Accessibility issues or difficulties with this website?
Call 919-962-2073 or email hchsadministration@unc.edu.

Collectrin ( deficiency in proximal tubules causes hypertension in mice and a variant associates with blood pressure in males in a Latino cohort.

TitleCollectrin ( deficiency in proximal tubules causes hypertension in mice and a variant associates with blood pressure in males in a Latino cohort.
Publication TypePublication
Year2023
AuthorsChu P-L, Gigliotti JC, Cechova S, Bodonyi-Kovacs G, Wang YT, Chen L, Wassertheil-Smoller S, Cai J, Isakson BE, Franceschini N, Le TH
JournalAm J Physiol Renal Physiol
Volume324
Issue1
PaginationF30-F42
Date Published2023 Jan 01
ISSN1522-1466
KeywordsAnimals, blood pressure, Female, genome-wide association study, Hispanic or Latino, Humans, Hypertension, Kidney Tubules, Proximal, Male, Membrane Glycoproteins, Mice, Mice, Knockout, Sodium Chloride, Dietary, Sodium-Hydrogen Exchanger 3
Abstract

Collectrin (), an angiotensin-converting enzyme 2 homologue, is a chaperone of amino acid transporters in the kidney and endothelium. Global collectrin knockout (KO) mice have hypertension, endothelial dysfunction, exaggerated salt sensitivity, and diminished renal blood flow. This phenotype is associated with altered nitric oxide and superoxide balance and increased proximal tubule (PT) Na/H exchanger isoform 3 (NHE3) expression. Collectrin is located on the X chromosome where genome-wide association population studies have largely been excluded. In the present study, we generated PT-specific collectrin KO (PT KO) mice to determine the precise contribution of PT collectrin in blood pressure homeostasis. We also examined the association of human single-nucleotide polymorphisms with blood pressure traits in 11,926 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Hispanic/Latino participants. PT KO mice exhibited hypertension, and this was associated with increased baseline NHE3 expression and diminished lithium excretion. However, PT KO mice did not display exaggerated salt sensitivity or a reduction in renal blood flow compared with control mice. Furthermore, PT KO mice exhibited enhanced endothelium-mediated dilation, suggesting a compensatory response to systemic hypertension induced by deficiency of collectrin in the PT. In HCHS/SOL participants, we observed sex-specific single-nucleotide polymorphism associations with diastolic blood pressure. In conclusion, loss of collectrin in the PT is sufficient to induce hypertension, at least in part, through activation of NHE3. Importantly, our model supports the notion that altered renal blood flow may be a determining factor for salt sensitivity. Further studies are needed to investigate the role of the TMEM27 locus on blood pressure and salt sensitivity in humans. The findings of our study are significant in several ways: ) loss of an amino acid chaperone in the proximal tubule is sufficient to cause hypertension, ) the results in global and proximal tubule-specific collectrin knockout mice support the notion that vascular dysfunction is required for salt sensitivity or that impaired renal tubule function causes hypertension but is not sufficient to cause salt sensitivity, and ) our study is the first to implicate a role of collectrin in human hypertension.

DOI10.1152/ajprenal.00176.2022
Alternate JournalAm J Physiol Renal Physiol
PubMed ID36264884
PubMed Central IDPMC9762972
Grant ListR01 DK113632 / DK / NIDDK NIH HHS / United States
MS#: 
0393
Manuscript Lead/Corresponding Author Affiliation: 
Affiliated Investigator - Not at HCHS/SOL site
ECI: 
Manuscript Status: 
Published