ABSTRACT
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons and lacks an effective treatment. The disease pathogenesis has not been clarified at present. Pathological transactive response DNA-binding protein 43 (TDP-43) plays an important role in the pathogenesis of ALS. Nuclear translocation of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) is found in a mutant TDP-43 transgenic cell model, but its downstream antioxidant enzyme expression is decreased. To elucidate the specific mechanism of Nrf2/ARE (antioxidant responsive element) signaling dysfunction, we constructed an ALS cell model with human mutant TDP-43 using the NSC-34 cell line to evaluate the impact of the TDP-43 mutation on the Nrf2/ARE pathway. We found the nuclear translocation of Nrf2, but the expression of total Nrf2, cytoplasmic Nrf2, and downstream phase II detoxifying enzyme (NQO1) was decreased in NSC-34 cells transfected with the TDP-43-M337V plasmid. Besides, TDP-43-M337V plasmid-transfected NSC-34 cells were rounded with reduced neurites, shortened axons, increased levels of intracellular lipid peroxidation products, and decreased viability, which suggests that the TDP-43-M337V plasmid weakened the antioxidant capacity of NSC-34 cells and increased their susceptibility to oxidative damage. We further showed that expression of the MafK protein and the Jun dimerization protein 2 (JDP2) was reduced in TDP-43-M337V plasmid-transfected NSC-34 cells, which might cause accumulation of Nrf2 in nuclei but a decrease in NQO1 expression. Taken together, our results confirmed that TDP-43-M337V impaired the Nrf2/ARE pathway by reducing the expression of MafK and JDP2 proteins, and provided information for further research on the molecular mechanisms of TDP-43-M337V in ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/metabolism , DNA-Binding Proteins/metabolism , MafK Transcription Factor/metabolism , Mutation, Missense , NF-E2-Related Factor 2/metabolism , Repressor Proteins/metabolism , Response Elements , Animals , Cell Line , DNA-Binding Proteins/genetics , MafK Transcription Factor/genetics , Mice , NAD(P)H Dehydrogenase (Quinone)/metabolism , Neurons/metabolism , Oxidative Stress , Repressor Proteins/geneticsABSTRACT
To study the impact of cold ischemia on tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) expression after liver transplantation, a stable model of partial liver transplantation in rats was established. The experimental animals were divided into the following groups: a partial hepatectomy control group, a group that received partial liver transplantation after 30 min of cold ischemia (experimental group A), and a group that received a partial liver transplantation after 10 h of cold ischemia (experimental group B). The survival rate was observed in each group. The liver tissue was sampled 1, 2, and 4 days after surgery, and immunohistochemical detection of proliferating cell nuclear antigen TNF-α and IL-10 was performed. The correlation between liver regeneration and TNF-α and IL-10 expression was analyzed, and the impact of the 2 cytokines on rat liver regeneration after liver transplantation was evaluated. The survival rates of rats in the partial hepatectomy control group, in the group that received a partial liver transplantation after 30 min of cold ischemia, and the group that received a partial liver transplantation after 10 h of cold ischemia were 100, 70, and 33.3%, respectively. The expression of proliferating cell nuclear antigen and TNF-α was decreased (P < 0.05), and IL-10 expression was increased (P < 0.05) in animals that received a partial liver transplant after 10 h of cold ischemia compared with that in the animals that received a partial liver transplant after 30 min of cold ischemia. We conclude that with the extension of cold ischemic time, liver regeneration and survival rate after liver transplantation decreased. TNF-α and IL-10 play important regulatory roles in the regeneration process of transplanted livers.
Subject(s)
Cold Ischemia/adverse effects , Interleukin-10/metabolism , Liver Transplantation/methods , Proliferating Cell Nuclear Antigen/metabolism , Tumor Necrosis Factor-alpha/metabolism , Animals , Hepatectomy , Interleukin-10/genetics , Liver/pathology , Liver Regeneration , Male , Proliferating Cell Nuclear Antigen/genetics , Rats , Rats, Wistar , Tumor Necrosis Factor-alpha/geneticsABSTRACT
The oriental leafworm moth, Spodoptera litura, is a major agricultural pest in southeast Asia and nearby Pacific regions. Two distinct trehalases have been identified in insects: soluble trehalase (Treh1) and membrane-bound trehalase (Treh2), although there is currently no information on these genes in S. litura. To characterize the distribution and function of treh, cDNAs of Treh proteins were cloned from S. litura. SpoliTreh1 cDNA has an open reading frame of 1758 nucleotides, which encodes a protein of 585 amino acids, with a predicted mass of approximately 67.07 kDa and an isoelectric point of 4.86. SpoliTreh2 cDNA has an open reading frame of 2325 nucleotides, encoding a protein of 645 amino acids, a mass of approximately 73.62 kDa, and an isoelectric point of 5.90. Northern blotting analysis revealed that SpoliTreh1 transcripts are in the midgut, fat body, tracheae, and epidermis, but not in the brain and Malpighian tubules of S. litura larvae, whereas SpoliTreh2 transcripts were found in all 6 tissues. SpoliTreh1 transcripts were highly expressed in the fat body of the pre-pupal stage, and SpoliTreh2 transcripts were highly expressed in the fat body of 3-day-old larvae of the 6th instar and during the 1st 6 days of the pupal stage, except the 2nd day. Both SpoliTreh1 and SpoliTreh2 were highly expressed in third-instar larvae.