Objective
Transgenic mice expressing
human TAR
DNA/
RNA binding protein 43 (hTDP-43)
mutant protein in
spinal cord motor neurons were constructed using HB9 promoter to establish a
disease model of
amyotrophic lateral sclerosis ( ALS) and explore the mechanism of ALS induced by hTDP-43
mutation.
Methods HB9 promoter junction mutant hTDP-43 vector was constructed
in vitro, and the positive
transgenic mouse strains were prepared by prokaryotic
injection and screened (There were 8-10
mutations at Q331K and M337V).
Gait analysis, rotary rod
fatigue test, and
suspension test were used to detect
locomotion ability of
mice.
Immunohistochemistry,
immunofluorescence staining and
Western blotting were used to detect hTDP-43, phosphorylated HTDP-43 ( p-hTDP-43) ,
Caspase-3, cleaved
Caspase-3, respectively. Expression of
ubiquitin, (3-tubulinIH(Tujl) , Ki67 and
cyclin-dependent kinase 5 (CDK5)
proteins were also detected. Results In
transgenic mice expressing mutant hTDP-43
protein in spinal
motor neurons, both hind
limbs were atrophied to the trunk side, and motor function showed progressive decline with increasing age. hTDP-43, p-hTDP-43,
Caspase-3, and cleaved
Caspase-3 were observed in spinal
motor neurons Caspase-3 positive
staining and
ubiquitin protein positive
inclusion body, and
in vitro isolation and
culture of spinal
motor neurons, it was found that hTDP-43 and
ubiquitin protein co-located in
choline acetyl translocation
enzyme ( ChAT) positive
motor neurons, accompanied by
ectopic expression of CDK5. Conclusion The mutant HDP 43
protein expressed in
mouse spinal cord motor neurons can promote the re-entry of differentiated mature
neurons into the
cell cycle, leading to the occurrence of ALS.