Stable isotope-based flux studies in nonalcoholic fatty liver disease.
*Citric acid cycle; *Fatty acid oxidation; *Fibrosis; *NAFLD; *Oxidative stress; *Stable isotopes; Animals; Humans; Isotopes/metabolism; Mass Spectrometry/*methods; Non-alcoholic Fatty Liver Disease/*metabolism
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is associated with the worldwide epidemics of obesity, diabetes and cardiovascular diseases. NAFLD ranges from benign fat accumulation in the liver (steatosis) to non-alcoholic steatohepatitis (NASH), and cirrhosis which can progress to hepatocellular carcinoma and liver failure. Mass spectrometry and magnetic resonance spectroscopy-coupled stable isotope-based flux studies provide new insights into the understanding of NAFLD pathogenesis and the disease progression. This review focuses mainly on the utilization of mass spectrometry-based methods for the understanding of metabolic abnormalities in the different stages of NAFLD. For example, stable isotope-based flux studies demonstrated multi-organ insulin resistance, dysregulated glucose, lipids and lipoprotein metabolism in patients with NAFLD. We also review recent developments in the stable isotope-based technologies for the study of mitochondrial dysfunction, oxidative stress and fibrogenesis in NAFLD. We highlight the limitations of current methodologies, discuss the emerging areas of research in this field, and future directions for the applications of stable isotopes to study NAFLD and its complications.
McCullough Arthur; Previs Stephen; Kasumov Takhar
Pharmacology & therapeutics
2018
2018-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.pharmthera.2017.07.008" target="_blank" rel="noreferrer noopener">10.1016/j.pharmthera.2017.07.008</a>
Turnover of histones and histone variants in postnatal rat brain: effects of alcohol exposure.
*2H2O-labeling; *Brain; *Genetic Variation; *Histone; *Mass spectrometry; *Post-translational modifications; *Postnatal alcohol exposure; *Turnover; Acetylation; Animal; Animals; Cell Proliferation; Disease Models; DNA Damage; Epigenesis; Female; Fetal Alcohol Spectrum Disorders/genetics/*metabolism; Genetic; Histones/*genetics/*metabolism; Humans; Post-Translational; Pregnancy; Protein Processing; Proteomics/*methods; Rats; Sprague-Dawley
BACKGROUND: Alcohol consumption during pregnancy is a significant public health problem and can result in a continuum of adverse outcomes to the fetus known as fetal alcohol spectrum disorders (FASD). Subjects with FASD show significant neurological deficits, ranging from microencephaly, neurobehavioral, and mental health problems to poor social adjustment and stress tolerance. Neurons are particularly sensitive to alcohol exposure. The neurotoxic action of alcohol, i.e., through ROS production, induces DNA damage and neuronal cell death by apoptosis. In addition, epigenetics, including DNA methylation, histone posttranslational modifications (PTMs), and non-coding RNA, play an important role in the neuropathology of FASD. However, little is known about the temporal dynamics and kinetics of histones and their PTMs in FASD. RESULTS: We examined the effects of postnatal alcohol exposure (PAE), an animal model of human third-trimester equivalent, on the kinetics of various histone proteins in two distinct brain regions, the frontal cortex, and the hypothalamus, using in vivo (2)H2O-labeling combined with mass spectrometry-based proteomics. We show that histones have long half-lives that are in the order of days. We also show that H3.3 and H2Az histone variants have faster turnovers than canonical histones and that acetylated histones, in general, have a faster turnover than unmodified and methylated histones. Our work is the first to show that PAE induces a differential reduction in turnover rates of histones in both brain regions studied. These alterations in histone turnover were associated with increased DNA damage and decreased cell proliferation in postnatal rat brain. CONCLUSION: Alterations in histone turnover might interfere with histone deposition and chromatin stability, resulting in deregulated cell-specific gene expression and therefore contribute to the development of the neurological disorders associated with FASD. Using in vivo (2)H2O-labeling and mass spectrometry-based proteomics might help in the understanding of histone turnover following alcohol exposure and could be of great importance in enabling researchers to identify novel targets and/or biomarkers for the prevention and management of fetal alcohol spectrum disorders.
Rachdaoui Nadia; Li Ling; Willard Belinda; Kasumov Takhar; Previs Stephen; Sarkar Dipak
Clinical epigenetics
2017
1905-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1186/s13148-017-0416-5" target="_blank" rel="noreferrer noopener">10.1186/s13148-017-0416-5</a>