Patulin suppresses α1-adrenergic receptor expression in HEK293 cells

Abstract

Patulin (PAT) is a common mycotoxin contaminant of apple products linked to impaired metabolic and kidney function. Adenosine monophosphate activated protein kinase (AMPK), abundantly expressed in the kidney, intercedes metabolic changes and renal injury. The alpha-1-adrenergic receptors (α1-AR) facilitate Epinephrine (Epi)-mediated AMPK activation, linking metabolism and kidney function. Preliminary molecular docking experiments examined potential interactions and AMPK-gamma subunit 3 (PRKAG3). The effect of PAT exposure (0.2–2.5 µM; 24 h) on the AMPK pathway and α1-AR was then investigated in HEK293 human kidney cells. AMPK agonist Epi determined direct effects on the α1-AR, metformin was used as an activator for AMPK, while buthionine sulphoximine (BSO) and N-acetyl cysteine (NAC) assessed GSH inhibition and supplementation respectively. ADRA1A and ADRA1D expression was determined by qPCR. α1-AR, ERK1/2/MAPK and PI3K/Akt protein expression was assessed using western blotting. PAT (1 µM) decreased α1-AR protein and mRNA and altered downstream signalling. This was consistent in cells stimulated with Epi and metformin. BSO potentiated the observed effect on α1-AR while NAC ameliorated these effects. Molecular docking studies performed on Human ADRA1A and PRKAG3 indicated direct interactions with PAT. This study is the first to show PAT modulates the AMPK pathway and α1-AR, supporting a mechanism of kidney injury.

The Nrf1 transcription factor is induced by patulin and protects against patulin cytotoxicity

“…Cells were treated with 10 or 20 μM of patulin for 24 h, and cell death was determined by trypan-blue exclusion assay. The concentrations chosen were within the range used in previous studies done on similar cell lines, and they are also within the range that is encountered in cases where exposure is beyond the maximum recommended limits in humans ( Pillay et al, 2020 ; Zhang et al, 2015 ; Zhong et al, 2018 ; Zhou et al, 2010 ). Compared to cells expressing Nrf1a, knockout cells showed decreased survival after treatment with patulin ( Fig.…”

Nanotechnology-integrated ferroptosis inducers: a sharp sword against tumor drug resistance

“…43 Thus, GSH depletion inhibits drug efflux by MRP, increases intracellular drug accumulation, and reverses drug resistance. 42,44 Furthermore, GSH is synthesized via two consecutive ATP-dependent reactions, 32 and GSH depletion influences GSH synthesis. A negativefeedback mechanism like this is conducive to reversing drug resistance in tumors.…”

“…Thus, intracellular GSH content affects mitochondrial function, such as electron transport chain function 41 and adenosine triphosphate (ATP) production. 42 The high expression of multidrug-resistance proteins, which are ATP-dependent efflux pumps with a broad substrate specificity, is one of the most common reasons for multiple-drug resistance (MDR). 43 Thus, GSH depletion inhibits drug efflux by MRP, increases intracellular drug accumulation, and reverses drug resistance.…”

“…GSH is involved in a multitude of physiological processes in the mitochondria, including the synthesis of ATP. 42 The decrease in ATP production can influence the function of ABC transporters and increase the sensitivity of MDR cells to chemotherapeutic molecules. Wang et al previously designed paclitaxel (PTX)-loaded mitochondria-targeted nano micelles (DA-P-SST/PTX) to overcome drug resistance (Fig.…”

Patulin alters alpha-adrenergic receptor signalling and induces epigenetic modifications in the kidneys of C57BL/6 mice

“…A recent study found PAT induced oxidative DNA damage in HEK293 kidney cells, leading to renal injury by targeting the α-adrenergic receptors expressed in the kidneys (Hering et al 2020 ; Pillay et al 2020 ). These receptors are activated by endogenous catecholamines (Michelotti et al 2007 ) and engage in signal transduction through the extracellular signal-regulated kinases/mitogen-activated protein kinases (ERK/MAPK) and phosphatidylinositide-3-kinase/protein kinase B (PI3K/AKT) signalling pathways (Karkoulias et al 2006 ).…”