Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (12): 2446-2453.doi: 10.3866/PKU.WHXB201706133

• ARTICLE • Previous Articles     Next Articles

Raman Spectroscopic Analysis of Chondrocyte Dedifferentiation during in vitro Proliferation

Lu-Di JIN1,Jing-Jing XU2,Yong ZHANG3,Yue-Zhou YU2,Chang LIU3,Dong-Ping ZHAO3,An-Pei YE1,3,*()   

  1. 1 Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
    2 Peking-Tsinghua Center for Life Sciences, Beijing 100871, P. R. China
    3 Key Laboratory for the Physics & Chemistry of Nano-devices, School of Electronics Engineering & Computer Science, Peking University, Beijing 100871, P. R. China
  • Received:2017-05-02 Published:2017-09-05
  • Contact: An-Pei YE
  • Supported by:
    the National Natural Science Foundation of China(U1636110);the National Key Technologies R & D Program of China(2012BAF14B14);the Medicine-Informatics Interdisciplinary Project of Peking University, China(2014-MI-19)


Seeded chondrocytes play a crucial role in current cartilage tissue engineering, yet both the quality and quantity of these cells could be impaired owing to cell dedifferentiation during in vitro proliferation. Here, we used micro-Raman spectroscopy to investigate changes in cellular components upon monolayer culturing of primary rat chondrocytes through multiple passages. Based on the average spectral profiles, we detected a series of Raman peaks and recognized related radicals such as nucleobases, pyranose rings, sulfate, tyrosine, proline, and amides at the single-chondrocyte level. Quantitative analysis of the Raman peak intensities showed that nucleic acids (at 789, 1094, 1576 cm-1) decreased significantly from passage 1 (P1) to passage 4 (P4), whereas lipids (at 1304 cm-1) and phosphate (at 957 cm-1) increased significantly. Moreover, the syntheses of two major hyaline cartilage-associated proteins, aggrecan and type-2 collagen, were impeded, as indicated by the marked decline in the levels of their specific components (glycosaminoglycan at 1042, 1063, 1126, 1160 cm-1, and hydroxyproline at 1207 cm-1). Taken together, these features reveal the diminished propagation and secretion abilities of passaged chondrocytes needed for matrix-induced implantation, and shed light on the molecular mechanism of chondrocyte dedifferentiation.

Key words: Chondrocyte, Dedifferentiation, Single-cell analysis, Micro-Raman spectroscopy, Molecular mechanism