03356nas a2200265 4500008004100000022001400041245012500055210006900180260001600249300000800265490000600273520241900279100001802698700001902716700003602735700002902771700002702800700002002827700001802847700002002865700002002885700003102905700001902936856013502955 2023 eng d a2058-771600aRapid degeneration of iPSC-derived motor neurons lacking Gdap1 engages a mitochondrial-sustained innate immune response.0 aRapid degeneration of iPSCderived motor neurons lacking Gdap1 en c2023 Jul 01 a2170 v93 a
Charcot-Marie-Tooth disease is a chronic hereditary motor and sensory polyneuropathy targeting Schwann cells and/or motor neurons. Its multifactorial and polygenic origin portrays a complex clinical phenotype of the disease with a wide range of genetic inheritance patterns. The disease-associated gene GDAP1 encodes for a mitochondrial outer membrane protein. Mouse and insect models with mutations in Gdap1 have reproduced several traits of the human disease. However, the precise function in the cell types affected by the disease remains unknown. Here, we use induced-pluripotent stem cells derived from a Gdap1 knockout mouse model to better understand the molecular and cellular phenotypes of the disease caused by the loss-of-function of this gene. Gdap1-null motor neurons display a fragile cell phenotype prone to early degeneration showing (1) altered mitochondrial morphology, with an increase in the fragmentation of these organelles, (2) activation of autophagy and mitophagy, (3) abnormal metabolism, characterized by a downregulation of Hexokinase 2 and ATP5b proteins, (4) increased reactive oxygen species and elevated mitochondrial membrane potential, and (5) increased innate immune response and p38 MAP kinase activation. Our data reveals the existence of an underlying Redox-inflammatory axis fueled by altered mitochondrial metabolism in the absence of Gdap1. As this biochemical axis encompasses a wide variety of druggable targets, our results may have implications for developing therapies using combinatorial pharmacological approaches and improving therefore human welfare. A Redox-immune axis underlying motor neuron degeneration caused by the absence of Gdap1. Our results show that Gdap1 motor neurons have a fragile cellular phenotype that is prone to degeneration. Gdap1 iPSCs differentiated into motor neurons showed an altered metabolic state: decreased glycolysis and increased OXPHOS. These alterations may lead to hyperpolarization of mitochondria and increased ROS levels. Excessive amounts of ROS might be the cause of increased mitophagy, p38 activation and inflammation as a cellular response to oxidative stress. The p38 MAPK pathway and the immune response may, in turn, have feedback mechanisms, leading to the induction of apoptosis and senescence, respectively. CAC, citric acid cycle; ETC, electronic transport chain; Glc, glucose; Lac, lactate; Pyr, pyruvate.
1 aLeón, Marian1 aPrieto, Javier1 aMolina-Navarro, María, Micaela1 aGarcia-Garcia, Francisco1 aBarneo-Muñoz, Manuela1 aPonsoda, Xavier1 aSáez, Rosana1 aPalau, Francesc1 aDopazo, Joaquin1 aBelmonte, Juan, Carlos Izp1 aTorres, Josema uhttps://www.clinbioinfosspa.es/content/rapid-degeneration-ipsc-derived-motor-neurons-lacking-gdap1-engages-mitochondrial-sustained02242nas a2200409 4500008004100000022001400041245006800055210006700123260001300190300001400203490000700217520102100224653001201245653002701257653002701284653001501311653001301326653003001339653000901369653002701378653001201405653002601417653002701443653002601470100001901496700001801515700002001533700002901553700001601582700001501598700002701613700002001640700002001660700002701680700001901707856010601726 2016 eng d a1551-400500aDysfunctional mitochondrial fission impairs cell reprogramming.0 aDysfunctional mitochondrial fission impairs cell reprogramming c2016 Dec a3240-32500 v153 aWe have recently shown that mitochondrial fission is induced early in reprogramming in a Drp1-dependent manner; however, the identity of the factors controlling Drp1 recruitment to mitochondria was unexplored. To investigate this, we used a panel of RNAi targeting factors involved in the regulation of mitochondrial dynamics and we observed that MiD51, Gdap1 and, to a lesser extent, Mff were found to play key roles in this process. Cells derived from Gdap1-null mice were used to further explore the role of this factor in cell reprogramming. Microarray data revealed a prominent down-regulation of cell cycle pathways in Gdap1-null cells early in reprogramming and cell cycle profiling uncovered a G2/M growth arrest in Gdap1-null cells undergoing reprogramming. High-Content analysis showed that this growth arrest was DNA damage-independent. We propose that lack of efficient mitochondrial fission impairs cell reprogramming by interfering with cell cycle progression in a DNA damage-independent manner.
10aAnimals10aCell Cycle Checkpoints10aCellular Reprogramming10aDNA Damage10aG2 Phase10aGene Knockdown Techniques10aMice10aMitochondrial Dynamics10aMitosis10aNerve Tissue Proteins10aPluripotent Stem Cells10aTranscription Factors1 aPrieto, Javier1 aLeón, Marian1 aPonsoda, Xavier1 aGarcia-Garcia, Francisco1 aBort, Roque1 aSerna, Eva1 aBarneo-Muñoz, Manuela1 aPalau, Francesc1 aDopazo, Joaquin1 aLópez-García, Carlos1 aTorres, Josema uhttps://www.clinbioinfosspa.es/content/dysfunctional-mitochondrial-fission-impairs-cell-reprogramming