{"title":"Label-free Assessment of the Nascent State of Rat Non-alcoholic Fatty Liver Disease Using Spontaneous Raman Microscopy.","authors":"Masashi Takemura, Kentaro Mochizuki, Yoshinori Harada, Akira Okajima, Michiyo Hayakawa, Ping Dai, Yoshito Itoh, Hideo Tanaka","doi":"10.1267/ahc.22-00013","DOIUrl":null,"url":null,"abstract":"<p><p>Spontaneous Raman microscopy, which can detect molecular vibrations in cells and tissues, could be a useful tool for the label-free assessment of non-alcoholic fatty liver disease (NAFLD). However, it is unclear whether it can be used to evaluate the nascent state of NAFLD. To address this, we analyzed the Raman spectra of rat liver tissues in the nascent state of NAFLD upon excitation at 532 nm. Raman and histochemical analyses were performed of liver tissues from rats fed a high-fat, high-cholesterol diet (HFHCD). Raman microscopic imaging analysis of formalin-fixed thin tissue slices showed hepatic steatosis, as revealed by the Raman band at 2,854 cm<sup>-1</sup>, whereas lipid droplets were not detectable by hematoxylin-eosin staining of images until 3 days after feeding a HFHCD. Raman signals of retinol at 1,588 cm<sup>-1</sup> emitted from hepatic stellate cells were distributed alongside hepatic cords; the retinol content rapidly decreased after feeding a HFHCD, whereas hepatic lipid content increased inversely. Raman microscopic analysis of the surface of fresh <i>ex vivo</i> livers enabled early detection of lipid accumulation after a 1-day feeding a HFHCD. In conclusion, spontaneous Raman microscopy can be applied to the label-free evaluation of the nascent state of NAFLD liver tissues.</p>","PeriodicalId":6888,"journal":{"name":"Acta Histochemica Et Cytochemica","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9043435/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Histochemica Et Cytochemica","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1267/ahc.22-00013","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/4/22 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Spontaneous Raman microscopy, which can detect molecular vibrations in cells and tissues, could be a useful tool for the label-free assessment of non-alcoholic fatty liver disease (NAFLD). However, it is unclear whether it can be used to evaluate the nascent state of NAFLD. To address this, we analyzed the Raman spectra of rat liver tissues in the nascent state of NAFLD upon excitation at 532 nm. Raman and histochemical analyses were performed of liver tissues from rats fed a high-fat, high-cholesterol diet (HFHCD). Raman microscopic imaging analysis of formalin-fixed thin tissue slices showed hepatic steatosis, as revealed by the Raman band at 2,854 cm-1, whereas lipid droplets were not detectable by hematoxylin-eosin staining of images until 3 days after feeding a HFHCD. Raman signals of retinol at 1,588 cm-1 emitted from hepatic stellate cells were distributed alongside hepatic cords; the retinol content rapidly decreased after feeding a HFHCD, whereas hepatic lipid content increased inversely. Raman microscopic analysis of the surface of fresh ex vivo livers enabled early detection of lipid accumulation after a 1-day feeding a HFHCD. In conclusion, spontaneous Raman microscopy can be applied to the label-free evaluation of the nascent state of NAFLD liver tissues.
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.