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ObjectiveTo investigate the effects of maltol aluminum exposure on miR-193a-3p, demethylase AlkB homolog 5 (ALKBH5), phosphatase and tensin homolog deleted on chromosome ten (PTEN) and protein kinase B (AKT), and whether miR-193a-3p is involved in aluminum-induced cognitive impairment by regulating ALKBH5/PTEN/AKT signaling pathway. Methods Specific pathogen-free male SD rats were randomly divided into control group and low-, medium- and high- dose groups according to their body weight, with eight rats in each group. Rats in the low-, medium-, and high- dose groups were intraperitoneally injected with maltol aluminum solution at concentrations of 10.00, 20.00, and 40.00 μmol/kg body weight, respectively, while the rats in control group were given an equal volume of 0.9% sodium chloride solution. Rats were injected for five days every week for three months. After injection, the novel object recognized test was used to assess the learning and memory ability of the rats. The relative expression of miR-193a-3p and B-cell lymphocytoma-2 (Bcl-2), Bcl-2 associated X protein (Bax) and cysteine aspartate protease-3 (Caspase-3) mRNA in rat hippocampus was detected using the real-time quantitative polymerase chain reaction. The relative protein expression of ALKBH5, PTEN, and AKT2 in the rat hippocampus was detected using Western blot. Results The discrimination index and the preference index of the new object recognition test of the rats in high-dose group were lower than those in control group and low-dose group (all P<0.05). The relative expression of miR-193a-3p and Bcl-2 mRNA in the hippocampus of the rats in high-dose group was lower than those in control group and low-dose group (all P<0.05). The relative mRNA expression of Bax in the high-dose group was higher than those in the control group and low-dose group (both P<0.05). The relative mRNA expression of Caspase-3 of the rats in the high-dose group was higher than that in the other three groups (both P<0.05). The relative protein expression of ALKBH5 in the hippocampus of the rats in the high-dose group was lower than that in the control group (P<0.05). The relative expression of PTEN protein was higher than those in the control group and low-dose group (both P<0.05). The relative protein expression of AKT2 was lower than those in the control group and low-dose group (both P<0.05). Conclusion Sub-chronic aluminum exposure can inhibit the expression of miR-193a-3p in the hippocampus of rats, which may disrupt the ALKBH5/PTEN/AKT pathway and affect normal neuronal homeostasis and cellular function. This pathway may play an important role in aluminum-induced cognitive impairment.
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AIM:To investigate the effects of subchronic aluminum exposure on the expression of silent infor-mation regulator(Sirt1),Kelch-like ECH-associated protein 1(Keap1),nuclear factor E2-related factor 2(Nrf2),and microRNA-128-3p(miR-128-3p)in the hippocampus of rats.Additionally,we aimed to explore the mechanism of miR-128-3p and the Sirt1-Keap1/Nrf2 signaling pathways in aluminum-induced cognitive impairment in rats.METHODS:Thirty-two healthy 6-week-old SPF male SD rats,weighing(190±20)g,were randomly divided into four groups based on body weight:control group,low-dose(10 μmol/kg)group,medium-dose(20 μmol/kg)group,and high-dose(40 μmol/kg)group,with 8 rats in each group.The rat exposure model was established by intraperitoneal injection of maltol alumi-num.The Morris water maze test was used to assess the learning and memory ability of the rats.Western blot analysis was performed to measure the protein expression of Sirt1,Keap1 and Nrf2 in the hippocampus,while RT-qPCR was used to measure the expression of miR-128-3p in the hippocampus.The level of reactive oxygen species(ROS)in the cerebral cor-tex was detected using fluorescence staining in frozen sections.RESULTS:(1)In the positioning cruise experiment,the escape latency of the aluminum exposure group was significantly higher than that of the control group on the 3rd,4th,and 5th days(P＜0.05).On day 6,the number of times the rats crossed the platform and the platform quadrant in the high-dose group was reduced compared to the control and low-dose groups(P＜0.01).(2)The expression levels of Sirt1 and Nrf2 in the hippocampal tissues of all groups decreased gradually with increasing maltol aluminum exposure dose.The ex-pression level of Keap1 increased gradually with increasing maltol aluminum exposure dose.The expression level of miR-128-3p in the high-dose group was significantly higher than that in the control group(P＜0.05).(3)The content of gluta-thione peroxidase in the hippocampus of rats decreased with increasing exposure dose,while ROS levels gradually in-creased.CONCLUSION:Subchronic aluminum exposure can increase the expression of miR-128-3p in the rat hippo-campus and suppress the Sirt1-Keap1/Nrf2 signaling pathway.This inhibition prevents the activation of the Sirt1-Keap1/Nrf2 signaling pathway,leading to a reduced antioxidant capacity.The imbalance in the antioxidant system in rats results in oxidative damage to nerve cells and a subsequent decline in cognitive function.
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OBJECTIVE@#To carry out genetic and metabolite analysis for an infant with cerebral creatine deficiency syndrome type 2 (CCDS2).@*METHODS@#Clinical data of the child was collected. Whole-exome sequencing was carried out to identify potential variants by next generation sequencing. Candidate variants were confirmed by Sanger sequencing. Metabolites were determined by tandem mass spectrometry and magnetic resonance spectroscopy. Treatment was carried out following the diagnosis and genetic counseling for the affected family.@*RESULTS@#Two novel heterozygous variants (c.289delC and c.392-1G>C) of the GAMT gene were identified in the proband, which were respectively inherited from her father and mother. In silico analysis suggested both variants to be pathogenic. Creatine (Cr) level of the child was very low, and cerebral guanidinoacetate (GAA) level was slightly increased. But both had recovered to normal in two weeks, and cerebral Cr level was significantly improved after two months. Intellectual and motor development of the child were significantly improved.@*CONCLUSION@#The child was diagnosed with CCDS type 2, for which pathogenic variants of the GAMT gene may be accountable. Treatment has attained a satisfactory effect for the patient.