Effect of Biofilm Forming on the Migration of Di(2-ethylhexyl)phthalate from PVC Plastics

Plastic additives, represented by plasticizers, are important components of plastic pollution. Biofilms inevitably form on plastic surfaces when plastic enters the aqueous environment. However, little is known about the effect of biofilms on plastic surfaces on the release of additives therein. In this study, PVC plastics with different levels of di(2-ethylhexyl)phthalate (DEHP) content were investigated to study the effect of biofilm growth on DEHP release. The presence of biofilms promoted the migration of DEHP from PVC plastics to the external environment. Relative to biofilm-free controls, although the presence of surface biofilm resulted in 0.8 to 11.6 times lower DEHP concentrations in water, the concentrations of the degradation product, monoethylhexyl phthalate (MEHP) in water, were 2.3 to 57.3 times higher. When the total release amounts of DEHP in the biofilm and in the water were combined, they were increased by 0.6-73 times after biofilm growth. However, most of the released DEHP was adsorbed in the biofilms and was subsequently degraded. The results of this study suggest that the biofilm as a new interface between plastics and the surrounding environment can affect the transport and transformation of plastic additives in the environment through barrier, adsorption, and degradation. Future research endeavors should aim to explore the transport dynamics and fate of plastic additives under various biofilm compositions as well as evaluate the ecological risks associated with their enrichment by biofilms.

StoMYB41 positively regulates the Solanum torvum response to Verticillium dahliae in an ABA dependent manner

MYB transcription factor despite their solid involvement in growth are potent regulator of plant stress response. Herein, we identified a MYB gene named as StoMYB41 in a wild eggplant species Solanum torvum. The expression level of StoMYB41 was higher in root than the tissues including stem, leaf, and seed. It induced significantly by Verticillium dahliae inoculation. StoMYB41 was localized in the nucleus and exhibited transcriptional activation activity. Silencing of StoMYB41 enhanced susceptibility of Solanum torvum against Verticillium dahliae, accompanied by higher disease index. The significant down-regulation of resistance marker gene StoABR1 comparing to the control plants was recorded in the silenced plants. Moreover, transient expression of StoMYB41 could trigger intense hypersensitive reaction mimic cell death, darker DAB and trypan blue staining, higher ion leakage, and induced the expression levels of StoABR1 and NbDEF1 in the leaves of Solanum torvum and Nicotiana benthamiana. Taken together, our data indicate that StoMYB41 acts as a positive regulator in Solanum torvum against Verticillium wilt.

Phthalates in plastic stationery in China and their exposure risks to school-aged children

Phthalates have been strictly banned in children's products in many countries. However, as a product with a high frequency of daily contact with children, stationery is not strictly regulated for phthalates in many countries and the occurrences and risks of phthalates in stationery are rarely reported. In this study, the contents of sixteen types of common phthalates in stationery were determined and the exposure risk of these phthalates to children was also estimated. The total contents of phthalates in all stationery ranged from 5.56 to 3.46 × 105 μg/g, with a median value of 1.48 × 104 μg/g. Polyvinyl chloride (PVC) desk mats (DMs) contained the highest contents of phthalates among all types of stationery. Percutaneous absorption and hand-to-mouth ingestion levels of phthalates for school-age children from the DMs were 2.03 × 10-5 - 10.14 μg/kg-Bw/day and 2.14 × 10-5 - 10.67 μg/kg-Bw/day, respectively. Di-2-ethylhexyl phthalate (DEHP) had the highest proportion, detection rate, and exposure level among all measured phthalates. Our study revealed that phthalates in PVC stationery, especially classroom DMs, at both contents and exposure risks, were higher than those in many other children's plastic products. It was necessary to strengthen the management of plastic stationery from the perspective of materials and phthalates addition.

AutoBar: Automatic Barrier Coverage Formation for Danger Keep Out Applications in Smart City

Barrier coverage is a fundamental application in wireless sensor networks, which are widely used for smart cities. In applications, the sensors form a barrier for the intruders and protect an area through intrusion detection. In this paper, we study a new branch of barrier coverage, namely warning barrier coverage (WBC). Different from the classic barrier coverage, WBC has the inverse protect direction, which moves the sensors surrounding a dangerous region and protects any unexpected visitors by warning them away from the dangers. WBC holds a promising prospect in many danger keep out applications for smart cities. For example, a WBC can enclose the debris area in the sea and alarm any approaching ships in order to avoid their damaging propellers. One special feature of WBC is that the target region is usually dangerous and its boundary is previously unknown. Hence, the scattered mobile nodes need to detect the boundary and form the barrier coverage themselves. It is challenging to form these distributed sensor nodes into a barrier because a node can sense only the local information and there is no global information of the unknown region or other nodes. To this end, in response to the newly proposed issue of the formation of barrier cover, we propose a novel solution AutoBar for mobile sensor nodes to automatically form a WBC for smart cities. Notably, this is the first work to trigger the coverage problem of the alarm barrier, wherein the regional information is not pre-known. To pursue the high coverage quality, we theoretically derive the optimal distribution pattern of sensor nodes using convex theory. Based on the analysis, we design a fully distributed algorithm that enables nodes to collaboratively move toward the optimal distribution pattern. In addition, AutoBar is able to reorganize the barrier even if any node is broken. To validate the feasibility of AutoBar, we develop the prototype of the specialized mobile node, which consists of two kinds of sensors: one for boundary detection and another for visitor detection. Based on the prototype, we conduct extensive real trace-driven simulations in various smart city scenarios. Performance results demonstrate that AutoBar outperforms the existing barrier coverage strategies in terms of coverage quality, formation duration, and communication overhead.

Transferability and reproducibility of the EpiSkin™ Micronucleus Assay

A novel in vitro 3D micronucleus assay was developed in China using the EpiSkin™ 3D human skin model. This EpiSkin™ Micronucleus Assay showed good predictivity and reproducibility during internal validation and is expected to contribute to in vitro genotoxicity testing as a follow-up for positive results from 2D micronucleus assay. Having developed the assay in one laboratory, further work focused on the transferability and inter-laboratory reproducibility in two additional Chinese authority laboratories (Guangdong Provincial Center for Disease Control and Prevention and Zhejiang Institute for Food and Drug Control). Formal training was provided for both laboratories, which resulted in good transferability based on the results of two positive compounds, such as mitomycin C and vinblastine. Independent experiments were then performed, and inter-laboratory reproducibility was checked using 2-acetylaminofluorene, 5-fluorouracil, 2,4-dichlorophenol, and d-limonene. The dose-responses of the positive control chemical, mitomycin C, were similar to those of the developing laboratory, and all test chemicals were correctly classified by all laboratories. Overall, there was a good transferability as well as intra- and inter-laboratory reproducibility of the EpiSkin™ Micronucleus Assay. This study further confirmed the assay's robustness and provided confidence to enter following validation stages for scientific acceptance.

