LPS-induces IL-6 and IL-8 gene expression in bovine endometrial cells "through DNA methylation"

Microbial responses and changes in metabolic products in bovine uteri infected with Staphylococcus aureus

There is mounting evidence that the uterine microbiota has an important role in the pathogenesis of endometritis, with invasion of pathogenic bacteria being a main cause of uterine microbial imbalance. However, mechanisms of uterine microbiota resistance to pathogen invasion remain unclear. In this study, an intrauterine infusion of Staphylococcus aureus was used as a bovine endometritis model; it significantly increased abundance of pathogenic bacteria (Streptococcus, Helccoccus, Fusobacterium, and Escherichia-Shigella) and significantly decreased abundance of probiotics (Allstipes, Bacteroides, Phascolarctobacterium, Romboutsia, and Prevotella). In addition, the metabolite aloe-emodin was positively correlated with Prevotella and based on combined analyses of omics and probiotics, the presence of its metabolite aloe-emodin in the uterus at least partially resisted Staphylococcus aureus invasion. Therefore, Aloe-emodin has potential for regulating microbial structure and preventing endometritis.

Chokeberry reduces inflammation in human preadipocytes

Chokeberry, Aronia melanocarpa, is an indigenous fruit from North America used as food and to prevent chronic disease by Indigenous Peoples. The objective of this study was to test anti-inflammatory effects of anthocyanin on palmitic acid (PA)-induced IL-6 gene expression, IL-6 DNA methylation, and histone (H3) acetylation. Additionally, we examined effects of anthocyanins Cyanidin-3-O-galactoside (C3Gal) and Cyanidin-3-glucoside (C3G) on IL-6 gene expression. Human primary pre-adipocytes were treated with chokeberry juice extract (CBE), C3Gal or C3G in the presence or absence of PA or lipopolysaccharide (LPS). CBE inhibited LPS- and PA-induced IL-6 mRNA expression (p < 0.0001), while C3G and C3Gal had smaller effects. Human IL-6 promoter DNA methylation was increased (p = 0.0256) in CBE treated cells compared to control. Histone H3 acetylations were not affected by CBE or PA treatment. These data indicate that CBE epigenetically reduced PA-induced inflammation by regulating IL-6 DNA methylation without affecting histone modifications in human preadipocyte cells.

DNMT1/miR-130a/ZEB1 Regulatory Pathway Affects the Inflammatory Response in Lipopolysaccharide-Induced Sepsis

Sepsis is a global health care issue that affects millions of people. DNA methyltransferase I (DNMT1)-mediated DNA methylation is involved in a number of human diseases by affecting many types of cellular progression events. However, the role and underlying molecular mechanism of DNMT1 in development of sepsis remain largely unknown. Lipopolysaccharide (LPS) induced lung fibrosis in the sepsis mouse model, and DNMT1 was upregulated in lung tissues of a sepsis mouse model compared with lung tissues from control mice. Then, this study demonstrated that LPS induced the production of interleukin (IL)-7 and tumor necrosis factor (TNF)-α and promoted DNMT1 expression in primary type II alveolar epithelial cells (AECII cells). Knockdown of DNMT1 inhibited IL-7 and TNF-α secretion in AECII cells exposed to LPS. Further study demonstrated that DNMT1 repressed the expression of miR-130a in AECII cells with or without LPS exposure. Next, this study demonstrated that miR-130a inhibited ZEB1 expression in AECII cells exposed to LPS. Ultimately, this study revealed the role of the DNMT1/miR-130a/ZEB1 regulatory pathway in AECII cells exposed to LPS. Overall, our data revealed that LPS induced the secretion of inflammatory factors by modulating the DNMT1/miR-130a/ZEB1 regulatory pathway in AECII cells, thus providing a novel theoretical basis that might be beneficial for establishment of diagnostic and therapeutic strategies for sepsis.

