Gene Expression In Epithelial Cells Research Articles

YAP Regulates NFI/KLF5 Transcriptional and Epigenetic Networks Directing Alveolar Epithelial Cell Differentiation

Ventilation is dependent upon the pulmonary alveoli which are lined by two major epithelial cell types, alveolar type 1 and 2 (AT1) and (AT2) cells. AT1 cells are located in close apposition to alveolar capillary endothelial cells to mediate gas exchange. AT2 cells synthesize and secrete pulmonary surfactant lipids and protein and serve as progenitor cells which proliferate and differentiate to repair the alveoli after injury. Herein, we developed transgenic mice in which YAP was activated or deleted to determine its roles in alveolar epithelial cell differentiation. Organoids from YAPactive mice selectively differentiated into AT1 cells demonstrating that YAP may be required for AT1 cell differentiation in-vitro . Activation of YAP in the postnatal lung increased epithelial cell proliferation, increased numbers of AT1 cells, and caused indeterminate differentiation of subsets of alveolar cells in-vivo, inducing atypical expression of genes normally restricted to conducting airway epithelial cells. Deletion of YAP increased expression of genes associated with mature AT2 cells. In combination with altered gene expression, YAP activation caused widespread changes in chromatin accessibility and ATAC sequencing demonstrated enhanced DNA accessibility in promoters of transcription factors and predicted target genes associated with alveolar cell differentiation. YAP participated with KLF5, NFIB, and NKX2-1 to regulate alveolar epithelial cell gene expression, together activating AGER, an AT1 signature gene. YAP plays a central role in a transcriptional network regulating alveolar epithelial differentiation.

Changes in Mitochondrial Morphology and Mitochondrial Fission/Fusion Gene Expression in Retinal Pigment Epithelial Cells During Oxidative Stress

Age-related macular degeneration (AMD) represents a serious impairment for the elderly. Because the pathogenesis of AMD has not been completely defined, the available therapeutic treatments are not ideal. Retinal pigment epithelial (RPE) cells are essential for photoreceptor cell maintenance and survival; however, the mechanisms underlying RPE cell damage and AMD remains to be elucidated. It is known that abnormal mitochondrial gene expression causes mitochondrial dysfunction, induces cell damage, and results in disease. In this study, ARPE-19 cells were treated with different concentrations of H2O2. It was found that excessive H2O2 concentration resulted in significant contraction of ARPE-19 cells and increased cell death, and destruction of mitochondrial structure as well as membrane and crest. RT-PCR results showed that decreased expression of the Fis1 gene was evident in H2O2-treated cells. There were no significant differences observed among the different H2O2 concentration groups. The expression of the fission genes, MTP18 and Dnmp1, and the fusion genes, Mnf1 and Mnf2, was not significantly different. Real-time PCR results revealed that the expression of the Fis1 gene decreased concomitantly with different concentrations of H2O2, whereas the expression of the Mfn2 gene increased by treatment with 200 μMH2O2. There were no significant differences in the expression of the other genes. These results indicate that abnormal expression of the mitochondrial Fis1 fission gene, and the Mfn2 fusion gene caused mitochondrial dysfunction in ARPE-19 cells. This indicates that the imbalance of mitochondrial dynamics may contribute to cell death in an oxidative stress environment.

Aryl hydrocarbon receptor deficiency enhanced airway inflammation and remodeling in a murine chronic asthma model

The aryl hydrocarbon receptor (AhR) is a ligand-dependent-activated transcriptional factor that regulates the metabolism of xenobiotic and endogenous compounds. Recent studies have shown that AhR is a novel master regulator of the mucosal immune system, including lungs and intestine. To elucidate the role of AhR in chronic severe asthma, AhR wild-type and knockout mice (AhR-/- ) were sensitized and challenged with ovalbumin for 4weeks. To uncover the underlying mechanisms, inflammatory cells profile and cytokines production were analyzed in bronchial lavage fluid (BALF) and lung tissue. Compared to wild-type mice, AhR-/- mice had exacerbated asthma symptoms, including airway inflammation, mucus production, airway hyperresponsiveness, and airway remodeling. BALF monocytes, neutrophils, eosinophils, and lymphocytes were all enhanced in OVA-immunized AhR-/- mice. In OVA-immunized AhR-/- mice, T helper (Th) 17 cell-specific cytokine IL-17A, as well as airway remodeling factors, including epithelial-mesenchymal transition (EMT) markers and vascular endothelial growth factor (VEGF), were all enhanced in lung tissue. Moreover, human cohort studies showed that AhR gene expression in bronchial epithelial cells decreases in severe asthma patients. Loss of AhR leads to worsening of allergic asthma symptoms, indicating its importance in maintaining normal lung function and mediating disease severity.

