Anthea LoBue , Zhixin Li , Sophia K. Heuser , Junjie Li , Francesca Leo , Lukas Vornholz , Luke S. Dunaway , Tatsiana Suvorava , Brant E. Isakson , Miriam M. Cortese-Krott
{"title":"Generation and characterization of a conditional eNOS knock out mouse model for cell-specific reactivation of eNOS in gain-of-function studies","authors":"Anthea LoBue , Zhixin Li , Sophia K. Heuser , Junjie Li , Francesca Leo , Lukas Vornholz , Luke S. Dunaway , Tatsiana Suvorava , Brant E. Isakson , Miriam M. Cortese-Krott","doi":"10.1016/j.niox.2024.10.009","DOIUrl":null,"url":null,"abstract":"<div><div>Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) in the vessel wall regulates blood pressure and cardiovascular hemodynamics. In this study, we generated conditional eNOS knock out (KO) mice characterized by a duplicated/inverted exon 2 flanked with two pairs of loxP regions (eNOS<sup>inv/inv</sup>); a Cre-recombinase activity induces cell-specific reactivation of eNOS, as a result of a flipping of the inverted exon 2 (eNOS<sup>fl</sup>). This work aimed to test the efficiency of the Cre-mediated cell-specific recombination and the resulting eNOS expression/function. As proof of concept, we crossed eNOS<sup>inv/inv</sup> mice with DeleterCre<sup>pos</sup> (DelCre<sup>pos</sup>) mice, expressing Cre recombinase in all cells. We generated heterozygous eNOS<sup>fl/inv</sup> or homozygous eNOS<sup>fl/fl</sup> mice, and eNOS<sup>inv/inv</sup> littermate mice. We found that both eNOS<sup>fl/fl</sup> and eNOS<sup>fl/inv</sup> mice express eNOS and the overall expression level depends on the number of mutated alleles, while eNOS<sup>inv/inv</sup> mice did not show any eNOS expression. Vascular endothelial function was restored in eNOS<sup>fl/fl</sup> and eNOS<sup>fl/inv</sup> mice, as determined by ACh-dependent vasodilation of aortic rings. Cre-dependent reactivation of eNOS in eNOS<sup>fl/fl</sup> and eNOS<sup>fl/inv</sup> mice rescued eNOS<sup>inv/inv</sup> (phenotypically global eNOS KO) mice from hypertension. These findings demonstrate that eNOS expression is restored in eNOS<sup>fl/fl</sup> mice at comparable physiological levels of WT mice, and its functional activity is independent on the number of the reactivated alleles. Therefore, eNOS<sup>inv/inv</sup> mice are a useful model for studying the effects of conditional reactivation of eNOS and gene dosage effects in specific cells for gain-of-function studies.</div></div>","PeriodicalId":19357,"journal":{"name":"Nitric oxide : biology and chemistry","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nitric oxide : biology and chemistry","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1089860324001368","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) in the vessel wall regulates blood pressure and cardiovascular hemodynamics. In this study, we generated conditional eNOS knock out (KO) mice characterized by a duplicated/inverted exon 2 flanked with two pairs of loxP regions (eNOSinv/inv); a Cre-recombinase activity induces cell-specific reactivation of eNOS, as a result of a flipping of the inverted exon 2 (eNOSfl). This work aimed to test the efficiency of the Cre-mediated cell-specific recombination and the resulting eNOS expression/function. As proof of concept, we crossed eNOSinv/inv mice with DeleterCrepos (DelCrepos) mice, expressing Cre recombinase in all cells. We generated heterozygous eNOSfl/inv or homozygous eNOSfl/fl mice, and eNOSinv/inv littermate mice. We found that both eNOSfl/fl and eNOSfl/inv mice express eNOS and the overall expression level depends on the number of mutated alleles, while eNOSinv/inv mice did not show any eNOS expression. Vascular endothelial function was restored in eNOSfl/fl and eNOSfl/inv mice, as determined by ACh-dependent vasodilation of aortic rings. Cre-dependent reactivation of eNOS in eNOSfl/fl and eNOSfl/inv mice rescued eNOSinv/inv (phenotypically global eNOS KO) mice from hypertension. These findings demonstrate that eNOS expression is restored in eNOSfl/fl mice at comparable physiological levels of WT mice, and its functional activity is independent on the number of the reactivated alleles. Therefore, eNOSinv/inv mice are a useful model for studying the effects of conditional reactivation of eNOS and gene dosage effects in specific cells for gain-of-function studies.
期刊介绍:
Nitric Oxide includes original research, methodology papers and reviews relating to nitric oxide and other gasotransmitters such as hydrogen sulfide and carbon monoxide. Special emphasis is placed on the biological chemistry, physiology, pharmacology, enzymology and pathological significance of these molecules in human health and disease. The journal also accepts manuscripts relating to plant and microbial studies involving these molecules.