APOE4 and Confluent White Matter Hyperintensities Have a Synergistic Effect on Episodic Memory Impairment in Prodromal Dementia.

BACKGROUND: White matter hyperintensities (WMH) are a known risk factor for cognitive decline. While the ɛ4 allele of apolipoprotein E gene (APOE4) is another risk factor for cognitive decline, it remains unclear how APOE4 affects the relationship between WMH and cognitive decline, specifically in the prodromal stage of dementia. OBJECTIVE: To determine how APOE4 moderates the relationship between WMH and cognition in prodromal dementia. METHODS: Two-hundred-sixteen participants with prodromal dementia underwent magnetic resonance imaging (MRI), neuropsychological testing (global and domain wise), cardiovascular risk factor assessments, and APOE genotyping. Visual ratings for WMH as well as total and lobar WMH volumes were quantified. Moderation analysis was performed to determine the influence of APOE4 on the relationship between WMH and performance on global and domain-specific cognitive measures. The role of confluent and non-confluent WMH on cognition was additionally studied using logistic regression. RESULTS: APOE4 carriers (n = 49) had poorer memory and higher global WMH (10.01 mL versus 6.23 mL, p = 0.04), temporal WMH (1.17 mL versus 0.58 mL, p = 0.01), and occipital WMH (0.38mL versus 0.22 mL, p = 0.02) compared to APOE4 non-carriers (n = 167). Moderation analysis revealed that APOE4 positivity strengthened the relationship between higher global as well as lobar WMH burden and poorer episodic memory. Furthermore, APOE4 carriers with confluent WMH were 4.81 times more likely to have impaired episodic memory compared to non-confluent WMH and non-APOE carriers. CONCLUSION: The impact of WMH on memory may be strongest among APOE4 carriers. Clinicians targeting WMH would need to consider the APOE4 allele and WMH severity status to strategize cognitive interventions.

Association of Genetic Variation in a Wnt Signaling Pathway Gene (ß-Catenin) with Susceptibility to Leukoaraiosis.

Aim: Blood-brain barrier (BBB) disruption is the primary initiating cause of cerebral small-vessel diseases including leukoaraiosis (LA). ß-Catenin is a key regulator of the BBB and plays an important role in cell-cell adhesion at adherens junctions by interacting with cadherin molecules. Thus, ß-Catenin may be a good candidate gene for LA. We performed a genetic analyses to investigate the association between ß-catenin alleles and LA. Materials and Methods: A total of 339 LA cases and 203 controls were enrolled from individuals who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of ß-catenin single nucleotide polymorphisms (SNPs), including rs1880481 C > A, rs13072632 C > T, and rs4135385 A > G, was performed by real-time polymerase chain reaction using a LightCycler 2.0. Results: Two SNPs, rs1880481 and rs4135385, showed significant differences in their allelic frequencies between the control and LA groups and the combinatorial effects of the risk alleles for these two SNPs also significantly increased the risk of LA. The G-T-A, A-T-A, and A-T-G haplotypes for the three SNPs showed significant differences in both types of LA: LA-periventricular white matter and LA-deep white matter. However, the C-T-G haplotype was only significantly different for LA-PVWM, while the A-C-A was only significantly different for LA-DWM. The combination of diabetes mellitis, hypertension, and these risk alleles increased the likelihood of both types of LA. Conclusion: This study provides evidence that ß-catenin polymorphisms and their associated haplotypes are associated with susceptibility to LA.

A Novel COL4A2 Mutation Associated with Recurrent Strokes.

Mutations in type four collagens, specifically COL4A1 and COL4A2, have been associated with cerebral small vessel disease (SVD), defined as lacunar infarcts, deep intracerebral hemorrhages (ICH), and leukoaraiosis. We present a case of a man with recurrent cerebral infarcts, related to a novel COL4A2 mutation, the p.A1534S variant. Magnetic resonance imaging demonstrated multiple lacunar infarcts, numerous deep and lobar microhemorrhages and advanced leukoaraiosis. Evaluation for COL4A2 mutations should be considered when suspecting a genetic cerebral small vessel disease.

