GLUT11, but not GLUT8 or GLUT12, is expressed in human skeletal muscle in a fibre type-specific pattern
GLUT11, but not GLUT8 or GLUT12, is expressed in human skeletal muscle in a fibre type-specific pattern
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DOI：
10.1007/s00424-003-1219-4
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发表时间：
2004-04-01
影响因子：
4.5
通讯作者：
Schroder, HD
中科院分区：
文献类型：
--
作者：
Gaster, M;Handberg, A;Schroder, HD
在过去的5年里，已经发现了9种新的糖转运蛋白。其中三种葡萄糖转运蛋白（GLUT） GLUT8、GLUT11和GLUT12的mRNA已在人类骨骼肌中检测到。在本研究中，我们使用免疫组织化学方法检测了GLUT亚型8、11和12在人类骨骼肌中的表达和定位模式。研究了久坐或训练的健康成人、胎儿肌肉（妊娠24周）、肥胖2型糖尿病患者以及患有多发性肌炎或肌萎缩性侧索硬化症（ALS）的患者的骨骼肌活检。发育中和成年肌纤维中GLUT8和glut12的免疫反应性均低于检测水平。然而，GLUT11免疫反应性存在于慢肌纤维中，而不存在于快肌纤维中。相反，由于GLUT4在所有研究的肌纤维中表达，因此GLUT11的表达模式与GLUT4的表达模式不同，这表明GLUT11具有独立于GLUT4的特殊功能。肥胖、2型糖尿病、训练、去神经和再神经支配（ALS）和再生（多发性肌炎）不能诱导GLUT8或-12的表达。同样，GLUT11免疫反应的纤维类型依赖模式没有改变。然而，一些慢肌纤维在再生过程中失去了GLUT11免疫反应性。我们的研究结果表明，与GLUT4相反，GLUT11的免疫反应性仅在慢肌纤维中表达，除了原发性肌病外，它不受生理和病理生理条件的影响。在生理和病理生理条件下，GLUT8和GLUT12在人体肌肉中似乎并不重要。
Nine novel sugar transporter-like proteins have been discovered in the past 5 years. The mRNA for three of these, the glucose transporters (GLUT) GLUT8, GLUT11 and GLUT12, have been detected in human skeletal muscle. In the present study, we examined the pattern of expression and localization of the GLUT isoforms 8, 11 and 12 in human skeletal muscle using an immunohistochemical approach. Biopsies of human skeletal muscle from sedentary or trained healthy adults, from fetal muscle (24 weeks of gestation), from obese type-2 diabetic subjects, and from patients suffering from polymyositis or amyotrophic lateral sclerosis (ALS) were studied. GLUT8 and 12 immunoreactivity was below detection level in both developing and adult muscle fibres. GLUT11 immunoreactivity, however, was present in slow-twitch muscle fibres, but not in fast twitch fibres. Since, in contrast, GLUT4 was expressed in all investigated muscle fibres, the pattern of expression of GLUT11 differs from that of GLUT4, suggesting a specialized function for GLUT11 with a regulation independent from that of GLUT4. Obesity, type-2 diabetes, training, conditions of de- and reinnervation (ALS) and regeneration (polymyositis) failed to induce GLUT8 or -12 expression. Likewise, the fibre type-dependent pattern of GLUT11 immunoreactivity was unaltered. However, some slow muscle fibres lose their GLUT11 immunoreactivity under regeneration. Our results indicate that GLUT11 immunoreactivity, in contrast to that of GLUT4, is expressed exclusively in slow-twitch muscle fibres and is unaffected by physiological and pathophysiological conditions except in primary myopathy. GLUT8 and GLUT12 do not appear to be of importance in human muscle under physiological and pathophysiological conditions.