Dietary Exposure to 2-Aminoanthracene Induces Morphological and Immunocytochemical Changes in Pancreatic Tissues of Fisher-344 Rats

Open source scientific bottle roller

Proprietary bottle rolling systems automate some laboratory applications, however, their high costs limit accessibility. This study provides designs of an open source bottle roller that is compatible with distributed digital manufacturing using 3-D printed parts and readily-available commercial components. The experimental results show that the open source bottle roller can be fabricated for CAD$210 (about USD$150) in materials, which is 86% less expensive than the most affordable proprietary bottle roller on the market. The design, however, is more robust with enhanced capabilities. The design can be adapted to the user's needs, but is already compatible with incubators with a low profile (dimensions 50 cm x46 cm x8.8 cm) and capable of being operated at elevated temperatures. The systems can be adjusted to revolves from 1 to 200 RPM, exceeding the rotational speed of most commercial systems. The open source bottle roller as tested has a capacity greater than 1.2 kg and can roll twelve 100 mL bottles simultaneously. Validation testing showed that it can operate for days at 80 RPM without human intervention or monitoring for days at both room temperature and elevated temperatures (50 °C). Future work includes adapting the designs for different sizes and for different fabrication techniques to further reduce costs and increase flexibility.

Hepatic genomic assessment of dietary ingestion of 2-aminoanthracene in Sprague Dawley rats

This research aims to investigate the effects of 2-aminoanthracene (2-AA), a polycyclic aromatic hydrocarbon (PAH), on the liver. PAH is a by-product of the incomplete combustion of fossil fuels. Specifically, the impact of 2-AA on different body tissues in animals has been reported. The liver is an organ central to the metabolism of PAHs, including 2-AA. Sprague Dawley rats ingested a well-defined dose of 2-AA in their diet (0, 50, and 100 mg/kg 2-AA) for 12 weeks. Hepatic global gene expression using Affymetrix Rat Genome 230 2.0 microarray was performed. Overall, more than 17,000 genes were expressed. Approximately 70 genes were upregulated, while 65 were downregulated when control rats were compared with low-dose animals. Similarly, 103 genes were upregulated and 49 downregulated when the high-concentration 2-AA group was compared with the control group rats. This result suggests that the magnitude of gene expression fold change depends on the dose of 2-AA ingested. Several differentially expressed genes are involved in biological processes such as gene transcription, cell cycle, and immune system function, indicating that the ingestion of 2-AA could impact these processes. The over-expression of genes related to liver inflammation, nonalcoholic liver disease, hepatic glucose processing, and PAH metabolism were noted.

Dietary ingestion of 2-aminoanthracene (2AA) and the risk for type-1 diabetes (T1D)

Type 1 diabetes (T1D) is an autoimmune disorder caused by the destruction of insulin-secreting β-cells.T1D is on the rise around the world. Exposure to polycyclic aromatic hydrocarbons (PAHs) including 2-aminoanthracene (2AA) is considered a contributor to TID increase. The contribution of the ingestion of 2AA toward T1D vulnerability is examined. 2AA is found in a variety of household products. Juvenile male Sprague Dawley rats ingested various amounts of 2AA contaminated diet for 12 weeks. Results showed marginal reduction in body weight gain for the 100 mg/kg treated animals. Glucose tolerance test (GTT) indicated no changes at six weeks. However, at week 12, both treated groups had higher levels of blood glucose than the control group. Serum insulin concentration was elevated in the 50 mg/kg group while reduced in the 100 mg/kg animals. Serum lactate dehydrogenase activity was elevated in treated groups. Evaluation of pancreatic inflammatory cytokines revealed overexpression of IL-1B, IL-6, and IL-7. Apoptotic genes in the pancreas of exposed rats were overly expressed. Histopathology and insulin immunohistochemistry data showed the presence of mesenteric vessels surrounded by lymphocyte and enlarged size of islet cells respectively in the high dose group. These results suggest 2AA ingestion may enhance T1D development.