Transcriptome Analysis of Eggplant under Salt Stress: AP2/ERF Transcription Factor SmERF1 Acts as a Positive Regulator of Salt Stress

Salt stress, a type of abiotic stress, impedes plant growth and development and strongly reduces crop yield. The molecular mechanisms underlying plant responses to salt stress remain largely unclear. To characterize the enriched pathways and genes that were affected during salt treatment, we performed mRNA sequencing (mRNA-seq) in eggplant roots and identified 8509 differentially expressed genes (DEGs) between the mock and 24 h under salt stress. Among these DEGs, we found that the AP2/ERF transcription factor family member SmERF1 belongs to the plant-pathogen interaction pathway, which was significantly upregulated by salt stress. We found that SmERF1 localizes in the nuclei with transcriptional activity. The results of the virus-induced gene silencing assay showed that SmERF1 silencing markedly enhanced the susceptibility of plants to salt stress, significantly downregulated the transcript expression levels of salt stress defense-related marker genes (9-cis-epoxycarotenoid dioxygenase [SmNCED1, SmNCED2], Dehydrin [SmDHN1], and Dehydrin (SmDHNX1), and reduced the activity of superoxide dismutase and catalase. Silencing SmERF1 promoted the generation of H₂O₂ and proline. In addition, the transient overexpression of SmERF1 triggered intense cell death in eggplant leaves, as assessed by the darker diaminobenzidine and trypan blue staining. These findings suggest that SmERF1 acts as a positive regulator of eggplant response to salt stress. Hence, our results suggest that AP2/ERF transcription factors play a vital role in the response to salt stress.

Urban natural wetland as a sink for microplastics: A case from Lalu Wetland in Tibet, China

Microplastics have been reported in a wide range of aquatic habitats. The wetlands are considered to be important roles in microplastic migration in water bodies. Nevertheless, knowledge about the occurrence and fate of microplastics in urban natural wetland is still limited for us to better understand how they become a sink of microplastics. In this study, the distribution and characteristics of microplastics in surface water, surface sediments, and sediment cores of the Lalu Wetland watershed, China's highest urban wetland, were investigated in August 2020 and January 2021. The abundances of microplastics in the surface water were 0.06-3.05 MPs/L. Microplastic abundance in the surface sediment and sediment core was 0.01-1.10 MPs/g and 0-16.23 MPs/g, respectively. The abundance of microplastics in the water was significantly lower in the wetland than that in the channel in the watershed. Comparing the wetland inlet and outlet water, the microplastic interception rates were 53% in January and 95% in August. The characteristics and seasonal variation of microplastics in the Lalu Wetland implied that urban natural wetlands were good at intercepting microplastics, and vegetation growth might play an important role on the interception of microplastics by the wetland. The increasing of microplastics from bottom to top in the sediment cores of Lalu Wetland also indicated that the ecological risks of microplastics accumulation in sediments of urban natural wetland required further attention.

Combining international survey datasets to identify indicators of stress during the COVID-19 pandemic: A machine learning approach to improve generalization

Introduction

The magnitude and exceptional opportunity to research the psychological distress of shelter in place resulted in a publication frenzy on a smorgasbord of research studies of variable scientific robustness. Confinement, fear of contagion, social isolation, financial hardship, etc. equated to stratospheric stress levels. The decline in protective factors as a function of quarantine anecdotally reflected historic rates of anxiety and depression.

Objectives

In this study, we combined 12 variegate datasets and developed an algorithm to build a model to identify key predictors of pandemic-related stress with high accuracy and generalizability.

Methods

This study reports on existing published data. We first describe the International (Adamson et al., 2020) and then the Italian dataset (Flesia et al., 2020). The time-frame (first wave of lockdown), method (survey), measurement tool (Perceived Stress Scale), and outcome measures were extremely similar to enable consolidation of datasets (see Figure1). The Flesia et al., (2020) data set was integrated into the Adamson et al., (2020) dataset as the first step towards data validation construction of the ML predictive model.

Results

We aim to demonstrate the strength of combining cross-cultural datasets, and the applicability of ML algorithms to facilitate the process and generate a predictive model that identifies and validates key predictors of pandemic-related stress and accommodates for interaction with demographic, cultural, and other mitigating factors while concurrently having high generalizability.

Conclusions

We believe our model provides clinicians, researchers, and decision-makers with evidence to investigate the moderators and mediators of stress, and introduce novel interventions to mitigate the long-term effects of the COVID-19 pandemic.

Disclosure

No significant relationships.

Association of urinary arsenic with insulin resistance: Cross-sectional analysis of the National Health and Nutrition Examination Survey, 2015-2016

BACKGROUND

Long-term arsenic exposure is associated with diabetes in adults, the mechanism of which involves insulin resistance. The relationship between arsenic and insulin resistance in adults is unclear. We analyzed the relationship between urinary arsenic and insulin resistance in US adults.

RESULTS

We identified 815 adults aged 20-79 years who participated in the 2015-2016 National Health and Nutrition Examination Survey (NHANES). Urinary arsenic, fasting glucose, serum insulin, and other key covariates were obtained from the NHANES data. The association between urinary arsenic and insulin resistance was evaluated by analyzing the urinary arsenic level and homeostasis model assessment-insulin resistance. The median total urinary arsenic level was 6.82 µg/L. After adjusting for possible confounding factors (gender, age, and body mass index), the 80th and 20th percentile odds ratio (OR) was 1.41 (95% confidence interval [CI] 1.07, 1.87); the OR of the 70th and 30th percentiles was 1.41 (95% CI 1.08, 1.84).

CONCLUSIONS

In most subgroups, after similar adjustment, the relationship between urine total arsenic and insulin resistance remained. Total arsenic exposure in urine may be associated with insulin resistance. Evidence from larger and more adequately powered cohort studies is needed to confirm our results.

Cognitive impairment, health literacy, secondary prevention capacity and behaviours in acute coronary syndrome patients at early discharge: a prospective observational study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): the Vanguard Grant, Heart Foundation

Background

Cognitive impairment (CI) following acute coronary syndrome (ACS) is poorly understood.

Purpose

We aimed to explore the prevalence of CI in ACS patients four weeks post hospitalisation, the association with secondary prevention capacity and behaviours.

Methods

ACS inpatients who were free from visual deficits and dementia diagnoses were recruited. The post four weeks hospitalisation assessments included cognitive screening (Montreal Cognitive Assessment [MoCA], and Hopkins Verbal Learning Test [HVLT]), health literacy (Newest Vital Sign), depression (Patient Health Questionnaire-9), physical activity (Physical Activity Scale for the Elderly and Fitbit-Flex activity tracker), medication knowledge and adherence, sociodemographic and clinical factors.

Results

Participants (n = 45) had an average age of 65.07 ± 11.21 years, 82.2% were male, 64.4% were married/partnered and 82.2% had high school education or higher. CI occurred in 28.9% using either instrument, 20% using MoCA only and 15.6% using HVLT ­only. Cognitive domains affected were delayed recall (median = 5, range = 0-6) and new verbal learning and memory (15.6%). Adequate health literacy was less common in patients with CI (61.4%) than patients with normal cognition (90.3%, p = 0.024). Furthermore, patients with CI had trends for lower levels of secondary prevention capacity and behaviours, including fewer patients with high medication adherence, unlikely to be married or have an intimate partner, more depressive symptoms and lower levels of physical activity.

Conclusions

CI occurs in almost 30% of ACS patients four weeks post discharge, however a single screening tool is not sufficient to identify all cases. CI affected delayed recall, new verbal learning and memory; was associated with worse health literacy and may have potential implications for secondary prevention capacity.

