MiR-133b Promotes neurite outgrowth by targeting RhoA expression.

BACKGROUND: MicroRNA-133b (miR-133b) has been shown to play a critical role in spinal cord regeneration. The aim of this study was to investigate the cellular role of miR-133b in neural cells. METHODS: PC12 cells and primary cortical neurons (PCNs) were transfected with lenti-miR-133b, lenti-miR-133b inhibitor, plasmid-shRNA-RhoA, plasmid-RhoA and their negative controls. After 48 hours of transfection, the levels of proteins and mRNA or miRNA were evaluated by Western blotting and qRT-PCR, respectively. Moreover, the neurite outgrowth was analyzed by Image J. For pharmacological experiments, inhibitors of MEK1/2 kinase (PD98059), phosphoinositide-3 kinase (PI3K) (LY294002) and ROCK (Y27632) were added into the culture medium. RESULTS: Overexpression of miR-133b in PC12 cells enhanced neurite outgrowth. Conversely, inhibition of miR-133b reduced neurite length. We further identified RhoA as a target and mediator of mir-133b for neurite extension by Western blot and knockdown experiment. Moreover, overexpression of RhoA could attenuate the neurite growth effects of miR-133b. Also, we observed that miR-133b activated MEK/ERK and PI3K/Akt signaling pathway by targeting RhoA. Finally, in PCNs, miR-133b also increased axon growth and attenuated axon growth restrictions from chondroitin sulfate proteoglycans (CSPG). CONCLUSIONS: In summary, our study suggested that miR-133b regulated neurite outgrowth via ERK1/2 and PI3K/Akt signaling pathway by RhoA suppression.

[Values of serum copper and serum free copper in the diagnosis and monitoring of Wilson's disease and its carriers].

OBJECTIVE: To explore the values of serum copper and serum free copper in the diagnosis of Wilson's disease (WD), its carrier and viral hepatitis and explore the guiding significance of monitoring serum copper in the treatment of WD. METHODS: A total of 80 WD patients (hepatic type, n = 60; encephalic type, n = 20), 30 carriers, 20 patients with viral hepatitis were enrolled and their levels of serum copper were determined. The neural symptoms were scored by modified Young grade. Hemogram, hepatic functions, blood clotting functions, serum copper and urinary copper were tested throughout all 8 courses of treatment with sodium dimercaptopropane sulfonate (DMPS). The patients were treated with zinc after discharging. All data were analyzed. RESULTS: The free serum copper increased in the patients with WD (0.17 mg/L ± 0.04 mg/L), carriers (0.13 mg/L ± 0.03 mg/L) and severe viral hepatitis (0.12 mg/L). A slight increase was also observed in the WD carriers. The level of serum copper was correlated with hepatic functions but not with the severity of neural symptoms. The serum copper increased in the patients with no improvement of neural symptoms. However, the serum copper decreased in the WD patients with the improvement of neural symptoms. The serum copper was stabilized at approximately 0.2 mg/L during the long-term treatment period. CONCLUSION: There is auxiliary diagnosis significance of serum copper in the determination of WD. Hepatic functions in hepatic type WD affect the level of serum copper. The serum copper of encephalic type WD can not indicate the severity of neural symptoms. The elevated level of serum copper indicates a poor prognosis. The serum copper is an effective marker in monitoring the development and therapeutic efficacy of the disease.