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At least 1,333 records · Page 74

Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles

Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10–200 μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24 h. The results showed that Ag NPs evoked significant toxicity in hESC-derived NPCs at 24 h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans. - Highlights: • This system served as a suitable model for developmental neurotoxicity testing. • Ag NPs induce the apoptosis in human neural cells by ROS generation. • Genes for development of neurons were dysregulated in response to Ag NPs. • Molecular events during early developmental neurotoxicity were proposed.

60 APPLIED LIFE SCIENCES↗

Comparison of the inhibitory effects of tolcapone and entacapone against human UDP-glucuronosyltransferases

Tolcapone and entacapone are two potent catechol-O-methyltransferase (COMT) inhibitors with a similar skeleton and displaying similar pharmacological activities. However, entacapone is a very safe drug used widely in the treatment of Parkinson's disease, while tolcapone is only in limited use for Parkinson's patients and needs careful monitoring of hepatic functions due to hepatotoxicity. This study aims to investigate and compare the inhibitory effects of entacapone and tolcapone on human UDP-glucosyltransferases (UGTs), as well as to evaluate the potential risks from the view of drug-drug interactions (DDI). The results demonstrated that both tolcapone and entacapone exhibited inhibitory effects on UGT1A1, UGT1A7, UGT1A9 and UGT1A10. In contrast to entacapone, tolcapone exhibited more potent inhibitory effects on UGT1A1, UGT1A7, and UGT1A10, while their inhibitory potentials against UGT1A9 were comparable. It is noteworthy that the inhibition constants (K{sub i}) of tolcapone and entacapone against bilirubin-O-glucuronidation in human liver microsomes (HLM) are determined as 0.68 μM and 30.82 μM, respectively, which means that the inhibition potency of tolcapone on UGT1A1 mediated bilirubin-O-glucuronidation in HLM is much higher than that of entacapone. Furthermore, the potential risks of tolcapone or entacapone via inhibition of human UGT1A1 were quantitatively predicted by the ratio of the areas under the plasma drug concentration-time curve (AUC). The results indicate that tolcapone may result in significant increase in AUC of bilirubin or the drugs primarily metabolized by UGT1A1, while entacapone is unlikely to cause a significant DDI through inhibition of UGT1A1. - Highlights: • Tolcapone and entacapone exhibited preferential inhibition against UGT1A enzymes. • In contrast to entacapone, tolcapone exhibited more potent inhibitory effects on human UGT1A1, 1 A7 and 1 A10. • Tolcapone may lead to significant increase in AUC of bilirubin. • This study provided new insights into the underlying mechanisms of tolcapone induced hepatotoxicity.

60 APPLIED LIFE SCIENCES↗

Smoking-related microRNAs and mRNAs in human peripheral blood mononuclear cells

Teenager smoking is of great importance in public health. Functional roles of microRNAs have been documented in smoke-induced gene expression changes, but comprehensive mechanisms of microRNA-mRNA regulation and benefits remained poorly understood. We conducted the Teenager Smoking Reduction Trial (TSRT) to investigate the causal association between active smoking reduction and whole-genome microRNA and mRNA expression changes in human peripheral blood mononuclear cells (PBMC). A total of 12 teenagers with a substantial reduction in smoke quantity and a decrease in urine cotinine/creatinine ratio were enrolled in genomic analyses. In Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA), differentially expressed genes altered by smoke reduction were mainly associated with glucocorticoid receptor signaling pathway. The integrative analysis of microRNA and mRNA found eleven differentially expressed microRNAs negatively correlated with predicted target genes. CD83 molecule regulated by miR-4498 in human PBMC, was critical for the canonical pathway of communication between innate and adaptive immune cells. Our data demonstrated that microRNAs could regulate immune responses in human PBMC after habitual smokers quit smoking and support the potential translational value of microRNAs in regulating disease-relevant gene expression caused by tobacco smoke. - Highlights: • We conducted a smoke reduction trial program and investigated the causal relationship between smoke and gene regulation. • MicroRNA and mRNA expression changes were examined in human PBMC. • MicroRNAs are important in regulating disease-causal genes after tobacco smoke reduction.

