Oligonucleotide correction of an intronic TIMMDC1 variant in cells of patients with severe neurodegenerative disorder

Abstract

TIMMDC1 encodes the Translocase of Inner Mitochondrial Membrane Domain-Containing protein 1 (TIMMDC1) subunit of complex I of the electron transport chain responsible for ATP production. We studied a consanguineous family with two affected children, now deceased, who presented with failure to thrive in the early postnatal period, poor feeding, hypotonia, peripheral neuropathy and drug-resistant epilepsy. Genome sequencing data revealed a known, deep intronic pathogenic variant TIMMDC1 c.597-1340A>G, also present in gnomAD (~1/5000 frequency), that enhances aberrant splicing. Using RNA and protein analysis we show almost complete loss of TIMMDC1 protein and compromised mitochondrial complex I function. We have designed and applied two different splice-switching antisense oligonucleotides (SSO) to restore normal TIMMDC1 mRNA processing and protein levels in patients’ cells. Quantitative proteomics and real-time metabolic analysis of mitochondrial function on patient fibroblasts treated with SSOs showed restoration of complex I subunit abundance and function. SSO-mediated therapy of this inevitably fatal TIMMDC1 neurologic disorder is an attractive possibility.

RNAseq Analysis of FABP4 Knockout Mouse Hippocampal Transcriptome Suggests a Role for WNT/β-Catenin in Preventing Obesity-Induced Cognitive Impairment

“…We further condensed these results into pathways that relate to metabolism and Wnt/β-Catenin signaling ( Table 3 ). Transcripts associated with the electron transport chain [ 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ] and citric acid cycle [ 76 , 77 , 78 , 79 ] were downregulated and upregulated, respectively. Transcripts relating to Wnt/β-Catenin signaling were upregulated [ 80 , 81 , 82 , 83 , 84 , 85 ].…”

“…The following supporting information can be downloaded at: . References [ 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 104 , 105 , 106 , 107 , 108 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 ,…”

Regulating PCCA gene expression by modulation of pseudoexon splicing patterns to rescue enzyme activity in propionic acidemia

“…Other examples of SSO-mediated blocking of an increasing number of disease-associated pseudoexons have been demonstrated to restore enzyme activity. 20 , 36 , 65 , 66 , 67 However, the delivery of antisense oligonucleotide molecules still poses a major challenge and is limited to a few organs, such as liver, kidneys, CNS, and eyes. 68 The liver would be the main target in the treatment of propionic acidemia.…”

Integrated multi-omics for rapid rare disease diagnosis on a national scale

“…Data were acquired on an Orbitrap Eclipse mass spectrometer (Thermo Fisher) coupled with an Ultimate 3000 HPLC (Thermo Fisher) and NanoESI interface. The system was equipped with an Acclaim Pepmap nano-trap column (Dionex-C18, 75 µm × 2 cm) and an Acclaim Pepmap RSLC analytical column (Dionex-C18, 75 µm × 50 cm), running in a data-independent acquisition mode with a previously described method 58 . Raw files were processed using Spectronaut (v.16.2.220903.53000, Rubin) against a data-dependent-acquired peptide library generated from deeply fractionated control fibroblast samples containing 150,106 peptide precursors.…”