"Molecular & Cellular Toxicology"

Soung, Young Hwa;Ford, Shane;Yan, Cecilia;Chung, Jun

doi: 10.1007/s13273-019-0026-8pmid: N/A

Abstract Purpose of review: Exosomes are nano-sized extracellular vesicles ranging from 30–150 nm in diameter. Exosomes interact with nearby or distantly localized recipient cells by involving ligand/receptor binding at the surface of recipient cells or fusion with plasma membrane of recipient cells. A number of recent literatures support the role of integrins in mediating metastatic process of cancer cell derived exosomes. While exosomes need to dock on the surface of recipient cells to transmit signals or transfer their contents, the process of docking and uptake of exosomes by recipient cells is poorly understood. This review discusses the recent reports that suggest the potential roles of exosomal integrins in mediating docking and uptake of exosomes, and how these processes are related to metastatic potentials of cancer cell derived exosomes. Recent findings: Exosomal integrins (α6β4, α6β1, αvβ5, αvβ3, αvβ6) and exosomal integrin ligands (vinculin, fibronectin) have been recently reported to play roles in cancer metastasis. As exosomes are involved in cell-to-cell communication, integrins and their ligands in cancer cell derived exosomes can contribute to progression by selecting target tissues and triggering integrin mediated signaling cascades to form new metastatic niche. Recent studies also suggest that exosomal integrins and their ligands can be targeted for developing exosome based diagnostics and therapies.

Lee, Hong-Jai;Shin, Bo-Young;Moon, Jae-Seung;Ho, Chun-Chang;Shin, Jin-Su;Kim, Soo-Ki;Lee, Sang-Kyou

doi: 10.1007/s13273-019-0027-7pmid: N/A

Abstract Backgrounds: Hepatitis C virus (HCV) has infected an estimated 170 million people worldwide, most of whom are chronic patient of HCV. However, the lack of standard in vitro culture system and suitable animal model for this virus hampers fundamental conquest against HCV infection. Methods: We evaluated whether humoral milieu such as serum or culture media, and its constituents, lipid and electrolyte and pH might affect the RNA level and envelope status of HCV in vitro, fnally increasing the infection effciency of HCV in vitro and in vivo. Results: We found that the RNA level of HCV is favorable in human serum, albeit adverse in mouse serum and Dulbecco’s Modifed Eagle Medium (DMEM), and the surface antigenicity in mouse serum showed higher than human serum and DMEM. Consistently, viral clearance was verifed by the increase of anti-HCV core ELISA assay in mouse serum and DMEM. Lipid analysis revealed that the LDL-cholesterol was decreased in the presence of HCV. In lipid removal analysis, the level of genome in mouse serum was signifcantly lower than human serum. For electrolytes analysis, the level of potassium in human serum was signifcantly lower than mouse serum and DMEM. Last, the RNA level and surface antigenicity of HCV in DMEM was significantly augmented in a pH-dependent manner, and the acidity showed higher the RNA level and surface antigenicity than neutral pH. Conclusion: This study clearly shows that the non-host humoral milieu such as mouse, and DMEM decreases the RNA level and surface antigenicity, clinically implying the decremental infectivity of HCV virions. This is the frst note to tune HCV viability via conditioning only host humoral milieu free of genetic approach.

Choi, Da Hyeon;Lee, Jue-Yeon;Nam, Jae-Hwan;Kim, Yang-Hoon;Park, Yoon Jeong;Park, Yoon Shin

