Author Correction: Transplanted miR-219-overexpressing oligodendrocyte precursor cells promoted remyelination and improved functional recovery in a chronic demyelinated model.

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Transplanted miR-219-overexpressing oligodendrocyte precursor cells promoted remyelination and improved functional recovery in a chronic demyelinated model.

Oligodendrocyte precursor cells (OPCs) have the ability to repair demyelinated lesions by maturing into myelin-producing oligodendrocytes. Recent evidence suggests that miR-219 helps regulate the differentiation of OPCs into oligodendrocytes. We performed oligodendrocyte differentiation studies using miR-219-overexpressing mouse embryonic stem cells (miR219-mESCs). The self-renewal and multiple differentiation properties of miR219-mESCs were analyzed by the expression of the stage-specific cell markers Nanog, Oct4, nestin, musashi1, GFAP, Tuj1 and O4. MiR-219 accelerated the differentiation of mESC-derived neural precursor cells (NPCs) into OPCs. We further transplanted OPCs derived from miR219-mESCs (miR219-OPCs) into cuprizone-induced chronically demyelinated mice to observe remyelination, which resulted in well-contained oligodendrocyte grafts that migrated along the corpus callosum and matured to express myelin basic protein (MBP). Ultrastructural studies further confirmed the presence of new myelin sheaths. Improved cognitive function in these mice was confirmed by behavioral tests. Importantly, the transplanted miR219-OPCs induced the proliferation of endogenous NPCs. In conclusion, these data demonstrate that miR-219 rapidly transforms mESCs into oligodendrocyte lineage cells and that the transplantation of miR219-OPCs not only promotes remyelination and improves cognitive function but also enhances the proliferation of host endogenous NPCs following chronic demyelination. These results support the potential of a therapeutic role for miR-219 in demyelinating diseases.

[Abnormal expression of miR-let-7b in primary biliary cirrhosis and its clinical significance].

OBJECTIVE: To evaluate the expression of microRNA (miR)-let-7b in peripheral blood cells of patients with primary biliary cirrhosis (PBC) and investigate its relationship to clinical disease parameters. METHODS: Peripheral blood and serum samples were obtained for study from 60 PBC patients and 60 healthy controls. Peripheral blood cells were extracted and subjected to real-time PCR to measure miR-let-7b expression. Serum levels of interleukin (IL)-18, total bilirubin (TBIL), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) were measured by standard biochemical assays. The relationship between miR-let-7b expression and disease parameters was assessed by Spearman's rank correlation test. RESULTS: PBC patients showed significantly lower expression of miR-let-7b in peripheral blood cells than healthy controls (P less than 0.001); moreover, the miR-let-7b expression level decreased in parallel to increases in disease severity (stage I > II / III > IV). In PBC patients, the miR-let-7b expression was significantly correlated with Mayo risk scores (r = -0.4930, P less than 0.001), IL-18 (r = -0.4643, P less than 0.001) and ALP (r = -4119, P less than 0.001), but not with TBIL or GGT. CONCLUSION: Decreased expression of miR-let-7b may be associated with development and progression of PBC, and this miRNA may represent a novel target of improved diagnostic and preventive strategies for PBC.

[MicroRNA profiling in T cells of peripheral blood mononuclear cell from patients with primary biliary cirrhosis].

OBJECTIVE: To explore the expression pattern of microRNA (miRNA) in T cells of peripheral blood mononuclear cell (PBMC) from patients with primary biliary cirrhosis (PBC). METHODS: The expression profile of miRNA in T cells of PBMC was determined by microarray assay and validated by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: In comparison with the healthy controls, 23 miRNA were down-regulated and 2 miRNA had a higher expression (all P < 0.05). As revealed by qRT-PCR, the expressions of miR-346, miR-17-5p, miR-20a and miR-let-7b decreased obviously while miR-451 and miR-129 became up-regulated. The results were in agreement with those of microarray. CONCLUSIONS: The PBC patients and healthy controls have significantly different expression profiles of microRNA in T cells of PBMC. The differential expression of microRNA may be involved in the pathogenesis of PBC.