘sporadic’ SVD. It aims to show how these provide new insights into the pathogenesis of SVD, and highlights the possible convergence of disease mechanisms in monogenic and sporadic SVD.

APOE and AGT in the Finnish p.Arg133Cys CADASIL population

BACKGROUND

CADASIL is an inherited systemic small vessel disease, the affected status of brain vessels leading to subcortical vascular dementia. The defective gene is NOTCH3 in which over 230 different pathogenic mutations have been identified. The clinical course of CADASIL is highly variable even within families. Previous studies have shown that additional genetic factors modify the phenotype.

AIMS AND METHODS

Altogether, 134 Finnish CADASIL patients with p.Arg133Cys mutation were analysed for possible associations between the apolipoprotein E (APOE) genotype, angiotensinogen (AGT) p.Met268Thr polymorphism or neutral p.Ala202Ala NOTCH3 polymorphism and earlier first-ever stroke or migraine.

RESULTS

We found no association between the APOE genotypes, AGT polymorphism, NOTCH3 polymorphism and earlier first-ever stroke or migraine.

CONCLUSIONS

The APOE, AGT and NOTCH3 polymorphism did not modify the onset of strokes or migraine in our CADASIL sample, which is one of the largest mutationally homogenous CADASIL populations published to date. International collaboration, pooled analyses and genomewide approaches are warranted to identify the genetic factors that modify the highly variable CADASIL phenotype.

Association of Notch3 single-nucleotide polymorphisms and lacunar infarctions in patients

Cerebrovascular disease is a leading cause of morbidity and mortality worldwide, which is influenced by genetic and environmental factors. The aim of the present study was to examine the association between single-nucleotide polymorphisms (SNPs) in Notch3 exons 3–6 and lacunar infarction by comparing SNPs between control subjects and those with lacunar infarction. A single-center case-control study was conducted to investigate the association between Notch3 SNPs and risk of stroke. A total of 140 patients were included in the study, 30 of whom had no infarction (control) and 110 had lacunar infarction. Lacunar patients were divided into the ‘pure lacunar’ and ‘lacunar + leukoarasis’ groups based on brain imaging. All the patients were of Chinese Han ethnicity, and the male to female ratio was 84:56. Patient clinical histories included hypertension, diabetes mellitus (DM), hyperlipidemia, and heart disease were recorded. The Notch3 sequence was obtained from the National Centser for Biotechnology Information database. Notch3 was amplified by polymerase chain reaction from whole blood samples, and exons 3–6 were sequenced to identify SNPs. The result showed that there was no significant difference in the prevalence of hypertension, DM, hyperlipidemia, and heart disease between the control and lacunar infarction patients. Notabley, the age of the lacunar + leukoarasis patients was significantly higher than that of the control and pure lacunar patients (P<0.05). Eight SNPs were detected at low frequencies, and only rs3815388 and rs1043994 exhibited slightly higher frequencies. A χ² test indicated that Notch3 SNPs, particularly rs1043994, were associated with lacunar infarction (P<0.05). In conclusion, the result of the present study have shown that Notch3 SNPs, particularly rs1043994, are associated with lacunar infarction.

Molecular characterization and expression analysis of mouse epidermal growth factor-like domain 8

Epidermal growth factor (EGF)-like (EGFL) domain, a common structural module in numerous secreted or transmembrane proteins, is generally involved in protein-protein interactions. To date, several EGFL proteins have been identified and characterized, but little is known about EGFL domain 8 (EGFL8). The present study reported the molecular characterization and expression analysis of EGFL8 in mice. Mouse EGFL8 amplified using a reverse transcription-polymerase chain reaction approach was sequenced and characterized. Mouse EGFL8 encodes a protein of 293 amino acids with two EGFL domains, an Emilin-like domain and a Ca(2+)-binding EGFL domain, which has a molecular mass of 32 kDa. The coding sequence has a high degree of amino acid sequence identity across species, and the EGFL domain has been highly conserved in various species during evolutionary radiation. A phylogenetic tree calculated using the neighbor-joining method revealed that EGFL8 and EGFL7 are more closely associated with each other than either is to EGFL3, and they cluster with EGFL6. It was found that mouse EGFL8 protein was highly expressed in diverse mouse tissue types, including the thymus, lymph nodes, testis, ovaries, epididymis, ductus deferens, ileum, colon, stomach, esophagus, lung, uterus, urinary bladder, skin, spleen, adrenal glands and penis. These results are of great use in understanding the biological roles of mouse EGFL8 for further study.

