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Objective To investigate the relationship between changes in protein tyrosine kinase 7 (PTK7) and receptor tyrosine kinase-like orphan receptor 2 ( ROR2) expression in the brainstem and the pathogenesis of amyotrophic lateral sclerosis (ALS). Methods Forty-four human superoxide dismutase 1( hSODl)-G93A mutant ALS transgenic mice were selected, and an equal number of wild-type littermates was used as control. The brainstems were isolated at da)' 70, day 95, day 108 and da)' 122 after birth, and the morphology of frypoglossal nucleus (12N) and nucleus of facial nerve(7N) neurons in the brainstem of the model mice were observed by Nissl staining. The mRNA and protein expression of PTK7 and ROR2 were detected by RT-PCR and Western blotting respectively, and the cellular localization and distribution of PTK7 and ROR2 in 12N and 7N were observed by immunofluorescence double-labeling technique. Results The result of Nissl staining showed that Nissl bodies in the neurons reduced distinctly with vacuolar degeneration of neurons, cell body atrophy and nuclear volume reduction in the 12N and 7N brainstems of ALS transgenic mice. RT-PCR result indicated that ROR2 and PTK7 mRNA level in the brainstem of ALS transgenic mice were up-regulated at da)' 70, da)' 95, day 108 and day 122 compared with wild-type littermates. Western blotting result showed that PTK7 protein was up-regulated at day 70, day 95, day 108 and day 122, ROR2 protein was up-regulated at day 70, day 95, day 108, and down-regulated at day 122 in the brainstem of ALS transgenic mice compared with wild-type littermates. Immunofluorescence result showed that ROR2/neuronal nuclei (NeuN)and PTK7/NeuN double positive cells, ROR2/glial fibrillary acidic protein (GFAP) and PTK7/GFAP double positive cells were observed in the 12N and 7N of the brainstem of ALS transgenic mice and wild-type mice, suggesting that ROR2 and PTK7 were expressed both in neurons and astrocytes. Conclusion PTK7 and ROR2 are abnormally expressed in the brainstem of ALS transgenic mice, which is closely related to the pathogenesis of ALS.
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Objective To investigate the relationship between the expressions of iron transport related proteins and the dysregulation of iron homeostasis in the spinal cord of amyotrophic lateral sclerosis (ALS) transgenic mice. Methods The hSOD1
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To investigate the anti-oxidative effect of celastrol on HO-induced oxidative stress in the cell model of amyotrophic lateral sclerosis (ALS) and its molecular mechanism, NSC34 motor neuron-like cells were transfected with EGFP-G93A-SOD1 plasmid and used as in vitro ALS cell model. SOD1transfected NSC34 cells were treated with different doses of HOand celastrol. The survival rate of the cells was detected by CCK-8 assay, and malondialdehyde (MDA) content was detected by corresponding kit. The mRNA expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione S-transferases (GST) were detected by real-time PCR. The activation of intracellular MEK/ERK and PI3K/Akt signal pathways was detected by Western blot. The results showed that pre-incubation of celastrol (50 nmol/L) for 4 h prior to HO(10 μmol/L) co-treatment for another 24 h significantly attenuated HO-induced cell death and MDA level in SOD1transfected NSC34 cells. Real-time PCR showed that the mRNA expressions of GCLC and GST were enhanced with pre-incubation of celastrol. Celastrol quickly induced phosphorylation of ERK1/2 and Akt within 30 min and 1 h respectively in SOD1transfected NSC34 cells. Pharmacological inhibitors of MEK (PD98059, 10 μmol/L) or Akt (MK2206, 10 μmol/L) could reverse the phosphorylation of ERK1/2 and Akt, and abolish up-regulation of GCLC and GST induced by celastrol at mRNA levels. Taken together, we conclude that celastrol exerts a beneficial antioxidant effect in SOD1NSC34 cells, which might be dependent on MEK/ERK and PI3K/Akt signaling pathway activation.