Aryl Hydrocarbon Receptor Repressor Is Hypomethylated in Psoriasis and Promotes Psoriasis-like Inflammation in HaCaT Cells

It is known that DNA hypomethylation of aryl hydrocarbon receptor repressor (AhRR), one of the epigenetic markers of environmental pollutants, causes skin diseases. However, the function and mechanisms are still unknown. We aimed to determine whether AhRR is hypomethylated in PBMC of psoriasis patients, as well as to examine the expression of psoriasis-related inflammatory cytokines and antimicrobial peptides after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in HaCaT cells overexpressing or silencing AhRR. AhRR was determined by qPCR, Western blot, immunohistochemistry, and immunocytochemistry in skin tissue and HaCaT cells. DNA methylation of AhRR was performed by Infinium Human Methylation450 BeadChip in PBMC of psoriasis patients and methylation-specific PCR (MSP) in HaCaT cells. NF-κB pp50 translocation and activity were performed by immunocytochemistry and luciferase reporter assay, respectively. We verified AhRR gene expression in the epidermis from psoriasis patients and healthy controls. AhRR hypomethylation in PBMC of psoriasis patients and pAhRR-HaCaT cells was confirmed. The expression level of AhRR was increased in both TCDD-treated HaCaT cells and pAhRR-HaCaT cells. NF-κB pp50 translocation and activity increased with TCDD. Our results showed that AhRR was hypomethylated and overexpressed in the lesional skin of patients with psoriasis, thereby increasing AhRR gene expression and regulating pro-inflammatory cytokines through the NF-κB signaling pathway in TCDD-treated HaCaT cells.

The Role of Host Cell DNA Methylation in the Immune Response to Bacterial Infection

Host cells undergo complex transcriptional reprogramming upon infection. Epigenetic changes play a key role in the immune response to bacteria, among which DNA modifications that include methylation have received much attention in recent years. The extent of DNA methylation is well known to regulate gene expression. Whilst historically DNA methylation was considered to be a stable epigenetic modification, accumulating evidence indicates that DNA methylation patterns can be altered rapidly upon exposure of cells to changing environments and pathogens. Furthermore, the action of proteins regulating DNA methylation, particularly DNA methyltransferases and ten-eleven translocation methylcytosine dioxygenases, may be modulated, at least in part, by bacteria. This review discusses the principles of DNA methylation, and recent insights about the regulation of host DNA methylation during bacterial infection.

Detrimental effects of lipopolysaccharide on the attachment and outgrowth of various trophoblastic spheroids on human endometrial epithelial cells

OBJECTIVE

Lipopolysaccharide (LPS) from Gram-negative bacteria causes poor uterine receptivity by inducing excessive inflammation at the maternal-fetal interface. This study aimed to investigate the detrimental effects of LPS on the attachment and outgrowth of various types of trophoblastic spheroids on endometrial epithelial cells (ECC-1 cells) in an in vitro model of implantation.

METHODS

Three types of spheroids with JAr, JEG-3, and JAr mixed JEG-3 (JmJ) cells were used to evaluate the effect of LPS on early implantation events. ECC-1 cells were treated with LPS to mimic endometrial infection, and the expression of inflammatory cytokines and adhesion molecules was analyzed by quantitative real-time polymerase chain reaction and western blotting. The attachment rates and outgrowth areas were evaluated in the various trophoblastic spheroids and ECC-1 cells treated with LPS.

RESULTS

LPS treatment significantly increased the mRNA expression of inflammatory cytokines (CXCL1, IL-8, and IL-33) and decreased the protein expression of adhesion molecules (ITGβ3 and ITGβ5) in ECC-1 cells. The attachment rates of JAr and JmJ spheroids on ECC-1 cells significantly decreased after treating the ECC-1 cells with 1 and 10 μg/mL LPS. In the outgrowth assay, JAr spheroids did not show any outgrowth areas. However, the outgrowth areas of JEG-3 spheroids were similar regardless of LPS treatment. LPS treatment of JmJ spheroids significantly decreased the outgrowth area after 72 hours of coincubation.

