AIM:To characterize how insulin-like growth factor 2(IGF2)m RNA binding protein p62/IMP2-2 promotes steatohepatitis in the absence of dietary cholesterol.METHODS:Non-alcoholic ...steatohepatitis(NASH)was induced in wild-type mice and in mice overexpressing p62 specifically in the liver by feeding the mice a methionine and choline deficient(MCD)diet for either two or four weeks.As a control,animals were fed a methionine and choline supplemented diet.Serum triglycerides,cholesterol,glucose,aspartate aminotransferase and alanine transaminase were determined by standard analytical techniques.Hepatic gene expression was determined by real-time reverse transcription-polymerase chain reaction.Generation of reactive oxygen species in liver tissue was quantified as thiobarbituric acid reactive substances using a photometric assay and malondialdehyde as a standard.Tissue fatty acid profiles and cholesterol levels were analyzed by gas chromatographymass spectrometry after hydrolysis.Hepatocellular iron accumulation was determined by Prussian blue staining in paraffin-embedded formalin-fixed tissue.Filipin staining on frozen liver tissue was used to quantify hepatic free cholesterol levels.Additionally,nuclear localization of the nuclear factor kappa B(NF-κB)subunit p65 was examined in frozen tissues.RESULTS:Liver-specific overexpression of the insulin-like growth factor 2 m RNA binding protein 2-2(IGF2BP2-2/IMP2-2/p62)induces steatosis with regular chow and amplifies NASH-induced fibrosis in the MCD mouse model.Activation of NF-κB and expression of NF-κB target genes suggested an increased inflammatory response in p62 transgenic animals.Analysis of hepatic lipid composition revealed an elevation of monounsaturated fatty acids as well as increased hepatic cholesterol.Moreover,serum cholesterol was significantly elevated in p62 transgenic mice.Dietary cholesterol represents a critical factor for the development of NASH from hepatic steatosis.Filipin staining revealed increased free cholesterol in p62 transgenic livers,which were not diet-derived.The m RNA levels of the rate-limiting enzyme for cholesterol synthesis 3-hydroxy-3-methyl-glutaryl-Co A reductase(HMG-Co A reductase or HMGCR)were not significantly upregulated,potentially due to increased cholesterol biosynthesis via elevated sterol regulatory element binding transcription factor 2(SREBF2)gene expression and increased irondeposition in transgenic animals.CONCLUSION:This study provides evidence that p62/IGF2BP2-2 drives the progression of NASH through elevation of hepatic iron deposition and increased production of hepatic free cholesterol.
Non-alcoholic steatohepatitis (NASH) represents a risk factor for the development of hepatocellular carcinoma (HCC) and is characterized by quantitative and qualitative changes in hepatic lipids. ...Since elongation of fatty acids from C16 to C18 has recently been reported to promote both hepatic lipid accumulation and inflammation we aimed to investigate whether a frequently used mouse NASH model reflects this clinically relevant feature and whether C16 to C18 elongation can be observed in HCC development. Feeding mice a methionine and choline deficient diet to model NASH not only increased total hepatic fatty acids and cholesterol, but also distinctly elevated the C18/C16 ratio, which was not changed in a model of simple steatosis (ob/ob mice). Depletion of Kupffer cells abrogated both quantitative and qualitative methionine-and-choline deficient (MCD)-induced alterations in hepatic lipids. Interestingly, mimicking inflammatory events in early hepatocarcinogenesis by diethylnitrosamine-induced carcinogenesis (48 h) increased hepatic lipids and the C18/C16 ratio. Analyses of human liver samples from patients with NASH or NASH-related HCC showed an elevated expression of the elongase ELOVL6, which is responsible for the elongation of C16 fatty acids. Taken together, our findings suggest a detrimental role of an altered fatty acid pattern in the progression of NASH-related liver disease.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The insulin-like growth factor 2 (
