Micro- and Nanosized Substances Cause Different Autophagy-Related Responses

Abstract

With rapid industrialization, humans produce an increasing number of products. The composition of these products is usually decomposed. However, some substances are not easily broken down and gradually become environmental pollutants. In addition, these substances may cause bioaccumulation, since the substances can be fragmented into micro- and nanoparticles. These particles or their interactions with other toxic matter circulate in humans via the food chain or air. Whether these micro- and nanoparticles interfere with extracellular vesicles (EVs) due to their similar sizes is unclear. Micro- and nanoparticles (MSs and NSs) induce several cell responses and are engulfed by cells depending on their size, for example, particulate matter with a diameter ≤2.5 μm (PM2.5). Autophagy is a mechanism by which pathogens are destroyed in cells. Some artificial materials are not easily decomposed in organisms. How do these cells or tissues respond? In addition, autophagy operates through two pathways (increasing cell death or cell survival) in tumorigenesis. Many MSs and NSs have been found that induce autophagy in various cells and tissues. As a result, this review focuses on how these particles interfere with cells and tissues. Here, we review MSs, NSs, and PM2.5, which result in different autophagy-related responses in various tissues or cells.

Fe-N Co-Doped Titanium Dioxide Nanoparticles Induce Cell Death in Human Lung Fibroblasts in a p53-Independent Manner

“…Autophagy can be one of the main mechanisms of cell survival that ensures the elimination of damaged organs and biomolecules, under the action of oxidative stress induced by NPs [59]. However, if the stress factor is applied for a longer period, dysfunctions occur in various organs, and autophagy serves as a cell death mechanism, promoting the self-destruction of cells [60]. However, the dual role of autophagy in both cell survival and programmed cell death, as well as the relationship between p53 protein activity and LC3 regulation, differs in a cell type dependent manner.…”

The impact of nanomaterials on autophagy across health and disease conditions

“…Autophagy plays a vital role in cellular responses against NMs and nPs exposure [ 78 ]. Whether it promotes survival or death largely depends on the type of NP or nP and the severity and timing of exposure [ 12 ].…”

“…In contrast to other NMs and nano-formulations, cells exposed to nPs majorly display stimulated autophagy [ 78 ]. Interestingly, activation of autophagy is an initial response, but autophagosomes tend to accumulate within the cells at later time points due to the accumulation of nPs in lysosomes [ 215 ] 215 , which impairs autophagy flux.…”

The influence of PM2.5 exposure on kidney diseases

“…Recently, studies have found the role of autophagy in renal injury caused by benzopyrene (BaP) (a common organic chemical in PM 2.5 ) and diesel particulate matter. 76 Autophagy is an important mechanism by which cells cope with intracellular or extracellular stress. During autophagy, some toxic components were degraded by autolysosomes to prevent cell damage.…”