Expression Of Methyltransferase Research Articles

Comprehensive Analysis of DNA Methyltransferases Expression in Primary and Relapsed Ovarian Carcinoma.

Despite recent advances in epithelial ovarian carcinoma (EOC) treatment, its recurrence and mortality rates have not improved significantly. DNA hypermethylation has generally been associated with an ominous prognosis and chemotherapy resistance, but the role of DNA methyltransferases (DNMTs) in EOC remains to be investigated. In the current study, we systematically retrieved gene expression data from patients with EOC and studied the immunohistochemical expression of DNMTs in 108 primary and 26 relapsed tumors. Our results showed that the DNMT1, DNMT3A, DNMT3B and DNMT3L RNA levels were higher and the DNMT2 level was lower in tumors compared to non-neoplastic tissue, and DNMT3A and DNMT2 expression decreased from Stage-II to Stage-IV carcinomas. The proteomic data also suggested that the DNMT1 and DNMT3A levels were increased in the tumors. Similarly, the DNMT1, DNMT3A and DNMT3L protein levels were overexpressed and DNMT2 expression was reduced in high-grade carcinomas compared to non-neoplastic tissue and low-grade tumors. Moreover, DNMT1 and DNMT3L were increased in relapsed tumors compared to their primaries. The DNMT3A, DNMT1 and DNMT3B mRNA levels were correlated with overall survival. Our study demonstrates that DNMT1 and DNMT3L are upregulated in primary high-grade EOC and further increase in relapses, whereas DNMT3A is upregulated only in the earlier stages of cancer progression. DNMT2 downregulation highlights the presumed tumor-suppressor activity of this gene in ovarian carcinoma.

MiR-216a reduces apoptosis of pulmonary microvascular endothelial cells in COPD by targeting DNMT1.

Abnormal apoptosis of pulmonary microvascular endothelial cells (PMVECs) participates in the pathogenesis of COPD. Studies have shown that microRNAs (miRNAs) contribute to the pathogenesis of pulmonary diseases by regulating cell apoptosis. The present study aimed to investigate the effects of miR-216a in cigarette smoke extract (CSE)-induced apoptosis of PMVECs in COPD and explore the potential mechanisms. The emphysema model mice were treated with CSE and CS exposure. The expression of miR-216a and DNA methyltransferase 1 (DNMT1) was assessed in emphysema mice and COPD patients. The miR-216a mimic and Lenti-DNMT1 were transfected into PMVECs to identify the underlying mechanisms. The expression levels of miR-216a and DNMT1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR) or Western blot. Moreover, cell apoptosis was examined by flow cytometry assays. The results show that the expression of miR-216a was decreased, whereas the expression of DNMT1 was increased in the lung tissue of emphysema mice and COPD patients. In addition, the expression of miR-216a was significantly reduced in CSE-treated PMVECs, and the overexpression of miR-216a attenuated CSE-induced PMVEC apoptosis. Furthermore, the expression of DNMT1 was increased in the CSE-induced PMVECs and then was reduced after the overexpression of miR-216a in the CSE-stimulated PMVECs. Luciferase reporter assays confirmed the target reaction between miR-216a and DNMT1. Also, the overexpression of DNMT1 was able to reverse the anti-apoptotic effect of miR-216a in CSE-induced PMVECs. The results indicate that miR-216a may play a crucial role in CSE-induced apoptosis by directly regulating its target gene DNMT1 in COPD. It provides insights into the function of MiR-216a/DNMT1 as a potential molecule in COPD.