IGF2
) mRNA binding proteins (IMPs/IGF2BPs) IMP1 and 3 are regarded as oncofetal proteins, whereas the hepatic IMP2 expression in adults is controversially ...discussed. The splice variant IMP2-2/p62 promotes steatohepatitis and hepatocellular carcinoma. Aim of this study was to clarify whether IMP2 is expressed in the adult liver and influences progression toward cirrhosis. IMP2 was expressed at higher levels in embryonic compared to adult tissues as quantified in embryonic, newborn, and adult C57BL/6J mouse livers and suggested by analysis of publicly available human data. In an
IMP2-2
transgenic mouse model microarray and qPCR analyses revealed increased expression of liver progenitor cell (LPC) markers
Bex1, Prom1, Spp1
, and
Cdh1
indicating a de-differentiated liver cell phenotype. Induction of these LPC markers was confirmed in human cirrhotic tissue datasets. The LPC marker SPP1 has been described to play a major role in fibrogenesis. Thus, DNA methylation was investigated in order to decipher the regulatory mechanism of
Spp1
induction. In
IMP2-2
transgenic mouse livers single CpG sites were differentially methylated, as quantified by amplicon sequencing, whereas human HCC samples of a human publicly available dataset showed promoter hypomethylation. In order to study the impact of IMP2 on fibrogenesis in the context of steatohepatitis wild-type or
IMP2-2
transgenic mice were fed either a methionine-choline deficient (MCD) or a control diet for 2–12 weeks. MCD-fed
IMP2-2
transgenic mice showed a higher incidence of ductular reaction (DR), accompanied by hepatic stellate cell activation, extracellular matrix (ECM) deposition, and induction of the LPC markers
Spp1, Cdh1
, and
Afp
suggesting the occurrence of de-differentiated cells in transgenic livers. In human cirrhotic samples
IMP2
overexpression correlated with LPC marker and ECM component expression. Progression of liver disease was induced by combined MCD and diethylnitrosamine (DEN) treatment. Combined MCD-DEN treatment resulted in shorter survival of
IMP2-2
transgenic compared to wild-type mice. Only
IMP2-2
transgenic livers progressed to cirrhosis, which was accompanied by strong DR. In conclusion, IMP2 is an oncofetal protein in the liver that promotes DR characterized by de-differentiated cells toward steatohepatitis-associated cirrhosis development with poor survival.
Workers in the chemical industry are often required to wear protective suits while performing tasks. While these suits can be life saving, they increase the difficulty and discomfort faced by the ...wearer. This research explores the performance of individuals wearing the highly cumbersome Level A suit. The suits are heat-retentive and can cause fatigue that affects performance by increasing response time and decreasing accuracy. Members of Missouri’s Civil Support Team (CST) served as subjects for this research. They conducted fine and gross motor tests. Their completion time and accuracy were evaluated both out-of-suit and in-suit for the Level A chemical protective suits.
A
t-test was conducted to evaluate the effect of the Level A suits on performance. Results showed a significant increase in completion time and errors for gross motor tasks. This type of task had up to a 103% increase in time required and up to a 34% decrease in accuracy. The suit’s impact on fine motor skill was also significant, but to a lesser extent. Repeated measures test was performed to evaluate any potential time-in-suit effect. A decrease in mean task completion time was observed for some of the tasks. There was a corresponding decrease in accuracy but no consistent time-in-suit effect was identified.
The results indicate the need for care when designing procedures and equipement to be used by humans wearing restrictive PPE. It is important to take human limitations into consideration in the design phase in order to decrease the need for human adaptation and increase system safety. To achieve this, understanding human factors is imperative when designing equipment, tasks, or procedures for workers wearing PPE.