Spermatozoa induce transcriptomic alterations in bovine oviductal epithelial cells prior to initial contact

The capability of spermatozoa to directly influence maternal gene expression is already established. Indeed, some of the changes induced by spermatozoa may have a direct functional importance in the pre-conceptional period. Although the mechanisms underlying these sperm-maternal interactions are not well characterized, it is possible that they could involve ligands that are released from the spermatozoa. This study therefore aimed to test whether physical contact between bovine spermatozoa and bovine oviductal epithelial cells (BOECs) is a prerequisite for spermatozoa-induced gene expression changes. We used two co-culture models: a contact co-culture model in which spermatozoa interact directly with BOECs, and a non-contact co-culture model in which an insert with the pore size of 0.4 μm was placed between spermatozoa and BOECs. Messenger RNA sequencing analysis of BOECs by RNA-seq revealed ten differentially expressed genes in contact system and 108 differentially expressed genes in the non-contact system after 10 h of co-culture. Retinol metabolism pathway and ovarian steroidogenesis pathway were significantly enriched in the non-contact co-culture system. Q-PCR analysis revealed that transcriptional responses can be rapid, with increased expression of four genes (DHRS3, CYP1B1, PTGS2, and ATF3) detectable within just 90 min of co-incubation, but with expression levels highly dependent on the type of co-culture system. The findings from our study demonstrate that direct contact with spermatozoa is not necessary to induce changes in gene expression of oviductal epithelial cells, suggesting that spermatozoa may be able to signal to maternal tissues in advance of their arrival.

Different Culture Conditions Affect Drug Transporter Gene Expression, Ultrastructure, and Permeability of Primary Human Nasal Epithelial Cells.

This study aimed to characterize a commercially available primary human nasal epithelial cell culture and its gene expression of a wide range of drug transporters under different culture conditions. Human nasal cells were cultured in three different types of culture media at the air-liquid (A-L) or liquid-liquid (L-L) interfaces for 1 or 3 wks. The effects of the different cell culture conditions were evaluated using light and electron microscopy, transepithelial electrical resistance (TEER) measurements, permeation studies with dextran, and gene expression profiling of 84 drug transporters. The type of culture medium affected cell ultrastructure, TEER, and dextran permeation across epithelia. The expression of 20 drug transporter genes depended on the culture interface and/or time in culture; the A-L interface and longer time in culture favored higher expression levels of five ABC and seven SLC transporters. Culture conditions influence the morphology, barrier formation, permeation properties, and drug transporter expression of human nasal epithelial cells, and this must be taken into consideration during the establishment and validation of in vitro models. A thorough characterization of a nasal epithelial model and its permeability properties is necessary to obtain an appropriate standardized model for the design of aerosol therapeutics and drug transport studies.

Integrative Omics Analyses Reveal Epigenetic Memory in Diabetic Renal Cells Regulating Genes Associated With Kidney Dysfunction.

Diabetic kidney disease (DKD) is a major complication of diabetes and the leading cause of end-stage renal failure. Epigenetics has been associated with metabolic memory in which prior periods of hyperglycemia enhance the future risk of developing DKD despite subsequent glycemic control. To understand the mechanistic role of such epigenetic memory in human DKD and to identify new therapeutic targets, we profiled gene expression, DNA methylation, and chromatin accessibility in kidney proximal tubule epithelial cells (PTECs) derived from subjects with and without type 2 diabetes (T2D). T2D-PTECs displayed persistent gene expression and epigenetic changes with and without transforming growth factor-β1 treatment, even after culturing in vitro under similar conditions as nondiabetic PTECs, signified by deregulation of fibrotic and transport-associated genes (TAGs). Motif analysis of differential DNA methylation and chromatin accessibility regions associated with genes differentially regulated in T2D revealed enrichment for SMAD3, HNF4A, and CTCF transcription factor binding sites. Furthermore, the downregulation of several TAGs in T2D (including CLDN10, CLDN14, CLDN16, SLC16A2, and SLC16A5) was associated with promoter hypermethylation, decreased chromatin accessibility, and reduced enrichment of HNF4A, histone H3-lysine-27-acetylation, and CTCF. Together, these integrative analyses reveal epigenetic memory underlying the deregulation of key target genes in T2D-PTECs that may contribute to sustained renal dysfunction in DKD.

