Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography
The cell nucleus is three-dimensionally and dynamically organized by nuclear components with high molecular density, such as chromatin and nuclear bodies. The structure and functions of these components are represented by the diffusion and interaction of related factors. Recent studies suggest that...
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MDPI AG
2019-07-01
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| Series: | Cells |
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| Online Access: | https://www.mdpi.com/2073-4409/8/7/699 |
| _version_ | 1797709585090347008 |
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| author | Tae-Keun Kim Byong-Wook Lee Fumihiko Fujii Jun Ki Kim Chan-Gi Pack |
| author_facet | Tae-Keun Kim Byong-Wook Lee Fumihiko Fujii Jun Ki Kim Chan-Gi Pack |
| author_sort | Tae-Keun Kim |
| collection | DOAJ |
| description | The cell nucleus is three-dimensionally and dynamically organized by nuclear components with high molecular density, such as chromatin and nuclear bodies. The structure and functions of these components are represented by the diffusion and interaction of related factors. Recent studies suggest that the nucleolus can be assessed using various protein probes, as the probes are highly mobile in this organelle, although it is known that they have a densely packed structure. However, physicochemical properties of the nucleolus itself, such as molecular density and volume when cellular conditions are changed, are not yet fully understood. In this study, physical parameters such as the refractive index (RI) and volume of the nucleoli in addition to the diffusion coefficient (<i>D</i>) of fluorescent probe protein inside the nucleolus are quantified and compared by combining label-free optical diffraction tomography (ODT) with confocal laser scanning microscopy (CLSM)-based fluorescence correlation spectroscopy (FCS). 3D evaluation of RI values and corresponding RI images of nucleoli in live HeLa cells successfully demonstrated varying various physiological conditions. Our complimentary method suggests that physical property of the nucleolus in live cell is sensitive to ATP depletion and transcriptional inhibition, while it is insensitive to hyper osmotic pressure when compared with the cytoplasm and nucleoplasm. The result demonstrates that the nucleolus has unique physicochemical properties when compared with other cellular components. |
| first_indexed | 2024-03-12T06:39:47Z |
| format | Article |
| id | doaj.art-0f1b1aa58a1d4e319594bf4fc11ccc85 |
| institution | Directory Open Access Journal |
| issn | 2073-4409 |
| language | English |
| last_indexed | 2024-03-12T06:39:47Z |
| publishDate | 2019-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cells |
| spelling | doaj.art-0f1b1aa58a1d4e319594bf4fc11ccc852023-09-03T01:04:54ZengMDPI AGCells2073-44092019-07-018769910.3390/cells8070699cells8070699Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction TomographyTae-Keun Kim0Byong-Wook Lee1Fumihiko Fujii2Jun Ki Kim3Chan-Gi Pack4Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, KoreaAsan Institute for Life Sciences, Asan Medical Center, Seoul 05505, KoreaDivision of Physical Pharmacy, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, JapanAsan Institute for Life Sciences, Asan Medical Center, Seoul 05505, KoreaAsan Institute for Life Sciences, Asan Medical Center, Seoul 05505, KoreaThe cell nucleus is three-dimensionally and dynamically organized by nuclear components with high molecular density, such as chromatin and nuclear bodies. The structure and functions of these components are represented by the diffusion and interaction of related factors. Recent studies suggest that the nucleolus can be assessed using various protein probes, as the probes are highly mobile in this organelle, although it is known that they have a densely packed structure. However, physicochemical properties of the nucleolus itself, such as molecular density and volume when cellular conditions are changed, are not yet fully understood. In this study, physical parameters such as the refractive index (RI) and volume of the nucleoli in addition to the diffusion coefficient (<i>D</i>) of fluorescent probe protein inside the nucleolus are quantified and compared by combining label-free optical diffraction tomography (ODT) with confocal laser scanning microscopy (CLSM)-based fluorescence correlation spectroscopy (FCS). 3D evaluation of RI values and corresponding RI images of nucleoli in live HeLa cells successfully demonstrated varying various physiological conditions. Our complimentary method suggests that physical property of the nucleolus in live cell is sensitive to ATP depletion and transcriptional inhibition, while it is insensitive to hyper osmotic pressure when compared with the cytoplasm and nucleoplasm. The result demonstrates that the nucleolus has unique physicochemical properties when compared with other cellular components.https://www.mdpi.com/2073-4409/8/7/699optical diffraction tomographyfluorescence correlation spectroscopynucleolusrefractive indexvolumediffusion coefficientliquid-liquid phase separation |
| spellingShingle | Tae-Keun Kim Byong-Wook Lee Fumihiko Fujii Jun Ki Kim Chan-Gi Pack Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography Cells optical diffraction tomography fluorescence correlation spectroscopy nucleolus refractive index volume diffusion coefficient liquid-liquid phase separation |
| title | Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography |
| title_full | Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography |
| title_fullStr | Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography |
| title_full_unstemmed | Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography |
| title_short | Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography |
| title_sort | physicochemical properties of nucleoli in live cells analyzed by label free optical diffraction tomography |
| topic | optical diffraction tomography fluorescence correlation spectroscopy nucleolus refractive index volume diffusion coefficient liquid-liquid phase separation |
| url | https://www.mdpi.com/2073-4409/8/7/699 |
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