Exercise modulates APOE expression in brain cortex of female APOE3 and APOE4 targeted replacement mice

Link among apolipoprotein E E4, gait, and cognition in neurodegenerative diseases: ONDRI study

INTRODUCTION

Apolipoprotein E E4 allele (APOE E4) and slow gait are independently associated with cognitive impairment and dementia. However, it is unknown whether their coexistence is associated with poorer cognitive performance and its underlying mechanism in neurodegenerative diseases.

METHODS

Gait speed, APOE E4, cognition, and neuroimaging were assessed in 480 older adults with neurodegeneration. Participants were grouped by APOE E4 presence and slow gait. Mediation analyses were conducted to determine if brain structures could explain the link between these factors and cognitive performance.

RESULTS

APOE E4 carriers with slow gait had the lowest global cognitive performance and smaller gray matter volumes compared to non-APOE E4 carriers with normal gait. Coexistence of APOE E4 and slow gait best predicted global and domain-specific poorer cognitive performances, mediated by smaller gray matter volume.

DISCUSSION

Gait slowness in APOE E4 carriers with neurodegenerative diseases may indicate extensive gray matter changes associated with poor cognition.

HIGHLIGHTS

APOE E4 and slow gait are risk factors for cognitive decline in neurodegenerative diseases. Slow gait and smaller gray matter volumes are associated, independently of APOE E4. Worse cognition in APOE E4 carriers with slow gait is explained by smaller GM volume. Gait slowness in APOE E4 carriers indicates poorer cognition-related brain changes.

Sister haplotypes and recombination disequilibrium: a new approach to identify associations of haplotypes with complex diseases

Haplotype-based association analysis has several advantages over single-SNP association analysis. However, to date all haplotype-disease associations have not excluded recombination interference among multiple loci and hence some results might be confounded by recombination interference. Association of sister haplotypes with a complex disease, based on recombination disequilibrium (RD) was presented. Sister haplotypes can be determined by translating notation of DNA base haplotypes to notation of genetic genotypes. Sister haplotypes provide haplotype pairs available for haplotype-disease association analysis. After performing RD tests in control and case cohorts, a two-by-two contingency table can be constructed using sister haplotype pair and case-control pair. With this standard two-by-two table, one can perform classical Chi-square test to find statistical haplotype-disease association. Applying this method to a haplotype dataset of Alzheimer disease (AD), association of sister haplotypes containing ApoE3/4 with risk for AD was identified under no RD. Haplotypes within gene IL-13 were not associated with risk for breast cancer in the case of no RD and no association of haplotypes in gene IL-17A with risk for coronary artery disease were detected without RD. The previously reported associations of haplotypes within these genes with risk for these diseases might be due to strong RD and/or inappropriate haplotype pairs.

Effects of voluntary, and forced exercises on neurotrophic factors and cognitive function in animal models of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the elderly. Cognitive dysfunction represents a common and challenging non-motor symptom for people with Parkinson's disease. The number of neurotrophic proteins in the brain is critical in neurodegenerative diseases such as Parkinson's. This research aims to compare the effects of two types of exercise, forced and voluntary, on spatial memory and learning and neurochemical factors (CDNF and BDNF).

METHODS

In this research, 60 male rats were randomly divided into six groups (n = 10): the control (CTL) group without exercise, the Parkinson's groups without and with forced (FE) and voluntary (VE) exercises, and the sham groups (with voluntary and forced exercise). The animals in the forced exercise group were placed on the treadmill for four weeks (five days a week). At the same time, voluntary exercise training groups were placed in a special cage equipped with a rotating wheel. At the end of 4 weeks, learning and spatial memory were evaluated with the Morris water maze test. BDNF and CDNF protein levels in the hippocampus were measured by the ELISA method.

RESULTS

The results showed that although the PD group without exercise was at a significantly lower level than other groups in terms of cognitive function and neurochemical factors, both types of exercise, could improve these problems.

CONCLUSION

According to our results, 4 weeks of voluntary and forced exercises were all found to reverse the cognitive impairments of PD rats.