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Purpose: This study aimed to evaluate the epigenetic reprogramming of ICR1 (KvDMR1) and ICR2 (H19DMR) and expression of genes controlled by them as well as those involved in methylation, demethylation, and pluripotency., Methods: We collected germinal vesicle (GV) and metaphase II (MII) oocytes, and preimplantation embryos at five stages [zygote, 4-8 cells, 8-16 cells, morula, and expanded blastocysts (ExB)]. DNA methylation was assessed by BiSeq, and the gene expression was evaluated using qPCR., Results: H19DMR showed an increased DNA methylation from GV to MII oocytes (68.04% and 98.05%, respectively), decreasing in zygotes (85.83%) until morula (61.65%), and ExB (63.63%). H19 and IGF2 showed increased expression in zygotes, which decreased in further stages. KvDMR1 was hypermethylated in both GV (71.82%) and MII (69.43%) and in zygotes (73.70%) up to morula (77.84%), with a loss of methylation at the ExB (36.64%). The zygote had higher expression of most genes, except for CDKN1C and PHLDA2, which were highly expressed in MII and GV oocytes, respectively. DNMTs showed increased expression in oocytes, followed by a reduction in the earliest stages of embryo development. TET1 was downregulated until 4-8-cell and upregulated in 8-16-cell embryos. TET2 and TET3 showed higher expression in oocytes, and a downregulation in MII oocytes and 4-8-cell embryo., Conclusion: We highlighted the heterogeneity in the DNA methylation of H19DMR and KvDMR1 and a dynamic expression pattern of genes controlled by them. The expression of DNMTs and TETs genes was also dynamic owing to epigenetic reprogramming., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The FKBP5 and NR3C1 genes play an important role in stress response, thus impacting mental health. Stress factor exposure in early life, such as maternal depression, may contribute to epigenetic modifications in stress response genes, increasing the susceptibility to different psychopathologies. The present study aimed to evaluate the DNA methylation profile in maternal-infant depression in regulatory regions of the FKBP5 gene and the alternative promoter of the NR3C1 gene., Methods: We evaluated 60 mother-infant pairs. The levels of DNA methylation were analyzed by the MSRED-qPCR technique., Results: We observed an increased DNA methylation profile in the NR3C1 gene promoter in children with depression and children exposed to maternal depression (p < 0.05). In addition, we observed a correlation of DNA methylation between mothers and offspring exposed to maternal depression. This correlation shows a possible intergenerational effect of maternal MDD exposure on the offspring. For FKBP5, we found a decrease in DNA methylation at intron 7 in children exposed to maternal MDD during pregnancy and a correlation of DNA methylation between mothers and children exposed to maternal MDD (p < 0.05)., Limitations: Although the individuals of this study are a rare group, the sample size of the study was small, and we evaluated the DNA methylation of only one CpG site for each region., Conclusion: These results indicate changes in DNA methylation levels in regulatory regions of FKBP5 and NR3C1 in the mother-child MDD context and represent a potential target of studies to understand the depression etiology and how it occurs between generations., Competing Interests: Declaration of competing interest JAC and JECH are co-inventors (Mechoulam R, Crippa JA, Guimaraes FS, Zuardi A, Hallak, JE, and Breuer A) of the patent “Fluorinated CBD compounds, compositions and uses thereof. Pub. No.: WO/2014/108899. International Application No.: PCT/IL2014/050023” Def. US no. Reg. 62193296; July 29, 2015; INPI on August 19, 2015 (BR1120150164927). The University of São Paulo has licensed the patent to Phytecs Pharm (USP Resolution 15.1.130002.1.1). USP has an agreement with Prati-Donaduzzi (Toledo, Brazil) to “develop a pharmaceutical product containing synthetic CBD and prove its safety and therapeutic efficacy in the treatment of epilepsy, schizophrenia, Parkinson's disease, and anxiety disorders.” JAC has received travel support from and is a medical advisor of the SCBD Centre, and has a grant from the University Global Partnership Network (UGPN) – “Global priorities in cannabinoid research excellence.” JAC is member of the international advisory board of the Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE; funded by the National Health and Medical Research Council through the Centre of Research Excellence). The other authors report no conflicts of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Multi-locus methylation defects (MLMDs) in imprinted loci have been