Higher PLIN5 but not PLIN3 content in isolated skeletal muscle mitochondria following acute in vivo contraction in rat hindlimb.
Higher PLIN5 but not PLIN3 content in isolated skeletal muscle mitochondria following acute in vivo contraction in rat hindlimb.
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DOI：
10.14814/phy2.12154
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发表时间：
2014-10-01
影响因子：
2.5
通讯作者：
Peters SJ
中科院分区：
文献类型：
--
作者：
Ramos SV;MacPherson RE;Turnbull PC;Bott KN;LeBlanc P;Ward WE;Peters SJ
收缩介导的脂解增加了脂滴和线粒体的结合，表明在骨骼肌中脂肪酸从脂滴到线粒体的通道中起重要作用。PLIN 3和PLIN 5对脂滴-线粒体相互作用特别感兴趣，因为PLIN 3能够在细胞内移动，而PLIN 5与骨骼肌线粒体缔合。本研究主要调查：1）如果在骨骼肌线粒体级分中检测到PLIN 3;和2）如果PLIN 3和/或PLIN 5的线粒体蛋白含量在刺激收缩后改变。第二个目的是确定PLIN 3和PLIN 5是否相关，以及这种相关性是否在收缩后发生变化。雄性Long Evans大鼠（n = 21;年龄，52天;体重= 317 ± 6 g）接受30 min后肢刺激（10 msec脉冲，10-20 V下100 Hz/3 sec;训练持续时间100 msec）。收缩导致肌内脂质含量减少约50%，通过红色腓肠肌的油红-O染色测量。采用差速离心法分离红腓肠肌线粒体，蛋白质印迹法检测线粒体蛋白质的表达。收缩30分钟后，线粒体PLIN 5含量高约1.6倍，在线粒体组分中检测到PLIN 3含量，并且在收缩后保持不变。观察到PLIN 3和PLIN 5之间的关联，并且在收缩后保持不变。PLIN 5可能在脂解过程中在线粒体中发挥作用，这与促进/调节线粒体脂肪酸氧化的作用一致。PLIN 3和PLIN 5可能在收缩诱导的脂解过程中共同作用于脂滴和线粒体。本研究调查了大鼠后肢肌肉收缩时线粒体中脂滴蛋白PLIN 3和PLIN 5的富集。在线粒体部分中检测到PLIN 3和PLIN 5两者，但是响应于设计用于引起肌肉脂解的30分钟电刺激收缩，PLIN 3含量与静息值相比没有变化，但是PLIN 5增加约1.6倍。这表明PLIN 5在收缩期间在线粒体中的急性作用尚未阐明。
Contraction‐mediated lipolysis increases the association of lipid droplets and mitochondria, indicating an important role in the passage of fatty acids from lipid droplets to mitochondria in skeletal muscle. PLIN3 and PLIN5 are of particular interest to the lipid droplet–mitochondria interaction because PLIN3 is able to move about within cells and PLIN5 associates with skeletal muscle mitochondria. This study primarily investigated: 1) if PLIN3 is detected in skeletal muscle mitochondrial fraction; and 2) if mitochondrial protein content of PLIN3 and/or PLIN5 changes following stimulated contraction. A secondary aim was to determine if PLIN3 and PLIN5 associate and whether this changes following contraction. Male Long Evans rats (n = 21; age, 52 days; weight = 317 ± 6 g) underwent 30 min of hindlimb stimulation (10 msec impulses, 100 Hz/3 sec at 10–20 V; train duration 100 msec). Contraction induced a ~50% reduction in intramuscular lipid content measured by oil red‐O staining of red gastrocnemius muscle. Mitochondria were isolated from red gastrocnemius muscle by differential centrifugation and proteins were detected by western blotting. Mitochondrial PLIN5 content was ~1.6‐fold higher following 30 min of contraction and PLIN3 content was detected in the mitochondrial fraction, and unchanged following contraction. An association between PLIN3 and PLIN5 was observed and remained unaltered following contraction. PLIN5 may play a role in mitochondria during lipolysis, which is consistent with a role in facilitating/regulating mitochondrial fatty acid oxidation. PLIN3 and PLIN5 may be working together on the lipid droplet and mitochondria during contraction‐induced lipolysis. This study investigates the mitochondrial enrichment of lipid droplet proteins, PLIN3 and PLIN5 in response to muscle contraction in rat hindlimb. Both PLIN3 and PLIN5 are detected in the mitochondrial fraction, but in response to 30 min electrically stimulated contraction designed to elicit muscle lipolysis, PLIN3 content does not change from resting values, but PLIN5 increased ~1.6 fold. This suggests an acute role for PLIN5 in mitochondria during contraction that has yet to be elucidated.