Recombinant human mitochondrial transcription factor A stimulates mitochondrial biogenesis and ATP synthesis, improves motor function after MPTP, reduces oxidative stress and increases survival after endotoxin

Abstract

Recombinant human mitochondrial transcription factor A protein (rhTFAM) was evaluated for its acute effects on cultured cells and chronic effects in mice. Fibroblasts incubated with rhTFAM acutely increased respiration in a chloramphenicol-sensitive manner. SH-SY5Y cells showed rhTFAM concentration-dependent reduction of methylpyridinium (MPP + )-induced oxidative stress and increases in lowered ATP levels and viability. Mice treated with weekly i.v. rhTFAM showed increased mitochondrial gene copy number, complex I protein levels and ATP production rates; oxidative damage to proteins was decreased ~50%. rhTFAM treatment improved motor recovery rate after treatment with MPTP and dose-dependently improved survival in the lipopolysaccharide model of endotoxin sepsis.

Mitochondrial Gene Therapy Improves Respiration, Biogenesis, and Transcription in G11778A Leber's Hereditary Optic Neuropathy and T8993G Leigh's Syndrome Cells

“…These striking results strengthen our previous observation of increased PGC-1a expression as a marker for mitochondrial biogenesis following treatment with mtDNA in complex with recombinant TFAM (Iyer et al, 2009b;Keeney et al, 2009;Thomas et al, 2011). Similar increasing trends were also observed in LS cells along with increased expression of PGC-1a, TFAM1, and TFAMB1 over 21 days, which strengthened our overall hypothesis that the mechanism for increases in mitochondrial respiration was by triggering the biogenesis pathway in vitro and in vivo (Iyer et al, 2009b;Keeney et al, 2009;Thomas et al, 2011).…”

“…In later studies, our results showed that rhTFAM improved respiration and mitochondrial gene expression of key genes by stimulating mitochondrial biogenesis in vitro and in vivo (Iyer et al, 2009b;Keeney et al, 2009;Thomas et al, 2011). In a more recent study, we also used this approach to introduce, replicate, and transcribe pathogenic mtDNA in human pluripotent stem cell-derived neural progenitor cells, while maintaining multipotency and successful differentiation into neuronal lineage in the short term (Iyer et al, 2011).…”

Mitochondrial Genetic Manipulation

“…To carry DNA into mammalian mitochondria in vivo, the proposed strategy challenged the protein import pathway and was based on the combination of a protein transduction domain (PTD; Suzuki 2012) with an MTS, both fused to the TFAM mitochondrial transcription factor Thomas et al 2011), yielding a carrier called mitochondrial-targeting domain (MTD)-TFAM. In such a system ( Fig.…”

“…Also, partial restoration of organelle function in human cells carrying mitochondrial mutations was achieved by targeting healthy donor mtDNA loaded on MTD-TFAM (Iyer et al 2012a). However, the MTD-TFAM protein alone promoted a similar boosting of mitochondrial functions in cell cultures and mice Keeney et al 2009;Thomas et al 2011). Conversely, with the aim of developing stem cell-based model systems, the MTD-TFAM carrier was used to provide mitochondria with mutated mtDNA copies in human neural progenitor cells (Iyer et al 2012b).…”

Transduction of Human Recombinant Proteins into Mitochondria as a Protein Therapeutic Approach for Mitochondrial Disorders

“…mitochondrial localization sequence) fusion protein transduced cells, translocated into mitochondria and increased cell respiration by increasing expression of genes involved in respiratory chain both in culture and in animal models (177). Furthermore, MTD-TFAM fusion protein improved motor function in mice treated with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), which is able to induce experimental parkinsonism (178). Wilson's group (49,179) used an MTS (from the human MnSOD mitochondrial protein) to target the DNA repair enzyme Exonuclease III (ExoIII) into the mitochondria of breast cancer cells via the PTD technology.…”