COL4A1 Mutation as a Cause of Familial Recurrent Intracerebral Hemorrhage.

The COL4A1 mutation is a very rare monogenic cause of small vessel disease related to recurrent intracerebral hemorrhage. We report a family in which the index case presented with two intracerebral hemorrhages in the basal ganglia with severe periventricular leukoaraiosis and a cataract and vascular tortuosity in the ophthalmological study. His twin brother also had severe leukoaraiosis and multiple subcortical microhemorrhages as well as a congenital cataract and vascular tortuosity in the retina. The older sister had a porencephalic cyst and involvement of the periventricular white matter and intracerebral hemorrhage. In single-gene testing, all three were found to have the same COL4A1 mutation. Intracerebral subcortical hemorrhages or microhemorrhages and severe subcortical leukoaraiosis in familial cases may be related to COL4 mutations.

Correlates of telomere length shortening in peripheral leukocytes of HIV-infected individuals and association with leukoaraiosis.

Telomere length (TL) is a marker of cellular and biological aging. Human immunodeficiency virus (HIV) infection has been reported to be associated with short TLs, which suggests that accelerated biological aging occurs in some cellular compartments of HIV+ individuals. In this study, we measured the TLs of peripheral leukocytes of HIV+ and healthy individuals and examined the biological and environmental correlates of TL. We also investigated the influence of TL on leukoaraiosis, an indicator of cerebral small vessel disease, in HIV+ individuals. Three hundred and twenty-five HIV+ individuals who received stable combination antiretroviral therapy (cART) for >1 year and achieved viral loads of <40 RNA copies/mL were enrolled along with 147 healthy individuals. Relative TLs of leukocytes were estimated by quantitative real-time polymerase chain reaction. Leukoaraiosis was assessed in 184 HIV+ individuals by fluid-attenuated inversion recovery magnetic resonance imaging. We analyzed several covariates, including markers of HIV infection, cART, and social/environmental factors; variables associated with TL length in univariate analyses were incorporated into multivariate models. The TLs of peripheral leukocytes of HIV+ individuals were significantly shorter than those of healthy individuals, and the rate of LT length decline with increasing age was greater. Linear regression analysis showed that in HIV+ individuals, increasing age, cART without integrase-stand transfer inhibitors (INSTI), failure to achieve viral loads of <40 copies/mL within 1 year of initiating cART, and substance use were significantly associated with shorter TLs, even after adjustment for the effects of age. Logistic regression analysis indicated an increasing risk of leukoaraiosis was associated with older age, shorter TLs, hypertension, and carotid artery plaque. Multivariate regression analysis indicated that older age and shorter TLs were significant risk factors for leukoaraiosis. In summary, our data showed that TL shortening in HIV+ individuals was independently associated with leukoaraiosis, and was associated with age, control of viral loads, use of INSTI, and substance use. Our results suggest that effective viral control and less toxic cART can help reduce TL shortening and improve outcomes among HIV+ individuals.

Evaluating apolipoprotein E genotype status and neuroprotective effects against white matter hyperintensity development in high-altitude careers.

OBJECTIVE: This study considers the use of a rapid molecular assay to evaluate apolipoprotein E (ApoE) status in military subjects who have been exposed to high altitude. We hypothesize that ApoE status may be protective against developing brain white matter hyperintensities (WMHs) after high altitude exposure. RESULTS: We tested 92 subjects who had been exposed to altitudes above 25,000 ft mean sea level, either as pilots or as altitude chamber technicians. We determined subject genetic status using rapid Taqman-style polymerase chain reaction genotyping and evaluated the association of ApoE subtype versus brain lesions using t-tests and two-way analyses of variance. Our results indicate that there is no significant association between ApoE genotype status and the presence of WMHs after high altitude exposure. We did observe a significantly higher number of hours spent at altitude for subjects with the ApoE E2 allele; however, the mechanism by which this may occur is not determined in this study. To more fully elucidate this effect, larger populations would be required to observe greater numbers of subjects with the E2 and E4 alleles.

Single-nucleotide polymorphisms of the adherent junction component cadherin gene are associated with leukoaraiosis.