Being married/having an intimate partner/being has protective effects for mild cognitive impairment in acute coronary syndrome patients

Background

Cardiovascular disease (CVD) is a leading cause of mortality and morbidity and is known to contribute to cognitive impairment, a condition common in CVD patients. Cognitive impairment (CI) is important to detect, manage and accommodate because it limits the capacity of CVD patients to learn about secondary prevention and engage in appropriate self-care including lifestyle change.

Purpose

Therefore this study aimed to determine the prevalence and predictors of cognitive impairment in acute coronary syndrome (ACS) patients during hospital admission.

Methods

ACS (myocardial infarction, unstable angina) inpatients (n=81) who did not have a neurocognitive diagnosis were recruited to a prospective descriptive study in 2019. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) and the Hopkins Verbal Learning Test (HVLT).

Results

The sample had an age mean of 63.49±10.86 (range 40–89) years, was mostly male (82.7%) and 50.6% were university educated. MI occurred in 56.8%, equally STEMI (28.4%) and nSTEMI (28.4%) with 70.4% treated by coronary intervention.

The mean education adjusted MOCA score was 25.73±3.05 (range 18–31) and 48.1% were classified as having mild CI (18–26). The domain with the worst performance was delayed recall/memory domain at mean 2.58±1.77 (of potential 0–5 points). The mean unadjusted recall score on HVLT was 19.56±6.18 (range 0–32), the mean z-score −0.69±1.21 (range −4.59–1.87) and 40.7% were classified as having mild CI (age and education adjusted Z-score ≥−1). Mild CI was classified by both MOCA and HVLT (both adjusted) in 24.7%.

Patients classified as having mild CI (MOCA) were significantly older (66.87 versus 60.36 years, p=0.006) and less likely and to be married or have an intimate partner (21% versus 32% p=0.039). When all factors were taken into account using multiple linear regression, higher MOCA scores in patients who were married/partnered (B=1.6) and lower scores with advancing age (B=−0.08).

Conclusions

Mild CI and decreased delayed recall is prevalent in ACS patients and patient education strategies need to be accommodate this. Being married/partnered may have protective effects, therefore additional support may need to be directed to single patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Heart Foundation of Australia Vanguard Award

Decreased Hepatocyte Autophagy Leads to Synergistic IL-1β and TNF Mouse Liver Injury and Inflammation

BACKGROUND AND AIMS

The proinflammatory cytokine IL-1β has been implicated in the pathophysiology of nonalcoholic and alcoholic steatohepatitis. How IL-1β promotes liver injury in these diseases is unclear, as no IL-1β receptor-linked death pathway has been identified. Autophagy functions in hepatocyte resistance to injury and death, and findings of decreased hepatic autophagy in many liver diseases suggest a role for impaired autophagy in disease pathogenesis. Recent findings that autophagy blocks mouse liver injury from lipopolysaccharide led to an examination of autophagy's function in hepatotoxicity from proinflammatory cytokines.

APPROACH AND RESULTS

AML12 cells with decreased autophagy from a lentiviral autophagy-related 5 (Atg5) knockdown were resistant to toxicity from TNF, but sensitized to death from IL-1β, which was markedly amplified by TNF co-treatment. IL-1β/TNF death was necrosis by trypan blue and propidium iodide positivity, absence of mitochondrial death pathway and caspase activation, and failure of a caspase inhibitor or necrostatin-1s to prevent death. IL-1β/TNF depleted autophagy-deficient cells of ATP, and ATP depletion and cell death were prevented by supplementation with the energy substrate pyruvate or oleate. Pharmacological inhibitors and genetic knockdown studies demonstrated that IL-1β/TNF-induced necrosis resulted from lysosomal permeabilization and release of cathepsins B and L in autophagy-deficient cells. Mice with a tamoxifen-inducible, hepatocyte-specific Atg5 knockout were similarly sensitized to cathepsin-dependent hepatocellular injury and death from IL-1β/TNF in combination, but neither IL-1β nor TNF alone. Knockout mice had increased hepatic inflammation, and IL-1β/TNF-treated, autophagy-deficient AML12 cells secreted exosomes with proinflammatory damage-associated molecular patterns.

CONCLUSIONS

The findings delineate mechanisms by which decreased hepatocyte autophagy promotes IL-1β/TNF-induced necrosis from impaired energy homeostasis and lysosomal permeabilization and inflammation through the secretion of exosomal damage-associated molecular patterns.

A signature of 14 immune-related gene pairs predicts overall survival in gastric cancer

OBJECTIVE

Increasing evidence demonstrates that immune signature plays an important role in the prognosis of gastric cancer (GC). We aimed to develop and validate a robust immune-related gene pair (IRGP) signature for predicting the prognosis of GC patients.

METHODS

RNA-Seq data and corresponding clinical information of GC cohort were downloaded from the TCGA (The Cancer Genome Atlas Program) data portal. GSE84437 and GSE15459 microarray datasets were included as independent external cohorts. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to build the best prognostic signature. All patients were classified into the high immune-risk and low immune-risk groups via the optimal cut-off of the signature scores determined by time-dependent receiver-operating characteristic (ROC) curve analysis. The prognostic role of the signature was measured by a log-rank test and a Cox proportional hazard regression model.

RESULTS

14 immune gene pairs consisting of 25 unique genes were identified to construct the immune prognostic signature. High immune-risk groups showed poor prognosis in the TCGA datasets and GSE84437 datasets as well as in the GSE15459 datasets (all P < 0.001). The 14-IRGP signature was an independent prognostic factor of GC after adjusting for other clinical factors (P < 0.05). Functional analysis revealed that DNA integrity checkpoint, DNA replication, T-cell receptor signaling pathway, and B-cell receptor signaling pathway were enriched in the low immune-risk groups. B cells naive and Monocytes were significantly higher in the high-risk group, and B-cell memory and T-cell CD4 memory activated were significantly higher in the low-risk group. The prognostic signature based on IRGP reflected infiltration by several types of immune cells.

CONCLUSION

The novel proposed clinical-immune signature is a promising biomarker for prediction overall survival in patients with GC and providing new insights into the treatment strategies.

Stathmin 1 Induces Murine Hepatocyte Proliferation and Increased Liver Mass

The endogenous cellular signals that initiate the transition of hepatocytes from quiescence to proliferation remain unclear. The protein stathmin 1 (STMN1) is highly expressed in dividing cells, including hepatocytes, and functions to promote cell mitosis through physical interactions with tubulin and microtubules that regulate mitotic spindle formation. The recent finding that STMN1 mediates the resistance of cultured hepatocytes to oxidant stress led to an examination of the expression and function of this protein in the liver in vivo. STMN1 messenger RNA (mRNA) and protein were essentially undetectable in normal mouse liver but increased markedly in response to oxidant injury from carbon tetrachloride. Similarly, levels of STMN1 mRNA and protein were increased in human livers from patients with acute fulminant hepatic failure. To determine STMN1 function in the liver in vivo, mice were infected with a control or Stmn1-expressing adenovirus. Stmn1 expression induced spontaneous liver enlargement with a doubling of the liver to body weight ratio. The increase in liver mass resulted, in part, from hepatocellular hypertrophy but mainly from an induction of hepatocyte proliferation. STMN1 expression led to marked increases in the numbers of 5-bromo-2'-deoxyuridine-positive and mitotic hepatocytes and hepatic nuclear levels of cyclins and cyclin-dependent kinases. STMN1-induced hepatocyte proliferation was followed by an apoptotic response and a return of the liver to its normal mass. Conclusion: STMN1 promotes entry of quiescent hepatocytes into the cell cycle. STMN1 expression by itself in the absence of any reduction in liver mass is sufficient to stimulate a hepatic proliferative response that significantly increases liver mass.