60 APPLIED LIFE SCIENCES↗

Assessment of the inhibitory effects of pyrethroids against human carboxylesterases

Pyrethroids are broad-spectrum insecticides that widely used in many countries, while humans may be exposed to these toxins by drinking or eating pesticide-contaminated foods. This study aimed to investigate the inhibitory effects of six commonly used pyrethroids against two major human carboxylesterases (CES) including CES1 and CES2. Three optical probe substrates for CES1 (DME, BMBT and DMCB) and a fluorescent probe substrate for CES2 (DDAB) were used to characterize the inhibitory effects of these pyrethroids. The results demonstrated that most of the tested pyrethroids showed moderate to weak inhibitory effects against both CES1 and CES2, but deltamethrin displayed strong inhibition towards CES1. The IC{sub 50} values of deltamethrin against CES1-mediated BMBT, DME, and DMCB hydrolysis were determined as 1.58 μM, 2.39 μM, and 3.3 μM, respectively. Moreover, deltamethrin was cell membrane permeable and capable of inhibition endogenous CES1 in living cells. Further investigation revealed that deltamethrin inhibited CES1-mediated BMBT hydrolysis via competitive manner but noncompetitively inhibited DME or DMCB hydrolysis. The inhibition behaviors of deltamethrin against CES1 were also studied by molecular docking simulation. The results demonstrated that CES1 had at least two different ligand-binding sites, one was the DME site and another was the BMBT site which was identical to the binding site of deltamethrin. In summary, deltamethrin was a strong reversible inhibitor against CES1 and it could tightly bind on CES1 at the same ligand-binding site as BMBT. These findings are helpful for the deep understanding of the interactions between xenobiotics and CES1. - Highlights: • The inhibitory effects of six commonly used pyrethroids on human carboxylesterases were investigated. • Deltamethrin displayed strong inhibitory effects against human carboxylesterase 1 (CES1). • Deltamethrin was cell membrane permeable and could inhibit intracellular CES1 in living cells. • Both experimental and docking studies demonstrated that CES1 had at least two different ligand-binding sites.

60 APPLIED LIFE SCIENCES↗

Species-specific effects of neuregulin-1β (cimaglermin alfa) on glucose handling in animal models and humans with heart failure

Neuregulin-1β is a member of the neuregulin family of growth factors and is critically important for normal development and functioning of the heart and brain. A recombinant version of neuregulin-1β, cimaglermin alfa (also known as glial growth factor 2 or GGF2) is being investigated as a possible therapy for heart failure. Previous studies suggest that neuregulin-1β stimulation of skeletal muscle increases glucose uptake and, specifically, sufficient doses of cimaglermin alfa acutely produce hypoglycemia in pigs. Since acute hypoglycemia could be a safety concern, blood glucose changes in the above pig study were further investigated. In addition, basal glucose and glucose disposal were investigated in mice. Finally, as part of standard clinical chemistry profiling in a single ascending-dose human safety study, blood glucose levels were evaluated in patients with heart failure after cimaglermin alfa treatment. A single intravenous injection of cimaglermin alfa at doses of 0.8 mg/kg and 2.6 mg/kg in mice resulted in a transient reduction of blood glucose concentrations of approximately 20% and 34%, respectively, at 2 h after the treatment compared to pre-treatment levels. Similar results were observed in diabetic mice. Treatment with cimaglermin alfa also increased blood glucose disposal following oral challenge in mice. However, no significant alterations in blood glucose concentrations were found in human heart failure patients at 0.5 and 2 h after treatment with cimaglermin alfa over an equivalent human dose range, based on body surface area. Taken together, these data indicate strong species differences in blood glucose handling after cimaglermin alfa treatment, and particularly do not indicate that this phenomenon should affect human subjects. - Highlights: • Cimaglermin alfa acutely reduced blood glucose levels in pigs, less so in mice. • Cimaglermin alfa did not reduce blood glucose levels in heart failure patients. • Effects of cimaglermin alfa on blood glucose regulation are species-dependent.

