Acrylamide induces HepG2 cell proliferation through upregulation of miR-21 expression

Detection and simultaneous imaging of acrylamide, miR-21 and miR-221 based on multicolor aggregation-induced emission nanoparticles and DNAzyme walker

Acrylamide (AA) in heat-processed foods has emerged as a global health problem, mainly carcinogenic, neurotoxic, and reproductive toxicity, and an increasing number of researchers have delved into elucidating its toxicological mechanisms. Studies have demonstrated that exposure of HepG2 by AA in a range of concentrations can induce the upregulation of miR-21 and miR-221. Monitoring the response of intracellular miRNAs can play an important role in unraveling the mechanisms of AA toxicity. Here, multicolor aggregation induced emission nano particle (AIENP) probes were constructed from three AIE dyes for simultaneous imaging of intracellular AA and AA-induced miR-21/miR-221 by combining the recognition function of AA aptamers and the signal amplification of a DNAzyme walker. The surface of these nanoparticles contains carboxyl groups, facilitating their linkage to a substrate chain modified with a fluorescent quencher group via an amide reaction. Optimization experiments were conducted to determine the optimal substrate-to-DNAzyme ratio, confirming its efficacy as a walker for signal amplification. Sensitive detection of AA, miR-21 and miR-221 was achieved in extracellular medium, with detection limits of 0.112 nM for AA, 0.007 pM and 0.003 pM for miR-21 and miR-221, respectively, demonstrating excellent selectivity. Intracellularly, ZIF-8 structure collapsed, releasing Zn2+, activating DNAzyme cleavage activity, and the fluorescence of multicolor AIENPs within HepG2 cells gradually recovered with increasing stimulation time (0-12 h) and concentrations of AA (0-500 μM). This dynamic response unveiled the relationship between AA exposure and miR-21/miR-221 expression, further validating the carcinogenicity of AA.

The role of microRNAs in acrylamide toxicity

The chemical compound known as Acrylamide (AA) is employed in different industries worldwide and is also found in thermal-processed food. AA has been acting as a reproductive toxicant, carcinogen, and neurotoxic in various animals, which may promote several toxic impacts in animal and human species. Up to now, various studies have focused on the harmful mechanisms and intervention actions of AA. However, the underlying mechanisms that AA and its toxic effects can exert have remained uncertain. MicroRNAs (miRNAs) are a class of short, non-coding RNAs that are able to act as epigenetic regulators. These molecules can regulate a wide range of cellular and molecular processes. In this regard, it has been shown that different chemical agents can dysregulate miRNAs. To determine the possible AA targets along with mechanisms of its toxicity, it is helpful to study the alteration in the profiles of miRNA regulation following AA intake. The current research aimed to evaluate the miRNAs' mediatory roles upon the AA's toxic potentials. This review study discussed the AA, which is made within the food matrix, the way it is consumed, and the potential impacts of AA on miRNAs and its association with different cancer types and degenerative diseases. The findings of this review paper indicated that AA might be capable of altering miRNA signatures in different tissues and exerting its carcinogen effects.

In Vivo Investigation of the Effect of Dietary Acrylamide and Evaluation of Its Clinical Relevance in Colon Cancer

Dietary exposure to acrylamide (AA) has been linked with carcinogenicity in the gastrointestinal (GI) tract. However, epidemiologic data on AA intake in relation to cancer risk are limited and contradictory, while the potential cancer-inducing molecular pathways following AA exposure remain elusive. In this study, we collected mechanistic information regarding the induction of carcinogenesis by dietary AA in the colon, using an established animal model. Male Balb/c mice received AA orally (0.1 mg/kg/day) daily for 4 weeks. RNA was extracted from colon tissue samples, followed by RNA sequencing. Comparative transcriptomic analysis between AA and mock-treated groups revealed a set of differentially expressed genes (DEGs) that were further processed using different databases through the STRING-DB portal, to reveal deregulated protein-protein interaction networks. We found that genes implicated in RNA metabolism, processing and formation of the ribosomal subunits and protein translation and metabolism are upregulated in AA-exposed colon tissue; these genes were also overexpressed in human colon adenocarcinoma samples and were negatively correlated with patient overall survival (OS), based on publicly available datasets. Further investigation of the potential role of these genes during the early stages of colon carcinogenesis may shed light into the underlying mechanisms induced by dietary AA exposure.

