Study on the toxic effects of Aβ1-42 oligomers in SHSY5Y with human A53T mutant α-synuclein over-expression / 中国神经精神疾病杂志

Objective To establish an in vitro cell model of Parkinson disease with SHSY5Y cells over-expressing human A53T mutant alpha-synuclein and to examine the effects of Aβ1-42 oligomer on cell survival and autophagy function in the cell model Method The recombinant lentivirus containing the A53T mutant alpha-synuclein gene or empty vector were transfected to SHSY5Y cells. The expression of α-synuclein mRNA in SHSY5Y cells was detected by RT-qPCR. The effect of Aβ1-42 oligomer on cell proliferation was detected with CCK-8 after incubation with Aβ1-42 oligomer for 24 hours. The autophagy-related proteins were evaluated with Western Blot. Result The mRNA and protein levels of alpha-synuclein were significantly increased in SHSY5Y cells expressing alpha-synuclein. There were no significant difference in the cell proliferation between alpha-synuclein group and control group (P<0.001) . Incubation with Aβ1-42 oligomer significantly decreased the proliferation rate in alpha-synuclein group in a dose-dependent manner compared with the control group. The levels of autophagy related proteins including LC3-Ⅱ and Beclin-1 were significantly lower in alpha-synuclein group than in control group (P<0.05). Conclusion This work has constructed an in vitro cell model of Parkinson′s disease. The over-expression of A53T mutant alpha-synuclein do not affect the cell survival whereas the Aβ1-42 oligomer exhibits toxic effects on cells expressing alpha-synuclein possible through suppression of the autophagy activation.

Screening of genetic mutations in a Chinese pedigree affected with hypokalemic periodic paralysis / 中华医学遗传学杂志

OBJECTIVE To screen for mutations in a Chinese pedigree affected with hypokalemic periodic paralysis. METHODS The proband and nine family members were enrolled for the analysis of CACNA1S and SCN4A gene mutations. Genomic DNA was extracted from peripheral blood samples. The coding regions of the two genes were amplified with PCR and subjected to Sanger sequencing. Potential impact of suspected mutations was predicted with Bioinformatics software. The mutations were also verified among 100 healthy controls. RESULTS The proband and 5 family members (including 5 males and 1 female) had presented with episodes of flaccid paralysis accompanied by low serum potassium. Genetic testing has identified a c.664C>T (p.Arg222Trp) mutation in the proband, which has been reported previously. The same mutation was identified in other 5 affected members from the family. No mutation of the CACNA1S gene was detected. CONCLUSION The c.664C>T mutation of the SCN4A gene probably underlies the hypokalemic periodic paralysis in this family. All patients from the family have shown a complete penetrance of the disease.

Topography and mechanical property of goat temporomandibular joint disc cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study is performed to investigate the cell topographies and biomechanical properties of two different types of temporomandibular joint (TMJ) discs from goats by using JPK Nano Wizard 3 biological atomic force microscopy (AFM). This process provides a guideline for selecting seed cells for TMJ disc tissue engineering.</p><p><b>METHODS</b>TMJ disc cells from primary goats were cultured by monolayer culture method. AFM was used to contact scan the topographies of the two types of TMJ disc cells under physiological environment. Approximately 20 chondrocyte-like and fibroblast-like cells were selected randomly to plot the force-versus-distance curves of the cytoplasm and nucleus. Young's modulus and adhesion were analyzed by JPK Data Processing.</p><p><b>RESULTS</b>The triangle-shapednucleus of the chondrocyte-like cell occupied a large portion of the cell. Cytoskeleton was arranged dendritically on the surface. Pseudopodia were extended from cell edges. The spindle-shaped nucleus of the fibroblast-like cell occupied a significantly larger region compared with the cytoplasmic region. Cytoskeleton was arranged regularly. Cell edges were smooth with less pseudopodia extended. No difference was found in the surface roughness between the two types of cells. According to the force-versus-distance curves, the Young's moduli of the two types of cells were not statistically different (P>0.05), but differences were found in the cytoplasmic regions (P=0.047). No statistical difference was found in the adhesions between the two types of cells (P>0.05).</p><p><b>CONCLUSION</b>The AFM topography and curves were compared and analyzed. The two types of TMJ disc cells exhibited significantly different topographies, but only slight difference in their mechanical abilities.</p>