Atherosclerotic Progression Attenuates the Expression of Nogo-B in Autopsied Coronary Artery: Pathology and Virtual Histology Intravascular Ultrasound Analysis

The relation of Nogo-B to atherosclerotic plaque progression is not well understood. Thus, the purpose of this study was to assess the expression of Nogo-B in fibroatheromas (FA) of different stages, classified using virtual histology intravascular ultrasound (VH-IVUS) analysis in 19 autopsied cases of non-sudden cardiac death. VH-IVUS imaging analysis was performed 30 mm from the ostium of each coronary artery. VH-IVUS revealed 11 early FAs (34.5+/-8.3 yr), 12 late FAs (42.6+/-16.6 yr), 8 thick-cap FAs (TkCFAs) (46.4+/-11.1 yr), and 6 thin-cap FAs (TCFAs) (51.8+/-6.8 yr). TkCFAs and TCFAs were defined as advanced FA. FA progression advanced with age (P=0.04). VH-IVUS analysis of small, early FAs showed smaller necrotic cores and relatively less calcium compared to more advanced FAs with large necrotic cores (P<0.001). Histopathology and immunohistochemical stains demonstrated that early or late FAs had smaller necrotic cores, less empty space of decalcification, and greater Nogo-B expression compared to advanced FAs (vs. early FA, P=0.013; vs. late FA, P=0.008, respectively). These findings suggest that FA progression is inversely associated with Nogo-B expression. Local reduction of Nogo-B may contribute to plaque formation and/or instability.

Knocking-down of Nogo-A gene expression in PC12 cell line by plasmid-based RNAi / 华中科技大学学报（医学）（英德文版）

To study the inhibitory effect of Nogo-A shRNA on cell line PC12, the Nogo-A shRNA (short hairpin RNA, or shRNA) was designed and synthesized. The annealed shRNA template was inserted into plasmid pGenesil-1 containing enhanced green fluorescent protein (EGFP) gene by gene cloning technique to generate eukaryotic expression vector. The recombinant plasmid was transfected into PC12 cells by lipofecamine2000 and the mRNA and protein expression level of Nogo-A gene was detected by RT-PCR and Western blotting 48 h after the transfection. Gene sequencing showed that that the Nogo-A shRNA eukaryotic expression vector was successfully constructed. No significant change was found in the Nogo-A mRNA and protein expression level in empty vector-transfected group as compared with controls (P>0.05), while the expression level in shRNA-transfected group decreased significantly (P<0.05). It is concluded that the pGenesil-1/Nogo-AshRNA recombinant plasmid can effectively suppress the expression of Nogo-A gene in PC12 cells.

Protein-mediated surface structuring in biomembranes

The lipids and proteins of biomembranes exhibit highly dissimilar conformations, geometrical shapes, amphipathicity, and thermodynamic properties which constrain their two-dimensional molecular packing, electrostatics, and interaction preferences. This causes inevitable development of large local tensions that frequently relax into phase or compositional immiscibility along lateral and transverse planes of the membrane. On the other hand, these effects constitute the very codes that mediate molecular and structural changes determining and controlling the possibilities for enzymatic activity, apposition and recombination in biomembranes. The presence of proteins constitutes a major perturbing factor for the membrane sculpturing both in terms of its surface topography and dynamics. We will focus on some results from our group within this context and summarize some recent evidence for the active involvement of extrinsic (myelin basic protein), integral (Folch-Lees proteolipid protein) and amphitropic (c-Fos and c-Jun) proteins, as well as a membrane-active amphitropic phosphohydrolytic enzyme (neutral sphingomyelinase), in the process of lateral segregation and dynamics of phase domains, sculpturing of the surface topography, and the bi-directional modulation of the membrane biochemical reactivity.