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Objective:To determine the effect of miR-122-5p on microglia polarization, apoptosis and inflammation after traumatic brain injury (TBI).Methods:A mouse model and an in vitro TBI model were established. Astrocytes were stimulated to synthesize and release exosomes by brain extracts. microRNA microarray analysis was used to analyze the significantly altered microRNAs. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to detect the expression of miR-122-5p in the in vivo and in vitro TBI model. TUNEL, immunofluorescence, and Western blot were performed to detect the effects of miR-122-5p inhibitors on microglia apoptosis, microglia M1/M2 phenotype transformation and the activation of NLRP3 inflammasome pathway and the phosphorylation of NF-κB after TBI.Results:The results of microRNA microarray analysis showed that 83 miRNAs were downregulated significantly (altered more than 2 folds, P < 0.05), among which miR-122-5p was significantly down-regulated ( P < 0.01). Expression of miR-122-5p was significantly decreased in the in vivo and in vitro TBI model [(1.00±0.00) vs. (0.41±0.15), P < 0.001; (1.00±0.00) vs. (0.34±0.07), P < 0.001]. TUNEL and immunofluorescence showed that miR-122-5p inhibitor significantly alleviated microglia apoptosis[(8.03±1.30) vs. (3.17±0.34), P < 0.001] and promoted microglia M1→M2 phenotype transformation ,M1 phenotype polarization was reduced [(56.96±13.70) vs. (34.70±3.47), P =0.002] and M2 phenotype polarization was increased [(30.46±3.67) vs. (40.74±2.49), P =0.005]. Western blot showed that NLRP3 inflammasome activation was inhibited and NF-κB phosphorylation was decreased when miR-122-5p was downregulated[(0.77±0.10) vs. (0.51±0.11), P =0.02; (0.73±0.08) vs. (0.50±0.07), P =0.003]. Conclusions:miR-122-5p is downregulated in microglia and exosomes secreted by astrocytes after TBI. miR-122-5p inhibitor can attenuate the microglia inflammatory response after TBI by inhibiting the activation of NLRP3 inflammasome pathway and the phosphorylation of NF-κB, promoting the microglia M1→M2 phenotypic transformation and reducing microglia apoptosis, thereby reducing the microglia inflammatory injury after TBI.
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Objective To investigate the clinical and aspartoacylase (ASPA) gene mutation characteristics of Canavan disease.Methods The clinical data of a child with Canavan disease diagnosed by gene detection who visited Children's Hospital Affiliated to Zhengzhou University in June 2018 were reviewed and analyzed.Results A one year and five months old girl presented with psychomotor retrogression,hypermyotonia,and tendon hyperreflexia.The urinary N-acetylaspartic acid levels were significantly higher (66.832 7,more than 60 times that of normal individuals).Magnetic resonance imaging of the brain showed a multiple and symmetrical hyperintense signal changes in the cerebral white matter.Two heterozygous mutations c.79_80del (p.Gly27Arg) and c.554G＞T (p.Gly185Val) were screened by targeted next generation sequencing.The results of Sanger sequencing showed the two mutations were compound heterozygous mutation derived from her father and mother,and the mutation c.554G＞T has never been reported.Conclusions The next generation sequencing can accurately detect ASPA gene mutation as the first choice for the diagnosis of Canavan disease.The mutation c.554G＞T enriches the gene mutation spectrum of Canavan disease.
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Objective To investigate the clinical,biochemical and genetic features of hereditary hypomagnesaemia with secondary hypocalcaemia.Methods Two boys came from different Chinese families.They were hospitalized at the Peking University First Hospital between 2014 and 2016 at the age of 9 years and 1 year and 2 months because of epilepsy and psychomotor retardation.Clinical investigation,laboratory examination,and medical imaging were performed for the etiological study.Whole-genome sequencing was used for the genetic analysis of the patients.Mutations of TRPM6 gene were confirmed by means of Sanger sequencing.Results Patient 1 presented with recurrent seizures and psychomotor retardation from the age of 3 months.Vision loss and psychomotor regression were noticed from the age of 9 years,accompanied with hypertension.Serum magnesium and total calcium were significandy decreased to 0.13-0.15 mmol/L and 1.43-2.00 mmol/L,respectively in patient 1.Serum potassium was reduced to 1.85-3.25 mmol/L.Blood parathyroid hormone was also decreased.On the TRPM6 gene of patient 1,2 novel non-sense mutations,c.2771G ＞ A (p.Trp924Ter) and c.115C ＞ T (p.Gln39Ter) were identified.Patient 2 presented with seizures and psychomotor retardation at the age of 2 weeks.Both of his serum magnesium (0.17-0.35 mmol/L) and serum total calcium (1.32-1.34 mmol/L) were significantly decreased.Blood parathyroid hormone was decreased.Two novel mutations (c.1239G ＞ A,p.W413X and c.146G ＞ A,p.C49Y) were found in the TRPM6 gene of patient 2.Severe hypomagnesaemia,hypocalcaemia and TRPM6 gene mutations confirmed the diagnosis of hereditary hypomagnesaemia with secondary hypocalcaemia in the 2 patients.After the large-dose supplement of magnesium sulfate,progressive clinical improvements were observed in the 2 patients.However,because of the severe brain damage,patient 1 still had psychomotor retardation.Patient 2 completely recovered.Conclusions Hereditary hypomagnesaemia with secondary hypocalcaemia is a severe inherited metabolic disease.Early diagnosis and large-dose magnesium supplement are the key to the good prognosis of the patients.In this study,2 Chinese children with the clinical onset of epilepsy and psychomotor retardation are reported.The diagnosis is made by way of blood biochemical assay and gene analysis.Four novel mutations on their TRPM6 gene are identified.