Objective:To investigate the effect and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomal microRNA-1297 (miR-1297) on hippocampal neuron damage in depressed rats.Methods:BMSCs and BMSCs-derived exosomes were prepared and identified. Rats were first injected with corticosterone to establish the model of depression, and then injected with BMSCs-derived exosomes. Superoxide dismutase (SOD), malondialdehyde (MDA), lactate dehydrogenase (LDH), TNF-α and IL-1β in rat serum samples, hippocampal tissues and neurons were detected. Expression of miR-1297 in hippocampal tissues and neurons was detected by RT-qPCR. A rat hippocampal neuron injury model was established to investigate the role of BMSC-derived exosomes and miR-1297 in neuronal apoptosis and proliferation. The targeting relationship between miR-1297 and connective tissue growth factor (CTGF) was analyzed using dual luciferase reporter genes.Results:In the hippocampus of depressed rats, the expression of miR-1297 was low, while the expression of CTGF was elevated. Exosomes derived from BMSCs can inhibit the expression of CTGF by up-regulating the level of miR-1297, thereby inhibiting neuronal cell apoptosis in the hippocampus of depressed rats, while increasing the level of SOD, and reducing inflammatory damage, and ultimately improving the behavioral function of depressed rats.Conclusions:Depressed rats showed decreased expression of miR-1297 and increased expression of CTGF. BMSC-derived exosomes inhibited CTGF expression through up-regulating miR-1297, thereby improving hippocampal neuron damage in rats with depression.

OBJECTIVETo construct a personalized full-length fully human antibody mammalian display library for children with systemic lupus erythematosus (SLE).

METHODSThe total RNA was isolated from the PBMCs of SLE children. The heavy chain variable region and kappa light chain (VH and LCκ) of the antibody genes were amplified by RT-PCR and inserted into the pDGB-HC-TM vector separately to construct the heavy chain and light chain libraries. The library DNAs were transfected into 293T cells and the expression of full-length fully human antibody on the surface of 293T cells was analyzed by flow cytometry.

RESULTSUsing 0.8 µg total RNA as the template, the VH and LCκ were amplified and the full-length fully human antibody mammalian display library was constructed. The VH and LCκ gene libraries had a size of 9.4×10(4) and 8.4×10(4), respectively. Sequence analysis of 10 clones randomly selected from the VH and LCκ gene libraries each showed that 8 heavy chain clones and 7 light chain clones contained correct open reading frames, and flow cytometry demonstrated that all the 15 clones express full-length antibodies on 293T cell surfaces. 293T cells co-transfected with the VH and LCκ gene libraries expressed the full-length antibodies on the cell surface.

CONCLUSIONThe personalized full-length fully human antibody library for SLE children constructed allows display of the full-length antibodies on mammalian cell surfaces, thus providing a valuable platform for analyzing the autoantibodies, their etiological role, and their clinical implications in SLE.

Amino Acid Sequence ; Child ; Gene Library ; Genetic Vectors ; Humans ; Immunoglobulin Heavy Chains ; genetics ; Immunoglobulin kappa-Chains ; genetics ; Lupus Erythematosus, Systemic ; genetics ; immunology ; Membrane Proteins ; genetics

Animals ; Chromosomal Proteins, Non-Histone ; chemistry ; genetics ; metabolism ; Humans ; Models, Molecular ; Mutation ; Transcription Factors ; chemistry ; genetics ; metabolism