Microarray analysis of gene expression in 3-methylcholanthrene-treated human endothelial cells

Apoliporotein L3 interferes with endothelial tube formation via regulation of ERK1/2, FAK and Akt signaling pathway

BACKGROUND AND AIMS

Endothelial cells are main actors in vascular homeostasis as they regulate vascular pressure and permeability as well as hemostasis and inflammation. Disturbed stimuli delivered to and by endothelial cells correlate with the so-called endothelial dysfunction and disrupt this homeostasis. As constituents of the inner layer of blood vessels, endothelial cells are also involved in angiogenesis. Apolipoprotein Ls (APOL) comprise a family of newly discovered apolipoproteins with yet poorly understood function, and are suggested to be involved in inflammatory processes and cell death mechanisms. Here we investigate the role of APOLs in endothelial cells stimulated with factors known to be involved in atherogenesis and their possible contribution to endothelial dysfunction with an emphasis on inflammation driven-angiogenesis in vitro.

METHODS

Using the CRISPR/Cas9 technique, we analyzed the effect of APOL3 gene knock out in HMEC-1 endothelial cells on cell migration, tubulogenesis, endothelial permeability, intracellular signal transduction as assessed by kinase phosphorylation, and angiogenesis gene expression (measured by qRT-PCR).

RESULTS

Our results indicate that among the family, APOL3 was the only member induced by myeloperoxidase, oxidized LDL, VEGF and FGF treatments. APOL3 invalidation increased endothelial permeability, reduced wound repair and tubule formation in vitro, the latter only in MPO and VEGF-induced conditions. Accordingly, some pro-angiogenic signaling pathways (ERK1/2 and FAK but not Akt) and some pro-angiogenic genes were partially inhibited in APOL3 knock out cells.

CONCLUSIONS

These findings suggest the involvement of APOL3 in angiogenesis in vitro and as a modulator of MAPK and FAK signaling in endothelial cells.

Omics tools: New challenges in aquatic nanotoxicology?

In recent years, the implication of genomics into ecotoxicological studies has been studied closely to allow a better understanding of organism's responses to environmental contaminants including engineering nanomaterials (ENMs). ENMs are increasingly produced for various applications including cosmetics, electronics, sports equipment, biomedicine and agriculture. Because of their small size, ENMs possess chemical or physical characteristics improved compared to the corresponding macro-sized material. As their application expend, the release of manufactured ENMs into the environment is likely to increase and concern over impacts for the aquatic ecosystem is growing. Several studies reported deleterious effect of ENMs to aquatic organisms, but there is little information about the molecular mechanisms of toxicity. The development of ecotoxicogenomic approaches will improve the characterization of cellular and molecular modes of action of ENMs to aquatic organisms and allow a better prediction of contaminants toxicity. This paper presents an overview of transciptomic/proteomic studies in freshwater and marine organisms exposed to ENMs. Overall, induction of gene expression in relations to defense mechanisms, immune responses, growth and reproduction were measured after ENMs exposures of organisms, but with different patterns depending on exposure duration and concentrations used. In addition, some studies reported a positive correlation between gene expression and cellular modifications, but not at the individual level.

Induction of Thioredoxin Reductase 1 by Korean Red Ginseng Water Extract Regulates Cytoprotective Effects on Human Endothelial Cells

Korean Red Ginseng is a popular herbal medicine and is widely used in many food products. KRG has biological benefits related to vascular diseases including diabetes, hypertension, atherosclerosis, and other cardiac diseases and KRG has antioxidant and anti-hyperlipidemic actions. KRG decreases the level of oxidative stress and suppresses proinflammatory cytokines and cell adhesion molecules, thus protecting endothelial dysfunction. Mammalian Thioredoxin reductase 1 is an NADPH-dependent selenoprotein, essential for antioxidant defense and DNA synthesis and repair, that regulates the redox system by modulating redox-sensitive transcription factors and thiol-containing proteins. Here, we show that KRG water extract increases the expression of TrxR1 in human umbilical vein endothelial cells via the p38 and PKC-δ signaling pathways. The induction of TrxR1 expression by KRG was confirmed by Western blot analysis and reverse transcription polymerase chain reaction. However, the increase in TrxR1 expression was abolished by specific silencing of the p38 and PKC-δ genes. In addition, we demonstrated that auranofin, a TrxR1 inhibitor, weakens the protective effect of KRG against H₂O₂-induced cell death as measured by the terminal transferase dUTP nick end labeling assay. These results suggest that KRG may have protective effects in vascular diseases by upregulating TrxR1 in endothelial cells, thereby inhibiting the generation of reactive oxygen species and cell death.

Ecotoxicogenomic approaches for understanding molecular mechanisms of environmental chemical toxicity using aquatic invertebrate, Daphnia model organism

Due to the rapid advent in genomics technologies and attention to ecological risk assessment, the term “ecotoxicogenomics” has recently emerged to describe integration of omics studies (i.e., transcriptomics, proteomics, metabolomics, and epigenomics) into ecotoxicological fields. Ecotoxicogenomics is defined as study of an entire set of genes or proteins expression in ecological organisms to provide insight on environmental toxicity, offering benefit in ecological risk assessment. Indeed, Daphnia is a model species to study aquatic environmental toxicity designated in the Organization for Economic Co-operation and Development’s toxicity test guideline and to investigate expression patterns using ecotoxicology-oriented genomics tools. Our main purpose is to demonstrate the potential utility of gene expression profiling in ecotoxicology by identifying novel biomarkers and relevant modes of toxicity in Daphnia magna. These approaches enable us to address adverse phenotypic outcomes linked to particular gene function(s) and mechanistic understanding of aquatic ecotoxicology as well as exploration of useful biomarkers. Furthermore, key challenges that currently face aquatic ecotoxicology (e.g., predicting toxicant responses among a broad spectrum of phytogenetic groups, predicting impact of temporal exposure on toxicant responses) necessitate the parallel use of other model organisms, both aquatic and terrestrial. By investigating gene expression profiling in an environmentally important organism, this provides viable support for the utility of ecotoxicogenomics.

Effect of Korean Red Ginseng treatment on the gene expression profile of diabetic rat retina

Background

Korean Red Ginseng (KRG) is a herbal medicine used in Asian countries and is very popular for its beneficial biological properties. Diabetes mellitus (DM) and its complications are rapidly becoming a global public health concern. The literature on transcriptional changes induced by KRG in rat models of diabetic retinopathy is limited. Considering these facts, we designed this study to determine whether retinopathy-associated genes are altered in retinas of rats with DM and whether the induced changes are reversed by KRG.

Methods

Male Sprague–Dawley rats were intravenously injected with streptozotocin (50 mg/kg body weight) to induce DM, following which, KRG powder (200 mg/kg body weight) was orally administered to the KRG-treated DM rat group for 10 wks. The rats were then sacrificed, and their retinas were harvested for total RNA extraction. Microarray gene expression profiling was performed on the extracted RNA samples.

Results

From among > 31,000 genes investigated, the expression of 268 genes was observed to be upregulated and that of 58 genes was downregulated, with twofold altered expression levels in the DM group compared with those in the control group. Moreover, 39 genes were upregulated more than twofold and 84 genes were downregulated in the KRG-treated group compared to the DM group. The expression of the genes was significantly reversed by KRG treatment; some of these genes were analyzed further to verify the results of the microarray experiments.

Conclusion

Taken together, our data suggest that reversed changes in the gene expression may mediate alleviating activities of KRG in rats with diabetic retinopathy.