N6-methyladenosine methyltransferase KIAA1429 promoted ovarian cancer aerobic glycolysis and progression through enhancing ENO1 expression

BackgroundDespite improvements in prognosis due to advances in treatment, including surgery, genetic screening, and molecular targeted therapy, the outcomes of ovarian cancer (OC) remain unsatisfactory. Internal mRNA modifications are extremely common in eukaryotes; N6-methyladenosine (m6A) alteration has significant effects on mRNA stability and translation, and it is involved in the pathophysiology of numerous diseases related to cancer.MethodsBioinformatics analysis, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of vir-like m6A methyltransferase associated (KIAA1429) in OC tissues and cell lines. Several different cell models and animal models were established to determine the role of KIAA1429 in glucose metabolism reprogramming and the underlying molecular mechanism of OC. The mechanism of oncology functional assays, co-immunoprecipitation and a luciferase reporter gene was employed to ascertain how KIAA1429 interacts with important molecular targets.ResultsWe reported that KIAA1429 was overexpressed in OC and predicted a poor prognosis. Functionally, KIAA1429 promoted cell growth by inducing proliferation and inhibiting necrosis. Mechanistically, KIAA1429 promoted tumor progression and glycolysis via stabilizing ENO1 mRNA in a way dependent on m6A. Furthermore, we investigated that the SPI1 transcription factor is the main transcription factor that regulates KIAA1429 transcription in OC.ConclusionOur findings revealed that SPI1/KIAA1429/ENO1 signaling is a novel molecular axis and raises awareness of the vital functions of the changes in KIAA1429 and m6A changes in the metabolic reprogramming of OC. These results identified new potential biomarkers and treatment targets for OC.

The role of breastfeeding in breast cancer prevention: a literature review.

Breast cancer stands as the most prevalent malignancy globally. Despite the array of treatment options, its mortality rate continues to rise annually. Thus, reevaluation of factors directly linked to breast cancer emergence is imperative, alongside the development of more effective preventive measures. Estrogen levels, profoundly tied to reproduction, play a pivotal role in breast cancer development. Speculation centers on the potential of breastfeeding to mitigate cancer risk in women. However, the precise mechanism remains elusive. Breastfeeding is a modifiable reproductive factor extensively studied. Studies highlight a direct connection between lack of breastfeeding and breast cancer emergence, potentially linked to DNA methyltransferase expression alteration, aberrant methylation levels, pregnancy-associated plasma protein-A, cellular microenvironment, and oncogenes. This study reviews recent mechanisms underlying breastfeeding's role in reducing breast cancer incidence.

A functional crosstalk between the H3K9 methylation writers and their reader HP1 in safeguarding embryonic stem cell identity.

Histone H3 lysine 9 (H3K9) methylation, as a hallmark of heterochromatin, has a central role in cell lineage and fate determination. Although evidence of a cooperation between H3K9 methylation writers and their readers has started to emerge, their actual interplay remains elusive. Here, we show that loss of H3K9 methylation readers, the Hp1 family, causes reduced expression of H3K9 methyltransferases, and that this subsequently leads to the exit of embryonic stem cells (ESCs) from pluripotency and a reciprocal gain of lineage-specific characteristics. Importantly, the phenotypes of Hp1-null ESCs can be rescued by ectopic expression of Setdb1, Nanog, and Oct4. Furthermore, Setdb1 ablation results in loss of ESC identity, which is accompanied by a reduction in the expression of Hp1 genes. Together, our data support a model in which the safeguarding of ESC identity involves the cooperation between the H3K9 methylation writers and their readers.

Epigenetic reprogramming around IFN1 and IFNy2 promoters in rainbow trout cells inoculated with infectious pancreatic necrosis virus (IPNV).

