Vaitkus Janina A, Celi Francesco S
Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
Exp Biol Med (Maywood). 2017 Mar;242(5):473-481. doi: 10.1177/1535370216683282. Epub 2016 Dec 8.
Adipose tissue (fat) is a heterogeneous organ, both in function and histology, distributed throughout the body. White adipose tissue, responsible for energy storage and more recently found to have endocrine and inflammation-modulatory activities, was historically thought to be the only type of fat present in adult humans. The recent demonstration of functional brown adipose tissue in adults, which is highly metabolic, shifted this paradigm. Additionally, recent studies demonstrate the ability of white adipose tissue to be induced toward the brown adipose phenotype - "beige" or "brite" adipose tissue - in a process referred to as "browning." While these adipose tissue depots are under investigation in the context of obesity, new evidence suggests a maladaptive role in other metabolic disturbances including cancer-associated cachexia, which is the topic of this review. This syndrome is multifactorial in nature and is an independent factor associated with poor prognosis. Here, we review the contributions of all three adipose depots - white, brown, and beige - to the development and progression of cancer-associated cachexia. Specifically, we focus on the local and systemic processes involving these adipose tissues that lead to increased energy expenditure and sustained negative energy balance. We highlight key findings from both animal and human studies and discuss areas within the field that need further exploration. Impact statement Cancer-associated cachexia (CAC) is a complex, multifactorial syndrome that negatively impacts patient quality of live and prognosis. This work reviews a component of CAC that lacks prior discussion: adipose tissue contributions. Uniquely, it discusses all three types of adipose tissue, white, beige, and brown, their interactions, and their contributions to the development and progression of CAC. Summarizing key bench and clinical studies, it provides information that will be useful to both basic and clinical researchers in designing experiments, studies, and clinical trials.
脂肪组织在功能和组织学上都是一种异质性器官,分布于全身。白色脂肪组织负责能量储存,最近还发现其具有内分泌和炎症调节活性,历史上一直被认为是成年人体内唯一存在的脂肪类型。成人体内功能性棕色脂肪组织的发现改变了这一范式,这种棕色脂肪组织代谢非常活跃。此外,最近的研究表明,白色脂肪组织能够在一个被称为“褐变”的过程中被诱导转变为棕色脂肪表型——“米色”或“亮”脂肪组织。虽然这些脂肪组织库在肥胖背景下正在被研究,但新证据表明它们在包括癌症相关性恶病质在内的其他代谢紊乱中起不良作用,这也是本综述的主题。这种综合征本质上是多因素的,是与预后不良相关的独立因素。在这里,我们综述了白色、棕色和米色这三种脂肪库对癌症相关性恶病质的发生和发展的作用。具体来说,我们关注涉及这些脂肪组织的局部和全身过程,这些过程导致能量消耗增加和持续的负能量平衡。我们强调了动物和人类研究的关键发现,并讨论了该领域内需要进一步探索的领域。影响声明癌症相关性恶病质(CAC)是一种复杂的多因素综合征,对患者的生活质量和预后产生负面影响。这项工作综述了CAC中一个此前缺乏讨论的组成部分:脂肪组织的作用。独特的是,它讨论了所有三种类型的脂肪组织,白色、米色和棕色,它们的相互作用,以及它们对CAC发生和发展的作用。总结关键的基础研究和临床研究,它提供了对基础研究人员和临床研究人员在设计实验、研究和临床试验时有用的信息。