Oral Primo-Colonizing Bacteria Modulate Inflammation and Gene Expression in Bronchial Epithelial Cells.

The microbiota of the mouth disperses into the lungs, and both compartments share similar phyla. Considering the importance of the microbiota in the maturation of the immunity and physiology during the first days of life, we hypothesized that primo-colonizing bacteria of the oral cavity may induce immune responses in bronchial epithelial cells. Herein, we have isolated and characterized 57 strains of the buccal cavity of two human newborns. These strains belong to Streptococcus, Staphylococcus, Enterococcus, Rothia and Pantoea genera, with Streptococcus being the most represented. The strains were co-incubated with a bronchial epithelial cell line (BEAS-2B), and we established their impact on a panel of cytokines/chemokines and global changes in gene expression. The Staphylococcus strains, which appeared soon after birth, induced a high production of IL-8, suggesting they can trigger inflammation, whereas the Streptococcus strains were less associated with inflammation pathways. The genera Streptococcus, Enterococcus and Pantoea induced differential profiles of cytokine/chemokine/growth factor and set of genes associated with maturation of morphology. Altogether, our results demonstrate that the microorganisms, primo-colonizing the oral cavity, impact immunity and morphology of the lung epithelial cells, with specific effects depending on the phylogeny of the strains.

Compressive stress induces collective migration through cytoskeletal remodelling in nasal polyp epithelium.

Nasal polyps in the nasal cavity and mucous discharge inside the maxillary sinus exhibit compressive stress on the nasal mucosal epithelium. However, there have been only a few studies on how compressive stress impacts the human nasal mucosal epithelium. We investigated the effect of compressive stress on collective migration, junctional proteins, transepithelial electri- cal resistance, epithelial permeability, and gene expression in well-differentiated normal human nasal epithelial (NHNE) cells and human nasal polyp epithelial (HNPE) cells. NHNE cells barely showed collective migration at compressive stress up to 150 mmH20. However, HNPE cells showed much greater degree of collective migration at a lower compressive stress of 100 mmH20. The cell migration of HNPE cells sub- jected to 100 mmH2O compression was significantly decreased at day 3 and was recovered to the status prior to the compressive stress by day 7, indicating that HNPE cells are relatively more sensitive to mechanical pressure than NHNE cells. Compressive stress also increased transepithelial electrical resistance and decreased epithelial permeability, indicating that the compressive stress disturbed the structural organization rather than physical interactions between cells. In addition, we found that compressive stress induced gene expressions relevant to airway inflammation and tissue remodelling in HNPE cells. Taken together, these findings demonstrate that compressive stress on nasal polyp epithelium is capable of inducing collective migration and induce increased expression of genes related to airway inflammation, innate immunity, and polyp remo- delling, even in the absence of inflammatory mediators.

Alcohol Use Disorders Are Associated With a Unique Impact on Airway Epithelial Cell Gene Expression.

Alcohol use disorders (AUDs) and cigarette smoking both increase risk for the development of community-acquired pneumonia (CAP), likely through adverse effects on proximal airway mucociliary clearance and pathogen recognition. Smoking-related alterations on airway gene expression are well described, but little is known about the impact of AUDs. We measured gene expression in human airway epithelial cells (AECs), hypothesizing that AUDs would be associated with novel differences in gene expression that could alter risk for CAP. Bronchoscopy with airway brushings was performed in participants with AUDs and controls to obtain AECs. An AUD Identification Test was used to define AUD. RNA was extracted from AECs, and mRNA expression data were collected on an Agilent micro-array. Differential expression analyses were performed on the filtered and normalized data with correction for multiple testing. Enrichment analyses were performed using clusterProfiler. Expression data from 19 control and 18 AUD participants were evaluated. After adjustment for smoking, AUDs were associated with significant differential expression of 520 AEC genes, including genes for ribosomal proteins and genes involved in protein folding. Enrichment analyses indicated significant differential expression of 24 pathways in AUDs, including those implicated in protein targeting to membrane and viral gene expression. Smoking-associated AEC gene expression differences mirrored previous reports, but differed from those associated with AUDs. AUDs have a distinct impact on AEC gene expression that may influence proximal airway function independent of smoking. Alcohol-associated alterations may influence risk for CAP through modifying key mechanisms important in protecting proximal airway integrity.