BACKGROUND: Leukoaraiosis (LA) is one of the manifestations of cerebral small vessel disease. Blood-brain barrier (BBB) disruption plays a key role in LA. Cadherin is a component of adherent junctions (AJ), which play a crucial role in cell-cell adhesion, cell-cell recognition and homeostasis in BBB development. We hypothesized that alterations in cadherin genes might be a potential cause of BBB abnormalities that result in LA. METHODS: A total of 339 LA individuals (LA-PVWM, 183; LA-DWM 156) were enrolled, who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of cadherin single-nucleotide polymorphisms (SNPs) (rs5030625, rs1801026, and rs16260) was performed by real-time polymerase chain reaction with LightSNiP reagents (coupled primer and probe) and FastStart DNAMaster HybProbe (Roche Diagnostic, GmBH, Mannheim, Germany) on a LightCycler 2.0 instrument. RESULTS: Two SNPs, rs1801026 and rs16260, were significantly different between the control and LA groups. The combinatorial effects of the three SNPs were also significant. The haplotypes G-T-C and GA-T-A increased the development of LA-PVWM (OR = 1.76 and OR = 40.7, respectively). The haplotypes G-T-A and GA-T-A increased the development of LA-DWM (OR = 2.56 and OR = 10.48, respectively), but G-C-C decreased the development of LA-DWM (OR = 17.57). CONCLUSION: This study provides evidence for genetic polymorphisms of the AJ component cadherin gene and the association of its haplotypes with LA.

Partial loss of function of colony-stimulating factor 1 receptor in a patient with white matter abnormalities.

BACKGROUND AND PURPOSE: Mutations in colony-stimulating factor 1 receptor (CSF1R) cause adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). Patients with ALSP can be misdiagnosed as having acute ischemic stroke due to hyperintensity lesions on diffusion-weighted magnetic resonance imaging. Mutant CSF1R proteins identified in ALSP show a complete loss of autophosphorylation of CSF1R. METHODS: We conducted mutation screening of CSF1R in 123 patients with definite acute ischemic cerebrovascular syndrome and positive family history of stroke. The pathogenicity of identified variants was evaluated using functional analyses. The levels of autophosphorylation of CSF1R in response to treatment with ligands of CSF1R were examined in cells transfected with wild-type and mutant CSF1R. RESULTS: We identified eight CSF1R variants, six were known non-pathogenic polymorphisms, whereas the other two were missense variants inducing substitution of amino acid residues (p.Glu573Lys and p.Gly747Arg). Functional assay showed that the levels of autophosphorylation of p.Gly747Arg were similar to those of wild-type when treated with ligands. The autophosphorylation of p.Glu573Lys was detectable, but significantly decreased compared with those of wild-type CSF1R (P < 0.001, two-way anova with Bonferroni). The clinical presentation of the patient with p.Glu573Lys was consistent with cerebral embolism. The patient did not have typical clinical findings of ALSP. However, periventricular white matter abnormalities, unrelated to the recent infarct, were evident on brain magnetic resonance imaging. CONCLUSIONS: In contrast to ALSP-associated missense mutations, CSF1R p.Glu573Lys variant in a patient with acute ischemic cerebrovascular syndrome showed a partial loss of autophosphorylation of CSF1R; its clinical significance warrants further investigation.

Higher prevalence of cerebral white matter hyperintensities in homozygous APOE-ɛ4 allele carriers aged 45-75: Results from the ALFA study.

