Mechanisms of Toxicity of Industrially Relevant Silicomanganese Dust on Human 1321N1 Astrocytoma Cells: An In Vitro Study

Abstract

Tremendous efforts are applied in the ferroalloy industry to control and reduce exposure to dust generated during the production process, as inhalable Mn-containing particulate matter has been linked to neurodegenerative diseases. This study aimed to investigate the toxicity and biological effects of dust particles from laboratory-scale processes where molten silicomanganese (SiMn) was exposed to air, using a human astrocytoma cell line, 1321N1, as model system. Characterization of the dust indicated presence of both nano-sized and larger particles averaging between 100 and 300 nm. The dust consisted mainly of Si, Mn and O. Investigation of cellular mechanisms showed a dose- and time-dependent effect on cell viability, with only minor changes in the expression of proteins involved in apoptosis. Moreover, gene expression of the neurotoxic biomarker amyloid precursor protein (APP) increased, whereas APP protein expression decreased. Finally, induction of gap junctional intercellular communication (GJIC) increased with higher doses and correlated with the other endpoints. Thus, the effects of SiMn dust on 1321N1 cells are highly dependent on the dose of exposure and involves changes in APP, apoptosis-related proteins and intercellular communication.

Application of Silicomanganese Fume as a Novel Bridging Material for Water-Based Drilling Fluids

“…2 The silicomanganese is one of them and known in the literature as SMFs. 3 − 8 The SMF is reported by several other researchers as a byproduct of the steelmaking industry. 6 , 9 , 10 In Spain, waste generation of the steelmaking industry is 15 to 20% of the production.…”

“…During the entire steelmaking process, several byproducts are generated such as blast furnace slag, steelmaking slag, fly ash, blast furnace clarifier sludges, blast furnace flue dust, mill scales, waste refractories, coke breeze, and silicomanganese fumes (SMFs) . The silicomanganese is one of them and known in the literature as SMFs. − The SMF is reported by several other researchers as a byproduct of the steelmaking industry. ,, In Spain, waste generation of the steelmaking industry is 15 to 20% of the production . In European Union, 22 million tons of slags were generated in 2010, and the majority of the waste generated was utilized as a landfill .…”

Cadmium Transforms Astrocytes into the A1 Subtype via Inducing Gap Junction Protein Connexin 43 into the Nucleus

“…Astrocytes, a type of multifunctional cell and active communication partners, form an integral part of the blood–brain barrier, contributing to protecting the brain from toxic metabolites and peripheral insults . Studies have found that quiescent astrocytes are activated, referred to as reactive astrocytes, in response to a variety of neural damages in the central nervous system .…”