ANKRD36 Is Involved in Hypertension by Altering Expression of ENaC Genes

Abstract

Rationale: Hypertension is the most important risk factor for cardiovascular and cerebrovascular diseases. Getting deep insight into the pathogenesis of hypertension is necessary. Objective: To investigate the role of ANKRD36 in hypertension. Methods and Results: We firstly recruited an essential hypertension cohort, and then performed genome-wide transcriptome analysis with peripheral blood mRNA. ANKRD36 (ankyrin repeat domain 36) was found to be significantly lower expressed in hypertension. The anchorin repeat domain mediates a variety of protein-protein interactions. The ENaC genes expression was found up-regulated in HUVECs with ANKRD36 knockdown by using Affymetrix expression profile chip. In HKC and HEK293T cells, ANKRD36 overexpression significantly down-regulated ENaC genes expression, and ANKRD36 knockdown up-regulated their expression. The ChIP assay and YY1 knockdown showed the expression of ENaC was regulated by ANKRD36 via YY1, a dual function transcription factor ubiquitously expressed in human tissues. CO-IP and fluorescence resonance energy transfer assay confirmed the interaction between ANKRD36 and YY1. The nucleo-cytoplasmic ratio of YY1 decreased when ANKRD36 was overexpressed, and also increased when ANKRD36 was knocked down. ANK2 domain of ANKRD36 was critical to its interacting with YY1. Ankrd36 knockout mice showed higher blood pressure levels and Na+ reabsorption, especially when fed with high-salt diet. Higher ENaC genes expression was observed in renal tubular epithelial cells from the knockout mice, and Yy1 knockdown mitigated the alteration. Ankrd36 knockout mice also showed more sensitive response to ENaC inhibitor amiloride treatment. Conclusions: We identified that ANKRD36 was involved in blood pressure regulation by interacting with YY1 and then altering ENaC genes expression. Lower expressed ANKRD36 in hypertension might be a potential therapeutic target, and the application of ENaC inhibitors on hypertension treatment might be extended when serum K+ levels are closely monitored.

A genome-wide association study identifies a novel association between SDC3 and apparent treatment-resistant hypertension

“…The Affymetrix human gene 2.0 ST profile chip was used to detect the whole transcript level. About 2.5 mL of venous blood was collected with PAXgene (Qiagen) venous blood collection tube, blood was used to extract RNA for further research [ 6 ].…”

“…The validation cohort included 65 aTRHs, 96 hypertensives, and 100 controls, which was screened from a previous cohort from Rizhao City, in the northern region of China from 2009 to 2010 which has been described previously [5,6]. The following strict inclusion criteria were used for both hypertension patients and controls: (1) Chinese Han people, (2) aged from 50-77 years, (3) BMI ranged from 19.4 kg/m 2 to 24.6 kg/m 2 , and (4) subjects were excluded when they had any known diseases including thyroid disease, hematological diseases, heart failure, valvular heart disease, liver or kidney dysfunctions, infections, autoimmune diseases, or tumors.…”

Lessons learned about epithelial sodium channels from transgenic mouse models

“…Principal cell-specific Ank-3 knockout mice showed decreased ENaC activity and increased sodium excretion supporting evidence that Ank-3 binding increased channel activity [52]. The ankyrin repeat domain 36 (ANKRD36) mediates a variety of protein-protein interactions and was found to be significantly lower expressed in hypertension [53 ▪▪ ]. Ankrd36 knockout mice showed higher blood pressure and Na + absorption on high salt diet associated with increased tubular ENaC expression by altering expression of ENaC genes [53 ▪▪ ].…”

Whole-exome sequencing study identifies genes associated with Alzheimer’s disease and related dementias

“…ANKRD36 has also been reported for an association with schizophrenia 15 , a severe psychiatric illness that may have a white matter deficit connection with AD 16 . ANKRD36 is also involved in hypertension 17 , a risk factor for AD. Many genes, such as CEACAM19, BCL3, BCAM, NECTIN2, TOMM40, APOE, CLASRP, and OPA3, are in the about 1M region around APOE on chromosome 19 and show both significant common-and rare-variant associations with AD.…”