Expression profiling meta-analysis of ACE2 and TMPRSS2, the putative anti-inflammatory receptor and priming protease of SARS-CoV-2 in human cells, and identification of putative modulators

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in hundreds of thousands of deaths worldwide. While the majority of people with COVID-19 won't require hospitalization, those who do may experience severe life-threatening complications, including acute respiratory distress syndrome. SARS-CoV-2 infects human cells by binding to the cellular surface protein angiotensin-converting enzyme 2 (ACE2); in addition, the cellular transmembrane serine protease 2 (TMPRSS2) is needed for priming of the spike (S) protein of the virus. Virus entry may also depend on the activity of the endosomal/lysosomal cysteine proteases cathepsin B, L (CTSB, CTSL) although their activity is likely dispensable. Given that the uncertainty of how COVID-19 kills, hampers doctors' ability to choose treatments the need for a deep understanding of COVID-19 biology is urgent. Herein, we performed an expression profiling meta-analysis of ACE2, TMPRSS2 and CTSB/L genes (and proteins) in public repository databases and found that all are widely expressed in human tissues; also, the ACE2 and TMPRSS2 genes tend to be co-regulated. The ACE2 and TMPRSS genes expression is (among others) suppressed by TNF, and is induced by pro-inflammatory conditions including obesity, Barrett's esophagus, stomach infection by helicobacter pylori, diabetes, autoimmune diseases and oxidized LDL; by exercise, as well as by growth factors, viruses' infections, cigarette smoke, interferons and androgens. Regarding currently investigated therapies interferon-beta induced ACE2 gene expression in bronchial epithelial cells, while chloroquine tends to upregulate CTSB/L genes. Finally, we analyzed KEGG pathways modulated by ACE2, TMPRSS2 and CTSB/L and probed DrugBank for drugs that target modules of the affected pathways. Our data indicate possible novel high-risk groups for COVID-19; provide a rich resource for future investigations of its pathogenesis and highlight the therapeutic challenges we face.

Exposure Effects Beyond the Epithelial Barrier: Transepithelial Induction of Oxidative Stress by Diesel Exhaust Particulates in Lung Fibroblasts in an Organotypic Human Airway Model.

In vitro bronchial epithelial monoculture models have been pivotal in defining the adverse effects of inhaled toxicant exposures; however, they are only representative of one cellular compartment and may not accurately reflect the effects of exposures on other cell types. Lung fibroblasts exist immediately beneath the bronchial epithelial barrier and play a central role in lung structure and function, as well as disease development and progression. We tested the hypothesis that in vitro exposure of a human bronchial epithelial cell barrier to the model oxidant diesel exhaust particulates caused transepithelial oxidative stress in the underlying lung fibroblasts using a human bronchial epithelial cell and lung fibroblast coculture model. We observed that diesel exhaust particulates caused transepithelial oxidative stress in underlying lung fibroblasts as indicated by intracellular accumulation of the reactive oxygen species hydrogen peroxide, oxidation of the cellular antioxidant glutathione, activation of NRF2, and induction of oxidative stress-responsive genes. Further, targeted antioxidant treatment of lung fibroblasts partially mitigated the oxidative stress response gene expression in adjacent human bronchial epithelial cells during diesel exhaust particulate exposure. This indicates that exposure-induced oxidative stress in the airway extends beyond the bronchial epithelial barrier and that lung fibroblasts are both a target and a mediator of the adverse effects of inhaled chemical exposures despite being separated from the inhaled material by an epithelial barrier. These findings illustrate the value of coculture models and suggest that transepithelial exposure effects should be considered in inhalation toxicology research and testing.