doi: 10.1007/s13273-019-0028-6pmid: N/A

Abstract Backgrounds: Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. However, little is known about the molecular mechanisms of HCC development, progression, or effective therapeutic approaches. Recently, granulin-epithelin precursor (GEP) has been suggested as a novel factor that can control HCC cell proliferation. Thus, we aimed to develop new cell-permeable and stable genetic agents that can control GEP expression in HepG2 cells. Methods: Small interfering RNA-GEP (GEP siRNA) was used for the development of therapeutic agents for HCC treatment. GEP siRNA was first modified by adding polyethylene glycol (PEG) at the terminus. Arginine-rich peptide (ARP) was chemically conjugated with PEGylated GEP siRNA. Chemical conjugates of GEP siRNA-PEG-ARP were evaluated for cytotoxicity and bioavailability, including stability against DNase I enzymatic activity and GSH. The conjugate was further evaluated for intracellular distribution and cell proliferation effects. Results: The optimal conjugation ratio of GEP siRNA to ARP was a 1:10 molar ratio, and stability was confirmed using DNase I and glutathione stability assays. Conjugates showed increased intracellular uptake and distribution in HepG2 cells. Interestingly, HepG2 cells treated with conjugates showed significantly decreased cell proliferation. Conclusion: These results provide insights into the importance of chemical modification of unstable genetic therapeutics for HCC treatment. Conjugation of PEGylated GEP siRNA with ARP may be a potential HCC therapeutic agent.

Su, Zhonghao;Dong, Zhuo;Guo, Chunxia;Xu, Ying;Shao, Shuijin;Qin, Zhenxia

doi: 10.1007/s13273-019-0029-5pmid: N/A

Abstract Backgrounds: β-Amyloid (Aβ) is a principal constituent of senile plaques in Alzheimer’s disease (AD) and induces neuronal cell death. The molecular mechanism of how Aβ evokes neuronal cell death remains complicated, which were investigated in the present study. Methods: Using the human neuroblastoma cell line SHSY5Y, we investigated the neurotoxic effects of human β-Amyloid 1–42 (Aβ1–42) aggregates on gene expression profile and protein expression profile by using the Agilent GeneChip Human 1A (V2) Oligo MicroArray, Quantitative Real-time PCR, PF-2D and Western blot analysis. Results: Our results show that Aβ1–42 specifically influences gene and protein expression such as EGR1, eIF5A, PDE8A, ERp57 and ERp5 in pathways associated with apoptotic process, protein translation, cAMP catabolic process and response to endoplasmic reticulum stress. Conclusion: Although Genes with significant changes in transcriptomic analysis matched very few of the proteins identified in proteomics analysis, our findings will strengthen our knowledge concerning the molecular mechanisms underlying AD.

Ryu, A-Reum;Lee, Mi-Young

doi: 10.1007/s13273-019-0030-zpmid: N/A

Abstract Backgrounds: Atopic dermatitis (AD) is a chronic, inflammatory, and relapsing skin disorder that occurs due to a Th1/Th2 cytokine imbalance and an elevation of immunoglobulin E (IgE) levels. We investigated whether chlorin e6 (Ce6)-mediated photodynamic therapy (PDT), which is commonly used for the clinical treatment of several cancers and non-neoplastic skin disorders, has a therapeutic effect on AD. Methods: β-hexosaminidase assay was performed in RBL-2H3 stimulated by DNP-BSA. Total IgE levels and serum cytokine levels were analyzed by ELISA assay. Eosinophils and mast cells were analyzed by hematoxylin- eosin stain and toluidine blue stain on ear of AD mouse model. Results: Ce6-mediated PDT significantly reduced the secretion of β-hexosaminidase in DNP-BSA-stimulated RBL-2H3 cells. In a DNCB-induced AD-like mouse model, serum IFN-γ was found to be elevated in conjunction with reduced IL-4 following Ce6-mediated PDT. The DNCB-induced serum IgE level was also reduced following Ce6-mediated PDT. In addition, DNCB-induced infiltration of eosinophils and mast cells was decreased by Ce6-mediated PDT in the mouse ear. Conclusion: Ce6-mediated PDT might be used as a potent therapeutics for AD via restoring Th1/Th2 balance and reducing over expressed immune cells.