Association of gene polymorphism with genetic susceptibility to stroke in Asian populations: a meta-analysis

Stroke is a heterogeneous multifactorial disease and is thought to have a polygenic basis. Case-control studies on gene sequence variations have identified a number of potential genetic predisposition factors, but due to the conflicting results, uncertainty remains on the effect of these polymorphisms on risk for the development of stroke. To qualitatively and quantitatively assess the risk associated with different gene polymorphisms for stroke in Asian populations, we comprehensively searched and identified all the studies of association. Clinically overt case-control studies were selected only if neuroimaging had been used as the confirmatory measure for diagnosis of stroke. We performed a meta-analysis of the three most investigated genes, viz., methylenetetrahydrofolate reductase (MTHFR), apolipoprotein E (ApoE) and angiotensin-converting enzyme (ACE). Statistically significant association with stroke were identified for C677T polymorphism of MTHFR [random effects odds ratio (OR) = 1.47, 95% confidence interval (95% CI) 1.19, 1.82; P = 0.0004] and marginally significant association was detected with allele epsilon 4 of ApoE (random effects OR = 1.47, 95% CI 1.00, 2.15; P = 0.049). The sensitivity analysis (exclusion of studies with controls not in Hardy-Weinberg equilibrium) revealed a significant association of stroke with the MTHFR C677T and ApoE epsilon 4 alleles but showed no association with ACE gene insertion/deletion polymorphism.

Investigating the Association Between Notch3 Polymorphism and Migraine

OBJECTIVE

The aim of the present study was to evaluate whether the functional Notch3 polymorphism T6746C, which is not causative for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), might be a risk factor for migraine.

BACKGROUND

It has been recently demonstrated that migraine is characterized by subclinical brain infarctions and white matter lesions. Several genetic risk factors have been associated with migraine, but no study has unraveled a possible relationship between migraine and Notch3, which is involved in vascular damage. Mutations in Notch3 gene have been demonstrated to be pathogenetic for CADASIL, a small vessel disease of the brain characterized by migraine.

METHODS

A total of 156 migraine patients and 128 nonheadache healthy volunteers entered the study. Demographic and clinical characteristics were carefully recorded, and a neurological work-up was performed. Moreover, each subject underwent a blood sampling for Notch3 genotype determination.

RESULTS

Notch3 genotypes as well as allele frequencies did not differ in migraine patients compared to controls, even adjusting for the presence of possible confounds. No difference has been found either in migraine patients with aura or in those without aura.

CONCLUSIONS

These findings support the view that functional polymorphism T6746C in Notch3 gene is not involved in increasing the risk of migraine or migraine subtypes.

Preliminary array analysis reveals novel genes regulated by ovarian steroids in the monkey raphe region

