Journal Article

Development and characterization of a fully humanized ACE2 mouse model

Ogala, Osarume, Slivano, Orazio J., Natekar, Janhavi, Griffin, Susan H., Salem, Amr R., Kumar, Ajay, Guglani, Anchala, Shoemaker, Robin, Ge, Chunyu, Basler, Christopher F., Miano, Joseph M., Wang, Gavin, Ogola, Benard O., Kumar, Mukesh, Elsharkawy, Amany, Doja, Jaser, Bryant, W. Bart

2025

Overview

Background Many humanized angiotensin-converting enzyme 2 ( ACE2 ) mouse models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection do not replicate human ACE2 protein expression and thus exhibit pathology infrequently observed in humans. To address this limitation, we designed and characterized a fully humanized ACE2 (h ACE2 ) mouse by replacing all exons/introns of the mouse Ace2 locus with human DNA comprising the entire ACE2 gene and an upstream long noncoding RNA (LncRNA). Results Compared to the popular Keratin18 ACE2 ( KRT18-ACE2 , K18 ) mouse model of SARS-CoV-2 infection, h ACE2 mice displayed a similar tissue expression profile of ACE2 as that seen in human tissues. Further, h ACE2 mice showed comparable blood pressure, angiotensin II metabolism, and renal cortical transcriptome as wild-type mice. Intranasal infection of K18 mice with the beta variant of SARS-CoV-2 resulted in high viral replication and inflammation of the lung and brain, weight loss, and compassionate euthanasia five days post-infection (PI). Similarly infected h ACE2 mice displayed viral replication and inflammation in the lung (but not in brain), sustained weight, and 100% survival up to 12 days PI, with clear evidence of acquired immunity. CRISPR-mediated disruption of the upstream LncRNA caused minimal effects on ACE2 mRNA and protein. Conclusions The h ACE2 model offers a more accurate approach to studying mechanisms underlying tissue-restricted expression of ACE2 , elucidating noncoding sequence variants and an upstream LncRNA, and defining pathways relevant to human disease and associated co-morbidities.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: ACE2 / ACE2 gene / Analysis / Angiotensin / Angiotensin II / Angiotensin-converting enzyme 2 / Angiotensin-Converting Enzyme 2 - genetics / Angiotensin-Converting Enzyme 2 - metabolism / Animal models / Animals / Antisense RNA / Biomedical and Life Sciences / Blood pressure / Brain / Coronaviruses / COVID-19 / COVID-19 - genetics / COVID-19 - pathology / COVID-19 - virology / CRISPR / Disease Models, Animal / Euthanasia / Exons / Females / Gender differences / Gene expression / Hormones / Human tissues / Humans / Infections / Inflammation / Introns / Kidneys / Laws, regulations and rules / Life Sciences / Long noncoding RNA / Lungs / Metabolism / Metabolites / Mice / Mice, Transgenic / Molecular weight / Mouse / Non-coding RNA / Pandemics / Pathogenesis / Peptides / Peptidyl-dipeptidase A / Protein expression / Proteins / Replication / Respiratory diseases / RNA, Long Noncoding - genetics / SARS-CoV-2 / SARS-CoV-2 - physiology / Severe acute respiratory syndrome coronavirus 2 / Transcriptomes / Viral diseases / Weight loss