A Human 2D Primary Organoid-Derived Epithelial Monolayer Model to Study Host-Pathogen Interaction in the Small Intestine.

Gut organoids are stem cell derived 3D models of the intestinal epithelium that are useful for studying interactions between enteric pathogens and their host. While the organoid model has been used for both bacterial and viral infections, this is a closed system with the luminal side being inaccessible without microinjection or disruption of the organoid polarization. In order to overcome this and simplify their applicability for transepithelial studies, permeable membrane based monolayer approaches are needed. In this paper, we demonstrate a method for generating a monolayer model of the human fetal intestinal polarized epithelium that is fully characterized and validated. Proximal and distal small intestinal organoids were used to generate 2D monolayer cultures, which were characterized with respect to epithelial cell types, polarization, barrier function, and gene expression. In addition, viral replication and bacterial translocation after apical infection with enteric pathogens Enterovirus A71 and Listeria monocytogenes were evaluated, with subsequent monitoring of the pro-inflammatory host response. This human 2D fetal intestinal monolayer model will be a valuable tool to study host-pathogen interactions and potentially reduce the use of animals in research.

The NF-κB signalling pathway regulates GLUT6 expression in endometrial cancer

BackgroundGene and protein expression of the glucose transporter GLUT6 are elevated in multiple cancers, including endometrial cancer. However, the extrinsic and intrinsic mechanisms that regulate GLUT6 expression in this malignancy are unknown. Herein we investigate the potential mechanisms regulating GLUT6 expression in endometrial cancer. MethodsData mining of the GLUT6 gene (SLC2A6) in The Cancer Genome Atlas (TCGA) PanCan datasets was performed in cBioPortal. A transcriptome PCR array was used to identify regulators of GLUT6 expression. The role of RELA in regulating GLUT6 gene and protein expression was investigated by overexpressing constitutively active and dominant-negative RELA in endometrial cells. Endometrial cells were treated with the pro-inflammatory cytokine TNFα and the expression of RELA, IκBα, TNFα, and GLUT6 were examined by Western blotting and RT-qPCR. ResultsGLUT6 is altered in 1% of all cancer samples (157 of 10, 967 samples) within TCGA datasets including 4.7% of uterine (endometrial) cancers. GLUT6 expression was positively co-expressed with multiple members of the NF-κB signalling pathway including NFKB2, RELB, NFKBIE, and TNF in endometrial cancer samples. A transcriptome PCR array identified RELA as the top potential transcriptional regulator of GLUT6 expression. Overexpression of constitutively active RELA increased GLUT6 gene expression in normal endometrial epithelial cells (hUE-Ts), while overexpression of dominant-negative RELA decreased GLUT6 expression in cancerous RL95–2 endometrial cells. TNFα treatment activated canonical NF-κB signalling and increased the expression of GLUT6, but not that of other glucose transporters (GLUTs 1, 3, 4, 8, 10, or 12) in endometrial cells. ConclusionsTNFα is a cytokine that is commonly increased in obesity-related endometrial cancer and the findings herein support a potential mechanism whereby TNFα may contribute to endometrial cancer initiation or progression by increasing GLUT6 expression. Furthermore, we identified RELA, an important downstream mediator of the TNFα signalling cascade, as a regulator of GLUT6 expression in endometrial cells. Future studies are warranted to determine how GLUT6 expression affects endometrial tumourigenesis or cancer progression.

Resveratrol mediates regulation of genes through microRNAs in the gut epithelial cells that may play a role in the gut health and amelioration of EAE in mice