Investigating the toxic effects of 2-aminoanthracene ingestion in pregnant Sprague Dawley dams

Polycyclic aromatic hydrocarbons (PAHs) refer to organic compounds that are byproducts of incomplete combustion of fossil fuels and wood. One specific polycyclic aromatic hydrocarbon, 2-aminoanthracene (2AA), is a member of a broader group of compounds known as anthracenes, which have been classified by the United States Agency for Toxic Substances and Disease Registry (ASTDR) as one of a group of PAHs of top concern based on their greater potential risk for exposure and greater harmful effects to humans, compared to other PAHs. Previous research has shown that 2AA affects genes involved in carbohydrate and lipid metabolism, inflammatory stress responses, and immune system responses, among other processes. The objective of the present study was to examine the toxicity of dietary ingestion of 2AA from gestation through the postnatal period. Pregnant dams (Day 1) were purchased from Taconic Hudson, NY, and assigned into dose regimens of 0 mg/kg- (control-C), 50 mg/kg- (low dose-LD) and 100 mg/kg-diet (high dose-HD) 2AA. Dams were fed 2AA contaminated diet during the period of gestation and postpartum. Insulin and H&E immunohistochemical staining were undertaken and indicated no significant changes between control and treated groups. However, percent pancreatic islets (islets within the pancreas) were larger in the exposed groups. The value was 1.5% in the control dams compared to 3.2% and 4.3% low dose and high dose groups respectively. Serum concentrations of albumin and lactate dehydrogenase (LDH) were increased in the exposed groups, with the HD group experiencing the greater increase. Analyses of Fabp4, Mgmt , Fas, Nhej1, Aldh1a1 and Ncam1 were conducted via real-time quantitative polymerase chain reaction (RT-pPCR), using β-Actin as the control gene. There was an up-regulation of the Mgmt and Nhej1 gene transcripts in the exposed groups, with the extent of upregulation being highest in the HD group. Taken together, a link between environmental exposure to 2AA and pancreatic effects appears to exist.

Assessment of the link between in utero exposure to 2-aminoanthracene (2AA) and type-1 diabetes (T1D)

BACKGROUND

A recent diabetes report revealed an increased incidence in diabetes including type 1-diabetes (T1D). The increase in the numbers of T1D incidences are thought to be related to environmental reasons such as the exposure to environmental chemicals including arylamine 2-aminoanthracene (2AA). T1D is an autoimmune disease of the pancreatic islet in which insulin-producing beta cells are destroyed by auto-reactive T-cells and monocytic cells.

METHODS

The purpose of this study is to examine the extent to which 2AA exposure contributes to T1D. Three groups of pregnant Sprague Dawley dams ingested various concentrations of dietary 2AA from gestation through the postnatal period. A select number of cytokines and adipokines previously noted to play a significant role in inflammatory response were analyzed in the pancreas of the pups for alteration. The anatomy of the pancreas was also evaluated to determine any histological changes.

RESULTS

Results showed over-expression of pro-inflammatory protein IL-6. Up-regulation of humoral genes IL-7 and IL-21 were also noted. Pathologic characterization showed no significant changes. Moreover, serum total protein was significantly reduced in exposed groups. Elevated serum glucose concentration seems to correspond to slightly lower insulin levels in serum. Cumulative neonatal weight gain analysis showed no major alterations between the control and gestationally-exposed rats.

CONCLUSION

It appears that systemic effects of 2AA ingestion were mild in the neonates. Further assessments of pups who lived longer than two weeks could be a useful way to measure the progression and possibly further support our hypothesis that 2AA can lead to systemic effects that are indicative of inducing T1D.

Investigating Susceptibility to Diabetes Using Features of the Adipose Tissue in Response to In Utero Polycyclic Aromatic Hydrocarbons Exposure

BACKGROUND

In recent times, there has been an increase in the incidence of type 2 diabetes mellitus (T2DM) particularly in children. Adipocyte dysfunction provide a critical link between obesity and insulin resistance resulting in diabetes outcome. Further, environmental chemical exposure during early years of life might be a significant contributing factor to the increase in the incidence of T2DM. This study tests the idea that exposure to environmental contaminants (2-aminoanthracene [2AA]) in utero will show effects in the adipose tissue (AT) that signify T2DM vulnerability. 2AA is a polycyclic aromatic hydrocarbon found in a variety of products.

METHODS

To accomplish the study objective, pregnant dams were fed various amounts of 2AA adulterated diets from gestation through postnatal period. The neonates and older offspring were analyzed for diabetic-like genes in the ATs and analysis of serum glucose. Furthermore, weight monitoring, histopathology and immunohistochemical (IHC) staining for CD68 in AT, adipocyte size determination and adiponectin amounts in serum were undertaken.

