Effect of MiR-155 Knockout Mediated by Dual sgRNAs on Drug Sensitivity of FLT3-ITD+AML / 中国实验血液学杂志

OBJECTIVE@#Two sgRNAs transfected FLT3-ITD+AML cell line MV411 with different binding sites were introduced into CRISPR/cas9 to obtain MV411 cells with miR-155 gene knockout. To compare the efficiency of miR-155 gene knockout by single and double sgRNA transfection and their effects on cell phenotypes.@*METHODS@#The lentiviral vectors were generated containing either single sgRNA or dual sgRNAs and packaged into lentivirus particles. PCR was conducted to measure gene editing efficiency, and miR-155 expression was evaluated by qPCR. CCK-8 assay was used to evaluate the cell proliferation, and calculate drug sensitivity of cells to adriamycin and quizartinib. Annexin V-APC/7-AAD staining was used to label cell apoptosis induced by adriamycin and quizartinib.@*RESULTS@#In the dual sgRNAs transfected cells, a cleavage band could be observed, meaning the success of gene editing. Compared with the single sgRNA transfected MV411 cells, the expression level of mature miR-155-5p was lower in the dual sgRNA transfected cells. And, dual sgRNA transfected MV411 were more sensitive to adriamycin and quizartinib with lower IC50 and higher apoptosis rate.@*CONCLUSION@#The inhibition rate of miR-155 gene expression transfected by dual sgRNA is higher than that by single sgRNA. Dual sgRNA transfection can inhibit cell proliferation, reverse drug resistance, and induce apoptosis more significantly. Compared with single sgRNA transfection, dual sgRNA transfection is a highly efficient gene editing scheme.

Identify Myeloid Differentiation-Related MiRNAs Response to ATRA Induction by RNA Sequencing and CRISPR/Cas9 Gene Editing / 中国实验血液学杂志

OBJECTIVE@#To identify differentiation related miRNA and evaluate roles of miRNA during ATRA induced myeloid differentiation.@*METHODS@#The small RNA sequencing was used to analyze differential expressed miRNAs in ATRA induced NB4 cells. Then the several up or down-regulated miRNA were selected as the research candidates. SgRNAs targeting the genome of each miRNA were designed and NB4 cells with inducible expression of Cas9 protein were generated. After transduced sgRNA into NB4/Cas9 cells, the mutation level by PCR and surveyor assay were evaluated. The cell differentiation level was investigated by surface CD11b expression via flow cytometry.@*RESULTS@#A total of 410 mature miRNAs which expressed in NB4 cells were detected out after treated by ATRA, 74 miRNAs were up-regulated and 55 were down-regulated miRNAs with DNA cleavage generated by CRISPR/Cas9 was assayed directly by PCR or surveyor assay, quantitative PCR showed that the expression of miRNA was downregulated, which evaluated that gene edition successfully inhibitied the expression of mature miRNA. MiR-223 knockout showed the myeloid differentation of NB4 significantly inhibitied, while miRNA-155 knockout showed the myeloid differentation of NB4 cells significantly increased.@*CONCLUSION@#CRISPR/Cas9 is a powerful tool for gene editing and can lead to miRNA knockout. Knockouts of miR-223 and miR-155 have shown a differentiation-related phenotype, and the potential mechanism is the integrative regulation of target genes.

A genotyping study of 13 cases of early-onset Charcot-Marie-Tooth disease / 中国当代儿科杂志

OBJECTIVE@#To study the clinical characteristics and genetic variation of early-onset Charcot-Marie-Tooth disease (CMT).@*METHODS@#Children with a clinical diagnosis of early-onset CMT were selected for the study. Relevant clinical data were collected, and electromyogram and CMT-related gene detection were performed and analyzed.@*RESULTS@#A total of 13 cases of early-onset CMT were enrolled, including 9 males (69%) and 4 females (31%). The mean age at consultation was 4.0±2.1 years. Among them, 12 children (92%) had an age of onset less than 2 years, 9 children (69%) were diagnosed with CMT type 1 (including 6 cases of Dejerine-Sottas syndrome), 1 child (8%) with intermediate form of CMT, and 3 children (23%) with CMT type 2. The genetic test results of these 13 children showed 6 cases (46%) of PMP22 duplication mutation, 3 cases (23%) of MPZ gene insertion mutation and point mutation, 3 cases (23%) of MFN2 gene point mutation, and 1 case (8%) of NEFL gene point mutation. Eleven cases (85%) carried known pathogenic mutations and 2 cases (15%) had novel mutations. The new variant c.394C>G (p.P132A) of the MPZ gene was rated as "possibly pathogenic" and the new variant c.326A>G (p.K109R) of the MFN2 gene was rated as "pathogenic".@*CONCLUSIONS@#Early-onset CMT is mainly caused by PMP22 gene duplication mutation and MPZ gene mutations. The clinical phenotype is mainly CMT type 1, among which Dejerine-Sottas syndrome accounts for a considerable proportion.