Infectious pancreatic necrosis virus (IPNV) has proven to effectively evade the host antiviral responses. This study clarifies whether the modulation of the antiviral immune response exerted by IPNV involves epigenetic mechanisms. An in-silico characterization of the rainbow trout IFN1 and IFNγ2 promoters was performed, identifying the islands or sequences rich in CpG dinucleotides and the putative transcription factor binding sites (TBS) for both gene promoters. RTS11 cells (rainbow trout monocyte/macrophage) were infected with IPNV, and the course of viral infection was followed up to 48h post infection (hpi). Infected cells showed increased IFN1 and IFNγ2 transcriptional expression at 6 and 24 hpi, respectively. IPNV infection caused increases and decreases in global IFNγ2 promoter methylation at 6 and 24 hpi, respectively. The CpG dinucleotides at positions -392 and+38 of this promoter were the most sensitive to methylation changes. The IFN1 promoter remained fully unmethylated during the course of the infection, similar to the control. The changes in the methylation pattern observed for the IFNγ2 promoter were coincident with the changes in DNA methyltransferase (DNMT) expression levels, increasing at 6 hpi and decreasing below basal level at 24 hpi. Similarly, the H4 histones associated with the IFN1 and IFNγ2 promoters were hyperacetylated at 6 hpi, subsequently decreasing their acetylation below basal levels at 24 hpi, in both promoters. Coincidentally with the above, overexpression of histone acetyltransferase (HAT) was observed at 6 hpi and of histone deacetylase (HDAC) at 24 hpi, with return to baseline of HAT. These results suggest that IPNV would epigenetically modulate the expression of IFN1 by changing acetylation levels of the histones H4 associated with its promoter. Also, the modulation of the expression of IFNy2 would be by switching methylation/demethylation levels of its promoter, in addition to changes in acetylation levels of histones H4 associated with this promoter. This study is the first to demonstrate the effect of epigenetic reprogramming after IPNV infection in salmonid cells, demonstrating that promoter methylation/demethylation level and changes in the histone code associated with promoters may play a role in the modulation of the immune response induced by the virus.

Role of clusterin gene 3’-UTR polymorphisms and promoter hypomethylation in the pathogenesis of pseudoexfoliation syndrome and pseudoexfoliation glaucoma

Pseudoexfoliation (PEX) is a multifactorial age-related disease characterized by the deposition of extracellular fibrillar aggregates in the anterior ocular tissues. This study aims to identify the genetic and epigenetic contribution of clusterin (CLU) in PEX pathology. CLU is a molecular chaperone upregulated in PEX and genetically associated with the disease. Sequencing of a 2.9 kb region encompassing the previously associated rs2279590 in 250 control and 313 PEX [(207 pseudoexfoliation syndrome (PEXS) and 106 pseudoexfoliation glaucoma (PEXG)] individuals identified three single nucleotide polymorphisms (SNPs), rs9331942, rs9331949 and rs9331950, in the 3’-UTR of CLU of which rs9331942 and rs9331949 were found to be significantly associated with PEXS and PEXG as risk factors. Following in silico analysis, in vitro luciferase reporter assays in human embryonic kidney cells revealed that risk alleles at rs9331942 and rs9331949 bind to miR-223 and miR-1283, respectively, suggesting differential regulation of clusterin in the presence of risk alleles at the SNPs. Further, through bisulfite sequencing, we also identified that CLU promoter is hypomethylated in DNA from blood and lens capsules of PEX patients compared to controls that correlated with decreased expression of DNA methyltransferase 1 (DNMT1). Promoter demethylation of CLU using DNMT inhibitor, 5′-aza-dC, in human lens epithelial cells increased CLU expression. Chromatin immunoprecipitation assays showed that the demethylated CLU promoter provides increased access to the transcription factor, Sp1, which might lead to enhanced expression of CLU. In conclusion, this study highlights the different molecular mechanisms of clusterin regulation in pseudoexfoliation pathology.

Prenatal cadmium exposure has intergenerational adverse effects on the Sertoli cells through FSHR pathway.

Exposure to cadmium (Cd) during pregnancy can potentially harm the reproductive system of male offspring, although the full extent of its heritable effects remains partially unresolved. In this study, we examined the intergenerational impacts of Cd using a distinct male-lineage transmission model. Pregnant Sprague-Dawley (SD) female rats (F0) were administered control or cadmium chloride (0.5, 1, 2 mgp/day) via intragastric administration from gestation day 1 to 20. Subsequently, the first filial generation (F1) male rats were mated with untreated females (not exposed to Cd) to produce the second filial generation (F2). Histopathological analysis of the F1 and F2 generations revealed abnormal testicular development, while ultrastructural examination indicated damage to Sertoli cells. Cd exposure also led to alterations in serum hormone levels (GnRH, FSH) and reduced FSHR protein expression in Sertoli cells in the F1 generation. Furthermore, Cd affected the mRNA and protein expression of FSHR pathway factors and DNA methyltransferase, albeit with distinct patterns and inconsistencies observed between the F1 and F2 generations. Overall, our findings indicate that prenatal Cd exposure, using a male-lineage transmission model, can induce inter-generational effects on male reproduction, particularly by causing toxicity in Sertoli cells. This effect appears to be primarily mediated through disruptions in the FSHR pathway and changes in DNA methyltransferase activity in the male testes.

