The Mechanism Of Graphene Oxide Antagonize Toxic Responese To Arsenic

Arsenic(As)pollution is a serious global problem and various technologies have been developed for As detoxification.Graphene oxide(GO)with its extraordinary structure and physicochemical properties has an excellent capability for the removal of As from contaminated water;however,the influence of GO on the toxic response to As(?)is largely unknown;the combined biological effects of GO and As(?)together with related mechanisms are still at the starting stage.In the present study,Caenorhabditis elegans(C.elegans)was used as an in vivo model to clarify the role of GO at a non-toxic concentration on the toxic response to As(?)and its underlying molecular mechanisms.The results are summarized as follows:1.The combined biological effects:using germline apoptosis,brood size,and the oocytes per gonad assays.We found that GO itself was non-toxic,irrespective of pretreatment or concurrent treatment with As(?),significantly blocked the toxic response to As(?).2.Physicochemical mechanism:High-performance liquid chromatography-inductive coupled atomic fluorescence spectrometer(HPLC-AFS)analysis revealed no chemical form changes of As(?)in the presence of GO.Using transmission electron microscopy(TEM),energy dispersive X-ray spectroscopy(EDX),and inductively coupled atomic fluorescence spectrometry(ICP-AFS)techniques,we found that GO had strong adsorption and enriching ability for As(?),and the adsorption effect plays a key role in GO antagonize toxic response to As(?).3.Biological mechanisms:GO triggered protective autophagy,leading to an efficient inhibition of oxidative stress,a major contributing factor,in As(?)toxicity.Using a laser ablation inductively coupled plasma-mass spectrometer(LA-ICP-MS)and loss-of-function mutants,our data further showed that GO accelerated the excretion of As(?)from nematodes by suppressing the expression of As(?)-binding protein(Galectin-1,LEC-1)Our data provided clear evidence that along with adsorption,the beneficial effects of GO in reducing As(?)-induced toxicity in vivo was mainly through protective autophagy coupled with downregulation of arsenic target protein expression,which might reveal new insights into the potential application of GO in water treatment and ecological risk assessment.