CONCLUSION

An in vitro implantation model using novel JmJ spheroids was established, and the inhibitory effects of LPS on ECC-1 endometrial epithelial cells were confirmed in the early implantation process.

Berberine attenuates the inflammatory response by activating the Keap1/Nrf2 signaling pathway in bovine endometrial epithelial cells

Endometritis is a common inflammatory disease that disturbs the rapid development of dairy farming. In the present study, we investigated the anti-inflammatory effects of berberine on the LPS-induced inflammatory response in bovine endometrial epithelial cells (bEECs) and the participation of the Keap1/Nrf2 signaling pathway in this process. Berberine treatment significantly reduced the LPS-induced expression levels of CRP, IL-1β, IL-6, and TNF-α in bEECs. The Nrf2 signaling pathway in these cells was also activated by berberine. We further evaluated the effects of Nrf2 activators and inhibitors on the downregulation of proinflammatory cytokines. The activator of Nrf2 significantly inhibited the production of these proinflammatory cytokines that was induced by LPS. However, an inhibitor of Nrf2 only partially inhibited the anti-inflammatory effects of berberine on the LPS-induced inflammatory response in bEECs. In conclusion, our findings suggest that berberine exerts anti-inflammatory effects partially by activating the Keap1/Nrf2 signaling pathway.

Pulmonary Inflammation and KRAS Mutation in Lung Cancer

Chronic lung infection and lung cancer are two of the most important pulmonary diseases. Respiratory infection and its associated inflammation have been increasingly investigated for their role in increasing the risk of respiratory diseases including chronic obstructive pulmonary disease (COPD) and lung cancer. Kirsten rat sarcoma viral oncogene (KRAS) is one of the most important regulators of cell proliferation, differentiation, and survival. KRAS mutations are among the most common drivers of cancer. Lung cancer harboring KRAS mutations accounted for ~25% of the incidence but the relationship between KRAS mutation and inflammation remains unclear. In this chapter, we will describe the roles of KRAS mutation in lung cancer and how elevated inflammatory responses may increase KRAS mutation rate and create a vicious cycle of chronic inflammation and KRAS mutation that likely results in persistent potentiation for KRAS-associated lung tumorigenesis. We will discuss in this chapter regarding the studies of KRAS gene mutations in specimens from lung cancer patients and in animal models for investigating the role of inflammation in increasing the risk of lung tumorigenesis driven primarily by oncogenic KRAS.

Impacts of Epigenetic Processes on the Health and Productivity of Livestock

The dynamic changes in the epigenome resulting from the intricate interactions of genetic and environmental factors play crucial roles in individual growth and development. Numerous studies in plants, rodents, and humans have provided evidence of the regulatory roles of epigenetic processes in health and disease. There is increasing pressure to increase livestock production in light of increasing food needs of an expanding human population and environment challenges, but there is limited related epigenetic data on livestock to complement genomic information and support advances in improvement breeding and health management. This review examines the recent discoveries on epigenetic processes due to DNA methylation, histone modification, and chromatin remodeling and their impacts on health and production traits in farm animals, including bovine, swine, sheep, goat, and poultry species. Most of the reports focused on epigenome profiling at the genome-wide or specific genic regions in response to developmental processes, environmental stressors, nutrition, and disease pathogens. The bulk of available data mainly characterized the epigenetic markers in tissues/organs or in relation to traits and detection of epigenetic regulatory mechanisms underlying livestock phenotype diversity. However, available data is inadequate to support gainful exploitation of epigenetic processes for improved animal health and productivity management. Increased research effort, which is vital to elucidate how epigenetic mechanisms affect the health and productivity of livestock, is currently limited due to several factors including lack of adequate analytical tools. In this review, we (1) summarize available evidence of the impacts of epigenetic processes on livestock production and health traits, (2) discuss the application of epigenetics data in livestock production, and (3) present gaps in livestock epigenetics research. Knowledge of the epigenetic factors influencing livestock health and productivity is vital for the management and improvement of livestock productivity.