Cerebral white matter hyperintensities are believed the consequence of small vessel disease and are associated with risk and progression of Alzheimer's disease. The ɛ4 allele of the APOE gene is the major factor accountable for Alzheimer's disease heritability. However, the relationship between white matter hyperintensities and APOE genotype in healthy subjects remains controversial. We investigated the association between APOE-ɛ4 and vascular risk factors with white matter hyperintensities, and explored their interactions, in a cohort of cognitively healthy adults (45-75 years). White matter hyperintensities were assessed with the Fazekas Scale from magnetic resonance images (575 participants: 74 APOE-ɛ4 homozygotes, 220 heterozygotes and 281 noncarriers) and classified into normal (Fazekas < 2) and pathological (≥2). Stepwise logistic regression was used to study the association between pathological Fazekas and APOE genotype after correcting for cardiovascular and sociodemographic factors. APOE-ɛ4 homozygotes, but not heterozygotes, bear a significantly higher risk (OR 3.432; 95% CI [1.297-9.082]; p = 0.013) of displaying pathological white matter hyperintensities. As expected, aging, hypertension and cardiovascular and dementia risk scales were also positively associated to pathological white matter hyperintensities, but these did not modulate the effect of APOE-ɛ4/ɛ4. In subjects at genetic risk of developing Alzheimer's disease, the control of modifiable risk factors of white matter hyperintensities is of particular relevance to reduce or delay dementia's onset.

Spectrum construction of differentially expressed circular RNAs in patients with leukoaraiosis and function analysis of differentially expressed genes.

Circular RNAs (circRNAs) are class of endogenous RNAs that have a role in the regulation of gene expression. The present study aimed to investigate the diagnostic value and role of circRNA in the pathogenesis of leukoaraiosis (LA). The present study performed Arraystar Human circRNA Array analysis of 6 samples from LA cases and 6 samples from control cases. Differentially expressed (DE) circRNAs between two samples were identified through fold­change (>1.5­fold) screening. Afterwards, based on DE circRNAs, the gene ontology (GO) analysis of upregulated DE genes identified from DE circRNAs demonstrated that DE genes were primarily associated with cellular metabolic processes, membrane­bound organelles and binding. However, none were enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Downregulated DE genes were enriched in cellular localization, cytoplasm and kinase binding. For the KEGG pathways, the downregulated DE genes were primarily associated with the insulin signaling pathway. The results of the present study indicated that the DE genes from differently expressed circRNAs may have an important role in the pathogenesis of LA and may be a novel targfet for further research.

Analysis of genetic polymorphisms associated with leukoaraiosis in the southern Chinese population: A case-control study.

Leukoaraiosis (LA) is a frequent neuroimaging finding commonly observed on brain MRIs of elderly people with prevalence ranging from 50% to 100%. Multiple susceptibility genes or genetic risk factors for LA have been identified in subjects of European descent. Here, we report the first replication study on several common and novel genetic variations in the Chinese population. In this study, a total of 244 subjects (201 LA patients and 43 controls) were enrolled according to our new and strict definition for LA. Subsequently, 6 genetic variants at 5 genes, rs3744028 in TRIM65, rs1055129 in TRIM47, rs1135889 in FBF1, rs1052053 in PMF1, and rs1801133 (C677T) and rs1801131(A1298C) in MTHFR, were selected for genotyping using polymerase chain reaction (PCR)-based pyrosequencing and restriction fragment length polymorphism (RFLP) together with capillary electrophoresis (CE) and agarose gel electrophoresis. Finally, Pearson's χ and multivariate logistic regression tests were used to examine the associations between the genotypes and LA. Among these candidate polymorphisms, except for rs1052053 and rs1801131, rs1135889 (P = 0.012) showed significant associations with LA in the dominant model, and the other 3 SNPs, rs3744028 (P = 0.043), rs1055129 (P = 0.038), and rs1801133 (P = 0.027), showed significant associations with LA in the recessive model. However, these differences no longer remained significant after adjusting for age, gender, hypertension, and diabetes mellitus and applying Bonferroni correction or Sidak correction for multiple testing. These results suggest that the above-mentioned genetic variants are not associated with LA risk. In summary, the study did not replicate the susceptibility of rs3744028, rs1055129, and rs1135889 at the Chr17q25 locus for LA nor did it find any other significant results for rs1052053, rs1801133, and rs1801131 in the Chinese population. It strongly indicated the ethnic differences in the genetics of LA. However, the associations of rs3744028 (TRIM65), rs1055129 (TRIM47), rs1135889 (FBF1), and rs1801133 (MTHFR) with LA before Bonferroni correction and Sidak correction for multiple testing are worth highlighting. Thus, we believe that a genome-wide association study and candidate gene association studies are needed to reassess the previous findings and screen novel risk genes for LA in China.

