GST-M1 is transcribed moreso than AKR7A2 in AFB₁-exposed human monocytes and lymphocytes

Abstract

Glutathione-S-transferases (GST) and aldo-keto reductases (AKR) are key aflatoxin (AF)-detoxifying enzymes. In this study, the expression of GST-M1, GST-T1, AKR-7A2, and AKR-7A3 genes in human monocytes and lymphocytes was analyzed after in vitro exposure to 10 or 100 ng AFB1/ml for 2 h. Unlike in pilot studies that showed that all four examined genes were present in HepG2 cells, in lymphocytes and monocytes, only GST-M1 and AKR-7A2 were detected. In fact, the induced expression of both GST-M1 and AKR-7A2 genes in human monocytes was moreso than that seen in AFB1-exposed lymphocytes. In addition, analyses of the effects of the exposures on cell cycle status were performed as, in cells lacking adequate detoxification capacities, it would be expected the cells would arrest at checkpoints in the cell cycle or progress to apoptotic/necrotic states. The results here indicated that only the high dose of AFB1 led to a change in cell cycle profiles and only in the monocytes (i.e. cells in S phase were significantly reduced). In general, the results here strongly suggest that human immune cell lineages appear to be able to increase their expression of AFB1-detoxifying enzymes (albeit to differing degrees) and, as a result, are able to counter potential toxicities from AFB1 and (likely) its metabolites.

Human Microglial Cells Undergo Proapoptotic Induction and Inflammatory Activation upon in vitro Exposure to a Naturally Occurring Level of Aflatoxin B₁

“…The lipophilic nature of AFB 1 facilitates its bioavailability and ease of entry to the bloodstream, organs, and cells. As such, different parts of the human body can be influenced by AFB 1 , including hepatocytes [3], the kidneys [4], respiratory system [5], reproductive system [6], leukocytes [7, 8] and murine neural cells [9]. Limited information is available on the impact of AFB 1 on the human CNS.…”

Estradiol 17 beta-dehydrogenase 5 is involved in aflatoxin B1 transportation

“…Enzymes in this family also play an important role in the phase II detoxification of a large number of pharmaceuticals, drugs, and xenobiotics (27). AKRs are thought to be key AF-detoxifying enzymes; AKR-7A2 genes were found to be induced in HepG2 cells (28,29). AFB1 was reported as a hepatotoxic secondary metabolic product (30), and the liver cell strain BRL was chosen in this study to detect if Akr1c6 plays a role in the toxicology of AFB1 to hepatocytes, while kidney cell line NRK was set as a negative control.…”

Stressed (acute) mice display neuroimmunodysregulation and defective innate immune response against coliform infection

“…Splenic immune cells and brain (sagittal sections of frontal part of whole brain) were separated accordingly [10,16]. The harvested RBC-free splenic cell suspensions were then washed (400 × g, 10 min, 4°C) twice with RPMI-1640, counted (in nigrosin solution) in a Neubauer chamber, and after cell viability assessment using nigrosin solution and the Neubauer chamber, in which necrotic cells appeared bright and dark-blue in the mixture [10][11][12][13][14][15][16], respectively, the cells and brain were eventually used for further cellular and molecular analyses.…”

“…Myeloid-derived mononuclear splenic cells (MDMSC; 7 × 10 6 ) and sections of whole brain were each used for RNA extraction and cDNA synthesis [11,12]. TLR4 expression in each set of samples was analyzed using qPCR assays.…”

“…TLR are also involved in many neurodegenerative diseases [3,[6][7][8]. TLR have also been increasingly used as novel immunemolecules to extrapolate dysregulatory/toxicity of hazard materials [9][10][11][12][13]. Studies on the effects of acute restraint stress (ARS) on TLR are rare.…”