Giant crystals inside mitochondria of equine chondrocytes

Author(s)
S. Nürnberger, C. Rentenberger, K. Thiel, B. Schädl, I. Grunwald, I. Ponomarev, S. Marlovits, C. Meyer, D. Barnewitz
Abstract

The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 1–2 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It is elongated, spanning a length of several micrometres through the whole cell. In some chondrocytes, several crystals were found, sometimes combined in a single mitochondrion. Crystals were preferentially aligned along the long axis of the cells, thus appearing in the same orientation as the chondrocytes in the tissue. Although no similar structures have been found in the cartilage of any other species investigated, they have been found in cartilage repair tissue formed within a mechanically stimulated equine chondrocyte construct. Crystals were mainly located in superficial regions of cartilage, especially in joint regions of well-developed superficial layers, more often in yearlings than in adult horses. These results indicate that intramitochondrial crystals are related to the high mechanical stress in the horse joint and potentially also to the increased metabolic activity of immature individuals.

Organisation(s)
Physics of Nanostructured Materials
Journal
Histochemistry and Cell Biology
Volume
147
Pages
635-649
No. of pages
15
ISSN
0948-6143
DOI
https://doi.org/10.1007/s00418-016-1516-6
Publication date
12-2016
Publication status
E-pub ahead of print
Peer reviewed
Yes
Austrian Fields of Science 2012
106052 Cell biology, 103042 Electron microscopy
Keywords
Cartilage, Chondrocytes, Histochemistry, Mitochondria, Protein crystals, Transmission electron microscopy
ASJC Scopus subject areas
Histology, Molecular Biology, Medical Laboratory Technology, Cell Biology
Portal url
https://ucris.univie.ac.at/portal/en/publications/giant-crystals-inside-mitochondria-of-equine-chondrocytes(46c7ae1c-61d2-4a00-a787-d40de7bb8012).html