Genetic Associations With White Matter Hyperintensities Confer Risk of Lacunar Stroke.

BACKGROUND AND PURPOSE: White matter hyperintensities (WMH) are increased in patients with lacunar stroke. Whether this is because of shared pathogenesis remains unknown. Using genetic data, we evaluated whether WMH-associated genetic susceptibility factors confer risk of lacunar stroke, and therefore whether they share pathogenesis. METHODS: We used a genetic risk score approach to test whether single nucleotide polymorphisms associated with WMH in community populations were associated with magnetic resonance imaging-confirmed lacunar stroke (n=1,373), as well as cardioembolic (n=1,331) and large vessel (n=1,472) Trial of Org 10172 in Acute Stroke Treatment subtypes, against 9,053 controls. Second, we separated lacunar strokes into those with WMH (n=568) and those without (n=787) and tested for association with the risk score in these 2 groups. In addition, we evaluated whether WMH-associated single nucleotide polymorphisms are associated with lacunar stroke, or in the 2 groups. RESULTS: The WMH genetic risk score was associated with lacunar stroke (odds ratio [OR; 95% confidence interval [CI]]=1.14 [1.06-1.22]; P=0.0003), in patients both with and without WMH (WMH: OR [95% CI]=1.15 [1.05-1.26]; P=0.003 and no WMH: OR [95% CI]=1.11 [1.02-1.21]; P=0.019). Conversely, the risk score was not associated with cardioembolic stroke (OR [95% CI]=1.03 [0.97-1.09]; P=0.63) or large vessel stroke (OR [95% CI]=0.99 [0.93,1.04]; P=0.39). However, none of the WMH-associated single nucleotide polymorphisms passed Bonferroni-corrected significance for association with lacunar stroke. CONCLUSIONS: Genetic variants that influence WMH are associated with an increased risk of lacunar stroke but not cardioembolic or large vessel stroke. Some genetic susceptibility factors seem to be shared across different radiological manifestations of small vessel disease.

Oxidative phosphorylation and lacunar stroke: Genome-wide enrichment analysis of common variants.

OBJECTIVE: We investigated whether oxidative phosphorylation (OXPHOS) abnormalities were associated with lacunar stroke, hypothesizing that these would be more strongly associated in patients with multiple lacunar infarcts and leukoaraiosis (LA). METHODS: In 1,012 MRI-confirmed lacunar stroke cases and 964 age-matched controls recruited from general practice surgeries, we investigated associations between common genetic variants within the OXPHOS pathway and lacunar stroke using a permutation-based enrichment approach. Cases were phenotyped using MRI into those with multiple infarcts or LA (MLI/LA) and those with isolated lacunar infarcts (ILI) based on the number of subcortical infarcts and degree of LA, using the Fazekas grading. Using gene-level association statistics, we tested for enrichment of genes in the OXPHOS pathway with all lacunar stroke and the 2 subtypes. RESULTS: There was a specific association with strong evidence of enrichment in the top 1% of genes in the MLI/LA (subtype p = 0.0017) but not in the ILI subtype (p = 1). Genes in the top percentile for the all lacunar stroke analysis were not significantly enriched (p = 0.07). CONCLUSIONS: Our results implicate the OXPHOS pathway in the pathogenesis of lacunar stroke, and show the association is specific to patients with the MLI/LA subtype. They show that MRI-based subtyping of lacunar stroke can provide insights into disease pathophysiology, and imply that different radiologic subtypes of lacunar stroke subtypes have distinct underlying pathophysiologic processes.

Single-Nucleotide Polymorphisms of Tight Junction Component Claudin-1 Associated with Leukoaraiosis.