Abstract Resveratrol (RES), found abundantly in red grapes, blue berries and peanuts, is an anti-inflammatory, anticancer, and antioxidant compound. We have previously shown that RES ameliorated EAE in mice regulating immune cell functions and differentiation. In this study, we investigated the effect of RES on gene expression in the gut epithelial cells of mice with EAE. To this end, epithelial cells from small intestine (SI) and colons of mice with EAE treated with vehicle or RES were isolated. Transcriptome arrays using total RNAs from epithelial cells of SI and colons were performed and data obtained from the arrays were analyzed using Transcriptome Analysis Console software. Results showed that there were 1,591 (1165 in SI and 426 in colon) genes that were up- or down-regulated (>2-fold) in the epithelial cells of mice with EAE treated with RES, when compared to vehicle. We selected two genes, α-defensins and Mucin 3, for further analysis. Upon analysis of their expression in the gut epithelial cells, α-defensins was downregulated in SI while Mucin 3 was upregulated in colon of EAE mice treated with RES. To understand the regulation of these two genes in the gut, we investigated the role of microRNAs (miRs). There were two miRs, miR-378 and miR-338, that showed strong binding affinity for α-defensins and Mucin 3 respectively. Upon analysis of their expression in epithelial cells, miR-378 was upregulated but miR-338 was downregulated, demonstrating their possible role in the regulation of α-defensins and Mucin 3 genes. Data obtained from this study demonstrates a possible role of miRs in the regulation of genes in the gut epithelial cells may play a role in improving the health of the gut and amelioration of EAE in mice.

Examination of methionine stimulation of gene expression in dairy cow mammary epithelial cells using RNA-sequencing.

In this research communication, a cell model with elevated β-CASEIN synthesis was established by stimulating bovine mammary epithelial cells with 0.6 mM methionine, and the genome-wide gene expression profiles of methionine-stimulated cells and untreated cells were investigated by RNA sequencing. A total of 458 differentially expressed genes (DEGs; 219 upregulated and 239 downregulated) were identified between the two groups. Gene Ontology (GO) analysis showed that the two highest-ranked GO terms in 'molecular function' category were 'binding' and 'catalytic activity', suggesting that milk protein synthesis in methionine-stimulated cells requires induction of gene expression to increase metabolic activity. Kyoto Encyclopedia of Genes and Genomes analysis revealed that within the 'environmental information processing' category, the subcategory that is most highly enriched for DEGs was 'signal transduction'. cGMP-PKG, Rap1, calcium, cAMP, PI3K-AKT, MAPK, and JAK-STAT are the pathways with the highest number of DEGs, suggesting that these signaling pathways have potential roles in mediating methionine-induced milk protein synthesis in bovine mammary epithelial cells. This study provides valuable insights into the physiological and metabolic adaptations in cells stimulated with methionine. Understanding the regulation of this transition is essential for effective intervention in the lactation process.

Identification and Characterization of the Lactating Mouse Mammary Gland Citrullinome.

Citrullination is a post-translational modification (PTM) in which positively charged peptidyl-arginine is converted into neutral peptidyl-citrulline by peptidylarginine deiminase (PAD or PADI) enzymes. The full protein citrullinome in many tissues is unknown. Herein, we used mass spectrometry and identified 107 citrullinated proteins in the lactation day 9 (L9) mouse mammary gland including histone H2A, α-tubulin, and β-casein. Given the importance of prolactin to lactation, we next tested if it stimulates PAD-catalyzed citrullination using mouse mammary epithelial CID-9 cells. Stimulation of CID-9 cells with 5 µg/mL prolactin for 10 min induced a 2-fold increase in histone H2A citrullination and a 4.5-fold increase in α-tubulin citrullination. We next investigated if prolactin-induced citrullination regulates the expression of lactation genes β-casein (Csn2) and butyrophilin (Btn1a1). Prolactin treatment for 12 h increased β-casein and butyrophilin mRNA expression; however, this increase was significantly inhibited by the pan-PAD inhibitor, BB-Cl-amidine (BB-ClA). We also examined the effect of tubulin citrullination on the overall polymerization rate of microtubules. Our results show that citrullinated tubulin had a higher maximum overall polymerization rate. Our work suggests that protein citrullination is an important PTM that regulates gene expression and microtubule dynamics in mammary epithelial cells.

CircRNA_0084043 contributes to the progression of diabetic retinopathy via sponging miR-140-3p and inducing TGFA gene expression in retinal pigment epithelial cells.