Decreased Macrophage Autophagy Promotes Liver Injury and Inflammation from Alcohol

BACKGROUND

One mechanism underlying the development of alcoholic liver disease is overactivation of the innate immune response. Recent investigations indicate that the lysosomal pathway of autophagy down-regulates the inflammatory state of hepatic macrophages, suggesting that macrophage autophagy may regulate innate immunity in alcoholic liver disease. The function of macrophage autophagy in the development of alcoholic liver disease was examined in studies employing mice with a myeloid-specific decrease in autophagy.

METHODS

Littermate control and Atg5^Δmye mice lacking Atg5-dependent myeloid autophagy were administered a Lieber-DeCarli control (CD) or ethanol diet (ED) alone or together with lipopolysaccharide (LPS) and examined for the degree of liver injury and inflammation.

RESULTS

Knockout mice with decreased macrophage autophagy had equivalent steatosis but increased mortality and liver injury from ED alone. Increased liver injury and hepatocyte death also occurred in Atg5^Δmye mice administered ED and LPS in association with systemic inflammation as indicated by elevated serum levels of proinflammatory cytokines. Hepatic macrophage and neutrophil infiltration were unaffected by decreased autophagy, but levels of proinflammatory cytokine gene induction were significantly increased in the livers but not adipose tissue of knockout mice treated with ED and LPS. Inflammasome activation was increased in ED/LPS-treated knockout mice resulting in elevated interleukin (IL)-1β production. Increased IL-1β promoted alcoholic liver disease as liver injury was decreased by the administration of an IL-1 receptor antagonist.

CONCLUSIONS

Macrophage autophagy functions to prevent liver injury from alcohol. This protection is mediated in part by down-regulation of inflammasome-dependent and inflammasome-independent hepatic inflammation. Therapies to increase autophagy may be effective in this disease through anti-inflammatory effects on macrophages.

Methylation analysis of p16, SLIT2, SCARA5, and Runx3 genes in hepatocellular carcinoma

This study is to investigate the methylation status of multiple tumor suppressor 1 (p16), secreted glycoprotein 2 (SLIT2), scavenger receptor class A, member 5 putative (SCARA5), and human runt-related transcription factor 3 (Runx3) genes in the peripheral blood of hepatocellular carcinoma (HCC).This is a case-control study. The peripheral blood samples were collected from 25 HCC patients, 25 patients with high risk of HCC (defined as "internal control group"), and 25 healthy individuals (defined as "external control group"), respectively. Then the methylation status of p16, SLIT2, SCARA5, and Runx3 genes in the blood samples were analyzed by pyrosequencing. The relationship between the methylation and the clinical features of HCC patients were evaluated.The methylation levels in the 7 CpG loci of p16 gene in HCC patients were low and without statistically significant difference (P > .05) compared to the control groups. Although the methylation levels of CpG3 and CpG4 in SLIT2 gene loci were higher than those of the control groups, there was no statistically significant difference (P > .05). However, the methylation rate of CpG2 locus in SCARA5 gene in HCC patients was significantly higher (P < .05). And the methylation rates of CpG1, CpG2, CpG3, CpG4, CpG5, and CpG8 in Runx3 gene in HCC patients were significantly different to that of control groups (P < .05). We also have analyzed the correlations between the CpG islands methylation of Runx3 or SCARA5 genes and the age, gender, hepatitis B, liver cirrhosis, alpha fetal protein, or hepatitis B surface antigen (HBsAg) of the HCC patients, which all showed no significant correlations (P > .05).The methylation status of SCARA5 and Runx3 genes are abnormal in HCC patients, which may further be used as molecular markers for early auxiliary diagnosis of liver cancer.

Pentamidine blocks hepatotoxic injury in mice

Toxin-induced liver diseases lack effective therapies despite increased understanding of the role factors such as an overactive innate immune response play in the pathogenesis of this form of hepatic injury. Pentamidine is an effective antimicrobial agent against several human pathogens, but studies have also suggested that this drug inhibits inflammation. This potential anti-inflammatory mechanism of action, together with the development of a new oral form of pentamidine isethionate VLX103, led to investigations of the effectiveness of this drug in the prevention and treatment of hepatotoxic liver injury. Pretreatment with a single injection of VLX103 in the d-galactosamine (GalN) and lipopolysaccharide (LPS) model of acute, fulminant liver injury dramatically decreased serum alanine aminotransferase levels, histological injury, the number of terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive cells and mortality compared with vehicle-injected controls. VLX103 decreased GalN/LPS induction of tumor necrosis factor (TNF) but had no effect on other proinflammatory cytokines. VLX103 prevented the proinflammatory activation of cultured hepatic macrophages and partially blocked liver injury from GalN/TNF. In GalN/LPS-treated mice, VLX103 decreased activation of both the mitochondrial death pathway and downstream effector caspases 3 and 7, which resulted from reduced c-Jun N-terminal kinase activation and initiator caspase 8 cleavage. Delaying VLX103 treatment for up to 3 hours after GalN/LPS administration was still remarkably effective in blocking liver injury in this model. Oral administration of VLX103 also decreased hepatotoxic injury in a second more chronic model of alcohol-induced liver injury, as demonstrated by decreased serum alanine and aspartate aminotransferase levels and numbers of TUNEL-positive cells.

CONCLUSION

VLX103 effectively decreases toxin-induced liver injury in mice and may be an effective therapy for this and other forms of human liver disease. (Hepatology 2017;66:922-935).

Autophagy confers resistance to lipopolysaccharide-induced mouse hepatocyte injury

During sepsis, bacterial products, particularly LPS, trigger injury in organs such as the liver. This common condition remains largely untreatable, in part due to a lack of understanding of how high concentrations of LPS cause cellular injury. In the liver, the lysosomal degradative pathway of autophagy performs essential hepatoprotective functions and is induced by LPS. We, therefore, examined whether hepatocyte autophagy protects against liver injury from septic levels of LPS. Mice with an inducible hepatocyte-specific knockout of the critical autophagy gene Atg7 were examined for their sensitivity to high-dose LPS. Increased liver injury occurred in knockout mice, as determined by significantly increased serum alanine aminotransferase levels, histological evidence of liver injury, terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling, and effector caspase-3 and -7 activation. Hepatic inflammation and proinflammatory cytokine induction were unaffected by the decrease in hepatocyte autophagy. Although knockout mice had normal NF-κB signaling, hepatic levels of Akt1 and Akt2 phosphorylation in response to LPS were decreased. Cultured hepatocytes from knockout mice displayed a generalized defect in Akt signaling in response to multiple stimuli, including LPS, TNF, and IL-1β. Akt activation mediates hepatocyte resistance to TNF cytotoxicity, and anti-TNF antibodies significantly decreased LPS-induced liver injury in knockout mice, indicating that the loss of autophagy sensitized to TNF-dependent liver damage. Hepatocyte autophagy, therefore, protects against LPS-induced liver injury. Conditions such as aging and steatosis that impair hepatic autophagy may predispose to poor outcomes from sepsis through this mechanism.

