[Effect of LncRNA GATA3-AS1 Targeting MiR-515-5p on Cell Proliferation and Apoptosis in Childhood Acute Lymphoblastic Leukemia Cells].

OBJECTIVE: To investigate the effects of long non-coding RNA (lncRNA) GATA3 antisense RNA 1 (GATA3-AS1) targeting miR-515-5p on the proliferation and apoptosis of childhood acute lymphoblastic leukemia (ALL) cells. METHODS: RT-qPCR was used to determine the expression of GATA3-AS1 and miR-515-5p in the plasma of controls and ALL children. Human ALL cells Jurkat were divided into si-GATA3-AS1, si-NC, miR-NC, miR-515-5p, si-GATA3-AS1+anti-miR-NC and si-GATA3-AS1+anti-miR-515-5p groups. CCK-8 assay was used to detect the cell proliferation, and flow cytometry was used to detect the cell apoptosis. The targeting relationship between GATA3-AS1 and miR-515-5p was determined by dual-luciferase reporter assay. RESULTS: The expression level of GATA3-AS1 in the plasma of ALL children was significantly higher than that of controls (P <0.001), while the expression level of miR-515-5p was significantly lower than that of controls (P <0.001). Compared with the si-NC group, the cell inhibition rate, apoptosis rate, and miR-515-5p expression level in si-GATA3-AS1 group were significantly increased (P <0.001). Compared with the miR-NC group, the cell inhibition rate and apoptosis rate in miR-515-5p group were significantly increased (P <0.001). GATA3-AS1 could directly and specifically bind to miR-515-5p. Compared with the si-GATA3-AS1+anti-miR-NC group, the cell inhibition rate and apoptosis rate in si-GATA3-AS1+anti-miR-515-5p group were significantly decreased (P <0.001). CONCLUSION: Down-regulation of GATA3-AS1 can inhibit proliferation and induce apoptosis of childhood ALL cells by targeting up-regulation of miR-515-5p expression.

Critical residues and motifs for homodimerization of the first transmembrane domain of the plasma membrane glycoprotein CD36.

The plasma transmembrane (TM) glycoprotein CD36 is critically involved in many essential signaling processes, especially the binding/uptake of long-chain fatty acids and oxidized low-density lipoproteins. The association of CD36 potentially activates cytosolic protein tyrosine kinases that are thought to associate with the C-terminal cytoplasmic tail of CD36. To understand the mechanisms by which CD36 mediates ligand binding and signal transduction, we have characterized the homo-oligomeric interaction of CD36 TM domains in membrane environments and with molecular dynamics (MD) simulations. Analysis of pyrene- and coumarin-labeled TM1 peptides in SDS by FRET confirmed the homodimerization of the CD36 TM1 peptide. Homodimerization assays of CD36 TM domains with the TOXCAT technique showed that its first TM (TM1) domain, but not the second TM (TM2) domain, could homodimerize in a cell membrane. Small-residue, site-specific mutation scanning revealed that the CD36 TM1 dimerization is mediated by the conserved small residues Gly12, Gly16, Ala20, and Gly23 Furthermore, molecular dynamics (MD) simulation studies demonstrated that CD36 TM1 exhibited a switching dimerization with two right-handed packing modes driven by the 12GXXXGXXXA20 and 20AXXG23 motifs, and the mutational effect of G16I and G23I revealed these representative conformations of CD36 TM1. This packing switch pattern of CD36 TM1 homodimer was further examined and confirmed by FRET analysis of monobromobimane (mBBr)-labeled CD36 TM1 peptides. Overall, this work provides a structural basis for understanding the role of TM association in regulating signal transduction via CD36.

Synthesis and antiviral activity of a novel class of (5-oxazolyl)phenyl amines.

A series of novel (5-oxazolyl)phenyl amine derivatives were synthesized and their antiviral activities against the hepatitis C virus (HCV) and the coxsackie virus B3 (CVB3) and B6 (CVB6) were evaluated in vitro. Bioassays showed that the synthesized compounds 17a1, 17a4, 17a6, 17b1, 17d1, 17e2 and 17g3 exhibited potent antiviral activity against HCV (IC50 = 0.28-0.92 µM) and most synthesized compounds exhibited low cytotoxicity in Huh7.5 cells, compared to telaprevir. The compounds 17a1, 17a4, 17a5, 17a6, 17b1, 17b2, 17g1 and 17g3 showed strong activity against the CVB3 and/or CVB6 at low concentrations (IC50 < 2.0 µM). The (5-oxazolyl)phenyl amines 17a1, 17a4, 17a8, 17b1, 17d1, 17e2, 17f3 and 17g3 were identified as the most active on the biological assays, and will be studied further.

The dimerization interface of the glycoprotein Ibß transmembrane domain corresponds to polar residues within a leucine zipper motif.

Experiments with the transmembrane (TM) domains of the glycoprotein (GP) Ib-IX complex have indicated that the associations between the TM domains of these subunits play an important role in the proper assembly of the complex. As a first step toward understanding these associations, we previously found that the Ibß TM domain dimerized strongly in Escherichia coli cell membranes and led to Ibß TM-CYTO (cytoplasmic domain) dimerization in the SDS-PAGE assay, while neither Ibα nor IX TM-CYTO was able to dimerize. In this study, we used the TOXCAT assay to probe the Ibß TM domain dimerization interface by Ala- and Leu-scanning mutagenesis. Our results show that this interface is based on a leucine zipper-like heptad repeat pattern of amino acids. Mutating either one of polar residues Gln129 or His139 to Leu or Ala disrupted Ibß TM dimerization dramatically, indicating that polar residues might form part of the leucine zipper-based dimerization interface. Furthermore, these specific mutational effects in the TOXCAT assay were confirmed in the thiol-disulfide exchange and SDS-PAGE assays. The computational modeling studies further revealed that the most likely leucine zipper interface involves hydrogen bonding of Gln129 and electrostatic interaction of the His139 side chain. Correlation of computer modeling results with experimental mutagenesis studies on the Ibß TM domain may provide insights for understanding the role of the association of TM domains on the assembly of GP Ib-IX complex.

[Survey on prevalence of 1 526 children with sleep disturbances in age of 2 to 12 years old in Chengdu].

OBJECTIVE: To find out the prevalence of sleep disturbances for children aged 2 to 12 years old in Chengdu. METHODS: Totally 1 600 children aged 2-12 years old were selected from 5 districts in Chengdu and investigated by using questionnaire. RESULTS: All 1 526 survey papers were returned. The average time of every day sleep in each age group (infant group, pre-school age group and school age group) were 12.12 hours, 10.42 hours and 9.47 hours. The sleep time of the children in those three groups were much less than the standard one. The proportion of the prevalence of sleep disturbance was 37.88%. Among them, there were snoring in 5.57%, choke/gargling in 1.25%, sleep inquietude in 7.86%, mouth breathing in 4.59%, sweating in 21.36%, member spasm in 2.82%, molar teeth in 8.26%, night talking in 4.02%, somnambulate in 0.2%, bedwetting in 1.95%, and difficulty falling asleep in 10.75%. There were significant differences shown in different sexes and ages, and in incidence of symptoms of some sleep disturbances. The affecting factors were the co-sleeping, tonsillitis, bronchitis, pollen allergy and their parent's snore. CONCLUSION: The prevalence of sleep disturbances being higher and more severe than before might be due to the less sleeping time in Chengdu in children aged 2 to 12 years old. More attention should be paid by parents, the Ministry of Education and the children's doctors.