Diabetic retinopathy (DR) is a frequent complication of diabetes and it can lead to visual impairment and blindness. However, the mechanism of their regulation remains little known. circRNAs can function as crucial competing endogenous RNA, which can sponge corresponding miRNAs and affect mRNA expression in various diseases, including DR. In our current research, we observed that circRNA_0084043 was elevated in high glucose (HG)-incubated ARPE-19 cells. Then, we focused on whether and how circRNA_0084043 participated in retinal vascular dysfunction under conditions diabetes. Apoptosis, inflammation and oxidative stress are hallmark of DR progression. This work was aimed to investigate the signaling mechanisms of circRNA_0084043 in these pathogenesis of DR. We discovered loss of circRNA_0084043 significantly increased cell survival and repressed HG-triggered apoptosis. In addition, knockdown of circRNA_0084043 remarkably reduced oxidative stress as evidenced by the down-regulated malondialdehyde (MDA) content, enhanced activities of Super Oxide Dismutase (SOD) and Glutathione peroxidase (GSH-PX). Addition, silence of circRNA_0084043 effectively restrained HG-stimulated inflammation as proved by repressing inflammatory cytokines Tumor Necrosis Factor α (TNF-α), Interleukin 6 (IL-6) and Cox-2 in ARPE-19 cells. Subsequently, we successfully predicted that miR-140-3p was a downstream target of circRNA_0084043, which could be negatively regulated by circRNA_0084043. Mechanistically, loss of miR-140-3p abrogated the beneficial effects of circRNA_0084043 siRNA on ARPE-19 cells. Transforming Growth Factor alpha (TGFA) can exhibit a role in multiple diseases. Taken these together, these data demonstrated that loss of circRNA_0084043 depressed HG-induced damage via sponging miR-140-3p and regulating TGFA.

Comparisons between Animal Models and Intestinal Crypt Cultures when Investigating the Impact of Fatty Acids on Gene Expression in Intestinal Epithelial Cells

Developmental delay of UDP‐glucuronosyltransferase 1A1 (UGT1A1) expression is central toward the development of neonatal hyperbilirubinemia, observed clinically as increased total serum bilirubin (TSB) in newborns. UGT1A1 is the sole enzyme responsible for the glucuronidation and detoxification of bilirubin. We have developed a murine model that resembles neonatal hyperbilirubinemia. In humanized UGT1 (hUGT1) mice, the expression of intestinal but not hepatic UGT1A1 is inversely associated with TSB levels. In addition, the expression of intestinal UGT1A1 is closely associated with proliferation and maturation of intestinal epithelial cells (IECs). It is known that fatty acids (FAs), the major component of breast milk, plays an important role in intestinal development. We have treated hUGT1 neonatal mice with oleic acid (OA, 16:1), a monounsaturated fatty acid. Following OA exposure, TSB levels in hUGT1 neonatal mice were reduced significantly, and RT‐qPCR analysis demonstrated that intestinal human UGT1A1 was induced, along with increased expression of Cyp4a10, a target gene of peroxisome proliferator‐activated receptor alpha (PPARα). In addition, IEC maturation markers including sucrase‐isomaltase (Sis) and alkaline phosphatase 3 (Akp3) are also induced. To examine the mechanism of OA induction, intestinal crypt cells were isolated from hUGT1 mice. The organoids were exposed to different fatty acids, including OA, palmitoleic acid (PA), arachidonic acid (AA), linoleic acid (LA), and docosahexaenoic acid (DHA). Gene expression parameters were monitored 24 hours after exposure. We found that OA‐ and PA‐treated organoids have similar survival rates in comparison to controls, but at similar concentrations of LA, DHA or AA cell death and decreased organoid viability was observed. At lower FA concentrations, RT‐qPCR analysis demonstrated that the UGT1A1 gene was not induced in any of the samples, including the IEC maturation markers Sis and Akp3. However, increased expression of the Cyp4a10 gene resulted in DHA, AA, and LA‐treated organoids. By comparing the in vivo and in vitro experiments, it suggests that unlike Cyp4a10, the regulation of UGT1A1 by fatty acids is associated with the development of the intestinal tract. Under current culture conditions, the application of intestinal organoid cultures in the study of developmental‐associated events is limited.Support or Funding InformationSupported in part by NIH grants GM126074 and ES010337

Inflammatory Gene Expression and Oxidative Stress in Human Lung Epithelial Cells Exposed to Combustion‐Produced PM2.5