Protective effect of Tanshinone IIA on LPS-induced canine endometritis

Canine endometritis is a common disease in dogs. This work intends to establish the model of lipopolysaccharide (LPS) -induced canine endometritis, and investigate the effect of Tanshinone IIA (Tan IIA) on canine endometritis. At first, we tested the rectal temperature and the production of IL-1β and TNF-α at 6 h, 12 h, 18 h and 24 h after LPS administration. Then 9 beagles were divided into 3 groups on average, all beagles received intraperitoneal injection of saline solution (group 1 and 2) or Tan IIA (group 3) at 6 h before and after LPS challenge. Beagles of group 2 and 3 were performed uterine infusion of LPS, and beagles of group 1 were performed uterine infusion of saline solution. The rectal temperature was measured 6 h, 12 h, 18 h, 24 h post-LPS challenge, all uterus were collected after 24 h post-LPS challenge. The results showed that canine endometritis can be established by LPS at the concentration of 0.5 mg/kg of body weight after 24 h performance. The rectal temperature, the production of IL-1β and TNF-α increased significantly when the model was established. The results showed that rectal temperature, production of IL-1β and TNF-α and the expression of IL-6 were significantly reduced after treatment with Tan IIA compared with the group of LPS challenge only. However, the expression of IL-10 increased after Tan IIA treatment. Considering the positive anti-inflammation effect on the LPS-induced canine endometritis, Tan IIA may be used as a therapeutic agent to treat the clinical canine endometritis.

DNA methylation studies in cattle

Investigation of the role of epigenetics in cattle breeding is gaining importance. DNA methylation represents an epigenetic modification which is essential for genomic stability and maintenance of development. Recently, DNA methylation research in cattle has intensified. The studies focus on the definition of methylomes in various organs and tissues in relation to the expression of genes underlying economically important traits, and explore methylome changes under developmental, environmental, disease, and diet influences. The investigations further characterize the methylation patterns of gametes in connection with their quality, and study methylome alterations in the developing naturally or assisted produced zygotes, embryos, and fetuses, considering their viability. A wide array of technologies developed for accurate and precise analysis of DNA methylation patterns is employed for both single-gene and genome-wide studies. Overall, the research is directed towards the identification of single methylation markers or their combinations which may be useful in the selection and breeding of animals to ensure cattle improvement.

How is small bowel permeability in endometriosis patients? a case control pilot study

Endometriosis is a chronic inflammatory disease of women of reproductive age. Small bowel (SB) permeability and lipopolysaccharides (LPS) could play a role in the perduration of low grade inflammation status and the pathogenesis of endometriosis. To clarify this hypothesis, we measured SB permeability through plasma values of LPS and urinary secretion of lactulose (La), mannitol (Ma) and their ratio (L/M) in patients with endometriosis compared with healthy controls (HC). Eight patients and 14 HC entered the study. SB permeability was evaluated by high-performance liquid chromatography of urine concentrations of La and Ma. Plasma levels of LPS were measured in the blood. Moreover, a nutritional, gastroenterological, quality of life evaluation was performed through validates questionnaires and complete gynaecological evaluations. The statistical analysis of the obtained data did not show differences in anthropometric and nutritional characteristics and gastrointestinal functional disease in the two groups. Patients reported higher levels of pelvic chronic pain (3.87 ± 2.99 vs 0.15 ± 0.55; pe = 0.001) and significantly higher LPS plasma levels (0.529 ± 0.11 vs 0.427 ± 0.08; p value = .027) than HC. Our results indicate that intestinal permeability is abnormal in endometriosis patients, and it might play a role in the pathogenesis of this chronic disease.

