Katta Anjaiah, Thulluri Srinivasarao, Manne Nandini D P K, Addagarla Hari S, Arvapalli Ravikumar, Nalabotu Siva K, Gadde Muralikrishna, Rice Kevin M, Blough Eric R
Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV 25755-1090, USA.
Cell Physiol Biochem. 2013;31(2-3):219-29. doi: 10.1159/000343363. Epub 2013 Feb 8.
Insulin resistance (IR) may decrease muscle adaptability. Heat shock proteins (HSPs), mitogen-activated protein kinases (MAPKs), and miRNA are thought to play a role in muscle hypertrophy but it is unclear if IR may affect their regulation.
Soleus muscles of lean Zucker (LZ) and insulin resistant obese Zucker (OZ) rats were overloaded for 7 or 21 days and subjected to immunoblotting and RT-PCR.
IR was associated with decreased muscle hypertrophy. Overload increased HSP27 phosphorylation in both the LZ and OZ rats at day 7 but only in the LZ at day 21. IR was associated with diminished overload induced MAPK phosphorylation and decreased expression of miR-1 and miR133. Overload decreased mir-1 levels in both the LZ and OZ but to a greater extent in the LZ animals.
These results suggest that alterations in the regulation of HSPs, MAPKs and miRNA may be associated with the diminished hypertrophy of IR muscle.
胰岛素抵抗（IR）可能会降低肌肉适应性。热休克蛋白（HSPs）、丝裂原活化蛋白激酶（MAPKs）和微小RNA（miRNA）被认为在肌肉肥大中起作用，但尚不清楚IR是否会影响它们的调控。
对瘦型 Zucker（LZ）大鼠和胰岛素抵抗肥胖型 Zucker（OZ）大鼠的比目鱼肌进行7天或21天的超负荷处理，并进行免疫印迹和逆转录聚合酶链反应（RT-PCR）。
IR与肌肉肥大减少有关。在第7天，超负荷使LZ和OZ大鼠的HSP27磷酸化增加，但在第21天仅使LZ大鼠的HSP27磷酸化增加。IR与超负荷诱导的MAPK磷酸化减少以及miR-1和miR133表达降低有关。超负荷使LZ和OZ大鼠的mir-1水平均降低，但在LZ动物中降低幅度更大。
这些结果表明，HSPs、MAPKs和miRNA调控的改变可能与IR肌肉肥大减少有关。