► The chemical protective suits reduce risks but make work more difficult for the user. ► We show a significant increase in completion time and errors for gross motor tasks. ► Fine motor skills are impacted to a lesser extent for workers in the suits. ► These challenges matter when designing work requiring these protective suits.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
AIM: To establish a simple method to quantify lipid classes in liver diseases and to decipher the lipid profile in p62/IMP2-2/IGF2BP2-2 transgenic mice.METHODS: Liver-specific overexpression of the ...insulin-like growth factor 2 mRNA binding protein p62/IMP2-2/IGF2BP2-2 was used as a model for steatosis.Steatohepatitis was induced by feeding a methioninecholine deficient diet. Steatosis was assessed histologically. For thin layer chromatographic analysis, lipids were extracted from freeze-dried tissues by hexane/2-propanol, dried, redissolved, and chromatographically separated by a two-solvent system. Dilution series of lipid standards were chromatographed, detected, andquantified. The detection was performed by either2’,7’-dichlorofluoresceine or a sulfuric acid/ethanol mixture.RESULTS: Histological analyses confirmed steatosis and steatohepatitis development. The extraction,chromatographic, and detection method showed high inter-assay reproducibility and allowed quantification of the different lipid classes. The analyses confirmed an increase of triglycerides and phosphatidylethanolamine and a decrease in phosphatidylcholine in the methionine-choline deficient diet. The method was used for the first time to asses the lipid classes induced in the p62-overexpressing mouse model and showed a significant increase in all detected lipid species with a prominent increase of triglycerides by 2-fold. Interestingly, the ratio of phosphatidylcholine to phosphatidylethanolamine was decreased, as previously suggested as a marker in the progression from steatosis to steatohepatitis.CONCLUSION: The thin layer chromatography analysis allows a reliable quantification of lipid classes and provides detailed insight into the lipogenic effect of p62.
Superparamagnetic iron oxide nanoparticles (SPION) are widely used both clinically and experimentally for diverse in vivo applications, such as contrast enhancement in magnetic resonance imaging, ...hyperthermia and drug delivery. Biomedical applications require particles to have defined physical and chemical properties, and to be stable in biological media. Despite a suggested low cytotoxic action, adverse reactions of SPION in concentrations relevant for biomedical use have not yet been studied in sufficient detail. In the present work we employed Endorem®, dextran-stabilized SPION approved as an intravenous contrast agent, and compared its action to a set of other nanoparticles with potential for magnetic resonance imaging applications. SPION in concentrations relevant for in vivo applications were rapidly taken up by endothelial cells and exhibited no direct cytotoxicity. Electric cell impedance sensing measurements demonstrated that SPION, but not BaSO4/Gd nanoparticles, impaired endothelial integrity, as was confirmed by increased intercellular gap formation in endothelial monolayers. These structural changes induced the subcellular translocation and inhibition of the cytoprotective and anti-atherosclerotic enzyme endothelial NO-synthase and reduced NO production. Lipopolysaccharide-induced inflammatory NO production of macrophages was not affected by SPION. In conclusion, our data suggest that SPION might substantially alter endothelial integrity and function at therapeutically relevant doses, which are not cytotoxic.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To meet societal needs, modern estuarine science needs to be interdisciplinary and collaborative, combine discovery with hypotheses testing, and be responsive to issues facing both regional and ...global stakeholders. Such an approach is best conducted with the benefit of data-rich environments, where information from sensors and models is openly accessible within convenient timeframes. Here, we introduce the operational infrastructure of one such data-rich environment, a collaboratory created to support (a) interdisciplinary research in the Columbia River estuary by the multi-institutional team of investigators of the Science and Technology Center for Coastal Margin Observation & Prediction and (b) the integration of scientific knowledge into regional decision making. Core components of the operational infrastructure are an observation network, a modeling system and a cyber-infrastructure, each of which is described. The observation network is anchored on an extensive array of long-term stations, many of them interdisciplinary, and is complemented by on-demand deployment of temporary stations and mobile platforms, often in coordinated field campaigns. The modeling system is based on finiteelement unstructured-grid codes and includes operational and process-oriented simulations of circulation, sediments and ecosystem processes. The flow of information is managed through a dedicated cyber-infrastructure, conversant with regional and national observing systems.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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