LPS-treatment of bovine endometrial epithelial cells causes differential DNA methylation of genes associated with inflammation and endometrial function

Background

Lipopolysaccharide (LPS) endotoxin stimulates pro-inflammatory pathways and is a key player in the pathological mechanisms involved in the development of endometritis. This study aimed to investigate LPS-induced DNA methylation changes in bovine endometrial epithelial cells (bEECs), which may affect endometrial function. Following in vitro culture, bEECs from three cows were either untreated (0) or exposed to 2 and 8 μg/mL LPS for 24 h.

Results

DNA samples extracted at 0 h and 24 h were sequenced using reduced representation bisulfite sequencing (RRBS). When comparing DNA methylation results at 24 h to time 0 h, a larger proportion of hypomethylated regions were identified in the LPS-treated groups, whereas the trend was opposite in controls. When comparing LPS groups to controls at 24 h, a total of 1291 differentially methylated regions (DMRs) were identified (55% hypomethylated and 45% hypermethylated). Integration of DNA methylation data obtained here with our previously published gene expression data obtained from the same samples showed a negative correlation (r = − 0.41 for gene promoter, r = − 0.22 for gene body regions, p < 0.05). Differential methylation analysis revealed that effects of LPS treatment were associated with methylation changes for genes involved in regulation of immune and inflammatory responses, cell adhesion, and external stimuli. Gene ontology and pathway analyses showed that most of the differentially methylated genes (DMGs) were associated with cell proliferation and apoptotic processes; and pathways such as calcium-, oxytocin- and MAPK-signaling pathways with recognized roles in innate immunity. Several DMGs were related to systemic inflammation and tissue re-modelling including HDAC4, IRAK1, AKT1, MAP3K6, Wnt7A and ADAMTS17.

Conclusions

The present results show that LPS altered the DNA methylation patterns of bovine endometrial epithelial cells. This information, combined with our previously reported changes in gene expression related to endometrial function, confirm that LPS activates pro-inflammatory mechanisms leading to perturbed immune balance and cell adhesion processes in the endometrium.

Telocytes inhibited inflammatory factor expression and enhanced cell migration in LPS-induced skin wound healing models in vitro and in vivo

Background

Cell proliferation and death are key components of wound healing and tissue repair. Telocytes (TCs) represent a newly discovered cell type that can protect tissue from acute injury via cell–cell communication with adjacent cells. The aim of this study was to use a mouse model of skin wound healing and lipopolysaccharide (LPS)-induced cell injury to evaluate the effects of TCs on skin wound healing in vivo and in vitro.

Material/methods

Immunohistochemical staining was performed to evaluate the alteration of TCs in tissues from normal and chronic wound patients. Then, a male C57BL/6 mouse wound model of the back was established. The mice were divided randomly into three groups, and wound healing was estimated according to the wound healing rate and histology. An LPS-induced co-culture model of a mouse lung telocyte cell line (TCs) with human keratinocyte (HaCaT), human dermal microvascular endothelial cell (HDMEC) or murine fibroblast (L929) cell lines was established to analyse the effects of TCs on constitutive cell types of the skin. Cell proliferation, migration and apoptosis were examined, and reactive oxygen species (ROS) and inflammatory factors in HaCaT cells, HDMECs, and L929 cells were detected to study the mechanisms involved in TC protection in skin wounds.

Results

TCs were significantly increased in tissues from chronic wound patients compared with healthy controls. Wound healing was significantly improved in wound mouse models treated with exogenous TCs compared with LPS-induced models. TCs reversed the LPS-induced inhibition of HaCaT cells and HDMECs and reduced the LPS-induced apoptosis of HaCaT cells and the death ratios of HDMECs and L929 cells. TCs reversed LPS-induced ROS in HDMECs and L929 cells and decreased inflammatory factor mRNA levels in HaCaT cells, HDMECs and L929 cells.

Conclusions

TCs reduce wound healing delay, and inflammatory responses caused by LPS might be mediated by inflammatory inhibition, thus restricting apoptosis and promoting migration of the main component cell types in the skin.