Impaired macrophage autophagy increases the immune response in obese mice by promoting proinflammatory macrophage polarization

Recent evidence that excessive lipid accumulation can decrease cellular levels of autophagy and that autophagy regulates immune responsiveness suggested that impaired macrophage autophagy may promote the increased innate immune activation that underlies obesity. Primary bone marrow-derived macrophages (BMDM) and peritoneal macrophages from high-fat diet (HFD)-fed mice had decreased levels of autophagic flux indicating a generalized impairment of macrophage autophagy in obese mice. To assess the effects of decreased macrophage autophagy on inflammation, mice with a Lyz2-Cre-mediated knockout of Atg5 in macrophages were fed a HFD and treated with low-dose lipopolysaccharide (LPS). Knockout mice developed systemic and hepatic inflammation with HFD feeding and LPS. This effect was liver specific as knockout mice did not have increased adipose tissue inflammation. The mechanism by which the loss of autophagy promoted inflammation was through the regulation of macrophage polarization. BMDM and Kupffer cells from knockout mice exhibited abnormalities in polarization with both increased proinflammatory M1 and decreased anti-inflammatory M2 polarization as determined by measures of genes and proteins. The heightened hepatic inflammatory response in HFD-fed, LPS-treated knockout mice led to liver injury without affecting steatosis. These findings demonstrate that autophagy has a critical regulatory function in macrophage polarization that downregulates inflammation. Defects in macrophage autophagy may underlie inflammatory disease states such as the decrease in macrophage autophagy with obesity that leads to hepatic inflammation and the progression to liver injury.

Macrophage autophagy limits acute toxic liver injury in mice through down regulation of interleukin-1β

BACKGROUND & AIMS

Overactivation of the innate immune response underlies many forms of liver injury including that caused by hepatotoxins. Recent studies have demonstrated that macrophage autophagy regulates innate immunity and resultant tissue inflammation. Although hepatocyte autophagy has been shown to modulate hepatic injury, little is known about the role of autophagy in hepatic macrophages during the inflammatory response to acute toxic liver injury. Our aim therefore was to determine whether macrophage autophagy functions to down regulate hepatic inflammation.

METHODS

Mice with a LysM-CRE-mediated macrophage knockout of the autophagy gene ATG5 were examined for their response to toxin-induced liver injury from D-galactosamine/lipopolysaccharide (GalN/LPS).

RESULTS

Knockout mice had increased liver injury from GalN/LPS as determined by significant increases in serum alanine aminotransferase, histological evidence of liver injury, positive terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling, caspase activation and mortality as compared to littermate controls. Levels of proinflammatory tumor necrosis factor and interleukin (IL)-6 hepatic mRNA and serum protein were unchanged, but serum IL-1β was significantly increased in knockout mice. The increase in serum IL-1β was secondary to elevated hepatic caspase 1 activation and inflammasome-mediated cleavage of pro-IL-1β to its active form. Cultured hepatic macrophages from GalN/LPS-treated knockout mice had similarly increased IL-1β production. Dysregulation of IL-1β was the mechanism of increased liver injury as an IL-1 receptor antagonist prevented injury in knockout mice in concert with decreased neutrophil activation.

CONCLUSIONS

Macrophage autophagy functions to limit acute toxin-induced liver injury and death by inhibiting the generation of inflammasome-dependent IL-1β.

Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK

Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

High-mobility group box 1 is dispensable for autophagy, mitochondrial quality control, and organ function in vivo

In vitro studies have demonstrated a critical role for high-mobility group box 1 (HMGB1) in autophagy and the autophagic clearance of dysfunctional mitochondria, resulting in severe mitochondrial fragmentation and profound disturbances of mitochondrial respiration in HMGB1-deficient cells. Here, we investigated the effects of HMGB1 deficiency on autophagy and mitochondrial function in vivo, using conditional Hmgb1 ablation in the liver and heart. Unexpectedly, deletion of Hmgb1 in hepatocytes or cardiomyocytes, two cell types with abundant mitochondria, did not alter mitochondrial structure or function, organ function, or long-term survival. Moreover, hepatic autophagy and mitophagy occurred normally in the absence of Hmgb1, and absence of Hmgb1 did not significantly affect baseline and glucocorticoid-induced hepatic gene expression. Collectively, our findings suggest that HMGB1 is dispensable for autophagy, mitochondrial quality control, the regulation of gene expression, and organ function in the adult organism.

Hepatic insulin receptor deficiency impairs the SREBP-2 response to feeding and statins

The liver plays a central role in metabolism and mediating insulin action. To dissect the effects of insulin on the liver in vivo, we have studied liver insulin receptor knockout (LIRKO) mice. Because LIRKO livers lack insulin receptors, they are unable to respond to insulin. Surprisingly, the most profound derangement observed in LIRKO livers by microarray analysis is a suppression of the cholesterologenic genes. Sterol regulatory element binding protein (SREBP)-2 promotes cholesterologenic gene transcription, and is inhibited by intracellular cholesterol. LIRKO livers show a slight increase in hepatic cholesterol, a 40% decrease in Srebp-2, and a 50-90% decrease in the cholesterologenic genes at the mRNA and protein levels. In control mice, SREBP-2 and cholesterologenic gene expression are suppressed by fasting and restored by refeeding; in LIRKO mice, this response is abolished. Similarly, the ability of statins to induce Srebp-2 and the cholesterologenic genes is lost in LIRKO livers. In contrast, ezetimibe treatment robustly induces Srepb-2 and its targets in LIRKO livers, raising the possibility that insulin may regulate SREBP-2 indirectly, by altering the accumulation or distribution of cholesterol within the hepatocyte. Taken together, these data indicate that cholesterol synthesis is a key target of insulin action in the liver.

Aging promotes the development of diet-induced murine steatohepatitis but not steatosis

The prevalence of the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD) in humans increases with age. It is unknown whether this association is secondary to the increased incidence of risk factors for NAFLD that occurs with aging, reflects the culmination of years of exposure to lifestyle factors such as a high-fat diet (HFD), or results from physiological changes that characterize aging. To examine this question, the development of NAFLD in response to a fixed period of HFD feeding was examined in mice of different ages. Mice aged 2, 8, and 18 months were fed 16 weeks of a low-fat diet or HFD. Increased body mass and insulin insensitivity occurred in response to HFD feeding irrespective of the age of the mice. The amount of HFD-induced hepatic steatosis as determined biochemically and histologically was also equivalent among the three ages. Liver injury occurred exclusively in the two older ages as reflected by increased serum alanine aminotransferase levels, positive terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling, and caspase activation. Older mice also had an elevated innate immune response with a more pronounced polarization of liver and adipose tissue macrophages into an M1 phenotype. Studies of cultured hepatocytes from young and old mice revealed that aged cells were selectively sensitized to the Fas death pathway.

CONCLUSION

Aging does not promote the development of hepatic steatosis but leads to increased hepatocellular injury and inflammation that may be due in part to sensitization to the Fas death pathway and increased M1 macrophage polarization.