60 APPLIED LIFE SCIENCES↗

Current nonclinical testing paradigm enables safe entry to First-In-Human clinical trials: The IQ consortium nonclinical to clinical translational database

The contribution of animal testing in drug development has been widely debated and challenged. An industry-wide nonclinical to clinical translational database was created to determine how safety assessments in animal models translate to First-In-Human clinical risk. The blinded database was composed of 182 molecules and contained animal toxicology data coupled with clinical observations from phase I human studies. Animal and clinical data were categorized by organ system and correlations determined. The 2 × 2 contingency table (true positive, false positive, true negative, false negative) was used for statistical analysis. Sensitivity was 48% with a 43% positive predictive value (PPV). The nonhuman primate had the strongest performance in predicting adverse effects, especially for gastrointestinal and nervous system categories. When the same target organ was identified in both the rodent and nonrodent, the PPV increased. Specificity was 84% with an 86% negative predictive value (NPV). The beagle dog had the strongest performance in predicting an absence of clinical adverse effects. If no target organ toxicity was observed in either test species, the NPV increased. While nonclinical studies can demonstrate great value in the PPV for certain species and organ categories, the NPV was the stronger predictive performance measure across test species and target organs indicating that an absence of toxicity in animal studies strongly predicts a similar outcome in the clinic. These results support the current regulatory paradigm of animal testing in supporting safe entry to clinical trials and provide context for emerging alternate models. - Highlights: • Translational database created to determine animal to human safety concordance. • 182 molecules with animal and clinical data; concordance parameters determined • Positive predictive value of 43%; Negative predictive value of 86% • Absence of toxicity in animal study strongly predicts similar outcome in the clinic. • Database supports animal testing to ensure human safety in the clinic.

60 APPLIED LIFE SCIENCES↗

Replication-competent human adenovirus 11p vectors can propagate in Vero cells

The use of continuous cell lines derived from the African green monkey kidney (AGMK) has led to major advances in virus vaccine development. However, to date, these cells have not been used to facilitate the creation of human adenoviruses because most human adenoviruses undergo abortive infections in them. Here, we report the susceptibility of AGMK-derived cells to adenovirus 11p (Ad11p) infection. First, we showed that CD46 molecules, which act as receptors for Ad11p, are expressed in AGMK cells. We then monitored Ad11p replication by measuring GFP expression as an indicator of viral transcription. We found that AGMK-derived cells were as capable as carcinoma cells at propagating full-length replication-competent Ad11p (RCAd11p) DNA. Of the AGMK cell lines tested, Vero cells had the greatest capacity for adenovirus production. Thus, AGMK cells can be used to evaluate RCAd11p-mediated gene delivery, and Vero cells can be used for the production of RCAd11pGFP vectors at relatively high yields. - Highlights: • Africa green monkey cell lines were monitored for human adenovirus 11p GFP vector infection. • Human CD46 molecules were detectable in these monkey cell lines. • Adenovirus 11p GFP vector can be propagated in Vero cells increases the safety of Ad11p-based vectors for clinical trials. • To use Vero cells for preparation of Ad11p vector avoids the potential inclusion of oncogenes from tumor cells.

60 APPLIED LIFE SCIENCES↗

Polyamine and methionine adenosyltransferase 2A crosstalk in human colon and liver cancer

Methionine adenosyltransferase (MAT) is an essential enzyme that is responsible for the biosynthesis of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. MAT1A is expressed in normal liver and MAT2A is expressed in all extrahepatic tissues. MAT2A expression is increased in human colon cancer and in colon cancer cells treated with mitogens, whereas silencing MAT2A resulted in apoptosis. The aim of the current work was to examine the mechanism responsible for MAT2A-dependent growth and apoptosis. We found that in RKO (human adenocarcinoma cell line) cells, MAT2A siRNA treatment lowered cellular SAMe and putrescine levels by 70–75%, increased apoptosis and inhibited growth. Putrescine supplementation blunted significantly MAT2A siRNA-induced apoptosis and growth suppression. Putrescine treatment (100 pmol/L) raised MAT2A mRNA level to 4.3-fold of control, increased the expression of c-Jun and c-Fos and binding to an AP-1 site in the human MAT2A promoter and the promoter activity. In human colon cancer specimens, the expression levels of MAT2A, ornithine decarboxylase (ODC), c-Jun and c-Fos are all elevated as compared to adjacent non-tumorous tissues. Overexpression of ODC in RKO cells also raised MAT2A mRNA level and MAT2A promoter activity. ODC and MAT2A are also overexpressed in liver cancer and consistently, similar MAT2A-ODC-putrescine interactions and effects on growth and apoptosis were observed in HepG2 cells. In conclusion, there is a crosstalk between polyamines and MAT2A. Increased MAT2A expression provides more SAMe for polyamines biosynthesis; increased polyamine (putrescine in this case) can activate MAT2A at the transcriptional level. This along with increased ODC expression in cancer all feed forward to further enhance the proliferative capacity of the cancer cell. -- Highlights: • MAT2A knockdown depletes putrescine and leads to apoptosis. • Putrescine attenuates MAT2A knockdown-induced apoptosis and growth suppression. • Putrescine induces AP-1, which activates MAT2A promoter to increase its expression. • Putrescine increases ornithine decarboxylase expression, which induce MAT2A promoter. • Expression of MAT2A correlates with that of ornithine decarboxylase in colon cancer.

