Genome-Wide Association Meta-Analysis of Individuals of European Ancestry Identifies Suggestive Loci for Sodium Intake, Potassium Intake, and Their Ratio Measured from 24-Hour or Half-Day Urine Samples

Identification of Novel Genetic Loci Affecting Age at Onset of Parkinson's Disease: A Genome-wide Association Study

BACKGROUND

The age at onset (AAO) of Parkinson's disease (PD) varies widely among individuals and significantly influences disease progression and prognosis. However, few genome-wide association studies (GWASs) have investigated genetic variants determining AAO, particularly in East Asian populations.

OBJECTIVES

To identify single-nucleotide polymorphisms (SNPs) affecting AAO of PD in Korean patients.

METHODS

We conducted a GWAS on AAO of PD in 1048 Korean patients using sex-adjusted linear regression models. Additionally, we conducted downstream analyses of our primary GWAS results.

RESULTS

rs2134545 demonstrated genome-wide significance (β = -2.459; standard error [SE] = 0.851; P = 1.898 × 10-8) and is an intergenic SNP near the ALCAM gene associated with an average AAO reduction of 3.47 years. Additionally, rs4366309 (LYST; MIR1537) demonstrated suggestive significance (β = 2.949; SE = 1.072; P = 8.68 × 10-8) and was associated with an average delay of 3.05 years. The polygenic risk score based on known PD risk loci also affected the AAO for European and Korean PD risk loci, respectively (β = -0.149; P < 0.001 and β = -0.096; P = 0.002). However, the proportion of variance was small (r2 = 0.022 and 0.009, respectively).

CONCLUSION

We identified a novel SNP associated with the AAO of PD near the ALCAM gene, distinct from previously reported PD risk loci. These findings need further functional validation; however, they suggest unique genetic pathways influencing the AAO of PD and highlight the need for further research in diverse populations. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The potassium puzzle: exploring the intriguing connection to albuminuria

Background

Studies have revealed a relationship between dietary potassium intake and albuminuria, despite the fact that the human body needs a lot of potassium. Our study concentrated on the link between dietary potassium intake and albuminuria.

Methods

This study used subgroup analysis and weighted multivariate regression analysis. Data from the National Health and Nutrition Examination Survey (NHANES) were examined to determine the urinary albumin-to-creatinine ratio (ACR) and participant age (20 years or older). ACR >30 mg/g was the threshold for albuminuria.

Results

7,564 individuals in all were included in the study. The link between the two was significant in both our original model (OR = 0.99; 95% CI, 0.98-0.99, p < 0.0001) and the minimum adjusted model (OR = 0.99; 95% CI, 0.98-0.99, p < 0.0001). A fully adjusted model did not change the significance of the negative correlation between potassium consumption and albuminuria (OR = 0.99; 95% CI, 0.98-1.00, p = 0.0005), indicating that each unit increase in potassium intake was related with a 1% decrease in the chance of developing albuminuria. The negative correlation between potassium intake and albuminuria was not significantly influenced by sex, age, BMI, hypertension, diabetes, or smoking, according to interaction tests (p for interaction >0.05).

Conclusion

Reduced risk of albuminuria was linked to higher dietary potassium intake. The particular mechanism linking the two still has to be explained by several inventive and prospective studies.

Voltage-gated ion channels are expressed in the Malpighian tubules and anal papillae of the yellow fever mosquito (Aedes aegypti), and may regulate ion transport during salt and water imbalance

Vectors of infectious disease include several species of Aedes mosquitoes. The life cycle of Aedes aegypti, the yellow fever mosquito, consists of a terrestrial adult and an aquatic larval life stage. Developing in coastal waters can expose larvae to fluctuating salinity, causing salt and water imbalance, which is addressed by two prime osmoregulatory organs - the Malpighian tubules (MTs) and anal papillae (AP). Voltage-gated ion channels (VGICs) have recently been implicated in the regulation of ion transport in the osmoregulatory epithelia of insects. In the current study, we: (i) generated MT transcriptomes of freshwater-acclimated and brackish water-exposed larvae of Ae. aegypti, (ii) detected expression of several voltage-gated Ca2+, K+, Na+ and non-ion-selective ion channels in the MTs and AP using transcriptomics, PCR and gel electrophoresis, (iii) demonstrated that mRNA abundance of many altered significantly following brackish water exposure, and (iv) immunolocalized CaV1, NALCN, TRP/Painless and KCNH8 in the MTs and AP of larvae using custom-made antibodies. We found CaV1 to be expressed in the apical membrane of MTs of both larvae and adults, and its inhibition to alter membrane potentials of this osmoregulatory epithelium. Our data demonstrate that multiple VGICs are expressed in osmoregulatory epithelia of Ae. aegypti and may play an important role in the autonomous regulation of ion transport.

New insights into the physiology and pathophysiology of the atypical sodium leak channel NALCN

Cell excitability and its modulation by hormones and neurotransmitters involve the concerted action of a large repertoire of membrane proteins, especially ion channels. Unique complements of coexpressed ion channels are exquisitely balanced against each other in different excitable cell types, establishing distinct electrical properties that are tailored for diverse physiological contributions, and dysfunction of any component may induce a disease state. A crucial parameter controlling cell excitability is the resting membrane potential (RMP) set by extra- and intracellular concentrations of ions, mainly Na+, K+, and Cl-, and their passive permeation across the cell membrane through leak ion channels. Indeed, dysregulation of RMP causes significant effects on cellular excitability. This review describes the molecular and physiological properties of the Na+ leak channel NALCN, which associates with its accessory subunits UNC-79, UNC-80, and NLF-1/FAM155 to conduct depolarizing background Na+ currents in various excitable cell types, especially neurons. Studies of animal models clearly demonstrate that NALCN contributes to fundamental physiological processes in the nervous system including the control of respiratory rhythm, circadian rhythm, sleep, and locomotor behavior. Furthermore, dysfunction of NALCN and its subunits is associated with severe pathological states in humans. The critical involvement of NALCN in physiology is now well established, but its study has been hampered by the lack of specific drugs that can block or agonize NALCN currents in vitro and in vivo. Molecular tools and animal models are now available to accelerate our understanding of how NALCN contributes to key physiological functions and the development of novel therapies for NALCN channelopathies.

Development and validation of a 13-gene signature associated with immune function for the detection of Alzheimer's disease

Current knowledge of Alzheimer's disease (AD) etiology and effective therapy remains limited. Thus, the identification of biomarkers is crucial to improve the detection and treatment of patients with AD. Using robust rank aggregation method to analyze the microarray data from Gene Expression Omnibus database, we identified 1138 differentially expressed genes in AD. We then explored 13 hub genes by weighted gene co-expression network analysis, least absolute shrinkage, and selection operator, and logistic regression in the training dataset. The detection model, which composed of CD163, CDC42SE1, CECR6, CSF1R, CYP27A1, EIF4E3, H2AFJ, IFIT2, IL10RA, KIAA1324, PSTPIP1, SLA, and TBC1D2 genes, along with APOE gene, showed that the area under the curve for detecting AD was 0.821 (95% confidence interval [CI] = 0.782-0.861) and the model was validated in ADNI dataset (area under the curve = 0.776; 95%CI = 0.686-0.865). Notably, the 13 genes in the model were highly enriched in immune function. These findings have implications for the detection and therapeutic target of AD.