Yun, So Yoon;Kim, Ju Yeun;Back, Moon Jung;Kim, Hee Soo;Ha, Hae Chan;Jang, Ji Min;Kim, Dae Kyong

doi: 10.1007/s13273-019-0031-ypmid: N/A

Abstract Backgrounds: Drug-induced liver injury (DILI) is a major causal factor for failure in clinical trials and withdrawal of drugs from pharmaceutical markets. Therefore, a human cell-based in vitro system has been established to overcome the limitations of preclinical trials. However, previous studies focused on the drug metabolism in each cell line or described to be superior in one single cell line for assessing DILI. In this study, we used Huh7, HepaRG, and Hepatosight-S cells to evaluate the liver toxicity and dysfunction driven by DILI-inducing drugs. Methods: Cytotoxicity of 17 DILI-inducing drugs was assessed by LDH release assay and the drug-induced liver dysfunction was confirmed by albumin secretion. Furthermore, we analyzed the expression levels of phase I and phase II enzymes and nuclear receptors in each cell lines. Results: DILI-inducing drugs were differently detected in each cell line because each cell line differs on the expression of drug metabolic enzymes which associated with reactivity on DILI inducing drugs. Conclusion: To predict the responses of DILI-inducing drugs in human liver cells, using diverse cell lines having different drug metabolic capabilities is more suitable for predicting DILI.

Wang, Xia;Zhao, Hongqin;Yang, Shaonan;Shao, Xiaojun;Nie, Shumin;Pan, Xudong

doi: 10.1007/s13273-019-0032-xpmid: N/A

Abstract Backgrounds: Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) is an lncRNA that has been suggested as a key regulator in the onset of atherosclerosis (AS). This study described the role of MAL-AT1 in oxidized low density lipoprotein (ox-LDL)-induced endothelial cells death. Methods: Human umbilical vein endothelial cells (HU-VECs) were subjected to ox-LDL, before which the expression of MALAT1 was overexpressed by transfection. CCK-8 assay, flow cytometer detection, and western blot were carried out to evaluate cell viability, apoptosis and autophagy. qRT-PCR and western blot analyses were performed to investigate the regulatory relationship between MALAT1, Matrix Gla protein (MGP) and mTOR signaling to decode the underlying mechanism. Results: Up-regulation of MALAT1 attenuated ox-LDL-induced HUVECs lose, as evidenced by the promoted cell viability, and the decreased apoptosis rate. This finding was coupled with the down-regulated p53, Bax, active-caspase-3, Beclin-1 and LC3-II, as well as the up-regulated Bcl-2 and p62. Meanwhile, MALAT1 up-regulation promoted the phosphorylation of p70S6K and mTOR, and the expression of MGP. MGP up-regulation exhibited MALAT1-like propoties in preventing ox-LDL-induced cell death and mTOR deactivation. Of contrast, MGP silence affected HUVECs survival and mTOR signaling resulted in contrary impacts. Conclusion: The present work described that MALAT1 up-regulation prevented ox-LDL-mediated apoptosis and autophagy in HUVECs. The protective effects of MALAT1 might be partially via up-regulating MGP, which led to the activation of mTOR signaling.

Kwak, Hyun-Jeong;Um, Jae-Young;Lee, Sang-Seob

doi: 10.1007/s13273-019-0033-9pmid: N/A

Abstract Backgrounds: Nitric oxide (NO) plays a key role in cardioprotection. Its role against cardioprotection is dependent on the level of NO. Although it is well known that NO preconditioning has cardioprotective effects, but its mechanism remains unsatisfactory. Methods: To induce NO preconditioning, H9c2 cells were treated with low NO concentration and subsequently induced apoptosis by high NO. The signalling and anti-apoptotic effects of NO preconditioning were monitored by Western blotting, facs analysis. Results: Sodium nitroprusside (SNP)-induced cytotoxicity was inhibited by low SNP (0.3 mM) preconditioning. Furthermore, low SNP phosphorylated Akt/FoxO1 in the presence of high SNP (1.5 mM), while phosphorylated Akt/FoxO1 and viability were reversed by PI3K inhibitor. Also, low NO-induced CREB phosphorylation with high NO was inhibited by PKA inhibitor, indicating that NO preconditioning protects NO-induced cytotoxicity in PKA dependently. Apoptotic inhibition with NO preconditioning was accompanied with increased Bcl-2, decreased Bax, and caspase3 activation, which was all reversed by LY294002. Conclusion: Our results indicate that low NO preconditioning prevent subsequent high NO-induced apoptosis via Akt/PKA/CREB activation in H9c2 cells.