Distinct functions of JNK and c-Jun in oxidant-induced hepatocyte death

Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-Jun dependent as it was blocked by TAM67, but independent of c-Jun phosphorylation. Death occurred by apoptosis and necrosis and activation of the mitochondrial death pathway. Short hairpin RNA knockdowns of total JNK or JNK2 sensitized to death from menadione, whereas a jnk1 knockdown was protective. Jnk2 null mouse primary hepatocytes were also sensitized to menadione death. JNK inhibition magnified decreases in cellular ATP content and β-oxidation induced by menadione. This effect mediated cell death as chemical inhibition of β-oxidation also sensitized cells to death from menadione, and supplementation with the β-oxidation substrate oleate blocked death. Components of the JNK/c-Jun signaling pathway have opposing functions in hepatocyte oxidant stress with JNK2 mediating resistance to cell death and c-Jun promoting death.

Neoadjuvant concurrent chemoradiotherapy for locally advanced esophageal cancer in a single high-volume center

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is now considered the standard of care by many centers in the treatment of both squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus. This study evaluates the effectiveness of a neoadjuvant CRT protocol, as regards pathological complete response (pCR) rate and long-term survival.

METHODS

From 2003 to 2011, at Upper G.I. Surgery Division of Verona University, 155 consecutive patients with locally advanced esophageal cancers (90 SCC, 65 adenocarcinoma) were treated with a single protocol of neoadjuvant CRT (docetaxel, cisplatin, and 5-fluorouracil with 50.4 Gy of concurrent radiotherapy). Response to CRT was evaluated through percentage of pathological complete response (pCR or ypT0N0), overall (OS) and disease-related survival (DRS), and pattern of relapse.

RESULTS

One hundred thirty-one patients (84.5 %) underwent surgery. Radical resection (R0) was achieved in 123 patients (79.3 %), and pCR in 65 (41.9 %). Postoperative mortality was 0.7 % (one case). Five-year OS and DRS were respectively 43 and 49 % in the entire cohort, 52 and 59 % in R0 cases, and 72 and 81 % in pCR cases. Survival did not significantly differ between SCC and adenocarcinoma, except for pCR cases. Forty-nine patients suffered from relapse, which was mainly systemic in adenocarcinoma. Only three out of 26 pCR patients with previous adenocarcinoma developed relapse, always systemic.

CONCLUSIONS

This study suggests that patients treated with the present protocol achieve good survival and high pCR rate. Further research is necessary to evaluate whether surgery on demand is feasible in selected patients, such as pCR patients with adenocarcinoma.

Hepatic insulin signaling is required for obesity-dependent expression of SREBP-1c mRNA but not for feeding-dependent expression

Dissecting the role of insulin in the complex regulation of triglyceride metabolism is necessary for understanding dyslipidemia and steatosis. Liver insulin receptor knockout (LIRKO) mice show that in the physiological context of feeding, hepatic insulin signaling is not required for the induction of mTORC1, an upstream activator of the lipogenic regulator, SREBP-1c. Feeding induces SREBP-1c mRNA in LIRKO livers, though not to the extent observed in controls. A high fructose diet also partially induces SREBP-1c and lipogenic gene expression in LIRKO livers. Insulin signaling becomes more important in the pathological context of obesity, as knockdown of the insulin receptor in ob/ob mice, a model of Type 2 diabetes, using antisense oligonucleotides, abolishes the induction of SREBP-1c and its targets by obesity and ameliorates steatosis. Thus, insulin-independent signaling pathways can partially compensate for insulin in the induction of SREBP-1c by feeding but the further induction by obesity/Type 2 diabetes is entirely dependent upon insulin.

Transcription factor EB: a central regulator of both the autophagosome and lysosome

Autophagy is a cellular catabolic process that relies on the cooperation of autophagosomes and lysosomes. During starvation, the cell expands both compartments to enhance degradation processes. We found that starvation activates a transcriptional program that controls major steps of the autophagic pathway, including autophagosome formation, autophagosome-lysosome fusion, and substrate degradation. The transcription factor EB (TFEB), a master gene for lysosomal biogenesis, coordinated this program by driving expression of autophagy and lysosomal genes. Nuclear localization and activity of TFEB were regulated by serine phosphorylation mediated by the extracellular signal-regulated kinase 2, whose activity was tuned by the levels of extracellular nutrients. Thus, a mitogen-activated protein kinase-dependent mechanism regulates autophagy by controlling the biogenesis and partnership of two distinct cellular organelles.

Is secretoneurin a new hormone?

Numerous small potentially bioactive peptides are derived from the selective processing of the ~600 amino acid secretogranin II (SgII) precursor, but only the 31-42 amino acid segment termed secretoneurin (SN) is well-conserved from sharks to mammals. Both SNa and SNb paralogs have been identified in some teleosts, likely arising as a result of the specific genome duplication event in this lineage. Only one copy of the putative lamprey SgII (188 amino acids) could be identified which gives rise to a divergent agnathan SN that contains the signature YTPQ-X-LA-X(7)-EL sequence typical of the central core of all known SN peptides. In rodent models, SN has regulatory effects on neuroinflammation and neurotransmitter release, and possesses therapeutic potential for the induction of angiogenesis. The wide distribution of SN in neuroendocrine neurons and pituitary cells suggests important endocrine roles. The clearest example of the endocrine action of SN is the stimulatory effects on pituitary luteinizing hormone release from goldfish pituitary and mouse LβT2 gonadotroph cells, indicative of an important role in reproduction. Several lines of evidence suggest that the SN receptor is most likely a G-protein coupled protein. Microarray analysis of SN effects on dispersed goldfish pituitary cells in vitro reveals novel SN actions that include effects on genes involved in notch signaling and the guanylate cyclase pathway. Intracerebroventricular injection of SN increases feeding and locomotory behaviors in goldfish. Given that SgII appeared early in vertebrate evolution, SN is an old peptide with emerging implications as a new multifunctional hormone.

Secretoneurin stimulates the production and release of luteinizing hormone in mouse L{beta}T2 gonadotropin cells

Secretoneurin (SN) is a functional secretogranin II (SgII)-derived peptide that stimulates luteinizing hormone (LH) production and its release in the goldfish. However, the effects of SN on the pituitary of mammalian species and the underlying mechanisms remain poorly understood. To study SN in mammals, we adopted the mouse LβT2 gonadotropin cell line that has characteristics consistent with normal pituitary gonadotrophs. Using radioimmunoassay and real-time RT-PCR, we demonstrated that static treatment with SN induced a significant increment of LH release and production in LβT2 cells in vitro. We found that GnRH increased cellular SgII mRNA level and total SN-immunoreactive protein release into the culture medium. We also report that SN activated the extracellular signal-regulated kinases (ERK) in either 10-min acute stimulation or 3-h chronic treatment. The SN-induced ERK activation was significantly blocked by pharmacological inhibition of MAPK kinase (MEK) with PD-98059 and protein kinase C (PKC) with bisindolylmaleimide. SN also increased the total cyclic adenosine monophosphate (cAMP) levels similarly to GnRH. However, SN did not activate the GnRH receptor. These data indicate that SN activates the protein kinase A (PKA) and cAMP-induced ERK signaling pathways in the LH-secreting mouse LβT2 pituitary cell line.

