Measuring propionyl-CoA carboxylase activity in phytohemagglutinin stimulated lymphocytes using high performance liquid chromatography

Immunological Memory and Affinity Maturation After Vaccination in Patients With Propionic Acidemia

Earlier studies have recommended routine childhood immunization in patients with propionic acidemia (PA); however, the literature presents insufficient data on the response to vaccines, notably specific IgG concentrations and avidity maturation, after measles, mumps, rubella (MMR), and diphtheria/tetanus (DiphtTe) vaccinations in this population. In patients with PA, cellular and humoral changes of the immune system (e.g. a decreased CD4+ T cell count, with a reversal of CD4/CD8 T cell ratio, a deficient gamma-globulin fraction, and in one case a decreased lymphocyte blastogenesis) have been reported. Former reports also detected pancytopenias accompanying febrile infections in PA patients. In the current study, we analyzed vaccine-specific IgG concentrations and avidity maturation after MMR and DiphtTe vaccinations in 10 patients with PA. Compared to gender and age matched controls, all 10 had protective IgG concentrations for at least one tested antigen, and in 6 out of 10 patients high relative avidity indices for measles and rubella were detected. In summary, the present study revealed a sufficient immune response and outcome, indicating an acceptable humoral memory in patients with PA after booster vaccinations.

Short-chain fatty acids activate acetyltransferase p300

Short-chain fatty acids (SCFAs) acetate, propionate, and butyrate are produced in large quantities by the gut microbiome and contribute to a wide array of physiological processes. While the underlying mechanisms are largely unknown, many effects of SCFAs have been traced to changes in the cell's epigenetic state. Here, we systematically investigate how SCFAs alter the epigenome. Using quantitative proteomics of histone modification states, we identified rapid and sustained increases in histone acetylation after the addition of butyrate or propionate, but not acetate. While decades of prior observations would suggest that hyperacetylation induced by SCFAs are due to inhibition of histone deacetylases (HDACs), we found that propionate and butyrate instead activate the acetyltransferase p300. Propionate and butyrate are rapidly converted to the corresponding acyl-CoAs which are then used by p300 to catalyze auto-acylation of the autoinhibitory loop, activating the enzyme for histone/protein acetylation. This data challenges the long-held belief that SCFAs mainly regulate chromatin by inhibiting HDACs, and instead reveals a previously unknown mechanism of HAT activation that can explain how an influx of low levels of SCFAs alters global chromatin states.

Anti-oxidant and anti-inflammatory effects of auraptene on phytohemagglutinin (PHA)-induced inflammation in human lymphocytes

BACKGROUND

Inflammation is characterized as a defensive response of our body against endogenous or exogenous stimuli. Chronic inflammation and oxidative stress play an important role in the pathogenesis of various disorders such as asthma, cancers, and multiple sclerosis. Recently, diverse pharmacological activities of auraptene, a natural prenyloxycoumarin, were reported. In the present study, we aimed to evaluate the anti-oxidative and anti-inflammatory effects of auraptene on human isolated lymphocytes.

METHOD

The effects of auraptene (10, 30 and 90 μM) and dexamethasone (0.1 mM) were evaluated on cell viability, reactive oxygen species (ROS), and malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities, and total glutathione content (GSH) as well as the secretion of interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α in phytohemagglutinin (PHA)-stimulated human lymphocytes.

RESULTS

Auraptene (10-90 μM) did not affect lymphocytes' viability after 48 h incubation. PHA markedly elevated ROS, MDA, IL-6, and TNF-α levels, while diminished the GSH content, and CAT and SOD activities in human lymphocytes (p < 0.001 for all cases). Treatment with auraptene (10-90 µM) significantly ameliorated ROS, MDA, IL-6, and TNF-α levels, and markedly increased GSH content, and CAT and SOD activities (p <  0.5-0.001).

CONCLUSION

Auraptene may possess promising healing effects in the different inflammatory disorders associated with activation of the acquired immune system such as multiple sclerosis and asthma.

Propionyl-CoA carboxylase - A review

Propionyl-CoA carboxylase (PCC) is the enzyme which catalyzes the carboxylation of propionyl-CoA to methylmalonyl-CoA and is encoded by the genes PCCA and PCCB to form a hetero-dodecamer. Dysfunction of PCC leads to the inherited metabolic disorder propionic acidemia, which can result in an affected individual presenting with metabolic acidosis, hyperammonemia, lethargy, vomiting and sometimes coma and death if not treated. Individuals with propionic acidemia also have a number of long term complications resulting from the dysfunction of the PCC enzyme. Here we present an overview of the current knowledge about the structure and function of PCC. We review an updated list of human variants which are published and provide an overview of the disease.