DNA methyltransferase DNMT1 inhibits lipopolysaccharide‑induced inflammatory response in human dental pulp cells involving the methylation changes of IL‑6 and TRAF6

Dental pulp inflammation is a pathological process characterized by local lesions in dental pulp and the accumulation of inflammatory mediators. DNA methylation of cytosine residues is a key epigenetic modification that is essential for gene transcription, and plays pivotal roles in inflammatory reactions and immune responses. However, the function of cytosine DNA methylation in the innate immune defense against the inflammation of dental pulp is poorly understood. To investigate the effect of DNA methylation in inflamed dental pulp upon innate immune responses, expression levels of the DNA methyltransferases (DNMT1, DNMT3a and DNMT3b) in human dental pulp cells (hDPCs) after lipopolysaccharide (LPS) stimulation were evaluated by western blotting and reverse transcription‑quantitative (RT‑q) PCR. Only DNMT1 expression was decreased, while the transcription of inflammatory cytokines was increased. In the immune responses of LPS‑induced hDPCs, the results of RT‑qPCR and ELISA showed that DNMT1 knockdown promoted the production of the pro‑inflammatory cytokines, interleukin (IL)‑6 and IL‑8. Western blotting demonstrated that DNMT1 knockdown increased the phosphorylation levels of IKKα/β and p38 in the NF‑κB and MAPK signaling pathways, respectively. Furthermore, MeDIP and RT‑qPCR analysis demonstrated that the 5‑methylcytosine levels of the IL‑6 and TNF receptor‑associated factor 6 (TRAF6) promoters were significantly decreased in DNMT1‑deficient hDPCs. Taken together, these results indicated that the expression of DNMT1 was decreased after LPS stimulation in hDPCs. DNMT1 depletion increased LPS‑induced cytokine secretion, and activated NF‑κB and MAPK signaling; these mechanisms may involve the decreased methylation levels of the IL‑6 and TRAF6 gene promoters. This study emphasized the role of DNMT1‑dependent DNA methylation on the inflammation of LPS‑infected dental pulp and provides a new rationale for the investigation of the molecular mechanisms of inflamed dental pulps.

Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling

Catalpol is the main active ingredient of an extract from Radix rehmanniae, which in a previous study showed a protective effect against various types of tissue injury. However, a protective effect of catalpol on uterine inflammation has not been reported. In this study, to investigate the protective mechanism of catalpol on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and mouse endometritis, in vitro and in vivo inflammation models were established. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blot (WB), and immunofluorescence techniques. The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, and chemokines such as C-X-C motif chemokine ligand 8 (CXCL8) and CXCL5, both in bEECs and in uterine tissue. From the experimental results of WB, qRT-PCR, and immunofluorescence, the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group. The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase (MPO) activity. The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.

Melatonin protects against lipopolysaccharide-induced epididymitis in sheep epididymal epithelial cells in vitro

Melatonin has protective effects against inflammation but its role in epididymitis is unknown. We addressed this in the present study using lipopolysaccharide (LPS)-stimulated sheep epididymal epithelial cells as an in vitro inflammation model. We found that interleukin (IL)-1β, IL-6, tumor necrosis factor α, and cyclooxygenase (COX)-2 mRNA levels; COX-2 and Toll-like receptor (TLR)-4 protein levels; and nuclear factor (NF)-κB p65 phosphorylation were increased by LPS treatment. These effects were reversed in a dose-dependent manner by melatonin (10^-11-10^-7 M). Quantitative reverse transcription PCR and immunofluorescence analyses showed that the melatonin receptors MT1 and MT2 were expressed in sheep epididymal epithelial cells. The inhibitory effect of melatonin on inflammation was abrogated by the MT1 and MT2 receptor antagonist luzindole and the MT2 ligand 4-phenyl-2-propanamide tetraldehyde. Thus, melatonin exerted anti-inflammatory effect in epididymal epithelial cells by inhibiting TLR4/NF-κB signaling, suggesting its potential as an effective drug for the treatment of epididymitis in sheep.