Phytoestrogen biological actions on Mammalian reproductive system and cancer growth

Phytoestrogens are a family of diverse polyphenolic compounds derived from nature plant that structurally or functionally mimic circulating estrogen in the mammalian reproductive system. They induce estrogenic and anti-estrogenic effects in the brain-pituitary-gonad axis (a principal endocrine system involving in reproductive regulation) and peripheral reproductive organs. The dichotomy of phytoestrogen-mediated actions elucidates that they play the biological activities via complex mechanisms and belong to various chemical classes. In comparison with their unobvious physiological functions in normal reproductive tissues, there are increasing investigations showing that phytoestrogen induces significant inhibitory effects on the growth of breast and ovarian cancers through different signaling pathways. This review summarized the results of the previous studies regarding principal signaling transductions for mediating the growth of the ovarian and breast cancers. Phytoestrogen potentially modulates the signaling molecules via: (1) blocking the nuclear and membrane estrogen receptors (ER), (2) interfering with the growth factor receptor, (3) inhibiting the G protein-coupled receptor in ER-deficient cells, (4) activating apoptosis and nullifying anti-apoptotic signals.

Secretoneurin is a potential paracrine factor from lactotrophs stimulating gonadotropin release in the goldfish pituitary

Secretoneurin (SN) is a functional neuropeptide derived from the evolutionarily conserved part of precursor protein secretogranin II (SgII). In the time course study, SN (10 nM) stimulates luteinizing hormone (LH) production and secretion after 6 h of static incubation of goldfish pituitary cells. Due to the existence of SN-immunoreactivity (SN-IR) in goldfish lactotrophs, endogenous SN might exert a paracrine effect on LH in the pituitary. In an in vitro immunoneutralization experiment, coincubation with anti-SN antiserum reduces the stimulatory effect of salmon gonadotropin-releasing hormone (sGnRH) on LH release by 64%. Using Western blot analysis, we demonstrate that sGnRH significantly increases the expression of the major SgII-derived peptide (∼57 kDa, with SN-IR) and prolactin (PRL) after 12 h in the static culture of goldfish pituitary cells. Furthermore, there exists a significant correlation between the levels of these two proteins (R = 0.76, P = 0.004). Another ∼30 kDa SgII-derived peptide containing SN is only observed in sGnRH-treated pituitary cells. Consistent with the Western blot analysis results, real-time RT-PCR analysis shows that a 12-h treatment with sGnRH induced 1.6- and 1.7-fold increments in SgII and PRL mRNA levels, respectively. SgII gene expression was also associated with PRL gene expression (R = 0.66; P = 0.02). PRL cells loaded with the calcium-sensitive dye, fura 2/AM, respond to sGnRH treatment with increases in intracellular Ca(2+) concentration level, suggesting a potential mechanism of GnRH on PRL cells and thus SgII processing and SN secretion. Taken together, endogenous lactotroph-generated SN, under the control of hypothalamic GnRH, exerts a paracrine action on neighboring gonadotrophs to stimulate LH release.

Obesity and genetics regulate microRNAs in islets, liver, and adipose of diabetic mice

Type 2 diabetes results from severe insulin resistance coupled with a failure of b cells to compensate by secreting sufficient insulin. Multiple genetic loci are involved in the development of diabetes, although the effect of each gene on diabetes susceptibility is thought to be small. MicroRNAs (miRNAs) are noncoding 19-22-nucleotide RNA molecules that potentially regulate the expression of thousands of genes. To understand the relationship between miRNA regulation and obesity-induced diabetes, we quantitatively profiled approximately 220 miRNAs in pancreatic islets, adipose tissue, and liver from diabetes-resistant (B6) and diabetes-susceptible (BTBR) mice. More than half of the miRNAs profiled were expressed in all three tissues, with many miRNAs in each tissue showing significant changes in response to genetic obesity. Furthermore, several miRNAs in each tissue were differentially responsive to obesity in B6 versus BTBR mice, suggesting that they may be involved in the pathogenesis of diabetes. In liver there were approximately 40 miRNAs that were downregulated in response to obesity in B6 but not BTBR mice, indicating that genetic differences between the mouse strains play a critical role in miRNA regulation. In order to elucidate the genetic architecture of hepatic miRNA expression, we measured the expression of miRNAs in genetically obese F2 mice. Approximately 10% of the miRNAs measured showed significant linkage (miR-eQTLs), identifying loci that control miRNA abundance. Understanding the influence that obesity and genetics exert on the regulation of miRNA expression will reveal the role miRNAs play in the context of obesity-induced type 2 diabetes.

Obesity and genetics regulate microRNAs in islets, liver, and adipose of diabetic mice

Type 2 diabetes results from severe insulin resistance coupled with a failure of b cells to compensate by secreting sufficient insulin. Multiple genetic loci are involved in the development of diabetes, although the effect of each gene on diabetes susceptibility is thought to be small. MicroRNAs (miRNAs) are noncoding 19-22-nucleotide RNA molecules that potentially regulate the expression of thousands of genes. To understand the relationship between miRNA regulation and obesity-induced diabetes, we quantitatively profiled approximately 220 miRNAs in pancreatic islets, adipose tissue, and liver from diabetes-resistant (B6) and diabetes-susceptible (BTBR) mice. More than half of the miRNAs profiled were expressed in all three tissues, with many miRNAs in each tissue showing significant changes in response to genetic obesity. Furthermore, several miRNAs in each tissue were differentially responsive to obesity in B6 versus BTBR mice, suggesting that they may be involved in the pathogenesis of diabetes. In liver there were approximately 40 miRNAs that were downregulated in response to obesity in B6 but not BTBR mice, indicating that genetic differences between the mouse strains play a critical role in miRNA regulation. In order to elucidate the genetic architecture of hepatic miRNA expression, we measured the expression of miRNAs in genetically obese F2 mice. Approximately 10% of the miRNAs measured showed significant linkage (miR-eQTLs), identifying loci that control miRNA abundance. Understanding the influence that obesity and genetics exert on the regulation of miRNA expression will reveal the role miRNAs play in the context of obesity-induced type 2 diabetes.

Secretoneurin as a hormone regulator in the pituitary

Secretoneurin (SN) is a 33-34 amino acid peptide derived from the most conserved sequence of the secretogranin (SgII) precursor. SgII is a granin protein found in the secretory granules of neuroendocrine tissues. There are two paralogs of teleost SgII that we name here SgIIa and SgIIb. Processing of these proteins would yield SNa and SNb in fish. Secretoneurin immunoreactivity is found within all the major pituitary cell types in mammals. In goldfish, it appears to be mainly expressed in the prolactin cells of the rostral pars distalis. We have investigated the paracrine role of goldfish SN (SNa) to stimulate luteinizing hormone from gonadotrophs in the neighboring proximal pars distalis. Another source of SN is the hypophysiotropic neurons that may deliver SN to target cells by direct pituitary innervation. Little else is known about the neuroendocrine role of SN. We also discuss the evolution, distribution and production of SN in the pituitary.

