• Amyloid precursor protein (APP) is a 100-140 kDa transmembrane glycoprotein that plays a key role in the pathogenesis of Alzheimer's disease (AD). In the disease state, β-secretase and γ-secretase aberrantly cleave APP, resulting in the release of amyloid β (Aβ) peptides Aβ40 and Aβ42, which are neurotoxic fragments capable of oligomerizing, aggregating, and subsequently forming plaques.
• Gene editing strategy: The B-App NL-F mice carried some mutations on the mouse App gene, including R684H, F681Y, and G676R mutations on the Aβ region, and the KM670/671NL (Swedish) mutation in exon 16 as well as the I716F (Beyreuther/Iberian) mutation in exon 17. This mice expressed humanized Aβ with two familial AD mutations.
• mRNA expression analysis: The App mRNA in B-App NL-F mice contained a humanized Aβ sequence (G676R*F681Y*R684H), along with Swedish (K670N*M671L), and Beyreuther/Iberian (I716F) mutations. These point mutations were confirmed via Sanger Sequencing.
• Protein expression analysis: The humanized Aβ was only detected in the brain of homozygous B-App NL-F mice, but not in wild-type mice.
• Application: This product is used for pharmacodynamics and safety evaluation of antibody drugs for Alzheimer's disease (AD), but is not suitable for small nucleic acid drugs

Gene targeting strategy for B-App NL-F mice. The B-App NL-F mice carried some mutations on the mouse App gene, including R684H, F681Y, and G676R mutations on the Aβ region, and the KM670/671NL (Swedish) mutation in exon 16 as well as the I716F (Beyreuther/Iberian) mutation in exon 17. This mice expressed humanized Aβ with two familial AD mutations.

Species specific analysis of App gene expression in wild-type C57BL/6JNifdc mice and homozygous B-App NL-F mice by RT-PCR. Brain RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-App NL-F mice (mut/mut), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse App primers. Mouse App mRNA was detectable in wild-type C57BL/6JNifdc and homozygous B-App NL-F mice, and point mutations were confirmed via Sanger Sequencing.

Western blot analysis of APP protein expression in homozygous B-App NL-F mice. Various tissue lysates were collected from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-App NL-F mice (mut/mut), and then analyzed by western blot with species-specific anti-amyloid precursor antibody (Abcam, ab133588). 50 μg total proteins were loaded for western blotting analysis. Humanized Aβ was detected in brain of homozygous B-App NL-F mice, but not in wild-type mice.

Western blot analysis of APP protein expression in homozygous B-App NL-F mice. Various tissue lysates were collected from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-App NL-F mice (mut/mut), and then analyzed by western blot with species-specific anti-amyloid precursor antibody (Abcam, ab133588). 50 μg total proteins were loaded for western blotting analysis. Humanized Aβ was detected in the cortex and hippocampus of homozygous B-App NL-F mice, but not in wild-type mice.

Histopathological analysis of brain in homozygous B-App NL-F mice. Brain was collected from homozygous B-App NL-F mice and processed into paraffin sections. The Aβ plaque in the cortex and hippocampus of 12-month-old male and female homozygous B-App NL-F mice was detected by IHC with anti-human β-Amyloid antibody (CST, #8243S). The Aβ plaque was detected in the cortex and hippocampus of 12-month-old homozygous B-App NL-F mice.

Histopathological analysis of brain in homozygous B-App NL-F mice. Brain was collected from homozygous B-App NL-F mice and processed into paraffin sections. The astrocytes in the cortex and hippocampus of 12-month-old male and female homozygous B-App NL-F mice was detected by IHC with anti-GFAP antibody (abcam, ab68428). The proliferating astrocytes were detected in the cortex of homozygous B-App NL-F mice during 12-month-old.

Histopathological analysis of brain in homozygous B-App NL-F mice. Brain was collected from homozygous B-App NL-F mice and processed into paraffin sections. The microglia cells in the cortex and hippocampus of 12-month-old male and female homozygous B-App NL-F mice was detected by IHC with anti-Iba1 antibody (abcam, ab178846). The microglia cells were detected in the cortex and hippocampus of 12-month-old homozygous B-App NL-F mice.