Inhibitory Effect of NPM Gene Knockdown on Proliferation of Chronic Myeloid Leukemia Cell Line K562 and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the role of nucleophosmin (NPM) in the proliferation of chronic myeloid leukemia cells (K562 cells) and its mechanism by RNAi technology.@*METHODS@#shRNA was used to inhibit the expression of NPM. The expression of NPM gene was detected by real-time quantitative PCR. The effect of inhibiting NPM gene on cell proliferation was detected by MTS assay. Change of cell cycle was detected by flow cytometry. Western blot was used to detect the expression of cell cycle-related proteins.@*RESULTS@#The shRNA lentiviral vector targeting at NPM gene was successfully constructed and used to transfect the K562 cells. The results showed that compared with the control groups, suppression of NPM gene expression in K562 cells could inhibit the cell proliferation and decrease the cell colony formation. Moreover, interference of NPM gene could prolong G/G phase and arrest cell cycle, which may be related to the down-regulation of NPM gene expression and activation of p21 protein expression, thereby inhibited the formation of CDK2/ Cyclin E complex.@*CONCLUSION@#Down-regulation of NPM gene expression in K562 cells can induce cell cycle arrest and inhibit cell proliferation.

Clinical and genetic analyses of a family with atypical nonketotic hyperglycinemia caused by compound heterozygous mutations in the GLDC gene / 中国当代儿科杂志

Nonketotic hyperglycinemia (NKH) is an autosomal recessive hereditary disease caused by a defect in the glycine cleavage system and is classified into typical and atypical NKH. Atypical NKH has complex manifestations and is difficult to diagnose in clinical practice. This article reports a family of NKH. The parents had normal phenotypes, and the older brother and the younger sister developed this disease in the neonatal period. The older brother manifested as intractable epilepsy, severe spastic diplegia, intellectual disability, an increased level of glycine in blood and cerebrospinal fluid, an increased glycine/creatinine ratio in urine, and an increased ratio of glycine concentration in cerebrospinal fluid and blood. The younger sister manifested as delayed language development, ataxia, chorea, mental and behavior disorders induced by pyrexia, hypotonia, an increased level of glycine in cerebrospinal fluid, and an increased ratio of glycine concentration in cerebrospinal fluid and blood. High-throughput sequencing found a maternal missense mutation, c.3006C>G (p.C1002W), and a paternal nonsense mutation, c.1256C>G (p.S419X), in the GLDC gene in both patients. These two mutations were thought to be pathogenic mutations by a biological software. H293T cells transfected with these two mutants of the GLDC gene had a down-regulated activity of glycine decarboxylase. NKH has various phenotypes, and high-throughput sequencing helps to make a confirmed diagnosis. Atypical NKH is associated with the downregulated activity of glycine decarboxylase caused by gene mutations.

Cannabinoid receptor 1 expression and pathological changes in rat hippocampus after deprivation of rapid eye movement sleep / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe the expression of cannabinoid receptor 1 (CB1R) mRNA and pathological changes in rat hippocampus after deprivation of rapid eye movement (REM) sleep.</p><p><b>METHODS</b>Totally 42 Sprague-Dawley male rats were randomly divided into cage control (CC), tank control (TC) and the sleep deprivation groups (SD). The SD and TC rats were sacrificed at the end of 1 d, 3 d and 5 d sleep deprivation periods, respectively. The modified multiple platform methods were established for the REM sleep deprivation. CB1R mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR). The hippocampus sections of different stages were observed with electron microscope.</p><p><b>RESULT</b>In SD 1 d group, the expression of CB1R mRNA was significantly increased compared with the CC, TC, SD 3 d and SD 5 d groups (P <0.05) while in SD 3 d group it was reduced. The expression of CB1R mRNA of SD 5 d group was significantly higher than that of the SD 3 d group (P <0.05). Neuron apoptosis was found in SD 3 d and SD 5 d groups.</p><p><b>CONCLUSION</b>Sleep deprivation can cause brain injury with the changes of CB1R mRNA expression.</p>