reported in Beckwith-Wiedemann Syndrome (BWS). Large offspring syndrome (LOS), a phenotypic subgroup of abnormal offspring syndrome (AOS), is considered a molecular and phenotypic model for BWS. Both LOS and BWS have presented epigenetic defects in some common imprinted loci. In this study, methylation-specific restriction digestion assay - quantitative PCR was used to analyze the DNA methylation pattern in differentially methylated regions (DMRs) of the H19 (H19-DMR), KCNQ1OT1 (KvDMR1) and PEG1/MEST (PEG1-DMR) genes in bovine clone tissues from calves that did not survive after birth. Individual and tissue-specific changes in DNA methylation levels in the bovine KvDMR1, H19-DMR, and PEG1-DMR were observed. In contrast to what has been reported in the literature on BWS and AOS/LOS, the KvDMR1 showed gain (GOM) and loss (LOM) of DNA methylation. LOM and GOM events were found in the DMRs studied in animals produced by the same nucleus donor cell line. This is the first report of epimutations in the PEG1-DMR and GOM at the KvDMR1 found in bovine clones. The findings showed that epigenetic modification in imprinted loci in cloned cattle occurred in a multi-locus pattern similar to that seen in human imprinting disorders. Other multi-locus analyzes must be done to elucidate the MLMD pattern in AOS in bovine clones., Competing Interests: Declaration of competing interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Cancer is a group of heterogeneous diseases characterized by several disruptions of the genetic and epigenetic components of cell biology. Some types of cancer have been shown to be constituted by a mosaic of cells with variable differentiation states, with more aggressive tumors being more undifferentiated. In most cases, undifferentiated tumor cells express associated embryonic markers such as the OCT4, NANOG, SOX2, and CARM1 genes. The ectopic or reminiscent expression of some master regulator genes of pluripotency has been indicated as the cause of the poorly differentiated state of tumors, and based on the evidence of some reports, can be used as a possible therapeutic target. Considering this information, a more detailed investigation of the expression of pluripotency-associated genes is necessary to evaluate the roles of these genes in the etiology of some tumors and their use targets of therapy., Methods: The expression of four pluripotency-related genes was investigated (OCT4, NANOG, SOX2, and CARM1) in the most malignant primary human brain tumor, glioblastoma (GBM)., Results and Conclusion: The results demonstrated a signature of OCT4/SOX2/CARM1 genes and a significant increase of CARM1 expression in GBM cases., (© The Author(s) 2021. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)

The FKBP5 gene codifies a co-chaperone protein associated with the modulation of glucocorticoid receptor interaction involved in the adaptive stress response. The FKBP5 intracellular concentration affects the binding affinity of the glucocorticoid receptor (GR) to glucocorticoids (GCs). This gene has glucocorticoid response elements (GREs) located in introns 2, 5 and 7, which affect its expression. Recent studies have examined GRE activity and the effects of genetic variants on transcript efficiency and their contribution to susceptibility to behavioral disorders. Epigenetic changes and environmental factors can influence the effects of these allele-specific variants, impacting the response to GCs of the FKBP5 gene. The main epigenetic mark investigated in FKBP5 intronic regions is DNA methylation, however, few studies have been performed for all GREs located in these regions. One of the major findings was the association of low DNA methylation levels in the intron 7 of FKBP5 in patients with psychiatric disorders. To date, there are no reports of DNA methylation in introns 2 and 5 of the gene associated with diagnoses of psychiatric disorders. This review highlights what has been discovered so far about the relationship between polymorphisms and epigenetic targets in intragenic regions, and reveals the gaps that need to be explored, mainly concerning the role of DNA methylation in these regions and how it acts in psychiatric disease susceptibility., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In vitro fertilization and somatic cell nuclear transfer are assisted reproduction technologies commonly used in humans and cattle, respectively. Despite advances in these technologies, molecular failures can occur, increasing the chance of the onset of imprinting disorders in the offspring. Large offspring syndrome/abnormal offspring syndrome (LOS/AOS) has been described in cattle and has features such as hypergrowth, malformation of