Lipoprotein A (LPA) is a type of particle similar to low-density lipoprotein (LDL) that is considered one of the risk factors for cardiovascular disease (CVD) such as atherosclerosis, coronary heart disease, stroke, etc ^[1]. LP(a) is similar in size and lipid content to LDL (low-density lipoprotein) and contains the lipoprotein ApoB-100. However, unlike LDL, LP(a) contains a variable-length lipoprotein called Apo(a), which covalently binds to ApoB-100 through a single disulfide bond. LP(a) plays an important role in systemic lipid transport, guiding inflammatory cells into blood vessel walls and leading to smooth muscle cell proliferation. Furthermore, it is involved in wound healing and tissue repair, interacting with the components of blood vessel walls and the extracellular matrix ^[2]. However, LP(a) can also cause arterial narrowing by adhering to the arterial wall, accelerating the formation of blood clots, and thereby triggering a series of pathological changes related to coronary heart disease, cardiovascular disease, atherosclerosis, thrombus formation, and stroke ^[3].

The plasma concentration of LP(a) is closely related to genetic factors and is primarily regulated by the LPA gene. Therefore, the LPA gene is an important potential target for cardiovascular disease treatment. The LPA gene encodes a serine protease that inhibits the activity of tissue-type plasminogen activator I. Fragments of this protein, generated through protein hydrolysis, can adhere to atherosclerotic lesions in arteries, promoting blood clot formation. The LPA gene is expressed in both humans and non-human primates but is not expressed in mice. Constructing mouse models expressing the human LPA gene is of significant importance for developing lipid-lowering drugs, which can drive the development of novel therapies for cardiovascular diseases. Currently, various novel therapies targeting the transcription rate of the LPA gene are under development, including small interfering RNA (siRNA) and antisense oligonucleotides (ASO) ^[4].

This strain was a conditional mouse model expressing the human LPA gene, where the ‘loxP-Stop-loxP-hLPA’ sequence was inserted into the intron 1 of the ROSA26 safe harbor locus. When this model is bred with tool mice expressing Cre recombinase, sequence recombination occurs in the Cre-positive cells and tissues of the offspring mice. After the Cre-recombinase-mediated deletion of the stop element (LSL), specific expression of the human LPA gene can be achieved. The B6-hLPA(CKI) mice can be used for research related to atherosclerosis, and thrombotic cardiovascular diseases, as well as the development, screening, and preclinical evaluation of human LPA gene-targeted drugs.