Hepatocyte-Specific Nampt Knockout Mouse Model

Nampt^loxP/loxP mice and Alb-Cre mice were used to generate a hepatocyte-specific Nampt knockout (HC-Nampt^-/-) animal model. Alb-Cre transgenic mice were purchased from Shanghai Biomodel Organism Science & Technology Development Co.,Ltd. (Shanghai, China). Cre is a P1 phage-derived site-specific DNA recombinase [14 (link)]. It involves identifying and splicing the DNA sequence between two loxP sites, resulting in a single loxP site on a linear DNA molecule when two loxP sites are aligned in the same direction. Albumin (Alb) is specifically and abundantly expressed in the hepatocyte, and as a liver-targeted promoter, it has been widely used to prepare hepatocyte-specific gene knockout mice models [15 (link)]. Nampt^loxP/loxP mice were initially constructed by Dr. Oberdan Leo and donated to our laboratory. The breeding strategy (Figure 1A) was that Nampt^loxP/loxP mice were crossed with Alb-Cre mice to generate Nampt^loxP/WTAlb-Cre mice, which were crossed with Nampt^loxP/loxP mice to generate Nampt^loxP/loxPAlb-Cre mice. Nampt^loxP/loxPAlb-Cre mice crossed with Nampt^loxP/loxP, as maternal generation mice only for reproduction, finally generating offspring, Nampt^loxP/loxP Alb-Cre mice, which were HC-Nampt^-/- and littermate controls. Nampt^loxP/loxP is considered wild type (WT). All Nampt^loxP/loxP mice used to breed were homozygous and had no Alb-Cre.