Epigenetically upregulating TROP2 and SLFN11 enhances therapeutic efficacy of TROP2 antibody drug conjugate sacitizumab govitecan

TROP2 antibody drug conjugates (ADCs) are under active development. We seek to determine whether we can enhance activity of TROP2 ADCs by increasing TROP2 expression. In metaplastic breast cancers (MpBC), there is limited expression of TROP2, and downregulating transcription factor ZEB1 upregulates E-cad and TROP2, thus sensitizing cancers to TROP2 ADC sacituzumab govitecan (SG). Demethylating agent decitabine decreases DNA methyltransferase expression and TROP2 promoter methylation and subsequently increases TROP2 expression. Decitabine treatment as well as overexpression of TROP2 significantly enhance SG antitumor activity. Decitabine also increases SLFN11, a biomarker of topoisomerase 1 inhibitor (TOP1) sensitivity and is synergistic with SG which has a TOP1 payload, in TROP2-expressing SLFN11-low BC cells. In conclusion, TROP2 and SLFN11 expression can be epigenetically modulated and the combination of demethylating agent decitabine with TROP2 ADCs may represent a novel therapeutic approach for tumors with low TROP2 or SLFN11 expression.

Cyhexatin causes developmental toxic effects by disrupting endocrine system and inducing behavioral inhibition, apoptosis and DNA hypomethylation in zebrafish (Danio rerio) larvae

Cyhexatin (CYT), an organotin acaricide, is extensively utilized in developing countries to mitigate plant diseases caused by mites and minimize agricultural crop losses. However, the comprehensive mechanisms underlying the developmental stage of non-target organisms remain largely unexplored. In this study, zebrafish embryos were firstly exposed to CYT (0.06, 0.12, and 0.20 ng/mL, referred to as CYTL, CYTM, and CYTH, respectively) from 2 hpf (hours post fertilization) to 30 dpf (days post fertilization). No developmental toxicity was observed in the CYTL and CYTM groups, except for induced deformed phenotypes in the CYTM group at 120 hpf. However, exposure to CYTH resulted in significant reductions in spontaneous movement (24 hpf), heart rate (48 hpf), hatching rate (48 and 72 hpf), body weight (30 dpf), whole body length (30 dpf), and locomotion (30 dpf). Additionally, CYTH exposure induced morphological malformations, including spinal curvature, pericardial edema, and tail curvature in zebrafish larvae. Moreover, CYTH treatment induced apoptosis, increased reactive oxygen species (ROS) production, and resulted in significant reductions in free T3, cholesterol, estradiol, and testosterone levels in zebrafish larvae, while free T4 levels were increased. RNA-Seq analysis indicated that CYTH exposure led to significant alterations in the genome-wide gene expression profiles of zebrafish, particularly in the thyroid hormone and steroid biosynthesis signaling pathways, indicating endocrine disruption. Furthermore, CYTH exposure induced global DNA hypomethylation, reduced S-adenosylmethionine (SAM) levels and the SAM/S-adenosylhomocysteine (SAH) ratio, elevated SAH levels, and suppressed the mRNA expression of DNA methyltransferases (DNMTs) while also downregulating DNMT1 at both the gene and protein levels in zebrafish larvae. Overall, this study partially elucidated the developmental toxicity and endocrine disruption caused by CYT in zebrafish, providing evidence of the environmental hazards associated with this acaricide.

