• Tissue inhibitor of metalloproteinases-4 (TIMP-4) is one of the member of the TIMP family, which regulates extracellular matrix remodeling and other cellular processes. TIMP4 inhibits a variety of proteases, such as ADAM and MMP family proteases.
• The exons 1~5 of mouse Timp4 gene that encode the full-length protein and 3’UTR are replaced by human counterparts in B-hTIMP4 mice. The promoter and 5’UTR region of the mouse gene are retained. The human TIMP4 expression is driven by endogenous mouse Timp4 promoter, while mouse Timp4 gene transcription and translation will be disrupted.
• Mouse Timp4 was only detectable in wild-type C57BL/6N mice. Human TIMP4 was detectable in homozygous B-hTIMP4 mice but not in wild-type mice.
• Homozygous mice developed normally.
• This model is useful in studying the role of TIMP4 in human cancers, and also can be used to evaluate the efficacy and safety of drugs targeting TIMP4.

Gene targeting strategy for B-hTIMP4 mice. The exons 1~5 of mouse Timp4 gene that encode the full-length protein and 3’UTR are replaced by human counterparts in B-hTIMP4 mice. The promoter and 5’UTR region of the mouse gene are retained. The human TIMP4 expression is driven by endogenous mouse Timp4 promoter, while mouse Timp4 gene transcription and translation will be disrupted.

Strain specific analysis of TIMP4 mRNA expression in wild-type C57BL/6N mice and B-hTIMP4 mice by RT-PCR. Heart RNA were isolated from wild-type C57BL/6N mice (+/+) and homozygous B-hTIMP4 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human TIMP4 primers. Mouse Timp4 mRNA was detectable only in C57BL/6N mice. Human TIMP4 mRNA was detectable only in homozygous B-hTIMP4 mice, and were confirmed via Sanger Sequencing.