We hypothesize that ovarian hormones may improve serotonin neuron survival. We sought the effect of estradiol (E) and progesterone (P) on novel gene expression in the macaque dorsal raphe region with Affymetrix array analysis. Nine spayed rhesus macaques were treated with either placebo, E or E+P via Silastic implant for 1 month prior to euthanasia (n=3 per treatment). RNA was extracted from a small block of midbrain containing the dorsal raphe and examined on an Agilent Bioanalyzer. The RNA from each monkey was labeled and hybridized to an Affymetrix HG_U95AV Human GeneChip Array. After filtering and sorting, 25 named genes remained that were regulated by E, and 24 named genes remained that were regulated by supplemental P. These genes further sorted into functional categories that would promote neuronal plasticity, transmitter synthesis, and trafficking, as well as reduce apoptosis. The relative abundance of four pivotal genes was examined in all nine animals with quantitative RT-PCR and normalized by glyceraldehyde 3-phosphate dehydrogenase (GAPDH). E+/-P caused a significant threefold reduction in JNK-1 (a pro-apoptosis gene, p<0.007); and a significant sixfold decrease in kynurenine mono-oxygenase (produces neurotoxic quinolones, p<0.05). GABA-A receptor (alpha3 subunit; benzodiazepine site) and E2F1 (interferes with cytokine signaling) were unaffected by E, but increased sevenfold (p<0.02) and fourfold (p<0.009), respectively, upon treatment with P. In summary, subsets of genes related to tissue remodeling or apoptosis were up- or down-regulated by E and P in a tissue block containing the dorsal raphe. These changes could promote cellular resilience in the region where serotonin neurons originate.

High throughput multiple combination extraction from large scale polymorphism data by exact tree method

Single nucleotide polymorphisms (SNPs) are increasingly becoming important in clinical settings as useful genetic markers. For the evaluation of genetic risk factors of multifactorial diseases, it is not sufficient to focus on individual SNPs. It is preferable to evaluate combinations of multiple markers, because it allows us to examine the interactions between multiple factors. If all the combinations possible were evaluated round-robin, the number of calculations would rapidly explode as the number of markers analyzed increased. To overcome this limitation, we devised the exact tree method based on decision tree analysis and applied it to 14 SNP data from 68 Japanese stroke patients and 189 healthy controls. From the obtained tree models, we succeeded in extracting multiple statistically significant combinations that elevate the risk of stroke. From this result, we inferred that this method would work more efficiently in the whole genome study, which handles thousands of genetic markers. This exploratory data mining method will facilitate the extraction of combinations from large-scale genetic data and provide a good foothold for further verificatory research.

Perioperative management of a CADASIL type arteriopathy patient

We report the anaesthetic management of a patient suffering from an ischaemic arteriopathy of the CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy) type. The anaesthetic implications of this pathology are discussed. By analogy with other cerebral arteriopathies, the aim of our management was to keep mean arterial blood pressure and end-tidal carbon dioxide so as to prevent any cerebral ischaemic or vasospastic phenomenon. We preserved the cerebral venous return by avoiding excessive head-down position. We used a balanced anaesthetic technique because it allows easier titration of the depth of anaesthesia with regard to mean arterial pressure. There is no contraindication to the use of loco-regional anaesthesia.

Yield of screening for CADASIL mutations in lacunar stroke and leukoaraiosis

BACKGROUND AND PURPOSE

Cerebral autosomal dominant arteriopathy subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic disorder typified by early onset lacunar strokes, subcortical dementia, psychiatric disturbances, and migraine. Mutations in the Notch3 gene are responsible. Atypical phenotypes have been recognized, and the disease is probably underdiagnosed in the wider stroke population. Therefore, we determined the yield of screening for Notch3 mutations in lacunar stroke with or without leukoaraiosis.

METHODS

Two hundred eighteen consecutive patients were studied. All had brain and carotid imaging. Polymerase chain reaction-single-stranded conformational polymorphism analysis was used to screen exons 3, 4, 5, and 6 of the Notch3 gene for mutations and polymorphisms.

RESULTS

A single mutation in exon 4 (C697T) was identified in a young patient, giving an overall carrier frequency of 0.05% (95% CI, 0.0 to 2.0). For patients with onset of lacunar stroke at < or =65 years and leukoaraiosis, the yield was 2.0% (95% CI, 0.4 to 10.9).

CONCLUSIONS

Notch3 mutations are rare in patients with typical strokes due to cerebral small-vessel disease. In the absence of classic features suggestive of CADASIL, screening for Notch3 mutations has a low yield.