Association of CYP46 gene polymorphism with sporadic Alzheimer's disease in Chinese Han populations: a meta-analysis

The Relationship Between CYP46A1 Polymorphism and Suicide Risk: A Preliminary Investigation

Suicide is a global public health issue, with a particularly high incidence in individuals suffering from Major Depressive Disorder (MDD). The role of cholesterol in suicide risk remains controversial, prompting investigations into genetic markers that may be implicated. This study examines the association between CYP46A1 polymorphisms, specifically SNPs rs754203 and rs4900442, and suicide risk in a Mexican MDD patient cohort. Our study involved 188 unrelated suicide death victims, 126 MDD patients, and 144 non-suicidal controls. Genotypic and allelic frequencies were assessed using the Real Time-polymerase chain reaction method, and associations with suicide risk were evaluated using chi-square tests. The study revealed significant differences in allelic and genotypic frequencies in rs754203 SNP between suicide death and controls. The CYP46A1 rs754203 genotype G/G was significantly linked with suicide, and the G allele was associated with a higher risk of suicide (OR = 1.370, 95% CI = 1.002-1.873). However, we did not observe any significant differences in genotype distribution or allele frequencies of CYP46A1 rs4900442. Our study suggests that carriers of the CYP46A1 rs754203 G allele (A/G + G/G) may play a role in suicidal behavior, especially in males. Our findings support that the CYP46A1 gene may be involved in susceptibility to suicide, which has not been investigated previously. These results underscore the importance of further research in different populations to elucidate the genetic underpinnings of the role of CYP46A1 in suicide risk and to develop targeted interventions for at-risk populations.

Increased Plasma Level of 24S-Hydroxycholesterol and Polymorphism of CYP46A1 SNP (rs754203) Are Associated With Mild Cognitive Impairment in Patients With Type 2 Diabetes

Background

Abnormal cholesterol metabolism is common in type 2 diabetes mellitus (T2DM) and causes dementia. Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol (24-OHC) and maintains cholesterol homeostasis in the brain.

Objective

This study aimed to investigate the roles of 24-OHC and the CYP46A1 (rs754203) polymorphism in patients with T2DM and mild cognitive impairment (MCI).

Methods

A total of 193 Chinese patients with T2DM were recruited into two groups according to the Montreal Cognitive Assessment (MoCA). Demographic and clinical data were collected, and neuropsychological tests were conducted. Enzyme-linked immunosorbent assay (ELISA) and Seqnome method were used to detect the concentration of plasma 24-OHC and the CYP46A1 rs754203 genotype, respectively.

Results

Compared with 118 healthy cognition participants, patients with MCI (n = 75) displayed a higher plasma level of 24-OHC and total cholesterol concentration (all p = 0.031), while no correlation was found between them. In the overall diabetes population, the plasma level of 24-OHC was negatively correlated with MoCA (r = −0.150, p = 0.039), and it was further proved to be an independent risk factor of diabetic MCI (OR = 1.848, p = 0.001). Additionally, patients with MCI and the CC genotype of CYP46A1 rs754203 showed the highest plasma level of 24-OHC even though the difference was not statistically significant, and they obtained low scores in both the verbal fluency test and Stroop color and word test A (p = 0.008 and p = 0.029, respectively).

Conclusion

In patients with T2DM, high plasma level of 24-OHC and the CC genotype carrier of CYP46A1 rs754203 may portend a high risk of developing early cognitive impairment, including attention and executive deficits.

Cholesterol 24-Hydroxylation by CYP46A1: Benefits of Modulation for Brain Diseases

Cholesterol 24-hydroxylation is the major mechanism for cholesterol removal from the brain and the reaction catalyzed by cytochrome P450 46A1 (CYP46A1), a CNS-specific enzyme. This review describes CYP46A1 in the context of cholesterol homeostasis in the brain and summarizes available experimental data on CYP46A1 association with different neurologic diseases, including the mechanisms by which changes in the CYP46A1 activity in the brain could be beneficial for these diseases. The modulation of CYP46A1 activity by genetic and pharmacologic means is also presented along with a brief synopsis of the two clinical trials that evaluate CYP46A1 as a therapeutic target for Alzheimer's disease as well as Dravet and Lennox-Gastaut syndromes.