60 APPLIED LIFE SCIENCES↗

Simvastatin rises reactive oxygen species levels and induces senescence in human melanoma cells by activation of p53/p21 pathway

Recent studies demonstrated that simvastatin has antitumor properties in several types of cancer cells, mainly by inducing apoptosis and inhibiting growth. The arrest of proliferation is a feature of cellular senescence; however, the occurrence of senescence in melanoma cells upon simvastatin treatment has not been investigated until now. Our results demonstrated that exposure of human metastatic melanoma cells (WM9) to simvastatin induces a senescent phenotype, characterized by G1 arrest, positive staining for senescence-associated β-galactosidase assay, and morphological changes. Also, the main pathways leading to cell senescence were examined in simvastatin-treated human melanoma cells, and the expression levels of phospho-p53 and p21 were upregulated by simvastatin, suggesting that cell cycle regulators and DNA damage pathways are involved in the onset of senescence. Since simvastatin can act as a pro-oxidant agent, and oxidative stress may be related to senescence, we measured the intracellular ROS levels in WM9 cells upon simvastatin treatment. Interestingly, we found an increased amount of intracellular ROS in these cells, which was accompanied by elevated expression of catalase and peroxiredoxin-1. Collectively, our results demonstrated that simvastatin can induce senescence in human melanoma cells by activation of p53/p21 pathway, and that oxidative stress may be related to this process. - Highlights: • Lower concentrations of simvastatin can induce senescent phenotype in melanoma cells. • Simvastatin induces senescence in human melanoma cells via p53/p21 pathway. • Senescent phenotype is related with increased intracellular ROS. • Partial detoxification of ROS by catalase/peroxiredoxin-1 could lead cells to senescence rather than apoptosis.

60 APPLIED LIFE SCIENCES↗

MiR-18a regulates the proliferation, migration and invasion of human glioblastoma cell by targeting neogenin

MiR-17-92 cluster has recently been reported as an oncogene in some tumors. However, the association of miR-18a, an important member of this cluster, with glioblastoma remains unknown. Therefore, this study aims to investigate the expression of miR-18a in glioblastoma and its role in biological behavior of U87 and U251 human glioblastoma cell lines. Quantitative RT-PCR results showed that miR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines compared with that in human brain tissues and primary normal human astrocytes, and the expression levels were increased along with the rising pathological grades of glioblastoma. Neogenin was identified as the target gene of miR-18a by dual-luciferase reporter assays. RT-PCR and western blot results showed that its expression levels were decreased along with the rising pathological grades of glioblastoma. Inhibition of miR-18a expression was established by transfecting exogenous miR-18a inhibitor into U87 and U251 cells, and its effects on the biological behavior of glioblastoma cells were studied using CCK-8 assay, transwell assay and flow cytometry. Inhibition of miR-18a expression in U87 and U251 cells significantly up-regulated neogenin, and dramatically suppressed the abilities of cell proliferation, migration and invasion, induced cell cycle arrest and promoted cellular apoptosis. Collectively, these results suggest that miR-18a may regulate biological behavior of human glioblastoma cells by targeting neogenin, and miR-18a can serve as a potential target in the treatment of glioblastoma. - Highlights: • MiR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines. • Neogenin was identified as the target gene of miR-18a. • Neogenin expressions were decreased along with the rising pathological grades of glioblastoma. • Inhibition of miR-18a suppressed biological behavior of glioma cells by up-regulating neogenin.

