Elexacaftor/tezacaftor/ivacaftor efficacy in intestinal organoids with rare CFTR variants in comparison to CFTR-F508del and CFTR-wild type controls.

Cystic fibrosis is a life-shortening genetic disease caused by pathological variants of the cystic fibrosis transmembrane conductance regulator gene. The CFTR modulator therapy elexacaftor, tezacaftor and ivacaftor (ETI) rescues CFTR protein function and has made a significant impact on the lives of many people with CF. In Europe, ETI is currently available for people with CF who have at least one F508del mutation whilst the effect of ETI on rare CFTR variants remains unknown, albeit that many of such variants may be restored through ETI.

Zebrafish polg2 knock-out recapitulates human POLG-disorders; implications for drug treatment.

The human mitochondrial DNA polymerase gamma is a holoenzyme, involved in mitochondrial DNA (mtDNA) replication and maintenance, composed of a catalytic subunit (POLG) and a dimeric accessory subunit (POLG2) conferring processivity. Mutations in POLG or POLG2 cause POLG-related diseases in humans, leading to a subset of Mendelian-inherited mitochondrial disorders characterized by mtDNA depletion (MDD) or accumulation of multiple deletions, presenting multi-organ defects and often leading to premature death at a young age. Considering the paucity of POLG2 models, we have generated a stable zebrafish polg2 mutant line (polg2) by CRISPR/Cas9 technology, carrying a 10-nucleotide deletion with frameshift mutation and premature stop codon.

Mitochondrial complex I activity in microglia sustains neuroinflammation.

Sustained smouldering, or low-grade activation, of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells. However, how these metabolic features act to perpetuate inflammation of the central nervous system is unclear.

The striking differences in the bioenergetics of brain and liver mitochondria are enhanced in mitochondrial disease.

Mitochondrial disorders are hallmarked by the dysfunction of oxidative phosphorylation (OXPHOS) yet are highly heterogeneous at the clinical and genetic levels. Striking tissue-specific pathological manifestations are a poorly understood feature of these conditions, even if the disease-causing genes are ubiquitously expressed. To investigate the functional basis of this phenomenon, we analyzed several OXPHOS-related bioenergetic parameters, including oxygen consumption rates, electron transfer system (ETS)-related coenzyme Q (mtCoQ) redox state and production of reactive oxygen species (ROS) in mouse brain and liver mitochondria fueled by different substrates.

Mitochondrial reverse electron transport in myeloid cells perpetuates neuroinflammation.

Sustained smouldering, or low grade, activation of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis (MS) . Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells . However, how these metabolic features act to perpetuate neuroinflammation is currently unknown.