Quantitative Ultrastructural Morphometry and Gene Expression of mTOR-Related Mitochondriogenesis within Glioblastoma Cells

International Journal of Molecular Sciences

Cinzia Fabrizi¹  Federica Fulceri²  Pietro Familiari³  Paola Lenzi⁴  Fiona Limanaqi⁴  Stefano Gambardella⁵  Francesco Fornai⁵  Rosangela Ferese⁵  Alessandro Frati⁵  Francesca Biagioni⁵ 

[1] Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Via A. Borelli 50, 00161 Rome, Italy;Department of Clinical and Experimental Medicine University of Pisa, via Roma 55, 56126 Pisa, Italy;Department of Human Neurosciences, Division of Neurosurgery, Sapienza University of Rome, 00185 Roma, Italy;Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, via Roma 55, 56126 Pisa, Italy;I.R.C.C.S. Neuromed, via Atinense 18, 86077 Pozzilli (IS), Italy;

关键词: autophagy;    mitophagy;    lysosomes;    mitochondrial biogenesis;    mitochondrial DNA;    PGC1;   

DOI  :  10.3390/ijms21134570

来源: DOAJ

【 摘 要 】

In glioblastoma (GBM) cells, an impairment of mitochondrial activity along with autophagy suppression occurs. Autophagy suppression in GBM promotes stemness, invasion, and poor prognosis. The autophagy deficit seems to be due, at least in part, to an abnormal up-regulation of the mammalian target of rapamycin (mTOR), which may be counteracted by pharmacological mTORC1 inhibition. Since autophagy activation is tightly bound to increased mitochondriogenesis, a defect in the synthesis of novel mitochondria is expected to occur in GBM cells. In an effort to measure a baseline deficit in mitochondria and promote mitochondriogenesis, the present study used two different GBM cell lines, both featuring mTOR hyperactivity. mTORC1 inhibition increases the expression of genes and proteins related to autophagy, mitophagy, and mitochondriogenesis. Autophagy activation was counted by RT-PCR of autophagy genes, LC3- immune-fluorescent puncta and immune-gold, as well as specific mitophagy-dependent BNIP3 stoichiometric increase in situ, within mitochondria. The activation of autophagy-related molecules and organelles after rapamycin exposure occurs concomitantly with progression of autophagosomes towards lysosomes. Remarkably, mitochondrial biogenesis and plasticity (increased mitochondrial number, integrity, and density as well as decreased mitochondrial area) was long- lasting for weeks following rapamycin withdrawal.

【 授权许可】

Unknown