The Notch1/Hes1 signaling pathway affects autophagy by adjusting DNA methyltransferases expression in a valproic acid-induced autism spectrum disorder model

As a pervasive neurodevelopmental disease, autism spectrum disorder (ASD) is caused by both hereditary and environmental elements. Research has demonstrated the functions of the Notch pathway and DNA methylation in the etiology of ASD. DNA methyltransferases DNMT3 and DNMT1 are responsible for methylation establishment and maintenance, respectively. In this study, we aimed to explore the association of DNA methyltransferases with the Notch pathway in ASD. Our results showed Notch1 and Hes1 were upregulated, while DNMT3A and DNMT3B were downregulated at the protein level in the prefrontal cortex (PFC), hippocampus (HC) and cerebellum (CB) of VPA-induced ASD rats compared with Control (Con) group. However, the protein levels of DNMT3A and DNMT3B were augmented after treatment with 3,5-difluorophenacetyl-L-alanyl-S-phenylglycine-2-butyl ester (DAPT), suggesting that abnormal Notch pathway activation may affect the expression of DNMT3A and DNMT3B. Besides, our previous findings revealed that the Notch pathway may participate in development of ASD by influencing autophagy. Therefore, we hypothesized the Notch pathway adjusts autophagy and contributes to ASD by affecting DNA methyltransferases. Our current results showed that after receiving the DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine (5-Aza-2'dc), the VPA + DAPT+5-Aza-2'dc (V + D + Aza) group exhibited reduced social interaction ability and increased stereotyped behaviors, and decreased expression of DNMT3A, DNMT3B and autophagy-related proteins, but did not show changes in Notch1 and Hes1 protein levels. Our results indicated that the Notch1/Hes1 pathway may adjust DNMT3A and DNMT3B expression and subsequently affect autophagy in the occurrence of ASD, providing new insight into the pathogenesis of ASD.

Evaluation of epigenetic-related gene expression (DNMT, HDAC1) in Iranian patients with systemic lupus erythematosus

BackgroundSystemic lupus erythematosus (SLE) is an autoimmune disease in which the immune system abnormally reacts against cells and tissues leading to inflammation. Epigenetic alterations, including DNA methylation and histone modification, have critical effects on autoimmune disease and SLE pathogenesis via dysregulation of critical genes. AimsThe purpose of this study was to evaluate the epigenetic-related gene expression of DNA methyltransferase (DNMT) and histone deacetylase 1 (HDAC1) in Iranian patients with SLE. MethodsThis matched case–control study included 16 people with SLE and 16 healthy people who were referred to the Rafsanjani rheumatology clinic, in southeast Iran. The expression of DNMT and HDAC1 genes was measured through a real-time PCR assay of blood samples. ResultsDNMT gene expression did not differ significantly between SLE and healthy groups (P=0.21). In contrast, HDAC1 gene expression was enhanced in the SLE group, but this enhancement failed to reach statistical significance (P=0.94). ConclusionThe results of this study suggest that overexpression of HDAC1 could serve as a diagnostic for SLE disease. Additional studies with larger sample sizes are required to confirm our findings. Evaluation of other genes related to SLE disease is essential and may help to make an accurate diagnosis of the disease.

Host DNA Demethylation Induced by DNMT1 Inhibition Up-Regulates Antiviral OASL Protein during Influenza a Virus Infection.

Influenza A virus (IAV) is a leading cause of human respiratory infections and poses a major public health concern. IAV replication can affect the expression of DNA methyltransferases (DNMTs), and the subsequent changes in DNA methylation regulate gene expression and may lead to abnormal gene transcription and translation, yet the underlying mechanisms of virus-induced epigenetic changes from DNA methylation and its role in virus-host interactions remain elusive. Here in this paper, we showed that DNMT1 expression could be suppressed following the inhibition of miR-142-5p or the PI3K/AKT signaling pathway during IAV infection, resulting in demethylation of the promotor region of the 2'-5'-oligoadenylate synthetase-like (OASL) protein and promotion of its expression in A549 cells. OASL expression enhanced RIG-I-mediated interferon induction and then suppressed replication of IAV. Our study elucidated an innate immunity mechanism by which up-regulation of OASL contributes to host antiviral responses via epigenetic modifications in IAV infection, which could provide important insights into the understanding of viral pathogenesis and host antiviral defense.

