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Objective:To study the role of SUMOylation in the process of therapeutic hypothermia on neural stem cells (NSCs) in neonatal hypoxic-ischemic encephalopathy.Methods:SUMOylation is an essential post-translational modification involving small ubiquitin-like modifiers (SUMOs). Primary-cultured NSCs from mice were assigned into four groups: control group, hypoxia group, hypothermia group and hypoxia+hypothermia group. Western Blot was used to detect the protein levels of SUMO2/3, hypoxia-inducible factor-1α (HIF-1α), peroxisome proliferator-activated receptor γ coactivator factor 1α (PGC-1α) and octamer binding transcription factor 4 (Oct4). The diameters of NSCs were compared. ELISA was used to detect lactate dehydrogenase (LDH) level. Apoptosis was examined using flow cytometry. Immunofluorescence method was used to measure the differentiation of NSCs into neuronal cells.Results:Compared with the control group, the levels of SUMO2/3, HIF-1αand PGC-1α in NSCs of the hypoxia group increased 33%, 126% and 140%, respectively ( P<0.05). Compared with the control group, the levels of SUMO2/3 and PGC-1α in NSCs of the hypothermia group increased 52% and 536%, respectively ( P<0.05). Compared with the hypoxia group, the levels of SUMO2/3, HIF-1α, PGC-1α and Oct4 in the hypoxia+hypothermia group increased 44%, 40%, 230% and 59%, respectively ( P<0.05). The diameters of NSCs in hypoxia group, hypothermia group and hypoxia+hypothermia group were smaller than control group, and hypoxia+hypothermia group smaller than hypoxia group ( P<0.05). No significant differences existed in LDH levels between hypothermia group and control group ( P>0.05). LDH level in hypoxia+hypothermia group were significantly lower than hypoxia group ( P<0.05). No significant differences existed in the cell death rates between hypothermia group and control group ( P>0.05). The cell death rate in hypoxia+hypothermia group was significantly lower than hypoxia group ( P<0.05). Compared with the control group, the expressions of Nestin in both hypoxia group and hypothermia group were increased, but neuron specific enolase (NSE) were decreased ( P<0.05). Compared with hypoxia group and hypothermia group, the level of Nestin in hypoxia+hypothermia group was further increased, while NSE was further decreased ( P<0.05). Conclusions:Therapeutic hypothermia may increase the tolerance of NSCs to hypoxia by enhancing SUMO modification of proteins, providing theoretical basis for the treatment of hypoxic-ischemic encephalopathy with therapeutic hypothermia.
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Objective@#To compare the predictive validity of writhing movements assessments of neurological outcome between high-risk preterm and full-term infants.@*Methods@#High-risk preterm and full-term infants who accepted the general movements(GMs) assessments from July 2013 to April 2014 and took part in follow-up regularly for 1 year in the Newborn Pediatrics Department of the Fifth Central Hospital of Tianjin were confirmed as the participants.GMs recordings during writhing movements period (at least once) and fidgety movements period (at least once) were collected and assessed.Neurological outcome was confirmed by Peabody Developmental Motor Scale-2(PDMS-2) when the patients were 1 year old.Then the predictive validities of writhing movements assessments of neurological outcome between high-risk preterm and full-term infants were calculated and compared.@*Results@#There was no significant difference in the detection rate of writhing movements between preterm and full-term infant groups(χ2=1.592, P=0.207). There was no significant difference in the detection rate of fidgety movements between preterm and full-term infant groups(χ2=1.605, P=0.205). The sensitivity was 92.9%, the specificity was 90.0%, and the negative predictive value was 97.8% in the stage of writhing movement to the motor development outcome in preterm infant group; the sensitivity was 85.7%, the specificity was 94.0%, and the negative predictive value was 95.9% in the stage of fidgety movement to the motor development outcome in preterm infant group; there was a good consistency between the assessment of writhing movement and neurological outcome confirmed by PDMS-2(Kappa=0.703, P<0.01). The specificity was 71.0%, the positive predictive value was 55.6% in the stage of writhing movement to the motor development outcome in full-term infant group; there was a worse consistency between the assessment of writhing movement and neurological outcome confirmed by PDMS-2(Kappa=0.555, P<0.01). Both the sensitivity and the specificity were 75.0% in the stage of writhing movement to the cerebral palsy in preterm infant group; there was a poor consistency between the assessment of writhing movement and neurological outcome confirmed by PDMS-2(Kappa=0.311, P<0.05). The specificity was 85.4%, the positive predictive value was 22.2% in the stage of writhing movement to the cerebral palsy in full-term infant group; there was still a poor consistency between the assessment of writhing movement and neurological outcome confirmed by PDMS-2(Kappa=0.319, P<0.05). Both the sensitivity and the negative predictive value were 100.0% in the stage of fidgety movement to the cerebral palsy in both preterm and full-term infant groups.@*Conclusions@#The predictive validity of writhing movements assessments to the motor development outcome in preterm infant group is higher than in full-term infant group, and it can be used as a tool for early and accurate prediction of neural development outcome of brain injured premature infants.The predictive validity of writhing movements assessments of the cerebral palsy is poor.Both the sensitivity and the negative predictive value were high in the stage of fidgety movement to the cerebral palsy in both preterm and full-term infant groups, and it may be used to predict the cerebral palsy earlier.
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Objective To explore the regulation mechanism for miR - 125a - 5P in epidermal growth factor receptor(EGFR)signaling pathway in medulloblastoma. Methods The potential targets of miR - 125a - 5P in the EGFR signaling pathway were predicted by TargetScan and Sanger software,there were 3 groups:control group,non -sense group and miR - 125a - 5P group. Their relationship,between miR - 125a - 5P and cyclin - dependent kinase in-hibitor 2B( CDKN2B),E2F transcription factor 3( E2F3),mitogen - activated protein kinase 14( MAPK14)and growth factor receptor - bound protein 10(GRB10),were tested by luciferase experiments. After miR - 125a - 5P oligo-nucleotide was transfected to D341 cells,miR - 125a - 5P level was detected by reverse transcription polymerase chain reaction. Then the thiazolyl blue tetrazolium bromide assay was used to draw the cell growth curves,and Transwell assay was used to detect cell migration ability. The expression levels of GRB10,EGFR,phosphatidylinositol 3 - kinase(PI3K) and Ras were tested by Western blot method. Results The results of luciferase experimental results showed that GRB10 was the only target gene of miR - 125a - 5P. After miR - 125a - 5P being transfected,the D341 cell prolifera-tion obviously declined markedly. Compared with control group[(38. 16 ± 7. 47)% ]and the non - sense group [(36. 79 ± 8. 94)% ],cell migration rate in the miR - 125a - 5P group was lowest[(13. 59 ± 4. 41)% ],and there was a significant difference among 3 groups(χ2 = 11. 495,P < 0. 05);in the miR - 125a - 5P group,the expression level of EGFR increased 1. 67 times,GRB10,PI3K and Ras levels were reduced to 23% ,61% and 42% . Conclusion miR - 125a - 5P can inhibit tumor growth by silenced GRB10 expression targeting EGFR downstream signaling pathways in medulloblastoma.