Background:

• The HJV gene is located on the long (q) arm of chromosome 1 at position 21.1. The HJV gene encodes the hemojuvelin protein, a crucial co-receptor that upregulates the iron-regulatory hormone hepcidin. Hepcidin is the master iron regulatory hormone, produced by the liver. Hemojuvelin is a key regulator of the hepcidin pathway. Its primary function is to control the absorption of dietary iron from the intestines and the release of recycled iron from storage sites. Mutations in this gene cause juvenile hemochromatosis (Type 2A), a severe disorder characterized by drastically low hepcidin levels, rapid iron overload, and multi-organ failure in young individuals.

Targeting strategy:

• The exons 1~4 of mouse Hjv gene that encodes the full-length protein was replaced by human HJV exons 1~4 in B-hRGMc mice. The 5’UTR and 3’UTR region of the mouse gene are replaced by human counterparts. The human HJV expression is driven by human HJV promoter, while mouse Hjv gene transcription and translation will be disrupted.

Verification: 

• Human RGMc was detectable in homozygous B-hRGMc mice.
• Mouse Rgmc mRNA was only detected in wild-type mice, human RGMC mRNA was only detected in homozygous B-hRGMc mice.

Application:

• This product can be used for efficacy or safety evaluation related to iron deficiency anemia.

Gene targeting strategy for B-hRGMc mice. The exons 1~4 of mouse Hjv gene that encodes the full-length protein was replaced by human HJV exons 1~4 in B-hRGMc mice. The 5’UTR and 3’UTR region of the mouse gene are replaced by human counterparts. The human HJV expression is driven by human HJV promoter, while mouse Hjv gene transcription and translation will be disrupted.

Western blot analysis of RGMc protein expression in homozygous B-hRGMc mice. Various tissue lysates were collected from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-hRGMc mice (H/H), and then analyzed by western blot with anti-RGMc antibody (Proteintech, 11758-1-AP). 40 μg total proteins were loaded for western blotting analysis. The RGMc protein was detectable in heart, liver, and kidney of wild-type C57BL/6JNifdc mice or homozygous B-hRGMc mice, as the antibody is cross-recognize both human and mouse RGMc.

Strain specific analysis of RGMC mRNA expression in wild-type C57BL/6JNifdc mice and homozygous B-hRGMc mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-hRGMc mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse and human primers. Mouse Rgmc mRNA was only detectable in wild-type mice. Human RGMC mRNA was only detectable in homozygous B-hRGMc mice.