Korean Red Ginseng Attenuates Particulate Matter-Induced Senescence of Skin Keratinocytes.

Skin is a direct target of fine particulate matter (PM2.5), as it is constantly exposed. Herein, we investigate whether Korean red ginseng (KRG) can inhibit PM2.5-induced senescence in skin keratinocytes. PM2.5-treated human keratinocyte cell lines and normal human epidermal keratinocytes showed characteristics of cellular senescence, including flat and enlarged forms; however, KRG suppressed them in both cell types. Moreover, while cells exposed to PM2.5 showed a higher level of p16INK4A expression (a senescence inducer), KRG inhibited its expression. Epigenetically, KRG decreased the expression of the ten-eleven translocation (TET) enzyme, a DNA demethylase induced by PM2.5, and increased the expression of DNA methyltransferases suppressed by PM2.5, resulting in the decreased methylation of the p16INK4A promoter region. Additionally, KRG decreased the expression of mixed-lineage leukemia 1 (MLL1), a histone methyltransferase, and histone acetyltransferase 1 (HAT1) induced by PM2.5. Contrastingly, KRG increased the expression of the enhancer of zeste homolog 2, a histone methyltransferase, and histone deacetyltransferase 1 reduced by PM2.5. Furthermore, KRG decreased TET1, MLL1, and HAT1 binding to the p16INK4A promoter, corresponding with the decreased mRNA expression of p16INK4A. These results suggest that KRG exerts protection against the PM2.5-induced senescence of skin keratinocytes via the epigenetic regulation of p16INK4A.

DNMT1 regulates miR-20a/TXNIP-mediated pyroptosis of retinal pigment epithelial cells through DNA methylation

BackgroundPyroptosis of retinal pigment epithelium (RPE) cells is associated with the etiology of diabetic retinopathy (DR). In this study, we investigated the effect of DNMT1 on RPE cell pyroptosis by regulating miR-20a/TXNIP expression through DNA methylation. MethodsHigh glucose (HG)-induced ARPE-19 cells and mice were injected with streptozotocin (STZ) to generate DR cells and animal models. RT‒qPCR was used to detect the expression of miR-20a, and methylation-specific PCR (MS-PCR) was used to determine the occurrence of methylation of miR-20a. The expression of pyroptosis-related proteins (caspase-1 and NLRP3) and DNA methyltransferase (DNMT1) was detected by western blotting, and the expression of inflammatory factors (IL-1β and IL-18) was detected by ELISA. Apoptosis was detected by flow cytometry and TUNEL. HE staining was used to observe the pathological changes in retinal tissue in mice. ResultsIn HG-induced DR cell models, the expression of miR-20a was significantly downregulated, while the expression of inflammatory factors (IL-1β, IL-18) and pyroptosis-associated proteins (caspase-1, NLRP3) was significantly upregulated. Transfection of miR-20a mimic can effectively reverse HG-induced pyroptosis and release of inflammatory factors. DNMT1 promotes miR-20a methylation and inhibits the expression of miR-20a. DNMT1-mediated methylation is involved in the pyroptosis process of high glucose-induced RPE cells, and silencing DNMT1 can promote the expression of miR-20a, thereby inhibiting the release of IL-1β and IL-18 and reducing the occurrence of cell pyroptosis. miR-20a targets negative regulation of TXNIP expression, and overexpression of TXNIP can effectively reverse the inhibitory effect of miR-20a on pyroptosis. The methylation inhibitor 5-AZ can inhibit the occurrence of pyroptosis and DR processes, while treatment with a miR-20a inhibitor or OE-TXNIP can reverse the effect of 5-AZ. ConclusionDNMT1 promotes DNA methylation, decreases the expression of miR-20a and increases the expression of TXNIP, which ultimately leads to the occurrence of pyroptosis in RPE cells.

