Description

• 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-G-F mice carried humanizing Aβ region R684H, F681Y, and G676R mutations, and the KM670/671NL (Swedish) mutation in exon 16 as well as the E693G (Arctic) and I716F (Beyreuther/Iberian) mutations in exon 17 of the mouse App gene. This mice expressed humanized Aβ with three familial AD mutations.
• mRNA expression analysis: The App mRNA in B-App NL-G-F mice contained a humanized Aβ sequence (G676R*F681Y*R684H), along with Swedish (K670N*M671L), Beyreuther/Iberian (I716F), and Arctic mutations (E693G). These point mutations were confirmed via Sanger Sequencing.
• Protein expression analysis: The humanized Aβ was only detected in brain of homozygous B-App NL-G-F mice, but not in wild type mice.
• Immunohistochemistry analysis: The Aβ plaques was exclusively detectable in homozygous B-App NL-G-F mice. Compared to wild-type mice, the number of activated astrocytes and microglia cells in the cortex and hippocampus significantly increases, indicating the presence of inflammation in the brain.
• Application: This product is used for pharmacodynamics and safety evaluation of Alzheimer's disease (AD).

Targeting strategy

Gene targeting strategy for B-App NL-G-F mice. The B-App NL-G-F mice carried humanizing Aβ region R684H, F681Y, and G676R mutations, and the KM670/671NL (Swedish) mutation in exon 16 as well as the E693G (Arctic) and I716F (Beyreuther/Iberian ) mutations in exon 17 of the mouse App gene. This B-App NL-G-F mice expressed humanized Aβ with three familial AD mutations.

mRNA expression analysis

Species specific analysis of App gene expression in wild-type C57BL/6JNifdc mice and homozygous B-App NL-G-F mice by RT-PCR. Brain RNA were isolated from wild-type C57BL/6J mice (+/+) and homozygous B-App NL-G-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/6J and homozygous mice, and point mutations were confirmed via Sanger Sequencing.

Protein expression analysis

Western blot analysis of APP protein expression in homozygous B-App NL-G-F mice. Various tissue lysates were collected from wild-type C57BL/6J mice (+/+) and homozygous B-App NL-G-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. Human Abeta sequence 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-G-F mice. Various tissue lysates were collected from wild-type C57BL/6J mice (+/+) and homozygous B-App NL-G-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. Human Abeta sequence was detected in brain of homozygous B-App NL-F mice, but not in wild-type mice.

Immunohistochemistry analysis

Histopathological analysis of brain in homozygous B-App NL-G-F mice. Brain was collected from wild-type (WT) mice, homozygous B-App NL-G-F mice and processed into paraffin sections. The Aβ plaque in the cortex and hippocampus of 6-month-old wild-type C57BL/6J mice and homozygous B-App NL-G-F mice was detected by IHC with anti-human β-Amyloid antibody (CST, #8243S). The Aβ plaque was exclusively detectable in homozygous B-App NL-G-F mice, but not in wild-type mice. There is no significant difference in Aβ plaques between female and male mice.

Histopathological analysis of brain in homozygous B-App NL-G-F mice. Brain was collected from wild-type (WT) mice, homozygous B-App NL-G-F mice and processed into paraffin sections. The expression of GFAP in the cortex and hippocampus of 6-month-old C57BL/6J mice and homozygous B-App NL-G-F mice was detected by IHC with anti-GFAP antibody (abcam, ab68428). Compared to wild-type mice, the number of activated astrocytes in the cortex and hippocampus significantly increases, indicating the presence of inflammation in the brain.

Histopathological analysis of brain in homozygous B-App NL-G-F mice. Brain was collected from wild-type (WT) mice, homozygous B-App NL-G-F mice and processed into paraffin sections. The expression of Iba1 in the cortex and hippocampus of 6-month-old C57BL/6J mice and homozygous B-App NL-G-F mice was detected by IHC with anti-Iba1 antibody (abcam, ab178846). Compared to wild-type mice, the number of activated microglias in the cortex and hippocampus significantly increases, indicating the presence of inflammation in the brain.