organs, and skeletal and placental defects. In humans, Beckwith-Wiedemann syndrome (BWS) has phenotypic characteristics similar to those found in LOS/AOS. In both syndromes, disruption of genomic imprinting associated with loss of parental-specific expression and parental-specific epigenetic marks is involved in the molecular etiology. Changes in the imprinting pattern of these genes lead to loss of imprinting (LOI) due to gain or loss of methylation, inducing the emergence of these syndromes. Several studies have reported locus-specific alterations in these syndromes, such as hypomethylation in imprinting control region 2 (KvDMR1) in BWS and LOS/AOS. These LOI events can occur at multiple imprinted loci in the same affected individual, which are called multi-locus methylation defect (MLMD) events. Although the bovine species has been proposed as a developmental model for human imprinting disorders, there is little information on bovine imprinted genes in the literature, even the correlation of epimutation data with clinical characteristics. In this study, we performed a systematic review of all the multi-locus LOI events described in human BWS and LOS/AOS, in order to determine in which imprinted genes the largest changes in the pattern of DNA methylation and expression occur, helping to fill gaps for a better understanding of the etiology of both syndromes., Competing Interests: Declaration of competing interest The authors declare no potential conflicts of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Gastric cancer is one of the most common cancers, and an increasing number of studies have found that microRNAs (miRNAs) play essential roles in gastric cancer progression; however, the roles of specific miRNAs involved in the immune response to this disease remain unclear. We compared the miRNA expression in tissues from primary gastric cancer patients and healthy controls to find miRNAs dysregulated in gastric cancer and used bioinformatics tools to determine potential roles of these miRNAs in the immune system. We evaluated 25 primary gastric cancer tissues and five healthy gastric tissues. Quantitative real-time polymerase chain reaction was performed for a set of miRNAs, followed by the prediction of their target genes and functional enrichment analysis of these targets. Analysis of a microarray dataset showed that the miRNA miR-196a-5p was significantly upregulated, while miR-374a-5p and miR-375 were downregulated in gastric cancer patients. In addition, miR-374-5p was significantly downregulated in patients with metastasis compared with its expression levels in non-metastatic patients (p = 0.03). Bioinformatics analysis suggested that the pathways regulated by these differentially expressed miRNAs were related to the immune response, cell adhesion, and cell migration. Most importantly, this study provides a new insight into the potential use of multiple miRNAs to find distinct pathways of immune regulation in gastric cancer.

XIST, in association with the shorter ncRNA RepA, are essential for the initiation of X chromosome inactivation (XCI) in mice. The molecular mechanisms controlling XIST and RepA expression are well characterized in that specie. However, little is known in livestock. We aimed to characterize the DNA methylation status along the 5' portion of XIST and to characterize its transcriptional profile during early development in cattle. Three genomic regions of XIST named here as promoter, RepA and DMR1 had their DNA methylation status characterized in gametes and embryos. Expression profile of XIST was evaluated, including sense and antisense transcription. Oocytes showed higher levels of methylation than spermatozoa that was demethylated. DMR1 was hypermethylated throughout oogenesis. At the 8-16-cell embryo stage DMR1 was completed demethylated. Interestingly, RepA gain methylation during oocyte maturation and was demethylated at the blastocyst stage, later than DMR1. These results suggest that DMR1 and RepA are transient differentially methylated regions in cattle. XIST RNA was detected in matured oocytes and in single cells from the 2-cell to the morula stage, confirming the presence of maternal and embryonic transcripts. Sense and antisense transcripts were detected along the XIST in blastocyst. In silico analysis identified 63 novel transcript candidates at bovine XIST locus from both the plus and minus strands. Taking together these results improve our understanding of the molecular mechanisms involved in XCI initiation in cattle. This information may be useful for the improvement of assisted reproductive technologies in livestock considering that in vitro conditions may impair epigenetic reprogramming.