Lee, Gihyun;Kang, Geun-Hyung;Bae, Hyunsu

doi: 10.1007/s13273-019-0034-8pmid: N/A

Abstract Backgrounds: Bee venom has been used as an alternative medicine for immune-related diseases such as multiple sclerosis (MS). Previously, we showed that Bee venom exerts a therapeutic effect in a mouse model of MS through regulatory T cells (Tregs) and Phospholipase A2 from bee venom (bvPLA2) induces a differentiation of Tregs. Methods: To induce EAE, C57BL/6 mice were injected MOG35-55 peptide in CFA and pertussis toxin. To ascertain whether Tregs were involved in the neural protective effect of bvPLA2, the mice received a PC61 an-ti-CD25 mAb to deplete Tregs or normal anti-rat IgG1 for an isotype control. To verify the necessity of enzymatic activity experimentally, we synthesized a recombinant bvPLA2 and mutant bvPLA2, which has no catalytic ability. Results: The limb paralysis caused by EAE was significantly attenuated in the bvPLA2-treated mice compared to the PBS-treated mice. The beneficial effects of bvPLA2 disappeared when Tregs were depleted. Synthetic bvPLA2 showed therapeutic effects such as those of the natural bvPLA2; however, the mutant which has no catalytic ability did not. Conclusion: Our findings suggest that bvPLA2 contributes to the control of MS and that its catalytic ability is needed for its therapeutic action.

Park, Chang-Beom;Jung, Jae-Woong;Yeom, Dong-Hyuk;Jang, Jiyi;Park, Jin-Woo;Kim, Young Jun

doi: 10.1007/s13273-019-0035-7pmid: N/A

Abstract Backgrounds: The concern in the toxicological impact of nanomaterials on aquatic organisms has grown, due to the high adsorption capacity for (in) organic compounds in the aquatic environment. In order to evaluate the toxicity of mixtures composed with metal ion and metal oxide nanoparticles and the interaction between components in binary mixtures, we tested the mixture toxicity of iron oxide nanoparticles (i.e., PVP-Fe3O4 NPs) and zinc sulfate (ZnSCU) on Daphnia magna. Methods: The toxicity of binary mixtures with different concentration-combinations were identified by the effective concentration values (ECxmix) based on the concentration-response curves. Concentration addition index (CAI) and effect addition index (EAI) were applied for examining the interaction between components in binary mixtures. Results: The findings from this study implied the ZnSO4 had a high toxic effect on D. magna more than PVP-Fe3O4 NPs and the synergistic toxicity in binary mixtures were depended on the toxic effects of ZnSO4 and their exposure concentration rather than those of PVP-Fe3O4 NPs. Interestingly, the antagonistic effects between ZnSO4 and PVP-Fe3O4 NPs in binary mixtures showed in the high concentration-combinations suggesting that antagonism in toxicity may be due to the high adsorption capacity of PVP-Fe3O4 NPs for organic compounds. Conclusion: In this study, synergistic- and antagonistic effects in binary mixtures with various concentrationcombinations will provide important information for elucidating the toxicity mechanism of mixtures composed inorganic compounds and metal oxide nanoparticles (MONPs). However, in order to conduct the risk assessment of environmental nanoparticle, further studies regarding the mixture toxicity of nanomaterials with environmentally relevant concentrations and the interaction between components will be required.