TY - JOUR

T1 - Tafazzin-dependent cardiolipin composition in C6 glioma cells correlates with changes in mitochondrial and cellular functions, and cellular proliferation

AU - Gürtler, Sarah

AU - Wolke, Carmen

AU - Otto, Oliver

AU - Heise, Nico

AU - Scholz, Fritz

AU - Laporte, Anna

AU - Elsner, Matthias

AU - Jörns, Anne

AU - Weinert, Sönke

AU - Döring, Mona

AU - Jansing, Steffen

AU - Gardemann, Andreas

AU - Lendeckel, Uwe

AU - Schild, Lorenz

N1 - Funding Information: We thank Daniela Peter, Elke Wölfel, Silke Niemann, Manja Möller, Ines Schultz and Doreen Biedenweg for excellent technical assistance. This work was supported by funding: the Deutsche Forschungsgemeinschaft , GRK 1947/1 (AL, FS, ME, NH, SG, UL). Oliver Otto acknowledges funding from the Bundesministerium für Wissenschaft und Forschung , Germany under the grant agreement 03Z22CN11 .

PY - 2019/4

Y1 - 2019/4

N2 - The mitochondrial phospholipid cardiolipin (CL) has been implicated with mitochondrial morphology, function and, more recently, with cellular proliferation. Tafazzin, an acyltransferase with key functions in CL remodeling determining actual CL composition, affects mitochondrial oxidative phosphorylation. Here, we show that the CRISPR-Cas9 mediated knock-out of tafazzin (Taz) is associated with substantial alterations of various mitochondrial and cellular characteristics in C6 glioma cells. The knock-out of tafazzin substantially changed the profile of fatty acids incorporated in CL and the distribution of molecular CL species. Taz knock-out was further associated with decreased capacity of oxidative phosphorylation that mainly originates from impaired complex I associated energy metabolism in C6 glioma cells. The lack of tafazzin switched energy metabolism from oxidative phosphorylation to glycolysis indicated by lower respiration rates, membrane potential and higher levels of mitochondria-derived reactive oxygen species but keeping the cellular ATP content unchanged. The impact of tafazzin on mitochondria was also indicated by altered morphology and arrangement in tafazzin deficient C6 glioma cells. In the cells we observed tafazzin-dependent changes in the distribution of cellular fatty acids as an indication of altered lipid metabolism as well as in stability/morphology. Most impressive is the dramatic reduction in cell proliferation in tafazzin deficient C6 glioma cells that is not mediated by reactive oxygen species. Our data clearly indicate that defects in CL phospholipid remodeling trigger a cascade of events including modifications in CL linked to subsequent alterations in mitochondrial and cellular functions.

AB - The mitochondrial phospholipid cardiolipin (CL) has been implicated with mitochondrial morphology, function and, more recently, with cellular proliferation. Tafazzin, an acyltransferase with key functions in CL remodeling determining actual CL composition, affects mitochondrial oxidative phosphorylation. Here, we show that the CRISPR-Cas9 mediated knock-out of tafazzin (Taz) is associated with substantial alterations of various mitochondrial and cellular characteristics in C6 glioma cells. The knock-out of tafazzin substantially changed the profile of fatty acids incorporated in CL and the distribution of molecular CL species. Taz knock-out was further associated with decreased capacity of oxidative phosphorylation that mainly originates from impaired complex I associated energy metabolism in C6 glioma cells. The lack of tafazzin switched energy metabolism from oxidative phosphorylation to glycolysis indicated by lower respiration rates, membrane potential and higher levels of mitochondria-derived reactive oxygen species but keeping the cellular ATP content unchanged. The impact of tafazzin on mitochondria was also indicated by altered morphology and arrangement in tafazzin deficient C6 glioma cells. In the cells we observed tafazzin-dependent changes in the distribution of cellular fatty acids as an indication of altered lipid metabolism as well as in stability/morphology. Most impressive is the dramatic reduction in cell proliferation in tafazzin deficient C6 glioma cells that is not mediated by reactive oxygen species. Our data clearly indicate that defects in CL phospholipid remodeling trigger a cascade of events including modifications in CL linked to subsequent alterations in mitochondrial and cellular functions.

KW - Animals

KW - CRISPR-Cas Systems

KW - Cardiolipins/metabolism

KW - Cell Line, Tumor

KW - Cell Proliferation

KW - Energy Metabolism

KW - Fatty Acids/metabolism

KW - Gene Knockout Techniques

KW - Glioma/genetics

KW - Glycolysis

KW - Mitochondria/metabolism

KW - Oxidative Phosphorylation

KW - Rats

KW - Transcription Factors/genetics

KW - Cell proliferation

KW - Tafazzin

KW - CRISPR-Cas

KW - Cardiolipin

UR - http://www.scopus.com/inward/record.url?scp=85060240249&partnerID=8YFLogxK

U2 - 10.1016/j.bbalip.2019.01.006

DO - 10.1016/j.bbalip.2019.01.006

M3 - Article

C2 - 30639735

VL - 1864

SP - 452

EP - 465

JO - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids

JF - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids

SN - 1388-1981

IS - 4

ER -