• The AGT gene encodes a protein (pre-angiotensinogen or angiotensinogen precursor) that is expressed in the liver. This protein is cleaved by renin when blood pressure drops, forming angiotensin I. Angiotensin I is then converted into the active form, angiotensin II, by ACE. This process helps regulate blood pressure and body fluid/electrolyte balance and plays a role in conditions like essential hypertension and preeclampsia.
• The exons 1-5 of mouse Agt gene that encode the whole molecule were replaced by human counterparts in B-hAGT mice. The promoter, 5’UTR and 3’UTR region of the mouse gene are replaced by human counterparts.
• Human AGT mRNA was detectable only in heterozygous B-hAGT mice, but not in wild-type C57BL/6 mice.
• Mouse AGT protein was both detectable in wild-type C57BL/6 mice and heterozygous B-hAGT mice. Human AGT was exclusively detectable in heterozygous B-hAGT mice.

Species specific analysis of AGT gene expression in wild-type C57BL/6 mice and heterozygous B-hAGT mice by RT-PCR. Livers were collected from wild-type C57BL/6 mice (+/+) and heterozygous B-hAGT mice (H/+). Human AGT mRNA was detectable only in heterozygous B-hAGT mice, but not in wild-type C57BL/6 mice.

Strain specific AGT expression analysis in wild-type C57BL/6JNifdc, homozygous humanized B-hAGT mice and homozygous humanized B-hAGT/hREN mice by ELISA. Serum was collected from wild-type C57BL/6JNifdc (+/+) (male, n=3, 7-week-old), homozygous B-hAGT mice (H/H) (male, n=3, 7-week-old) and homozygous B-hAGT/hREN mice (H/H;H/H) (male, n=3, 7-week-old). Expression level of mouse and human AGT were analyzed by ELISA(mouse AGT ELISA kit: Abcam, ab245718; human AGT ELISA kit:Abcam, ab287170). Mouse AGT was exclusively detectable in wild-type C57BL/6JNifdc. Human AGT was exclusively detectable in homozygous B-hAGT mice and B-hAGT/hREN mice. Values are expressed as mean ± SEM.

The inhibitory efficiency of the AGT targeted nucleic acid drugs in homozygous B-hAGT mice. B-hAGT mice were randomly divided into two groups (6-8 weeks old, female). The human AGT targeted nucleic acid drugs (synthesized according to patents) and PBS were administered to the mice individually. The nucleic acid drugs were administered in the form of PBS aqueous solution. The mice were sacrificed on day 28, and the liver tissue was collected to detect the expression level of human AGT mRNA by qPCR. (A) The schematic diagram of experimental processing. (B) The expression of human AGT mRNA in liver after treatment and the changes in AGT protein expression levels in plasma on day 7, 14, 21, and 28 after administration compared to the levels before administration. The inhibition rate in the treatment group of mRNA level was 96%. The human AGT in the treatment group (G2) was reduced compared to the control group (G1), demonstrating that B-hAGT mice provide a powerful preclinical model for in vivo evaluation of human AGT targeted nucleic acid drugs. Values are expressed as mean ± SEM.