BACKGROUND: The blood-brain barrier (BBB) plays a major role in the development of leukoaraiosis (LA). The junctional complex of BBB consists of tight junction (TJ) and adherens junction (AJ). Claudin-1 is the integral component of TJ. The aim of this study was to evaluate whether genetic variations in claudin-1 gene are associated with the development of LA. METHODS: LA has to be diagnosed based on images. A total of 228 LA cases and 203 controls were enrolled from the individuals who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of claudin-1 single-nucleotide polymorphisms (SNPs) (rs17501010, rs893051, and rs9290927) was performed by real-time polymerase chain reaction with LightSNiP reagents (coupled primer and probe) and FastStart DNAMaster HybProbe (Roche Diagnostic, GmBH, Mannheim, Germany) in LightCycler 2.0. RESULTS: Among the 3 SNPs of claudin-1, a significant genetic difference was found only between control and LA (both LA-periventricular white matter [PVWM] and LA-subcortical deep white matter) with SNP rs9290927. However, their haplotypes G-G-T and G-C-A were significantly different between LA-PVWM and control, which increase the development of LA-PVWM with odds ratios of 1.45 and .57, respectively. CONCLUSIONS: This study demonstrated first evidence of genetic polymorphism of TJ component claudin-1 and their haplotypes associated with LA.

Genetic associations of leukoaraiosis indicate pathophysiological mechanisms in white matter lesions etiology.

Leukoaraiosis (LA), also called white matter lesions (WMLs) and white matter hyperintensities (WMHs), is a frequent neuroimaging finding commonly seen on magnetic resonance imaging brain scans of elderly people with prevalence ranging from 50% to 100%. Although it remains asymptomatic, LA is not considered to be benign, and it is showed to be related to a host of poor clinical outcomes and increases the risk of disability, dementia, depression, stroke, and the overall morbidity and mortality. Pathologically, LA is characterized by loss of myelin and axons, patchy demyelination, and denudation of ependyma in regions of WMH. Age and hypertension are the most importantly established risk factors for LA. However, the precise pathogenic mechanisms remain unclear. Together with the previous findings, our recent genetic results strongly supported that LA is associated with immune response and neuroinflammation. Therefore, we confidently hypothesized that LA was not only a common neuroimaging phenomenon in the elderly but also an emerging neuroinflammatory disorder in the central nervous system. This article focusing on neuroimaging classification, genetics basis, and putative molecular mechanism introduced the basic knowledge and current status of LA and put forward some of our research ideas and results from our molecular genetics research, which may pave the way for deciphering the putative pathogenic mechanism, risk factor, epigenetic index, and its application in diagnostic agents or drug target for prevention and treatment. Thus, it could provide clinicians and researchers with a specific and modern overview of LA to enable the understanding of recent progress and future directions in this illness.

Association of rs2075575 and rs9951307 polymorphisms of AQP-4 gene with leukoaraiosis.

BACKGROUND: Leukoaraiosis (LA) is associated with structural and functional vascular changes that correlate with motor and gait disturbances, depressive symptoms, urinary disturbances, and dementia. The blood-brain barrier (BBB) plays a key role in development of lacunar stroke, leukoaraiosis, and other feature of cerebral small-vessel disease, and there are numerous studies examining changes in the BBB with normal aging and in dementia and LA. Aquaporin-4 (AQP-4), the primary water channel protein in the central nervous system, is involved in BBB development, function, and integrity, and its dysfunction induces several neurologic diseases. The aim of our study was to evaluate whether genetic variations in AQP-4 gene are associated with the development of LA. METHODS: DNA was amplified and the single-nucleotide polymorphisms in AQP-4 gene were investigated by melting curve analysis using real-time polymerase chain reaction. RESULTS: The frequency of both T allele and CT/TT genotypes of rs2075575 was significantly higher in LA group than in control group (C versus T, P = .0145; CC versus CT/TT, P = .038). However, no significant difference was observed between LA group and control group in rs9951307. Interestingly, the rs9951307 AG + GG genotype may confer a synergistic effect in odds ratio (OR) values when combined with the rs2075575 CT + TT genotypes (OR = 1.65 → 2.51). The C-A haplotype was significantly different between LA group and the control group (P = .005). By stratified analysis, rs2075575 and rs9951307 polymorphisms were statistically significant in the subjects with hypertension and hemoglobin A1c (P < .05), whereas the rs2075575 polymorphism was associated with high serum cholesterol (P < .05) and the rs9951307 polymorphism was associated with low serum homocysteine (P < .05). CONCLUSIONS: Our results indicate that AQP-4 genetic variations and haplotypes might contribute to the risk factors for LA.