New insights into granin-derived peptides: evolution and endocrine roles

The granin protein family is composed of two chromogranin and five secretogranin members that are acidic, heat-stable proteins in secretory granules in cells of the nervous and endocrine systems. We report that there is little evidence for evolutionary relationships among the granins except for the chromogranin group. The main granin members, including chromogranin A and B, and secretogranin II are moderately conserved in the vertebrates. Several small bioactive peptides can be generated by proteolysis from those homologous domains existing within the granin precursors, reflecting the conservation of biological activities in different vertebrates. In this context, we focus on reviewing the distribution and function of the major granin-derived peptides, including vasostatin, bovine CgB(1-41) and secretoneurin in vertebrate endocrine systems, especially those associated with growth, glucose metabolism and reproduction.

The secretogranin II-derived peptide secretoneurin stimulates luteinizing hormone secretion from gonadotrophs

Secretoneurin (SN) is a 33- to 34-amino acid neuropeptide derived from secretogranin-II, a member of the chromogranin family. We previously synthesized a putative goldfish (gf) SN and demonstrated its ability to stimulate LH release in vivo. However, it was not known whether goldfish actually produced the free SN peptide or whether SN directly stimulates LH release from isolated pituitary cells. Using a combination of reverse-phase HPLC and mass spectrometry analysis, we isolated for the first time a 34-amino acid free gfSN peptide from the whole brain. Moreover, Western blot analysis indicated the existence of this peptide in goldfish pituitary. Immunocytochemical localization studies revealed the presence of SN immunoreactivity in prolactin cells of rostral pars distalis of the anterior pituitary. Additionally, we found that magnocellular cells of the goldfish preoptic region are highly immunoreactive for SN. These neurons send heavily labeled projections that pass through the pituitary stalk and innervate the neurointermediate and anterior lobes. In static 12-h incubation of dispersed pituitary cells, application of SN antiserum reduced LH levels, whereas 1 and 10 nM gfSN, respectively, induced 2.5-fold (P < 0.001) and 1.9-fold (P < 0.01) increments of LH release into the medium, increases similar to those elicited by 100 nM concentrations of GnRH. Like GnRH, gfSN elevated intracellular Ca(2+) in identified gonadotrophs. Whereas we do not yet know the relative contribution of neural SN or pituitary SN to LH release, we propose that SN could act as a neuroendocrine and/or paracrine factor to regulate LH release from the anterior pituitary.

Effects of fluoxetine on the reproductive axis of female goldfish (Carassius auratus)

We investigated the effects of fluoxetine, a selective serotonin reuptake inhibitor, on neuroendocrine function and the reproductive axis in female goldfish. Fish were given intraperitoneal injections of fluoxetine twice a week for 14 days, resulting in five injections of 5 μg fluoxetine/g body wt. We measured the monoamine neurotransmitters serotonin, dopamine, and norepinephrine in addition to their metabolites with HPLC. Homovanillic acid, a metabolite in the dopaminergic pathway, increased significantly in the hypothalamus. Plasma estradiol levels were measured by radioimmunoassay and were significantly reduced approximately threefold after fluoxetine treatment. We found that fluoxetine also significantly reduced the expression of estrogen receptor (ER)β1 mRNA by 4-fold in both the hypothalamus and the telencephalon and ERα mRNA by 1.7-fold in the telencephalon. Fluoxetine had no effect on the expression of ERβ2 mRNA in the hypothalamus or telencephalon. Microarray analysis identified isotocin, a neuropeptide that stimulates reproductive behavior in fish, as a candidate gene affected by fluoxetine treatment. Real-time RT-PCR verified that isotocin mRNA was downregulated approximately sixfold in the hypothalamus and fivefold in the telencephalon. Intraperitoneal injection of isotocin (1 μg/g) increased plasma estradiol, providing a potential link between changes in isotocin gene expression and decreased circulating estrogen in fluoxetine-injected fish. Our results reveal targets of serotonergic modulation in the neuroendocrine brain and indicate that fluoxetine has the potential to affect sex hormones and modulate genes involved in reproductive function and behavior in the brain of female goldfish. We discuss these findings in the context of endocrine disruption because fluoxetine has been detected in the environment.

Inactivation of Escherichia coli by O- water

AIMS

To clarify the effects of O(-) (atomic oxygen radical anion) water on the viability and morphological alteration of Escherichia coli.

METHODS AND RESULTS

O(-) water (OW) was prepared by bubbling of O(-)/argon (Ar) flux into deionized water. O(-) and hydrogen peroxide (H(2)O(2)) in the resultant OW were analysed by electron paramagnetic resonance and ultraviolet (UV) absorption spectroscopy. The population of E. coli treated by a typical OW of pH 4.30 +/- 0.20 [(2.5 +/- 0.8) x 10(-3) mmol l(-1) O(-); 0.5 +/- 0.2 mmol l(-1) H(2)O(2)) was reduced by more than 3 log CFU ml(-1) within 60 min at 30 degrees C. Through scanning electron microscopy observation, the OW-treated cells appeared dramatically collapsed. The release of nucleic acid induced by OW was identified by UV absorption spectroscopy.

CONCLUSIONS

O(-) water can result in inactivation of E. coli, nucleic acid release and cellular damage under the controlled laboratory conditions in excess of 15-30 min. Reactive oxygen species may play an important role in the inactivation process.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study first revealed that OW could inactivate E. coli, which may be potentially useful in developing a novel approach for the microbial decontamination of food, water or heat-sensitive material.

Secretoneurin stimulates goldfish pituitary luteinizing hormone production

Secretoneurin (SN), a 33-34 amino acid neuropeptide is derived from endoproteolysis of secretogranin II (SgII), a member protein of the chromogranin family. SN is widely distributed in various tissues of vertebrates especially in pituitary and hypothalamus, and is a potential new hormone. In vivo, i.p. injection of SN increased luteinizing hormone (LH) release in goldfish pretreated with the dopamine antagonist domperidone. In 6-h static incubation of goldfish pituitary fragments, 10 and 100 nM but not 1 nM concentrations of goldfish SN had a direct stimulatory effect to increase LH release by 2.3- and 1.5-fold (p<0.05), respectively. In addition, 500 nM SN induced a 2.6-fold increase in LHbeta subunit messenger RNA (mRNA) levels in pituitary fragments, regardless of whether LHbeta mRNA levels were expressed relative to 18S ribosomal RNA or beta-actin mRNA. We suggest that the stimulatory actions of SN on LH release may be a part of a paracrine or autocrine feedback loop in the pituitary.

Proteolytic processing and differential distribution of secretogranin-II in goldfish

Secretoneurin (SN) is a 33-34 amino acid neuropeptide derived by endoproteolysis of secretogranin-II (SgII), a chromogranin. A multi-antigenic strategy was used to generate a rabbit polyclonal goldfish SN antiserum that was characterized for Western blot analysis. In the goldfish pituitary two intermediate proteins containing SN and likely processed from the 69.6-kDa SgII precursor were detected. No immunoreactive proteins were observed in the goldfish interrenal, ovary, cerebellum, and telencephalon whereas SgII mRNA was expressed in all these tissues. Immunoreactive levels of the approximately 57 kDa product were higher in the pars distalis (PD) than in the neurointermediate lobe (NIL). The abundance of the approximately 57 kDa protein indicates that this SgII-product containing the SN sequence is a major stored form in secretory granules of the goldfish pituitary. High expression and processing of SN in the hypothalamus and pituitary suggest important roles for SgII-derived peptides in neuroendocrine tissues.