DNA methylation is involved in pro-inflammatory cytokines expression in T-2 toxin-induced liver injury

Currently, T-2 toxin has been reported to cause liver toxicity with the effects of oxidative stress and inflammation; however, the underlying mechanism of T-2 toxin-induced liver injury is not fully understood. Increasing lines of evidence show that DNA methylation affects the expression of inflammatory cytokine, and plays a crucial role in autoimmune diseases. Nevertheless, the potential role of DNA methylation in the hepatotoxicity of T-2 toxin has not been explored. In this study, female Wistar rats were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at 1, 3 and 7 days post-exposure. In vitro, a normal rat liver cell line (BRL) was exposed to different concentrations of T-2 toxin. Histopathological analysis was used to investigate damage to the liver, which was detected at the molecular level by RT-PCR, Western blot and immunohistochemical assays, methylation-specific PCR (MSP), bisulfite sequencing (BSP), and flow cytometry. The results showed that T-2 toxin significantly increased the levels of DNA methyltransferases (DNMT1, DNMT3A), which were mainly concentrated at the site of liver injury. The 5-methylcytosine (5-mC) level of genomic DNA was also raised in T-2 toxin-treated rat livers. The expression of inflammatory cytokines (IL-6, IL-1β, IL-11, IL-1α, and TNF-α) increased both in vivo and in vitro under T-2 toxin treatment. Notably, DNA demethylation directly increased the expression of cytokines IL-11, IL-6, IL-α, and TNF-α under T-2 toxin exposure. DNA methylation inhibitors combined with T-2 toxin directly or indirectly induced the production of inflammatory cytokines and aggravate cell apoptosis. Our study uncovered for the first time that DNA methylation is related to the expression of inflammatory cytokines in T-2 toxin-induced liver injury. These findings suggested that DNA methylation is a potential mechanism of T-2 toxin-induced hepatotoxicity.

DNA Methylation Inhibitor 5-Aza-2'-Deoxycytidine Modulates Endometrial Receptivity Through Upregulating HOXA10 Expression

Endometrial receptivity is a critical factor for embryo implantation. A decrease in endometrial homeobox A10 (HOXA10) expression is associated with hypermethylation of its promoter and lower endometrial receptivity in animals and humans. 5-Aza-2'-deoxycytidine (AZA) is a DNA methyltransferase inhibitor. However, whether demethylation of the HOXA10 gene could increase the receptivity of the human endometrium remains unknown. Homeobox A10 promoter methylation was analyzed using bisulfite genomic sequencing polymerase chain reaction. Quantitative real time polymerase chain reaction and Western blotting were used to analyze the expression of HOXA10 and its downstream target genes (integrin subunit β 3 [ITGB3] and insulin growth factor binding protein 1 [IGFBP1]) in Ishikawa cells treated with or without AZA for 24 hours. Their protein expression was analyzed with or without HOXA10 siRNA treatment. The effect of AZA on embryo implantation was examined using a Jeg-3 spheroid-endometrial cell attachment assay. The percentage of methylated CpG islands in the HOXA10 promoter was 72.0% without AZA treatment. However, it was 38% and 35% in the 1 and 10 μM AZA treatment groups, respectively. 5-Aza-2'-deoxycytidine strongly induced the expression of HOXA10, ITGB3, and IGFBP1 messenger RNA and their protein expression. Homeobox A10 knockdown led to decreased expression of HOXA10, ITGB3, and IGFBP1, with or without AZA treatment. The attachment rate of Jeg-3 spheroids increased significantly from 82% (control) to 95% (AZA 1 μM) and 96% (AZA 10 μM) after AZA treatment. 5-Aza-2'-deoxycytidine could upregulate the expression of ITGB3 and IGFBP1 via HOXA10 upregulation, and upregulation of ITGB3 and IGFBP1 plays an important role in endometrial receptivity during implantation. 5-Aza-2'-deoxycytidine may improve endometrial receptivity by upregulating the expression of HOXA10.