Research progress in role of composition and structure of basement membrane in epithelial cell polarization and its mechanism / 吉林大学学报(医学版)

The basement membrane is a specialized extracellular matrix between the epithelium and the mesenchyme.In stratified epithelium,only the basal cells in contact with the basement membrane exhibit the apical-basal polarity,whereas the epithelial cells do being not in contact with the basement membrane do not exhibit the apical-basal polarity.The basement membrane plays an important role in epithelial cell polarization.It is an important extracellular matrix(ECM)structure in the multicellular organisms,is situated between the epithelium and the mesenchyme,and is produced jointly by the epithelial cells and mesenchymal cells.Its components mainly include Laminin,type Ⅳ collagen(Col-Ⅳ),nidogen(NDG),and heparan sulfate proteoglycans(HSPG),and each component plays the different role in influencing the epithelial cell polarity.The network scaffold formed by Col-Ⅳ and Laminin is the main structure of the basement membrane,and the integrity of the structure affects the epithelial cell polarization.This review summarizes the composition and structure of the basement membrane,focuses on its role in epithelial cell polarization and its mechanism,and compiles the current status of biomimetic basement membrane materials that promotes the epithelial cell polarization,and provides the theoretical foundation for further exploration of the establishment and maintenance of epithelial cell polarity.

Author Correction: Definitive evidence of the presence of 24-methylenecycloartanyl ferulate and 24-methylenecycloartanyl caffeate in barley.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Definitive evidence of the presence of 24-methylenecycloartanyl ferulate and 24-methylenecycloartanyl caffeate in barley.

γ-Oryzanol (OZ), which has a lot of beneficial effects, is a mixture of ferulic acid esters of triterpene alcohols (i.e., triterpene alcohol type of OZ (TTA-OZ)) and ferulic acid esters of plant sterols (i.e., plant sterol type of OZ (PS-OZ)). Although it has been reported that OZ is found in several kinds of cereal typified by rice, TTA-OZ (e.g., 24-methylenecycloartanyl ferulate (24MCA-FA)) has been believed to be characteristic to rice and has not been found in other cereals. In this study, we isolated a compound considered as a TTA-OZ (i.e., 24MCA-FA) from barley and determined the chemical structure using by HPLC-UV-MS, high-resolution MS, and NMR. Based on these results, we proved for the first time that barley certainly contains 24MCA-FA (i.e., TTA-OZ). During the isolation and purification of 24MCA-FA from barley, we found the prospect that a compound with similar properties to OZ (compound-X) might exist. To confirm this finding, the compound-X was also isolated, determined the chemical structure, and identified as a caffeic acid ester of 24-methylenecycloartanol (24MCA-CA), which has rarely been reported before. We also quantified these compounds in various species of barley cultivars and found for the first time the existence of 24MCA-FA and 24MCA-CA in various barley. Through these findings, it opens the possibility to use barley as a new source of 24MCA-FA and 24MCA-CA.

Study of Microelectrode Array Probe for Simultaneous Detection of Glutamate and Local Field Potential during Brain Death / 分析化学

High extracellular potassium can induce spreading depression-like depolarizations, elevations of extracellular glutamate and even neuronal death in normal brain. To investigate the contribution of high potassium in vivo, a microelectrode arrays ( MEAs ) probe integrated with recording sites for glutamate concentration (50í150 μm) and local field potential ( LFP) ( diameter=15 μm) was fabricated by Micro-electro-mechanical-systems ( MEMS) technologies. We implanted the MEA probe acutely in the rat brain and exposed the brain to a high potassium solution. During these multi-modal recordings, it was observed that high potassium elevated extracellular glutamate while suppressing the LFP irreversibly. This is one of the first studies in which a dual mode MEA probes is applied in vivo for neuronal death, and it is concluded that our MEA probes are capable of examining specific spatiotemporal relationships between electrical and chemical signaling in the brain.