{"title":"Cold-induced Conversion of Connective Tissue Skeleton in Brown Adipose Tissues.","authors":"Masako Yudasaka, Yuko Okamatsu-Ogura, Takeshi Tanaka, Kumiko Saeki, Hiromichi Kataura","doi":"10.1267/ahc.21-00030","DOIUrl":null,"url":null,"abstract":"<p><p>Thermogenesis <i>via</i> fatty acid-induced uncoupled mitochondrial respiration is the primary function of brown adipose tissue (BAT). In response to changes in ambient temperatures, the weight and specific gravity of BAT change, depending on the quantity of lipid droplets stored in brown adipocytes (BA). Such conditions should result in the reconstruction of connective tissue skeletons, especially of collagen fiber networks, although the mechanisms have not been clarified. This study showed that, within 4 hr of exposing mice to a cold environment, collagen fibers in the extracellular matrix (ECM) of BAT became discontinuous, twisted, emancipated, and curtailed. Surprisingly, the structure of collagen fibers returned to normal after the mice were kept at room temperature for 19 hr, indicating that the alterations in collagen fiber structures are physiological processes association with adaptation to cold environments. These dynamic changes in connective tissue skeletons were not observed in white adipose tissues, suggesting that they are unique to BAT. Interestingly, the vascular permeability of BAT was also augmented by exposure to cold. Collectively, these findings indicate that dynamic changes in ECM collagen fibers provide high flexibility to BAT, enabling the adjustment of tissue structures and the regulation of vascular permeability, resulting in adaptation to changes in ambient temperatures.</p>","PeriodicalId":6888,"journal":{"name":"Acta Histochemica Et Cytochemica","volume":"54 5","pages":"131-141"},"PeriodicalIF":1.6000,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/3f/a3/21-00030.PMC8569133.pdf","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Histochemica Et Cytochemica","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1267/ahc.21-00030","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/10/6 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 2
Abstract
Thermogenesis via fatty acid-induced uncoupled mitochondrial respiration is the primary function of brown adipose tissue (BAT). In response to changes in ambient temperatures, the weight and specific gravity of BAT change, depending on the quantity of lipid droplets stored in brown adipocytes (BA). Such conditions should result in the reconstruction of connective tissue skeletons, especially of collagen fiber networks, although the mechanisms have not been clarified. This study showed that, within 4 hr of exposing mice to a cold environment, collagen fibers in the extracellular matrix (ECM) of BAT became discontinuous, twisted, emancipated, and curtailed. Surprisingly, the structure of collagen fibers returned to normal after the mice were kept at room temperature for 19 hr, indicating that the alterations in collagen fiber structures are physiological processes association with adaptation to cold environments. These dynamic changes in connective tissue skeletons were not observed in white adipose tissues, suggesting that they are unique to BAT. Interestingly, the vascular permeability of BAT was also augmented by exposure to cold. Collectively, these findings indicate that dynamic changes in ECM collagen fibers provide high flexibility to BAT, enabling the adjustment of tissue structures and the regulation of vascular permeability, resulting in adaptation to changes in ambient temperatures.
期刊介绍:
Acta Histochemica et Cytochemica is the official online journal of the Japan Society of Histochemistry and Cytochemistry. It is intended primarily for rapid publication of concise, original articles in the fields of histochemistry and cytochemistry. Manuscripts oriented towards methodological subjects that contain significant technical advances in these fields are also welcome. Manuscripts in English are accepted from investigators in any country, whether or not they are members of the Japan Society of Histochemistry and Cytochemistry. Manuscripts should be original work that has not been previously published and is not being considered for publication elsewhere, with the exception of abstracts. Manuscripts with essentially the same content as a paper that has been published or accepted, or is under consideration for publication, will not be considered. All submitted papers will be peer-reviewed by at least two referees selected by an appropriate Associate Editor. Acceptance is based on scientific significance, originality, and clarity. When required, a revised manuscript should be submitted within 3 months, otherwise it will be considered to be a new submission. The Editor-in-Chief will make all final decisions regarding acceptance.