60 APPLIED LIFE SCIENCES↗

In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

60 APPLIED LIFE SCIENCES↗

SurR9C84A protects and recovers human cardiomyocytes from hypoxia induced apoptosis

Survivin, as an anti-apoptotic protein and a cell cycle regulator, is recently gaining importance for its regenerative potential in salvaging injured hypoxic cells of vital organs such as heart. Different strategies are being employed to upregulate survivin expression in dying hypoxic cardiomyocytes. We investigated the cardioprotective potential of a cell permeable survivin mutant protein SurR9C84A, for the management of hypoxia mediated cardiomyocyte apoptosis, in a novel and clinically relevant model employing primary human cardiomyocytes (HCM). The aim of this research work was to study the efficacy and mechanism of SurR9C84A facilitated cardioprotection and regeneration in hypoxic HCM. To mimic hypoxic microenvironment in vitro, well characterized HCM were treated with 100 µm (48 h) cobalt chloride to induce hypoxia. Hypoxia induced (HI) HCM were further treated with SurR9C84A (1 µg/mL) in order to analyse its cardioprotective efficacy. Confocal microscopy showed rapid internalization of SurR9C84A and scanning electron microscopy revealed the reinstatement of cytoskeleton projections in HI HCM. SurR9C84A treatment increased cell viability, reduced cell death via, apoptosis (Annexin-V assay), and downregulated free cardiac troponin T and MMP-9 expression. SurR9C84A also upregulated the expression of proliferation markers (PCNA and Ki-67) and downregulated mitochondrial depolarization and ROS levels thereby, impeding cell death. Human Apoptosis Array further revealed that SurR9C84A downregulated expression of pro-apoptotic markers and augmented expression of HSPs and HTRA2/Omi. SurR9C84A treatment led to enhanced levels of survivin, VEGF, PI3K and pAkt. SurR9C84A proved non-toxic to normoxic HCM, as validated through unaltered cell proliferation and other marker levels. Its pre-treatment exhibited lesser susceptibility to hypoxia/damage. SurR9C84A holds a promising clinical potential for human cardiomyocyte survival and proliferation following hypoxic injury. - Highlights: • Protection/regeneration of dying myocardium post myocardial infarction is important. • Downregulation of survivin induces apoptosis in hypoxic human cardiomyocytes (HCM). • Bio-replenishment with SurR9-C84A reinstates HCM survival, recovery and growth. • SurR9-C84A targets mitochondrial depolarization, fcTnT and ROS generation in HCM. • SurR9-C84A upregulates survivin, PCNA, PI3K/Akt pathway, VEGF and HSP levels. • SurR9-C84A holds promise as a treatment and preventive agent to replenish survivin.

60 APPLIED LIFE SCIENCES↗

Hepatocyte nuclear factor 4A improves hepatic differentiation of immortalized adult human hepatocytes and improves liver function and survival

Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes, but insufficient differentiation and phenotypic instability restrict their clinical application. This study aimed to determine the role of hepatocyte nuclear factor 4A (HNF4A) in hepatic differentiation of IHH, and whether encapsulation of IHH overexpressing HNF4A could improve liver function and survival in rats with acute liver failure (ALF). Primary human hepatocytes were transduced with lentivirus-mediated catalytic subunit of human telomerase reverse transcriptase (hTERT) to establish IHH. Cells were analyzed for telomerase activity, proliferative capacity, hepatocyte markers, and tumorigenicity (c-myc) expression. Hepatocyte markers, hepatocellular functions, and morphology were studied in the HNF4A-overexpressing IHH. Hepatocyte markers and karyotype analysis were completed in the primary hepatocytes using shRNA knockdown of HNF4A. Nuclear translocation of β-catenin was assessed. Rat models of ALF were treated with encapsulated IHH or HNF4A-overexpressing IHH. A HNF4A-positive IHH line was established, which was non-tumorigenic and conserved properties of primary hepatocytes. HNF4A overexpression significantly enhanced mRNA levels of genes related to hepatic differentiation in IHH. Urea levels were increased by the overexpression of HNF4A, as measured 24 h after ammonium chloride addition, similar to that of primary hepatocytes. Chromosomal abnormalities were observed in primary hepatocytes transfected with HNF4A shRNA. HNF4α overexpression could significantly promote β-catenin activation. Transplantation of HNF4A overexpressing IHH resulted in better liver function and survival of rats with ALF compared with IHH. HNF4A improved hepatic differentiation of IHH. Transplantation of HNF4A-overexpressing IHH could improve the liver function and survival in a rat model of ALF. - Highlights: • Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes. • Hepatocyte nuclear factor 4A (HNF4A) plays a role in hepatic differentiation. • HNF4A improved hepatic differentiation of IHH. • Transplantation of HNF4A-overexpressing IHH could improve liver function.