Cyclooxygenase 2 genetic polymorphism may increase the risk of developing leukoaraiosis in Chinese.

Cyclooxygenase-2 (COX-2) is a key enzyme involved in the conversion of arachidonic acid into prostaglandins, which are important mediators of inflammation. To clarify the role of inflammation in the pathogenesis of cerebral small vessel disease (SVD), we investigate the possible modulating effect of the functional COX-2 polymorphisms -1195G > A (rs689466) and -765G > C (rs20417) on the risk for development of cerebral SVD in a Chinese population. Genomic DNA of 116 patients with lacunar infarction (LI), 334 patients with leukoaraiosis (LA) and 450 control subjects was genotyped for the COX-2 -1195G > A and -765G > C polymorphisms using polymerase chain reaction-restriction fragment length polymorphism. Distribution of genotypes and haplotypes in patients and controls were compared. The genotype distribution of the -765G > C polymorphism was not different between the patients with LI or LA and the control group. The 1195A allele carriers was identified independently to be related with LA (adjusted OR = 1.41, 95 % confidence interval (CI) = 1.09-2.10, P = 0.03) but not associated with LI. The linkage disequilibrium analysis showed that -1195G > A and -765G > C SNPs are moderate linkage disequilibrium in this study population (D' = 0.70, r(2) = 0.16). Compared with G-1195-G-765 haplotype, the haplotype of A-1195-G-765 showed significantly increased the risk of LA (OR = 1.24, 95 % CI = 1.10-1.55, P = 0.04) but not LI. In conclusion, we found that -1195G > A polymorphism and A-1195-G-765 haplotype of COX-2 were associated with susceptibility to LA in a Chinese population.

White matter lesions and brain gray matter volume in cognitively normal elders.

Cerebral white matter lesions (WMLs) reflect small vessel disease, are common in elderly individuals, and are associated with cognitive impairment. We sought to determine the relationships between WMLs, age, gray matter (GM) volume, and cognition in the Cardiovascular Health Study (CHS). From the Cardiovascular Health Study we selected 740 cognitively normal controls with a 1.5 T magnetic resonance imaging (MRI) scan of the brain and a detailed diagnostic evaluation. WML severity was determined using a standardized visual rating system. GM volumes were analyzed using voxel-based morphometry implemented in the Statistical Parametric Mapping software. WMLs were inversely correlated with GM volume, with the greatest volume loss in the frontal cortex. Age-related atrophy was observed in the hippocampus and posterior cingulate cortex. Regression analyses revealed links among age, APOE*4 allele, hypertension, WMLs, GM volume, and digit symbol substitution test scores. Both advancing age and hypertension predict higher WML load, which is itself associated with GM atrophy. Longitudinal data are needed to confirm the temporal sequence of events leading to a decline in cognitive function.

Evaluation of the MTHFR A1298C variant in leukoaraiosis.

Vascular demyelinization of the white matter of the brain is referred to as leukoaraiosis (LA). This very frequent entity is associated with a cognitive decline, thereby resulting in a deteriorating quality of life. Besides poorly controlled hypertension and aging, its development is reported to be associated with an elevated serum homocysteine level. Although the methylenetetrahydrofolate reductase (MTHFR) C677T genetic variant is associated with an elevated serum homocysteine level, it has not been proved to be an independent risk factor for LA. The aim of the present study was to examine whether the MTHFR A1298C genetic variant, which is also believed to be unfavorable, is associated with the presence of LA. The clinical and genetic data on 198 LA patients and 235 neuroimaging alteration-free controls were analyzed. The presence of the A1298C or the 1298CC variant was calculated to be a risk factor for LA, as compared with the absence of both of them. The clustering of the heterozygous A1298C and C677T variants was proved to involve the risk of LA. Our results suggest that the MTHFR A1298C variant confers an independent genetic risk of LA, and this pathological role may be amplified by the MTHFR C677T variant.