The SERPINA1 gene encodes alpha-1 antitrypsin (AAT), a serine protease inhibitor primarily synthesized and secreted by hepatocytes in the liver, with additional expression in immune cells such as macrophages. AAT's main function is to inhibit neutrophil-derived proteases (e.g., elastase) to protect lung tissue from enzymatic degradation. This glycoprotein is crucial for maintaining lung tissue elasticity and regulating inflammatory responses. Mutations in the Serpina1 gene, particularly the Z variant (Glu342Lys), lead to alpha-1 antitrypsin deficiency (AATD), resulting in emphysema and chronic obstructive pulmonary disease (COPD) due to uncontrolled protease activity. Additionally, misfolded AAT accumulation in hepatocytes may cause cirrhosis or hepatocellular carcinoma ^[1-3]. The affected tissues primarily include the liver and lungs, with the former being damaged by protein aggregation and the latter by tissue destruction. This highlights AAT's systemic role in protease regulation and disease pathology. In mice, the Serpina1 gene cluster is located on chromosome 12, spanning a 230 kb genomic region, and encompasses five liver-specific human SERPINA1 homologous genes, which are arranged in the following order: Serpina1b, Serpina1d, Serpina1a, Serpina1c, and Serpina1e. The B6-hSERPINA1 mouse is a humanized model constructed by replacing the mouse Serpina1 gene cluster (from upstream of mouse Serpina1e to downstream of mouse Serpina1b) with the human SERPINA1 gene (from upstream to downstream of human SERPINA1). Homozygous B6-hSERPINA1 mice are viable and fertile and can be used to study the pathogenic mechanisms of emphysema and chronic obstructive pulmonary disease (COPD), cirrhosis, and hepatocellular carcinoma, as well as to develop related therapeutic approaches.

The SERPINA1 gene encodes alpha-1 antitrypsin (AAT), a serine protease inhibitor primarily synthesized and secreted by hepatocytes in the liver, with additional expression in immune cells such as macrophages. AAT's main function is to inhibit neutrophil-derived proteases (e.g., elastase) to protect lung tissue from enzymatic degradation. This glycoprotein is crucial for maintaining lung tissue elasticity and regulating inflammatory responses. Mutations in the Serpina1 gene, particularly the Z variant (such as the most common mutation p.E366K), can cause alpha-1 antitrypsin deficiency (AATD), which in turn leads to emphysema and chronic obstructive pulmonary disease (COPD). The pathological mechanism of these diseases stems from dysregulated protease activity. Additionally, the intracellular accumulation of misfolded AAT in hepatocytes may also induce cirrhosis or hepatocellular carcinoma ^[1-3]. Individuals carrying the ZZ genotype face the highest risk of developing pulmonary and hepatic disease manifestations: in the liver, protein aggregation causes cellular damage; in the lungs, tissue destruction triggers disease ^[4]. This highlights AAT's systemic role in protease regulation and disease pathology. The TG-hSERPINA1*E366K mouse is generated by integrating the Human SERPINA1 Genomic DNA (the region from ~5kb upstream of exon 1 to ~3kb downstream of exon 5) into the mouse genome via transgenesis (TG) technology. A p.E366K (GAG to AAG) point mutation is introduced into exon 5 of this integrated human SERPINA1 sequence. This model can be used to study diseases such as alpha-1 antitrypsin deficiency (AATD), emphysema, chronic obstructive pulmonary disease (COPD), cirrhosis, and hepatocellular carcinoma, as well as to develop relevant therapeutic strategies.

Sqle is located on chromosome 15 of mice. SgRNA and ssDNA were designed using Nuclease Technology; Sqle conditional knockout mice were obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Atxn7l3 is located on chromosome 11 of mice. Nuclease Technology will be used to design sgRNA; Atxn7l3 knockout mice will be obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.