Association between DCHS2 gene and mild cognitive impairment and Alzheimer's disease in an elderly Brazilian sample

The construction of a novel prognostic prediction model for glioma based on GWAS-identified prognostic-related risk loci

Backgrounds

Glioma is a highly malignant brain tumor with a grim prognosis. Genetic factors play a role in glioma development. While some susceptibility loci associated with glioma have been identified, the risk loci associated with prognosis have received less attention. This study aims to identify risk loci associated with glioma prognosis and establish a prognostic prediction model for glioma patients in the Chinese Han population.

Methods

A genome-wide association study (GWAS) was conducted to identify risk loci in 484 adult patients with glioma. Cox regression analysis was performed to assess the association between GWAS-risk loci and overall survival as well as progression-free survival in glioma. The prognostic model was constructed using LASSO Cox regression analysis and multivariate Cox regression analysis. The nomogram model was constructed based on the single nucleotide polymorphism (SNP) classifier and clinical indicators, enabling the prediction of survival rates at 1-year, 2-year, and 3-year intervals. Additionally, the receiver operator characteristic (ROC) curve was employed to evaluate the prediction value of the nomogram. Finally, functional enrichment and tumor-infiltrating immune analyses were conducted to examine the biological functions of the associated genes.

Results

Our study found suggestive evidence that a total of 57 SNPs were correlated with glioma prognosis (p < 5 × 10-5). Subsequently, we identified 25 SNPs with the most significant impact on glioma prognosis and developed a prognostic model based on these SNPs. The 25 SNP-based classifier and clinical factors (including age, gender, surgery, and chemotherapy) were identified as independent prognostic risk factors. Subsequently, we constructed a prognostic nomogram based on independent prognostic factors to predict individualized survival. ROC analyses further showed that the prediction accuracy of the nomogram (AUC = 0.956) comprising the 25 SNP-based classifier and clinical factors was significantly superior to that of each individual variable.

Conclusion

We identified a SNP classifier and clinical indicators that can predict the prognosis of glioma patients and established a prognostic prediction model in the Chinese Han population. This study offers valuable insights for clinical practice, enabling improved evaluation of patients' prognosis and informing treatment options.

Human amnion epithelial cell therapy reduces hypertension-induced vascular stiffening and cognitive impairment

Vascular inflammation and fibrosis are hallmarks of hypertension and contribute to the development of cardiovascular disease and cognitive impairment. However, current anti-hypertensive drugs do not treat the underlying tissue damage, such as inflammation-associated fibrosis. Human amnion epithelial cells have several properties amenable for treating vascular pathology. This study tested the effect of amnion epithelial cells on vascular pathology and cognitive impairment during hypertension. Male C57Bl6 mice (8-12 weeks) were administered vehicle (saline; n = 58) or angiotensin II (0.7 mg/kg/d, n = 56) subcutaneously for 14 d. After surgery, a subset of mice were injected with 106 amnion epithelial cells intravenously. Angiotensin II infusion increased systolic blood pressure, aortic pulse wave velocity, accumulation of aortic leukocytes, and aortic mRNA expression of collagen subtypes compared to vehicle-infused mice (n = 9-11, P < 0.05). Administration of amnion epithelial cells attenuated these effects of angiotensin II (P < 0.05). Angiotensin II-induced cognitive impairment was prevented by amnion epithelial cell therapy (n = 7-9, P < 0.05). In the brain, amnion epithelial cells modulated some of the inflammatory genes that angiotensin II promoted differential expression of (n = 6, p-adjusted < 0.05). These findings suggest that amnion epithelial cells could be explored as a potential therapy to inhibit vascular pathology and cognitive impairment during hypertension.

Race-Related Association between APOE Genotype and Alzheimer's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The global race-dependent association of Alzheimer's disease (AD) and apolipoprotein E (APOE) genotype is not well understood. Transethnic analysis of APOE could clarify the role of genetics in AD risk across populations.

OBJECTIVE

This study aims to determine how race and APOE genotype affect the risks for AD.