60 APPLIED LIFE SCIENCES↗

Docetaxel promotes the generation of anti-tumorigenic human macrophages

Highlights: • Docetaxel does not induce monocyte derived Mo-MDSCs. • Docetaxel promotes the differentiation of monocytes into M1 macrophages. • Docetaxel increases the antigen presentation ability of myeloid cells. The taxanes Docetaxel and Paclitaxel are two of the standard chemotherapies for patients with metastatic breast cancer. The functional effect of Docetaxel and Paclitaxel on human innate immune cells of the myeloid lineage is not well established, nor is the effects these agents have on differentiation of monocytes into macrophages and dendritic cells. Therefore, the aim with this project was to determine the effects of Docetaxel and Paclitaxel on primary human monocyte differentiation, activation and function. For this purpose, primary human monocytes were isolated from healthy donors and cultured with or without Docetaxel and Paclitaxel. We found that Docetaxel promoted the differentiation of primary human monocytes into pro-inflammatory macrophages with an M1 phenotype and an ability to present antigens to T cells. Monocytes treated with Docetaxel also displayed an elevated secretion of IL-8 and IL-1β, but did not promote generation of monocytic myeloid-derived suppressor cells. In conclusion, Docetaxel appears to have an immune stimulatory effect that would be beneficial for an anti-tumorigenic type of immune response, whereas Paclitaxel seems to have less effect on myeloid cells.

60 APPLIED LIFE SCIENCES↗

The IRF9-SIRT1-P53 axis is involved in the growth of human acute myeloid leukemia

Highlights: • IRF9 expression is increased in human acute myeloid leukemia (AML). • IRF9 represses AML cell growth. • IRF9 induces AML cell apoptosis. • IRF9 inhibits the expression of SIRT1. • IRF9 promotes p53 deacetylation and regulates p53 target genes. Acute myeloid leukemia (AML) is a highly heterogeneous disease, with biologically and prognostically different subtypes. Although a growing number of distinct AML subsets have been increasingly characterized, patient management has remained disappointingly uniform. The molecular mechanism underlying AML needs to be further investigated. Here we identify IRF9 as a negative regulator of human AML. We show that IRF9 mRNA and protein levels are down-regulated in human AML samples compared with samples from healthy donors. IRF9 knockdown promotes proliferation, colony formation and survival of OCI/AML-2 and OCI/AML-3 cells, whereas IRF9 overexpression obtains oppose results. Mechanism analysis shows that IRF9 binds SIRT1 promoter and represses SIRT1 expression in OCI/AML-2 and OCI/AML-3 cells. In AML samples, the expression of SIRT1 is up-regulated and negatively correlated with IRF9 level. IRF9 also increases the acetylation of p53, a deacetylation substrate of SIRT1, and promotes the expression of p53 target genes. Knockdown of p53 blocks the effects of IRF9 on cell survival and growth in vitro. These findings provide evidence that IRF9 serves as an important regulator in human AML by repressing SIRT1-p53 pathway and that IRF9 may be a potential target for AML treatment.