Role of DNA methylation during recovery from spinal cord injury with and without β2-adrenergic receptor agonism

Daily treatment with the FDA-approved β2-adrenergic receptor agonist formoterol beginning 8 h after severe spinal cord injury (SCI) induces mitochondrial biogenesis and improves recovery in mice. We observed decreased DNA methyltransferase (DNMT) expression, global DNA methylation and methylation of the mitochondrial genes PGC-1α and NDUFS1 in the injury site of formoterol-treated mice 1 DPI, but this effect was lost by 7 DPI. To investigate the role of DNA methylation on recovery post-SCI, injured mice were treated daily with formoterol or vehicle, plus the DNMT inhibitor decitabine (DAC) on days 7–9. While DAC had no apparent effect on formoterol-induced recovery, mice treated with vehicle plus DAC exhibited increased BMS scores compared to vehicle alone beginning 15 DPI, reaching a degree of functional recovery similar to that of formoterol-treated mice by 21 DPI. Furthermore, DAC treatment increased injury site mitochondrial protein expression in vehicle-treated mice to levels comparable to that of formoterol-treated mice. The effect of DNMT inhibition on pain response with and without formoterol was assessed following moderate SCI. While all injured mice not treated with DAC displayed thermal hyperalgesia by 21 DPI, mice treated with formoterol exhibited decreased thermal hyperalgesia compared to vehicle-treated mice by 35 DPI. Injured mice treated with DAC, regardless of formoterol treatment, did not demonstrate thermal hyperalgesia at any time point assessed. Although these data do not suggest enhanced formoterol-induced recovery with DNMT inhibition, our findings indicate the importance of DNA methylation post-SCI and support both DNMT inhibition and formoterol as potential therapeutic avenues.

Assessing the Impact of Polyethylene Nano/Microplastic Exposure on Human Vaginal Keratinocytes.

The global rise of single-use throw-away plastic products has elicited a massive increase in the nano/microplastics (N/MPLs) exposure burden in humans. Recently, it has been demonstrated that disposable period products may release N/MPLs with usage, which represents a potential threat to women's health which has not been scientifically addressed yet. By using polyethyl ene (PE) particles (200 nm to 9 μm), we showed that acute exposure to a high concentration of N/MPLs induced cell toxicity in vaginal keratinocytes after effective cellular uptake, as viability and apoptosis data suggest, along with transmission electron microscopy (TEM) observations. The internalised N/MPLs altered the expression of junctional and adherence proteins and the organisation of the actin cortex, influencing the level of genes involved in oxidative stress signalling pathways and that of miRNAs related to epithelial barrier function. When the exposure to PE N/MPLs was discontinued or became chronic, cells were able to recover from the negative effects on viability and differentiation/proliferation gene expression in a few days. However, in all cases, PE N/MPL exposure prompted a sustained alteration of DNA methyltransferase and DNA demethylase expression, which might impact epigenetic regulation processes, leading to accelerated cell ageing and inflammation, or the occurrence of malignant transformation.

Dimethylglycine, a methionine metabolite, participates in the suppressive effect of methionine on 1-fluoro-2,4-dinitrobenzene-induced dermatitis.

Allergic contact dermatitis (ACD) is a common skin disorder caused by contact with allergens. The optimal treatment for ACD is to avoid contact with allergens. However, in some cases, avoiding exposure is not possible when the allergens are unknown. Therefore, establishing treatment methods other than allergen avoidance is important. We previously reported that the continuous administration of methionine, an essential amino acid, in a mouse model of atopic dermatitis alleviated its symptoms. In the present study, we investigated the effect of methionine on a mouse model of ACD caused by 1-fluoro-2,4-dinitrobenzene (DNFB). Differences in the effect of methionine were observed in DNFB-induced ACD model mice based on the mouse strain used. This difference was attributed to the suppression of hepatic dimethylglycine (DMG) production, which is associated with the suppression of hepatic betaine-homocysteine methyltransferase (Bhmt) expression by ACD. Although we did not reveal the mechanism underlying DMG suppression, our study suggests the presence of interactions between the liver and skin in dermatitis, such as the regulation of hepatic metabolic enzyme expression in dermatitis and the alleviation of dermatitis symptoms by the hepatic metabolism status of DMG.

