ABSTRACT
Philadelphia chromosome (Ph) positive (Ph+) B cell acute lymphoblastic leukemia (B-ALL) is the most common genetic abnormality associated with B-ALL and has been shown to confer the worst prognosis to both children and adults. Increasing evidence has revealed that high tribbles homologue 3 (TRIB3) expression contributes to multi-cancer development and progression, but the underlying role and molecular mechanisms of TRIB3 in Ph+ B-ALL remain unclear. Here, we report that TRIB3 expression was enhanced in Ph+ B-ALL patient samples and positively associated with the expression of breakpoint cluster region-Abelson tyrosine kinase (BCR-ABL). We further demonstrated that deletion of TRIB3 attenuated the progression of Ph+ B-ALL by reducing BCR-ABL expression. Mechanistically, TRIB3 interacted with lysosomal cysteine proteinase cathepsin Z (CTSZ) to suppress CTSZ-mediated BCR-ABL degradation, which enhanced BCR-ABL activity, causing high proliferation of Ph+ B-ALL cells. Thus, our study indicated that inhibiting the expression of TRIB3 to regulate BCR-ABL kinase activity may be exploited as an additional target therapy for Ph+ ALL. Procedures for animal study were performed with approval of the Animal Care and Use Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College. The procedure of human leukemia sample was approved by the Ethics Committee of Chinese Academy of Medical Sciences and Peking Union Medical College (KT2019055-EC-1).
ABSTRACT
Objective@#To investigate the significance of endoplasmic reticulum stress-associated gene tri-bbles pseudokinase 3 (TRIB3) in the long-term brain injury in rats with developing epilepy.@*Methods@#Thirty male SD rats aged 21 days were randomly divided into the control group and the epilepsy group, 15 rats in each group.The rats in the epilepsy group were intraperitoneally injected with kainic acid (10 mg/kg) to induce seizures, while the rats in the control group were injected with the equal volume of 9 g/L saline.The rats in two groups were euthanized at 30 d after kainic acid administration.The damage to the ultrastructure of the cortex were observed by using transmission electron microscopy.Neuronal apoptosis in the cortex of rats was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) assay.The expression and localization of glucose regulated protein 78 (GRP78), CCAAT/enhancer binding protein-homologous protein (CHOP), TRIB3, and the activation of protein kinase B (AKT) in the cortex were examined by using Western blot analysis and immunohistochemistry.@*Results@#Compared with the control group, the different ultrastructural changes were observed in the cortex in the epilepsy group rats.TUNEL assay indicated that the number of apoptosis cells of cortex in the epilepsy group was increased.The protein levels of GRP78 and TRIB3 were upregulated in the cortex of the epileptic rats (1.280±0.272, 1.725±0.570), compared with the control group (1.000±0.000, 1.000±0.000), and the differences were statistically significant (all P<0.05). There was no significant change in CHOP protein between the control group and the epilepsy group.The level of phosphorylated AKT(p-AKT) was decreased in the cortex of the epilepsy group (0.150±0.047), compared with the control group (1.000±0.000), and the difference was statistically significant (P<0.05).@*Conclusions@#The brain injury caused by epilepsy in the developing rats can sustain to the stage of mature rats, and the endoplasmic reti-culum stress-associated gene TRIB3 is involved in the pathogenesis of long-term brain damage in the rats with deve-loping epilepsy.
ABSTRACT
Objective To investigate the significance of endoplasmic reticulum stress _associated gene tri_bbles pseudokinase 3(TRIB3)in the long_term brain injury in rats with developing epilepy. Methods Thirty male SD rats aged 21 days were randomly divided into the control group and the epilepsy group,15 rats in each group. The rats in the epilepsy group were intraperitoneally injected with kainic acid(10 mg/kg)to induce seizures,while the rats in the control group were injected with the equal volume of 9 g/L saline. The rats in two groups were euthanized at 30 d after kainic acid administration. The damage to the ultrastructure of the cortex were observed by using transmission elec_tron microscopy. Neuronal apoptosis in the cortex of rats was detected by terminal_deoxynucleoitidyl transferase media_ted nick end labeling( TUNEL)assay. The expression and localization of glucose regulated protein 78( xRP78), CCAAT/enhancer binding protein _ homologous protein( CHOP ),TRIB3,and the activation of protein kinase B (AKT)in the cortex were examined by using Western blot analysis and immunohistochemistry. Results Compared with the control group,the different ultrastructural changes were observed in the cortex in the epilepsy group rats. TUNEL assay indicated that the number of apoptosis cells of cortex in the epilepsy group was increased. The protein levels of xRP78 and TRIB3 were upregulated in the cortex of the epileptic rats(1. 280 ± 0. 272,1. 725 ± 0. 570),com_pared with the control group(1. 000 ± 0. 000,1. 000 ± 0. 000),and the differences were statistically significant( all P<0. 05). There was no significant change in CHOP protein between the control group and the epilepsy group. The level of phosphorylated AKT(p_AKT)was decreased in the cortex of the epilepsy group(0. 150 ± 0. 047),compared with the control group(1. 000 ± 0. 000),and the difference was statistically significant(P<0. 05). Conclusions The brain injury caused by epilepsy in the developing rats can sustain to the stage of mature rats,and the endoplasmic reti_culum stress_associated gene TRIB3 is involved in the pathogenesis of long_term brain damage in the rats with deve_loping epilepsy.
ABSTRACT
Objective:To explore the kinase activity of novel receptor interacting protein kinase 3 (RIPK3) mutants. Methods:The four amino acids (Q84WDF87) of RIPK3 were mutated respectively and these mutants were co-transfected with mixed lineage kinase domain like pseudokinase (MLKL) into HEK293T cells. The auto-phosphorylation of these mutants at S232 and phosphorylation of MLKL at S345 were detected by Western blotting. The interaction between RIPK3 and MLKL was tested by co-immunoprecipitation. The oligomerization of MLKL was detected by non-reducing gel. Results:The kinase activities of RIPK3ΔQ84, RIPK3ΔW85 and RIPK3ΔD86 were effectively decreased. Nevertheless, the kinase activities of RIPK3Q84A/RIPK3Q84E, RIPK3W85Y and RIPK3D86A/RIPK3D86Y did not change markedly. The auto-phosphorylation of RIPK3W85A at S232 was decreased without affecting phosphorylation and oligomerization of MLKL. Conclusion:The amino acid site Q84, W85 or D86 plays a critical role in RIPK3 kinase activity. The kinase activity of RIPK3W85A is decreased, but it does not affect MLKL.