60 APPLIED LIFE SCIENCES↗

Connexin 43 regulates the expression of wound healing-related genes in human gingival and skin fibroblasts

Highlights: • Cx43 distinctly forms gap junctions and hemichannels (HCs) in human skin and gingiva. • Compared to human gingival fibroblasts, skin fibroblasts contained few Cx43 HCs. • Cx43 distinctly regulates gene expression in human gingival and skin fibroblasts. Fibroblasts are the most abundant connective tissue cells and play an important role in wound healing. It is possible that faster and scarless wound healing in oral mucosal gingiva relative to skin may relate to the distinct phenotype of the fibroblasts residing in these tissues. Connexin 43 (Cx43) is the most ubiquitous Cx in skin (SFBLs) and gingival fibroblasts (GFBLs), and assembles into hemichannels (HCs) and gap junctions (GJs) on the cell membrane. We hypothesized that SFBLs and GFBLs display distinct expression or function of Cx43, and that this may partly underlie the different wound healing outcomes in skin and gingiva. Here we show that Cx43 distinctly formed Cx43 GJs and HCs in human skin and gingiva in vivo. However, in SFBLs, in contrast to GFBLs, only a small proportion of total Cx43 assembled into HC plaques. Using an in vivo-like 3D culture model, we further show that the GJ, HC, and channel-independent functions of Cx43 distinctly regulated wound healing-related gene expression in GFBLs and SFBLs. Therefore, the distinct wound healing outcomes in skin and gingiva may partly relate to the inherently different assembly and function of Cx43 in the resident fibroblasts.

60 APPLIED LIFE SCIENCES↗

The aging proteostasis decline: From nematode to human

The aging proteostasis decline manifests in a failure of aging cells and organisms to properly respond to proteotoxic challenges. This proteostasis collapse has long been considered a hallmark of aging in nematodes, and has recently been shown to occur also in human cells upon entry to senescence, opening the way to exploring the phenomenon in the broader context of human aging. Cellular senescence is part of the normal human physiology of aging, with senescent cell accumulation as a prominent feature of aged tissues. Being highly resistant to cell death, senescent cells, as they accumulate, become pro-inflammatory and promote disease. Here we discuss the causes of human senescence proteostasis decline, in view of the current literature on nematodes, on the one hand, and senescence, on the other hand. We review two major aspects of the phenomenon: (1) the decline in transcriptional activation of stress-response pathways, and (2) impairments in proteasome function. We further outline potential underlying mechanisms of transcriptional proteostasis decline, focusing on reduced chromatin dynamics and compromised nuclear integrity. Finally, we discuss potential strategies for reinforcing proteostasis as a means to improve organismal health and address the relationship to senolytics.

60 APPLIED LIFE SCIENCES↗

Metformin attenuates expression of angiogenic and inflammatory genes in human endometriotic stromal cells

Highlights: • Metformin reduced cell migration, and proliferation of endometriotic stromal cells. • Metformin attenuated the expression of angiogenic and inflammatory genes in human endometriotic stromal cells. • Metformin could be used as an effective adjuvant in endometriosis treatment. Endometriosis is a benign gynecological disease that is manifested by the presence and growth of endometrial cells and glands outside the uterine. Active angiogenesis, migration, and invasion of endometrial tissue outside the uterine are critical for the development of endometriosis and lead to the survival and growth of endometriotic lesions. Metformin, as an anti-diabetic agent, represents anti-angiogenic property. Here, we performed a study using human normal endometrial stromal cells (N-ESCs) from healthy endometrial tissue and human eutopic endometrial stromal cells (EU-ESCs) and ectopic endometrial stromal cells (ECT-ESCs) from endometriosis patients. ESCs were cultured and treated with different concentrations of Metformin (0–20 mmol/l) for 72 h to evaluate Metformin effect on cell viability, proliferation, migration was measured by methyl thiazolyl tetrazolium (MTT) assay and scratch test respectively as well as expression of angiogenesis and migration markers. The Metformin reduced cell migration, and proliferation of endometriotic stromal cells in a time and concentration dependently manner. Furthermore, Metformin attenuated the expression of angiogenic and inflammatory genes in human endometriotic stromal cells. The direct anti-proliferative effect on ECT-ESCs combined with the effects of Metformin on inflammatory and angiogenesis-related genes expression supports its therapeutic potential for endometriosis. Metformin could be used as an effective adjuvant in endometriosis treatment.

60 APPLIED LIFE SCIENCES↗