N 6 -methyladenosine (M 6 A) in fetal offspring modifies mitochondrial gene expression following gestational nano-TiO 2 inhalation exposure.
Amina KunovacQuincy A HathawayDharendra ThapaAndrya J DurrAndrew D TaylorSaira RizwanDaud SharifStephen J ValentineJohn M HollanderPublished in: Nanotoxicology (2024)
N 6 -methyladenosine (m 6 A) is the most prominent epitranscriptomic modification to RNA in eukaryotes, but it's role in adaptive changes within the gestational environment are poorly understood. We propose that gestational exposure to nano titanium dioxide (TiO 2 ) contributes to cardiac m 6 A methylation in fetal offspring and influences mitochondrial gene expression. 10-week-old pregnant female FVB/NJ wild-type mice underwent 6 nonconsecutive days of whole-body inhalation exposure beginning on gestational day (GD) 5. Mice were exposed to filtered room air or nano-TiO 2 with a target aerosol mass concentration of 12 mg/m 3 . At GD 15 mice were humanely killed and cardiac RNA and mitochondrial proteins extracted. Immunoprecipitation with m 6 A antibodies was performed followed by sequencing of immunoprecipitant (m 6 A) and input (mRNA) on the Illumina NextSeq 2000. Protein extraction, preparation, and LC-MS/MS were used for mitochondrial protein quantification. There were no differences in maternal or fetal pup weights, number of pups, or pup heart weights between exposure and control groups. Transcriptomic sequencing revealed 3648 differentially expressed mRNA in nano-TiO 2 exposed mice ( Padj ≤ 0.05). Transcripts involved in mitochondrial bioenergetics were significantly downregulated (83 of 85 genes). 921 transcripts revealed significant m 6 A methylation sites ( Padj ≤ 0.10). 311 of the 921 mRNA were identified to have both 1) significantly altered expression and 2) differentially methylated sites. Mitochondrial proteomics revealed decreased expression of ATP Synthase subunits in the exposed group ( P ≤ 0.05). The lack of m 6 A modifications to mitochondrial transcripts suggests a mechanism for decreased transcript stability and reduced protein expression due to gestational nano-TiO 2 inhalation exposure.
Keyphrases
- oxidative stress
- weight gain
- gene expression
- pregnant women
- wild type
- single cell
- birth weight
- dna methylation
- binding protein
- high fat diet induced
- quantum dots
- poor prognosis
- genome wide
- high fat diet
- type diabetes
- rna seq
- mass spectrometry
- heart failure
- adipose tissue
- metabolic syndrome
- magnetic resonance imaging
- randomized controlled trial
- long non coding rna
- atrial fibrillation
- gestational age
- nucleic acid
- high throughput sequencing
- bioinformatics analysis