A novel splice-site variant of the LAMB3 gene is associated with junctional epidermolysis bullosa

Background: Junctional epidermolysis bullosa (JEB) is a rare inherited genetic disorder in which pathogenic mutations are mostly located within exons of the associated genes. This report describes a novel variant located at a splice site. Objectives: To confirm the diagnosis of the JEB family and identify the pathogenic variant. Materials & Methods: We collected clinical data and DNA from the members of the family. Whole-exome sequencing (WES) and Sanger sequencing were used to detect gene variants. The pMINI minigene system was used to design in vitro experiments, to confirm the pathogenic variants. Results: A novel splice-site variant (c.629-12T>G) of the LAMB3 gene was detected in all patients and was shown to be a pathogenic variant. Conclusion: The diagnosis of JEB should depend on gene sequencing, and variants at splice sites may also cause the disease.

[Effect of Metformin on Proliferation, Differentiation and Apoptosis of THP-1 Cells].

OBJECTIVE: To investigate the effect of metformin on proliferation, differentiation and apoptosis of THP-1 cells and explore its possible mechanism. MEHODS: THP-1 cells were cultured with different concentrations of metformin for 24 h and 48 h. The cell proliferation was evaluated by CCK-8, the cell apoptosis was analyzed by Annexin V/7-AAD double labeling, the expression of CD14 and CD11b (surface differentiation antigens on THP-1 cells) was evaluated by flow cytometry, the BCL-XL, BAX, BIM and caspase-3 mRNA expressions of THP-1 cells were detected by real time quantitative PCR. RESULTS: Metformin could significantly inhibit the growth of THP-1 cells in a time- and dose- dependent manner. After treated with 20 mmol/L metformin for 24 h, the expressions of CD14 and CD11b in THP-1 cells didn't change much (P>0.05), the early apoptosis rates in exprimental and control groups were (2.02±0.85)% and (4.46±1.33)% respectively, the late apoptosis rates in experimental and control groups were (1.43±0.83)% and (3.31±0.59)% respectively. In process of inducing effect of 20 mmol/L metformin on THP-1 cells, the expressions of BCL-XL and BIM did not significantly changed, while the expressions of BAX and caspase-3 significantly increased (P<0.01). CONCLUSION: Metformin can effectively inhibit proliferation and induce apoptosis of THP-1 cells. However, it has no significant effect on differentiation of THP-1 cells, its mechanism inducing apoptosis maybe related with up-regulating BAX and caspase-3.