RESULTS

Up-regulation of adiponectin and interleukin-6 genes were noted in the pups and older rats. Combination of intrauterine 2AA toxicity with moderate high fat diet exhibited gene expression patterns similar to those of the neonates. Elevated serum glucose levels were noted in treated groups. IHC of the AT indicated no significant malformations; however, CD68+ cells were greater in the animals treated to 2AA. Similarly, mean sizes of the adipocytes were larger in treated and combined 2AA and moderate high fat animals. Adiponectin was reduced in 2AA groups.

CONCLUSION

From the preceding, it appears intrauterine 2AA disturbance, when combined with excess fat accumulation will lead to greater risk for the diabetic condition.

Inflammatory effect of 2-aminoanthracene (2AA) on adipose tissue gene expression in pregnant Sprague Dawley rats

Adipocyte dysfunction may be a critical link between obesity and insulin resistance as a result of abnormal fat storage and mobilization. Adipocytes uniquely secrete adipokines and cytokines, such as leptin and TNFα, wich promote insulin sensitivity. Previously we reported insulin-signaling related altered gene expression in animals exposed to 2-Aminoanthracene (2AA). 2AA is an amino-substituted polycyclic aromatic hydrocarbon used in manufacturing dyes, chemicals, inks, resins, and polyurethanes. The objective of this study was to examine the inflammation related effects of 2AA exposure from gestation to postnatal period on dams that ingested 2AA. To examine 2AA effects, pregnant dams were assigned into dose regimens of 2AA. Dams were fed 2AA contaminated diet during the period of gestation and postpartum. The expression of key gene transcripts reported to be important in mediating inflammatory processes was examined via quantitative RT-PCR. Histologic examination of adipose tissue (AT) was also carried out to understand the anatomy of AT due to 2AA exposure during gestation and two weeks postpartum. Examination of the adipose tissue for microscopic changes revealed no alterations between control and low-dose animals. However, AT of the high-dose animals was infiltrated by increased numbers of CD68+mononuclear cells (macrophages) and small numbers of eosinophils and mast cells, consistent with inflammation. In addition, analysis of the mRNA expression of cytokines and adipokines demonstrated the importance of inflammation in AT dysfunction. For instance, TNFα, LEPTIN and IL-6 transcripts were relatively more expressed in the low dose animals than in the high dose and control rats. At the protein level, however, high amounts of cytokines were noted. The effects of 2AA on pregnant dams appear to be more pronounced in the high dose group than in the low dose group, possibly indicating increased susceptibility of rat offspring within this group to elicit a diabetic-type response.

Hepatic gene expression analysis of 2-aminoanthracene exposed Fisher-344 rats reveal patterns indicative of liver carcinoma and type 2 diabetes

The goal of the present study was to examine hepatic differential gene expression patterns in Fisher-344 rats in response to dietary 2-aminoanthracene (2AA) ingestion for 14 and 28 days. Twenty four post-weaning 3-4 week old F-344 male rats were exposed to 0 mgkg(-1)-diet (control), 50 mgkg(-1)-diet (low dose), 75 mgkg(-1)-diet (medium dose) and 100 mgkg(-1)-diet (high dose) 2AA for 14 and 28 days. This was followed by analysis of the liver for global gene expression changes. In both time points, the numbers of genes affected seem to correlate with the dose of 2AA. Sixteen mRNAs were differentially expressed in all treatment groups for the short-term exposure group. Similarly, 51 genes were commonly expressed in all 28-day exposure group. Almost all the genes seem to have higher expression relative to the controls. In contrast, cytochrome P450 family 4, subfamily a, polypeptide 8 (Cyp4a8), and monocyte to macrophage differentiation-associated (Mmd2) were down-regulated relative to controls. Differentially expressed mRNAs were further analyzed for associations via DAVID. GO categories show the effect of 2AA to be linked with genes responsible for carbohydrate utilization and transport, lipid metabolic processes, stress responses such as inflammation and apoptosis processes, immune system response, DNA damage response, cancer processes and circadian rhythm. The data from the current study identified altered hepatic gene expression profiles that may be associated with carcinoma, autoimmune response, and/or type 2 diabetes. Possible biomarkers due to 2AA toxicity in the liver for future study include Abcb1a, Nhej1, Adam8, Cdkn1a, Mgmt, and Nrcam.