Expression profiling of N6-methyladenosine-modified mRNA in PC12 cells in response to unconjugated bilirubin

BackgroundAbnormal methylation of N6-methyladenosine (m6A) is reportedly associated with central nervous system disorders. However, the role of m6A mRNA methylation in unconjugated bilirubin (UCB) neurotoxicity requires further research.MethodsRat pheochromocytoma PC12 cells treated with UCB were used as in vitro models. After the PC12 cells were treated with UCB (0, 12, 18, and 24 µM) for 24 h, the total RNA m6A levels were measured using an m6A RNA methylation quantification kit. The expression of m6A demethylases and methyltransferases was detected through western blotting. We determined the m6A mRNA methylation profile in PC12 cells exposed to UCB (0 and 18 µM) for 24 h using methylated RNA immunoprecipitation sequencing (MeRIP-seq).ResultsCompared with the control group, UCB (18 and 24 µM) treatment decreased the expression of the m6A demethylase ALKBH5 and increased the expression of the methyltransferases METTL3 and METTL14, which resulted in an increase in the total m6A levels in PC12 cells. Furthermore, 1533 m6A peaks were significantly elevated and 1331 peaks were reduced in the UCB (18 µM)-treated groups compared with those in the control group. Genes with differential m6A peaks were mainly enriched in protein processing in the endoplasmic reticulum, ubiquitin-mediated proteolysis, cell cycle, and endocytosis. Through combined analysis of the MeRIP-seq and RNA sequencing data, 129 genes with differentially methylated m6A peaks and differentially expressed mRNA levels were identified.ConclusionOur study suggests that the modulation of m6A methylation modifications plays a significant role in UCB neurotoxicity.

Effects of Dietary Oleacein Treatment on Endothelial Dysfunction and Lupus Nephritis in Balb/C Pristane-Induced Mice.

Systemic lupus erythematosus (SLE) is a chronic immune-inflammatory disease characterized by multiorgan affectation and lowered self-tolerance. Additionally, epigenetic changes have been described as playing a pivotal role in SLE. This work aims to assess the effects of oleacein (OLA), one of the main extra virgin olive oil secoiridoids, when used to supplement the diet of a murine pristane-induced SLE model. In the study, 12-week-old female BALB/c mice were injected with pristane and fed with an OLA-enriched diet (0.01 % (w/w)) for 24 weeks. The presence of immune complexes was evaluated by immunohistochemistry and immunofluorescence. Endothelial dysfunction was studied in thoracic aortas. Signaling pathways and oxidative-inflammatory-related mediators were evaluated by Western blotting. Moreover, we studied epigenetic changes such as DNA methyltransferase (DNMT-1) and micro(mi)RNAs expression in renal tissue. Nutritional treatment with OLA reduced the deposition of immune complexes, ameliorating kidney damage. These protective effects could be related to the modulation of mitogen-activated protein kinases, the Janus kinase/signal transducer and transcription activator of transcription, nuclear factor kappa, nuclear-factor-erythroid-2-related factor 2, inflammasome signaling pathways, and the regulation of miRNAs (miRNA-126, miRNA-146a, miRNA-24-3p, and miRNA-123) and DNMT-1 expression. Moreover, the OLA-enriched diet normalized endothelial nitric oxide synthase and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 overexpression. These preliminary results suggest that an OLA-supplemented diet could constitute a new alternative nutraceutical therapy in the management of SLE, supporting this compound as a novel epigenetic modulator of the immunoinflammatory response.