Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations.
Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations.
复制标题
两个线粒体亚群中大鼠心脏鞘脂池的特征。
DOI：
10.1016/j.bbrc.2010.06.077
复制
发表时间：
2010
影响因子：
3.1
通讯作者：
Hagen,ToryM
中科院分区：
文献类型：
--
作者：
Monette,JeffreyS;Gomez,LuisA;Moreau,RegisF;Bemer,BrettA;Taylor,AlanW;Hagen,ToryM
Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemmal mitochondria (SSM) were isolated, lipids extracted, and sphingolipids quantified by LC–tandem mass spectrometry. Results showed that sphingomyelin (∼10,000pmol/mg protein) was the predominant sphingolipid regardless of mitochondrial subpopulation, and measurable amounts of ceramide (∼70pmol/mg protein) sphingosine, and sphinganine were also found in IFM and SSM. Both mitochondrial populations contained similar quantities of sphingolipids except for ceramide which was much higher in SSM. Analysis of sphingolipid isoforms revealed ten different sphingomyelins and six ceramides that differed from 16- to 24-carbon units in their acyl side chains. Sub-fractionation experiments further showed that sphingolipids are a constituent part of the inner mitochondrial membrane. Furthermore, inner membrane ceramide levels were 32% lower versus whole mitochondria (45pmol/mg protein). Three ceramide isotypes (C20-, C22-, and C24-ceramide) accounted for the lower amounts. The concentrations of the ceramides present in the inner membranes of SSM and IFM differed greatly. Overall, mitochondrial sphingolipid content reflected levels seen in cardiac tissue, but the specific ceramide distribution distinguished IFM and SSM from each other.
