Physical activity is a strong stimulus influencing the overall physiology of the human body. Exercises lead to biochemical changes in various tissues and exert an impact on gene expression. Exercise-induced changes in gene expression may be mediated by epigenetic modifications, which rearrange the chromatin structure and therefore modulate its accessibility for transcription factors. One of such epigenetic mark is DNA methylation that involves an attachment of a methyl group to the fifth carbon of cytosine residue present in CG dinucleotides (CpG). DNA methylation is catalyzed by a family of DNA methyltransferases. This reversible DNA modification results in the recruitment of proteins containing methyl binding domain and further transcriptional co-repressors leading to the silencing of gene expression. The accumulation of CpG dinucleotides, referred as CpG islands, occurs at the promoter regions in a great majority of human genes. Therefore, changes in DNA methylation profile affect the transcription of multiple genes. A growing body of evidence indicates that exercise training modulates DNA methylation in muscles and adipose tissue. Some of these epigenetic markers were associated with a reduced risk of chronic diseases. This review summarizes the current knowledge about the influence of physical activity on the DNA methylation status in humans.

Molecules built of RNA have been the subjects of numerous studies, which have made known new functions and structures that these molecules can create. In recent years, thanks to next-generation sequencing, it is possible to observe very small RNAs and the number of newly discovered RNA molecules is rapidly increasing. Among other small oligonucleotides, structures derived from tRNA and snoRNA molecules have been observed, and these molecules were determined to not be precursors of known RNA molecules. These structures have attracted the attention of researchers because the level of accumulation of tRNA or snoRNA fragments was relatively high. Additionally, other parts of the parent molecules were absent. Derivatives of well-known RNA molecules also have functions that are different from their parent molecules. They are mainly involved in regulating the expression of genetic information in a similar way to miRNA. In addition, some of the miRNAs that have been described are derivatives of tRNA or snoRNA. Most of the research on these newly discovered molecules is based on their detection and on the study of the macro effects that they exert, in the absence of a description of the molecular mechanism by which they arise and work.

Background: Delayed food anaphylaxis upon consumption of red meat is attributed to specific IgE-antibodies directed to galactose-α-1,3-galactose (α-Gal). Anaphylactic reactions may occur after ingestion of meat from different mammals, mainly beef and pork, but reactions to lamb, rabbit or horse have also been reported. In particular, pork kidney has been shown to trigger symptoms that were more severe and occurred within a shorter delay. The objective of the present study was the identification and characterization of pork kidney proteins carrying α-Gal carbohydrates and mediating delayed allergic reactions through specific IgE to α-Gal. Materials and methods: A cohort of 59 patients with specific IgE to α-Gal was screened by immunoblot for IgE-reactive proteins in pork kidney extract. Proteins were purified by affinity chromatography and identified by Edman sequencing and peptide mass fingerprinting. Isolated proteins were used in immunoassays using patient sera and α-Gal specific antibodies. Allergenicity was assayed in basophil activation and skin prick test. Results: Multiple IgE-binding proteins were detected in protein extracts of pork kidney by immunoblot using patient sera and an anti-α-Gal antibody. Reactive bands were located in the high molecular weight range of 100 to ≥200 kDa. Two major IgE-binding proteins were identified as porcine angiotensin I converting enzyme (ACE I) and aminopeptidase N (AP-N). IgE-binding to both proteins was lost by periodate treatment, resulting in oxidation of carbohydrates. Addition of α-Gal inhibited IgE-reactivity to both peptidases. Allergenicity was confirmed by activation of patient basophils and positive skin prick tests. Conclusions: Two IgE-reactive cell membrane peptidases carrying α-Gal epitopes were identified in pork kidney, a tissue which is known as potent inducer of red meat-induced anaphylaxis. Allergenicity and clinical relevance of these proteins were confirmed in patients with delayed anaphylaxis to red meat by skin prick test and basophil activation.

Physical exercise results in structural remodeling in tissues and modifies cellular metabolism. Changes in gene expression lie at the root of these adaptations. Epigenetic changes are one of the factors responsible for such exercise-related alterations. One-hour acute exercise will change DNMT1, HDAC1, and JHDM1D transcriptions in PBMC. This study examined changes in the expression of genes responsible for epigenetic modifications (HDAC1, DNMT1, and JHDM1D) during and after an incremental exercise test on a treadmill and a 30-min recovery. Blood samples from 9 highly trained triathletes were tested. Examination of the transcripts showed no significant changes. Correlations between transcript results and biochemical indices revealed a significant (p = 0.007) relationship between JHDM1D mRNA and the number of monocytes at peak exercise intensity (exhaustion), while there was no significant (p = 0.053) correlation at rest. There are no rapid changes in the mRNA levels of the genes studied in blood cells in competitive athletes during acute exercise and recovery. Due to the small group of subjects studied, more extensive research is needed to verify correlations between transcription and biochemical variables.

Background:The adaptation of the organism to exercise in the context of gene expression profile is an interesting phenomenon. Exercise can change the expression of individual genes due to changes in the degree of DNA methylation, changes in miRNA expression, or through methylation or acetylation of histones.Hypothesis:Acute exercise increases the expression of genes such as HDAC1, DNMT1, and JHDM1D that can affect epigenetic modifications in PBMCs.Methods:The aim of this study was to determine whether there was a change in gene expression in the blood cells during acute exercise and after a 1-hour recovery. The transcriptions of genes involved in epigenetic modifications (HDAC1, HDAC1 and JHDM1D) were examined in 9 professional athletes at rest, during consecutive stages of a treadmill exercise until exhaustion, and following recovery.Results:No significant differences in the level of transcript were observed in the course of the experiment in the tested PBMC cells. On the other hand, a significant (p = 0.007) correlation was observed in the level of the JHDM1D gene transcript and the number of monocytes in the samples obtained after reaching peak exercise intensity, but in the initial samples this correlation was not significant (p = 0.053).Conclusion:Acute physical exercise does not rapidly alter the transcript levels of the JHDM1D, DNMT1 and HDAC1 genes in PBMCs. The observed correlation between the level of JHDM1D mRNA and the level of monocytes and HDAC1 with lymphocytes requires further investigation.