The fundamental structure of cell membranes is bilayers composed of phospholipids, and the vital function of the phospholipids in the membrane is to help keep it fluid and semi-permeable. Conventional glycerophospholipids have acyl chains attached to the sn-1 and sn-2 positions of the glycerol backbone via an ester bond. Ether lipids are a unique class of glycerophospholipids that have an alkyl chain attached to the sn-1 position by an ether bond (glycerol-ether lipids). In ether lipids, the alcohol group attached to the phosphate is generally choline or ethanolamine. Ether-linked phospholipids such as 1-alkyl-2-acyl-phosphatidylcholine and dialkylphosphatidylcholine are also found in the plasma and organelle membranes of mammalian species. Ether lipids form approximately 20% of the total phospholipid in mammals with different tissue distribution; brain, heart, spleen and white blood cells have the highest levels, while liver have a very little amount of ether lipids.
Studies on the formation and thermodynamic properties of ether-linked phospholipid bilayer membranes have indicated that in contrast to ester-linked phospholipid, the formation of the non-bilayer structure takes place spontaneously. This is attributed to the weaker interaction between polar headgroups in the ether-linked than that in the ester-linked phospholipids. It has also shown that the phase behavior of the ether-linked phospholipid bilayer membranes in ambient pressure is almost equivalent to that of the ester-linked phospholipid bilayer membranes under high temperatures and pressures, and the difference in the phase behavior decrease as the alkyl-chain length increases.
Due to distinctive properties of ether lipids, liposomes made from ether lipids exhibit very unique characteristics and performance: a) the ether bonds are more stable than ester linkages over a wide range of acidic or alkaline pH; b) stability properties of the liposomes is enhanced by bipolar lipids, and the saturated alkyl chains gives stability towards degradation in oxidative conditions; c) the unusual stereochemistry of the glycerol backbone enhance the resistance against the attacks by other organism phospholipases.
Phospholipase A2 (PLA2) cannot hydrolyze the ether lipid liposomes. Diether lipids do not go through hydrolysis due to having an ether bond instead of an acyl bond and therefore to do that, they are a suitable candidate for experiments that needs to be performed at a higher temperature for an extended period of time. For more information about hydrolysis and oxidation of phospholipids see here.
Saturated diether lipids can neither be hydrolyzed nor oxidized.
ebiomall.com
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Bone Mesenchymal Stem Cells 作为一个细胞群体，还没有发现有特定细胞表面marker. 对于那些可以代表自我更新和分化的marker, 也不清楚到底要发现哪一个的表达才能确定该细胞就是BMSC。
目前常用的方法，就是采用培养，colony-forming unit-fibroblasts (CFU-F)这个方法。一般BMSC可以24-48小时贴壁。
流式细胞计数，比如STRO-1，但是一般认为STRO-1阳性的细胞更趋向于造血干细胞，和BMSC简单区别还不是很清楚。
这里有个培养分化的产品
http://www.rndsystems.com/pdf/SC020.pdf
GlucosestarvationcausestranslocationofAMPKβ2tothelysosomeinHEK-293cellsthatisdependentonN-myristoylation.Theexperimentwasperformedinβ2KOcellsasinFig.1c,exceptthatthelysosomalMarkerLAMP1(taggedwithRFP)wasco-expressedwiththewild-typeormutantAMPKβ2.Upperpanelsshowmergedimagesstainedblue(4′,6-diamidino-2-phenylindole(DAPI),nuclei),red(LAMP1,lysosomes)andgreen(AMPKβ2,detectedusingantibodyvalidatedine),incellsincubatedwithorwithoutglucosefor20 min.Lowersmallpanelsaremagnificationsoftheareasindicatedbydashedboxesintheupperpanels,showing(LtoR)redandgreenchannelsandmergedimages.
下面的这段话是图注，图注的意思我明白，但是我想知道merge后的图看什么颜色的荧光，蓝色是细胞核，红色是lysosome(位于胞质），绿色是AMPKβ2，该实验是想观察AMPKβ2是否转位到lysosome上了，如果确实发生了AMPKβ2转位到lysosome上，那么merge后是红色与绿色融合在一起，是吗？融合在一起发什么颜色的光了？
