Brown adipocytes postnatally arise through both differentiation from progenitors and conversion from white adipocytes in Syrian hamster
Brown adipocytes postnatally arise through both differentiation from progenitors and conversion from white adipocytes in Syrian hamster
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叙利亚仓鼠出生后通过祖细胞分化和白色脂肪细胞转化产生棕色脂肪细胞
DOI：
10.1152/japplphysiol.00622.2017
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发表时间：
2018
影响因子：
3.3
通讯作者：
Kimura Kazuhiro
中科院分区：
文献类型：
--
作者：
Okamatsu-Ogura Yuko;Nio-Kobayashi Junko;Nagaya Kazuki;Tsubota Ayumi;Kimura Kazuhiro
为了研究叙利亚仓鼠出生后棕色脂肪组织 (BAT) 的发育，我们对 5-16 日龄幼鼠的肩胛间脂肪组织进行了组织学检查，重点关注棕色脂肪细胞是如何产生的。 5日龄仓鼠的肩胛间脂肪主要由含有大单眼脂滴的白色脂肪细胞组成，如在典型的白色脂肪组织（WAT）中观察到的。第 7 天，肩胛间脂肪组织边缘附近出现了对 Ki67 具有强免疫反应性的小型增殖性非脂肪细胞簇。 Ki67阳性区域面积在第10天扩大到总组织面积的约50%。在第16天，肩胛间脂肪显示出典型的BAT特征。在第10天及之后清楚地检测到棕色脂肪细胞特异性标记物解偶联蛋白-1，而在第7天未检测到。在肩胛间脂肪从WAT转化为BAT的过程中，单房脂肪细胞完全迅速消失，没有明显的凋亡。 Ki67 和单羧酸转运蛋白 1 (MCT1)（棕色脂肪细胞的另一种选择性标记）的双重免疫荧光染色显示，大多数增殖细胞属于棕色脂肪细胞谱系。电子显微镜检查显示，一些白色脂肪细胞除了大脂滴外还含有小脂滴，并且与祖细胞和成熟棕色脂肪细胞一样表达MCT1，这意味着从白色脂肪细胞直接转变为棕色脂肪细胞。这些结果表明，叙利亚仓鼠的 BAT 在出生后通过两种不同的途径发育：棕色脂肪细胞祖细胞的增殖和分化以及单房脂肪细胞向多房棕色脂肪细胞的转化。然而，这些组织之间的界限是模糊的。在这项研究中，我们对叙利亚仓鼠的 BAT 发育过程进行了组织学评估，结果显示出生后 WAT 转化为 BAT。我们的结果表明，棕色脂肪细胞通过两种不同的途径产生：棕色脂肪细胞祖细胞的增殖和分化以及白色脂肪细胞的转化。
To investigate the postnatal development of brown adipose tissue (BAT) in Syrian hamsters, we histologically examined interscapular fat tissue from 5–16-day-old pups, focusing on how brown adipocytes arise. Interscapular fat of 5-day-old hamsters mainly consisted of white adipocytes containing large unilocular lipid droplets, as observed in typical white adipose tissue (WAT). Onday 7, clusters of small, proliferative nonadipocytes with a strong immunoreactivity for Ki67 appeared near the edge of the interscapular fat tissue. The area of the Ki67-positive regions expanded to ~50% of the total tissue area byday 10. The interscapular fat showed the typical BAT feature byday 16. A brown adipocyte-specific marker, uncoupling protein-1, was clearly detected onday 10and thereafter, while not detected onday 7. During conversion of interscapular fat from WAT to BAT, unilocular adipocytes completely and rapidly disappeared without obvious apoptosis. Dual immunofluorescence staining for Ki67 and monocarboxylate transporter 1 (MCT1), another selective marker for brown adipocytes, revealed that most of the proliferating cells were of the brown adipocyte lineage. Electron microscopic examination showed that some of the white adipocytes contained small lipid droplets in addition to the large droplet and expressed MCT1 as do progenitor and mature brown adipocytes, implying a direct conversion from white to brown adipocytes. These results suggest that BAT of Syrian hamsters develops postnatally through two different pathways: the proliferation and differentiation of brown adipocyte progenitors and the conversion of unilocular adipocytes to multilocular brown adipocytes.NEW & NOTEWORTHYBrown and white adipose tissues (BAT and WAT, respectively) are quite different in morphological features and function; however, the boundary between these tissues is obscure. In this study, we histologically evaluated the process of BAT development in Syrian hamsters, which shows postnatal conversion of WAT to BAT. Our results suggest that brown adipocytes arise through two different pathways: the proliferation and differentiation of brown adipocyte progenitors and the conversion from white adipocytes.