Stabilization of glutathione redox dynamics and CYP2E1 by green synthesized Moringa oleifera-mediated zinc oxide nanoparticles against acrylamide induced hepatotoxicity in rat model: Morphometric and molecular perspectives

The terrible reality is that acrylamide (AA) is a common food contaminant found in a wide variety of commonly consumed foods. This research involves the advancement of a more dependable technique for the bio-fabrication of zinc oxide nanoparticles (ZNPs) through the green method using Moringa Oleifera extract (MO-ZNPs) as an efficient chelating agent for acrylamide (AA). The effects of AA on glutathione redox dynamics, liver function, lipid profile, and zinc residues in Sprague Dawley rats are investigated. Finally, the microarchitecture and immunohistochemical staining of Caspase-3 and CYP2E1 were determined in the liver tissue of rats. Four separate groups, including control, MO-ZNPs (10 mg/kg b.wt), AA (20 mg/kg b.wt), and AA + MO-ZNPs for 60 days. The results revealed a suppressed activity of glutathione redox enzymes (GSH, GPX,and GSR) on both molecular and biochemical levels. Also, AA caused elevated liver enzymes, hepatosomatic index, and immunohistochemical staining of caspase-3 and CYP2E1 expression. MO-ZNPs co-treatment, on the other hand, stabilized glutathione-related enzyme gene expression, normalized hepatocellular enzyme levels, and restored hepatic tissue microarchitectures. It could be assumed that MO-ZNPs is a promising hepatoprotective molecule for alleviating AA-induced hepatotoxicity. We witnessed changes in glutathione redox dynamics to be restorative. Glutathione and cytochrome P450 2E1 play crucial roles in AA detoxification, so maintaining a healthy glutathione redox cycle is necessary for disposing of AA toxicity.

The Chemopreventive Effects of Polyphenols and Coffee, Based upon a DMBA Mouse Model with microRNA and mTOR Gene Expression Biomarkers

Polyphenols are capable of decreasing cancer risk. We examined the chemopreventive effects of a green tea (Camellia sinensis) extract, polyphenol extract (a mixture of blackberry (Rubus fruticosus), blackcurrants (Ribes nigrum), and added resveratrol phytoalexin), Chinese bayberry (Myrica rubra) extract, and a coffee (Coffea arabica) extract on 7,12-dimethylbenz[a]anthracene (DMBA) carcinogen-increased miR-134, miR-132, miR-124-1, miR-9-3, and mTOR gene expressions in the liver, spleen, and kidneys of CBA/Ca mice. The elevation was quenched significantly in the organs, except for miR-132 in the liver of the Chinese bayberry extract-consuming group, and miR-132 in the kidneys of the polyphenol-fed group. In the coffee extract-consuming group, only miR-9-3 and mTOR decreased significantly in the liver; also, miR-134 decreased significantly in the spleen, and, additionally, miR-124-1 decreased significantly in the kidney. Our results are supported by literature data, particularly the DMBA generated ROS-induced inflammatory and proliferative signal transducers, such as TNF, IL1, IL6, and NF-κB; as well as oncogenes, namely RAS and MYC. The examined chemopreventive agents, besides the obvious antioxidant and anti-inflammatory effects, mainly blocked the mentioned DMBA-activated factors and the mitogen-activated protein kinase (MAPK) as well, and, at the same time, induced PTEN as well as SIRT tumor suppressor genes.

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

The intake of carcinogenic and chemopreventive compounds are important nutritional factors related to the development of malignant tumorous diseases. Repetitive long interspersed element-1 (LINE-1) DNA methylation pattern plays a key role in both carcinogenesis and chemoprevention. In our present in vivo animal model, we examined LINE-1 DNA methylation pattern as potential biomarker in the liver, spleen and kidney of mice consuming green tea (Camellia sinensis) extract (catechins 80%), a chinese bayberry (Morella rubra) extract (myricetin 80%), a flavonoid extract (with added resveratrol) and coffee (Coffee arabica) extract. In the organs examined, carcinogen 7,12-dimethylbenz(a)anthracene (DMBA)-induced hypomethylation was prevented by all test materials except chinese bayberry extract in the kidneys. Moreover, the flavonoid extract caused significant hypermethylation in the liver compared to untreated controls and to other test materials. The tested chemopreventive substances have antioxidant, anti-inflammatory properties and regulate molecular biological signaling pathways. They increase glutathione levels, induce antioxidant enzymes, which decrease free radical damage caused by DMBA, and ultimately, they are able to increase the activity of DNA methyltransferase enzymes. Furthermore, flavonoids in the liver may inhibit the procarcinogen to carcinogen activation of DMBA through the inhibition of CYP1A1 enzyme. At the same time, paradoxically, myricetin can act as a prooxidant as a result of free radical damage, which can explain that it did not prevent hypomethylation in the kidneys. Our results demonstrated that LINE-1 DNA methylation pattern is a useful potential biomarker for detecting and monitoring carcinogenic and chemopreventive effects of dietary compounds.