ObjectiveAir pollution is a lasting global health hazard which has a serious toxicological effects on human health. Long and short term exposure to air pollutants has been associated with respiratory and cardiovascular diseases, skin diseases, and long‐term chronic diseases such as cancer and asthma. Although air pollution is produced by a variety of sources, one of the major air pollutants is fine particulate matter ranging mostly from 2.5 to 10 μm (PM2.5 to PM10). Carbon black, produced by incomplete combustion of heavy petroleum products (soot), comprises a significant portion of PM. Growing evidence suggests that many of the adverse health effects of PM are associated with oxidative stress and inflammatory responses. This work focuses on the identification of oxidative and pro‐inflammatory factors induced by exposure of human lung epithelial cells to combustion‐produced soot in various surface chemistry forms.MethodsA lung epithelial cell line (BEAS‐2B) was exposed to lab‐generated R‐250 carbon black (nascent, nitric acid‐treated, and ozone‐treated carbon) for 6hr and 24hr incubation times, at different concentrations (0–100 ug/mL). Cell viability was measured using the MultiTox‐Fluor Multiplex Assay. RNA and protein were extracted from cells to evaluate expression of inflammatory cytokines (IL‐1b, IL‐6) and genes related to the inflammatory response and oxidative stress (SOD2, NFE2L2, HO‐1, and CCL2) by real time polymerase chain reaction (PCR). The expression of protein oxidation products (carbonylated proteins) was measured using ELISA Protein Carbonyl Kit. Cell apoptosis was measured by western blot detection of cleaved Caspase‐3.ResultsCell viability was decreased with increasing PM2.5 treatment concentrations at both time points. Nitric acid‐treated carbon resulted in the largest decrease in cell viability. Nitric acid and ozone‐treated particles resulted in increased protein carbonylation when compared to the nascent particles, indicating oxidative stress. Protein carbonylation significantly increased from 6hr to 24hr PM2.5 exposure, particularly for the nitric acid‐treated particles. Gene expression of the inflammatory cytokines IL‐1b, and IL‐6 was upregulated with increasing concentrations of PM2.5 exposure (1.56–50 ug/mL), particularly for nitric acid‐treated particles. An increase in gene expression was observed for oxidative stress markers CCL2, SOD2, NFE2L2 and HO‐1 higher concentrations of PM2.5 exposure (1.56–12.5 ug/mL).ConclusionExposure of PM2.5 to human lung epithelial cells decrease cell viability and increases inflammatory responses and oxidative stress. PM2.5 surface functional groups strongly influence the extent of toxicity, and future experiments will focus on how functional groups affect cell viability and the observed inflammatory responses of human lung epithelial cells.Support or Funding InformationThis work was supported by startup funds from The University of North Carolina at Chapel Hill and Penn State College of Medicine (PS), and the Penn State University Human Health & the Environment Seed Grant (PS, RVW).

Regulation of Gene Expression through Gut Microbiota-Dependent DNA Methylation in Colonic Epithelial Cells.

A huge number of commensal bacteria inhabit the intestine, which is equipped with the largest immune system in the body. Recently, the regulation of various physiological functions of the host by these bacteria has attracted attention. In this study, the effects of commensal bacteria on gene expression in colonic epithelial cells (CoECs) were investigated with focus on regulation of DNA methylation. RNA sequencing analyses of CoECs from conventional, germ-free, and MyD88-/- mice indicated that, out of the genes affected by commensal bacteria, those downregulated in a MyD88-independent manner were most frequently observed. Furthermore, when the 5' regions of genes downregulated by commensal bacteria in CoECs were captured using a customized array and immunoprecipitated with the anti-methyl cytosine Ab, a certain population of these genes was found to be highly methylated. Comprehensive analysis of DNA methylation in the 5' regions of genes in CoECs from conventional and germ-free mice upon pull-down assay with methyl-CpG-binding domain protein 2 directly demonstrated that DNA methylation in these regions was influenced by commensal bacteria. Actually, commensal bacteria were shown to control expression of Aldh1a1, which encodes a retinoic acid-producing enzyme and plays an important role in the maintenance of intestinal homeostasis via DNA methylation in the overlapping 5' region of Tmem267 and 3110070M22Rik genes in CoECs. Collectively, it can be concluded that regulation of DNA methylation in the 5' regions of a specific population of genes in CoECs acts as a mechanism by which commensal bacteria have physiological effects on the host.