METHODS

We performed a systematic search of PubMed, Embase, Web of Science, and the Cochrane Library since 1993 to Aug 25, 2020. A total of 10,395 reports were identified, and 133 were eligible for analysis with data on 77,402 participants. Studies contained AD clinical diagnostic and APOE genotype data. Homogeneous data sets were pooled in case-control analyses. Odds ratios and 95% confidence intervals for developing AD were calculated for populations of different races and APOE genotypes.

RESULTS

The proportion of APOE genotypes and alleles differed between populations of different races. Results showed that APOEɛ4 was a risk factor for AD, whereas APOEɛ2 protected against it. The effects of APOEɛ4 and ɛ2 on AD risk were distinct in various races, they were substantially attenuated among Black people. Sub-group analysis found a higher frequency of APOEɛ4/ɛ4 and lower frequency of APOEɛ3/ɛ3 among early-onset AD than late-onset AD in a combined group and different races.

CONCLUSION

Our meta-analysis suggests that the association of APOE genotypes and AD differ between races. These results enhance our understanding of APOE-related risk for AD across race backgrounds and provide new insights into precision medicine for AD.

Millipore xMap® Luminex (HATMAG-68K): An Accurate and Cost-Effective Method for Evaluating Alzheimer's Biomarkers in Cerebrospinal Fluid

Background: Alzheimer's disease (AD) biomarkers are of great relevance in clinical research, especially after the AT(N) framework. They enable early diagnosis, disease staging and research with new promising drugs, monitoring therapeutic response. However, the high cost and low availability of the most well-known methods limits their use in low and medium-income countries. In this context, Millipore xMap^® Luminex may be a cost-effective alternative. In our study, using INNOTEST^® as reference, we assess the diagnostic accuracy of Millipore xMap^® and propose a cutoff point for AD. Methods: We performed lumbar puncture of seven older individuals with clinically defined AD, 17 with amnestic mild cognitive impairment (aMCI) and 11 without objective cognitive impairment-control group (CG). Cerebrospinal fluid (CSF) biomarkers concentrations for aB42, p-Tau, and t-Tau were measured by INNOTEST^® and Millipore xMap^®, and then the techniques were compared to assess the diagnostic accuracy of the new test and to define a cutoff. Results: INNOTEST^® and Millipore xMap^® measurements showed all correlations >0.8 for the same biomarker, except for t-Tau that was 0.66. Millipore xMap^® measurements showed a robust accuracy for all biomarkers, with AUC higher than 0.808 (t-Tau), and the best for Aβ42 (AUC = 0.952). The most accurate cutoffs were found at 1012.98 pg/ml (Aβ42), 64.54 pg/ml (p-tau), 3251.81 pg/ml (t-tau), 3.370 (t-Tau/Aβ42), and 0.059 (p-Tau/Aβ42). Conclusion: Given its good accuracy and cost-effectiveness, Milliplex xMap^® tests seems a reliable and promising tool, especially for low and middle-income countries.

The APOE ε4 exerts differential effects on familial and other subtypes of Alzheimer's disease

INTRODUCTION

The genetic risk effects of apolipoprotein E (APOE) on familial Alzheimer's disease (FAD) with or without gene mutations, sporadic AD (SAD), and normal controls (NC) remain unclear in the Chinese population.

METHODS

In total, 15 119 subjects, including 311 FAD patients without PSEN1, PSEN2, APP, TREM2, and SORL1 pathogenic mutations (FAD [unknown]); 126 FAD patients with PSENs/APP mutations (FAD [PSENs/APP]); 7234 SAD patients; and 7448 NC were enrolled. The risk effects of APOE ε4 were analyzed across groups.

RESULTS

The prevalence of the APOE ε4 genotype in FAD (unknown), FAD (PSENs/APP), SAD, and NC groups was 56.27%, 26.19%, 36.23%, and 19.54%, respectively. Further, the APOE ε4 positive genotype had predictive power for FAD (unknown) risk (odds ratio: 4.51, 95% confidence interval: 3.57-5.45, P < .001).

DISCUSSION

APOE ε4 positive genotype may cause familial aggregation, and the investigation of multiple interventions targeting APOE pathological function to reduce the risk for this disease warrants attention.